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-rw-r--r--src/go.mod10
-rw-r--r--src/go.sum17
-rw-r--r--src/go/ast/ast.go1063
-rw-r--r--src/go/ast/ast_test.go79
-rw-r--r--src/go/ast/commentmap.go332
-rw-r--r--src/go/ast/commentmap_test.go170
-rw-r--r--src/go/ast/example_test.go206
-rw-r--r--src/go/ast/filter.go497
-rw-r--r--src/go/ast/filter_test.go86
-rw-r--r--src/go/ast/import.go230
-rw-r--r--src/go/ast/issues_test.go42
-rw-r--r--src/go/ast/print.go254
-rw-r--r--src/go/ast/print_test.go97
-rw-r--r--src/go/ast/resolve.go174
-rw-r--r--src/go/ast/scope.go160
-rw-r--r--src/go/ast/walk.go386
-rw-r--r--src/go/build/build.go1986
-rw-r--r--src/go/build/build_test.go712
-rw-r--r--src/go/build/constraint/expr.go574
-rw-r--r--src/go/build/constraint/expr_test.go317
-rw-r--r--src/go/build/deps_test.go877
-rw-r--r--src/go/build/doc.go98
-rw-r--r--src/go/build/gc.go17
-rw-r--r--src/go/build/gccgo.go14
-rw-r--r--src/go/build/read.go546
-rw-r--r--src/go/build/read_test.go321
-rw-r--r--src/go/build/syslist.go11
-rw-r--r--src/go/build/syslist_test.go62
-rw-r--r--src/go/build/testdata/cgo_disabled/cgo_disabled.go5
-rw-r--r--src/go/build/testdata/cgo_disabled/empty.go1
-rw-r--r--src/go/build/testdata/doc/a_test.go2
-rw-r--r--src/go/build/testdata/doc/b_test.go1
-rw-r--r--src/go/build/testdata/doc/c_test.go1
-rw-r--r--src/go/build/testdata/doc/d_test.go2
-rw-r--r--src/go/build/testdata/doc/e.go1
-rw-r--r--src/go/build/testdata/doc/f.go2
-rw-r--r--src/go/build/testdata/empty/dummy0
-rw-r--r--src/go/build/testdata/multi/file.go5
-rw-r--r--src/go/build/testdata/multi/file_appengine.go5
-rw-r--r--src/go/build/testdata/other/file/file.go5
-rw-r--r--src/go/build/testdata/other/main.go11
-rw-r--r--src/go/build/testdata/withvendor/src/a/b/b.go3
-rw-r--r--src/go/build/testdata/withvendor/src/a/vendor/c/d/d.go1
-rw-r--r--src/go/constant/example_test.go180
-rw-r--r--src/go/constant/value.go1391
-rw-r--r--src/go/constant/value_test.go708
-rw-r--r--src/go/doc/Makefile7
-rw-r--r--src/go/doc/comment.go513
-rw-r--r--src/go/doc/comment_test.go247
-rw-r--r--src/go/doc/doc.go222
-rw-r--r--src/go/doc/doc_test.go164
-rw-r--r--src/go/doc/example.go547
-rw-r--r--src/go/doc/example_test.go718
-rw-r--r--src/go/doc/exports.go309
-rw-r--r--src/go/doc/filter.go105
-rw-r--r--src/go/doc/headscan.go115
-rw-r--r--src/go/doc/reader.go917
-rw-r--r--src/go/doc/synopsis.go83
-rw-r--r--src/go/doc/synopsis_test.go52
-rw-r--r--src/go/doc/testdata/a.0.golden52
-rw-r--r--src/go/doc/testdata/a.1.golden52
-rw-r--r--src/go/doc/testdata/a.2.golden52
-rw-r--r--src/go/doc/testdata/a0.go40
-rw-r--r--src/go/doc/testdata/a1.go12
-rw-r--r--src/go/doc/testdata/b.0.golden71
-rw-r--r--src/go/doc/testdata/b.1.golden83
-rw-r--r--src/go/doc/testdata/b.2.golden71
-rw-r--r--src/go/doc/testdata/b.go58
-rw-r--r--src/go/doc/testdata/benchmark.go293
-rw-r--r--src/go/doc/testdata/blank.0.golden62
-rw-r--r--src/go/doc/testdata/blank.1.golden83
-rw-r--r--src/go/doc/testdata/blank.2.golden62
-rw-r--r--src/go/doc/testdata/blank.go75
-rw-r--r--src/go/doc/testdata/bugpara.0.golden20
-rw-r--r--src/go/doc/testdata/bugpara.1.golden20
-rw-r--r--src/go/doc/testdata/bugpara.2.golden20
-rw-r--r--src/go/doc/testdata/bugpara.go9
-rw-r--r--src/go/doc/testdata/c.0.golden48
-rw-r--r--src/go/doc/testdata/c.1.golden48
-rw-r--r--src/go/doc/testdata/c.2.golden48
-rw-r--r--src/go/doc/testdata/c.go62
-rw-r--r--src/go/doc/testdata/d.0.golden104
-rw-r--r--src/go/doc/testdata/d.1.golden104
-rw-r--r--src/go/doc/testdata/d.2.golden104
-rw-r--r--src/go/doc/testdata/d1.go57
-rw-r--r--src/go/doc/testdata/d2.go45
-rw-r--r--src/go/doc/testdata/e.0.golden109
-rw-r--r--src/go/doc/testdata/e.1.golden144
-rw-r--r--src/go/doc/testdata/e.2.golden130
-rw-r--r--src/go/doc/testdata/e.go147
-rw-r--r--src/go/doc/testdata/error1.0.golden30
-rw-r--r--src/go/doc/testdata/error1.1.golden32
-rw-r--r--src/go/doc/testdata/error1.2.golden30
-rw-r--r--src/go/doc/testdata/error1.go24
-rw-r--r--src/go/doc/testdata/error2.0.golden27
-rw-r--r--src/go/doc/testdata/error2.1.golden37
-rw-r--r--src/go/doc/testdata/error2.2.golden27
-rw-r--r--src/go/doc/testdata/error2.go29
-rw-r--r--src/go/doc/testdata/example.go81
-rw-r--r--src/go/doc/testdata/f.0.golden13
-rw-r--r--src/go/doc/testdata/f.1.golden16
-rw-r--r--src/go/doc/testdata/f.2.golden13
-rw-r--r--src/go/doc/testdata/f.go14
-rw-r--r--src/go/doc/testdata/g.0.golden32
-rw-r--r--src/go/doc/testdata/g.1.golden34
-rw-r--r--src/go/doc/testdata/g.2.golden32
-rw-r--r--src/go/doc/testdata/g.go25
-rw-r--r--src/go/doc/testdata/issue12839.0.golden51
-rw-r--r--src/go/doc/testdata/issue12839.1.golden54
-rw-r--r--src/go/doc/testdata/issue12839.2.golden51
-rw-r--r--src/go/doc/testdata/issue12839.go69
-rw-r--r--src/go/doc/testdata/issue13742.0.golden25
-rw-r--r--src/go/doc/testdata/issue13742.1.golden25
-rw-r--r--src/go/doc/testdata/issue13742.2.golden25
-rw-r--r--src/go/doc/testdata/issue13742.go18
-rw-r--r--src/go/doc/testdata/issue16153.0.golden32
-rw-r--r--src/go/doc/testdata/issue16153.1.golden34
-rw-r--r--src/go/doc/testdata/issue16153.2.golden32
-rw-r--r--src/go/doc/testdata/issue16153.go27
-rw-r--r--src/go/doc/testdata/issue17788.0.golden8
-rw-r--r--src/go/doc/testdata/issue17788.1.golden8
-rw-r--r--src/go/doc/testdata/issue17788.2.golden8
-rw-r--r--src/go/doc/testdata/issue17788.go8
-rw-r--r--src/go/doc/testdata/issue22856.0.golden45
-rw-r--r--src/go/doc/testdata/issue22856.1.golden45
-rw-r--r--src/go/doc/testdata/issue22856.2.golden45
-rw-r--r--src/go/doc/testdata/issue22856.go27
-rw-r--r--src/go/doc/testdata/predeclared.0.golden8
-rw-r--r--src/go/doc/testdata/predeclared.1.golden22
-rw-r--r--src/go/doc/testdata/predeclared.2.golden8
-rw-r--r--src/go/doc/testdata/predeclared.go22
-rw-r--r--src/go/doc/testdata/template.txt68
-rw-r--r--src/go/doc/testdata/testing.0.golden156
-rw-r--r--src/go/doc/testdata/testing.1.golden298
-rw-r--r--src/go/doc/testdata/testing.2.golden156
-rw-r--r--src/go/doc/testdata/testing.go404
-rw-r--r--src/go/format/benchmark_test.go91
-rw-r--r--src/go/format/example_test.go39
-rw-r--r--src/go/format/format.go135
-rw-r--r--src/go/format/format_test.go183
-rw-r--r--src/go/format/internal.go176
-rw-r--r--src/go/importer/importer.go122
-rw-r--r--src/go/importer/importer_test.go87
-rw-r--r--src/go/internal/gccgoimporter/ar.go171
-rw-r--r--src/go/internal/gccgoimporter/gccgoinstallation.go97
-rw-r--r--src/go/internal/gccgoimporter/gccgoinstallation_test.go192
-rw-r--r--src/go/internal/gccgoimporter/importer.go261
-rw-r--r--src/go/internal/gccgoimporter/importer_test.go209
-rw-r--r--src/go/internal/gccgoimporter/parser.go1284
-rw-r--r--src/go/internal/gccgoimporter/parser_test.go78
-rw-r--r--src/go/internal/gccgoimporter/testdata/aliases.go65
-rw-r--r--src/go/internal/gccgoimporter/testdata/aliases.gox33
-rw-r--r--src/go/internal/gccgoimporter/testdata/complexnums.go6
-rw-r--r--src/go/internal/gccgoimporter/testdata/complexnums.gox8
-rw-r--r--src/go/internal/gccgoimporter/testdata/conversions.go5
-rw-r--r--src/go/internal/gccgoimporter/testdata/conversions.gox6
-rw-r--r--src/go/internal/gccgoimporter/testdata/escapeinfo.go13
-rw-r--r--src/go/internal/gccgoimporter/testdata/escapeinfo.goxbin0 -> 824 bytes
-rw-r--r--src/go/internal/gccgoimporter/testdata/imports.go5
-rw-r--r--src/go/internal/gccgoimporter/testdata/imports.gox7
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue27856.go9
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue27856.gox9
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue29198.go37
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue29198.gox86
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue30628.go18
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue30628.gox28
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue31540.go26
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue31540.gox16
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue34182.go17
-rw-r--r--src/go/internal/gccgoimporter/testdata/issue34182.gox13
-rw-r--r--src/go/internal/gccgoimporter/testdata/libimportsar.abin0 -> 9302 bytes
-rw-r--r--src/go/internal/gccgoimporter/testdata/nointerface.go12
-rw-r--r--src/go/internal/gccgoimporter/testdata/nointerface.gox8
-rw-r--r--src/go/internal/gccgoimporter/testdata/notinheap.go4
-rw-r--r--src/go/internal/gccgoimporter/testdata/notinheap.gox7
-rw-r--r--src/go/internal/gccgoimporter/testdata/pointer.go3
-rw-r--r--src/go/internal/gccgoimporter/testdata/pointer.gox4
-rw-r--r--src/go/internal/gccgoimporter/testdata/time.goxbin0 -> 7977 bytes
-rw-r--r--src/go/internal/gccgoimporter/testdata/unicode.goxbin0 -> 7945 bytes
-rw-r--r--src/go/internal/gccgoimporter/testdata/v1reflect.goxbin0 -> 10872 bytes
-rw-r--r--src/go/internal/gcimporter/exportdata.go91
-rw-r--r--src/go/internal/gcimporter/gcimporter.go174
-rw-r--r--src/go/internal/gcimporter/gcimporter_test.go619
-rw-r--r--src/go/internal/gcimporter/iimport.go618
-rw-r--r--src/go/internal/gcimporter/support.go130
-rw-r--r--src/go/internal/gcimporter/testdata/a.go14
-rw-r--r--src/go/internal/gcimporter/testdata/b.go11
-rw-r--r--src/go/internal/gcimporter/testdata/exports.go88
-rw-r--r--src/go/internal/gcimporter/testdata/issue15920.go11
-rw-r--r--src/go/internal/gcimporter/testdata/issue20046.go9
-rw-r--r--src/go/internal/gcimporter/testdata/issue25301.go17
-rw-r--r--src/go/internal/gcimporter/testdata/issue25596.go13
-rw-r--r--src/go/internal/gcimporter/testdata/p.go13
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test.go28
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.11_0i.abin0 -> 2420 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.11_6b.abin0 -> 2426 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.11_999b.abin0 -> 2600 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.11_999i.abin0 -> 2420 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.7_0.abin0 -> 1862 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.7_1.abin0 -> 2316 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.8_4.abin0 -> 1658 bytes
-rw-r--r--src/go/internal/gcimporter/testdata/versions/test_go1.8_5.abin0 -> 1658 bytes
-rw-r--r--src/go/internal/srcimporter/srcimporter.go265
-rw-r--r--src/go/internal/srcimporter/srcimporter_test.go254
-rw-r--r--src/go/internal/srcimporter/testdata/issue20855/issue20855.go7
-rw-r--r--src/go/internal/srcimporter/testdata/issue23092/issue23092.go5
-rw-r--r--src/go/internal/srcimporter/testdata/issue24392/issue24392.go5
-rw-r--r--src/go/parser/error_test.go187
-rw-r--r--src/go/parser/example_test.go43
-rw-r--r--src/go/parser/interface.go241
-rw-r--r--src/go/parser/parser.go2591
-rw-r--r--src/go/parser/parser_test.go579
-rw-r--r--src/go/parser/performance_test.go30
-rw-r--r--src/go/parser/short_test.go136
-rw-r--r--src/go/parser/testdata/commas.src19
-rw-r--r--src/go/parser/testdata/issue11377.src27
-rw-r--r--src/go/parser/testdata/issue23434.src25
-rw-r--r--src/go/parser/testdata/issue3106.src46
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-rw-r--r--src/go/parser/testdata/issue42951/not_a_file.go/invalid.go1
-rw-r--r--src/go/printer/example_test.go67
-rw-r--r--src/go/printer/nodes.go1844
-rw-r--r--src/go/printer/performance_test.go58
-rw-r--r--src/go/printer/printer.go1377
-rw-r--r--src/go/printer/printer_test.go814
-rw-r--r--src/go/printer/testdata/alignment.golden172
-rw-r--r--src/go/printer/testdata/alignment.input179
-rw-r--r--src/go/printer/testdata/comments.golden759
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-rw-r--r--src/go/types/testdata/expr0.src180
-rw-r--r--src/go/types/testdata/expr1.src127
-rw-r--r--src/go/types/testdata/expr2.src260
-rw-r--r--src/go/types/testdata/expr3.src563
-rw-r--r--src/go/types/testdata/gotos.src560
-rw-r--r--src/go/types/testdata/importC.src54
-rw-r--r--src/go/types/testdata/importdecl0a.src53
-rw-r--r--src/go/types/testdata/importdecl0b.src33
-rw-r--r--src/go/types/testdata/importdecl1a.src22
-rw-r--r--src/go/types/testdata/importdecl1b.src11
-rw-r--r--src/go/types/testdata/init0.src106
-rw-r--r--src/go/types/testdata/init1.src97
-rw-r--r--src/go/types/testdata/init2.src139
-rw-r--r--src/go/types/testdata/issue25008a.src15
-rw-r--r--src/go/types/testdata/issue25008b.src9
-rw-r--r--src/go/types/testdata/issues.src365
-rw-r--r--src/go/types/testdata/labels.src207
-rw-r--r--src/go/types/testdata/literals.src111
-rw-r--r--src/go/types/testdata/methodsets.src214
-rw-r--r--src/go/types/testdata/shifts.src395
-rw-r--r--src/go/types/testdata/stmt0.src980
-rw-r--r--src/go/types/testdata/stmt1.src259
-rw-r--r--src/go/types/testdata/vardecl.src206
-rw-r--r--src/go/types/token_test.go47
-rw-r--r--src/go/types/type.go523
-rw-r--r--src/go/types/typestring.go307
-rw-r--r--src/go/types/typestring_test.go221
-rw-r--r--src/go/types/typexpr.go764
-rw-r--r--src/go/types/universe.go238
364 files changed, 77491 insertions, 0 deletions
diff --git a/src/go.mod b/src/go.mod
new file mode 100644
index 0000000..25e7992
--- /dev/null
+++ b/src/go.mod
@@ -0,0 +1,10 @@
+module std
+
+go 1.16
+
+require (
+ golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897
+ golang.org/x/net v0.0.0-20211101194150-d8c3cde3c676
+ golang.org/x/sys v0.0.0-20201204225414-ed752295db88 // indirect
+ golang.org/x/text v0.3.4 // indirect
+)
diff --git a/src/go.sum b/src/go.sum
new file mode 100644
index 0000000..e5467ea
--- /dev/null
+++ b/src/go.sum
@@ -0,0 +1,17 @@
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897 h1:pLI5jrR7OSLijeIDcmRxNmw2api+jEfxLoykJVice/E=
+golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20211101194150-d8c3cde3c676 h1:HdGRNh1uWfD+9WfeSGYgD64N7Nmu3oMnSkdZAONtoU8=
+golang.org/x/net v0.0.0-20211101194150-d8c3cde3c676/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201204225414-ed752295db88 h1:KmZPnMocC93w341XZp26yTJg8Za7lhb2KhkYmixoeso=
+golang.org/x/sys v0.0.0-20201204225414-ed752295db88/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.4 h1:0YWbFKbhXG/wIiuHDSKpS0Iy7FSA+u45VtBMfQcFTTc=
+golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
diff --git a/src/go/ast/ast.go b/src/go/ast/ast.go
new file mode 100644
index 0000000..300966a
--- /dev/null
+++ b/src/go/ast/ast.go
@@ -0,0 +1,1063 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ast declares the types used to represent syntax trees for Go
+// packages.
+//
+package ast
+
+import (
+ "go/token"
+ "strings"
+)
+
+// ----------------------------------------------------------------------------
+// Interfaces
+//
+// There are 3 main classes of nodes: Expressions and type nodes,
+// statement nodes, and declaration nodes. The node names usually
+// match the corresponding Go spec production names to which they
+// correspond. The node fields correspond to the individual parts
+// of the respective productions.
+//
+// All nodes contain position information marking the beginning of
+// the corresponding source text segment; it is accessible via the
+// Pos accessor method. Nodes may contain additional position info
+// for language constructs where comments may be found between parts
+// of the construct (typically any larger, parenthesized subpart).
+// That position information is needed to properly position comments
+// when printing the construct.
+
+// All node types implement the Node interface.
+type Node interface {
+ Pos() token.Pos // position of first character belonging to the node
+ End() token.Pos // position of first character immediately after the node
+}
+
+// All expression nodes implement the Expr interface.
+type Expr interface {
+ Node
+ exprNode()
+}
+
+// All statement nodes implement the Stmt interface.
+type Stmt interface {
+ Node
+ stmtNode()
+}
+
+// All declaration nodes implement the Decl interface.
+type Decl interface {
+ Node
+ declNode()
+}
+
+// ----------------------------------------------------------------------------
+// Comments
+
+// A Comment node represents a single //-style or /*-style comment.
+//
+// The Text field contains the comment text without carriage returns (\r) that
+// may have been present in the source. Because a comment's end position is
+// computed using len(Text), the position reported by End() does not match the
+// true source end position for comments containing carriage returns.
+type Comment struct {
+ Slash token.Pos // position of "/" starting the comment
+ Text string // comment text (excluding '\n' for //-style comments)
+}
+
+func (c *Comment) Pos() token.Pos { return c.Slash }
+func (c *Comment) End() token.Pos { return token.Pos(int(c.Slash) + len(c.Text)) }
+
+// A CommentGroup represents a sequence of comments
+// with no other tokens and no empty lines between.
+//
+type CommentGroup struct {
+ List []*Comment // len(List) > 0
+}
+
+func (g *CommentGroup) Pos() token.Pos { return g.List[0].Pos() }
+func (g *CommentGroup) End() token.Pos { return g.List[len(g.List)-1].End() }
+
+func isWhitespace(ch byte) bool { return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' }
+
+func stripTrailingWhitespace(s string) string {
+ i := len(s)
+ for i > 0 && isWhitespace(s[i-1]) {
+ i--
+ }
+ return s[0:i]
+}
+
+// Text returns the text of the comment.
+// Comment markers (//, /*, and */), the first space of a line comment, and
+// leading and trailing empty lines are removed.
+// Comment directives like "//line" and "//go:noinline" are also removed.
+// Multiple empty lines are reduced to one, and trailing space on lines is trimmed.
+// Unless the result is empty, it is newline-terminated.
+func (g *CommentGroup) Text() string {
+ if g == nil {
+ return ""
+ }
+ comments := make([]string, len(g.List))
+ for i, c := range g.List {
+ comments[i] = c.Text
+ }
+
+ lines := make([]string, 0, 10) // most comments are less than 10 lines
+ for _, c := range comments {
+ // Remove comment markers.
+ // The parser has given us exactly the comment text.
+ switch c[1] {
+ case '/':
+ //-style comment (no newline at the end)
+ c = c[2:]
+ if len(c) == 0 {
+ // empty line
+ break
+ }
+ if c[0] == ' ' {
+ // strip first space - required for Example tests
+ c = c[1:]
+ break
+ }
+ if isDirective(c) {
+ // Ignore //go:noinline, //line, and so on.
+ continue
+ }
+ case '*':
+ /*-style comment */
+ c = c[2 : len(c)-2]
+ }
+
+ // Split on newlines.
+ cl := strings.Split(c, "\n")
+
+ // Walk lines, stripping trailing white space and adding to list.
+ for _, l := range cl {
+ lines = append(lines, stripTrailingWhitespace(l))
+ }
+ }
+
+ // Remove leading blank lines; convert runs of
+ // interior blank lines to a single blank line.
+ n := 0
+ for _, line := range lines {
+ if line != "" || n > 0 && lines[n-1] != "" {
+ lines[n] = line
+ n++
+ }
+ }
+ lines = lines[0:n]
+
+ // Add final "" entry to get trailing newline from Join.
+ if n > 0 && lines[n-1] != "" {
+ lines = append(lines, "")
+ }
+
+ return strings.Join(lines, "\n")
+}
+
+// isDirective reports whether c is a comment directive.
+func isDirective(c string) bool {
+ // "//line " is a line directive.
+ // (The // has been removed.)
+ if strings.HasPrefix(c, "line ") {
+ return true
+ }
+
+ // "//[a-z0-9]+:[a-z0-9]"
+ // (The // has been removed.)
+ colon := strings.Index(c, ":")
+ if colon <= 0 || colon+1 >= len(c) {
+ return false
+ }
+ for i := 0; i <= colon+1; i++ {
+ if i == colon {
+ continue
+ }
+ b := c[i]
+ if !('a' <= b && b <= 'z' || '0' <= b && b <= '9') {
+ return false
+ }
+ }
+ return true
+}
+
+// ----------------------------------------------------------------------------
+// Expressions and types
+
+// A Field represents a Field declaration list in a struct type,
+// a method list in an interface type, or a parameter/result declaration
+// in a signature.
+// Field.Names is nil for unnamed parameters (parameter lists which only contain types)
+// and embedded struct fields. In the latter case, the field name is the type name.
+//
+type Field struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Names []*Ident // field/method/parameter names; or nil
+ Type Expr // field/method/parameter type
+ Tag *BasicLit // field tag; or nil
+ Comment *CommentGroup // line comments; or nil
+}
+
+func (f *Field) Pos() token.Pos {
+ if len(f.Names) > 0 {
+ return f.Names[0].Pos()
+ }
+ return f.Type.Pos()
+}
+
+func (f *Field) End() token.Pos {
+ if f.Tag != nil {
+ return f.Tag.End()
+ }
+ return f.Type.End()
+}
+
+// A FieldList represents a list of Fields, enclosed by parentheses or braces.
+type FieldList struct {
+ Opening token.Pos // position of opening parenthesis/brace, if any
+ List []*Field // field list; or nil
+ Closing token.Pos // position of closing parenthesis/brace, if any
+}
+
+func (f *FieldList) Pos() token.Pos {
+ if f.Opening.IsValid() {
+ return f.Opening
+ }
+ // the list should not be empty in this case;
+ // be conservative and guard against bad ASTs
+ if len(f.List) > 0 {
+ return f.List[0].Pos()
+ }
+ return token.NoPos
+}
+
+func (f *FieldList) End() token.Pos {
+ if f.Closing.IsValid() {
+ return f.Closing + 1
+ }
+ // the list should not be empty in this case;
+ // be conservative and guard against bad ASTs
+ if n := len(f.List); n > 0 {
+ return f.List[n-1].End()
+ }
+ return token.NoPos
+}
+
+// NumFields returns the number of parameters or struct fields represented by a FieldList.
+func (f *FieldList) NumFields() int {
+ n := 0
+ if f != nil {
+ for _, g := range f.List {
+ m := len(g.Names)
+ if m == 0 {
+ m = 1
+ }
+ n += m
+ }
+ }
+ return n
+}
+
+// An expression is represented by a tree consisting of one
+// or more of the following concrete expression nodes.
+//
+type (
+ // A BadExpr node is a placeholder for an expression containing
+ // syntax errors for which a correct expression node cannot be
+ // created.
+ //
+ BadExpr struct {
+ From, To token.Pos // position range of bad expression
+ }
+
+ // An Ident node represents an identifier.
+ Ident struct {
+ NamePos token.Pos // identifier position
+ Name string // identifier name
+ Obj *Object // denoted object; or nil
+ }
+
+ // An Ellipsis node stands for the "..." type in a
+ // parameter list or the "..." length in an array type.
+ //
+ Ellipsis struct {
+ Ellipsis token.Pos // position of "..."
+ Elt Expr // ellipsis element type (parameter lists only); or nil
+ }
+
+ // A BasicLit node represents a literal of basic type.
+ //
+ // Note that for the CHAR and STRING kinds, the literal is stored
+ // with its quotes. For example, for a double-quoted STRING, the
+ // first and the last rune in the Value field will be ". The
+ // Unquote and UnquoteChar functions in the strconv package can be
+ // used to unquote STRING and CHAR values, respectively.
+ BasicLit struct {
+ ValuePos token.Pos // literal position
+ Kind token.Token // token.INT, token.FLOAT, token.IMAG, token.CHAR, or token.STRING
+ Value string // literal string; e.g. 42, 0x7f, 3.14, 1e-9, 2.4i, 'a', '\x7f', "foo" or `\m\n\o`
+ }
+
+ // A FuncLit node represents a function literal.
+ FuncLit struct {
+ Type *FuncType // function type
+ Body *BlockStmt // function body
+ }
+
+ // A CompositeLit node represents a composite literal.
+ CompositeLit struct {
+ Type Expr // literal type; or nil
+ Lbrace token.Pos // position of "{"
+ Elts []Expr // list of composite elements; or nil
+ Rbrace token.Pos // position of "}"
+ Incomplete bool // true if (source) expressions are missing in the Elts list
+ }
+
+ // A ParenExpr node represents a parenthesized expression.
+ ParenExpr struct {
+ Lparen token.Pos // position of "("
+ X Expr // parenthesized expression
+ Rparen token.Pos // position of ")"
+ }
+
+ // A SelectorExpr node represents an expression followed by a selector.
+ SelectorExpr struct {
+ X Expr // expression
+ Sel *Ident // field selector
+ }
+
+ // An IndexExpr node represents an expression followed by an index.
+ IndexExpr struct {
+ X Expr // expression
+ Lbrack token.Pos // position of "["
+ Index Expr // index expression
+ Rbrack token.Pos // position of "]"
+ }
+
+ // A SliceExpr node represents an expression followed by slice indices.
+ SliceExpr struct {
+ X Expr // expression
+ Lbrack token.Pos // position of "["
+ Low Expr // begin of slice range; or nil
+ High Expr // end of slice range; or nil
+ Max Expr // maximum capacity of slice; or nil
+ Slice3 bool // true if 3-index slice (2 colons present)
+ Rbrack token.Pos // position of "]"
+ }
+
+ // A TypeAssertExpr node represents an expression followed by a
+ // type assertion.
+ //
+ TypeAssertExpr struct {
+ X Expr // expression
+ Lparen token.Pos // position of "("
+ Type Expr // asserted type; nil means type switch X.(type)
+ Rparen token.Pos // position of ")"
+ }
+
+ // A CallExpr node represents an expression followed by an argument list.
+ CallExpr struct {
+ Fun Expr // function expression
+ Lparen token.Pos // position of "("
+ Args []Expr // function arguments; or nil
+ Ellipsis token.Pos // position of "..." (token.NoPos if there is no "...")
+ Rparen token.Pos // position of ")"
+ }
+
+ // A StarExpr node represents an expression of the form "*" Expression.
+ // Semantically it could be a unary "*" expression, or a pointer type.
+ //
+ StarExpr struct {
+ Star token.Pos // position of "*"
+ X Expr // operand
+ }
+
+ // A UnaryExpr node represents a unary expression.
+ // Unary "*" expressions are represented via StarExpr nodes.
+ //
+ UnaryExpr struct {
+ OpPos token.Pos // position of Op
+ Op token.Token // operator
+ X Expr // operand
+ }
+
+ // A BinaryExpr node represents a binary expression.
+ BinaryExpr struct {
+ X Expr // left operand
+ OpPos token.Pos // position of Op
+ Op token.Token // operator
+ Y Expr // right operand
+ }
+
+ // A KeyValueExpr node represents (key : value) pairs
+ // in composite literals.
+ //
+ KeyValueExpr struct {
+ Key Expr
+ Colon token.Pos // position of ":"
+ Value Expr
+ }
+)
+
+// The direction of a channel type is indicated by a bit
+// mask including one or both of the following constants.
+//
+type ChanDir int
+
+const (
+ SEND ChanDir = 1 << iota
+ RECV
+)
+
+// A type is represented by a tree consisting of one
+// or more of the following type-specific expression
+// nodes.
+//
+type (
+ // An ArrayType node represents an array or slice type.
+ ArrayType struct {
+ Lbrack token.Pos // position of "["
+ Len Expr // Ellipsis node for [...]T array types, nil for slice types
+ Elt Expr // element type
+ }
+
+ // A StructType node represents a struct type.
+ StructType struct {
+ Struct token.Pos // position of "struct" keyword
+ Fields *FieldList // list of field declarations
+ Incomplete bool // true if (source) fields are missing in the Fields list
+ }
+
+ // Pointer types are represented via StarExpr nodes.
+
+ // A FuncType node represents a function type.
+ FuncType struct {
+ Func token.Pos // position of "func" keyword (token.NoPos if there is no "func")
+ Params *FieldList // (incoming) parameters; non-nil
+ Results *FieldList // (outgoing) results; or nil
+ }
+
+ // An InterfaceType node represents an interface type.
+ InterfaceType struct {
+ Interface token.Pos // position of "interface" keyword
+ Methods *FieldList // list of methods
+ Incomplete bool // true if (source) methods are missing in the Methods list
+ }
+
+ // A MapType node represents a map type.
+ MapType struct {
+ Map token.Pos // position of "map" keyword
+ Key Expr
+ Value Expr
+ }
+
+ // A ChanType node represents a channel type.
+ ChanType struct {
+ Begin token.Pos // position of "chan" keyword or "<-" (whichever comes first)
+ Arrow token.Pos // position of "<-" (token.NoPos if there is no "<-")
+ Dir ChanDir // channel direction
+ Value Expr // value type
+ }
+)
+
+// Pos and End implementations for expression/type nodes.
+
+func (x *BadExpr) Pos() token.Pos { return x.From }
+func (x *Ident) Pos() token.Pos { return x.NamePos }
+func (x *Ellipsis) Pos() token.Pos { return x.Ellipsis }
+func (x *BasicLit) Pos() token.Pos { return x.ValuePos }
+func (x *FuncLit) Pos() token.Pos { return x.Type.Pos() }
+func (x *CompositeLit) Pos() token.Pos {
+ if x.Type != nil {
+ return x.Type.Pos()
+ }
+ return x.Lbrace
+}
+func (x *ParenExpr) Pos() token.Pos { return x.Lparen }
+func (x *SelectorExpr) Pos() token.Pos { return x.X.Pos() }
+func (x *IndexExpr) Pos() token.Pos { return x.X.Pos() }
+func (x *SliceExpr) Pos() token.Pos { return x.X.Pos() }
+func (x *TypeAssertExpr) Pos() token.Pos { return x.X.Pos() }
+func (x *CallExpr) Pos() token.Pos { return x.Fun.Pos() }
+func (x *StarExpr) Pos() token.Pos { return x.Star }
+func (x *UnaryExpr) Pos() token.Pos { return x.OpPos }
+func (x *BinaryExpr) Pos() token.Pos { return x.X.Pos() }
+func (x *KeyValueExpr) Pos() token.Pos { return x.Key.Pos() }
+func (x *ArrayType) Pos() token.Pos { return x.Lbrack }
+func (x *StructType) Pos() token.Pos { return x.Struct }
+func (x *FuncType) Pos() token.Pos {
+ if x.Func.IsValid() || x.Params == nil { // see issue 3870
+ return x.Func
+ }
+ return x.Params.Pos() // interface method declarations have no "func" keyword
+}
+func (x *InterfaceType) Pos() token.Pos { return x.Interface }
+func (x *MapType) Pos() token.Pos { return x.Map }
+func (x *ChanType) Pos() token.Pos { return x.Begin }
+
+func (x *BadExpr) End() token.Pos { return x.To }
+func (x *Ident) End() token.Pos { return token.Pos(int(x.NamePos) + len(x.Name)) }
+func (x *Ellipsis) End() token.Pos {
+ if x.Elt != nil {
+ return x.Elt.End()
+ }
+ return x.Ellipsis + 3 // len("...")
+}
+func (x *BasicLit) End() token.Pos { return token.Pos(int(x.ValuePos) + len(x.Value)) }
+func (x *FuncLit) End() token.Pos { return x.Body.End() }
+func (x *CompositeLit) End() token.Pos { return x.Rbrace + 1 }
+func (x *ParenExpr) End() token.Pos { return x.Rparen + 1 }
+func (x *SelectorExpr) End() token.Pos { return x.Sel.End() }
+func (x *IndexExpr) End() token.Pos { return x.Rbrack + 1 }
+func (x *SliceExpr) End() token.Pos { return x.Rbrack + 1 }
+func (x *TypeAssertExpr) End() token.Pos { return x.Rparen + 1 }
+func (x *CallExpr) End() token.Pos { return x.Rparen + 1 }
+func (x *StarExpr) End() token.Pos { return x.X.End() }
+func (x *UnaryExpr) End() token.Pos { return x.X.End() }
+func (x *BinaryExpr) End() token.Pos { return x.Y.End() }
+func (x *KeyValueExpr) End() token.Pos { return x.Value.End() }
+func (x *ArrayType) End() token.Pos { return x.Elt.End() }
+func (x *StructType) End() token.Pos { return x.Fields.End() }
+func (x *FuncType) End() token.Pos {
+ if x.Results != nil {
+ return x.Results.End()
+ }
+ return x.Params.End()
+}
+func (x *InterfaceType) End() token.Pos { return x.Methods.End() }
+func (x *MapType) End() token.Pos { return x.Value.End() }
+func (x *ChanType) End() token.Pos { return x.Value.End() }
+
+// exprNode() ensures that only expression/type nodes can be
+// assigned to an Expr.
+//
+func (*BadExpr) exprNode() {}
+func (*Ident) exprNode() {}
+func (*Ellipsis) exprNode() {}
+func (*BasicLit) exprNode() {}
+func (*FuncLit) exprNode() {}
+func (*CompositeLit) exprNode() {}
+func (*ParenExpr) exprNode() {}
+func (*SelectorExpr) exprNode() {}
+func (*IndexExpr) exprNode() {}
+func (*SliceExpr) exprNode() {}
+func (*TypeAssertExpr) exprNode() {}
+func (*CallExpr) exprNode() {}
+func (*StarExpr) exprNode() {}
+func (*UnaryExpr) exprNode() {}
+func (*BinaryExpr) exprNode() {}
+func (*KeyValueExpr) exprNode() {}
+
+func (*ArrayType) exprNode() {}
+func (*StructType) exprNode() {}
+func (*FuncType) exprNode() {}
+func (*InterfaceType) exprNode() {}
+func (*MapType) exprNode() {}
+func (*ChanType) exprNode() {}
+
+// ----------------------------------------------------------------------------
+// Convenience functions for Idents
+
+// NewIdent creates a new Ident without position.
+// Useful for ASTs generated by code other than the Go parser.
+//
+func NewIdent(name string) *Ident { return &Ident{token.NoPos, name, nil} }
+
+// IsExported reports whether name starts with an upper-case letter.
+//
+func IsExported(name string) bool { return token.IsExported(name) }
+
+// IsExported reports whether id starts with an upper-case letter.
+//
+func (id *Ident) IsExported() bool { return token.IsExported(id.Name) }
+
+func (id *Ident) String() string {
+ if id != nil {
+ return id.Name
+ }
+ return "<nil>"
+}
+
+// ----------------------------------------------------------------------------
+// Statements
+
+// A statement is represented by a tree consisting of one
+// or more of the following concrete statement nodes.
+//
+type (
+ // A BadStmt node is a placeholder for statements containing
+ // syntax errors for which no correct statement nodes can be
+ // created.
+ //
+ BadStmt struct {
+ From, To token.Pos // position range of bad statement
+ }
+
+ // A DeclStmt node represents a declaration in a statement list.
+ DeclStmt struct {
+ Decl Decl // *GenDecl with CONST, TYPE, or VAR token
+ }
+
+ // An EmptyStmt node represents an empty statement.
+ // The "position" of the empty statement is the position
+ // of the immediately following (explicit or implicit) semicolon.
+ //
+ EmptyStmt struct {
+ Semicolon token.Pos // position of following ";"
+ Implicit bool // if set, ";" was omitted in the source
+ }
+
+ // A LabeledStmt node represents a labeled statement.
+ LabeledStmt struct {
+ Label *Ident
+ Colon token.Pos // position of ":"
+ Stmt Stmt
+ }
+
+ // An ExprStmt node represents a (stand-alone) expression
+ // in a statement list.
+ //
+ ExprStmt struct {
+ X Expr // expression
+ }
+
+ // A SendStmt node represents a send statement.
+ SendStmt struct {
+ Chan Expr
+ Arrow token.Pos // position of "<-"
+ Value Expr
+ }
+
+ // An IncDecStmt node represents an increment or decrement statement.
+ IncDecStmt struct {
+ X Expr
+ TokPos token.Pos // position of Tok
+ Tok token.Token // INC or DEC
+ }
+
+ // An AssignStmt node represents an assignment or
+ // a short variable declaration.
+ //
+ AssignStmt struct {
+ Lhs []Expr
+ TokPos token.Pos // position of Tok
+ Tok token.Token // assignment token, DEFINE
+ Rhs []Expr
+ }
+
+ // A GoStmt node represents a go statement.
+ GoStmt struct {
+ Go token.Pos // position of "go" keyword
+ Call *CallExpr
+ }
+
+ // A DeferStmt node represents a defer statement.
+ DeferStmt struct {
+ Defer token.Pos // position of "defer" keyword
+ Call *CallExpr
+ }
+
+ // A ReturnStmt node represents a return statement.
+ ReturnStmt struct {
+ Return token.Pos // position of "return" keyword
+ Results []Expr // result expressions; or nil
+ }
+
+ // A BranchStmt node represents a break, continue, goto,
+ // or fallthrough statement.
+ //
+ BranchStmt struct {
+ TokPos token.Pos // position of Tok
+ Tok token.Token // keyword token (BREAK, CONTINUE, GOTO, FALLTHROUGH)
+ Label *Ident // label name; or nil
+ }
+
+ // A BlockStmt node represents a braced statement list.
+ BlockStmt struct {
+ Lbrace token.Pos // position of "{"
+ List []Stmt
+ Rbrace token.Pos // position of "}", if any (may be absent due to syntax error)
+ }
+
+ // An IfStmt node represents an if statement.
+ IfStmt struct {
+ If token.Pos // position of "if" keyword
+ Init Stmt // initialization statement; or nil
+ Cond Expr // condition
+ Body *BlockStmt
+ Else Stmt // else branch; or nil
+ }
+
+ // A CaseClause represents a case of an expression or type switch statement.
+ CaseClause struct {
+ Case token.Pos // position of "case" or "default" keyword
+ List []Expr // list of expressions or types; nil means default case
+ Colon token.Pos // position of ":"
+ Body []Stmt // statement list; or nil
+ }
+
+ // A SwitchStmt node represents an expression switch statement.
+ SwitchStmt struct {
+ Switch token.Pos // position of "switch" keyword
+ Init Stmt // initialization statement; or nil
+ Tag Expr // tag expression; or nil
+ Body *BlockStmt // CaseClauses only
+ }
+
+ // A TypeSwitchStmt node represents a type switch statement.
+ TypeSwitchStmt struct {
+ Switch token.Pos // position of "switch" keyword
+ Init Stmt // initialization statement; or nil
+ Assign Stmt // x := y.(type) or y.(type)
+ Body *BlockStmt // CaseClauses only
+ }
+
+ // A CommClause node represents a case of a select statement.
+ CommClause struct {
+ Case token.Pos // position of "case" or "default" keyword
+ Comm Stmt // send or receive statement; nil means default case
+ Colon token.Pos // position of ":"
+ Body []Stmt // statement list; or nil
+ }
+
+ // A SelectStmt node represents a select statement.
+ SelectStmt struct {
+ Select token.Pos // position of "select" keyword
+ Body *BlockStmt // CommClauses only
+ }
+
+ // A ForStmt represents a for statement.
+ ForStmt struct {
+ For token.Pos // position of "for" keyword
+ Init Stmt // initialization statement; or nil
+ Cond Expr // condition; or nil
+ Post Stmt // post iteration statement; or nil
+ Body *BlockStmt
+ }
+
+ // A RangeStmt represents a for statement with a range clause.
+ RangeStmt struct {
+ For token.Pos // position of "for" keyword
+ Key, Value Expr // Key, Value may be nil
+ TokPos token.Pos // position of Tok; invalid if Key == nil
+ Tok token.Token // ILLEGAL if Key == nil, ASSIGN, DEFINE
+ X Expr // value to range over
+ Body *BlockStmt
+ }
+)
+
+// Pos and End implementations for statement nodes.
+
+func (s *BadStmt) Pos() token.Pos { return s.From }
+func (s *DeclStmt) Pos() token.Pos { return s.Decl.Pos() }
+func (s *EmptyStmt) Pos() token.Pos { return s.Semicolon }
+func (s *LabeledStmt) Pos() token.Pos { return s.Label.Pos() }
+func (s *ExprStmt) Pos() token.Pos { return s.X.Pos() }
+func (s *SendStmt) Pos() token.Pos { return s.Chan.Pos() }
+func (s *IncDecStmt) Pos() token.Pos { return s.X.Pos() }
+func (s *AssignStmt) Pos() token.Pos { return s.Lhs[0].Pos() }
+func (s *GoStmt) Pos() token.Pos { return s.Go }
+func (s *DeferStmt) Pos() token.Pos { return s.Defer }
+func (s *ReturnStmt) Pos() token.Pos { return s.Return }
+func (s *BranchStmt) Pos() token.Pos { return s.TokPos }
+func (s *BlockStmt) Pos() token.Pos { return s.Lbrace }
+func (s *IfStmt) Pos() token.Pos { return s.If }
+func (s *CaseClause) Pos() token.Pos { return s.Case }
+func (s *SwitchStmt) Pos() token.Pos { return s.Switch }
+func (s *TypeSwitchStmt) Pos() token.Pos { return s.Switch }
+func (s *CommClause) Pos() token.Pos { return s.Case }
+func (s *SelectStmt) Pos() token.Pos { return s.Select }
+func (s *ForStmt) Pos() token.Pos { return s.For }
+func (s *RangeStmt) Pos() token.Pos { return s.For }
+
+func (s *BadStmt) End() token.Pos { return s.To }
+func (s *DeclStmt) End() token.Pos { return s.Decl.End() }
+func (s *EmptyStmt) End() token.Pos {
+ if s.Implicit {
+ return s.Semicolon
+ }
+ return s.Semicolon + 1 /* len(";") */
+}
+func (s *LabeledStmt) End() token.Pos { return s.Stmt.End() }
+func (s *ExprStmt) End() token.Pos { return s.X.End() }
+func (s *SendStmt) End() token.Pos { return s.Value.End() }
+func (s *IncDecStmt) End() token.Pos {
+ return s.TokPos + 2 /* len("++") */
+}
+func (s *AssignStmt) End() token.Pos { return s.Rhs[len(s.Rhs)-1].End() }
+func (s *GoStmt) End() token.Pos { return s.Call.End() }
+func (s *DeferStmt) End() token.Pos { return s.Call.End() }
+func (s *ReturnStmt) End() token.Pos {
+ if n := len(s.Results); n > 0 {
+ return s.Results[n-1].End()
+ }
+ return s.Return + 6 // len("return")
+}
+func (s *BranchStmt) End() token.Pos {
+ if s.Label != nil {
+ return s.Label.End()
+ }
+ return token.Pos(int(s.TokPos) + len(s.Tok.String()))
+}
+func (s *BlockStmt) End() token.Pos {
+ if s.Rbrace.IsValid() {
+ return s.Rbrace + 1
+ }
+ if n := len(s.List); n > 0 {
+ return s.List[n-1].End()
+ }
+ return s.Lbrace + 1
+}
+func (s *IfStmt) End() token.Pos {
+ if s.Else != nil {
+ return s.Else.End()
+ }
+ return s.Body.End()
+}
+func (s *CaseClause) End() token.Pos {
+ if n := len(s.Body); n > 0 {
+ return s.Body[n-1].End()
+ }
+ return s.Colon + 1
+}
+func (s *SwitchStmt) End() token.Pos { return s.Body.End() }
+func (s *TypeSwitchStmt) End() token.Pos { return s.Body.End() }
+func (s *CommClause) End() token.Pos {
+ if n := len(s.Body); n > 0 {
+ return s.Body[n-1].End()
+ }
+ return s.Colon + 1
+}
+func (s *SelectStmt) End() token.Pos { return s.Body.End() }
+func (s *ForStmt) End() token.Pos { return s.Body.End() }
+func (s *RangeStmt) End() token.Pos { return s.Body.End() }
+
+// stmtNode() ensures that only statement nodes can be
+// assigned to a Stmt.
+//
+func (*BadStmt) stmtNode() {}
+func (*DeclStmt) stmtNode() {}
+func (*EmptyStmt) stmtNode() {}
+func (*LabeledStmt) stmtNode() {}
+func (*ExprStmt) stmtNode() {}
+func (*SendStmt) stmtNode() {}
+func (*IncDecStmt) stmtNode() {}
+func (*AssignStmt) stmtNode() {}
+func (*GoStmt) stmtNode() {}
+func (*DeferStmt) stmtNode() {}
+func (*ReturnStmt) stmtNode() {}
+func (*BranchStmt) stmtNode() {}
+func (*BlockStmt) stmtNode() {}
+func (*IfStmt) stmtNode() {}
+func (*CaseClause) stmtNode() {}
+func (*SwitchStmt) stmtNode() {}
+func (*TypeSwitchStmt) stmtNode() {}
+func (*CommClause) stmtNode() {}
+func (*SelectStmt) stmtNode() {}
+func (*ForStmt) stmtNode() {}
+func (*RangeStmt) stmtNode() {}
+
+// ----------------------------------------------------------------------------
+// Declarations
+
+// A Spec node represents a single (non-parenthesized) import,
+// constant, type, or variable declaration.
+//
+type (
+ // The Spec type stands for any of *ImportSpec, *ValueSpec, and *TypeSpec.
+ Spec interface {
+ Node
+ specNode()
+ }
+
+ // An ImportSpec node represents a single package import.
+ ImportSpec struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Name *Ident // local package name (including "."); or nil
+ Path *BasicLit // import path
+ Comment *CommentGroup // line comments; or nil
+ EndPos token.Pos // end of spec (overrides Path.Pos if nonzero)
+ }
+
+ // A ValueSpec node represents a constant or variable declaration
+ // (ConstSpec or VarSpec production).
+ //
+ ValueSpec struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Names []*Ident // value names (len(Names) > 0)
+ Type Expr // value type; or nil
+ Values []Expr // initial values; or nil
+ Comment *CommentGroup // line comments; or nil
+ }
+
+ // A TypeSpec node represents a type declaration (TypeSpec production).
+ TypeSpec struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Name *Ident // type name
+ Assign token.Pos // position of '=', if any
+ Type Expr // *Ident, *ParenExpr, *SelectorExpr, *StarExpr, or any of the *XxxTypes
+ Comment *CommentGroup // line comments; or nil
+ }
+)
+
+// Pos and End implementations for spec nodes.
+
+func (s *ImportSpec) Pos() token.Pos {
+ if s.Name != nil {
+ return s.Name.Pos()
+ }
+ return s.Path.Pos()
+}
+func (s *ValueSpec) Pos() token.Pos { return s.Names[0].Pos() }
+func (s *TypeSpec) Pos() token.Pos { return s.Name.Pos() }
+
+func (s *ImportSpec) End() token.Pos {
+ if s.EndPos != 0 {
+ return s.EndPos
+ }
+ return s.Path.End()
+}
+
+func (s *ValueSpec) End() token.Pos {
+ if n := len(s.Values); n > 0 {
+ return s.Values[n-1].End()
+ }
+ if s.Type != nil {
+ return s.Type.End()
+ }
+ return s.Names[len(s.Names)-1].End()
+}
+func (s *TypeSpec) End() token.Pos { return s.Type.End() }
+
+// specNode() ensures that only spec nodes can be
+// assigned to a Spec.
+//
+func (*ImportSpec) specNode() {}
+func (*ValueSpec) specNode() {}
+func (*TypeSpec) specNode() {}
+
+// A declaration is represented by one of the following declaration nodes.
+//
+type (
+ // A BadDecl node is a placeholder for a declaration containing
+ // syntax errors for which a correct declaration node cannot be
+ // created.
+ //
+ BadDecl struct {
+ From, To token.Pos // position range of bad declaration
+ }
+
+ // A GenDecl node (generic declaration node) represents an import,
+ // constant, type or variable declaration. A valid Lparen position
+ // (Lparen.IsValid()) indicates a parenthesized declaration.
+ //
+ // Relationship between Tok value and Specs element type:
+ //
+ // token.IMPORT *ImportSpec
+ // token.CONST *ValueSpec
+ // token.TYPE *TypeSpec
+ // token.VAR *ValueSpec
+ //
+ GenDecl struct {
+ Doc *CommentGroup // associated documentation; or nil
+ TokPos token.Pos // position of Tok
+ Tok token.Token // IMPORT, CONST, TYPE, VAR
+ Lparen token.Pos // position of '(', if any
+ Specs []Spec
+ Rparen token.Pos // position of ')', if any
+ }
+
+ // A FuncDecl node represents a function declaration.
+ FuncDecl struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Recv *FieldList // receiver (methods); or nil (functions)
+ Name *Ident // function/method name
+ Type *FuncType // function signature: parameters, results, and position of "func" keyword
+ Body *BlockStmt // function body; or nil for external (non-Go) function
+ }
+)
+
+// Pos and End implementations for declaration nodes.
+
+func (d *BadDecl) Pos() token.Pos { return d.From }
+func (d *GenDecl) Pos() token.Pos { return d.TokPos }
+func (d *FuncDecl) Pos() token.Pos { return d.Type.Pos() }
+
+func (d *BadDecl) End() token.Pos { return d.To }
+func (d *GenDecl) End() token.Pos {
+ if d.Rparen.IsValid() {
+ return d.Rparen + 1
+ }
+ return d.Specs[0].End()
+}
+func (d *FuncDecl) End() token.Pos {
+ if d.Body != nil {
+ return d.Body.End()
+ }
+ return d.Type.End()
+}
+
+// declNode() ensures that only declaration nodes can be
+// assigned to a Decl.
+//
+func (*BadDecl) declNode() {}
+func (*GenDecl) declNode() {}
+func (*FuncDecl) declNode() {}
+
+// ----------------------------------------------------------------------------
+// Files and packages
+
+// A File node represents a Go source file.
+//
+// The Comments list contains all comments in the source file in order of
+// appearance, including the comments that are pointed to from other nodes
+// via Doc and Comment fields.
+//
+// For correct printing of source code containing comments (using packages
+// go/format and go/printer), special care must be taken to update comments
+// when a File's syntax tree is modified: For printing, comments are interspersed
+// between tokens based on their position. If syntax tree nodes are
+// removed or moved, relevant comments in their vicinity must also be removed
+// (from the File.Comments list) or moved accordingly (by updating their
+// positions). A CommentMap may be used to facilitate some of these operations.
+//
+// Whether and how a comment is associated with a node depends on the
+// interpretation of the syntax tree by the manipulating program: Except for Doc
+// and Comment comments directly associated with nodes, the remaining comments
+// are "free-floating" (see also issues #18593, #20744).
+//
+type File struct {
+ Doc *CommentGroup // associated documentation; or nil
+ Package token.Pos // position of "package" keyword
+ Name *Ident // package name
+ Decls []Decl // top-level declarations; or nil
+ Scope *Scope // package scope (this file only)
+ Imports []*ImportSpec // imports in this file
+ Unresolved []*Ident // unresolved identifiers in this file
+ Comments []*CommentGroup // list of all comments in the source file
+}
+
+func (f *File) Pos() token.Pos { return f.Package }
+func (f *File) End() token.Pos {
+ if n := len(f.Decls); n > 0 {
+ return f.Decls[n-1].End()
+ }
+ return f.Name.End()
+}
+
+// A Package node represents a set of source files
+// collectively building a Go package.
+//
+type Package struct {
+ Name string // package name
+ Scope *Scope // package scope across all files
+ Imports map[string]*Object // map of package id -> package object
+ Files map[string]*File // Go source files by filename
+}
+
+func (p *Package) Pos() token.Pos { return token.NoPos }
+func (p *Package) End() token.Pos { return token.NoPos }
diff --git a/src/go/ast/ast_test.go b/src/go/ast/ast_test.go
new file mode 100644
index 0000000..71b2d6c
--- /dev/null
+++ b/src/go/ast/ast_test.go
@@ -0,0 +1,79 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+ "testing"
+)
+
+var comments = []struct {
+ list []string
+ text string
+}{
+ {[]string{"//"}, ""},
+ {[]string{"// "}, ""},
+ {[]string{"//", "//", "// "}, ""},
+ {[]string{"// foo "}, "foo\n"},
+ {[]string{"//", "//", "// foo"}, "foo\n"},
+ {[]string{"// foo bar "}, "foo bar\n"},
+ {[]string{"// foo", "// bar"}, "foo\nbar\n"},
+ {[]string{"// foo", "//", "//", "//", "// bar"}, "foo\n\nbar\n"},
+ {[]string{"// foo", "/* bar */"}, "foo\n bar\n"},
+ {[]string{"//", "//", "//", "// foo", "//", "//", "//"}, "foo\n"},
+
+ {[]string{"/**/"}, ""},
+ {[]string{"/* */"}, ""},
+ {[]string{"/**/", "/**/", "/* */"}, ""},
+ {[]string{"/* Foo */"}, " Foo\n"},
+ {[]string{"/* Foo Bar */"}, " Foo Bar\n"},
+ {[]string{"/* Foo*/", "/* Bar*/"}, " Foo\n Bar\n"},
+ {[]string{"/* Foo*/", "/**/", "/**/", "/**/", "// Bar"}, " Foo\n\nBar\n"},
+ {[]string{"/* Foo*/", "/*\n*/", "//", "/*\n*/", "// Bar"}, " Foo\n\nBar\n"},
+ {[]string{"/* Foo*/", "// Bar"}, " Foo\nBar\n"},
+ {[]string{"/* Foo\n Bar*/"}, " Foo\n Bar\n"},
+
+ {[]string{"// foo", "//go:noinline", "// bar", "//:baz"}, "foo\nbar\n:baz\n"},
+ {[]string{"// foo", "//lint123:ignore", "// bar"}, "foo\nbar\n"},
+}
+
+func TestCommentText(t *testing.T) {
+ for i, c := range comments {
+ list := make([]*Comment, len(c.list))
+ for i, s := range c.list {
+ list[i] = &Comment{Text: s}
+ }
+
+ text := (&CommentGroup{list}).Text()
+ if text != c.text {
+ t.Errorf("case %d: got %q; expected %q", i, text, c.text)
+ }
+ }
+}
+
+var isDirectiveTests = []struct {
+ in string
+ ok bool
+}{
+ {"abc", false},
+ {"go:inline", true},
+ {"Go:inline", false},
+ {"go:Inline", false},
+ {":inline", false},
+ {"lint:ignore", true},
+ {"lint:1234", true},
+ {"1234:lint", true},
+ {"go: inline", false},
+ {"go:", false},
+ {"go:*", false},
+ {"go:x*", true},
+}
+
+func TestIsDirective(t *testing.T) {
+ for _, tt := range isDirectiveTests {
+ if ok := isDirective(tt.in); ok != tt.ok {
+ t.Errorf("isDirective(%q) = %v, want %v", tt.in, ok, tt.ok)
+ }
+ }
+}
diff --git a/src/go/ast/commentmap.go b/src/go/ast/commentmap.go
new file mode 100644
index 0000000..2a653a6
--- /dev/null
+++ b/src/go/ast/commentmap.go
@@ -0,0 +1,332 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+ "bytes"
+ "fmt"
+ "go/token"
+ "sort"
+)
+
+type byPos []*CommentGroup
+
+func (a byPos) Len() int { return len(a) }
+func (a byPos) Less(i, j int) bool { return a[i].Pos() < a[j].Pos() }
+func (a byPos) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// sortComments sorts the list of comment groups in source order.
+//
+func sortComments(list []*CommentGroup) {
+ // TODO(gri): Does it make sense to check for sorted-ness
+ // first (because we know that sorted-ness is
+ // very likely)?
+ if orderedList := byPos(list); !sort.IsSorted(orderedList) {
+ sort.Sort(orderedList)
+ }
+}
+
+// A CommentMap maps an AST node to a list of comment groups
+// associated with it. See NewCommentMap for a description of
+// the association.
+//
+type CommentMap map[Node][]*CommentGroup
+
+func (cmap CommentMap) addComment(n Node, c *CommentGroup) {
+ list := cmap[n]
+ if len(list) == 0 {
+ list = []*CommentGroup{c}
+ } else {
+ list = append(list, c)
+ }
+ cmap[n] = list
+}
+
+type byInterval []Node
+
+func (a byInterval) Len() int { return len(a) }
+func (a byInterval) Less(i, j int) bool {
+ pi, pj := a[i].Pos(), a[j].Pos()
+ return pi < pj || pi == pj && a[i].End() > a[j].End()
+}
+func (a byInterval) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// nodeList returns the list of nodes of the AST n in source order.
+//
+func nodeList(n Node) []Node {
+ var list []Node
+ Inspect(n, func(n Node) bool {
+ // don't collect comments
+ switch n.(type) {
+ case nil, *CommentGroup, *Comment:
+ return false
+ }
+ list = append(list, n)
+ return true
+ })
+ // Note: The current implementation assumes that Inspect traverses the
+ // AST in depth-first and thus _source_ order. If AST traversal
+ // does not follow source order, the sorting call below will be
+ // required.
+ // sort.Sort(byInterval(list))
+ return list
+}
+
+// A commentListReader helps iterating through a list of comment groups.
+//
+type commentListReader struct {
+ fset *token.FileSet
+ list []*CommentGroup
+ index int
+ comment *CommentGroup // comment group at current index
+ pos, end token.Position // source interval of comment group at current index
+}
+
+func (r *commentListReader) eol() bool {
+ return r.index >= len(r.list)
+}
+
+func (r *commentListReader) next() {
+ if !r.eol() {
+ r.comment = r.list[r.index]
+ r.pos = r.fset.Position(r.comment.Pos())
+ r.end = r.fset.Position(r.comment.End())
+ r.index++
+ }
+}
+
+// A nodeStack keeps track of nested nodes.
+// A node lower on the stack lexically contains the nodes higher on the stack.
+//
+type nodeStack []Node
+
+// push pops all nodes that appear lexically before n
+// and then pushes n on the stack.
+//
+func (s *nodeStack) push(n Node) {
+ s.pop(n.Pos())
+ *s = append((*s), n)
+}
+
+// pop pops all nodes that appear lexically before pos
+// (i.e., whose lexical extent has ended before or at pos).
+// It returns the last node popped.
+//
+func (s *nodeStack) pop(pos token.Pos) (top Node) {
+ i := len(*s)
+ for i > 0 && (*s)[i-1].End() <= pos {
+ top = (*s)[i-1]
+ i--
+ }
+ *s = (*s)[0:i]
+ return top
+}
+
+// NewCommentMap creates a new comment map by associating comment groups
+// of the comments list with the nodes of the AST specified by node.
+//
+// A comment group g is associated with a node n if:
+//
+// - g starts on the same line as n ends
+// - g starts on the line immediately following n, and there is
+// at least one empty line after g and before the next node
+// - g starts before n and is not associated to the node before n
+// via the previous rules
+//
+// NewCommentMap tries to associate a comment group to the "largest"
+// node possible: For instance, if the comment is a line comment
+// trailing an assignment, the comment is associated with the entire
+// assignment rather than just the last operand in the assignment.
+//
+func NewCommentMap(fset *token.FileSet, node Node, comments []*CommentGroup) CommentMap {
+ if len(comments) == 0 {
+ return nil // no comments to map
+ }
+
+ cmap := make(CommentMap)
+
+ // set up comment reader r
+ tmp := make([]*CommentGroup, len(comments))
+ copy(tmp, comments) // don't change incoming comments
+ sortComments(tmp)
+ r := commentListReader{fset: fset, list: tmp} // !r.eol() because len(comments) > 0
+ r.next()
+
+ // create node list in lexical order
+ nodes := nodeList(node)
+ nodes = append(nodes, nil) // append sentinel
+
+ // set up iteration variables
+ var (
+ p Node // previous node
+ pend token.Position // end of p
+ pg Node // previous node group (enclosing nodes of "importance")
+ pgend token.Position // end of pg
+ stack nodeStack // stack of node groups
+ )
+
+ for _, q := range nodes {
+ var qpos token.Position
+ if q != nil {
+ qpos = fset.Position(q.Pos()) // current node position
+ } else {
+ // set fake sentinel position to infinity so that
+ // all comments get processed before the sentinel
+ const infinity = 1 << 30
+ qpos.Offset = infinity
+ qpos.Line = infinity
+ }
+
+ // process comments before current node
+ for r.end.Offset <= qpos.Offset {
+ // determine recent node group
+ if top := stack.pop(r.comment.Pos()); top != nil {
+ pg = top
+ pgend = fset.Position(pg.End())
+ }
+ // Try to associate a comment first with a node group
+ // (i.e., a node of "importance" such as a declaration);
+ // if that fails, try to associate it with the most recent
+ // node.
+ // TODO(gri) try to simplify the logic below
+ var assoc Node
+ switch {
+ case pg != nil &&
+ (pgend.Line == r.pos.Line ||
+ pgend.Line+1 == r.pos.Line && r.end.Line+1 < qpos.Line):
+ // 1) comment starts on same line as previous node group ends, or
+ // 2) comment starts on the line immediately after the
+ // previous node group and there is an empty line before
+ // the current node
+ // => associate comment with previous node group
+ assoc = pg
+ case p != nil &&
+ (pend.Line == r.pos.Line ||
+ pend.Line+1 == r.pos.Line && r.end.Line+1 < qpos.Line ||
+ q == nil):
+ // same rules apply as above for p rather than pg,
+ // but also associate with p if we are at the end (q == nil)
+ assoc = p
+ default:
+ // otherwise, associate comment with current node
+ if q == nil {
+ // we can only reach here if there was no p
+ // which would imply that there were no nodes
+ panic("internal error: no comments should be associated with sentinel")
+ }
+ assoc = q
+ }
+ cmap.addComment(assoc, r.comment)
+ if r.eol() {
+ return cmap
+ }
+ r.next()
+ }
+
+ // update previous node
+ p = q
+ pend = fset.Position(p.End())
+
+ // update previous node group if we see an "important" node
+ switch q.(type) {
+ case *File, *Field, Decl, Spec, Stmt:
+ stack.push(q)
+ }
+ }
+
+ return cmap
+}
+
+// Update replaces an old node in the comment map with the new node
+// and returns the new node. Comments that were associated with the
+// old node are associated with the new node.
+//
+func (cmap CommentMap) Update(old, new Node) Node {
+ if list := cmap[old]; len(list) > 0 {
+ delete(cmap, old)
+ cmap[new] = append(cmap[new], list...)
+ }
+ return new
+}
+
+// Filter returns a new comment map consisting of only those
+// entries of cmap for which a corresponding node exists in
+// the AST specified by node.
+//
+func (cmap CommentMap) Filter(node Node) CommentMap {
+ umap := make(CommentMap)
+ Inspect(node, func(n Node) bool {
+ if g := cmap[n]; len(g) > 0 {
+ umap[n] = g
+ }
+ return true
+ })
+ return umap
+}
+
+// Comments returns the list of comment groups in the comment map.
+// The result is sorted in source order.
+//
+func (cmap CommentMap) Comments() []*CommentGroup {
+ list := make([]*CommentGroup, 0, len(cmap))
+ for _, e := range cmap {
+ list = append(list, e...)
+ }
+ sortComments(list)
+ return list
+}
+
+func summary(list []*CommentGroup) string {
+ const maxLen = 40
+ var buf bytes.Buffer
+
+ // collect comments text
+loop:
+ for _, group := range list {
+ // Note: CommentGroup.Text() does too much work for what we
+ // need and would only replace this innermost loop.
+ // Just do it explicitly.
+ for _, comment := range group.List {
+ if buf.Len() >= maxLen {
+ break loop
+ }
+ buf.WriteString(comment.Text)
+ }
+ }
+
+ // truncate if too long
+ if buf.Len() > maxLen {
+ buf.Truncate(maxLen - 3)
+ buf.WriteString("...")
+ }
+
+ // replace any invisibles with blanks
+ bytes := buf.Bytes()
+ for i, b := range bytes {
+ switch b {
+ case '\t', '\n', '\r':
+ bytes[i] = ' '
+ }
+ }
+
+ return string(bytes)
+}
+
+func (cmap CommentMap) String() string {
+ var buf bytes.Buffer
+ fmt.Fprintln(&buf, "CommentMap {")
+ for node, comment := range cmap {
+ // print name of identifiers; print node type for other nodes
+ var s string
+ if ident, ok := node.(*Ident); ok {
+ s = ident.Name
+ } else {
+ s = fmt.Sprintf("%T", node)
+ }
+ fmt.Fprintf(&buf, "\t%p %20s: %s\n", node, s, summary(comment))
+ }
+ fmt.Fprintln(&buf, "}")
+ return buf.String()
+}
diff --git a/src/go/ast/commentmap_test.go b/src/go/ast/commentmap_test.go
new file mode 100644
index 0000000..38c62b0
--- /dev/null
+++ b/src/go/ast/commentmap_test.go
@@ -0,0 +1,170 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// To avoid a cyclic dependency with go/parser, this file is in a separate package.
+
+package ast_test
+
+import (
+ "bytes"
+ "fmt"
+ . "go/ast"
+ "go/parser"
+ "go/token"
+ "sort"
+ "testing"
+)
+
+const src = `
+// the very first comment
+
+// package p
+package p /* the name is p */
+
+// imports
+import (
+ "bytes" // bytes
+ "fmt" // fmt
+ "go/ast"
+ "go/parser"
+)
+
+// T
+type T struct {
+ a, b, c int // associated with a, b, c
+ // associated with x, y
+ x, y float64 // float values
+ z complex128 // complex value
+}
+// also associated with T
+
+// x
+var x = 0 // x = 0
+// also associated with x
+
+// f1
+func f1() {
+ /* associated with s1 */
+ s1()
+ // also associated with s1
+
+ // associated with s2
+
+ // also associated with s2
+ s2() // line comment for s2
+}
+// associated with f1
+// also associated with f1
+
+// associated with f2
+
+// f2
+func f2() {
+}
+
+func f3() {
+ i := 1 /* 1 */ + 2 // addition
+ _ = i
+}
+
+// the very last comment
+`
+
+// res maps a key of the form "line number: node type"
+// to the associated comments' text.
+//
+var res = map[string]string{
+ " 5: *ast.File": "the very first comment\npackage p\n",
+ " 5: *ast.Ident": " the name is p\n",
+ " 8: *ast.GenDecl": "imports\n",
+ " 9: *ast.ImportSpec": "bytes\n",
+ "10: *ast.ImportSpec": "fmt\n",
+ "16: *ast.GenDecl": "T\nalso associated with T\n",
+ "17: *ast.Field": "associated with a, b, c\n",
+ "19: *ast.Field": "associated with x, y\nfloat values\n",
+ "20: *ast.Field": "complex value\n",
+ "25: *ast.GenDecl": "x\nx = 0\nalso associated with x\n",
+ "29: *ast.FuncDecl": "f1\nassociated with f1\nalso associated with f1\n",
+ "31: *ast.ExprStmt": " associated with s1\nalso associated with s1\n",
+ "37: *ast.ExprStmt": "associated with s2\nalso associated with s2\nline comment for s2\n",
+ "45: *ast.FuncDecl": "associated with f2\nf2\n",
+ "49: *ast.AssignStmt": "addition\n",
+ "49: *ast.BasicLit": " 1\n",
+ "50: *ast.Ident": "the very last comment\n",
+}
+
+func ctext(list []*CommentGroup) string {
+ var buf bytes.Buffer
+ for _, g := range list {
+ buf.WriteString(g.Text())
+ }
+ return buf.String()
+}
+
+func TestCommentMap(t *testing.T) {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ cmap := NewCommentMap(fset, f, f.Comments)
+
+ // very correct association of comments
+ for n, list := range cmap {
+ key := fmt.Sprintf("%2d: %T", fset.Position(n.Pos()).Line, n)
+ got := ctext(list)
+ want := res[key]
+ if got != want {
+ t.Errorf("%s: got %q; want %q", key, got, want)
+ }
+ }
+
+ // verify that no comments got lost
+ if n := len(cmap.Comments()); n != len(f.Comments) {
+ t.Errorf("got %d comment groups in map; want %d", n, len(f.Comments))
+ }
+
+ // support code to update test:
+ // set genMap to true to generate res map
+ const genMap = false
+ if genMap {
+ out := make([]string, 0, len(cmap))
+ for n, list := range cmap {
+ out = append(out, fmt.Sprintf("\t\"%2d: %T\":\t%q,", fset.Position(n.Pos()).Line, n, ctext(list)))
+ }
+ sort.Strings(out)
+ for _, s := range out {
+ fmt.Println(s)
+ }
+ }
+}
+
+func TestFilter(t *testing.T) {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ cmap := NewCommentMap(fset, f, f.Comments)
+
+ // delete variable declaration
+ for i, decl := range f.Decls {
+ if gen, ok := decl.(*GenDecl); ok && gen.Tok == token.VAR {
+ copy(f.Decls[i:], f.Decls[i+1:])
+ f.Decls = f.Decls[:len(f.Decls)-1]
+ break
+ }
+ }
+
+ // check if comments are filtered correctly
+ cc := cmap.Filter(f)
+ for n, list := range cc {
+ key := fmt.Sprintf("%2d: %T", fset.Position(n.Pos()).Line, n)
+ got := ctext(list)
+ want := res[key]
+ if key == "25: *ast.GenDecl" || got != want {
+ t.Errorf("%s: got %q; want %q", key, got, want)
+ }
+ }
+}
diff --git a/src/go/ast/example_test.go b/src/go/ast/example_test.go
new file mode 100644
index 0000000..e3013f6
--- /dev/null
+++ b/src/go/ast/example_test.go
@@ -0,0 +1,206 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/format"
+ "go/parser"
+ "go/token"
+)
+
+// This example demonstrates how to inspect the AST of a Go program.
+func ExampleInspect() {
+ // src is the input for which we want to inspect the AST.
+ src := `
+package p
+const c = 1.0
+var X = f(3.14)*2 + c
+`
+
+ // Create the AST by parsing src.
+ fset := token.NewFileSet() // positions are relative to fset
+ f, err := parser.ParseFile(fset, "src.go", src, 0)
+ if err != nil {
+ panic(err)
+ }
+
+ // Inspect the AST and print all identifiers and literals.
+ ast.Inspect(f, func(n ast.Node) bool {
+ var s string
+ switch x := n.(type) {
+ case *ast.BasicLit:
+ s = x.Value
+ case *ast.Ident:
+ s = x.Name
+ }
+ if s != "" {
+ fmt.Printf("%s:\t%s\n", fset.Position(n.Pos()), s)
+ }
+ return true
+ })
+
+ // Output:
+ // src.go:2:9: p
+ // src.go:3:7: c
+ // src.go:3:11: 1.0
+ // src.go:4:5: X
+ // src.go:4:9: f
+ // src.go:4:11: 3.14
+ // src.go:4:17: 2
+ // src.go:4:21: c
+}
+
+// This example shows what an AST looks like when printed for debugging.
+func ExamplePrint() {
+ // src is the input for which we want to print the AST.
+ src := `
+package main
+func main() {
+ println("Hello, World!")
+}
+`
+
+ // Create the AST by parsing src.
+ fset := token.NewFileSet() // positions are relative to fset
+ f, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ panic(err)
+ }
+
+ // Print the AST.
+ ast.Print(fset, f)
+
+ // Output:
+ // 0 *ast.File {
+ // 1 . Package: 2:1
+ // 2 . Name: *ast.Ident {
+ // 3 . . NamePos: 2:9
+ // 4 . . Name: "main"
+ // 5 . }
+ // 6 . Decls: []ast.Decl (len = 1) {
+ // 7 . . 0: *ast.FuncDecl {
+ // 8 . . . Name: *ast.Ident {
+ // 9 . . . . NamePos: 3:6
+ // 10 . . . . Name: "main"
+ // 11 . . . . Obj: *ast.Object {
+ // 12 . . . . . Kind: func
+ // 13 . . . . . Name: "main"
+ // 14 . . . . . Decl: *(obj @ 7)
+ // 15 . . . . }
+ // 16 . . . }
+ // 17 . . . Type: *ast.FuncType {
+ // 18 . . . . Func: 3:1
+ // 19 . . . . Params: *ast.FieldList {
+ // 20 . . . . . Opening: 3:10
+ // 21 . . . . . Closing: 3:11
+ // 22 . . . . }
+ // 23 . . . }
+ // 24 . . . Body: *ast.BlockStmt {
+ // 25 . . . . Lbrace: 3:13
+ // 26 . . . . List: []ast.Stmt (len = 1) {
+ // 27 . . . . . 0: *ast.ExprStmt {
+ // 28 . . . . . . X: *ast.CallExpr {
+ // 29 . . . . . . . Fun: *ast.Ident {
+ // 30 . . . . . . . . NamePos: 4:2
+ // 31 . . . . . . . . Name: "println"
+ // 32 . . . . . . . }
+ // 33 . . . . . . . Lparen: 4:9
+ // 34 . . . . . . . Args: []ast.Expr (len = 1) {
+ // 35 . . . . . . . . 0: *ast.BasicLit {
+ // 36 . . . . . . . . . ValuePos: 4:10
+ // 37 . . . . . . . . . Kind: STRING
+ // 38 . . . . . . . . . Value: "\"Hello, World!\""
+ // 39 . . . . . . . . }
+ // 40 . . . . . . . }
+ // 41 . . . . . . . Ellipsis: -
+ // 42 . . . . . . . Rparen: 4:25
+ // 43 . . . . . . }
+ // 44 . . . . . }
+ // 45 . . . . }
+ // 46 . . . . Rbrace: 5:1
+ // 47 . . . }
+ // 48 . . }
+ // 49 . }
+ // 50 . Scope: *ast.Scope {
+ // 51 . . Objects: map[string]*ast.Object (len = 1) {
+ // 52 . . . "main": *(obj @ 11)
+ // 53 . . }
+ // 54 . }
+ // 55 . Unresolved: []*ast.Ident (len = 1) {
+ // 56 . . 0: *(obj @ 29)
+ // 57 . }
+ // 58 }
+}
+
+// This example illustrates how to remove a variable declaration
+// in a Go program while maintaining correct comment association
+// using an ast.CommentMap.
+func ExampleCommentMap() {
+ // src is the input for which we create the AST that we
+ // are going to manipulate.
+ src := `
+// This is the package comment.
+package main
+
+// This comment is associated with the hello constant.
+const hello = "Hello, World!" // line comment 1
+
+// This comment is associated with the foo variable.
+var foo = hello // line comment 2
+
+// This comment is associated with the main function.
+func main() {
+ fmt.Println(hello) // line comment 3
+}
+`
+
+ // Create the AST by parsing src.
+ fset := token.NewFileSet() // positions are relative to fset
+ f, err := parser.ParseFile(fset, "src.go", src, parser.ParseComments)
+ if err != nil {
+ panic(err)
+ }
+
+ // Create an ast.CommentMap from the ast.File's comments.
+ // This helps keeping the association between comments
+ // and AST nodes.
+ cmap := ast.NewCommentMap(fset, f, f.Comments)
+
+ // Remove the first variable declaration from the list of declarations.
+ for i, decl := range f.Decls {
+ if gen, ok := decl.(*ast.GenDecl); ok && gen.Tok == token.VAR {
+ copy(f.Decls[i:], f.Decls[i+1:])
+ f.Decls = f.Decls[:len(f.Decls)-1]
+ break
+ }
+ }
+
+ // Use the comment map to filter comments that don't belong anymore
+ // (the comments associated with the variable declaration), and create
+ // the new comments list.
+ f.Comments = cmap.Filter(f).Comments()
+
+ // Print the modified AST.
+ var buf bytes.Buffer
+ if err := format.Node(&buf, fset, f); err != nil {
+ panic(err)
+ }
+ fmt.Printf("%s", buf.Bytes())
+
+ // Output:
+ // // This is the package comment.
+ // package main
+ //
+ // // This comment is associated with the hello constant.
+ // const hello = "Hello, World!" // line comment 1
+ //
+ // // This comment is associated with the main function.
+ // func main() {
+ // fmt.Println(hello) // line comment 3
+ // }
+}
diff --git a/src/go/ast/filter.go b/src/go/ast/filter.go
new file mode 100644
index 0000000..c398e6e
--- /dev/null
+++ b/src/go/ast/filter.go
@@ -0,0 +1,497 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+ "go/token"
+ "sort"
+)
+
+// ----------------------------------------------------------------------------
+// Export filtering
+
+// exportFilter is a special filter function to extract exported nodes.
+func exportFilter(name string) bool {
+ return IsExported(name)
+}
+
+// FileExports trims the AST for a Go source file in place such that
+// only exported nodes remain: all top-level identifiers which are not exported
+// and their associated information (such as type, initial value, or function
+// body) are removed. Non-exported fields and methods of exported types are
+// stripped. The File.Comments list is not changed.
+//
+// FileExports reports whether there are exported declarations.
+//
+func FileExports(src *File) bool {
+ return filterFile(src, exportFilter, true)
+}
+
+// PackageExports trims the AST for a Go package in place such that
+// only exported nodes remain. The pkg.Files list is not changed, so that
+// file names and top-level package comments don't get lost.
+//
+// PackageExports reports whether there are exported declarations;
+// it returns false otherwise.
+//
+func PackageExports(pkg *Package) bool {
+ return filterPackage(pkg, exportFilter, true)
+}
+
+// ----------------------------------------------------------------------------
+// General filtering
+
+type Filter func(string) bool
+
+func filterIdentList(list []*Ident, f Filter) []*Ident {
+ j := 0
+ for _, x := range list {
+ if f(x.Name) {
+ list[j] = x
+ j++
+ }
+ }
+ return list[0:j]
+}
+
+// fieldName assumes that x is the type of an anonymous field and
+// returns the corresponding field name. If x is not an acceptable
+// anonymous field, the result is nil.
+//
+func fieldName(x Expr) *Ident {
+ switch t := x.(type) {
+ case *Ident:
+ return t
+ case *SelectorExpr:
+ if _, ok := t.X.(*Ident); ok {
+ return t.Sel
+ }
+ case *StarExpr:
+ return fieldName(t.X)
+ }
+ return nil
+}
+
+func filterFieldList(fields *FieldList, filter Filter, export bool) (removedFields bool) {
+ if fields == nil {
+ return false
+ }
+ list := fields.List
+ j := 0
+ for _, f := range list {
+ keepField := false
+ if len(f.Names) == 0 {
+ // anonymous field
+ name := fieldName(f.Type)
+ keepField = name != nil && filter(name.Name)
+ } else {
+ n := len(f.Names)
+ f.Names = filterIdentList(f.Names, filter)
+ if len(f.Names) < n {
+ removedFields = true
+ }
+ keepField = len(f.Names) > 0
+ }
+ if keepField {
+ if export {
+ filterType(f.Type, filter, export)
+ }
+ list[j] = f
+ j++
+ }
+ }
+ if j < len(list) {
+ removedFields = true
+ }
+ fields.List = list[0:j]
+ return
+}
+
+func filterCompositeLit(lit *CompositeLit, filter Filter, export bool) {
+ n := len(lit.Elts)
+ lit.Elts = filterExprList(lit.Elts, filter, export)
+ if len(lit.Elts) < n {
+ lit.Incomplete = true
+ }
+}
+
+func filterExprList(list []Expr, filter Filter, export bool) []Expr {
+ j := 0
+ for _, exp := range list {
+ switch x := exp.(type) {
+ case *CompositeLit:
+ filterCompositeLit(x, filter, export)
+ case *KeyValueExpr:
+ if x, ok := x.Key.(*Ident); ok && !filter(x.Name) {
+ continue
+ }
+ if x, ok := x.Value.(*CompositeLit); ok {
+ filterCompositeLit(x, filter, export)
+ }
+ }
+ list[j] = exp
+ j++
+ }
+ return list[0:j]
+}
+
+func filterParamList(fields *FieldList, filter Filter, export bool) bool {
+ if fields == nil {
+ return false
+ }
+ var b bool
+ for _, f := range fields.List {
+ if filterType(f.Type, filter, export) {
+ b = true
+ }
+ }
+ return b
+}
+
+func filterType(typ Expr, f Filter, export bool) bool {
+ switch t := typ.(type) {
+ case *Ident:
+ return f(t.Name)
+ case *ParenExpr:
+ return filterType(t.X, f, export)
+ case *ArrayType:
+ return filterType(t.Elt, f, export)
+ case *StructType:
+ if filterFieldList(t.Fields, f, export) {
+ t.Incomplete = true
+ }
+ return len(t.Fields.List) > 0
+ case *FuncType:
+ b1 := filterParamList(t.Params, f, export)
+ b2 := filterParamList(t.Results, f, export)
+ return b1 || b2
+ case *InterfaceType:
+ if filterFieldList(t.Methods, f, export) {
+ t.Incomplete = true
+ }
+ return len(t.Methods.List) > 0
+ case *MapType:
+ b1 := filterType(t.Key, f, export)
+ b2 := filterType(t.Value, f, export)
+ return b1 || b2
+ case *ChanType:
+ return filterType(t.Value, f, export)
+ }
+ return false
+}
+
+func filterSpec(spec Spec, f Filter, export bool) bool {
+ switch s := spec.(type) {
+ case *ValueSpec:
+ s.Names = filterIdentList(s.Names, f)
+ s.Values = filterExprList(s.Values, f, export)
+ if len(s.Names) > 0 {
+ if export {
+ filterType(s.Type, f, export)
+ }
+ return true
+ }
+ case *TypeSpec:
+ if f(s.Name.Name) {
+ if export {
+ filterType(s.Type, f, export)
+ }
+ return true
+ }
+ if !export {
+ // For general filtering (not just exports),
+ // filter type even if name is not filtered
+ // out.
+ // If the type contains filtered elements,
+ // keep the declaration.
+ return filterType(s.Type, f, export)
+ }
+ }
+ return false
+}
+
+func filterSpecList(list []Spec, f Filter, export bool) []Spec {
+ j := 0
+ for _, s := range list {
+ if filterSpec(s, f, export) {
+ list[j] = s
+ j++
+ }
+ }
+ return list[0:j]
+}
+
+// FilterDecl trims the AST for a Go declaration in place by removing
+// all names (including struct field and interface method names, but
+// not from parameter lists) that don't pass through the filter f.
+//
+// FilterDecl reports whether there are any declared names left after
+// filtering.
+//
+func FilterDecl(decl Decl, f Filter) bool {
+ return filterDecl(decl, f, false)
+}
+
+func filterDecl(decl Decl, f Filter, export bool) bool {
+ switch d := decl.(type) {
+ case *GenDecl:
+ d.Specs = filterSpecList(d.Specs, f, export)
+ return len(d.Specs) > 0
+ case *FuncDecl:
+ return f(d.Name.Name)
+ }
+ return false
+}
+
+// FilterFile trims the AST for a Go file in place by removing all
+// names from top-level declarations (including struct field and
+// interface method names, but not from parameter lists) that don't
+// pass through the filter f. If the declaration is empty afterwards,
+// the declaration is removed from the AST. Import declarations are
+// always removed. The File.Comments list is not changed.
+//
+// FilterFile reports whether there are any top-level declarations
+// left after filtering.
+//
+func FilterFile(src *File, f Filter) bool {
+ return filterFile(src, f, false)
+}
+
+func filterFile(src *File, f Filter, export bool) bool {
+ j := 0
+ for _, d := range src.Decls {
+ if filterDecl(d, f, export) {
+ src.Decls[j] = d
+ j++
+ }
+ }
+ src.Decls = src.Decls[0:j]
+ return j > 0
+}
+
+// FilterPackage trims the AST for a Go package in place by removing
+// all names from top-level declarations (including struct field and
+// interface method names, but not from parameter lists) that don't
+// pass through the filter f. If the declaration is empty afterwards,
+// the declaration is removed from the AST. The pkg.Files list is not
+// changed, so that file names and top-level package comments don't get
+// lost.
+//
+// FilterPackage reports whether there are any top-level declarations
+// left after filtering.
+//
+func FilterPackage(pkg *Package, f Filter) bool {
+ return filterPackage(pkg, f, false)
+}
+
+func filterPackage(pkg *Package, f Filter, export bool) bool {
+ hasDecls := false
+ for _, src := range pkg.Files {
+ if filterFile(src, f, export) {
+ hasDecls = true
+ }
+ }
+ return hasDecls
+}
+
+// ----------------------------------------------------------------------------
+// Merging of package files
+
+// The MergeMode flags control the behavior of MergePackageFiles.
+type MergeMode uint
+
+const (
+ // If set, duplicate function declarations are excluded.
+ FilterFuncDuplicates MergeMode = 1 << iota
+ // If set, comments that are not associated with a specific
+ // AST node (as Doc or Comment) are excluded.
+ FilterUnassociatedComments
+ // If set, duplicate import declarations are excluded.
+ FilterImportDuplicates
+)
+
+// nameOf returns the function (foo) or method name (foo.bar) for
+// the given function declaration. If the AST is incorrect for the
+// receiver, it assumes a function instead.
+//
+func nameOf(f *FuncDecl) string {
+ if r := f.Recv; r != nil && len(r.List) == 1 {
+ // looks like a correct receiver declaration
+ t := r.List[0].Type
+ // dereference pointer receiver types
+ if p, _ := t.(*StarExpr); p != nil {
+ t = p.X
+ }
+ // the receiver type must be a type name
+ if p, _ := t.(*Ident); p != nil {
+ return p.Name + "." + f.Name.Name
+ }
+ // otherwise assume a function instead
+ }
+ return f.Name.Name
+}
+
+// separator is an empty //-style comment that is interspersed between
+// different comment groups when they are concatenated into a single group
+//
+var separator = &Comment{token.NoPos, "//"}
+
+// MergePackageFiles creates a file AST by merging the ASTs of the
+// files belonging to a package. The mode flags control merging behavior.
+//
+func MergePackageFiles(pkg *Package, mode MergeMode) *File {
+ // Count the number of package docs, comments and declarations across
+ // all package files. Also, compute sorted list of filenames, so that
+ // subsequent iterations can always iterate in the same order.
+ ndocs := 0
+ ncomments := 0
+ ndecls := 0
+ filenames := make([]string, len(pkg.Files))
+ i := 0
+ for filename, f := range pkg.Files {
+ filenames[i] = filename
+ i++
+ if f.Doc != nil {
+ ndocs += len(f.Doc.List) + 1 // +1 for separator
+ }
+ ncomments += len(f.Comments)
+ ndecls += len(f.Decls)
+ }
+ sort.Strings(filenames)
+
+ // Collect package comments from all package files into a single
+ // CommentGroup - the collected package documentation. In general
+ // there should be only one file with a package comment; but it's
+ // better to collect extra comments than drop them on the floor.
+ var doc *CommentGroup
+ var pos token.Pos
+ if ndocs > 0 {
+ list := make([]*Comment, ndocs-1) // -1: no separator before first group
+ i := 0
+ for _, filename := range filenames {
+ f := pkg.Files[filename]
+ if f.Doc != nil {
+ if i > 0 {
+ // not the first group - add separator
+ list[i] = separator
+ i++
+ }
+ for _, c := range f.Doc.List {
+ list[i] = c
+ i++
+ }
+ if f.Package > pos {
+ // Keep the maximum package clause position as
+ // position for the package clause of the merged
+ // files.
+ pos = f.Package
+ }
+ }
+ }
+ doc = &CommentGroup{list}
+ }
+
+ // Collect declarations from all package files.
+ var decls []Decl
+ if ndecls > 0 {
+ decls = make([]Decl, ndecls)
+ funcs := make(map[string]int) // map of func name -> decls index
+ i := 0 // current index
+ n := 0 // number of filtered entries
+ for _, filename := range filenames {
+ f := pkg.Files[filename]
+ for _, d := range f.Decls {
+ if mode&FilterFuncDuplicates != 0 {
+ // A language entity may be declared multiple
+ // times in different package files; only at
+ // build time declarations must be unique.
+ // For now, exclude multiple declarations of
+ // functions - keep the one with documentation.
+ //
+ // TODO(gri): Expand this filtering to other
+ // entities (const, type, vars) if
+ // multiple declarations are common.
+ if f, isFun := d.(*FuncDecl); isFun {
+ name := nameOf(f)
+ if j, exists := funcs[name]; exists {
+ // function declared already
+ if decls[j] != nil && decls[j].(*FuncDecl).Doc == nil {
+ // existing declaration has no documentation;
+ // ignore the existing declaration
+ decls[j] = nil
+ } else {
+ // ignore the new declaration
+ d = nil
+ }
+ n++ // filtered an entry
+ } else {
+ funcs[name] = i
+ }
+ }
+ }
+ decls[i] = d
+ i++
+ }
+ }
+
+ // Eliminate nil entries from the decls list if entries were
+ // filtered. We do this using a 2nd pass in order to not disturb
+ // the original declaration order in the source (otherwise, this
+ // would also invalidate the monotonically increasing position
+ // info within a single file).
+ if n > 0 {
+ i = 0
+ for _, d := range decls {
+ if d != nil {
+ decls[i] = d
+ i++
+ }
+ }
+ decls = decls[0:i]
+ }
+ }
+
+ // Collect import specs from all package files.
+ var imports []*ImportSpec
+ if mode&FilterImportDuplicates != 0 {
+ seen := make(map[string]bool)
+ for _, filename := range filenames {
+ f := pkg.Files[filename]
+ for _, imp := range f.Imports {
+ if path := imp.Path.Value; !seen[path] {
+ // TODO: consider handling cases where:
+ // - 2 imports exist with the same import path but
+ // have different local names (one should probably
+ // keep both of them)
+ // - 2 imports exist but only one has a comment
+ // - 2 imports exist and they both have (possibly
+ // different) comments
+ imports = append(imports, imp)
+ seen[path] = true
+ }
+ }
+ }
+ } else {
+ // Iterate over filenames for deterministic order.
+ for _, filename := range filenames {
+ f := pkg.Files[filename]
+ imports = append(imports, f.Imports...)
+ }
+ }
+
+ // Collect comments from all package files.
+ var comments []*CommentGroup
+ if mode&FilterUnassociatedComments == 0 {
+ comments = make([]*CommentGroup, ncomments)
+ i := 0
+ for _, filename := range filenames {
+ f := pkg.Files[filename]
+ i += copy(comments[i:], f.Comments)
+ }
+ }
+
+ // TODO(gri) need to compute unresolved identifiers!
+ return &File{doc, pos, NewIdent(pkg.Name), decls, pkg.Scope, imports, nil, comments}
+}
diff --git a/src/go/ast/filter_test.go b/src/go/ast/filter_test.go
new file mode 100644
index 0000000..9fd86cb
--- /dev/null
+++ b/src/go/ast/filter_test.go
@@ -0,0 +1,86 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// To avoid a cyclic dependency with go/parser, this file is in a separate package.
+
+package ast_test
+
+import (
+ "bytes"
+ "go/ast"
+ "go/format"
+ "go/parser"
+ "go/token"
+ "testing"
+)
+
+const input = `package p
+
+type t1 struct{}
+type t2 struct{}
+
+func f1() {}
+func f1() {}
+func f2() {}
+
+func (*t1) f1() {}
+func (t1) f1() {}
+func (t1) f2() {}
+
+func (t2) f1() {}
+func (t2) f2() {}
+func (x *t2) f2() {}
+`
+
+// Calling ast.MergePackageFiles with ast.FilterFuncDuplicates
+// keeps a duplicate entry with attached documentation in favor
+// of one without, and it favors duplicate entries appearing
+// later in the source over ones appearing earlier. This is why
+// (*t2).f2 is kept and t2.f2 is eliminated in this test case.
+//
+const golden = `package p
+
+type t1 struct{}
+type t2 struct{}
+
+func f1() {}
+func f2() {}
+
+func (t1) f1() {}
+func (t1) f2() {}
+
+func (t2) f1() {}
+
+func (x *t2) f2() {}
+`
+
+func TestFilterDuplicates(t *testing.T) {
+ // parse input
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "", input, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // create package
+ files := map[string]*ast.File{"": file}
+ pkg, err := ast.NewPackage(fset, files, nil, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // filter
+ merged := ast.MergePackageFiles(pkg, ast.FilterFuncDuplicates)
+
+ // pretty-print
+ var buf bytes.Buffer
+ if err := format.Node(&buf, fset, merged); err != nil {
+ t.Fatal(err)
+ }
+ output := buf.String()
+
+ if output != golden {
+ t.Errorf("incorrect output:\n%s", output)
+ }
+}
diff --git a/src/go/ast/import.go b/src/go/ast/import.go
new file mode 100644
index 0000000..7fdf137
--- /dev/null
+++ b/src/go/ast/import.go
@@ -0,0 +1,230 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+ "go/token"
+ "sort"
+ "strconv"
+)
+
+// SortImports sorts runs of consecutive import lines in import blocks in f.
+// It also removes duplicate imports when it is possible to do so without data loss.
+func SortImports(fset *token.FileSet, f *File) {
+ for _, d := range f.Decls {
+ d, ok := d.(*GenDecl)
+ if !ok || d.Tok != token.IMPORT {
+ // Not an import declaration, so we're done.
+ // Imports are always first.
+ break
+ }
+
+ if !d.Lparen.IsValid() {
+ // Not a block: sorted by default.
+ continue
+ }
+
+ // Identify and sort runs of specs on successive lines.
+ i := 0
+ specs := d.Specs[:0]
+ for j, s := range d.Specs {
+ if j > i && lineAt(fset, s.Pos()) > 1+lineAt(fset, d.Specs[j-1].End()) {
+ // j begins a new run. End this one.
+ specs = append(specs, sortSpecs(fset, f, d.Specs[i:j])...)
+ i = j
+ }
+ }
+ specs = append(specs, sortSpecs(fset, f, d.Specs[i:])...)
+ d.Specs = specs
+
+ // Deduping can leave a blank line before the rparen; clean that up.
+ if len(d.Specs) > 0 {
+ lastSpec := d.Specs[len(d.Specs)-1]
+ lastLine := lineAt(fset, lastSpec.Pos())
+ rParenLine := lineAt(fset, d.Rparen)
+ for rParenLine > lastLine+1 {
+ rParenLine--
+ fset.File(d.Rparen).MergeLine(rParenLine)
+ }
+ }
+ }
+}
+
+func lineAt(fset *token.FileSet, pos token.Pos) int {
+ return fset.PositionFor(pos, false).Line
+}
+
+func importPath(s Spec) string {
+ t, err := strconv.Unquote(s.(*ImportSpec).Path.Value)
+ if err == nil {
+ return t
+ }
+ return ""
+}
+
+func importName(s Spec) string {
+ n := s.(*ImportSpec).Name
+ if n == nil {
+ return ""
+ }
+ return n.Name
+}
+
+func importComment(s Spec) string {
+ c := s.(*ImportSpec).Comment
+ if c == nil {
+ return ""
+ }
+ return c.Text()
+}
+
+// collapse indicates whether prev may be removed, leaving only next.
+func collapse(prev, next Spec) bool {
+ if importPath(next) != importPath(prev) || importName(next) != importName(prev) {
+ return false
+ }
+ return prev.(*ImportSpec).Comment == nil
+}
+
+type posSpan struct {
+ Start token.Pos
+ End token.Pos
+}
+
+type cgPos struct {
+ left bool // true if comment is to the left of the spec, false otherwise.
+ cg *CommentGroup
+}
+
+func sortSpecs(fset *token.FileSet, f *File, specs []Spec) []Spec {
+ // Can't short-circuit here even if specs are already sorted,
+ // since they might yet need deduplication.
+ // A lone import, however, may be safely ignored.
+ if len(specs) <= 1 {
+ return specs
+ }
+
+ // Record positions for specs.
+ pos := make([]posSpan, len(specs))
+ for i, s := range specs {
+ pos[i] = posSpan{s.Pos(), s.End()}
+ }
+
+ // Identify comments in this range.
+ begSpecs := pos[0].Start
+ endSpecs := pos[len(pos)-1].End
+ beg := fset.File(begSpecs).LineStart(lineAt(fset, begSpecs))
+ endLine := lineAt(fset, endSpecs)
+ endFile := fset.File(endSpecs)
+ var end token.Pos
+ if endLine == endFile.LineCount() {
+ end = endSpecs
+ } else {
+ end = endFile.LineStart(endLine + 1) // beginning of next line
+ }
+ first := len(f.Comments)
+ last := -1
+ for i, g := range f.Comments {
+ if g.End() >= end {
+ break
+ }
+ // g.End() < end
+ if beg <= g.Pos() {
+ // comment is within the range [beg, end[ of import declarations
+ if i < first {
+ first = i
+ }
+ if i > last {
+ last = i
+ }
+ }
+ }
+
+ var comments []*CommentGroup
+ if last >= 0 {
+ comments = f.Comments[first : last+1]
+ }
+
+ // Assign each comment to the import spec on the same line.
+ importComments := map[*ImportSpec][]cgPos{}
+ specIndex := 0
+ for _, g := range comments {
+ for specIndex+1 < len(specs) && pos[specIndex+1].Start <= g.Pos() {
+ specIndex++
+ }
+ var left bool
+ // A block comment can appear before the first import spec.
+ if specIndex == 0 && pos[specIndex].Start > g.Pos() {
+ left = true
+ } else if specIndex+1 < len(specs) && // Or it can appear on the left of an import spec.
+ lineAt(fset, pos[specIndex].Start)+1 == lineAt(fset, g.Pos()) {
+ specIndex++
+ left = true
+ }
+ s := specs[specIndex].(*ImportSpec)
+ importComments[s] = append(importComments[s], cgPos{left: left, cg: g})
+ }
+
+ // Sort the import specs by import path.
+ // Remove duplicates, when possible without data loss.
+ // Reassign the import paths to have the same position sequence.
+ // Reassign each comment to the spec on the same line.
+ // Sort the comments by new position.
+ sort.Slice(specs, func(i, j int) bool {
+ ipath := importPath(specs[i])
+ jpath := importPath(specs[j])
+ if ipath != jpath {
+ return ipath < jpath
+ }
+ iname := importName(specs[i])
+ jname := importName(specs[j])
+ if iname != jname {
+ return iname < jname
+ }
+ return importComment(specs[i]) < importComment(specs[j])
+ })
+
+ // Dedup. Thanks to our sorting, we can just consider
+ // adjacent pairs of imports.
+ deduped := specs[:0]
+ for i, s := range specs {
+ if i == len(specs)-1 || !collapse(s, specs[i+1]) {
+ deduped = append(deduped, s)
+ } else {
+ p := s.Pos()
+ fset.File(p).MergeLine(lineAt(fset, p))
+ }
+ }
+ specs = deduped
+
+ // Fix up comment positions
+ for i, s := range specs {
+ s := s.(*ImportSpec)
+ if s.Name != nil {
+ s.Name.NamePos = pos[i].Start
+ }
+ s.Path.ValuePos = pos[i].Start
+ s.EndPos = pos[i].End
+ for _, g := range importComments[s] {
+ for _, c := range g.cg.List {
+ if g.left {
+ c.Slash = pos[i].Start - 1
+ } else {
+ // An import spec can have both block comment and a line comment
+ // to its right. In that case, both of them will have the same pos.
+ // But while formatting the AST, the line comment gets moved to
+ // after the block comment.
+ c.Slash = pos[i].End
+ }
+ }
+ }
+ }
+
+ sort.Slice(comments, func(i, j int) bool {
+ return comments[i].Pos() < comments[j].Pos()
+ })
+
+ return specs
+}
diff --git a/src/go/ast/issues_test.go b/src/go/ast/issues_test.go
new file mode 100644
index 0000000..788c557
--- /dev/null
+++ b/src/go/ast/issues_test.go
@@ -0,0 +1,42 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast_test
+
+import (
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "testing"
+)
+
+func TestIssue33649(t *testing.T) {
+ for _, src := range []string{
+ `package p; func _()`,
+ `package p; func _() {`,
+ `package p; func _() { _ = 0`,
+ `package p; func _() { _ = 0 }`,
+ } {
+ fset := token.NewFileSet()
+ f, _ := parser.ParseFile(fset, "", src, parser.AllErrors)
+ if f == nil {
+ panic("invalid test setup: parser didn't return an AST")
+ }
+
+ // find corresponding token.File
+ var tf *token.File
+ fset.Iterate(func(f *token.File) bool {
+ tf = f
+ return true
+ })
+ tfEnd := tf.Base() + tf.Size()
+
+ fd := f.Decls[len(f.Decls)-1].(*ast.FuncDecl)
+ fdEnd := int(fd.End())
+
+ if fdEnd != tfEnd {
+ t.Errorf("%q: got fdEnd = %d; want %d (base = %d, size = %d)", src, fdEnd, tfEnd, tf.Base(), tf.Size())
+ }
+ }
+}
diff --git a/src/go/ast/print.go b/src/go/ast/print.go
new file mode 100644
index 0000000..d86d9ba
--- /dev/null
+++ b/src/go/ast/print.go
@@ -0,0 +1,254 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains printing support for ASTs.
+
+package ast
+
+import (
+ "fmt"
+ "go/token"
+ "io"
+ "os"
+ "reflect"
+)
+
+// A FieldFilter may be provided to Fprint to control the output.
+type FieldFilter func(name string, value reflect.Value) bool
+
+// NotNilFilter returns true for field values that are not nil;
+// it returns false otherwise.
+func NotNilFilter(_ string, v reflect.Value) bool {
+ switch v.Kind() {
+ case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+ return !v.IsNil()
+ }
+ return true
+}
+
+// Fprint prints the (sub-)tree starting at AST node x to w.
+// If fset != nil, position information is interpreted relative
+// to that file set. Otherwise positions are printed as integer
+// values (file set specific offsets).
+//
+// A non-nil FieldFilter f may be provided to control the output:
+// struct fields for which f(fieldname, fieldvalue) is true are
+// printed; all others are filtered from the output. Unexported
+// struct fields are never printed.
+func Fprint(w io.Writer, fset *token.FileSet, x interface{}, f FieldFilter) error {
+ return fprint(w, fset, x, f)
+}
+
+func fprint(w io.Writer, fset *token.FileSet, x interface{}, f FieldFilter) (err error) {
+ // setup printer
+ p := printer{
+ output: w,
+ fset: fset,
+ filter: f,
+ ptrmap: make(map[interface{}]int),
+ last: '\n', // force printing of line number on first line
+ }
+
+ // install error handler
+ defer func() {
+ if e := recover(); e != nil {
+ err = e.(localError).err // re-panics if it's not a localError
+ }
+ }()
+
+ // print x
+ if x == nil {
+ p.printf("nil\n")
+ return
+ }
+ p.print(reflect.ValueOf(x))
+ p.printf("\n")
+
+ return
+}
+
+// Print prints x to standard output, skipping nil fields.
+// Print(fset, x) is the same as Fprint(os.Stdout, fset, x, NotNilFilter).
+func Print(fset *token.FileSet, x interface{}) error {
+ return Fprint(os.Stdout, fset, x, NotNilFilter)
+}
+
+type printer struct {
+ output io.Writer
+ fset *token.FileSet
+ filter FieldFilter
+ ptrmap map[interface{}]int // *T -> line number
+ indent int // current indentation level
+ last byte // the last byte processed by Write
+ line int // current line number
+}
+
+var indent = []byte(". ")
+
+func (p *printer) Write(data []byte) (n int, err error) {
+ var m int
+ for i, b := range data {
+ // invariant: data[0:n] has been written
+ if b == '\n' {
+ m, err = p.output.Write(data[n : i+1])
+ n += m
+ if err != nil {
+ return
+ }
+ p.line++
+ } else if p.last == '\n' {
+ _, err = fmt.Fprintf(p.output, "%6d ", p.line)
+ if err != nil {
+ return
+ }
+ for j := p.indent; j > 0; j-- {
+ _, err = p.output.Write(indent)
+ if err != nil {
+ return
+ }
+ }
+ }
+ p.last = b
+ }
+ if len(data) > n {
+ m, err = p.output.Write(data[n:])
+ n += m
+ }
+ return
+}
+
+// localError wraps locally caught errors so we can distinguish
+// them from genuine panics which we don't want to return as errors.
+type localError struct {
+ err error
+}
+
+// printf is a convenience wrapper that takes care of print errors.
+func (p *printer) printf(format string, args ...interface{}) {
+ if _, err := fmt.Fprintf(p, format, args...); err != nil {
+ panic(localError{err})
+ }
+}
+
+// Implementation note: Print is written for AST nodes but could be
+// used to print arbitrary data structures; such a version should
+// probably be in a different package.
+//
+// Note: This code detects (some) cycles created via pointers but
+// not cycles that are created via slices or maps containing the
+// same slice or map. Code for general data structures probably
+// should catch those as well.
+
+func (p *printer) print(x reflect.Value) {
+ if !NotNilFilter("", x) {
+ p.printf("nil")
+ return
+ }
+
+ switch x.Kind() {
+ case reflect.Interface:
+ p.print(x.Elem())
+
+ case reflect.Map:
+ p.printf("%s (len = %d) {", x.Type(), x.Len())
+ if x.Len() > 0 {
+ p.indent++
+ p.printf("\n")
+ for _, key := range x.MapKeys() {
+ p.print(key)
+ p.printf(": ")
+ p.print(x.MapIndex(key))
+ p.printf("\n")
+ }
+ p.indent--
+ }
+ p.printf("}")
+
+ case reflect.Ptr:
+ p.printf("*")
+ // type-checked ASTs may contain cycles - use ptrmap
+ // to keep track of objects that have been printed
+ // already and print the respective line number instead
+ ptr := x.Interface()
+ if line, exists := p.ptrmap[ptr]; exists {
+ p.printf("(obj @ %d)", line)
+ } else {
+ p.ptrmap[ptr] = p.line
+ p.print(x.Elem())
+ }
+
+ case reflect.Array:
+ p.printf("%s {", x.Type())
+ if x.Len() > 0 {
+ p.indent++
+ p.printf("\n")
+ for i, n := 0, x.Len(); i < n; i++ {
+ p.printf("%d: ", i)
+ p.print(x.Index(i))
+ p.printf("\n")
+ }
+ p.indent--
+ }
+ p.printf("}")
+
+ case reflect.Slice:
+ if s, ok := x.Interface().([]byte); ok {
+ p.printf("%#q", s)
+ return
+ }
+ p.printf("%s (len = %d) {", x.Type(), x.Len())
+ if x.Len() > 0 {
+ p.indent++
+ p.printf("\n")
+ for i, n := 0, x.Len(); i < n; i++ {
+ p.printf("%d: ", i)
+ p.print(x.Index(i))
+ p.printf("\n")
+ }
+ p.indent--
+ }
+ p.printf("}")
+
+ case reflect.Struct:
+ t := x.Type()
+ p.printf("%s {", t)
+ p.indent++
+ first := true
+ for i, n := 0, t.NumField(); i < n; i++ {
+ // exclude non-exported fields because their
+ // values cannot be accessed via reflection
+ if name := t.Field(i).Name; IsExported(name) {
+ value := x.Field(i)
+ if p.filter == nil || p.filter(name, value) {
+ if first {
+ p.printf("\n")
+ first = false
+ }
+ p.printf("%s: ", name)
+ p.print(value)
+ p.printf("\n")
+ }
+ }
+ }
+ p.indent--
+ p.printf("}")
+
+ default:
+ v := x.Interface()
+ switch v := v.(type) {
+ case string:
+ // print strings in quotes
+ p.printf("%q", v)
+ return
+ case token.Pos:
+ // position values can be printed nicely if we have a file set
+ if p.fset != nil {
+ p.printf("%s", p.fset.Position(v))
+ return
+ }
+ }
+ // default
+ p.printf("%v", v)
+ }
+}
diff --git a/src/go/ast/print_test.go b/src/go/ast/print_test.go
new file mode 100644
index 0000000..210f164
--- /dev/null
+++ b/src/go/ast/print_test.go
@@ -0,0 +1,97 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+ "bytes"
+ "strings"
+ "testing"
+)
+
+var tests = []struct {
+ x interface{} // x is printed as s
+ s string
+}{
+ // basic types
+ {nil, "0 nil"},
+ {true, "0 true"},
+ {42, "0 42"},
+ {3.14, "0 3.14"},
+ {1 + 2.718i, "0 (1+2.718i)"},
+ {"foobar", "0 \"foobar\""},
+
+ // maps
+ {map[Expr]string{}, `0 map[ast.Expr]string (len = 0) {}`},
+ {map[string]int{"a": 1},
+ `0 map[string]int (len = 1) {
+ 1 . "a": 1
+ 2 }`},
+
+ // pointers
+ {new(int), "0 *0"},
+
+ // arrays
+ {[0]int{}, `0 [0]int {}`},
+ {[3]int{1, 2, 3},
+ `0 [3]int {
+ 1 . 0: 1
+ 2 . 1: 2
+ 3 . 2: 3
+ 4 }`},
+ {[...]int{42},
+ `0 [1]int {
+ 1 . 0: 42
+ 2 }`},
+
+ // slices
+ {[]int{}, `0 []int (len = 0) {}`},
+ {[]int{1, 2, 3},
+ `0 []int (len = 3) {
+ 1 . 0: 1
+ 2 . 1: 2
+ 3 . 2: 3
+ 4 }`},
+
+ // structs
+ {struct{}{}, `0 struct {} {}`},
+ {struct{ x int }{007}, `0 struct { x int } {}`},
+ {struct{ X, y int }{42, 991},
+ `0 struct { X int; y int } {
+ 1 . X: 42
+ 2 }`},
+ {struct{ X, Y int }{42, 991},
+ `0 struct { X int; Y int } {
+ 1 . X: 42
+ 2 . Y: 991
+ 3 }`},
+}
+
+// Split s into lines, trim whitespace from all lines, and return
+// the concatenated non-empty lines.
+func trim(s string) string {
+ lines := strings.Split(s, "\n")
+ i := 0
+ for _, line := range lines {
+ line = strings.TrimSpace(line)
+ if line != "" {
+ lines[i] = line
+ i++
+ }
+ }
+ return strings.Join(lines[0:i], "\n")
+}
+
+func TestPrint(t *testing.T) {
+ var buf bytes.Buffer
+ for _, test := range tests {
+ buf.Reset()
+ if err := Fprint(&buf, nil, test.x, nil); err != nil {
+ t.Errorf("Fprint failed: %s", err)
+ }
+ if s, ts := trim(buf.String()), trim(test.s); s != ts {
+ t.Errorf("got:\n%s\nexpected:\n%s\n", s, ts)
+ }
+ }
+}
diff --git a/src/go/ast/resolve.go b/src/go/ast/resolve.go
new file mode 100644
index 0000000..c1830b5
--- /dev/null
+++ b/src/go/ast/resolve.go
@@ -0,0 +1,174 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements NewPackage.
+
+package ast
+
+import (
+ "fmt"
+ "go/scanner"
+ "go/token"
+ "strconv"
+)
+
+type pkgBuilder struct {
+ fset *token.FileSet
+ errors scanner.ErrorList
+}
+
+func (p *pkgBuilder) error(pos token.Pos, msg string) {
+ p.errors.Add(p.fset.Position(pos), msg)
+}
+
+func (p *pkgBuilder) errorf(pos token.Pos, format string, args ...interface{}) {
+ p.error(pos, fmt.Sprintf(format, args...))
+}
+
+func (p *pkgBuilder) declare(scope, altScope *Scope, obj *Object) {
+ alt := scope.Insert(obj)
+ if alt == nil && altScope != nil {
+ // see if there is a conflicting declaration in altScope
+ alt = altScope.Lookup(obj.Name)
+ }
+ if alt != nil {
+ prevDecl := ""
+ if pos := alt.Pos(); pos.IsValid() {
+ prevDecl = fmt.Sprintf("\n\tprevious declaration at %s", p.fset.Position(pos))
+ }
+ p.error(obj.Pos(), fmt.Sprintf("%s redeclared in this block%s", obj.Name, prevDecl))
+ }
+}
+
+func resolve(scope *Scope, ident *Ident) bool {
+ for ; scope != nil; scope = scope.Outer {
+ if obj := scope.Lookup(ident.Name); obj != nil {
+ ident.Obj = obj
+ return true
+ }
+ }
+ return false
+}
+
+// An Importer resolves import paths to package Objects.
+// The imports map records the packages already imported,
+// indexed by package id (canonical import path).
+// An Importer must determine the canonical import path and
+// check the map to see if it is already present in the imports map.
+// If so, the Importer can return the map entry. Otherwise, the
+// Importer should load the package data for the given path into
+// a new *Object (pkg), record pkg in the imports map, and then
+// return pkg.
+type Importer func(imports map[string]*Object, path string) (pkg *Object, err error)
+
+// NewPackage creates a new Package node from a set of File nodes. It resolves
+// unresolved identifiers across files and updates each file's Unresolved list
+// accordingly. If a non-nil importer and universe scope are provided, they are
+// used to resolve identifiers not declared in any of the package files. Any
+// remaining unresolved identifiers are reported as undeclared. If the files
+// belong to different packages, one package name is selected and files with
+// different package names are reported and then ignored.
+// The result is a package node and a scanner.ErrorList if there were errors.
+//
+func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, universe *Scope) (*Package, error) {
+ var p pkgBuilder
+ p.fset = fset
+
+ // complete package scope
+ pkgName := ""
+ pkgScope := NewScope(universe)
+ for _, file := range files {
+ // package names must match
+ switch name := file.Name.Name; {
+ case pkgName == "":
+ pkgName = name
+ case name != pkgName:
+ p.errorf(file.Package, "package %s; expected %s", name, pkgName)
+ continue // ignore this file
+ }
+
+ // collect top-level file objects in package scope
+ for _, obj := range file.Scope.Objects {
+ p.declare(pkgScope, nil, obj)
+ }
+ }
+
+ // package global mapping of imported package ids to package objects
+ imports := make(map[string]*Object)
+
+ // complete file scopes with imports and resolve identifiers
+ for _, file := range files {
+ // ignore file if it belongs to a different package
+ // (error has already been reported)
+ if file.Name.Name != pkgName {
+ continue
+ }
+
+ // build file scope by processing all imports
+ importErrors := false
+ fileScope := NewScope(pkgScope)
+ for _, spec := range file.Imports {
+ if importer == nil {
+ importErrors = true
+ continue
+ }
+ path, _ := strconv.Unquote(spec.Path.Value)
+ pkg, err := importer(imports, path)
+ if err != nil {
+ p.errorf(spec.Path.Pos(), "could not import %s (%s)", path, err)
+ importErrors = true
+ continue
+ }
+ // TODO(gri) If a local package name != "." is provided,
+ // global identifier resolution could proceed even if the
+ // import failed. Consider adjusting the logic here a bit.
+
+ // local name overrides imported package name
+ name := pkg.Name
+ if spec.Name != nil {
+ name = spec.Name.Name
+ }
+
+ // add import to file scope
+ if name == "." {
+ // merge imported scope with file scope
+ for _, obj := range pkg.Data.(*Scope).Objects {
+ p.declare(fileScope, pkgScope, obj)
+ }
+ } else if name != "_" {
+ // declare imported package object in file scope
+ // (do not re-use pkg in the file scope but create
+ // a new object instead; the Decl field is different
+ // for different files)
+ obj := NewObj(Pkg, name)
+ obj.Decl = spec
+ obj.Data = pkg.Data
+ p.declare(fileScope, pkgScope, obj)
+ }
+ }
+
+ // resolve identifiers
+ if importErrors {
+ // don't use the universe scope without correct imports
+ // (objects in the universe may be shadowed by imports;
+ // with missing imports, identifiers might get resolved
+ // incorrectly to universe objects)
+ pkgScope.Outer = nil
+ }
+ i := 0
+ for _, ident := range file.Unresolved {
+ if !resolve(fileScope, ident) {
+ p.errorf(ident.Pos(), "undeclared name: %s", ident.Name)
+ file.Unresolved[i] = ident
+ i++
+ }
+
+ }
+ file.Unresolved = file.Unresolved[0:i]
+ pkgScope.Outer = universe // reset universe scope
+ }
+
+ p.errors.Sort()
+ return &Package{pkgName, pkgScope, imports, files}, p.errors.Err()
+}
diff --git a/src/go/ast/scope.go b/src/go/ast/scope.go
new file mode 100644
index 0000000..a400c71
--- /dev/null
+++ b/src/go/ast/scope.go
@@ -0,0 +1,160 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements scopes and the objects they contain.
+
+package ast
+
+import (
+ "bytes"
+ "fmt"
+ "go/token"
+)
+
+// A Scope maintains the set of named language entities declared
+// in the scope and a link to the immediately surrounding (outer)
+// scope.
+//
+type Scope struct {
+ Outer *Scope
+ Objects map[string]*Object
+}
+
+// NewScope creates a new scope nested in the outer scope.
+func NewScope(outer *Scope) *Scope {
+ const n = 4 // initial scope capacity
+ return &Scope{outer, make(map[string]*Object, n)}
+}
+
+// Lookup returns the object with the given name if it is
+// found in scope s, otherwise it returns nil. Outer scopes
+// are ignored.
+//
+func (s *Scope) Lookup(name string) *Object {
+ return s.Objects[name]
+}
+
+// Insert attempts to insert a named object obj into the scope s.
+// If the scope already contains an object alt with the same name,
+// Insert leaves the scope unchanged and returns alt. Otherwise
+// it inserts obj and returns nil.
+//
+func (s *Scope) Insert(obj *Object) (alt *Object) {
+ if alt = s.Objects[obj.Name]; alt == nil {
+ s.Objects[obj.Name] = obj
+ }
+ return
+}
+
+// Debugging support
+func (s *Scope) String() string {
+ var buf bytes.Buffer
+ fmt.Fprintf(&buf, "scope %p {", s)
+ if s != nil && len(s.Objects) > 0 {
+ fmt.Fprintln(&buf)
+ for _, obj := range s.Objects {
+ fmt.Fprintf(&buf, "\t%s %s\n", obj.Kind, obj.Name)
+ }
+ }
+ fmt.Fprintf(&buf, "}\n")
+ return buf.String()
+}
+
+// ----------------------------------------------------------------------------
+// Objects
+
+// An Object describes a named language entity such as a package,
+// constant, type, variable, function (incl. methods), or label.
+//
+// The Data fields contains object-specific data:
+//
+// Kind Data type Data value
+// Pkg *Scope package scope
+// Con int iota for the respective declaration
+//
+type Object struct {
+ Kind ObjKind
+ Name string // declared name
+ Decl interface{} // corresponding Field, XxxSpec, FuncDecl, LabeledStmt, AssignStmt, Scope; or nil
+ Data interface{} // object-specific data; or nil
+ Type interface{} // placeholder for type information; may be nil
+}
+
+// NewObj creates a new object of a given kind and name.
+func NewObj(kind ObjKind, name string) *Object {
+ return &Object{Kind: kind, Name: name}
+}
+
+// Pos computes the source position of the declaration of an object name.
+// The result may be an invalid position if it cannot be computed
+// (obj.Decl may be nil or not correct).
+func (obj *Object) Pos() token.Pos {
+ name := obj.Name
+ switch d := obj.Decl.(type) {
+ case *Field:
+ for _, n := range d.Names {
+ if n.Name == name {
+ return n.Pos()
+ }
+ }
+ case *ImportSpec:
+ if d.Name != nil && d.Name.Name == name {
+ return d.Name.Pos()
+ }
+ return d.Path.Pos()
+ case *ValueSpec:
+ for _, n := range d.Names {
+ if n.Name == name {
+ return n.Pos()
+ }
+ }
+ case *TypeSpec:
+ if d.Name.Name == name {
+ return d.Name.Pos()
+ }
+ case *FuncDecl:
+ if d.Name.Name == name {
+ return d.Name.Pos()
+ }
+ case *LabeledStmt:
+ if d.Label.Name == name {
+ return d.Label.Pos()
+ }
+ case *AssignStmt:
+ for _, x := range d.Lhs {
+ if ident, isIdent := x.(*Ident); isIdent && ident.Name == name {
+ return ident.Pos()
+ }
+ }
+ case *Scope:
+ // predeclared object - nothing to do for now
+ }
+ return token.NoPos
+}
+
+// ObjKind describes what an object represents.
+type ObjKind int
+
+// The list of possible Object kinds.
+const (
+ Bad ObjKind = iota // for error handling
+ Pkg // package
+ Con // constant
+ Typ // type
+ Var // variable
+ Fun // function or method
+ Lbl // label
+)
+
+var objKindStrings = [...]string{
+ Bad: "bad",
+ Pkg: "package",
+ Con: "const",
+ Typ: "type",
+ Var: "var",
+ Fun: "func",
+ Lbl: "label",
+}
+
+func (kind ObjKind) String() string { return objKindStrings[kind] }
diff --git a/src/go/ast/walk.go b/src/go/ast/walk.go
new file mode 100644
index 0000000..8ca2195
--- /dev/null
+++ b/src/go/ast/walk.go
@@ -0,0 +1,386 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ast
+
+import "fmt"
+
+// A Visitor's Visit method is invoked for each node encountered by Walk.
+// If the result visitor w is not nil, Walk visits each of the children
+// of node with the visitor w, followed by a call of w.Visit(nil).
+type Visitor interface {
+ Visit(node Node) (w Visitor)
+}
+
+// Helper functions for common node lists. They may be empty.
+
+func walkIdentList(v Visitor, list []*Ident) {
+ for _, x := range list {
+ Walk(v, x)
+ }
+}
+
+func walkExprList(v Visitor, list []Expr) {
+ for _, x := range list {
+ Walk(v, x)
+ }
+}
+
+func walkStmtList(v Visitor, list []Stmt) {
+ for _, x := range list {
+ Walk(v, x)
+ }
+}
+
+func walkDeclList(v Visitor, list []Decl) {
+ for _, x := range list {
+ Walk(v, x)
+ }
+}
+
+// TODO(gri): Investigate if providing a closure to Walk leads to
+// simpler use (and may help eliminate Inspect in turn).
+
+// Walk traverses an AST in depth-first order: It starts by calling
+// v.Visit(node); node must not be nil. If the visitor w returned by
+// v.Visit(node) is not nil, Walk is invoked recursively with visitor
+// w for each of the non-nil children of node, followed by a call of
+// w.Visit(nil).
+//
+func Walk(v Visitor, node Node) {
+ if v = v.Visit(node); v == nil {
+ return
+ }
+
+ // walk children
+ // (the order of the cases matches the order
+ // of the corresponding node types in ast.go)
+ switch n := node.(type) {
+ // Comments and fields
+ case *Comment:
+ // nothing to do
+
+ case *CommentGroup:
+ for _, c := range n.List {
+ Walk(v, c)
+ }
+
+ case *Field:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ walkIdentList(v, n.Names)
+ Walk(v, n.Type)
+ if n.Tag != nil {
+ Walk(v, n.Tag)
+ }
+ if n.Comment != nil {
+ Walk(v, n.Comment)
+ }
+
+ case *FieldList:
+ for _, f := range n.List {
+ Walk(v, f)
+ }
+
+ // Expressions
+ case *BadExpr, *Ident, *BasicLit:
+ // nothing to do
+
+ case *Ellipsis:
+ if n.Elt != nil {
+ Walk(v, n.Elt)
+ }
+
+ case *FuncLit:
+ Walk(v, n.Type)
+ Walk(v, n.Body)
+
+ case *CompositeLit:
+ if n.Type != nil {
+ Walk(v, n.Type)
+ }
+ walkExprList(v, n.Elts)
+
+ case *ParenExpr:
+ Walk(v, n.X)
+
+ case *SelectorExpr:
+ Walk(v, n.X)
+ Walk(v, n.Sel)
+
+ case *IndexExpr:
+ Walk(v, n.X)
+ Walk(v, n.Index)
+
+ case *SliceExpr:
+ Walk(v, n.X)
+ if n.Low != nil {
+ Walk(v, n.Low)
+ }
+ if n.High != nil {
+ Walk(v, n.High)
+ }
+ if n.Max != nil {
+ Walk(v, n.Max)
+ }
+
+ case *TypeAssertExpr:
+ Walk(v, n.X)
+ if n.Type != nil {
+ Walk(v, n.Type)
+ }
+
+ case *CallExpr:
+ Walk(v, n.Fun)
+ walkExprList(v, n.Args)
+
+ case *StarExpr:
+ Walk(v, n.X)
+
+ case *UnaryExpr:
+ Walk(v, n.X)
+
+ case *BinaryExpr:
+ Walk(v, n.X)
+ Walk(v, n.Y)
+
+ case *KeyValueExpr:
+ Walk(v, n.Key)
+ Walk(v, n.Value)
+
+ // Types
+ case *ArrayType:
+ if n.Len != nil {
+ Walk(v, n.Len)
+ }
+ Walk(v, n.Elt)
+
+ case *StructType:
+ Walk(v, n.Fields)
+
+ case *FuncType:
+ if n.Params != nil {
+ Walk(v, n.Params)
+ }
+ if n.Results != nil {
+ Walk(v, n.Results)
+ }
+
+ case *InterfaceType:
+ Walk(v, n.Methods)
+
+ case *MapType:
+ Walk(v, n.Key)
+ Walk(v, n.Value)
+
+ case *ChanType:
+ Walk(v, n.Value)
+
+ // Statements
+ case *BadStmt:
+ // nothing to do
+
+ case *DeclStmt:
+ Walk(v, n.Decl)
+
+ case *EmptyStmt:
+ // nothing to do
+
+ case *LabeledStmt:
+ Walk(v, n.Label)
+ Walk(v, n.Stmt)
+
+ case *ExprStmt:
+ Walk(v, n.X)
+
+ case *SendStmt:
+ Walk(v, n.Chan)
+ Walk(v, n.Value)
+
+ case *IncDecStmt:
+ Walk(v, n.X)
+
+ case *AssignStmt:
+ walkExprList(v, n.Lhs)
+ walkExprList(v, n.Rhs)
+
+ case *GoStmt:
+ Walk(v, n.Call)
+
+ case *DeferStmt:
+ Walk(v, n.Call)
+
+ case *ReturnStmt:
+ walkExprList(v, n.Results)
+
+ case *BranchStmt:
+ if n.Label != nil {
+ Walk(v, n.Label)
+ }
+
+ case *BlockStmt:
+ walkStmtList(v, n.List)
+
+ case *IfStmt:
+ if n.Init != nil {
+ Walk(v, n.Init)
+ }
+ Walk(v, n.Cond)
+ Walk(v, n.Body)
+ if n.Else != nil {
+ Walk(v, n.Else)
+ }
+
+ case *CaseClause:
+ walkExprList(v, n.List)
+ walkStmtList(v, n.Body)
+
+ case *SwitchStmt:
+ if n.Init != nil {
+ Walk(v, n.Init)
+ }
+ if n.Tag != nil {
+ Walk(v, n.Tag)
+ }
+ Walk(v, n.Body)
+
+ case *TypeSwitchStmt:
+ if n.Init != nil {
+ Walk(v, n.Init)
+ }
+ Walk(v, n.Assign)
+ Walk(v, n.Body)
+
+ case *CommClause:
+ if n.Comm != nil {
+ Walk(v, n.Comm)
+ }
+ walkStmtList(v, n.Body)
+
+ case *SelectStmt:
+ Walk(v, n.Body)
+
+ case *ForStmt:
+ if n.Init != nil {
+ Walk(v, n.Init)
+ }
+ if n.Cond != nil {
+ Walk(v, n.Cond)
+ }
+ if n.Post != nil {
+ Walk(v, n.Post)
+ }
+ Walk(v, n.Body)
+
+ case *RangeStmt:
+ if n.Key != nil {
+ Walk(v, n.Key)
+ }
+ if n.Value != nil {
+ Walk(v, n.Value)
+ }
+ Walk(v, n.X)
+ Walk(v, n.Body)
+
+ // Declarations
+ case *ImportSpec:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ if n.Name != nil {
+ Walk(v, n.Name)
+ }
+ Walk(v, n.Path)
+ if n.Comment != nil {
+ Walk(v, n.Comment)
+ }
+
+ case *ValueSpec:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ walkIdentList(v, n.Names)
+ if n.Type != nil {
+ Walk(v, n.Type)
+ }
+ walkExprList(v, n.Values)
+ if n.Comment != nil {
+ Walk(v, n.Comment)
+ }
+
+ case *TypeSpec:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ Walk(v, n.Name)
+ Walk(v, n.Type)
+ if n.Comment != nil {
+ Walk(v, n.Comment)
+ }
+
+ case *BadDecl:
+ // nothing to do
+
+ case *GenDecl:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ for _, s := range n.Specs {
+ Walk(v, s)
+ }
+
+ case *FuncDecl:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ if n.Recv != nil {
+ Walk(v, n.Recv)
+ }
+ Walk(v, n.Name)
+ Walk(v, n.Type)
+ if n.Body != nil {
+ Walk(v, n.Body)
+ }
+
+ // Files and packages
+ case *File:
+ if n.Doc != nil {
+ Walk(v, n.Doc)
+ }
+ Walk(v, n.Name)
+ walkDeclList(v, n.Decls)
+ // don't walk n.Comments - they have been
+ // visited already through the individual
+ // nodes
+
+ case *Package:
+ for _, f := range n.Files {
+ Walk(v, f)
+ }
+
+ default:
+ panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))
+ }
+
+ v.Visit(nil)
+}
+
+type inspector func(Node) bool
+
+func (f inspector) Visit(node Node) Visitor {
+ if f(node) {
+ return f
+ }
+ return nil
+}
+
+// Inspect traverses an AST in depth-first order: It starts by calling
+// f(node); node must not be nil. If f returns true, Inspect invokes f
+// recursively for each of the non-nil children of node, followed by a
+// call of f(nil).
+//
+func Inspect(node Node, f func(Node) bool) {
+ Walk(inspector(f), node)
+}
diff --git a/src/go/build/build.go b/src/go/build/build.go
new file mode 100644
index 0000000..217fadf
--- /dev/null
+++ b/src/go/build/build.go
@@ -0,0 +1,1986 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "go/ast"
+ "go/doc"
+ "go/token"
+ exec "internal/execabs"
+ "internal/goroot"
+ "internal/goversion"
+ "io"
+ "io/fs"
+ "io/ioutil"
+ "os"
+ pathpkg "path"
+ "path/filepath"
+ "runtime"
+ "sort"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+// A Context specifies the supporting context for a build.
+type Context struct {
+ GOARCH string // target architecture
+ GOOS string // target operating system
+ GOROOT string // Go root
+ GOPATH string // Go path
+
+ // Dir is the caller's working directory, or the empty string to use
+ // the current directory of the running process. In module mode, this is used
+ // to locate the main module.
+ //
+ // If Dir is non-empty, directories passed to Import and ImportDir must
+ // be absolute.
+ Dir string
+
+ CgoEnabled bool // whether cgo files are included
+ UseAllFiles bool // use files regardless of +build lines, file names
+ Compiler string // compiler to assume when computing target paths
+
+ // The build and release tags specify build constraints
+ // that should be considered satisfied when processing +build lines.
+ // Clients creating a new context may customize BuildTags, which
+ // defaults to empty, but it is usually an error to customize ReleaseTags,
+ // which defaults to the list of Go releases the current release is compatible with.
+ // BuildTags is not set for the Default build Context.
+ // In addition to the BuildTags and ReleaseTags, build constraints
+ // consider the values of GOARCH and GOOS as satisfied tags.
+ // The last element in ReleaseTags is assumed to be the current release.
+ BuildTags []string
+ ReleaseTags []string
+
+ // The install suffix specifies a suffix to use in the name of the installation
+ // directory. By default it is empty, but custom builds that need to keep
+ // their outputs separate can set InstallSuffix to do so. For example, when
+ // using the race detector, the go command uses InstallSuffix = "race", so
+ // that on a Linux/386 system, packages are written to a directory named
+ // "linux_386_race" instead of the usual "linux_386".
+ InstallSuffix string
+
+ // By default, Import uses the operating system's file system calls
+ // to read directories and files. To read from other sources,
+ // callers can set the following functions. They all have default
+ // behaviors that use the local file system, so clients need only set
+ // the functions whose behaviors they wish to change.
+
+ // JoinPath joins the sequence of path fragments into a single path.
+ // If JoinPath is nil, Import uses filepath.Join.
+ JoinPath func(elem ...string) string
+
+ // SplitPathList splits the path list into a slice of individual paths.
+ // If SplitPathList is nil, Import uses filepath.SplitList.
+ SplitPathList func(list string) []string
+
+ // IsAbsPath reports whether path is an absolute path.
+ // If IsAbsPath is nil, Import uses filepath.IsAbs.
+ IsAbsPath func(path string) bool
+
+ // IsDir reports whether the path names a directory.
+ // If IsDir is nil, Import calls os.Stat and uses the result's IsDir method.
+ IsDir func(path string) bool
+
+ // HasSubdir reports whether dir is lexically a subdirectory of
+ // root, perhaps multiple levels below. It does not try to check
+ // whether dir exists.
+ // If so, HasSubdir sets rel to a slash-separated path that
+ // can be joined to root to produce a path equivalent to dir.
+ // If HasSubdir is nil, Import uses an implementation built on
+ // filepath.EvalSymlinks.
+ HasSubdir func(root, dir string) (rel string, ok bool)
+
+ // ReadDir returns a slice of fs.FileInfo, sorted by Name,
+ // describing the content of the named directory.
+ // If ReadDir is nil, Import uses ioutil.ReadDir.
+ ReadDir func(dir string) ([]fs.FileInfo, error)
+
+ // OpenFile opens a file (not a directory) for reading.
+ // If OpenFile is nil, Import uses os.Open.
+ OpenFile func(path string) (io.ReadCloser, error)
+}
+
+// joinPath calls ctxt.JoinPath (if not nil) or else filepath.Join.
+func (ctxt *Context) joinPath(elem ...string) string {
+ if f := ctxt.JoinPath; f != nil {
+ return f(elem...)
+ }
+ return filepath.Join(elem...)
+}
+
+// splitPathList calls ctxt.SplitPathList (if not nil) or else filepath.SplitList.
+func (ctxt *Context) splitPathList(s string) []string {
+ if f := ctxt.SplitPathList; f != nil {
+ return f(s)
+ }
+ return filepath.SplitList(s)
+}
+
+// isAbsPath calls ctxt.IsAbsPath (if not nil) or else filepath.IsAbs.
+func (ctxt *Context) isAbsPath(path string) bool {
+ if f := ctxt.IsAbsPath; f != nil {
+ return f(path)
+ }
+ return filepath.IsAbs(path)
+}
+
+// isDir calls ctxt.IsDir (if not nil) or else uses os.Stat.
+func (ctxt *Context) isDir(path string) bool {
+ if f := ctxt.IsDir; f != nil {
+ return f(path)
+ }
+ fi, err := os.Stat(path)
+ return err == nil && fi.IsDir()
+}
+
+// hasSubdir calls ctxt.HasSubdir (if not nil) or else uses
+// the local file system to answer the question.
+func (ctxt *Context) hasSubdir(root, dir string) (rel string, ok bool) {
+ if f := ctxt.HasSubdir; f != nil {
+ return f(root, dir)
+ }
+
+ // Try using paths we received.
+ if rel, ok = hasSubdir(root, dir); ok {
+ return
+ }
+
+ // Try expanding symlinks and comparing
+ // expanded against unexpanded and
+ // expanded against expanded.
+ rootSym, _ := filepath.EvalSymlinks(root)
+ dirSym, _ := filepath.EvalSymlinks(dir)
+
+ if rel, ok = hasSubdir(rootSym, dir); ok {
+ return
+ }
+ if rel, ok = hasSubdir(root, dirSym); ok {
+ return
+ }
+ return hasSubdir(rootSym, dirSym)
+}
+
+// hasSubdir reports if dir is within root by performing lexical analysis only.
+func hasSubdir(root, dir string) (rel string, ok bool) {
+ const sep = string(filepath.Separator)
+ root = filepath.Clean(root)
+ if !strings.HasSuffix(root, sep) {
+ root += sep
+ }
+ dir = filepath.Clean(dir)
+ if !strings.HasPrefix(dir, root) {
+ return "", false
+ }
+ return filepath.ToSlash(dir[len(root):]), true
+}
+
+// readDir calls ctxt.ReadDir (if not nil) or else ioutil.ReadDir.
+func (ctxt *Context) readDir(path string) ([]fs.FileInfo, error) {
+ if f := ctxt.ReadDir; f != nil {
+ return f(path)
+ }
+ return ioutil.ReadDir(path)
+}
+
+// openFile calls ctxt.OpenFile (if not nil) or else os.Open.
+func (ctxt *Context) openFile(path string) (io.ReadCloser, error) {
+ if fn := ctxt.OpenFile; fn != nil {
+ return fn(path)
+ }
+
+ f, err := os.Open(path)
+ if err != nil {
+ return nil, err // nil interface
+ }
+ return f, nil
+}
+
+// isFile determines whether path is a file by trying to open it.
+// It reuses openFile instead of adding another function to the
+// list in Context.
+func (ctxt *Context) isFile(path string) bool {
+ f, err := ctxt.openFile(path)
+ if err != nil {
+ return false
+ }
+ f.Close()
+ return true
+}
+
+// gopath returns the list of Go path directories.
+func (ctxt *Context) gopath() []string {
+ var all []string
+ for _, p := range ctxt.splitPathList(ctxt.GOPATH) {
+ if p == "" || p == ctxt.GOROOT {
+ // Empty paths are uninteresting.
+ // If the path is the GOROOT, ignore it.
+ // People sometimes set GOPATH=$GOROOT.
+ // Do not get confused by this common mistake.
+ continue
+ }
+ if strings.HasPrefix(p, "~") {
+ // Path segments starting with ~ on Unix are almost always
+ // users who have incorrectly quoted ~ while setting GOPATH,
+ // preventing it from expanding to $HOME.
+ // The situation is made more confusing by the fact that
+ // bash allows quoted ~ in $PATH (most shells do not).
+ // Do not get confused by this, and do not try to use the path.
+ // It does not exist, and printing errors about it confuses
+ // those users even more, because they think "sure ~ exists!".
+ // The go command diagnoses this situation and prints a
+ // useful error.
+ // On Windows, ~ is used in short names, such as c:\progra~1
+ // for c:\program files.
+ continue
+ }
+ all = append(all, p)
+ }
+ return all
+}
+
+// SrcDirs returns a list of package source root directories.
+// It draws from the current Go root and Go path but omits directories
+// that do not exist.
+func (ctxt *Context) SrcDirs() []string {
+ var all []string
+ if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
+ dir := ctxt.joinPath(ctxt.GOROOT, "src")
+ if ctxt.isDir(dir) {
+ all = append(all, dir)
+ }
+ }
+ for _, p := range ctxt.gopath() {
+ dir := ctxt.joinPath(p, "src")
+ if ctxt.isDir(dir) {
+ all = append(all, dir)
+ }
+ }
+ return all
+}
+
+// Default is the default Context for builds.
+// It uses the GOARCH, GOOS, GOROOT, and GOPATH environment variables
+// if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
+var Default Context = defaultContext()
+
+func defaultGOPATH() string {
+ env := "HOME"
+ if runtime.GOOS == "windows" {
+ env = "USERPROFILE"
+ } else if runtime.GOOS == "plan9" {
+ env = "home"
+ }
+ if home := os.Getenv(env); home != "" {
+ def := filepath.Join(home, "go")
+ if filepath.Clean(def) == filepath.Clean(runtime.GOROOT()) {
+ // Don't set the default GOPATH to GOROOT,
+ // as that will trigger warnings from the go tool.
+ return ""
+ }
+ return def
+ }
+ return ""
+}
+
+var defaultReleaseTags []string
+
+func defaultContext() Context {
+ var c Context
+
+ c.GOARCH = envOr("GOARCH", runtime.GOARCH)
+ c.GOOS = envOr("GOOS", runtime.GOOS)
+ c.GOROOT = pathpkg.Clean(runtime.GOROOT())
+ c.GOPATH = envOr("GOPATH", defaultGOPATH())
+ c.Compiler = runtime.Compiler
+
+ // Each major Go release in the Go 1.x series adds a new
+ // "go1.x" release tag. That is, the go1.x tag is present in
+ // all releases >= Go 1.x. Code that requires Go 1.x or later
+ // should say "+build go1.x", and code that should only be
+ // built before Go 1.x (perhaps it is the stub to use in that
+ // case) should say "+build !go1.x".
+ // The last element in ReleaseTags is the current release.
+ for i := 1; i <= goversion.Version; i++ {
+ c.ReleaseTags = append(c.ReleaseTags, "go1."+strconv.Itoa(i))
+ }
+
+ defaultReleaseTags = append([]string{}, c.ReleaseTags...) // our own private copy
+
+ env := os.Getenv("CGO_ENABLED")
+ if env == "" {
+ env = defaultCGO_ENABLED
+ }
+ switch env {
+ case "1":
+ c.CgoEnabled = true
+ case "0":
+ c.CgoEnabled = false
+ default:
+ // cgo must be explicitly enabled for cross compilation builds
+ if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
+ c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
+ break
+ }
+ c.CgoEnabled = false
+ }
+
+ return c
+}
+
+func envOr(name, def string) string {
+ s := os.Getenv(name)
+ if s == "" {
+ return def
+ }
+ return s
+}
+
+// An ImportMode controls the behavior of the Import method.
+type ImportMode uint
+
+const (
+ // If FindOnly is set, Import stops after locating the directory
+ // that should contain the sources for a package. It does not
+ // read any files in the directory.
+ FindOnly ImportMode = 1 << iota
+
+ // If AllowBinary is set, Import can be satisfied by a compiled
+ // package object without corresponding sources.
+ //
+ // Deprecated:
+ // The supported way to create a compiled-only package is to
+ // write source code containing a //go:binary-only-package comment at
+ // the top of the file. Such a package will be recognized
+ // regardless of this flag setting (because it has source code)
+ // and will have BinaryOnly set to true in the returned Package.
+ AllowBinary
+
+ // If ImportComment is set, parse import comments on package statements.
+ // Import returns an error if it finds a comment it cannot understand
+ // or finds conflicting comments in multiple source files.
+ // See golang.org/s/go14customimport for more information.
+ ImportComment
+
+ // By default, Import searches vendor directories
+ // that apply in the given source directory before searching
+ // the GOROOT and GOPATH roots.
+ // If an Import finds and returns a package using a vendor
+ // directory, the resulting ImportPath is the complete path
+ // to the package, including the path elements leading up
+ // to and including "vendor".
+ // For example, if Import("y", "x/subdir", 0) finds
+ // "x/vendor/y", the returned package's ImportPath is "x/vendor/y",
+ // not plain "y".
+ // See golang.org/s/go15vendor for more information.
+ //
+ // Setting IgnoreVendor ignores vendor directories.
+ //
+ // In contrast to the package's ImportPath,
+ // the returned package's Imports, TestImports, and XTestImports
+ // are always the exact import paths from the source files:
+ // Import makes no attempt to resolve or check those paths.
+ IgnoreVendor
+)
+
+// A Package describes the Go package found in a directory.
+type Package struct {
+ Dir string // directory containing package sources
+ Name string // package name
+ ImportComment string // path in import comment on package statement
+ Doc string // documentation synopsis
+ ImportPath string // import path of package ("" if unknown)
+ Root string // root of Go tree where this package lives
+ SrcRoot string // package source root directory ("" if unknown)
+ PkgRoot string // package install root directory ("" if unknown)
+ PkgTargetRoot string // architecture dependent install root directory ("" if unknown)
+ BinDir string // command install directory ("" if unknown)
+ Goroot bool // package found in Go root
+ PkgObj string // installed .a file
+ AllTags []string // tags that can influence file selection in this directory
+ ConflictDir string // this directory shadows Dir in $GOPATH
+ BinaryOnly bool // cannot be rebuilt from source (has //go:binary-only-package comment)
+
+ // Source files
+ GoFiles []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
+ CgoFiles []string // .go source files that import "C"
+ IgnoredGoFiles []string // .go source files ignored for this build (including ignored _test.go files)
+ InvalidGoFiles []string // .go source files with detected problems (parse error, wrong package name, and so on)
+ IgnoredOtherFiles []string // non-.go source files ignored for this build
+ CFiles []string // .c source files
+ CXXFiles []string // .cc, .cpp and .cxx source files
+ MFiles []string // .m (Objective-C) source files
+ HFiles []string // .h, .hh, .hpp and .hxx source files
+ FFiles []string // .f, .F, .for and .f90 Fortran source files
+ SFiles []string // .s source files
+ SwigFiles []string // .swig files
+ SwigCXXFiles []string // .swigcxx files
+ SysoFiles []string // .syso system object files to add to archive
+
+ // Cgo directives
+ CgoCFLAGS []string // Cgo CFLAGS directives
+ CgoCPPFLAGS []string // Cgo CPPFLAGS directives
+ CgoCXXFLAGS []string // Cgo CXXFLAGS directives
+ CgoFFLAGS []string // Cgo FFLAGS directives
+ CgoLDFLAGS []string // Cgo LDFLAGS directives
+ CgoPkgConfig []string // Cgo pkg-config directives
+
+ // Test information
+ TestGoFiles []string // _test.go files in package
+ XTestGoFiles []string // _test.go files outside package
+
+ // Dependency information
+ Imports []string // import paths from GoFiles, CgoFiles
+ ImportPos map[string][]token.Position // line information for Imports
+ TestImports []string // import paths from TestGoFiles
+ TestImportPos map[string][]token.Position // line information for TestImports
+ XTestImports []string // import paths from XTestGoFiles
+ XTestImportPos map[string][]token.Position // line information for XTestImports
+
+ // //go:embed patterns found in Go source files
+ // For example, if a source file says
+ // //go:embed a* b.c
+ // then the list will contain those two strings as separate entries.
+ // (See package embed for more details about //go:embed.)
+ EmbedPatterns []string // patterns from GoFiles, CgoFiles
+ EmbedPatternPos map[string][]token.Position // line information for EmbedPatterns
+ TestEmbedPatterns []string // patterns from TestGoFiles
+ TestEmbedPatternPos map[string][]token.Position // line information for TestEmbedPatterns
+ XTestEmbedPatterns []string // patterns from XTestGoFiles
+ XTestEmbedPatternPos map[string][]token.Position // line information for XTestEmbedPatternPos
+}
+
+// IsCommand reports whether the package is considered a
+// command to be installed (not just a library).
+// Packages named "main" are treated as commands.
+func (p *Package) IsCommand() bool {
+ return p.Name == "main"
+}
+
+// ImportDir is like Import but processes the Go package found in
+// the named directory.
+func (ctxt *Context) ImportDir(dir string, mode ImportMode) (*Package, error) {
+ return ctxt.Import(".", dir, mode)
+}
+
+// NoGoError is the error used by Import to describe a directory
+// containing no buildable Go source files. (It may still contain
+// test files, files hidden by build tags, and so on.)
+type NoGoError struct {
+ Dir string
+}
+
+func (e *NoGoError) Error() string {
+ return "no buildable Go source files in " + e.Dir
+}
+
+// MultiplePackageError describes a directory containing
+// multiple buildable Go source files for multiple packages.
+type MultiplePackageError struct {
+ Dir string // directory containing files
+ Packages []string // package names found
+ Files []string // corresponding files: Files[i] declares package Packages[i]
+}
+
+func (e *MultiplePackageError) Error() string {
+ // Error string limited to two entries for compatibility.
+ return fmt.Sprintf("found packages %s (%s) and %s (%s) in %s", e.Packages[0], e.Files[0], e.Packages[1], e.Files[1], e.Dir)
+}
+
+func nameExt(name string) string {
+ i := strings.LastIndex(name, ".")
+ if i < 0 {
+ return ""
+ }
+ return name[i:]
+}
+
+// Import returns details about the Go package named by the import path,
+// interpreting local import paths relative to the srcDir directory.
+// If the path is a local import path naming a package that can be imported
+// using a standard import path, the returned package will set p.ImportPath
+// to that path.
+//
+// In the directory containing the package, .go, .c, .h, and .s files are
+// considered part of the package except for:
+//
+// - .go files in package documentation
+// - files starting with _ or . (likely editor temporary files)
+// - files with build constraints not satisfied by the context
+//
+// If an error occurs, Import returns a non-nil error and a non-nil
+// *Package containing partial information.
+//
+func (ctxt *Context) Import(path string, srcDir string, mode ImportMode) (*Package, error) {
+ p := &Package{
+ ImportPath: path,
+ }
+ if path == "" {
+ return p, fmt.Errorf("import %q: invalid import path", path)
+ }
+
+ var pkgtargetroot string
+ var pkga string
+ var pkgerr error
+ suffix := ""
+ if ctxt.InstallSuffix != "" {
+ suffix = "_" + ctxt.InstallSuffix
+ }
+ switch ctxt.Compiler {
+ case "gccgo":
+ pkgtargetroot = "pkg/gccgo_" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
+ case "gc":
+ pkgtargetroot = "pkg/" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
+ default:
+ // Save error for end of function.
+ pkgerr = fmt.Errorf("import %q: unknown compiler %q", path, ctxt.Compiler)
+ }
+ setPkga := func() {
+ switch ctxt.Compiler {
+ case "gccgo":
+ dir, elem := pathpkg.Split(p.ImportPath)
+ pkga = pkgtargetroot + "/" + dir + "lib" + elem + ".a"
+ case "gc":
+ pkga = pkgtargetroot + "/" + p.ImportPath + ".a"
+ }
+ }
+ setPkga()
+
+ binaryOnly := false
+ if IsLocalImport(path) {
+ pkga = "" // local imports have no installed path
+ if srcDir == "" {
+ return p, fmt.Errorf("import %q: import relative to unknown directory", path)
+ }
+ if !ctxt.isAbsPath(path) {
+ p.Dir = ctxt.joinPath(srcDir, path)
+ }
+ // p.Dir directory may or may not exist. Gather partial information first, check if it exists later.
+ // Determine canonical import path, if any.
+ // Exclude results where the import path would include /testdata/.
+ inTestdata := func(sub string) bool {
+ return strings.Contains(sub, "/testdata/") || strings.HasSuffix(sub, "/testdata") || strings.HasPrefix(sub, "testdata/") || sub == "testdata"
+ }
+ if ctxt.GOROOT != "" {
+ root := ctxt.joinPath(ctxt.GOROOT, "src")
+ if sub, ok := ctxt.hasSubdir(root, p.Dir); ok && !inTestdata(sub) {
+ p.Goroot = true
+ p.ImportPath = sub
+ p.Root = ctxt.GOROOT
+ setPkga() // p.ImportPath changed
+ goto Found
+ }
+ }
+ all := ctxt.gopath()
+ for i, root := range all {
+ rootsrc := ctxt.joinPath(root, "src")
+ if sub, ok := ctxt.hasSubdir(rootsrc, p.Dir); ok && !inTestdata(sub) {
+ // We found a potential import path for dir,
+ // but check that using it wouldn't find something
+ // else first.
+ if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
+ if dir := ctxt.joinPath(ctxt.GOROOT, "src", sub); ctxt.isDir(dir) {
+ p.ConflictDir = dir
+ goto Found
+ }
+ }
+ for _, earlyRoot := range all[:i] {
+ if dir := ctxt.joinPath(earlyRoot, "src", sub); ctxt.isDir(dir) {
+ p.ConflictDir = dir
+ goto Found
+ }
+ }
+
+ // sub would not name some other directory instead of this one.
+ // Record it.
+ p.ImportPath = sub
+ p.Root = root
+ setPkga() // p.ImportPath changed
+ goto Found
+ }
+ }
+ // It's okay that we didn't find a root containing dir.
+ // Keep going with the information we have.
+ } else {
+ if strings.HasPrefix(path, "/") {
+ return p, fmt.Errorf("import %q: cannot import absolute path", path)
+ }
+
+ if err := ctxt.importGo(p, path, srcDir, mode); err == nil {
+ goto Found
+ } else if err != errNoModules {
+ return p, err
+ }
+
+ gopath := ctxt.gopath() // needed twice below; avoid computing many times
+
+ // tried records the location of unsuccessful package lookups
+ var tried struct {
+ vendor []string
+ goroot string
+ gopath []string
+ }
+
+ // Vendor directories get first chance to satisfy import.
+ if mode&IgnoreVendor == 0 && srcDir != "" {
+ searchVendor := func(root string, isGoroot bool) bool {
+ sub, ok := ctxt.hasSubdir(root, srcDir)
+ if !ok || !strings.HasPrefix(sub, "src/") || strings.Contains(sub, "/testdata/") {
+ return false
+ }
+ for {
+ vendor := ctxt.joinPath(root, sub, "vendor")
+ if ctxt.isDir(vendor) {
+ dir := ctxt.joinPath(vendor, path)
+ if ctxt.isDir(dir) && hasGoFiles(ctxt, dir) {
+ p.Dir = dir
+ p.ImportPath = strings.TrimPrefix(pathpkg.Join(sub, "vendor", path), "src/")
+ p.Goroot = isGoroot
+ p.Root = root
+ setPkga() // p.ImportPath changed
+ return true
+ }
+ tried.vendor = append(tried.vendor, dir)
+ }
+ i := strings.LastIndex(sub, "/")
+ if i < 0 {
+ break
+ }
+ sub = sub[:i]
+ }
+ return false
+ }
+ if ctxt.Compiler != "gccgo" && searchVendor(ctxt.GOROOT, true) {
+ goto Found
+ }
+ for _, root := range gopath {
+ if searchVendor(root, false) {
+ goto Found
+ }
+ }
+ }
+
+ // Determine directory from import path.
+ if ctxt.GOROOT != "" {
+ // If the package path starts with "vendor/", only search GOROOT before
+ // GOPATH if the importer is also within GOROOT. That way, if the user has
+ // vendored in a package that is subsequently included in the standard
+ // distribution, they'll continue to pick up their own vendored copy.
+ gorootFirst := srcDir == "" || !strings.HasPrefix(path, "vendor/")
+ if !gorootFirst {
+ _, gorootFirst = ctxt.hasSubdir(ctxt.GOROOT, srcDir)
+ }
+ if gorootFirst {
+ dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
+ if ctxt.Compiler != "gccgo" {
+ isDir := ctxt.isDir(dir)
+ binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
+ if isDir || binaryOnly {
+ p.Dir = dir
+ p.Goroot = true
+ p.Root = ctxt.GOROOT
+ goto Found
+ }
+ }
+ tried.goroot = dir
+ }
+ }
+ if ctxt.Compiler == "gccgo" && goroot.IsStandardPackage(ctxt.GOROOT, ctxt.Compiler, path) {
+ p.Dir = ctxt.joinPath(ctxt.GOROOT, "src", path)
+ p.Goroot = true
+ p.Root = ctxt.GOROOT
+ goto Found
+ }
+ for _, root := range gopath {
+ dir := ctxt.joinPath(root, "src", path)
+ isDir := ctxt.isDir(dir)
+ binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(root, pkga))
+ if isDir || binaryOnly {
+ p.Dir = dir
+ p.Root = root
+ goto Found
+ }
+ tried.gopath = append(tried.gopath, dir)
+ }
+
+ // If we tried GOPATH first due to a "vendor/" prefix, fall back to GOPATH.
+ // That way, the user can still get useful results from 'go list' for
+ // standard-vendored paths passed on the command line.
+ if ctxt.GOROOT != "" && tried.goroot == "" {
+ dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
+ if ctxt.Compiler != "gccgo" {
+ isDir := ctxt.isDir(dir)
+ binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
+ if isDir || binaryOnly {
+ p.Dir = dir
+ p.Goroot = true
+ p.Root = ctxt.GOROOT
+ goto Found
+ }
+ }
+ tried.goroot = dir
+ }
+
+ // package was not found
+ var paths []string
+ format := "\t%s (vendor tree)"
+ for _, dir := range tried.vendor {
+ paths = append(paths, fmt.Sprintf(format, dir))
+ format = "\t%s"
+ }
+ if tried.goroot != "" {
+ paths = append(paths, fmt.Sprintf("\t%s (from $GOROOT)", tried.goroot))
+ } else {
+ paths = append(paths, "\t($GOROOT not set)")
+ }
+ format = "\t%s (from $GOPATH)"
+ for _, dir := range tried.gopath {
+ paths = append(paths, fmt.Sprintf(format, dir))
+ format = "\t%s"
+ }
+ if len(tried.gopath) == 0 {
+ paths = append(paths, "\t($GOPATH not set. For more details see: 'go help gopath')")
+ }
+ return p, fmt.Errorf("cannot find package %q in any of:\n%s", path, strings.Join(paths, "\n"))
+ }
+
+Found:
+ if p.Root != "" {
+ p.SrcRoot = ctxt.joinPath(p.Root, "src")
+ p.PkgRoot = ctxt.joinPath(p.Root, "pkg")
+ p.BinDir = ctxt.joinPath(p.Root, "bin")
+ if pkga != "" {
+ p.PkgTargetRoot = ctxt.joinPath(p.Root, pkgtargetroot)
+ p.PkgObj = ctxt.joinPath(p.Root, pkga)
+ }
+ }
+
+ // If it's a local import path, by the time we get here, we still haven't checked
+ // that p.Dir directory exists. This is the right time to do that check.
+ // We can't do it earlier, because we want to gather partial information for the
+ // non-nil *Package returned when an error occurs.
+ // We need to do this before we return early on FindOnly flag.
+ if IsLocalImport(path) && !ctxt.isDir(p.Dir) {
+ if ctxt.Compiler == "gccgo" && p.Goroot {
+ // gccgo has no sources for GOROOT packages.
+ return p, nil
+ }
+
+ // package was not found
+ return p, fmt.Errorf("cannot find package %q in:\n\t%s", path, p.Dir)
+ }
+
+ if mode&FindOnly != 0 {
+ return p, pkgerr
+ }
+ if binaryOnly && (mode&AllowBinary) != 0 {
+ return p, pkgerr
+ }
+
+ if ctxt.Compiler == "gccgo" && p.Goroot {
+ // gccgo has no sources for GOROOT packages.
+ return p, nil
+ }
+
+ dirs, err := ctxt.readDir(p.Dir)
+ if err != nil {
+ return p, err
+ }
+
+ var badGoError error
+ var Sfiles []string // files with ".S"(capital S)/.sx(capital s equivalent for case insensitive filesystems)
+ var firstFile, firstCommentFile string
+ embedPos := make(map[string][]token.Position)
+ testEmbedPos := make(map[string][]token.Position)
+ xTestEmbedPos := make(map[string][]token.Position)
+ importPos := make(map[string][]token.Position)
+ testImportPos := make(map[string][]token.Position)
+ xTestImportPos := make(map[string][]token.Position)
+ allTags := make(map[string]bool)
+ fset := token.NewFileSet()
+ for _, d := range dirs {
+ if d.IsDir() {
+ continue
+ }
+ if d.Mode()&fs.ModeSymlink != 0 {
+ if ctxt.isDir(ctxt.joinPath(p.Dir, d.Name())) {
+ // Symlinks to directories are not source files.
+ continue
+ }
+ }
+
+ name := d.Name()
+ ext := nameExt(name)
+
+ badFile := func(err error) {
+ if badGoError == nil {
+ badGoError = err
+ }
+ p.InvalidGoFiles = append(p.InvalidGoFiles, name)
+ }
+
+ info, err := ctxt.matchFile(p.Dir, name, allTags, &p.BinaryOnly, fset)
+ if err != nil {
+ badFile(err)
+ continue
+ }
+ if info == nil {
+ if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
+ // not due to build constraints - don't report
+ } else if ext == ".go" {
+ p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
+ } else if fileListForExt(p, ext) != nil {
+ p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, name)
+ }
+ continue
+ }
+ data, filename := info.header, info.name
+
+ // Going to save the file. For non-Go files, can stop here.
+ switch ext {
+ case ".go":
+ // keep going
+ case ".S", ".sx":
+ // special case for cgo, handled at end
+ Sfiles = append(Sfiles, name)
+ continue
+ default:
+ if list := fileListForExt(p, ext); list != nil {
+ *list = append(*list, name)
+ }
+ continue
+ }
+
+ if info.parseErr != nil {
+ badFile(info.parseErr)
+ continue
+ }
+ pf := info.parsed
+
+ pkg := pf.Name.Name
+ if pkg == "documentation" {
+ p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
+ continue
+ }
+
+ isTest := strings.HasSuffix(name, "_test.go")
+ isXTest := false
+ if isTest && strings.HasSuffix(pkg, "_test") {
+ isXTest = true
+ pkg = pkg[:len(pkg)-len("_test")]
+ }
+
+ if p.Name == "" {
+ p.Name = pkg
+ firstFile = name
+ } else if pkg != p.Name {
+ badFile(&MultiplePackageError{
+ Dir: p.Dir,
+ Packages: []string{p.Name, pkg},
+ Files: []string{firstFile, name},
+ })
+ p.InvalidGoFiles = append(p.InvalidGoFiles, name)
+ }
+ // Grab the first package comment as docs, provided it is not from a test file.
+ if pf.Doc != nil && p.Doc == "" && !isTest && !isXTest {
+ p.Doc = doc.Synopsis(pf.Doc.Text())
+ }
+
+ if mode&ImportComment != 0 {
+ qcom, line := findImportComment(data)
+ if line != 0 {
+ com, err := strconv.Unquote(qcom)
+ if err != nil {
+ badFile(fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
+ } else if p.ImportComment == "" {
+ p.ImportComment = com
+ firstCommentFile = name
+ } else if p.ImportComment != com {
+ badFile(fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
+ }
+ }
+ }
+
+ // Record imports and information about cgo.
+ isCgo := false
+ for _, imp := range info.imports {
+ if imp.path == "C" {
+ if isTest {
+ badFile(fmt.Errorf("use of cgo in test %s not supported", filename))
+ continue
+ }
+ isCgo = true
+ if imp.doc != nil {
+ if err := ctxt.saveCgo(filename, p, imp.doc); err != nil {
+ badFile(err)
+ }
+ }
+ }
+ }
+
+ var fileList *[]string
+ var importMap, embedMap map[string][]token.Position
+ switch {
+ case isCgo:
+ allTags["cgo"] = true
+ if ctxt.CgoEnabled {
+ fileList = &p.CgoFiles
+ importMap = importPos
+ embedMap = embedPos
+ } else {
+ // Ignore imports and embeds from cgo files if cgo is disabled.
+ fileList = &p.IgnoredGoFiles
+ }
+ case isXTest:
+ fileList = &p.XTestGoFiles
+ importMap = xTestImportPos
+ embedMap = xTestEmbedPos
+ case isTest:
+ fileList = &p.TestGoFiles
+ importMap = testImportPos
+ embedMap = testEmbedPos
+ default:
+ fileList = &p.GoFiles
+ importMap = importPos
+ embedMap = embedPos
+ }
+ *fileList = append(*fileList, name)
+ if importMap != nil {
+ for _, imp := range info.imports {
+ importMap[imp.path] = append(importMap[imp.path], fset.Position(imp.pos))
+ }
+ }
+ if embedMap != nil {
+ for _, emb := range info.embeds {
+ embedMap[emb.pattern] = append(embedMap[emb.pattern], emb.pos)
+ }
+ }
+ }
+
+ for tag := range allTags {
+ p.AllTags = append(p.AllTags, tag)
+ }
+ sort.Strings(p.AllTags)
+
+ p.EmbedPatterns, p.EmbedPatternPos = cleanDecls(embedPos)
+ p.TestEmbedPatterns, p.TestEmbedPatternPos = cleanDecls(testEmbedPos)
+ p.XTestEmbedPatterns, p.XTestEmbedPatternPos = cleanDecls(xTestEmbedPos)
+
+ p.Imports, p.ImportPos = cleanDecls(importPos)
+ p.TestImports, p.TestImportPos = cleanDecls(testImportPos)
+ p.XTestImports, p.XTestImportPos = cleanDecls(xTestImportPos)
+
+ // add the .S/.sx files only if we are using cgo
+ // (which means gcc will compile them).
+ // The standard assemblers expect .s files.
+ if len(p.CgoFiles) > 0 {
+ p.SFiles = append(p.SFiles, Sfiles...)
+ sort.Strings(p.SFiles)
+ } else {
+ p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
+ sort.Strings(p.IgnoredOtherFiles)
+ }
+
+ if badGoError != nil {
+ return p, badGoError
+ }
+ if len(p.GoFiles)+len(p.CgoFiles)+len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
+ return p, &NoGoError{p.Dir}
+ }
+ return p, pkgerr
+}
+
+func fileListForExt(p *Package, ext string) *[]string {
+ switch ext {
+ case ".c":
+ return &p.CFiles
+ case ".cc", ".cpp", ".cxx":
+ return &p.CXXFiles
+ case ".m":
+ return &p.MFiles
+ case ".h", ".hh", ".hpp", ".hxx":
+ return &p.HFiles
+ case ".f", ".F", ".for", ".f90":
+ return &p.FFiles
+ case ".s", ".S", ".sx":
+ return &p.SFiles
+ case ".swig":
+ return &p.SwigFiles
+ case ".swigcxx":
+ return &p.SwigCXXFiles
+ case ".syso":
+ return &p.SysoFiles
+ }
+ return nil
+}
+
+func uniq(list []string) []string {
+ if list == nil {
+ return nil
+ }
+ out := make([]string, len(list))
+ copy(out, list)
+ sort.Strings(out)
+ uniq := out[:0]
+ for _, x := range out {
+ if len(uniq) == 0 || uniq[len(uniq)-1] != x {
+ uniq = append(uniq, x)
+ }
+ }
+ return uniq
+}
+
+var errNoModules = errors.New("not using modules")
+
+// importGo checks whether it can use the go command to find the directory for path.
+// If using the go command is not appropriate, importGo returns errNoModules.
+// Otherwise, importGo tries using the go command and reports whether that succeeded.
+// Using the go command lets build.Import and build.Context.Import find code
+// in Go modules. In the long term we want tools to use go/packages (currently golang.org/x/tools/go/packages),
+// which will also use the go command.
+// Invoking the go command here is not very efficient in that it computes information
+// about the requested package and all dependencies and then only reports about the requested package.
+// Then we reinvoke it for every dependency. But this is still better than not working at all.
+// See golang.org/issue/26504.
+func (ctxt *Context) importGo(p *Package, path, srcDir string, mode ImportMode) error {
+ // To invoke the go command,
+ // we must not being doing special things like AllowBinary or IgnoreVendor,
+ // and all the file system callbacks must be nil (we're meant to use the local file system).
+ if mode&AllowBinary != 0 || mode&IgnoreVendor != 0 ||
+ ctxt.JoinPath != nil || ctxt.SplitPathList != nil || ctxt.IsAbsPath != nil || ctxt.IsDir != nil || ctxt.HasSubdir != nil || ctxt.ReadDir != nil || ctxt.OpenFile != nil || !equal(ctxt.ReleaseTags, defaultReleaseTags) {
+ return errNoModules
+ }
+
+ // Predict whether module aware mode is enabled by checking the value of
+ // GO111MODULE and looking for a go.mod file in the source directory or
+ // one of its parents. Running 'go env GOMOD' in the source directory would
+ // give a canonical answer, but we'd prefer not to execute another command.
+ go111Module := os.Getenv("GO111MODULE")
+ switch go111Module {
+ case "off":
+ return errNoModules
+ default: // "", "on", "auto", anything else
+ // Maybe use modules.
+ }
+
+ if srcDir != "" {
+ var absSrcDir string
+ if filepath.IsAbs(srcDir) {
+ absSrcDir = srcDir
+ } else if ctxt.Dir != "" {
+ return fmt.Errorf("go/build: Dir is non-empty, so relative srcDir is not allowed: %v", srcDir)
+ } else {
+ // Find the absolute source directory. hasSubdir does not handle
+ // relative paths (and can't because the callbacks don't support this).
+ var err error
+ absSrcDir, err = filepath.Abs(srcDir)
+ if err != nil {
+ return errNoModules
+ }
+ }
+
+ // If the source directory is in GOROOT, then the in-process code works fine
+ // and we should keep using it. Moreover, the 'go list' approach below doesn't
+ // take standard-library vendoring into account and will fail.
+ if _, ok := ctxt.hasSubdir(filepath.Join(ctxt.GOROOT, "src"), absSrcDir); ok {
+ return errNoModules
+ }
+ }
+
+ // For efficiency, if path is a standard library package, let the usual lookup code handle it.
+ if ctxt.GOROOT != "" {
+ dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
+ if ctxt.isDir(dir) {
+ return errNoModules
+ }
+ }
+
+ // If GO111MODULE=auto, look to see if there is a go.mod.
+ // Since go1.13, it doesn't matter if we're inside GOPATH.
+ if go111Module == "auto" {
+ var (
+ parent string
+ err error
+ )
+ if ctxt.Dir == "" {
+ parent, err = os.Getwd()
+ if err != nil {
+ // A nonexistent working directory can't be in a module.
+ return errNoModules
+ }
+ } else {
+ parent, err = filepath.Abs(ctxt.Dir)
+ if err != nil {
+ // If the caller passed a bogus Dir explicitly, that's materially
+ // different from not having modules enabled.
+ return err
+ }
+ }
+ for {
+ if f, err := ctxt.openFile(ctxt.joinPath(parent, "go.mod")); err == nil {
+ buf := make([]byte, 100)
+ _, err := f.Read(buf)
+ f.Close()
+ if err == nil || err == io.EOF {
+ // go.mod exists and is readable (is a file, not a directory).
+ break
+ }
+ }
+ d := filepath.Dir(parent)
+ if len(d) >= len(parent) {
+ return errNoModules // reached top of file system, no go.mod
+ }
+ parent = d
+ }
+ }
+
+ cmd := exec.Command("go", "list", "-e", "-compiler="+ctxt.Compiler, "-tags="+strings.Join(ctxt.BuildTags, ","), "-installsuffix="+ctxt.InstallSuffix, "-f={{.Dir}}\n{{.ImportPath}}\n{{.Root}}\n{{.Goroot}}\n{{if .Error}}{{.Error}}{{end}}\n", "--", path)
+
+ if ctxt.Dir != "" {
+ cmd.Dir = ctxt.Dir
+ }
+
+ var stdout, stderr strings.Builder
+ cmd.Stdout = &stdout
+ cmd.Stderr = &stderr
+
+ cgo := "0"
+ if ctxt.CgoEnabled {
+ cgo = "1"
+ }
+ cmd.Env = append(os.Environ(),
+ "GOOS="+ctxt.GOOS,
+ "GOARCH="+ctxt.GOARCH,
+ "GOROOT="+ctxt.GOROOT,
+ "GOPATH="+ctxt.GOPATH,
+ "CGO_ENABLED="+cgo,
+ )
+
+ if err := cmd.Run(); err != nil {
+ return fmt.Errorf("go/build: go list %s: %v\n%s\n", path, err, stderr.String())
+ }
+
+ f := strings.SplitN(stdout.String(), "\n", 5)
+ if len(f) != 5 {
+ return fmt.Errorf("go/build: importGo %s: unexpected output:\n%s\n", path, stdout.String())
+ }
+ dir := f[0]
+ errStr := strings.TrimSpace(f[4])
+ if errStr != "" && dir == "" {
+ // If 'go list' could not locate the package (dir is empty),
+ // return the same error that 'go list' reported.
+ return errors.New(errStr)
+ }
+
+ // If 'go list' did locate the package, ignore the error.
+ // It was probably related to loading source files, and we'll
+ // encounter it ourselves shortly if the FindOnly flag isn't set.
+ p.Dir = dir
+ p.ImportPath = f[1]
+ p.Root = f[2]
+ p.Goroot = f[3] == "true"
+ return nil
+}
+
+func equal(x, y []string) bool {
+ if len(x) != len(y) {
+ return false
+ }
+ for i, xi := range x {
+ if xi != y[i] {
+ return false
+ }
+ }
+ return true
+}
+
+// hasGoFiles reports whether dir contains any files with names ending in .go.
+// For a vendor check we must exclude directories that contain no .go files.
+// Otherwise it is not possible to vendor just a/b/c and still import the
+// non-vendored a/b. See golang.org/issue/13832.
+func hasGoFiles(ctxt *Context, dir string) bool {
+ ents, _ := ctxt.readDir(dir)
+ for _, ent := range ents {
+ if !ent.IsDir() && strings.HasSuffix(ent.Name(), ".go") {
+ return true
+ }
+ }
+ return false
+}
+
+func findImportComment(data []byte) (s string, line int) {
+ // expect keyword package
+ word, data := parseWord(data)
+ if string(word) != "package" {
+ return "", 0
+ }
+
+ // expect package name
+ _, data = parseWord(data)
+
+ // now ready for import comment, a // or /* */ comment
+ // beginning and ending on the current line.
+ for len(data) > 0 && (data[0] == ' ' || data[0] == '\t' || data[0] == '\r') {
+ data = data[1:]
+ }
+
+ var comment []byte
+ switch {
+ case bytes.HasPrefix(data, slashSlash):
+ i := bytes.Index(data, newline)
+ if i < 0 {
+ i = len(data)
+ }
+ comment = data[2:i]
+ case bytes.HasPrefix(data, slashStar):
+ data = data[2:]
+ i := bytes.Index(data, starSlash)
+ if i < 0 {
+ // malformed comment
+ return "", 0
+ }
+ comment = data[:i]
+ if bytes.Contains(comment, newline) {
+ return "", 0
+ }
+ }
+ comment = bytes.TrimSpace(comment)
+
+ // split comment into `import`, `"pkg"`
+ word, arg := parseWord(comment)
+ if string(word) != "import" {
+ return "", 0
+ }
+
+ line = 1 + bytes.Count(data[:cap(data)-cap(arg)], newline)
+ return strings.TrimSpace(string(arg)), line
+}
+
+var (
+ slashSlash = []byte("//")
+ slashStar = []byte("/*")
+ starSlash = []byte("*/")
+ newline = []byte("\n")
+)
+
+// skipSpaceOrComment returns data with any leading spaces or comments removed.
+func skipSpaceOrComment(data []byte) []byte {
+ for len(data) > 0 {
+ switch data[0] {
+ case ' ', '\t', '\r', '\n':
+ data = data[1:]
+ continue
+ case '/':
+ if bytes.HasPrefix(data, slashSlash) {
+ i := bytes.Index(data, newline)
+ if i < 0 {
+ return nil
+ }
+ data = data[i+1:]
+ continue
+ }
+ if bytes.HasPrefix(data, slashStar) {
+ data = data[2:]
+ i := bytes.Index(data, starSlash)
+ if i < 0 {
+ return nil
+ }
+ data = data[i+2:]
+ continue
+ }
+ }
+ break
+ }
+ return data
+}
+
+// parseWord skips any leading spaces or comments in data
+// and then parses the beginning of data as an identifier or keyword,
+// returning that word and what remains after the word.
+func parseWord(data []byte) (word, rest []byte) {
+ data = skipSpaceOrComment(data)
+
+ // Parse past leading word characters.
+ rest = data
+ for {
+ r, size := utf8.DecodeRune(rest)
+ if unicode.IsLetter(r) || '0' <= r && r <= '9' || r == '_' {
+ rest = rest[size:]
+ continue
+ }
+ break
+ }
+
+ word = data[:len(data)-len(rest)]
+ if len(word) == 0 {
+ return nil, nil
+ }
+
+ return word, rest
+}
+
+// MatchFile reports whether the file with the given name in the given directory
+// matches the context and would be included in a Package created by ImportDir
+// of that directory.
+//
+// MatchFile considers the name of the file and may use ctxt.OpenFile to
+// read some or all of the file's content.
+func (ctxt *Context) MatchFile(dir, name string) (match bool, err error) {
+ info, err := ctxt.matchFile(dir, name, nil, nil, nil)
+ return info != nil, err
+}
+
+var dummyPkg Package
+
+// fileInfo records information learned about a file included in a build.
+type fileInfo struct {
+ name string // full name including dir
+ header []byte
+ fset *token.FileSet
+ parsed *ast.File
+ parseErr error
+ imports []fileImport
+ embeds []fileEmbed
+ embedErr error
+}
+
+type fileImport struct {
+ path string
+ pos token.Pos
+ doc *ast.CommentGroup
+}
+
+type fileEmbed struct {
+ pattern string
+ pos token.Position
+}
+
+// matchFile determines whether the file with the given name in the given directory
+// should be included in the package being constructed.
+// If the file should be included, matchFile returns a non-nil *fileInfo (and a nil error).
+// Non-nil errors are reserved for unexpected problems.
+//
+// If name denotes a Go program, matchFile reads until the end of the
+// imports and returns that section of the file in the fileInfo's header field,
+// even though it only considers text until the first non-comment
+// for +build lines.
+//
+// If allTags is non-nil, matchFile records any encountered build tag
+// by setting allTags[tag] = true.
+func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binaryOnly *bool, fset *token.FileSet) (*fileInfo, error) {
+ if strings.HasPrefix(name, "_") ||
+ strings.HasPrefix(name, ".") {
+ return nil, nil
+ }
+
+ i := strings.LastIndex(name, ".")
+ if i < 0 {
+ i = len(name)
+ }
+ ext := name[i:]
+
+ if !ctxt.goodOSArchFile(name, allTags) && !ctxt.UseAllFiles {
+ return nil, nil
+ }
+
+ if ext != ".go" && fileListForExt(&dummyPkg, ext) == nil {
+ // skip
+ return nil, nil
+ }
+
+ info := &fileInfo{name: ctxt.joinPath(dir, name), fset: fset}
+ if ext == ".syso" {
+ // binary, no reading
+ return info, nil
+ }
+
+ f, err := ctxt.openFile(info.name)
+ if err != nil {
+ return nil, err
+ }
+
+ if strings.HasSuffix(name, ".go") {
+ err = readGoInfo(f, info)
+ if strings.HasSuffix(name, "_test.go") {
+ binaryOnly = nil // ignore //go:binary-only-package comments in _test.go files
+ }
+ } else {
+ binaryOnly = nil // ignore //go:binary-only-package comments in non-Go sources
+ info.header, err = readComments(f)
+ }
+ f.Close()
+ if err != nil {
+ return nil, fmt.Errorf("read %s: %v", info.name, err)
+ }
+
+ // Look for +build comments to accept or reject the file.
+ ok, sawBinaryOnly, err := ctxt.shouldBuild(info.header, allTags)
+ if err != nil {
+ return nil, err
+ }
+ if !ok && !ctxt.UseAllFiles {
+ return nil, nil
+ }
+
+ if binaryOnly != nil && sawBinaryOnly {
+ *binaryOnly = true
+ }
+
+ return info, nil
+}
+
+func cleanDecls(m map[string][]token.Position) ([]string, map[string][]token.Position) {
+ all := make([]string, 0, len(m))
+ for path := range m {
+ all = append(all, path)
+ }
+ sort.Strings(all)
+ return all, m
+}
+
+// Import is shorthand for Default.Import.
+func Import(path, srcDir string, mode ImportMode) (*Package, error) {
+ return Default.Import(path, srcDir, mode)
+}
+
+// ImportDir is shorthand for Default.ImportDir.
+func ImportDir(dir string, mode ImportMode) (*Package, error) {
+ return Default.ImportDir(dir, mode)
+}
+
+var (
+ bSlashSlash = []byte(slashSlash)
+ bStarSlash = []byte(starSlash)
+ bSlashStar = []byte(slashStar)
+
+ goBuildComment = []byte("//go:build")
+
+ errGoBuildWithoutBuild = errors.New("//go:build comment without // +build comment")
+ errMultipleGoBuild = errors.New("multiple //go:build comments") // unused in Go 1.(N-1)
+)
+
+func isGoBuildComment(line []byte) bool {
+ if !bytes.HasPrefix(line, goBuildComment) {
+ return false
+ }
+ line = bytes.TrimSpace(line)
+ rest := line[len(goBuildComment):]
+ return len(rest) == 0 || len(bytes.TrimSpace(rest)) < len(rest)
+}
+
+// Special comment denoting a binary-only package.
+// See https://golang.org/design/2775-binary-only-packages
+// for more about the design of binary-only packages.
+var binaryOnlyComment = []byte("//go:binary-only-package")
+
+// shouldBuild reports whether it is okay to use this file,
+// The rule is that in the file's leading run of // comments
+// and blank lines, which must be followed by a blank line
+// (to avoid including a Go package clause doc comment),
+// lines beginning with '// +build' are taken as build directives.
+//
+// The file is accepted only if each such line lists something
+// matching the file. For example:
+//
+// // +build windows linux
+//
+// marks the file as applicable only on Windows and Linux.
+//
+// For each build tag it consults, shouldBuild sets allTags[tag] = true.
+//
+// shouldBuild reports whether the file should be built
+// and whether a //go:binary-only-package comment was found.
+func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) (shouldBuild, binaryOnly bool, err error) {
+
+ // Pass 1. Identify leading run of // comments and blank lines,
+ // which must be followed by a blank line.
+ // Also identify any //go:build comments.
+ content, goBuild, sawBinaryOnly, err := parseFileHeader(content)
+ if err != nil {
+ return false, false, err
+ }
+
+ // Pass 2. Process each +build line in the run.
+ p := content
+ shouldBuild = true
+ sawBuild := false
+ for len(p) > 0 {
+ line := p
+ if i := bytes.IndexByte(line, '\n'); i >= 0 {
+ line, p = line[:i], p[i+1:]
+ } else {
+ p = p[len(p):]
+ }
+ line = bytes.TrimSpace(line)
+ if !bytes.HasPrefix(line, bSlashSlash) {
+ continue
+ }
+ line = bytes.TrimSpace(line[len(bSlashSlash):])
+ if len(line) > 0 && line[0] == '+' {
+ // Looks like a comment +line.
+ f := strings.Fields(string(line))
+ if f[0] == "+build" {
+ sawBuild = true
+ ok := false
+ for _, tok := range f[1:] {
+ if ctxt.match(tok, allTags) {
+ ok = true
+ }
+ }
+ if !ok {
+ shouldBuild = false
+ }
+ }
+ }
+ }
+
+ if goBuild != nil && !sawBuild {
+ return false, false, errGoBuildWithoutBuild
+ }
+
+ return shouldBuild, sawBinaryOnly, nil
+}
+
+func parseFileHeader(content []byte) (trimmed, goBuild []byte, sawBinaryOnly bool, err error) {
+ end := 0
+ p := content
+ ended := false // found non-blank, non-// line, so stopped accepting // +build lines
+ inSlashStar := false // in /* */ comment
+
+Lines:
+ for len(p) > 0 {
+ line := p
+ if i := bytes.IndexByte(line, '\n'); i >= 0 {
+ line, p = line[:i], p[i+1:]
+ } else {
+ p = p[len(p):]
+ }
+ line = bytes.TrimSpace(line)
+ if len(line) == 0 && !ended { // Blank line
+ // Remember position of most recent blank line.
+ // When we find the first non-blank, non-// line,
+ // this "end" position marks the latest file position
+ // where a // +build line can appear.
+ // (It must appear _before_ a blank line before the non-blank, non-// line.
+ // Yes, that's confusing, which is part of why we moved to //go:build lines.)
+ // Note that ended==false here means that inSlashStar==false,
+ // since seeing a /* would have set ended==true.
+ end = len(content) - len(p)
+ continue Lines
+ }
+ if !bytes.HasPrefix(line, slashSlash) { // Not comment line
+ ended = true
+ }
+
+ if !inSlashStar && isGoBuildComment(line) {
+ if false && goBuild != nil { // enabled in Go 1.N
+ return nil, nil, false, errMultipleGoBuild
+ }
+ goBuild = line
+ }
+ if !inSlashStar && bytes.Equal(line, binaryOnlyComment) {
+ sawBinaryOnly = true
+ }
+
+ Comments:
+ for len(line) > 0 {
+ if inSlashStar {
+ if i := bytes.Index(line, starSlash); i >= 0 {
+ inSlashStar = false
+ line = bytes.TrimSpace(line[i+len(starSlash):])
+ continue Comments
+ }
+ continue Lines
+ }
+ if bytes.HasPrefix(line, bSlashSlash) {
+ continue Lines
+ }
+ if bytes.HasPrefix(line, bSlashStar) {
+ inSlashStar = true
+ line = bytes.TrimSpace(line[len(bSlashStar):])
+ continue Comments
+ }
+ // Found non-comment text.
+ break Lines
+ }
+ }
+
+ return content[:end], goBuild, sawBinaryOnly, nil
+}
+
+// saveCgo saves the information from the #cgo lines in the import "C" comment.
+// These lines set CFLAGS, CPPFLAGS, CXXFLAGS and LDFLAGS and pkg-config directives
+// that affect the way cgo's C code is built.
+func (ctxt *Context) saveCgo(filename string, di *Package, cg *ast.CommentGroup) error {
+ text := cg.Text()
+ for _, line := range strings.Split(text, "\n") {
+ orig := line
+
+ // Line is
+ // #cgo [GOOS/GOARCH...] LDFLAGS: stuff
+ //
+ line = strings.TrimSpace(line)
+ if len(line) < 5 || line[:4] != "#cgo" || (line[4] != ' ' && line[4] != '\t') {
+ continue
+ }
+
+ // Split at colon.
+ line = strings.TrimSpace(line[4:])
+ i := strings.Index(line, ":")
+ if i < 0 {
+ return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
+ }
+ line, argstr := line[:i], line[i+1:]
+
+ // Parse GOOS/GOARCH stuff.
+ f := strings.Fields(line)
+ if len(f) < 1 {
+ return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
+ }
+
+ cond, verb := f[:len(f)-1], f[len(f)-1]
+ if len(cond) > 0 {
+ ok := false
+ for _, c := range cond {
+ if ctxt.match(c, nil) {
+ ok = true
+ break
+ }
+ }
+ if !ok {
+ continue
+ }
+ }
+
+ args, err := splitQuoted(argstr)
+ if err != nil {
+ return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
+ }
+ var ok bool
+ for i, arg := range args {
+ if arg, ok = expandSrcDir(arg, di.Dir); !ok {
+ return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
+ }
+ args[i] = arg
+ }
+
+ switch verb {
+ case "CFLAGS", "CPPFLAGS", "CXXFLAGS", "FFLAGS", "LDFLAGS":
+ // Change relative paths to absolute.
+ ctxt.makePathsAbsolute(args, di.Dir)
+ }
+
+ switch verb {
+ case "CFLAGS":
+ di.CgoCFLAGS = append(di.CgoCFLAGS, args...)
+ case "CPPFLAGS":
+ di.CgoCPPFLAGS = append(di.CgoCPPFLAGS, args...)
+ case "CXXFLAGS":
+ di.CgoCXXFLAGS = append(di.CgoCXXFLAGS, args...)
+ case "FFLAGS":
+ di.CgoFFLAGS = append(di.CgoFFLAGS, args...)
+ case "LDFLAGS":
+ di.CgoLDFLAGS = append(di.CgoLDFLAGS, args...)
+ case "pkg-config":
+ di.CgoPkgConfig = append(di.CgoPkgConfig, args...)
+ default:
+ return fmt.Errorf("%s: invalid #cgo verb: %s", filename, orig)
+ }
+ }
+ return nil
+}
+
+// expandSrcDir expands any occurrence of ${SRCDIR}, making sure
+// the result is safe for the shell.
+func expandSrcDir(str string, srcdir string) (string, bool) {
+ // "\" delimited paths cause safeCgoName to fail
+ // so convert native paths with a different delimiter
+ // to "/" before starting (eg: on windows).
+ srcdir = filepath.ToSlash(srcdir)
+
+ chunks := strings.Split(str, "${SRCDIR}")
+ if len(chunks) < 2 {
+ return str, safeCgoName(str)
+ }
+ ok := true
+ for _, chunk := range chunks {
+ ok = ok && (chunk == "" || safeCgoName(chunk))
+ }
+ ok = ok && (srcdir == "" || safeCgoName(srcdir))
+ res := strings.Join(chunks, srcdir)
+ return res, ok && res != ""
+}
+
+// makePathsAbsolute looks for compiler options that take paths and
+// makes them absolute. We do this because through the 1.8 release we
+// ran the compiler in the package directory, so any relative -I or -L
+// options would be relative to that directory. In 1.9 we changed to
+// running the compiler in the build directory, to get consistent
+// build results (issue #19964). To keep builds working, we change any
+// relative -I or -L options to be absolute.
+//
+// Using filepath.IsAbs and filepath.Join here means the results will be
+// different on different systems, but that's OK: -I and -L options are
+// inherently system-dependent.
+func (ctxt *Context) makePathsAbsolute(args []string, srcDir string) {
+ nextPath := false
+ for i, arg := range args {
+ if nextPath {
+ if !filepath.IsAbs(arg) {
+ args[i] = filepath.Join(srcDir, arg)
+ }
+ nextPath = false
+ } else if strings.HasPrefix(arg, "-I") || strings.HasPrefix(arg, "-L") {
+ if len(arg) == 2 {
+ nextPath = true
+ } else {
+ if !filepath.IsAbs(arg[2:]) {
+ args[i] = arg[:2] + filepath.Join(srcDir, arg[2:])
+ }
+ }
+ }
+ }
+}
+
+// NOTE: $ is not safe for the shell, but it is allowed here because of linker options like -Wl,$ORIGIN.
+// We never pass these arguments to a shell (just to programs we construct argv for), so this should be okay.
+// See golang.org/issue/6038.
+// The @ is for OS X. See golang.org/issue/13720.
+// The % is for Jenkins. See golang.org/issue/16959.
+// The ! is because module paths may use them. See golang.org/issue/26716.
+// The ~ and ^ are for sr.ht. See golang.org/issue/32260.
+const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@%! ~^"
+
+func safeCgoName(s string) bool {
+ if s == "" {
+ return false
+ }
+ for i := 0; i < len(s); i++ {
+ if c := s[i]; c < utf8.RuneSelf && strings.IndexByte(safeString, c) < 0 {
+ return false
+ }
+ }
+ return true
+}
+
+// splitQuoted splits the string s around each instance of one or more consecutive
+// white space characters while taking into account quotes and escaping, and
+// returns an array of substrings of s or an empty list if s contains only white space.
+// Single quotes and double quotes are recognized to prevent splitting within the
+// quoted region, and are removed from the resulting substrings. If a quote in s
+// isn't closed err will be set and r will have the unclosed argument as the
+// last element. The backslash is used for escaping.
+//
+// For example, the following string:
+//
+// a b:"c d" 'e''f' "g\""
+//
+// Would be parsed as:
+//
+// []string{"a", "b:c d", "ef", `g"`}
+//
+func splitQuoted(s string) (r []string, err error) {
+ var args []string
+ arg := make([]rune, len(s))
+ escaped := false
+ quoted := false
+ quote := '\x00'
+ i := 0
+ for _, rune := range s {
+ switch {
+ case escaped:
+ escaped = false
+ case rune == '\\':
+ escaped = true
+ continue
+ case quote != '\x00':
+ if rune == quote {
+ quote = '\x00'
+ continue
+ }
+ case rune == '"' || rune == '\'':
+ quoted = true
+ quote = rune
+ continue
+ case unicode.IsSpace(rune):
+ if quoted || i > 0 {
+ quoted = false
+ args = append(args, string(arg[:i]))
+ i = 0
+ }
+ continue
+ }
+ arg[i] = rune
+ i++
+ }
+ if quoted || i > 0 {
+ args = append(args, string(arg[:i]))
+ }
+ if quote != 0 {
+ err = errors.New("unclosed quote")
+ } else if escaped {
+ err = errors.New("unfinished escaping")
+ }
+ return args, err
+}
+
+// match reports whether the name is one of:
+//
+// $GOOS
+// $GOARCH
+// cgo (if cgo is enabled)
+// !cgo (if cgo is disabled)
+// ctxt.Compiler
+// !ctxt.Compiler
+// tag (if tag is listed in ctxt.BuildTags or ctxt.ReleaseTags)
+// !tag (if tag is not listed in ctxt.BuildTags or ctxt.ReleaseTags)
+// a comma-separated list of any of these
+//
+func (ctxt *Context) match(name string, allTags map[string]bool) bool {
+ if name == "" {
+ if allTags != nil {
+ allTags[name] = true
+ }
+ return false
+ }
+ if i := strings.Index(name, ","); i >= 0 {
+ // comma-separated list
+ ok1 := ctxt.match(name[:i], allTags)
+ ok2 := ctxt.match(name[i+1:], allTags)
+ return ok1 && ok2
+ }
+ if strings.HasPrefix(name, "!!") { // bad syntax, reject always
+ return false
+ }
+ if strings.HasPrefix(name, "!") { // negation
+ return len(name) > 1 && !ctxt.match(name[1:], allTags)
+ }
+
+ if allTags != nil {
+ allTags[name] = true
+ }
+
+ // Tags must be letters, digits, underscores or dots.
+ // Unlike in Go identifiers, all digits are fine (e.g., "386").
+ for _, c := range name {
+ if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
+ return false
+ }
+ }
+
+ // special tags
+ if ctxt.CgoEnabled && name == "cgo" {
+ return true
+ }
+ if name == ctxt.GOOS || name == ctxt.GOARCH || name == ctxt.Compiler {
+ return true
+ }
+ if ctxt.GOOS == "android" && name == "linux" {
+ return true
+ }
+ if ctxt.GOOS == "illumos" && name == "solaris" {
+ return true
+ }
+ if ctxt.GOOS == "ios" && name == "darwin" {
+ return true
+ }
+
+ // other tags
+ for _, tag := range ctxt.BuildTags {
+ if tag == name {
+ return true
+ }
+ }
+ for _, tag := range ctxt.ReleaseTags {
+ if tag == name {
+ return true
+ }
+ }
+
+ return false
+}
+
+// goodOSArchFile returns false if the name contains a $GOOS or $GOARCH
+// suffix which does not match the current system.
+// The recognized name formats are:
+//
+// name_$(GOOS).*
+// name_$(GOARCH).*
+// name_$(GOOS)_$(GOARCH).*
+// name_$(GOOS)_test.*
+// name_$(GOARCH)_test.*
+// name_$(GOOS)_$(GOARCH)_test.*
+//
+// Exceptions:
+// if GOOS=android, then files with GOOS=linux are also matched.
+// if GOOS=illumos, then files with GOOS=solaris are also matched.
+// if GOOS=ios, then files with GOOS=darwin are also matched.
+func (ctxt *Context) goodOSArchFile(name string, allTags map[string]bool) bool {
+ if dot := strings.Index(name, "."); dot != -1 {
+ name = name[:dot]
+ }
+
+ // Before Go 1.4, a file called "linux.go" would be equivalent to having a
+ // build tag "linux" in that file. For Go 1.4 and beyond, we require this
+ // auto-tagging to apply only to files with a non-empty prefix, so
+ // "foo_linux.go" is tagged but "linux.go" is not. This allows new operating
+ // systems, such as android, to arrive without breaking existing code with
+ // innocuous source code in "android.go". The easiest fix: cut everything
+ // in the name before the initial _.
+ i := strings.Index(name, "_")
+ if i < 0 {
+ return true
+ }
+ name = name[i:] // ignore everything before first _
+
+ l := strings.Split(name, "_")
+ if n := len(l); n > 0 && l[n-1] == "test" {
+ l = l[:n-1]
+ }
+ n := len(l)
+ if n >= 2 && knownOS[l[n-2]] && knownArch[l[n-1]] {
+ return ctxt.match(l[n-1], allTags) && ctxt.match(l[n-2], allTags)
+ }
+ if n >= 1 && (knownOS[l[n-1]] || knownArch[l[n-1]]) {
+ return ctxt.match(l[n-1], allTags)
+ }
+ return true
+}
+
+var knownOS = make(map[string]bool)
+var knownArch = make(map[string]bool)
+
+func init() {
+ for _, v := range strings.Fields(goosList) {
+ knownOS[v] = true
+ }
+ for _, v := range strings.Fields(goarchList) {
+ knownArch[v] = true
+ }
+}
+
+// ToolDir is the directory containing build tools.
+var ToolDir = getToolDir()
+
+// IsLocalImport reports whether the import path is
+// a local import path, like ".", "..", "./foo", or "../foo".
+func IsLocalImport(path string) bool {
+ return path == "." || path == ".." ||
+ strings.HasPrefix(path, "./") || strings.HasPrefix(path, "../")
+}
+
+// ArchChar returns "?" and an error.
+// In earlier versions of Go, the returned string was used to derive
+// the compiler and linker tool names, the default object file suffix,
+// and the default linker output name. As of Go 1.5, those strings
+// no longer vary by architecture; they are compile, link, .o, and a.out, respectively.
+func ArchChar(goarch string) (string, error) {
+ return "?", errors.New("architecture letter no longer used")
+}
diff --git a/src/go/build/build_test.go b/src/go/build/build_test.go
new file mode 100644
index 0000000..d13ea81
--- /dev/null
+++ b/src/go/build/build_test.go
@@ -0,0 +1,712 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+ "flag"
+ "internal/testenv"
+ "io"
+ "os"
+ "path/filepath"
+ "reflect"
+ "runtime"
+ "strings"
+ "testing"
+)
+
+func TestMain(m *testing.M) {
+ flag.Parse()
+ if goTool, err := testenv.GoTool(); err == nil {
+ os.Setenv("PATH", filepath.Dir(goTool)+string(os.PathListSeparator)+os.Getenv("PATH"))
+ }
+ os.Exit(m.Run())
+}
+
+func TestMatch(t *testing.T) {
+ ctxt := Default
+ what := "default"
+ match := func(tag string, want map[string]bool) {
+ t.Helper()
+ m := make(map[string]bool)
+ if !ctxt.match(tag, m) {
+ t.Errorf("%s context should match %s, does not", what, tag)
+ }
+ if !reflect.DeepEqual(m, want) {
+ t.Errorf("%s tags = %v, want %v", tag, m, want)
+ }
+ }
+ nomatch := func(tag string, want map[string]bool) {
+ t.Helper()
+ m := make(map[string]bool)
+ if ctxt.match(tag, m) {
+ t.Errorf("%s context should NOT match %s, does", what, tag)
+ }
+ if !reflect.DeepEqual(m, want) {
+ t.Errorf("%s tags = %v, want %v", tag, m, want)
+ }
+ }
+
+ match(runtime.GOOS+","+runtime.GOARCH, map[string]bool{runtime.GOOS: true, runtime.GOARCH: true})
+ match(runtime.GOOS+","+runtime.GOARCH+",!foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
+ nomatch(runtime.GOOS+","+runtime.GOARCH+",foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
+
+ what = "modified"
+ ctxt.BuildTags = []string{"foo"}
+ match(runtime.GOOS+","+runtime.GOARCH, map[string]bool{runtime.GOOS: true, runtime.GOARCH: true})
+ match(runtime.GOOS+","+runtime.GOARCH+",foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
+ nomatch(runtime.GOOS+","+runtime.GOARCH+",!foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
+ match(runtime.GOOS+","+runtime.GOARCH+",!bar", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "bar": true})
+ nomatch(runtime.GOOS+","+runtime.GOARCH+",bar", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "bar": true})
+}
+
+func TestDotSlashImport(t *testing.T) {
+ p, err := ImportDir("testdata/other", 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if len(p.Imports) != 1 || p.Imports[0] != "./file" {
+ t.Fatalf("testdata/other: Imports=%v, want [./file]", p.Imports)
+ }
+
+ p1, err := Import("./file", "testdata/other", 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if p1.Name != "file" {
+ t.Fatalf("./file: Name=%q, want %q", p1.Name, "file")
+ }
+ dir := filepath.Clean("testdata/other/file") // Clean to use \ on Windows
+ if p1.Dir != dir {
+ t.Fatalf("./file: Dir=%q, want %q", p1.Name, dir)
+ }
+}
+
+func TestEmptyImport(t *testing.T) {
+ p, err := Import("", Default.GOROOT, FindOnly)
+ if err == nil {
+ t.Fatal(`Import("") returned nil error.`)
+ }
+ if p == nil {
+ t.Fatal(`Import("") returned nil package.`)
+ }
+ if p.ImportPath != "" {
+ t.Fatalf("ImportPath=%q, want %q.", p.ImportPath, "")
+ }
+}
+
+func TestEmptyFolderImport(t *testing.T) {
+ _, err := Import(".", "testdata/empty", 0)
+ if _, ok := err.(*NoGoError); !ok {
+ t.Fatal(`Import("testdata/empty") did not return NoGoError.`)
+ }
+}
+
+func TestMultiplePackageImport(t *testing.T) {
+ _, err := Import(".", "testdata/multi", 0)
+ mpe, ok := err.(*MultiplePackageError)
+ if !ok {
+ t.Fatal(`Import("testdata/multi") did not return MultiplePackageError.`)
+ }
+ want := &MultiplePackageError{
+ Dir: filepath.FromSlash("testdata/multi"),
+ Packages: []string{"main", "test_package"},
+ Files: []string{"file.go", "file_appengine.go"},
+ }
+ if !reflect.DeepEqual(mpe, want) {
+ t.Errorf("got %#v; want %#v", mpe, want)
+ }
+}
+
+func TestLocalDirectory(t *testing.T) {
+ if runtime.GOOS == "ios" {
+ t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
+ }
+
+ cwd, err := os.Getwd()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ p, err := ImportDir(cwd, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if p.ImportPath != "go/build" {
+ t.Fatalf("ImportPath=%q, want %q", p.ImportPath, "go/build")
+ }
+}
+
+var shouldBuildTests = []struct {
+ name string
+ content string
+ tags map[string]bool
+ binaryOnly bool
+ shouldBuild bool
+ err error
+}{
+ {
+ name: "Yes",
+ content: "// +build yes\n\n" +
+ "package main\n",
+ tags: map[string]bool{"yes": true},
+ shouldBuild: true,
+ },
+ {
+ name: "Or",
+ content: "// +build no yes\n\n" +
+ "package main\n",
+ tags: map[string]bool{"yes": true, "no": true},
+ shouldBuild: true,
+ },
+ {
+ name: "And",
+ content: "// +build no,yes\n\n" +
+ "package main\n",
+ tags: map[string]bool{"yes": true, "no": true},
+ shouldBuild: false,
+ },
+ {
+ name: "Cgo",
+ content: "// +build cgo\n\n" +
+ "// Copyright The Go Authors.\n\n" +
+ "// This package implements parsing of tags like\n" +
+ "// +build tag1\n" +
+ "package build",
+ tags: map[string]bool{"cgo": true},
+ shouldBuild: false,
+ },
+ {
+ name: "AfterPackage",
+ content: "// Copyright The Go Authors.\n\n" +
+ "package build\n\n" +
+ "// shouldBuild checks tags given by lines of the form\n" +
+ "// +build tag\n" +
+ "func shouldBuild(content []byte)\n",
+ tags: map[string]bool{},
+ shouldBuild: true,
+ },
+ {
+ name: "TooClose",
+ content: "// +build yes\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: true,
+ },
+ {
+ name: "TooCloseNo",
+ content: "// +build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: true,
+ },
+ {
+ name: "BinaryOnly",
+ content: "//go:binary-only-package\n" +
+ "// +build yes\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ binaryOnly: true,
+ shouldBuild: true,
+ },
+ {
+ name: "ValidGoBuild",
+ content: "// +build yes\n\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{"yes": true},
+ shouldBuild: true,
+ },
+ {
+ name: "MissingBuild",
+ content: "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+ {
+ name: "MissingBuild2",
+ content: "/* */\n" +
+ "// +build yes\n\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+ {
+ name: "MissingBuild2",
+ content: "/*\n" +
+ "// +build yes\n\n" +
+ "*/\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+ {
+ name: "Comment1",
+ content: "/*\n" +
+ "//go:build no\n" +
+ "*/\n\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: true,
+ },
+ {
+ name: "Comment2",
+ content: "/*\n" +
+ "text\n" +
+ "*/\n\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+ {
+ name: "Comment3",
+ content: "/*/*/ /* hi *//* \n" +
+ "text\n" +
+ "*/\n\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+ {
+ name: "Comment4",
+ content: "/**///go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: true,
+ },
+ {
+ name: "Comment5",
+ content: "/**/\n" +
+ "//go:build no\n" +
+ "package main\n",
+ tags: map[string]bool{},
+ shouldBuild: false,
+ err: errGoBuildWithoutBuild,
+ },
+}
+
+func TestShouldBuild(t *testing.T) {
+ for _, tt := range shouldBuildTests {
+ t.Run(tt.name, func(t *testing.T) {
+ ctx := &Context{BuildTags: []string{"yes"}}
+ tags := map[string]bool{}
+ shouldBuild, binaryOnly, err := ctx.shouldBuild([]byte(tt.content), tags)
+ if shouldBuild != tt.shouldBuild || binaryOnly != tt.binaryOnly || !reflect.DeepEqual(tags, tt.tags) || err != tt.err {
+ t.Errorf("mismatch:\n"+
+ "have shouldBuild=%v, binaryOnly=%v, tags=%v, err=%v\n"+
+ "want shouldBuild=%v, binaryOnly=%v, tags=%v, err=%v",
+ shouldBuild, binaryOnly, tags, err,
+ tt.shouldBuild, tt.binaryOnly, tt.tags, tt.err)
+ }
+ })
+ }
+}
+
+func TestGoodOSArchFile(t *testing.T) {
+ ctx := &Context{BuildTags: []string{"linux"}, GOOS: "darwin"}
+ m := map[string]bool{}
+ want := map[string]bool{"linux": true}
+ if !ctx.goodOSArchFile("hello_linux.go", m) {
+ t.Errorf("goodOSArchFile(hello_linux.go) = false, want true")
+ }
+ if !reflect.DeepEqual(m, want) {
+ t.Errorf("goodOSArchFile(hello_linux.go) tags = %v, want %v", m, want)
+ }
+}
+
+type readNopCloser struct {
+ io.Reader
+}
+
+func (r readNopCloser) Close() error {
+ return nil
+}
+
+var (
+ ctxtP9 = Context{GOARCH: "arm", GOOS: "plan9"}
+ ctxtAndroid = Context{GOARCH: "arm", GOOS: "android"}
+)
+
+var matchFileTests = []struct {
+ ctxt Context
+ name string
+ data string
+ match bool
+}{
+ {ctxtP9, "foo_arm.go", "", true},
+ {ctxtP9, "foo1_arm.go", "// +build linux\n\npackage main\n", false},
+ {ctxtP9, "foo_darwin.go", "", false},
+ {ctxtP9, "foo.go", "", true},
+ {ctxtP9, "foo1.go", "// +build linux\n\npackage main\n", false},
+ {ctxtP9, "foo.badsuffix", "", false},
+ {ctxtAndroid, "foo_linux.go", "", true},
+ {ctxtAndroid, "foo_android.go", "", true},
+ {ctxtAndroid, "foo_plan9.go", "", false},
+ {ctxtAndroid, "android.go", "", true},
+ {ctxtAndroid, "plan9.go", "", true},
+ {ctxtAndroid, "plan9_test.go", "", true},
+ {ctxtAndroid, "arm.s", "", true},
+ {ctxtAndroid, "amd64.s", "", true},
+}
+
+func TestMatchFile(t *testing.T) {
+ for _, tt := range matchFileTests {
+ ctxt := tt.ctxt
+ ctxt.OpenFile = func(path string) (r io.ReadCloser, err error) {
+ if path != "x+"+tt.name {
+ t.Fatalf("OpenFile asked for %q, expected %q", path, "x+"+tt.name)
+ }
+ return &readNopCloser{strings.NewReader(tt.data)}, nil
+ }
+ ctxt.JoinPath = func(elem ...string) string {
+ return strings.Join(elem, "+")
+ }
+ match, err := ctxt.MatchFile("x", tt.name)
+ if match != tt.match || err != nil {
+ t.Fatalf("MatchFile(%q) = %v, %v, want %v, nil", tt.name, match, err, tt.match)
+ }
+ }
+}
+
+func TestImportCmd(t *testing.T) {
+ if runtime.GOOS == "ios" {
+ t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
+ }
+
+ p, err := Import("cmd/internal/objfile", "", 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !strings.HasSuffix(filepath.ToSlash(p.Dir), "src/cmd/internal/objfile") {
+ t.Fatalf("Import cmd/internal/objfile returned Dir=%q, want %q", filepath.ToSlash(p.Dir), ".../src/cmd/internal/objfile")
+ }
+}
+
+var (
+ expandSrcDirPath = filepath.Join(string(filepath.Separator)+"projects", "src", "add")
+)
+
+var expandSrcDirTests = []struct {
+ input, expected string
+}{
+ {"-L ${SRCDIR}/libs -ladd", "-L /projects/src/add/libs -ladd"},
+ {"${SRCDIR}/add_linux_386.a -pthread -lstdc++", "/projects/src/add/add_linux_386.a -pthread -lstdc++"},
+ {"Nothing to expand here!", "Nothing to expand here!"},
+ {"$", "$"},
+ {"$$", "$$"},
+ {"${", "${"},
+ {"$}", "$}"},
+ {"$FOO ${BAR}", "$FOO ${BAR}"},
+ {"Find me the $SRCDIRECTORY.", "Find me the $SRCDIRECTORY."},
+ {"$SRCDIR is missing braces", "$SRCDIR is missing braces"},
+}
+
+func TestExpandSrcDir(t *testing.T) {
+ for _, test := range expandSrcDirTests {
+ output, _ := expandSrcDir(test.input, expandSrcDirPath)
+ if output != test.expected {
+ t.Errorf("%q expands to %q with SRCDIR=%q when %q is expected", test.input, output, expandSrcDirPath, test.expected)
+ } else {
+ t.Logf("%q expands to %q with SRCDIR=%q", test.input, output, expandSrcDirPath)
+ }
+ }
+}
+
+func TestShellSafety(t *testing.T) {
+ tests := []struct {
+ input, srcdir, expected string
+ result bool
+ }{
+ {"-I${SRCDIR}/../include", "/projects/src/issue 11868", "-I/projects/src/issue 11868/../include", true},
+ {"-I${SRCDIR}", "~wtf$@%^", "-I~wtf$@%^", true},
+ {"-X${SRCDIR}/1,${SRCDIR}/2", "/projects/src/issue 11868", "-X/projects/src/issue 11868/1,/projects/src/issue 11868/2", true},
+ {"-I/tmp -I/tmp", "/tmp2", "-I/tmp -I/tmp", true},
+ {"-I/tmp", "/tmp/[0]", "-I/tmp", true},
+ {"-I${SRCDIR}/dir", "/tmp/[0]", "-I/tmp/[0]/dir", false},
+ {"-I${SRCDIR}/dir", "/tmp/go go", "-I/tmp/go go/dir", true},
+ {"-I${SRCDIR}/dir dir", "/tmp/go", "-I/tmp/go/dir dir", true},
+ }
+ for _, test := range tests {
+ output, ok := expandSrcDir(test.input, test.srcdir)
+ if ok != test.result {
+ t.Errorf("Expected %t while %q expands to %q with SRCDIR=%q; got %t", test.result, test.input, output, test.srcdir, ok)
+ }
+ if output != test.expected {
+ t.Errorf("Expected %q while %q expands with SRCDIR=%q; got %q", test.expected, test.input, test.srcdir, output)
+ }
+ }
+}
+
+// Want to get a "cannot find package" error when directory for package does not exist.
+// There should be valid partial information in the returned non-nil *Package.
+func TestImportDirNotExist(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // really must just have source
+ ctxt := Default
+
+ emptyDir, err := os.MkdirTemp("", t.Name())
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(emptyDir)
+
+ ctxt.GOPATH = emptyDir
+ ctxt.Dir = emptyDir
+
+ tests := []struct {
+ label string
+ path, srcDir string
+ mode ImportMode
+ }{
+ {"Import(full, 0)", "go/build/doesnotexist", "", 0},
+ {"Import(local, 0)", "./doesnotexist", filepath.Join(ctxt.GOROOT, "src/go/build"), 0},
+ {"Import(full, FindOnly)", "go/build/doesnotexist", "", FindOnly},
+ {"Import(local, FindOnly)", "./doesnotexist", filepath.Join(ctxt.GOROOT, "src/go/build"), FindOnly},
+ }
+
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+
+ for _, GO111MODULE := range []string{"off", "on"} {
+ t.Run("GO111MODULE="+GO111MODULE, func(t *testing.T) {
+ os.Setenv("GO111MODULE", GO111MODULE)
+
+ for _, test := range tests {
+ p, err := ctxt.Import(test.path, test.srcDir, test.mode)
+
+ errOk := (err != nil && strings.HasPrefix(err.Error(), "cannot find package"))
+ wantErr := `"cannot find package" error`
+ if test.srcDir == "" {
+ if err != nil && strings.Contains(err.Error(), "is not in GOROOT") {
+ errOk = true
+ }
+ wantErr = `"cannot find package" or "is not in GOROOT" error`
+ }
+ if !errOk {
+ t.Errorf("%s got error: %q, want %s", test.label, err, wantErr)
+ }
+ // If an error occurs, build.Import is documented to return
+ // a non-nil *Package containing partial information.
+ if p == nil {
+ t.Fatalf(`%s got nil p, want non-nil *Package`, test.label)
+ }
+ // Verify partial information in p.
+ if p.ImportPath != "go/build/doesnotexist" {
+ t.Errorf(`%s got p.ImportPath: %q, want "go/build/doesnotexist"`, test.label, p.ImportPath)
+ }
+ }
+ })
+ }
+}
+
+func TestImportVendor(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // really must just have source
+
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+ os.Setenv("GO111MODULE", "off")
+
+ ctxt := Default
+ wd, err := os.Getwd()
+ if err != nil {
+ t.Fatal(err)
+ }
+ ctxt.GOPATH = filepath.Join(wd, "testdata/withvendor")
+ p, err := ctxt.Import("c/d", filepath.Join(ctxt.GOPATH, "src/a/b"), 0)
+ if err != nil {
+ t.Fatalf("cannot find vendored c/d from testdata src/a/b directory: %v", err)
+ }
+ want := "a/vendor/c/d"
+ if p.ImportPath != want {
+ t.Fatalf("Import succeeded but found %q, want %q", p.ImportPath, want)
+ }
+}
+
+func TestImportVendorFailure(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // really must just have source
+
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+ os.Setenv("GO111MODULE", "off")
+
+ ctxt := Default
+ wd, err := os.Getwd()
+ if err != nil {
+ t.Fatal(err)
+ }
+ ctxt.GOPATH = filepath.Join(wd, "testdata/withvendor")
+ p, err := ctxt.Import("x.com/y/z", filepath.Join(ctxt.GOPATH, "src/a/b"), 0)
+ if err == nil {
+ t.Fatalf("found made-up package x.com/y/z in %s", p.Dir)
+ }
+
+ e := err.Error()
+ if !strings.Contains(e, " (vendor tree)") {
+ t.Fatalf("error on failed import does not mention GOROOT/src/vendor directory:\n%s", e)
+ }
+}
+
+func TestImportVendorParentFailure(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // really must just have source
+
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+ os.Setenv("GO111MODULE", "off")
+
+ ctxt := Default
+ wd, err := os.Getwd()
+ if err != nil {
+ t.Fatal(err)
+ }
+ ctxt.GOPATH = filepath.Join(wd, "testdata/withvendor")
+ // This import should fail because the vendor/c directory has no source code.
+ p, err := ctxt.Import("c", filepath.Join(ctxt.GOPATH, "src/a/b"), 0)
+ if err == nil {
+ t.Fatalf("found empty parent in %s", p.Dir)
+ }
+ if p != nil && p.Dir != "" {
+ t.Fatalf("decided to use %s", p.Dir)
+ }
+ e := err.Error()
+ if !strings.Contains(e, " (vendor tree)") {
+ t.Fatalf("error on failed import does not mention GOROOT/src/vendor directory:\n%s", e)
+ }
+}
+
+// Check that a package is loaded in module mode if GO111MODULE=on, even when
+// no go.mod file is present. It should fail to resolve packages outside std.
+// Verifies golang.org/issue/34669.
+func TestImportPackageOutsideModule(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ // Disable module fetching for this test so that 'go list' fails quickly
+ // without trying to find the latest version of a module.
+ defer os.Setenv("GOPROXY", os.Getenv("GOPROXY"))
+ os.Setenv("GOPROXY", "off")
+
+ // Create a GOPATH in a temporary directory. We don't use testdata
+ // because it's in GOROOT, which interferes with the module heuristic.
+ gopath, err := os.MkdirTemp("", "gobuild-notmodule")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(gopath)
+ if err := os.MkdirAll(filepath.Join(gopath, "src/example.com/p"), 0777); err != nil {
+ t.Fatal(err)
+ }
+ if err := os.WriteFile(filepath.Join(gopath, "src/example.com/p/p.go"), []byte("package p"), 0666); err != nil {
+ t.Fatal(err)
+ }
+
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+ os.Setenv("GO111MODULE", "on")
+ defer os.Setenv("GOPATH", os.Getenv("GOPATH"))
+ os.Setenv("GOPATH", gopath)
+ ctxt := Default
+ ctxt.GOPATH = gopath
+ ctxt.Dir = filepath.Join(gopath, "src/example.com/p")
+
+ want := "go.mod file not found in current directory or any parent directory"
+ if _, err := ctxt.Import("example.com/p", gopath, FindOnly); err == nil {
+ t.Fatal("importing package when no go.mod is present succeeded unexpectedly")
+ } else if errStr := err.Error(); !strings.Contains(errStr, want) {
+ t.Fatalf("error when importing package when no go.mod is present: got %q; want %q", errStr, want)
+ } else {
+ t.Logf(`ctxt.Import("example.com/p", _, FindOnly): %v`, err)
+ }
+}
+
+func TestImportDirTarget(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // really must just have source
+ ctxt := Default
+ ctxt.GOPATH = ""
+ p, err := ctxt.ImportDir(filepath.Join(ctxt.GOROOT, "src/path"), 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if p.PkgTargetRoot == "" || p.PkgObj == "" {
+ t.Errorf("p.PkgTargetRoot == %q, p.PkgObj == %q, want non-empty", p.PkgTargetRoot, p.PkgObj)
+ }
+}
+
+// TestIssue23594 prevents go/build from regressing and populating Package.Doc
+// from comments in test files.
+func TestIssue23594(t *testing.T) {
+ // Package testdata/doc contains regular and external test files
+ // with comments attached to their package declarations. The names of the files
+ // ensure that we see the comments from the test files first.
+ p, err := ImportDir("testdata/doc", 0)
+ if err != nil {
+ t.Fatalf("could not import testdata: %v", err)
+ }
+
+ if p.Doc != "Correct" {
+ t.Fatalf("incorrectly set .Doc to %q", p.Doc)
+ }
+}
+
+// TestMissingImportErrorRepetition checks that when an unknown package is
+// imported, the package path is only shown once in the error.
+// Verifies golang.org/issue/34752.
+func TestMissingImportErrorRepetition(t *testing.T) {
+ testenv.MustHaveGoBuild(t) // need 'go list' internally
+ tmp, err := os.MkdirTemp("", "")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(tmp)
+ if err := os.WriteFile(filepath.Join(tmp, "go.mod"), []byte("module m"), 0666); err != nil {
+ t.Fatal(err)
+ }
+ defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
+ os.Setenv("GO111MODULE", "on")
+ defer os.Setenv("GOPROXY", os.Getenv("GOPROXY"))
+ os.Setenv("GOPROXY", "off")
+ defer os.Setenv("GONOPROXY", os.Getenv("GONOPROXY"))
+ os.Setenv("GONOPROXY", "none")
+
+ ctxt := Default
+ ctxt.Dir = tmp
+
+ pkgPath := "example.com/hello"
+ _, err = ctxt.Import(pkgPath, tmp, FindOnly)
+ if err == nil {
+ t.Fatal("unexpected success")
+ }
+
+ // Don't count the package path with a URL like https://...?go-get=1.
+ // See golang.org/issue/35986.
+ errStr := strings.ReplaceAll(err.Error(), "://"+pkgPath+"?go-get=1", "://...?go-get=1")
+
+ // Also don't count instances in suggested "go get" or similar commands
+ // (see https://golang.org/issue/41576). The suggested command typically
+ // follows a semicolon.
+ errStr = strings.SplitN(errStr, ";", 2)[0]
+
+ if n := strings.Count(errStr, pkgPath); n != 1 {
+ t.Fatalf("package path %q appears in error %d times; should appear once\nerror: %v", pkgPath, n, err)
+ }
+}
+
+// TestCgoImportsIgnored checks that imports in cgo files are not included
+// in the imports list when cgo is disabled.
+// Verifies golang.org/issue/35946.
+func TestCgoImportsIgnored(t *testing.T) {
+ ctxt := Default
+ ctxt.CgoEnabled = false
+ p, err := ctxt.ImportDir("testdata/cgo_disabled", 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for _, path := range p.Imports {
+ if path == "should/be/ignored" {
+ t.Errorf("found import %q in ignored cgo file", path)
+ }
+ }
+}
diff --git a/src/go/build/constraint/expr.go b/src/go/build/constraint/expr.go
new file mode 100644
index 0000000..3b27870
--- /dev/null
+++ b/src/go/build/constraint/expr.go
@@ -0,0 +1,574 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package constraint implements parsing and evaluation of build constraint lines.
+// See https://golang.org/cmd/go/#hdr-Build_constraints for documentation about build constraints themselves.
+//
+// This package parses both the original “// +build” syntax and the “//go:build” syntax that will be added in Go 1.17.
+// The parser is being included in Go 1.16 to allow tools that need to process Go 1.17 source code
+// to still be built against the Go 1.16 release.
+// See https://golang.org/design/draft-gobuild for details about the “//go:build” syntax.
+package constraint
+
+import (
+ "errors"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+// An Expr is a build tag constraint expression.
+// The underlying concrete type is *AndExpr, *OrExpr, *NotExpr, or *TagExpr.
+type Expr interface {
+ // String returns the string form of the expression,
+ // using the boolean syntax used in //go:build lines.
+ String() string
+
+ // Eval reports whether the expression evaluates to true.
+ // It calls ok(tag) as needed to find out whether a given build tag
+ // is satisfied by the current build configuration.
+ Eval(ok func(tag string) bool) bool
+
+ // The presence of an isExpr method explicitly marks the type as an Expr.
+ // Only implementations in this package should be used as Exprs.
+ isExpr()
+}
+
+// A TagExpr is an Expr for the single tag Tag.
+type TagExpr struct {
+ Tag string // for example, “linux” or “cgo”
+}
+
+func (x *TagExpr) isExpr() {}
+
+func (x *TagExpr) Eval(ok func(tag string) bool) bool {
+ return ok(x.Tag)
+}
+
+func (x *TagExpr) String() string {
+ return x.Tag
+}
+
+func tag(tag string) Expr { return &TagExpr{tag} }
+
+// A NotExpr represents the expression !X (the negation of X).
+type NotExpr struct {
+ X Expr
+}
+
+func (x *NotExpr) isExpr() {}
+
+func (x *NotExpr) Eval(ok func(tag string) bool) bool {
+ return !x.X.Eval(ok)
+}
+
+func (x *NotExpr) String() string {
+ s := x.X.String()
+ switch x.X.(type) {
+ case *AndExpr, *OrExpr:
+ s = "(" + s + ")"
+ }
+ return "!" + s
+}
+
+func not(x Expr) Expr { return &NotExpr{x} }
+
+// An AndExpr represents the expression X && Y.
+type AndExpr struct {
+ X, Y Expr
+}
+
+func (x *AndExpr) isExpr() {}
+
+func (x *AndExpr) Eval(ok func(tag string) bool) bool {
+ // Note: Eval both, to make sure ok func observes all tags.
+ xok := x.X.Eval(ok)
+ yok := x.Y.Eval(ok)
+ return xok && yok
+}
+
+func (x *AndExpr) String() string {
+ return andArg(x.X) + " && " + andArg(x.Y)
+}
+
+func andArg(x Expr) string {
+ s := x.String()
+ if _, ok := x.(*OrExpr); ok {
+ s = "(" + s + ")"
+ }
+ return s
+}
+
+func and(x, y Expr) Expr {
+ return &AndExpr{x, y}
+}
+
+// An OrExpr represents the expression X || Y.
+type OrExpr struct {
+ X, Y Expr
+}
+
+func (x *OrExpr) isExpr() {}
+
+func (x *OrExpr) Eval(ok func(tag string) bool) bool {
+ // Note: Eval both, to make sure ok func observes all tags.
+ xok := x.X.Eval(ok)
+ yok := x.Y.Eval(ok)
+ return xok || yok
+}
+
+func (x *OrExpr) String() string {
+ return orArg(x.X) + " || " + orArg(x.Y)
+}
+
+func orArg(x Expr) string {
+ s := x.String()
+ if _, ok := x.(*AndExpr); ok {
+ s = "(" + s + ")"
+ }
+ return s
+}
+
+func or(x, y Expr) Expr {
+ return &OrExpr{x, y}
+}
+
+// A SyntaxError reports a syntax error in a parsed build expression.
+type SyntaxError struct {
+ Offset int // byte offset in input where error was detected
+ Err string // description of error
+}
+
+func (e *SyntaxError) Error() string {
+ return e.Err
+}
+
+var errNotConstraint = errors.New("not a build constraint")
+
+// Parse parses a single build constraint line of the form “//go:build ...” or “// +build ...”
+// and returns the corresponding boolean expression.
+func Parse(line string) (Expr, error) {
+ if text, ok := splitGoBuild(line); ok {
+ return parseExpr(text)
+ }
+ if text, ok := splitPlusBuild(line); ok {
+ return parsePlusBuildExpr(text), nil
+ }
+ return nil, errNotConstraint
+}
+
+// IsGoBuild reports whether the line of text is a “//go:build” constraint.
+// It only checks the prefix of the text, not that the expression itself parses.
+func IsGoBuild(line string) bool {
+ _, ok := splitGoBuild(line)
+ return ok
+}
+
+// splitGoBuild splits apart the leading //go:build prefix in line from the build expression itself.
+// It returns "", false if the input is not a //go:build line or if the input contains multiple lines.
+func splitGoBuild(line string) (expr string, ok bool) {
+ // A single trailing newline is OK; otherwise multiple lines are not.
+ if len(line) > 0 && line[len(line)-1] == '\n' {
+ line = line[:len(line)-1]
+ }
+ if strings.Contains(line, "\n") {
+ return "", false
+ }
+
+ if !strings.HasPrefix(line, "//go:build") {
+ return "", false
+ }
+
+ line = strings.TrimSpace(line)
+ line = line[len("//go:build"):]
+
+ // If strings.TrimSpace finds more to trim after removing the //go:build prefix,
+ // it means that the prefix was followed by a space, making this a //go:build line
+ // (as opposed to a //go:buildsomethingelse line).
+ // If line is empty, we had "//go:build" by itself, which also counts.
+ trim := strings.TrimSpace(line)
+ if len(line) == len(trim) && line != "" {
+ return "", false
+ }
+
+ return trim, true
+}
+
+// An exprParser holds state for parsing a build expression.
+type exprParser struct {
+ s string // input string
+ i int // next read location in s
+
+ tok string // last token read
+ isTag bool
+ pos int // position (start) of last token
+}
+
+// parseExpr parses a boolean build tag expression.
+func parseExpr(text string) (x Expr, err error) {
+ defer func() {
+ if e := recover(); e != nil {
+ if e, ok := e.(*SyntaxError); ok {
+ err = e
+ return
+ }
+ panic(e) // unreachable unless parser has a bug
+ }
+ }()
+
+ p := &exprParser{s: text}
+ x = p.or()
+ if p.tok != "" {
+ panic(&SyntaxError{Offset: p.pos, Err: "unexpected token " + p.tok})
+ }
+ return x, nil
+}
+
+// or parses a sequence of || expressions.
+// On entry, the next input token has not yet been lexed.
+// On exit, the next input token has been lexed and is in p.tok.
+func (p *exprParser) or() Expr {
+ x := p.and()
+ for p.tok == "||" {
+ x = or(x, p.and())
+ }
+ return x
+}
+
+// and parses a sequence of && expressions.
+// On entry, the next input token has not yet been lexed.
+// On exit, the next input token has been lexed and is in p.tok.
+func (p *exprParser) and() Expr {
+ x := p.not()
+ for p.tok == "&&" {
+ x = and(x, p.not())
+ }
+ return x
+}
+
+// not parses a ! expression.
+// On entry, the next input token has not yet been lexed.
+// On exit, the next input token has been lexed and is in p.tok.
+func (p *exprParser) not() Expr {
+ p.lex()
+ if p.tok == "!" {
+ p.lex()
+ if p.tok == "!" {
+ panic(&SyntaxError{Offset: p.pos, Err: "double negation not allowed"})
+ }
+ return not(p.atom())
+ }
+ return p.atom()
+}
+
+// atom parses a tag or a parenthesized expression.
+// On entry, the next input token HAS been lexed.
+// On exit, the next input token has been lexed and is in p.tok.
+func (p *exprParser) atom() Expr {
+ // first token already in p.tok
+ if p.tok == "(" {
+ pos := p.pos
+ defer func() {
+ if e := recover(); e != nil {
+ if e, ok := e.(*SyntaxError); ok && e.Err == "unexpected end of expression" {
+ e.Err = "missing close paren"
+ }
+ panic(e)
+ }
+ }()
+ x := p.or()
+ if p.tok != ")" {
+ panic(&SyntaxError{Offset: pos, Err: "missing close paren"})
+ }
+ p.lex()
+ return x
+ }
+
+ if !p.isTag {
+ if p.tok == "" {
+ panic(&SyntaxError{Offset: p.pos, Err: "unexpected end of expression"})
+ }
+ panic(&SyntaxError{Offset: p.pos, Err: "unexpected token " + p.tok})
+ }
+ tok := p.tok
+ p.lex()
+ return tag(tok)
+}
+
+// lex finds and consumes the next token in the input stream.
+// On return, p.tok is set to the token text,
+// p.isTag reports whether the token was a tag,
+// and p.pos records the byte offset of the start of the token in the input stream.
+// If lex reaches the end of the input, p.tok is set to the empty string.
+// For any other syntax error, lex panics with a SyntaxError.
+func (p *exprParser) lex() {
+ p.isTag = false
+ for p.i < len(p.s) && (p.s[p.i] == ' ' || p.s[p.i] == '\t') {
+ p.i++
+ }
+ if p.i >= len(p.s) {
+ p.tok = ""
+ p.pos = p.i
+ return
+ }
+ switch p.s[p.i] {
+ case '(', ')', '!':
+ p.pos = p.i
+ p.i++
+ p.tok = p.s[p.pos:p.i]
+ return
+
+ case '&', '|':
+ if p.i+1 >= len(p.s) || p.s[p.i+1] != p.s[p.i] {
+ panic(&SyntaxError{Offset: p.i, Err: "invalid syntax at " + string(rune(p.s[p.i]))})
+ }
+ p.pos = p.i
+ p.i += 2
+ p.tok = p.s[p.pos:p.i]
+ return
+ }
+
+ tag := p.s[p.i:]
+ for i, c := range tag {
+ if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
+ tag = tag[:i]
+ break
+ }
+ }
+ if tag == "" {
+ c, _ := utf8.DecodeRuneInString(p.s[p.i:])
+ panic(&SyntaxError{Offset: p.i, Err: "invalid syntax at " + string(c)})
+ }
+
+ p.pos = p.i
+ p.i += len(tag)
+ p.tok = p.s[p.pos:p.i]
+ p.isTag = true
+ return
+}
+
+// IsPlusBuild reports whether the line of text is a “// +build” constraint.
+// It only checks the prefix of the text, not that the expression itself parses.
+func IsPlusBuild(line string) bool {
+ _, ok := splitPlusBuild(line)
+ return ok
+}
+
+// splitGoBuild splits apart the leading //go:build prefix in line from the build expression itself.
+// It returns "", false if the input is not a //go:build line or if the input contains multiple lines.
+func splitPlusBuild(line string) (expr string, ok bool) {
+ // A single trailing newline is OK; otherwise multiple lines are not.
+ if len(line) > 0 && line[len(line)-1] == '\n' {
+ line = line[:len(line)-1]
+ }
+ if strings.Contains(line, "\n") {
+ return "", false
+ }
+
+ if !strings.HasPrefix(line, "//") {
+ return "", false
+ }
+ line = line[len("//"):]
+ // Note the space is optional; "//+build" is recognized too.
+ line = strings.TrimSpace(line)
+
+ if !strings.HasPrefix(line, "+build") {
+ return "", false
+ }
+ line = line[len("+build"):]
+
+ // If strings.TrimSpace finds more to trim after removing the +build prefix,
+ // it means that the prefix was followed by a space, making this a +build line
+ // (as opposed to a +buildsomethingelse line).
+ // If line is empty, we had "// +build" by itself, which also counts.
+ trim := strings.TrimSpace(line)
+ if len(line) == len(trim) && line != "" {
+ return "", false
+ }
+
+ return trim, true
+}
+
+// parsePlusBuildExpr parses a legacy build tag expression (as used with “// +build”).
+func parsePlusBuildExpr(text string) Expr {
+ var x Expr
+ for _, clause := range strings.Fields(text) {
+ var y Expr
+ for _, lit := range strings.Split(clause, ",") {
+ var z Expr
+ var neg bool
+ if strings.HasPrefix(lit, "!!") || lit == "!" {
+ z = tag("ignore")
+ } else {
+ if strings.HasPrefix(lit, "!") {
+ neg = true
+ lit = lit[len("!"):]
+ }
+ if isValidTag(lit) {
+ z = tag(lit)
+ } else {
+ z = tag("ignore")
+ }
+ if neg {
+ z = not(z)
+ }
+ }
+ if y == nil {
+ y = z
+ } else {
+ y = and(y, z)
+ }
+ }
+ if x == nil {
+ x = y
+ } else {
+ x = or(x, y)
+ }
+ }
+ return x
+}
+
+// isValidTag reports whether the word is a valid build tag.
+// Tags must be letters, digits, underscores or dots.
+// Unlike in Go identifiers, all digits are fine (e.g., "386").
+func isValidTag(word string) bool {
+ if word == "" {
+ return false
+ }
+ for _, c := range word {
+ if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
+ return false
+ }
+ }
+ return true
+}
+
+var errComplex = errors.New("expression too complex for // +build lines")
+
+// PlusBuildLines returns a sequence of “// +build” lines that evaluate to the build expression x.
+// If the expression is too complex to convert directly to “// +build” lines, PlusBuildLines returns an error.
+func PlusBuildLines(x Expr) ([]string, error) {
+ // Push all NOTs to the expression leaves, so that //go:build !(x && y) can be treated as !x || !y.
+ // This rewrite is both efficient and commonly needed, so it's worth doing.
+ // Essentially all other possible rewrites are too expensive and too rarely needed.
+ x = pushNot(x, false)
+
+ // Split into AND of ORs of ANDs of literals (tag or NOT tag).
+ var split [][][]Expr
+ for _, or := range appendSplitAnd(nil, x) {
+ var ands [][]Expr
+ for _, and := range appendSplitOr(nil, or) {
+ var lits []Expr
+ for _, lit := range appendSplitAnd(nil, and) {
+ switch lit.(type) {
+ case *TagExpr, *NotExpr:
+ lits = append(lits, lit)
+ default:
+ return nil, errComplex
+ }
+ }
+ ands = append(ands, lits)
+ }
+ split = append(split, ands)
+ }
+
+ // If all the ORs have length 1 (no actual OR'ing going on),
+ // push the top-level ANDs to the bottom level, so that we get
+ // one // +build line instead of many.
+ maxOr := 0
+ for _, or := range split {
+ if maxOr < len(or) {
+ maxOr = len(or)
+ }
+ }
+ if maxOr == 1 {
+ var lits []Expr
+ for _, or := range split {
+ lits = append(lits, or[0]...)
+ }
+ split = [][][]Expr{{lits}}
+ }
+
+ // Prepare the +build lines.
+ var lines []string
+ for _, or := range split {
+ line := "// +build"
+ for _, and := range or {
+ clause := ""
+ for i, lit := range and {
+ if i > 0 {
+ clause += ","
+ }
+ clause += lit.String()
+ }
+ line += " " + clause
+ }
+ lines = append(lines, line)
+ }
+
+ return lines, nil
+}
+
+// pushNot applies DeMorgan's law to push negations down the expression,
+// so that only tags are negated in the result.
+// (It applies the rewrites !(X && Y) => (!X || !Y) and !(X || Y) => (!X && !Y).)
+func pushNot(x Expr, not bool) Expr {
+ switch x := x.(type) {
+ default:
+ // unreachable
+ return x
+ case *NotExpr:
+ if _, ok := x.X.(*TagExpr); ok && !not {
+ return x
+ }
+ return pushNot(x.X, !not)
+ case *TagExpr:
+ if not {
+ return &NotExpr{X: x}
+ }
+ return x
+ case *AndExpr:
+ x1 := pushNot(x.X, not)
+ y1 := pushNot(x.Y, not)
+ if not {
+ return or(x1, y1)
+ }
+ if x1 == x.X && y1 == x.Y {
+ return x
+ }
+ return and(x1, y1)
+ case *OrExpr:
+ x1 := pushNot(x.X, not)
+ y1 := pushNot(x.Y, not)
+ if not {
+ return and(x1, y1)
+ }
+ if x1 == x.X && y1 == x.Y {
+ return x
+ }
+ return or(x1, y1)
+ }
+}
+
+// appendSplitAnd appends x to list while splitting apart any top-level && expressions.
+// For example, appendSplitAnd({W}, X && Y && Z) = {W, X, Y, Z}.
+func appendSplitAnd(list []Expr, x Expr) []Expr {
+ if x, ok := x.(*AndExpr); ok {
+ list = appendSplitAnd(list, x.X)
+ list = appendSplitAnd(list, x.Y)
+ return list
+ }
+ return append(list, x)
+}
+
+// appendSplitOr appends x to list while splitting apart any top-level || expressions.
+// For example, appendSplitOr({W}, X || Y || Z) = {W, X, Y, Z}.
+func appendSplitOr(list []Expr, x Expr) []Expr {
+ if x, ok := x.(*OrExpr); ok {
+ list = appendSplitOr(list, x.X)
+ list = appendSplitOr(list, x.Y)
+ return list
+ }
+ return append(list, x)
+}
diff --git a/src/go/build/constraint/expr_test.go b/src/go/build/constraint/expr_test.go
new file mode 100644
index 0000000..4979f8b
--- /dev/null
+++ b/src/go/build/constraint/expr_test.go
@@ -0,0 +1,317 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package constraint
+
+import (
+ "fmt"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+var exprStringTests = []struct {
+ x Expr
+ out string
+}{
+ {
+ x: tag("abc"),
+ out: "abc",
+ },
+ {
+ x: not(tag("abc")),
+ out: "!abc",
+ },
+ {
+ x: not(and(tag("abc"), tag("def"))),
+ out: "!(abc && def)",
+ },
+ {
+ x: and(tag("abc"), or(tag("def"), tag("ghi"))),
+ out: "abc && (def || ghi)",
+ },
+ {
+ x: or(and(tag("abc"), tag("def")), tag("ghi")),
+ out: "(abc && def) || ghi",
+ },
+}
+
+func TestExprString(t *testing.T) {
+ for i, tt := range exprStringTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ s := tt.x.String()
+ if s != tt.out {
+ t.Errorf("String() mismatch:\nhave %s\nwant %s", s, tt.out)
+ }
+ })
+ }
+}
+
+var lexTests = []struct {
+ in string
+ out string
+}{
+ {"", ""},
+ {"x", "x"},
+ {"x.y", "x.y"},
+ {"x_y", "x_y"},
+ {"αx", "αx"},
+ {"αx²", "αx err: invalid syntax at ²"},
+ {"go1.2", "go1.2"},
+ {"x y", "x y"},
+ {"x!y", "x ! y"},
+ {"&&||!()xy yx ", "&& || ! ( ) xy yx"},
+ {"x~", "x err: invalid syntax at ~"},
+ {"x ~", "x err: invalid syntax at ~"},
+ {"x &", "x err: invalid syntax at &"},
+ {"x &y", "x err: invalid syntax at &"},
+}
+
+func TestLex(t *testing.T) {
+ for i, tt := range lexTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ p := &exprParser{s: tt.in}
+ out := ""
+ for {
+ tok, err := lexHelp(p)
+ if tok == "" && err == nil {
+ break
+ }
+ if out != "" {
+ out += " "
+ }
+ if err != nil {
+ out += "err: " + err.Error()
+ break
+ }
+ out += tok
+ }
+ if out != tt.out {
+ t.Errorf("lex(%q):\nhave %s\nwant %s", tt.in, out, tt.out)
+ }
+ })
+ }
+}
+
+func lexHelp(p *exprParser) (tok string, err error) {
+ defer func() {
+ if e := recover(); e != nil {
+ if e, ok := e.(*SyntaxError); ok {
+ err = e
+ return
+ }
+ panic(e)
+ }
+ }()
+
+ p.lex()
+ return p.tok, nil
+}
+
+var parseExprTests = []struct {
+ in string
+ x Expr
+}{
+ {"x", tag("x")},
+ {"x&&y", and(tag("x"), tag("y"))},
+ {"x||y", or(tag("x"), tag("y"))},
+ {"(x)", tag("x")},
+ {"x||y&&z", or(tag("x"), and(tag("y"), tag("z")))},
+ {"x&&y||z", or(and(tag("x"), tag("y")), tag("z"))},
+ {"x&&(y||z)", and(tag("x"), or(tag("y"), tag("z")))},
+ {"(x||y)&&z", and(or(tag("x"), tag("y")), tag("z"))},
+ {"!(x&&y)", not(and(tag("x"), tag("y")))},
+}
+
+func TestParseExpr(t *testing.T) {
+ for i, tt := range parseExprTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x, err := parseExpr(tt.in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if x.String() != tt.x.String() {
+ t.Errorf("parseExpr(%q):\nhave %s\nwant %s", tt.in, x, tt.x)
+ }
+ })
+ }
+}
+
+var parseExprErrorTests = []struct {
+ in string
+ err error
+}{
+ {"x && ", &SyntaxError{Offset: 5, Err: "unexpected end of expression"}},
+ {"x && (", &SyntaxError{Offset: 6, Err: "missing close paren"}},
+ {"x && ||", &SyntaxError{Offset: 5, Err: "unexpected token ||"}},
+ {"x && !", &SyntaxError{Offset: 6, Err: "unexpected end of expression"}},
+ {"x && !!", &SyntaxError{Offset: 6, Err: "double negation not allowed"}},
+ {"x !", &SyntaxError{Offset: 2, Err: "unexpected token !"}},
+ {"x && (y", &SyntaxError{Offset: 5, Err: "missing close paren"}},
+}
+
+func TestParseError(t *testing.T) {
+ for i, tt := range parseExprErrorTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x, err := parseExpr(tt.in)
+ if err == nil {
+ t.Fatalf("parseExpr(%q) = %v, want error", tt.in, x)
+ }
+ if !reflect.DeepEqual(err, tt.err) {
+ t.Fatalf("parseExpr(%q): wrong error:\nhave %#v\nwant %#v", tt.in, err, tt.err)
+ }
+ })
+ }
+}
+
+var exprEvalTests = []struct {
+ in string
+ ok bool
+ tags string
+}{
+ {"x", false, "x"},
+ {"x && y", false, "x y"},
+ {"x || y", false, "x y"},
+ {"!x && yes", true, "x yes"},
+ {"yes || y", true, "y yes"},
+}
+
+func TestExprEval(t *testing.T) {
+ for i, tt := range exprEvalTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x, err := parseExpr(tt.in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ tags := make(map[string]bool)
+ wantTags := make(map[string]bool)
+ for _, tag := range strings.Fields(tt.tags) {
+ wantTags[tag] = true
+ }
+ hasTag := func(tag string) bool {
+ tags[tag] = true
+ return tag == "yes"
+ }
+ ok := x.Eval(hasTag)
+ if ok != tt.ok || !reflect.DeepEqual(tags, wantTags) {
+ t.Errorf("Eval(%#q):\nhave ok=%v, tags=%v\nwant ok=%v, tags=%v",
+ tt.in, ok, tags, tt.ok, wantTags)
+ }
+ })
+ }
+}
+
+var parsePlusBuildExprTests = []struct {
+ in string
+ x Expr
+}{
+ {"x", tag("x")},
+ {"x,y", and(tag("x"), tag("y"))},
+ {"x y", or(tag("x"), tag("y"))},
+ {"x y,z", or(tag("x"), and(tag("y"), tag("z")))},
+ {"x,y z", or(and(tag("x"), tag("y")), tag("z"))},
+ {"x,!y !z", or(and(tag("x"), not(tag("y"))), not(tag("z")))},
+ {"!! x", or(tag("ignore"), tag("x"))},
+ {"!!x", tag("ignore")},
+ {"!x", not(tag("x"))},
+ {"!", tag("ignore")},
+}
+
+func TestParsePlusBuildExpr(t *testing.T) {
+ for i, tt := range parsePlusBuildExprTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x := parsePlusBuildExpr(tt.in)
+ if x.String() != tt.x.String() {
+ t.Errorf("parsePlusBuildExpr(%q):\nhave %v\nwant %v", tt.in, x, tt.x)
+ }
+ })
+ }
+}
+
+var constraintTests = []struct {
+ in string
+ x Expr
+ err error
+}{
+ {"//+build x y", or(tag("x"), tag("y")), nil},
+ {"// +build x y \n", or(tag("x"), tag("y")), nil},
+ {"// +build x y \n ", nil, errNotConstraint},
+ {"// +build x y \nmore", nil, errNotConstraint},
+ {" //+build x y", nil, errNotConstraint},
+
+ {"//go:build x && y", and(tag("x"), tag("y")), nil},
+ {"//go:build x && y\n", and(tag("x"), tag("y")), nil},
+ {"//go:build x && y\n ", nil, errNotConstraint},
+ {"//go:build x && y\nmore", nil, errNotConstraint},
+ {" //go:build x && y", nil, errNotConstraint},
+}
+
+func TestParse(t *testing.T) {
+ for i, tt := range constraintTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x, err := Parse(tt.in)
+ if err != nil {
+ if tt.err == nil {
+ t.Errorf("Constraint(%q): unexpected error: %v", tt.in, err)
+ } else if tt.err != err {
+ t.Errorf("Constraint(%q): error %v, want %v", tt.in, err, tt.err)
+ }
+ return
+ }
+ if tt.err != nil {
+ t.Errorf("Constraint(%q) = %v, want error %v", tt.in, x, tt.err)
+ return
+ }
+ if x.String() != tt.x.String() {
+ t.Errorf("Constraint(%q):\nhave %v\nwant %v", tt.in, x, tt.x)
+ }
+ })
+ }
+}
+
+var plusBuildLinesTests = []struct {
+ in string
+ out []string
+ err error
+}{
+ {"x", []string{"x"}, nil},
+ {"x && !y", []string{"x,!y"}, nil},
+ {"x || y", []string{"x y"}, nil},
+ {"x && (y || z)", []string{"x", "y z"}, nil},
+ {"!(x && y)", []string{"!x !y"}, nil},
+ {"x || (y && z)", []string{"x y,z"}, nil},
+ {"w && (x || (y && z))", []string{"w", "x y,z"}, nil},
+ {"v || (w && (x || (y && z)))", nil, errComplex},
+}
+
+func TestPlusBuildLines(t *testing.T) {
+ for i, tt := range plusBuildLinesTests {
+ t.Run(fmt.Sprint(i), func(t *testing.T) {
+ x, err := parseExpr(tt.in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ lines, err := PlusBuildLines(x)
+ if err != nil {
+ if tt.err == nil {
+ t.Errorf("PlusBuildLines(%q): unexpected error: %v", tt.in, err)
+ } else if tt.err != err {
+ t.Errorf("PlusBuildLines(%q): error %v, want %v", tt.in, err, tt.err)
+ }
+ return
+ }
+ if tt.err != nil {
+ t.Errorf("PlusBuildLines(%q) = %v, want error %v", tt.in, lines, tt.err)
+ return
+ }
+ var want []string
+ for _, line := range tt.out {
+ want = append(want, "// +build "+line)
+ }
+ if !reflect.DeepEqual(lines, want) {
+ t.Errorf("PlusBuildLines(%q):\nhave %q\nwant %q", tt.in, lines, want)
+ }
+ })
+ }
+}
diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
new file mode 100644
index 0000000..c97c668
--- /dev/null
+++ b/src/go/build/deps_test.go
@@ -0,0 +1,877 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file exercises the import parser but also checks that
+// some low-level packages do not have new dependencies added.
+
+package build
+
+import (
+ "bytes"
+ "fmt"
+ "go/token"
+ "internal/testenv"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "runtime"
+ "sort"
+ "strings"
+ "testing"
+)
+
+// depsRules defines the expected dependencies between packages in
+// the Go source tree. It is a statement of policy.
+//
+// DO NOT CHANGE THIS DATA TO FIX BUILDS.
+// Existing packages should not have their constraints relaxed
+// without prior discussion.
+// Negative assertions should almost never be removed.
+//
+// The general syntax of a rule is:
+//
+// a, b < c, d;
+//
+// which means c and d come after a and b in the partial order
+// (that is, c and d can import a and b),
+// but doesn't provide a relative order between a vs b or c vs d.
+//
+// The rules can chain together, as in:
+//
+// e < f, g < h;
+//
+// which is equivalent to
+//
+// e < f, g;
+// f, g < h;
+//
+// Except for the special bottom element "NONE", each name
+// must appear exactly once on the right-hand side of a rule.
+// That rule serves as the definition of the allowed dependencies
+// for that name. The definition must appear before any uses
+// of the name on the left-hand side of a rule. (That is, the
+// rules themselves must be ordered according to the partial
+// order, for easier reading by people.)
+//
+// Negative assertions double-check the partial order:
+//
+// i !< j
+//
+// means that it must NOT be the case that i < j.
+// Negative assertions may appear anywhere in the rules,
+// even before i and j have been defined.
+//
+// Comments begin with #.
+//
+// All-caps names are pseudo-names for specific points
+// in the dependency lattice.
+//
+var depsRules = `
+ # No dependencies allowed for any of these packages.
+ NONE
+ < container/list, container/ring,
+ internal/cfg, internal/cpu,
+ internal/goversion, internal/nettrace,
+ unicode/utf8, unicode/utf16, unicode,
+ unsafe;
+
+ # RUNTIME is the core runtime group of packages, all of them very light-weight.
+ internal/cpu, unsafe
+ < internal/bytealg
+ < internal/unsafeheader
+ < runtime/internal/sys
+ < runtime/internal/atomic
+ < runtime/internal/math
+ < runtime
+ < sync/atomic
+ < internal/race
+ < sync
+ < internal/reflectlite
+ < errors
+ < internal/oserror, math/bits
+ < RUNTIME;
+
+ RUNTIME
+ < sort
+ < container/heap;
+
+ RUNTIME
+ < io;
+
+ syscall !< io;
+ reflect !< sort;
+
+ RUNTIME, unicode/utf8
+ < path;
+
+ unicode !< path;
+
+ # SYSCALL is RUNTIME plus the packages necessary for basic system calls.
+ RUNTIME, unicode/utf8, unicode/utf16
+ < internal/syscall/windows/sysdll, syscall/js
+ < syscall
+ < internal/syscall/unix, internal/syscall/windows, internal/syscall/windows/registry
+ < internal/syscall/execenv
+ < SYSCALL;
+
+ # TIME is SYSCALL plus the core packages about time, including context.
+ SYSCALL
+ < time/tzdata
+ < time
+ < context
+ < TIME;
+
+ TIME, io, path, sort
+ < io/fs;
+
+ # MATH is RUNTIME plus the basic math packages.
+ RUNTIME
+ < math
+ < MATH;
+
+ unicode !< math;
+
+ MATH
+ < math/cmplx;
+
+ MATH
+ < math/rand;
+
+ MATH
+ < runtime/metrics;
+
+ MATH, unicode/utf8
+ < strconv;
+
+ unicode !< strconv;
+
+ # STR is basic string and buffer manipulation.
+ RUNTIME, io, unicode/utf8, unicode/utf16, unicode
+ < bytes, strings
+ < bufio;
+
+ bufio, path, strconv
+ < STR;
+
+ # OS is basic OS access, including helpers (path/filepath, os/exec, etc).
+ # OS includes string routines, but those must be layered above package os.
+ # OS does not include reflection.
+ io/fs
+ < internal/testlog
+ < internal/poll
+ < os
+ < os/signal;
+
+ io/fs
+ < embed;
+
+ unicode, fmt !< os, os/signal;
+
+ os/signal, STR
+ < path/filepath
+ < io/ioutil, os/exec;
+
+ io/ioutil, os/exec, os/signal
+ < OS;
+
+ reflect !< OS;
+
+ OS
+ < golang.org/x/sys/cpu;
+
+ # FMT is OS (which includes string routines) plus reflect and fmt.
+ # It does not include package log, which should be avoided in core packages.
+ strconv, unicode
+ < reflect;
+
+ os, reflect
+ < internal/fmtsort
+ < fmt;
+
+ OS, fmt
+ < FMT;
+
+ log !< FMT;
+
+ OS, FMT
+ < internal/execabs;
+
+ OS, internal/execabs
+ < internal/goroot;
+
+ # Misc packages needing only FMT.
+ FMT
+ < flag,
+ html,
+ mime/quotedprintable,
+ net/internal/socktest,
+ net/url,
+ runtime/debug,
+ runtime/trace,
+ text/scanner,
+ text/tabwriter;
+
+ # encodings
+ # core ones do not use fmt.
+ io, strconv
+ < encoding;
+
+ encoding, reflect
+ < encoding/binary
+ < encoding/base32, encoding/base64;
+
+ fmt !< encoding/base32, encoding/base64;
+
+ FMT, encoding/base32, encoding/base64
+ < encoding/ascii85, encoding/csv, encoding/gob, encoding/hex,
+ encoding/json, encoding/pem, encoding/xml, mime;
+
+ # hashes
+ io
+ < hash
+ < hash/adler32, hash/crc32, hash/crc64, hash/fnv, hash/maphash;
+
+ # math/big
+ FMT, encoding/binary, math/rand
+ < math/big;
+
+ # compression
+ FMT, encoding/binary, hash/adler32, hash/crc32
+ < compress/bzip2, compress/flate, compress/lzw
+ < archive/zip, compress/gzip, compress/zlib;
+
+ # templates
+ FMT
+ < text/template/parse;
+
+ net/url, text/template/parse
+ < text/template
+ < internal/lazytemplate;
+
+ encoding/json, html, text/template
+ < html/template;
+
+ # regexp
+ FMT
+ < regexp/syntax
+ < regexp
+ < internal/lazyregexp;
+
+ # suffix array
+ encoding/binary, regexp
+ < index/suffixarray;
+
+ # executable parsing
+ FMT, encoding/binary, compress/zlib
+ < debug/dwarf
+ < debug/elf, debug/gosym, debug/macho, debug/pe, debug/plan9obj, internal/xcoff
+ < DEBUG;
+
+ # go parser and friends.
+ FMT
+ < go/token
+ < go/scanner
+ < go/ast
+ < go/parser;
+
+ go/parser, text/tabwriter
+ < go/printer
+ < go/format;
+
+ go/parser, internal/lazyregexp, text/template
+ < go/doc;
+
+ math/big, go/token
+ < go/constant;
+
+ container/heap, go/constant, go/parser
+ < go/types;
+
+ FMT
+ < go/build/constraint;
+
+ go/doc, go/parser, internal/goroot, internal/goversion
+ < go/build;
+
+ DEBUG, go/build, go/types, text/scanner
+ < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
+ < go/importer;
+
+ # databases
+ FMT
+ < database/sql/internal
+ < database/sql/driver
+ < database/sql;
+
+ # images
+ FMT, compress/lzw, compress/zlib
+ < image/color
+ < image, image/color/palette
+ < image/internal/imageutil
+ < image/draw
+ < image/gif, image/jpeg, image/png;
+
+ # cgo, delayed as long as possible.
+ # If you add a dependency on CGO, you must add the package
+ # to cgoPackages in cmd/dist/test.go as well.
+ RUNTIME
+ < C
+ < runtime/cgo
+ < CGO
+ < runtime/race, runtime/msan;
+
+ # Bulk of the standard library must not use cgo.
+ # The prohibition stops at net and os/user.
+ C !< fmt, go/types, CRYPTO-MATH;
+
+ CGO, OS
+ < plugin;
+
+ CGO, FMT
+ < os/user
+ < archive/tar;
+
+ sync
+ < internal/singleflight;
+
+ os
+ < golang.org/x/net/dns/dnsmessage,
+ golang.org/x/net/lif,
+ golang.org/x/net/route;
+
+ # net is unavoidable when doing any networking,
+ # so large dependencies must be kept out.
+ # This is a long-looking list but most of these
+ # are small with few dependencies.
+ CGO,
+ golang.org/x/net/dns/dnsmessage,
+ golang.org/x/net/lif,
+ golang.org/x/net/route,
+ internal/nettrace,
+ internal/poll,
+ internal/singleflight,
+ internal/race,
+ os
+ < net;
+
+ fmt, unicode !< net;
+ math/rand !< net; # net uses runtime instead
+
+ # NET is net plus net-helper packages.
+ FMT, net
+ < net/textproto;
+
+ mime, net/textproto, net/url
+ < NET;
+
+ # logging - most packages should not import; http and up is allowed
+ FMT
+ < log;
+
+ log !< crypto/tls, database/sql, go/importer, testing;
+
+ FMT, log, net
+ < log/syslog;
+
+ NET, log
+ < net/mail;
+
+ # CRYPTO is core crypto algorithms - no cgo, fmt, net.
+ # Unfortunately, stuck with reflect via encoding/binary.
+ encoding/binary, golang.org/x/sys/cpu, hash
+ < crypto
+ < crypto/subtle
+ < crypto/internal/subtle
+ < crypto/cipher
+ < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
+ crypto/sha1, crypto/sha256, crypto/sha512
+ < CRYPTO;
+
+ CGO, fmt, net !< CRYPTO;
+
+ # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
+ CRYPTO, FMT, math/big
+ < crypto/rand
+ < crypto/internal/randutil
+ < crypto/ed25519/internal/edwards25519
+ < crypto/ed25519
+ < encoding/asn1
+ < golang.org/x/crypto/cryptobyte/asn1
+ < golang.org/x/crypto/cryptobyte
+ < golang.org/x/crypto/curve25519
+ < crypto/dsa, crypto/elliptic, crypto/rsa
+ < crypto/ecdsa
+ < CRYPTO-MATH;
+
+ CGO, net !< CRYPTO-MATH;
+
+ # TLS, Prince of Dependencies.
+ CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
+ < golang.org/x/crypto/internal/subtle
+ < golang.org/x/crypto/chacha20
+ < golang.org/x/crypto/poly1305
+ < golang.org/x/crypto/chacha20poly1305
+ < golang.org/x/crypto/hkdf
+ < crypto/x509/internal/macos
+ < crypto/x509/pkix
+ < crypto/x509
+ < crypto/tls;
+
+ # crypto-aware packages
+
+ NET, crypto/rand, mime/quotedprintable
+ < mime/multipart;
+
+ crypto/tls
+ < net/smtp;
+
+ # HTTP, King of Dependencies.
+
+ FMT
+ < golang.org/x/net/http2/hpack, net/http/internal;
+
+ FMT, NET, container/list, encoding/binary, log
+ < golang.org/x/text/transform
+ < golang.org/x/text/unicode/norm
+ < golang.org/x/text/unicode/bidi
+ < golang.org/x/text/secure/bidirule
+ < golang.org/x/net/idna
+ < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
+
+ NET, crypto/tls
+ < net/http/httptrace;
+
+ compress/gzip,
+ golang.org/x/net/http/httpguts,
+ golang.org/x/net/http/httpproxy,
+ golang.org/x/net/http2/hpack,
+ net/http/internal,
+ net/http/httptrace,
+ mime/multipart,
+ log
+ < net/http;
+
+ # HTTP-aware packages
+
+ encoding/json, net/http
+ < expvar;
+
+ net/http
+ < net/http/cookiejar, net/http/httputil;
+
+ net/http, flag
+ < net/http/httptest;
+
+ net/http, regexp
+ < net/http/cgi
+ < net/http/fcgi;
+
+ # Profiling
+ FMT, compress/gzip, encoding/binary, text/tabwriter
+ < runtime/pprof;
+
+ OS, compress/gzip, regexp
+ < internal/profile;
+
+ html, internal/profile, net/http, runtime/pprof, runtime/trace
+ < net/http/pprof;
+
+ # RPC
+ encoding/gob, encoding/json, go/token, html/template, net/http
+ < net/rpc
+ < net/rpc/jsonrpc;
+
+ # System Information
+ internal/cpu, sync
+ < internal/sysinfo;
+
+ # Test-only
+ log
+ < testing/iotest
+ < testing/fstest;
+
+ FMT, flag, math/rand
+ < testing/quick;
+
+ FMT, flag, runtime/debug, runtime/trace, internal/sysinfo
+ < testing;
+
+ internal/testlog, runtime/pprof, regexp
+ < testing/internal/testdeps;
+
+ OS, flag, testing, internal/cfg
+ < internal/testenv;
+
+ OS, encoding/base64
+ < internal/obscuretestdata;
+
+ CGO, OS, fmt
+ < os/signal/internal/pty;
+
+ NET, testing, math/rand
+ < golang.org/x/net/nettest;
+
+ FMT, container/heap, math/rand
+ < internal/trace;
+`
+
+// listStdPkgs returns the same list of packages as "go list std".
+func listStdPkgs(goroot string) ([]string, error) {
+ // Based on cmd/go's matchPackages function.
+ var pkgs []string
+
+ src := filepath.Join(goroot, "src") + string(filepath.Separator)
+ walkFn := func(path string, d fs.DirEntry, err error) error {
+ if err != nil || !d.IsDir() || path == src {
+ return nil
+ }
+
+ base := filepath.Base(path)
+ if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
+ return filepath.SkipDir
+ }
+
+ name := filepath.ToSlash(path[len(src):])
+ if name == "builtin" || name == "cmd" {
+ return filepath.SkipDir
+ }
+
+ pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
+ return nil
+ }
+ if err := filepath.WalkDir(src, walkFn); err != nil {
+ return nil, err
+ }
+ return pkgs, nil
+}
+
+func TestDependencies(t *testing.T) {
+ if !testenv.HasSrc() {
+ // Tests run in a limited file system and we do not
+ // provide access to every source file.
+ t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
+ }
+
+ ctxt := Default
+ all, err := listStdPkgs(ctxt.GOROOT)
+ if err != nil {
+ t.Fatal(err)
+ }
+ sort.Strings(all)
+
+ sawImport := map[string]map[string]bool{} // from package => to package => true
+ policy := depsPolicy(t)
+
+ for _, pkg := range all {
+ imports, err := findImports(pkg)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+ if sawImport[pkg] == nil {
+ sawImport[pkg] = map[string]bool{}
+ }
+ ok := policy[pkg]
+ var bad []string
+ for _, imp := range imports {
+ sawImport[pkg][imp] = true
+ if !ok[imp] {
+ bad = append(bad, imp)
+ }
+ }
+ if bad != nil {
+ t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
+ }
+ }
+
+ // depPath returns the path between the given from and to packages.
+ // It returns the empty string if there's no dependency path.
+ var depPath func(string, string) string
+ depPath = func(from, to string) string {
+ if sawImport[from][to] {
+ return from + " => " + to
+ }
+ for pkg := range sawImport[from] {
+ if p := depPath(pkg, to); p != "" {
+ return from + " => " + p
+ }
+ }
+ return ""
+ }
+}
+
+var buildIgnore = []byte("\n// +build ignore")
+
+func findImports(pkg string) ([]string, error) {
+ vpkg := pkg
+ if strings.HasPrefix(pkg, "golang.org") {
+ vpkg = "vendor/" + pkg
+ }
+ dir := filepath.Join(Default.GOROOT, "src", vpkg)
+ files, err := os.ReadDir(dir)
+ if err != nil {
+ return nil, err
+ }
+ var imports []string
+ var haveImport = map[string]bool{}
+ fset := token.NewFileSet()
+ for _, file := range files {
+ name := file.Name()
+ if name == "slice_go14.go" || name == "slice_go18.go" {
+ // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
+ continue
+ }
+ if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
+ continue
+ }
+ info := fileInfo{
+ name: filepath.Join(dir, name),
+ fset: fset,
+ }
+ f, err := os.Open(info.name)
+ if err != nil {
+ return nil, err
+ }
+ err = readGoInfo(f, &info)
+ f.Close()
+ if err != nil {
+ return nil, fmt.Errorf("reading %v: %v", name, err)
+ }
+ if bytes.Contains(info.header, buildIgnore) {
+ continue
+ }
+ for _, imp := range info.imports {
+ path := imp.path
+ if !haveImport[path] {
+ haveImport[path] = true
+ imports = append(imports, path)
+ }
+ }
+ }
+ sort.Strings(imports)
+ return imports, nil
+}
+
+// depsPolicy returns a map m such that m[p][d] == true when p can import d.
+func depsPolicy(t *testing.T) map[string]map[string]bool {
+ allowed := map[string]map[string]bool{"NONE": {}}
+ disallowed := [][2][]string{}
+
+ parseDepsRules(t, func(deps []string, op string, users []string) {
+ if op == "!<" {
+ disallowed = append(disallowed, [2][]string{deps, users})
+ return
+ }
+ for _, u := range users {
+ if allowed[u] != nil {
+ t.Errorf("multiple deps lists for %s", u)
+ }
+ allowed[u] = make(map[string]bool)
+ for _, d := range deps {
+ if allowed[d] == nil {
+ t.Errorf("use of %s before its deps list", d)
+ }
+ allowed[u][d] = true
+ }
+ }
+ })
+
+ // Check for missing deps info.
+ for _, deps := range allowed {
+ for d := range deps {
+ if allowed[d] == nil {
+ t.Errorf("missing deps list for %s", d)
+ }
+ }
+ }
+
+ // Complete transitive allowed deps.
+ for k := range allowed {
+ for i := range allowed {
+ for j := range allowed {
+ if i != k && k != j && allowed[i][k] && allowed[k][j] {
+ if i == j {
+ // Can only happen along with a "use of X before deps" error above,
+ // but this error is more specific - it makes clear that reordering the
+ // rules will not be enough to fix the problem.
+ t.Errorf("deps policy cycle: %s < %s < %s", j, k, i)
+ }
+ allowed[i][j] = true
+ }
+ }
+ }
+ }
+
+ // Check negative assertions against completed allowed deps.
+ for _, bad := range disallowed {
+ deps, users := bad[0], bad[1]
+ for _, d := range deps {
+ for _, u := range users {
+ if allowed[u][d] {
+ t.Errorf("deps policy incorrect: assertion failed: %s !< %s", d, u)
+ }
+ }
+ }
+ }
+
+ if t.Failed() {
+ t.FailNow()
+ }
+
+ return allowed
+}
+
+// parseDepsRules parses depsRules, calling save(deps, op, users)
+// for each deps < users or deps !< users rule
+// (op is "<" or "!<").
+func parseDepsRules(t *testing.T, save func(deps []string, op string, users []string)) {
+ p := &depsParser{t: t, lineno: 1, text: depsRules}
+
+ var prev []string
+ var op string
+ for {
+ list, tok := p.nextList()
+ if tok == "" {
+ if prev == nil {
+ break
+ }
+ p.syntaxError("unexpected EOF")
+ }
+ if prev != nil {
+ save(prev, op, list)
+ }
+ prev = list
+ if tok == ";" {
+ prev = nil
+ op = ""
+ continue
+ }
+ if tok != "<" && tok != "!<" {
+ p.syntaxError("missing <")
+ }
+ op = tok
+ }
+}
+
+// A depsParser parses the depsRules syntax described above.
+type depsParser struct {
+ t *testing.T
+ lineno int
+ lastWord string
+ text string
+}
+
+// syntaxError reports a parsing error.
+func (p *depsParser) syntaxError(msg string) {
+ p.t.Fatalf("deps:%d: syntax error: %s near %s", p.lineno, msg, p.lastWord)
+}
+
+// nextList parses and returns a comma-separated list of names.
+func (p *depsParser) nextList() (list []string, token string) {
+ for {
+ tok := p.nextToken()
+ switch tok {
+ case "":
+ if len(list) == 0 {
+ return nil, ""
+ }
+ fallthrough
+ case ",", "<", "!<", ";":
+ p.syntaxError("bad list syntax")
+ }
+ list = append(list, tok)
+
+ tok = p.nextToken()
+ if tok != "," {
+ return list, tok
+ }
+ }
+}
+
+// nextToken returns the next token in the deps rules,
+// one of ";" "," "<" "!<" or a name.
+func (p *depsParser) nextToken() string {
+ for {
+ if p.text == "" {
+ return ""
+ }
+ switch p.text[0] {
+ case ';', ',', '<':
+ t := p.text[:1]
+ p.text = p.text[1:]
+ return t
+
+ case '!':
+ if len(p.text) < 2 || p.text[1] != '<' {
+ p.syntaxError("unexpected token !")
+ }
+ p.text = p.text[2:]
+ return "!<"
+
+ case '#':
+ i := strings.Index(p.text, "\n")
+ if i < 0 {
+ i = len(p.text)
+ }
+ p.text = p.text[i:]
+ continue
+
+ case '\n':
+ p.lineno++
+ fallthrough
+ case ' ', '\t':
+ p.text = p.text[1:]
+ continue
+
+ default:
+ i := strings.IndexAny(p.text, "!;,<#\n \t")
+ if i < 0 {
+ i = len(p.text)
+ }
+ t := p.text[:i]
+ p.text = p.text[i:]
+ p.lastWord = t
+ return t
+ }
+ }
+}
+
+// TestStdlibLowercase tests that all standard library package names are
+// lowercase. See Issue 40065.
+func TestStdlibLowercase(t *testing.T) {
+ if !testenv.HasSrc() {
+ t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
+ }
+
+ ctxt := Default
+ all, err := listStdPkgs(ctxt.GOROOT)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ for _, pkgname := range all {
+ if strings.ToLower(pkgname) != pkgname {
+ t.Errorf("package %q should not use upper-case path", pkgname)
+ }
+ }
+}
+
+// TestFindImports tests that findImports works. See #43249.
+func TestFindImports(t *testing.T) {
+ imports, err := findImports("go/build")
+ if err != nil {
+ t.Fatal(err)
+ }
+ t.Logf("go/build imports %q", imports)
+ want := []string{"bytes", "os", "path/filepath", "strings"}
+wantLoop:
+ for _, w := range want {
+ for _, imp := range imports {
+ if imp == w {
+ continue wantLoop
+ }
+ }
+ t.Errorf("expected to find %q in import list", w)
+ }
+}
diff --git a/src/go/build/doc.go b/src/go/build/doc.go
new file mode 100644
index 0000000..2c6f0a8
--- /dev/null
+++ b/src/go/build/doc.go
@@ -0,0 +1,98 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package build gathers information about Go packages.
+//
+// Go Path
+//
+// The Go path is a list of directory trees containing Go source code.
+// It is consulted to resolve imports that cannot be found in the standard
+// Go tree. The default path is the value of the GOPATH environment
+// variable, interpreted as a path list appropriate to the operating system
+// (on Unix, the variable is a colon-separated string;
+// on Windows, a semicolon-separated string;
+// on Plan 9, a list).
+//
+// Each directory listed in the Go path must have a prescribed structure:
+//
+// The src/ directory holds source code. The path below 'src' determines
+// the import path or executable name.
+//
+// The pkg/ directory holds installed package objects.
+// As in the Go tree, each target operating system and
+// architecture pair has its own subdirectory of pkg
+// (pkg/GOOS_GOARCH).
+//
+// If DIR is a directory listed in the Go path, a package with
+// source in DIR/src/foo/bar can be imported as "foo/bar" and
+// has its compiled form installed to "DIR/pkg/GOOS_GOARCH/foo/bar.a"
+// (or, for gccgo, "DIR/pkg/gccgo/foo/libbar.a").
+//
+// The bin/ directory holds compiled commands.
+// Each command is named for its source directory, but only
+// using the final element, not the entire path. That is, the
+// command with source in DIR/src/foo/quux is installed into
+// DIR/bin/quux, not DIR/bin/foo/quux. The foo/ is stripped
+// so that you can add DIR/bin to your PATH to get at the
+// installed commands.
+//
+// Here's an example directory layout:
+//
+// GOPATH=/home/user/gocode
+//
+// /home/user/gocode/
+// src/
+// foo/
+// bar/ (go code in package bar)
+// x.go
+// quux/ (go code in package main)
+// y.go
+// bin/
+// quux (installed command)
+// pkg/
+// linux_amd64/
+// foo/
+// bar.a (installed package object)
+//
+// Build Constraints
+//
+// A build constraint, also known as a build tag, is a line comment that begins
+//
+// // +build
+//
+// that lists the conditions under which a file should be included in the
+// package. Build constraints may also be part of a file's name
+// (for example, source_windows.go will only be included if the target
+// operating system is windows).
+//
+// See 'go help buildconstraint'
+// (https://golang.org/cmd/go/#hdr-Build_constraints) for details.
+//
+// Binary-Only Packages
+//
+// In Go 1.12 and earlier, it was possible to distribute packages in binary
+// form without including the source code used for compiling the package.
+// The package was distributed with a source file not excluded by build
+// constraints and containing a "//go:binary-only-package" comment. Like a
+// build constraint, this comment appeared at the top of a file, preceded
+// only by blank lines and other line comments and with a blank line
+// following the comment, to separate it from the package documentation.
+// Unlike build constraints, this comment is only recognized in non-test
+// Go source files.
+//
+// The minimal source code for a binary-only package was therefore:
+//
+// //go:binary-only-package
+//
+// package mypkg
+//
+// The source code could include additional Go code. That code was never
+// compiled but would be processed by tools like godoc and might be useful
+// as end-user documentation.
+//
+// "go build" and other commands no longer support binary-only-packages.
+// Import and ImportDir will still set the BinaryOnly flag in packages
+// containing these comments for use in tools and error messages.
+//
+package build
diff --git a/src/go/build/gc.go b/src/go/build/gc.go
new file mode 100644
index 0000000..3025cd5
--- /dev/null
+++ b/src/go/build/gc.go
@@ -0,0 +1,17 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build gc
+
+package build
+
+import (
+ "path/filepath"
+ "runtime"
+)
+
+// getToolDir returns the default value of ToolDir.
+func getToolDir() string {
+ return filepath.Join(runtime.GOROOT(), "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
+}
diff --git a/src/go/build/gccgo.go b/src/go/build/gccgo.go
new file mode 100644
index 0000000..c6aac9a
--- /dev/null
+++ b/src/go/build/gccgo.go
@@ -0,0 +1,14 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build gccgo
+
+package build
+
+import "runtime"
+
+// getToolDir returns the default value of ToolDir.
+func getToolDir() string {
+ return envOr("GCCGOTOOLDIR", runtime.GCCGOTOOLDIR)
+}
diff --git a/src/go/build/read.go b/src/go/build/read.go
new file mode 100644
index 0000000..aa7c6ee
--- /dev/null
+++ b/src/go/build/read.go
@@ -0,0 +1,546 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+ "bufio"
+ "errors"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "io"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+type importReader struct {
+ b *bufio.Reader
+ buf []byte
+ peek byte
+ err error
+ eof bool
+ nerr int
+ pos token.Position
+}
+
+func newImportReader(name string, r io.Reader) *importReader {
+ return &importReader{
+ b: bufio.NewReader(r),
+ pos: token.Position{
+ Filename: name,
+ Line: 1,
+ Column: 1,
+ },
+ }
+}
+
+func isIdent(c byte) bool {
+ return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '_' || c >= utf8.RuneSelf
+}
+
+var (
+ errSyntax = errors.New("syntax error")
+ errNUL = errors.New("unexpected NUL in input")
+)
+
+// syntaxError records a syntax error, but only if an I/O error has not already been recorded.
+func (r *importReader) syntaxError() {
+ if r.err == nil {
+ r.err = errSyntax
+ }
+}
+
+// readByte reads the next byte from the input, saves it in buf, and returns it.
+// If an error occurs, readByte records the error in r.err and returns 0.
+func (r *importReader) readByte() byte {
+ c, err := r.b.ReadByte()
+ if err == nil {
+ r.buf = append(r.buf, c)
+ if c == 0 {
+ err = errNUL
+ }
+ }
+ if err != nil {
+ if err == io.EOF {
+ r.eof = true
+ } else if r.err == nil {
+ r.err = err
+ }
+ c = 0
+ }
+ return c
+}
+
+// readByteNoBuf is like readByte but doesn't buffer the byte.
+// It exhausts r.buf before reading from r.b.
+func (r *importReader) readByteNoBuf() byte {
+ var c byte
+ var err error
+ if len(r.buf) > 0 {
+ c = r.buf[0]
+ r.buf = r.buf[1:]
+ } else {
+ c, err = r.b.ReadByte()
+ if err == nil && c == 0 {
+ err = errNUL
+ }
+ }
+
+ if err != nil {
+ if err == io.EOF {
+ r.eof = true
+ } else if r.err == nil {
+ r.err = err
+ }
+ return 0
+ }
+ r.pos.Offset++
+ if c == '\n' {
+ r.pos.Line++
+ r.pos.Column = 1
+ } else {
+ r.pos.Column++
+ }
+ return c
+}
+
+// peekByte returns the next byte from the input reader but does not advance beyond it.
+// If skipSpace is set, peekByte skips leading spaces and comments.
+func (r *importReader) peekByte(skipSpace bool) byte {
+ if r.err != nil {
+ if r.nerr++; r.nerr > 10000 {
+ panic("go/build: import reader looping")
+ }
+ return 0
+ }
+
+ // Use r.peek as first input byte.
+ // Don't just return r.peek here: it might have been left by peekByte(false)
+ // and this might be peekByte(true).
+ c := r.peek
+ if c == 0 {
+ c = r.readByte()
+ }
+ for r.err == nil && !r.eof {
+ if skipSpace {
+ // For the purposes of this reader, semicolons are never necessary to
+ // understand the input and are treated as spaces.
+ switch c {
+ case ' ', '\f', '\t', '\r', '\n', ';':
+ c = r.readByte()
+ continue
+
+ case '/':
+ c = r.readByte()
+ if c == '/' {
+ for c != '\n' && r.err == nil && !r.eof {
+ c = r.readByte()
+ }
+ } else if c == '*' {
+ var c1 byte
+ for (c != '*' || c1 != '/') && r.err == nil {
+ if r.eof {
+ r.syntaxError()
+ }
+ c, c1 = c1, r.readByte()
+ }
+ } else {
+ r.syntaxError()
+ }
+ c = r.readByte()
+ continue
+ }
+ }
+ break
+ }
+ r.peek = c
+ return r.peek
+}
+
+// nextByte is like peekByte but advances beyond the returned byte.
+func (r *importReader) nextByte(skipSpace bool) byte {
+ c := r.peekByte(skipSpace)
+ r.peek = 0
+ return c
+}
+
+var goEmbed = []byte("go:embed")
+
+// findEmbed advances the input reader to the next //go:embed comment.
+// It reports whether it found a comment.
+// (Otherwise it found an error or EOF.)
+func (r *importReader) findEmbed(first bool) bool {
+ // The import block scan stopped after a non-space character,
+ // so the reader is not at the start of a line on the first call.
+ // After that, each //go:embed extraction leaves the reader
+ // at the end of a line.
+ startLine := !first
+ var c byte
+ for r.err == nil && !r.eof {
+ c = r.readByteNoBuf()
+ Reswitch:
+ switch c {
+ default:
+ startLine = false
+
+ case '\n':
+ startLine = true
+
+ case ' ', '\t':
+ // leave startLine alone
+
+ case '"':
+ startLine = false
+ for r.err == nil {
+ if r.eof {
+ r.syntaxError()
+ }
+ c = r.readByteNoBuf()
+ if c == '\\' {
+ r.readByteNoBuf()
+ if r.err != nil {
+ r.syntaxError()
+ return false
+ }
+ continue
+ }
+ if c == '"' {
+ c = r.readByteNoBuf()
+ goto Reswitch
+ }
+ }
+ goto Reswitch
+
+ case '`':
+ startLine = false
+ for r.err == nil {
+ if r.eof {
+ r.syntaxError()
+ }
+ c = r.readByteNoBuf()
+ if c == '`' {
+ c = r.readByteNoBuf()
+ goto Reswitch
+ }
+ }
+
+ case '/':
+ c = r.readByteNoBuf()
+ switch c {
+ default:
+ startLine = false
+ goto Reswitch
+
+ case '*':
+ var c1 byte
+ for (c != '*' || c1 != '/') && r.err == nil {
+ if r.eof {
+ r.syntaxError()
+ }
+ c, c1 = c1, r.readByteNoBuf()
+ }
+ startLine = false
+
+ case '/':
+ if startLine {
+ // Try to read this as a //go:embed comment.
+ for i := range goEmbed {
+ c = r.readByteNoBuf()
+ if c != goEmbed[i] {
+ goto SkipSlashSlash
+ }
+ }
+ c = r.readByteNoBuf()
+ if c == ' ' || c == '\t' {
+ // Found one!
+ return true
+ }
+ }
+ SkipSlashSlash:
+ for c != '\n' && r.err == nil && !r.eof {
+ c = r.readByteNoBuf()
+ }
+ startLine = true
+ }
+ }
+ }
+ return false
+}
+
+// readKeyword reads the given keyword from the input.
+// If the keyword is not present, readKeyword records a syntax error.
+func (r *importReader) readKeyword(kw string) {
+ r.peekByte(true)
+ for i := 0; i < len(kw); i++ {
+ if r.nextByte(false) != kw[i] {
+ r.syntaxError()
+ return
+ }
+ }
+ if isIdent(r.peekByte(false)) {
+ r.syntaxError()
+ }
+}
+
+// readIdent reads an identifier from the input.
+// If an identifier is not present, readIdent records a syntax error.
+func (r *importReader) readIdent() {
+ c := r.peekByte(true)
+ if !isIdent(c) {
+ r.syntaxError()
+ return
+ }
+ for isIdent(r.peekByte(false)) {
+ r.peek = 0
+ }
+}
+
+// readString reads a quoted string literal from the input.
+// If an identifier is not present, readString records a syntax error.
+func (r *importReader) readString() {
+ switch r.nextByte(true) {
+ case '`':
+ for r.err == nil {
+ if r.nextByte(false) == '`' {
+ break
+ }
+ if r.eof {
+ r.syntaxError()
+ }
+ }
+ case '"':
+ for r.err == nil {
+ c := r.nextByte(false)
+ if c == '"' {
+ break
+ }
+ if r.eof || c == '\n' {
+ r.syntaxError()
+ }
+ if c == '\\' {
+ r.nextByte(false)
+ }
+ }
+ default:
+ r.syntaxError()
+ }
+}
+
+// readImport reads an import clause - optional identifier followed by quoted string -
+// from the input.
+func (r *importReader) readImport() {
+ c := r.peekByte(true)
+ if c == '.' {
+ r.peek = 0
+ } else if isIdent(c) {
+ r.readIdent()
+ }
+ r.readString()
+}
+
+// readComments is like io.ReadAll, except that it only reads the leading
+// block of comments in the file.
+func readComments(f io.Reader) ([]byte, error) {
+ r := newImportReader("", f)
+ r.peekByte(true)
+ if r.err == nil && !r.eof {
+ // Didn't reach EOF, so must have found a non-space byte. Remove it.
+ r.buf = r.buf[:len(r.buf)-1]
+ }
+ return r.buf, r.err
+}
+
+// readGoInfo expects a Go file as input and reads the file up to and including the import section.
+// It records what it learned in *info.
+// If info.fset is non-nil, readGoInfo parses the file and sets info.parsed, info.parseErr,
+// info.imports, info.embeds, and info.embedErr.
+//
+// It only returns an error if there are problems reading the file,
+// not for syntax errors in the file itself.
+func readGoInfo(f io.Reader, info *fileInfo) error {
+ r := newImportReader(info.name, f)
+
+ r.readKeyword("package")
+ r.readIdent()
+ for r.peekByte(true) == 'i' {
+ r.readKeyword("import")
+ if r.peekByte(true) == '(' {
+ r.nextByte(false)
+ for r.peekByte(true) != ')' && r.err == nil {
+ r.readImport()
+ }
+ r.nextByte(false)
+ } else {
+ r.readImport()
+ }
+ }
+
+ info.header = r.buf
+
+ // If we stopped successfully before EOF, we read a byte that told us we were done.
+ // Return all but that last byte, which would cause a syntax error if we let it through.
+ if r.err == nil && !r.eof {
+ info.header = r.buf[:len(r.buf)-1]
+ }
+
+ // If we stopped for a syntax error, consume the whole file so that
+ // we are sure we don't change the errors that go/parser returns.
+ if r.err == errSyntax {
+ r.err = nil
+ for r.err == nil && !r.eof {
+ r.readByte()
+ }
+ info.header = r.buf
+ }
+ if r.err != nil {
+ return r.err
+ }
+
+ if info.fset == nil {
+ return nil
+ }
+
+ // Parse file header & record imports.
+ info.parsed, info.parseErr = parser.ParseFile(info.fset, info.name, info.header, parser.ImportsOnly|parser.ParseComments)
+ if info.parseErr != nil {
+ return nil
+ }
+
+ hasEmbed := false
+ for _, decl := range info.parsed.Decls {
+ d, ok := decl.(*ast.GenDecl)
+ if !ok {
+ continue
+ }
+ for _, dspec := range d.Specs {
+ spec, ok := dspec.(*ast.ImportSpec)
+ if !ok {
+ continue
+ }
+ quoted := spec.Path.Value
+ path, err := strconv.Unquote(quoted)
+ if err != nil {
+ return fmt.Errorf("parser returned invalid quoted string: <%s>", quoted)
+ }
+ if path == "embed" {
+ hasEmbed = true
+ }
+
+ doc := spec.Doc
+ if doc == nil && len(d.Specs) == 1 {
+ doc = d.Doc
+ }
+ info.imports = append(info.imports, fileImport{path, spec.Pos(), doc})
+ }
+ }
+
+ // If the file imports "embed",
+ // we have to look for //go:embed comments
+ // in the remainder of the file.
+ // The compiler will enforce the mapping of comments to
+ // declared variables. We just need to know the patterns.
+ // If there were //go:embed comments earlier in the file
+ // (near the package statement or imports), the compiler
+ // will reject them. They can be (and have already been) ignored.
+ if hasEmbed {
+ var line []byte
+ for first := true; r.findEmbed(first); first = false {
+ line = line[:0]
+ pos := r.pos
+ for {
+ c := r.readByteNoBuf()
+ if c == '\n' || r.err != nil || r.eof {
+ break
+ }
+ line = append(line, c)
+ }
+ // Add args if line is well-formed.
+ // Ignore badly-formed lines - the compiler will report them when it finds them,
+ // and we can pretend they are not there to help go list succeed with what it knows.
+ embs, err := parseGoEmbed(string(line), pos)
+ if err == nil {
+ info.embeds = append(info.embeds, embs...)
+ }
+ }
+ }
+
+ return nil
+}
+
+// parseGoEmbed parses the text following "//go:embed" to extract the glob patterns.
+// It accepts unquoted space-separated patterns as well as double-quoted and back-quoted Go strings.
+// This is based on a similar function in cmd/compile/internal/gc/noder.go;
+// this version calculates position information as well.
+func parseGoEmbed(args string, pos token.Position) ([]fileEmbed, error) {
+ trimBytes := func(n int) {
+ pos.Offset += n
+ pos.Column += utf8.RuneCountInString(args[:n])
+ args = args[n:]
+ }
+ trimSpace := func() {
+ trim := strings.TrimLeftFunc(args, unicode.IsSpace)
+ trimBytes(len(args) - len(trim))
+ }
+
+ var list []fileEmbed
+ for trimSpace(); args != ""; trimSpace() {
+ var path string
+ pathPos := pos
+ Switch:
+ switch args[0] {
+ default:
+ i := len(args)
+ for j, c := range args {
+ if unicode.IsSpace(c) {
+ i = j
+ break
+ }
+ }
+ path = args[:i]
+ trimBytes(i)
+
+ case '`':
+ i := strings.Index(args[1:], "`")
+ if i < 0 {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ path = args[1 : 1+i]
+ trimBytes(1 + i + 1)
+
+ case '"':
+ i := 1
+ for ; i < len(args); i++ {
+ if args[i] == '\\' {
+ i++
+ continue
+ }
+ if args[i] == '"' {
+ q, err := strconv.Unquote(args[:i+1])
+ if err != nil {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args[:i+1])
+ }
+ path = q
+ trimBytes(i + 1)
+ break Switch
+ }
+ }
+ if i >= len(args) {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ }
+
+ if args != "" {
+ r, _ := utf8.DecodeRuneInString(args)
+ if !unicode.IsSpace(r) {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ }
+ list = append(list, fileEmbed{path, pathPos})
+ }
+ return list, nil
+}
diff --git a/src/go/build/read_test.go b/src/go/build/read_test.go
new file mode 100644
index 0000000..32e6bae
--- /dev/null
+++ b/src/go/build/read_test.go
@@ -0,0 +1,321 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+ "fmt"
+ "go/token"
+ "io"
+ "strings"
+ "testing"
+)
+
+const quote = "`"
+
+type readTest struct {
+ // Test input contains ℙ where readGoInfo should stop.
+ in string
+ err string
+}
+
+var readGoInfoTests = []readTest{
+ {
+ `package p`,
+ "",
+ },
+ {
+ `package p; import "x"`,
+ "",
+ },
+ {
+ `package p; import . "x"`,
+ "",
+ },
+ {
+ `package p; import "x";ℙvar x = 1`,
+ "",
+ },
+ {
+ `package p
+
+ // comment
+
+ import "x"
+ import _ "x"
+ import a "x"
+
+ /* comment */
+
+ import (
+ "x" /* comment */
+ _ "x"
+ a "x" // comment
+ ` + quote + `x` + quote + `
+ _ /*comment*/ ` + quote + `x` + quote + `
+ a ` + quote + `x` + quote + `
+ )
+ import (
+ )
+ import ()
+ import()import()import()
+ import();import();import()
+
+ ℙvar x = 1
+ `,
+ "",
+ },
+}
+
+var readCommentsTests = []readTest{
+ {
+ `ℙpackage p`,
+ "",
+ },
+ {
+ `ℙpackage p; import "x"`,
+ "",
+ },
+ {
+ `ℙpackage p; import . "x"`,
+ "",
+ },
+ {
+ `// foo
+
+ /* bar */
+
+ /* quux */ // baz
+
+ /*/ zot */
+
+ // asdf
+ ℙHello, world`,
+ "",
+ },
+}
+
+func testRead(t *testing.T, tests []readTest, read func(io.Reader) ([]byte, error)) {
+ for i, tt := range tests {
+ var in, testOut string
+ j := strings.Index(tt.in, "ℙ")
+ if j < 0 {
+ in = tt.in
+ testOut = tt.in
+ } else {
+ in = tt.in[:j] + tt.in[j+len("ℙ"):]
+ testOut = tt.in[:j]
+ }
+ r := strings.NewReader(in)
+ buf, err := read(r)
+ if err != nil {
+ if tt.err == "" {
+ t.Errorf("#%d: err=%q, expected success (%q)", i, err, string(buf))
+ } else if !strings.Contains(err.Error(), tt.err) {
+ t.Errorf("#%d: err=%q, expected %q", i, err, tt.err)
+ }
+ continue
+ }
+ if tt.err != "" {
+ t.Errorf("#%d: success, expected %q", i, tt.err)
+ continue
+ }
+
+ out := string(buf)
+ if out != testOut {
+ t.Errorf("#%d: wrong output:\nhave %q\nwant %q\n", i, out, testOut)
+ }
+ }
+}
+
+func TestReadGoInfo(t *testing.T) {
+ testRead(t, readGoInfoTests, func(r io.Reader) ([]byte, error) {
+ var info fileInfo
+ err := readGoInfo(r, &info)
+ return info.header, err
+ })
+}
+
+func TestReadComments(t *testing.T) {
+ testRead(t, readCommentsTests, readComments)
+}
+
+var readFailuresTests = []readTest{
+ {
+ `package`,
+ "syntax error",
+ },
+ {
+ "package p\n\x00\nimport `math`\n",
+ "unexpected NUL in input",
+ },
+ {
+ `package p; import`,
+ "syntax error",
+ },
+ {
+ `package p; import "`,
+ "syntax error",
+ },
+ {
+ "package p; import ` \n\n",
+ "syntax error",
+ },
+ {
+ `package p; import "x`,
+ "syntax error",
+ },
+ {
+ `package p; import _`,
+ "syntax error",
+ },
+ {
+ `package p; import _ "`,
+ "syntax error",
+ },
+ {
+ `package p; import _ "x`,
+ "syntax error",
+ },
+ {
+ `package p; import .`,
+ "syntax error",
+ },
+ {
+ `package p; import . "`,
+ "syntax error",
+ },
+ {
+ `package p; import . "x`,
+ "syntax error",
+ },
+ {
+ `package p; import (`,
+ "syntax error",
+ },
+ {
+ `package p; import ("`,
+ "syntax error",
+ },
+ {
+ `package p; import ("x`,
+ "syntax error",
+ },
+ {
+ `package p; import ("x"`,
+ "syntax error",
+ },
+}
+
+func TestReadFailuresIgnored(t *testing.T) {
+ // Syntax errors should not be reported (false arg to readImports).
+ // Instead, entire file should be the output and no error.
+ // Convert tests not to return syntax errors.
+ tests := make([]readTest, len(readFailuresTests))
+ copy(tests, readFailuresTests)
+ for i := range tests {
+ tt := &tests[i]
+ if !strings.Contains(tt.err, "NUL") {
+ tt.err = ""
+ }
+ }
+ testRead(t, tests, func(r io.Reader) ([]byte, error) {
+ var info fileInfo
+ err := readGoInfo(r, &info)
+ return info.header, err
+ })
+}
+
+var readEmbedTests = []struct {
+ in, out string
+}{
+ {
+ "package p\n",
+ "",
+ },
+ {
+ "package p\nimport \"embed\"\nvar i int\n//go:embed x y z\nvar files embed.FS",
+ `test:4:12:x
+ test:4:14:y
+ test:4:16:z`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar i int\n//go:embed x \"\\x79\" `z`\nvar files embed.FS",
+ `test:4:12:x
+ test:4:14:y
+ test:4:21:z`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar i int\n//go:embed x y\n//go:embed z\nvar files embed.FS",
+ `test:4:12:x
+ test:4:14:y
+ test:5:12:z`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar i int\n\t //go:embed x y\n\t //go:embed z\n\t var files embed.FS",
+ `test:4:14:x
+ test:4:16:y
+ test:5:14:z`,
+ },
+ {
+ "package p\nimport \"embed\"\n//go:embed x y z\nvar files embed.FS",
+ `test:3:12:x
+ test:3:14:y
+ test:3:16:z`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar s = \"/*\"\n//go:embed x\nvar files embed.FS",
+ `test:4:12:x`,
+ },
+ {
+ `package p
+ import "embed"
+ var s = "\"\\\\"
+ //go:embed x
+ var files embed.FS`,
+ `test:4:15:x`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar s = `/*`\n//go:embed x\nvar files embed.FS",
+ `test:4:12:x`,
+ },
+ {
+ "package p\nimport \"embed\"\nvar s = z/ *y\n//go:embed pointer\nvar pointer embed.FS",
+ "test:4:12:pointer",
+ },
+ {
+ "package p\n//go:embed x y z\n", // no import, no scan
+ "",
+ },
+ {
+ "package p\n//go:embed x y z\nvar files embed.FS", // no import, no scan
+ "",
+ },
+}
+
+func TestReadEmbed(t *testing.T) {
+ fset := token.NewFileSet()
+ for i, tt := range readEmbedTests {
+ info := fileInfo{
+ name: "test",
+ fset: fset,
+ }
+ err := readGoInfo(strings.NewReader(tt.in), &info)
+ if err != nil {
+ t.Errorf("#%d: %v", i, err)
+ continue
+ }
+ b := &strings.Builder{}
+ sep := ""
+ for _, emb := range info.embeds {
+ fmt.Fprintf(b, "%s%v:%s", sep, emb.pos, emb.pattern)
+ sep = "\n"
+ }
+ got := b.String()
+ want := strings.Join(strings.Fields(tt.out), "\n")
+ if got != want {
+ t.Errorf("#%d: embeds:\n%s\nwant:\n%s", i, got, want)
+ }
+ }
+}
diff --git a/src/go/build/syslist.go b/src/go/build/syslist.go
new file mode 100644
index 0000000..1275f7c
--- /dev/null
+++ b/src/go/build/syslist.go
@@ -0,0 +1,11 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+// List of past, present, and future known GOOS and GOARCH values.
+// Do not remove from this list, as these are used for go/build filename matching.
+
+const goosList = "aix android darwin dragonfly freebsd hurd illumos ios js linux nacl netbsd openbsd plan9 solaris windows zos "
+const goarchList = "386 amd64 amd64p32 arm armbe arm64 arm64be ppc64 ppc64le mips mipsle mips64 mips64le mips64p32 mips64p32le ppc riscv riscv64 s390 s390x sparc sparc64 wasm "
diff --git a/src/go/build/syslist_test.go b/src/go/build/syslist_test.go
new file mode 100644
index 0000000..2b7b4c7
--- /dev/null
+++ b/src/go/build/syslist_test.go
@@ -0,0 +1,62 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+ "runtime"
+ "testing"
+)
+
+var (
+ thisOS = runtime.GOOS
+ thisArch = runtime.GOARCH
+ otherOS = anotherOS()
+ otherArch = anotherArch()
+)
+
+func anotherOS() string {
+ if thisOS != "darwin" && thisOS != "ios" {
+ return "darwin"
+ }
+ return "linux"
+}
+
+func anotherArch() string {
+ if thisArch != "amd64" {
+ return "amd64"
+ }
+ return "386"
+}
+
+type GoodFileTest struct {
+ name string
+ result bool
+}
+
+var tests = []GoodFileTest{
+ {"file.go", true},
+ {"file.c", true},
+ {"file_foo.go", true},
+ {"file_" + thisArch + ".go", true},
+ {"file_" + otherArch + ".go", false},
+ {"file_" + thisOS + ".go", true},
+ {"file_" + otherOS + ".go", false},
+ {"file_" + thisOS + "_" + thisArch + ".go", true},
+ {"file_" + otherOS + "_" + thisArch + ".go", false},
+ {"file_" + thisOS + "_" + otherArch + ".go", false},
+ {"file_" + otherOS + "_" + otherArch + ".go", false},
+ {"file_foo_" + thisArch + ".go", true},
+ {"file_foo_" + otherArch + ".go", false},
+ {"file_" + thisOS + ".c", true},
+ {"file_" + otherOS + ".c", false},
+}
+
+func TestGoodOSArch(t *testing.T) {
+ for _, test := range tests {
+ if Default.goodOSArchFile(test.name, make(map[string]bool)) != test.result {
+ t.Fatalf("goodOSArchFile(%q) != %v", test.name, test.result)
+ }
+ }
+}
diff --git a/src/go/build/testdata/cgo_disabled/cgo_disabled.go b/src/go/build/testdata/cgo_disabled/cgo_disabled.go
new file mode 100644
index 0000000..d1edb99
--- /dev/null
+++ b/src/go/build/testdata/cgo_disabled/cgo_disabled.go
@@ -0,0 +1,5 @@
+package cgo_disabled
+
+import "C"
+
+import _ "should/be/ignored"
diff --git a/src/go/build/testdata/cgo_disabled/empty.go b/src/go/build/testdata/cgo_disabled/empty.go
new file mode 100644
index 0000000..63afe42
--- /dev/null
+++ b/src/go/build/testdata/cgo_disabled/empty.go
@@ -0,0 +1 @@
+package cgo_disabled
diff --git a/src/go/build/testdata/doc/a_test.go b/src/go/build/testdata/doc/a_test.go
new file mode 100644
index 0000000..1c07b56
--- /dev/null
+++ b/src/go/build/testdata/doc/a_test.go
@@ -0,0 +1,2 @@
+// Doc from xtests
+package doc_test
diff --git a/src/go/build/testdata/doc/b_test.go b/src/go/build/testdata/doc/b_test.go
new file mode 100644
index 0000000..0cf1605
--- /dev/null
+++ b/src/go/build/testdata/doc/b_test.go
@@ -0,0 +1 @@
+package doc_test
diff --git a/src/go/build/testdata/doc/c_test.go b/src/go/build/testdata/doc/c_test.go
new file mode 100644
index 0000000..1025707
--- /dev/null
+++ b/src/go/build/testdata/doc/c_test.go
@@ -0,0 +1 @@
+package doc
diff --git a/src/go/build/testdata/doc/d_test.go b/src/go/build/testdata/doc/d_test.go
new file mode 100644
index 0000000..ec19564
--- /dev/null
+++ b/src/go/build/testdata/doc/d_test.go
@@ -0,0 +1,2 @@
+// Doc from regular tests.
+package doc
diff --git a/src/go/build/testdata/doc/e.go b/src/go/build/testdata/doc/e.go
new file mode 100644
index 0000000..1025707
--- /dev/null
+++ b/src/go/build/testdata/doc/e.go
@@ -0,0 +1 @@
+package doc
diff --git a/src/go/build/testdata/doc/f.go b/src/go/build/testdata/doc/f.go
new file mode 100644
index 0000000..ab1d0bc
--- /dev/null
+++ b/src/go/build/testdata/doc/f.go
@@ -0,0 +1,2 @@
+// Correct
+package doc
diff --git a/src/go/build/testdata/empty/dummy b/src/go/build/testdata/empty/dummy
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/go/build/testdata/empty/dummy
diff --git a/src/go/build/testdata/multi/file.go b/src/go/build/testdata/multi/file.go
new file mode 100644
index 0000000..ee946eb
--- /dev/null
+++ b/src/go/build/testdata/multi/file.go
@@ -0,0 +1,5 @@
+// Test data - not compiled.
+
+package main
+
+func main() {}
diff --git a/src/go/build/testdata/multi/file_appengine.go b/src/go/build/testdata/multi/file_appengine.go
new file mode 100644
index 0000000..4ea31e7
--- /dev/null
+++ b/src/go/build/testdata/multi/file_appengine.go
@@ -0,0 +1,5 @@
+// Test data - not compiled.
+
+package test_package
+
+func init() {}
diff --git a/src/go/build/testdata/other/file/file.go b/src/go/build/testdata/other/file/file.go
new file mode 100644
index 0000000..bbfd3e9
--- /dev/null
+++ b/src/go/build/testdata/other/file/file.go
@@ -0,0 +1,5 @@
+// Test data - not compiled.
+
+package file
+
+func F() {}
diff --git a/src/go/build/testdata/other/main.go b/src/go/build/testdata/other/main.go
new file mode 100644
index 0000000..e090435
--- /dev/null
+++ b/src/go/build/testdata/other/main.go
@@ -0,0 +1,11 @@
+// Test data - not compiled.
+
+package main
+
+import (
+ "./file"
+)
+
+func main() {
+ file.F()
+}
diff --git a/src/go/build/testdata/withvendor/src/a/b/b.go b/src/go/build/testdata/withvendor/src/a/b/b.go
new file mode 100644
index 0000000..4405d54
--- /dev/null
+++ b/src/go/build/testdata/withvendor/src/a/b/b.go
@@ -0,0 +1,3 @@
+package b
+
+import _ "c/d"
diff --git a/src/go/build/testdata/withvendor/src/a/vendor/c/d/d.go b/src/go/build/testdata/withvendor/src/a/vendor/c/d/d.go
new file mode 100644
index 0000000..142fb42
--- /dev/null
+++ b/src/go/build/testdata/withvendor/src/a/vendor/c/d/d.go
@@ -0,0 +1 @@
+package d
diff --git a/src/go/constant/example_test.go b/src/go/constant/example_test.go
new file mode 100644
index 0000000..6443ee6
--- /dev/null
+++ b/src/go/constant/example_test.go
@@ -0,0 +1,180 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package constant_test
+
+import (
+ "fmt"
+ "go/constant"
+ "go/token"
+ "math"
+ "sort"
+)
+
+func Example_complexNumbers() {
+ // Create the complex number 2.3 + 5i.
+ ar := constant.MakeFloat64(2.3)
+ ai := constant.MakeImag(constant.MakeInt64(5))
+ a := constant.BinaryOp(ar, token.ADD, ai)
+
+ // Compute (2.3 + 5i) * 11.
+ b := constant.MakeUint64(11)
+ c := constant.BinaryOp(a, token.MUL, b)
+
+ // Convert c into a complex128.
+ Ar, exact := constant.Float64Val(constant.Real(c))
+ if !exact {
+ fmt.Printf("Could not represent real part %s exactly as float64\n", constant.Real(c))
+ }
+ Ai, exact := constant.Float64Val(constant.Imag(c))
+ if !exact {
+ fmt.Printf("Could not represent imaginary part %s as exactly as float64\n", constant.Imag(c))
+ }
+ C := complex(Ar, Ai)
+
+ fmt.Println("literal", 25.3+55i)
+ fmt.Println("go/constant", c)
+ fmt.Println("complex128", C)
+
+ // Output:
+ //
+ // Could not represent real part 25.3 exactly as float64
+ // literal (25.3+55i)
+ // go/constant (25.3 + 55i)
+ // complex128 (25.299999999999997+55i)
+}
+
+func ExampleBinaryOp() {
+ // 11 / 0.5
+ a := constant.MakeUint64(11)
+ b := constant.MakeFloat64(0.5)
+ c := constant.BinaryOp(a, token.QUO, b)
+ fmt.Println(c)
+
+ // Output: 22
+}
+
+func ExampleUnaryOp() {
+ vs := []constant.Value{
+ constant.MakeBool(true),
+ constant.MakeFloat64(2.7),
+ constant.MakeUint64(42),
+ }
+
+ for i, v := range vs {
+ switch v.Kind() {
+ case constant.Bool:
+ vs[i] = constant.UnaryOp(token.NOT, v, 0)
+
+ case constant.Float:
+ vs[i] = constant.UnaryOp(token.SUB, v, 0)
+
+ case constant.Int:
+ // Use 16-bit precision.
+ // This would be equivalent to ^uint16(v).
+ vs[i] = constant.UnaryOp(token.XOR, v, 16)
+ }
+ }
+
+ for _, v := range vs {
+ fmt.Println(v)
+ }
+
+ // Output:
+ //
+ // false
+ // -2.7
+ // 65493
+}
+
+func ExampleCompare() {
+ vs := []constant.Value{
+ constant.MakeString("Z"),
+ constant.MakeString("bacon"),
+ constant.MakeString("go"),
+ constant.MakeString("Frame"),
+ constant.MakeString("defer"),
+ constant.MakeFromLiteral(`"a"`, token.STRING, 0),
+ }
+
+ sort.Slice(vs, func(i, j int) bool {
+ // Equivalent to vs[i] <= vs[j].
+ return constant.Compare(vs[i], token.LEQ, vs[j])
+ })
+
+ for _, v := range vs {
+ fmt.Println(constant.StringVal(v))
+ }
+
+ // Output:
+ //
+ // Frame
+ // Z
+ // a
+ // bacon
+ // defer
+ // go
+}
+
+func ExampleSign() {
+ zero := constant.MakeInt64(0)
+ one := constant.MakeInt64(1)
+ negOne := constant.MakeInt64(-1)
+
+ mkComplex := func(a, b constant.Value) constant.Value {
+ b = constant.MakeImag(b)
+ return constant.BinaryOp(a, token.ADD, b)
+ }
+
+ vs := []constant.Value{
+ negOne,
+ mkComplex(zero, negOne),
+ mkComplex(one, negOne),
+ mkComplex(negOne, one),
+ mkComplex(negOne, negOne),
+ zero,
+ mkComplex(zero, zero),
+ one,
+ mkComplex(zero, one),
+ mkComplex(one, one),
+ }
+
+ for _, v := range vs {
+ fmt.Printf("% d %s\n", constant.Sign(v), v)
+ }
+
+ // Output:
+ //
+ // -1 -1
+ // -1 (0 + -1i)
+ // -1 (1 + -1i)
+ // -1 (-1 + 1i)
+ // -1 (-1 + -1i)
+ // 0 0
+ // 0 (0 + 0i)
+ // 1 1
+ // 1 (0 + 1i)
+ // 1 (1 + 1i)
+}
+
+func ExampleVal() {
+ maxint := constant.MakeInt64(math.MaxInt64)
+ fmt.Printf("%v\n", constant.Val(maxint))
+
+ e := constant.MakeFloat64(math.E)
+ fmt.Printf("%v\n", constant.Val(e))
+
+ b := constant.MakeBool(true)
+ fmt.Printf("%v\n", constant.Val(b))
+
+ b = constant.Make(false)
+ fmt.Printf("%v\n", constant.Val(b))
+
+ // Output:
+ //
+ // 9223372036854775807
+ // 6121026514868073/2251799813685248
+ // true
+ // false
+}
diff --git a/src/go/constant/value.go b/src/go/constant/value.go
new file mode 100644
index 0000000..4641442
--- /dev/null
+++ b/src/go/constant/value.go
@@ -0,0 +1,1391 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package constant implements Values representing untyped
+// Go constants and their corresponding operations.
+//
+// A special Unknown value may be used when a value
+// is unknown due to an error. Operations on unknown
+// values produce unknown values unless specified
+// otherwise.
+//
+package constant
+
+import (
+ "fmt"
+ "go/token"
+ "math"
+ "math/big"
+ "strconv"
+ "strings"
+ "sync"
+ "unicode/utf8"
+)
+
+// Kind specifies the kind of value represented by a Value.
+type Kind int
+
+const (
+ // unknown values
+ Unknown Kind = iota
+
+ // non-numeric values
+ Bool
+ String
+
+ // numeric values
+ Int
+ Float
+ Complex
+)
+
+// A Value represents the value of a Go constant.
+type Value interface {
+ // Kind returns the value kind.
+ Kind() Kind
+
+ // String returns a short, quoted (human-readable) form of the value.
+ // For numeric values, the result may be an approximation;
+ // for String values the result may be a shortened string.
+ // Use ExactString for a string representing a value exactly.
+ String() string
+
+ // ExactString returns an exact, quoted (human-readable) form of the value.
+ // If the Value is of Kind String, use StringVal to obtain the unquoted string.
+ ExactString() string
+
+ // Prevent external implementations.
+ implementsValue()
+}
+
+// ----------------------------------------------------------------------------
+// Implementations
+
+// Maximum supported mantissa precision.
+// The spec requires at least 256 bits; typical implementations use 512 bits.
+const prec = 512
+
+// TODO(gri) Consider storing "error" information in an unknownVal so clients
+// can provide better error messages. For instance, if a number is
+// too large (incl. infinity), that could be recorded in unknownVal.
+// See also #20583 and #42695 for use cases.
+
+type (
+ unknownVal struct{}
+ boolVal bool
+ stringVal struct {
+ // Lazy value: either a string (l,r==nil) or an addition (l,r!=nil).
+ mu sync.Mutex
+ s string
+ l, r *stringVal
+ }
+ int64Val int64 // Int values representable as an int64
+ intVal struct{ val *big.Int } // Int values not representable as an int64
+ ratVal struct{ val *big.Rat } // Float values representable as a fraction
+ floatVal struct{ val *big.Float } // Float values not representable as a fraction
+ complexVal struct{ re, im Value }
+)
+
+func (unknownVal) Kind() Kind { return Unknown }
+func (boolVal) Kind() Kind { return Bool }
+func (*stringVal) Kind() Kind { return String }
+func (int64Val) Kind() Kind { return Int }
+func (intVal) Kind() Kind { return Int }
+func (ratVal) Kind() Kind { return Float }
+func (floatVal) Kind() Kind { return Float }
+func (complexVal) Kind() Kind { return Complex }
+
+func (unknownVal) String() string { return "unknown" }
+func (x boolVal) String() string { return strconv.FormatBool(bool(x)) }
+
+// String returns a possibly shortened quoted form of the String value.
+func (x *stringVal) String() string {
+ const maxLen = 72 // a reasonable length
+ s := strconv.Quote(x.string())
+ if utf8.RuneCountInString(s) > maxLen {
+ // The string without the enclosing quotes is greater than maxLen-2 runes
+ // long. Remove the last 3 runes (including the closing '"') by keeping
+ // only the first maxLen-3 runes; then add "...".
+ i := 0
+ for n := 0; n < maxLen-3; n++ {
+ _, size := utf8.DecodeRuneInString(s[i:])
+ i += size
+ }
+ s = s[:i] + "..."
+ }
+ return s
+}
+
+// string constructs and returns the actual string literal value.
+// If x represents an addition, then it rewrites x to be a single
+// string, to speed future calls. This lazy construction avoids
+// building different string values for all subpieces of a large
+// concatenation. See golang.org/issue/23348.
+func (x *stringVal) string() string {
+ x.mu.Lock()
+ if x.l != nil {
+ x.s = strings.Join(reverse(x.appendReverse(nil)), "")
+ x.l = nil
+ x.r = nil
+ }
+ s := x.s
+ x.mu.Unlock()
+
+ return s
+}
+
+// reverse reverses x in place and returns it.
+func reverse(x []string) []string {
+ n := len(x)
+ for i := 0; i+i < n; i++ {
+ x[i], x[n-1-i] = x[n-1-i], x[i]
+ }
+ return x
+}
+
+// appendReverse appends to list all of x's subpieces, but in reverse,
+// and returns the result. Appending the reversal allows processing
+// the right side in a recursive call and the left side in a loop.
+// Because a chain like a + b + c + d + e is actually represented
+// as ((((a + b) + c) + d) + e), the left-side loop avoids deep recursion.
+// x must be locked.
+func (x *stringVal) appendReverse(list []string) []string {
+ y := x
+ for y.r != nil {
+ y.r.mu.Lock()
+ list = y.r.appendReverse(list)
+ y.r.mu.Unlock()
+
+ l := y.l
+ if y != x {
+ y.mu.Unlock()
+ }
+ l.mu.Lock()
+ y = l
+ }
+ s := y.s
+ if y != x {
+ y.mu.Unlock()
+ }
+ return append(list, s)
+}
+
+func (x int64Val) String() string { return strconv.FormatInt(int64(x), 10) }
+func (x intVal) String() string { return x.val.String() }
+func (x ratVal) String() string { return rtof(x).String() }
+
+// String returns a decimal approximation of the Float value.
+func (x floatVal) String() string {
+ f := x.val
+
+ // Don't try to convert infinities (will not terminate).
+ if f.IsInf() {
+ return f.String()
+ }
+
+ // Use exact fmt formatting if in float64 range (common case):
+ // proceed if f doesn't underflow to 0 or overflow to inf.
+ if x, _ := f.Float64(); f.Sign() == 0 == (x == 0) && !math.IsInf(x, 0) {
+ return fmt.Sprintf("%.6g", x)
+ }
+
+ // Out of float64 range. Do approximate manual to decimal
+ // conversion to avoid precise but possibly slow Float
+ // formatting.
+ // f = mant * 2**exp
+ var mant big.Float
+ exp := f.MantExp(&mant) // 0.5 <= |mant| < 1.0
+
+ // approximate float64 mantissa m and decimal exponent d
+ // f ~ m * 10**d
+ m, _ := mant.Float64() // 0.5 <= |m| < 1.0
+ d := float64(exp) * (math.Ln2 / math.Ln10) // log_10(2)
+
+ // adjust m for truncated (integer) decimal exponent e
+ e := int64(d)
+ m *= math.Pow(10, d-float64(e))
+
+ // ensure 1 <= |m| < 10
+ switch am := math.Abs(m); {
+ case am < 1-0.5e-6:
+ // The %.6g format below rounds m to 5 digits after the
+ // decimal point. Make sure that m*10 < 10 even after
+ // rounding up: m*10 + 0.5e-5 < 10 => m < 1 - 0.5e6.
+ m *= 10
+ e--
+ case am >= 10:
+ m /= 10
+ e++
+ }
+
+ return fmt.Sprintf("%.6ge%+d", m, e)
+}
+
+func (x complexVal) String() string { return fmt.Sprintf("(%s + %si)", x.re, x.im) }
+
+func (x unknownVal) ExactString() string { return x.String() }
+func (x boolVal) ExactString() string { return x.String() }
+func (x *stringVal) ExactString() string { return strconv.Quote(x.string()) }
+func (x int64Val) ExactString() string { return x.String() }
+func (x intVal) ExactString() string { return x.String() }
+
+func (x ratVal) ExactString() string {
+ r := x.val
+ if r.IsInt() {
+ return r.Num().String()
+ }
+ return r.String()
+}
+
+func (x floatVal) ExactString() string { return x.val.Text('p', 0) }
+
+func (x complexVal) ExactString() string {
+ return fmt.Sprintf("(%s + %si)", x.re.ExactString(), x.im.ExactString())
+}
+
+func (unknownVal) implementsValue() {}
+func (boolVal) implementsValue() {}
+func (*stringVal) implementsValue() {}
+func (int64Val) implementsValue() {}
+func (ratVal) implementsValue() {}
+func (intVal) implementsValue() {}
+func (floatVal) implementsValue() {}
+func (complexVal) implementsValue() {}
+
+func newInt() *big.Int { return new(big.Int) }
+func newRat() *big.Rat { return new(big.Rat) }
+func newFloat() *big.Float { return new(big.Float).SetPrec(prec) }
+
+func i64toi(x int64Val) intVal { return intVal{newInt().SetInt64(int64(x))} }
+func i64tor(x int64Val) ratVal { return ratVal{newRat().SetInt64(int64(x))} }
+func i64tof(x int64Val) floatVal { return floatVal{newFloat().SetInt64(int64(x))} }
+func itor(x intVal) ratVal { return ratVal{newRat().SetInt(x.val)} }
+func itof(x intVal) floatVal { return floatVal{newFloat().SetInt(x.val)} }
+
+func rtof(x ratVal) floatVal {
+ a := newFloat().SetInt(x.val.Num())
+ b := newFloat().SetInt(x.val.Denom())
+ return floatVal{a.Quo(a, b)}
+}
+
+func vtoc(x Value) complexVal { return complexVal{x, int64Val(0)} }
+
+func makeInt(x *big.Int) Value {
+ if x.IsInt64() {
+ return int64Val(x.Int64())
+ }
+ return intVal{x}
+}
+
+// Permit fractions with component sizes up to maxExp
+// before switching to using floating-point numbers.
+const maxExp = 4 << 10
+
+func makeRat(x *big.Rat) Value {
+ a := x.Num()
+ b := x.Denom()
+ if a.BitLen() < maxExp && b.BitLen() < maxExp {
+ // ok to remain fraction
+ return ratVal{x}
+ }
+ // components too large => switch to float
+ fa := newFloat().SetInt(a)
+ fb := newFloat().SetInt(b)
+ return floatVal{fa.Quo(fa, fb)}
+}
+
+var floatVal0 = floatVal{newFloat()}
+
+func makeFloat(x *big.Float) Value {
+ // convert -0
+ if x.Sign() == 0 {
+ return floatVal0
+ }
+ if x.IsInf() {
+ return unknownVal{}
+ }
+ return floatVal{x}
+}
+
+func makeComplex(re, im Value) Value {
+ if re.Kind() == Unknown || im.Kind() == Unknown {
+ return unknownVal{}
+ }
+ return complexVal{re, im}
+}
+
+func makeFloatFromLiteral(lit string) Value {
+ if f, ok := newFloat().SetString(lit); ok {
+ if smallRat(f) {
+ // ok to use rationals
+ if f.Sign() == 0 {
+ // Issue 20228: If the float underflowed to zero, parse just "0".
+ // Otherwise, lit might contain a value with a large negative exponent,
+ // such as -6e-1886451601. As a float, that will underflow to 0,
+ // but it'll take forever to parse as a Rat.
+ lit = "0"
+ }
+ if r, ok := newRat().SetString(lit); ok {
+ return ratVal{r}
+ }
+ }
+ // otherwise use floats
+ return makeFloat(f)
+ }
+ return nil
+}
+
+// smallRat reports whether x would lead to "reasonably"-sized fraction
+// if converted to a *big.Rat.
+func smallRat(x *big.Float) bool {
+ if !x.IsInf() {
+ e := x.MantExp(nil)
+ return -maxExp < e && e < maxExp
+ }
+ return false
+}
+
+// ----------------------------------------------------------------------------
+// Factories
+
+// MakeUnknown returns the Unknown value.
+func MakeUnknown() Value { return unknownVal{} }
+
+// MakeBool returns the Bool value for b.
+func MakeBool(b bool) Value { return boolVal(b) }
+
+// MakeString returns the String value for s.
+func MakeString(s string) Value { return &stringVal{s: s} }
+
+// MakeInt64 returns the Int value for x.
+func MakeInt64(x int64) Value { return int64Val(x) }
+
+// MakeUint64 returns the Int value for x.
+func MakeUint64(x uint64) Value {
+ if x < 1<<63 {
+ return int64Val(int64(x))
+ }
+ return intVal{newInt().SetUint64(x)}
+}
+
+// MakeFloat64 returns the Float value for x.
+// If x is -0.0, the result is 0.0.
+// If x is not finite, the result is an Unknown.
+func MakeFloat64(x float64) Value {
+ if math.IsInf(x, 0) || math.IsNaN(x) {
+ return unknownVal{}
+ }
+ return ratVal{newRat().SetFloat64(x + 0)} // convert -0 to 0
+}
+
+// MakeFromLiteral returns the corresponding integer, floating-point,
+// imaginary, character, or string value for a Go literal string. The
+// tok value must be one of token.INT, token.FLOAT, token.IMAG,
+// token.CHAR, or token.STRING. The final argument must be zero.
+// If the literal string syntax is invalid, the result is an Unknown.
+func MakeFromLiteral(lit string, tok token.Token, zero uint) Value {
+ if zero != 0 {
+ panic("MakeFromLiteral called with non-zero last argument")
+ }
+
+ switch tok {
+ case token.INT:
+ if x, err := strconv.ParseInt(lit, 0, 64); err == nil {
+ return int64Val(x)
+ }
+ if x, ok := newInt().SetString(lit, 0); ok {
+ return intVal{x}
+ }
+
+ case token.FLOAT:
+ if x := makeFloatFromLiteral(lit); x != nil {
+ return x
+ }
+
+ case token.IMAG:
+ if n := len(lit); n > 0 && lit[n-1] == 'i' {
+ if im := makeFloatFromLiteral(lit[:n-1]); im != nil {
+ return makeComplex(int64Val(0), im)
+ }
+ }
+
+ case token.CHAR:
+ if n := len(lit); n >= 2 {
+ if code, _, _, err := strconv.UnquoteChar(lit[1:n-1], '\''); err == nil {
+ return MakeInt64(int64(code))
+ }
+ }
+
+ case token.STRING:
+ if s, err := strconv.Unquote(lit); err == nil {
+ return MakeString(s)
+ }
+
+ default:
+ panic(fmt.Sprintf("%v is not a valid token", tok))
+ }
+
+ return unknownVal{}
+}
+
+// ----------------------------------------------------------------------------
+// Accessors
+//
+// For unknown arguments the result is the zero value for the respective
+// accessor type, except for Sign, where the result is 1.
+
+// BoolVal returns the Go boolean value of x, which must be a Bool or an Unknown.
+// If x is Unknown, the result is false.
+func BoolVal(x Value) bool {
+ switch x := x.(type) {
+ case boolVal:
+ return bool(x)
+ case unknownVal:
+ return false
+ default:
+ panic(fmt.Sprintf("%v not a Bool", x))
+ }
+}
+
+// StringVal returns the Go string value of x, which must be a String or an Unknown.
+// If x is Unknown, the result is "".
+func StringVal(x Value) string {
+ switch x := x.(type) {
+ case *stringVal:
+ return x.string()
+ case unknownVal:
+ return ""
+ default:
+ panic(fmt.Sprintf("%v not a String", x))
+ }
+}
+
+// Int64Val returns the Go int64 value of x and whether the result is exact;
+// x must be an Int or an Unknown. If the result is not exact, its value is undefined.
+// If x is Unknown, the result is (0, false).
+func Int64Val(x Value) (int64, bool) {
+ switch x := x.(type) {
+ case int64Val:
+ return int64(x), true
+ case intVal:
+ return x.val.Int64(), false // not an int64Val and thus not exact
+ case unknownVal:
+ return 0, false
+ default:
+ panic(fmt.Sprintf("%v not an Int", x))
+ }
+}
+
+// Uint64Val returns the Go uint64 value of x and whether the result is exact;
+// x must be an Int or an Unknown. If the result is not exact, its value is undefined.
+// If x is Unknown, the result is (0, false).
+func Uint64Val(x Value) (uint64, bool) {
+ switch x := x.(type) {
+ case int64Val:
+ return uint64(x), x >= 0
+ case intVal:
+ return x.val.Uint64(), x.val.IsUint64()
+ case unknownVal:
+ return 0, false
+ default:
+ panic(fmt.Sprintf("%v not an Int", x))
+ }
+}
+
+// Float32Val is like Float64Val but for float32 instead of float64.
+func Float32Val(x Value) (float32, bool) {
+ switch x := x.(type) {
+ case int64Val:
+ f := float32(x)
+ return f, int64Val(f) == x
+ case intVal:
+ f, acc := newFloat().SetInt(x.val).Float32()
+ return f, acc == big.Exact
+ case ratVal:
+ return x.val.Float32()
+ case floatVal:
+ f, acc := x.val.Float32()
+ return f, acc == big.Exact
+ case unknownVal:
+ return 0, false
+ default:
+ panic(fmt.Sprintf("%v not a Float", x))
+ }
+}
+
+// Float64Val returns the nearest Go float64 value of x and whether the result is exact;
+// x must be numeric or an Unknown, but not Complex. For values too small (too close to 0)
+// to represent as float64, Float64Val silently underflows to 0. The result sign always
+// matches the sign of x, even for 0.
+// If x is Unknown, the result is (0, false).
+func Float64Val(x Value) (float64, bool) {
+ switch x := x.(type) {
+ case int64Val:
+ f := float64(int64(x))
+ return f, int64Val(f) == x
+ case intVal:
+ f, acc := newFloat().SetInt(x.val).Float64()
+ return f, acc == big.Exact
+ case ratVal:
+ return x.val.Float64()
+ case floatVal:
+ f, acc := x.val.Float64()
+ return f, acc == big.Exact
+ case unknownVal:
+ return 0, false
+ default:
+ panic(fmt.Sprintf("%v not a Float", x))
+ }
+}
+
+// Val returns the underlying value for a given constant. Since it returns an
+// interface, it is up to the caller to type assert the result to the expected
+// type. The possible dynamic return types are:
+//
+// x Kind type of result
+// -----------------------------------------
+// Bool bool
+// String string
+// Int int64 or *big.Int
+// Float *big.Float or *big.Rat
+// everything else nil
+//
+func Val(x Value) interface{} {
+ switch x := x.(type) {
+ case boolVal:
+ return bool(x)
+ case *stringVal:
+ return x.string()
+ case int64Val:
+ return int64(x)
+ case intVal:
+ return x.val
+ case ratVal:
+ return x.val
+ case floatVal:
+ return x.val
+ default:
+ return nil
+ }
+}
+
+// Make returns the Value for x.
+//
+// type of x result Kind
+// ----------------------------
+// bool Bool
+// string String
+// int64 Int
+// *big.Int Int
+// *big.Float Float
+// *big.Rat Float
+// anything else Unknown
+//
+func Make(x interface{}) Value {
+ switch x := x.(type) {
+ case bool:
+ return boolVal(x)
+ case string:
+ return &stringVal{s: x}
+ case int64:
+ return int64Val(x)
+ case *big.Int:
+ return makeInt(x)
+ case *big.Rat:
+ return makeRat(x)
+ case *big.Float:
+ return makeFloat(x)
+ default:
+ return unknownVal{}
+ }
+}
+
+// BitLen returns the number of bits required to represent
+// the absolute value x in binary representation; x must be an Int or an Unknown.
+// If x is Unknown, the result is 0.
+func BitLen(x Value) int {
+ switch x := x.(type) {
+ case int64Val:
+ return i64toi(x).val.BitLen()
+ case intVal:
+ return x.val.BitLen()
+ case unknownVal:
+ return 0
+ default:
+ panic(fmt.Sprintf("%v not an Int", x))
+ }
+}
+
+// Sign returns -1, 0, or 1 depending on whether x < 0, x == 0, or x > 0;
+// x must be numeric or Unknown. For complex values x, the sign is 0 if x == 0,
+// otherwise it is != 0. If x is Unknown, the result is 1.
+func Sign(x Value) int {
+ switch x := x.(type) {
+ case int64Val:
+ switch {
+ case x < 0:
+ return -1
+ case x > 0:
+ return 1
+ }
+ return 0
+ case intVal:
+ return x.val.Sign()
+ case ratVal:
+ return x.val.Sign()
+ case floatVal:
+ return x.val.Sign()
+ case complexVal:
+ return Sign(x.re) | Sign(x.im)
+ case unknownVal:
+ return 1 // avoid spurious division by zero errors
+ default:
+ panic(fmt.Sprintf("%v not numeric", x))
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Support for assembling/disassembling numeric values
+
+const (
+ // Compute the size of a Word in bytes.
+ _m = ^big.Word(0)
+ _log = _m>>8&1 + _m>>16&1 + _m>>32&1
+ wordSize = 1 << _log
+)
+
+// Bytes returns the bytes for the absolute value of x in little-
+// endian binary representation; x must be an Int.
+func Bytes(x Value) []byte {
+ var t intVal
+ switch x := x.(type) {
+ case int64Val:
+ t = i64toi(x)
+ case intVal:
+ t = x
+ default:
+ panic(fmt.Sprintf("%v not an Int", x))
+ }
+
+ words := t.val.Bits()
+ bytes := make([]byte, len(words)*wordSize)
+
+ i := 0
+ for _, w := range words {
+ for j := 0; j < wordSize; j++ {
+ bytes[i] = byte(w)
+ w >>= 8
+ i++
+ }
+ }
+ // remove leading 0's
+ for i > 0 && bytes[i-1] == 0 {
+ i--
+ }
+
+ return bytes[:i]
+}
+
+// MakeFromBytes returns the Int value given the bytes of its little-endian
+// binary representation. An empty byte slice argument represents 0.
+func MakeFromBytes(bytes []byte) Value {
+ words := make([]big.Word, (len(bytes)+(wordSize-1))/wordSize)
+
+ i := 0
+ var w big.Word
+ var s uint
+ for _, b := range bytes {
+ w |= big.Word(b) << s
+ if s += 8; s == wordSize*8 {
+ words[i] = w
+ i++
+ w = 0
+ s = 0
+ }
+ }
+ // store last word
+ if i < len(words) {
+ words[i] = w
+ i++
+ }
+ // remove leading 0's
+ for i > 0 && words[i-1] == 0 {
+ i--
+ }
+
+ return makeInt(newInt().SetBits(words[:i]))
+}
+
+// Num returns the numerator of x; x must be Int, Float, or Unknown.
+// If x is Unknown, or if it is too large or small to represent as a
+// fraction, the result is Unknown. Otherwise the result is an Int
+// with the same sign as x.
+func Num(x Value) Value {
+ switch x := x.(type) {
+ case int64Val, intVal:
+ return x
+ case ratVal:
+ return makeInt(x.val.Num())
+ case floatVal:
+ if smallRat(x.val) {
+ r, _ := x.val.Rat(nil)
+ return makeInt(r.Num())
+ }
+ case unknownVal:
+ break
+ default:
+ panic(fmt.Sprintf("%v not Int or Float", x))
+ }
+ return unknownVal{}
+}
+
+// Denom returns the denominator of x; x must be Int, Float, or Unknown.
+// If x is Unknown, or if it is too large or small to represent as a
+// fraction, the result is Unknown. Otherwise the result is an Int >= 1.
+func Denom(x Value) Value {
+ switch x := x.(type) {
+ case int64Val, intVal:
+ return int64Val(1)
+ case ratVal:
+ return makeInt(x.val.Denom())
+ case floatVal:
+ if smallRat(x.val) {
+ r, _ := x.val.Rat(nil)
+ return makeInt(r.Denom())
+ }
+ case unknownVal:
+ break
+ default:
+ panic(fmt.Sprintf("%v not Int or Float", x))
+ }
+ return unknownVal{}
+}
+
+// MakeImag returns the Complex value x*i;
+// x must be Int, Float, or Unknown.
+// If x is Unknown, the result is Unknown.
+func MakeImag(x Value) Value {
+ switch x.(type) {
+ case unknownVal:
+ return x
+ case int64Val, intVal, ratVal, floatVal:
+ return makeComplex(int64Val(0), x)
+ default:
+ panic(fmt.Sprintf("%v not Int or Float", x))
+ }
+}
+
+// Real returns the real part of x, which must be a numeric or unknown value.
+// If x is Unknown, the result is Unknown.
+func Real(x Value) Value {
+ switch x := x.(type) {
+ case unknownVal, int64Val, intVal, ratVal, floatVal:
+ return x
+ case complexVal:
+ return x.re
+ default:
+ panic(fmt.Sprintf("%v not numeric", x))
+ }
+}
+
+// Imag returns the imaginary part of x, which must be a numeric or unknown value.
+// If x is Unknown, the result is Unknown.
+func Imag(x Value) Value {
+ switch x := x.(type) {
+ case unknownVal:
+ return x
+ case int64Val, intVal, ratVal, floatVal:
+ return int64Val(0)
+ case complexVal:
+ return x.im
+ default:
+ panic(fmt.Sprintf("%v not numeric", x))
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Numeric conversions
+
+// ToInt converts x to an Int value if x is representable as an Int.
+// Otherwise it returns an Unknown.
+func ToInt(x Value) Value {
+ switch x := x.(type) {
+ case int64Val, intVal:
+ return x
+
+ case ratVal:
+ if x.val.IsInt() {
+ return makeInt(x.val.Num())
+ }
+
+ case floatVal:
+ // avoid creation of huge integers
+ // (Existing tests require permitting exponents of at least 1024;
+ // allow any value that would also be permissible as a fraction.)
+ if smallRat(x.val) {
+ i := newInt()
+ if _, acc := x.val.Int(i); acc == big.Exact {
+ return makeInt(i)
+ }
+
+ // If we can get an integer by rounding up or down,
+ // assume x is not an integer because of rounding
+ // errors in prior computations.
+
+ const delta = 4 // a small number of bits > 0
+ var t big.Float
+ t.SetPrec(prec - delta)
+
+ // try rounding down a little
+ t.SetMode(big.ToZero)
+ t.Set(x.val)
+ if _, acc := t.Int(i); acc == big.Exact {
+ return makeInt(i)
+ }
+
+ // try rounding up a little
+ t.SetMode(big.AwayFromZero)
+ t.Set(x.val)
+ if _, acc := t.Int(i); acc == big.Exact {
+ return makeInt(i)
+ }
+ }
+
+ case complexVal:
+ if re := ToFloat(x); re.Kind() == Float {
+ return ToInt(re)
+ }
+ }
+
+ return unknownVal{}
+}
+
+// ToFloat converts x to a Float value if x is representable as a Float.
+// Otherwise it returns an Unknown.
+func ToFloat(x Value) Value {
+ switch x := x.(type) {
+ case int64Val:
+ return i64tof(x)
+ case intVal:
+ return itof(x)
+ case ratVal, floatVal:
+ return x
+ case complexVal:
+ if im := ToInt(x.im); im.Kind() == Int && Sign(im) == 0 {
+ // imaginary component is 0
+ return ToFloat(x.re)
+ }
+ }
+ return unknownVal{}
+}
+
+// ToComplex converts x to a Complex value if x is representable as a Complex.
+// Otherwise it returns an Unknown.
+func ToComplex(x Value) Value {
+ switch x := x.(type) {
+ case int64Val:
+ return vtoc(i64tof(x))
+ case intVal:
+ return vtoc(itof(x))
+ case ratVal:
+ return vtoc(x)
+ case floatVal:
+ return vtoc(x)
+ case complexVal:
+ return x
+ }
+ return unknownVal{}
+}
+
+// ----------------------------------------------------------------------------
+// Operations
+
+// is32bit reports whether x can be represented using 32 bits.
+func is32bit(x int64) bool {
+ const s = 32
+ return -1<<(s-1) <= x && x <= 1<<(s-1)-1
+}
+
+// is63bit reports whether x can be represented using 63 bits.
+func is63bit(x int64) bool {
+ const s = 63
+ return -1<<(s-1) <= x && x <= 1<<(s-1)-1
+}
+
+// UnaryOp returns the result of the unary expression op y.
+// The operation must be defined for the operand.
+// If prec > 0 it specifies the ^ (xor) result size in bits.
+// If y is Unknown, the result is Unknown.
+//
+func UnaryOp(op token.Token, y Value, prec uint) Value {
+ switch op {
+ case token.ADD:
+ switch y.(type) {
+ case unknownVal, int64Val, intVal, ratVal, floatVal, complexVal:
+ return y
+ }
+
+ case token.SUB:
+ switch y := y.(type) {
+ case unknownVal:
+ return y
+ case int64Val:
+ if z := -y; z != y {
+ return z // no overflow
+ }
+ return makeInt(newInt().Neg(big.NewInt(int64(y))))
+ case intVal:
+ return makeInt(newInt().Neg(y.val))
+ case ratVal:
+ return makeRat(newRat().Neg(y.val))
+ case floatVal:
+ return makeFloat(newFloat().Neg(y.val))
+ case complexVal:
+ re := UnaryOp(token.SUB, y.re, 0)
+ im := UnaryOp(token.SUB, y.im, 0)
+ return makeComplex(re, im)
+ }
+
+ case token.XOR:
+ z := newInt()
+ switch y := y.(type) {
+ case unknownVal:
+ return y
+ case int64Val:
+ z.Not(big.NewInt(int64(y)))
+ case intVal:
+ z.Not(y.val)
+ default:
+ goto Error
+ }
+ // For unsigned types, the result will be negative and
+ // thus "too large": We must limit the result precision
+ // to the type's precision.
+ if prec > 0 {
+ z.AndNot(z, newInt().Lsh(big.NewInt(-1), prec)) // z &^= (-1)<<prec
+ }
+ return makeInt(z)
+
+ case token.NOT:
+ switch y := y.(type) {
+ case unknownVal:
+ return y
+ case boolVal:
+ return !y
+ }
+ }
+
+Error:
+ panic(fmt.Sprintf("invalid unary operation %s%v", op, y))
+}
+
+func ord(x Value) int {
+ switch x.(type) {
+ default:
+ // force invalid value into "x position" in match
+ // (don't panic here so that callers can provide a better error message)
+ return -1
+ case unknownVal:
+ return 0
+ case boolVal, *stringVal:
+ return 1
+ case int64Val:
+ return 2
+ case intVal:
+ return 3
+ case ratVal:
+ return 4
+ case floatVal:
+ return 5
+ case complexVal:
+ return 6
+ }
+}
+
+// match returns the matching representation (same type) with the
+// smallest complexity for two values x and y. If one of them is
+// numeric, both of them must be numeric. If one of them is Unknown
+// or invalid (say, nil) both results are that value.
+//
+func match(x, y Value) (_, _ Value) {
+ if ord(x) > ord(y) {
+ y, x = match(y, x)
+ return x, y
+ }
+ // ord(x) <= ord(y)
+
+ switch x := x.(type) {
+ case boolVal, *stringVal, complexVal:
+ return x, y
+
+ case int64Val:
+ switch y := y.(type) {
+ case int64Val:
+ return x, y
+ case intVal:
+ return i64toi(x), y
+ case ratVal:
+ return i64tor(x), y
+ case floatVal:
+ return i64tof(x), y
+ case complexVal:
+ return vtoc(x), y
+ }
+
+ case intVal:
+ switch y := y.(type) {
+ case intVal:
+ return x, y
+ case ratVal:
+ return itor(x), y
+ case floatVal:
+ return itof(x), y
+ case complexVal:
+ return vtoc(x), y
+ }
+
+ case ratVal:
+ switch y := y.(type) {
+ case ratVal:
+ return x, y
+ case floatVal:
+ return rtof(x), y
+ case complexVal:
+ return vtoc(x), y
+ }
+
+ case floatVal:
+ switch y := y.(type) {
+ case floatVal:
+ return x, y
+ case complexVal:
+ return vtoc(x), y
+ }
+ }
+
+ // force unknown and invalid values into "x position" in callers of match
+ // (don't panic here so that callers can provide a better error message)
+ return x, x
+}
+
+// BinaryOp returns the result of the binary expression x op y.
+// The operation must be defined for the operands. If one of the
+// operands is Unknown, the result is Unknown.
+// BinaryOp doesn't handle comparisons or shifts; use Compare
+// or Shift instead.
+//
+// To force integer division of Int operands, use op == token.QUO_ASSIGN
+// instead of token.QUO; the result is guaranteed to be Int in this case.
+// Division by zero leads to a run-time panic.
+//
+func BinaryOp(x_ Value, op token.Token, y_ Value) Value {
+ x, y := match(x_, y_)
+
+ switch x := x.(type) {
+ case unknownVal:
+ return x
+
+ case boolVal:
+ y := y.(boolVal)
+ switch op {
+ case token.LAND:
+ return x && y
+ case token.LOR:
+ return x || y
+ }
+
+ case int64Val:
+ a := int64(x)
+ b := int64(y.(int64Val))
+ var c int64
+ switch op {
+ case token.ADD:
+ if !is63bit(a) || !is63bit(b) {
+ return makeInt(newInt().Add(big.NewInt(a), big.NewInt(b)))
+ }
+ c = a + b
+ case token.SUB:
+ if !is63bit(a) || !is63bit(b) {
+ return makeInt(newInt().Sub(big.NewInt(a), big.NewInt(b)))
+ }
+ c = a - b
+ case token.MUL:
+ if !is32bit(a) || !is32bit(b) {
+ return makeInt(newInt().Mul(big.NewInt(a), big.NewInt(b)))
+ }
+ c = a * b
+ case token.QUO:
+ return makeRat(big.NewRat(a, b))
+ case token.QUO_ASSIGN: // force integer division
+ c = a / b
+ case token.REM:
+ c = a % b
+ case token.AND:
+ c = a & b
+ case token.OR:
+ c = a | b
+ case token.XOR:
+ c = a ^ b
+ case token.AND_NOT:
+ c = a &^ b
+ default:
+ goto Error
+ }
+ return int64Val(c)
+
+ case intVal:
+ a := x.val
+ b := y.(intVal).val
+ c := newInt()
+ switch op {
+ case token.ADD:
+ c.Add(a, b)
+ case token.SUB:
+ c.Sub(a, b)
+ case token.MUL:
+ c.Mul(a, b)
+ case token.QUO:
+ return makeRat(newRat().SetFrac(a, b))
+ case token.QUO_ASSIGN: // force integer division
+ c.Quo(a, b)
+ case token.REM:
+ c.Rem(a, b)
+ case token.AND:
+ c.And(a, b)
+ case token.OR:
+ c.Or(a, b)
+ case token.XOR:
+ c.Xor(a, b)
+ case token.AND_NOT:
+ c.AndNot(a, b)
+ default:
+ goto Error
+ }
+ return makeInt(c)
+
+ case ratVal:
+ a := x.val
+ b := y.(ratVal).val
+ c := newRat()
+ switch op {
+ case token.ADD:
+ c.Add(a, b)
+ case token.SUB:
+ c.Sub(a, b)
+ case token.MUL:
+ c.Mul(a, b)
+ case token.QUO:
+ c.Quo(a, b)
+ default:
+ goto Error
+ }
+ return makeRat(c)
+
+ case floatVal:
+ a := x.val
+ b := y.(floatVal).val
+ c := newFloat()
+ switch op {
+ case token.ADD:
+ c.Add(a, b)
+ case token.SUB:
+ c.Sub(a, b)
+ case token.MUL:
+ c.Mul(a, b)
+ case token.QUO:
+ c.Quo(a, b)
+ default:
+ goto Error
+ }
+ return makeFloat(c)
+
+ case complexVal:
+ y := y.(complexVal)
+ a, b := x.re, x.im
+ c, d := y.re, y.im
+ var re, im Value
+ switch op {
+ case token.ADD:
+ // (a+c) + i(b+d)
+ re = add(a, c)
+ im = add(b, d)
+ case token.SUB:
+ // (a-c) + i(b-d)
+ re = sub(a, c)
+ im = sub(b, d)
+ case token.MUL:
+ // (ac-bd) + i(bc+ad)
+ ac := mul(a, c)
+ bd := mul(b, d)
+ bc := mul(b, c)
+ ad := mul(a, d)
+ re = sub(ac, bd)
+ im = add(bc, ad)
+ case token.QUO:
+ // (ac+bd)/s + i(bc-ad)/s, with s = cc + dd
+ ac := mul(a, c)
+ bd := mul(b, d)
+ bc := mul(b, c)
+ ad := mul(a, d)
+ cc := mul(c, c)
+ dd := mul(d, d)
+ s := add(cc, dd)
+ re = add(ac, bd)
+ re = quo(re, s)
+ im = sub(bc, ad)
+ im = quo(im, s)
+ default:
+ goto Error
+ }
+ return makeComplex(re, im)
+
+ case *stringVal:
+ if op == token.ADD {
+ return &stringVal{l: x, r: y.(*stringVal)}
+ }
+ }
+
+Error:
+ panic(fmt.Sprintf("invalid binary operation %v %s %v", x_, op, y_))
+}
+
+func add(x, y Value) Value { return BinaryOp(x, token.ADD, y) }
+func sub(x, y Value) Value { return BinaryOp(x, token.SUB, y) }
+func mul(x, y Value) Value { return BinaryOp(x, token.MUL, y) }
+func quo(x, y Value) Value { return BinaryOp(x, token.QUO, y) }
+
+// Shift returns the result of the shift expression x op s
+// with op == token.SHL or token.SHR (<< or >>). x must be
+// an Int or an Unknown. If x is Unknown, the result is x.
+//
+func Shift(x Value, op token.Token, s uint) Value {
+ switch x := x.(type) {
+ case unknownVal:
+ return x
+
+ case int64Val:
+ if s == 0 {
+ return x
+ }
+ switch op {
+ case token.SHL:
+ z := i64toi(x).val
+ return makeInt(z.Lsh(z, s))
+ case token.SHR:
+ return x >> s
+ }
+
+ case intVal:
+ if s == 0 {
+ return x
+ }
+ z := newInt()
+ switch op {
+ case token.SHL:
+ return makeInt(z.Lsh(x.val, s))
+ case token.SHR:
+ return makeInt(z.Rsh(x.val, s))
+ }
+ }
+
+ panic(fmt.Sprintf("invalid shift %v %s %d", x, op, s))
+}
+
+func cmpZero(x int, op token.Token) bool {
+ switch op {
+ case token.EQL:
+ return x == 0
+ case token.NEQ:
+ return x != 0
+ case token.LSS:
+ return x < 0
+ case token.LEQ:
+ return x <= 0
+ case token.GTR:
+ return x > 0
+ case token.GEQ:
+ return x >= 0
+ }
+ panic(fmt.Sprintf("invalid comparison %v %s 0", x, op))
+}
+
+// Compare returns the result of the comparison x op y.
+// The comparison must be defined for the operands.
+// If one of the operands is Unknown, the result is
+// false.
+//
+func Compare(x_ Value, op token.Token, y_ Value) bool {
+ x, y := match(x_, y_)
+
+ switch x := x.(type) {
+ case unknownVal:
+ return false
+
+ case boolVal:
+ y := y.(boolVal)
+ switch op {
+ case token.EQL:
+ return x == y
+ case token.NEQ:
+ return x != y
+ }
+
+ case int64Val:
+ y := y.(int64Val)
+ switch op {
+ case token.EQL:
+ return x == y
+ case token.NEQ:
+ return x != y
+ case token.LSS:
+ return x < y
+ case token.LEQ:
+ return x <= y
+ case token.GTR:
+ return x > y
+ case token.GEQ:
+ return x >= y
+ }
+
+ case intVal:
+ return cmpZero(x.val.Cmp(y.(intVal).val), op)
+
+ case ratVal:
+ return cmpZero(x.val.Cmp(y.(ratVal).val), op)
+
+ case floatVal:
+ return cmpZero(x.val.Cmp(y.(floatVal).val), op)
+
+ case complexVal:
+ y := y.(complexVal)
+ re := Compare(x.re, token.EQL, y.re)
+ im := Compare(x.im, token.EQL, y.im)
+ switch op {
+ case token.EQL:
+ return re && im
+ case token.NEQ:
+ return !re || !im
+ }
+
+ case *stringVal:
+ xs := x.string()
+ ys := y.(*stringVal).string()
+ switch op {
+ case token.EQL:
+ return xs == ys
+ case token.NEQ:
+ return xs != ys
+ case token.LSS:
+ return xs < ys
+ case token.LEQ:
+ return xs <= ys
+ case token.GTR:
+ return xs > ys
+ case token.GEQ:
+ return xs >= ys
+ }
+ }
+
+ panic(fmt.Sprintf("invalid comparison %v %s %v", x_, op, y_))
+}
diff --git a/src/go/constant/value_test.go b/src/go/constant/value_test.go
new file mode 100644
index 0000000..2866774
--- /dev/null
+++ b/src/go/constant/value_test.go
@@ -0,0 +1,708 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package constant
+
+import (
+ "fmt"
+ "go/token"
+ "math"
+ "math/big"
+ "strings"
+ "testing"
+)
+
+var intTests = []string{
+ // 0-octals
+ `0_123 = 0123`,
+ `0123_456 = 0123456`,
+
+ // decimals
+ `1_234 = 1234`,
+ `1_234_567 = 1234567`,
+
+ // hexadecimals
+ `0X_0 = 0`,
+ `0X_1234 = 0x1234`,
+ `0X_CAFE_f00d = 0xcafef00d`,
+
+ // octals
+ `0o0 = 0`,
+ `0o1234 = 01234`,
+ `0o01234567 = 01234567`,
+
+ `0O0 = 0`,
+ `0O1234 = 01234`,
+ `0O01234567 = 01234567`,
+
+ `0o_0 = 0`,
+ `0o_1234 = 01234`,
+ `0o0123_4567 = 01234567`,
+
+ `0O_0 = 0`,
+ `0O_1234 = 01234`,
+ `0O0123_4567 = 01234567`,
+
+ // binaries
+ `0b0 = 0`,
+ `0b1011 = 0xb`,
+ `0b00101101 = 0x2d`,
+
+ `0B0 = 0`,
+ `0B1011 = 0xb`,
+ `0B00101101 = 0x2d`,
+
+ `0b_0 = 0`,
+ `0b10_11 = 0xb`,
+ `0b_0010_1101 = 0x2d`,
+}
+
+// The RHS operand may be a floating-point quotient n/d of two integer values n and d.
+var floatTests = []string{
+ // decimal floats
+ `1_2_3. = 123.`,
+ `0_123. = 123.`,
+
+ `0_0e0 = 0.`,
+ `1_2_3e0 = 123.`,
+ `0_123e0 = 123.`,
+
+ `0e-0_0 = 0.`,
+ `1_2_3E+0 = 123.`,
+ `0123E1_2_3 = 123e123`,
+
+ `0.e+1 = 0.`,
+ `123.E-1_0 = 123e-10`,
+ `01_23.e123 = 123e123`,
+
+ `.0e-1 = .0`,
+ `.123E+10 = .123e10`,
+ `.0123E123 = .0123e123`,
+
+ `1_2_3.123 = 123.123`,
+ `0123.01_23 = 123.0123`,
+
+ `1e-1000000000 = 0`,
+ `1e+1000000000 = ?`,
+ `6e5518446744 = ?`,
+ `-6e5518446744 = ?`,
+
+ // hexadecimal floats
+ `0x0.p+0 = 0.`,
+ `0Xdeadcafe.p-10 = 0xdeadcafe/1024`,
+ `0x1234.P84 = 0x1234000000000000000000000`,
+
+ `0x.1p-0 = 1/16`,
+ `0X.deadcafep4 = 0xdeadcafe/0x10000000`,
+ `0x.1234P+12 = 0x1234/0x10`,
+
+ `0x0p0 = 0.`,
+ `0Xdeadcafep+1 = 0x1bd5b95fc`,
+ `0x1234P-10 = 0x1234/1024`,
+
+ `0x0.0p0 = 0.`,
+ `0Xdead.cafep+1 = 0x1bd5b95fc/0x10000`,
+ `0x12.34P-10 = 0x1234/0x40000`,
+
+ `0Xdead_cafep+1 = 0xdeadcafep+1`,
+ `0x_1234P-10 = 0x1234p-10`,
+
+ `0X_dead_cafe.p-10 = 0xdeadcafe.p-10`,
+ `0x12_34.P1_2_3 = 0x1234.p123`,
+}
+
+var imagTests = []string{
+ `1_234i = 1234i`,
+ `1_234_567i = 1234567i`,
+
+ `0.i = 0i`,
+ `123.i = 123i`,
+ `0123.i = 123i`,
+
+ `0.e+1i = 0i`,
+ `123.E-1_0i = 123e-10i`,
+ `01_23.e123i = 123e123i`,
+
+ `1e-1000000000i = 0i`,
+ `1e+1000000000i = ?`,
+ `6e5518446744i = ?`,
+ `-6e5518446744i = ?`,
+}
+
+func testNumbers(t *testing.T, kind token.Token, tests []string) {
+ for _, test := range tests {
+ a := strings.Split(test, " = ")
+ if len(a) != 2 {
+ t.Errorf("invalid test case: %s", test)
+ continue
+ }
+
+ x := MakeFromLiteral(a[0], kind, 0)
+ var y Value
+ if a[1] == "?" {
+ y = MakeUnknown()
+ } else {
+ if i := strings.Index(a[1], "/"); i >= 0 && kind == token.FLOAT {
+ n := MakeFromLiteral(a[1][:i], token.INT, 0)
+ d := MakeFromLiteral(a[1][i+1:], token.INT, 0)
+ y = BinaryOp(n, token.QUO, d)
+ } else {
+ y = MakeFromLiteral(a[1], kind, 0)
+ }
+ if y.Kind() == Unknown {
+ panic(fmt.Sprintf("invalid test case: %s %d", test, y.Kind()))
+ }
+ }
+
+ xk := x.Kind()
+ yk := y.Kind()
+ if xk != yk {
+ t.Errorf("%s: got kind %d != %d", test, xk, yk)
+ continue
+ }
+
+ if yk == Unknown {
+ continue
+ }
+
+ if !Compare(x, token.EQL, y) {
+ t.Errorf("%s: %s != %s", test, x, y)
+ }
+ }
+}
+
+// TestNumbers verifies that differently written literals
+// representing the same number do have the same value.
+func TestNumbers(t *testing.T) {
+ testNumbers(t, token.INT, intTests)
+ testNumbers(t, token.FLOAT, floatTests)
+ testNumbers(t, token.IMAG, imagTests)
+}
+
+var opTests = []string{
+ // unary operations
+ `+ 0 = 0`,
+ `+ ? = ?`,
+ `- 1 = -1`,
+ `- ? = ?`,
+ `^ 0 = -1`,
+ `^ ? = ?`,
+
+ `! true = false`,
+ `! false = true`,
+ `! ? = ?`,
+
+ // etc.
+
+ // binary operations
+ `"" + "" = ""`,
+ `"foo" + "" = "foo"`,
+ `"" + "bar" = "bar"`,
+ `"foo" + "bar" = "foobar"`,
+
+ `0 + 0 = 0`,
+ `0 + 0.1 = 0.1`,
+ `0 + 0.1i = 0.1i`,
+ `0.1 + 0.9 = 1`,
+ `1e100 + 1e100 = 2e100`,
+ `? + 0 = ?`,
+ `0 + ? = ?`,
+
+ `0 - 0 = 0`,
+ `0 - 0.1 = -0.1`,
+ `0 - 0.1i = -0.1i`,
+ `1e100 - 1e100 = 0`,
+ `? - 0 = ?`,
+ `0 - ? = ?`,
+
+ `0 * 0 = 0`,
+ `1 * 0.1 = 0.1`,
+ `1 * 0.1i = 0.1i`,
+ `1i * 1i = -1`,
+ `? * 0 = ?`,
+ `0 * ? = ?`,
+ `0 * 1e+1000000000 = ?`,
+
+ `0 / 0 = "division_by_zero"`,
+ `10 / 2 = 5`,
+ `5 / 3 = 5/3`,
+ `5i / 3i = 5/3`,
+ `? / 0 = ?`,
+ `0 / ? = ?`,
+ `0 * 1e+1000000000i = ?`,
+
+ `0 % 0 = "runtime_error:_integer_divide_by_zero"`, // TODO(gri) should be the same as for /
+ `10 % 3 = 1`,
+ `? % 0 = ?`,
+ `0 % ? = ?`,
+
+ `0 & 0 = 0`,
+ `12345 & 0 = 0`,
+ `0xff & 0xf = 0xf`,
+ `? & 0 = ?`,
+ `0 & ? = ?`,
+
+ `0 | 0 = 0`,
+ `12345 | 0 = 12345`,
+ `0xb | 0xa0 = 0xab`,
+ `? | 0 = ?`,
+ `0 | ? = ?`,
+
+ `0 ^ 0 = 0`,
+ `1 ^ -1 = -2`,
+ `? ^ 0 = ?`,
+ `0 ^ ? = ?`,
+
+ `0 &^ 0 = 0`,
+ `0xf &^ 1 = 0xe`,
+ `1 &^ 0xf = 0`,
+ // etc.
+
+ // shifts
+ `0 << 0 = 0`,
+ `1 << 10 = 1024`,
+ `0 >> 0 = 0`,
+ `1024 >> 10 == 1`,
+ `? << 0 == ?`,
+ `? >> 10 == ?`,
+ // etc.
+
+ // comparisons
+ `false == false = true`,
+ `false == true = false`,
+ `true == false = false`,
+ `true == true = true`,
+
+ `false != false = false`,
+ `false != true = true`,
+ `true != false = true`,
+ `true != true = false`,
+
+ `"foo" == "bar" = false`,
+ `"foo" != "bar" = true`,
+ `"foo" < "bar" = false`,
+ `"foo" <= "bar" = false`,
+ `"foo" > "bar" = true`,
+ `"foo" >= "bar" = true`,
+
+ `0 == 0 = true`,
+ `0 != 0 = false`,
+ `0 < 10 = true`,
+ `10 <= 10 = true`,
+ `0 > 10 = false`,
+ `10 >= 10 = true`,
+
+ `1/123456789 == 1/123456789 == true`,
+ `1/123456789 != 1/123456789 == false`,
+ `1/123456789 < 1/123456788 == true`,
+ `1/123456788 <= 1/123456789 == false`,
+ `0.11 > 0.11 = false`,
+ `0.11 >= 0.11 = true`,
+
+ `? == 0 = false`,
+ `? != 0 = false`,
+ `? < 10 = false`,
+ `? <= 10 = false`,
+ `? > 10 = false`,
+ `? >= 10 = false`,
+
+ `0 == ? = false`,
+ `0 != ? = false`,
+ `0 < ? = false`,
+ `10 <= ? = false`,
+ `0 > ? = false`,
+ `10 >= ? = false`,
+
+ // etc.
+}
+
+func TestOps(t *testing.T) {
+ for _, test := range opTests {
+ a := strings.Split(test, " ")
+ i := 0 // operator index
+
+ var x, x0 Value
+ switch len(a) {
+ case 4:
+ // unary operation
+ case 5:
+ // binary operation
+ x, x0 = val(a[0]), val(a[0])
+ i = 1
+ default:
+ t.Errorf("invalid test case: %s", test)
+ continue
+ }
+
+ op, ok := optab[a[i]]
+ if !ok {
+ panic("missing optab entry for " + a[i])
+ }
+
+ y, y0 := val(a[i+1]), val(a[i+1])
+
+ got := doOp(x, op, y)
+ want := val(a[i+3])
+ if !eql(got, want) {
+ t.Errorf("%s: got %s; want %s", test, got, want)
+ continue
+ }
+
+ if x0 != nil && !eql(x, x0) {
+ t.Errorf("%s: x changed to %s", test, x)
+ continue
+ }
+
+ if !eql(y, y0) {
+ t.Errorf("%s: y changed to %s", test, y)
+ continue
+ }
+ }
+}
+
+func eql(x, y Value) bool {
+ _, ux := x.(unknownVal)
+ _, uy := y.(unknownVal)
+ if ux || uy {
+ return ux == uy
+ }
+ return Compare(x, token.EQL, y)
+}
+
+// ----------------------------------------------------------------------------
+// String tests
+
+var xxx = strings.Repeat("x", 68)
+var issue14262 = `"بموجب الشروط التالية نسب المصنف — يجب عليك أن تنسب العمل بالطريقة التي تحددها المؤلف أو المرخص (ولكن ليس بأي حال من الأحوال أن توحي وتقترح بتحول أو استخدامك للعمل). المشاركة على قدم المساواة — إذا كنت يعدل ، والتغيير ، أو الاستفادة من هذا العمل ، قد ينتج عن توزيع العمل إلا في ظل تشابه او تطابق فى واحد لهذا الترخيص."`
+
+var stringTests = []struct {
+ input, short, exact string
+}{
+ // Unknown
+ {"", "unknown", "unknown"},
+ {"0x", "unknown", "unknown"},
+ {"'", "unknown", "unknown"},
+ {"1f0", "unknown", "unknown"},
+ {"unknown", "unknown", "unknown"},
+
+ // Bool
+ {"true", "true", "true"},
+ {"false", "false", "false"},
+
+ // String
+ {`""`, `""`, `""`},
+ {`"foo"`, `"foo"`, `"foo"`},
+ {`"` + xxx + `xx"`, `"` + xxx + `xx"`, `"` + xxx + `xx"`},
+ {`"` + xxx + `xxx"`, `"` + xxx + `...`, `"` + xxx + `xxx"`},
+ {`"` + xxx + xxx + `xxx"`, `"` + xxx + `...`, `"` + xxx + xxx + `xxx"`},
+ {issue14262, `"بموجب الشروط التالية نسب المصنف — يجب عليك أن تنسب العمل بالطريقة ال...`, issue14262},
+
+ // Int
+ {"0", "0", "0"},
+ {"-1", "-1", "-1"},
+ {"12345", "12345", "12345"},
+ {"-12345678901234567890", "-12345678901234567890", "-12345678901234567890"},
+ {"12345678901234567890", "12345678901234567890", "12345678901234567890"},
+
+ // Float
+ {"0.", "0", "0"},
+ {"-0.0", "0", "0"},
+ {"10.0", "10", "10"},
+ {"2.1", "2.1", "21/10"},
+ {"-2.1", "-2.1", "-21/10"},
+ {"1e9999", "1e+9999", "0x.f8d4a9da224650a8cb2959e10d985ad92adbd44c62917e608b1f24c0e1b76b6f61edffeb15c135a4b601637315f7662f325f82325422b244286a07663c9415d2p+33216"},
+ {"1e-9999", "1e-9999", "0x.83b01ba6d8c0425eec1b21e96f7742d63c2653ed0a024cf8a2f9686df578d7b07d7a83d84df6a2ec70a921d1f6cd5574893a7eda4d28ee719e13a5dce2700759p-33215"},
+ {"2.71828182845904523536028747135266249775724709369995957496696763", "2.71828", "271828182845904523536028747135266249775724709369995957496696763/100000000000000000000000000000000000000000000000000000000000000"},
+ {"0e9999999999", "0", "0"}, // issue #16176
+ {"-6e-1886451601", "0", "0"}, // issue #20228
+
+ // Complex
+ {"0i", "(0 + 0i)", "(0 + 0i)"},
+ {"-0i", "(0 + 0i)", "(0 + 0i)"},
+ {"10i", "(0 + 10i)", "(0 + 10i)"},
+ {"-10i", "(0 + -10i)", "(0 + -10i)"},
+ {"1e9999i", "(0 + 1e+9999i)", "(0 + 0x.f8d4a9da224650a8cb2959e10d985ad92adbd44c62917e608b1f24c0e1b76b6f61edffeb15c135a4b601637315f7662f325f82325422b244286a07663c9415d2p+33216i)"},
+}
+
+func TestString(t *testing.T) {
+ for _, test := range stringTests {
+ x := val(test.input)
+ if got := x.String(); got != test.short {
+ t.Errorf("%s: got %q; want %q as short string", test.input, got, test.short)
+ }
+ if got := x.ExactString(); got != test.exact {
+ t.Errorf("%s: got %q; want %q as exact string", test.input, got, test.exact)
+ }
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Support functions
+
+func val(lit string) Value {
+ if len(lit) == 0 {
+ return MakeUnknown()
+ }
+
+ switch lit {
+ case "?":
+ return MakeUnknown()
+ case "true":
+ return MakeBool(true)
+ case "false":
+ return MakeBool(false)
+ }
+
+ if i := strings.IndexByte(lit, '/'); i >= 0 {
+ // assume fraction
+ a := MakeFromLiteral(lit[:i], token.INT, 0)
+ b := MakeFromLiteral(lit[i+1:], token.INT, 0)
+ return BinaryOp(a, token.QUO, b)
+ }
+
+ tok := token.INT
+ switch first, last := lit[0], lit[len(lit)-1]; {
+ case first == '"' || first == '`':
+ tok = token.STRING
+ lit = strings.ReplaceAll(lit, "_", " ")
+ case first == '\'':
+ tok = token.CHAR
+ case last == 'i':
+ tok = token.IMAG
+ default:
+ if !strings.HasPrefix(lit, "0x") && strings.ContainsAny(lit, "./Ee") {
+ tok = token.FLOAT
+ }
+ }
+
+ return MakeFromLiteral(lit, tok, 0)
+}
+
+var optab = map[string]token.Token{
+ "!": token.NOT,
+
+ "+": token.ADD,
+ "-": token.SUB,
+ "*": token.MUL,
+ "/": token.QUO,
+ "%": token.REM,
+
+ "<<": token.SHL,
+ ">>": token.SHR,
+
+ "&": token.AND,
+ "|": token.OR,
+ "^": token.XOR,
+ "&^": token.AND_NOT,
+
+ "==": token.EQL,
+ "!=": token.NEQ,
+ "<": token.LSS,
+ "<=": token.LEQ,
+ ">": token.GTR,
+ ">=": token.GEQ,
+}
+
+func panicHandler(v *Value) {
+ switch p := recover().(type) {
+ case nil:
+ // nothing to do
+ case string:
+ *v = MakeString(p)
+ case error:
+ *v = MakeString(p.Error())
+ default:
+ panic(p)
+ }
+}
+
+func doOp(x Value, op token.Token, y Value) (z Value) {
+ defer panicHandler(&z)
+
+ if x == nil {
+ return UnaryOp(op, y, 0)
+ }
+
+ switch op {
+ case token.EQL, token.NEQ, token.LSS, token.LEQ, token.GTR, token.GEQ:
+ return MakeBool(Compare(x, op, y))
+ case token.SHL, token.SHR:
+ s, _ := Int64Val(y)
+ return Shift(x, op, uint(s))
+ default:
+ return BinaryOp(x, op, y)
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Other tests
+
+var fracTests = []string{
+ "0",
+ "1",
+ "-1",
+ "1.2",
+ "-0.991",
+ "2.718281828",
+ "3.14159265358979323e-10",
+ "1e100",
+ "1e1000",
+}
+
+func TestFractions(t *testing.T) {
+ for _, test := range fracTests {
+ x := val(test)
+ // We don't check the actual numerator and denominator because they
+ // are unlikely to be 100% correct due to floatVal rounding errors.
+ // Instead, we compute the fraction again and compare the rounded
+ // result.
+ q := BinaryOp(Num(x), token.QUO, Denom(x))
+ got := q.String()
+ want := x.String()
+ if got != want {
+ t.Errorf("%s: got quotient %s, want %s", x, got, want)
+ }
+ }
+}
+
+var bytesTests = []string{
+ "0",
+ "1",
+ "123456789",
+ "123456789012345678901234567890123456789012345678901234567890",
+}
+
+func TestBytes(t *testing.T) {
+ for _, test := range bytesTests {
+ x := val(test)
+ bytes := Bytes(x)
+
+ // special case 0
+ if Sign(x) == 0 && len(bytes) != 0 {
+ t.Errorf("%s: got %v; want empty byte slice", test, bytes)
+ }
+
+ if n := len(bytes); n > 0 && bytes[n-1] == 0 {
+ t.Errorf("%s: got %v; want no leading 0 byte", test, bytes)
+ }
+
+ if got := MakeFromBytes(bytes); !eql(got, x) {
+ t.Errorf("%s: got %s; want %s (bytes = %v)", test, got, x, bytes)
+ }
+ }
+}
+
+func TestUnknown(t *testing.T) {
+ u := MakeUnknown()
+ var values = []Value{
+ u,
+ MakeBool(false), // token.ADD ok below, operation is never considered
+ MakeString(""),
+ MakeInt64(1),
+ MakeFromLiteral("''", token.CHAR, 0),
+ MakeFromLiteral("-1234567890123456789012345678901234567890", token.INT, 0),
+ MakeFloat64(1.2),
+ MakeImag(MakeFloat64(1.2)),
+ }
+ for _, val := range values {
+ x, y := val, u
+ for i := range [2]int{} {
+ if i == 1 {
+ x, y = y, x
+ }
+ if got := BinaryOp(x, token.ADD, y); got.Kind() != Unknown {
+ t.Errorf("%s + %s: got %s; want %s", x, y, got, u)
+ }
+ if got := Compare(x, token.EQL, y); got {
+ t.Errorf("%s == %s: got true; want false", x, y)
+ }
+ }
+ }
+}
+
+func TestMakeFloat64(t *testing.T) {
+ var zero float64
+ for _, arg := range []float64{
+ -math.MaxFloat32,
+ -10,
+ -0.5,
+ -zero,
+ zero,
+ 1,
+ 10,
+ 123456789.87654321e-23,
+ 1e10,
+ math.MaxFloat64,
+ } {
+ val := MakeFloat64(arg)
+ if val.Kind() != Float {
+ t.Errorf("%v: got kind = %d; want %d", arg, val.Kind(), Float)
+ }
+
+ // -0.0 is mapped to 0.0
+ got, exact := Float64Val(val)
+ if !exact || math.Float64bits(got) != math.Float64bits(arg+0) {
+ t.Errorf("%v: got %v (exact = %v)", arg, got, exact)
+ }
+ }
+
+ // infinity
+ for sign := range []int{-1, 1} {
+ arg := math.Inf(sign)
+ val := MakeFloat64(arg)
+ if val.Kind() != Unknown {
+ t.Errorf("%v: got kind = %d; want %d", arg, val.Kind(), Unknown)
+ }
+ }
+}
+
+type makeTestCase struct {
+ kind Kind
+ arg, want interface{}
+}
+
+func dup(k Kind, x interface{}) makeTestCase { return makeTestCase{k, x, x} }
+
+func TestMake(t *testing.T) {
+ for _, test := range []makeTestCase{
+ {Bool, false, false},
+ {String, "hello", "hello"},
+
+ {Int, int64(1), int64(1)},
+ {Int, big.NewInt(10), int64(10)},
+ {Int, new(big.Int).Lsh(big.NewInt(1), 62), int64(1 << 62)},
+ dup(Int, new(big.Int).Lsh(big.NewInt(1), 63)),
+
+ {Float, big.NewFloat(0), floatVal0.val},
+ dup(Float, big.NewFloat(2.0)),
+ dup(Float, big.NewRat(1, 3)),
+ } {
+ val := Make(test.arg)
+ got := Val(val)
+ if val.Kind() != test.kind || got != test.want {
+ t.Errorf("got %v (%T, kind = %d); want %v (%T, kind = %d)",
+ got, got, val.Kind(), test.want, test.want, test.kind)
+ }
+ }
+}
+
+func BenchmarkStringAdd(b *testing.B) {
+ for size := 1; size <= 65536; size *= 4 {
+ b.Run(fmt.Sprint(size), func(b *testing.B) {
+ b.ReportAllocs()
+ n := int64(0)
+ for i := 0; i < b.N; i++ {
+ x := MakeString(strings.Repeat("x", 100))
+ y := x
+ for j := 0; j < size-1; j++ {
+ y = BinaryOp(y, token.ADD, x)
+ }
+ n += int64(len(StringVal(y)))
+ }
+ if n != int64(b.N)*int64(size)*100 {
+ b.Fatalf("bad string %d != %d", n, int64(b.N)*int64(size)*100)
+ }
+ })
+ }
+}
diff --git a/src/go/doc/Makefile b/src/go/doc/Makefile
new file mode 100644
index 0000000..ca4948f
--- /dev/null
+++ b/src/go/doc/Makefile
@@ -0,0 +1,7 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+# Script to test heading detection heuristic
+headscan: headscan.go
+ go build headscan.go
diff --git a/src/go/doc/comment.go b/src/go/doc/comment.go
new file mode 100644
index 0000000..92131a3
--- /dev/null
+++ b/src/go/doc/comment.go
@@ -0,0 +1,513 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Godoc comment extraction and comment -> HTML formatting.
+
+package doc
+
+import (
+ "bytes"
+ "internal/lazyregexp"
+ "io"
+ "strings"
+ "text/template" // for HTMLEscape
+ "unicode"
+ "unicode/utf8"
+)
+
+const (
+ ldquo = "&ldquo;"
+ rdquo = "&rdquo;"
+ ulquo = "“"
+ urquo = "”"
+)
+
+var (
+ htmlQuoteReplacer = strings.NewReplacer(ulquo, ldquo, urquo, rdquo)
+ unicodeQuoteReplacer = strings.NewReplacer("``", ulquo, "''", urquo)
+)
+
+// Escape comment text for HTML. If nice is set,
+// also turn `` into &ldquo; and '' into &rdquo;.
+func commentEscape(w io.Writer, text string, nice bool) {
+ if nice {
+ // In the first pass, we convert `` and '' into their unicode equivalents.
+ // This prevents them from being escaped in HTMLEscape.
+ text = convertQuotes(text)
+ var buf bytes.Buffer
+ template.HTMLEscape(&buf, []byte(text))
+ // Now we convert the unicode quotes to their HTML escaped entities to maintain old behavior.
+ // We need to use a temp buffer to read the string back and do the conversion,
+ // otherwise HTMLEscape will escape & to &amp;
+ htmlQuoteReplacer.WriteString(w, buf.String())
+ return
+ }
+ template.HTMLEscape(w, []byte(text))
+}
+
+func convertQuotes(text string) string {
+ return unicodeQuoteReplacer.Replace(text)
+}
+
+const (
+ // Regexp for Go identifiers
+ identRx = `[\pL_][\pL_0-9]*`
+
+ // Regexp for URLs
+ // Match parens, and check later for balance - see #5043, #22285
+ // Match .,:;?! within path, but not at end - see #18139, #16565
+ // This excludes some rare yet valid urls ending in common punctuation
+ // in order to allow sentences ending in URLs.
+
+ // protocol (required) e.g. http
+ protoPart = `(https?|ftp|file|gopher|mailto|nntp)`
+ // host (required) e.g. www.example.com or [::1]:8080
+ hostPart = `([a-zA-Z0-9_@\-.\[\]:]+)`
+ // path+query+fragment (optional) e.g. /path/index.html?q=foo#bar
+ pathPart = `([.,:;?!]*[a-zA-Z0-9$'()*+&#=@~_/\-\[\]%])*`
+
+ urlRx = protoPart + `://` + hostPart + pathPart
+)
+
+var matchRx = lazyregexp.New(`(` + urlRx + `)|(` + identRx + `)`)
+
+var (
+ html_a = []byte(`<a href="`)
+ html_aq = []byte(`">`)
+ html_enda = []byte("</a>")
+ html_i = []byte("<i>")
+ html_endi = []byte("</i>")
+ html_p = []byte("<p>\n")
+ html_endp = []byte("</p>\n")
+ html_pre = []byte("<pre>")
+ html_endpre = []byte("</pre>\n")
+ html_h = []byte(`<h3 id="`)
+ html_hq = []byte(`">`)
+ html_endh = []byte("</h3>\n")
+)
+
+// Emphasize and escape a line of text for HTML. URLs are converted into links;
+// if the URL also appears in the words map, the link is taken from the map (if
+// the corresponding map value is the empty string, the URL is not converted
+// into a link). Go identifiers that appear in the words map are italicized; if
+// the corresponding map value is not the empty string, it is considered a URL
+// and the word is converted into a link. If nice is set, the remaining text's
+// appearance is improved where it makes sense (e.g., `` is turned into &ldquo;
+// and '' into &rdquo;).
+func emphasize(w io.Writer, line string, words map[string]string, nice bool) {
+ for {
+ m := matchRx.FindStringSubmatchIndex(line)
+ if m == nil {
+ break
+ }
+ // m >= 6 (two parenthesized sub-regexps in matchRx, 1st one is urlRx)
+
+ // write text before match
+ commentEscape(w, line[0:m[0]], nice)
+
+ // adjust match for URLs
+ match := line[m[0]:m[1]]
+ if strings.Contains(match, "://") {
+ m0, m1 := m[0], m[1]
+ for _, s := range []string{"()", "{}", "[]"} {
+ open, close := s[:1], s[1:] // E.g., "(" and ")"
+ // require opening parentheses before closing parentheses (#22285)
+ if i := strings.Index(match, close); i >= 0 && i < strings.Index(match, open) {
+ m1 = m0 + i
+ match = line[m0:m1]
+ }
+ // require balanced pairs of parentheses (#5043)
+ for i := 0; strings.Count(match, open) != strings.Count(match, close) && i < 10; i++ {
+ m1 = strings.LastIndexAny(line[:m1], s)
+ match = line[m0:m1]
+ }
+ }
+ if m1 != m[1] {
+ // redo matching with shortened line for correct indices
+ m = matchRx.FindStringSubmatchIndex(line[:m[0]+len(match)])
+ }
+ }
+
+ // analyze match
+ url := ""
+ italics := false
+ if words != nil {
+ url, italics = words[match]
+ }
+ if m[2] >= 0 {
+ // match against first parenthesized sub-regexp; must be match against urlRx
+ if !italics {
+ // no alternative URL in words list, use match instead
+ url = match
+ }
+ italics = false // don't italicize URLs
+ }
+
+ // write match
+ if len(url) > 0 {
+ w.Write(html_a)
+ template.HTMLEscape(w, []byte(url))
+ w.Write(html_aq)
+ }
+ if italics {
+ w.Write(html_i)
+ }
+ commentEscape(w, match, nice)
+ if italics {
+ w.Write(html_endi)
+ }
+ if len(url) > 0 {
+ w.Write(html_enda)
+ }
+
+ // advance
+ line = line[m[1]:]
+ }
+ commentEscape(w, line, nice)
+}
+
+func indentLen(s string) int {
+ i := 0
+ for i < len(s) && (s[i] == ' ' || s[i] == '\t') {
+ i++
+ }
+ return i
+}
+
+func isBlank(s string) bool {
+ return len(s) == 0 || (len(s) == 1 && s[0] == '\n')
+}
+
+func commonPrefix(a, b string) string {
+ i := 0
+ for i < len(a) && i < len(b) && a[i] == b[i] {
+ i++
+ }
+ return a[0:i]
+}
+
+func unindent(block []string) {
+ if len(block) == 0 {
+ return
+ }
+
+ // compute maximum common white prefix
+ prefix := block[0][0:indentLen(block[0])]
+ for _, line := range block {
+ if !isBlank(line) {
+ prefix = commonPrefix(prefix, line[0:indentLen(line)])
+ }
+ }
+ n := len(prefix)
+
+ // remove
+ for i, line := range block {
+ if !isBlank(line) {
+ block[i] = line[n:]
+ }
+ }
+}
+
+// heading returns the trimmed line if it passes as a section heading;
+// otherwise it returns the empty string.
+func heading(line string) string {
+ line = strings.TrimSpace(line)
+ if len(line) == 0 {
+ return ""
+ }
+
+ // a heading must start with an uppercase letter
+ r, _ := utf8.DecodeRuneInString(line)
+ if !unicode.IsLetter(r) || !unicode.IsUpper(r) {
+ return ""
+ }
+
+ // it must end in a letter or digit:
+ r, _ = utf8.DecodeLastRuneInString(line)
+ if !unicode.IsLetter(r) && !unicode.IsDigit(r) {
+ return ""
+ }
+
+ // exclude lines with illegal characters. we allow "(),"
+ if strings.ContainsAny(line, ";:!?+*/=[]{}_^°&§~%#@<\">\\") {
+ return ""
+ }
+
+ // allow "'" for possessive "'s" only
+ for b := line; ; {
+ i := strings.IndexRune(b, '\'')
+ if i < 0 {
+ break
+ }
+ if i+1 >= len(b) || b[i+1] != 's' || (i+2 < len(b) && b[i+2] != ' ') {
+ return "" // not followed by "s "
+ }
+ b = b[i+2:]
+ }
+
+ // allow "." when followed by non-space
+ for b := line; ; {
+ i := strings.IndexRune(b, '.')
+ if i < 0 {
+ break
+ }
+ if i+1 >= len(b) || b[i+1] == ' ' {
+ return "" // not followed by non-space
+ }
+ b = b[i+1:]
+ }
+
+ return line
+}
+
+type op int
+
+const (
+ opPara op = iota
+ opHead
+ opPre
+)
+
+type block struct {
+ op op
+ lines []string
+}
+
+var nonAlphaNumRx = lazyregexp.New(`[^a-zA-Z0-9]`)
+
+func anchorID(line string) string {
+ // Add a "hdr-" prefix to avoid conflicting with IDs used for package symbols.
+ return "hdr-" + nonAlphaNumRx.ReplaceAllString(line, "_")
+}
+
+// ToHTML converts comment text to formatted HTML.
+// The comment was prepared by DocReader,
+// so it is known not to have leading, trailing blank lines
+// nor to have trailing spaces at the end of lines.
+// The comment markers have already been removed.
+//
+// Each span of unindented non-blank lines is converted into
+// a single paragraph. There is one exception to the rule: a span that
+// consists of a single line, is followed by another paragraph span,
+// begins with a capital letter, and contains no punctuation
+// other than parentheses and commas is formatted as a heading.
+//
+// A span of indented lines is converted into a <pre> block,
+// with the common indent prefix removed.
+//
+// URLs in the comment text are converted into links; if the URL also appears
+// in the words map, the link is taken from the map (if the corresponding map
+// value is the empty string, the URL is not converted into a link).
+//
+// A pair of (consecutive) backticks (`) is converted to a unicode left quote (“), and a pair of (consecutive)
+// single quotes (') is converted to a unicode right quote (”).
+//
+// Go identifiers that appear in the words map are italicized; if the corresponding
+// map value is not the empty string, it is considered a URL and the word is converted
+// into a link.
+func ToHTML(w io.Writer, text string, words map[string]string) {
+ for _, b := range blocks(text) {
+ switch b.op {
+ case opPara:
+ w.Write(html_p)
+ for _, line := range b.lines {
+ emphasize(w, line, words, true)
+ }
+ w.Write(html_endp)
+ case opHead:
+ w.Write(html_h)
+ id := ""
+ for _, line := range b.lines {
+ if id == "" {
+ id = anchorID(line)
+ w.Write([]byte(id))
+ w.Write(html_hq)
+ }
+ commentEscape(w, line, true)
+ }
+ if id == "" {
+ w.Write(html_hq)
+ }
+ w.Write(html_endh)
+ case opPre:
+ w.Write(html_pre)
+ for _, line := range b.lines {
+ emphasize(w, line, nil, false)
+ }
+ w.Write(html_endpre)
+ }
+ }
+}
+
+func blocks(text string) []block {
+ var (
+ out []block
+ para []string
+
+ lastWasBlank = false
+ lastWasHeading = false
+ )
+
+ close := func() {
+ if para != nil {
+ out = append(out, block{opPara, para})
+ para = nil
+ }
+ }
+
+ lines := strings.SplitAfter(text, "\n")
+ unindent(lines)
+ for i := 0; i < len(lines); {
+ line := lines[i]
+ if isBlank(line) {
+ // close paragraph
+ close()
+ i++
+ lastWasBlank = true
+ continue
+ }
+ if indentLen(line) > 0 {
+ // close paragraph
+ close()
+
+ // count indented or blank lines
+ j := i + 1
+ for j < len(lines) && (isBlank(lines[j]) || indentLen(lines[j]) > 0) {
+ j++
+ }
+ // but not trailing blank lines
+ for j > i && isBlank(lines[j-1]) {
+ j--
+ }
+ pre := lines[i:j]
+ i = j
+
+ unindent(pre)
+
+ // put those lines in a pre block
+ out = append(out, block{opPre, pre})
+ lastWasHeading = false
+ continue
+ }
+
+ if lastWasBlank && !lastWasHeading && i+2 < len(lines) &&
+ isBlank(lines[i+1]) && !isBlank(lines[i+2]) && indentLen(lines[i+2]) == 0 {
+ // current line is non-blank, surrounded by blank lines
+ // and the next non-blank line is not indented: this
+ // might be a heading.
+ if head := heading(line); head != "" {
+ close()
+ out = append(out, block{opHead, []string{head}})
+ i += 2
+ lastWasHeading = true
+ continue
+ }
+ }
+
+ // open paragraph
+ lastWasBlank = false
+ lastWasHeading = false
+ para = append(para, lines[i])
+ i++
+ }
+ close()
+
+ return out
+}
+
+// ToText prepares comment text for presentation in textual output.
+// It wraps paragraphs of text to width or fewer Unicode code points
+// and then prefixes each line with the indent. In preformatted sections
+// (such as program text), it prefixes each non-blank line with preIndent.
+//
+// A pair of (consecutive) backticks (`) is converted to a unicode left quote (“), and a pair of (consecutive)
+// single quotes (') is converted to a unicode right quote (”).
+func ToText(w io.Writer, text string, indent, preIndent string, width int) {
+ l := lineWrapper{
+ out: w,
+ width: width,
+ indent: indent,
+ }
+ for _, b := range blocks(text) {
+ switch b.op {
+ case opPara:
+ // l.write will add leading newline if required
+ for _, line := range b.lines {
+ line = convertQuotes(line)
+ l.write(line)
+ }
+ l.flush()
+ case opHead:
+ w.Write(nl)
+ for _, line := range b.lines {
+ line = convertQuotes(line)
+ l.write(line + "\n")
+ }
+ l.flush()
+ case opPre:
+ w.Write(nl)
+ for _, line := range b.lines {
+ if isBlank(line) {
+ w.Write([]byte("\n"))
+ } else {
+ w.Write([]byte(preIndent))
+ w.Write([]byte(line))
+ }
+ }
+ }
+ }
+}
+
+type lineWrapper struct {
+ out io.Writer
+ printed bool
+ width int
+ indent string
+ n int
+ pendSpace int
+}
+
+var nl = []byte("\n")
+var space = []byte(" ")
+var prefix = []byte("// ")
+
+func (l *lineWrapper) write(text string) {
+ if l.n == 0 && l.printed {
+ l.out.Write(nl) // blank line before new paragraph
+ }
+ l.printed = true
+
+ needsPrefix := false
+ isComment := strings.HasPrefix(text, "//")
+ for _, f := range strings.Fields(text) {
+ w := utf8.RuneCountInString(f)
+ // wrap if line is too long
+ if l.n > 0 && l.n+l.pendSpace+w > l.width {
+ l.out.Write(nl)
+ l.n = 0
+ l.pendSpace = 0
+ needsPrefix = isComment && !strings.HasPrefix(f, "//")
+ }
+ if l.n == 0 {
+ l.out.Write([]byte(l.indent))
+ }
+ if needsPrefix {
+ l.out.Write(prefix)
+ needsPrefix = false
+ }
+ l.out.Write(space[:l.pendSpace])
+ l.out.Write([]byte(f))
+ l.n += l.pendSpace + w
+ l.pendSpace = 1
+ }
+}
+
+func (l *lineWrapper) flush() {
+ if l.n == 0 {
+ return
+ }
+ l.out.Write(nl)
+ l.pendSpace = 0
+ l.n = 0
+}
diff --git a/src/go/doc/comment_test.go b/src/go/doc/comment_test.go
new file mode 100644
index 0000000..6d1b209
--- /dev/null
+++ b/src/go/doc/comment_test.go
@@ -0,0 +1,247 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import (
+ "bytes"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+var headingTests = []struct {
+ line string
+ ok bool
+}{
+ {"Section", true},
+ {"A typical usage", true},
+ {"ΔΛΞ is Greek", true},
+ {"Foo 42", true},
+ {"", false},
+ {"section", false},
+ {"A typical usage:", false},
+ {"This code:", false},
+ {"δ is Greek", false},
+ {"Foo §", false},
+ {"Fermat's Last Sentence", true},
+ {"Fermat's", true},
+ {"'sX", false},
+ {"Ted 'Too' Bar", false},
+ {"Use n+m", false},
+ {"Scanning:", false},
+ {"N:M", false},
+}
+
+func TestIsHeading(t *testing.T) {
+ for _, tt := range headingTests {
+ if h := heading(tt.line); (len(h) > 0) != tt.ok {
+ t.Errorf("isHeading(%q) = %v, want %v", tt.line, h, tt.ok)
+ }
+ }
+}
+
+var blocksTests = []struct {
+ in string
+ out []block
+ text string
+}{
+ {
+ in: `Para 1.
+Para 1 line 2.
+
+Para 2.
+
+Section
+
+Para 3.
+
+ pre
+ pre1
+
+Para 4.
+
+ pre
+ pre1
+
+ pre2
+
+Para 5.
+
+
+ pre
+
+
+ pre1
+ pre2
+
+Para 6.
+ pre
+ pre2
+`,
+ out: []block{
+ {opPara, []string{"Para 1.\n", "Para 1 line 2.\n"}},
+ {opPara, []string{"Para 2.\n"}},
+ {opHead, []string{"Section"}},
+ {opPara, []string{"Para 3.\n"}},
+ {opPre, []string{"pre\n", "pre1\n"}},
+ {opPara, []string{"Para 4.\n"}},
+ {opPre, []string{"pre\n", "pre1\n", "\n", "pre2\n"}},
+ {opPara, []string{"Para 5.\n"}},
+ {opPre, []string{"pre\n", "\n", "\n", "pre1\n", "pre2\n"}},
+ {opPara, []string{"Para 6.\n"}},
+ {opPre, []string{"pre\n", "pre2\n"}},
+ },
+ text: `. Para 1. Para 1 line 2.
+
+. Para 2.
+
+
+. Section
+
+. Para 3.
+
+$ pre
+$ pre1
+
+. Para 4.
+
+$ pre
+$ pre1
+
+$ pre2
+
+. Para 5.
+
+$ pre
+
+
+$ pre1
+$ pre2
+
+. Para 6.
+
+$ pre
+$ pre2
+`,
+ },
+ {
+ in: "Para.\n\tshould not be ``escaped''",
+ out: []block{
+ {opPara, []string{"Para.\n"}},
+ {opPre, []string{"should not be ``escaped''"}},
+ },
+ text: ". Para.\n\n$ should not be ``escaped''",
+ },
+ {
+ in: "// A very long line of 46 char for line wrapping.",
+ out: []block{
+ {opPara, []string{"// A very long line of 46 char for line wrapping."}},
+ },
+ text: `. // A very long line of 46 char for line
+. // wrapping.
+`,
+ },
+ {
+ in: `/* A very long line of 46 char for line wrapping.
+A very long line of 46 char for line wrapping. */`,
+ out: []block{
+ {opPara, []string{"/* A very long line of 46 char for line wrapping.\n", "A very long line of 46 char for line wrapping. */"}},
+ },
+ text: `. /* A very long line of 46 char for line
+. wrapping. A very long line of 46 char
+. for line wrapping. */
+`,
+ },
+ {
+ in: `A line of 36 char for line wrapping.
+//Another line starting with //`,
+ out: []block{
+ {opPara, []string{"A line of 36 char for line wrapping.\n",
+ "//Another line starting with //"}},
+ },
+ text: `. A line of 36 char for line wrapping.
+. //Another line starting with //
+`,
+ },
+}
+
+func TestBlocks(t *testing.T) {
+ for i, tt := range blocksTests {
+ b := blocks(tt.in)
+ if !reflect.DeepEqual(b, tt.out) {
+ t.Errorf("#%d: mismatch\nhave: %v\nwant: %v", i, b, tt.out)
+ }
+ }
+}
+
+func TestToText(t *testing.T) {
+ var buf bytes.Buffer
+ for i, tt := range blocksTests {
+ ToText(&buf, tt.in, ". ", "$\t", 40)
+ if have := buf.String(); have != tt.text {
+ t.Errorf("#%d: mismatch\nhave: %s\nwant: %s\nhave vs want:\n%q\n%q", i, have, tt.text, have, tt.text)
+ }
+ buf.Reset()
+ }
+}
+
+var emphasizeTests = []struct {
+ in, out string
+}{
+ {"", ""},
+ {"http://[::1]:8080/foo.txt", `<a href="http://[::1]:8080/foo.txt">http://[::1]:8080/foo.txt</a>`},
+ {"before (https://www.google.com) after", `before (<a href="https://www.google.com">https://www.google.com</a>) after`},
+ {"before https://www.google.com:30/x/y/z:b::c. After", `before <a href="https://www.google.com:30/x/y/z:b::c">https://www.google.com:30/x/y/z:b::c</a>. After`},
+ {"http://www.google.com/path/:;!-/?query=%34b#093124", `<a href="http://www.google.com/path/:;!-/?query=%34b#093124">http://www.google.com/path/:;!-/?query=%34b#093124</a>`},
+ {"http://www.google.com/path/:;!-/?query=%34bar#093124", `<a href="http://www.google.com/path/:;!-/?query=%34bar#093124">http://www.google.com/path/:;!-/?query=%34bar#093124</a>`},
+ {"http://www.google.com/index.html! After", `<a href="http://www.google.com/index.html">http://www.google.com/index.html</a>! After`},
+ {"http://www.google.com/", `<a href="http://www.google.com/">http://www.google.com/</a>`},
+ {"https://www.google.com/", `<a href="https://www.google.com/">https://www.google.com/</a>`},
+ {"http://www.google.com/path.", `<a href="http://www.google.com/path">http://www.google.com/path</a>.`},
+ {"http://en.wikipedia.org/wiki/Camellia_(cipher)", `<a href="http://en.wikipedia.org/wiki/Camellia_(cipher)">http://en.wikipedia.org/wiki/Camellia_(cipher)</a>`},
+ {"(http://www.google.com/)", `(<a href="http://www.google.com/">http://www.google.com/</a>)`},
+ {"http://gmail.com)", `<a href="http://gmail.com">http://gmail.com</a>)`},
+ {"((http://gmail.com))", `((<a href="http://gmail.com">http://gmail.com</a>))`},
+ {"http://gmail.com ((http://gmail.com)) ()", `<a href="http://gmail.com">http://gmail.com</a> ((<a href="http://gmail.com">http://gmail.com</a>)) ()`},
+ {"Foo bar http://example.com/ quux!", `Foo bar <a href="http://example.com/">http://example.com/</a> quux!`},
+ {"Hello http://example.com/%2f/ /world.", `Hello <a href="http://example.com/%2f/">http://example.com/%2f/</a> /world.`},
+ {"Lorem http: ipsum //host/path", "Lorem http: ipsum //host/path"},
+ {"javascript://is/not/linked", "javascript://is/not/linked"},
+ {"http://foo", `<a href="http://foo">http://foo</a>`},
+ {"art by [[https://www.example.com/person/][Person Name]]", `art by [[<a href="https://www.example.com/person/">https://www.example.com/person/</a>][Person Name]]`},
+ {"please visit (http://golang.org/)", `please visit (<a href="http://golang.org/">http://golang.org/</a>)`},
+ {"please visit http://golang.org/hello())", `please visit <a href="http://golang.org/hello()">http://golang.org/hello()</a>)`},
+ {"http://git.qemu.org/?p=qemu.git;a=blob;f=qapi-schema.json;hb=HEAD", `<a href="http://git.qemu.org/?p=qemu.git;a=blob;f=qapi-schema.json;hb=HEAD">http://git.qemu.org/?p=qemu.git;a=blob;f=qapi-schema.json;hb=HEAD</a>`},
+ {"https://foo.bar/bal/x(])", `<a href="https://foo.bar/bal/x(">https://foo.bar/bal/x(</a>])`}, // inner ] causes (]) to be cut off from URL
+ {"foo [ http://bar(])", `foo [ <a href="http://bar(">http://bar(</a>])`}, // outer [ causes ]) to be cut off from URL
+}
+
+func TestEmphasize(t *testing.T) {
+ for i, tt := range emphasizeTests {
+ var buf bytes.Buffer
+ emphasize(&buf, tt.in, nil, true)
+ out := buf.String()
+ if out != tt.out {
+ t.Errorf("#%d: mismatch\nhave: %v\nwant: %v", i, out, tt.out)
+ }
+ }
+}
+
+func TestCommentEscape(t *testing.T) {
+ commentTests := []struct {
+ in, out string
+ }{
+ {"typically invoked as ``go tool asm'',", "typically invoked as " + ldquo + "go tool asm" + rdquo + ","},
+ {"For more detail, run ``go help test'' and ``go help testflag''", "For more detail, run " + ldquo + "go help test" + rdquo + " and " + ldquo + "go help testflag" + rdquo},
+ }
+ for i, tt := range commentTests {
+ var buf strings.Builder
+ commentEscape(&buf, tt.in, true)
+ out := buf.String()
+ if out != tt.out {
+ t.Errorf("#%d: mismatch\nhave: %q\nwant: %q", i, out, tt.out)
+ }
+ }
+}
diff --git a/src/go/doc/doc.go b/src/go/doc/doc.go
new file mode 100644
index 0000000..79d3899
--- /dev/null
+++ b/src/go/doc/doc.go
@@ -0,0 +1,222 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package doc extracts source code documentation from a Go AST.
+package doc
+
+import (
+ "fmt"
+ "go/ast"
+ "go/token"
+ "strings"
+)
+
+// Package is the documentation for an entire package.
+type Package struct {
+ Doc string
+ Name string
+ ImportPath string
+ Imports []string
+ Filenames []string
+ Notes map[string][]*Note
+
+ // Deprecated: For backward compatibility Bugs is still populated,
+ // but all new code should use Notes instead.
+ Bugs []string
+
+ // declarations
+ Consts []*Value
+ Types []*Type
+ Vars []*Value
+ Funcs []*Func
+
+ // Examples is a sorted list of examples associated with
+ // the package. Examples are extracted from _test.go files
+ // provided to NewFromFiles.
+ Examples []*Example
+}
+
+// Value is the documentation for a (possibly grouped) var or const declaration.
+type Value struct {
+ Doc string
+ Names []string // var or const names in declaration order
+ Decl *ast.GenDecl
+
+ order int
+}
+
+// Type is the documentation for a type declaration.
+type Type struct {
+ Doc string
+ Name string
+ Decl *ast.GenDecl
+
+ // associated declarations
+ Consts []*Value // sorted list of constants of (mostly) this type
+ Vars []*Value // sorted list of variables of (mostly) this type
+ Funcs []*Func // sorted list of functions returning this type
+ Methods []*Func // sorted list of methods (including embedded ones) of this type
+
+ // Examples is a sorted list of examples associated with
+ // this type. Examples are extracted from _test.go files
+ // provided to NewFromFiles.
+ Examples []*Example
+}
+
+// Func is the documentation for a func declaration.
+type Func struct {
+ Doc string
+ Name string
+ Decl *ast.FuncDecl
+
+ // methods
+ // (for functions, these fields have the respective zero value)
+ Recv string // actual receiver "T" or "*T"
+ Orig string // original receiver "T" or "*T"
+ Level int // embedding level; 0 means not embedded
+
+ // Examples is a sorted list of examples associated with this
+ // function or method. Examples are extracted from _test.go files
+ // provided to NewFromFiles.
+ Examples []*Example
+}
+
+// A Note represents a marked comment starting with "MARKER(uid): note body".
+// Any note with a marker of 2 or more upper case [A-Z] letters and a uid of
+// at least one character is recognized. The ":" following the uid is optional.
+// Notes are collected in the Package.Notes map indexed by the notes marker.
+type Note struct {
+ Pos, End token.Pos // position range of the comment containing the marker
+ UID string // uid found with the marker
+ Body string // note body text
+}
+
+// Mode values control the operation of New and NewFromFiles.
+type Mode int
+
+const (
+ // AllDecls says to extract documentation for all package-level
+ // declarations, not just exported ones.
+ AllDecls Mode = 1 << iota
+
+ // AllMethods says to show all embedded methods, not just the ones of
+ // invisible (unexported) anonymous fields.
+ AllMethods
+
+ // PreserveAST says to leave the AST unmodified. Originally, pieces of
+ // the AST such as function bodies were nil-ed out to save memory in
+ // godoc, but not all programs want that behavior.
+ PreserveAST
+)
+
+// New computes the package documentation for the given package AST.
+// New takes ownership of the AST pkg and may edit or overwrite it.
+// To have the Examples fields populated, use NewFromFiles and include
+// the package's _test.go files.
+//
+func New(pkg *ast.Package, importPath string, mode Mode) *Package {
+ var r reader
+ r.readPackage(pkg, mode)
+ r.computeMethodSets()
+ r.cleanupTypes()
+ return &Package{
+ Doc: r.doc,
+ Name: pkg.Name,
+ ImportPath: importPath,
+ Imports: sortedKeys(r.imports),
+ Filenames: r.filenames,
+ Notes: r.notes,
+ Bugs: noteBodies(r.notes["BUG"]),
+ Consts: sortedValues(r.values, token.CONST),
+ Types: sortedTypes(r.types, mode&AllMethods != 0),
+ Vars: sortedValues(r.values, token.VAR),
+ Funcs: sortedFuncs(r.funcs, true),
+ }
+}
+
+// NewFromFiles computes documentation for a package.
+//
+// The package is specified by a list of *ast.Files and corresponding
+// file set, which must not be nil.
+// NewFromFiles uses all provided files when computing documentation,
+// so it is the caller's responsibility to provide only the files that
+// match the desired build context. "go/build".Context.MatchFile can
+// be used for determining whether a file matches a build context with
+// the desired GOOS and GOARCH values, and other build constraints.
+// The import path of the package is specified by importPath.
+//
+// Examples found in _test.go files are associated with the corresponding
+// type, function, method, or the package, based on their name.
+// If the example has a suffix in its name, it is set in the
+// Example.Suffix field. Examples with malformed names are skipped.
+//
+// Optionally, a single extra argument of type Mode can be provided to
+// control low-level aspects of the documentation extraction behavior.
+//
+// NewFromFiles takes ownership of the AST files and may edit them,
+// unless the PreserveAST Mode bit is on.
+//
+func NewFromFiles(fset *token.FileSet, files []*ast.File, importPath string, opts ...interface{}) (*Package, error) {
+ // Check for invalid API usage.
+ if fset == nil {
+ panic(fmt.Errorf("doc.NewFromFiles: no token.FileSet provided (fset == nil)"))
+ }
+ var mode Mode
+ switch len(opts) { // There can only be 0 or 1 options, so a simple switch works for now.
+ case 0:
+ // Nothing to do.
+ case 1:
+ m, ok := opts[0].(Mode)
+ if !ok {
+ panic(fmt.Errorf("doc.NewFromFiles: option argument type must be doc.Mode"))
+ }
+ mode = m
+ default:
+ panic(fmt.Errorf("doc.NewFromFiles: there must not be more than 1 option argument"))
+ }
+
+ // Collect .go and _test.go files.
+ var (
+ goFiles = make(map[string]*ast.File)
+ testGoFiles []*ast.File
+ )
+ for i := range files {
+ f := fset.File(files[i].Pos())
+ if f == nil {
+ return nil, fmt.Errorf("file files[%d] is not found in the provided file set", i)
+ }
+ switch name := f.Name(); {
+ case strings.HasSuffix(name, ".go") && !strings.HasSuffix(name, "_test.go"):
+ goFiles[name] = files[i]
+ case strings.HasSuffix(name, "_test.go"):
+ testGoFiles = append(testGoFiles, files[i])
+ default:
+ return nil, fmt.Errorf("file files[%d] filename %q does not have a .go extension", i, name)
+ }
+ }
+
+ // TODO(dmitshur,gri): A relatively high level call to ast.NewPackage with a simpleImporter
+ // ast.Importer implementation is made below. It might be possible to short-circuit and simplify.
+
+ // Compute package documentation.
+ pkg, _ := ast.NewPackage(fset, goFiles, simpleImporter, nil) // Ignore errors that can happen due to unresolved identifiers.
+ p := New(pkg, importPath, mode)
+ classifyExamples(p, Examples(testGoFiles...))
+ return p, nil
+}
+
+// simpleImporter returns a (dummy) package object named by the last path
+// component of the provided package path (as is the convention for packages).
+// This is sufficient to resolve package identifiers without doing an actual
+// import. It never returns an error.
+func simpleImporter(imports map[string]*ast.Object, path string) (*ast.Object, error) {
+ pkg := imports[path]
+ if pkg == nil {
+ // note that strings.LastIndex returns -1 if there is no "/"
+ pkg = ast.NewObj(ast.Pkg, path[strings.LastIndex(path, "/")+1:])
+ pkg.Data = ast.NewScope(nil) // required by ast.NewPackage for dot-import
+ imports[path] = pkg
+ }
+ return pkg, nil
+}
diff --git a/src/go/doc/doc_test.go b/src/go/doc/doc_test.go
new file mode 100644
index 0000000..cbdca62
--- /dev/null
+++ b/src/go/doc/doc_test.go
@@ -0,0 +1,164 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import (
+ "bytes"
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strings"
+ "testing"
+ "text/template"
+)
+
+var update = flag.Bool("update", false, "update golden (.out) files")
+var files = flag.String("files", "", "consider only Go test files matching this regular expression")
+
+const dataDir = "testdata"
+
+var templateTxt = readTemplate("template.txt")
+
+func readTemplate(filename string) *template.Template {
+ t := template.New(filename)
+ t.Funcs(template.FuncMap{
+ "node": nodeFmt,
+ "synopsis": synopsisFmt,
+ "indent": indentFmt,
+ })
+ return template.Must(t.ParseFiles(filepath.Join(dataDir, filename)))
+}
+
+func nodeFmt(node interface{}, fset *token.FileSet) string {
+ var buf bytes.Buffer
+ printer.Fprint(&buf, fset, node)
+ return strings.ReplaceAll(strings.TrimSpace(buf.String()), "\n", "\n\t")
+}
+
+func synopsisFmt(s string) string {
+ const n = 64
+ if len(s) > n {
+ // cut off excess text and go back to a word boundary
+ s = s[0:n]
+ if i := strings.LastIndexAny(s, "\t\n "); i >= 0 {
+ s = s[0:i]
+ }
+ s = strings.TrimSpace(s) + " ..."
+ }
+ return "// " + strings.ReplaceAll(s, "\n", " ")
+}
+
+func indentFmt(indent, s string) string {
+ end := ""
+ if strings.HasSuffix(s, "\n") {
+ end = "\n"
+ s = s[:len(s)-1]
+ }
+ return indent + strings.ReplaceAll(s, "\n", "\n"+indent) + end
+}
+
+func isGoFile(fi fs.FileInfo) bool {
+ name := fi.Name()
+ return !fi.IsDir() &&
+ len(name) > 0 && name[0] != '.' && // ignore .files
+ filepath.Ext(name) == ".go"
+}
+
+type bundle struct {
+ *Package
+ FSet *token.FileSet
+}
+
+func test(t *testing.T, mode Mode) {
+ // determine file filter
+ filter := isGoFile
+ if *files != "" {
+ rx, err := regexp.Compile(*files)
+ if err != nil {
+ t.Fatal(err)
+ }
+ filter = func(fi fs.FileInfo) bool {
+ return isGoFile(fi) && rx.MatchString(fi.Name())
+ }
+ }
+
+ // get packages
+ fset := token.NewFileSet()
+ pkgs, err := parser.ParseDir(fset, dataDir, filter, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // test packages
+ for _, pkg := range pkgs {
+ importPath := dataDir + "/" + pkg.Name
+ var files []*ast.File
+ for _, f := range pkg.Files {
+ files = append(files, f)
+ }
+ doc, err := NewFromFiles(fset, files, importPath, mode)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+
+ // golden files always use / in filenames - canonicalize them
+ for i, filename := range doc.Filenames {
+ doc.Filenames[i] = filepath.ToSlash(filename)
+ }
+
+ // print documentation
+ var buf bytes.Buffer
+ if err := templateTxt.Execute(&buf, bundle{doc, fset}); err != nil {
+ t.Error(err)
+ continue
+ }
+ got := buf.Bytes()
+
+ // update golden file if necessary
+ golden := filepath.Join(dataDir, fmt.Sprintf("%s.%d.golden", pkg.Name, mode))
+ if *update {
+ err := os.WriteFile(golden, got, 0644)
+ if err != nil {
+ t.Error(err)
+ }
+ continue
+ }
+
+ // get golden file
+ want, err := os.ReadFile(golden)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+
+ // compare
+ if !bytes.Equal(got, want) {
+ t.Errorf("package %s\n\tgot:\n%s\n\twant:\n%s", pkg.Name, got, want)
+ }
+ }
+}
+
+func Test(t *testing.T) {
+ test(t, 0)
+ test(t, AllDecls)
+ test(t, AllMethods)
+}
+
+func TestAnchorID(t *testing.T) {
+ const in = "Important Things 2 Know & Stuff"
+ const want = "hdr-Important_Things_2_Know___Stuff"
+ got := anchorID(in)
+ if got != want {
+ t.Errorf("anchorID(%q) = %q; want %q", in, got, want)
+ }
+}
diff --git a/src/go/doc/example.go b/src/go/doc/example.go
new file mode 100644
index 0000000..125fd53
--- /dev/null
+++ b/src/go/doc/example.go
@@ -0,0 +1,547 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Extract example functions from file ASTs.
+
+package doc
+
+import (
+ "go/ast"
+ "go/token"
+ "internal/lazyregexp"
+ "path"
+ "sort"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+// An Example represents an example function found in a test source file.
+type Example struct {
+ Name string // name of the item being exemplified (including optional suffix)
+ Suffix string // example suffix, without leading '_' (only populated by NewFromFiles)
+ Doc string // example function doc string
+ Code ast.Node
+ Play *ast.File // a whole program version of the example
+ Comments []*ast.CommentGroup
+ Output string // expected output
+ Unordered bool
+ EmptyOutput bool // expect empty output
+ Order int // original source code order
+}
+
+// Examples returns the examples found in testFiles, sorted by Name field.
+// The Order fields record the order in which the examples were encountered.
+// The Suffix field is not populated when Examples is called directly, it is
+// only populated by NewFromFiles for examples it finds in _test.go files.
+//
+// Playable Examples must be in a package whose name ends in "_test".
+// An Example is "playable" (the Play field is non-nil) in either of these
+// circumstances:
+// - The example function is self-contained: the function references only
+// identifiers from other packages (or predeclared identifiers, such as
+// "int") and the test file does not include a dot import.
+// - The entire test file is the example: the file contains exactly one
+// example function, zero test or benchmark functions, and at least one
+// top-level function, type, variable, or constant declaration other
+// than the example function.
+func Examples(testFiles ...*ast.File) []*Example {
+ var list []*Example
+ for _, file := range testFiles {
+ hasTests := false // file contains tests or benchmarks
+ numDecl := 0 // number of non-import declarations in the file
+ var flist []*Example
+ for _, decl := range file.Decls {
+ if g, ok := decl.(*ast.GenDecl); ok && g.Tok != token.IMPORT {
+ numDecl++
+ continue
+ }
+ f, ok := decl.(*ast.FuncDecl)
+ if !ok || f.Recv != nil {
+ continue
+ }
+ numDecl++
+ name := f.Name.Name
+ if isTest(name, "Test") || isTest(name, "Benchmark") {
+ hasTests = true
+ continue
+ }
+ if !isTest(name, "Example") {
+ continue
+ }
+ if params := f.Type.Params; len(params.List) != 0 {
+ continue // function has params; not a valid example
+ }
+ if f.Body == nil { // ast.File.Body nil dereference (see issue 28044)
+ continue
+ }
+ var doc string
+ if f.Doc != nil {
+ doc = f.Doc.Text()
+ }
+ output, unordered, hasOutput := exampleOutput(f.Body, file.Comments)
+ flist = append(flist, &Example{
+ Name: name[len("Example"):],
+ Doc: doc,
+ Code: f.Body,
+ Play: playExample(file, f),
+ Comments: file.Comments,
+ Output: output,
+ Unordered: unordered,
+ EmptyOutput: output == "" && hasOutput,
+ Order: len(flist),
+ })
+ }
+ if !hasTests && numDecl > 1 && len(flist) == 1 {
+ // If this file only has one example function, some
+ // other top-level declarations, and no tests or
+ // benchmarks, use the whole file as the example.
+ flist[0].Code = file
+ flist[0].Play = playExampleFile(file)
+ }
+ list = append(list, flist...)
+ }
+ // sort by name
+ sort.Slice(list, func(i, j int) bool {
+ return list[i].Name < list[j].Name
+ })
+ return list
+}
+
+var outputPrefix = lazyregexp.New(`(?i)^[[:space:]]*(unordered )?output:`)
+
+// Extracts the expected output and whether there was a valid output comment
+func exampleOutput(b *ast.BlockStmt, comments []*ast.CommentGroup) (output string, unordered, ok bool) {
+ if _, last := lastComment(b, comments); last != nil {
+ // test that it begins with the correct prefix
+ text := last.Text()
+ if loc := outputPrefix.FindStringSubmatchIndex(text); loc != nil {
+ if loc[2] != -1 {
+ unordered = true
+ }
+ text = text[loc[1]:]
+ // Strip zero or more spaces followed by \n or a single space.
+ text = strings.TrimLeft(text, " ")
+ if len(text) > 0 && text[0] == '\n' {
+ text = text[1:]
+ }
+ return text, unordered, true
+ }
+ }
+ return "", false, false // no suitable comment found
+}
+
+// isTest tells whether name looks like a test, example, or benchmark.
+// It is a Test (say) if there is a character after Test that is not a
+// lower-case letter. (We don't want Testiness.)
+func isTest(name, prefix string) bool {
+ if !strings.HasPrefix(name, prefix) {
+ return false
+ }
+ if len(name) == len(prefix) { // "Test" is ok
+ return true
+ }
+ rune, _ := utf8.DecodeRuneInString(name[len(prefix):])
+ return !unicode.IsLower(rune)
+}
+
+// playExample synthesizes a new *ast.File based on the provided
+// file with the provided function body as the body of main.
+func playExample(file *ast.File, f *ast.FuncDecl) *ast.File {
+ body := f.Body
+
+ if !strings.HasSuffix(file.Name.Name, "_test") {
+ // We don't support examples that are part of the
+ // greater package (yet).
+ return nil
+ }
+
+ // Collect top-level declarations in the file.
+ topDecls := make(map[*ast.Object]ast.Decl)
+ typMethods := make(map[string][]ast.Decl)
+
+ for _, decl := range file.Decls {
+ switch d := decl.(type) {
+ case *ast.FuncDecl:
+ if d.Recv == nil {
+ topDecls[d.Name.Obj] = d
+ } else {
+ if len(d.Recv.List) == 1 {
+ t := d.Recv.List[0].Type
+ tname, _ := baseTypeName(t)
+ typMethods[tname] = append(typMethods[tname], d)
+ }
+ }
+ case *ast.GenDecl:
+ for _, spec := range d.Specs {
+ switch s := spec.(type) {
+ case *ast.TypeSpec:
+ topDecls[s.Name.Obj] = d
+ case *ast.ValueSpec:
+ for _, name := range s.Names {
+ topDecls[name.Obj] = d
+ }
+ }
+ }
+ }
+ }
+
+ // Find unresolved identifiers and uses of top-level declarations.
+ unresolved := make(map[string]bool)
+ var depDecls []ast.Decl
+ hasDepDecls := make(map[ast.Decl]bool)
+
+ var inspectFunc func(ast.Node) bool
+ inspectFunc = func(n ast.Node) bool {
+ switch e := n.(type) {
+ case *ast.Ident:
+ if e.Obj == nil && e.Name != "_" {
+ unresolved[e.Name] = true
+ } else if d := topDecls[e.Obj]; d != nil {
+ if !hasDepDecls[d] {
+ hasDepDecls[d] = true
+ depDecls = append(depDecls, d)
+ }
+ }
+ return true
+ case *ast.SelectorExpr:
+ // For selector expressions, only inspect the left hand side.
+ // (For an expression like fmt.Println, only add "fmt" to the
+ // set of unresolved names, not "Println".)
+ ast.Inspect(e.X, inspectFunc)
+ return false
+ case *ast.KeyValueExpr:
+ // For key value expressions, only inspect the value
+ // as the key should be resolved by the type of the
+ // composite literal.
+ ast.Inspect(e.Value, inspectFunc)
+ return false
+ }
+ return true
+ }
+ ast.Inspect(body, inspectFunc)
+ for i := 0; i < len(depDecls); i++ {
+ switch d := depDecls[i].(type) {
+ case *ast.FuncDecl:
+ // Inspect types of parameters and results. See #28492.
+ if d.Type.Params != nil {
+ for _, p := range d.Type.Params.List {
+ ast.Inspect(p.Type, inspectFunc)
+ }
+ }
+ if d.Type.Results != nil {
+ for _, r := range d.Type.Results.List {
+ ast.Inspect(r.Type, inspectFunc)
+ }
+ }
+
+ ast.Inspect(d.Body, inspectFunc)
+ case *ast.GenDecl:
+ for _, spec := range d.Specs {
+ switch s := spec.(type) {
+ case *ast.TypeSpec:
+ ast.Inspect(s.Type, inspectFunc)
+
+ depDecls = append(depDecls, typMethods[s.Name.Name]...)
+ case *ast.ValueSpec:
+ if s.Type != nil {
+ ast.Inspect(s.Type, inspectFunc)
+ }
+ for _, val := range s.Values {
+ ast.Inspect(val, inspectFunc)
+ }
+ }
+ }
+ }
+ }
+
+ // Remove predeclared identifiers from unresolved list.
+ for n := range unresolved {
+ if predeclaredTypes[n] || predeclaredConstants[n] || predeclaredFuncs[n] {
+ delete(unresolved, n)
+ }
+ }
+
+ // Use unresolved identifiers to determine the imports used by this
+ // example. The heuristic assumes package names match base import
+ // paths for imports w/o renames (should be good enough most of the time).
+ namedImports := make(map[string]string) // [name]path
+ var blankImports []ast.Spec // _ imports
+ for _, s := range file.Imports {
+ p, err := strconv.Unquote(s.Path.Value)
+ if err != nil {
+ continue
+ }
+ if p == "syscall/js" {
+ // We don't support examples that import syscall/js,
+ // because the package syscall/js is not available in the playground.
+ return nil
+ }
+ n := path.Base(p)
+ if s.Name != nil {
+ n = s.Name.Name
+ switch n {
+ case "_":
+ blankImports = append(blankImports, s)
+ continue
+ case ".":
+ // We can't resolve dot imports (yet).
+ return nil
+ }
+ }
+ if unresolved[n] {
+ namedImports[n] = p
+ delete(unresolved, n)
+ }
+ }
+
+ // If there are other unresolved identifiers, give up because this
+ // synthesized file is not going to build.
+ if len(unresolved) > 0 {
+ return nil
+ }
+
+ // Include documentation belonging to blank imports.
+ var comments []*ast.CommentGroup
+ for _, s := range blankImports {
+ if c := s.(*ast.ImportSpec).Doc; c != nil {
+ comments = append(comments, c)
+ }
+ }
+
+ // Include comments that are inside the function body.
+ for _, c := range file.Comments {
+ if body.Pos() <= c.Pos() && c.End() <= body.End() {
+ comments = append(comments, c)
+ }
+ }
+
+ // Strip the "Output:" or "Unordered output:" comment and adjust body
+ // end position.
+ body, comments = stripOutputComment(body, comments)
+
+ // Include documentation belonging to dependent declarations.
+ for _, d := range depDecls {
+ switch d := d.(type) {
+ case *ast.GenDecl:
+ if d.Doc != nil {
+ comments = append(comments, d.Doc)
+ }
+ case *ast.FuncDecl:
+ if d.Doc != nil {
+ comments = append(comments, d.Doc)
+ }
+ }
+ }
+
+ // Synthesize import declaration.
+ importDecl := &ast.GenDecl{
+ Tok: token.IMPORT,
+ Lparen: 1, // Need non-zero Lparen and Rparen so that printer
+ Rparen: 1, // treats this as a factored import.
+ }
+ for n, p := range namedImports {
+ s := &ast.ImportSpec{Path: &ast.BasicLit{Value: strconv.Quote(p)}}
+ if path.Base(p) != n {
+ s.Name = ast.NewIdent(n)
+ }
+ importDecl.Specs = append(importDecl.Specs, s)
+ }
+ importDecl.Specs = append(importDecl.Specs, blankImports...)
+
+ // Synthesize main function.
+ funcDecl := &ast.FuncDecl{
+ Name: ast.NewIdent("main"),
+ Type: f.Type,
+ Body: body,
+ }
+
+ decls := make([]ast.Decl, 0, 2+len(depDecls))
+ decls = append(decls, importDecl)
+ decls = append(decls, depDecls...)
+ decls = append(decls, funcDecl)
+
+ sort.Slice(decls, func(i, j int) bool {
+ return decls[i].Pos() < decls[j].Pos()
+ })
+
+ sort.Slice(comments, func(i, j int) bool {
+ return comments[i].Pos() < comments[j].Pos()
+ })
+
+ // Synthesize file.
+ return &ast.File{
+ Name: ast.NewIdent("main"),
+ Decls: decls,
+ Comments: comments,
+ }
+}
+
+// playExampleFile takes a whole file example and synthesizes a new *ast.File
+// such that the example is function main in package main.
+func playExampleFile(file *ast.File) *ast.File {
+ // Strip copyright comment if present.
+ comments := file.Comments
+ if len(comments) > 0 && strings.HasPrefix(comments[0].Text(), "Copyright") {
+ comments = comments[1:]
+ }
+
+ // Copy declaration slice, rewriting the ExampleX function to main.
+ var decls []ast.Decl
+ for _, d := range file.Decls {
+ if f, ok := d.(*ast.FuncDecl); ok && isTest(f.Name.Name, "Example") {
+ // Copy the FuncDecl, as it may be used elsewhere.
+ newF := *f
+ newF.Name = ast.NewIdent("main")
+ newF.Body, comments = stripOutputComment(f.Body, comments)
+ d = &newF
+ }
+ decls = append(decls, d)
+ }
+
+ // Copy the File, as it may be used elsewhere.
+ f := *file
+ f.Name = ast.NewIdent("main")
+ f.Decls = decls
+ f.Comments = comments
+ return &f
+}
+
+// stripOutputComment finds and removes the "Output:" or "Unordered output:"
+// comment from body and comments, and adjusts the body block's end position.
+func stripOutputComment(body *ast.BlockStmt, comments []*ast.CommentGroup) (*ast.BlockStmt, []*ast.CommentGroup) {
+ // Do nothing if there is no "Output:" or "Unordered output:" comment.
+ i, last := lastComment(body, comments)
+ if last == nil || !outputPrefix.MatchString(last.Text()) {
+ return body, comments
+ }
+
+ // Copy body and comments, as the originals may be used elsewhere.
+ newBody := &ast.BlockStmt{
+ Lbrace: body.Lbrace,
+ List: body.List,
+ Rbrace: last.Pos(),
+ }
+ newComments := make([]*ast.CommentGroup, len(comments)-1)
+ copy(newComments, comments[:i])
+ copy(newComments[i:], comments[i+1:])
+ return newBody, newComments
+}
+
+// lastComment returns the last comment inside the provided block.
+func lastComment(b *ast.BlockStmt, c []*ast.CommentGroup) (i int, last *ast.CommentGroup) {
+ if b == nil {
+ return
+ }
+ pos, end := b.Pos(), b.End()
+ for j, cg := range c {
+ if cg.Pos() < pos {
+ continue
+ }
+ if cg.End() > end {
+ break
+ }
+ i, last = j, cg
+ }
+ return
+}
+
+// classifyExamples classifies examples and assigns them to the Examples field
+// of the relevant Func, Type, or Package that the example is associated with.
+//
+// The classification process is ambiguous in some cases:
+//
+// - ExampleFoo_Bar matches a type named Foo_Bar
+// or a method named Foo.Bar.
+// - ExampleFoo_bar matches a type named Foo_bar
+// or Foo (with a "bar" suffix).
+//
+// Examples with malformed names are not associated with anything.
+//
+func classifyExamples(p *Package, examples []*Example) {
+ if len(examples) == 0 {
+ return
+ }
+
+ // Mapping of names for funcs, types, and methods to the example listing.
+ ids := make(map[string]*[]*Example)
+ ids[""] = &p.Examples // package-level examples have an empty name
+ for _, f := range p.Funcs {
+ if !token.IsExported(f.Name) {
+ continue
+ }
+ ids[f.Name] = &f.Examples
+ }
+ for _, t := range p.Types {
+ if !token.IsExported(t.Name) {
+ continue
+ }
+ ids[t.Name] = &t.Examples
+ for _, f := range t.Funcs {
+ if !token.IsExported(f.Name) {
+ continue
+ }
+ ids[f.Name] = &f.Examples
+ }
+ for _, m := range t.Methods {
+ if !token.IsExported(m.Name) {
+ continue
+ }
+ ids[strings.TrimPrefix(m.Recv, "*")+"_"+m.Name] = &m.Examples
+ }
+ }
+
+ // Group each example with the associated func, type, or method.
+ for _, ex := range examples {
+ // Consider all possible split points for the suffix
+ // by starting at the end of string (no suffix case),
+ // then trying all positions that contain a '_' character.
+ //
+ // An association is made on the first successful match.
+ // Examples with malformed names that match nothing are skipped.
+ for i := len(ex.Name); i >= 0; i = strings.LastIndexByte(ex.Name[:i], '_') {
+ prefix, suffix, ok := splitExampleName(ex.Name, i)
+ if !ok {
+ continue
+ }
+ exs, ok := ids[prefix]
+ if !ok {
+ continue
+ }
+ ex.Suffix = suffix
+ *exs = append(*exs, ex)
+ break
+ }
+ }
+
+ // Sort list of example according to the user-specified suffix name.
+ for _, exs := range ids {
+ sort.Slice((*exs), func(i, j int) bool {
+ return (*exs)[i].Suffix < (*exs)[j].Suffix
+ })
+ }
+}
+
+// splitExampleName attempts to split example name s at index i,
+// and reports if that produces a valid split. The suffix may be
+// absent. Otherwise, it must start with a lower-case letter and
+// be preceded by '_'.
+//
+// One of i == len(s) or s[i] == '_' must be true.
+func splitExampleName(s string, i int) (prefix, suffix string, ok bool) {
+ if i == len(s) {
+ return s, "", true
+ }
+ if i == len(s)-1 {
+ return "", "", false
+ }
+ prefix, suffix = s[:i], s[i+1:]
+ return prefix, suffix, isExampleSuffix(suffix)
+}
+
+func isExampleSuffix(s string) bool {
+ r, size := utf8.DecodeRuneInString(s)
+ return size > 0 && unicode.IsLower(r)
+}
diff --git a/src/go/doc/example_test.go b/src/go/doc/example_test.go
new file mode 100644
index 0000000..7c96f03
--- /dev/null
+++ b/src/go/doc/example_test.go
@@ -0,0 +1,718 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/doc"
+ "go/format"
+ "go/parser"
+ "go/token"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+const exampleTestFile = `
+package foo_test
+
+import (
+ "flag"
+ "fmt"
+ "log"
+ "sort"
+ "os/exec"
+)
+
+func ExampleHello() {
+ fmt.Println("Hello, world!")
+ // Output: Hello, world!
+}
+
+func ExampleImport() {
+ out, err := exec.Command("date").Output()
+ if err != nil {
+ log.Fatal(err)
+ }
+ fmt.Printf("The date is %s\n", out)
+}
+
+func ExampleKeyValue() {
+ v := struct {
+ a string
+ b int
+ }{
+ a: "A",
+ b: 1,
+ }
+ fmt.Print(v)
+ // Output: a: "A", b: 1
+}
+
+func ExampleKeyValueImport() {
+ f := flag.Flag{
+ Name: "play",
+ }
+ fmt.Print(f)
+ // Output: Name: "play"
+}
+
+var keyValueTopDecl = struct {
+ a string
+ b int
+}{
+ a: "B",
+ b: 2,
+}
+
+func ExampleKeyValueTopDecl() {
+ fmt.Print(keyValueTopDecl)
+ // Output: a: "B", b: 2
+}
+
+// Person represents a person by name and age.
+type Person struct {
+ Name string
+ Age int
+}
+
+// String returns a string representation of the Person.
+func (p Person) String() string {
+ return fmt.Sprintf("%s: %d", p.Name, p.Age)
+}
+
+// ByAge implements sort.Interface for []Person based on
+// the Age field.
+type ByAge []Person
+
+// Len returns the number of elements in ByAge.
+func (a (ByAge)) Len() int { return len(a) }
+
+// Swap swaps the elements in ByAge.
+func (a ByAge) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a ByAge) Less(i, j int) bool { return a[i].Age < a[j].Age }
+
+// people is the array of Person
+var people = []Person{
+ {"Bob", 31},
+ {"John", 42},
+ {"Michael", 17},
+ {"Jenny", 26},
+}
+
+func ExampleSort() {
+ fmt.Println(people)
+ sort.Sort(ByAge(people))
+ fmt.Println(people)
+ // Output:
+ // [Bob: 31 John: 42 Michael: 17 Jenny: 26]
+ // [Michael: 17 Jenny: 26 Bob: 31 John: 42]
+}
+`
+
+var exampleTestCases = []struct {
+ Name, Play, Output string
+}{
+ {
+ Name: "Hello",
+ Play: exampleHelloPlay,
+ Output: "Hello, world!\n",
+ },
+ {
+ Name: "Import",
+ Play: exampleImportPlay,
+ },
+ {
+ Name: "KeyValue",
+ Play: exampleKeyValuePlay,
+ Output: "a: \"A\", b: 1\n",
+ },
+ {
+ Name: "KeyValueImport",
+ Play: exampleKeyValueImportPlay,
+ Output: "Name: \"play\"\n",
+ },
+ {
+ Name: "KeyValueTopDecl",
+ Play: exampleKeyValueTopDeclPlay,
+ Output: "a: \"B\", b: 2\n",
+ },
+ {
+ Name: "Sort",
+ Play: exampleSortPlay,
+ Output: "[Bob: 31 John: 42 Michael: 17 Jenny: 26]\n[Michael: 17 Jenny: 26 Bob: 31 John: 42]\n",
+ },
+}
+
+const exampleHelloPlay = `package main
+
+import (
+ "fmt"
+)
+
+func main() {
+ fmt.Println("Hello, world!")
+}
+`
+const exampleImportPlay = `package main
+
+import (
+ "fmt"
+ "log"
+ "os/exec"
+)
+
+func main() {
+ out, err := exec.Command("date").Output()
+ if err != nil {
+ log.Fatal(err)
+ }
+ fmt.Printf("The date is %s\n", out)
+}
+`
+
+const exampleKeyValuePlay = `package main
+
+import (
+ "fmt"
+)
+
+func main() {
+ v := struct {
+ a string
+ b int
+ }{
+ a: "A",
+ b: 1,
+ }
+ fmt.Print(v)
+}
+`
+
+const exampleKeyValueImportPlay = `package main
+
+import (
+ "flag"
+ "fmt"
+)
+
+func main() {
+ f := flag.Flag{
+ Name: "play",
+ }
+ fmt.Print(f)
+}
+`
+
+const exampleKeyValueTopDeclPlay = `package main
+
+import (
+ "fmt"
+)
+
+var keyValueTopDecl = struct {
+ a string
+ b int
+}{
+ a: "B",
+ b: 2,
+}
+
+func main() {
+ fmt.Print(keyValueTopDecl)
+}
+`
+
+const exampleSortPlay = `package main
+
+import (
+ "fmt"
+ "sort"
+)
+
+// Person represents a person by name and age.
+type Person struct {
+ Name string
+ Age int
+}
+
+// String returns a string representation of the Person.
+func (p Person) String() string {
+ return fmt.Sprintf("%s: %d", p.Name, p.Age)
+}
+
+// ByAge implements sort.Interface for []Person based on
+// the Age field.
+type ByAge []Person
+
+// Len returns the number of elements in ByAge.
+func (a ByAge) Len() int { return len(a) }
+
+// Swap swaps the elements in ByAge.
+func (a ByAge) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a ByAge) Less(i, j int) bool { return a[i].Age < a[j].Age }
+
+// people is the array of Person
+var people = []Person{
+ {"Bob", 31},
+ {"John", 42},
+ {"Michael", 17},
+ {"Jenny", 26},
+}
+
+func main() {
+ fmt.Println(people)
+ sort.Sort(ByAge(people))
+ fmt.Println(people)
+}
+`
+
+func TestExamples(t *testing.T) {
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "test.go", strings.NewReader(exampleTestFile), parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for i, e := range doc.Examples(file) {
+ c := exampleTestCases[i]
+ if e.Name != c.Name {
+ t.Errorf("got Name == %q, want %q", e.Name, c.Name)
+ }
+ if w := c.Play; w != "" {
+ g := formatFile(t, fset, e.Play)
+ if g != w {
+ t.Errorf("%s: got Play == %q, want %q", c.Name, g, w)
+ }
+ }
+ if g, w := e.Output, c.Output; g != w {
+ t.Errorf("%s: got Output == %q, want %q", c.Name, g, w)
+ }
+ }
+}
+
+const exampleWholeFile = `package foo_test
+
+type X int
+
+func (X) Foo() {
+}
+
+func (X) TestBlah() {
+}
+
+func (X) BenchmarkFoo() {
+}
+
+func Example() {
+ fmt.Println("Hello, world!")
+ // Output: Hello, world!
+}
+`
+
+const exampleWholeFileOutput = `package main
+
+type X int
+
+func (X) Foo() {
+}
+
+func (X) TestBlah() {
+}
+
+func (X) BenchmarkFoo() {
+}
+
+func main() {
+ fmt.Println("Hello, world!")
+}
+`
+
+const exampleWholeFileFunction = `package foo_test
+
+func Foo(x int) {
+}
+
+func Example() {
+ fmt.Println("Hello, world!")
+ // Output: Hello, world!
+}
+`
+
+const exampleWholeFileFunctionOutput = `package main
+
+func Foo(x int) {
+}
+
+func main() {
+ fmt.Println("Hello, world!")
+}
+`
+
+var exampleWholeFileTestCases = []struct {
+ Title, Source, Play, Output string
+}{
+ {
+ "Methods",
+ exampleWholeFile,
+ exampleWholeFileOutput,
+ "Hello, world!\n",
+ },
+ {
+ "Function",
+ exampleWholeFileFunction,
+ exampleWholeFileFunctionOutput,
+ "Hello, world!\n",
+ },
+}
+
+func TestExamplesWholeFile(t *testing.T) {
+ for _, c := range exampleWholeFileTestCases {
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "test.go", strings.NewReader(c.Source), parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ es := doc.Examples(file)
+ if len(es) != 1 {
+ t.Fatalf("%s: wrong number of examples; got %d want 1", c.Title, len(es))
+ }
+ e := es[0]
+ if e.Name != "" {
+ t.Errorf("%s: got Name == %q, want %q", c.Title, e.Name, "")
+ }
+ if g, w := formatFile(t, fset, e.Play), c.Play; g != w {
+ t.Errorf("%s: got Play == %q, want %q", c.Title, g, w)
+ }
+ if g, w := e.Output, c.Output; g != w {
+ t.Errorf("%s: got Output == %q, want %q", c.Title, g, w)
+ }
+ }
+}
+
+const exampleInspectSignature = `package foo_test
+
+import (
+ "bytes"
+ "io"
+)
+
+func getReader() io.Reader { return nil }
+
+func do(b bytes.Reader) {}
+
+func Example() {
+ getReader()
+ do()
+ // Output:
+}
+
+func ExampleIgnored() {
+}
+`
+
+const exampleInspectSignatureOutput = `package main
+
+import (
+ "bytes"
+ "io"
+)
+
+func getReader() io.Reader { return nil }
+
+func do(b bytes.Reader) {}
+
+func main() {
+ getReader()
+ do()
+}
+`
+
+func TestExampleInspectSignature(t *testing.T) {
+ // Verify that "bytes" and "io" are imported. See issue #28492.
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "test.go", strings.NewReader(exampleInspectSignature), parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ es := doc.Examples(file)
+ if len(es) != 2 {
+ t.Fatalf("wrong number of examples; got %d want 2", len(es))
+ }
+ // We are interested in the first example only.
+ e := es[0]
+ if e.Name != "" {
+ t.Errorf("got Name == %q, want %q", e.Name, "")
+ }
+ if g, w := formatFile(t, fset, e.Play), exampleInspectSignatureOutput; g != w {
+ t.Errorf("got Play == %q, want %q", g, w)
+ }
+ if g, w := e.Output, ""; g != w {
+ t.Errorf("got Output == %q, want %q", g, w)
+ }
+}
+
+const exampleEmpty = `
+package p
+func Example() {}
+func Example_a()
+`
+
+const exampleEmptyOutput = `package main
+
+func main() {}
+func main()
+`
+
+func TestExampleEmpty(t *testing.T) {
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "test.go", strings.NewReader(exampleEmpty), parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ es := doc.Examples(file)
+ if len(es) != 1 {
+ t.Fatalf("wrong number of examples; got %d want 1", len(es))
+ }
+ e := es[0]
+ if e.Name != "" {
+ t.Errorf("got Name == %q, want %q", e.Name, "")
+ }
+ if g, w := formatFile(t, fset, e.Play), exampleEmptyOutput; g != w {
+ t.Errorf("got Play == %q, want %q", g, w)
+ }
+ if g, w := e.Output, ""; g != w {
+ t.Errorf("got Output == %q, want %q", g, w)
+ }
+}
+
+func formatFile(t *testing.T, fset *token.FileSet, n *ast.File) string {
+ if n == nil {
+ return "<nil>"
+ }
+ var buf bytes.Buffer
+ if err := format.Node(&buf, fset, n); err != nil {
+ t.Fatal(err)
+ }
+ return buf.String()
+}
+
+// This example illustrates how to use NewFromFiles
+// to compute package documentation with examples.
+func ExampleNewFromFiles() {
+ // src and test are two source files that make up
+ // a package whose documentation will be computed.
+ const src = `
+// This is the package comment.
+package p
+
+import "fmt"
+
+// This comment is associated with the Greet function.
+func Greet(who string) {
+ fmt.Printf("Hello, %s!\n", who)
+}
+`
+ const test = `
+package p_test
+
+// This comment is associated with the ExampleGreet_world example.
+func ExampleGreet_world() {
+ Greet("world")
+}
+`
+
+ // Create the AST by parsing src and test.
+ fset := token.NewFileSet()
+ files := []*ast.File{
+ mustParse(fset, "src.go", src),
+ mustParse(fset, "src_test.go", test),
+ }
+
+ // Compute package documentation with examples.
+ p, err := doc.NewFromFiles(fset, files, "example.com/p")
+ if err != nil {
+ panic(err)
+ }
+
+ fmt.Printf("package %s - %s", p.Name, p.Doc)
+ fmt.Printf("func %s - %s", p.Funcs[0].Name, p.Funcs[0].Doc)
+ fmt.Printf(" ⤷ example with suffix %q - %s", p.Funcs[0].Examples[0].Suffix, p.Funcs[0].Examples[0].Doc)
+
+ // Output:
+ // package p - This is the package comment.
+ // func Greet - This comment is associated with the Greet function.
+ // ⤷ example with suffix "world" - This comment is associated with the ExampleGreet_world example.
+}
+
+func TestClassifyExamples(t *testing.T) {
+ const src = `
+package p
+
+const Const1 = 0
+var Var1 = 0
+
+type (
+ Type1 int
+ Type1_Foo int
+ Type1_foo int
+ type2 int
+
+ Embed struct { Type1 }
+ Uembed struct { type2 }
+)
+
+func Func1() {}
+func Func1_Foo() {}
+func Func1_foo() {}
+func func2() {}
+
+func (Type1) Func1() {}
+func (Type1) Func1_Foo() {}
+func (Type1) Func1_foo() {}
+func (Type1) func2() {}
+
+func (type2) Func1() {}
+
+type (
+ Conflict int
+ Conflict_Conflict int
+ Conflict_conflict int
+)
+
+func (Conflict) Conflict() {}
+`
+ const test = `
+package p_test
+
+func ExampleConst1() {} // invalid - no support for consts and vars
+func ExampleVar1() {} // invalid - no support for consts and vars
+
+func Example() {}
+func Example_() {} // invalid - suffix must start with a lower-case letter
+func Example_suffix() {}
+func Example_suffix_xX_X_x() {}
+func Example_世界() {} // invalid - suffix must start with a lower-case letter
+func Example_123() {} // invalid - suffix must start with a lower-case letter
+func Example_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+
+func ExampleType1() {}
+func ExampleType1_() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_suffix() {}
+func ExampleType1_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_Foo() {}
+func ExampleType1_Foo_suffix() {}
+func ExampleType1_Foo_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_foo() {}
+func ExampleType1_foo_suffix() {}
+func ExampleType1_foo_Suffix() {} // matches Type1, instead of Type1_foo
+func Exampletype2() {} // invalid - cannot match unexported
+
+func ExampleFunc1() {}
+func ExampleFunc1_() {} // invalid - suffix must start with a lower-case letter
+func ExampleFunc1_suffix() {}
+func ExampleFunc1_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleFunc1_Foo() {}
+func ExampleFunc1_Foo_suffix() {}
+func ExampleFunc1_Foo_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleFunc1_foo() {}
+func ExampleFunc1_foo_suffix() {}
+func ExampleFunc1_foo_Suffix() {} // matches Func1, instead of Func1_foo
+func Examplefunc1() {} // invalid - cannot match unexported
+
+func ExampleType1_Func1() {}
+func ExampleType1_Func1_() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_Func1_suffix() {}
+func ExampleType1_Func1_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_Func1_Foo() {}
+func ExampleType1_Func1_Foo_suffix() {}
+func ExampleType1_Func1_Foo_BadSuffix() {} // invalid - suffix must start with a lower-case letter
+func ExampleType1_Func1_foo() {}
+func ExampleType1_Func1_foo_suffix() {}
+func ExampleType1_Func1_foo_Suffix() {} // matches Type1.Func1, instead of Type1.Func1_foo
+func ExampleType1_func2() {} // matches Type1, instead of Type1.func2
+
+func ExampleEmbed_Func1() {} // invalid - no support for forwarded methods from embedding exported type
+func ExampleUembed_Func1() {} // methods from embedding unexported types are OK
+func ExampleUembed_Func1_suffix() {}
+
+func ExampleConflict_Conflict() {} // ambiguous with either Conflict or Conflict_Conflict type
+func ExampleConflict_conflict() {} // ambiguous with either Conflict or Conflict_conflict type
+func ExampleConflict_Conflict_suffix() {} // ambiguous with either Conflict or Conflict_Conflict type
+func ExampleConflict_conflict_suffix() {} // ambiguous with either Conflict or Conflict_conflict type
+`
+
+ // Parse literal source code as a *doc.Package.
+ fset := token.NewFileSet()
+ files := []*ast.File{
+ mustParse(fset, "src.go", src),
+ mustParse(fset, "src_test.go", test),
+ }
+ p, err := doc.NewFromFiles(fset, files, "example.com/p")
+ if err != nil {
+ t.Fatalf("doc.NewFromFiles: %v", err)
+ }
+
+ // Collect the association of examples to top-level identifiers.
+ got := map[string][]string{}
+ got[""] = exampleNames(p.Examples)
+ for _, f := range p.Funcs {
+ got[f.Name] = exampleNames(f.Examples)
+ }
+ for _, t := range p.Types {
+ got[t.Name] = exampleNames(t.Examples)
+ for _, f := range t.Funcs {
+ got[f.Name] = exampleNames(f.Examples)
+ }
+ for _, m := range t.Methods {
+ got[t.Name+"."+m.Name] = exampleNames(m.Examples)
+ }
+ }
+
+ want := map[string][]string{
+ "": {"", "suffix", "suffix_xX_X_x"}, // Package-level examples.
+
+ "Type1": {"", "foo_Suffix", "func2", "suffix"},
+ "Type1_Foo": {"", "suffix"},
+ "Type1_foo": {"", "suffix"},
+
+ "Func1": {"", "foo_Suffix", "suffix"},
+ "Func1_Foo": {"", "suffix"},
+ "Func1_foo": {"", "suffix"},
+
+ "Type1.Func1": {"", "foo_Suffix", "suffix"},
+ "Type1.Func1_Foo": {"", "suffix"},
+ "Type1.Func1_foo": {"", "suffix"},
+
+ "Uembed.Func1": {"", "suffix"},
+
+ // These are implementation dependent due to the ambiguous parsing.
+ "Conflict_Conflict": {"", "suffix"},
+ "Conflict_conflict": {"", "suffix"},
+ }
+
+ for id := range got {
+ if !reflect.DeepEqual(got[id], want[id]) {
+ t.Errorf("classification mismatch for %q:\ngot %q\nwant %q", id, got[id], want[id])
+ }
+ }
+}
+
+func exampleNames(exs []*doc.Example) (out []string) {
+ for _, ex := range exs {
+ out = append(out, ex.Suffix)
+ }
+ return out
+}
+
+func mustParse(fset *token.FileSet, filename, src string) *ast.File {
+ f, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
+ if err != nil {
+ panic(err)
+ }
+ return f
+}
diff --git a/src/go/doc/exports.go b/src/go/doc/exports.go
new file mode 100644
index 0000000..819c030
--- /dev/null
+++ b/src/go/doc/exports.go
@@ -0,0 +1,309 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements export filtering of an AST.
+
+package doc
+
+import (
+ "go/ast"
+ "go/token"
+)
+
+// filterIdentList removes unexported names from list in place
+// and returns the resulting list.
+//
+func filterIdentList(list []*ast.Ident) []*ast.Ident {
+ j := 0
+ for _, x := range list {
+ if token.IsExported(x.Name) {
+ list[j] = x
+ j++
+ }
+ }
+ return list[0:j]
+}
+
+var underscore = ast.NewIdent("_")
+
+func filterCompositeLit(lit *ast.CompositeLit, filter Filter, export bool) {
+ n := len(lit.Elts)
+ lit.Elts = filterExprList(lit.Elts, filter, export)
+ if len(lit.Elts) < n {
+ lit.Incomplete = true
+ }
+}
+
+func filterExprList(list []ast.Expr, filter Filter, export bool) []ast.Expr {
+ j := 0
+ for _, exp := range list {
+ switch x := exp.(type) {
+ case *ast.CompositeLit:
+ filterCompositeLit(x, filter, export)
+ case *ast.KeyValueExpr:
+ if x, ok := x.Key.(*ast.Ident); ok && !filter(x.Name) {
+ continue
+ }
+ if x, ok := x.Value.(*ast.CompositeLit); ok {
+ filterCompositeLit(x, filter, export)
+ }
+ }
+ list[j] = exp
+ j++
+ }
+ return list[0:j]
+}
+
+// updateIdentList replaces all unexported identifiers with underscore
+// and reports whether at least one exported name exists.
+func updateIdentList(list []*ast.Ident) (hasExported bool) {
+ for i, x := range list {
+ if token.IsExported(x.Name) {
+ hasExported = true
+ } else {
+ list[i] = underscore
+ }
+ }
+ return hasExported
+}
+
+// hasExportedName reports whether list contains any exported names.
+//
+func hasExportedName(list []*ast.Ident) bool {
+ for _, x := range list {
+ if x.IsExported() {
+ return true
+ }
+ }
+ return false
+}
+
+// removeErrorField removes anonymous fields named "error" from an interface.
+// This is called when "error" has been determined to be a local name,
+// not the predeclared type.
+//
+func removeErrorField(ityp *ast.InterfaceType) {
+ list := ityp.Methods.List // we know that ityp.Methods != nil
+ j := 0
+ for _, field := range list {
+ keepField := true
+ if n := len(field.Names); n == 0 {
+ // anonymous field
+ if fname, _ := baseTypeName(field.Type); fname == "error" {
+ keepField = false
+ }
+ }
+ if keepField {
+ list[j] = field
+ j++
+ }
+ }
+ if j < len(list) {
+ ityp.Incomplete = true
+ }
+ ityp.Methods.List = list[0:j]
+}
+
+// filterFieldList removes unexported fields (field names) from the field list
+// in place and reports whether fields were removed. Anonymous fields are
+// recorded with the parent type. filterType is called with the types of
+// all remaining fields.
+//
+func (r *reader) filterFieldList(parent *namedType, fields *ast.FieldList, ityp *ast.InterfaceType) (removedFields bool) {
+ if fields == nil {
+ return
+ }
+ list := fields.List
+ j := 0
+ for _, field := range list {
+ keepField := false
+ if n := len(field.Names); n == 0 {
+ // anonymous field
+ fname := r.recordAnonymousField(parent, field.Type)
+ if token.IsExported(fname) {
+ keepField = true
+ } else if ityp != nil && fname == "error" {
+ // possibly the predeclared error interface; keep
+ // it for now but remember this interface so that
+ // it can be fixed if error is also defined locally
+ keepField = true
+ r.remember(ityp)
+ }
+ } else {
+ field.Names = filterIdentList(field.Names)
+ if len(field.Names) < n {
+ removedFields = true
+ }
+ if len(field.Names) > 0 {
+ keepField = true
+ }
+ }
+ if keepField {
+ r.filterType(nil, field.Type)
+ list[j] = field
+ j++
+ }
+ }
+ if j < len(list) {
+ removedFields = true
+ }
+ fields.List = list[0:j]
+ return
+}
+
+// filterParamList applies filterType to each parameter type in fields.
+//
+func (r *reader) filterParamList(fields *ast.FieldList) {
+ if fields != nil {
+ for _, f := range fields.List {
+ r.filterType(nil, f.Type)
+ }
+ }
+}
+
+// filterType strips any unexported struct fields or method types from typ
+// in place. If fields (or methods) have been removed, the corresponding
+// struct or interface type has the Incomplete field set to true.
+//
+func (r *reader) filterType(parent *namedType, typ ast.Expr) {
+ switch t := typ.(type) {
+ case *ast.Ident:
+ // nothing to do
+ case *ast.ParenExpr:
+ r.filterType(nil, t.X)
+ case *ast.ArrayType:
+ r.filterType(nil, t.Elt)
+ case *ast.StructType:
+ if r.filterFieldList(parent, t.Fields, nil) {
+ t.Incomplete = true
+ }
+ case *ast.FuncType:
+ r.filterParamList(t.Params)
+ r.filterParamList(t.Results)
+ case *ast.InterfaceType:
+ if r.filterFieldList(parent, t.Methods, t) {
+ t.Incomplete = true
+ }
+ case *ast.MapType:
+ r.filterType(nil, t.Key)
+ r.filterType(nil, t.Value)
+ case *ast.ChanType:
+ r.filterType(nil, t.Value)
+ }
+}
+
+func (r *reader) filterSpec(spec ast.Spec) bool {
+ switch s := spec.(type) {
+ case *ast.ImportSpec:
+ // always keep imports so we can collect them
+ return true
+ case *ast.ValueSpec:
+ s.Values = filterExprList(s.Values, token.IsExported, true)
+ if len(s.Values) > 0 || s.Type == nil && len(s.Values) == 0 {
+ // If there are values declared on RHS, just replace the unexported
+ // identifiers on the LHS with underscore, so that it matches
+ // the sequence of expression on the RHS.
+ //
+ // Similarly, if there are no type and values, then this expression
+ // must be following an iota expression, where order matters.
+ if updateIdentList(s.Names) {
+ r.filterType(nil, s.Type)
+ return true
+ }
+ } else {
+ s.Names = filterIdentList(s.Names)
+ if len(s.Names) > 0 {
+ r.filterType(nil, s.Type)
+ return true
+ }
+ }
+ case *ast.TypeSpec:
+ if name := s.Name.Name; token.IsExported(name) {
+ r.filterType(r.lookupType(s.Name.Name), s.Type)
+ return true
+ } else if name == "error" {
+ // special case: remember that error is declared locally
+ r.errorDecl = true
+ }
+ }
+ return false
+}
+
+// copyConstType returns a copy of typ with position pos.
+// typ must be a valid constant type.
+// In practice, only (possibly qualified) identifiers are possible.
+//
+func copyConstType(typ ast.Expr, pos token.Pos) ast.Expr {
+ switch typ := typ.(type) {
+ case *ast.Ident:
+ return &ast.Ident{Name: typ.Name, NamePos: pos}
+ case *ast.SelectorExpr:
+ if id, ok := typ.X.(*ast.Ident); ok {
+ // presumably a qualified identifier
+ return &ast.SelectorExpr{
+ Sel: ast.NewIdent(typ.Sel.Name),
+ X: &ast.Ident{Name: id.Name, NamePos: pos},
+ }
+ }
+ }
+ return nil // shouldn't happen, but be conservative and don't panic
+}
+
+func (r *reader) filterSpecList(list []ast.Spec, tok token.Token) []ast.Spec {
+ if tok == token.CONST {
+ // Propagate any type information that would get lost otherwise
+ // when unexported constants are filtered.
+ var prevType ast.Expr
+ for _, spec := range list {
+ spec := spec.(*ast.ValueSpec)
+ if spec.Type == nil && len(spec.Values) == 0 && prevType != nil {
+ // provide current spec with an explicit type
+ spec.Type = copyConstType(prevType, spec.Pos())
+ }
+ if hasExportedName(spec.Names) {
+ // exported names are preserved so there's no need to propagate the type
+ prevType = nil
+ } else {
+ prevType = spec.Type
+ }
+ }
+ }
+
+ j := 0
+ for _, s := range list {
+ if r.filterSpec(s) {
+ list[j] = s
+ j++
+ }
+ }
+ return list[0:j]
+}
+
+func (r *reader) filterDecl(decl ast.Decl) bool {
+ switch d := decl.(type) {
+ case *ast.GenDecl:
+ d.Specs = r.filterSpecList(d.Specs, d.Tok)
+ return len(d.Specs) > 0
+ case *ast.FuncDecl:
+ // ok to filter these methods early because any
+ // conflicting method will be filtered here, too -
+ // thus, removing these methods early will not lead
+ // to the false removal of possible conflicts
+ return token.IsExported(d.Name.Name)
+ }
+ return false
+}
+
+// fileExports removes unexported declarations from src in place.
+//
+func (r *reader) fileExports(src *ast.File) {
+ j := 0
+ for _, d := range src.Decls {
+ if r.filterDecl(d) {
+ src.Decls[j] = d
+ j++
+ }
+ }
+ src.Decls = src.Decls[0:j]
+}
diff --git a/src/go/doc/filter.go b/src/go/doc/filter.go
new file mode 100644
index 0000000..a6f243f
--- /dev/null
+++ b/src/go/doc/filter.go
@@ -0,0 +1,105 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import "go/ast"
+
+type Filter func(string) bool
+
+func matchFields(fields *ast.FieldList, f Filter) bool {
+ if fields != nil {
+ for _, field := range fields.List {
+ for _, name := range field.Names {
+ if f(name.Name) {
+ return true
+ }
+ }
+ }
+ }
+ return false
+}
+
+func matchDecl(d *ast.GenDecl, f Filter) bool {
+ for _, d := range d.Specs {
+ switch v := d.(type) {
+ case *ast.ValueSpec:
+ for _, name := range v.Names {
+ if f(name.Name) {
+ return true
+ }
+ }
+ case *ast.TypeSpec:
+ if f(v.Name.Name) {
+ return true
+ }
+ switch t := v.Type.(type) {
+ case *ast.StructType:
+ if matchFields(t.Fields, f) {
+ return true
+ }
+ case *ast.InterfaceType:
+ if matchFields(t.Methods, f) {
+ return true
+ }
+ }
+ }
+ }
+ return false
+}
+
+func filterValues(a []*Value, f Filter) []*Value {
+ w := 0
+ for _, vd := range a {
+ if matchDecl(vd.Decl, f) {
+ a[w] = vd
+ w++
+ }
+ }
+ return a[0:w]
+}
+
+func filterFuncs(a []*Func, f Filter) []*Func {
+ w := 0
+ for _, fd := range a {
+ if f(fd.Name) {
+ a[w] = fd
+ w++
+ }
+ }
+ return a[0:w]
+}
+
+func filterTypes(a []*Type, f Filter) []*Type {
+ w := 0
+ for _, td := range a {
+ n := 0 // number of matches
+ if matchDecl(td.Decl, f) {
+ n = 1
+ } else {
+ // type name doesn't match, but we may have matching consts, vars, factories or methods
+ td.Consts = filterValues(td.Consts, f)
+ td.Vars = filterValues(td.Vars, f)
+ td.Funcs = filterFuncs(td.Funcs, f)
+ td.Methods = filterFuncs(td.Methods, f)
+ n += len(td.Consts) + len(td.Vars) + len(td.Funcs) + len(td.Methods)
+ }
+ if n > 0 {
+ a[w] = td
+ w++
+ }
+ }
+ return a[0:w]
+}
+
+// Filter eliminates documentation for names that don't pass through the filter f.
+// TODO(gri): Recognize "Type.Method" as a name.
+//
+func (p *Package) Filter(f Filter) {
+ p.Consts = filterValues(p.Consts, f)
+ p.Vars = filterValues(p.Vars, f)
+ p.Types = filterTypes(p.Types, f)
+ p.Funcs = filterFuncs(p.Funcs, f)
+ p.Doc = "" // don't show top-level package doc
+}
diff --git a/src/go/doc/headscan.go b/src/go/doc/headscan.go
new file mode 100644
index 0000000..fe26a0e
--- /dev/null
+++ b/src/go/doc/headscan.go
@@ -0,0 +1,115 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+/*
+ The headscan command extracts comment headings from package files;
+ it is used to detect false positives which may require an adjustment
+ to the comment formatting heuristics in comment.go.
+
+ Usage: headscan [-root root_directory]
+
+ By default, the $GOROOT/src directory is scanned.
+*/
+package main
+
+import (
+ "bytes"
+ "flag"
+ "fmt"
+ "go/doc"
+ "go/parser"
+ "go/token"
+ "internal/lazyregexp"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "runtime"
+ "strings"
+)
+
+var (
+ root = flag.String("root", filepath.Join(runtime.GOROOT(), "src"), "root of filesystem tree to scan")
+ verbose = flag.Bool("v", false, "verbose mode")
+)
+
+// ToHTML in comment.go assigns a (possibly blank) ID to each heading
+var html_h = lazyregexp.New(`<h3 id="[^"]*">`)
+
+const html_endh = "</h3>\n"
+
+func isGoFile(fi fs.FileInfo) bool {
+ return strings.HasSuffix(fi.Name(), ".go") &&
+ !strings.HasSuffix(fi.Name(), "_test.go")
+}
+
+func appendHeadings(list []string, comment string) []string {
+ var buf bytes.Buffer
+ doc.ToHTML(&buf, comment, nil)
+ for s := buf.String(); ; {
+ loc := html_h.FindStringIndex(s)
+ if len(loc) == 0 {
+ break
+ }
+ i := loc[1]
+ j := strings.Index(s, html_endh)
+ if j < 0 {
+ list = append(list, s[i:]) // incorrect HTML
+ break
+ }
+ list = append(list, s[i:j])
+ s = s[j+len(html_endh):]
+ }
+ return list
+}
+
+func main() {
+ flag.Parse()
+ fset := token.NewFileSet()
+ nheadings := 0
+ err := filepath.WalkDir(*root, func(path string, info fs.DirEntry, err error) error {
+ if !info.IsDir() {
+ return nil
+ }
+ pkgs, err := parser.ParseDir(fset, path, isGoFile, parser.ParseComments)
+ if err != nil {
+ if *verbose {
+ fmt.Fprintln(os.Stderr, err)
+ }
+ return nil
+ }
+ for _, pkg := range pkgs {
+ d := doc.New(pkg, path, doc.Mode(0))
+ list := appendHeadings(nil, d.Doc)
+ for _, d := range d.Consts {
+ list = appendHeadings(list, d.Doc)
+ }
+ for _, d := range d.Types {
+ list = appendHeadings(list, d.Doc)
+ }
+ for _, d := range d.Vars {
+ list = appendHeadings(list, d.Doc)
+ }
+ for _, d := range d.Funcs {
+ list = appendHeadings(list, d.Doc)
+ }
+ if len(list) > 0 {
+ // directories may contain multiple packages;
+ // print path and package name
+ fmt.Printf("%s (package %s)\n", path, pkg.Name)
+ for _, h := range list {
+ fmt.Printf("\t%s\n", h)
+ }
+ nheadings += len(list)
+ }
+ }
+ return nil
+ })
+ if err != nil {
+ fmt.Fprintln(os.Stderr, err)
+ os.Exit(1)
+ }
+ fmt.Println(nheadings, "headings found")
+}
diff --git a/src/go/doc/reader.go b/src/go/doc/reader.go
new file mode 100644
index 0000000..c277b35
--- /dev/null
+++ b/src/go/doc/reader.go
@@ -0,0 +1,917 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import (
+ "go/ast"
+ "go/token"
+ "internal/lazyregexp"
+ "sort"
+ "strconv"
+)
+
+// ----------------------------------------------------------------------------
+// function/method sets
+//
+// Internally, we treat functions like methods and collect them in method sets.
+
+// A methodSet describes a set of methods. Entries where Decl == nil are conflict
+// entries (more than one method with the same name at the same embedding level).
+//
+type methodSet map[string]*Func
+
+// recvString returns a string representation of recv of the
+// form "T", "*T", or "BADRECV" (if not a proper receiver type).
+//
+func recvString(recv ast.Expr) string {
+ switch t := recv.(type) {
+ case *ast.Ident:
+ return t.Name
+ case *ast.StarExpr:
+ return "*" + recvString(t.X)
+ }
+ return "BADRECV"
+}
+
+// set creates the corresponding Func for f and adds it to mset.
+// If there are multiple f's with the same name, set keeps the first
+// one with documentation; conflicts are ignored. The boolean
+// specifies whether to leave the AST untouched.
+//
+func (mset methodSet) set(f *ast.FuncDecl, preserveAST bool) {
+ name := f.Name.Name
+ if g := mset[name]; g != nil && g.Doc != "" {
+ // A function with the same name has already been registered;
+ // since it has documentation, assume f is simply another
+ // implementation and ignore it. This does not happen if the
+ // caller is using go/build.ScanDir to determine the list of
+ // files implementing a package.
+ return
+ }
+ // function doesn't exist or has no documentation; use f
+ recv := ""
+ if f.Recv != nil {
+ var typ ast.Expr
+ // be careful in case of incorrect ASTs
+ if list := f.Recv.List; len(list) == 1 {
+ typ = list[0].Type
+ }
+ recv = recvString(typ)
+ }
+ mset[name] = &Func{
+ Doc: f.Doc.Text(),
+ Name: name,
+ Decl: f,
+ Recv: recv,
+ Orig: recv,
+ }
+ if !preserveAST {
+ f.Doc = nil // doc consumed - remove from AST
+ }
+}
+
+// add adds method m to the method set; m is ignored if the method set
+// already contains a method with the same name at the same or a higher
+// level than m.
+//
+func (mset methodSet) add(m *Func) {
+ old := mset[m.Name]
+ if old == nil || m.Level < old.Level {
+ mset[m.Name] = m
+ return
+ }
+ if m.Level == old.Level {
+ // conflict - mark it using a method with nil Decl
+ mset[m.Name] = &Func{
+ Name: m.Name,
+ Level: m.Level,
+ }
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Named types
+
+// baseTypeName returns the name of the base type of x (or "")
+// and whether the type is imported or not.
+//
+func baseTypeName(x ast.Expr) (name string, imported bool) {
+ switch t := x.(type) {
+ case *ast.Ident:
+ return t.Name, false
+ case *ast.SelectorExpr:
+ if _, ok := t.X.(*ast.Ident); ok {
+ // only possible for qualified type names;
+ // assume type is imported
+ return t.Sel.Name, true
+ }
+ case *ast.ParenExpr:
+ return baseTypeName(t.X)
+ case *ast.StarExpr:
+ return baseTypeName(t.X)
+ }
+ return
+}
+
+// An embeddedSet describes a set of embedded types.
+type embeddedSet map[*namedType]bool
+
+// A namedType represents a named unqualified (package local, or possibly
+// predeclared) type. The namedType for a type name is always found via
+// reader.lookupType.
+//
+type namedType struct {
+ doc string // doc comment for type
+ name string // type name
+ decl *ast.GenDecl // nil if declaration hasn't been seen yet
+
+ isEmbedded bool // true if this type is embedded
+ isStruct bool // true if this type is a struct
+ embedded embeddedSet // true if the embedded type is a pointer
+
+ // associated declarations
+ values []*Value // consts and vars
+ funcs methodSet
+ methods methodSet
+}
+
+// ----------------------------------------------------------------------------
+// AST reader
+
+// reader accumulates documentation for a single package.
+// It modifies the AST: Comments (declaration documentation)
+// that have been collected by the reader are set to nil
+// in the respective AST nodes so that they are not printed
+// twice (once when printing the documentation and once when
+// printing the corresponding AST node).
+//
+type reader struct {
+ mode Mode
+
+ // package properties
+ doc string // package documentation, if any
+ filenames []string
+ notes map[string][]*Note
+
+ // declarations
+ imports map[string]int
+ hasDotImp bool // if set, package contains a dot import
+ values []*Value // consts and vars
+ order int // sort order of const and var declarations (when we can't use a name)
+ types map[string]*namedType
+ funcs methodSet
+
+ // support for package-local error type declarations
+ errorDecl bool // if set, type "error" was declared locally
+ fixlist []*ast.InterfaceType // list of interfaces containing anonymous field "error"
+}
+
+func (r *reader) isVisible(name string) bool {
+ return r.mode&AllDecls != 0 || token.IsExported(name)
+}
+
+// lookupType returns the base type with the given name.
+// If the base type has not been encountered yet, a new
+// type with the given name but no associated declaration
+// is added to the type map.
+//
+func (r *reader) lookupType(name string) *namedType {
+ if name == "" || name == "_" {
+ return nil // no type docs for anonymous types
+ }
+ if typ, found := r.types[name]; found {
+ return typ
+ }
+ // type not found - add one without declaration
+ typ := &namedType{
+ name: name,
+ embedded: make(embeddedSet),
+ funcs: make(methodSet),
+ methods: make(methodSet),
+ }
+ r.types[name] = typ
+ return typ
+}
+
+// recordAnonymousField registers fieldType as the type of an
+// anonymous field in the parent type. If the field is imported
+// (qualified name) or the parent is nil, the field is ignored.
+// The function returns the field name.
+//
+func (r *reader) recordAnonymousField(parent *namedType, fieldType ast.Expr) (fname string) {
+ fname, imp := baseTypeName(fieldType)
+ if parent == nil || imp {
+ return
+ }
+ if ftype := r.lookupType(fname); ftype != nil {
+ ftype.isEmbedded = true
+ _, ptr := fieldType.(*ast.StarExpr)
+ parent.embedded[ftype] = ptr
+ }
+ return
+}
+
+func (r *reader) readDoc(comment *ast.CommentGroup) {
+ // By convention there should be only one package comment
+ // but collect all of them if there are more than one.
+ text := comment.Text()
+ if r.doc == "" {
+ r.doc = text
+ return
+ }
+ r.doc += "\n" + text
+}
+
+func (r *reader) remember(typ *ast.InterfaceType) {
+ r.fixlist = append(r.fixlist, typ)
+}
+
+func specNames(specs []ast.Spec) []string {
+ names := make([]string, 0, len(specs)) // reasonable estimate
+ for _, s := range specs {
+ // s guaranteed to be an *ast.ValueSpec by readValue
+ for _, ident := range s.(*ast.ValueSpec).Names {
+ names = append(names, ident.Name)
+ }
+ }
+ return names
+}
+
+// readValue processes a const or var declaration.
+//
+func (r *reader) readValue(decl *ast.GenDecl) {
+ // determine if decl should be associated with a type
+ // Heuristic: For each typed entry, determine the type name, if any.
+ // If there is exactly one type name that is sufficiently
+ // frequent, associate the decl with the respective type.
+ domName := ""
+ domFreq := 0
+ prev := ""
+ n := 0
+ for _, spec := range decl.Specs {
+ s, ok := spec.(*ast.ValueSpec)
+ if !ok {
+ continue // should not happen, but be conservative
+ }
+ name := ""
+ switch {
+ case s.Type != nil:
+ // a type is present; determine its name
+ if n, imp := baseTypeName(s.Type); !imp {
+ name = n
+ }
+ case decl.Tok == token.CONST && len(s.Values) == 0:
+ // no type or value is present but we have a constant declaration;
+ // use the previous type name (possibly the empty string)
+ name = prev
+ }
+ if name != "" {
+ // entry has a named type
+ if domName != "" && domName != name {
+ // more than one type name - do not associate
+ // with any type
+ domName = ""
+ break
+ }
+ domName = name
+ domFreq++
+ }
+ prev = name
+ n++
+ }
+
+ // nothing to do w/o a legal declaration
+ if n == 0 {
+ return
+ }
+
+ // determine values list with which to associate the Value for this decl
+ values := &r.values
+ const threshold = 0.75
+ if domName != "" && r.isVisible(domName) && domFreq >= int(float64(len(decl.Specs))*threshold) {
+ // typed entries are sufficiently frequent
+ if typ := r.lookupType(domName); typ != nil {
+ values = &typ.values // associate with that type
+ }
+ }
+
+ *values = append(*values, &Value{
+ Doc: decl.Doc.Text(),
+ Names: specNames(decl.Specs),
+ Decl: decl,
+ order: r.order,
+ })
+ if r.mode&PreserveAST == 0 {
+ decl.Doc = nil // doc consumed - remove from AST
+ }
+ // Note: It's important that the order used here is global because the cleanupTypes
+ // methods may move values associated with types back into the global list. If the
+ // order is list-specific, sorting is not deterministic because the same order value
+ // may appear multiple times (was bug, found when fixing #16153).
+ r.order++
+}
+
+// fields returns a struct's fields or an interface's methods.
+//
+func fields(typ ast.Expr) (list []*ast.Field, isStruct bool) {
+ var fields *ast.FieldList
+ switch t := typ.(type) {
+ case *ast.StructType:
+ fields = t.Fields
+ isStruct = true
+ case *ast.InterfaceType:
+ fields = t.Methods
+ }
+ if fields != nil {
+ list = fields.List
+ }
+ return
+}
+
+// readType processes a type declaration.
+//
+func (r *reader) readType(decl *ast.GenDecl, spec *ast.TypeSpec) {
+ typ := r.lookupType(spec.Name.Name)
+ if typ == nil {
+ return // no name or blank name - ignore the type
+ }
+
+ // A type should be added at most once, so typ.decl
+ // should be nil - if it is not, simply overwrite it.
+ typ.decl = decl
+
+ // compute documentation
+ doc := spec.Doc
+ if doc == nil {
+ // no doc associated with the spec, use the declaration doc, if any
+ doc = decl.Doc
+ }
+ if r.mode&PreserveAST == 0 {
+ spec.Doc = nil // doc consumed - remove from AST
+ decl.Doc = nil // doc consumed - remove from AST
+ }
+ typ.doc = doc.Text()
+
+ // record anonymous fields (they may contribute methods)
+ // (some fields may have been recorded already when filtering
+ // exports, but that's ok)
+ var list []*ast.Field
+ list, typ.isStruct = fields(spec.Type)
+ for _, field := range list {
+ if len(field.Names) == 0 {
+ r.recordAnonymousField(typ, field.Type)
+ }
+ }
+}
+
+// isPredeclared reports whether n denotes a predeclared type.
+//
+func (r *reader) isPredeclared(n string) bool {
+ return predeclaredTypes[n] && r.types[n] == nil
+}
+
+// readFunc processes a func or method declaration.
+//
+func (r *reader) readFunc(fun *ast.FuncDecl) {
+ // strip function body if requested.
+ if r.mode&PreserveAST == 0 {
+ fun.Body = nil
+ }
+
+ // associate methods with the receiver type, if any
+ if fun.Recv != nil {
+ // method
+ if len(fun.Recv.List) == 0 {
+ // should not happen (incorrect AST); (See issue 17788)
+ // don't show this method
+ return
+ }
+ recvTypeName, imp := baseTypeName(fun.Recv.List[0].Type)
+ if imp {
+ // should not happen (incorrect AST);
+ // don't show this method
+ return
+ }
+ if typ := r.lookupType(recvTypeName); typ != nil {
+ typ.methods.set(fun, r.mode&PreserveAST != 0)
+ }
+ // otherwise ignore the method
+ // TODO(gri): There may be exported methods of non-exported types
+ // that can be called because of exported values (consts, vars, or
+ // function results) of that type. Could determine if that is the
+ // case and then show those methods in an appropriate section.
+ return
+ }
+
+ // Associate factory functions with the first visible result type, as long as
+ // others are predeclared types.
+ if fun.Type.Results.NumFields() >= 1 {
+ var typ *namedType // type to associate the function with
+ numResultTypes := 0
+ for _, res := range fun.Type.Results.List {
+ factoryType := res.Type
+ if t, ok := factoryType.(*ast.ArrayType); ok {
+ // We consider functions that return slices or arrays of type
+ // T (or pointers to T) as factory functions of T.
+ factoryType = t.Elt
+ }
+ if n, imp := baseTypeName(factoryType); !imp && r.isVisible(n) && !r.isPredeclared(n) {
+ if t := r.lookupType(n); t != nil {
+ typ = t
+ numResultTypes++
+ if numResultTypes > 1 {
+ break
+ }
+ }
+ }
+ }
+ // If there is exactly one result type,
+ // associate the function with that type.
+ if numResultTypes == 1 {
+ typ.funcs.set(fun, r.mode&PreserveAST != 0)
+ return
+ }
+ }
+
+ // just an ordinary function
+ r.funcs.set(fun, r.mode&PreserveAST != 0)
+}
+
+var (
+ noteMarker = `([A-Z][A-Z]+)\(([^)]+)\):?` // MARKER(uid), MARKER at least 2 chars, uid at least 1 char
+ noteMarkerRx = lazyregexp.New(`^[ \t]*` + noteMarker) // MARKER(uid) at text start
+ noteCommentRx = lazyregexp.New(`^/[/*][ \t]*` + noteMarker) // MARKER(uid) at comment start
+)
+
+// readNote collects a single note from a sequence of comments.
+//
+func (r *reader) readNote(list []*ast.Comment) {
+ text := (&ast.CommentGroup{List: list}).Text()
+ if m := noteMarkerRx.FindStringSubmatchIndex(text); m != nil {
+ // The note body starts after the marker.
+ // We remove any formatting so that we don't
+ // get spurious line breaks/indentation when
+ // showing the TODO body.
+ body := clean(text[m[1]:], keepNL)
+ if body != "" {
+ marker := text[m[2]:m[3]]
+ r.notes[marker] = append(r.notes[marker], &Note{
+ Pos: list[0].Pos(),
+ End: list[len(list)-1].End(),
+ UID: text[m[4]:m[5]],
+ Body: body,
+ })
+ }
+ }
+}
+
+// readNotes extracts notes from comments.
+// A note must start at the beginning of a comment with "MARKER(uid):"
+// and is followed by the note body (e.g., "// BUG(gri): fix this").
+// The note ends at the end of the comment group or at the start of
+// another note in the same comment group, whichever comes first.
+//
+func (r *reader) readNotes(comments []*ast.CommentGroup) {
+ for _, group := range comments {
+ i := -1 // comment index of most recent note start, valid if >= 0
+ list := group.List
+ for j, c := range list {
+ if noteCommentRx.MatchString(c.Text) {
+ if i >= 0 {
+ r.readNote(list[i:j])
+ }
+ i = j
+ }
+ }
+ if i >= 0 {
+ r.readNote(list[i:])
+ }
+ }
+}
+
+// readFile adds the AST for a source file to the reader.
+//
+func (r *reader) readFile(src *ast.File) {
+ // add package documentation
+ if src.Doc != nil {
+ r.readDoc(src.Doc)
+ if r.mode&PreserveAST == 0 {
+ src.Doc = nil // doc consumed - remove from AST
+ }
+ }
+
+ // add all declarations but for functions which are processed in a separate pass
+ for _, decl := range src.Decls {
+ switch d := decl.(type) {
+ case *ast.GenDecl:
+ switch d.Tok {
+ case token.IMPORT:
+ // imports are handled individually
+ for _, spec := range d.Specs {
+ if s, ok := spec.(*ast.ImportSpec); ok {
+ if import_, err := strconv.Unquote(s.Path.Value); err == nil {
+ r.imports[import_] = 1
+ if s.Name != nil && s.Name.Name == "." {
+ r.hasDotImp = true
+ }
+ }
+ }
+ }
+ case token.CONST, token.VAR:
+ // constants and variables are always handled as a group
+ r.readValue(d)
+ case token.TYPE:
+ // types are handled individually
+ if len(d.Specs) == 1 && !d.Lparen.IsValid() {
+ // common case: single declaration w/o parentheses
+ // (if a single declaration is parenthesized,
+ // create a new fake declaration below, so that
+ // go/doc type declarations always appear w/o
+ // parentheses)
+ if s, ok := d.Specs[0].(*ast.TypeSpec); ok {
+ r.readType(d, s)
+ }
+ break
+ }
+ for _, spec := range d.Specs {
+ if s, ok := spec.(*ast.TypeSpec); ok {
+ // use an individual (possibly fake) declaration
+ // for each type; this also ensures that each type
+ // gets to (re-)use the declaration documentation
+ // if there's none associated with the spec itself
+ fake := &ast.GenDecl{
+ Doc: d.Doc,
+ // don't use the existing TokPos because it
+ // will lead to the wrong selection range for
+ // the fake declaration if there are more
+ // than one type in the group (this affects
+ // src/cmd/godoc/godoc.go's posLink_urlFunc)
+ TokPos: s.Pos(),
+ Tok: token.TYPE,
+ Specs: []ast.Spec{s},
+ }
+ r.readType(fake, s)
+ }
+ }
+ }
+ }
+ }
+
+ // collect MARKER(...): annotations
+ r.readNotes(src.Comments)
+ if r.mode&PreserveAST == 0 {
+ src.Comments = nil // consumed unassociated comments - remove from AST
+ }
+}
+
+func (r *reader) readPackage(pkg *ast.Package, mode Mode) {
+ // initialize reader
+ r.filenames = make([]string, len(pkg.Files))
+ r.imports = make(map[string]int)
+ r.mode = mode
+ r.types = make(map[string]*namedType)
+ r.funcs = make(methodSet)
+ r.notes = make(map[string][]*Note)
+
+ // sort package files before reading them so that the
+ // result does not depend on map iteration order
+ i := 0
+ for filename := range pkg.Files {
+ r.filenames[i] = filename
+ i++
+ }
+ sort.Strings(r.filenames)
+
+ // process files in sorted order
+ for _, filename := range r.filenames {
+ f := pkg.Files[filename]
+ if mode&AllDecls == 0 {
+ r.fileExports(f)
+ }
+ r.readFile(f)
+ }
+
+ // process functions now that we have better type information
+ for _, f := range pkg.Files {
+ for _, decl := range f.Decls {
+ if d, ok := decl.(*ast.FuncDecl); ok {
+ r.readFunc(d)
+ }
+ }
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Types
+
+func customizeRecv(f *Func, recvTypeName string, embeddedIsPtr bool, level int) *Func {
+ if f == nil || f.Decl == nil || f.Decl.Recv == nil || len(f.Decl.Recv.List) != 1 {
+ return f // shouldn't happen, but be safe
+ }
+
+ // copy existing receiver field and set new type
+ newField := *f.Decl.Recv.List[0]
+ origPos := newField.Type.Pos()
+ _, origRecvIsPtr := newField.Type.(*ast.StarExpr)
+ newIdent := &ast.Ident{NamePos: origPos, Name: recvTypeName}
+ var typ ast.Expr = newIdent
+ if !embeddedIsPtr && origRecvIsPtr {
+ newIdent.NamePos++ // '*' is one character
+ typ = &ast.StarExpr{Star: origPos, X: newIdent}
+ }
+ newField.Type = typ
+
+ // copy existing receiver field list and set new receiver field
+ newFieldList := *f.Decl.Recv
+ newFieldList.List = []*ast.Field{&newField}
+
+ // copy existing function declaration and set new receiver field list
+ newFuncDecl := *f.Decl
+ newFuncDecl.Recv = &newFieldList
+
+ // copy existing function documentation and set new declaration
+ newF := *f
+ newF.Decl = &newFuncDecl
+ newF.Recv = recvString(typ)
+ // the Orig field never changes
+ newF.Level = level
+
+ return &newF
+}
+
+// collectEmbeddedMethods collects the embedded methods of typ in mset.
+//
+func (r *reader) collectEmbeddedMethods(mset methodSet, typ *namedType, recvTypeName string, embeddedIsPtr bool, level int, visited embeddedSet) {
+ visited[typ] = true
+ for embedded, isPtr := range typ.embedded {
+ // Once an embedded type is embedded as a pointer type
+ // all embedded types in those types are treated like
+ // pointer types for the purpose of the receiver type
+ // computation; i.e., embeddedIsPtr is sticky for this
+ // embedding hierarchy.
+ thisEmbeddedIsPtr := embeddedIsPtr || isPtr
+ for _, m := range embedded.methods {
+ // only top-level methods are embedded
+ if m.Level == 0 {
+ mset.add(customizeRecv(m, recvTypeName, thisEmbeddedIsPtr, level))
+ }
+ }
+ if !visited[embedded] {
+ r.collectEmbeddedMethods(mset, embedded, recvTypeName, thisEmbeddedIsPtr, level+1, visited)
+ }
+ }
+ delete(visited, typ)
+}
+
+// computeMethodSets determines the actual method sets for each type encountered.
+//
+func (r *reader) computeMethodSets() {
+ for _, t := range r.types {
+ // collect embedded methods for t
+ if t.isStruct {
+ // struct
+ r.collectEmbeddedMethods(t.methods, t, t.name, false, 1, make(embeddedSet))
+ } else {
+ // interface
+ // TODO(gri) fix this
+ }
+ }
+
+ // if error was declared locally, don't treat it as exported field anymore
+ if r.errorDecl {
+ for _, ityp := range r.fixlist {
+ removeErrorField(ityp)
+ }
+ }
+}
+
+// cleanupTypes removes the association of functions and methods with
+// types that have no declaration. Instead, these functions and methods
+// are shown at the package level. It also removes types with missing
+// declarations or which are not visible.
+//
+func (r *reader) cleanupTypes() {
+ for _, t := range r.types {
+ visible := r.isVisible(t.name)
+ predeclared := predeclaredTypes[t.name]
+
+ if t.decl == nil && (predeclared || visible && (t.isEmbedded || r.hasDotImp)) {
+ // t.name is a predeclared type (and was not redeclared in this package),
+ // or it was embedded somewhere but its declaration is missing (because
+ // the AST is incomplete), or we have a dot-import (and all bets are off):
+ // move any associated values, funcs, and methods back to the top-level so
+ // that they are not lost.
+ // 1) move values
+ r.values = append(r.values, t.values...)
+ // 2) move factory functions
+ for name, f := range t.funcs {
+ // in a correct AST, package-level function names
+ // are all different - no need to check for conflicts
+ r.funcs[name] = f
+ }
+ // 3) move methods
+ if !predeclared {
+ for name, m := range t.methods {
+ // don't overwrite functions with the same name - drop them
+ if _, found := r.funcs[name]; !found {
+ r.funcs[name] = m
+ }
+ }
+ }
+ }
+ // remove types w/o declaration or which are not visible
+ if t.decl == nil || !visible {
+ delete(r.types, t.name)
+ }
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Sorting
+
+type data struct {
+ n int
+ swap func(i, j int)
+ less func(i, j int) bool
+}
+
+func (d *data) Len() int { return d.n }
+func (d *data) Swap(i, j int) { d.swap(i, j) }
+func (d *data) Less(i, j int) bool { return d.less(i, j) }
+
+// sortBy is a helper function for sorting
+func sortBy(less func(i, j int) bool, swap func(i, j int), n int) {
+ sort.Sort(&data{n, swap, less})
+}
+
+func sortedKeys(m map[string]int) []string {
+ list := make([]string, len(m))
+ i := 0
+ for key := range m {
+ list[i] = key
+ i++
+ }
+ sort.Strings(list)
+ return list
+}
+
+// sortingName returns the name to use when sorting d into place.
+//
+func sortingName(d *ast.GenDecl) string {
+ if len(d.Specs) == 1 {
+ if s, ok := d.Specs[0].(*ast.ValueSpec); ok {
+ return s.Names[0].Name
+ }
+ }
+ return ""
+}
+
+func sortedValues(m []*Value, tok token.Token) []*Value {
+ list := make([]*Value, len(m)) // big enough in any case
+ i := 0
+ for _, val := range m {
+ if val.Decl.Tok == tok {
+ list[i] = val
+ i++
+ }
+ }
+ list = list[0:i]
+
+ sortBy(
+ func(i, j int) bool {
+ if ni, nj := sortingName(list[i].Decl), sortingName(list[j].Decl); ni != nj {
+ return ni < nj
+ }
+ return list[i].order < list[j].order
+ },
+ func(i, j int) { list[i], list[j] = list[j], list[i] },
+ len(list),
+ )
+
+ return list
+}
+
+func sortedTypes(m map[string]*namedType, allMethods bool) []*Type {
+ list := make([]*Type, len(m))
+ i := 0
+ for _, t := range m {
+ list[i] = &Type{
+ Doc: t.doc,
+ Name: t.name,
+ Decl: t.decl,
+ Consts: sortedValues(t.values, token.CONST),
+ Vars: sortedValues(t.values, token.VAR),
+ Funcs: sortedFuncs(t.funcs, true),
+ Methods: sortedFuncs(t.methods, allMethods),
+ }
+ i++
+ }
+
+ sortBy(
+ func(i, j int) bool { return list[i].Name < list[j].Name },
+ func(i, j int) { list[i], list[j] = list[j], list[i] },
+ len(list),
+ )
+
+ return list
+}
+
+func removeStar(s string) string {
+ if len(s) > 0 && s[0] == '*' {
+ return s[1:]
+ }
+ return s
+}
+
+func sortedFuncs(m methodSet, allMethods bool) []*Func {
+ list := make([]*Func, len(m))
+ i := 0
+ for _, m := range m {
+ // determine which methods to include
+ switch {
+ case m.Decl == nil:
+ // exclude conflict entry
+ case allMethods, m.Level == 0, !token.IsExported(removeStar(m.Orig)):
+ // forced inclusion, method not embedded, or method
+ // embedded but original receiver type not exported
+ list[i] = m
+ i++
+ }
+ }
+ list = list[0:i]
+ sortBy(
+ func(i, j int) bool { return list[i].Name < list[j].Name },
+ func(i, j int) { list[i], list[j] = list[j], list[i] },
+ len(list),
+ )
+ return list
+}
+
+// noteBodies returns a list of note body strings given a list of notes.
+// This is only used to populate the deprecated Package.Bugs field.
+//
+func noteBodies(notes []*Note) []string {
+ var list []string
+ for _, n := range notes {
+ list = append(list, n.Body)
+ }
+ return list
+}
+
+// ----------------------------------------------------------------------------
+// Predeclared identifiers
+
+// IsPredeclared reports whether s is a predeclared identifier.
+func IsPredeclared(s string) bool {
+ return predeclaredTypes[s] || predeclaredFuncs[s] || predeclaredConstants[s]
+}
+
+var predeclaredTypes = map[string]bool{
+ "bool": true,
+ "byte": true,
+ "complex64": true,
+ "complex128": true,
+ "error": true,
+ "float32": true,
+ "float64": true,
+ "int": true,
+ "int8": true,
+ "int16": true,
+ "int32": true,
+ "int64": true,
+ "rune": true,
+ "string": true,
+ "uint": true,
+ "uint8": true,
+ "uint16": true,
+ "uint32": true,
+ "uint64": true,
+ "uintptr": true,
+}
+
+var predeclaredFuncs = map[string]bool{
+ "append": true,
+ "cap": true,
+ "close": true,
+ "complex": true,
+ "copy": true,
+ "delete": true,
+ "imag": true,
+ "len": true,
+ "make": true,
+ "new": true,
+ "panic": true,
+ "print": true,
+ "println": true,
+ "real": true,
+ "recover": true,
+}
+
+var predeclaredConstants = map[string]bool{
+ "false": true,
+ "iota": true,
+ "nil": true,
+ "true": true,
+}
diff --git a/src/go/doc/synopsis.go b/src/go/doc/synopsis.go
new file mode 100644
index 0000000..3fa1616
--- /dev/null
+++ b/src/go/doc/synopsis.go
@@ -0,0 +1,83 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import (
+ "strings"
+ "unicode"
+)
+
+// firstSentenceLen returns the length of the first sentence in s.
+// The sentence ends after the first period followed by space and
+// not preceded by exactly one uppercase letter.
+//
+func firstSentenceLen(s string) int {
+ var ppp, pp, p rune
+ for i, q := range s {
+ if q == '\n' || q == '\r' || q == '\t' {
+ q = ' '
+ }
+ if q == ' ' && p == '.' && (!unicode.IsUpper(pp) || unicode.IsUpper(ppp)) {
+ return i
+ }
+ if p == '。' || p == '.' {
+ return i
+ }
+ ppp, pp, p = pp, p, q
+ }
+ return len(s)
+}
+
+const (
+ keepNL = 1 << iota
+)
+
+// clean replaces each sequence of space, \n, \r, or \t characters
+// with a single space and removes any trailing and leading spaces.
+// If the keepNL flag is set, newline characters are passed through
+// instead of being change to spaces.
+func clean(s string, flags int) string {
+ var b []byte
+ p := byte(' ')
+ for i := 0; i < len(s); i++ {
+ q := s[i]
+ if (flags&keepNL) == 0 && q == '\n' || q == '\r' || q == '\t' {
+ q = ' '
+ }
+ if q != ' ' || p != ' ' {
+ b = append(b, q)
+ p = q
+ }
+ }
+ // remove trailing blank, if any
+ if n := len(b); n > 0 && p == ' ' {
+ b = b[0 : n-1]
+ }
+ return string(b)
+}
+
+// Synopsis returns a cleaned version of the first sentence in s.
+// That sentence ends after the first period followed by space and
+// not preceded by exactly one uppercase letter. The result string
+// has no \n, \r, or \t characters and uses only single spaces between
+// words. If s starts with any of the IllegalPrefixes, the result
+// is the empty string.
+//
+func Synopsis(s string) string {
+ s = clean(s[0:firstSentenceLen(s)], 0)
+ for _, prefix := range IllegalPrefixes {
+ if strings.HasPrefix(strings.ToLower(s), prefix) {
+ return ""
+ }
+ }
+ s = convertQuotes(s)
+ return s
+}
+
+var IllegalPrefixes = []string{
+ "copyright",
+ "all rights",
+ "author",
+}
diff --git a/src/go/doc/synopsis_test.go b/src/go/doc/synopsis_test.go
new file mode 100644
index 0000000..3f443dc
--- /dev/null
+++ b/src/go/doc/synopsis_test.go
@@ -0,0 +1,52 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import "testing"
+
+var tests = []struct {
+ txt string
+ fsl int
+ syn string
+}{
+ {"", 0, ""},
+ {"foo", 3, "foo"},
+ {"foo.", 4, "foo."},
+ {"foo.bar", 7, "foo.bar"},
+ {" foo. ", 6, "foo."},
+ {" foo\t bar.\n", 12, "foo bar."},
+ {" foo\t bar.\n", 12, "foo bar."},
+ {"a b\n\nc\r\rd\t\t", 12, "a b c d"},
+ {"a b\n\nc\r\rd\t\t . BLA", 15, "a b c d ."},
+ {"Package poems by T.S.Eliot. To rhyme...", 27, "Package poems by T.S.Eliot."},
+ {"Package poems by T. S. Eliot. To rhyme...", 29, "Package poems by T. S. Eliot."},
+ {"foo implements the foo ABI. The foo ABI is...", 27, "foo implements the foo ABI."},
+ {"Package\nfoo. ..", 12, "Package foo."},
+ {"P . Q.", 3, "P ."},
+ {"P. Q. ", 8, "P. Q."},
+ {"Package Καλημέρα κόσμε.", 36, "Package Καλημέρα κόσμε."},
+ {"Package こんにちは 世界\n", 31, "Package こんにちは 世界"},
+ {"Package こんにちは。世界", 26, "Package こんにちは。"},
+ {"Package 안녕.世界", 17, "Package 안녕."},
+ {"Package foo does bar.", 21, "Package foo does bar."},
+ {"Copyright 2012 Google, Inc. Package foo does bar.", 27, ""},
+ {"All Rights reserved. Package foo does bar.", 20, ""},
+ {"All rights reserved. Package foo does bar.", 20, ""},
+ {"Authors: foo@bar.com. Package foo does bar.", 21, ""},
+ {"typically invoked as ``go tool asm'',", 37, "typically invoked as " + ulquo + "go tool asm" + urquo + ","},
+}
+
+func TestSynopsis(t *testing.T) {
+ for _, e := range tests {
+ fsl := firstSentenceLen(e.txt)
+ if fsl != e.fsl {
+ t.Errorf("got fsl = %d; want %d for %q\n", fsl, e.fsl, e.txt)
+ }
+ syn := Synopsis(e.txt)
+ if syn != e.syn {
+ t.Errorf("got syn = %q; want %q for %q\n", syn, e.syn, e.txt)
+ }
+ }
+}
diff --git a/src/go/doc/testdata/a.0.golden b/src/go/doc/testdata/a.0.golden
new file mode 100644
index 0000000..7e680b8
--- /dev/null
+++ b/src/go/doc/testdata/a.0.golden
@@ -0,0 +1,52 @@
+// comment 0 comment 1
+PACKAGE a
+
+IMPORTPATH
+ testdata/a
+
+FILENAMES
+ testdata/a0.go
+ testdata/a1.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ bug0
+
+ bug1
+
+
+BUGS
+BUG(uid) bug0
+
+BUG(uid) bug1
+
+
+NOTES
+NOTE(uid)
+
+NOTE(foo) 1 of 4 - this is the first line of note 1
+ - note 1 continues on this 2nd line
+ - note 1 continues on this 3rd line
+
+NOTE(foo) 2 of 4
+
+NOTE(bar) 3 of 4
+
+NOTE(bar) 4 of 4
+ - this is the last line of note 4
+
+NOTE(bam) This note which contains a (parenthesized) subphrase
+ must appear in its entirety.
+
+NOTE(xxx) The ':' after the marker and uid is optional.
+
+
+SECBUGS
+SECBUG(uid) sec hole 0
+ need to fix asap
+
+
+TODOS
+TODO(uid) todo0
+
+TODO(uid) todo1
+
diff --git a/src/go/doc/testdata/a.1.golden b/src/go/doc/testdata/a.1.golden
new file mode 100644
index 0000000..7e680b8
--- /dev/null
+++ b/src/go/doc/testdata/a.1.golden
@@ -0,0 +1,52 @@
+// comment 0 comment 1
+PACKAGE a
+
+IMPORTPATH
+ testdata/a
+
+FILENAMES
+ testdata/a0.go
+ testdata/a1.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ bug0
+
+ bug1
+
+
+BUGS
+BUG(uid) bug0
+
+BUG(uid) bug1
+
+
+NOTES
+NOTE(uid)
+
+NOTE(foo) 1 of 4 - this is the first line of note 1
+ - note 1 continues on this 2nd line
+ - note 1 continues on this 3rd line
+
+NOTE(foo) 2 of 4
+
+NOTE(bar) 3 of 4
+
+NOTE(bar) 4 of 4
+ - this is the last line of note 4
+
+NOTE(bam) This note which contains a (parenthesized) subphrase
+ must appear in its entirety.
+
+NOTE(xxx) The ':' after the marker and uid is optional.
+
+
+SECBUGS
+SECBUG(uid) sec hole 0
+ need to fix asap
+
+
+TODOS
+TODO(uid) todo0
+
+TODO(uid) todo1
+
diff --git a/src/go/doc/testdata/a.2.golden b/src/go/doc/testdata/a.2.golden
new file mode 100644
index 0000000..7e680b8
--- /dev/null
+++ b/src/go/doc/testdata/a.2.golden
@@ -0,0 +1,52 @@
+// comment 0 comment 1
+PACKAGE a
+
+IMPORTPATH
+ testdata/a
+
+FILENAMES
+ testdata/a0.go
+ testdata/a1.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ bug0
+
+ bug1
+
+
+BUGS
+BUG(uid) bug0
+
+BUG(uid) bug1
+
+
+NOTES
+NOTE(uid)
+
+NOTE(foo) 1 of 4 - this is the first line of note 1
+ - note 1 continues on this 2nd line
+ - note 1 continues on this 3rd line
+
+NOTE(foo) 2 of 4
+
+NOTE(bar) 3 of 4
+
+NOTE(bar) 4 of 4
+ - this is the last line of note 4
+
+NOTE(bam) This note which contains a (parenthesized) subphrase
+ must appear in its entirety.
+
+NOTE(xxx) The ':' after the marker and uid is optional.
+
+
+SECBUGS
+SECBUG(uid) sec hole 0
+ need to fix asap
+
+
+TODOS
+TODO(uid) todo0
+
+TODO(uid) todo1
+
diff --git a/src/go/doc/testdata/a0.go b/src/go/doc/testdata/a0.go
new file mode 100644
index 0000000..2420c8a
--- /dev/null
+++ b/src/go/doc/testdata/a0.go
@@ -0,0 +1,40 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// comment 0
+package a
+
+//BUG(uid): bug0
+
+//TODO(uid): todo0
+
+// A note with some spaces after it, should be ignored (watch out for
+// emacs modes that remove trailing whitespace).
+//NOTE(uid):
+
+// SECBUG(uid): sec hole 0
+// need to fix asap
+
+// Multiple notes may be in the same comment group and should be
+// recognized individually. Notes may start in the middle of a
+// comment group as long as they start at the beginning of an
+// individual comment.
+//
+// NOTE(foo): 1 of 4 - this is the first line of note 1
+// - note 1 continues on this 2nd line
+// - note 1 continues on this 3rd line
+// NOTE(foo): 2 of 4
+// NOTE(bar): 3 of 4
+/* NOTE(bar): 4 of 4 */
+// - this is the last line of note 4
+//
+//
+
+// NOTE(bam): This note which contains a (parenthesized) subphrase
+// must appear in its entirety.
+
+// NOTE(xxx) The ':' after the marker and uid is optional.
+
+// NOTE(): NO uid - should not show up.
+// NOTE() NO uid - should not show up.
diff --git a/src/go/doc/testdata/a1.go b/src/go/doc/testdata/a1.go
new file mode 100644
index 0000000..9fad1e0
--- /dev/null
+++ b/src/go/doc/testdata/a1.go
@@ -0,0 +1,12 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// comment 1
+package a
+
+//BUG(uid): bug1
+
+//TODO(uid): todo1
+
+//TODO(): ignored
diff --git a/src/go/doc/testdata/b.0.golden b/src/go/doc/testdata/b.0.golden
new file mode 100644
index 0000000..9d93392
--- /dev/null
+++ b/src/go/doc/testdata/b.0.golden
@@ -0,0 +1,71 @@
+//
+PACKAGE b
+
+IMPORTPATH
+ testdata/b
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/b.go
+
+CONSTANTS
+ //
+ const (
+ C1 notExported = iota
+ C2
+
+ C4
+ C5
+ )
+
+ //
+ const C notExported = 0
+
+ //
+ const Pi = 3.14 // Pi
+
+
+VARIABLES
+ //
+ var (
+ U1, U2, U4, U5 notExported
+
+ U7 notExported = 7
+ )
+
+ //
+ var MaxInt int // MaxInt
+
+ //
+ var V notExported
+
+ //
+ var V1, V2, V4, V5 notExported
+
+
+FUNCTIONS
+ //
+ func F(x int) int
+
+ //
+ func F1() notExported
+
+ // Always under the package functions list.
+ func NotAFactory() int
+
+ // Associated with uint type if AllDecls is set.
+ func UintFactory() uint
+
+
+TYPES
+ //
+ type T struct{} // T
+
+ //
+ var V T // v
+
+ //
+ func (x *T) M()
+
diff --git a/src/go/doc/testdata/b.1.golden b/src/go/doc/testdata/b.1.golden
new file mode 100644
index 0000000..66c47b5
--- /dev/null
+++ b/src/go/doc/testdata/b.1.golden
@@ -0,0 +1,83 @@
+//
+PACKAGE b
+
+IMPORTPATH
+ testdata/b
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/b.go
+
+CONSTANTS
+ //
+ const Pi = 3.14 // Pi
+
+
+VARIABLES
+ //
+ var MaxInt int // MaxInt
+
+
+FUNCTIONS
+ //
+ func F(x int) int
+
+ // Always under the package functions list.
+ func NotAFactory() int
+
+
+TYPES
+ //
+ type T struct{} // T
+
+ //
+ var V T // v
+
+ //
+ func (x *T) M()
+
+ //
+ type notExported int
+
+ //
+ const (
+ C1 notExported = iota
+ C2
+ c3
+ C4
+ C5
+ )
+
+ //
+ const C notExported = 0
+
+ //
+ var (
+ U1, U2, u3, U4, U5 notExported
+ u6 notExported
+ U7 notExported = 7
+ )
+
+ //
+ var V notExported
+
+ //
+ var V1, V2, v3, V4, V5 notExported
+
+ //
+ func F1() notExported
+
+ //
+ func f2() notExported
+
+ // Should only appear if AllDecls is set.
+ type uint struct{} // overrides a predeclared type uint
+
+ // Associated with uint type if AllDecls is set.
+ func UintFactory() uint
+
+ // Associated with uint type if AllDecls is set.
+ func uintFactory() uint
+
diff --git a/src/go/doc/testdata/b.2.golden b/src/go/doc/testdata/b.2.golden
new file mode 100644
index 0000000..9d93392
--- /dev/null
+++ b/src/go/doc/testdata/b.2.golden
@@ -0,0 +1,71 @@
+//
+PACKAGE b
+
+IMPORTPATH
+ testdata/b
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/b.go
+
+CONSTANTS
+ //
+ const (
+ C1 notExported = iota
+ C2
+
+ C4
+ C5
+ )
+
+ //
+ const C notExported = 0
+
+ //
+ const Pi = 3.14 // Pi
+
+
+VARIABLES
+ //
+ var (
+ U1, U2, U4, U5 notExported
+
+ U7 notExported = 7
+ )
+
+ //
+ var MaxInt int // MaxInt
+
+ //
+ var V notExported
+
+ //
+ var V1, V2, V4, V5 notExported
+
+
+FUNCTIONS
+ //
+ func F(x int) int
+
+ //
+ func F1() notExported
+
+ // Always under the package functions list.
+ func NotAFactory() int
+
+ // Associated with uint type if AllDecls is set.
+ func UintFactory() uint
+
+
+TYPES
+ //
+ type T struct{} // T
+
+ //
+ var V T // v
+
+ //
+ func (x *T) M()
+
diff --git a/src/go/doc/testdata/b.go b/src/go/doc/testdata/b.go
new file mode 100644
index 0000000..e50663b
--- /dev/null
+++ b/src/go/doc/testdata/b.go
@@ -0,0 +1,58 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "a"
+
+// ----------------------------------------------------------------------------
+// Basic declarations
+
+const Pi = 3.14 // Pi
+var MaxInt int // MaxInt
+type T struct{} // T
+var V T // v
+func F(x int) int {} // F
+func (x *T) M() {} // M
+
+// Corner cases: association with (presumed) predeclared types
+
+// Always under the package functions list.
+func NotAFactory() int {}
+
+// Associated with uint type if AllDecls is set.
+func UintFactory() uint {}
+
+// Associated with uint type if AllDecls is set.
+func uintFactory() uint {}
+
+// Should only appear if AllDecls is set.
+type uint struct{} // overrides a predeclared type uint
+
+// ----------------------------------------------------------------------------
+// Exported declarations associated with non-exported types must always be shown.
+
+type notExported int
+
+const C notExported = 0
+
+const (
+ C1 notExported = iota
+ C2
+ c3
+ C4
+ C5
+)
+
+var V notExported
+var V1, V2, v3, V4, V5 notExported
+
+var (
+ U1, U2, u3, U4, U5 notExported
+ u6 notExported
+ U7 notExported = 7
+)
+
+func F1() notExported {}
+func f2() notExported {}
diff --git a/src/go/doc/testdata/benchmark.go b/src/go/doc/testdata/benchmark.go
new file mode 100644
index 0000000..1d581f0
--- /dev/null
+++ b/src/go/doc/testdata/benchmark.go
@@ -0,0 +1,293 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing
+
+import (
+ "flag"
+ "fmt"
+ "os"
+ "runtime"
+ "time"
+)
+
+var matchBenchmarks = flag.String("test.bench", "", "regular expression to select benchmarks to run")
+var benchTime = flag.Duration("test.benchtime", 1*time.Second, "approximate run time for each benchmark")
+
+// An internal type but exported because it is cross-package; part of the implementation
+// of go test.
+type InternalBenchmark struct {
+ Name string
+ F func(b *B)
+}
+
+// B is a type passed to Benchmark functions to manage benchmark
+// timing and to specify the number of iterations to run.
+type B struct {
+ common
+ N int
+ benchmark InternalBenchmark
+ bytes int64
+ timerOn bool
+ result BenchmarkResult
+}
+
+// StartTimer starts timing a test. This function is called automatically
+// before a benchmark starts, but it can also used to resume timing after
+// a call to StopTimer.
+func (b *B) StartTimer() {
+ if !b.timerOn {
+ b.start = time.Now()
+ b.timerOn = true
+ }
+}
+
+// StopTimer stops timing a test. This can be used to pause the timer
+// while performing complex initialization that you don't
+// want to measure.
+func (b *B) StopTimer() {
+ if b.timerOn {
+ b.duration += time.Now().Sub(b.start)
+ b.timerOn = false
+ }
+}
+
+// ResetTimer sets the elapsed benchmark time to zero.
+// It does not affect whether the timer is running.
+func (b *B) ResetTimer() {
+ if b.timerOn {
+ b.start = time.Now()
+ }
+ b.duration = 0
+}
+
+// SetBytes records the number of bytes processed in a single operation.
+// If this is called, the benchmark will report ns/op and MB/s.
+func (b *B) SetBytes(n int64) { b.bytes = n }
+
+func (b *B) nsPerOp() int64 {
+ if b.N <= 0 {
+ return 0
+ }
+ return b.duration.Nanoseconds() / int64(b.N)
+}
+
+// runN runs a single benchmark for the specified number of iterations.
+func (b *B) runN(n int) {
+ // Try to get a comparable environment for each run
+ // by clearing garbage from previous runs.
+ runtime.GC()
+ b.N = n
+ b.ResetTimer()
+ b.StartTimer()
+ b.benchmark.F(b)
+ b.StopTimer()
+}
+
+func min(x, y int) int {
+ if x > y {
+ return y
+ }
+ return x
+}
+
+func max(x, y int) int {
+ if x < y {
+ return y
+ }
+ return x
+}
+
+// roundDown10 rounds a number down to the nearest power of 10.
+func roundDown10(n int) int {
+ var tens = 0
+ // tens = floor(log_10(n))
+ for n > 10 {
+ n = n / 10
+ tens++
+ }
+ // result = 10^tens
+ result := 1
+ for i := 0; i < tens; i++ {
+ result *= 10
+ }
+ return result
+}
+
+// roundUp rounds x up to a number of the form [1eX, 2eX, 5eX].
+func roundUp(n int) int {
+ base := roundDown10(n)
+ if n < (2 * base) {
+ return 2 * base
+ }
+ if n < (5 * base) {
+ return 5 * base
+ }
+ return 10 * base
+}
+
+// run times the benchmark function in a separate goroutine.
+func (b *B) run() BenchmarkResult {
+ go b.launch()
+ <-b.signal
+ return b.result
+}
+
+// launch launches the benchmark function. It gradually increases the number
+// of benchmark iterations until the benchmark runs for a second in order
+// to get a reasonable measurement. It prints timing information in this form
+// testing.BenchmarkHello 100000 19 ns/op
+// launch is run by the fun function as a separate goroutine.
+func (b *B) launch() {
+ // Run the benchmark for a single iteration in case it's expensive.
+ n := 1
+
+ // Signal that we're done whether we return normally
+ // or by FailNow's runtime.Goexit.
+ defer func() {
+ b.signal <- b
+ }()
+
+ b.runN(n)
+ // Run the benchmark for at least the specified amount of time.
+ d := *benchTime
+ for !b.failed && b.duration < d && n < 1e9 {
+ last := n
+ // Predict iterations/sec.
+ if b.nsPerOp() == 0 {
+ n = 1e9
+ } else {
+ n = int(d.Nanoseconds() / b.nsPerOp())
+ }
+ // Run more iterations than we think we'll need for a second (1.5x).
+ // Don't grow too fast in case we had timing errors previously.
+ // Be sure to run at least one more than last time.
+ n = max(min(n+n/2, 100*last), last+1)
+ // Round up to something easy to read.
+ n = roundUp(n)
+ b.runN(n)
+ }
+ b.result = BenchmarkResult{b.N, b.duration, b.bytes}
+}
+
+// The results of a benchmark run.
+type BenchmarkResult struct {
+ N int // The number of iterations.
+ T time.Duration // The total time taken.
+ Bytes int64 // Bytes processed in one iteration.
+}
+
+func (r BenchmarkResult) NsPerOp() int64 {
+ if r.N <= 0 {
+ return 0
+ }
+ return r.T.Nanoseconds() / int64(r.N)
+}
+
+func (r BenchmarkResult) mbPerSec() float64 {
+ if r.Bytes <= 0 || r.T <= 0 || r.N <= 0 {
+ return 0
+ }
+ return (float64(r.Bytes) * float64(r.N) / 1e6) / r.T.Seconds()
+}
+
+func (r BenchmarkResult) String() string {
+ mbs := r.mbPerSec()
+ mb := ""
+ if mbs != 0 {
+ mb = fmt.Sprintf("\t%7.2f MB/s", mbs)
+ }
+ nsop := r.NsPerOp()
+ ns := fmt.Sprintf("%10d ns/op", nsop)
+ if r.N > 0 && nsop < 100 {
+ // The format specifiers here make sure that
+ // the ones digits line up for all three possible formats.
+ if nsop < 10 {
+ ns = fmt.Sprintf("%13.2f ns/op", float64(r.T.Nanoseconds())/float64(r.N))
+ } else {
+ ns = fmt.Sprintf("%12.1f ns/op", float64(r.T.Nanoseconds())/float64(r.N))
+ }
+ }
+ return fmt.Sprintf("%8d\t%s%s", r.N, ns, mb)
+}
+
+// An internal function but exported because it is cross-package; part of the implementation
+// of go test.
+func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks []InternalBenchmark) {
+ // If no flag was specified, don't run benchmarks.
+ if len(*matchBenchmarks) == 0 {
+ return
+ }
+ for _, Benchmark := range benchmarks {
+ matched, err := matchString(*matchBenchmarks, Benchmark.Name)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "testing: invalid regexp for -test.bench: %s\n", err)
+ os.Exit(1)
+ }
+ if !matched {
+ continue
+ }
+ for _, procs := range cpuList {
+ runtime.GOMAXPROCS(procs)
+ b := &B{
+ common: common{
+ signal: make(chan interface{}),
+ },
+ benchmark: Benchmark,
+ }
+ benchName := Benchmark.Name
+ if procs != 1 {
+ benchName = fmt.Sprintf("%s-%d", Benchmark.Name, procs)
+ }
+ fmt.Printf("%s\t", benchName)
+ r := b.run()
+ if b.failed {
+ // The output could be very long here, but probably isn't.
+ // We print it all, regardless, because we don't want to trim the reason
+ // the benchmark failed.
+ fmt.Printf("--- FAIL: %s\n%s", benchName, b.output)
+ continue
+ }
+ fmt.Printf("%v\n", r)
+ // Unlike with tests, we ignore the -chatty flag and always print output for
+ // benchmarks since the output generation time will skew the results.
+ if len(b.output) > 0 {
+ b.trimOutput()
+ fmt.Printf("--- BENCH: %s\n%s", benchName, b.output)
+ }
+ if p := runtime.GOMAXPROCS(-1); p != procs {
+ fmt.Fprintf(os.Stderr, "testing: %s left GOMAXPROCS set to %d\n", benchName, p)
+ }
+ }
+ }
+}
+
+// trimOutput shortens the output from a benchmark, which can be very long.
+func (b *B) trimOutput() {
+ // The output is likely to appear multiple times because the benchmark
+ // is run multiple times, but at least it will be seen. This is not a big deal
+ // because benchmarks rarely print, but just in case, we trim it if it's too long.
+ const maxNewlines = 10
+ for nlCount, j := 0, 0; j < len(b.output); j++ {
+ if b.output[j] == '\n' {
+ nlCount++
+ if nlCount >= maxNewlines {
+ b.output = append(b.output[:j], "\n\t... [output truncated]\n"...)
+ break
+ }
+ }
+ }
+}
+
+// Benchmark benchmarks a single function. Useful for creating
+// custom benchmarks that do not use go test.
+func Benchmark(f func(b *B)) BenchmarkResult {
+ b := &B{
+ common: common{
+ signal: make(chan interface{}),
+ },
+ benchmark: InternalBenchmark{"", f},
+ }
+ return b.run()
+}
diff --git a/src/go/doc/testdata/blank.0.golden b/src/go/doc/testdata/blank.0.golden
new file mode 100644
index 0000000..70f2929
--- /dev/null
+++ b/src/go/doc/testdata/blank.0.golden
@@ -0,0 +1,62 @@
+// Package blank is a go/doc test for the handling of _. See issue ...
+PACKAGE blank
+
+IMPORTPATH
+ testdata/blank
+
+IMPORTS
+ os
+
+FILENAMES
+ testdata/blank.go
+
+CONSTANTS
+ // T constants counting from unexported constants.
+ const (
+ C1 T
+ C2
+
+ C3
+
+ C4 int
+ )
+
+ // Constants with a single type that is not propagated.
+ const (
+ Default = 0644
+ Useless = 0312
+ WideOpen = 0777
+ )
+
+ // Constants with an imported type that is propagated.
+ const (
+ M1 os.FileMode
+ M2
+ M3
+ )
+
+ // Package constants.
+ const (
+ I1 int
+ I2
+ )
+
+
+TYPES
+ // S has a padding field.
+ type S struct {
+ H uint32
+
+ A uint8
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T int
+
+ // T constants counting from a blank constant.
+ const (
+ T1 T
+ T2
+ )
+
diff --git a/src/go/doc/testdata/blank.1.golden b/src/go/doc/testdata/blank.1.golden
new file mode 100644
index 0000000..8098cb6
--- /dev/null
+++ b/src/go/doc/testdata/blank.1.golden
@@ -0,0 +1,83 @@
+// Package blank is a go/doc test for the handling of _. See issue ...
+PACKAGE blank
+
+IMPORTPATH
+ testdata/blank
+
+IMPORTS
+ os
+
+FILENAMES
+ testdata/blank.go
+
+CONSTANTS
+ // T constants counting from unexported constants.
+ const (
+ tweedledee T = iota
+ tweedledum
+ C1
+ C2
+ alice
+ C3
+ redQueen int = iota
+ C4
+ )
+
+ // Constants with a single type that is not propagated.
+ const (
+ zero os.FileMode = 0
+ Default = 0644
+ Useless = 0312
+ WideOpen = 0777
+ )
+
+ // Constants with an imported type that is propagated.
+ const (
+ zero os.FileMode = 0
+ M1
+ M2
+ M3
+ )
+
+ // Package constants.
+ const (
+ _ int = iota
+ I1
+ I2
+ )
+
+ // Unexported constants counting from blank iota. See issue 9615.
+ const (
+ _ = iota
+ one = iota + 1
+ )
+
+
+VARIABLES
+ //
+ var _ = T(55)
+
+
+FUNCTIONS
+ //
+ func _()
+
+
+TYPES
+ // S has a padding field.
+ type S struct {
+ H uint32
+ _ uint8
+ A uint8
+ }
+
+ //
+ type T int
+
+ // T constants counting from a blank constant.
+ const (
+ _ T = iota
+ T1
+ T2
+ )
+
diff --git a/src/go/doc/testdata/blank.2.golden b/src/go/doc/testdata/blank.2.golden
new file mode 100644
index 0000000..70f2929
--- /dev/null
+++ b/src/go/doc/testdata/blank.2.golden
@@ -0,0 +1,62 @@
+// Package blank is a go/doc test for the handling of _. See issue ...
+PACKAGE blank
+
+IMPORTPATH
+ testdata/blank
+
+IMPORTS
+ os
+
+FILENAMES
+ testdata/blank.go
+
+CONSTANTS
+ // T constants counting from unexported constants.
+ const (
+ C1 T
+ C2
+
+ C3
+
+ C4 int
+ )
+
+ // Constants with a single type that is not propagated.
+ const (
+ Default = 0644
+ Useless = 0312
+ WideOpen = 0777
+ )
+
+ // Constants with an imported type that is propagated.
+ const (
+ M1 os.FileMode
+ M2
+ M3
+ )
+
+ // Package constants.
+ const (
+ I1 int
+ I2
+ )
+
+
+TYPES
+ // S has a padding field.
+ type S struct {
+ H uint32
+
+ A uint8
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T int
+
+ // T constants counting from a blank constant.
+ const (
+ T1 T
+ T2
+ )
+
diff --git a/src/go/doc/testdata/blank.go b/src/go/doc/testdata/blank.go
new file mode 100644
index 0000000..5ea6186
--- /dev/null
+++ b/src/go/doc/testdata/blank.go
@@ -0,0 +1,75 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package blank is a go/doc test for the handling of _.
+// See issue 5397.
+package blank
+
+import "os"
+
+type T int
+
+// T constants counting from a blank constant.
+const (
+ _ T = iota
+ T1
+ T2
+)
+
+// T constants counting from unexported constants.
+const (
+ tweedledee T = iota
+ tweedledum
+ C1
+ C2
+ alice
+ C3
+ redQueen int = iota
+ C4
+)
+
+// Constants with a single type that is not propagated.
+const (
+ zero os.FileMode = 0
+ Default = 0644
+ Useless = 0312
+ WideOpen = 0777
+)
+
+// Constants with an imported type that is propagated.
+const (
+ zero os.FileMode = 0
+ M1
+ M2
+ M3
+)
+
+// Package constants.
+const (
+ _ int = iota
+ I1
+ I2
+)
+
+// Unexported constants counting from blank iota.
+// See issue 9615.
+const (
+ _ = iota
+ one = iota + 1
+)
+
+// Blanks not in doc output:
+
+// S has a padding field.
+type S struct {
+ H uint32
+ _ uint8
+ A uint8
+}
+
+func _() {}
+
+type _ T
+
+var _ = T(55)
diff --git a/src/go/doc/testdata/bugpara.0.golden b/src/go/doc/testdata/bugpara.0.golden
new file mode 100644
index 0000000..5804859
--- /dev/null
+++ b/src/go/doc/testdata/bugpara.0.golden
@@ -0,0 +1,20 @@
+//
+PACKAGE bugpara
+
+IMPORTPATH
+ testdata/bugpara
+
+FILENAMES
+ testdata/bugpara.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
+
+BUGS
+BUG(rsc) Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
diff --git a/src/go/doc/testdata/bugpara.1.golden b/src/go/doc/testdata/bugpara.1.golden
new file mode 100644
index 0000000..5804859
--- /dev/null
+++ b/src/go/doc/testdata/bugpara.1.golden
@@ -0,0 +1,20 @@
+//
+PACKAGE bugpara
+
+IMPORTPATH
+ testdata/bugpara
+
+FILENAMES
+ testdata/bugpara.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
+
+BUGS
+BUG(rsc) Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
diff --git a/src/go/doc/testdata/bugpara.2.golden b/src/go/doc/testdata/bugpara.2.golden
new file mode 100644
index 0000000..5804859
--- /dev/null
+++ b/src/go/doc/testdata/bugpara.2.golden
@@ -0,0 +1,20 @@
+//
+PACKAGE bugpara
+
+IMPORTPATH
+ testdata/bugpara
+
+FILENAMES
+ testdata/bugpara.go
+
+BUGS .Bugs is now deprecated, please use .Notes instead
+ Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
+
+BUGS
+BUG(rsc) Sometimes bugs have multiple paragraphs.
+
+ Like this one.
+
diff --git a/src/go/doc/testdata/bugpara.go b/src/go/doc/testdata/bugpara.go
new file mode 100644
index 0000000..0360a6f
--- /dev/null
+++ b/src/go/doc/testdata/bugpara.go
@@ -0,0 +1,9 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bugpara
+
+// BUG(rsc): Sometimes bugs have multiple paragraphs.
+//
+// Like this one.
diff --git a/src/go/doc/testdata/c.0.golden b/src/go/doc/testdata/c.0.golden
new file mode 100644
index 0000000..e21959b
--- /dev/null
+++ b/src/go/doc/testdata/c.0.golden
@@ -0,0 +1,48 @@
+//
+PACKAGE c
+
+IMPORTPATH
+ testdata/c
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/c.go
+
+TYPES
+ // A (should see this)
+ type A struct{}
+
+ // B (should see this)
+ type B struct{}
+
+ // C (should see this)
+ type C struct{}
+
+ // D (should see this)
+ type D struct{}
+
+ // E1 (should see this)
+ type E1 struct{}
+
+ // E (should see this for E2 and E3)
+ type E2 struct{}
+
+ // E (should see this for E2 and E3)
+ type E3 struct{}
+
+ // E4 (should see this)
+ type E4 struct{}
+
+ //
+ type T1 struct{}
+
+ //
+ func (t1 *T1) M()
+
+ // T2 must not show methods of local T1
+ type T2 struct {
+ a.T1 // not the same as locally declared T1
+ }
+
diff --git a/src/go/doc/testdata/c.1.golden b/src/go/doc/testdata/c.1.golden
new file mode 100644
index 0000000..e21959b
--- /dev/null
+++ b/src/go/doc/testdata/c.1.golden
@@ -0,0 +1,48 @@
+//
+PACKAGE c
+
+IMPORTPATH
+ testdata/c
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/c.go
+
+TYPES
+ // A (should see this)
+ type A struct{}
+
+ // B (should see this)
+ type B struct{}
+
+ // C (should see this)
+ type C struct{}
+
+ // D (should see this)
+ type D struct{}
+
+ // E1 (should see this)
+ type E1 struct{}
+
+ // E (should see this for E2 and E3)
+ type E2 struct{}
+
+ // E (should see this for E2 and E3)
+ type E3 struct{}
+
+ // E4 (should see this)
+ type E4 struct{}
+
+ //
+ type T1 struct{}
+
+ //
+ func (t1 *T1) M()
+
+ // T2 must not show methods of local T1
+ type T2 struct {
+ a.T1 // not the same as locally declared T1
+ }
+
diff --git a/src/go/doc/testdata/c.2.golden b/src/go/doc/testdata/c.2.golden
new file mode 100644
index 0000000..e21959b
--- /dev/null
+++ b/src/go/doc/testdata/c.2.golden
@@ -0,0 +1,48 @@
+//
+PACKAGE c
+
+IMPORTPATH
+ testdata/c
+
+IMPORTS
+ a
+
+FILENAMES
+ testdata/c.go
+
+TYPES
+ // A (should see this)
+ type A struct{}
+
+ // B (should see this)
+ type B struct{}
+
+ // C (should see this)
+ type C struct{}
+
+ // D (should see this)
+ type D struct{}
+
+ // E1 (should see this)
+ type E1 struct{}
+
+ // E (should see this for E2 and E3)
+ type E2 struct{}
+
+ // E (should see this for E2 and E3)
+ type E3 struct{}
+
+ // E4 (should see this)
+ type E4 struct{}
+
+ //
+ type T1 struct{}
+
+ //
+ func (t1 *T1) M()
+
+ // T2 must not show methods of local T1
+ type T2 struct {
+ a.T1 // not the same as locally declared T1
+ }
+
diff --git a/src/go/doc/testdata/c.go b/src/go/doc/testdata/c.go
new file mode 100644
index 0000000..e0f3919
--- /dev/null
+++ b/src/go/doc/testdata/c.go
@@ -0,0 +1,62 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package c
+
+import "a"
+
+// ----------------------------------------------------------------------------
+// Test that empty declarations don't cause problems
+
+const ()
+
+type ()
+
+var ()
+
+// ----------------------------------------------------------------------------
+// Test that types with documentation on both, the Decl and the Spec node
+// are handled correctly.
+
+// A (should see this)
+type A struct{}
+
+// B (should see this)
+type (
+ B struct{}
+)
+
+type (
+ // C (should see this)
+ C struct{}
+)
+
+// D (should not see this)
+type (
+ // D (should see this)
+ D struct{}
+)
+
+// E (should see this for E2 and E3)
+type (
+ // E1 (should see this)
+ E1 struct{}
+ E2 struct{}
+ E3 struct{}
+ // E4 (should see this)
+ E4 struct{}
+)
+
+// ----------------------------------------------------------------------------
+// Test that local and imported types are different when
+// handling anonymous fields.
+
+type T1 struct{}
+
+func (t1 *T1) M() {}
+
+// T2 must not show methods of local T1
+type T2 struct {
+ a.T1 // not the same as locally declared T1
+}
diff --git a/src/go/doc/testdata/d.0.golden b/src/go/doc/testdata/d.0.golden
new file mode 100644
index 0000000..c005199
--- /dev/null
+++ b/src/go/doc/testdata/d.0.golden
@@ -0,0 +1,104 @@
+//
+PACKAGE d
+
+IMPORTPATH
+ testdata/d
+
+FILENAMES
+ testdata/d1.go
+ testdata/d2.go
+
+CONSTANTS
+ // CBx constants should appear before CAx constants.
+ const (
+ CB2 = iota // before CB1
+ CB1 // before CB0
+ CB0 // at end
+ )
+
+ // CAx constants should appear after CBx constants.
+ const (
+ CA2 = iota // before CA1
+ CA1 // before CA0
+ CA0 // at end
+ )
+
+ // C0 should be first.
+ const C0 = 0
+
+ // C1 should be second.
+ const C1 = 1
+
+ // C2 should be third.
+ const C2 = 2
+
+ //
+ const (
+ // Single const declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Cungrouped = 0
+ )
+
+
+VARIABLES
+ // VBx variables should appear before VAx variables.
+ var (
+ VB2 int // before VB1
+ VB1 int // before VB0
+ VB0 int // at end
+ )
+
+ // VAx variables should appear after VBx variables.
+ var (
+ VA2 int // before VA1
+ VA1 int // before VA0
+ VA0 int // at end
+ )
+
+ // V0 should be first.
+ var V0 uintptr
+
+ // V1 should be second.
+ var V1 uint
+
+ // V2 should be third.
+ var V2 int
+
+ //
+ var (
+ // Single var declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Vungrouped = 0
+ )
+
+
+FUNCTIONS
+ // F0 should be first.
+ func F0()
+
+ // F1 should be second.
+ func F1()
+
+ // F2 should be third.
+ func F2()
+
+
+TYPES
+ // T0 should be first.
+ type T0 struct{}
+
+ // T1 should be second.
+ type T1 struct{}
+
+ // T2 should be third.
+ type T2 struct{}
+
+ // TG0 should be first.
+ type TG0 struct{}
+
+ // TG1 should be second.
+ type TG1 struct{}
+
+ // TG2 should be third.
+ type TG2 struct{}
+
diff --git a/src/go/doc/testdata/d.1.golden b/src/go/doc/testdata/d.1.golden
new file mode 100644
index 0000000..c005199
--- /dev/null
+++ b/src/go/doc/testdata/d.1.golden
@@ -0,0 +1,104 @@
+//
+PACKAGE d
+
+IMPORTPATH
+ testdata/d
+
+FILENAMES
+ testdata/d1.go
+ testdata/d2.go
+
+CONSTANTS
+ // CBx constants should appear before CAx constants.
+ const (
+ CB2 = iota // before CB1
+ CB1 // before CB0
+ CB0 // at end
+ )
+
+ // CAx constants should appear after CBx constants.
+ const (
+ CA2 = iota // before CA1
+ CA1 // before CA0
+ CA0 // at end
+ )
+
+ // C0 should be first.
+ const C0 = 0
+
+ // C1 should be second.
+ const C1 = 1
+
+ // C2 should be third.
+ const C2 = 2
+
+ //
+ const (
+ // Single const declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Cungrouped = 0
+ )
+
+
+VARIABLES
+ // VBx variables should appear before VAx variables.
+ var (
+ VB2 int // before VB1
+ VB1 int // before VB0
+ VB0 int // at end
+ )
+
+ // VAx variables should appear after VBx variables.
+ var (
+ VA2 int // before VA1
+ VA1 int // before VA0
+ VA0 int // at end
+ )
+
+ // V0 should be first.
+ var V0 uintptr
+
+ // V1 should be second.
+ var V1 uint
+
+ // V2 should be third.
+ var V2 int
+
+ //
+ var (
+ // Single var declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Vungrouped = 0
+ )
+
+
+FUNCTIONS
+ // F0 should be first.
+ func F0()
+
+ // F1 should be second.
+ func F1()
+
+ // F2 should be third.
+ func F2()
+
+
+TYPES
+ // T0 should be first.
+ type T0 struct{}
+
+ // T1 should be second.
+ type T1 struct{}
+
+ // T2 should be third.
+ type T2 struct{}
+
+ // TG0 should be first.
+ type TG0 struct{}
+
+ // TG1 should be second.
+ type TG1 struct{}
+
+ // TG2 should be third.
+ type TG2 struct{}
+
diff --git a/src/go/doc/testdata/d.2.golden b/src/go/doc/testdata/d.2.golden
new file mode 100644
index 0000000..c005199
--- /dev/null
+++ b/src/go/doc/testdata/d.2.golden
@@ -0,0 +1,104 @@
+//
+PACKAGE d
+
+IMPORTPATH
+ testdata/d
+
+FILENAMES
+ testdata/d1.go
+ testdata/d2.go
+
+CONSTANTS
+ // CBx constants should appear before CAx constants.
+ const (
+ CB2 = iota // before CB1
+ CB1 // before CB0
+ CB0 // at end
+ )
+
+ // CAx constants should appear after CBx constants.
+ const (
+ CA2 = iota // before CA1
+ CA1 // before CA0
+ CA0 // at end
+ )
+
+ // C0 should be first.
+ const C0 = 0
+
+ // C1 should be second.
+ const C1 = 1
+
+ // C2 should be third.
+ const C2 = 2
+
+ //
+ const (
+ // Single const declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Cungrouped = 0
+ )
+
+
+VARIABLES
+ // VBx variables should appear before VAx variables.
+ var (
+ VB2 int // before VB1
+ VB1 int // before VB0
+ VB0 int // at end
+ )
+
+ // VAx variables should appear after VBx variables.
+ var (
+ VA2 int // before VA1
+ VA1 int // before VA0
+ VA0 int // at end
+ )
+
+ // V0 should be first.
+ var V0 uintptr
+
+ // V1 should be second.
+ var V1 uint
+
+ // V2 should be third.
+ var V2 int
+
+ //
+ var (
+ // Single var declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Vungrouped = 0
+ )
+
+
+FUNCTIONS
+ // F0 should be first.
+ func F0()
+
+ // F1 should be second.
+ func F1()
+
+ // F2 should be third.
+ func F2()
+
+
+TYPES
+ // T0 should be first.
+ type T0 struct{}
+
+ // T1 should be second.
+ type T1 struct{}
+
+ // T2 should be third.
+ type T2 struct{}
+
+ // TG0 should be first.
+ type TG0 struct{}
+
+ // TG1 should be second.
+ type TG1 struct{}
+
+ // TG2 should be third.
+ type TG2 struct{}
+
diff --git a/src/go/doc/testdata/d1.go b/src/go/doc/testdata/d1.go
new file mode 100644
index 0000000..ebd6941
--- /dev/null
+++ b/src/go/doc/testdata/d1.go
@@ -0,0 +1,57 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test cases for sort order of declarations.
+
+package d
+
+// C2 should be third.
+const C2 = 2
+
+// V2 should be third.
+var V2 int
+
+// CBx constants should appear before CAx constants.
+const (
+ CB2 = iota // before CB1
+ CB1 // before CB0
+ CB0 // at end
+)
+
+// VBx variables should appear before VAx variables.
+var (
+ VB2 int // before VB1
+ VB1 int // before VB0
+ VB0 int // at end
+)
+
+const (
+ // Single const declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Cungrouped = 0
+)
+
+var (
+ // Single var declarations inside ()'s are considered ungrouped
+ // and show up in sorted order.
+ Vungrouped = 0
+)
+
+// T2 should be third.
+type T2 struct{}
+
+// Grouped types are sorted nevertheless.
+type (
+ // TG2 should be third.
+ TG2 struct{}
+
+ // TG1 should be second.
+ TG1 struct{}
+
+ // TG0 should be first.
+ TG0 struct{}
+)
+
+// F2 should be third.
+func F2() {}
diff --git a/src/go/doc/testdata/d2.go b/src/go/doc/testdata/d2.go
new file mode 100644
index 0000000..2f56f4f
--- /dev/null
+++ b/src/go/doc/testdata/d2.go
@@ -0,0 +1,45 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test cases for sort order of declarations.
+
+package d
+
+// C1 should be second.
+const C1 = 1
+
+// C0 should be first.
+const C0 = 0
+
+// V1 should be second.
+var V1 uint
+
+// V0 should be first.
+var V0 uintptr
+
+// CAx constants should appear after CBx constants.
+const (
+ CA2 = iota // before CA1
+ CA1 // before CA0
+ CA0 // at end
+)
+
+// VAx variables should appear after VBx variables.
+var (
+ VA2 int // before VA1
+ VA1 int // before VA0
+ VA0 int // at end
+)
+
+// T1 should be second.
+type T1 struct{}
+
+// T0 should be first.
+type T0 struct{}
+
+// F1 should be second.
+func F1() {}
+
+// F0 should be first.
+func F0() {}
diff --git a/src/go/doc/testdata/e.0.golden b/src/go/doc/testdata/e.0.golden
new file mode 100644
index 0000000..6987e58
--- /dev/null
+++ b/src/go/doc/testdata/e.0.golden
@@ -0,0 +1,109 @@
+// The package e is a go/doc test for embedded methods.
+PACKAGE e
+
+IMPORTPATH
+ testdata/e
+
+FILENAMES
+ testdata/e.go
+
+TYPES
+ // T1 has no embedded (level 1) M method due to conflict.
+ type T1 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T2 has only M as top-level method.
+ type T2 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T2.M should appear as method of T2.
+ func (T2) M()
+
+ // T3 has only M as top-level method.
+ type T3 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T3.M should appear as method of T3.
+ func (T3) M()
+
+ //
+ type T4 struct{}
+
+ // T4.M should appear as method of T5 only if AllMethods is set.
+ func (*T4) M()
+
+ //
+ type T5 struct {
+ T4
+ }
+
+ //
+ type U1 struct {
+ *U1
+ }
+
+ // U1.M should appear as method of U1.
+ func (*U1) M()
+
+ //
+ type U2 struct {
+ *U3
+ }
+
+ // U2.M should appear as method of U2 and as method of U3 only if ...
+ func (*U2) M()
+
+ //
+ type U3 struct {
+ *U2
+ }
+
+ // U3.N should appear as method of U3 and as method of U2 only if ...
+ func (*U3) N()
+
+ //
+ type U4 struct {
+ // contains filtered or unexported fields
+ }
+
+ // U4.M should appear as method of U4.
+ func (*U4) M()
+
+ //
+ type V1 struct {
+ *V2
+ *V5
+ }
+
+ //
+ type V2 struct {
+ *V3
+ }
+
+ //
+ type V3 struct {
+ *V4
+ }
+
+ //
+ type V4 struct {
+ *V5
+ }
+
+ // V4.M should appear as method of V2 and V3 if AllMethods is set.
+ func (*V4) M()
+
+ //
+ type V5 struct {
+ *V6
+ }
+
+ //
+ type V6 struct{}
+
+ // V6.M should appear as method of V1 and V5 if AllMethods is set.
+ func (*V6) M()
+
diff --git a/src/go/doc/testdata/e.1.golden b/src/go/doc/testdata/e.1.golden
new file mode 100644
index 0000000..cbe22e0
--- /dev/null
+++ b/src/go/doc/testdata/e.1.golden
@@ -0,0 +1,144 @@
+// The package e is a go/doc test for embedded methods.
+PACKAGE e
+
+IMPORTPATH
+ testdata/e
+
+FILENAMES
+ testdata/e.go
+
+TYPES
+ // T1 has no embedded (level 1) M method due to conflict.
+ type T1 struct {
+ t1
+ t2
+ }
+
+ // T2 has only M as top-level method.
+ type T2 struct {
+ t1
+ }
+
+ // T2.M should appear as method of T2.
+ func (T2) M()
+
+ // T3 has only M as top-level method.
+ type T3 struct {
+ t1e
+ t2e
+ }
+
+ // T3.M should appear as method of T3.
+ func (T3) M()
+
+ //
+ type T4 struct{}
+
+ // T4.M should appear as method of T5 only if AllMethods is set.
+ func (*T4) M()
+
+ //
+ type T5 struct {
+ T4
+ }
+
+ //
+ type U1 struct {
+ *U1
+ }
+
+ // U1.M should appear as method of U1.
+ func (*U1) M()
+
+ //
+ type U2 struct {
+ *U3
+ }
+
+ // U2.M should appear as method of U2 and as method of U3 only if ...
+ func (*U2) M()
+
+ //
+ type U3 struct {
+ *U2
+ }
+
+ // U3.N should appear as method of U3 and as method of U2 only if ...
+ func (*U3) N()
+
+ //
+ type U4 struct {
+ *u5
+ }
+
+ // U4.M should appear as method of U4.
+ func (*U4) M()
+
+ //
+ type V1 struct {
+ *V2
+ *V5
+ }
+
+ //
+ type V2 struct {
+ *V3
+ }
+
+ //
+ type V3 struct {
+ *V4
+ }
+
+ //
+ type V4 struct {
+ *V5
+ }
+
+ // V4.M should appear as method of V2 and V3 if AllMethods is set.
+ func (*V4) M()
+
+ //
+ type V5 struct {
+ *V6
+ }
+
+ //
+ type V6 struct{}
+
+ // V6.M should appear as method of V1 and V5 if AllMethods is set.
+ func (*V6) M()
+
+ //
+ type t1 struct{}
+
+ // t1.M should not appear as method in a Tx type.
+ func (t1) M()
+
+ //
+ type t1e struct {
+ t1
+ }
+
+ // t1.M should not appear as method in a Tx type.
+ func (t1e) M()
+
+ //
+ type t2 struct{}
+
+ // t2.M should not appear as method in a Tx type.
+ func (t2) M()
+
+ //
+ type t2e struct {
+ t2
+ }
+
+ // t2.M should not appear as method in a Tx type.
+ func (t2e) M()
+
+ //
+ type u5 struct {
+ *U4
+ }
+
diff --git a/src/go/doc/testdata/e.2.golden b/src/go/doc/testdata/e.2.golden
new file mode 100644
index 0000000..e7b05e8
--- /dev/null
+++ b/src/go/doc/testdata/e.2.golden
@@ -0,0 +1,130 @@
+// The package e is a go/doc test for embedded methods.
+PACKAGE e
+
+IMPORTPATH
+ testdata/e
+
+FILENAMES
+ testdata/e.go
+
+TYPES
+ // T1 has no embedded (level 1) M method due to conflict.
+ type T1 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T2 has only M as top-level method.
+ type T2 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T2.M should appear as method of T2.
+ func (T2) M()
+
+ // T3 has only M as top-level method.
+ type T3 struct {
+ // contains filtered or unexported fields
+ }
+
+ // T3.M should appear as method of T3.
+ func (T3) M()
+
+ //
+ type T4 struct{}
+
+ // T4.M should appear as method of T5 only if AllMethods is set.
+ func (*T4) M()
+
+ //
+ type T5 struct {
+ T4
+ }
+
+ // T4.M should appear as method of T5 only if AllMethods is set.
+ func (*T5) M()
+
+ //
+ type U1 struct {
+ *U1
+ }
+
+ // U1.M should appear as method of U1.
+ func (*U1) M()
+
+ //
+ type U2 struct {
+ *U3
+ }
+
+ // U2.M should appear as method of U2 and as method of U3 only if ...
+ func (*U2) M()
+
+ // U3.N should appear as method of U3 and as method of U2 only if ...
+ func (U2) N()
+
+ //
+ type U3 struct {
+ *U2
+ }
+
+ // U2.M should appear as method of U2 and as method of U3 only if ...
+ func (U3) M()
+
+ // U3.N should appear as method of U3 and as method of U2 only if ...
+ func (*U3) N()
+
+ //
+ type U4 struct {
+ // contains filtered or unexported fields
+ }
+
+ // U4.M should appear as method of U4.
+ func (*U4) M()
+
+ //
+ type V1 struct {
+ *V2
+ *V5
+ }
+
+ // V6.M should appear as method of V1 and V5 if AllMethods is set.
+ func (V1) M()
+
+ //
+ type V2 struct {
+ *V3
+ }
+
+ // V4.M should appear as method of V2 and V3 if AllMethods is set.
+ func (V2) M()
+
+ //
+ type V3 struct {
+ *V4
+ }
+
+ // V4.M should appear as method of V2 and V3 if AllMethods is set.
+ func (V3) M()
+
+ //
+ type V4 struct {
+ *V5
+ }
+
+ // V4.M should appear as method of V2 and V3 if AllMethods is set.
+ func (*V4) M()
+
+ //
+ type V5 struct {
+ *V6
+ }
+
+ // V6.M should appear as method of V1 and V5 if AllMethods is set.
+ func (V5) M()
+
+ //
+ type V6 struct{}
+
+ // V6.M should appear as method of V1 and V5 if AllMethods is set.
+ func (*V6) M()
+
diff --git a/src/go/doc/testdata/e.go b/src/go/doc/testdata/e.go
new file mode 100644
index 0000000..ec432e3
--- /dev/null
+++ b/src/go/doc/testdata/e.go
@@ -0,0 +1,147 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The package e is a go/doc test for embedded methods.
+package e
+
+// ----------------------------------------------------------------------------
+// Conflicting methods M must not show up.
+
+type t1 struct{}
+
+// t1.M should not appear as method in a Tx type.
+func (t1) M() {}
+
+type t2 struct{}
+
+// t2.M should not appear as method in a Tx type.
+func (t2) M() {}
+
+// T1 has no embedded (level 1) M method due to conflict.
+type T1 struct {
+ t1
+ t2
+}
+
+// ----------------------------------------------------------------------------
+// Higher-level method M wins over lower-level method M.
+
+// T2 has only M as top-level method.
+type T2 struct {
+ t1
+}
+
+// T2.M should appear as method of T2.
+func (T2) M() {}
+
+// ----------------------------------------------------------------------------
+// Higher-level method M wins over lower-level conflicting methods M.
+
+type t1e struct {
+ t1
+}
+
+type t2e struct {
+ t2
+}
+
+// T3 has only M as top-level method.
+type T3 struct {
+ t1e
+ t2e
+}
+
+// T3.M should appear as method of T3.
+func (T3) M() {}
+
+// ----------------------------------------------------------------------------
+// Don't show conflicting methods M embedded via an exported and non-exported
+// type.
+
+// T1 has no embedded (level 1) M method due to conflict.
+type T4 struct {
+ t2
+ T2
+}
+
+// ----------------------------------------------------------------------------
+// Don't show embedded methods of exported anonymous fields unless AllMethods
+// is set.
+
+type T4 struct{}
+
+// T4.M should appear as method of T5 only if AllMethods is set.
+func (*T4) M() {}
+
+type T5 struct {
+ T4
+}
+
+// ----------------------------------------------------------------------------
+// Recursive type declarations must not lead to endless recursion.
+
+type U1 struct {
+ *U1
+}
+
+// U1.M should appear as method of U1.
+func (*U1) M() {}
+
+type U2 struct {
+ *U3
+}
+
+// U2.M should appear as method of U2 and as method of U3 only if AllMethods is set.
+func (*U2) M() {}
+
+type U3 struct {
+ *U2
+}
+
+// U3.N should appear as method of U3 and as method of U2 only if AllMethods is set.
+func (*U3) N() {}
+
+type U4 struct {
+ *u5
+}
+
+// U4.M should appear as method of U4.
+func (*U4) M() {}
+
+type u5 struct {
+ *U4
+}
+
+// ----------------------------------------------------------------------------
+// A higher-level embedded type (and its methods) wins over the same type (and
+// its methods) embedded at a lower level.
+
+type V1 struct {
+ *V2
+ *V5
+}
+
+type V2 struct {
+ *V3
+}
+
+type V3 struct {
+ *V4
+}
+
+type V4 struct {
+ *V5
+}
+
+type V5 struct {
+ *V6
+}
+
+type V6 struct{}
+
+// V4.M should appear as method of V2 and V3 if AllMethods is set.
+func (*V4) M() {}
+
+// V6.M should appear as method of V1 and V5 if AllMethods is set.
+func (*V6) M() {}
diff --git a/src/go/doc/testdata/error1.0.golden b/src/go/doc/testdata/error1.0.golden
new file mode 100644
index 0000000..6c6fe5d
--- /dev/null
+++ b/src/go/doc/testdata/error1.0.golden
@@ -0,0 +1,30 @@
+//
+PACKAGE error1
+
+IMPORTPATH
+ testdata/error1
+
+FILENAMES
+ testdata/error1.go
+
+TYPES
+ //
+ type I0 interface {
+ // When embedded, the predeclared error interface
+ // must remain visible in interface types.
+ error
+ }
+
+ //
+ type S0 struct {
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // error should be visible
+ error
+ }
+ }
+
diff --git a/src/go/doc/testdata/error1.1.golden b/src/go/doc/testdata/error1.1.golden
new file mode 100644
index 0000000..a8dc2e7
--- /dev/null
+++ b/src/go/doc/testdata/error1.1.golden
@@ -0,0 +1,32 @@
+//
+PACKAGE error1
+
+IMPORTPATH
+ testdata/error1
+
+FILENAMES
+ testdata/error1.go
+
+TYPES
+ //
+ type I0 interface {
+ // When embedded, the predeclared error interface
+ // must remain visible in interface types.
+ error
+ }
+
+ //
+ type S0 struct {
+ // In struct types, an embedded error must only be visible
+ // if AllDecls is set.
+ error
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // error should be visible
+ error
+ }
+ }
+
diff --git a/src/go/doc/testdata/error1.2.golden b/src/go/doc/testdata/error1.2.golden
new file mode 100644
index 0000000..6c6fe5d
--- /dev/null
+++ b/src/go/doc/testdata/error1.2.golden
@@ -0,0 +1,30 @@
+//
+PACKAGE error1
+
+IMPORTPATH
+ testdata/error1
+
+FILENAMES
+ testdata/error1.go
+
+TYPES
+ //
+ type I0 interface {
+ // When embedded, the predeclared error interface
+ // must remain visible in interface types.
+ error
+ }
+
+ //
+ type S0 struct {
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // error should be visible
+ error
+ }
+ }
+
diff --git a/src/go/doc/testdata/error1.go b/src/go/doc/testdata/error1.go
new file mode 100644
index 0000000..3c777a7
--- /dev/null
+++ b/src/go/doc/testdata/error1.go
@@ -0,0 +1,24 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package error1
+
+type I0 interface {
+ // When embedded, the predeclared error interface
+ // must remain visible in interface types.
+ error
+}
+
+type T0 struct {
+ ExportedField interface {
+ // error should be visible
+ error
+ }
+}
+
+type S0 struct {
+ // In struct types, an embedded error must only be visible
+ // if AllDecls is set.
+ error
+}
diff --git a/src/go/doc/testdata/error2.0.golden b/src/go/doc/testdata/error2.0.golden
new file mode 100644
index 0000000..dedfe41
--- /dev/null
+++ b/src/go/doc/testdata/error2.0.golden
@@ -0,0 +1,27 @@
+//
+PACKAGE error2
+
+IMPORTPATH
+ testdata/error2
+
+FILENAMES
+ testdata/error2.go
+
+TYPES
+ //
+ type I0 interface {
+ // contains filtered or unexported methods
+ }
+
+ //
+ type S0 struct {
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // contains filtered or unexported methods
+ }
+ }
+
diff --git a/src/go/doc/testdata/error2.1.golden b/src/go/doc/testdata/error2.1.golden
new file mode 100644
index 0000000..dbcc1b0
--- /dev/null
+++ b/src/go/doc/testdata/error2.1.golden
@@ -0,0 +1,37 @@
+//
+PACKAGE error2
+
+IMPORTPATH
+ testdata/error2
+
+FILENAMES
+ testdata/error2.go
+
+TYPES
+ //
+ type I0 interface {
+ // When embedded, the locally-declared error interface
+ // is only visible if all declarations are shown.
+ error
+ }
+
+ //
+ type S0 struct {
+ // In struct types, an embedded error must only be visible
+ // if AllDecls is set.
+ error
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // error should not be visible
+ error
+ }
+ }
+
+ // This error declaration shadows the predeclared error type.
+ type error interface {
+ Error() string
+ }
+
diff --git a/src/go/doc/testdata/error2.2.golden b/src/go/doc/testdata/error2.2.golden
new file mode 100644
index 0000000..dedfe41
--- /dev/null
+++ b/src/go/doc/testdata/error2.2.golden
@@ -0,0 +1,27 @@
+//
+PACKAGE error2
+
+IMPORTPATH
+ testdata/error2
+
+FILENAMES
+ testdata/error2.go
+
+TYPES
+ //
+ type I0 interface {
+ // contains filtered or unexported methods
+ }
+
+ //
+ type S0 struct {
+ // contains filtered or unexported fields
+ }
+
+ //
+ type T0 struct {
+ ExportedField interface {
+ // contains filtered or unexported methods
+ }
+ }
+
diff --git a/src/go/doc/testdata/error2.go b/src/go/doc/testdata/error2.go
new file mode 100644
index 0000000..6ee96c2
--- /dev/null
+++ b/src/go/doc/testdata/error2.go
@@ -0,0 +1,29 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package error2
+
+type I0 interface {
+ // When embedded, the locally-declared error interface
+ // is only visible if all declarations are shown.
+ error
+}
+
+type T0 struct {
+ ExportedField interface {
+ // error should not be visible
+ error
+ }
+}
+
+type S0 struct {
+ // In struct types, an embedded error must only be visible
+ // if AllDecls is set.
+ error
+}
+
+// This error declaration shadows the predeclared error type.
+type error interface {
+ Error() string
+}
diff --git a/src/go/doc/testdata/example.go b/src/go/doc/testdata/example.go
new file mode 100644
index 0000000..fdeda13
--- /dev/null
+++ b/src/go/doc/testdata/example.go
@@ -0,0 +1,81 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "os"
+ "strings"
+ "time"
+)
+
+type InternalExample struct {
+ Name string
+ F func()
+ Output string
+}
+
+func RunExamples(examples []InternalExample) (ok bool) {
+ ok = true
+
+ var eg InternalExample
+
+ stdout, stderr := os.Stdout, os.Stderr
+ defer func() {
+ os.Stdout, os.Stderr = stdout, stderr
+ if e := recover(); e != nil {
+ fmt.Printf("--- FAIL: %s\npanic: %v\n", eg.Name, e)
+ os.Exit(1)
+ }
+ }()
+
+ for _, eg = range examples {
+ if *chatty {
+ fmt.Printf("=== RUN: %s\n", eg.Name)
+ }
+
+ // capture stdout and stderr
+ r, w, err := os.Pipe()
+ if err != nil {
+ fmt.Fprintln(os.Stderr, err)
+ os.Exit(1)
+ }
+ os.Stdout, os.Stderr = w, w
+ outC := make(chan string)
+ go func() {
+ buf := new(bytes.Buffer)
+ _, err := io.Copy(buf, r)
+ if err != nil {
+ fmt.Fprintf(stderr, "testing: copying pipe: %v\n", err)
+ os.Exit(1)
+ }
+ outC <- buf.String()
+ }()
+
+ // run example
+ t0 := time.Now()
+ eg.F()
+ dt := time.Now().Sub(t0)
+
+ // close pipe, restore stdout/stderr, get output
+ w.Close()
+ os.Stdout, os.Stderr = stdout, stderr
+ out := <-outC
+
+ // report any errors
+ tstr := fmt.Sprintf("(%.2f seconds)", dt.Seconds())
+ if g, e := strings.TrimSpace(out), strings.TrimSpace(eg.Output); g != e {
+ fmt.Printf("--- FAIL: %s %s\ngot:\n%s\nwant:\n%s\n",
+ eg.Name, tstr, g, e)
+ ok = false
+ } else if *chatty {
+ fmt.Printf("--- PASS: %s %s\n", eg.Name, tstr)
+ }
+ }
+
+ return
+}
diff --git a/src/go/doc/testdata/f.0.golden b/src/go/doc/testdata/f.0.golden
new file mode 100644
index 0000000..8175901
--- /dev/null
+++ b/src/go/doc/testdata/f.0.golden
@@ -0,0 +1,13 @@
+// The package f is a go/doc test for functions and factory ...
+PACKAGE f
+
+IMPORTPATH
+ testdata/f
+
+FILENAMES
+ testdata/f.go
+
+FUNCTIONS
+ // Exported must always be visible. Was issue 2824.
+ func Exported() private
+
diff --git a/src/go/doc/testdata/f.1.golden b/src/go/doc/testdata/f.1.golden
new file mode 100644
index 0000000..ba68e88
--- /dev/null
+++ b/src/go/doc/testdata/f.1.golden
@@ -0,0 +1,16 @@
+// The package f is a go/doc test for functions and factory ...
+PACKAGE f
+
+IMPORTPATH
+ testdata/f
+
+FILENAMES
+ testdata/f.go
+
+TYPES
+ //
+ type private struct{}
+
+ // Exported must always be visible. Was issue 2824.
+ func Exported() private
+
diff --git a/src/go/doc/testdata/f.2.golden b/src/go/doc/testdata/f.2.golden
new file mode 100644
index 0000000..8175901
--- /dev/null
+++ b/src/go/doc/testdata/f.2.golden
@@ -0,0 +1,13 @@
+// The package f is a go/doc test for functions and factory ...
+PACKAGE f
+
+IMPORTPATH
+ testdata/f
+
+FILENAMES
+ testdata/f.go
+
+FUNCTIONS
+ // Exported must always be visible. Was issue 2824.
+ func Exported() private
+
diff --git a/src/go/doc/testdata/f.go b/src/go/doc/testdata/f.go
new file mode 100644
index 0000000..7e9add9
--- /dev/null
+++ b/src/go/doc/testdata/f.go
@@ -0,0 +1,14 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The package f is a go/doc test for functions and factory methods.
+package f
+
+// ----------------------------------------------------------------------------
+// Factory functions for non-exported types must not get lost.
+
+type private struct{}
+
+// Exported must always be visible. Was issue 2824.
+func Exported() private {}
diff --git a/src/go/doc/testdata/g.0.golden b/src/go/doc/testdata/g.0.golden
new file mode 100644
index 0000000..487cf06
--- /dev/null
+++ b/src/go/doc/testdata/g.0.golden
@@ -0,0 +1,32 @@
+// The package g is a go/doc test for mixed exported/unexported ...
+PACKAGE g
+
+IMPORTPATH
+ testdata/g
+
+FILENAMES
+ testdata/g.go
+
+CONSTANTS
+ //
+ const (
+ A, _ = iota, iota
+ _, D
+ E, _
+ G, H
+ )
+
+
+VARIABLES
+ //
+ var (
+ _, C2, _ = 1, 2, 3
+ C4, _, C6 = 4, 5, 6
+ _, C8, _ = 7, 8, 9
+ )
+
+ //
+ var (
+ _, X = f()
+ )
+
diff --git a/src/go/doc/testdata/g.1.golden b/src/go/doc/testdata/g.1.golden
new file mode 100644
index 0000000..438441a
--- /dev/null
+++ b/src/go/doc/testdata/g.1.golden
@@ -0,0 +1,34 @@
+// The package g is a go/doc test for mixed exported/unexported ...
+PACKAGE g
+
+IMPORTPATH
+ testdata/g
+
+FILENAMES
+ testdata/g.go
+
+CONSTANTS
+ //
+ const (
+ A, b = iota, iota
+ c, D
+ E, f
+ G, H
+ )
+
+
+VARIABLES
+ //
+ var (
+ c1, C2, c3 = 1, 2, 3
+ C4, c5, C6 = 4, 5, 6
+ c7, C8, c9 = 7, 8, 9
+ xx, yy, zz = 0, 0, 0 // all unexported and hidden
+ )
+
+ //
+ var (
+ x, X = f()
+ y, z = f()
+ )
+
diff --git a/src/go/doc/testdata/g.2.golden b/src/go/doc/testdata/g.2.golden
new file mode 100644
index 0000000..487cf06
--- /dev/null
+++ b/src/go/doc/testdata/g.2.golden
@@ -0,0 +1,32 @@
+// The package g is a go/doc test for mixed exported/unexported ...
+PACKAGE g
+
+IMPORTPATH
+ testdata/g
+
+FILENAMES
+ testdata/g.go
+
+CONSTANTS
+ //
+ const (
+ A, _ = iota, iota
+ _, D
+ E, _
+ G, H
+ )
+
+
+VARIABLES
+ //
+ var (
+ _, C2, _ = 1, 2, 3
+ C4, _, C6 = 4, 5, 6
+ _, C8, _ = 7, 8, 9
+ )
+
+ //
+ var (
+ _, X = f()
+ )
+
diff --git a/src/go/doc/testdata/g.go b/src/go/doc/testdata/g.go
new file mode 100644
index 0000000..ceeb417
--- /dev/null
+++ b/src/go/doc/testdata/g.go
@@ -0,0 +1,25 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The package g is a go/doc test for mixed exported/unexported values.
+package g
+
+const (
+ A, b = iota, iota
+ c, D
+ E, f
+ G, H
+)
+
+var (
+ c1, C2, c3 = 1, 2, 3
+ C4, c5, C6 = 4, 5, 6
+ c7, C8, c9 = 7, 8, 9
+ xx, yy, zz = 0, 0, 0 // all unexported and hidden
+)
+
+var (
+ x, X = f()
+ y, z = f()
+)
diff --git a/src/go/doc/testdata/issue12839.0.golden b/src/go/doc/testdata/issue12839.0.golden
new file mode 100644
index 0000000..6b59774
--- /dev/null
+++ b/src/go/doc/testdata/issue12839.0.golden
@@ -0,0 +1,51 @@
+// Package issue12839 is a go/doc test to test association of a ...
+PACKAGE issue12839
+
+IMPORTPATH
+ testdata/issue12839
+
+IMPORTS
+ p
+
+FILENAMES
+ testdata/issue12839.go
+
+FUNCTIONS
+ // F1 should not be associated with T1
+ func F1() (*T1, *T2)
+
+ // F10 should not be associated with T1.
+ func F10() (T1, T2, error)
+
+ // F4 should not be associated with a type (same as F1)
+ func F4() (a T1, b T2)
+
+ // F9 should not be associated with T1.
+ func F9() (int, T1, T2)
+
+
+TYPES
+ //
+ type T1 struct{}
+
+ // F2 should be associated with T1
+ func F2() (a, b, c T1)
+
+ // F3 should be associated with T1 because b.T3 is from a ...
+ func F3() (a T1, b p.T3)
+
+ // F5 should be associated with T1.
+ func F5() (T1, error)
+
+ // F6 should be associated with T1.
+ func F6() (*T1, error)
+
+ // F7 should be associated with T1.
+ func F7() (T1, string)
+
+ // F8 should be associated with T1.
+ func F8() (int, T1, string)
+
+ //
+ type T2 struct{}
+
diff --git a/src/go/doc/testdata/issue12839.1.golden b/src/go/doc/testdata/issue12839.1.golden
new file mode 100644
index 0000000..4b9b9f6
--- /dev/null
+++ b/src/go/doc/testdata/issue12839.1.golden
@@ -0,0 +1,54 @@
+// Package issue12839 is a go/doc test to test association of a ...
+PACKAGE issue12839
+
+IMPORTPATH
+ testdata/issue12839
+
+IMPORTS
+ p
+
+FILENAMES
+ testdata/issue12839.go
+
+FUNCTIONS
+ // F1 should not be associated with T1
+ func F1() (*T1, *T2)
+
+ // F10 should not be associated with T1.
+ func F10() (T1, T2, error)
+
+ // F4 should not be associated with a type (same as F1)
+ func F4() (a T1, b T2)
+
+ // F9 should not be associated with T1.
+ func F9() (int, T1, T2)
+
+
+TYPES
+ //
+ type T1 struct{}
+
+ // F2 should be associated with T1
+ func F2() (a, b, c T1)
+
+ // F3 should be associated with T1 because b.T3 is from a ...
+ func F3() (a T1, b p.T3)
+
+ // F5 should be associated with T1.
+ func F5() (T1, error)
+
+ // F6 should be associated with T1.
+ func F6() (*T1, error)
+
+ // F7 should be associated with T1.
+ func F7() (T1, string)
+
+ // F8 should be associated with T1.
+ func F8() (int, T1, string)
+
+ //
+ func (t T1) hello() string
+
+ //
+ type T2 struct{}
+
diff --git a/src/go/doc/testdata/issue12839.2.golden b/src/go/doc/testdata/issue12839.2.golden
new file mode 100644
index 0000000..6b59774
--- /dev/null
+++ b/src/go/doc/testdata/issue12839.2.golden
@@ -0,0 +1,51 @@
+// Package issue12839 is a go/doc test to test association of a ...
+PACKAGE issue12839
+
+IMPORTPATH
+ testdata/issue12839
+
+IMPORTS
+ p
+
+FILENAMES
+ testdata/issue12839.go
+
+FUNCTIONS
+ // F1 should not be associated with T1
+ func F1() (*T1, *T2)
+
+ // F10 should not be associated with T1.
+ func F10() (T1, T2, error)
+
+ // F4 should not be associated with a type (same as F1)
+ func F4() (a T1, b T2)
+
+ // F9 should not be associated with T1.
+ func F9() (int, T1, T2)
+
+
+TYPES
+ //
+ type T1 struct{}
+
+ // F2 should be associated with T1
+ func F2() (a, b, c T1)
+
+ // F3 should be associated with T1 because b.T3 is from a ...
+ func F3() (a T1, b p.T3)
+
+ // F5 should be associated with T1.
+ func F5() (T1, error)
+
+ // F6 should be associated with T1.
+ func F6() (*T1, error)
+
+ // F7 should be associated with T1.
+ func F7() (T1, string)
+
+ // F8 should be associated with T1.
+ func F8() (int, T1, string)
+
+ //
+ type T2 struct{}
+
diff --git a/src/go/doc/testdata/issue12839.go b/src/go/doc/testdata/issue12839.go
new file mode 100644
index 0000000..51c7ac1
--- /dev/null
+++ b/src/go/doc/testdata/issue12839.go
@@ -0,0 +1,69 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package issue12839 is a go/doc test to test association of a function
+// that returns multiple types.
+// See golang.org/issue/12839.
+// (See also golang.org/issue/27928.)
+package issue12839
+
+import "p"
+
+type T1 struct{}
+
+type T2 struct{}
+
+func (t T1) hello() string {
+ return "hello"
+}
+
+// F1 should not be associated with T1
+func F1() (*T1, *T2) {
+ return &T1{}, &T2{}
+}
+
+// F2 should be associated with T1
+func F2() (a, b, c T1) {
+ return T1{}, T1{}, T1{}
+}
+
+// F3 should be associated with T1 because b.T3 is from a different package
+func F3() (a T1, b p.T3) {
+ return T1{}, p.T3{}
+}
+
+// F4 should not be associated with a type (same as F1)
+func F4() (a T1, b T2) {
+ return T1{}, T2{}
+}
+
+// F5 should be associated with T1.
+func F5() (T1, error) {
+ return T1{}, nil
+}
+
+// F6 should be associated with T1.
+func F6() (*T1, error) {
+ return &T1{}, nil
+}
+
+// F7 should be associated with T1.
+func F7() (T1, string) {
+ return T1{}, nil
+}
+
+// F8 should be associated with T1.
+func F8() (int, T1, string) {
+ return 0, T1{}, nil
+}
+
+// F9 should not be associated with T1.
+func F9() (int, T1, T2) {
+ return 0, T1{}, T2{}
+}
+
+// F10 should not be associated with T1.
+func F10() (T1, T2, error) {
+ return T1{}, T2{}, nil
+}
diff --git a/src/go/doc/testdata/issue13742.0.golden b/src/go/doc/testdata/issue13742.0.golden
new file mode 100644
index 0000000..8dee9aa
--- /dev/null
+++ b/src/go/doc/testdata/issue13742.0.golden
@@ -0,0 +1,25 @@
+//
+PACKAGE issue13742
+
+IMPORTPATH
+ testdata/issue13742
+
+IMPORTS
+ go/ast
+
+FILENAMES
+ testdata/issue13742.go
+
+FUNCTIONS
+ // Both F0 and G0 should appear as functions.
+ func F0(Node)
+
+ // Both F1 and G1 should appear as functions.
+ func F1(ast.Node)
+
+ //
+ func G0() Node
+
+ //
+ func G1() ast.Node
+
diff --git a/src/go/doc/testdata/issue13742.1.golden b/src/go/doc/testdata/issue13742.1.golden
new file mode 100644
index 0000000..8dee9aa
--- /dev/null
+++ b/src/go/doc/testdata/issue13742.1.golden
@@ -0,0 +1,25 @@
+//
+PACKAGE issue13742
+
+IMPORTPATH
+ testdata/issue13742
+
+IMPORTS
+ go/ast
+
+FILENAMES
+ testdata/issue13742.go
+
+FUNCTIONS
+ // Both F0 and G0 should appear as functions.
+ func F0(Node)
+
+ // Both F1 and G1 should appear as functions.
+ func F1(ast.Node)
+
+ //
+ func G0() Node
+
+ //
+ func G1() ast.Node
+
diff --git a/src/go/doc/testdata/issue13742.2.golden b/src/go/doc/testdata/issue13742.2.golden
new file mode 100644
index 0000000..8dee9aa
--- /dev/null
+++ b/src/go/doc/testdata/issue13742.2.golden
@@ -0,0 +1,25 @@
+//
+PACKAGE issue13742
+
+IMPORTPATH
+ testdata/issue13742
+
+IMPORTS
+ go/ast
+
+FILENAMES
+ testdata/issue13742.go
+
+FUNCTIONS
+ // Both F0 and G0 should appear as functions.
+ func F0(Node)
+
+ // Both F1 and G1 should appear as functions.
+ func F1(ast.Node)
+
+ //
+ func G0() Node
+
+ //
+ func G1() ast.Node
+
diff --git a/src/go/doc/testdata/issue13742.go b/src/go/doc/testdata/issue13742.go
new file mode 100644
index 0000000..dbc1941
--- /dev/null
+++ b/src/go/doc/testdata/issue13742.go
@@ -0,0 +1,18 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue13742
+
+import (
+ "go/ast"
+ . "go/ast"
+)
+
+// Both F0 and G0 should appear as functions.
+func F0(Node) {}
+func G0() Node { return nil }
+
+// Both F1 and G1 should appear as functions.
+func F1(ast.Node) {}
+func G1() ast.Node { return nil }
diff --git a/src/go/doc/testdata/issue16153.0.golden b/src/go/doc/testdata/issue16153.0.golden
new file mode 100644
index 0000000..189260b
--- /dev/null
+++ b/src/go/doc/testdata/issue16153.0.golden
@@ -0,0 +1,32 @@
+//
+PACKAGE issue16153
+
+IMPORTPATH
+ testdata/issue16153
+
+FILENAMES
+ testdata/issue16153.go
+
+CONSTANTS
+ //
+ const (
+ X3 int64 = iota
+ Y3 = 1
+ )
+
+ //
+ const (
+ X4 int64 = iota
+ Y4
+ )
+
+ // original test case
+ const (
+ Y1 = 256
+ )
+
+ // variations
+ const (
+ Y2 uint8
+ )
+
diff --git a/src/go/doc/testdata/issue16153.1.golden b/src/go/doc/testdata/issue16153.1.golden
new file mode 100644
index 0000000..803df3e
--- /dev/null
+++ b/src/go/doc/testdata/issue16153.1.golden
@@ -0,0 +1,34 @@
+//
+PACKAGE issue16153
+
+IMPORTPATH
+ testdata/issue16153
+
+FILENAMES
+ testdata/issue16153.go
+
+CONSTANTS
+ // original test case
+ const (
+ x1 uint8 = 255
+ Y1 = 256
+ )
+
+ // variations
+ const (
+ x2 uint8 = 255
+ Y2
+ )
+
+ //
+ const (
+ X3 int64 = iota
+ Y3 = 1
+ )
+
+ //
+ const (
+ X4 int64 = iota
+ Y4
+ )
+
diff --git a/src/go/doc/testdata/issue16153.2.golden b/src/go/doc/testdata/issue16153.2.golden
new file mode 100644
index 0000000..189260b
--- /dev/null
+++ b/src/go/doc/testdata/issue16153.2.golden
@@ -0,0 +1,32 @@
+//
+PACKAGE issue16153
+
+IMPORTPATH
+ testdata/issue16153
+
+FILENAMES
+ testdata/issue16153.go
+
+CONSTANTS
+ //
+ const (
+ X3 int64 = iota
+ Y3 = 1
+ )
+
+ //
+ const (
+ X4 int64 = iota
+ Y4
+ )
+
+ // original test case
+ const (
+ Y1 = 256
+ )
+
+ // variations
+ const (
+ Y2 uint8
+ )
+
diff --git a/src/go/doc/testdata/issue16153.go b/src/go/doc/testdata/issue16153.go
new file mode 100644
index 0000000..528be42
--- /dev/null
+++ b/src/go/doc/testdata/issue16153.go
@@ -0,0 +1,27 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue16153
+
+// original test case
+const (
+ x1 uint8 = 255
+ Y1 = 256
+)
+
+// variations
+const (
+ x2 uint8 = 255
+ Y2
+)
+
+const (
+ X3 int64 = iota
+ Y3 = 1
+)
+
+const (
+ X4 int64 = iota
+ Y4
+)
diff --git a/src/go/doc/testdata/issue17788.0.golden b/src/go/doc/testdata/issue17788.0.golden
new file mode 100644
index 0000000..42c00da
--- /dev/null
+++ b/src/go/doc/testdata/issue17788.0.golden
@@ -0,0 +1,8 @@
+//
+PACKAGE issue17788
+
+IMPORTPATH
+ testdata/issue17788
+
+FILENAMES
+ testdata/issue17788.go
diff --git a/src/go/doc/testdata/issue17788.1.golden b/src/go/doc/testdata/issue17788.1.golden
new file mode 100644
index 0000000..42c00da
--- /dev/null
+++ b/src/go/doc/testdata/issue17788.1.golden
@@ -0,0 +1,8 @@
+//
+PACKAGE issue17788
+
+IMPORTPATH
+ testdata/issue17788
+
+FILENAMES
+ testdata/issue17788.go
diff --git a/src/go/doc/testdata/issue17788.2.golden b/src/go/doc/testdata/issue17788.2.golden
new file mode 100644
index 0000000..42c00da
--- /dev/null
+++ b/src/go/doc/testdata/issue17788.2.golden
@@ -0,0 +1,8 @@
+//
+PACKAGE issue17788
+
+IMPORTPATH
+ testdata/issue17788
+
+FILENAMES
+ testdata/issue17788.go
diff --git a/src/go/doc/testdata/issue17788.go b/src/go/doc/testdata/issue17788.go
new file mode 100644
index 0000000..883ad5f
--- /dev/null
+++ b/src/go/doc/testdata/issue17788.go
@@ -0,0 +1,8 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue17788
+
+func ( /* receiver type */ ) f0() {
+}
diff --git a/src/go/doc/testdata/issue22856.0.golden b/src/go/doc/testdata/issue22856.0.golden
new file mode 100644
index 0000000..a88f43f
--- /dev/null
+++ b/src/go/doc/testdata/issue22856.0.golden
@@ -0,0 +1,45 @@
+//
+PACKAGE issue22856
+
+IMPORTPATH
+ testdata/issue22856
+
+FILENAMES
+ testdata/issue22856.go
+
+FUNCTIONS
+ // NewPointerSliceOfSlice is not a factory function because slices ...
+ func NewPointerSliceOfSlice() [][]*T
+
+ // NewSlice3 is not a factory function because 3 nested slices of ...
+ func NewSlice3() [][][]T
+
+ // NewSliceOfSlice is not a factory function because slices of a ...
+ func NewSliceOfSlice() [][]T
+
+
+TYPES
+ //
+ type T struct{}
+
+ //
+ func New() T
+
+ //
+ func NewArray() [1]T
+
+ //
+ func NewPointer() *T
+
+ //
+ func NewPointerArray() [1]*T
+
+ //
+ func NewPointerOfPointer() **T
+
+ //
+ func NewPointerSlice() []*T
+
+ //
+ func NewSlice() []T
+
diff --git a/src/go/doc/testdata/issue22856.1.golden b/src/go/doc/testdata/issue22856.1.golden
new file mode 100644
index 0000000..a88f43f
--- /dev/null
+++ b/src/go/doc/testdata/issue22856.1.golden
@@ -0,0 +1,45 @@
+//
+PACKAGE issue22856
+
+IMPORTPATH
+ testdata/issue22856
+
+FILENAMES
+ testdata/issue22856.go
+
+FUNCTIONS
+ // NewPointerSliceOfSlice is not a factory function because slices ...
+ func NewPointerSliceOfSlice() [][]*T
+
+ // NewSlice3 is not a factory function because 3 nested slices of ...
+ func NewSlice3() [][][]T
+
+ // NewSliceOfSlice is not a factory function because slices of a ...
+ func NewSliceOfSlice() [][]T
+
+
+TYPES
+ //
+ type T struct{}
+
+ //
+ func New() T
+
+ //
+ func NewArray() [1]T
+
+ //
+ func NewPointer() *T
+
+ //
+ func NewPointerArray() [1]*T
+
+ //
+ func NewPointerOfPointer() **T
+
+ //
+ func NewPointerSlice() []*T
+
+ //
+ func NewSlice() []T
+
diff --git a/src/go/doc/testdata/issue22856.2.golden b/src/go/doc/testdata/issue22856.2.golden
new file mode 100644
index 0000000..a88f43f
--- /dev/null
+++ b/src/go/doc/testdata/issue22856.2.golden
@@ -0,0 +1,45 @@
+//
+PACKAGE issue22856
+
+IMPORTPATH
+ testdata/issue22856
+
+FILENAMES
+ testdata/issue22856.go
+
+FUNCTIONS
+ // NewPointerSliceOfSlice is not a factory function because slices ...
+ func NewPointerSliceOfSlice() [][]*T
+
+ // NewSlice3 is not a factory function because 3 nested slices of ...
+ func NewSlice3() [][][]T
+
+ // NewSliceOfSlice is not a factory function because slices of a ...
+ func NewSliceOfSlice() [][]T
+
+
+TYPES
+ //
+ type T struct{}
+
+ //
+ func New() T
+
+ //
+ func NewArray() [1]T
+
+ //
+ func NewPointer() *T
+
+ //
+ func NewPointerArray() [1]*T
+
+ //
+ func NewPointerOfPointer() **T
+
+ //
+ func NewPointerSlice() []*T
+
+ //
+ func NewSlice() []T
+
diff --git a/src/go/doc/testdata/issue22856.go b/src/go/doc/testdata/issue22856.go
new file mode 100644
index 0000000..f456998
--- /dev/null
+++ b/src/go/doc/testdata/issue22856.go
@@ -0,0 +1,27 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue22856
+
+type T struct{}
+
+func New() T { return T{} }
+func NewPointer() *T { return &T{} }
+func NewPointerSlice() []*T { return []*T{&T{}} }
+func NewSlice() []T { return []T{T{}} }
+func NewPointerOfPointer() **T { x := &T{}; return &x }
+func NewArray() [1]T { return [1]T{T{}} }
+func NewPointerArray() [1]*T { return [1]*T{&T{}} }
+
+// NewSliceOfSlice is not a factory function because slices of a slice of
+// type *T are not factory functions of type T.
+func NewSliceOfSlice() [][]T { return []T{[]T{}} }
+
+// NewPointerSliceOfSlice is not a factory function because slices of a
+// slice of type *T are not factory functions of type T.
+func NewPointerSliceOfSlice() [][]*T { return []*T{[]*T{}} }
+
+// NewSlice3 is not a factory function because 3 nested slices of type T
+// are not factory functions of type T.
+func NewSlice3() [][][]T { return []T{[]T{[]T{}}} }
diff --git a/src/go/doc/testdata/predeclared.0.golden b/src/go/doc/testdata/predeclared.0.golden
new file mode 100644
index 0000000..9f37b06
--- /dev/null
+++ b/src/go/doc/testdata/predeclared.0.golden
@@ -0,0 +1,8 @@
+// Package predeclared is a go/doc test for handling of exported ...
+PACKAGE predeclared
+
+IMPORTPATH
+ testdata/predeclared
+
+FILENAMES
+ testdata/predeclared.go
diff --git a/src/go/doc/testdata/predeclared.1.golden b/src/go/doc/testdata/predeclared.1.golden
new file mode 100644
index 0000000..2ff8ee6
--- /dev/null
+++ b/src/go/doc/testdata/predeclared.1.golden
@@ -0,0 +1,22 @@
+// Package predeclared is a go/doc test for handling of exported ...
+PACKAGE predeclared
+
+IMPORTPATH
+ testdata/predeclared
+
+FILENAMES
+ testdata/predeclared.go
+
+TYPES
+ //
+ type bool int
+
+ // Must not be visible.
+ func (b bool) String() string
+
+ //
+ type error struct{}
+
+ // Must not be visible.
+ func (e error) Error() string
+
diff --git a/src/go/doc/testdata/predeclared.2.golden b/src/go/doc/testdata/predeclared.2.golden
new file mode 100644
index 0000000..9f37b06
--- /dev/null
+++ b/src/go/doc/testdata/predeclared.2.golden
@@ -0,0 +1,8 @@
+// Package predeclared is a go/doc test for handling of exported ...
+PACKAGE predeclared
+
+IMPORTPATH
+ testdata/predeclared
+
+FILENAMES
+ testdata/predeclared.go
diff --git a/src/go/doc/testdata/predeclared.go b/src/go/doc/testdata/predeclared.go
new file mode 100644
index 0000000..c6dd806
--- /dev/null
+++ b/src/go/doc/testdata/predeclared.go
@@ -0,0 +1,22 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package predeclared is a go/doc test for handling of
+// exported methods on locally-defined predeclared types.
+// See issue 9860.
+package predeclared
+
+type error struct{}
+
+// Must not be visible.
+func (e error) Error() string {
+ return ""
+}
+
+type bool int
+
+// Must not be visible.
+func (b bool) String() string {
+ return ""
+}
diff --git a/src/go/doc/testdata/template.txt b/src/go/doc/testdata/template.txt
new file mode 100644
index 0000000..1b07382
--- /dev/null
+++ b/src/go/doc/testdata/template.txt
@@ -0,0 +1,68 @@
+{{synopsis .Doc}}
+PACKAGE {{.Name}}
+
+IMPORTPATH
+ {{.ImportPath}}
+
+{{with .Imports}}IMPORTS
+{{range .}} {{.}}
+{{end}}
+{{end}}{{/*
+
+*/}}FILENAMES
+{{range .Filenames}} {{.}}
+{{end}}{{/*
+
+*/}}{{with .Consts}}
+CONSTANTS
+{{range .}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{end}}{{/*
+
+*/}}{{with .Vars}}
+VARIABLES
+{{range .}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{end}}{{/*
+
+*/}}{{with .Funcs}}
+FUNCTIONS
+{{range .}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{end}}{{/*
+
+*/}}{{with .Types}}
+TYPES
+{{range .}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{range .Consts}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{/*
+
+*/}}{{range .Vars}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{/*
+
+*/}}{{range .Funcs}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{/*
+
+*/}}{{range .Methods}} {{synopsis .Doc}}
+ {{node .Decl $.FSet}}
+
+{{end}}{{end}}{{end}}{{/*
+
+*/}}{{with .Bugs}}
+BUGS .Bugs is now deprecated, please use .Notes instead
+{{range .}}{{indent "\t" .}}
+{{end}}{{end}}{{with .Notes}}{{range $marker, $content := .}}
+{{$marker}}S
+{{range $content}}{{$marker}}({{.UID}}){{indent "\t" .Body}}
+{{end}}{{end}}{{end}} \ No newline at end of file
diff --git a/src/go/doc/testdata/testing.0.golden b/src/go/doc/testdata/testing.0.golden
new file mode 100644
index 0000000..83cf37c
--- /dev/null
+++ b/src/go/doc/testdata/testing.0.golden
@@ -0,0 +1,156 @@
+// Package testing provides support for automated testing of Go ...
+PACKAGE testing
+
+IMPORTPATH
+ testdata/testing
+
+IMPORTS
+ bytes
+ flag
+ fmt
+ io
+ os
+ runtime
+ runtime/pprof
+ strconv
+ strings
+ time
+
+FILENAMES
+ testdata/benchmark.go
+ testdata/example.go
+ testdata/testing.go
+
+FUNCTIONS
+ // An internal function but exported because it is cross-package; ...
+ func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample)
+
+ // An internal function but exported because it is cross-package; ...
+ func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks []InternalBenchmark)
+
+ //
+ func RunExamples(examples []InternalExample) (ok bool)
+
+ //
+ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalTest) (ok bool)
+
+ // Short reports whether the -test.short flag is set.
+ func Short() bool
+
+
+TYPES
+ // B is a type passed to Benchmark functions to manage benchmark ...
+ type B struct {
+ N int
+ // contains filtered or unexported fields
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *B) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *B) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *B) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *B) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *B) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *B) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *B) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *B) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *B) Logf(format string, args ...interface{})
+
+ // ResetTimer sets the elapsed benchmark time to zero. It does not ...
+ func (b *B) ResetTimer()
+
+ // SetBytes records the number of bytes processed in a single ...
+ func (b *B) SetBytes(n int64)
+
+ // StartTimer starts timing a test. This function is called ...
+ func (b *B) StartTimer()
+
+ // StopTimer stops timing a test. This can be used to pause the ...
+ func (b *B) StopTimer()
+
+ // The results of a benchmark run.
+ type BenchmarkResult struct {
+ N int // The number of iterations.
+ T time.Duration // The total time taken.
+ Bytes int64 // Bytes processed in one iteration.
+ }
+
+ // Benchmark benchmarks a single function. Useful for creating ...
+ func Benchmark(f func(b *B)) BenchmarkResult
+
+ //
+ func (r BenchmarkResult) NsPerOp() int64
+
+ //
+ func (r BenchmarkResult) String() string
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalBenchmark struct {
+ Name string
+ F func(b *B)
+ }
+
+ //
+ type InternalExample struct {
+ Name string
+ F func()
+ Output string
+ }
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalTest struct {
+ Name string
+ F func(*T)
+ }
+
+ // T is a type passed to Test functions to manage test state and ...
+ type T struct {
+ // contains filtered or unexported fields
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *T) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *T) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *T) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *T) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *T) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *T) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *T) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *T) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *T) Logf(format string, args ...interface{})
+
+ // Parallel signals that this test is to be run in parallel with ...
+ func (t *T) Parallel()
+
diff --git a/src/go/doc/testdata/testing.1.golden b/src/go/doc/testdata/testing.1.golden
new file mode 100644
index 0000000..b9d1451
--- /dev/null
+++ b/src/go/doc/testdata/testing.1.golden
@@ -0,0 +1,298 @@
+// Package testing provides support for automated testing of Go ...
+PACKAGE testing
+
+IMPORTPATH
+ testdata/testing
+
+IMPORTS
+ bytes
+ flag
+ fmt
+ io
+ os
+ runtime
+ runtime/pprof
+ strconv
+ strings
+ time
+
+FILENAMES
+ testdata/benchmark.go
+ testdata/example.go
+ testdata/testing.go
+
+VARIABLES
+ //
+ var (
+ // The short flag requests that tests run more quickly, but its functionality
+ // is provided by test writers themselves. The testing package is just its
+ // home. The all.bash installation script sets it to make installation more
+ // efficient, but by default the flag is off so a plain "go test" will do a
+ // full test of the package.
+ short = flag.Bool("test.short", false, "run smaller test suite to save time")
+
+ // Report as tests are run; default is silent for success.
+ chatty = flag.Bool("test.v", false, "verbose: print additional output")
+ match = flag.String("test.run", "", "regular expression to select tests to run")
+ memProfile = flag.String("test.memprofile", "", "write a memory profile to the named file after execution")
+ memProfileRate = flag.Int("test.memprofilerate", 0, "if >=0, sets runtime.MemProfileRate")
+ cpuProfile = flag.String("test.cpuprofile", "", "write a cpu profile to the named file during execution")
+ timeout = flag.Duration("test.timeout", 0, "if positive, sets an aggregate time limit for all tests")
+ cpuListStr = flag.String("test.cpu", "", "comma-separated list of number of CPUs to use for each test")
+ parallel = flag.Int("test.parallel", runtime.GOMAXPROCS(0), "maximum test parallelism")
+
+ cpuList []int
+ )
+
+ //
+ var benchTime = flag.Duration("test.benchtime", 1*time.Second, "approximate run time for each benchmark")
+
+ //
+ var matchBenchmarks = flag.String("test.bench", "", "regular expression to select benchmarks to run")
+
+ //
+ var timer *time.Timer
+
+
+FUNCTIONS
+ // An internal function but exported because it is cross-package; ...
+ func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample)
+
+ // An internal function but exported because it is cross-package; ...
+ func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks []InternalBenchmark)
+
+ //
+ func RunExamples(examples []InternalExample) (ok bool)
+
+ //
+ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalTest) (ok bool)
+
+ // Short reports whether the -test.short flag is set.
+ func Short() bool
+
+ // after runs after all testing.
+ func after()
+
+ // alarm is called if the timeout expires.
+ func alarm()
+
+ // before runs before all testing.
+ func before()
+
+ // decorate inserts the final newline if needed and indentation ...
+ func decorate(s string, addFileLine bool) string
+
+ //
+ func max(x, y int) int
+
+ //
+ func min(x, y int) int
+
+ //
+ func parseCpuList()
+
+ // roundDown10 rounds a number down to the nearest power of 10.
+ func roundDown10(n int) int
+
+ // roundUp rounds x up to a number of the form [1eX, 2eX, 5eX].
+ func roundUp(n int) int
+
+ // startAlarm starts an alarm if requested.
+ func startAlarm()
+
+ // stopAlarm turns off the alarm.
+ func stopAlarm()
+
+ //
+ func tRunner(t *T, test *InternalTest)
+
+
+TYPES
+ // B is a type passed to Benchmark functions to manage benchmark ...
+ type B struct {
+ common
+ N int
+ benchmark InternalBenchmark
+ bytes int64
+ timerOn bool
+ result BenchmarkResult
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *B) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *B) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *B) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *B) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *B) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *B) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *B) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *B) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *B) Logf(format string, args ...interface{})
+
+ // ResetTimer sets the elapsed benchmark time to zero. It does not ...
+ func (b *B) ResetTimer()
+
+ // SetBytes records the number of bytes processed in a single ...
+ func (b *B) SetBytes(n int64)
+
+ // StartTimer starts timing a test. This function is called ...
+ func (b *B) StartTimer()
+
+ // StopTimer stops timing a test. This can be used to pause the ...
+ func (b *B) StopTimer()
+
+ // launch launches the benchmark function. It gradually increases ...
+ func (b *B) launch()
+
+ // log generates the output. It's always at the same stack depth.
+ func (c *B) log(s string)
+
+ //
+ func (b *B) nsPerOp() int64
+
+ // run times the benchmark function in a separate goroutine.
+ func (b *B) run() BenchmarkResult
+
+ // runN runs a single benchmark for the specified number of ...
+ func (b *B) runN(n int)
+
+ // trimOutput shortens the output from a benchmark, which can be ...
+ func (b *B) trimOutput()
+
+ // The results of a benchmark run.
+ type BenchmarkResult struct {
+ N int // The number of iterations.
+ T time.Duration // The total time taken.
+ Bytes int64 // Bytes processed in one iteration.
+ }
+
+ // Benchmark benchmarks a single function. Useful for creating ...
+ func Benchmark(f func(b *B)) BenchmarkResult
+
+ //
+ func (r BenchmarkResult) NsPerOp() int64
+
+ //
+ func (r BenchmarkResult) String() string
+
+ //
+ func (r BenchmarkResult) mbPerSec() float64
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalBenchmark struct {
+ Name string
+ F func(b *B)
+ }
+
+ //
+ type InternalExample struct {
+ Name string
+ F func()
+ Output string
+ }
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalTest struct {
+ Name string
+ F func(*T)
+ }
+
+ // T is a type passed to Test functions to manage test state and ...
+ type T struct {
+ common
+ name string // Name of test.
+ startParallel chan bool // Parallel tests will wait on this.
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *T) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *T) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *T) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *T) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *T) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *T) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *T) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *T) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *T) Logf(format string, args ...interface{})
+
+ // Parallel signals that this test is to be run in parallel with ...
+ func (t *T) Parallel()
+
+ // log generates the output. It's always at the same stack depth.
+ func (c *T) log(s string)
+
+ //
+ func (t *T) report()
+
+ // common holds the elements common between T and B and captures ...
+ type common struct {
+ output []byte // Output generated by test or benchmark.
+ failed bool // Test or benchmark has failed.
+ start time.Time // Time test or benchmark started
+ duration time.Duration
+ self interface{} // To be sent on signal channel when done.
+ signal chan interface{} // Output for serial tests.
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *common) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *common) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *common) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *common) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *common) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *common) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *common) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *common) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *common) Logf(format string, args ...interface{})
+
+ // log generates the output. It's always at the same stack depth.
+ func (c *common) log(s string)
+
diff --git a/src/go/doc/testdata/testing.2.golden b/src/go/doc/testdata/testing.2.golden
new file mode 100644
index 0000000..83cf37c
--- /dev/null
+++ b/src/go/doc/testdata/testing.2.golden
@@ -0,0 +1,156 @@
+// Package testing provides support for automated testing of Go ...
+PACKAGE testing
+
+IMPORTPATH
+ testdata/testing
+
+IMPORTS
+ bytes
+ flag
+ fmt
+ io
+ os
+ runtime
+ runtime/pprof
+ strconv
+ strings
+ time
+
+FILENAMES
+ testdata/benchmark.go
+ testdata/example.go
+ testdata/testing.go
+
+FUNCTIONS
+ // An internal function but exported because it is cross-package; ...
+ func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample)
+
+ // An internal function but exported because it is cross-package; ...
+ func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks []InternalBenchmark)
+
+ //
+ func RunExamples(examples []InternalExample) (ok bool)
+
+ //
+ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalTest) (ok bool)
+
+ // Short reports whether the -test.short flag is set.
+ func Short() bool
+
+
+TYPES
+ // B is a type passed to Benchmark functions to manage benchmark ...
+ type B struct {
+ N int
+ // contains filtered or unexported fields
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *B) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *B) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *B) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *B) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *B) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *B) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *B) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *B) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *B) Logf(format string, args ...interface{})
+
+ // ResetTimer sets the elapsed benchmark time to zero. It does not ...
+ func (b *B) ResetTimer()
+
+ // SetBytes records the number of bytes processed in a single ...
+ func (b *B) SetBytes(n int64)
+
+ // StartTimer starts timing a test. This function is called ...
+ func (b *B) StartTimer()
+
+ // StopTimer stops timing a test. This can be used to pause the ...
+ func (b *B) StopTimer()
+
+ // The results of a benchmark run.
+ type BenchmarkResult struct {
+ N int // The number of iterations.
+ T time.Duration // The total time taken.
+ Bytes int64 // Bytes processed in one iteration.
+ }
+
+ // Benchmark benchmarks a single function. Useful for creating ...
+ func Benchmark(f func(b *B)) BenchmarkResult
+
+ //
+ func (r BenchmarkResult) NsPerOp() int64
+
+ //
+ func (r BenchmarkResult) String() string
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalBenchmark struct {
+ Name string
+ F func(b *B)
+ }
+
+ //
+ type InternalExample struct {
+ Name string
+ F func()
+ Output string
+ }
+
+ // An internal type but exported because it is cross-package; part ...
+ type InternalTest struct {
+ Name string
+ F func(*T)
+ }
+
+ // T is a type passed to Test functions to manage test state and ...
+ type T struct {
+ // contains filtered or unexported fields
+ }
+
+ // Error is equivalent to Log() followed by Fail().
+ func (c *T) Error(args ...interface{})
+
+ // Errorf is equivalent to Logf() followed by Fail().
+ func (c *T) Errorf(format string, args ...interface{})
+
+ // Fail marks the function as having failed but continues ...
+ func (c *T) Fail()
+
+ // FailNow marks the function as having failed and stops its ...
+ func (c *T) FailNow()
+
+ // Failed reports whether the function has failed.
+ func (c *T) Failed() bool
+
+ // Fatal is equivalent to Log() followed by FailNow().
+ func (c *T) Fatal(args ...interface{})
+
+ // Fatalf is equivalent to Logf() followed by FailNow().
+ func (c *T) Fatalf(format string, args ...interface{})
+
+ // Log formats its arguments using default formatting, analogous ...
+ func (c *T) Log(args ...interface{})
+
+ // Logf formats its arguments according to the format, analogous ...
+ func (c *T) Logf(format string, args ...interface{})
+
+ // Parallel signals that this test is to be run in parallel with ...
+ func (t *T) Parallel()
+
diff --git a/src/go/doc/testdata/testing.go b/src/go/doc/testdata/testing.go
new file mode 100644
index 0000000..52810f7
--- /dev/null
+++ b/src/go/doc/testdata/testing.go
@@ -0,0 +1,404 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package testing provides support for automated testing of Go packages.
+// It is intended to be used in concert with the ``go test'' utility, which automates
+// execution of any function of the form
+// func TestXxx(*testing.T)
+// where Xxx can be any alphanumeric string (but the first letter must not be in
+// [a-z]) and serves to identify the test routine.
+// These TestXxx routines should be declared within the package they are testing.
+//
+// Functions of the form
+// func BenchmarkXxx(*testing.B)
+// are considered benchmarks, and are executed by go test when the -test.bench
+// flag is provided.
+//
+// A sample benchmark function looks like this:
+// func BenchmarkHello(b *testing.B) {
+// for i := 0; i < b.N; i++ {
+// fmt.Sprintf("hello")
+// }
+// }
+// The benchmark package will vary b.N until the benchmark function lasts
+// long enough to be timed reliably. The output
+// testing.BenchmarkHello 10000000 282 ns/op
+// means that the loop ran 10000000 times at a speed of 282 ns per loop.
+//
+// If a benchmark needs some expensive setup before running, the timer
+// may be stopped:
+// func BenchmarkBigLen(b *testing.B) {
+// b.StopTimer()
+// big := NewBig()
+// b.StartTimer()
+// for i := 0; i < b.N; i++ {
+// big.Len()
+// }
+// }
+package testing
+
+import (
+ "flag"
+ "fmt"
+ "os"
+ "runtime"
+ "runtime/pprof"
+ "strconv"
+ "strings"
+ "time"
+)
+
+var (
+ // The short flag requests that tests run more quickly, but its functionality
+ // is provided by test writers themselves. The testing package is just its
+ // home. The all.bash installation script sets it to make installation more
+ // efficient, but by default the flag is off so a plain "go test" will do a
+ // full test of the package.
+ short = flag.Bool("test.short", false, "run smaller test suite to save time")
+
+ // Report as tests are run; default is silent for success.
+ chatty = flag.Bool("test.v", false, "verbose: print additional output")
+ match = flag.String("test.run", "", "regular expression to select tests to run")
+ memProfile = flag.String("test.memprofile", "", "write a memory profile to the named file after execution")
+ memProfileRate = flag.Int("test.memprofilerate", 0, "if >=0, sets runtime.MemProfileRate")
+ cpuProfile = flag.String("test.cpuprofile", "", "write a cpu profile to the named file during execution")
+ timeout = flag.Duration("test.timeout", 0, "if positive, sets an aggregate time limit for all tests")
+ cpuListStr = flag.String("test.cpu", "", "comma-separated list of number of CPUs to use for each test")
+ parallel = flag.Int("test.parallel", runtime.GOMAXPROCS(0), "maximum test parallelism")
+
+ cpuList []int
+)
+
+// common holds the elements common between T and B and
+// captures common methods such as Errorf.
+type common struct {
+ output []byte // Output generated by test or benchmark.
+ failed bool // Test or benchmark has failed.
+ start time.Time // Time test or benchmark started
+ duration time.Duration
+ self interface{} // To be sent on signal channel when done.
+ signal chan interface{} // Output for serial tests.
+}
+
+// Short reports whether the -test.short flag is set.
+func Short() bool {
+ return *short
+}
+
+// decorate inserts the final newline if needed and indentation tabs for formatting.
+// If addFileLine is true, it also prefixes the string with the file and line of the call site.
+func decorate(s string, addFileLine bool) string {
+ if addFileLine {
+ _, file, line, ok := runtime.Caller(3) // decorate + log + public function.
+ if ok {
+ // Truncate file name at last file name separator.
+ if index := strings.LastIndex(file, "/"); index >= 0 {
+ file = file[index+1:]
+ } else if index = strings.LastIndex(file, "\\"); index >= 0 {
+ file = file[index+1:]
+ }
+ } else {
+ file = "???"
+ line = 1
+ }
+ s = fmt.Sprintf("%s:%d: %s", file, line, s)
+ }
+ s = "\t" + s // Every line is indented at least one tab.
+ n := len(s)
+ if n > 0 && s[n-1] != '\n' {
+ s += "\n"
+ n++
+ }
+ for i := 0; i < n-1; i++ { // -1 to avoid final newline
+ if s[i] == '\n' {
+ // Second and subsequent lines are indented an extra tab.
+ return s[0:i+1] + "\t" + decorate(s[i+1:n], false)
+ }
+ }
+ return s
+}
+
+// T is a type passed to Test functions to manage test state and support formatted test logs.
+// Logs are accumulated during execution and dumped to standard error when done.
+type T struct {
+ common
+ name string // Name of test.
+ startParallel chan bool // Parallel tests will wait on this.
+}
+
+// Fail marks the function as having failed but continues execution.
+func (c *common) Fail() { c.failed = true }
+
+// Failed reports whether the function has failed.
+func (c *common) Failed() bool { return c.failed }
+
+// FailNow marks the function as having failed and stops its execution.
+// Execution will continue at the next Test.
+func (c *common) FailNow() {
+ c.Fail()
+
+ // Calling runtime.Goexit will exit the goroutine, which
+ // will run the deferred functions in this goroutine,
+ // which will eventually run the deferred lines in tRunner,
+ // which will signal to the test loop that this test is done.
+ //
+ // A previous version of this code said:
+ //
+ // c.duration = ...
+ // c.signal <- c.self
+ // runtime.Goexit()
+ //
+ // This previous version duplicated code (those lines are in
+ // tRunner no matter what), but worse the goroutine teardown
+ // implicit in runtime.Goexit was not guaranteed to complete
+ // before the test exited. If a test deferred an important cleanup
+ // function (like removing temporary files), there was no guarantee
+ // it would run on a test failure. Because we send on c.signal during
+ // a top-of-stack deferred function now, we know that the send
+ // only happens after any other stacked defers have completed.
+ runtime.Goexit()
+}
+
+// log generates the output. It's always at the same stack depth.
+func (c *common) log(s string) {
+ c.output = append(c.output, decorate(s, true)...)
+}
+
+// Log formats its arguments using default formatting, analogous to Println(),
+// and records the text in the error log.
+func (c *common) Log(args ...interface{}) { c.log(fmt.Sprintln(args...)) }
+
+// Logf formats its arguments according to the format, analogous to Printf(),
+// and records the text in the error log.
+func (c *common) Logf(format string, args ...interface{}) { c.log(fmt.Sprintf(format, args...)) }
+
+// Error is equivalent to Log() followed by Fail().
+func (c *common) Error(args ...interface{}) {
+ c.log(fmt.Sprintln(args...))
+ c.Fail()
+}
+
+// Errorf is equivalent to Logf() followed by Fail().
+func (c *common) Errorf(format string, args ...interface{}) {
+ c.log(fmt.Sprintf(format, args...))
+ c.Fail()
+}
+
+// Fatal is equivalent to Log() followed by FailNow().
+func (c *common) Fatal(args ...interface{}) {
+ c.log(fmt.Sprintln(args...))
+ c.FailNow()
+}
+
+// Fatalf is equivalent to Logf() followed by FailNow().
+func (c *common) Fatalf(format string, args ...interface{}) {
+ c.log(fmt.Sprintf(format, args...))
+ c.FailNow()
+}
+
+// Parallel signals that this test is to be run in parallel with (and only with)
+// other parallel tests in this CPU group.
+func (t *T) Parallel() {
+ t.signal <- (*T)(nil) // Release main testing loop
+ <-t.startParallel // Wait for serial tests to finish
+}
+
+// An internal type but exported because it is cross-package; part of the implementation
+// of go test.
+type InternalTest struct {
+ Name string
+ F func(*T)
+}
+
+func tRunner(t *T, test *InternalTest) {
+ t.start = time.Now()
+
+ // When this goroutine is done, either because test.F(t)
+ // returned normally or because a test failure triggered
+ // a call to runtime.Goexit, record the duration and send
+ // a signal saying that the test is done.
+ defer func() {
+ t.duration = time.Now().Sub(t.start)
+ t.signal <- t
+ }()
+
+ test.F(t)
+}
+
+// An internal function but exported because it is cross-package; part of the implementation
+// of go test.
+func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample) {
+ flag.Parse()
+ parseCpuList()
+
+ before()
+ startAlarm()
+ testOk := RunTests(matchString, tests)
+ exampleOk := RunExamples(examples)
+ if !testOk || !exampleOk {
+ fmt.Println("FAIL")
+ os.Exit(1)
+ }
+ fmt.Println("PASS")
+ stopAlarm()
+ RunBenchmarks(matchString, benchmarks)
+ after()
+}
+
+func (t *T) report() {
+ tstr := fmt.Sprintf("(%.2f seconds)", t.duration.Seconds())
+ format := "--- %s: %s %s\n%s"
+ if t.failed {
+ fmt.Printf(format, "FAIL", t.name, tstr, t.output)
+ } else if *chatty {
+ fmt.Printf(format, "PASS", t.name, tstr, t.output)
+ }
+}
+
+func RunTests(matchString func(pat, str string) (bool, error), tests []InternalTest) (ok bool) {
+ ok = true
+ if len(tests) == 0 {
+ fmt.Fprintln(os.Stderr, "testing: warning: no tests to run")
+ return
+ }
+ for _, procs := range cpuList {
+ runtime.GOMAXPROCS(procs)
+ // We build a new channel tree for each run of the loop.
+ // collector merges in one channel all the upstream signals from parallel tests.
+ // If all tests pump to the same channel, a bug can occur where a test
+ // kicks off a goroutine that Fails, yet the test still delivers a completion signal,
+ // which skews the counting.
+ var collector = make(chan interface{})
+
+ numParallel := 0
+ startParallel := make(chan bool)
+
+ for i := 0; i < len(tests); i++ {
+ matched, err := matchString(*match, tests[i].Name)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "testing: invalid regexp for -test.run: %s\n", err)
+ os.Exit(1)
+ }
+ if !matched {
+ continue
+ }
+ testName := tests[i].Name
+ if procs != 1 {
+ testName = fmt.Sprintf("%s-%d", tests[i].Name, procs)
+ }
+ t := &T{
+ common: common{
+ signal: make(chan interface{}),
+ },
+ name: testName,
+ startParallel: startParallel,
+ }
+ t.self = t
+ if *chatty {
+ fmt.Printf("=== RUN %s\n", t.name)
+ }
+ go tRunner(t, &tests[i])
+ out := (<-t.signal).(*T)
+ if out == nil { // Parallel run.
+ go func() {
+ collector <- <-t.signal
+ }()
+ numParallel++
+ continue
+ }
+ t.report()
+ ok = ok && !out.failed
+ }
+
+ running := 0
+ for numParallel+running > 0 {
+ if running < *parallel && numParallel > 0 {
+ startParallel <- true
+ running++
+ numParallel--
+ continue
+ }
+ t := (<-collector).(*T)
+ t.report()
+ ok = ok && !t.failed
+ running--
+ }
+ }
+ return
+}
+
+// before runs before all testing.
+func before() {
+ if *memProfileRate > 0 {
+ runtime.MemProfileRate = *memProfileRate
+ }
+ if *cpuProfile != "" {
+ f, err := os.Create(*cpuProfile)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "testing: %s", err)
+ return
+ }
+ if err := pprof.StartCPUProfile(f); err != nil {
+ fmt.Fprintf(os.Stderr, "testing: can't start cpu profile: %s", err)
+ f.Close()
+ return
+ }
+ // Could save f so after can call f.Close; not worth the effort.
+ }
+
+}
+
+// after runs after all testing.
+func after() {
+ if *cpuProfile != "" {
+ pprof.StopCPUProfile() // flushes profile to disk
+ }
+ if *memProfile != "" {
+ f, err := os.Create(*memProfile)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "testing: %s", err)
+ return
+ }
+ if err = pprof.WriteHeapProfile(f); err != nil {
+ fmt.Fprintf(os.Stderr, "testing: can't write %s: %s", *memProfile, err)
+ }
+ f.Close()
+ }
+}
+
+var timer *time.Timer
+
+// startAlarm starts an alarm if requested.
+func startAlarm() {
+ if *timeout > 0 {
+ timer = time.AfterFunc(*timeout, alarm)
+ }
+}
+
+// stopAlarm turns off the alarm.
+func stopAlarm() {
+ if *timeout > 0 {
+ timer.Stop()
+ }
+}
+
+// alarm is called if the timeout expires.
+func alarm() {
+ panic("test timed out")
+}
+
+func parseCpuList() {
+ if len(*cpuListStr) == 0 {
+ cpuList = append(cpuList, runtime.GOMAXPROCS(-1))
+ } else {
+ for _, val := range strings.Split(*cpuListStr, ",") {
+ cpu, err := strconv.Atoi(val)
+ if err != nil || cpu <= 0 {
+ fmt.Fprintf(os.Stderr, "testing: invalid value %q for -test.cpu", val)
+ os.Exit(1)
+ }
+ cpuList = append(cpuList, cpu)
+ }
+ }
+}
diff --git a/src/go/format/benchmark_test.go b/src/go/format/benchmark_test.go
new file mode 100644
index 0000000..ac19aa3
--- /dev/null
+++ b/src/go/format/benchmark_test.go
@@ -0,0 +1,91 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file provides a simple framework to add benchmarks
+// based on generated input (source) files.
+
+package format_test
+
+import (
+ "bytes"
+ "flag"
+ "fmt"
+ "go/format"
+ "os"
+ "testing"
+)
+
+var debug = flag.Bool("debug", false, "write .src files containing formatting input; for debugging")
+
+// array1 generates an array literal with n elements of the form:
+//
+// var _ = [...]byte{
+// // 0
+// 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+// 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+// 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+// 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+// 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+// // 40
+// 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+// 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+// ...
+//
+func array1(buf *bytes.Buffer, n int) {
+ buf.WriteString("var _ = [...]byte{\n")
+ for i := 0; i < n; {
+ if i%10 == 0 {
+ fmt.Fprintf(buf, "\t// %d\n", i)
+ }
+ buf.WriteByte('\t')
+ for j := 0; j < 8; j++ {
+ fmt.Fprintf(buf, "0x%02x, ", byte(i))
+ i++
+ }
+ buf.WriteString("\n")
+ }
+ buf.WriteString("}\n")
+}
+
+var tests = []struct {
+ name string
+ gen func(*bytes.Buffer, int)
+ n int
+}{
+ {"array1", array1, 10000},
+ // add new test cases here as needed
+}
+
+func BenchmarkFormat(b *testing.B) {
+ var src bytes.Buffer
+ for _, t := range tests {
+ src.Reset()
+ src.WriteString("package p\n")
+ t.gen(&src, t.n)
+ data := src.Bytes()
+
+ if *debug {
+ filename := t.name + ".src"
+ err := os.WriteFile(filename, data, 0660)
+ if err != nil {
+ b.Fatalf("couldn't write %s: %v", filename, err)
+ }
+ }
+
+ b.Run(fmt.Sprintf("%s-%d", t.name, t.n), func(b *testing.B) {
+ b.SetBytes(int64(len(data)))
+ b.ReportAllocs()
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ var err error
+ sink, err = format.Source(data)
+ if err != nil {
+ b.Fatal(err)
+ }
+ }
+ })
+ }
+}
+
+var sink []byte
diff --git a/src/go/format/example_test.go b/src/go/format/example_test.go
new file mode 100644
index 0000000..5b6789a
--- /dev/null
+++ b/src/go/format/example_test.go
@@ -0,0 +1,39 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package format_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/format"
+ "go/parser"
+ "go/token"
+ "log"
+)
+
+func ExampleNode() {
+ const expr = "(6+2*3)/4"
+
+ // parser.ParseExpr parses the argument and returns the
+ // corresponding ast.Node.
+ node, err := parser.ParseExpr(expr)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Create a FileSet for node. Since the node does not come
+ // from a real source file, fset will be empty.
+ fset := token.NewFileSet()
+
+ var buf bytes.Buffer
+ err = format.Node(&buf, fset, node)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ fmt.Println(buf.String())
+
+ // Output: (6 + 2*3) / 4
+}
diff --git a/src/go/format/format.go b/src/go/format/format.go
new file mode 100644
index 0000000..a603d96
--- /dev/null
+++ b/src/go/format/format.go
@@ -0,0 +1,135 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package format implements standard formatting of Go source.
+//
+// Note that formatting of Go source code changes over time, so tools relying on
+// consistent formatting should execute a specific version of the gofmt binary
+// instead of using this package. That way, the formatting will be stable, and
+// the tools won't need to be recompiled each time gofmt changes.
+//
+// For example, pre-submit checks that use this package directly would behave
+// differently depending on what Go version each developer uses, causing the
+// check to be inherently fragile.
+package format
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "io"
+)
+
+// Keep these in sync with cmd/gofmt/gofmt.go.
+const (
+ tabWidth = 8
+ printerMode = printer.UseSpaces | printer.TabIndent | printerNormalizeNumbers
+
+ // printerNormalizeNumbers means to canonicalize number literal prefixes
+ // and exponents while printing. See https://golang.org/doc/go1.13#gofmt.
+ //
+ // This value is defined in go/printer specifically for go/format and cmd/gofmt.
+ printerNormalizeNumbers = 1 << 30
+)
+
+var config = printer.Config{Mode: printerMode, Tabwidth: tabWidth}
+
+const parserMode = parser.ParseComments
+
+// Node formats node in canonical gofmt style and writes the result to dst.
+//
+// The node type must be *ast.File, *printer.CommentedNode, []ast.Decl,
+// []ast.Stmt, or assignment-compatible to ast.Expr, ast.Decl, ast.Spec,
+// or ast.Stmt. Node does not modify node. Imports are not sorted for
+// nodes representing partial source files (for instance, if the node is
+// not an *ast.File or a *printer.CommentedNode not wrapping an *ast.File).
+//
+// The function may return early (before the entire result is written)
+// and return a formatting error, for instance due to an incorrect AST.
+//
+func Node(dst io.Writer, fset *token.FileSet, node interface{}) error {
+ // Determine if we have a complete source file (file != nil).
+ var file *ast.File
+ var cnode *printer.CommentedNode
+ switch n := node.(type) {
+ case *ast.File:
+ file = n
+ case *printer.CommentedNode:
+ if f, ok := n.Node.(*ast.File); ok {
+ file = f
+ cnode = n
+ }
+ }
+
+ // Sort imports if necessary.
+ if file != nil && hasUnsortedImports(file) {
+ // Make a copy of the AST because ast.SortImports is destructive.
+ // TODO(gri) Do this more efficiently.
+ var buf bytes.Buffer
+ err := config.Fprint(&buf, fset, file)
+ if err != nil {
+ return err
+ }
+ file, err = parser.ParseFile(fset, "", buf.Bytes(), parserMode)
+ if err != nil {
+ // We should never get here. If we do, provide good diagnostic.
+ return fmt.Errorf("format.Node internal error (%s)", err)
+ }
+ ast.SortImports(fset, file)
+
+ // Use new file with sorted imports.
+ node = file
+ if cnode != nil {
+ node = &printer.CommentedNode{Node: file, Comments: cnode.Comments}
+ }
+ }
+
+ return config.Fprint(dst, fset, node)
+}
+
+// Source formats src in canonical gofmt style and returns the result
+// or an (I/O or syntax) error. src is expected to be a syntactically
+// correct Go source file, or a list of Go declarations or statements.
+//
+// If src is a partial source file, the leading and trailing space of src
+// is applied to the result (such that it has the same leading and trailing
+// space as src), and the result is indented by the same amount as the first
+// line of src containing code. Imports are not sorted for partial source files.
+//
+func Source(src []byte) ([]byte, error) {
+ fset := token.NewFileSet()
+ file, sourceAdj, indentAdj, err := parse(fset, "", src, true)
+ if err != nil {
+ return nil, err
+ }
+
+ if sourceAdj == nil {
+ // Complete source file.
+ // TODO(gri) consider doing this always.
+ ast.SortImports(fset, file)
+ }
+
+ return format(fset, file, sourceAdj, indentAdj, src, config)
+}
+
+func hasUnsortedImports(file *ast.File) bool {
+ for _, d := range file.Decls {
+ d, ok := d.(*ast.GenDecl)
+ if !ok || d.Tok != token.IMPORT {
+ // Not an import declaration, so we're done.
+ // Imports are always first.
+ return false
+ }
+ if d.Lparen.IsValid() {
+ // For now assume all grouped imports are unsorted.
+ // TODO(gri) Should check if they are sorted already.
+ return true
+ }
+ // Ungrouped imports are sorted by default.
+ }
+ return false
+}
diff --git a/src/go/format/format_test.go b/src/go/format/format_test.go
new file mode 100644
index 0000000..27f4c74
--- /dev/null
+++ b/src/go/format/format_test.go
@@ -0,0 +1,183 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package format
+
+import (
+ "bytes"
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "os"
+ "strings"
+ "testing"
+)
+
+const testfile = "format_test.go"
+
+func diff(t *testing.T, dst, src []byte) {
+ line := 1
+ offs := 0 // line offset
+ for i := 0; i < len(dst) && i < len(src); i++ {
+ d := dst[i]
+ s := src[i]
+ if d != s {
+ t.Errorf("dst:%d: %s\n", line, dst[offs:i+1])
+ t.Errorf("src:%d: %s\n", line, src[offs:i+1])
+ return
+ }
+ if s == '\n' {
+ line++
+ offs = i + 1
+ }
+ }
+ if len(dst) != len(src) {
+ t.Errorf("len(dst) = %d, len(src) = %d\nsrc = %q", len(dst), len(src), src)
+ }
+}
+
+func TestNode(t *testing.T) {
+ src, err := os.ReadFile(testfile)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, testfile, src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var buf bytes.Buffer
+
+ if err = Node(&buf, fset, file); err != nil {
+ t.Fatal("Node failed:", err)
+ }
+
+ diff(t, buf.Bytes(), src)
+}
+
+// Node is documented to not modify the AST.
+// Test that it is so even when numbers are normalized.
+func TestNodeNoModify(t *testing.T) {
+ const (
+ src = "package p\n\nconst _ = 0000000123i\n"
+ golden = "package p\n\nconst _ = 123i\n"
+ )
+
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // Capture original address and value of a BasicLit node
+ // which will undergo formatting changes during printing.
+ wantLit := file.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0].(*ast.BasicLit)
+ wantVal := wantLit.Value
+
+ var buf bytes.Buffer
+ if err = Node(&buf, fset, file); err != nil {
+ t.Fatal("Node failed:", err)
+ }
+ diff(t, buf.Bytes(), []byte(golden))
+
+ // Check if anything changed after Node returned.
+ gotLit := file.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0].(*ast.BasicLit)
+ gotVal := gotLit.Value
+
+ if gotLit != wantLit {
+ t.Errorf("got *ast.BasicLit address %p, want %p", gotLit, wantLit)
+ }
+ if gotVal != wantVal {
+ t.Errorf("got *ast.BasicLit value %q, want %q", gotVal, wantVal)
+ }
+}
+
+func TestSource(t *testing.T) {
+ src, err := os.ReadFile(testfile)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ res, err := Source(src)
+ if err != nil {
+ t.Fatal("Source failed:", err)
+ }
+
+ diff(t, res, src)
+}
+
+// Test cases that are expected to fail are marked by the prefix "ERROR".
+// The formatted result must look the same as the input for successful tests.
+var tests = []string{
+ // declaration lists
+ `import "go/format"`,
+ "var x int",
+ "var x int\n\ntype T struct{}",
+
+ // statement lists
+ "x := 0",
+ "f(a, b, c)\nvar x int = f(1, 2, 3)",
+
+ // indentation, leading and trailing space
+ "\tx := 0\n\tgo f()",
+ "\tx := 0\n\tgo f()\n\n\n",
+ "\n\t\t\n\n\tx := 0\n\tgo f()\n\n\n",
+ "\n\t\t\n\n\t\t\tx := 0\n\t\t\tgo f()\n\n\n",
+ "\n\t\t\n\n\t\t\tx := 0\n\t\t\tconst s = `\nfoo\n`\n\n\n", // no indentation added inside raw strings
+ "\n\t\t\n\n\t\t\tx := 0\n\t\t\tconst s = `\n\t\tfoo\n`\n\n\n", // no indentation removed inside raw strings
+
+ // comments
+ "/* Comment */",
+ "\t/* Comment */ ",
+ "\n/* Comment */ ",
+ "i := 5 /* Comment */", // issue #5551
+ "\ta()\n//line :1", // issue #11276
+ "\t//xxx\n\ta()\n//line :2", // issue #11276
+ "\ta() //line :1\n\tb()\n", // issue #11276
+ "x := 0\n//line :1\n//line :2", // issue #11276
+
+ // whitespace
+ "", // issue #11275
+ " ", // issue #11275
+ "\t", // issue #11275
+ "\t\t", // issue #11275
+ "\n", // issue #11275
+ "\n\n", // issue #11275
+ "\t\n", // issue #11275
+
+ // erroneous programs
+ "ERROR1 + 2 +",
+ "ERRORx := 0",
+}
+
+func String(s string) (string, error) {
+ res, err := Source([]byte(s))
+ if err != nil {
+ return "", err
+ }
+ return string(res), nil
+}
+
+func TestPartial(t *testing.T) {
+ for _, src := range tests {
+ if strings.HasPrefix(src, "ERROR") {
+ // test expected to fail
+ src = src[5:] // remove ERROR prefix
+ res, err := String(src)
+ if err == nil && res == src {
+ t.Errorf("formatting succeeded but was expected to fail:\n%q", src)
+ }
+ } else {
+ // test expected to succeed
+ res, err := String(src)
+ if err != nil {
+ t.Errorf("formatting failed (%s):\n%q", err, src)
+ } else if res != src {
+ t.Errorf("formatting incorrect:\nsource: %q\nresult: %q", src, res)
+ }
+ }
+ }
+}
diff --git a/src/go/format/internal.go b/src/go/format/internal.go
new file mode 100644
index 0000000..2f3b0e4
--- /dev/null
+++ b/src/go/format/internal.go
@@ -0,0 +1,176 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// TODO(gri): This file and the file src/cmd/gofmt/internal.go are
+// the same (but for this comment and the package name). Do not modify
+// one without the other. Determine if we can factor out functionality
+// in a public API. See also #11844 for context.
+
+package format
+
+import (
+ "bytes"
+ "go/ast"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "strings"
+)
+
+// parse parses src, which was read from the named file,
+// as a Go source file, declaration, or statement list.
+func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
+ file *ast.File,
+ sourceAdj func(src []byte, indent int) []byte,
+ indentAdj int,
+ err error,
+) {
+ // Try as whole source file.
+ file, err = parser.ParseFile(fset, filename, src, parserMode)
+ // If there's no error, return. If the error is that the source file didn't begin with a
+ // package line and source fragments are ok, fall through to
+ // try as a source fragment. Stop and return on any other error.
+ if err == nil || !fragmentOk || !strings.Contains(err.Error(), "expected 'package'") {
+ return
+ }
+
+ // If this is a declaration list, make it a source file
+ // by inserting a package clause.
+ // Insert using a ';', not a newline, so that the line numbers
+ // in psrc match the ones in src.
+ psrc := append([]byte("package p;"), src...)
+ file, err = parser.ParseFile(fset, filename, psrc, parserMode)
+ if err == nil {
+ sourceAdj = func(src []byte, indent int) []byte {
+ // Remove the package clause.
+ // Gofmt has turned the ';' into a '\n'.
+ src = src[indent+len("package p\n"):]
+ return bytes.TrimSpace(src)
+ }
+ return
+ }
+ // If the error is that the source file didn't begin with a
+ // declaration, fall through to try as a statement list.
+ // Stop and return on any other error.
+ if !strings.Contains(err.Error(), "expected declaration") {
+ return
+ }
+
+ // If this is a statement list, make it a source file
+ // by inserting a package clause and turning the list
+ // into a function body. This handles expressions too.
+ // Insert using a ';', not a newline, so that the line numbers
+ // in fsrc match the ones in src. Add an extra '\n' before the '}'
+ // to make sure comments are flushed before the '}'.
+ fsrc := append(append([]byte("package p; func _() {"), src...), '\n', '\n', '}')
+ file, err = parser.ParseFile(fset, filename, fsrc, parserMode)
+ if err == nil {
+ sourceAdj = func(src []byte, indent int) []byte {
+ // Cap adjusted indent to zero.
+ if indent < 0 {
+ indent = 0
+ }
+ // Remove the wrapping.
+ // Gofmt has turned the "; " into a "\n\n".
+ // There will be two non-blank lines with indent, hence 2*indent.
+ src = src[2*indent+len("package p\n\nfunc _() {"):]
+ // Remove only the "}\n" suffix: remaining whitespaces will be trimmed anyway
+ src = src[:len(src)-len("}\n")]
+ return bytes.TrimSpace(src)
+ }
+ // Gofmt has also indented the function body one level.
+ // Adjust that with indentAdj.
+ indentAdj = -1
+ }
+
+ // Succeeded, or out of options.
+ return
+}
+
+// format formats the given package file originally obtained from src
+// and adjusts the result based on the original source via sourceAdj
+// and indentAdj.
+func format(
+ fset *token.FileSet,
+ file *ast.File,
+ sourceAdj func(src []byte, indent int) []byte,
+ indentAdj int,
+ src []byte,
+ cfg printer.Config,
+) ([]byte, error) {
+ if sourceAdj == nil {
+ // Complete source file.
+ var buf bytes.Buffer
+ err := cfg.Fprint(&buf, fset, file)
+ if err != nil {
+ return nil, err
+ }
+ return buf.Bytes(), nil
+ }
+
+ // Partial source file.
+ // Determine and prepend leading space.
+ i, j := 0, 0
+ for j < len(src) && isSpace(src[j]) {
+ if src[j] == '\n' {
+ i = j + 1 // byte offset of last line in leading space
+ }
+ j++
+ }
+ var res []byte
+ res = append(res, src[:i]...)
+
+ // Determine and prepend indentation of first code line.
+ // Spaces are ignored unless there are no tabs,
+ // in which case spaces count as one tab.
+ indent := 0
+ hasSpace := false
+ for _, b := range src[i:j] {
+ switch b {
+ case ' ':
+ hasSpace = true
+ case '\t':
+ indent++
+ }
+ }
+ if indent == 0 && hasSpace {
+ indent = 1
+ }
+ for i := 0; i < indent; i++ {
+ res = append(res, '\t')
+ }
+
+ // Format the source.
+ // Write it without any leading and trailing space.
+ cfg.Indent = indent + indentAdj
+ var buf bytes.Buffer
+ err := cfg.Fprint(&buf, fset, file)
+ if err != nil {
+ return nil, err
+ }
+ out := sourceAdj(buf.Bytes(), cfg.Indent)
+
+ // If the adjusted output is empty, the source
+ // was empty but (possibly) for white space.
+ // The result is the incoming source.
+ if len(out) == 0 {
+ return src, nil
+ }
+
+ // Otherwise, append output to leading space.
+ res = append(res, out...)
+
+ // Determine and append trailing space.
+ i = len(src)
+ for i > 0 && isSpace(src[i-1]) {
+ i--
+ }
+ return append(res, src[i:]...), nil
+}
+
+// isSpace reports whether the byte is a space character.
+// isSpace defines a space as being among the following bytes: ' ', '\t', '\n' and '\r'.
+func isSpace(b byte) bool {
+ return b == ' ' || b == '\t' || b == '\n' || b == '\r'
+}
diff --git a/src/go/importer/importer.go b/src/go/importer/importer.go
new file mode 100644
index 0000000..23118d3
--- /dev/null
+++ b/src/go/importer/importer.go
@@ -0,0 +1,122 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package importer provides access to export data importers.
+package importer
+
+import (
+ "go/build"
+ "go/internal/gccgoimporter"
+ "go/internal/gcimporter"
+ "go/internal/srcimporter"
+ "go/token"
+ "go/types"
+ "io"
+ "runtime"
+)
+
+// A Lookup function returns a reader to access package data for
+// a given import path, or an error if no matching package is found.
+type Lookup func(path string) (io.ReadCloser, error)
+
+// ForCompiler returns an Importer for importing from installed packages
+// for the compilers "gc" and "gccgo", or for importing directly
+// from the source if the compiler argument is "source". In this
+// latter case, importing may fail under circumstances where the
+// exported API is not entirely defined in pure Go source code
+// (if the package API depends on cgo-defined entities, the type
+// checker won't have access to those).
+//
+// The lookup function is called each time the resulting importer needs
+// to resolve an import path. In this mode the importer can only be
+// invoked with canonical import paths (not relative or absolute ones);
+// it is assumed that the translation to canonical import paths is being
+// done by the client of the importer.
+//
+// A lookup function must be provided for correct module-aware operation.
+// Deprecated: If lookup is nil, for backwards-compatibility, the importer
+// will attempt to resolve imports in the $GOPATH workspace.
+func ForCompiler(fset *token.FileSet, compiler string, lookup Lookup) types.Importer {
+ switch compiler {
+ case "gc":
+ return &gcimports{
+ fset: fset,
+ packages: make(map[string]*types.Package),
+ lookup: lookup,
+ }
+
+ case "gccgo":
+ var inst gccgoimporter.GccgoInstallation
+ if err := inst.InitFromDriver("gccgo"); err != nil {
+ return nil
+ }
+ return &gccgoimports{
+ packages: make(map[string]*types.Package),
+ importer: inst.GetImporter(nil, nil),
+ lookup: lookup,
+ }
+
+ case "source":
+ if lookup != nil {
+ panic("source importer for custom import path lookup not supported (issue #13847).")
+ }
+
+ return srcimporter.New(&build.Default, fset, make(map[string]*types.Package))
+ }
+
+ // compiler not supported
+ return nil
+}
+
+// For calls ForCompiler with a new FileSet.
+//
+// Deprecated: Use ForCompiler, which populates a FileSet
+// with the positions of objects created by the importer.
+func For(compiler string, lookup Lookup) types.Importer {
+ return ForCompiler(token.NewFileSet(), compiler, lookup)
+}
+
+// Default returns an Importer for the compiler that built the running binary.
+// If available, the result implements types.ImporterFrom.
+func Default() types.Importer {
+ return For(runtime.Compiler, nil)
+}
+
+// gc importer
+
+type gcimports struct {
+ fset *token.FileSet
+ packages map[string]*types.Package
+ lookup Lookup
+}
+
+func (m *gcimports) Import(path string) (*types.Package, error) {
+ return m.ImportFrom(path, "" /* no vendoring */, 0)
+}
+
+func (m *gcimports) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
+ if mode != 0 {
+ panic("mode must be 0")
+ }
+ return gcimporter.Import(m.fset, m.packages, path, srcDir, m.lookup)
+}
+
+// gccgo importer
+
+type gccgoimports struct {
+ packages map[string]*types.Package
+ importer gccgoimporter.Importer
+ lookup Lookup
+}
+
+func (m *gccgoimports) Import(path string) (*types.Package, error) {
+ return m.ImportFrom(path, "" /* no vendoring */, 0)
+}
+
+func (m *gccgoimports) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
+ if mode != 0 {
+ panic("mode must be 0")
+ }
+ return m.importer(m.packages, path, srcDir, m.lookup)
+}
diff --git a/src/go/importer/importer_test.go b/src/go/importer/importer_test.go
new file mode 100644
index 0000000..0f5121d
--- /dev/null
+++ b/src/go/importer/importer_test.go
@@ -0,0 +1,87 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package importer
+
+import (
+ "go/token"
+ "internal/testenv"
+ "io"
+ "os"
+ "os/exec"
+ "runtime"
+ "strings"
+ "testing"
+)
+
+func TestForCompiler(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ const thePackage = "math/big"
+ out, err := exec.Command(testenv.GoToolPath(t), "list", "-f={{context.Compiler}}:{{.Target}}", thePackage).CombinedOutput()
+ if err != nil {
+ t.Fatalf("go list %s: %v\n%s", thePackage, err, out)
+ }
+ target := strings.TrimSpace(string(out))
+ i := strings.Index(target, ":")
+ compiler, target := target[:i], target[i+1:]
+ if !strings.HasSuffix(target, ".a") {
+ t.Fatalf("unexpected package %s target %q (not *.a)", thePackage, target)
+ }
+
+ if compiler == "gccgo" {
+ t.Skip("golang.org/issue/22500")
+ }
+
+ fset := token.NewFileSet()
+
+ t.Run("LookupDefault", func(t *testing.T) {
+ imp := ForCompiler(fset, compiler, nil)
+ pkg, err := imp.Import(thePackage)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if pkg.Path() != thePackage {
+ t.Fatalf("Path() = %q, want %q", pkg.Path(), thePackage)
+ }
+
+ // Check that the fileset positions are accurate.
+ // https://github.com/golang/go#28995
+ mathBigInt := pkg.Scope().Lookup("Int")
+ posn := fset.Position(mathBigInt.Pos()) // "$GOROOT/src/math/big/int.go:25:1"
+ filename := strings.Replace(posn.Filename, "$GOROOT", runtime.GOROOT(), 1)
+ data, err := os.ReadFile(filename)
+ if err != nil {
+ t.Fatalf("can't read file containing declaration of math/big.Int: %v", err)
+ }
+ lines := strings.Split(string(data), "\n")
+ if posn.Line > len(lines) || !strings.HasPrefix(lines[posn.Line-1], "type Int") {
+ t.Fatalf("Object %v position %s does not contain its declaration",
+ mathBigInt, posn)
+ }
+ })
+
+ t.Run("LookupCustom", func(t *testing.T) {
+ lookup := func(path string) (io.ReadCloser, error) {
+ if path != "math/bigger" {
+ t.Fatalf("lookup called with unexpected path %q", path)
+ }
+ f, err := os.Open(target)
+ if err != nil {
+ t.Fatal(err)
+ }
+ return f, nil
+ }
+ imp := ForCompiler(fset, compiler, lookup)
+ pkg, err := imp.Import("math/bigger")
+ if err != nil {
+ t.Fatal(err)
+ }
+ // Even though we open math/big.a, the import request was for math/bigger
+ // and that should be recorded in pkg.Path(), at least for the gc toolchain.
+ if pkg.Path() != "math/bigger" {
+ t.Fatalf("Path() = %q, want %q", pkg.Path(), "math/bigger")
+ }
+ })
+}
diff --git a/src/go/internal/gccgoimporter/ar.go b/src/go/internal/gccgoimporter/ar.go
new file mode 100644
index 0000000..443aa26
--- /dev/null
+++ b/src/go/internal/gccgoimporter/ar.go
@@ -0,0 +1,171 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "bytes"
+ "debug/elf"
+ "errors"
+ "fmt"
+ "internal/xcoff"
+ "io"
+ "strconv"
+ "strings"
+)
+
+// Magic strings for different archive file formats.
+const (
+ armag = "!<arch>\n"
+ armagt = "!<thin>\n"
+ armagb = "<bigaf>\n"
+)
+
+// Offsets and sizes for fields in a standard archive header.
+const (
+ arNameOff = 0
+ arNameSize = 16
+ arDateOff = arNameOff + arNameSize
+ arDateSize = 12
+ arUIDOff = arDateOff + arDateSize
+ arUIDSize = 6
+ arGIDOff = arUIDOff + arUIDSize
+ arGIDSize = 6
+ arModeOff = arGIDOff + arGIDSize
+ arModeSize = 8
+ arSizeOff = arModeOff + arModeSize
+ arSizeSize = 10
+ arFmagOff = arSizeOff + arSizeSize
+ arFmagSize = 2
+
+ arHdrSize = arFmagOff + arFmagSize
+)
+
+// The contents of the fmag field of a standard archive header.
+const arfmag = "`\n"
+
+// arExportData takes an archive file and returns a ReadSeeker for the
+// export data in that file. This assumes that there is only one
+// object in the archive containing export data, which is not quite
+// what gccgo does; gccgo concatenates together all the export data
+// for all the objects in the file. In practice that case does not arise.
+func arExportData(archive io.ReadSeeker) (io.ReadSeeker, error) {
+ if _, err := archive.Seek(0, io.SeekStart); err != nil {
+ return nil, err
+ }
+
+ var buf [len(armag)]byte
+ if _, err := archive.Read(buf[:]); err != nil {
+ return nil, err
+ }
+
+ switch string(buf[:]) {
+ case armag:
+ return standardArExportData(archive)
+ case armagt:
+ return nil, errors.New("unsupported thin archive")
+ case armagb:
+ return aixBigArExportData(archive)
+ default:
+ return nil, fmt.Errorf("unrecognized archive file format %q", buf[:])
+ }
+}
+
+// standardArExportData returns export data from a standard archive.
+func standardArExportData(archive io.ReadSeeker) (io.ReadSeeker, error) {
+ off := int64(len(armag))
+ for {
+ var hdrBuf [arHdrSize]byte
+ if _, err := archive.Read(hdrBuf[:]); err != nil {
+ return nil, err
+ }
+ off += arHdrSize
+
+ if bytes.Compare(hdrBuf[arFmagOff:arFmagOff+arFmagSize], []byte(arfmag)) != 0 {
+ return nil, fmt.Errorf("archive header format header (%q)", hdrBuf[:])
+ }
+
+ size, err := strconv.ParseInt(strings.TrimSpace(string(hdrBuf[arSizeOff:arSizeOff+arSizeSize])), 10, 64)
+ if err != nil {
+ return nil, fmt.Errorf("error parsing size in archive header (%q): %v", hdrBuf[:], err)
+ }
+
+ fn := hdrBuf[arNameOff : arNameOff+arNameSize]
+ if fn[0] == '/' && (fn[1] == ' ' || fn[1] == '/' || bytes.Compare(fn[:8], []byte("/SYM64/ ")) == 0) {
+ // Archive symbol table or extended name table,
+ // which we don't care about.
+ } else {
+ archiveAt := readerAtFromSeeker(archive)
+ ret, err := elfFromAr(io.NewSectionReader(archiveAt, off, size))
+ if ret != nil || err != nil {
+ return ret, err
+ }
+ }
+
+ if size&1 != 0 {
+ size++
+ }
+ off += size
+ if _, err := archive.Seek(off, io.SeekStart); err != nil {
+ return nil, err
+ }
+ }
+}
+
+// elfFromAr tries to get export data from an archive member as an ELF file.
+// If there is no export data, this returns nil, nil.
+func elfFromAr(member *io.SectionReader) (io.ReadSeeker, error) {
+ ef, err := elf.NewFile(member)
+ if err != nil {
+ return nil, err
+ }
+ sec := ef.Section(".go_export")
+ if sec == nil {
+ return nil, nil
+ }
+ return sec.Open(), nil
+}
+
+// aixBigArExportData returns export data from an AIX big archive.
+func aixBigArExportData(archive io.ReadSeeker) (io.ReadSeeker, error) {
+ archiveAt := readerAtFromSeeker(archive)
+ arch, err := xcoff.NewArchive(archiveAt)
+ if err != nil {
+ return nil, err
+ }
+
+ for _, mem := range arch.Members {
+ f, err := arch.GetFile(mem.Name)
+ if err != nil {
+ return nil, err
+ }
+ sdat := f.CSect(".go_export")
+ if sdat != nil {
+ return bytes.NewReader(sdat), nil
+ }
+ }
+
+ return nil, fmt.Errorf(".go_export not found in this archive")
+}
+
+// readerAtFromSeeker turns an io.ReadSeeker into an io.ReaderAt.
+// This is only safe because there won't be any concurrent seeks
+// while this code is executing.
+func readerAtFromSeeker(rs io.ReadSeeker) io.ReaderAt {
+ if ret, ok := rs.(io.ReaderAt); ok {
+ return ret
+ }
+ return seekerReadAt{rs}
+}
+
+type seekerReadAt struct {
+ seeker io.ReadSeeker
+}
+
+func (sra seekerReadAt) ReadAt(p []byte, off int64) (int, error) {
+ if _, err := sra.seeker.Seek(off, io.SeekStart); err != nil {
+ return 0, err
+ }
+ return sra.seeker.Read(p)
+}
diff --git a/src/go/internal/gccgoimporter/gccgoinstallation.go b/src/go/internal/gccgoimporter/gccgoinstallation.go
new file mode 100644
index 0000000..e90a3cc
--- /dev/null
+++ b/src/go/internal/gccgoimporter/gccgoinstallation.go
@@ -0,0 +1,97 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "bufio"
+ "go/types"
+ exec "internal/execabs"
+ "os"
+ "path/filepath"
+ "strings"
+)
+
+// Information about a specific installation of gccgo.
+type GccgoInstallation struct {
+ // Version of gcc (e.g. 4.8.0).
+ GccVersion string
+
+ // Target triple (e.g. x86_64-unknown-linux-gnu).
+ TargetTriple string
+
+ // Built-in library paths used by this installation.
+ LibPaths []string
+}
+
+// Ask the driver at the given path for information for this GccgoInstallation.
+// The given arguments are passed directly to the call of the driver.
+func (inst *GccgoInstallation) InitFromDriver(gccgoPath string, args ...string) (err error) {
+ argv := append([]string{"-###", "-S", "-x", "go", "-"}, args...)
+ cmd := exec.Command(gccgoPath, argv...)
+ stderr, err := cmd.StderrPipe()
+ if err != nil {
+ return
+ }
+
+ err = cmd.Start()
+ if err != nil {
+ return
+ }
+
+ scanner := bufio.NewScanner(stderr)
+ for scanner.Scan() {
+ line := scanner.Text()
+ switch {
+ case strings.HasPrefix(line, "Target: "):
+ inst.TargetTriple = line[8:]
+
+ case line[0] == ' ':
+ args := strings.Fields(line)
+ for _, arg := range args[1:] {
+ if strings.HasPrefix(arg, "-L") {
+ inst.LibPaths = append(inst.LibPaths, arg[2:])
+ }
+ }
+ }
+ }
+
+ argv = append([]string{"-dumpversion"}, args...)
+ stdout, err := exec.Command(gccgoPath, argv...).Output()
+ if err != nil {
+ return
+ }
+ inst.GccVersion = strings.TrimSpace(string(stdout))
+
+ return
+}
+
+// Return the list of export search paths for this GccgoInstallation.
+func (inst *GccgoInstallation) SearchPaths() (paths []string) {
+ for _, lpath := range inst.LibPaths {
+ spath := filepath.Join(lpath, "go", inst.GccVersion)
+ fi, err := os.Stat(spath)
+ if err != nil || !fi.IsDir() {
+ continue
+ }
+ paths = append(paths, spath)
+
+ spath = filepath.Join(spath, inst.TargetTriple)
+ fi, err = os.Stat(spath)
+ if err != nil || !fi.IsDir() {
+ continue
+ }
+ paths = append(paths, spath)
+ }
+
+ paths = append(paths, inst.LibPaths...)
+
+ return
+}
+
+// Return an importer that searches incpaths followed by the gcc installation's
+// built-in search paths and the current directory.
+func (inst *GccgoInstallation) GetImporter(incpaths []string, initmap map[*types.Package]InitData) Importer {
+ return GetImporter(append(append(incpaths, inst.SearchPaths()...), "."), initmap)
+}
diff --git a/src/go/internal/gccgoimporter/gccgoinstallation_test.go b/src/go/internal/gccgoimporter/gccgoinstallation_test.go
new file mode 100644
index 0000000..df0188a
--- /dev/null
+++ b/src/go/internal/gccgoimporter/gccgoinstallation_test.go
@@ -0,0 +1,192 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "go/types"
+ "testing"
+)
+
+// importablePackages is a list of packages that we verify that we can
+// import. This should be all standard library packages in all relevant
+// versions of gccgo. Note that since gccgo follows a different release
+// cycle, and since different systems have different versions installed,
+// we can't use the last-two-versions rule of the gc toolchain.
+var importablePackages = [...]string{
+ "archive/tar",
+ "archive/zip",
+ "bufio",
+ "bytes",
+ "compress/bzip2",
+ "compress/flate",
+ "compress/gzip",
+ "compress/lzw",
+ "compress/zlib",
+ "container/heap",
+ "container/list",
+ "container/ring",
+ "crypto/aes",
+ "crypto/cipher",
+ "crypto/des",
+ "crypto/dsa",
+ "crypto/ecdsa",
+ "crypto/elliptic",
+ "crypto",
+ "crypto/hmac",
+ "crypto/md5",
+ "crypto/rand",
+ "crypto/rc4",
+ "crypto/rsa",
+ "crypto/sha1",
+ "crypto/sha256",
+ "crypto/sha512",
+ "crypto/subtle",
+ "crypto/tls",
+ "crypto/x509",
+ "crypto/x509/pkix",
+ "database/sql/driver",
+ "database/sql",
+ "debug/dwarf",
+ "debug/elf",
+ "debug/gosym",
+ "debug/macho",
+ "debug/pe",
+ "encoding/ascii85",
+ "encoding/asn1",
+ "encoding/base32",
+ "encoding/base64",
+ "encoding/binary",
+ "encoding/csv",
+ "encoding/gob",
+ // "encoding", // Added in GCC 4.9.
+ "encoding/hex",
+ "encoding/json",
+ "encoding/pem",
+ "encoding/xml",
+ "errors",
+ "expvar",
+ "flag",
+ "fmt",
+ "go/ast",
+ "go/build",
+ "go/doc",
+ // "go/format", // Added in GCC 4.8.
+ "go/parser",
+ "go/printer",
+ "go/scanner",
+ "go/token",
+ "hash/adler32",
+ "hash/crc32",
+ "hash/crc64",
+ "hash/fnv",
+ "hash",
+ "html",
+ "html/template",
+ "image/color",
+ // "image/color/palette", // Added in GCC 4.9.
+ "image/draw",
+ "image/gif",
+ "image",
+ "image/jpeg",
+ "image/png",
+ "index/suffixarray",
+ "io",
+ "io/ioutil",
+ "log",
+ "log/syslog",
+ "math/big",
+ "math/cmplx",
+ "math",
+ "math/rand",
+ "mime",
+ "mime/multipart",
+ "net",
+ "net/http/cgi",
+ // "net/http/cookiejar", // Added in GCC 4.8.
+ "net/http/fcgi",
+ "net/http",
+ "net/http/httptest",
+ "net/http/httputil",
+ "net/http/pprof",
+ "net/mail",
+ "net/rpc",
+ "net/rpc/jsonrpc",
+ "net/smtp",
+ "net/textproto",
+ "net/url",
+ "os/exec",
+ "os",
+ "os/signal",
+ "os/user",
+ "path/filepath",
+ "path",
+ "reflect",
+ "regexp",
+ "regexp/syntax",
+ "runtime/debug",
+ "runtime",
+ "runtime/pprof",
+ "sort",
+ "strconv",
+ "strings",
+ "sync/atomic",
+ "sync",
+ "syscall",
+ "testing",
+ "testing/iotest",
+ "testing/quick",
+ "text/scanner",
+ "text/tabwriter",
+ "text/template",
+ "text/template/parse",
+ "time",
+ "unicode",
+ "unicode/utf16",
+ "unicode/utf8",
+}
+
+func TestInstallationImporter(t *testing.T) {
+ // This test relies on gccgo being around.
+ gpath := gccgoPath()
+ if gpath == "" {
+ t.Skip("This test needs gccgo")
+ }
+
+ var inst GccgoInstallation
+ err := inst.InitFromDriver(gpath)
+ if err != nil {
+ t.Fatal(err)
+ }
+ imp := inst.GetImporter(nil, nil)
+
+ // Ensure we don't regress the number of packages we can parse. First import
+ // all packages into the same map and then each individually.
+ pkgMap := make(map[string]*types.Package)
+ for _, pkg := range importablePackages {
+ _, err = imp(pkgMap, pkg, ".", nil)
+ if err != nil {
+ t.Error(err)
+ }
+ }
+
+ for _, pkg := range importablePackages {
+ _, err = imp(make(map[string]*types.Package), pkg, ".", nil)
+ if err != nil {
+ t.Error(err)
+ }
+ }
+
+ // Test for certain specific entities in the imported data.
+ for _, test := range [...]importerTest{
+ {pkgpath: "io", name: "Reader", want: "type Reader interface{Read(p []byte) (n int, err error)}"},
+ {pkgpath: "io", name: "ReadWriter", want: "type ReadWriter interface{Reader; Writer}"},
+ {pkgpath: "math", name: "Pi", want: "const Pi untyped float"},
+ {pkgpath: "math", name: "Sin", want: "func Sin(x float64) float64"},
+ {pkgpath: "sort", name: "Search", want: "func Search(n int, f func(int) bool) int"},
+ {pkgpath: "unsafe", name: "Pointer", want: "type Pointer"},
+ } {
+ runImporterTest(t, imp, nil, &test)
+ }
+}
diff --git a/src/go/internal/gccgoimporter/importer.go b/src/go/internal/gccgoimporter/importer.go
new file mode 100644
index 0000000..94f2def
--- /dev/null
+++ b/src/go/internal/gccgoimporter/importer.go
@@ -0,0 +1,261 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gccgoimporter implements Import for gccgo-generated object files.
+package gccgoimporter // import "go/internal/gccgoimporter"
+
+import (
+ "bytes"
+ "debug/elf"
+ "fmt"
+ "go/types"
+ "internal/xcoff"
+ "io"
+ "os"
+ "path/filepath"
+ "strings"
+)
+
+// A PackageInit describes an imported package that needs initialization.
+type PackageInit struct {
+ Name string // short package name
+ InitFunc string // name of init function
+ Priority int // priority of init function, see InitData.Priority
+}
+
+// The gccgo-specific init data for a package.
+type InitData struct {
+ // Initialization priority of this package relative to other packages.
+ // This is based on the maximum depth of the package's dependency graph;
+ // it is guaranteed to be greater than that of its dependencies.
+ Priority int
+
+ // The list of packages which this package depends on to be initialized,
+ // including itself if needed. This is the subset of the transitive closure of
+ // the package's dependencies that need initialization.
+ Inits []PackageInit
+}
+
+// Locate the file from which to read export data.
+// This is intended to replicate the logic in gofrontend.
+func findExportFile(searchpaths []string, pkgpath string) (string, error) {
+ for _, spath := range searchpaths {
+ pkgfullpath := filepath.Join(spath, pkgpath)
+ pkgdir, name := filepath.Split(pkgfullpath)
+
+ for _, filepath := range [...]string{
+ pkgfullpath,
+ pkgfullpath + ".gox",
+ pkgdir + "lib" + name + ".so",
+ pkgdir + "lib" + name + ".a",
+ pkgfullpath + ".o",
+ } {
+ fi, err := os.Stat(filepath)
+ if err == nil && !fi.IsDir() {
+ return filepath, nil
+ }
+ }
+ }
+
+ return "", fmt.Errorf("%s: could not find export data (tried %s)", pkgpath, strings.Join(searchpaths, ":"))
+}
+
+const (
+ gccgov1Magic = "v1;\n"
+ gccgov2Magic = "v2;\n"
+ gccgov3Magic = "v3;\n"
+ goimporterMagic = "\n$$ "
+ archiveMagic = "!<ar"
+ aixbigafMagic = "<big"
+)
+
+// Opens the export data file at the given path. If this is an ELF file,
+// searches for and opens the .go_export section. If this is an archive,
+// reads the export data from the first member, which is assumed to be an ELF file.
+// This is intended to replicate the logic in gofrontend.
+func openExportFile(fpath string) (reader io.ReadSeeker, closer io.Closer, err error) {
+ f, err := os.Open(fpath)
+ if err != nil {
+ return
+ }
+ closer = f
+ defer func() {
+ if err != nil && closer != nil {
+ f.Close()
+ }
+ }()
+
+ var magic [4]byte
+ _, err = f.ReadAt(magic[:], 0)
+ if err != nil {
+ return
+ }
+
+ var objreader io.ReaderAt
+ switch string(magic[:]) {
+ case gccgov1Magic, gccgov2Magic, gccgov3Magic, goimporterMagic:
+ // Raw export data.
+ reader = f
+ return
+
+ case archiveMagic, aixbigafMagic:
+ reader, err = arExportData(f)
+ return
+
+ default:
+ objreader = f
+ }
+
+ ef, err := elf.NewFile(objreader)
+ if err == nil {
+ sec := ef.Section(".go_export")
+ if sec == nil {
+ err = fmt.Errorf("%s: .go_export section not found", fpath)
+ return
+ }
+ reader = sec.Open()
+ return
+ }
+
+ xf, err := xcoff.NewFile(objreader)
+ if err == nil {
+ sdat := xf.CSect(".go_export")
+ if sdat == nil {
+ err = fmt.Errorf("%s: .go_export section not found", fpath)
+ return
+ }
+ reader = bytes.NewReader(sdat)
+ return
+ }
+
+ err = fmt.Errorf("%s: unrecognized file format", fpath)
+ return
+}
+
+// An Importer resolves import paths to Packages. The imports map records
+// packages already known, indexed by package path.
+// An importer must determine the canonical package path and check imports
+// to see if it is already present in the map. If so, the Importer can return
+// the map entry. Otherwise, the importer must load the package data for the
+// given path into a new *Package, record it in imports map, and return the
+// package.
+type Importer func(imports map[string]*types.Package, path, srcDir string, lookup func(string) (io.ReadCloser, error)) (*types.Package, error)
+
+func GetImporter(searchpaths []string, initmap map[*types.Package]InitData) Importer {
+ return func(imports map[string]*types.Package, pkgpath, srcDir string, lookup func(string) (io.ReadCloser, error)) (pkg *types.Package, err error) {
+ // TODO(gri): Use srcDir.
+ // Or not. It's possible that srcDir will fade in importance as
+ // the go command and other tools provide a translation table
+ // for relative imports (like ./foo or vendored imports).
+ if pkgpath == "unsafe" {
+ return types.Unsafe, nil
+ }
+
+ var reader io.ReadSeeker
+ var fpath string
+ var rc io.ReadCloser
+ if lookup != nil {
+ if p := imports[pkgpath]; p != nil && p.Complete() {
+ return p, nil
+ }
+ rc, err = lookup(pkgpath)
+ if err != nil {
+ return nil, err
+ }
+ }
+ if rc != nil {
+ defer rc.Close()
+ rs, ok := rc.(io.ReadSeeker)
+ if !ok {
+ return nil, fmt.Errorf("gccgo importer requires lookup to return an io.ReadSeeker, have %T", rc)
+ }
+ reader = rs
+ fpath = "<lookup " + pkgpath + ">"
+ // Take name from Name method (like on os.File) if present.
+ if n, ok := rc.(interface{ Name() string }); ok {
+ fpath = n.Name()
+ }
+ } else {
+ fpath, err = findExportFile(searchpaths, pkgpath)
+ if err != nil {
+ return nil, err
+ }
+
+ r, closer, err := openExportFile(fpath)
+ if err != nil {
+ return nil, err
+ }
+ if closer != nil {
+ defer closer.Close()
+ }
+ reader = r
+ }
+
+ var magics string
+ magics, err = readMagic(reader)
+ if err != nil {
+ return
+ }
+
+ if magics == archiveMagic || magics == aixbigafMagic {
+ reader, err = arExportData(reader)
+ if err != nil {
+ return
+ }
+ magics, err = readMagic(reader)
+ if err != nil {
+ return
+ }
+ }
+
+ switch magics {
+ case gccgov1Magic, gccgov2Magic, gccgov3Magic:
+ var p parser
+ p.init(fpath, reader, imports)
+ pkg = p.parsePackage()
+ if initmap != nil {
+ initmap[pkg] = p.initdata
+ }
+
+ // Excluded for now: Standard gccgo doesn't support this import format currently.
+ // case goimporterMagic:
+ // var data []byte
+ // data, err = io.ReadAll(reader)
+ // if err != nil {
+ // return
+ // }
+ // var n int
+ // n, pkg, err = importer.ImportData(imports, data)
+ // if err != nil {
+ // return
+ // }
+
+ // if initmap != nil {
+ // suffixreader := bytes.NewReader(data[n:])
+ // var p parser
+ // p.init(fpath, suffixreader, nil)
+ // p.parseInitData()
+ // initmap[pkg] = p.initdata
+ // }
+
+ default:
+ err = fmt.Errorf("unrecognized magic string: %q", magics)
+ }
+
+ return
+ }
+}
+
+// readMagic reads the four bytes at the start of a ReadSeeker and
+// returns them as a string.
+func readMagic(reader io.ReadSeeker) (string, error) {
+ var magic [4]byte
+ if _, err := reader.Read(magic[:]); err != nil {
+ return "", err
+ }
+ if _, err := reader.Seek(0, io.SeekStart); err != nil {
+ return "", err
+ }
+ return string(magic[:]), nil
+}
diff --git a/src/go/internal/gccgoimporter/importer_test.go b/src/go/internal/gccgoimporter/importer_test.go
new file mode 100644
index 0000000..35240c8
--- /dev/null
+++ b/src/go/internal/gccgoimporter/importer_test.go
@@ -0,0 +1,209 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "go/types"
+ "internal/testenv"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "regexp"
+ "strconv"
+ "testing"
+)
+
+type importerTest struct {
+ pkgpath, name, want, wantval string
+ wantinits []string
+ gccgoVersion int // minimum gccgo version (0 => any)
+}
+
+func runImporterTest(t *testing.T, imp Importer, initmap map[*types.Package]InitData, test *importerTest) {
+ pkg, err := imp(make(map[string]*types.Package), test.pkgpath, ".", nil)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ if test.name != "" {
+ obj := pkg.Scope().Lookup(test.name)
+ if obj == nil {
+ t.Errorf("%s: object not found", test.name)
+ return
+ }
+
+ got := types.ObjectString(obj, types.RelativeTo(pkg))
+ if got != test.want {
+ t.Errorf("%s: got %q; want %q", test.name, got, test.want)
+ }
+
+ if test.wantval != "" {
+ gotval := obj.(*types.Const).Val().String()
+ if gotval != test.wantval {
+ t.Errorf("%s: got val %q; want val %q", test.name, gotval, test.wantval)
+ }
+ }
+ }
+
+ if len(test.wantinits) > 0 {
+ initdata := initmap[pkg]
+ found := false
+ // Check that the package's own init function has the package's priority
+ for _, pkginit := range initdata.Inits {
+ if pkginit.InitFunc == test.wantinits[0] {
+ found = true
+ break
+ }
+ }
+
+ if !found {
+ t.Errorf("%s: could not find expected function %q", test.pkgpath, test.wantinits[0])
+ }
+
+ // FIXME: the original version of this test was written against
+ // the v1 export data scheme for capturing init functions, so it
+ // verified the priority values. We moved away from the priority
+ // scheme some time ago; it is not clear how much work it would be
+ // to validate the new init export data.
+ }
+}
+
+// When adding tests to this list, be sure to set the 'gccgoVersion'
+// field if the testcases uses a "recent" Go addition (ex: aliases).
+var importerTests = [...]importerTest{
+ {pkgpath: "pointer", name: "Int8Ptr", want: "type Int8Ptr *int8"},
+ {pkgpath: "complexnums", name: "NN", want: "const NN untyped complex", wantval: "(-1 + -1i)"},
+ {pkgpath: "complexnums", name: "NP", want: "const NP untyped complex", wantval: "(-1 + 1i)"},
+ {pkgpath: "complexnums", name: "PN", want: "const PN untyped complex", wantval: "(1 + -1i)"},
+ {pkgpath: "complexnums", name: "PP", want: "const PP untyped complex", wantval: "(1 + 1i)"},
+ {pkgpath: "conversions", name: "Bits", want: "const Bits Units", wantval: `"bits"`},
+ {pkgpath: "time", name: "Duration", want: "type Duration int64"},
+ {pkgpath: "time", name: "Nanosecond", want: "const Nanosecond Duration", wantval: "1"},
+ {pkgpath: "unicode", name: "IsUpper", want: "func IsUpper(r rune) bool"},
+ {pkgpath: "unicode", name: "MaxRune", want: "const MaxRune untyped rune", wantval: "1114111"},
+ {pkgpath: "imports", wantinits: []string{"imports..import", "fmt..import"}},
+ {pkgpath: "importsar", name: "Hello", want: "var Hello string"},
+ {pkgpath: "aliases", name: "A14", gccgoVersion: 7, want: "type A14 = func(int, T0) chan T2"},
+ {pkgpath: "aliases", name: "C0", gccgoVersion: 7, want: "type C0 struct{f1 C1; f2 C1}"},
+ {pkgpath: "escapeinfo", name: "NewT", want: "func NewT(data []byte) *T"},
+ {pkgpath: "issue27856", name: "M", gccgoVersion: 7, want: "type M struct{E F}"},
+ {pkgpath: "v1reflect", name: "Type", want: "type Type interface{Align() int; AssignableTo(u Type) bool; Bits() int; ChanDir() ChanDir; Elem() Type; Field(i int) StructField; FieldAlign() int; FieldByIndex(index []int) StructField; FieldByName(name string) (StructField, bool); FieldByNameFunc(match func(string) bool) (StructField, bool); Implements(u Type) bool; In(i int) Type; IsVariadic() bool; Key() Type; Kind() Kind; Len() int; Method(int) Method; MethodByName(string) (Method, bool); Name() string; NumField() int; NumIn() int; NumMethod() int; NumOut() int; Out(i int) Type; PkgPath() string; Size() uintptr; String() string; common() *commonType; rawString() string; runtimeType() *runtimeType; uncommon() *uncommonType}"},
+ {pkgpath: "nointerface", name: "I", want: "type I int"},
+ {pkgpath: "issue29198", name: "FooServer", gccgoVersion: 7, want: "type FooServer struct{FooServer *FooServer; user string; ctx context.Context}"},
+ {pkgpath: "issue30628", name: "Apple", want: "type Apple struct{hey sync.RWMutex; x int; RQ [517]struct{Count uintptr; NumBytes uintptr; Last uintptr}}"},
+ {pkgpath: "issue31540", name: "S", gccgoVersion: 7, want: "type S struct{b int; map[Y]Z}"},
+ {pkgpath: "issue34182", name: "T1", want: "type T1 struct{f *T2}"},
+ {pkgpath: "notinheap", name: "S", want: "type S struct{}"},
+}
+
+func TestGoxImporter(t *testing.T) {
+ testenv.MustHaveExec(t)
+ initmap := make(map[*types.Package]InitData)
+ imp := GetImporter([]string{"testdata"}, initmap)
+
+ for _, test := range importerTests {
+ runImporterTest(t, imp, initmap, &test)
+ }
+}
+
+// gccgoPath returns a path to gccgo if it is present (either in
+// path or specified via GCCGO environment variable), or an
+// empty string if no gccgo is available.
+func gccgoPath() string {
+ gccgoname := os.Getenv("GCCGO")
+ if gccgoname == "" {
+ gccgoname = "gccgo"
+ }
+ if gpath, gerr := exec.LookPath(gccgoname); gerr == nil {
+ return gpath
+ }
+ return ""
+}
+
+func TestObjImporter(t *testing.T) {
+ // This test relies on gccgo being around.
+ gpath := gccgoPath()
+ if gpath == "" {
+ t.Skip("This test needs gccgo")
+ }
+
+ verout, err := exec.Command(gpath, "--version").CombinedOutput()
+ if err != nil {
+ t.Logf("%s", verout)
+ t.Fatal(err)
+ }
+ vers := regexp.MustCompile(`([0-9]+)\.([0-9]+)`).FindSubmatch(verout)
+ if len(vers) == 0 {
+ t.Fatalf("could not find version number in %s", verout)
+ }
+ major, err := strconv.Atoi(string(vers[1]))
+ if err != nil {
+ t.Fatal(err)
+ }
+ minor, err := strconv.Atoi(string(vers[2]))
+ if err != nil {
+ t.Fatal(err)
+ }
+ t.Logf("gccgo version %d.%d", major, minor)
+
+ tmpdir, err := os.MkdirTemp("", "TestObjImporter")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(tmpdir)
+
+ initmap := make(map[*types.Package]InitData)
+ imp := GetImporter([]string{tmpdir}, initmap)
+
+ artmpdir, err := os.MkdirTemp("", "TestObjImporter")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(artmpdir)
+
+ arinitmap := make(map[*types.Package]InitData)
+ arimp := GetImporter([]string{artmpdir}, arinitmap)
+
+ for _, test := range importerTests {
+ if major < test.gccgoVersion {
+ // Support for type aliases was added in GCC 7.
+ t.Logf("skipping %q: not supported before gccgo version %d", test.pkgpath, test.gccgoVersion)
+ continue
+ }
+
+ gofile := filepath.Join("testdata", test.pkgpath+".go")
+ if _, err := os.Stat(gofile); os.IsNotExist(err) {
+ continue
+ }
+ ofile := filepath.Join(tmpdir, test.pkgpath+".o")
+ afile := filepath.Join(artmpdir, "lib"+test.pkgpath+".a")
+
+ cmd := exec.Command(gpath, "-fgo-pkgpath="+test.pkgpath, "-c", "-o", ofile, gofile)
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ t.Logf("%s", out)
+ t.Fatalf("gccgo %s failed: %s", gofile, err)
+ }
+
+ runImporterTest(t, imp, initmap, &test)
+
+ cmd = exec.Command("ar", "cr", afile, ofile)
+ out, err = cmd.CombinedOutput()
+ if err != nil {
+ t.Logf("%s", out)
+ t.Fatalf("ar cr %s %s failed: %s", afile, ofile, err)
+ }
+
+ runImporterTest(t, arimp, arinitmap, &test)
+
+ if err = os.Remove(ofile); err != nil {
+ t.Fatal(err)
+ }
+ if err = os.Remove(afile); err != nil {
+ t.Fatal(err)
+ }
+ }
+}
diff --git a/src/go/internal/gccgoimporter/parser.go b/src/go/internal/gccgoimporter/parser.go
new file mode 100644
index 0000000..1b1d07d
--- /dev/null
+++ b/src/go/internal/gccgoimporter/parser.go
@@ -0,0 +1,1284 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "go/constant"
+ "go/token"
+ "go/types"
+ "io"
+ "strconv"
+ "strings"
+ "text/scanner"
+ "unicode/utf8"
+)
+
+type parser struct {
+ scanner *scanner.Scanner
+ version string // format version
+ tok rune // current token
+ lit string // literal string; only valid for Ident, Int, String tokens
+ pkgpath string // package path of imported package
+ pkgname string // name of imported package
+ pkg *types.Package // reference to imported package
+ imports map[string]*types.Package // package path -> package object
+ typeList []types.Type // type number -> type
+ typeData []string // unparsed type data (v3 and later)
+ fixups []fixupRecord // fixups to apply at end of parsing
+ initdata InitData // package init priority data
+ aliases map[int]string // maps saved type number to alias name
+}
+
+// When reading export data it's possible to encounter a defined type
+// N1 with an underlying defined type N2 while we are still reading in
+// that defined type N2; see issues #29006 and #29198 for instances
+// of this. Example:
+//
+// type N1 N2
+// type N2 struct {
+// ...
+// p *N1
+// }
+//
+// To handle such cases, the parser generates a fixup record (below) and
+// delays setting of N1's underlying type until parsing is complete, at
+// which point fixups are applied.
+
+type fixupRecord struct {
+ toUpdate *types.Named // type to modify when fixup is processed
+ target types.Type // type that was incomplete when fixup was created
+}
+
+func (p *parser) init(filename string, src io.Reader, imports map[string]*types.Package) {
+ p.scanner = new(scanner.Scanner)
+ p.initScanner(filename, src)
+ p.imports = imports
+ p.aliases = make(map[int]string)
+ p.typeList = make([]types.Type, 1 /* type numbers start at 1 */, 16)
+}
+
+func (p *parser) initScanner(filename string, src io.Reader) {
+ p.scanner.Init(src)
+ p.scanner.Error = func(_ *scanner.Scanner, msg string) { p.error(msg) }
+ p.scanner.Mode = scanner.ScanIdents | scanner.ScanInts | scanner.ScanFloats | scanner.ScanStrings
+ p.scanner.Whitespace = 1<<'\t' | 1<<' '
+ p.scanner.Filename = filename // for good error messages
+ p.next()
+}
+
+type importError struct {
+ pos scanner.Position
+ err error
+}
+
+func (e importError) Error() string {
+ return fmt.Sprintf("import error %s (byte offset = %d): %s", e.pos, e.pos.Offset, e.err)
+}
+
+func (p *parser) error(err interface{}) {
+ if s, ok := err.(string); ok {
+ err = errors.New(s)
+ }
+ // panic with a runtime.Error if err is not an error
+ panic(importError{p.scanner.Pos(), err.(error)})
+}
+
+func (p *parser) errorf(format string, args ...interface{}) {
+ p.error(fmt.Errorf(format, args...))
+}
+
+func (p *parser) expect(tok rune) string {
+ lit := p.lit
+ if p.tok != tok {
+ p.errorf("expected %s, got %s (%s)", scanner.TokenString(tok), scanner.TokenString(p.tok), lit)
+ }
+ p.next()
+ return lit
+}
+
+func (p *parser) expectEOL() {
+ if p.version == "v1" || p.version == "v2" {
+ p.expect(';')
+ }
+ p.expect('\n')
+}
+
+func (p *parser) expectKeyword(keyword string) {
+ lit := p.expect(scanner.Ident)
+ if lit != keyword {
+ p.errorf("expected keyword %s, got %q", keyword, lit)
+ }
+}
+
+func (p *parser) parseString() string {
+ str, err := strconv.Unquote(p.expect(scanner.String))
+ if err != nil {
+ p.error(err)
+ }
+ return str
+}
+
+// unquotedString = { unquotedStringChar } .
+// unquotedStringChar = <neither a whitespace nor a ';' char> .
+func (p *parser) parseUnquotedString() string {
+ if p.tok == scanner.EOF {
+ p.error("unexpected EOF")
+ }
+ var buf bytes.Buffer
+ buf.WriteString(p.scanner.TokenText())
+ // This loop needs to examine each character before deciding whether to consume it. If we see a semicolon,
+ // we need to let it be consumed by p.next().
+ for ch := p.scanner.Peek(); ch != '\n' && ch != ';' && ch != scanner.EOF && p.scanner.Whitespace&(1<<uint(ch)) == 0; ch = p.scanner.Peek() {
+ buf.WriteRune(ch)
+ p.scanner.Next()
+ }
+ p.next()
+ return buf.String()
+}
+
+func (p *parser) next() {
+ p.tok = p.scanner.Scan()
+ switch p.tok {
+ case scanner.Ident, scanner.Int, scanner.Float, scanner.String, '·':
+ p.lit = p.scanner.TokenText()
+ default:
+ p.lit = ""
+ }
+}
+
+func (p *parser) parseQualifiedName() (path, name string) {
+ return p.parseQualifiedNameStr(p.parseString())
+}
+
+func (p *parser) parseUnquotedQualifiedName() (path, name string) {
+ return p.parseQualifiedNameStr(p.parseUnquotedString())
+}
+
+// qualifiedName = [ ["."] unquotedString "." ] unquotedString .
+//
+// The above production uses greedy matching.
+func (p *parser) parseQualifiedNameStr(unquotedName string) (pkgpath, name string) {
+ parts := strings.Split(unquotedName, ".")
+ if parts[0] == "" {
+ parts = parts[1:]
+ }
+
+ switch len(parts) {
+ case 0:
+ p.errorf("malformed qualified name: %q", unquotedName)
+ case 1:
+ // unqualified name
+ pkgpath = p.pkgpath
+ name = parts[0]
+ default:
+ // qualified name, which may contain periods
+ pkgpath = strings.Join(parts[0:len(parts)-1], ".")
+ name = parts[len(parts)-1]
+ }
+
+ return
+}
+
+// getPkg returns the package for a given path. If the package is
+// not found but we have a package name, create the package and
+// add it to the p.imports map.
+//
+func (p *parser) getPkg(pkgpath, name string) *types.Package {
+ // package unsafe is not in the imports map - handle explicitly
+ if pkgpath == "unsafe" {
+ return types.Unsafe
+ }
+ pkg := p.imports[pkgpath]
+ if pkg == nil && name != "" {
+ pkg = types.NewPackage(pkgpath, name)
+ p.imports[pkgpath] = pkg
+ }
+ return pkg
+}
+
+// parseExportedName is like parseQualifiedName, but
+// the package path is resolved to an imported *types.Package.
+//
+// ExportedName = string [string] .
+func (p *parser) parseExportedName() (pkg *types.Package, name string) {
+ path, name := p.parseQualifiedName()
+ var pkgname string
+ if p.tok == scanner.String {
+ pkgname = p.parseString()
+ }
+ pkg = p.getPkg(path, pkgname)
+ if pkg == nil {
+ p.errorf("package %s (path = %q) not found", name, path)
+ }
+ return
+}
+
+// Name = QualifiedName | "?" .
+func (p *parser) parseName() string {
+ if p.tok == '?' {
+ // Anonymous.
+ p.next()
+ return ""
+ }
+ // The package path is redundant for us. Don't try to parse it.
+ _, name := p.parseUnquotedQualifiedName()
+ return name
+}
+
+func deref(typ types.Type) types.Type {
+ if p, _ := typ.(*types.Pointer); p != nil {
+ typ = p.Elem()
+ }
+ return typ
+}
+
+// Field = Name Type [string] .
+func (p *parser) parseField(pkg *types.Package) (field *types.Var, tag string) {
+ name := p.parseName()
+ typ, n := p.parseTypeExtended(pkg)
+ anon := false
+ if name == "" {
+ anon = true
+ // Alias?
+ if aname, ok := p.aliases[n]; ok {
+ name = aname
+ } else {
+ switch typ := deref(typ).(type) {
+ case *types.Basic:
+ name = typ.Name()
+ case *types.Named:
+ name = typ.Obj().Name()
+ default:
+ p.error("embedded field expected")
+ }
+ }
+ }
+ field = types.NewField(token.NoPos, pkg, name, typ, anon)
+ if p.tok == scanner.String {
+ tag = p.parseString()
+ }
+ return
+}
+
+// Param = Name ["..."] Type .
+func (p *parser) parseParam(pkg *types.Package) (param *types.Var, isVariadic bool) {
+ name := p.parseName()
+ // Ignore names invented for inlinable functions.
+ if strings.HasPrefix(name, "p.") || strings.HasPrefix(name, "r.") || strings.HasPrefix(name, "$ret") {
+ name = ""
+ }
+ if p.tok == '<' && p.scanner.Peek() == 'e' {
+ // EscInfo = "<esc:" int ">" . (optional and ignored)
+ p.next()
+ p.expectKeyword("esc")
+ p.expect(':')
+ p.expect(scanner.Int)
+ p.expect('>')
+ }
+ if p.tok == '.' {
+ p.next()
+ p.expect('.')
+ p.expect('.')
+ isVariadic = true
+ }
+ typ := p.parseType(pkg)
+ if isVariadic {
+ typ = types.NewSlice(typ)
+ }
+ param = types.NewParam(token.NoPos, pkg, name, typ)
+ return
+}
+
+// Var = Name Type .
+func (p *parser) parseVar(pkg *types.Package) *types.Var {
+ name := p.parseName()
+ v := types.NewVar(token.NoPos, pkg, name, p.parseType(pkg))
+ if name[0] == '.' || name[0] == '<' {
+ // This is an unexported variable,
+ // or a variable defined in a different package.
+ // We only want to record exported variables.
+ return nil
+ }
+ return v
+}
+
+// Conversion = "convert" "(" Type "," ConstValue ")" .
+func (p *parser) parseConversion(pkg *types.Package) (val constant.Value, typ types.Type) {
+ p.expectKeyword("convert")
+ p.expect('(')
+ typ = p.parseType(pkg)
+ p.expect(',')
+ val, _ = p.parseConstValue(pkg)
+ p.expect(')')
+ return
+}
+
+// ConstValue = string | "false" | "true" | ["-"] (int ["'"] | FloatOrComplex) | Conversion .
+// FloatOrComplex = float ["i" | ("+"|"-") float "i"] .
+func (p *parser) parseConstValue(pkg *types.Package) (val constant.Value, typ types.Type) {
+ // v3 changed to $false, $true, $convert, to avoid confusion
+ // with variable names in inline function bodies.
+ if p.tok == '$' {
+ p.next()
+ if p.tok != scanner.Ident {
+ p.errorf("expected identifier after '$', got %s (%q)", scanner.TokenString(p.tok), p.lit)
+ }
+ }
+
+ switch p.tok {
+ case scanner.String:
+ str := p.parseString()
+ val = constant.MakeString(str)
+ typ = types.Typ[types.UntypedString]
+ return
+
+ case scanner.Ident:
+ b := false
+ switch p.lit {
+ case "false":
+ case "true":
+ b = true
+
+ case "convert":
+ return p.parseConversion(pkg)
+
+ default:
+ p.errorf("expected const value, got %s (%q)", scanner.TokenString(p.tok), p.lit)
+ }
+
+ p.next()
+ val = constant.MakeBool(b)
+ typ = types.Typ[types.UntypedBool]
+ return
+ }
+
+ sign := ""
+ if p.tok == '-' {
+ p.next()
+ sign = "-"
+ }
+
+ switch p.tok {
+ case scanner.Int:
+ val = constant.MakeFromLiteral(sign+p.lit, token.INT, 0)
+ if val == nil {
+ p.error("could not parse integer literal")
+ }
+
+ p.next()
+ if p.tok == '\'' {
+ p.next()
+ typ = types.Typ[types.UntypedRune]
+ } else {
+ typ = types.Typ[types.UntypedInt]
+ }
+
+ case scanner.Float:
+ re := sign + p.lit
+ p.next()
+
+ var im string
+ switch p.tok {
+ case '+':
+ p.next()
+ im = p.expect(scanner.Float)
+
+ case '-':
+ p.next()
+ im = "-" + p.expect(scanner.Float)
+
+ case scanner.Ident:
+ // re is in fact the imaginary component. Expect "i" below.
+ im = re
+ re = "0"
+
+ default:
+ val = constant.MakeFromLiteral(re, token.FLOAT, 0)
+ if val == nil {
+ p.error("could not parse float literal")
+ }
+ typ = types.Typ[types.UntypedFloat]
+ return
+ }
+
+ p.expectKeyword("i")
+ reval := constant.MakeFromLiteral(re, token.FLOAT, 0)
+ if reval == nil {
+ p.error("could not parse real component of complex literal")
+ }
+ imval := constant.MakeFromLiteral(im+"i", token.IMAG, 0)
+ if imval == nil {
+ p.error("could not parse imag component of complex literal")
+ }
+ val = constant.BinaryOp(reval, token.ADD, imval)
+ typ = types.Typ[types.UntypedComplex]
+
+ default:
+ p.errorf("expected const value, got %s (%q)", scanner.TokenString(p.tok), p.lit)
+ }
+
+ return
+}
+
+// Const = Name [Type] "=" ConstValue .
+func (p *parser) parseConst(pkg *types.Package) *types.Const {
+ name := p.parseName()
+ var typ types.Type
+ if p.tok == '<' {
+ typ = p.parseType(pkg)
+ }
+ p.expect('=')
+ val, vtyp := p.parseConstValue(pkg)
+ if typ == nil {
+ typ = vtyp
+ }
+ return types.NewConst(token.NoPos, pkg, name, typ, val)
+}
+
+// reserved is a singleton type used to fill type map slots that have
+// been reserved (i.e., for which a type number has been parsed) but
+// which don't have their actual type yet. When the type map is updated,
+// the actual type must replace a reserved entry (or we have an internal
+// error). Used for self-verification only - not required for correctness.
+var reserved = new(struct{ types.Type })
+
+// reserve reserves the type map entry n for future use.
+func (p *parser) reserve(n int) {
+ // Notes:
+ // - for pre-V3 export data, the type numbers we see are
+ // guaranteed to be in increasing order, so we append a
+ // reserved entry onto the list.
+ // - for V3+ export data, type numbers can appear in
+ // any order, however the 'types' section tells us the
+ // total number of types, hence typeList is pre-allocated.
+ if len(p.typeData) == 0 {
+ if n != len(p.typeList) {
+ p.errorf("invalid type number %d (out of sync)", n)
+ }
+ p.typeList = append(p.typeList, reserved)
+ } else {
+ if p.typeList[n] != nil {
+ p.errorf("previously visited type number %d", n)
+ }
+ p.typeList[n] = reserved
+ }
+}
+
+// update sets the type map entries for the entries in nlist to t.
+// An entry in nlist can be a type number in p.typeList,
+// used to resolve named types, or it can be a *types.Pointer,
+// used to resolve pointers to named types in case they are referenced
+// by embedded fields.
+func (p *parser) update(t types.Type, nlist []interface{}) {
+ if t == reserved {
+ p.errorf("internal error: update(%v) invoked on reserved", nlist)
+ }
+ if t == nil {
+ p.errorf("internal error: update(%v) invoked on nil", nlist)
+ }
+ for _, n := range nlist {
+ switch n := n.(type) {
+ case int:
+ if p.typeList[n] == t {
+ continue
+ }
+ if p.typeList[n] != reserved {
+ p.errorf("internal error: update(%v): %d not reserved", nlist, n)
+ }
+ p.typeList[n] = t
+ case *types.Pointer:
+ if *n != (types.Pointer{}) {
+ elem := n.Elem()
+ if elem == t {
+ continue
+ }
+ p.errorf("internal error: update: pointer already set to %v, expected %v", elem, t)
+ }
+ *n = *types.NewPointer(t)
+ default:
+ p.errorf("internal error: %T on nlist", n)
+ }
+ }
+}
+
+// NamedType = TypeName [ "=" ] Type { Method } .
+// TypeName = ExportedName .
+// Method = "func" "(" Param ")" Name ParamList ResultList [InlineBody] ";" .
+func (p *parser) parseNamedType(nlist []interface{}) types.Type {
+ pkg, name := p.parseExportedName()
+ scope := pkg.Scope()
+ obj := scope.Lookup(name)
+ if obj != nil && obj.Type() == nil {
+ p.errorf("%v has nil type", obj)
+ }
+
+ if p.tok == scanner.Ident && p.lit == "notinheap" {
+ p.next()
+ // The go/types package has no way of recording that
+ // this type is marked notinheap. Presumably no user
+ // of this package actually cares.
+ }
+
+ // type alias
+ if p.tok == '=' {
+ p.next()
+ p.aliases[nlist[len(nlist)-1].(int)] = name
+ if obj != nil {
+ // use the previously imported (canonical) type
+ t := obj.Type()
+ p.update(t, nlist)
+ p.parseType(pkg) // discard
+ return t
+ }
+ t := p.parseType(pkg, nlist...)
+ obj = types.NewTypeName(token.NoPos, pkg, name, t)
+ scope.Insert(obj)
+ return t
+ }
+
+ // defined type
+ if obj == nil {
+ // A named type may be referred to before the underlying type
+ // is known - set it up.
+ tname := types.NewTypeName(token.NoPos, pkg, name, nil)
+ types.NewNamed(tname, nil, nil)
+ scope.Insert(tname)
+ obj = tname
+ }
+
+ // use the previously imported (canonical), or newly created type
+ t := obj.Type()
+ p.update(t, nlist)
+
+ nt, ok := t.(*types.Named)
+ if !ok {
+ // This can happen for unsafe.Pointer, which is a TypeName holding a Basic type.
+ pt := p.parseType(pkg)
+ if pt != t {
+ p.error("unexpected underlying type for non-named TypeName")
+ }
+ return t
+ }
+
+ underlying := p.parseType(pkg)
+ if nt.Underlying() == nil {
+ if underlying.Underlying() == nil {
+ fix := fixupRecord{toUpdate: nt, target: underlying}
+ p.fixups = append(p.fixups, fix)
+ } else {
+ nt.SetUnderlying(underlying.Underlying())
+ }
+ }
+
+ if p.tok == '\n' {
+ p.next()
+ // collect associated methods
+ for p.tok == scanner.Ident {
+ p.expectKeyword("func")
+ if p.tok == '/' {
+ // Skip a /*nointerface*/ or /*asm ID */ comment.
+ p.expect('/')
+ p.expect('*')
+ if p.expect(scanner.Ident) == "asm" {
+ p.parseUnquotedString()
+ }
+ p.expect('*')
+ p.expect('/')
+ }
+ p.expect('(')
+ receiver, _ := p.parseParam(pkg)
+ p.expect(')')
+ name := p.parseName()
+ params, isVariadic := p.parseParamList(pkg)
+ results := p.parseResultList(pkg)
+ p.skipInlineBody()
+ p.expectEOL()
+
+ sig := types.NewSignature(receiver, params, results, isVariadic)
+ nt.AddMethod(types.NewFunc(token.NoPos, pkg, name, sig))
+ }
+ }
+
+ return nt
+}
+
+func (p *parser) parseInt64() int64 {
+ lit := p.expect(scanner.Int)
+ n, err := strconv.ParseInt(lit, 10, 64)
+ if err != nil {
+ p.error(err)
+ }
+ return n
+}
+
+func (p *parser) parseInt() int {
+ lit := p.expect(scanner.Int)
+ n, err := strconv.ParseInt(lit, 10, 0 /* int */)
+ if err != nil {
+ p.error(err)
+ }
+ return int(n)
+}
+
+// ArrayOrSliceType = "[" [ int ] "]" Type .
+func (p *parser) parseArrayOrSliceType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expect('[')
+ if p.tok == ']' {
+ p.next()
+
+ t := new(types.Slice)
+ p.update(t, nlist)
+
+ *t = *types.NewSlice(p.parseType(pkg))
+ return t
+ }
+
+ t := new(types.Array)
+ p.update(t, nlist)
+
+ len := p.parseInt64()
+ p.expect(']')
+
+ *t = *types.NewArray(p.parseType(pkg), len)
+ return t
+}
+
+// MapType = "map" "[" Type "]" Type .
+func (p *parser) parseMapType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expectKeyword("map")
+
+ t := new(types.Map)
+ p.update(t, nlist)
+
+ p.expect('[')
+ key := p.parseType(pkg)
+ p.expect(']')
+ elem := p.parseType(pkg)
+
+ *t = *types.NewMap(key, elem)
+ return t
+}
+
+// ChanType = "chan" ["<-" | "-<"] Type .
+func (p *parser) parseChanType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expectKeyword("chan")
+
+ t := new(types.Chan)
+ p.update(t, nlist)
+
+ dir := types.SendRecv
+ switch p.tok {
+ case '-':
+ p.next()
+ p.expect('<')
+ dir = types.SendOnly
+
+ case '<':
+ // don't consume '<' if it belongs to Type
+ if p.scanner.Peek() == '-' {
+ p.next()
+ p.expect('-')
+ dir = types.RecvOnly
+ }
+ }
+
+ *t = *types.NewChan(dir, p.parseType(pkg))
+ return t
+}
+
+// StructType = "struct" "{" { Field } "}" .
+func (p *parser) parseStructType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expectKeyword("struct")
+
+ t := new(types.Struct)
+ p.update(t, nlist)
+
+ var fields []*types.Var
+ var tags []string
+
+ p.expect('{')
+ for p.tok != '}' && p.tok != scanner.EOF {
+ field, tag := p.parseField(pkg)
+ p.expect(';')
+ fields = append(fields, field)
+ tags = append(tags, tag)
+ }
+ p.expect('}')
+
+ *t = *types.NewStruct(fields, tags)
+ return t
+}
+
+// ParamList = "(" [ { Parameter "," } Parameter ] ")" .
+func (p *parser) parseParamList(pkg *types.Package) (*types.Tuple, bool) {
+ var list []*types.Var
+ isVariadic := false
+
+ p.expect('(')
+ for p.tok != ')' && p.tok != scanner.EOF {
+ if len(list) > 0 {
+ p.expect(',')
+ }
+ par, variadic := p.parseParam(pkg)
+ list = append(list, par)
+ if variadic {
+ if isVariadic {
+ p.error("... not on final argument")
+ }
+ isVariadic = true
+ }
+ }
+ p.expect(')')
+
+ return types.NewTuple(list...), isVariadic
+}
+
+// ResultList = Type | ParamList .
+func (p *parser) parseResultList(pkg *types.Package) *types.Tuple {
+ switch p.tok {
+ case '<':
+ p.next()
+ if p.tok == scanner.Ident && p.lit == "inl" {
+ return nil
+ }
+ taa, _ := p.parseTypeAfterAngle(pkg)
+ return types.NewTuple(types.NewParam(token.NoPos, pkg, "", taa))
+
+ case '(':
+ params, _ := p.parseParamList(pkg)
+ return params
+
+ default:
+ return nil
+ }
+}
+
+// FunctionType = ParamList ResultList .
+func (p *parser) parseFunctionType(pkg *types.Package, nlist []interface{}) *types.Signature {
+ t := new(types.Signature)
+ p.update(t, nlist)
+
+ params, isVariadic := p.parseParamList(pkg)
+ results := p.parseResultList(pkg)
+
+ *t = *types.NewSignature(nil, params, results, isVariadic)
+ return t
+}
+
+// Func = Name FunctionType [InlineBody] .
+func (p *parser) parseFunc(pkg *types.Package) *types.Func {
+ if p.tok == '/' {
+ // Skip an /*asm ID */ comment.
+ p.expect('/')
+ p.expect('*')
+ if p.expect(scanner.Ident) == "asm" {
+ p.parseUnquotedString()
+ }
+ p.expect('*')
+ p.expect('/')
+ }
+
+ name := p.parseName()
+ f := types.NewFunc(token.NoPos, pkg, name, p.parseFunctionType(pkg, nil))
+ p.skipInlineBody()
+
+ if name[0] == '.' || name[0] == '<' || strings.ContainsRune(name, '$') {
+ // This is an unexported function,
+ // or a function defined in a different package,
+ // or a type$equal or type$hash function.
+ // We only want to record exported functions.
+ return nil
+ }
+
+ return f
+}
+
+// InterfaceType = "interface" "{" { ("?" Type | Func) ";" } "}" .
+func (p *parser) parseInterfaceType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expectKeyword("interface")
+
+ t := new(types.Interface)
+ p.update(t, nlist)
+
+ var methods []*types.Func
+ var embeddeds []types.Type
+
+ p.expect('{')
+ for p.tok != '}' && p.tok != scanner.EOF {
+ if p.tok == '?' {
+ p.next()
+ embeddeds = append(embeddeds, p.parseType(pkg))
+ } else {
+ method := p.parseFunc(pkg)
+ if method != nil {
+ methods = append(methods, method)
+ }
+ }
+ p.expect(';')
+ }
+ p.expect('}')
+
+ *t = *types.NewInterfaceType(methods, embeddeds)
+ return t
+}
+
+// PointerType = "*" ("any" | Type) .
+func (p *parser) parsePointerType(pkg *types.Package, nlist []interface{}) types.Type {
+ p.expect('*')
+ if p.tok == scanner.Ident {
+ p.expectKeyword("any")
+ t := types.Typ[types.UnsafePointer]
+ p.update(t, nlist)
+ return t
+ }
+
+ t := new(types.Pointer)
+ p.update(t, nlist)
+
+ *t = *types.NewPointer(p.parseType(pkg, t))
+
+ return t
+}
+
+// TypeSpec = NamedType | MapType | ChanType | StructType | InterfaceType | PointerType | ArrayOrSliceType | FunctionType .
+func (p *parser) parseTypeSpec(pkg *types.Package, nlist []interface{}) types.Type {
+ switch p.tok {
+ case scanner.String:
+ return p.parseNamedType(nlist)
+
+ case scanner.Ident:
+ switch p.lit {
+ case "map":
+ return p.parseMapType(pkg, nlist)
+
+ case "chan":
+ return p.parseChanType(pkg, nlist)
+
+ case "struct":
+ return p.parseStructType(pkg, nlist)
+
+ case "interface":
+ return p.parseInterfaceType(pkg, nlist)
+ }
+
+ case '*':
+ return p.parsePointerType(pkg, nlist)
+
+ case '[':
+ return p.parseArrayOrSliceType(pkg, nlist)
+
+ case '(':
+ return p.parseFunctionType(pkg, nlist)
+ }
+
+ p.errorf("expected type name or literal, got %s", scanner.TokenString(p.tok))
+ return nil
+}
+
+const (
+ // From gofrontend/go/export.h
+ // Note that these values are negative in the gofrontend and have been made positive
+ // in the gccgoimporter.
+ gccgoBuiltinINT8 = 1
+ gccgoBuiltinINT16 = 2
+ gccgoBuiltinINT32 = 3
+ gccgoBuiltinINT64 = 4
+ gccgoBuiltinUINT8 = 5
+ gccgoBuiltinUINT16 = 6
+ gccgoBuiltinUINT32 = 7
+ gccgoBuiltinUINT64 = 8
+ gccgoBuiltinFLOAT32 = 9
+ gccgoBuiltinFLOAT64 = 10
+ gccgoBuiltinINT = 11
+ gccgoBuiltinUINT = 12
+ gccgoBuiltinUINTPTR = 13
+ gccgoBuiltinBOOL = 15
+ gccgoBuiltinSTRING = 16
+ gccgoBuiltinCOMPLEX64 = 17
+ gccgoBuiltinCOMPLEX128 = 18
+ gccgoBuiltinERROR = 19
+ gccgoBuiltinBYTE = 20
+ gccgoBuiltinRUNE = 21
+)
+
+func lookupBuiltinType(typ int) types.Type {
+ return [...]types.Type{
+ gccgoBuiltinINT8: types.Typ[types.Int8],
+ gccgoBuiltinINT16: types.Typ[types.Int16],
+ gccgoBuiltinINT32: types.Typ[types.Int32],
+ gccgoBuiltinINT64: types.Typ[types.Int64],
+ gccgoBuiltinUINT8: types.Typ[types.Uint8],
+ gccgoBuiltinUINT16: types.Typ[types.Uint16],
+ gccgoBuiltinUINT32: types.Typ[types.Uint32],
+ gccgoBuiltinUINT64: types.Typ[types.Uint64],
+ gccgoBuiltinFLOAT32: types.Typ[types.Float32],
+ gccgoBuiltinFLOAT64: types.Typ[types.Float64],
+ gccgoBuiltinINT: types.Typ[types.Int],
+ gccgoBuiltinUINT: types.Typ[types.Uint],
+ gccgoBuiltinUINTPTR: types.Typ[types.Uintptr],
+ gccgoBuiltinBOOL: types.Typ[types.Bool],
+ gccgoBuiltinSTRING: types.Typ[types.String],
+ gccgoBuiltinCOMPLEX64: types.Typ[types.Complex64],
+ gccgoBuiltinCOMPLEX128: types.Typ[types.Complex128],
+ gccgoBuiltinERROR: types.Universe.Lookup("error").Type(),
+ gccgoBuiltinBYTE: types.Universe.Lookup("byte").Type(),
+ gccgoBuiltinRUNE: types.Universe.Lookup("rune").Type(),
+ }[typ]
+}
+
+// Type = "<" "type" ( "-" int | int [ TypeSpec ] ) ">" .
+//
+// parseType updates the type map to t for all type numbers n.
+//
+func (p *parser) parseType(pkg *types.Package, n ...interface{}) types.Type {
+ p.expect('<')
+ t, _ := p.parseTypeAfterAngle(pkg, n...)
+ return t
+}
+
+// (*parser).Type after reading the "<".
+func (p *parser) parseTypeAfterAngle(pkg *types.Package, n ...interface{}) (t types.Type, n1 int) {
+ p.expectKeyword("type")
+
+ n1 = 0
+ switch p.tok {
+ case scanner.Int:
+ n1 = p.parseInt()
+ if p.tok == '>' {
+ if len(p.typeData) > 0 && p.typeList[n1] == nil {
+ p.parseSavedType(pkg, n1, n)
+ }
+ t = p.typeList[n1]
+ if len(p.typeData) == 0 && t == reserved {
+ p.errorf("invalid type cycle, type %d not yet defined (nlist=%v)", n1, n)
+ }
+ p.update(t, n)
+ } else {
+ p.reserve(n1)
+ t = p.parseTypeSpec(pkg, append(n, n1))
+ }
+
+ case '-':
+ p.next()
+ n1 := p.parseInt()
+ t = lookupBuiltinType(n1)
+ p.update(t, n)
+
+ default:
+ p.errorf("expected type number, got %s (%q)", scanner.TokenString(p.tok), p.lit)
+ return nil, 0
+ }
+
+ if t == nil || t == reserved {
+ p.errorf("internal error: bad return from parseType(%v)", n)
+ }
+
+ p.expect('>')
+ return
+}
+
+// parseTypeExtended is identical to parseType, but if the type in
+// question is a saved type, returns the index as well as the type
+// pointer (index returned is zero if we parsed a builtin).
+func (p *parser) parseTypeExtended(pkg *types.Package, n ...interface{}) (t types.Type, n1 int) {
+ p.expect('<')
+ t, n1 = p.parseTypeAfterAngle(pkg, n...)
+ return
+}
+
+// InlineBody = "<inl:NN>" .{NN}
+// Reports whether a body was skipped.
+func (p *parser) skipInlineBody() {
+ // We may or may not have seen the '<' already, depending on
+ // whether the function had a result type or not.
+ if p.tok == '<' {
+ p.next()
+ p.expectKeyword("inl")
+ } else if p.tok != scanner.Ident || p.lit != "inl" {
+ return
+ } else {
+ p.next()
+ }
+
+ p.expect(':')
+ want := p.parseInt()
+ p.expect('>')
+
+ defer func(w uint64) {
+ p.scanner.Whitespace = w
+ }(p.scanner.Whitespace)
+ p.scanner.Whitespace = 0
+
+ got := 0
+ for got < want {
+ r := p.scanner.Next()
+ if r == scanner.EOF {
+ p.error("unexpected EOF")
+ }
+ got += utf8.RuneLen(r)
+ }
+}
+
+// Types = "types" maxp1 exportedp1 (offset length)* .
+func (p *parser) parseTypes(pkg *types.Package) {
+ maxp1 := p.parseInt()
+ exportedp1 := p.parseInt()
+ p.typeList = make([]types.Type, maxp1, maxp1)
+
+ type typeOffset struct {
+ offset int
+ length int
+ }
+ var typeOffsets []typeOffset
+
+ total := 0
+ for i := 1; i < maxp1; i++ {
+ len := p.parseInt()
+ typeOffsets = append(typeOffsets, typeOffset{total, len})
+ total += len
+ }
+
+ defer func(w uint64) {
+ p.scanner.Whitespace = w
+ }(p.scanner.Whitespace)
+ p.scanner.Whitespace = 0
+
+ // We should now have p.tok pointing to the final newline.
+ // The next runes from the scanner should be the type data.
+
+ var sb strings.Builder
+ for sb.Len() < total {
+ r := p.scanner.Next()
+ if r == scanner.EOF {
+ p.error("unexpected EOF")
+ }
+ sb.WriteRune(r)
+ }
+ allTypeData := sb.String()
+
+ p.typeData = []string{""} // type 0, unused
+ for _, to := range typeOffsets {
+ p.typeData = append(p.typeData, allTypeData[to.offset:to.offset+to.length])
+ }
+
+ for i := 1; i < int(exportedp1); i++ {
+ p.parseSavedType(pkg, i, nil)
+ }
+}
+
+// parseSavedType parses one saved type definition.
+func (p *parser) parseSavedType(pkg *types.Package, i int, nlist []interface{}) {
+ defer func(s *scanner.Scanner, tok rune, lit string) {
+ p.scanner = s
+ p.tok = tok
+ p.lit = lit
+ }(p.scanner, p.tok, p.lit)
+
+ p.scanner = new(scanner.Scanner)
+ p.initScanner(p.scanner.Filename, strings.NewReader(p.typeData[i]))
+ p.expectKeyword("type")
+ id := p.parseInt()
+ if id != i {
+ p.errorf("type ID mismatch: got %d, want %d", id, i)
+ }
+ if p.typeList[i] == reserved {
+ p.errorf("internal error: %d already reserved in parseSavedType", i)
+ }
+ if p.typeList[i] == nil {
+ p.reserve(i)
+ p.parseTypeSpec(pkg, append(nlist, i))
+ }
+ if p.typeList[i] == nil || p.typeList[i] == reserved {
+ p.errorf("internal error: parseSavedType(%d,%v) reserved/nil", i, nlist)
+ }
+}
+
+// PackageInit = unquotedString unquotedString int .
+func (p *parser) parsePackageInit() PackageInit {
+ name := p.parseUnquotedString()
+ initfunc := p.parseUnquotedString()
+ priority := -1
+ if p.version == "v1" {
+ priority = p.parseInt()
+ }
+ return PackageInit{Name: name, InitFunc: initfunc, Priority: priority}
+}
+
+// Create the package if we have parsed both the package path and package name.
+func (p *parser) maybeCreatePackage() {
+ if p.pkgname != "" && p.pkgpath != "" {
+ p.pkg = p.getPkg(p.pkgpath, p.pkgname)
+ }
+}
+
+// InitDataDirective = ( "v1" | "v2" | "v3" ) ";" |
+// "priority" int ";" |
+// "init" { PackageInit } ";" |
+// "checksum" unquotedString ";" .
+func (p *parser) parseInitDataDirective() {
+ if p.tok != scanner.Ident {
+ // unexpected token kind; panic
+ p.expect(scanner.Ident)
+ }
+
+ switch p.lit {
+ case "v1", "v2", "v3":
+ p.version = p.lit
+ p.next()
+ p.expect(';')
+ p.expect('\n')
+
+ case "priority":
+ p.next()
+ p.initdata.Priority = p.parseInt()
+ p.expectEOL()
+
+ case "init":
+ p.next()
+ for p.tok != '\n' && p.tok != ';' && p.tok != scanner.EOF {
+ p.initdata.Inits = append(p.initdata.Inits, p.parsePackageInit())
+ }
+ p.expectEOL()
+
+ case "init_graph":
+ p.next()
+ // The graph data is thrown away for now.
+ for p.tok != '\n' && p.tok != ';' && p.tok != scanner.EOF {
+ p.parseInt64()
+ p.parseInt64()
+ }
+ p.expectEOL()
+
+ case "checksum":
+ // Don't let the scanner try to parse the checksum as a number.
+ defer func(mode uint) {
+ p.scanner.Mode = mode
+ }(p.scanner.Mode)
+ p.scanner.Mode &^= scanner.ScanInts | scanner.ScanFloats
+ p.next()
+ p.parseUnquotedString()
+ p.expectEOL()
+
+ default:
+ p.errorf("unexpected identifier: %q", p.lit)
+ }
+}
+
+// Directive = InitDataDirective |
+// "package" unquotedString [ unquotedString ] [ unquotedString ] ";" |
+// "pkgpath" unquotedString ";" |
+// "prefix" unquotedString ";" |
+// "import" unquotedString unquotedString string ";" |
+// "indirectimport" unquotedString unquotedstring ";" |
+// "func" Func ";" |
+// "type" Type ";" |
+// "var" Var ";" |
+// "const" Const ";" .
+func (p *parser) parseDirective() {
+ if p.tok != scanner.Ident {
+ // unexpected token kind; panic
+ p.expect(scanner.Ident)
+ }
+
+ switch p.lit {
+ case "v1", "v2", "v3", "priority", "init", "init_graph", "checksum":
+ p.parseInitDataDirective()
+
+ case "package":
+ p.next()
+ p.pkgname = p.parseUnquotedString()
+ p.maybeCreatePackage()
+ if p.version != "v1" && p.tok != '\n' && p.tok != ';' {
+ p.parseUnquotedString()
+ p.parseUnquotedString()
+ }
+ p.expectEOL()
+
+ case "pkgpath":
+ p.next()
+ p.pkgpath = p.parseUnquotedString()
+ p.maybeCreatePackage()
+ p.expectEOL()
+
+ case "prefix":
+ p.next()
+ p.pkgpath = p.parseUnquotedString()
+ p.expectEOL()
+
+ case "import":
+ p.next()
+ pkgname := p.parseUnquotedString()
+ pkgpath := p.parseUnquotedString()
+ p.getPkg(pkgpath, pkgname)
+ p.parseString()
+ p.expectEOL()
+
+ case "indirectimport":
+ p.next()
+ pkgname := p.parseUnquotedString()
+ pkgpath := p.parseUnquotedString()
+ p.getPkg(pkgpath, pkgname)
+ p.expectEOL()
+
+ case "types":
+ p.next()
+ p.parseTypes(p.pkg)
+ p.expectEOL()
+
+ case "func":
+ p.next()
+ fun := p.parseFunc(p.pkg)
+ if fun != nil {
+ p.pkg.Scope().Insert(fun)
+ }
+ p.expectEOL()
+
+ case "type":
+ p.next()
+ p.parseType(p.pkg)
+ p.expectEOL()
+
+ case "var":
+ p.next()
+ v := p.parseVar(p.pkg)
+ if v != nil {
+ p.pkg.Scope().Insert(v)
+ }
+ p.expectEOL()
+
+ case "const":
+ p.next()
+ c := p.parseConst(p.pkg)
+ p.pkg.Scope().Insert(c)
+ p.expectEOL()
+
+ default:
+ p.errorf("unexpected identifier: %q", p.lit)
+ }
+}
+
+// Package = { Directive } .
+func (p *parser) parsePackage() *types.Package {
+ for p.tok != scanner.EOF {
+ p.parseDirective()
+ }
+ for _, f := range p.fixups {
+ if f.target.Underlying() == nil {
+ p.errorf("internal error: fixup can't be applied, loop required")
+ }
+ f.toUpdate.SetUnderlying(f.target.Underlying())
+ }
+ p.fixups = nil
+ for _, typ := range p.typeList {
+ if it, ok := typ.(*types.Interface); ok {
+ it.Complete()
+ }
+ }
+ p.pkg.MarkComplete()
+ return p.pkg
+}
diff --git a/src/go/internal/gccgoimporter/parser_test.go b/src/go/internal/gccgoimporter/parser_test.go
new file mode 100644
index 0000000..00128b4
--- /dev/null
+++ b/src/go/internal/gccgoimporter/parser_test.go
@@ -0,0 +1,78 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gccgoimporter
+
+import (
+ "bytes"
+ "go/types"
+ "strings"
+ "testing"
+ "text/scanner"
+)
+
+var typeParserTests = []struct {
+ id, typ, want, underlying, methods string
+}{
+ {id: "foo", typ: "<type -1>", want: "int8"},
+ {id: "foo", typ: "<type 1 *<type -19>>", want: "*error"},
+ {id: "foo", typ: "<type 1 *any>", want: "unsafe.Pointer"},
+ {id: "foo", typ: "<type 1 \"Bar\" <type 2 *<type 1>>>", want: "foo.Bar", underlying: "*foo.Bar"},
+ {id: "foo", typ: "<type 1 \"bar.Foo\" \"bar\" <type -1>\nfunc (? <type 1>) M ();\n>", want: "bar.Foo", underlying: "int8", methods: "func (bar.Foo).M()"},
+ {id: "foo", typ: "<type 1 \".bar.foo\" \"bar\" <type -1>>", want: "bar.foo", underlying: "int8"},
+ {id: "foo", typ: "<type 1 []<type -1>>", want: "[]int8"},
+ {id: "foo", typ: "<type 1 [42]<type -1>>", want: "[42]int8"},
+ {id: "foo", typ: "<type 1 map [<type -1>] <type -2>>", want: "map[int8]int16"},
+ {id: "foo", typ: "<type 1 chan <type -1>>", want: "chan int8"},
+ {id: "foo", typ: "<type 1 chan <- <type -1>>", want: "<-chan int8"},
+ {id: "foo", typ: "<type 1 chan -< <type -1>>", want: "chan<- int8"},
+ {id: "foo", typ: "<type 1 struct { I8 <type -1>; I16 <type -2> \"i16\"; }>", want: "struct{I8 int8; I16 int16 \"i16\"}"},
+ {id: "foo", typ: "<type 1 interface { Foo (a <type -1>, b <type -2>) <type -1>; Bar (? <type -2>, ? ...<type -1>) (? <type -2>, ? <type -1>); Baz (); }>", want: "interface{Bar(int16, ...int8) (int16, int8); Baz(); Foo(a int8, b int16) int8}"},
+ {id: "foo", typ: "<type 1 (? <type -1>) <type -2>>", want: "func(int8) int16"},
+}
+
+func TestTypeParser(t *testing.T) {
+ for _, test := range typeParserTests {
+ var p parser
+ p.init("test.gox", strings.NewReader(test.typ), make(map[string]*types.Package))
+ p.version = "v2"
+ p.pkgname = test.id
+ p.pkgpath = test.id
+ p.maybeCreatePackage()
+ typ := p.parseType(p.pkg)
+
+ if p.tok != scanner.EOF {
+ t.Errorf("expected full parse, stopped at %q", p.lit)
+ }
+
+ // interfaces must be explicitly completed
+ if ityp, _ := typ.(*types.Interface); ityp != nil {
+ ityp.Complete()
+ }
+
+ got := typ.String()
+ if got != test.want {
+ t.Errorf("got type %q, expected %q", got, test.want)
+ }
+
+ if test.underlying != "" {
+ underlying := typ.Underlying().String()
+ if underlying != test.underlying {
+ t.Errorf("got underlying type %q, expected %q", underlying, test.underlying)
+ }
+ }
+
+ if test.methods != "" {
+ nt := typ.(*types.Named)
+ var buf bytes.Buffer
+ for i := 0; i != nt.NumMethods(); i++ {
+ buf.WriteString(nt.Method(i).String())
+ }
+ methods := buf.String()
+ if methods != test.methods {
+ t.Errorf("got methods %q, expected %q", methods, test.methods)
+ }
+ }
+ }
+}
diff --git a/src/go/internal/gccgoimporter/testdata/aliases.go b/src/go/internal/gccgoimporter/testdata/aliases.go
new file mode 100644
index 0000000..cfb59b3
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/aliases.go
@@ -0,0 +1,65 @@
+package aliases
+
+type (
+ T0 [10]int
+ T1 []byte
+ T2 struct {
+ x int
+ }
+ T3 interface {
+ m() T2
+ }
+ T4 func(int, T0) chan T2
+)
+
+// basic aliases
+type (
+ Ai = int
+ A0 = T0
+ A1 = T1
+ A2 = T2
+ A3 = T3
+ A4 = T4
+
+ A10 = [10]int
+ A11 = []byte
+ A12 = struct {
+ x int
+ }
+ A13 = interface {
+ m() A2
+ }
+ A14 = func(int, A0) chan A2
+)
+
+// alias receiver types
+func (T0) m1() {}
+func (A0) m2() {}
+
+// alias receiver types (long type declaration chains)
+type (
+ V0 = V1
+ V1 = (V2)
+ V2 = (V3)
+ V3 = T0
+)
+
+func (V1) n() {}
+
+// cycles
+type C0 struct {
+ f1 C1
+ f2 C2
+}
+
+type (
+ C1 *C0
+ C2 = C1
+)
+
+type (
+ C5 struct {
+ f *C6
+ }
+ C6 = C5
+)
diff --git a/src/go/internal/gccgoimporter/testdata/aliases.gox b/src/go/internal/gccgoimporter/testdata/aliases.gox
new file mode 100644
index 0000000..2428c06
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/aliases.gox
@@ -0,0 +1,33 @@
+v2;
+package aliases;
+prefix go;
+package aliases go.aliases go.aliases;
+type <type 1 "A0" = <type 2 "T0" <type 3 [10 ] <type -11>>
+ func (? <esc:0x1> <type 2>) .go.aliases.m1 ();
+ func (? <esc:0x1> <type 1>) .go.aliases.m2 ();
+ func (? <esc:0x1> <type 4 "V1" = <type 5 "V2" = <type 6 "V3" = <type 2>>>>) .go.aliases.n ();
+>>;
+type <type 7 "A1" = <type 8 "T1" <type 9 [] <type -20>>>>;
+type <type 10 "A10" = <type 11 [10 ] <type -11>>>;
+type <type 12 "A11" = <type 13 [] <type -20>>>;
+type <type 14 "A12" = <type 15 struct { .go.aliases.x <type -11>; }>>;
+type <type 16 "A13" = <type 17 interface { .go.aliases.m () <type 18 "A2" = <type 19 "T2" <type 20 struct { .go.aliases.x <type -11>; }>>>; }>>;
+type <type 21 "A14" = <type 22 (? <type -11>, ? <type 1>) <type 23 chan <type 18>>>>;
+type <type 18>;
+type <type 24 "A3" = <type 25 "T3" <type 26 interface { .go.aliases.m () <type 19>; }>>>;
+type <type 27 "A4" = <type 28 "T4" <type 29 (? <type -11>, ? <type 2>) <type 30 chan <type 19>>>>>;
+type <type 31 "Ai" = <type -11>>;
+type <type 32 "C0" <type 33 struct { .go.aliases.f1 <type 34 "C1" <type 35 *<type 32>>>; .go.aliases.f2 <type 36 "C2" = <type 34>>; }>>;
+type <type 34>;
+type <type 36>;
+type <type 37 "C5" <type 38 struct { .go.aliases.f <type 39 *<type 40 "C6" = <type 37>>>; }>>;
+type <type 40>;
+type <type 2>;
+type <type 8>;
+type <type 19>;
+type <type 25>;
+type <type 28>;
+type <type 41 "V0" = <type 4>>;
+type <type 4>;
+type <type 5>;
+type <type 6>;
diff --git a/src/go/internal/gccgoimporter/testdata/complexnums.go b/src/go/internal/gccgoimporter/testdata/complexnums.go
new file mode 100644
index 0000000..a51b6b0
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/complexnums.go
@@ -0,0 +1,6 @@
+package complexnums
+
+const NN = -1 - 1i
+const NP = -1 + 1i
+const PN = 1 - 1i
+const PP = 1 + 1i
diff --git a/src/go/internal/gccgoimporter/testdata/complexnums.gox b/src/go/internal/gccgoimporter/testdata/complexnums.gox
new file mode 100644
index 0000000..b66524f
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/complexnums.gox
@@ -0,0 +1,8 @@
+v1;
+package complexnums;
+pkgpath complexnums;
+priority 1;
+const NN = -0.1E1-0.1E1i ;
+const NP = -0.1E1+0.1E1i ;
+const PN = 0.1E1-0.1E1i ;
+const PP = 0.1E1+0.1E1i ;
diff --git a/src/go/internal/gccgoimporter/testdata/conversions.go b/src/go/internal/gccgoimporter/testdata/conversions.go
new file mode 100644
index 0000000..653927a
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/conversions.go
@@ -0,0 +1,5 @@
+package conversions
+
+type Units string
+
+const Bits = Units("bits")
diff --git a/src/go/internal/gccgoimporter/testdata/conversions.gox b/src/go/internal/gccgoimporter/testdata/conversions.gox
new file mode 100644
index 0000000..7de6cda
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/conversions.gox
@@ -0,0 +1,6 @@
+v2;
+package conversions;
+prefix go;
+package conversions go.conversions go.conversions;
+const Bits <type 1 "Units" <type -16>> = convert(<type 1>, "bits");
+type <type 1>;
diff --git a/src/go/internal/gccgoimporter/testdata/escapeinfo.go b/src/go/internal/gccgoimporter/testdata/escapeinfo.go
new file mode 100644
index 0000000..103ad95
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/escapeinfo.go
@@ -0,0 +1,13 @@
+// Test case for escape info in export data. To compile and extract .gox file:
+// gccgo -fgo-optimize-allocs -c escapeinfo.go
+// objcopy -j .go_export escapeinfo.o escapeinfo.gox
+
+package escapeinfo
+
+type T struct{ data []byte }
+
+func NewT(data []byte) *T {
+ return &T{data}
+}
+
+func (*T) Read(p []byte) {}
diff --git a/src/go/internal/gccgoimporter/testdata/escapeinfo.gox b/src/go/internal/gccgoimporter/testdata/escapeinfo.gox
new file mode 100644
index 0000000..1db8156
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/escapeinfo.gox
Binary files differ
diff --git a/src/go/internal/gccgoimporter/testdata/imports.go b/src/go/internal/gccgoimporter/testdata/imports.go
new file mode 100644
index 0000000..7907316
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/imports.go
@@ -0,0 +1,5 @@
+package imports
+
+import "fmt"
+
+var Hello = fmt.Sprintf("Hello, world")
diff --git a/src/go/internal/gccgoimporter/testdata/imports.gox b/src/go/internal/gccgoimporter/testdata/imports.gox
new file mode 100644
index 0000000..958a4f5
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/imports.gox
@@ -0,0 +1,7 @@
+v1;
+package imports;
+pkgpath imports;
+priority 7;
+import fmt fmt "fmt";
+init imports imports..import 7 math math..import 1 runtime runtime..import 1 strconv strconv..import 2 io io..import 3 reflect reflect..import 3 syscall syscall..import 3 time time..import 4 os os..import 5 fmt fmt..import 6;
+var Hello <type -16>;
diff --git a/src/go/internal/gccgoimporter/testdata/issue27856.go b/src/go/internal/gccgoimporter/testdata/issue27856.go
new file mode 100644
index 0000000..bf361e1
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue27856.go
@@ -0,0 +1,9 @@
+package lib
+
+type M struct {
+ E E
+}
+type F struct {
+ _ *M
+}
+type E = F
diff --git a/src/go/internal/gccgoimporter/testdata/issue27856.gox b/src/go/internal/gccgoimporter/testdata/issue27856.gox
new file mode 100644
index 0000000..6665e64
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue27856.gox
@@ -0,0 +1,9 @@
+v2;
+package main;
+pkgpath main;
+import runtime runtime "runtime";
+init runtime runtime..import sys runtime_internal_sys..import;
+init_graph 0 1;
+type <type 1 "E" = <type 2 "F" <type 3 struct { .main._ <type 4 *<type 5 "M" <type 6 struct { E <type 1>; }>>>; }>>>;
+type <type 2>;
+type <type 5>;
diff --git a/src/go/internal/gccgoimporter/testdata/issue29198.go b/src/go/internal/gccgoimporter/testdata/issue29198.go
new file mode 100644
index 0000000..75c2162
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue29198.go
@@ -0,0 +1,37 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package server
+
+import (
+ "context"
+ "errors"
+)
+
+type A struct {
+ x int
+}
+
+func (a *A) AMethod(y int) *Server {
+ return nil
+}
+
+// FooServer is a server that provides Foo services
+type FooServer Server
+
+func (f *FooServer) WriteEvents(ctx context.Context, x int) error {
+ return errors.New("hey!")
+}
+
+type Server struct {
+ FooServer *FooServer
+ user string
+ ctx context.Context
+}
+
+func New(sctx context.Context, u string) (*Server, error) {
+ s := &Server{user: u, ctx: sctx}
+ s.FooServer = (*FooServer)(s)
+ return s, nil
+}
diff --git a/src/go/internal/gccgoimporter/testdata/issue29198.gox b/src/go/internal/gccgoimporter/testdata/issue29198.gox
new file mode 100644
index 0000000..905c866
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue29198.gox
@@ -0,0 +1,86 @@
+v2;
+package server;
+pkgpath issue29198;
+import context context "context";
+import errors errors "errors";
+init context context..import fmt fmt..import poll internal_poll..import testlog internal_testlog..import io io..import os os..import reflect reflect..import runtime runtime..import sys runtime_internal_sys..import strconv strconv..import sync sync..import syscall syscall..import time time..import unicode unicode..import;
+init_graph 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 11 0 12 0 13 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 1 13 2 4 2 7 2 8 2 10 2 11 2 12 4 7 4 8 4 10 5 2 5 3 5 4 5 7 5 8 5 10 5 11 5 12 6 7 6 8 6 9 6 10 6 13 7 8 9 7 9 8 10 7 10 8 11 7 11 8 11 10 12 7 12 8 12 10 12 11;
+type <type 1 "A" <type 2 struct { .issue29198.x <type -11>; }>
+ func (a <esc:0x1> <type 3 *<type 1>>) AMethod (y <type -11>) <type 4 *<type 5 "Server" <type 6 struct { FooServer <type 7 *<type 8 "FooServer" <type 5>
+ func (f <esc:0x1> <type 9 *<type 8>>) WriteEvents (ctx <esc:0x1> <type 10 "context.Context" <type 11 interface { Deadline () (deadline <type 12 "time.Time" "time" <type 13 struct { .time.wall <type -8>; .time.ext <type -4>; .time.loc <type 14 *<type 15 "time.Location" <type 16 struct { .time.name <type -16>; .time.zone <type 17 [] <type 18 ".time.zone" <type 19 struct { .time.name <type -16>; .time.offset <type -11>; .time.isDST <type -15>; }>>>; .time.tx <type 20 [] <type 21 ".time.zoneTrans" <type 22 struct { .time.when <type -4>; .time.index <type -5>; .time.isstd <type -15>; .time.isutc <type -15>; }>>>; .time.cacheStart <type -4>; .time.cacheEnd <type -4>; .time.cacheZone <type 23 *<type 18>>; }>
+ func (l <esc:0x22> <type 24 *<type 15>>) String () <type -16>;
+ func (l <esc:0x1> <type 24>) .time.lookupFirstZone () <type -11>;
+ func (l <esc:0x12> <type 24>) .time.get () <type 24>;
+ func (l <esc:0x32> <type 24>) .time.lookup (sec <type -4>) (name <type -16>, offset <type -11>, isDST <type -15>, start <type -4>, end <type -4>);
+ func (l <esc:0x1> <type 24>) .time.lookupName (name <esc:0x1> <type -16>, unix <type -4>) (offset <type -11>, ok <type -15>);
+ func (l <esc:0x1> <type 24>) .time.firstZoneUsed () <type -15>;
+>>; }>
+ func (t <esc:0x12> <type 12>) In (loc <type 14>) <type 12>;
+ func (t <esc:0x1> <type 12>) .time.date (full <type -15>) (year <type -11>, month <type 25 "time.Month" <type -11>
+ func (m <type 25>) String () <type -16>;
+>, day <type -11>, yday <type -11>);
+ func (t <esc:0x1> <type 12>) Sub (u <esc:0x1> <type 12>) <type 26 "time.Duration" <type -4>
+ func (d <type 26>) Truncate (m <type 26>) <type 26>;
+ func (d <type 26>) String () <type -16>;
+ func (d <type 26>) Round (m <type 26>) <type 26>;
+ func (d <type 26>) Seconds () <type -10>;
+ func (d <type 26>) Nanoseconds () <type -4>;
+ func (d <type 26>) Minutes () <type -10>;
+ func (d <type 26>) Hours () <type -10>;
+>;
+ func (t <esc:0x12> <type 12>) Add (d <type 26>) <type 12>;
+ func (t <esc:0x12> <type 12>) UTC () <type 12>;
+ func (t <type 12>) AddDate (years <type -11>, months <type -11>, days <type -11>) <type 12>;
+ func (t <esc:0x1> <type 12>) MarshalBinary () (? <type 27 [] <type -20>>, ? <type -19>);
+ func (t <esc:0x1> <type 12>) Nanosecond () <type -11>;
+ func (t <esc:0x12> <type 12>) Round (d <type 26>) <type 12>;
+ func (t <esc:0x1> <type 12>) Minute () <type -11>;
+ func (t <esc:0x1> <type 12>) Clock () (hour <type -11>, min <type -11>, sec <type -11>);
+ func (t <esc:0x1> <type 12>) ISOWeek () (year <type -11>, week <type -11>);
+ func (t <esc:0x1> <type 12>) Day () <type -11>;
+ func (t <esc:0x1> <type 28 *<type 12>>) .time.mono () <type -4>;
+ func (t <esc:0x1> <type 12>) UnixNano () <type -4>;
+ func (t <esc:0x1> <type 28>) .time.sec () <type -4>;
+ func (t <esc:0x1> <type 12>) Second () <type -11>;
+ func (t <esc:0x1> <type 12>) Before (u <esc:0x1> <type 12>) <type -15>;
+ func (t <esc:0x1> <type 28>) UnmarshalBinary (data <esc:0x1> <type 29 [] <type -20>>) <type -19>;
+ func (t <esc:0x1> <type 12>) Month () <type 25>;
+ func (t <esc:0x1> <type 12>) YearDay () <type -11>;
+ func (t <esc:0x12> <type 12>) Location () <type 14>;
+ func (t <esc:0x32> <type 12>) Zone () (name <type -16>, offset <type -11>);
+ func (t <esc:0x12> <type 12>) Local () <type 12>;
+ func (t <esc:0x1> <type 28>) .time.setLoc (loc <type 14>);
+ func (t <esc:0x12> <type 12>) Truncate (d <type 26>) <type 12>;
+ func (t <esc:0x1> <type 12>) MarshalJSON () (? <type 30 [] <type -20>>, ? <type -19>);
+ func (t <esc:0x1> <type 12>) AppendFormat (b <esc:0x12> <type 31 [] <type -20>>, layout <esc:0x1> <type -16>) <type 32 [] <type -20>>;
+ func (t <esc:0x1> <type 28>) GobDecode (data <esc:0x1> <type 33 [] <type -20>>) <type -19>;
+ func (t <esc:0x1> <type 28>) UnmarshalJSON (data <esc:0x1> <type 34 [] <type -20>>) <type -19>;
+ func (t <esc:0x1> <type 12>) MarshalText () (? <type 35 [] <type -20>>, ? <type -19>);
+ func (t <esc:0x1> <type 12>) GobEncode () (? <type 36 [] <type -20>>, ? <type -19>);
+ func (t <esc:0x1> <type 28>) .time.stripMono ();
+ func (t <esc:0x1> <type 12>) After (u <esc:0x1> <type 12>) <type -15>;
+ func (t <esc:0x1> <type 12>) Hour () <type -11>;
+ func (t <esc:0x1> <type 28>) UnmarshalText (data <esc:0x1> <type 37 [] <type -20>>) <type -19>;
+ func (t <esc:0x1> <type 12>) Equal (u <esc:0x1> <type 12>) <type -15>;
+ func (t <esc:0x1> <type 28>) .time.setMono (m <type -4>);
+ func (t <esc:0x1> <type 12>) Year () <type -11>;
+ func (t <esc:0x1> <type 12>) IsZero () <type -15>;
+ func (t <esc:0x1> <type 28>) .time.addSec (d <type -4>);
+ func (t <esc:0x1> <type 12>) Weekday () <type 38 "time.Weekday" <type -11>
+ func (d <type 38>) String () <type -16>;
+>;
+ func (t <esc:0x1> <type 12>) String () <type -16>;
+ func (t <esc:0x1> <type 28>) .time.nsec () <type -3>;
+ func (t <esc:0x1> <type 12>) Format (layout <esc:0x1> <type -16>) <type -16>;
+ func (t <esc:0x1> <type 28>) .time.unixSec () <type -4>;
+ func (t <esc:0x1> <type 12>) Unix () <type -4>;
+ func (t <esc:0x1> <type 12>) .time.abs () <type -8>;
+ func (t <esc:0x32> <type 12>) .time.locabs () (name <type -16>, offset <type -11>, abs <type -8>);
+ func (t <esc:0x1> <type 12>) Date () (year <type -11>, month <type 25>, day <type -11>);
+>, ok <type -15>); Done () <type 39 chan <- <type 40 struct { }>>; Err () <type -19>; Value (key <type 41 interface { }>) <type 42 interface { }>; }>>, x <type -11>) <type -19>;
+>>; .issue29198.user <type -16>; .issue29198.ctx <type 10>; }>>>;
+>;
+type <type 8>;
+func New (sctx <type 10>, u <type -16>) (? <type 43 *<type 5>>, ? <type -19>);
+type <type 5>;
+checksum 86C8D76B2582F55A8BD2CA9E00060358EC1CE214;
diff --git a/src/go/internal/gccgoimporter/testdata/issue30628.go b/src/go/internal/gccgoimporter/testdata/issue30628.go
new file mode 100644
index 0000000..8fd7c13
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue30628.go
@@ -0,0 +1,18 @@
+package issue30628
+
+import (
+ "os"
+ "sync"
+)
+
+const numR = int32(os.O_TRUNC + 5)
+
+type Apple struct {
+ hey sync.RWMutex
+ x int
+ RQ [numR]struct {
+ Count uintptr
+ NumBytes uintptr
+ Last uintptr
+ }
+}
diff --git a/src/go/internal/gccgoimporter/testdata/issue30628.gox b/src/go/internal/gccgoimporter/testdata/issue30628.gox
new file mode 100644
index 0000000..0ff6259
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue30628.gox
@@ -0,0 +1,28 @@
+v3;
+package issue30628
+pkgpath issue30628
+import os os "os"
+import sync sync "sync"
+init cpu internal..z2fcpu..import poll internal..z2fpoll..import testlog internal..z2ftestlog..import io io..import os os..import runtime runtime..import sys runtime..z2finternal..z2fsys..import sync sync..import syscall syscall..import time time..import
+init_graph 1 0 1 3 1 5 1 6 1 7 1 8 1 9 3 0 3 5 3 6 3 7 4 0 4 1 4 2 4 3 4 5 4 6 4 7 4 8 4 9 5 0 5 6 7 0 7 5 7 6 8 0 8 5 8 6 8 7 9 0 9 5 9 6 9 7 9 8
+types 13 2 24 84 208 17 30 41 147 86 17 64 25 75
+type 1 "Apple" <type 2>
+type 2 struct { .issue30628.hey <type 3>; .issue30628.x <type -11>; RQ <type 11>; }
+type 3 "sync.RWMutex" <type 7>
+ func (rw <type 4>) Lock ()
+ func (rw <esc:0x12> <type 4>) RLocker () ($ret8 <type 5>)
+ func (rw <type 4>) RUnlock ()
+ func (rw <type 4>) Unlock ()
+ func (rw <type 4>) RLock ()
+type 4 *<type 3>
+type 5 "sync.Locker" <type 6>
+type 6 interface { Lock (); Unlock (); }
+type 7 struct { .sync.w <type 8>; .sync.writerSem <type -7>; .sync.readerSem <type -7>; .sync.readerCount <type -3>; .sync.readerWait <type -3>; }
+type 8 "sync.Mutex" <type 10>
+ func (m <type 9>) Unlock ()
+ func (m <type 9>) Lock ()
+type 9 *<type 8>
+type 10 struct { .sync.state <type -3>; .sync.sema <type -7>; }
+type 11 [517 ] <type 12>
+type 12 struct { Count <type -13>; NumBytes <type -13>; Last <type -13>; }
+checksum 199DCF6D3EE2FCF39F715B4E42B5F87F5B15D3AF
diff --git a/src/go/internal/gccgoimporter/testdata/issue31540.go b/src/go/internal/gccgoimporter/testdata/issue31540.go
new file mode 100644
index 0000000..2c6799e
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue31540.go
@@ -0,0 +1,26 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue31540
+
+type Y struct {
+ q int
+}
+
+type Z map[int]int
+
+type X = map[Y]Z
+
+type A1 = X
+
+type A2 = A1
+
+type S struct {
+ b int
+ A2
+}
+
+func Hallo() S {
+ return S{}
+}
diff --git a/src/go/internal/gccgoimporter/testdata/issue31540.gox b/src/go/internal/gccgoimporter/testdata/issue31540.gox
new file mode 100644
index 0000000..abdc696
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue31540.gox
@@ -0,0 +1,16 @@
+v3;
+package issue31540
+pkgpath issue31540
+types 11 7 23 23 20 22 20 21 57 31 45 36
+type 1 "A1" = <type 4>
+type 2 "A2" = <type 1>
+type 3 "S" <type 7>
+type 4 "X" = <type 8>
+type 5 "Y" <type 9>
+type 6 "Z" <type 10>
+type 7 struct { .go.mapalias.b <type -11>; ? <type 2>; }
+type 8 map [<type 5>] <type 6>
+type 9 struct { .go.mapalias.q <type -11>; }
+type 10 map [<type -11>] <type -11>
+func Hallo () <type 3>
+checksum C3FAF2524A90BC11225EE65D059BF27DFB69134B
diff --git a/src/go/internal/gccgoimporter/testdata/issue34182.go b/src/go/internal/gccgoimporter/testdata/issue34182.go
new file mode 100644
index 0000000..2a5c333
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue34182.go
@@ -0,0 +1,17 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue34182
+
+type T1 struct {
+ f *T2
+}
+
+type T2 struct {
+ f T3
+}
+
+type T3 struct {
+ *T2
+}
diff --git a/src/go/internal/gccgoimporter/testdata/issue34182.gox b/src/go/internal/gccgoimporter/testdata/issue34182.gox
new file mode 100644
index 0000000..671a7d6
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/issue34182.gox
@@ -0,0 +1,13 @@
+v3;
+package issue34182
+pkgpath issue34182
+init issue34182 ~go.issue34182
+types 8 4 21 21 21 17 30 45 45
+type 1 "T1" <type 6>
+type 2 "T2" <type 7>
+type 3 "T3" <type 5>
+type 4 *<type 2>
+type 5 struct { ? <type 4>; }
+type 6 struct { .go.issue34182.f <type 4>; }
+type 7 struct { .go.issue34182.f <type 3>; }
+checksum FF02C49BAF44B06C087ED4E573F7CC880C79C208
diff --git a/src/go/internal/gccgoimporter/testdata/libimportsar.a b/src/go/internal/gccgoimporter/testdata/libimportsar.a
new file mode 100644
index 0000000..6f30758
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/libimportsar.a
Binary files differ
diff --git a/src/go/internal/gccgoimporter/testdata/nointerface.go b/src/go/internal/gccgoimporter/testdata/nointerface.go
new file mode 100644
index 0000000..6a545f2
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/nointerface.go
@@ -0,0 +1,12 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package nointerface
+
+type I int
+
+//go:nointerface
+func (p *I) Get() int { return int(*p) }
+
+func (p *I) Set(v int) { *p = I(v) }
diff --git a/src/go/internal/gccgoimporter/testdata/nointerface.gox b/src/go/internal/gccgoimporter/testdata/nointerface.gox
new file mode 100644
index 0000000..7b73d17
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/nointerface.gox
@@ -0,0 +1,8 @@
+v3;
+package nointerface
+pkgpath nointerface
+types 3 2 133 17
+type 1 "I" <type -11>
+ func /*nointerface*/ (p <esc:0x1> <type 2>) Get () <type -11>
+ func (p <esc:0x1> <type 2>) Set (v <type -11>)
+type 2 *<type 1>
diff --git a/src/go/internal/gccgoimporter/testdata/notinheap.go b/src/go/internal/gccgoimporter/testdata/notinheap.go
new file mode 100644
index 0000000..b1ac967
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/notinheap.go
@@ -0,0 +1,4 @@
+package notinheap
+
+//go:notinheap
+type S struct{}
diff --git a/src/go/internal/gccgoimporter/testdata/notinheap.gox b/src/go/internal/gccgoimporter/testdata/notinheap.gox
new file mode 100644
index 0000000..cc438e7
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/notinheap.gox
@@ -0,0 +1,7 @@
+v3;
+package notinheap
+pkgpath notinheap
+init notinheap ~notinheap
+types 3 2 30 18
+type 1 "S" notinheap <type 2>
+type 2 struct { }
diff --git a/src/go/internal/gccgoimporter/testdata/pointer.go b/src/go/internal/gccgoimporter/testdata/pointer.go
new file mode 100644
index 0000000..4ebc671
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/pointer.go
@@ -0,0 +1,3 @@
+package pointer
+
+type Int8Ptr *int8
diff --git a/src/go/internal/gccgoimporter/testdata/pointer.gox b/src/go/internal/gccgoimporter/testdata/pointer.gox
new file mode 100644
index 0000000..d96ebbd
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/pointer.gox
@@ -0,0 +1,4 @@
+v1;
+package pointer;
+pkgpath pointer;
+type <type 1 "Int8Ptr" <type 2 *<type -1>>>;
diff --git a/src/go/internal/gccgoimporter/testdata/time.gox b/src/go/internal/gccgoimporter/testdata/time.gox
new file mode 100644
index 0000000..80c2dbc
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/time.gox
Binary files differ
diff --git a/src/go/internal/gccgoimporter/testdata/unicode.gox b/src/go/internal/gccgoimporter/testdata/unicode.gox
new file mode 100644
index 0000000..e70e539
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/unicode.gox
Binary files differ
diff --git a/src/go/internal/gccgoimporter/testdata/v1reflect.gox b/src/go/internal/gccgoimporter/testdata/v1reflect.gox
new file mode 100644
index 0000000..ea46841
--- /dev/null
+++ b/src/go/internal/gccgoimporter/testdata/v1reflect.gox
Binary files differ
diff --git a/src/go/internal/gcimporter/exportdata.go b/src/go/internal/gcimporter/exportdata.go
new file mode 100644
index 0000000..c12e459
--- /dev/null
+++ b/src/go/internal/gcimporter/exportdata.go
@@ -0,0 +1,91 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements FindExportData.
+
+package gcimporter
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "strconv"
+ "strings"
+)
+
+func readGopackHeader(r *bufio.Reader) (name string, size int, err error) {
+ // See $GOROOT/include/ar.h.
+ hdr := make([]byte, 16+12+6+6+8+10+2)
+ _, err = io.ReadFull(r, hdr)
+ if err != nil {
+ return
+ }
+ // leave for debugging
+ if false {
+ fmt.Printf("header: %s", hdr)
+ }
+ s := strings.TrimSpace(string(hdr[16+12+6+6+8:][:10]))
+ size, err = strconv.Atoi(s)
+ if err != nil || hdr[len(hdr)-2] != '`' || hdr[len(hdr)-1] != '\n' {
+ err = fmt.Errorf("invalid archive header")
+ return
+ }
+ name = strings.TrimSpace(string(hdr[:16]))
+ return
+}
+
+// FindExportData positions the reader r at the beginning of the
+// export data section of an underlying GC-created object/archive
+// file by reading from it. The reader must be positioned at the
+// start of the file before calling this function. The hdr result
+// is the string before the export data, either "$$" or "$$B".
+//
+func FindExportData(r *bufio.Reader) (hdr string, err error) {
+ // Read first line to make sure this is an object file.
+ line, err := r.ReadSlice('\n')
+ if err != nil {
+ err = fmt.Errorf("can't find export data (%v)", err)
+ return
+ }
+
+ if string(line) == "!<arch>\n" {
+ // Archive file. Scan to __.PKGDEF.
+ var name string
+ if name, _, err = readGopackHeader(r); err != nil {
+ return
+ }
+
+ // First entry should be __.PKGDEF.
+ if name != "__.PKGDEF" {
+ err = fmt.Errorf("go archive is missing __.PKGDEF")
+ return
+ }
+
+ // Read first line of __.PKGDEF data, so that line
+ // is once again the first line of the input.
+ if line, err = r.ReadSlice('\n'); err != nil {
+ err = fmt.Errorf("can't find export data (%v)", err)
+ return
+ }
+ }
+
+ // Now at __.PKGDEF in archive or still at beginning of file.
+ // Either way, line should begin with "go object ".
+ if !strings.HasPrefix(string(line), "go object ") {
+ err = fmt.Errorf("not a Go object file")
+ return
+ }
+
+ // Skip over object header to export data.
+ // Begins after first line starting with $$.
+ for line[0] != '$' {
+ if line, err = r.ReadSlice('\n'); err != nil {
+ err = fmt.Errorf("can't find export data (%v)", err)
+ return
+ }
+ }
+ hdr = string(line)
+
+ return
+}
diff --git a/src/go/internal/gcimporter/gcimporter.go b/src/go/internal/gcimporter/gcimporter.go
new file mode 100644
index 0000000..b74daca
--- /dev/null
+++ b/src/go/internal/gcimporter/gcimporter.go
@@ -0,0 +1,174 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gcimporter implements Import for gc-generated object files.
+package gcimporter // import "go/internal/gcimporter"
+
+import (
+ "bufio"
+ "fmt"
+ "go/build"
+ "go/token"
+ "go/types"
+ "io"
+ "os"
+ "path/filepath"
+ "strings"
+)
+
+// debugging/development support
+const debug = false
+
+var pkgExts = [...]string{".a", ".o"}
+
+// FindPkg returns the filename and unique package id for an import
+// path based on package information provided by build.Import (using
+// the build.Default build.Context). A relative srcDir is interpreted
+// relative to the current working directory.
+// If no file was found, an empty filename is returned.
+//
+func FindPkg(path, srcDir string) (filename, id string) {
+ if path == "" {
+ return
+ }
+
+ var noext string
+ switch {
+ default:
+ // "x" -> "$GOPATH/pkg/$GOOS_$GOARCH/x.ext", "x"
+ // Don't require the source files to be present.
+ if abs, err := filepath.Abs(srcDir); err == nil { // see issue 14282
+ srcDir = abs
+ }
+ bp, _ := build.Import(path, srcDir, build.FindOnly|build.AllowBinary)
+ if bp.PkgObj == "" {
+ id = path // make sure we have an id to print in error message
+ return
+ }
+ noext = strings.TrimSuffix(bp.PkgObj, ".a")
+ id = bp.ImportPath
+
+ case build.IsLocalImport(path):
+ // "./x" -> "/this/directory/x.ext", "/this/directory/x"
+ noext = filepath.Join(srcDir, path)
+ id = noext
+
+ case filepath.IsAbs(path):
+ // for completeness only - go/build.Import
+ // does not support absolute imports
+ // "/x" -> "/x.ext", "/x"
+ noext = path
+ id = path
+ }
+
+ if false { // for debugging
+ if path != id {
+ fmt.Printf("%s -> %s\n", path, id)
+ }
+ }
+
+ // try extensions
+ for _, ext := range pkgExts {
+ filename = noext + ext
+ if f, err := os.Stat(filename); err == nil && !f.IsDir() {
+ return
+ }
+ }
+
+ filename = "" // not found
+ return
+}
+
+// Import imports a gc-generated package given its import path and srcDir, adds
+// the corresponding package object to the packages map, and returns the object.
+// The packages map must contain all packages already imported.
+//
+func Import(fset *token.FileSet, packages map[string]*types.Package, path, srcDir string, lookup func(path string) (io.ReadCloser, error)) (pkg *types.Package, err error) {
+ var rc io.ReadCloser
+ var id string
+ if lookup != nil {
+ // With custom lookup specified, assume that caller has
+ // converted path to a canonical import path for use in the map.
+ if path == "unsafe" {
+ return types.Unsafe, nil
+ }
+ id = path
+
+ // No need to re-import if the package was imported completely before.
+ if pkg = packages[id]; pkg != nil && pkg.Complete() {
+ return
+ }
+ f, err := lookup(path)
+ if err != nil {
+ return nil, err
+ }
+ rc = f
+ } else {
+ var filename string
+ filename, id = FindPkg(path, srcDir)
+ if filename == "" {
+ if path == "unsafe" {
+ return types.Unsafe, nil
+ }
+ return nil, fmt.Errorf("can't find import: %q", id)
+ }
+
+ // no need to re-import if the package was imported completely before
+ if pkg = packages[id]; pkg != nil && pkg.Complete() {
+ return
+ }
+
+ // open file
+ f, err := os.Open(filename)
+ if err != nil {
+ return nil, err
+ }
+ defer func() {
+ if err != nil {
+ // add file name to error
+ err = fmt.Errorf("%s: %v", filename, err)
+ }
+ }()
+ rc = f
+ }
+ defer rc.Close()
+
+ var hdr string
+ buf := bufio.NewReader(rc)
+ if hdr, err = FindExportData(buf); err != nil {
+ return
+ }
+
+ switch hdr {
+ case "$$\n":
+ err = fmt.Errorf("import %q: old textual export format no longer supported (recompile library)", path)
+
+ case "$$B\n":
+ var data []byte
+ data, err = io.ReadAll(buf)
+ if err != nil {
+ break
+ }
+
+ // The indexed export format starts with an 'i'; the older
+ // binary export format starts with a 'c', 'd', or 'v'
+ // (from "version"). Select appropriate importer.
+ if len(data) > 0 && data[0] == 'i' {
+ _, pkg, err = iImportData(fset, packages, data[1:], id)
+ } else {
+ err = fmt.Errorf("import %q: old binary export format no longer supported (recompile library)", path)
+ }
+
+ default:
+ err = fmt.Errorf("import %q: unknown export data header: %q", path, hdr)
+ }
+
+ return
+}
+
+type byPath []*types.Package
+
+func (a byPath) Len() int { return len(a) }
+func (a byPath) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a byPath) Less(i, j int) bool { return a[i].Path() < a[j].Path() }
diff --git a/src/go/internal/gcimporter/gcimporter_test.go b/src/go/internal/gcimporter/gcimporter_test.go
new file mode 100644
index 0000000..3c76aaf
--- /dev/null
+++ b/src/go/internal/gcimporter/gcimporter_test.go
@@ -0,0 +1,619 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gcimporter
+
+import (
+ "bytes"
+ "fmt"
+ "internal/testenv"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "runtime"
+ "strings"
+ "testing"
+ "time"
+
+ "go/token"
+ "go/types"
+)
+
+// skipSpecialPlatforms causes the test to be skipped for platforms where
+// builders (build.golang.org) don't have access to compiled packages for
+// import.
+func skipSpecialPlatforms(t *testing.T) {
+ switch platform := runtime.GOOS + "-" + runtime.GOARCH; platform {
+ case "darwin-arm64":
+ t.Skipf("no compiled packages available for import on %s", platform)
+ }
+}
+
+// compile runs the compiler on filename, with dirname as the working directory,
+// and writes the output file to outdirname.
+func compile(t *testing.T, dirname, filename, outdirname string) string {
+ // filename must end with ".go"
+ if !strings.HasSuffix(filename, ".go") {
+ t.Fatalf("filename doesn't end in .go: %s", filename)
+ }
+ basename := filepath.Base(filename)
+ outname := filepath.Join(outdirname, basename[:len(basename)-2]+"o")
+ cmd := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-o", outname, filename)
+ cmd.Dir = dirname
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ t.Logf("%s", out)
+ t.Fatalf("go tool compile %s failed: %s", filename, err)
+ }
+ return outname
+}
+
+func testPath(t *testing.T, path, srcDir string) *types.Package {
+ t0 := time.Now()
+ fset := token.NewFileSet()
+ pkg, err := Import(fset, make(map[string]*types.Package), path, srcDir, nil)
+ if err != nil {
+ t.Errorf("testPath(%s): %s", path, err)
+ return nil
+ }
+ t.Logf("testPath(%s): %v", path, time.Since(t0))
+ return pkg
+}
+
+const maxTime = 30 * time.Second
+
+func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
+ dirname := filepath.Join(runtime.GOROOT(), "pkg", runtime.GOOS+"_"+runtime.GOARCH, dir)
+ list, err := os.ReadDir(dirname)
+ if err != nil {
+ t.Fatalf("testDir(%s): %s", dirname, err)
+ }
+ for _, f := range list {
+ if time.Now().After(endTime) {
+ t.Log("testing time used up")
+ return
+ }
+ switch {
+ case !f.IsDir():
+ // try extensions
+ for _, ext := range pkgExts {
+ if strings.HasSuffix(f.Name(), ext) {
+ name := f.Name()[0 : len(f.Name())-len(ext)] // remove extension
+ if testPath(t, filepath.Join(dir, name), dir) != nil {
+ nimports++
+ }
+ }
+ }
+ case f.IsDir():
+ nimports += testDir(t, filepath.Join(dir, f.Name()), endTime)
+ }
+ }
+ return
+}
+
+func mktmpdir(t *testing.T) string {
+ tmpdir, err := os.MkdirTemp("", "gcimporter_test")
+ if err != nil {
+ t.Fatal("mktmpdir:", err)
+ }
+ if err := os.Mkdir(filepath.Join(tmpdir, "testdata"), 0700); err != nil {
+ os.RemoveAll(tmpdir)
+ t.Fatal("mktmpdir:", err)
+ }
+ return tmpdir
+}
+
+func TestImportTestdata(t *testing.T) {
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ tmpdir := mktmpdir(t)
+ defer os.RemoveAll(tmpdir)
+
+ compile(t, "testdata", "exports.go", filepath.Join(tmpdir, "testdata"))
+
+ if pkg := testPath(t, "./testdata/exports", tmpdir); pkg != nil {
+ // The package's Imports list must include all packages
+ // explicitly imported by exports.go, plus all packages
+ // referenced indirectly via exported objects in exports.go.
+ // With the textual export format, the list may also include
+ // additional packages that are not strictly required for
+ // import processing alone (they are exported to err "on
+ // the safe side").
+ // TODO(gri) update the want list to be precise, now that
+ // the textual export data is gone.
+ got := fmt.Sprint(pkg.Imports())
+ for _, want := range []string{"go/ast", "go/token"} {
+ if !strings.Contains(got, want) {
+ t.Errorf(`Package("exports").Imports() = %s, does not contain %s`, got, want)
+ }
+ }
+ }
+}
+
+func TestVersionHandling(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ const dir = "./testdata/versions"
+ list, err := os.ReadDir(dir)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ tmpdir := mktmpdir(t)
+ defer os.RemoveAll(tmpdir)
+ corruptdir := filepath.Join(tmpdir, "testdata", "versions")
+ if err := os.Mkdir(corruptdir, 0700); err != nil {
+ t.Fatal(err)
+ }
+
+ fset := token.NewFileSet()
+
+ for _, f := range list {
+ name := f.Name()
+ if !strings.HasSuffix(name, ".a") {
+ continue // not a package file
+ }
+ if strings.Contains(name, "corrupted") {
+ continue // don't process a leftover corrupted file
+ }
+ pkgpath := "./" + name[:len(name)-2]
+
+ if testing.Verbose() {
+ t.Logf("importing %s", name)
+ }
+
+ // test that export data can be imported
+ _, err := Import(fset, make(map[string]*types.Package), pkgpath, dir, nil)
+ if err != nil {
+ // ok to fail if it fails with a no longer supported error for select files
+ if strings.Contains(err.Error(), "no longer supported") {
+ switch name {
+ case "test_go1.7_0.a", "test_go1.7_1.a",
+ "test_go1.8_4.a", "test_go1.8_5.a",
+ "test_go1.11_6b.a", "test_go1.11_999b.a":
+ continue
+ }
+ // fall through
+ }
+ // ok to fail if it fails with a newer version error for select files
+ if strings.Contains(err.Error(), "newer version") {
+ switch name {
+ case "test_go1.11_999i.a":
+ continue
+ }
+ // fall through
+ }
+ t.Errorf("import %q failed: %v", pkgpath, err)
+ continue
+ }
+
+ // create file with corrupted export data
+ // 1) read file
+ data, err := os.ReadFile(filepath.Join(dir, name))
+ if err != nil {
+ t.Fatal(err)
+ }
+ // 2) find export data
+ i := bytes.Index(data, []byte("\n$$B\n")) + 5
+ j := bytes.Index(data[i:], []byte("\n$$\n")) + i
+ if i < 0 || j < 0 || i > j {
+ t.Fatalf("export data section not found (i = %d, j = %d)", i, j)
+ }
+ // 3) corrupt the data (increment every 7th byte)
+ for k := j - 13; k >= i; k -= 7 {
+ data[k]++
+ }
+ // 4) write the file
+ pkgpath += "_corrupted"
+ filename := filepath.Join(corruptdir, pkgpath) + ".a"
+ os.WriteFile(filename, data, 0666)
+
+ // test that importing the corrupted file results in an error
+ _, err = Import(fset, make(map[string]*types.Package), pkgpath, corruptdir, nil)
+ if err == nil {
+ t.Errorf("import corrupted %q succeeded", pkgpath)
+ } else if msg := err.Error(); !strings.Contains(msg, "version skew") {
+ t.Errorf("import %q error incorrect (%s)", pkgpath, msg)
+ }
+ }
+}
+
+func TestImportStdLib(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ dt := maxTime
+ if testing.Short() && testenv.Builder() == "" {
+ dt = 10 * time.Millisecond
+ }
+ nimports := testDir(t, "", time.Now().Add(dt)) // installed packages
+ t.Logf("tested %d imports", nimports)
+}
+
+var importedObjectTests = []struct {
+ name string
+ want string
+}{
+ // non-interfaces
+ {"crypto.Hash", "type Hash uint"},
+ {"go/ast.ObjKind", "type ObjKind int"},
+ {"go/types.Qualifier", "type Qualifier func(*Package) string"},
+ {"go/types.Comparable", "func Comparable(T Type) bool"},
+ {"math.Pi", "const Pi untyped float"},
+ {"math.Sin", "func Sin(x float64) float64"},
+ {"go/ast.NotNilFilter", "func NotNilFilter(_ string, v reflect.Value) bool"},
+ {"go/internal/gcimporter.FindPkg", "func FindPkg(path string, srcDir string) (filename string, id string)"},
+
+ // interfaces
+ {"context.Context", "type Context interface{Deadline() (deadline time.Time, ok bool); Done() <-chan struct{}; Err() error; Value(key interface{}) interface{}}"},
+ {"crypto.Decrypter", "type Decrypter interface{Decrypt(rand io.Reader, msg []byte, opts DecrypterOpts) (plaintext []byte, err error); Public() PublicKey}"},
+ {"encoding.BinaryMarshaler", "type BinaryMarshaler interface{MarshalBinary() (data []byte, err error)}"},
+ {"io.Reader", "type Reader interface{Read(p []byte) (n int, err error)}"},
+ {"io.ReadWriter", "type ReadWriter interface{Reader; Writer}"},
+ {"go/ast.Node", "type Node interface{End() go/token.Pos; Pos() go/token.Pos}"},
+ {"go/types.Type", "type Type interface{String() string; Underlying() Type}"},
+}
+
+func TestImportedTypes(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ fset := token.NewFileSet()
+ for _, test := range importedObjectTests {
+ s := strings.Split(test.name, ".")
+ if len(s) != 2 {
+ t.Fatal("inconsistent test data")
+ }
+ importPath := s[0]
+ objName := s[1]
+
+ pkg, err := Import(fset, make(map[string]*types.Package), importPath, ".", nil)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+
+ obj := pkg.Scope().Lookup(objName)
+ if obj == nil {
+ t.Errorf("%s: object not found", test.name)
+ continue
+ }
+
+ got := types.ObjectString(obj, types.RelativeTo(pkg))
+ if got != test.want {
+ t.Errorf("%s: got %q; want %q", test.name, got, test.want)
+ }
+
+ if named, _ := obj.Type().(*types.Named); named != nil {
+ verifyInterfaceMethodRecvs(t, named, 0)
+ }
+ }
+}
+
+// verifyInterfaceMethodRecvs verifies that method receiver types
+// are named if the methods belong to a named interface type.
+func verifyInterfaceMethodRecvs(t *testing.T, named *types.Named, level int) {
+ // avoid endless recursion in case of an embedding bug that lead to a cycle
+ if level > 10 {
+ t.Errorf("%s: embeds itself", named)
+ return
+ }
+
+ iface, _ := named.Underlying().(*types.Interface)
+ if iface == nil {
+ return // not an interface
+ }
+
+ // check explicitly declared methods
+ for i := 0; i < iface.NumExplicitMethods(); i++ {
+ m := iface.ExplicitMethod(i)
+ recv := m.Type().(*types.Signature).Recv()
+ if recv == nil {
+ t.Errorf("%s: missing receiver type", m)
+ continue
+ }
+ if recv.Type() != named {
+ t.Errorf("%s: got recv type %s; want %s", m, recv.Type(), named)
+ }
+ }
+
+ // check embedded interfaces (if they are named, too)
+ for i := 0; i < iface.NumEmbeddeds(); i++ {
+ // embedding of interfaces cannot have cycles; recursion will terminate
+ if etype, _ := iface.EmbeddedType(i).(*types.Named); etype != nil {
+ verifyInterfaceMethodRecvs(t, etype, level+1)
+ }
+ }
+}
+
+func TestIssue5815(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ pkg := importPkg(t, "strings", ".")
+
+ scope := pkg.Scope()
+ for _, name := range scope.Names() {
+ obj := scope.Lookup(name)
+ if obj.Pkg() == nil {
+ t.Errorf("no pkg for %s", obj)
+ }
+ if tname, _ := obj.(*types.TypeName); tname != nil {
+ named := tname.Type().(*types.Named)
+ for i := 0; i < named.NumMethods(); i++ {
+ m := named.Method(i)
+ if m.Pkg() == nil {
+ t.Errorf("no pkg for %s", m)
+ }
+ }
+ }
+ }
+}
+
+// Smoke test to ensure that imported methods get the correct package.
+func TestCorrectMethodPackage(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ imports := make(map[string]*types.Package)
+ fset := token.NewFileSet()
+ _, err := Import(fset, imports, "net/http", ".", nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ mutex := imports["sync"].Scope().Lookup("Mutex").(*types.TypeName).Type()
+ mset := types.NewMethodSet(types.NewPointer(mutex)) // methods of *sync.Mutex
+ sel := mset.Lookup(nil, "Lock")
+ lock := sel.Obj().(*types.Func)
+ if got, want := lock.Pkg().Path(), "sync"; got != want {
+ t.Errorf("got package path %q; want %q", got, want)
+ }
+}
+
+func TestIssue13566(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ tmpdir := mktmpdir(t)
+ defer os.RemoveAll(tmpdir)
+ testoutdir := filepath.Join(tmpdir, "testdata")
+
+ // b.go needs to be compiled from the output directory so that the compiler can
+ // find the compiled package a. We pass the full path to compile() so that we
+ // don't have to copy the file to that directory.
+ bpath, err := filepath.Abs(filepath.Join("testdata", "b.go"))
+ if err != nil {
+ t.Fatal(err)
+ }
+ compile(t, "testdata", "a.go", testoutdir)
+ compile(t, testoutdir, bpath, testoutdir)
+
+ // import must succeed (test for issue at hand)
+ pkg := importPkg(t, "./testdata/b", tmpdir)
+
+ // make sure all indirectly imported packages have names
+ for _, imp := range pkg.Imports() {
+ if imp.Name() == "" {
+ t.Errorf("no name for %s package", imp.Path())
+ }
+ }
+}
+
+func TestIssue13898(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // import go/internal/gcimporter which imports go/types partially
+ fset := token.NewFileSet()
+ imports := make(map[string]*types.Package)
+ _, err := Import(fset, imports, "go/internal/gcimporter", ".", nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // look for go/types package
+ var goTypesPkg *types.Package
+ for path, pkg := range imports {
+ if path == "go/types" {
+ goTypesPkg = pkg
+ break
+ }
+ }
+ if goTypesPkg == nil {
+ t.Fatal("go/types not found")
+ }
+
+ // look for go/types.Object type
+ obj := lookupObj(t, goTypesPkg.Scope(), "Object")
+ typ, ok := obj.Type().(*types.Named)
+ if !ok {
+ t.Fatalf("go/types.Object type is %v; wanted named type", typ)
+ }
+
+ // lookup go/types.Object.Pkg method
+ m, index, indirect := types.LookupFieldOrMethod(typ, false, nil, "Pkg")
+ if m == nil {
+ t.Fatalf("go/types.Object.Pkg not found (index = %v, indirect = %v)", index, indirect)
+ }
+
+ // the method must belong to go/types
+ if m.Pkg().Path() != "go/types" {
+ t.Fatalf("found %v; want go/types", m.Pkg())
+ }
+}
+
+func TestIssue15517(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ tmpdir := mktmpdir(t)
+ defer os.RemoveAll(tmpdir)
+
+ compile(t, "testdata", "p.go", filepath.Join(tmpdir, "testdata"))
+
+ // Multiple imports of p must succeed without redeclaration errors.
+ // We use an import path that's not cleaned up so that the eventual
+ // file path for the package is different from the package path; this
+ // will expose the error if it is present.
+ //
+ // (Issue: Both the textual and the binary importer used the file path
+ // of the package to be imported as key into the shared packages map.
+ // However, the binary importer then used the package path to identify
+ // the imported package to mark it as complete; effectively marking the
+ // wrong package as complete. By using an "unclean" package path, the
+ // file and package path are different, exposing the problem if present.
+ // The same issue occurs with vendoring.)
+ imports := make(map[string]*types.Package)
+ fset := token.NewFileSet()
+ for i := 0; i < 3; i++ {
+ if _, err := Import(fset, imports, "./././testdata/p", tmpdir, nil); err != nil {
+ t.Fatal(err)
+ }
+ }
+}
+
+func TestIssue15920(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ compileAndImportPkg(t, "issue15920")
+}
+
+func TestIssue20046(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ // "./issue20046".V.M must exist
+ pkg := compileAndImportPkg(t, "issue20046")
+ obj := lookupObj(t, pkg.Scope(), "V")
+ if m, index, indirect := types.LookupFieldOrMethod(obj.Type(), false, nil, "M"); m == nil {
+ t.Fatalf("V.M not found (index = %v, indirect = %v)", index, indirect)
+ }
+}
+func TestIssue25301(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ compileAndImportPkg(t, "issue25301")
+}
+
+func TestIssue25596(t *testing.T) {
+ skipSpecialPlatforms(t)
+
+ // This package only handles gc export data.
+ if runtime.Compiler != "gc" {
+ t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+ }
+
+ // On windows, we have to set the -D option for the compiler to avoid having a drive
+ // letter and an illegal ':' in the import path - just skip it (see also issue #3483).
+ if runtime.GOOS == "windows" {
+ t.Skip("avoid dealing with relative paths/drive letters on windows")
+ }
+
+ compileAndImportPkg(t, "issue25596")
+}
+
+func importPkg(t *testing.T, path, srcDir string) *types.Package {
+ fset := token.NewFileSet()
+ pkg, err := Import(fset, make(map[string]*types.Package), path, srcDir, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+ return pkg
+}
+
+func compileAndImportPkg(t *testing.T, name string) *types.Package {
+ tmpdir := mktmpdir(t)
+ defer os.RemoveAll(tmpdir)
+ compile(t, "testdata", name+".go", filepath.Join(tmpdir, "testdata"))
+ return importPkg(t, "./testdata/"+name, tmpdir)
+}
+
+func lookupObj(t *testing.T, scope *types.Scope, name string) types.Object {
+ if obj := scope.Lookup(name); obj != nil {
+ return obj
+ }
+ t.Fatalf("%s not found", name)
+ return nil
+}
diff --git a/src/go/internal/gcimporter/iimport.go b/src/go/internal/gcimporter/iimport.go
new file mode 100644
index 0000000..c59dd16
--- /dev/null
+++ b/src/go/internal/gcimporter/iimport.go
@@ -0,0 +1,618 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Indexed package import.
+// See cmd/compile/internal/gc/iexport.go for the export data format.
+
+package gcimporter
+
+import (
+ "bytes"
+ "encoding/binary"
+ "fmt"
+ "go/constant"
+ "go/token"
+ "go/types"
+ "io"
+ "sort"
+)
+
+type intReader struct {
+ *bytes.Reader
+ path string
+}
+
+func (r *intReader) int64() int64 {
+ i, err := binary.ReadVarint(r.Reader)
+ if err != nil {
+ errorf("import %q: read varint error: %v", r.path, err)
+ }
+ return i
+}
+
+func (r *intReader) uint64() uint64 {
+ i, err := binary.ReadUvarint(r.Reader)
+ if err != nil {
+ errorf("import %q: read varint error: %v", r.path, err)
+ }
+ return i
+}
+
+const predeclReserved = 32
+
+type itag uint64
+
+const (
+ // Types
+ definedType itag = iota
+ pointerType
+ sliceType
+ arrayType
+ chanType
+ mapType
+ signatureType
+ structType
+ interfaceType
+)
+
+// iImportData imports a package from the serialized package data
+// and returns the number of bytes consumed and a reference to the package.
+// If the export data version is not recognized or the format is otherwise
+// compromised, an error is returned.
+func iImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
+ const currentVersion = 1
+ version := int64(-1)
+ defer func() {
+ if e := recover(); e != nil {
+ if version > currentVersion {
+ err = fmt.Errorf("cannot import %q (%v), export data is newer version - update tool", path, e)
+ } else {
+ err = fmt.Errorf("cannot import %q (%v), possibly version skew - reinstall package", path, e)
+ }
+ }
+ }()
+
+ r := &intReader{bytes.NewReader(data), path}
+
+ version = int64(r.uint64())
+ switch version {
+ case currentVersion, 0:
+ default:
+ errorf("unknown iexport format version %d", version)
+ }
+
+ sLen := int64(r.uint64())
+ dLen := int64(r.uint64())
+
+ whence, _ := r.Seek(0, io.SeekCurrent)
+ stringData := data[whence : whence+sLen]
+ declData := data[whence+sLen : whence+sLen+dLen]
+ r.Seek(sLen+dLen, io.SeekCurrent)
+
+ p := iimporter{
+ ipath: path,
+ version: int(version),
+
+ stringData: stringData,
+ stringCache: make(map[uint64]string),
+ pkgCache: make(map[uint64]*types.Package),
+
+ declData: declData,
+ pkgIndex: make(map[*types.Package]map[string]uint64),
+ typCache: make(map[uint64]types.Type),
+
+ fake: fakeFileSet{
+ fset: fset,
+ files: make(map[string]*token.File),
+ },
+ }
+
+ for i, pt := range predeclared {
+ p.typCache[uint64(i)] = pt
+ }
+
+ pkgList := make([]*types.Package, r.uint64())
+ for i := range pkgList {
+ pkgPathOff := r.uint64()
+ pkgPath := p.stringAt(pkgPathOff)
+ pkgName := p.stringAt(r.uint64())
+ _ = r.uint64() // package height; unused by go/types
+
+ if pkgPath == "" {
+ pkgPath = path
+ }
+ pkg := imports[pkgPath]
+ if pkg == nil {
+ pkg = types.NewPackage(pkgPath, pkgName)
+ imports[pkgPath] = pkg
+ } else if pkg.Name() != pkgName {
+ errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
+ }
+
+ p.pkgCache[pkgPathOff] = pkg
+
+ nameIndex := make(map[string]uint64)
+ for nSyms := r.uint64(); nSyms > 0; nSyms-- {
+ name := p.stringAt(r.uint64())
+ nameIndex[name] = r.uint64()
+ }
+
+ p.pkgIndex[pkg] = nameIndex
+ pkgList[i] = pkg
+ }
+
+ localpkg := pkgList[0]
+
+ names := make([]string, 0, len(p.pkgIndex[localpkg]))
+ for name := range p.pkgIndex[localpkg] {
+ names = append(names, name)
+ }
+ sort.Strings(names)
+ for _, name := range names {
+ p.doDecl(localpkg, name)
+ }
+
+ for _, typ := range p.interfaceList {
+ typ.Complete()
+ }
+
+ // record all referenced packages as imports
+ list := append(([]*types.Package)(nil), pkgList[1:]...)
+ sort.Sort(byPath(list))
+ localpkg.SetImports(list)
+
+ // package was imported completely and without errors
+ localpkg.MarkComplete()
+
+ consumed, _ := r.Seek(0, io.SeekCurrent)
+ return int(consumed), localpkg, nil
+}
+
+type iimporter struct {
+ ipath string
+ version int
+
+ stringData []byte
+ stringCache map[uint64]string
+ pkgCache map[uint64]*types.Package
+
+ declData []byte
+ pkgIndex map[*types.Package]map[string]uint64
+ typCache map[uint64]types.Type
+
+ fake fakeFileSet
+ interfaceList []*types.Interface
+}
+
+func (p *iimporter) doDecl(pkg *types.Package, name string) {
+ // See if we've already imported this declaration.
+ if obj := pkg.Scope().Lookup(name); obj != nil {
+ return
+ }
+
+ off, ok := p.pkgIndex[pkg][name]
+ if !ok {
+ errorf("%v.%v not in index", pkg, name)
+ }
+
+ r := &importReader{p: p, currPkg: pkg}
+ r.declReader.Reset(p.declData[off:])
+
+ r.obj(name)
+}
+
+func (p *iimporter) stringAt(off uint64) string {
+ if s, ok := p.stringCache[off]; ok {
+ return s
+ }
+
+ slen, n := binary.Uvarint(p.stringData[off:])
+ if n <= 0 {
+ errorf("varint failed")
+ }
+ spos := off + uint64(n)
+ s := string(p.stringData[spos : spos+slen])
+ p.stringCache[off] = s
+ return s
+}
+
+func (p *iimporter) pkgAt(off uint64) *types.Package {
+ if pkg, ok := p.pkgCache[off]; ok {
+ return pkg
+ }
+ path := p.stringAt(off)
+ errorf("missing package %q in %q", path, p.ipath)
+ return nil
+}
+
+func (p *iimporter) typAt(off uint64, base *types.Named) types.Type {
+ if t, ok := p.typCache[off]; ok && (base == nil || !isInterface(t)) {
+ return t
+ }
+
+ if off < predeclReserved {
+ errorf("predeclared type missing from cache: %v", off)
+ }
+
+ r := &importReader{p: p}
+ r.declReader.Reset(p.declData[off-predeclReserved:])
+ t := r.doType(base)
+
+ if base == nil || !isInterface(t) {
+ p.typCache[off] = t
+ }
+ return t
+}
+
+type importReader struct {
+ p *iimporter
+ declReader bytes.Reader
+ currPkg *types.Package
+ prevFile string
+ prevLine int64
+ prevColumn int64
+}
+
+func (r *importReader) obj(name string) {
+ tag := r.byte()
+ pos := r.pos()
+
+ switch tag {
+ case 'A':
+ typ := r.typ()
+
+ r.declare(types.NewTypeName(pos, r.currPkg, name, typ))
+
+ case 'C':
+ typ, val := r.value()
+
+ r.declare(types.NewConst(pos, r.currPkg, name, typ, val))
+
+ case 'F':
+ sig := r.signature(nil)
+
+ r.declare(types.NewFunc(pos, r.currPkg, name, sig))
+
+ case 'T':
+ // Types can be recursive. We need to setup a stub
+ // declaration before recursing.
+ obj := types.NewTypeName(pos, r.currPkg, name, nil)
+ named := types.NewNamed(obj, nil, nil)
+ r.declare(obj)
+
+ underlying := r.p.typAt(r.uint64(), named).Underlying()
+ named.SetUnderlying(underlying)
+
+ if !isInterface(underlying) {
+ for n := r.uint64(); n > 0; n-- {
+ mpos := r.pos()
+ mname := r.ident()
+ recv := r.param()
+ msig := r.signature(recv)
+
+ named.AddMethod(types.NewFunc(mpos, r.currPkg, mname, msig))
+ }
+ }
+
+ case 'V':
+ typ := r.typ()
+
+ r.declare(types.NewVar(pos, r.currPkg, name, typ))
+
+ default:
+ errorf("unexpected tag: %v", tag)
+ }
+}
+
+func (r *importReader) declare(obj types.Object) {
+ obj.Pkg().Scope().Insert(obj)
+}
+
+func (r *importReader) value() (typ types.Type, val constant.Value) {
+ typ = r.typ()
+
+ switch b := typ.Underlying().(*types.Basic); b.Info() & types.IsConstType {
+ case types.IsBoolean:
+ val = constant.MakeBool(r.bool())
+
+ case types.IsString:
+ val = constant.MakeString(r.string())
+
+ case types.IsInteger:
+ val = r.mpint(b)
+
+ case types.IsFloat:
+ val = r.mpfloat(b)
+
+ case types.IsComplex:
+ re := r.mpfloat(b)
+ im := r.mpfloat(b)
+ val = constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
+
+ default:
+ errorf("unexpected type %v", typ) // panics
+ panic("unreachable")
+ }
+
+ return
+}
+
+func intSize(b *types.Basic) (signed bool, maxBytes uint) {
+ if (b.Info() & types.IsUntyped) != 0 {
+ return true, 64
+ }
+
+ switch b.Kind() {
+ case types.Float32, types.Complex64:
+ return true, 3
+ case types.Float64, types.Complex128:
+ return true, 7
+ }
+
+ signed = (b.Info() & types.IsUnsigned) == 0
+ switch b.Kind() {
+ case types.Int8, types.Uint8:
+ maxBytes = 1
+ case types.Int16, types.Uint16:
+ maxBytes = 2
+ case types.Int32, types.Uint32:
+ maxBytes = 4
+ default:
+ maxBytes = 8
+ }
+
+ return
+}
+
+func (r *importReader) mpint(b *types.Basic) constant.Value {
+ signed, maxBytes := intSize(b)
+
+ maxSmall := 256 - maxBytes
+ if signed {
+ maxSmall = 256 - 2*maxBytes
+ }
+ if maxBytes == 1 {
+ maxSmall = 256
+ }
+
+ n, _ := r.declReader.ReadByte()
+ if uint(n) < maxSmall {
+ v := int64(n)
+ if signed {
+ v >>= 1
+ if n&1 != 0 {
+ v = ^v
+ }
+ }
+ return constant.MakeInt64(v)
+ }
+
+ v := -n
+ if signed {
+ v = -(n &^ 1) >> 1
+ }
+ if v < 1 || uint(v) > maxBytes {
+ errorf("weird decoding: %v, %v => %v", n, signed, v)
+ }
+
+ buf := make([]byte, v)
+ io.ReadFull(&r.declReader, buf)
+
+ // convert to little endian
+ // TODO(gri) go/constant should have a more direct conversion function
+ // (e.g., once it supports a big.Float based implementation)
+ for i, j := 0, len(buf)-1; i < j; i, j = i+1, j-1 {
+ buf[i], buf[j] = buf[j], buf[i]
+ }
+
+ x := constant.MakeFromBytes(buf)
+ if signed && n&1 != 0 {
+ x = constant.UnaryOp(token.SUB, x, 0)
+ }
+ return x
+}
+
+func (r *importReader) mpfloat(b *types.Basic) constant.Value {
+ x := r.mpint(b)
+ if constant.Sign(x) == 0 {
+ return x
+ }
+
+ exp := r.int64()
+ switch {
+ case exp > 0:
+ x = constant.Shift(x, token.SHL, uint(exp))
+ case exp < 0:
+ d := constant.Shift(constant.MakeInt64(1), token.SHL, uint(-exp))
+ x = constant.BinaryOp(x, token.QUO, d)
+ }
+ return x
+}
+
+func (r *importReader) ident() string {
+ return r.string()
+}
+
+func (r *importReader) qualifiedIdent() (*types.Package, string) {
+ name := r.string()
+ pkg := r.pkg()
+ return pkg, name
+}
+
+func (r *importReader) pos() token.Pos {
+ if r.p.version >= 1 {
+ r.posv1()
+ } else {
+ r.posv0()
+ }
+
+ if r.prevFile == "" && r.prevLine == 0 && r.prevColumn == 0 {
+ return token.NoPos
+ }
+ return r.p.fake.pos(r.prevFile, int(r.prevLine), int(r.prevColumn))
+}
+
+func (r *importReader) posv0() {
+ delta := r.int64()
+ if delta != deltaNewFile {
+ r.prevLine += delta
+ } else if l := r.int64(); l == -1 {
+ r.prevLine += deltaNewFile
+ } else {
+ r.prevFile = r.string()
+ r.prevLine = l
+ }
+}
+
+func (r *importReader) posv1() {
+ delta := r.int64()
+ r.prevColumn += delta >> 1
+ if delta&1 != 0 {
+ delta = r.int64()
+ r.prevLine += delta >> 1
+ if delta&1 != 0 {
+ r.prevFile = r.string()
+ }
+ }
+}
+
+func (r *importReader) typ() types.Type {
+ return r.p.typAt(r.uint64(), nil)
+}
+
+func isInterface(t types.Type) bool {
+ _, ok := t.(*types.Interface)
+ return ok
+}
+
+func (r *importReader) pkg() *types.Package { return r.p.pkgAt(r.uint64()) }
+func (r *importReader) string() string { return r.p.stringAt(r.uint64()) }
+
+func (r *importReader) doType(base *types.Named) types.Type {
+ switch k := r.kind(); k {
+ default:
+ errorf("unexpected kind tag in %q: %v", r.p.ipath, k)
+ return nil
+
+ case definedType:
+ pkg, name := r.qualifiedIdent()
+ r.p.doDecl(pkg, name)
+ return pkg.Scope().Lookup(name).(*types.TypeName).Type()
+ case pointerType:
+ return types.NewPointer(r.typ())
+ case sliceType:
+ return types.NewSlice(r.typ())
+ case arrayType:
+ n := r.uint64()
+ return types.NewArray(r.typ(), int64(n))
+ case chanType:
+ dir := chanDir(int(r.uint64()))
+ return types.NewChan(dir, r.typ())
+ case mapType:
+ return types.NewMap(r.typ(), r.typ())
+ case signatureType:
+ r.currPkg = r.pkg()
+ return r.signature(nil)
+
+ case structType:
+ r.currPkg = r.pkg()
+
+ fields := make([]*types.Var, r.uint64())
+ tags := make([]string, len(fields))
+ for i := range fields {
+ fpos := r.pos()
+ fname := r.ident()
+ ftyp := r.typ()
+ emb := r.bool()
+ tag := r.string()
+
+ fields[i] = types.NewField(fpos, r.currPkg, fname, ftyp, emb)
+ tags[i] = tag
+ }
+ return types.NewStruct(fields, tags)
+
+ case interfaceType:
+ r.currPkg = r.pkg()
+
+ embeddeds := make([]types.Type, r.uint64())
+ for i := range embeddeds {
+ _ = r.pos()
+ embeddeds[i] = r.typ()
+ }
+
+ methods := make([]*types.Func, r.uint64())
+ for i := range methods {
+ mpos := r.pos()
+ mname := r.ident()
+
+ // TODO(mdempsky): Matches bimport.go, but I
+ // don't agree with this.
+ var recv *types.Var
+ if base != nil {
+ recv = types.NewVar(token.NoPos, r.currPkg, "", base)
+ }
+
+ msig := r.signature(recv)
+ methods[i] = types.NewFunc(mpos, r.currPkg, mname, msig)
+ }
+
+ typ := types.NewInterfaceType(methods, embeddeds)
+ r.p.interfaceList = append(r.p.interfaceList, typ)
+ return typ
+ }
+}
+
+func (r *importReader) kind() itag {
+ return itag(r.uint64())
+}
+
+func (r *importReader) signature(recv *types.Var) *types.Signature {
+ params := r.paramList()
+ results := r.paramList()
+ variadic := params.Len() > 0 && r.bool()
+ return types.NewSignature(recv, params, results, variadic)
+}
+
+func (r *importReader) paramList() *types.Tuple {
+ xs := make([]*types.Var, r.uint64())
+ for i := range xs {
+ xs[i] = r.param()
+ }
+ return types.NewTuple(xs...)
+}
+
+func (r *importReader) param() *types.Var {
+ pos := r.pos()
+ name := r.ident()
+ typ := r.typ()
+ return types.NewParam(pos, r.currPkg, name, typ)
+}
+
+func (r *importReader) bool() bool {
+ return r.uint64() != 0
+}
+
+func (r *importReader) int64() int64 {
+ n, err := binary.ReadVarint(&r.declReader)
+ if err != nil {
+ errorf("readVarint: %v", err)
+ }
+ return n
+}
+
+func (r *importReader) uint64() uint64 {
+ n, err := binary.ReadUvarint(&r.declReader)
+ if err != nil {
+ errorf("readUvarint: %v", err)
+ }
+ return n
+}
+
+func (r *importReader) byte() byte {
+ x, err := r.declReader.ReadByte()
+ if err != nil {
+ errorf("declReader.ReadByte: %v", err)
+ }
+ return x
+}
diff --git a/src/go/internal/gcimporter/support.go b/src/go/internal/gcimporter/support.go
new file mode 100644
index 0000000..b8bb14d
--- /dev/null
+++ b/src/go/internal/gcimporter/support.go
@@ -0,0 +1,130 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements support functionality for iimport.go.
+
+package gcimporter
+
+import (
+ "fmt"
+ "go/token"
+ "go/types"
+ "sync"
+)
+
+func errorf(format string, args ...interface{}) {
+ panic(fmt.Sprintf(format, args...))
+}
+
+// deltaNewFile is a magic line delta offset indicating a new file.
+// We use -64 because it is rare; see issue 20080 and CL 41619.
+// -64 is the smallest int that fits in a single byte as a varint.
+const deltaNewFile = -64
+
+// Synthesize a token.Pos
+type fakeFileSet struct {
+ fset *token.FileSet
+ files map[string]*token.File
+}
+
+func (s *fakeFileSet) pos(file string, line, column int) token.Pos {
+ // TODO(mdempsky): Make use of column.
+
+ // Since we don't know the set of needed file positions, we
+ // reserve maxlines positions per file.
+ const maxlines = 64 * 1024
+ f := s.files[file]
+ if f == nil {
+ f = s.fset.AddFile(file, -1, maxlines)
+ s.files[file] = f
+ // Allocate the fake linebreak indices on first use.
+ // TODO(adonovan): opt: save ~512KB using a more complex scheme?
+ fakeLinesOnce.Do(func() {
+ fakeLines = make([]int, maxlines)
+ for i := range fakeLines {
+ fakeLines[i] = i
+ }
+ })
+ f.SetLines(fakeLines)
+ }
+
+ if line > maxlines {
+ line = 1
+ }
+
+ // Treat the file as if it contained only newlines
+ // and column=1: use the line number as the offset.
+ return f.Pos(line - 1)
+}
+
+var (
+ fakeLines []int
+ fakeLinesOnce sync.Once
+)
+
+func chanDir(d int) types.ChanDir {
+ // tag values must match the constants in cmd/compile/internal/gc/go.go
+ switch d {
+ case 1 /* Crecv */ :
+ return types.RecvOnly
+ case 2 /* Csend */ :
+ return types.SendOnly
+ case 3 /* Cboth */ :
+ return types.SendRecv
+ default:
+ errorf("unexpected channel dir %d", d)
+ return 0
+ }
+}
+
+var predeclared = []types.Type{
+ // basic types
+ types.Typ[types.Bool],
+ types.Typ[types.Int],
+ types.Typ[types.Int8],
+ types.Typ[types.Int16],
+ types.Typ[types.Int32],
+ types.Typ[types.Int64],
+ types.Typ[types.Uint],
+ types.Typ[types.Uint8],
+ types.Typ[types.Uint16],
+ types.Typ[types.Uint32],
+ types.Typ[types.Uint64],
+ types.Typ[types.Uintptr],
+ types.Typ[types.Float32],
+ types.Typ[types.Float64],
+ types.Typ[types.Complex64],
+ types.Typ[types.Complex128],
+ types.Typ[types.String],
+
+ // basic type aliases
+ types.Universe.Lookup("byte").Type(),
+ types.Universe.Lookup("rune").Type(),
+
+ // error
+ types.Universe.Lookup("error").Type(),
+
+ // untyped types
+ types.Typ[types.UntypedBool],
+ types.Typ[types.UntypedInt],
+ types.Typ[types.UntypedRune],
+ types.Typ[types.UntypedFloat],
+ types.Typ[types.UntypedComplex],
+ types.Typ[types.UntypedString],
+ types.Typ[types.UntypedNil],
+
+ // package unsafe
+ types.Typ[types.UnsafePointer],
+
+ // invalid type
+ types.Typ[types.Invalid], // only appears in packages with errors
+
+ // used internally by gc; never used by this package or in .a files
+ anyType{},
+}
+
+type anyType struct{}
+
+func (t anyType) Underlying() types.Type { return t }
+func (t anyType) String() string { return "any" }
diff --git a/src/go/internal/gcimporter/testdata/a.go b/src/go/internal/gcimporter/testdata/a.go
new file mode 100644
index 0000000..56e4292
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/a.go
@@ -0,0 +1,14 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Input for TestIssue13566
+
+package a
+
+import "encoding/json"
+
+type A struct {
+ a *A
+ json json.RawMessage
+}
diff --git a/src/go/internal/gcimporter/testdata/b.go b/src/go/internal/gcimporter/testdata/b.go
new file mode 100644
index 0000000..4196678
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/b.go
@@ -0,0 +1,11 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Input for TestIssue13566
+
+package b
+
+import "./a"
+
+type A a.A
diff --git a/src/go/internal/gcimporter/testdata/exports.go b/src/go/internal/gcimporter/testdata/exports.go
new file mode 100644
index 0000000..8ba3242
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/exports.go
@@ -0,0 +1,88 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is used to generate an object file which
+// serves as test file for gcimporter_test.go.
+
+package exports
+
+import "go/ast"
+
+// Issue 3682: Correctly read dotted identifiers from export data.
+const init1 = 0
+
+func init() {}
+
+const (
+ C0 int = 0
+ C1 = 3.14159265
+ C2 = 2.718281828i
+ C3 = -123.456e-789
+ C4 = +123.456e+789
+ C5 = 1234i
+ C6 = "foo\n"
+ C7 = `bar\n`
+)
+
+type (
+ T1 int
+ T2 [10]int
+ T3 []int
+ T4 *int
+ T5 chan int
+ T6a chan<- int
+ T6b chan (<-chan int)
+ T6c chan<- (chan int)
+ T7 <-chan *ast.File
+ T8 struct{}
+ T9 struct {
+ a int
+ b, c float32
+ d []string `go:"tag"`
+ }
+ T10 struct {
+ T8
+ T9
+ _ *T10
+ }
+ T11 map[int]string
+ T12 interface{}
+ T13 interface {
+ m1()
+ m2(int) float32
+ }
+ T14 interface {
+ T12
+ T13
+ m3(x ...struct{}) []T9
+ }
+ T15 func()
+ T16 func(int)
+ T17 func(x int)
+ T18 func() float32
+ T19 func() (x float32)
+ T20 func(...interface{})
+ T21 struct{ next *T21 }
+ T22 struct{ link *T23 }
+ T23 struct{ link *T22 }
+ T24 *T24
+ T25 *T26
+ T26 *T27
+ T27 *T25
+ T28 func(T28) T28
+)
+
+var (
+ V0 int
+ V1 = -991.0
+ V2 float32 = 1.2
+)
+
+func F1() {}
+func F2(x int) {}
+func F3() int { return 0 }
+func F4() float32 { return 0 }
+func F5(a, b, c int, u, v, w struct{ x, y T1 }, more ...interface{}) (p, q, r chan<- T10)
+
+func (p *T1) M1()
diff --git a/src/go/internal/gcimporter/testdata/issue15920.go b/src/go/internal/gcimporter/testdata/issue15920.go
new file mode 100644
index 0000000..c70f7d8
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/issue15920.go
@@ -0,0 +1,11 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// The underlying type of Error is the underlying type of error.
+// Make sure we can import this again without problems.
+type Error error
+
+func F() Error { return nil }
diff --git a/src/go/internal/gcimporter/testdata/issue20046.go b/src/go/internal/gcimporter/testdata/issue20046.go
new file mode 100644
index 0000000..c63ee82
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/issue20046.go
@@ -0,0 +1,9 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+var V interface {
+ M()
+}
diff --git a/src/go/internal/gcimporter/testdata/issue25301.go b/src/go/internal/gcimporter/testdata/issue25301.go
new file mode 100644
index 0000000..e3dc98b
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/issue25301.go
@@ -0,0 +1,17 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue25301
+
+type (
+ A = interface {
+ M()
+ }
+ T interface {
+ A
+ }
+ S struct{}
+)
+
+func (S) M() { println("m") }
diff --git a/src/go/internal/gcimporter/testdata/issue25596.go b/src/go/internal/gcimporter/testdata/issue25596.go
new file mode 100644
index 0000000..8923373
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/issue25596.go
@@ -0,0 +1,13 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue25596
+
+type E interface {
+ M() T
+}
+
+type T interface {
+ E
+}
diff --git a/src/go/internal/gcimporter/testdata/p.go b/src/go/internal/gcimporter/testdata/p.go
new file mode 100644
index 0000000..9e2e705
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/p.go
@@ -0,0 +1,13 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Input for TestIssue15517
+
+package p
+
+const C = 0
+
+var V int
+
+func F() {}
diff --git a/src/go/internal/gcimporter/testdata/versions/test.go b/src/go/internal/gcimporter/testdata/versions/test.go
new file mode 100644
index 0000000..227fc09
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test.go
@@ -0,0 +1,28 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// To create a test case for a new export format version,
+// build this package with the latest compiler and store
+// the resulting .a file appropriately named in the versions
+// directory. The VersionHandling test will pick it up.
+//
+// In the testdata/versions:
+//
+// go build -o test_go1.$X_$Y.a test.go
+//
+// with $X = Go version and $Y = export format version
+// (add 'b' or 'i' to distinguish between binary and
+// indexed format starting with 1.11 as long as both
+// formats are supported).
+//
+// Make sure this source is extended such that it exercises
+// whatever export format change has taken place.
+
+package test
+
+// Any release before and including Go 1.7 didn't encode
+// the package for a blank struct field.
+type BlankField struct {
+ _ int
+}
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.11_0i.a b/src/go/internal/gcimporter/testdata/versions/test_go1.11_0i.a
new file mode 100644
index 0000000..b00fefe
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.11_0i.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.11_6b.a b/src/go/internal/gcimporter/testdata/versions/test_go1.11_6b.a
new file mode 100644
index 0000000..c0a211e
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.11_6b.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.11_999b.a b/src/go/internal/gcimporter/testdata/versions/test_go1.11_999b.a
new file mode 100644
index 0000000..c35d22d
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.11_999b.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.11_999i.a b/src/go/internal/gcimporter/testdata/versions/test_go1.11_999i.a
new file mode 100644
index 0000000..99401d7
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.11_999i.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.7_0.a b/src/go/internal/gcimporter/testdata/versions/test_go1.7_0.a
new file mode 100644
index 0000000..edb6c3f
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.7_0.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.7_1.a b/src/go/internal/gcimporter/testdata/versions/test_go1.7_1.a
new file mode 100644
index 0000000..554d04a
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.7_1.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.8_4.a b/src/go/internal/gcimporter/testdata/versions/test_go1.8_4.a
new file mode 100644
index 0000000..26b8531
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.8_4.a
Binary files differ
diff --git a/src/go/internal/gcimporter/testdata/versions/test_go1.8_5.a b/src/go/internal/gcimporter/testdata/versions/test_go1.8_5.a
new file mode 100644
index 0000000..60e52ef
--- /dev/null
+++ b/src/go/internal/gcimporter/testdata/versions/test_go1.8_5.a
Binary files differ
diff --git a/src/go/internal/srcimporter/srcimporter.go b/src/go/internal/srcimporter/srcimporter.go
new file mode 100644
index 0000000..438ae0f
--- /dev/null
+++ b/src/go/internal/srcimporter/srcimporter.go
@@ -0,0 +1,265 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package srcimporter implements importing directly
+// from source files rather than installed packages.
+package srcimporter // import "go/internal/srcimporter"
+
+import (
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "go/types"
+ exec "internal/execabs"
+ "io"
+ "os"
+ "path/filepath"
+ "strings"
+ "sync"
+ _ "unsafe" // for go:linkname
+)
+
+// An Importer provides the context for importing packages from source code.
+type Importer struct {
+ ctxt *build.Context
+ fset *token.FileSet
+ sizes types.Sizes
+ packages map[string]*types.Package
+}
+
+// NewImporter returns a new Importer for the given context, file set, and map
+// of packages. The context is used to resolve import paths to package paths,
+// and identifying the files belonging to the package. If the context provides
+// non-nil file system functions, they are used instead of the regular package
+// os functions. The file set is used to track position information of package
+// files; and imported packages are added to the packages map.
+func New(ctxt *build.Context, fset *token.FileSet, packages map[string]*types.Package) *Importer {
+ return &Importer{
+ ctxt: ctxt,
+ fset: fset,
+ sizes: types.SizesFor(ctxt.Compiler, ctxt.GOARCH), // uses go/types default if GOARCH not found
+ packages: packages,
+ }
+}
+
+// Importing is a sentinel taking the place in Importer.packages
+// for a package that is in the process of being imported.
+var importing types.Package
+
+// Import(path) is a shortcut for ImportFrom(path, ".", 0).
+func (p *Importer) Import(path string) (*types.Package, error) {
+ return p.ImportFrom(path, ".", 0) // use "." rather than "" (see issue #24441)
+}
+
+// ImportFrom imports the package with the given import path resolved from the given srcDir,
+// adds the new package to the set of packages maintained by the importer, and returns the
+// package. Package path resolution and file system operations are controlled by the context
+// maintained with the importer. The import mode must be zero but is otherwise ignored.
+// Packages that are not comprised entirely of pure Go files may fail to import because the
+// type checker may not be able to determine all exported entities (e.g. due to cgo dependencies).
+func (p *Importer) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
+ if mode != 0 {
+ panic("non-zero import mode")
+ }
+
+ if abs, err := p.absPath(srcDir); err == nil { // see issue #14282
+ srcDir = abs
+ }
+ bp, err := p.ctxt.Import(path, srcDir, 0)
+ if err != nil {
+ return nil, err // err may be *build.NoGoError - return as is
+ }
+
+ // package unsafe is known to the type checker
+ if bp.ImportPath == "unsafe" {
+ return types.Unsafe, nil
+ }
+
+ // no need to re-import if the package was imported completely before
+ pkg := p.packages[bp.ImportPath]
+ if pkg != nil {
+ if pkg == &importing {
+ return nil, fmt.Errorf("import cycle through package %q", bp.ImportPath)
+ }
+ if !pkg.Complete() {
+ // Package exists but is not complete - we cannot handle this
+ // at the moment since the source importer replaces the package
+ // wholesale rather than augmenting it (see #19337 for details).
+ // Return incomplete package with error (see #16088).
+ return pkg, fmt.Errorf("reimported partially imported package %q", bp.ImportPath)
+ }
+ return pkg, nil
+ }
+
+ p.packages[bp.ImportPath] = &importing
+ defer func() {
+ // clean up in case of error
+ // TODO(gri) Eventually we may want to leave a (possibly empty)
+ // package in the map in all cases (and use that package to
+ // identify cycles). See also issue 16088.
+ if p.packages[bp.ImportPath] == &importing {
+ p.packages[bp.ImportPath] = nil
+ }
+ }()
+
+ var filenames []string
+ filenames = append(filenames, bp.GoFiles...)
+ filenames = append(filenames, bp.CgoFiles...)
+
+ files, err := p.parseFiles(bp.Dir, filenames)
+ if err != nil {
+ return nil, err
+ }
+
+ // type-check package files
+ var firstHardErr error
+ conf := types.Config{
+ IgnoreFuncBodies: true,
+ // continue type-checking after the first error
+ Error: func(err error) {
+ if firstHardErr == nil && !err.(types.Error).Soft {
+ firstHardErr = err
+ }
+ },
+ Importer: p,
+ Sizes: p.sizes,
+ }
+ if len(bp.CgoFiles) > 0 {
+ if p.ctxt.OpenFile != nil {
+ // cgo, gcc, pkg-config, etc. do not support
+ // build.Context's VFS.
+ conf.FakeImportC = true
+ } else {
+ setUsesCgo(&conf)
+ file, err := p.cgo(bp)
+ if err != nil {
+ return nil, err
+ }
+ files = append(files, file)
+ }
+ }
+
+ pkg, err = conf.Check(bp.ImportPath, p.fset, files, nil)
+ if err != nil {
+ // If there was a hard error it is possibly unsafe
+ // to use the package as it may not be fully populated.
+ // Do not return it (see also #20837, #20855).
+ if firstHardErr != nil {
+ pkg = nil
+ err = firstHardErr // give preference to first hard error over any soft error
+ }
+ return pkg, fmt.Errorf("type-checking package %q failed (%v)", bp.ImportPath, err)
+ }
+ if firstHardErr != nil {
+ // this can only happen if we have a bug in go/types
+ panic("package is not safe yet no error was returned")
+ }
+
+ p.packages[bp.ImportPath] = pkg
+ return pkg, nil
+}
+
+func (p *Importer) parseFiles(dir string, filenames []string) ([]*ast.File, error) {
+ // use build.Context's OpenFile if there is one
+ open := p.ctxt.OpenFile
+ if open == nil {
+ open = func(name string) (io.ReadCloser, error) { return os.Open(name) }
+ }
+
+ files := make([]*ast.File, len(filenames))
+ errors := make([]error, len(filenames))
+
+ var wg sync.WaitGroup
+ wg.Add(len(filenames))
+ for i, filename := range filenames {
+ go func(i int, filepath string) {
+ defer wg.Done()
+ src, err := open(filepath)
+ if err != nil {
+ errors[i] = err // open provides operation and filename in error
+ return
+ }
+ files[i], errors[i] = parser.ParseFile(p.fset, filepath, src, 0)
+ src.Close() // ignore Close error - parsing may have succeeded which is all we need
+ }(i, p.joinPath(dir, filename))
+ }
+ wg.Wait()
+
+ // if there are errors, return the first one for deterministic results
+ for _, err := range errors {
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ return files, nil
+}
+
+func (p *Importer) cgo(bp *build.Package) (*ast.File, error) {
+ tmpdir, err := os.MkdirTemp("", "srcimporter")
+ if err != nil {
+ return nil, err
+ }
+ defer os.RemoveAll(tmpdir)
+
+ args := []string{"go", "tool", "cgo", "-objdir", tmpdir}
+ if bp.Goroot {
+ switch bp.ImportPath {
+ case "runtime/cgo":
+ args = append(args, "-import_runtime_cgo=false", "-import_syscall=false")
+ case "runtime/race":
+ args = append(args, "-import_syscall=false")
+ }
+ }
+ args = append(args, "--")
+ args = append(args, strings.Fields(os.Getenv("CGO_CPPFLAGS"))...)
+ args = append(args, bp.CgoCPPFLAGS...)
+ if len(bp.CgoPkgConfig) > 0 {
+ cmd := exec.Command("pkg-config", append([]string{"--cflags"}, bp.CgoPkgConfig...)...)
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ return nil, err
+ }
+ args = append(args, strings.Fields(string(out))...)
+ }
+ args = append(args, "-I", tmpdir)
+ args = append(args, strings.Fields(os.Getenv("CGO_CFLAGS"))...)
+ args = append(args, bp.CgoCFLAGS...)
+ args = append(args, bp.CgoFiles...)
+
+ cmd := exec.Command(args[0], args[1:]...)
+ cmd.Dir = bp.Dir
+ if err := cmd.Run(); err != nil {
+ return nil, err
+ }
+
+ return parser.ParseFile(p.fset, filepath.Join(tmpdir, "_cgo_gotypes.go"), nil, 0)
+}
+
+// context-controlled file system operations
+
+func (p *Importer) absPath(path string) (string, error) {
+ // TODO(gri) This should be using p.ctxt.AbsPath which doesn't
+ // exist but probably should. See also issue #14282.
+ return filepath.Abs(path)
+}
+
+func (p *Importer) isAbsPath(path string) bool {
+ if f := p.ctxt.IsAbsPath; f != nil {
+ return f(path)
+ }
+ return filepath.IsAbs(path)
+}
+
+func (p *Importer) joinPath(elem ...string) string {
+ if f := p.ctxt.JoinPath; f != nil {
+ return f(elem...)
+ }
+ return filepath.Join(elem...)
+}
+
+//go:linkname setUsesCgo go/types.srcimporter_setUsesCgo
+func setUsesCgo(conf *types.Config)
diff --git a/src/go/internal/srcimporter/srcimporter_test.go b/src/go/internal/srcimporter/srcimporter_test.go
new file mode 100644
index 0000000..05b12f1
--- /dev/null
+++ b/src/go/internal/srcimporter/srcimporter_test.go
@@ -0,0 +1,254 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package srcimporter
+
+import (
+ "flag"
+ "go/build"
+ "go/token"
+ "go/types"
+ "internal/testenv"
+ "os"
+ "path"
+ "path/filepath"
+ "runtime"
+ "strings"
+ "testing"
+ "time"
+)
+
+func TestMain(m *testing.M) {
+ flag.Parse()
+ if goTool, err := testenv.GoTool(); err == nil {
+ os.Setenv("PATH", filepath.Dir(goTool)+string(os.PathListSeparator)+os.Getenv("PATH"))
+ }
+ os.Exit(m.Run())
+}
+
+const maxTime = 2 * time.Second
+
+var importer = New(&build.Default, token.NewFileSet(), make(map[string]*types.Package))
+
+func doImport(t *testing.T, path, srcDir string) {
+ t0 := time.Now()
+ if _, err := importer.ImportFrom(path, srcDir, 0); err != nil {
+ // don't report an error if there's no buildable Go files
+ if _, nogo := err.(*build.NoGoError); !nogo {
+ t.Errorf("import %q failed (%v)", path, err)
+ }
+ return
+ }
+ t.Logf("import %q: %v", path, time.Since(t0))
+}
+
+// walkDir imports the all the packages with the given path
+// prefix recursively. It returns the number of packages
+// imported and whether importing was aborted because time
+// has passed endTime.
+func walkDir(t *testing.T, path string, endTime time.Time) (int, bool) {
+ if time.Now().After(endTime) {
+ t.Log("testing time used up")
+ return 0, true
+ }
+
+ // ignore fake packages and testdata directories
+ if path == "builtin" || path == "unsafe" || strings.HasSuffix(path, "testdata") {
+ return 0, false
+ }
+
+ list, err := os.ReadDir(filepath.Join(runtime.GOROOT(), "src", path))
+ if err != nil {
+ t.Fatalf("walkDir %s failed (%v)", path, err)
+ }
+
+ nimports := 0
+ hasGoFiles := false
+ for _, f := range list {
+ if f.IsDir() {
+ n, abort := walkDir(t, filepath.Join(path, f.Name()), endTime)
+ nimports += n
+ if abort {
+ return nimports, true
+ }
+ } else if strings.HasSuffix(f.Name(), ".go") {
+ hasGoFiles = true
+ }
+ }
+
+ if hasGoFiles {
+ doImport(t, path, "")
+ nimports++
+ }
+
+ return nimports, false
+}
+
+func TestImportStdLib(t *testing.T) {
+ if !testenv.HasSrc() {
+ t.Skip("no source code available")
+ }
+
+ if testing.Short() && testenv.Builder() == "" {
+ t.Skip("skipping in -short mode")
+ }
+ dt := maxTime
+ nimports, _ := walkDir(t, "", time.Now().Add(dt)) // installed packages
+ t.Logf("tested %d imports", nimports)
+}
+
+var importedObjectTests = []struct {
+ name string
+ want string
+}{
+ {"flag.Bool", "func Bool(name string, value bool, usage string) *bool"},
+ {"io.Reader", "type Reader interface{Read(p []byte) (n int, err error)}"},
+ {"io.ReadWriter", "type ReadWriter interface{Reader; Writer}"}, // go/types.gcCompatibilityMode is off => interface not flattened
+ {"math.Pi", "const Pi untyped float"},
+ {"math.Sin", "func Sin(x float64) float64"},
+ {"math/big.Int", "type Int struct{neg bool; abs nat}"},
+ {"golang.org/x/text/unicode/norm.MaxSegmentSize", "const MaxSegmentSize untyped int"},
+}
+
+func TestImportedTypes(t *testing.T) {
+ if !testenv.HasSrc() {
+ t.Skip("no source code available")
+ }
+
+ for _, test := range importedObjectTests {
+ i := strings.LastIndex(test.name, ".")
+ if i < 0 {
+ t.Fatal("invalid test data format")
+ }
+ importPath := test.name[:i]
+ objName := test.name[i+1:]
+
+ pkg, err := importer.ImportFrom(importPath, ".", 0)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+
+ obj := pkg.Scope().Lookup(objName)
+ if obj == nil {
+ t.Errorf("%s: object not found", test.name)
+ continue
+ }
+
+ got := types.ObjectString(obj, types.RelativeTo(pkg))
+ if got != test.want {
+ t.Errorf("%s: got %q; want %q", test.name, got, test.want)
+ }
+
+ if named, _ := obj.Type().(*types.Named); named != nil {
+ verifyInterfaceMethodRecvs(t, named, 0)
+ }
+ }
+}
+
+// verifyInterfaceMethodRecvs verifies that method receiver types
+// are named if the methods belong to a named interface type.
+func verifyInterfaceMethodRecvs(t *testing.T, named *types.Named, level int) {
+ // avoid endless recursion in case of an embedding bug that lead to a cycle
+ if level > 10 {
+ t.Errorf("%s: embeds itself", named)
+ return
+ }
+
+ iface, _ := named.Underlying().(*types.Interface)
+ if iface == nil {
+ return // not an interface
+ }
+
+ // check explicitly declared methods
+ for i := 0; i < iface.NumExplicitMethods(); i++ {
+ m := iface.ExplicitMethod(i)
+ recv := m.Type().(*types.Signature).Recv()
+ if recv == nil {
+ t.Errorf("%s: missing receiver type", m)
+ continue
+ }
+ if recv.Type() != named {
+ t.Errorf("%s: got recv type %s; want %s", m, recv.Type(), named)
+ }
+ }
+
+ // check embedded interfaces (they are named, too)
+ for i := 0; i < iface.NumEmbeddeds(); i++ {
+ // embedding of interfaces cannot have cycles; recursion will terminate
+ verifyInterfaceMethodRecvs(t, iface.Embedded(i), level+1)
+ }
+}
+
+func TestReimport(t *testing.T) {
+ if !testenv.HasSrc() {
+ t.Skip("no source code available")
+ }
+
+ // Reimporting a partially imported (incomplete) package is not supported (see issue #19337).
+ // Make sure we recognize the situation and report an error.
+
+ mathPkg := types.NewPackage("math", "math") // incomplete package
+ importer := New(&build.Default, token.NewFileSet(), map[string]*types.Package{mathPkg.Path(): mathPkg})
+ _, err := importer.ImportFrom("math", ".", 0)
+ if err == nil || !strings.HasPrefix(err.Error(), "reimport") {
+ t.Errorf("got %v; want reimport error", err)
+ }
+}
+
+func TestIssue20855(t *testing.T) {
+ if !testenv.HasSrc() {
+ t.Skip("no source code available")
+ }
+
+ pkg, err := importer.ImportFrom("go/internal/srcimporter/testdata/issue20855", ".", 0)
+ if err == nil || !strings.Contains(err.Error(), "missing function body") {
+ t.Fatalf("got unexpected or no error: %v", err)
+ }
+ if pkg == nil {
+ t.Error("got no package despite no hard errors")
+ }
+}
+
+func testImportPath(t *testing.T, pkgPath string) {
+ if !testenv.HasSrc() {
+ t.Skip("no source code available")
+ }
+
+ pkgName := path.Base(pkgPath)
+
+ pkg, err := importer.Import(pkgPath)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if pkg.Name() != pkgName {
+ t.Errorf("got %q; want %q", pkg.Name(), pkgName)
+ }
+
+ if pkg.Path() != pkgPath {
+ t.Errorf("got %q; want %q", pkg.Path(), pkgPath)
+ }
+}
+
+// TestIssue23092 tests relative imports.
+func TestIssue23092(t *testing.T) {
+ testImportPath(t, "./testdata/issue23092")
+}
+
+// TestIssue24392 tests imports against a path containing 'testdata'.
+func TestIssue24392(t *testing.T) {
+ testImportPath(t, "go/internal/srcimporter/testdata/issue24392")
+}
+
+func TestCgo(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+ testenv.MustHaveCGO(t)
+
+ importer := New(&build.Default, token.NewFileSet(), make(map[string]*types.Package))
+ _, err := importer.ImportFrom("./misc/cgo/test", runtime.GOROOT(), 0)
+ if err != nil {
+ t.Fatalf("Import failed: %v", err)
+ }
+}
diff --git a/src/go/internal/srcimporter/testdata/issue20855/issue20855.go b/src/go/internal/srcimporter/testdata/issue20855/issue20855.go
new file mode 100644
index 0000000..d55448b
--- /dev/null
+++ b/src/go/internal/srcimporter/testdata/issue20855/issue20855.go
@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue20855
+
+func init() // "missing function body" is a soft error
diff --git a/src/go/internal/srcimporter/testdata/issue23092/issue23092.go b/src/go/internal/srcimporter/testdata/issue23092/issue23092.go
new file mode 100644
index 0000000..608698b
--- /dev/null
+++ b/src/go/internal/srcimporter/testdata/issue23092/issue23092.go
@@ -0,0 +1,5 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue23092
diff --git a/src/go/internal/srcimporter/testdata/issue24392/issue24392.go b/src/go/internal/srcimporter/testdata/issue24392/issue24392.go
new file mode 100644
index 0000000..8ad5221
--- /dev/null
+++ b/src/go/internal/srcimporter/testdata/issue24392/issue24392.go
@@ -0,0 +1,5 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue24392
diff --git a/src/go/parser/error_test.go b/src/go/parser/error_test.go
new file mode 100644
index 0000000..358a844
--- /dev/null
+++ b/src/go/parser/error_test.go
@@ -0,0 +1,187 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements a parser test harness. The files in the testdata
+// directory are parsed and the errors reported are compared against the
+// error messages expected in the test files. The test files must end in
+// .src rather than .go so that they are not disturbed by gofmt runs.
+//
+// Expected errors are indicated in the test files by putting a comment
+// of the form /* ERROR "rx" */ immediately following an offending token.
+// The harness will verify that an error matching the regular expression
+// rx is reported at that source position.
+//
+// For instance, the following test file indicates that a "not declared"
+// error should be reported for the undeclared variable x:
+//
+// package p
+// func f() {
+// _ = x /* ERROR "not declared" */ + 1
+// }
+
+package parser
+
+import (
+ "go/scanner"
+ "go/token"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strings"
+ "testing"
+)
+
+const testdata = "testdata"
+
+// getFile assumes that each filename occurs at most once
+func getFile(fset *token.FileSet, filename string) (file *token.File) {
+ fset.Iterate(func(f *token.File) bool {
+ if f.Name() == filename {
+ if file != nil {
+ panic(filename + " used multiple times")
+ }
+ file = f
+ }
+ return true
+ })
+ return file
+}
+
+func getPos(fset *token.FileSet, filename string, offset int) token.Pos {
+ if f := getFile(fset, filename); f != nil {
+ return f.Pos(offset)
+ }
+ return token.NoPos
+}
+
+// ERROR comments must be of the form /* ERROR "rx" */ and rx is
+// a regular expression that matches the expected error message.
+// The special form /* ERROR HERE "rx" */ must be used for error
+// messages that appear immediately after a token, rather than at
+// a token's position.
+//
+var errRx = regexp.MustCompile(`^/\* *ERROR *(HERE)? *"([^"]*)" *\*/$`)
+
+// expectedErrors collects the regular expressions of ERROR comments found
+// in files and returns them as a map of error positions to error messages.
+//
+func expectedErrors(fset *token.FileSet, filename string, src []byte) map[token.Pos]string {
+ errors := make(map[token.Pos]string)
+
+ var s scanner.Scanner
+ // file was parsed already - do not add it again to the file
+ // set otherwise the position information returned here will
+ // not match the position information collected by the parser
+ s.Init(getFile(fset, filename), src, nil, scanner.ScanComments)
+ var prev token.Pos // position of last non-comment, non-semicolon token
+ var here token.Pos // position immediately after the token at position prev
+
+ for {
+ pos, tok, lit := s.Scan()
+ switch tok {
+ case token.EOF:
+ return errors
+ case token.COMMENT:
+ s := errRx.FindStringSubmatch(lit)
+ if len(s) == 3 {
+ pos := prev
+ if s[1] == "HERE" {
+ pos = here
+ }
+ errors[pos] = string(s[2])
+ }
+ case token.SEMICOLON:
+ // don't use the position of auto-inserted (invisible) semicolons
+ if lit != ";" {
+ break
+ }
+ fallthrough
+ default:
+ prev = pos
+ var l int // token length
+ if tok.IsLiteral() {
+ l = len(lit)
+ } else {
+ l = len(tok.String())
+ }
+ here = prev + token.Pos(l)
+ }
+ }
+}
+
+// compareErrors compares the map of expected error messages with the list
+// of found errors and reports discrepancies.
+//
+func compareErrors(t *testing.T, fset *token.FileSet, expected map[token.Pos]string, found scanner.ErrorList) {
+ for _, error := range found {
+ // error.Pos is a token.Position, but we want
+ // a token.Pos so we can do a map lookup
+ pos := getPos(fset, error.Pos.Filename, error.Pos.Offset)
+ if msg, found := expected[pos]; found {
+ // we expect a message at pos; check if it matches
+ rx, err := regexp.Compile(msg)
+ if err != nil {
+ t.Errorf("%s: %v", error.Pos, err)
+ continue
+ }
+ if match := rx.MatchString(error.Msg); !match {
+ t.Errorf("%s: %q does not match %q", error.Pos, error.Msg, msg)
+ continue
+ }
+ // we have a match - eliminate this error
+ delete(expected, pos)
+ } else {
+ // To keep in mind when analyzing failed test output:
+ // If the same error position occurs multiple times in errors,
+ // this message will be triggered (because the first error at
+ // the position removes this position from the expected errors).
+ t.Errorf("%s: unexpected error: %s", error.Pos, error.Msg)
+ }
+ }
+
+ // there should be no expected errors left
+ if len(expected) > 0 {
+ t.Errorf("%d errors not reported:", len(expected))
+ for pos, msg := range expected {
+ t.Errorf("%s: %s\n", fset.Position(pos), msg)
+ }
+ }
+}
+
+func checkErrors(t *testing.T, filename string, input interface{}) {
+ src, err := readSource(filename, input)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ fset := token.NewFileSet()
+ _, err = ParseFile(fset, filename, src, DeclarationErrors|AllErrors)
+ found, ok := err.(scanner.ErrorList)
+ if err != nil && !ok {
+ t.Error(err)
+ return
+ }
+ found.RemoveMultiples()
+
+ // we are expecting the following errors
+ // (collect these after parsing a file so that it is found in the file set)
+ expected := expectedErrors(fset, filename, src)
+
+ // verify errors returned by the parser
+ compareErrors(t, fset, expected, found)
+}
+
+func TestErrors(t *testing.T) {
+ list, err := os.ReadDir(testdata)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for _, d := range list {
+ name := d.Name()
+ if !d.IsDir() && !strings.HasPrefix(name, ".") && strings.HasSuffix(name, ".src") {
+ checkErrors(t, filepath.Join(testdata, name), nil)
+ }
+ }
+}
diff --git a/src/go/parser/example_test.go b/src/go/parser/example_test.go
new file mode 100644
index 0000000..c2f7f29
--- /dev/null
+++ b/src/go/parser/example_test.go
@@ -0,0 +1,43 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package parser_test
+
+import (
+ "fmt"
+ "go/parser"
+ "go/token"
+)
+
+func ExampleParseFile() {
+ fset := token.NewFileSet() // positions are relative to fset
+
+ src := `package foo
+
+import (
+ "fmt"
+ "time"
+)
+
+func bar() {
+ fmt.Println(time.Now())
+}`
+
+ // Parse src but stop after processing the imports.
+ f, err := parser.ParseFile(fset, "", src, parser.ImportsOnly)
+ if err != nil {
+ fmt.Println(err)
+ return
+ }
+
+ // Print the imports from the file's AST.
+ for _, s := range f.Imports {
+ fmt.Println(s.Path.Value)
+ }
+
+ // output:
+ //
+ // "fmt"
+ // "time"
+}
diff --git a/src/go/parser/interface.go b/src/go/parser/interface.go
new file mode 100644
index 0000000..56ff5fe
--- /dev/null
+++ b/src/go/parser/interface.go
@@ -0,0 +1,241 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the exported entry points for invoking the parser.
+
+package parser
+
+import (
+ "bytes"
+ "errors"
+ "go/ast"
+ "go/token"
+ "io"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "strings"
+)
+
+// If src != nil, readSource converts src to a []byte if possible;
+// otherwise it returns an error. If src == nil, readSource returns
+// the result of reading the file specified by filename.
+//
+func readSource(filename string, src interface{}) ([]byte, error) {
+ if src != nil {
+ switch s := src.(type) {
+ case string:
+ return []byte(s), nil
+ case []byte:
+ return s, nil
+ case *bytes.Buffer:
+ // is io.Reader, but src is already available in []byte form
+ if s != nil {
+ return s.Bytes(), nil
+ }
+ case io.Reader:
+ return io.ReadAll(s)
+ }
+ return nil, errors.New("invalid source")
+ }
+ return os.ReadFile(filename)
+}
+
+// A Mode value is a set of flags (or 0).
+// They control the amount of source code parsed and other optional
+// parser functionality.
+//
+type Mode uint
+
+const (
+ PackageClauseOnly Mode = 1 << iota // stop parsing after package clause
+ ImportsOnly // stop parsing after import declarations
+ ParseComments // parse comments and add them to AST
+ Trace // print a trace of parsed productions
+ DeclarationErrors // report declaration errors
+ SpuriousErrors // same as AllErrors, for backward-compatibility
+ AllErrors = SpuriousErrors // report all errors (not just the first 10 on different lines)
+)
+
+// ParseFile parses the source code of a single Go source file and returns
+// the corresponding ast.File node. The source code may be provided via
+// the filename of the source file, or via the src parameter.
+//
+// If src != nil, ParseFile parses the source from src and the filename is
+// only used when recording position information. The type of the argument
+// for the src parameter must be string, []byte, or io.Reader.
+// If src == nil, ParseFile parses the file specified by filename.
+//
+// The mode parameter controls the amount of source text parsed and other
+// optional parser functionality. Position information is recorded in the
+// file set fset, which must not be nil.
+//
+// If the source couldn't be read, the returned AST is nil and the error
+// indicates the specific failure. If the source was read but syntax
+// errors were found, the result is a partial AST (with ast.Bad* nodes
+// representing the fragments of erroneous source code). Multiple errors
+// are returned via a scanner.ErrorList which is sorted by source position.
+//
+func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (f *ast.File, err error) {
+ if fset == nil {
+ panic("parser.ParseFile: no token.FileSet provided (fset == nil)")
+ }
+
+ // get source
+ text, err := readSource(filename, src)
+ if err != nil {
+ return nil, err
+ }
+
+ var p parser
+ defer func() {
+ if e := recover(); e != nil {
+ // resume same panic if it's not a bailout
+ if _, ok := e.(bailout); !ok {
+ panic(e)
+ }
+ }
+
+ // set result values
+ if f == nil {
+ // source is not a valid Go source file - satisfy
+ // ParseFile API and return a valid (but) empty
+ // *ast.File
+ f = &ast.File{
+ Name: new(ast.Ident),
+ Scope: ast.NewScope(nil),
+ }
+ }
+
+ p.errors.Sort()
+ err = p.errors.Err()
+ }()
+
+ // parse source
+ p.init(fset, filename, text, mode)
+ f = p.parseFile()
+
+ return
+}
+
+// ParseDir calls ParseFile for all files with names ending in ".go" in the
+// directory specified by path and returns a map of package name -> package
+// AST with all the packages found.
+//
+// If filter != nil, only the files with fs.FileInfo entries passing through
+// the filter (and ending in ".go") are considered. The mode bits are passed
+// to ParseFile unchanged. Position information is recorded in fset, which
+// must not be nil.
+//
+// If the directory couldn't be read, a nil map and the respective error are
+// returned. If a parse error occurred, a non-nil but incomplete map and the
+// first error encountered are returned.
+//
+func ParseDir(fset *token.FileSet, path string, filter func(fs.FileInfo) bool, mode Mode) (pkgs map[string]*ast.Package, first error) {
+ list, err := os.ReadDir(path)
+ if err != nil {
+ return nil, err
+ }
+
+ pkgs = make(map[string]*ast.Package)
+ for _, d := range list {
+ if d.IsDir() || !strings.HasSuffix(d.Name(), ".go") {
+ continue
+ }
+ if filter != nil {
+ info, err := d.Info()
+ if err != nil {
+ return nil, err
+ }
+ if !filter(info) {
+ continue
+ }
+ }
+ filename := filepath.Join(path, d.Name())
+ if src, err := ParseFile(fset, filename, nil, mode); err == nil {
+ name := src.Name.Name
+ pkg, found := pkgs[name]
+ if !found {
+ pkg = &ast.Package{
+ Name: name,
+ Files: make(map[string]*ast.File),
+ }
+ pkgs[name] = pkg
+ }
+ pkg.Files[filename] = src
+ } else if first == nil {
+ first = err
+ }
+ }
+
+ return
+}
+
+// ParseExprFrom is a convenience function for parsing an expression.
+// The arguments have the same meaning as for ParseFile, but the source must
+// be a valid Go (type or value) expression. Specifically, fset must not
+// be nil.
+//
+// If the source couldn't be read, the returned AST is nil and the error
+// indicates the specific failure. If the source was read but syntax
+// errors were found, the result is a partial AST (with ast.Bad* nodes
+// representing the fragments of erroneous source code). Multiple errors
+// are returned via a scanner.ErrorList which is sorted by source position.
+//
+func ParseExprFrom(fset *token.FileSet, filename string, src interface{}, mode Mode) (expr ast.Expr, err error) {
+ if fset == nil {
+ panic("parser.ParseExprFrom: no token.FileSet provided (fset == nil)")
+ }
+
+ // get source
+ text, err := readSource(filename, src)
+ if err != nil {
+ return nil, err
+ }
+
+ var p parser
+ defer func() {
+ if e := recover(); e != nil {
+ // resume same panic if it's not a bailout
+ if _, ok := e.(bailout); !ok {
+ panic(e)
+ }
+ }
+ p.errors.Sort()
+ err = p.errors.Err()
+ }()
+
+ // parse expr
+ p.init(fset, filename, text, mode)
+ // Set up pkg-level scopes to avoid nil-pointer errors.
+ // This is not needed for a correct expression x as the
+ // parser will be ok with a nil topScope, but be cautious
+ // in case of an erroneous x.
+ p.openScope()
+ p.pkgScope = p.topScope
+ expr = p.parseRhsOrType()
+ p.closeScope()
+ assert(p.topScope == nil, "unbalanced scopes")
+
+ // If a semicolon was inserted, consume it;
+ // report an error if there's more tokens.
+ if p.tok == token.SEMICOLON && p.lit == "\n" {
+ p.next()
+ }
+ p.expect(token.EOF)
+
+ return
+}
+
+// ParseExpr is a convenience function for obtaining the AST of an expression x.
+// The position information recorded in the AST is undefined. The filename used
+// in error messages is the empty string.
+//
+// If syntax errors were found, the result is a partial AST (with ast.Bad* nodes
+// representing the fragments of erroneous source code). Multiple errors are
+// returned via a scanner.ErrorList which is sorted by source position.
+//
+func ParseExpr(x string) (ast.Expr, error) {
+ return ParseExprFrom(token.NewFileSet(), "", []byte(x), 0)
+}
diff --git a/src/go/parser/parser.go b/src/go/parser/parser.go
new file mode 100644
index 0000000..31a7398
--- /dev/null
+++ b/src/go/parser/parser.go
@@ -0,0 +1,2591 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package parser implements a parser for Go source files. Input may be
+// provided in a variety of forms (see the various Parse* functions); the
+// output is an abstract syntax tree (AST) representing the Go source. The
+// parser is invoked through one of the Parse* functions.
+//
+// The parser accepts a larger language than is syntactically permitted by
+// the Go spec, for simplicity, and for improved robustness in the presence
+// of syntax errors. For instance, in method declarations, the receiver is
+// treated like an ordinary parameter list and thus may contain multiple
+// entries where the spec permits exactly one. Consequently, the corresponding
+// field in the AST (ast.FuncDecl.Recv) field is not restricted to one entry.
+//
+package parser
+
+import (
+ "fmt"
+ "go/ast"
+ "go/scanner"
+ "go/token"
+ "strconv"
+ "strings"
+ "unicode"
+)
+
+// The parser structure holds the parser's internal state.
+type parser struct {
+ file *token.File
+ errors scanner.ErrorList
+ scanner scanner.Scanner
+
+ // Tracing/debugging
+ mode Mode // parsing mode
+ trace bool // == (mode & Trace != 0)
+ indent int // indentation used for tracing output
+
+ // Comments
+ comments []*ast.CommentGroup
+ leadComment *ast.CommentGroup // last lead comment
+ lineComment *ast.CommentGroup // last line comment
+
+ // Next token
+ pos token.Pos // token position
+ tok token.Token // one token look-ahead
+ lit string // token literal
+
+ // Error recovery
+ // (used to limit the number of calls to parser.advance
+ // w/o making scanning progress - avoids potential endless
+ // loops across multiple parser functions during error recovery)
+ syncPos token.Pos // last synchronization position
+ syncCnt int // number of parser.advance calls without progress
+
+ // Non-syntactic parser control
+ exprLev int // < 0: in control clause, >= 0: in expression
+ inRhs bool // if set, the parser is parsing a rhs expression
+
+ // Ordinary identifier scopes
+ pkgScope *ast.Scope // pkgScope.Outer == nil
+ topScope *ast.Scope // top-most scope; may be pkgScope
+ unresolved []*ast.Ident // unresolved identifiers
+ imports []*ast.ImportSpec // list of imports
+
+ // Label scopes
+ // (maintained by open/close LabelScope)
+ labelScope *ast.Scope // label scope for current function
+ targetStack [][]*ast.Ident // stack of unresolved labels
+}
+
+func (p *parser) init(fset *token.FileSet, filename string, src []byte, mode Mode) {
+ p.file = fset.AddFile(filename, -1, len(src))
+ var m scanner.Mode
+ if mode&ParseComments != 0 {
+ m = scanner.ScanComments
+ }
+ eh := func(pos token.Position, msg string) { p.errors.Add(pos, msg) }
+ p.scanner.Init(p.file, src, eh, m)
+
+ p.mode = mode
+ p.trace = mode&Trace != 0 // for convenience (p.trace is used frequently)
+
+ p.next()
+}
+
+// ----------------------------------------------------------------------------
+// Scoping support
+
+func (p *parser) openScope() {
+ p.topScope = ast.NewScope(p.topScope)
+}
+
+func (p *parser) closeScope() {
+ p.topScope = p.topScope.Outer
+}
+
+func (p *parser) openLabelScope() {
+ p.labelScope = ast.NewScope(p.labelScope)
+ p.targetStack = append(p.targetStack, nil)
+}
+
+func (p *parser) closeLabelScope() {
+ // resolve labels
+ n := len(p.targetStack) - 1
+ scope := p.labelScope
+ for _, ident := range p.targetStack[n] {
+ ident.Obj = scope.Lookup(ident.Name)
+ if ident.Obj == nil && p.mode&DeclarationErrors != 0 {
+ p.error(ident.Pos(), fmt.Sprintf("label %s undefined", ident.Name))
+ }
+ }
+ // pop label scope
+ p.targetStack = p.targetStack[0:n]
+ p.labelScope = p.labelScope.Outer
+}
+
+func (p *parser) declare(decl, data interface{}, scope *ast.Scope, kind ast.ObjKind, idents ...*ast.Ident) {
+ for _, ident := range idents {
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ obj := ast.NewObj(kind, ident.Name)
+ // remember the corresponding declaration for redeclaration
+ // errors and global variable resolution/typechecking phase
+ obj.Decl = decl
+ obj.Data = data
+ ident.Obj = obj
+ if ident.Name != "_" {
+ if alt := scope.Insert(obj); alt != nil && p.mode&DeclarationErrors != 0 {
+ prevDecl := ""
+ if pos := alt.Pos(); pos.IsValid() {
+ prevDecl = fmt.Sprintf("\n\tprevious declaration at %s", p.file.Position(pos))
+ }
+ p.error(ident.Pos(), fmt.Sprintf("%s redeclared in this block%s", ident.Name, prevDecl))
+ }
+ }
+ }
+}
+
+func (p *parser) shortVarDecl(decl *ast.AssignStmt, list []ast.Expr) {
+ // Go spec: A short variable declaration may redeclare variables
+ // provided they were originally declared in the same block with
+ // the same type, and at least one of the non-blank variables is new.
+ n := 0 // number of new variables
+ for _, x := range list {
+ if ident, isIdent := x.(*ast.Ident); isIdent {
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ obj := ast.NewObj(ast.Var, ident.Name)
+ // remember corresponding assignment for other tools
+ obj.Decl = decl
+ ident.Obj = obj
+ if ident.Name != "_" {
+ if alt := p.topScope.Insert(obj); alt != nil {
+ ident.Obj = alt // redeclaration
+ } else {
+ n++ // new declaration
+ }
+ }
+ } else {
+ p.errorExpected(x.Pos(), "identifier on left side of :=")
+ }
+ }
+ if n == 0 && p.mode&DeclarationErrors != 0 {
+ p.error(list[0].Pos(), "no new variables on left side of :=")
+ }
+}
+
+// The unresolved object is a sentinel to mark identifiers that have been added
+// to the list of unresolved identifiers. The sentinel is only used for verifying
+// internal consistency.
+var unresolved = new(ast.Object)
+
+// If x is an identifier, tryResolve attempts to resolve x by looking up
+// the object it denotes. If no object is found and collectUnresolved is
+// set, x is marked as unresolved and collected in the list of unresolved
+// identifiers.
+//
+func (p *parser) tryResolve(x ast.Expr, collectUnresolved bool) {
+ // nothing to do if x is not an identifier or the blank identifier
+ ident, _ := x.(*ast.Ident)
+ if ident == nil {
+ return
+ }
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ if ident.Name == "_" {
+ return
+ }
+ // try to resolve the identifier
+ for s := p.topScope; s != nil; s = s.Outer {
+ if obj := s.Lookup(ident.Name); obj != nil {
+ ident.Obj = obj
+ return
+ }
+ }
+ // all local scopes are known, so any unresolved identifier
+ // must be found either in the file scope, package scope
+ // (perhaps in another file), or universe scope --- collect
+ // them so that they can be resolved later
+ if collectUnresolved {
+ ident.Obj = unresolved
+ p.unresolved = append(p.unresolved, ident)
+ }
+}
+
+func (p *parser) resolve(x ast.Expr) {
+ p.tryResolve(x, true)
+}
+
+// ----------------------------------------------------------------------------
+// Parsing support
+
+func (p *parser) printTrace(a ...interface{}) {
+ const dots = ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "
+ const n = len(dots)
+ pos := p.file.Position(p.pos)
+ fmt.Printf("%5d:%3d: ", pos.Line, pos.Column)
+ i := 2 * p.indent
+ for i > n {
+ fmt.Print(dots)
+ i -= n
+ }
+ // i <= n
+ fmt.Print(dots[0:i])
+ fmt.Println(a...)
+}
+
+func trace(p *parser, msg string) *parser {
+ p.printTrace(msg, "(")
+ p.indent++
+ return p
+}
+
+// Usage pattern: defer un(trace(p, "..."))
+func un(p *parser) {
+ p.indent--
+ p.printTrace(")")
+}
+
+// Advance to the next token.
+func (p *parser) next0() {
+ // Because of one-token look-ahead, print the previous token
+ // when tracing as it provides a more readable output. The
+ // very first token (!p.pos.IsValid()) is not initialized
+ // (it is token.ILLEGAL), so don't print it .
+ if p.trace && p.pos.IsValid() {
+ s := p.tok.String()
+ switch {
+ case p.tok.IsLiteral():
+ p.printTrace(s, p.lit)
+ case p.tok.IsOperator(), p.tok.IsKeyword():
+ p.printTrace("\"" + s + "\"")
+ default:
+ p.printTrace(s)
+ }
+ }
+
+ p.pos, p.tok, p.lit = p.scanner.Scan()
+}
+
+// Consume a comment and return it and the line on which it ends.
+func (p *parser) consumeComment() (comment *ast.Comment, endline int) {
+ // /*-style comments may end on a different line than where they start.
+ // Scan the comment for '\n' chars and adjust endline accordingly.
+ endline = p.file.Line(p.pos)
+ if p.lit[1] == '*' {
+ // don't use range here - no need to decode Unicode code points
+ for i := 0; i < len(p.lit); i++ {
+ if p.lit[i] == '\n' {
+ endline++
+ }
+ }
+ }
+
+ comment = &ast.Comment{Slash: p.pos, Text: p.lit}
+ p.next0()
+
+ return
+}
+
+// Consume a group of adjacent comments, add it to the parser's
+// comments list, and return it together with the line at which
+// the last comment in the group ends. A non-comment token or n
+// empty lines terminate a comment group.
+//
+func (p *parser) consumeCommentGroup(n int) (comments *ast.CommentGroup, endline int) {
+ var list []*ast.Comment
+ endline = p.file.Line(p.pos)
+ for p.tok == token.COMMENT && p.file.Line(p.pos) <= endline+n {
+ var comment *ast.Comment
+ comment, endline = p.consumeComment()
+ list = append(list, comment)
+ }
+
+ // add comment group to the comments list
+ comments = &ast.CommentGroup{List: list}
+ p.comments = append(p.comments, comments)
+
+ return
+}
+
+// Advance to the next non-comment token. In the process, collect
+// any comment groups encountered, and remember the last lead and
+// line comments.
+//
+// A lead comment is a comment group that starts and ends in a
+// line without any other tokens and that is followed by a non-comment
+// token on the line immediately after the comment group.
+//
+// A line comment is a comment group that follows a non-comment
+// token on the same line, and that has no tokens after it on the line
+// where it ends.
+//
+// Lead and line comments may be considered documentation that is
+// stored in the AST.
+//
+func (p *parser) next() {
+ p.leadComment = nil
+ p.lineComment = nil
+ prev := p.pos
+ p.next0()
+
+ if p.tok == token.COMMENT {
+ var comment *ast.CommentGroup
+ var endline int
+
+ if p.file.Line(p.pos) == p.file.Line(prev) {
+ // The comment is on same line as the previous token; it
+ // cannot be a lead comment but may be a line comment.
+ comment, endline = p.consumeCommentGroup(0)
+ if p.file.Line(p.pos) != endline || p.tok == token.EOF {
+ // The next token is on a different line, thus
+ // the last comment group is a line comment.
+ p.lineComment = comment
+ }
+ }
+
+ // consume successor comments, if any
+ endline = -1
+ for p.tok == token.COMMENT {
+ comment, endline = p.consumeCommentGroup(1)
+ }
+
+ if endline+1 == p.file.Line(p.pos) {
+ // The next token is following on the line immediately after the
+ // comment group, thus the last comment group is a lead comment.
+ p.leadComment = comment
+ }
+ }
+}
+
+// A bailout panic is raised to indicate early termination.
+type bailout struct{}
+
+func (p *parser) error(pos token.Pos, msg string) {
+ epos := p.file.Position(pos)
+
+ // If AllErrors is not set, discard errors reported on the same line
+ // as the last recorded error and stop parsing if there are more than
+ // 10 errors.
+ if p.mode&AllErrors == 0 {
+ n := len(p.errors)
+ if n > 0 && p.errors[n-1].Pos.Line == epos.Line {
+ return // discard - likely a spurious error
+ }
+ if n > 10 {
+ panic(bailout{})
+ }
+ }
+
+ p.errors.Add(epos, msg)
+}
+
+func (p *parser) errorExpected(pos token.Pos, msg string) {
+ msg = "expected " + msg
+ if pos == p.pos {
+ // the error happened at the current position;
+ // make the error message more specific
+ switch {
+ case p.tok == token.SEMICOLON && p.lit == "\n":
+ msg += ", found newline"
+ case p.tok.IsLiteral():
+ // print 123 rather than 'INT', etc.
+ msg += ", found " + p.lit
+ default:
+ msg += ", found '" + p.tok.String() + "'"
+ }
+ }
+ p.error(pos, msg)
+}
+
+func (p *parser) expect(tok token.Token) token.Pos {
+ pos := p.pos
+ if p.tok != tok {
+ p.errorExpected(pos, "'"+tok.String()+"'")
+ }
+ p.next() // make progress
+ return pos
+}
+
+// expect2 is like expect, but it returns an invalid position
+// if the expected token is not found.
+func (p *parser) expect2(tok token.Token) (pos token.Pos) {
+ if p.tok == tok {
+ pos = p.pos
+ } else {
+ p.errorExpected(p.pos, "'"+tok.String()+"'")
+ }
+ p.next() // make progress
+ return
+}
+
+// expectClosing is like expect but provides a better error message
+// for the common case of a missing comma before a newline.
+//
+func (p *parser) expectClosing(tok token.Token, context string) token.Pos {
+ if p.tok != tok && p.tok == token.SEMICOLON && p.lit == "\n" {
+ p.error(p.pos, "missing ',' before newline in "+context)
+ p.next()
+ }
+ return p.expect(tok)
+}
+
+func (p *parser) expectSemi() {
+ // semicolon is optional before a closing ')' or '}'
+ if p.tok != token.RPAREN && p.tok != token.RBRACE {
+ switch p.tok {
+ case token.COMMA:
+ // permit a ',' instead of a ';' but complain
+ p.errorExpected(p.pos, "';'")
+ fallthrough
+ case token.SEMICOLON:
+ p.next()
+ default:
+ p.errorExpected(p.pos, "';'")
+ p.advance(stmtStart)
+ }
+ }
+}
+
+func (p *parser) atComma(context string, follow token.Token) bool {
+ if p.tok == token.COMMA {
+ return true
+ }
+ if p.tok != follow {
+ msg := "missing ','"
+ if p.tok == token.SEMICOLON && p.lit == "\n" {
+ msg += " before newline"
+ }
+ p.error(p.pos, msg+" in "+context)
+ return true // "insert" comma and continue
+ }
+ return false
+}
+
+func assert(cond bool, msg string) {
+ if !cond {
+ panic("go/parser internal error: " + msg)
+ }
+}
+
+// advance consumes tokens until the current token p.tok
+// is in the 'to' set, or token.EOF. For error recovery.
+func (p *parser) advance(to map[token.Token]bool) {
+ for ; p.tok != token.EOF; p.next() {
+ if to[p.tok] {
+ // Return only if parser made some progress since last
+ // sync or if it has not reached 10 advance calls without
+ // progress. Otherwise consume at least one token to
+ // avoid an endless parser loop (it is possible that
+ // both parseOperand and parseStmt call advance and
+ // correctly do not advance, thus the need for the
+ // invocation limit p.syncCnt).
+ if p.pos == p.syncPos && p.syncCnt < 10 {
+ p.syncCnt++
+ return
+ }
+ if p.pos > p.syncPos {
+ p.syncPos = p.pos
+ p.syncCnt = 0
+ return
+ }
+ // Reaching here indicates a parser bug, likely an
+ // incorrect token list in this function, but it only
+ // leads to skipping of possibly correct code if a
+ // previous error is present, and thus is preferred
+ // over a non-terminating parse.
+ }
+ }
+}
+
+var stmtStart = map[token.Token]bool{
+ token.BREAK: true,
+ token.CONST: true,
+ token.CONTINUE: true,
+ token.DEFER: true,
+ token.FALLTHROUGH: true,
+ token.FOR: true,
+ token.GO: true,
+ token.GOTO: true,
+ token.IF: true,
+ token.RETURN: true,
+ token.SELECT: true,
+ token.SWITCH: true,
+ token.TYPE: true,
+ token.VAR: true,
+}
+
+var declStart = map[token.Token]bool{
+ token.CONST: true,
+ token.TYPE: true,
+ token.VAR: true,
+}
+
+var exprEnd = map[token.Token]bool{
+ token.COMMA: true,
+ token.COLON: true,
+ token.SEMICOLON: true,
+ token.RPAREN: true,
+ token.RBRACK: true,
+ token.RBRACE: true,
+}
+
+// safePos returns a valid file position for a given position: If pos
+// is valid to begin with, safePos returns pos. If pos is out-of-range,
+// safePos returns the EOF position.
+//
+// This is hack to work around "artificial" end positions in the AST which
+// are computed by adding 1 to (presumably valid) token positions. If the
+// token positions are invalid due to parse errors, the resulting end position
+// may be past the file's EOF position, which would lead to panics if used
+// later on.
+//
+func (p *parser) safePos(pos token.Pos) (res token.Pos) {
+ defer func() {
+ if recover() != nil {
+ res = token.Pos(p.file.Base() + p.file.Size()) // EOF position
+ }
+ }()
+ _ = p.file.Offset(pos) // trigger a panic if position is out-of-range
+ return pos
+}
+
+// ----------------------------------------------------------------------------
+// Identifiers
+
+func (p *parser) parseIdent() *ast.Ident {
+ pos := p.pos
+ name := "_"
+ if p.tok == token.IDENT {
+ name = p.lit
+ p.next()
+ } else {
+ p.expect(token.IDENT) // use expect() error handling
+ }
+ return &ast.Ident{NamePos: pos, Name: name}
+}
+
+func (p *parser) parseIdentList() (list []*ast.Ident) {
+ if p.trace {
+ defer un(trace(p, "IdentList"))
+ }
+
+ list = append(list, p.parseIdent())
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.parseIdent())
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Common productions
+
+// If lhs is set, result list elements which are identifiers are not resolved.
+func (p *parser) parseExprList(lhs bool) (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "ExpressionList"))
+ }
+
+ list = append(list, p.checkExpr(p.parseExpr(lhs)))
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.checkExpr(p.parseExpr(lhs)))
+ }
+
+ return
+}
+
+func (p *parser) parseLhsList() []ast.Expr {
+ old := p.inRhs
+ p.inRhs = false
+ list := p.parseExprList(true)
+ switch p.tok {
+ case token.DEFINE:
+ // lhs of a short variable declaration
+ // but doesn't enter scope until later:
+ // caller must call p.shortVarDecl(p.makeIdentList(list))
+ // at appropriate time.
+ case token.COLON:
+ // lhs of a label declaration or a communication clause of a select
+ // statement (parseLhsList is not called when parsing the case clause
+ // of a switch statement):
+ // - labels are declared by the caller of parseLhsList
+ // - for communication clauses, if there is a stand-alone identifier
+ // followed by a colon, we have a syntax error; there is no need
+ // to resolve the identifier in that case
+ default:
+ // identifiers must be declared elsewhere
+ for _, x := range list {
+ p.resolve(x)
+ }
+ }
+ p.inRhs = old
+ return list
+}
+
+func (p *parser) parseRhsList() []ast.Expr {
+ old := p.inRhs
+ p.inRhs = true
+ list := p.parseExprList(false)
+ p.inRhs = old
+ return list
+}
+
+// ----------------------------------------------------------------------------
+// Types
+
+func (p *parser) parseType() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Type"))
+ }
+
+ typ := p.tryType()
+
+ if typ == nil {
+ pos := p.pos
+ p.errorExpected(pos, "type")
+ p.advance(exprEnd)
+ return &ast.BadExpr{From: pos, To: p.pos}
+ }
+
+ return typ
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) parseTypeName() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "TypeName"))
+ }
+
+ ident := p.parseIdent()
+ // don't resolve ident yet - it may be a parameter or field name
+
+ if p.tok == token.PERIOD {
+ // ident is a package name
+ p.next()
+ p.resolve(ident)
+ sel := p.parseIdent()
+ return &ast.SelectorExpr{X: ident, Sel: sel}
+ }
+
+ return ident
+}
+
+func (p *parser) parseArrayType() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "ArrayType"))
+ }
+
+ lbrack := p.expect(token.LBRACK)
+ p.exprLev++
+ var len ast.Expr
+ // always permit ellipsis for more fault-tolerant parsing
+ if p.tok == token.ELLIPSIS {
+ len = &ast.Ellipsis{Ellipsis: p.pos}
+ p.next()
+ } else if p.tok != token.RBRACK {
+ len = p.parseRhs()
+ }
+ p.exprLev--
+ p.expect(token.RBRACK)
+ elt := p.parseType()
+
+ return &ast.ArrayType{Lbrack: lbrack, Len: len, Elt: elt}
+}
+
+func (p *parser) makeIdentList(list []ast.Expr) []*ast.Ident {
+ idents := make([]*ast.Ident, len(list))
+ for i, x := range list {
+ ident, isIdent := x.(*ast.Ident)
+ if !isIdent {
+ if _, isBad := x.(*ast.BadExpr); !isBad {
+ // only report error if it's a new one
+ p.errorExpected(x.Pos(), "identifier")
+ }
+ ident = &ast.Ident{NamePos: x.Pos(), Name: "_"}
+ }
+ idents[i] = ident
+ }
+ return idents
+}
+
+func (p *parser) parseFieldDecl(scope *ast.Scope) *ast.Field {
+ if p.trace {
+ defer un(trace(p, "FieldDecl"))
+ }
+
+ doc := p.leadComment
+
+ // 1st FieldDecl
+ // A type name used as an anonymous field looks like a field identifier.
+ var list []ast.Expr
+ for {
+ list = append(list, p.parseVarType(false))
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ }
+
+ typ := p.tryVarType(false)
+
+ // analyze case
+ var idents []*ast.Ident
+ if typ != nil {
+ // IdentifierList Type
+ idents = p.makeIdentList(list)
+ } else {
+ // ["*"] TypeName (AnonymousField)
+ typ = list[0] // we always have at least one element
+ if n := len(list); n > 1 {
+ p.errorExpected(p.pos, "type")
+ typ = &ast.BadExpr{From: p.pos, To: p.pos}
+ } else if !isTypeName(deref(typ)) {
+ p.errorExpected(typ.Pos(), "anonymous field")
+ typ = &ast.BadExpr{From: typ.Pos(), To: p.safePos(typ.End())}
+ }
+ }
+
+ // Tag
+ var tag *ast.BasicLit
+ if p.tok == token.STRING {
+ tag = &ast.BasicLit{ValuePos: p.pos, Kind: p.tok, Value: p.lit}
+ p.next()
+ }
+
+ p.expectSemi() // call before accessing p.linecomment
+
+ field := &ast.Field{Doc: doc, Names: idents, Type: typ, Tag: tag, Comment: p.lineComment}
+ p.declare(field, nil, scope, ast.Var, idents...)
+ p.resolve(typ)
+
+ return field
+}
+
+func (p *parser) parseStructType() *ast.StructType {
+ if p.trace {
+ defer un(trace(p, "StructType"))
+ }
+
+ pos := p.expect(token.STRUCT)
+ lbrace := p.expect(token.LBRACE)
+ scope := ast.NewScope(nil) // struct scope
+ var list []*ast.Field
+ for p.tok == token.IDENT || p.tok == token.MUL || p.tok == token.LPAREN {
+ // a field declaration cannot start with a '(' but we accept
+ // it here for more robust parsing and better error messages
+ // (parseFieldDecl will check and complain if necessary)
+ list = append(list, p.parseFieldDecl(scope))
+ }
+ rbrace := p.expect(token.RBRACE)
+
+ return &ast.StructType{
+ Struct: pos,
+ Fields: &ast.FieldList{
+ Opening: lbrace,
+ List: list,
+ Closing: rbrace,
+ },
+ }
+}
+
+func (p *parser) parsePointerType() *ast.StarExpr {
+ if p.trace {
+ defer un(trace(p, "PointerType"))
+ }
+
+ star := p.expect(token.MUL)
+ base := p.parseType()
+
+ return &ast.StarExpr{Star: star, X: base}
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) tryVarType(isParam bool) ast.Expr {
+ if isParam && p.tok == token.ELLIPSIS {
+ pos := p.pos
+ p.next()
+ typ := p.tryIdentOrType() // don't use parseType so we can provide better error message
+ if typ != nil {
+ p.resolve(typ)
+ } else {
+ p.error(pos, "'...' parameter is missing type")
+ typ = &ast.BadExpr{From: pos, To: p.pos}
+ }
+ return &ast.Ellipsis{Ellipsis: pos, Elt: typ}
+ }
+ return p.tryIdentOrType()
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) parseVarType(isParam bool) ast.Expr {
+ typ := p.tryVarType(isParam)
+ if typ == nil {
+ pos := p.pos
+ p.errorExpected(pos, "type")
+ p.next() // make progress
+ typ = &ast.BadExpr{From: pos, To: p.pos}
+ }
+ return typ
+}
+
+func (p *parser) parseParameterList(scope *ast.Scope, ellipsisOk bool) (params []*ast.Field) {
+ if p.trace {
+ defer un(trace(p, "ParameterList"))
+ }
+
+ // 1st ParameterDecl
+ // A list of identifiers looks like a list of type names.
+ var list []ast.Expr
+ for {
+ list = append(list, p.parseVarType(ellipsisOk))
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ if p.tok == token.RPAREN {
+ break
+ }
+ }
+
+ // analyze case
+ if typ := p.tryVarType(ellipsisOk); typ != nil {
+ // IdentifierList Type
+ idents := p.makeIdentList(list)
+ field := &ast.Field{Names: idents, Type: typ}
+ params = append(params, field)
+ // Go spec: The scope of an identifier denoting a function
+ // parameter or result variable is the function body.
+ p.declare(field, nil, scope, ast.Var, idents...)
+ p.resolve(typ)
+ if !p.atComma("parameter list", token.RPAREN) {
+ return
+ }
+ p.next()
+ for p.tok != token.RPAREN && p.tok != token.EOF {
+ idents := p.parseIdentList()
+ typ := p.parseVarType(ellipsisOk)
+ field := &ast.Field{Names: idents, Type: typ}
+ params = append(params, field)
+ // Go spec: The scope of an identifier denoting a function
+ // parameter or result variable is the function body.
+ p.declare(field, nil, scope, ast.Var, idents...)
+ p.resolve(typ)
+ if !p.atComma("parameter list", token.RPAREN) {
+ break
+ }
+ p.next()
+ }
+ return
+ }
+
+ // Type { "," Type } (anonymous parameters)
+ params = make([]*ast.Field, len(list))
+ for i, typ := range list {
+ p.resolve(typ)
+ params[i] = &ast.Field{Type: typ}
+ }
+ return
+}
+
+func (p *parser) parseParameters(scope *ast.Scope, ellipsisOk bool) *ast.FieldList {
+ if p.trace {
+ defer un(trace(p, "Parameters"))
+ }
+
+ var params []*ast.Field
+ lparen := p.expect(token.LPAREN)
+ if p.tok != token.RPAREN {
+ params = p.parseParameterList(scope, ellipsisOk)
+ }
+ rparen := p.expect(token.RPAREN)
+
+ return &ast.FieldList{Opening: lparen, List: params, Closing: rparen}
+}
+
+func (p *parser) parseResult(scope *ast.Scope) *ast.FieldList {
+ if p.trace {
+ defer un(trace(p, "Result"))
+ }
+
+ if p.tok == token.LPAREN {
+ return p.parseParameters(scope, false)
+ }
+
+ typ := p.tryType()
+ if typ != nil {
+ list := make([]*ast.Field, 1)
+ list[0] = &ast.Field{Type: typ}
+ return &ast.FieldList{List: list}
+ }
+
+ return nil
+}
+
+func (p *parser) parseSignature(scope *ast.Scope) (params, results *ast.FieldList) {
+ if p.trace {
+ defer un(trace(p, "Signature"))
+ }
+
+ params = p.parseParameters(scope, true)
+ results = p.parseResult(scope)
+
+ return
+}
+
+func (p *parser) parseFuncType() (*ast.FuncType, *ast.Scope) {
+ if p.trace {
+ defer un(trace(p, "FuncType"))
+ }
+
+ pos := p.expect(token.FUNC)
+ scope := ast.NewScope(p.topScope) // function scope
+ params, results := p.parseSignature(scope)
+
+ return &ast.FuncType{Func: pos, Params: params, Results: results}, scope
+}
+
+func (p *parser) parseMethodSpec(scope *ast.Scope) *ast.Field {
+ if p.trace {
+ defer un(trace(p, "MethodSpec"))
+ }
+
+ doc := p.leadComment
+ var idents []*ast.Ident
+ var typ ast.Expr
+ x := p.parseTypeName()
+ if ident, isIdent := x.(*ast.Ident); isIdent && p.tok == token.LPAREN {
+ // method
+ idents = []*ast.Ident{ident}
+ scope := ast.NewScope(nil) // method scope
+ params, results := p.parseSignature(scope)
+ typ = &ast.FuncType{Func: token.NoPos, Params: params, Results: results}
+ } else {
+ // embedded interface
+ typ = x
+ p.resolve(typ)
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ spec := &ast.Field{Doc: doc, Names: idents, Type: typ, Comment: p.lineComment}
+ p.declare(spec, nil, scope, ast.Fun, idents...)
+
+ return spec
+}
+
+func (p *parser) parseInterfaceType() *ast.InterfaceType {
+ if p.trace {
+ defer un(trace(p, "InterfaceType"))
+ }
+
+ pos := p.expect(token.INTERFACE)
+ lbrace := p.expect(token.LBRACE)
+ scope := ast.NewScope(nil) // interface scope
+ var list []*ast.Field
+ for p.tok == token.IDENT {
+ list = append(list, p.parseMethodSpec(scope))
+ }
+ rbrace := p.expect(token.RBRACE)
+
+ return &ast.InterfaceType{
+ Interface: pos,
+ Methods: &ast.FieldList{
+ Opening: lbrace,
+ List: list,
+ Closing: rbrace,
+ },
+ }
+}
+
+func (p *parser) parseMapType() *ast.MapType {
+ if p.trace {
+ defer un(trace(p, "MapType"))
+ }
+
+ pos := p.expect(token.MAP)
+ p.expect(token.LBRACK)
+ key := p.parseType()
+ p.expect(token.RBRACK)
+ value := p.parseType()
+
+ return &ast.MapType{Map: pos, Key: key, Value: value}
+}
+
+func (p *parser) parseChanType() *ast.ChanType {
+ if p.trace {
+ defer un(trace(p, "ChanType"))
+ }
+
+ pos := p.pos
+ dir := ast.SEND | ast.RECV
+ var arrow token.Pos
+ if p.tok == token.CHAN {
+ p.next()
+ if p.tok == token.ARROW {
+ arrow = p.pos
+ p.next()
+ dir = ast.SEND
+ }
+ } else {
+ arrow = p.expect(token.ARROW)
+ p.expect(token.CHAN)
+ dir = ast.RECV
+ }
+ value := p.parseType()
+
+ return &ast.ChanType{Begin: pos, Arrow: arrow, Dir: dir, Value: value}
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) tryIdentOrType() ast.Expr {
+ switch p.tok {
+ case token.IDENT:
+ return p.parseTypeName()
+ case token.LBRACK:
+ return p.parseArrayType()
+ case token.STRUCT:
+ return p.parseStructType()
+ case token.MUL:
+ return p.parsePointerType()
+ case token.FUNC:
+ typ, _ := p.parseFuncType()
+ return typ
+ case token.INTERFACE:
+ return p.parseInterfaceType()
+ case token.MAP:
+ return p.parseMapType()
+ case token.CHAN, token.ARROW:
+ return p.parseChanType()
+ case token.LPAREN:
+ lparen := p.pos
+ p.next()
+ typ := p.parseType()
+ rparen := p.expect(token.RPAREN)
+ return &ast.ParenExpr{Lparen: lparen, X: typ, Rparen: rparen}
+ }
+
+ // no type found
+ return nil
+}
+
+func (p *parser) tryType() ast.Expr {
+ typ := p.tryIdentOrType()
+ if typ != nil {
+ p.resolve(typ)
+ }
+ return typ
+}
+
+// ----------------------------------------------------------------------------
+// Blocks
+
+func (p *parser) parseStmtList() (list []ast.Stmt) {
+ if p.trace {
+ defer un(trace(p, "StatementList"))
+ }
+
+ for p.tok != token.CASE && p.tok != token.DEFAULT && p.tok != token.RBRACE && p.tok != token.EOF {
+ list = append(list, p.parseStmt())
+ }
+
+ return
+}
+
+func (p *parser) parseBody(scope *ast.Scope) *ast.BlockStmt {
+ if p.trace {
+ defer un(trace(p, "Body"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ p.topScope = scope // open function scope
+ p.openLabelScope()
+ list := p.parseStmtList()
+ p.closeLabelScope()
+ p.closeScope()
+ rbrace := p.expect2(token.RBRACE)
+
+ return &ast.BlockStmt{Lbrace: lbrace, List: list, Rbrace: rbrace}
+}
+
+func (p *parser) parseBlockStmt() *ast.BlockStmt {
+ if p.trace {
+ defer un(trace(p, "BlockStmt"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ p.openScope()
+ list := p.parseStmtList()
+ p.closeScope()
+ rbrace := p.expect2(token.RBRACE)
+
+ return &ast.BlockStmt{Lbrace: lbrace, List: list, Rbrace: rbrace}
+}
+
+// ----------------------------------------------------------------------------
+// Expressions
+
+func (p *parser) parseFuncTypeOrLit() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "FuncTypeOrLit"))
+ }
+
+ typ, scope := p.parseFuncType()
+ if p.tok != token.LBRACE {
+ // function type only
+ return typ
+ }
+
+ p.exprLev++
+ body := p.parseBody(scope)
+ p.exprLev--
+
+ return &ast.FuncLit{Type: typ, Body: body}
+}
+
+// parseOperand may return an expression or a raw type (incl. array
+// types of the form [...]T. Callers must verify the result.
+// If lhs is set and the result is an identifier, it is not resolved.
+//
+func (p *parser) parseOperand(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Operand"))
+ }
+
+ switch p.tok {
+ case token.IDENT:
+ x := p.parseIdent()
+ if !lhs {
+ p.resolve(x)
+ }
+ return x
+
+ case token.INT, token.FLOAT, token.IMAG, token.CHAR, token.STRING:
+ x := &ast.BasicLit{ValuePos: p.pos, Kind: p.tok, Value: p.lit}
+ p.next()
+ return x
+
+ case token.LPAREN:
+ lparen := p.pos
+ p.next()
+ p.exprLev++
+ x := p.parseRhsOrType() // types may be parenthesized: (some type)
+ p.exprLev--
+ rparen := p.expect(token.RPAREN)
+ return &ast.ParenExpr{Lparen: lparen, X: x, Rparen: rparen}
+
+ case token.FUNC:
+ return p.parseFuncTypeOrLit()
+ }
+
+ if typ := p.tryIdentOrType(); typ != nil {
+ // could be type for composite literal or conversion
+ _, isIdent := typ.(*ast.Ident)
+ assert(!isIdent, "type cannot be identifier")
+ return typ
+ }
+
+ // we have an error
+ pos := p.pos
+ p.errorExpected(pos, "operand")
+ p.advance(stmtStart)
+ return &ast.BadExpr{From: pos, To: p.pos}
+}
+
+func (p *parser) parseSelector(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Selector"))
+ }
+
+ sel := p.parseIdent()
+
+ return &ast.SelectorExpr{X: x, Sel: sel}
+}
+
+func (p *parser) parseTypeAssertion(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "TypeAssertion"))
+ }
+
+ lparen := p.expect(token.LPAREN)
+ var typ ast.Expr
+ if p.tok == token.TYPE {
+ // type switch: typ == nil
+ p.next()
+ } else {
+ typ = p.parseType()
+ }
+ rparen := p.expect(token.RPAREN)
+
+ return &ast.TypeAssertExpr{X: x, Type: typ, Lparen: lparen, Rparen: rparen}
+}
+
+func (p *parser) parseIndexOrSlice(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "IndexOrSlice"))
+ }
+
+ const N = 3 // change the 3 to 2 to disable 3-index slices
+ lbrack := p.expect(token.LBRACK)
+ p.exprLev++
+ var index [N]ast.Expr
+ var colons [N - 1]token.Pos
+ if p.tok != token.COLON {
+ index[0] = p.parseRhs()
+ }
+ ncolons := 0
+ for p.tok == token.COLON && ncolons < len(colons) {
+ colons[ncolons] = p.pos
+ ncolons++
+ p.next()
+ if p.tok != token.COLON && p.tok != token.RBRACK && p.tok != token.EOF {
+ index[ncolons] = p.parseRhs()
+ }
+ }
+ p.exprLev--
+ rbrack := p.expect(token.RBRACK)
+
+ if ncolons > 0 {
+ // slice expression
+ slice3 := false
+ if ncolons == 2 {
+ slice3 = true
+ // Check presence of 2nd and 3rd index here rather than during type-checking
+ // to prevent erroneous programs from passing through gofmt (was issue 7305).
+ if index[1] == nil {
+ p.error(colons[0], "2nd index required in 3-index slice")
+ index[1] = &ast.BadExpr{From: colons[0] + 1, To: colons[1]}
+ }
+ if index[2] == nil {
+ p.error(colons[1], "3rd index required in 3-index slice")
+ index[2] = &ast.BadExpr{From: colons[1] + 1, To: rbrack}
+ }
+ }
+ return &ast.SliceExpr{X: x, Lbrack: lbrack, Low: index[0], High: index[1], Max: index[2], Slice3: slice3, Rbrack: rbrack}
+ }
+
+ return &ast.IndexExpr{X: x, Lbrack: lbrack, Index: index[0], Rbrack: rbrack}
+}
+
+func (p *parser) parseCallOrConversion(fun ast.Expr) *ast.CallExpr {
+ if p.trace {
+ defer un(trace(p, "CallOrConversion"))
+ }
+
+ lparen := p.expect(token.LPAREN)
+ p.exprLev++
+ var list []ast.Expr
+ var ellipsis token.Pos
+ for p.tok != token.RPAREN && p.tok != token.EOF && !ellipsis.IsValid() {
+ list = append(list, p.parseRhsOrType()) // builtins may expect a type: make(some type, ...)
+ if p.tok == token.ELLIPSIS {
+ ellipsis = p.pos
+ p.next()
+ }
+ if !p.atComma("argument list", token.RPAREN) {
+ break
+ }
+ p.next()
+ }
+ p.exprLev--
+ rparen := p.expectClosing(token.RPAREN, "argument list")
+
+ return &ast.CallExpr{Fun: fun, Lparen: lparen, Args: list, Ellipsis: ellipsis, Rparen: rparen}
+}
+
+func (p *parser) parseValue(keyOk bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Element"))
+ }
+
+ if p.tok == token.LBRACE {
+ return p.parseLiteralValue(nil)
+ }
+
+ // Because the parser doesn't know the composite literal type, it cannot
+ // know if a key that's an identifier is a struct field name or a name
+ // denoting a value. The former is not resolved by the parser or the
+ // resolver.
+ //
+ // Instead, _try_ to resolve such a key if possible. If it resolves,
+ // it a) has correctly resolved, or b) incorrectly resolved because
+ // the key is a struct field with a name matching another identifier.
+ // In the former case we are done, and in the latter case we don't
+ // care because the type checker will do a separate field lookup.
+ //
+ // If the key does not resolve, it a) must be defined at the top
+ // level in another file of the same package, the universe scope, or be
+ // undeclared; or b) it is a struct field. In the former case, the type
+ // checker can do a top-level lookup, and in the latter case it will do
+ // a separate field lookup.
+ x := p.checkExpr(p.parseExpr(keyOk))
+ if keyOk {
+ if p.tok == token.COLON {
+ // Try to resolve the key but don't collect it
+ // as unresolved identifier if it fails so that
+ // we don't get (possibly false) errors about
+ // undeclared names.
+ p.tryResolve(x, false)
+ } else {
+ // not a key
+ p.resolve(x)
+ }
+ }
+
+ return x
+}
+
+func (p *parser) parseElement() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Element"))
+ }
+
+ x := p.parseValue(true)
+ if p.tok == token.COLON {
+ colon := p.pos
+ p.next()
+ x = &ast.KeyValueExpr{Key: x, Colon: colon, Value: p.parseValue(false)}
+ }
+
+ return x
+}
+
+func (p *parser) parseElementList() (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "ElementList"))
+ }
+
+ for p.tok != token.RBRACE && p.tok != token.EOF {
+ list = append(list, p.parseElement())
+ if !p.atComma("composite literal", token.RBRACE) {
+ break
+ }
+ p.next()
+ }
+
+ return
+}
+
+func (p *parser) parseLiteralValue(typ ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "LiteralValue"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ var elts []ast.Expr
+ p.exprLev++
+ if p.tok != token.RBRACE {
+ elts = p.parseElementList()
+ }
+ p.exprLev--
+ rbrace := p.expectClosing(token.RBRACE, "composite literal")
+ return &ast.CompositeLit{Type: typ, Lbrace: lbrace, Elts: elts, Rbrace: rbrace}
+}
+
+// checkExpr checks that x is an expression (and not a type).
+func (p *parser) checkExpr(x ast.Expr) ast.Expr {
+ switch unparen(x).(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.BasicLit:
+ case *ast.FuncLit:
+ case *ast.CompositeLit:
+ case *ast.ParenExpr:
+ panic("unreachable")
+ case *ast.SelectorExpr:
+ case *ast.IndexExpr:
+ case *ast.SliceExpr:
+ case *ast.TypeAssertExpr:
+ // If t.Type == nil we have a type assertion of the form
+ // y.(type), which is only allowed in type switch expressions.
+ // It's hard to exclude those but for the case where we are in
+ // a type switch. Instead be lenient and test this in the type
+ // checker.
+ case *ast.CallExpr:
+ case *ast.StarExpr:
+ case *ast.UnaryExpr:
+ case *ast.BinaryExpr:
+ default:
+ // all other nodes are not proper expressions
+ p.errorExpected(x.Pos(), "expression")
+ x = &ast.BadExpr{From: x.Pos(), To: p.safePos(x.End())}
+ }
+ return x
+}
+
+// isTypeName reports whether x is a (qualified) TypeName.
+func isTypeName(x ast.Expr) bool {
+ switch t := x.(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.SelectorExpr:
+ _, isIdent := t.X.(*ast.Ident)
+ return isIdent
+ default:
+ return false // all other nodes are not type names
+ }
+ return true
+}
+
+// isLiteralType reports whether x is a legal composite literal type.
+func isLiteralType(x ast.Expr) bool {
+ switch t := x.(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.SelectorExpr:
+ _, isIdent := t.X.(*ast.Ident)
+ return isIdent
+ case *ast.ArrayType:
+ case *ast.StructType:
+ case *ast.MapType:
+ default:
+ return false // all other nodes are not legal composite literal types
+ }
+ return true
+}
+
+// If x is of the form *T, deref returns T, otherwise it returns x.
+func deref(x ast.Expr) ast.Expr {
+ if p, isPtr := x.(*ast.StarExpr); isPtr {
+ x = p.X
+ }
+ return x
+}
+
+// If x is of the form (T), unparen returns unparen(T), otherwise it returns x.
+func unparen(x ast.Expr) ast.Expr {
+ if p, isParen := x.(*ast.ParenExpr); isParen {
+ x = unparen(p.X)
+ }
+ return x
+}
+
+// checkExprOrType checks that x is an expression or a type
+// (and not a raw type such as [...]T).
+//
+func (p *parser) checkExprOrType(x ast.Expr) ast.Expr {
+ switch t := unparen(x).(type) {
+ case *ast.ParenExpr:
+ panic("unreachable")
+ case *ast.ArrayType:
+ if len, isEllipsis := t.Len.(*ast.Ellipsis); isEllipsis {
+ p.error(len.Pos(), "expected array length, found '...'")
+ x = &ast.BadExpr{From: x.Pos(), To: p.safePos(x.End())}
+ }
+ }
+
+ // all other nodes are expressions or types
+ return x
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parsePrimaryExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "PrimaryExpr"))
+ }
+
+ x := p.parseOperand(lhs)
+L:
+ for {
+ switch p.tok {
+ case token.PERIOD:
+ p.next()
+ if lhs {
+ p.resolve(x)
+ }
+ switch p.tok {
+ case token.IDENT:
+ x = p.parseSelector(p.checkExprOrType(x))
+ case token.LPAREN:
+ x = p.parseTypeAssertion(p.checkExpr(x))
+ default:
+ pos := p.pos
+ p.errorExpected(pos, "selector or type assertion")
+ p.next() // make progress
+ sel := &ast.Ident{NamePos: pos, Name: "_"}
+ x = &ast.SelectorExpr{X: x, Sel: sel}
+ }
+ case token.LBRACK:
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseIndexOrSlice(p.checkExpr(x))
+ case token.LPAREN:
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseCallOrConversion(p.checkExprOrType(x))
+ case token.LBRACE:
+ if isLiteralType(x) && (p.exprLev >= 0 || !isTypeName(x)) {
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseLiteralValue(x)
+ } else {
+ break L
+ }
+ default:
+ break L
+ }
+ lhs = false // no need to try to resolve again
+ }
+
+ return x
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parseUnaryExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "UnaryExpr"))
+ }
+
+ switch p.tok {
+ case token.ADD, token.SUB, token.NOT, token.XOR, token.AND:
+ pos, op := p.pos, p.tok
+ p.next()
+ x := p.parseUnaryExpr(false)
+ return &ast.UnaryExpr{OpPos: pos, Op: op, X: p.checkExpr(x)}
+
+ case token.ARROW:
+ // channel type or receive expression
+ arrow := p.pos
+ p.next()
+
+ // If the next token is token.CHAN we still don't know if it
+ // is a channel type or a receive operation - we only know
+ // once we have found the end of the unary expression. There
+ // are two cases:
+ //
+ // <- type => (<-type) must be channel type
+ // <- expr => <-(expr) is a receive from an expression
+ //
+ // In the first case, the arrow must be re-associated with
+ // the channel type parsed already:
+ //
+ // <- (chan type) => (<-chan type)
+ // <- (chan<- type) => (<-chan (<-type))
+
+ x := p.parseUnaryExpr(false)
+
+ // determine which case we have
+ if typ, ok := x.(*ast.ChanType); ok {
+ // (<-type)
+
+ // re-associate position info and <-
+ dir := ast.SEND
+ for ok && dir == ast.SEND {
+ if typ.Dir == ast.RECV {
+ // error: (<-type) is (<-(<-chan T))
+ p.errorExpected(typ.Arrow, "'chan'")
+ }
+ arrow, typ.Begin, typ.Arrow = typ.Arrow, arrow, arrow
+ dir, typ.Dir = typ.Dir, ast.RECV
+ typ, ok = typ.Value.(*ast.ChanType)
+ }
+ if dir == ast.SEND {
+ p.errorExpected(arrow, "channel type")
+ }
+
+ return x
+ }
+
+ // <-(expr)
+ return &ast.UnaryExpr{OpPos: arrow, Op: token.ARROW, X: p.checkExpr(x)}
+
+ case token.MUL:
+ // pointer type or unary "*" expression
+ pos := p.pos
+ p.next()
+ x := p.parseUnaryExpr(false)
+ return &ast.StarExpr{Star: pos, X: p.checkExprOrType(x)}
+ }
+
+ return p.parsePrimaryExpr(lhs)
+}
+
+func (p *parser) tokPrec() (token.Token, int) {
+ tok := p.tok
+ if p.inRhs && tok == token.ASSIGN {
+ tok = token.EQL
+ }
+ return tok, tok.Precedence()
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parseBinaryExpr(lhs bool, prec1 int) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "BinaryExpr"))
+ }
+
+ x := p.parseUnaryExpr(lhs)
+ for {
+ op, oprec := p.tokPrec()
+ if oprec < prec1 {
+ return x
+ }
+ pos := p.expect(op)
+ if lhs {
+ p.resolve(x)
+ lhs = false
+ }
+ y := p.parseBinaryExpr(false, oprec+1)
+ x = &ast.BinaryExpr{X: p.checkExpr(x), OpPos: pos, Op: op, Y: p.checkExpr(y)}
+ }
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+// The result may be a type or even a raw type ([...]int). Callers must
+// check the result (using checkExpr or checkExprOrType), depending on
+// context.
+func (p *parser) parseExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Expression"))
+ }
+
+ return p.parseBinaryExpr(lhs, token.LowestPrec+1)
+}
+
+func (p *parser) parseRhs() ast.Expr {
+ old := p.inRhs
+ p.inRhs = true
+ x := p.checkExpr(p.parseExpr(false))
+ p.inRhs = old
+ return x
+}
+
+func (p *parser) parseRhsOrType() ast.Expr {
+ old := p.inRhs
+ p.inRhs = true
+ x := p.checkExprOrType(p.parseExpr(false))
+ p.inRhs = old
+ return x
+}
+
+// ----------------------------------------------------------------------------
+// Statements
+
+// Parsing modes for parseSimpleStmt.
+const (
+ basic = iota
+ labelOk
+ rangeOk
+)
+
+// parseSimpleStmt returns true as 2nd result if it parsed the assignment
+// of a range clause (with mode == rangeOk). The returned statement is an
+// assignment with a right-hand side that is a single unary expression of
+// the form "range x". No guarantees are given for the left-hand side.
+func (p *parser) parseSimpleStmt(mode int) (ast.Stmt, bool) {
+ if p.trace {
+ defer un(trace(p, "SimpleStmt"))
+ }
+
+ x := p.parseLhsList()
+
+ switch p.tok {
+ case
+ token.DEFINE, token.ASSIGN, token.ADD_ASSIGN,
+ token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN,
+ token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN,
+ token.XOR_ASSIGN, token.SHL_ASSIGN, token.SHR_ASSIGN, token.AND_NOT_ASSIGN:
+ // assignment statement, possibly part of a range clause
+ pos, tok := p.pos, p.tok
+ p.next()
+ var y []ast.Expr
+ isRange := false
+ if mode == rangeOk && p.tok == token.RANGE && (tok == token.DEFINE || tok == token.ASSIGN) {
+ pos := p.pos
+ p.next()
+ y = []ast.Expr{&ast.UnaryExpr{OpPos: pos, Op: token.RANGE, X: p.parseRhs()}}
+ isRange = true
+ } else {
+ y = p.parseRhsList()
+ }
+ as := &ast.AssignStmt{Lhs: x, TokPos: pos, Tok: tok, Rhs: y}
+ if tok == token.DEFINE {
+ p.shortVarDecl(as, x)
+ }
+ return as, isRange
+ }
+
+ if len(x) > 1 {
+ p.errorExpected(x[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+
+ switch p.tok {
+ case token.COLON:
+ // labeled statement
+ colon := p.pos
+ p.next()
+ if label, isIdent := x[0].(*ast.Ident); mode == labelOk && isIdent {
+ // Go spec: The scope of a label is the body of the function
+ // in which it is declared and excludes the body of any nested
+ // function.
+ stmt := &ast.LabeledStmt{Label: label, Colon: colon, Stmt: p.parseStmt()}
+ p.declare(stmt, nil, p.labelScope, ast.Lbl, label)
+ return stmt, false
+ }
+ // The label declaration typically starts at x[0].Pos(), but the label
+ // declaration may be erroneous due to a token after that position (and
+ // before the ':'). If SpuriousErrors is not set, the (only) error
+ // reported for the line is the illegal label error instead of the token
+ // before the ':' that caused the problem. Thus, use the (latest) colon
+ // position for error reporting.
+ p.error(colon, "illegal label declaration")
+ return &ast.BadStmt{From: x[0].Pos(), To: colon + 1}, false
+
+ case token.ARROW:
+ // send statement
+ arrow := p.pos
+ p.next()
+ y := p.parseRhs()
+ return &ast.SendStmt{Chan: x[0], Arrow: arrow, Value: y}, false
+
+ case token.INC, token.DEC:
+ // increment or decrement
+ s := &ast.IncDecStmt{X: x[0], TokPos: p.pos, Tok: p.tok}
+ p.next()
+ return s, false
+ }
+
+ // expression
+ return &ast.ExprStmt{X: x[0]}, false
+}
+
+func (p *parser) parseCallExpr(callType string) *ast.CallExpr {
+ x := p.parseRhsOrType() // could be a conversion: (some type)(x)
+ if call, isCall := x.(*ast.CallExpr); isCall {
+ return call
+ }
+ if _, isBad := x.(*ast.BadExpr); !isBad {
+ // only report error if it's a new one
+ p.error(p.safePos(x.End()), fmt.Sprintf("function must be invoked in %s statement", callType))
+ }
+ return nil
+}
+
+func (p *parser) parseGoStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "GoStmt"))
+ }
+
+ pos := p.expect(token.GO)
+ call := p.parseCallExpr("go")
+ p.expectSemi()
+ if call == nil {
+ return &ast.BadStmt{From: pos, To: pos + 2} // len("go")
+ }
+
+ return &ast.GoStmt{Go: pos, Call: call}
+}
+
+func (p *parser) parseDeferStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "DeferStmt"))
+ }
+
+ pos := p.expect(token.DEFER)
+ call := p.parseCallExpr("defer")
+ p.expectSemi()
+ if call == nil {
+ return &ast.BadStmt{From: pos, To: pos + 5} // len("defer")
+ }
+
+ return &ast.DeferStmt{Defer: pos, Call: call}
+}
+
+func (p *parser) parseReturnStmt() *ast.ReturnStmt {
+ if p.trace {
+ defer un(trace(p, "ReturnStmt"))
+ }
+
+ pos := p.pos
+ p.expect(token.RETURN)
+ var x []ast.Expr
+ if p.tok != token.SEMICOLON && p.tok != token.RBRACE {
+ x = p.parseRhsList()
+ }
+ p.expectSemi()
+
+ return &ast.ReturnStmt{Return: pos, Results: x}
+}
+
+func (p *parser) parseBranchStmt(tok token.Token) *ast.BranchStmt {
+ if p.trace {
+ defer un(trace(p, "BranchStmt"))
+ }
+
+ pos := p.expect(tok)
+ var label *ast.Ident
+ if tok != token.FALLTHROUGH && p.tok == token.IDENT {
+ label = p.parseIdent()
+ // add to list of unresolved targets
+ n := len(p.targetStack) - 1
+ p.targetStack[n] = append(p.targetStack[n], label)
+ }
+ p.expectSemi()
+
+ return &ast.BranchStmt{TokPos: pos, Tok: tok, Label: label}
+}
+
+func (p *parser) makeExpr(s ast.Stmt, want string) ast.Expr {
+ if s == nil {
+ return nil
+ }
+ if es, isExpr := s.(*ast.ExprStmt); isExpr {
+ return p.checkExpr(es.X)
+ }
+ found := "simple statement"
+ if _, isAss := s.(*ast.AssignStmt); isAss {
+ found = "assignment"
+ }
+ p.error(s.Pos(), fmt.Sprintf("expected %s, found %s (missing parentheses around composite literal?)", want, found))
+ return &ast.BadExpr{From: s.Pos(), To: p.safePos(s.End())}
+}
+
+// parseIfHeader is an adjusted version of parser.header
+// in cmd/compile/internal/syntax/parser.go, which has
+// been tuned for better error handling.
+func (p *parser) parseIfHeader() (init ast.Stmt, cond ast.Expr) {
+ if p.tok == token.LBRACE {
+ p.error(p.pos, "missing condition in if statement")
+ cond = &ast.BadExpr{From: p.pos, To: p.pos}
+ return
+ }
+ // p.tok != token.LBRACE
+
+ outer := p.exprLev
+ p.exprLev = -1
+
+ if p.tok != token.SEMICOLON {
+ // accept potential variable declaration but complain
+ if p.tok == token.VAR {
+ p.next()
+ p.error(p.pos, fmt.Sprintf("var declaration not allowed in 'IF' initializer"))
+ }
+ init, _ = p.parseSimpleStmt(basic)
+ }
+
+ var condStmt ast.Stmt
+ var semi struct {
+ pos token.Pos
+ lit string // ";" or "\n"; valid if pos.IsValid()
+ }
+ if p.tok != token.LBRACE {
+ if p.tok == token.SEMICOLON {
+ semi.pos = p.pos
+ semi.lit = p.lit
+ p.next()
+ } else {
+ p.expect(token.SEMICOLON)
+ }
+ if p.tok != token.LBRACE {
+ condStmt, _ = p.parseSimpleStmt(basic)
+ }
+ } else {
+ condStmt = init
+ init = nil
+ }
+
+ if condStmt != nil {
+ cond = p.makeExpr(condStmt, "boolean expression")
+ } else if semi.pos.IsValid() {
+ if semi.lit == "\n" {
+ p.error(semi.pos, "unexpected newline, expecting { after if clause")
+ } else {
+ p.error(semi.pos, "missing condition in if statement")
+ }
+ }
+
+ // make sure we have a valid AST
+ if cond == nil {
+ cond = &ast.BadExpr{From: p.pos, To: p.pos}
+ }
+
+ p.exprLev = outer
+ return
+}
+
+func (p *parser) parseIfStmt() *ast.IfStmt {
+ if p.trace {
+ defer un(trace(p, "IfStmt"))
+ }
+
+ pos := p.expect(token.IF)
+ p.openScope()
+ defer p.closeScope()
+
+ init, cond := p.parseIfHeader()
+ body := p.parseBlockStmt()
+
+ var else_ ast.Stmt
+ if p.tok == token.ELSE {
+ p.next()
+ switch p.tok {
+ case token.IF:
+ else_ = p.parseIfStmt()
+ case token.LBRACE:
+ else_ = p.parseBlockStmt()
+ p.expectSemi()
+ default:
+ p.errorExpected(p.pos, "if statement or block")
+ else_ = &ast.BadStmt{From: p.pos, To: p.pos}
+ }
+ } else {
+ p.expectSemi()
+ }
+
+ return &ast.IfStmt{If: pos, Init: init, Cond: cond, Body: body, Else: else_}
+}
+
+func (p *parser) parseTypeList() (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "TypeList"))
+ }
+
+ list = append(list, p.parseType())
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.parseType())
+ }
+
+ return
+}
+
+func (p *parser) parseCaseClause(typeSwitch bool) *ast.CaseClause {
+ if p.trace {
+ defer un(trace(p, "CaseClause"))
+ }
+
+ pos := p.pos
+ var list []ast.Expr
+ if p.tok == token.CASE {
+ p.next()
+ if typeSwitch {
+ list = p.parseTypeList()
+ } else {
+ list = p.parseRhsList()
+ }
+ } else {
+ p.expect(token.DEFAULT)
+ }
+
+ colon := p.expect(token.COLON)
+ p.openScope()
+ body := p.parseStmtList()
+ p.closeScope()
+
+ return &ast.CaseClause{Case: pos, List: list, Colon: colon, Body: body}
+}
+
+func isTypeSwitchAssert(x ast.Expr) bool {
+ a, ok := x.(*ast.TypeAssertExpr)
+ return ok && a.Type == nil
+}
+
+func (p *parser) isTypeSwitchGuard(s ast.Stmt) bool {
+ switch t := s.(type) {
+ case *ast.ExprStmt:
+ // x.(type)
+ return isTypeSwitchAssert(t.X)
+ case *ast.AssignStmt:
+ // v := x.(type)
+ if len(t.Lhs) == 1 && len(t.Rhs) == 1 && isTypeSwitchAssert(t.Rhs[0]) {
+ switch t.Tok {
+ case token.ASSIGN:
+ // permit v = x.(type) but complain
+ p.error(t.TokPos, "expected ':=', found '='")
+ fallthrough
+ case token.DEFINE:
+ return true
+ }
+ }
+ }
+ return false
+}
+
+func (p *parser) parseSwitchStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "SwitchStmt"))
+ }
+
+ pos := p.expect(token.SWITCH)
+ p.openScope()
+ defer p.closeScope()
+
+ var s1, s2 ast.Stmt
+ if p.tok != token.LBRACE {
+ prevLev := p.exprLev
+ p.exprLev = -1
+ if p.tok != token.SEMICOLON {
+ s2, _ = p.parseSimpleStmt(basic)
+ }
+ if p.tok == token.SEMICOLON {
+ p.next()
+ s1 = s2
+ s2 = nil
+ if p.tok != token.LBRACE {
+ // A TypeSwitchGuard may declare a variable in addition
+ // to the variable declared in the initial SimpleStmt.
+ // Introduce extra scope to avoid redeclaration errors:
+ //
+ // switch t := 0; t := x.(T) { ... }
+ //
+ // (this code is not valid Go because the first t
+ // cannot be accessed and thus is never used, the extra
+ // scope is needed for the correct error message).
+ //
+ // If we don't have a type switch, s2 must be an expression.
+ // Having the extra nested but empty scope won't affect it.
+ p.openScope()
+ defer p.closeScope()
+ s2, _ = p.parseSimpleStmt(basic)
+ }
+ }
+ p.exprLev = prevLev
+ }
+
+ typeSwitch := p.isTypeSwitchGuard(s2)
+ lbrace := p.expect(token.LBRACE)
+ var list []ast.Stmt
+ for p.tok == token.CASE || p.tok == token.DEFAULT {
+ list = append(list, p.parseCaseClause(typeSwitch))
+ }
+ rbrace := p.expect(token.RBRACE)
+ p.expectSemi()
+ body := &ast.BlockStmt{Lbrace: lbrace, List: list, Rbrace: rbrace}
+
+ if typeSwitch {
+ return &ast.TypeSwitchStmt{Switch: pos, Init: s1, Assign: s2, Body: body}
+ }
+
+ return &ast.SwitchStmt{Switch: pos, Init: s1, Tag: p.makeExpr(s2, "switch expression"), Body: body}
+}
+
+func (p *parser) parseCommClause() *ast.CommClause {
+ if p.trace {
+ defer un(trace(p, "CommClause"))
+ }
+
+ p.openScope()
+ pos := p.pos
+ var comm ast.Stmt
+ if p.tok == token.CASE {
+ p.next()
+ lhs := p.parseLhsList()
+ if p.tok == token.ARROW {
+ // SendStmt
+ if len(lhs) > 1 {
+ p.errorExpected(lhs[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+ arrow := p.pos
+ p.next()
+ rhs := p.parseRhs()
+ comm = &ast.SendStmt{Chan: lhs[0], Arrow: arrow, Value: rhs}
+ } else {
+ // RecvStmt
+ if tok := p.tok; tok == token.ASSIGN || tok == token.DEFINE {
+ // RecvStmt with assignment
+ if len(lhs) > 2 {
+ p.errorExpected(lhs[0].Pos(), "1 or 2 expressions")
+ // continue with first two expressions
+ lhs = lhs[0:2]
+ }
+ pos := p.pos
+ p.next()
+ rhs := p.parseRhs()
+ as := &ast.AssignStmt{Lhs: lhs, TokPos: pos, Tok: tok, Rhs: []ast.Expr{rhs}}
+ if tok == token.DEFINE {
+ p.shortVarDecl(as, lhs)
+ }
+ comm = as
+ } else {
+ // lhs must be single receive operation
+ if len(lhs) > 1 {
+ p.errorExpected(lhs[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+ comm = &ast.ExprStmt{X: lhs[0]}
+ }
+ }
+ } else {
+ p.expect(token.DEFAULT)
+ }
+
+ colon := p.expect(token.COLON)
+ body := p.parseStmtList()
+ p.closeScope()
+
+ return &ast.CommClause{Case: pos, Comm: comm, Colon: colon, Body: body}
+}
+
+func (p *parser) parseSelectStmt() *ast.SelectStmt {
+ if p.trace {
+ defer un(trace(p, "SelectStmt"))
+ }
+
+ pos := p.expect(token.SELECT)
+ lbrace := p.expect(token.LBRACE)
+ var list []ast.Stmt
+ for p.tok == token.CASE || p.tok == token.DEFAULT {
+ list = append(list, p.parseCommClause())
+ }
+ rbrace := p.expect(token.RBRACE)
+ p.expectSemi()
+ body := &ast.BlockStmt{Lbrace: lbrace, List: list, Rbrace: rbrace}
+
+ return &ast.SelectStmt{Select: pos, Body: body}
+}
+
+func (p *parser) parseForStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "ForStmt"))
+ }
+
+ pos := p.expect(token.FOR)
+ p.openScope()
+ defer p.closeScope()
+
+ var s1, s2, s3 ast.Stmt
+ var isRange bool
+ if p.tok != token.LBRACE {
+ prevLev := p.exprLev
+ p.exprLev = -1
+ if p.tok != token.SEMICOLON {
+ if p.tok == token.RANGE {
+ // "for range x" (nil lhs in assignment)
+ pos := p.pos
+ p.next()
+ y := []ast.Expr{&ast.UnaryExpr{OpPos: pos, Op: token.RANGE, X: p.parseRhs()}}
+ s2 = &ast.AssignStmt{Rhs: y}
+ isRange = true
+ } else {
+ s2, isRange = p.parseSimpleStmt(rangeOk)
+ }
+ }
+ if !isRange && p.tok == token.SEMICOLON {
+ p.next()
+ s1 = s2
+ s2 = nil
+ if p.tok != token.SEMICOLON {
+ s2, _ = p.parseSimpleStmt(basic)
+ }
+ p.expectSemi()
+ if p.tok != token.LBRACE {
+ s3, _ = p.parseSimpleStmt(basic)
+ }
+ }
+ p.exprLev = prevLev
+ }
+
+ body := p.parseBlockStmt()
+ p.expectSemi()
+
+ if isRange {
+ as := s2.(*ast.AssignStmt)
+ // check lhs
+ var key, value ast.Expr
+ switch len(as.Lhs) {
+ case 0:
+ // nothing to do
+ case 1:
+ key = as.Lhs[0]
+ case 2:
+ key, value = as.Lhs[0], as.Lhs[1]
+ default:
+ p.errorExpected(as.Lhs[len(as.Lhs)-1].Pos(), "at most 2 expressions")
+ return &ast.BadStmt{From: pos, To: p.safePos(body.End())}
+ }
+ // parseSimpleStmt returned a right-hand side that
+ // is a single unary expression of the form "range x"
+ x := as.Rhs[0].(*ast.UnaryExpr).X
+ return &ast.RangeStmt{
+ For: pos,
+ Key: key,
+ Value: value,
+ TokPos: as.TokPos,
+ Tok: as.Tok,
+ X: x,
+ Body: body,
+ }
+ }
+
+ // regular for statement
+ return &ast.ForStmt{
+ For: pos,
+ Init: s1,
+ Cond: p.makeExpr(s2, "boolean or range expression"),
+ Post: s3,
+ Body: body,
+ }
+}
+
+func (p *parser) parseStmt() (s ast.Stmt) {
+ if p.trace {
+ defer un(trace(p, "Statement"))
+ }
+
+ switch p.tok {
+ case token.CONST, token.TYPE, token.VAR:
+ s = &ast.DeclStmt{Decl: p.parseDecl(stmtStart)}
+ case
+ // tokens that may start an expression
+ token.IDENT, token.INT, token.FLOAT, token.IMAG, token.CHAR, token.STRING, token.FUNC, token.LPAREN, // operands
+ token.LBRACK, token.STRUCT, token.MAP, token.CHAN, token.INTERFACE, // composite types
+ token.ADD, token.SUB, token.MUL, token.AND, token.XOR, token.ARROW, token.NOT: // unary operators
+ s, _ = p.parseSimpleStmt(labelOk)
+ // because of the required look-ahead, labeled statements are
+ // parsed by parseSimpleStmt - don't expect a semicolon after
+ // them
+ if _, isLabeledStmt := s.(*ast.LabeledStmt); !isLabeledStmt {
+ p.expectSemi()
+ }
+ case token.GO:
+ s = p.parseGoStmt()
+ case token.DEFER:
+ s = p.parseDeferStmt()
+ case token.RETURN:
+ s = p.parseReturnStmt()
+ case token.BREAK, token.CONTINUE, token.GOTO, token.FALLTHROUGH:
+ s = p.parseBranchStmt(p.tok)
+ case token.LBRACE:
+ s = p.parseBlockStmt()
+ p.expectSemi()
+ case token.IF:
+ s = p.parseIfStmt()
+ case token.SWITCH:
+ s = p.parseSwitchStmt()
+ case token.SELECT:
+ s = p.parseSelectStmt()
+ case token.FOR:
+ s = p.parseForStmt()
+ case token.SEMICOLON:
+ // Is it ever possible to have an implicit semicolon
+ // producing an empty statement in a valid program?
+ // (handle correctly anyway)
+ s = &ast.EmptyStmt{Semicolon: p.pos, Implicit: p.lit == "\n"}
+ p.next()
+ case token.RBRACE:
+ // a semicolon may be omitted before a closing "}"
+ s = &ast.EmptyStmt{Semicolon: p.pos, Implicit: true}
+ default:
+ // no statement found
+ pos := p.pos
+ p.errorExpected(pos, "statement")
+ p.advance(stmtStart)
+ s = &ast.BadStmt{From: pos, To: p.pos}
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Declarations
+
+type parseSpecFunction func(doc *ast.CommentGroup, keyword token.Token, iota int) ast.Spec
+
+func isValidImport(lit string) bool {
+ const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
+ s, _ := strconv.Unquote(lit) // go/scanner returns a legal string literal
+ for _, r := range s {
+ if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
+ return false
+ }
+ }
+ return s != ""
+}
+
+func (p *parser) parseImportSpec(doc *ast.CommentGroup, _ token.Token, _ int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "ImportSpec"))
+ }
+
+ var ident *ast.Ident
+ switch p.tok {
+ case token.PERIOD:
+ ident = &ast.Ident{NamePos: p.pos, Name: "."}
+ p.next()
+ case token.IDENT:
+ ident = p.parseIdent()
+ }
+
+ pos := p.pos
+ var path string
+ if p.tok == token.STRING {
+ path = p.lit
+ if !isValidImport(path) {
+ p.error(pos, "invalid import path: "+path)
+ }
+ p.next()
+ } else {
+ p.expect(token.STRING) // use expect() error handling
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ // collect imports
+ spec := &ast.ImportSpec{
+ Doc: doc,
+ Name: ident,
+ Path: &ast.BasicLit{ValuePos: pos, Kind: token.STRING, Value: path},
+ Comment: p.lineComment,
+ }
+ p.imports = append(p.imports, spec)
+
+ return spec
+}
+
+func (p *parser) parseValueSpec(doc *ast.CommentGroup, keyword token.Token, iota int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, keyword.String()+"Spec"))
+ }
+
+ pos := p.pos
+ idents := p.parseIdentList()
+ typ := p.tryType()
+ var values []ast.Expr
+ // always permit optional initialization for more tolerant parsing
+ if p.tok == token.ASSIGN {
+ p.next()
+ values = p.parseRhsList()
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ switch keyword {
+ case token.VAR:
+ if typ == nil && values == nil {
+ p.error(pos, "missing variable type or initialization")
+ }
+ case token.CONST:
+ if values == nil && (iota == 0 || typ != nil) {
+ p.error(pos, "missing constant value")
+ }
+ }
+
+ // Go spec: The scope of a constant or variable identifier declared inside
+ // a function begins at the end of the ConstSpec or VarSpec and ends at
+ // the end of the innermost containing block.
+ // (Global identifiers are resolved in a separate phase after parsing.)
+ spec := &ast.ValueSpec{
+ Doc: doc,
+ Names: idents,
+ Type: typ,
+ Values: values,
+ Comment: p.lineComment,
+ }
+ kind := ast.Con
+ if keyword == token.VAR {
+ kind = ast.Var
+ }
+ p.declare(spec, iota, p.topScope, kind, idents...)
+
+ return spec
+}
+
+func (p *parser) parseTypeSpec(doc *ast.CommentGroup, _ token.Token, _ int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "TypeSpec"))
+ }
+
+ ident := p.parseIdent()
+
+ // Go spec: The scope of a type identifier declared inside a function begins
+ // at the identifier in the TypeSpec and ends at the end of the innermost
+ // containing block.
+ // (Global identifiers are resolved in a separate phase after parsing.)
+ spec := &ast.TypeSpec{Doc: doc, Name: ident}
+ p.declare(spec, nil, p.topScope, ast.Typ, ident)
+ if p.tok == token.ASSIGN {
+ spec.Assign = p.pos
+ p.next()
+ }
+ spec.Type = p.parseType()
+ p.expectSemi() // call before accessing p.linecomment
+ spec.Comment = p.lineComment
+
+ return spec
+}
+
+func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction) *ast.GenDecl {
+ if p.trace {
+ defer un(trace(p, "GenDecl("+keyword.String()+")"))
+ }
+
+ doc := p.leadComment
+ pos := p.expect(keyword)
+ var lparen, rparen token.Pos
+ var list []ast.Spec
+ if p.tok == token.LPAREN {
+ lparen = p.pos
+ p.next()
+ for iota := 0; p.tok != token.RPAREN && p.tok != token.EOF; iota++ {
+ list = append(list, f(p.leadComment, keyword, iota))
+ }
+ rparen = p.expect(token.RPAREN)
+ p.expectSemi()
+ } else {
+ list = append(list, f(nil, keyword, 0))
+ }
+
+ return &ast.GenDecl{
+ Doc: doc,
+ TokPos: pos,
+ Tok: keyword,
+ Lparen: lparen,
+ Specs: list,
+ Rparen: rparen,
+ }
+}
+
+func (p *parser) parseFuncDecl() *ast.FuncDecl {
+ if p.trace {
+ defer un(trace(p, "FunctionDecl"))
+ }
+
+ doc := p.leadComment
+ pos := p.expect(token.FUNC)
+ scope := ast.NewScope(p.topScope) // function scope
+
+ var recv *ast.FieldList
+ if p.tok == token.LPAREN {
+ recv = p.parseParameters(scope, false)
+ }
+
+ ident := p.parseIdent()
+
+ params, results := p.parseSignature(scope)
+
+ var body *ast.BlockStmt
+ if p.tok == token.LBRACE {
+ body = p.parseBody(scope)
+ p.expectSemi()
+ } else if p.tok == token.SEMICOLON {
+ p.next()
+ if p.tok == token.LBRACE {
+ // opening { of function declaration on next line
+ p.error(p.pos, "unexpected semicolon or newline before {")
+ body = p.parseBody(scope)
+ p.expectSemi()
+ }
+ } else {
+ p.expectSemi()
+ }
+
+ decl := &ast.FuncDecl{
+ Doc: doc,
+ Recv: recv,
+ Name: ident,
+ Type: &ast.FuncType{
+ Func: pos,
+ Params: params,
+ Results: results,
+ },
+ Body: body,
+ }
+ if recv == nil {
+ // Go spec: The scope of an identifier denoting a constant, type,
+ // variable, or function (but not method) declared at top level
+ // (outside any function) is the package block.
+ //
+ // init() functions cannot be referred to and there may
+ // be more than one - don't put them in the pkgScope
+ if ident.Name != "init" {
+ p.declare(decl, nil, p.pkgScope, ast.Fun, ident)
+ }
+ }
+
+ return decl
+}
+
+func (p *parser) parseDecl(sync map[token.Token]bool) ast.Decl {
+ if p.trace {
+ defer un(trace(p, "Declaration"))
+ }
+
+ var f parseSpecFunction
+ switch p.tok {
+ case token.CONST, token.VAR:
+ f = p.parseValueSpec
+
+ case token.TYPE:
+ f = p.parseTypeSpec
+
+ case token.FUNC:
+ return p.parseFuncDecl()
+
+ default:
+ pos := p.pos
+ p.errorExpected(pos, "declaration")
+ p.advance(sync)
+ return &ast.BadDecl{From: pos, To: p.pos}
+ }
+
+ return p.parseGenDecl(p.tok, f)
+}
+
+// ----------------------------------------------------------------------------
+// Source files
+
+func (p *parser) parseFile() *ast.File {
+ if p.trace {
+ defer un(trace(p, "File"))
+ }
+
+ // Don't bother parsing the rest if we had errors scanning the first token.
+ // Likely not a Go source file at all.
+ if p.errors.Len() != 0 {
+ return nil
+ }
+
+ // package clause
+ doc := p.leadComment
+ pos := p.expect(token.PACKAGE)
+ // Go spec: The package clause is not a declaration;
+ // the package name does not appear in any scope.
+ ident := p.parseIdent()
+ if ident.Name == "_" && p.mode&DeclarationErrors != 0 {
+ p.error(p.pos, "invalid package name _")
+ }
+ p.expectSemi()
+
+ // Don't bother parsing the rest if we had errors parsing the package clause.
+ // Likely not a Go source file at all.
+ if p.errors.Len() != 0 {
+ return nil
+ }
+
+ p.openScope()
+ p.pkgScope = p.topScope
+ var decls []ast.Decl
+ if p.mode&PackageClauseOnly == 0 {
+ // import decls
+ for p.tok == token.IMPORT {
+ decls = append(decls, p.parseGenDecl(token.IMPORT, p.parseImportSpec))
+ }
+
+ if p.mode&ImportsOnly == 0 {
+ // rest of package body
+ for p.tok != token.EOF {
+ decls = append(decls, p.parseDecl(declStart))
+ }
+ }
+ }
+ p.closeScope()
+ assert(p.topScope == nil, "unbalanced scopes")
+ assert(p.labelScope == nil, "unbalanced label scopes")
+
+ // resolve global identifiers within the same file
+ i := 0
+ for _, ident := range p.unresolved {
+ // i <= index for current ident
+ assert(ident.Obj == unresolved, "object already resolved")
+ ident.Obj = p.pkgScope.Lookup(ident.Name) // also removes unresolved sentinel
+ if ident.Obj == nil {
+ p.unresolved[i] = ident
+ i++
+ }
+ }
+
+ return &ast.File{
+ Doc: doc,
+ Package: pos,
+ Name: ident,
+ Decls: decls,
+ Scope: p.pkgScope,
+ Imports: p.imports,
+ Unresolved: p.unresolved[0:i],
+ Comments: p.comments,
+ }
+}
diff --git a/src/go/parser/parser_test.go b/src/go/parser/parser_test.go
new file mode 100644
index 0000000..a4f882d
--- /dev/null
+++ b/src/go/parser/parser_test.go
@@ -0,0 +1,579 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package parser
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/token"
+ "io/fs"
+ "strings"
+ "testing"
+)
+
+var validFiles = []string{
+ "parser.go",
+ "parser_test.go",
+ "error_test.go",
+ "short_test.go",
+}
+
+func TestParse(t *testing.T) {
+ for _, filename := range validFiles {
+ _, err := ParseFile(token.NewFileSet(), filename, nil, DeclarationErrors)
+ if err != nil {
+ t.Fatalf("ParseFile(%s): %v", filename, err)
+ }
+ }
+}
+
+func nameFilter(filename string) bool {
+ switch filename {
+ case "parser.go", "interface.go", "parser_test.go":
+ return true
+ case "parser.go.orig":
+ return true // permit but should be ignored by ParseDir
+ }
+ return false
+}
+
+func dirFilter(f fs.FileInfo) bool { return nameFilter(f.Name()) }
+
+func TestParseFile(t *testing.T) {
+ src := "package p\nvar _=s[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]"
+ _, err := ParseFile(token.NewFileSet(), "", src, 0)
+ if err == nil {
+ t.Errorf("ParseFile(%s) succeeded unexpectedly", src)
+ }
+}
+
+func TestParseExprFrom(t *testing.T) {
+ src := "s[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]"
+ _, err := ParseExprFrom(token.NewFileSet(), "", src, 0)
+ if err == nil {
+ t.Errorf("ParseExprFrom(%s) succeeded unexpectedly", src)
+ }
+}
+
+func TestParseDir(t *testing.T) {
+ path := "."
+ pkgs, err := ParseDir(token.NewFileSet(), path, dirFilter, 0)
+ if err != nil {
+ t.Fatalf("ParseDir(%s): %v", path, err)
+ }
+ if n := len(pkgs); n != 1 {
+ t.Errorf("got %d packages; want 1", n)
+ }
+ pkg := pkgs["parser"]
+ if pkg == nil {
+ t.Errorf(`package "parser" not found`)
+ return
+ }
+ if n := len(pkg.Files); n != 3 {
+ t.Errorf("got %d package files; want 3", n)
+ }
+ for filename := range pkg.Files {
+ if !nameFilter(filename) {
+ t.Errorf("unexpected package file: %s", filename)
+ }
+ }
+}
+
+func TestIssue42951(t *testing.T) {
+ path := "./testdata/issue42951"
+ _, err := ParseDir(token.NewFileSet(), path, nil, 0)
+ if err != nil {
+ t.Errorf("ParseDir(%s): %v", path, err)
+ }
+}
+
+func TestParseExpr(t *testing.T) {
+ // just kicking the tires:
+ // a valid arithmetic expression
+ src := "a + b"
+ x, err := ParseExpr(src)
+ if err != nil {
+ t.Errorf("ParseExpr(%q): %v", src, err)
+ }
+ // sanity check
+ if _, ok := x.(*ast.BinaryExpr); !ok {
+ t.Errorf("ParseExpr(%q): got %T, want *ast.BinaryExpr", src, x)
+ }
+
+ // a valid type expression
+ src = "struct{x *int}"
+ x, err = ParseExpr(src)
+ if err != nil {
+ t.Errorf("ParseExpr(%q): %v", src, err)
+ }
+ // sanity check
+ if _, ok := x.(*ast.StructType); !ok {
+ t.Errorf("ParseExpr(%q): got %T, want *ast.StructType", src, x)
+ }
+
+ // an invalid expression
+ src = "a + *"
+ x, err = ParseExpr(src)
+ if err == nil {
+ t.Errorf("ParseExpr(%q): got no error", src)
+ }
+ if x == nil {
+ t.Errorf("ParseExpr(%q): got no (partial) result", src)
+ }
+ if _, ok := x.(*ast.BinaryExpr); !ok {
+ t.Errorf("ParseExpr(%q): got %T, want *ast.BinaryExpr", src, x)
+ }
+
+ // a valid expression followed by extra tokens is invalid
+ src = "a[i] := x"
+ if _, err := ParseExpr(src); err == nil {
+ t.Errorf("ParseExpr(%q): got no error", src)
+ }
+
+ // a semicolon is not permitted unless automatically inserted
+ src = "a + b\n"
+ if _, err := ParseExpr(src); err != nil {
+ t.Errorf("ParseExpr(%q): got error %s", src, err)
+ }
+ src = "a + b;"
+ if _, err := ParseExpr(src); err == nil {
+ t.Errorf("ParseExpr(%q): got no error", src)
+ }
+
+ // various other stuff following a valid expression
+ const validExpr = "a + b"
+ const anything = "dh3*#D)#_"
+ for _, c := range "!)]};," {
+ src := validExpr + string(c) + anything
+ if _, err := ParseExpr(src); err == nil {
+ t.Errorf("ParseExpr(%q): got no error", src)
+ }
+ }
+
+ // ParseExpr must not crash
+ for _, src := range valids {
+ ParseExpr(src)
+ }
+}
+
+func TestColonEqualsScope(t *testing.T) {
+ f, err := ParseFile(token.NewFileSet(), "", `package p; func f() { x, y, z := x, y, z }`, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // RHS refers to undefined globals; LHS does not.
+ as := f.Decls[0].(*ast.FuncDecl).Body.List[0].(*ast.AssignStmt)
+ for _, v := range as.Rhs {
+ id := v.(*ast.Ident)
+ if id.Obj != nil {
+ t.Errorf("rhs %s has Obj, should not", id.Name)
+ }
+ }
+ for _, v := range as.Lhs {
+ id := v.(*ast.Ident)
+ if id.Obj == nil {
+ t.Errorf("lhs %s does not have Obj, should", id.Name)
+ }
+ }
+}
+
+func TestVarScope(t *testing.T) {
+ f, err := ParseFile(token.NewFileSet(), "", `package p; func f() { var x, y, z = x, y, z }`, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // RHS refers to undefined globals; LHS does not.
+ as := f.Decls[0].(*ast.FuncDecl).Body.List[0].(*ast.DeclStmt).Decl.(*ast.GenDecl).Specs[0].(*ast.ValueSpec)
+ for _, v := range as.Values {
+ id := v.(*ast.Ident)
+ if id.Obj != nil {
+ t.Errorf("rhs %s has Obj, should not", id.Name)
+ }
+ }
+ for _, id := range as.Names {
+ if id.Obj == nil {
+ t.Errorf("lhs %s does not have Obj, should", id.Name)
+ }
+ }
+}
+
+func TestObjects(t *testing.T) {
+ const src = `
+package p
+import fmt "fmt"
+const pi = 3.14
+type T struct{}
+var x int
+func f() { L: }
+`
+
+ f, err := ParseFile(token.NewFileSet(), "", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ objects := map[string]ast.ObjKind{
+ "p": ast.Bad, // not in a scope
+ "fmt": ast.Bad, // not resolved yet
+ "pi": ast.Con,
+ "T": ast.Typ,
+ "x": ast.Var,
+ "int": ast.Bad, // not resolved yet
+ "f": ast.Fun,
+ "L": ast.Lbl,
+ }
+
+ ast.Inspect(f, func(n ast.Node) bool {
+ if ident, ok := n.(*ast.Ident); ok {
+ obj := ident.Obj
+ if obj == nil {
+ if objects[ident.Name] != ast.Bad {
+ t.Errorf("no object for %s", ident.Name)
+ }
+ return true
+ }
+ if obj.Name != ident.Name {
+ t.Errorf("names don't match: obj.Name = %s, ident.Name = %s", obj.Name, ident.Name)
+ }
+ kind := objects[ident.Name]
+ if obj.Kind != kind {
+ t.Errorf("%s: obj.Kind = %s; want %s", ident.Name, obj.Kind, kind)
+ }
+ }
+ return true
+ })
+}
+
+func TestUnresolved(t *testing.T) {
+ f, err := ParseFile(token.NewFileSet(), "", `
+package p
+//
+func f1a(int)
+func f2a(byte, int, float)
+func f3a(a, b int, c float)
+func f4a(...complex)
+func f5a(a s1a, b ...complex)
+//
+func f1b(*int)
+func f2b([]byte, (int), *float)
+func f3b(a, b *int, c []float)
+func f4b(...*complex)
+func f5b(a s1a, b ...[]complex)
+//
+type s1a struct { int }
+type s2a struct { byte; int; s1a }
+type s3a struct { a, b int; c float }
+//
+type s1b struct { *int }
+type s2b struct { byte; int; *float }
+type s3b struct { a, b *s3b; c []float }
+`, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ want := "int " + // f1a
+ "byte int float " + // f2a
+ "int float " + // f3a
+ "complex " + // f4a
+ "complex " + // f5a
+ //
+ "int " + // f1b
+ "byte int float " + // f2b
+ "int float " + // f3b
+ "complex " + // f4b
+ "complex " + // f5b
+ //
+ "int " + // s1a
+ "byte int " + // s2a
+ "int float " + // s3a
+ //
+ "int " + // s1a
+ "byte int float " + // s2a
+ "float " // s3a
+
+ // collect unresolved identifiers
+ var buf bytes.Buffer
+ for _, u := range f.Unresolved {
+ buf.WriteString(u.Name)
+ buf.WriteByte(' ')
+ }
+ got := buf.String()
+
+ if got != want {
+ t.Errorf("\ngot: %s\nwant: %s", got, want)
+ }
+}
+
+var imports = map[string]bool{
+ `"a"`: true,
+ "`a`": true,
+ `"a/b"`: true,
+ `"a.b"`: true,
+ `"m\x61th"`: true,
+ `"greek/αβ"`: true,
+ `""`: false,
+
+ // Each of these pairs tests both `` vs "" strings
+ // and also use of invalid characters spelled out as
+ // escape sequences and written directly.
+ // For example `"\x00"` tests import "\x00"
+ // while "`\x00`" tests import `<actual-NUL-byte>`.
+ `"\x00"`: false,
+ "`\x00`": false,
+ `"\x7f"`: false,
+ "`\x7f`": false,
+ `"a!"`: false,
+ "`a!`": false,
+ `"a b"`: false,
+ "`a b`": false,
+ `"a\\b"`: false,
+ "`a\\b`": false,
+ "\"`a`\"": false,
+ "`\"a\"`": false,
+ `"\x80\x80"`: false,
+ "`\x80\x80`": false,
+ `"\xFFFD"`: false,
+ "`\xFFFD`": false,
+}
+
+func TestImports(t *testing.T) {
+ for path, isValid := range imports {
+ src := fmt.Sprintf("package p; import %s", path)
+ _, err := ParseFile(token.NewFileSet(), "", src, 0)
+ switch {
+ case err != nil && isValid:
+ t.Errorf("ParseFile(%s): got %v; expected no error", src, err)
+ case err == nil && !isValid:
+ t.Errorf("ParseFile(%s): got no error; expected one", src)
+ }
+ }
+}
+
+func TestCommentGroups(t *testing.T) {
+ f, err := ParseFile(token.NewFileSet(), "", `
+package p /* 1a */ /* 1b */ /* 1c */ // 1d
+/* 2a
+*/
+// 2b
+const pi = 3.1415
+/* 3a */ // 3b
+/* 3c */ const e = 2.7182
+
+// Example from issue 3139
+func ExampleCount() {
+ fmt.Println(strings.Count("cheese", "e"))
+ fmt.Println(strings.Count("five", "")) // before & after each rune
+ // Output:
+ // 3
+ // 5
+}
+`, ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ expected := [][]string{
+ {"/* 1a */", "/* 1b */", "/* 1c */", "// 1d"},
+ {"/* 2a\n*/", "// 2b"},
+ {"/* 3a */", "// 3b", "/* 3c */"},
+ {"// Example from issue 3139"},
+ {"// before & after each rune"},
+ {"// Output:", "// 3", "// 5"},
+ }
+ if len(f.Comments) != len(expected) {
+ t.Fatalf("got %d comment groups; expected %d", len(f.Comments), len(expected))
+ }
+ for i, exp := range expected {
+ got := f.Comments[i].List
+ if len(got) != len(exp) {
+ t.Errorf("got %d comments in group %d; expected %d", len(got), i, len(exp))
+ continue
+ }
+ for j, exp := range exp {
+ got := got[j].Text
+ if got != exp {
+ t.Errorf("got %q in group %d; expected %q", got, i, exp)
+ }
+ }
+ }
+}
+
+func getField(file *ast.File, fieldname string) *ast.Field {
+ parts := strings.Split(fieldname, ".")
+ for _, d := range file.Decls {
+ if d, ok := d.(*ast.GenDecl); ok && d.Tok == token.TYPE {
+ for _, s := range d.Specs {
+ if s, ok := s.(*ast.TypeSpec); ok && s.Name.Name == parts[0] {
+ if s, ok := s.Type.(*ast.StructType); ok {
+ for _, f := range s.Fields.List {
+ for _, name := range f.Names {
+ if name.Name == parts[1] {
+ return f
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ return nil
+}
+
+// Don't use ast.CommentGroup.Text() - we want to see exact comment text.
+func commentText(c *ast.CommentGroup) string {
+ var buf bytes.Buffer
+ if c != nil {
+ for _, c := range c.List {
+ buf.WriteString(c.Text)
+ }
+ }
+ return buf.String()
+}
+
+func checkFieldComments(t *testing.T, file *ast.File, fieldname, lead, line string) {
+ f := getField(file, fieldname)
+ if f == nil {
+ t.Fatalf("field not found: %s", fieldname)
+ }
+ if got := commentText(f.Doc); got != lead {
+ t.Errorf("got lead comment %q; expected %q", got, lead)
+ }
+ if got := commentText(f.Comment); got != line {
+ t.Errorf("got line comment %q; expected %q", got, line)
+ }
+}
+
+func TestLeadAndLineComments(t *testing.T) {
+ f, err := ParseFile(token.NewFileSet(), "", `
+package p
+type T struct {
+ /* F1 lead comment */
+ //
+ F1 int /* F1 */ // line comment
+ // F2 lead
+ // comment
+ F2 int // F2 line comment
+ // f3 lead comment
+ f3 int // f3 line comment
+}
+`, ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ checkFieldComments(t, f, "T.F1", "/* F1 lead comment *///", "/* F1 */// line comment")
+ checkFieldComments(t, f, "T.F2", "// F2 lead// comment", "// F2 line comment")
+ checkFieldComments(t, f, "T.f3", "// f3 lead comment", "// f3 line comment")
+ ast.FileExports(f)
+ checkFieldComments(t, f, "T.F1", "/* F1 lead comment *///", "/* F1 */// line comment")
+ checkFieldComments(t, f, "T.F2", "// F2 lead// comment", "// F2 line comment")
+ if getField(f, "T.f3") != nil {
+ t.Error("not expected to find T.f3")
+ }
+}
+
+// TestIssue9979 verifies that empty statements are contained within their enclosing blocks.
+func TestIssue9979(t *testing.T) {
+ for _, src := range []string{
+ "package p; func f() {;}",
+ "package p; func f() {L:}",
+ "package p; func f() {L:;}",
+ "package p; func f() {L:\n}",
+ "package p; func f() {L:\n;}",
+ "package p; func f() { ; }",
+ "package p; func f() { L: }",
+ "package p; func f() { L: ; }",
+ "package p; func f() { L: \n}",
+ "package p; func f() { L: \n; }",
+ } {
+ fset := token.NewFileSet()
+ f, err := ParseFile(fset, "", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var pos, end token.Pos
+ ast.Inspect(f, func(x ast.Node) bool {
+ switch s := x.(type) {
+ case *ast.BlockStmt:
+ pos, end = s.Pos()+1, s.End()-1 // exclude "{", "}"
+ case *ast.LabeledStmt:
+ pos, end = s.Pos()+2, s.End() // exclude "L:"
+ case *ast.EmptyStmt:
+ // check containment
+ if s.Pos() < pos || s.End() > end {
+ t.Errorf("%s: %T[%d, %d] not inside [%d, %d]", src, s, s.Pos(), s.End(), pos, end)
+ }
+ // check semicolon
+ offs := fset.Position(s.Pos()).Offset
+ if ch := src[offs]; ch != ';' != s.Implicit {
+ want := "want ';'"
+ if s.Implicit {
+ want = "but ';' is implicit"
+ }
+ t.Errorf("%s: found %q at offset %d; %s", src, ch, offs, want)
+ }
+ }
+ return true
+ })
+ }
+}
+
+// TestIncompleteSelection ensures that an incomplete selector
+// expression is parsed as a (blank) *ast.SelectorExpr, not a
+// *ast.BadExpr.
+func TestIncompleteSelection(t *testing.T) {
+ for _, src := range []string{
+ "package p; var _ = fmt.", // at EOF
+ "package p; var _ = fmt.\ntype X int", // not at EOF
+ } {
+ fset := token.NewFileSet()
+ f, err := ParseFile(fset, "", src, 0)
+ if err == nil {
+ t.Errorf("ParseFile(%s) succeeded unexpectedly", src)
+ continue
+ }
+
+ const wantErr = "expected selector or type assertion"
+ if !strings.Contains(err.Error(), wantErr) {
+ t.Errorf("ParseFile returned wrong error %q, want %q", err, wantErr)
+ }
+
+ var sel *ast.SelectorExpr
+ ast.Inspect(f, func(n ast.Node) bool {
+ if n, ok := n.(*ast.SelectorExpr); ok {
+ sel = n
+ }
+ return true
+ })
+ if sel == nil {
+ t.Error("found no *ast.SelectorExpr")
+ continue
+ }
+ const wantSel = "&{fmt _}"
+ if fmt.Sprint(sel) != wantSel {
+ t.Errorf("found selector %s, want %s", sel, wantSel)
+ continue
+ }
+ }
+}
+
+func TestLastLineComment(t *testing.T) {
+ const src = `package main
+type x int // comment
+`
+ fset := token.NewFileSet()
+ f, err := ParseFile(fset, "", src, ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ comment := f.Decls[0].(*ast.GenDecl).Specs[0].(*ast.TypeSpec).Comment.List[0].Text
+ if comment != "// comment" {
+ t.Errorf("got %q, want %q", comment, "// comment")
+ }
+}
diff --git a/src/go/parser/performance_test.go b/src/go/parser/performance_test.go
new file mode 100644
index 0000000..f81bcee
--- /dev/null
+++ b/src/go/parser/performance_test.go
@@ -0,0 +1,30 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package parser
+
+import (
+ "go/token"
+ "os"
+ "testing"
+)
+
+var src = readFile("parser.go")
+
+func readFile(filename string) []byte {
+ data, err := os.ReadFile(filename)
+ if err != nil {
+ panic(err)
+ }
+ return data
+}
+
+func BenchmarkParse(b *testing.B) {
+ b.SetBytes(int64(len(src)))
+ for i := 0; i < b.N; i++ {
+ if _, err := ParseFile(token.NewFileSet(), "", src, ParseComments); err != nil {
+ b.Fatalf("benchmark failed due to parse error: %s", err)
+ }
+ }
+}
diff --git a/src/go/parser/short_test.go b/src/go/parser/short_test.go
new file mode 100644
index 0000000..49bb681
--- /dev/null
+++ b/src/go/parser/short_test.go
@@ -0,0 +1,136 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains test cases for short valid and invalid programs.
+
+package parser
+
+import "testing"
+
+var valids = []string{
+ "package p\n",
+ `package p;`,
+ `package p; import "fmt"; func f() { fmt.Println("Hello, World!") };`,
+ `package p; func f() { if f(T{}) {} };`,
+ `package p; func f() { _ = <-chan int(nil) };`,
+ `package p; func f() { _ = (<-chan int)(nil) };`,
+ `package p; func f() { _ = (<-chan <-chan int)(nil) };`,
+ `package p; func f() { _ = <-chan <-chan <-chan <-chan <-int(nil) };`,
+ `package p; func f(func() func() func());`,
+ `package p; func f(...T);`,
+ `package p; func f(float, ...int);`,
+ `package p; func f(x int, a ...int) { f(0, a...); f(1, a...,) };`,
+ `package p; func f(int,) {};`,
+ `package p; func f(...int,) {};`,
+ `package p; func f(x ...int,) {};`,
+ `package p; type T []int; var a []bool; func f() { if a[T{42}[0]] {} };`,
+ `package p; type T []int; func g(int) bool { return true }; func f() { if g(T{42}[0]) {} };`,
+ `package p; type T []int; func f() { for _ = range []int{T{42}[0]} {} };`,
+ `package p; var a = T{{1, 2}, {3, 4}}`,
+ `package p; func f() { select { case <- c: case c <- d: case c <- <- d: case <-c <- d: } };`,
+ `package p; func f() { select { case x := (<-c): } };`,
+ `package p; func f() { if ; true {} };`,
+ `package p; func f() { switch ; {} };`,
+ `package p; func f() { for _ = range "foo" + "bar" {} };`,
+ `package p; func f() { var s []int; g(s[:], s[i:], s[:j], s[i:j], s[i:j:k], s[:j:k]) };`,
+ `package p; var ( _ = (struct {*T}).m; _ = (interface {T}).m )`,
+ `package p; func ((T),) m() {}`,
+ `package p; func ((*T),) m() {}`,
+ `package p; func (*(T),) m() {}`,
+ `package p; func _(x []int) { for range x {} }`,
+ `package p; func _() { if [T{}.n]int{} {} }`,
+ `package p; func _() { map[int]int{}[0]++; map[int]int{}[0] += 1 }`,
+ `package p; func _(x interface{f()}) { interface{f()}(x).f() }`,
+ `package p; func _(x chan int) { chan int(x) <- 0 }`,
+ `package p; const (x = 0; y; z)`, // issue 9639
+ `package p; var _ = map[P]int{P{}:0, {}:1}`,
+ `package p; var _ = map[*P]int{&P{}:0, {}:1}`,
+ `package p; type T = int`,
+ `package p; type (T = p.T; _ = struct{}; x = *T)`,
+}
+
+func TestValid(t *testing.T) {
+ for _, src := range valids {
+ checkErrors(t, src, src)
+ }
+}
+
+var invalids = []string{
+ `foo /* ERROR "expected 'package'" */ !`,
+ `package p; func f() { if { /* ERROR "missing condition" */ } };`,
+ `package p; func f() { if ; /* ERROR "missing condition" */ {} };`,
+ `package p; func f() { if f(); /* ERROR "missing condition" */ {} };`,
+ `package p; func f() { if _ = range /* ERROR "expected operand" */ x; true {} };`,
+ `package p; func f() { switch _ /* ERROR "expected switch expression" */ = range x; true {} };`,
+ `package p; func f() { for _ = range x ; /* ERROR "expected '{'" */ ; {} };`,
+ `package p; func f() { for ; ; _ = range /* ERROR "expected operand" */ x {} };`,
+ `package p; func f() { for ; _ /* ERROR "expected boolean or range expression" */ = range x ; {} };`,
+ `package p; func f() { switch t = /* ERROR "expected ':=', found '='" */ t.(type) {} };`,
+ `package p; func f() { switch t /* ERROR "expected switch expression" */ , t = t.(type) {} };`,
+ `package p; func f() { switch t /* ERROR "expected switch expression" */ = t.(type), t {} };`,
+ `package p; var a = [ /* ERROR "expected expression" */ 1]int;`,
+ `package p; var a = [ /* ERROR "expected expression" */ ...]int;`,
+ `package p; var a = struct /* ERROR "expected expression" */ {}`,
+ `package p; var a = func /* ERROR "expected expression" */ ();`,
+ `package p; var a = interface /* ERROR "expected expression" */ {}`,
+ `package p; var a = [ /* ERROR "expected expression" */ ]int`,
+ `package p; var a = map /* ERROR "expected expression" */ [int]int`,
+ `package p; var a = chan /* ERROR "expected expression" */ int;`,
+ `package p; var a = []int{[ /* ERROR "expected expression" */ ]int};`,
+ `package p; var a = ( /* ERROR "expected expression" */ []int);`,
+ `package p; var a = a[[ /* ERROR "expected expression" */ ]int:[]int];`,
+ `package p; var a = <- /* ERROR "expected expression" */ chan int;`,
+ `package p; func f() { select { case _ <- chan /* ERROR "expected expression" */ int: } };`,
+ `package p; func f() { _ = (<-<- /* ERROR "expected 'chan'" */ chan int)(nil) };`,
+ `package p; func f() { _ = (<-chan<-chan<-chan<-chan<-chan<- /* ERROR "expected channel type" */ int)(nil) };`,
+ `package p; func f() { var t []int; t /* ERROR "expected identifier on left side of :=" */ [0] := 0 };`,
+ `package p; func f() { if x := g(); x /* ERROR "expected boolean expression" */ = 0 {}};`,
+ `package p; func f() { _ = x = /* ERROR "expected '=='" */ 0 {}};`,
+ `package p; func f() { _ = 1 == func()int { var x bool; x = x = /* ERROR "expected '=='" */ true; return x }() };`,
+ `package p; func f() { var s []int; _ = s[] /* ERROR "expected operand" */ };`,
+ `package p; func f() { var s []int; _ = s[i:j: /* ERROR "3rd index required" */ ] };`,
+ `package p; func f() { var s []int; _ = s[i: /* ERROR "2nd index required" */ :k] };`,
+ `package p; func f() { var s []int; _ = s[i: /* ERROR "2nd index required" */ :] };`,
+ `package p; func f() { var s []int; _ = s[: /* ERROR "2nd index required" */ :] };`,
+ `package p; func f() { var s []int; _ = s[: /* ERROR "2nd index required" */ ::] };`,
+ `package p; func f() { var s []int; _ = s[i:j:k: /* ERROR "expected ']'" */ l] };`,
+ `package p; func f() { for x /* ERROR "boolean or range expression" */ = []string {} }`,
+ `package p; func f() { for x /* ERROR "boolean or range expression" */ := []string {} }`,
+ `package p; func f() { for i /* ERROR "boolean or range expression" */ , x = []string {} }`,
+ `package p; func f() { for i /* ERROR "boolean or range expression" */ , x := []string {} }`,
+ `package p; func f() { go f /* ERROR HERE "function must be invoked" */ }`,
+ `package p; func f() { defer func() {} /* ERROR HERE "function must be invoked" */ }`,
+ `package p; func f() { go func() { func() { f(x func /* ERROR "missing ','" */ (){}) } } }`,
+ `package p; func f(x func(), u v func /* ERROR "missing ','" */ ()){}`,
+
+ // issue 8656
+ `package p; func f() (a b string /* ERROR "missing ','" */ , ok bool)`,
+
+ // issue 9639
+ `package p; var x /* ERROR "missing variable type or initialization" */ , y, z;`,
+ `package p; const x /* ERROR "missing constant value" */ ;`,
+ `package p; const x /* ERROR "missing constant value" */ int;`,
+ `package p; const (x = 0; y; z /* ERROR "missing constant value" */ int);`,
+
+ // issue 12437
+ `package p; var _ = struct { x int, /* ERROR "expected ';', found ','" */ }{};`,
+ `package p; var _ = struct { x int, /* ERROR "expected ';', found ','" */ y float }{};`,
+
+ // issue 11611
+ `package p; type _ struct { int, } /* ERROR "expected type, found '}'" */ ;`,
+ `package p; type _ struct { int, float } /* ERROR "expected type, found '}'" */ ;`,
+ `package p; type _ struct { ( /* ERROR "expected anonymous field" */ int) };`,
+ `package p; func _()(x, y, z ... /* ERROR "expected '\)', found '...'" */ int){}`,
+ `package p; func _()(... /* ERROR "expected type, found '...'" */ int){}`,
+
+ // issue 13475
+ `package p; func f() { if true {} else ; /* ERROR "expected if statement or block" */ }`,
+ `package p; func f() { if true {} else defer /* ERROR "expected if statement or block" */ f() }`,
+}
+
+func TestInvalid(t *testing.T) {
+ for _, src := range invalids {
+ checkErrors(t, src, src)
+ }
+}
diff --git a/src/go/parser/testdata/commas.src b/src/go/parser/testdata/commas.src
new file mode 100644
index 0000000..e0603cf
--- /dev/null
+++ b/src/go/parser/testdata/commas.src
@@ -0,0 +1,19 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for error messages/parser synchronization
+// after missing commas.
+
+package p
+
+var _ = []int{
+ 0/* ERROR HERE "missing ','" */
+}
+
+var _ = []int{
+ 0,
+ 1,
+ 2,
+ 3/* ERROR HERE "missing ','" */
+}
diff --git a/src/go/parser/testdata/issue11377.src b/src/go/parser/testdata/issue11377.src
new file mode 100644
index 0000000..1c43800
--- /dev/null
+++ b/src/go/parser/testdata/issue11377.src
@@ -0,0 +1,27 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for issue 11377: Better synchronization of
+// parser after certain syntax errors.
+
+package p
+
+func bad1() {
+ if f()) /* ERROR "expected ';', found '\)'" */ {
+ return
+ }
+}
+
+// There shouldn't be any errors down below.
+
+func F1() {}
+func F2() {}
+func F3() {}
+func F4() {}
+func F5() {}
+func F6() {}
+func F7() {}
+func F8() {}
+func F9() {}
+func F10() {}
diff --git a/src/go/parser/testdata/issue23434.src b/src/go/parser/testdata/issue23434.src
new file mode 100644
index 0000000..24a0832
--- /dev/null
+++ b/src/go/parser/testdata/issue23434.src
@@ -0,0 +1,25 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for issue 23434: Better synchronization of
+// parser after missing type. There should be exactly
+// one error each time, with now follow errors.
+
+package p
+
+func g() {
+ m := make(map[string]! /* ERROR "expected type, found '!'" */ )
+ for {
+ x := 1
+ print(x)
+ }
+}
+
+func f() {
+ m := make(map[string]) /* ERROR "expected type, found '\)'" */
+ for {
+ x := 1
+ print(x)
+ }
+}
diff --git a/src/go/parser/testdata/issue3106.src b/src/go/parser/testdata/issue3106.src
new file mode 100644
index 0000000..2db10be
--- /dev/null
+++ b/src/go/parser/testdata/issue3106.src
@@ -0,0 +1,46 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for issue 3106: Better synchronization of
+// parser after certain syntax errors.
+
+package main
+
+func f() {
+ var m Mutex
+ c := MakeCond(&m)
+ percent := 0
+ const step = 10
+ for i := 0; i < 5; i++ {
+ go func() {
+ for {
+ // Emulates some useful work.
+ time.Sleep(1e8)
+ m.Lock()
+ defer
+ if /* ERROR "expected ';', found 'if'" */ percent == 100 {
+ m.Unlock()
+ break
+ }
+ percent++
+ if percent % step == 0 {
+ //c.Signal()
+ }
+ m.Unlock()
+ }
+ }()
+ }
+ for {
+ m.Lock()
+ if percent == 0 || percent % step != 0 {
+ c.Wait()
+ }
+ fmt.Print(",")
+ if percent == 100 {
+ m.Unlock()
+ break
+ }
+ m.Unlock()
+ }
+}
diff --git a/src/go/parser/testdata/issue34946.src b/src/go/parser/testdata/issue34946.src
new file mode 100644
index 0000000..6bb15e1
--- /dev/null
+++ b/src/go/parser/testdata/issue34946.src
@@ -0,0 +1,22 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for issue 34946: Better synchronization of
+// parser for function declarations that start their
+// body's opening { on a new line.
+
+package p
+
+// accept Allman/BSD-style declaration but complain
+// (implicit semicolon between signature and body)
+func _() int
+{ /* ERROR "unexpected semicolon or newline before {" */
+ { return 0 }
+}
+
+func _() {}
+
+func _(); { /* ERROR "unexpected semicolon or newline before {" */ }
+
+func _() {}
diff --git a/src/go/parser/testdata/issue42951/not_a_file.go/invalid.go b/src/go/parser/testdata/issue42951/not_a_file.go/invalid.go
new file mode 100644
index 0000000..bb698be
--- /dev/null
+++ b/src/go/parser/testdata/issue42951/not_a_file.go/invalid.go
@@ -0,0 +1 @@
+This file should not be parsed by ParseDir.
diff --git a/src/go/printer/example_test.go b/src/go/printer/example_test.go
new file mode 100644
index 0000000..3081693
--- /dev/null
+++ b/src/go/printer/example_test.go
@@ -0,0 +1,67 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package printer_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "strings"
+ "testing"
+)
+
+// Dummy test function so that godoc does not use the entire file as example.
+func Test(*testing.T) {}
+
+func parseFunc(filename, functionname string) (fun *ast.FuncDecl, fset *token.FileSet) {
+ fset = token.NewFileSet()
+ if file, err := parser.ParseFile(fset, filename, nil, 0); err == nil {
+ for _, d := range file.Decls {
+ if f, ok := d.(*ast.FuncDecl); ok && f.Name.Name == functionname {
+ fun = f
+ return
+ }
+ }
+ }
+ panic("function not found")
+}
+
+func ExampleFprint() {
+ // Parse source file and extract the AST without comments for
+ // this function, with position information referring to the
+ // file set fset.
+ funcAST, fset := parseFunc("example_test.go", "ExampleFprint")
+
+ // Print the function body into buffer buf.
+ // The file set is provided to the printer so that it knows
+ // about the original source formatting and can add additional
+ // line breaks where they were present in the source.
+ var buf bytes.Buffer
+ printer.Fprint(&buf, fset, funcAST.Body)
+
+ // Remove braces {} enclosing the function body, unindent,
+ // and trim leading and trailing white space.
+ s := buf.String()
+ s = s[1 : len(s)-1]
+ s = strings.TrimSpace(strings.ReplaceAll(s, "\n\t", "\n"))
+
+ // Print the cleaned-up body text to stdout.
+ fmt.Println(s)
+
+ // output:
+ // funcAST, fset := parseFunc("example_test.go", "ExampleFprint")
+ //
+ // var buf bytes.Buffer
+ // printer.Fprint(&buf, fset, funcAST.Body)
+ //
+ // s := buf.String()
+ // s = s[1 : len(s)-1]
+ // s = strings.TrimSpace(strings.ReplaceAll(s, "\n\t", "\n"))
+ //
+ // fmt.Println(s)
+}
diff --git a/src/go/printer/nodes.go b/src/go/printer/nodes.go
new file mode 100644
index 0000000..95b9e91
--- /dev/null
+++ b/src/go/printer/nodes.go
@@ -0,0 +1,1844 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements printing of AST nodes; specifically
+// expressions, statements, declarations, and files. It uses
+// the print functionality implemented in printer.go.
+
+package printer
+
+import (
+ "bytes"
+ "go/ast"
+ "go/token"
+ "math"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+// Formatting issues:
+// - better comment formatting for /*-style comments at the end of a line (e.g. a declaration)
+// when the comment spans multiple lines; if such a comment is just two lines, formatting is
+// not idempotent
+// - formatting of expression lists
+// - should use blank instead of tab to separate one-line function bodies from
+// the function header unless there is a group of consecutive one-liners
+
+// ----------------------------------------------------------------------------
+// Common AST nodes.
+
+// Print as many newlines as necessary (but at least min newlines) to get to
+// the current line. ws is printed before the first line break. If newSection
+// is set, the first line break is printed as formfeed. Returns 0 if no line
+// breaks were printed, returns 1 if there was exactly one newline printed,
+// and returns a value > 1 if there was a formfeed or more than one newline
+// printed.
+//
+// TODO(gri): linebreak may add too many lines if the next statement at "line"
+// is preceded by comments because the computation of n assumes
+// the current position before the comment and the target position
+// after the comment. Thus, after interspersing such comments, the
+// space taken up by them is not considered to reduce the number of
+// linebreaks. At the moment there is no easy way to know about
+// future (not yet interspersed) comments in this function.
+//
+func (p *printer) linebreak(line, min int, ws whiteSpace, newSection bool) (nbreaks int) {
+ n := nlimit(line - p.pos.Line)
+ if n < min {
+ n = min
+ }
+ if n > 0 {
+ p.print(ws)
+ if newSection {
+ p.print(formfeed)
+ n--
+ nbreaks = 2
+ }
+ nbreaks += n
+ for ; n > 0; n-- {
+ p.print(newline)
+ }
+ }
+ return
+}
+
+// setComment sets g as the next comment if g != nil and if node comments
+// are enabled - this mode is used when printing source code fragments such
+// as exports only. It assumes that there is no pending comment in p.comments
+// and at most one pending comment in the p.comment cache.
+func (p *printer) setComment(g *ast.CommentGroup) {
+ if g == nil || !p.useNodeComments {
+ return
+ }
+ if p.comments == nil {
+ // initialize p.comments lazily
+ p.comments = make([]*ast.CommentGroup, 1)
+ } else if p.cindex < len(p.comments) {
+ // for some reason there are pending comments; this
+ // should never happen - handle gracefully and flush
+ // all comments up to g, ignore anything after that
+ p.flush(p.posFor(g.List[0].Pos()), token.ILLEGAL)
+ p.comments = p.comments[0:1]
+ // in debug mode, report error
+ p.internalError("setComment found pending comments")
+ }
+ p.comments[0] = g
+ p.cindex = 0
+ // don't overwrite any pending comment in the p.comment cache
+ // (there may be a pending comment when a line comment is
+ // immediately followed by a lead comment with no other
+ // tokens between)
+ if p.commentOffset == infinity {
+ p.nextComment() // get comment ready for use
+ }
+}
+
+type exprListMode uint
+
+const (
+ commaTerm exprListMode = 1 << iota // list is optionally terminated by a comma
+ noIndent // no extra indentation in multi-line lists
+)
+
+// If indent is set, a multi-line identifier list is indented after the
+// first linebreak encountered.
+func (p *printer) identList(list []*ast.Ident, indent bool) {
+ // convert into an expression list so we can re-use exprList formatting
+ xlist := make([]ast.Expr, len(list))
+ for i, x := range list {
+ xlist[i] = x
+ }
+ var mode exprListMode
+ if !indent {
+ mode = noIndent
+ }
+ p.exprList(token.NoPos, xlist, 1, mode, token.NoPos, false)
+}
+
+const filteredMsg = "contains filtered or unexported fields"
+
+// Print a list of expressions. If the list spans multiple
+// source lines, the original line breaks are respected between
+// expressions.
+//
+// TODO(gri) Consider rewriting this to be independent of []ast.Expr
+// so that we can use the algorithm for any kind of list
+// (e.g., pass list via a channel over which to range).
+func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exprListMode, next0 token.Pos, isIncomplete bool) {
+ if len(list) == 0 {
+ if isIncomplete {
+ prev := p.posFor(prev0)
+ next := p.posFor(next0)
+ if prev.IsValid() && prev.Line == next.Line {
+ p.print("/* " + filteredMsg + " */")
+ } else {
+ p.print(newline)
+ p.print(indent, "// "+filteredMsg, unindent, newline)
+ }
+ }
+ return
+ }
+
+ prev := p.posFor(prev0)
+ next := p.posFor(next0)
+ line := p.lineFor(list[0].Pos())
+ endLine := p.lineFor(list[len(list)-1].End())
+
+ if prev.IsValid() && prev.Line == line && line == endLine {
+ // all list entries on a single line
+ for i, x := range list {
+ if i > 0 {
+ // use position of expression following the comma as
+ // comma position for correct comment placement
+ p.print(x.Pos(), token.COMMA, blank)
+ }
+ p.expr0(x, depth)
+ }
+ if isIncomplete {
+ p.print(token.COMMA, blank, "/* "+filteredMsg+" */")
+ }
+ return
+ }
+
+ // list entries span multiple lines;
+ // use source code positions to guide line breaks
+
+ // Don't add extra indentation if noIndent is set;
+ // i.e., pretend that the first line is already indented.
+ ws := ignore
+ if mode&noIndent == 0 {
+ ws = indent
+ }
+
+ // The first linebreak is always a formfeed since this section must not
+ // depend on any previous formatting.
+ prevBreak := -1 // index of last expression that was followed by a linebreak
+ if prev.IsValid() && prev.Line < line && p.linebreak(line, 0, ws, true) > 0 {
+ ws = ignore
+ prevBreak = 0
+ }
+
+ // initialize expression/key size: a zero value indicates expr/key doesn't fit on a single line
+ size := 0
+
+ // We use the ratio between the geometric mean of the previous key sizes and
+ // the current size to determine if there should be a break in the alignment.
+ // To compute the geometric mean we accumulate the ln(size) values (lnsum)
+ // and the number of sizes included (count).
+ lnsum := 0.0
+ count := 0
+
+ // print all list elements
+ prevLine := prev.Line
+ for i, x := range list {
+ line = p.lineFor(x.Pos())
+
+ // Determine if the next linebreak, if any, needs to use formfeed:
+ // in general, use the entire node size to make the decision; for
+ // key:value expressions, use the key size.
+ // TODO(gri) for a better result, should probably incorporate both
+ // the key and the node size into the decision process
+ useFF := true
+
+ // Determine element size: All bets are off if we don't have
+ // position information for the previous and next token (likely
+ // generated code - simply ignore the size in this case by setting
+ // it to 0).
+ prevSize := size
+ const infinity = 1e6 // larger than any source line
+ size = p.nodeSize(x, infinity)
+ pair, isPair := x.(*ast.KeyValueExpr)
+ if size <= infinity && prev.IsValid() && next.IsValid() {
+ // x fits on a single line
+ if isPair {
+ size = p.nodeSize(pair.Key, infinity) // size <= infinity
+ }
+ } else {
+ // size too large or we don't have good layout information
+ size = 0
+ }
+
+ // If the previous line and the current line had single-
+ // line-expressions and the key sizes are small or the
+ // ratio between the current key and the geometric mean
+ // if the previous key sizes does not exceed a threshold,
+ // align columns and do not use formfeed.
+ if prevSize > 0 && size > 0 {
+ const smallSize = 40
+ if count == 0 || prevSize <= smallSize && size <= smallSize {
+ useFF = false
+ } else {
+ const r = 2.5 // threshold
+ geomean := math.Exp(lnsum / float64(count)) // count > 0
+ ratio := float64(size) / geomean
+ useFF = r*ratio <= 1 || r <= ratio
+ }
+ }
+
+ needsLinebreak := 0 < prevLine && prevLine < line
+ if i > 0 {
+ // Use position of expression following the comma as
+ // comma position for correct comment placement, but
+ // only if the expression is on the same line.
+ if !needsLinebreak {
+ p.print(x.Pos())
+ }
+ p.print(token.COMMA)
+ needsBlank := true
+ if needsLinebreak {
+ // Lines are broken using newlines so comments remain aligned
+ // unless useFF is set or there are multiple expressions on
+ // the same line in which case formfeed is used.
+ nbreaks := p.linebreak(line, 0, ws, useFF || prevBreak+1 < i)
+ if nbreaks > 0 {
+ ws = ignore
+ prevBreak = i
+ needsBlank = false // we got a line break instead
+ }
+ // If there was a new section or more than one new line
+ // (which means that the tabwriter will implicitly break
+ // the section), reset the geomean variables since we are
+ // starting a new group of elements with the next element.
+ if nbreaks > 1 {
+ lnsum = 0
+ count = 0
+ }
+ }
+ if needsBlank {
+ p.print(blank)
+ }
+ }
+
+ if len(list) > 1 && isPair && size > 0 && needsLinebreak {
+ // We have a key:value expression that fits onto one line
+ // and it's not on the same line as the prior expression:
+ // Use a column for the key such that consecutive entries
+ // can align if possible.
+ // (needsLinebreak is set if we started a new line before)
+ p.expr(pair.Key)
+ p.print(pair.Colon, token.COLON, vtab)
+ p.expr(pair.Value)
+ } else {
+ p.expr0(x, depth)
+ }
+
+ if size > 0 {
+ lnsum += math.Log(float64(size))
+ count++
+ }
+
+ prevLine = line
+ }
+
+ if mode&commaTerm != 0 && next.IsValid() && p.pos.Line < next.Line {
+ // Print a terminating comma if the next token is on a new line.
+ p.print(token.COMMA)
+ if isIncomplete {
+ p.print(newline)
+ p.print("// " + filteredMsg)
+ }
+ if ws == ignore && mode&noIndent == 0 {
+ // unindent if we indented
+ p.print(unindent)
+ }
+ p.print(formfeed) // terminating comma needs a line break to look good
+ return
+ }
+
+ if isIncomplete {
+ p.print(token.COMMA, newline)
+ p.print("// "+filteredMsg, newline)
+ }
+
+ if ws == ignore && mode&noIndent == 0 {
+ // unindent if we indented
+ p.print(unindent)
+ }
+}
+
+func (p *printer) parameters(fields *ast.FieldList) {
+ p.print(fields.Opening, token.LPAREN)
+ if len(fields.List) > 0 {
+ prevLine := p.lineFor(fields.Opening)
+ ws := indent
+ for i, par := range fields.List {
+ // determine par begin and end line (may be different
+ // if there are multiple parameter names for this par
+ // or the type is on a separate line)
+ var parLineBeg int
+ if len(par.Names) > 0 {
+ parLineBeg = p.lineFor(par.Names[0].Pos())
+ } else {
+ parLineBeg = p.lineFor(par.Type.Pos())
+ }
+ var parLineEnd = p.lineFor(par.Type.End())
+ // separating "," if needed
+ needsLinebreak := 0 < prevLine && prevLine < parLineBeg
+ if i > 0 {
+ // use position of parameter following the comma as
+ // comma position for correct comma placement, but
+ // only if the next parameter is on the same line
+ if !needsLinebreak {
+ p.print(par.Pos())
+ }
+ p.print(token.COMMA)
+ }
+ // separator if needed (linebreak or blank)
+ if needsLinebreak && p.linebreak(parLineBeg, 0, ws, true) > 0 {
+ // break line if the opening "(" or previous parameter ended on a different line
+ ws = ignore
+ } else if i > 0 {
+ p.print(blank)
+ }
+ // parameter names
+ if len(par.Names) > 0 {
+ // Very subtle: If we indented before (ws == ignore), identList
+ // won't indent again. If we didn't (ws == indent), identList will
+ // indent if the identList spans multiple lines, and it will outdent
+ // again at the end (and still ws == indent). Thus, a subsequent indent
+ // by a linebreak call after a type, or in the next multi-line identList
+ // will do the right thing.
+ p.identList(par.Names, ws == indent)
+ p.print(blank)
+ }
+ // parameter type
+ p.expr(stripParensAlways(par.Type))
+ prevLine = parLineEnd
+ }
+ // if the closing ")" is on a separate line from the last parameter,
+ // print an additional "," and line break
+ if closing := p.lineFor(fields.Closing); 0 < prevLine && prevLine < closing {
+ p.print(token.COMMA)
+ p.linebreak(closing, 0, ignore, true)
+ }
+ // unindent if we indented
+ if ws == ignore {
+ p.print(unindent)
+ }
+ }
+ p.print(fields.Closing, token.RPAREN)
+}
+
+func (p *printer) signature(params, result *ast.FieldList) {
+ if params != nil {
+ p.parameters(params)
+ } else {
+ p.print(token.LPAREN, token.RPAREN)
+ }
+ n := result.NumFields()
+ if n > 0 {
+ // result != nil
+ p.print(blank)
+ if n == 1 && result.List[0].Names == nil {
+ // single anonymous result; no ()'s
+ p.expr(stripParensAlways(result.List[0].Type))
+ return
+ }
+ p.parameters(result)
+ }
+}
+
+func identListSize(list []*ast.Ident, maxSize int) (size int) {
+ for i, x := range list {
+ if i > 0 {
+ size += len(", ")
+ }
+ size += utf8.RuneCountInString(x.Name)
+ if size >= maxSize {
+ break
+ }
+ }
+ return
+}
+
+func (p *printer) isOneLineFieldList(list []*ast.Field) bool {
+ if len(list) != 1 {
+ return false // allow only one field
+ }
+ f := list[0]
+ if f.Tag != nil || f.Comment != nil {
+ return false // don't allow tags or comments
+ }
+ // only name(s) and type
+ const maxSize = 30 // adjust as appropriate, this is an approximate value
+ namesSize := identListSize(f.Names, maxSize)
+ if namesSize > 0 {
+ namesSize = 1 // blank between names and types
+ }
+ typeSize := p.nodeSize(f.Type, maxSize)
+ return namesSize+typeSize <= maxSize
+}
+
+func (p *printer) setLineComment(text string) {
+ p.setComment(&ast.CommentGroup{List: []*ast.Comment{{Slash: token.NoPos, Text: text}}})
+}
+
+func (p *printer) fieldList(fields *ast.FieldList, isStruct, isIncomplete bool) {
+ lbrace := fields.Opening
+ list := fields.List
+ rbrace := fields.Closing
+ hasComments := isIncomplete || p.commentBefore(p.posFor(rbrace))
+ srcIsOneLine := lbrace.IsValid() && rbrace.IsValid() && p.lineFor(lbrace) == p.lineFor(rbrace)
+
+ if !hasComments && srcIsOneLine {
+ // possibly a one-line struct/interface
+ if len(list) == 0 {
+ // no blank between keyword and {} in this case
+ p.print(lbrace, token.LBRACE, rbrace, token.RBRACE)
+ return
+ } else if p.isOneLineFieldList(list) {
+ // small enough - print on one line
+ // (don't use identList and ignore source line breaks)
+ p.print(lbrace, token.LBRACE, blank)
+ f := list[0]
+ if isStruct {
+ for i, x := range f.Names {
+ if i > 0 {
+ // no comments so no need for comma position
+ p.print(token.COMMA, blank)
+ }
+ p.expr(x)
+ }
+ if len(f.Names) > 0 {
+ p.print(blank)
+ }
+ p.expr(f.Type)
+ } else { // interface
+ if ftyp, isFtyp := f.Type.(*ast.FuncType); isFtyp {
+ // method
+ p.expr(f.Names[0])
+ p.signature(ftyp.Params, ftyp.Results)
+ } else {
+ // embedded interface
+ p.expr(f.Type)
+ }
+ }
+ p.print(blank, rbrace, token.RBRACE)
+ return
+ }
+ }
+ // hasComments || !srcIsOneLine
+
+ p.print(blank, lbrace, token.LBRACE, indent)
+ if hasComments || len(list) > 0 {
+ p.print(formfeed)
+ }
+
+ if isStruct {
+
+ sep := vtab
+ if len(list) == 1 {
+ sep = blank
+ }
+ var line int
+ for i, f := range list {
+ if i > 0 {
+ p.linebreak(p.lineFor(f.Pos()), 1, ignore, p.linesFrom(line) > 0)
+ }
+ extraTabs := 0
+ p.setComment(f.Doc)
+ p.recordLine(&line)
+ if len(f.Names) > 0 {
+ // named fields
+ p.identList(f.Names, false)
+ p.print(sep)
+ p.expr(f.Type)
+ extraTabs = 1
+ } else {
+ // anonymous field
+ p.expr(f.Type)
+ extraTabs = 2
+ }
+ if f.Tag != nil {
+ if len(f.Names) > 0 && sep == vtab {
+ p.print(sep)
+ }
+ p.print(sep)
+ p.expr(f.Tag)
+ extraTabs = 0
+ }
+ if f.Comment != nil {
+ for ; extraTabs > 0; extraTabs-- {
+ p.print(sep)
+ }
+ p.setComment(f.Comment)
+ }
+ }
+ if isIncomplete {
+ if len(list) > 0 {
+ p.print(formfeed)
+ }
+ p.flush(p.posFor(rbrace), token.RBRACE) // make sure we don't lose the last line comment
+ p.setLineComment("// " + filteredMsg)
+ }
+
+ } else { // interface
+
+ var line int
+ for i, f := range list {
+ if i > 0 {
+ p.linebreak(p.lineFor(f.Pos()), 1, ignore, p.linesFrom(line) > 0)
+ }
+ p.setComment(f.Doc)
+ p.recordLine(&line)
+ if ftyp, isFtyp := f.Type.(*ast.FuncType); isFtyp {
+ // method
+ p.expr(f.Names[0])
+ p.signature(ftyp.Params, ftyp.Results)
+ } else {
+ // embedded interface
+ p.expr(f.Type)
+ }
+ p.setComment(f.Comment)
+ }
+ if isIncomplete {
+ if len(list) > 0 {
+ p.print(formfeed)
+ }
+ p.flush(p.posFor(rbrace), token.RBRACE) // make sure we don't lose the last line comment
+ p.setLineComment("// contains filtered or unexported methods")
+ }
+
+ }
+ p.print(unindent, formfeed, rbrace, token.RBRACE)
+}
+
+// ----------------------------------------------------------------------------
+// Expressions
+
+func walkBinary(e *ast.BinaryExpr) (has4, has5 bool, maxProblem int) {
+ switch e.Op.Precedence() {
+ case 4:
+ has4 = true
+ case 5:
+ has5 = true
+ }
+
+ switch l := e.X.(type) {
+ case *ast.BinaryExpr:
+ if l.Op.Precedence() < e.Op.Precedence() {
+ // parens will be inserted.
+ // pretend this is an *ast.ParenExpr and do nothing.
+ break
+ }
+ h4, h5, mp := walkBinary(l)
+ has4 = has4 || h4
+ has5 = has5 || h5
+ if maxProblem < mp {
+ maxProblem = mp
+ }
+ }
+
+ switch r := e.Y.(type) {
+ case *ast.BinaryExpr:
+ if r.Op.Precedence() <= e.Op.Precedence() {
+ // parens will be inserted.
+ // pretend this is an *ast.ParenExpr and do nothing.
+ break
+ }
+ h4, h5, mp := walkBinary(r)
+ has4 = has4 || h4
+ has5 = has5 || h5
+ if maxProblem < mp {
+ maxProblem = mp
+ }
+
+ case *ast.StarExpr:
+ if e.Op == token.QUO { // `*/`
+ maxProblem = 5
+ }
+
+ case *ast.UnaryExpr:
+ switch e.Op.String() + r.Op.String() {
+ case "/*", "&&", "&^":
+ maxProblem = 5
+ case "++", "--":
+ if maxProblem < 4 {
+ maxProblem = 4
+ }
+ }
+ }
+ return
+}
+
+func cutoff(e *ast.BinaryExpr, depth int) int {
+ has4, has5, maxProblem := walkBinary(e)
+ if maxProblem > 0 {
+ return maxProblem + 1
+ }
+ if has4 && has5 {
+ if depth == 1 {
+ return 5
+ }
+ return 4
+ }
+ if depth == 1 {
+ return 6
+ }
+ return 4
+}
+
+func diffPrec(expr ast.Expr, prec int) int {
+ x, ok := expr.(*ast.BinaryExpr)
+ if !ok || prec != x.Op.Precedence() {
+ return 1
+ }
+ return 0
+}
+
+func reduceDepth(depth int) int {
+ depth--
+ if depth < 1 {
+ depth = 1
+ }
+ return depth
+}
+
+// Format the binary expression: decide the cutoff and then format.
+// Let's call depth == 1 Normal mode, and depth > 1 Compact mode.
+// (Algorithm suggestion by Russ Cox.)
+//
+// The precedences are:
+// 5 * / % << >> & &^
+// 4 + - | ^
+// 3 == != < <= > >=
+// 2 &&
+// 1 ||
+//
+// The only decision is whether there will be spaces around levels 4 and 5.
+// There are never spaces at level 6 (unary), and always spaces at levels 3 and below.
+//
+// To choose the cutoff, look at the whole expression but excluding primary
+// expressions (function calls, parenthesized exprs), and apply these rules:
+//
+// 1) If there is a binary operator with a right side unary operand
+// that would clash without a space, the cutoff must be (in order):
+//
+// /* 6
+// && 6
+// &^ 6
+// ++ 5
+// -- 5
+//
+// (Comparison operators always have spaces around them.)
+//
+// 2) If there is a mix of level 5 and level 4 operators, then the cutoff
+// is 5 (use spaces to distinguish precedence) in Normal mode
+// and 4 (never use spaces) in Compact mode.
+//
+// 3) If there are no level 4 operators or no level 5 operators, then the
+// cutoff is 6 (always use spaces) in Normal mode
+// and 4 (never use spaces) in Compact mode.
+//
+func (p *printer) binaryExpr(x *ast.BinaryExpr, prec1, cutoff, depth int) {
+ prec := x.Op.Precedence()
+ if prec < prec1 {
+ // parenthesis needed
+ // Note: The parser inserts an ast.ParenExpr node; thus this case
+ // can only occur if the AST is created in a different way.
+ p.print(token.LPAREN)
+ p.expr0(x, reduceDepth(depth)) // parentheses undo one level of depth
+ p.print(token.RPAREN)
+ return
+ }
+
+ printBlank := prec < cutoff
+
+ ws := indent
+ p.expr1(x.X, prec, depth+diffPrec(x.X, prec))
+ if printBlank {
+ p.print(blank)
+ }
+ xline := p.pos.Line // before the operator (it may be on the next line!)
+ yline := p.lineFor(x.Y.Pos())
+ p.print(x.OpPos, x.Op)
+ if xline != yline && xline > 0 && yline > 0 {
+ // at least one line break, but respect an extra empty line
+ // in the source
+ if p.linebreak(yline, 1, ws, true) > 0 {
+ ws = ignore
+ printBlank = false // no blank after line break
+ }
+ }
+ if printBlank {
+ p.print(blank)
+ }
+ p.expr1(x.Y, prec+1, depth+1)
+ if ws == ignore {
+ p.print(unindent)
+ }
+}
+
+func isBinary(expr ast.Expr) bool {
+ _, ok := expr.(*ast.BinaryExpr)
+ return ok
+}
+
+func (p *printer) expr1(expr ast.Expr, prec1, depth int) {
+ p.print(expr.Pos())
+
+ switch x := expr.(type) {
+ case *ast.BadExpr:
+ p.print("BadExpr")
+
+ case *ast.Ident:
+ p.print(x)
+
+ case *ast.BinaryExpr:
+ if depth < 1 {
+ p.internalError("depth < 1:", depth)
+ depth = 1
+ }
+ p.binaryExpr(x, prec1, cutoff(x, depth), depth)
+
+ case *ast.KeyValueExpr:
+ p.expr(x.Key)
+ p.print(x.Colon, token.COLON, blank)
+ p.expr(x.Value)
+
+ case *ast.StarExpr:
+ const prec = token.UnaryPrec
+ if prec < prec1 {
+ // parenthesis needed
+ p.print(token.LPAREN)
+ p.print(token.MUL)
+ p.expr(x.X)
+ p.print(token.RPAREN)
+ } else {
+ // no parenthesis needed
+ p.print(token.MUL)
+ p.expr(x.X)
+ }
+
+ case *ast.UnaryExpr:
+ const prec = token.UnaryPrec
+ if prec < prec1 {
+ // parenthesis needed
+ p.print(token.LPAREN)
+ p.expr(x)
+ p.print(token.RPAREN)
+ } else {
+ // no parenthesis needed
+ p.print(x.Op)
+ if x.Op == token.RANGE {
+ // TODO(gri) Remove this code if it cannot be reached.
+ p.print(blank)
+ }
+ p.expr1(x.X, prec, depth)
+ }
+
+ case *ast.BasicLit:
+ if p.Config.Mode&normalizeNumbers != 0 {
+ x = normalizedNumber(x)
+ }
+ p.print(x)
+
+ case *ast.FuncLit:
+ p.print(x.Type.Pos(), token.FUNC)
+ // See the comment in funcDecl about how the header size is computed.
+ startCol := p.out.Column - len("func")
+ p.signature(x.Type.Params, x.Type.Results)
+ p.funcBody(p.distanceFrom(x.Type.Pos(), startCol), blank, x.Body)
+
+ case *ast.ParenExpr:
+ if _, hasParens := x.X.(*ast.ParenExpr); hasParens {
+ // don't print parentheses around an already parenthesized expression
+ // TODO(gri) consider making this more general and incorporate precedence levels
+ p.expr0(x.X, depth)
+ } else {
+ p.print(token.LPAREN)
+ p.expr0(x.X, reduceDepth(depth)) // parentheses undo one level of depth
+ p.print(x.Rparen, token.RPAREN)
+ }
+
+ case *ast.SelectorExpr:
+ p.selectorExpr(x, depth, false)
+
+ case *ast.TypeAssertExpr:
+ p.expr1(x.X, token.HighestPrec, depth)
+ p.print(token.PERIOD, x.Lparen, token.LPAREN)
+ if x.Type != nil {
+ p.expr(x.Type)
+ } else {
+ p.print(token.TYPE)
+ }
+ p.print(x.Rparen, token.RPAREN)
+
+ case *ast.IndexExpr:
+ // TODO(gri): should treat[] like parentheses and undo one level of depth
+ p.expr1(x.X, token.HighestPrec, 1)
+ p.print(x.Lbrack, token.LBRACK)
+ p.expr0(x.Index, depth+1)
+ p.print(x.Rbrack, token.RBRACK)
+
+ case *ast.SliceExpr:
+ // TODO(gri): should treat[] like parentheses and undo one level of depth
+ p.expr1(x.X, token.HighestPrec, 1)
+ p.print(x.Lbrack, token.LBRACK)
+ indices := []ast.Expr{x.Low, x.High}
+ if x.Max != nil {
+ indices = append(indices, x.Max)
+ }
+ // determine if we need extra blanks around ':'
+ var needsBlanks bool
+ if depth <= 1 {
+ var indexCount int
+ var hasBinaries bool
+ for _, x := range indices {
+ if x != nil {
+ indexCount++
+ if isBinary(x) {
+ hasBinaries = true
+ }
+ }
+ }
+ if indexCount > 1 && hasBinaries {
+ needsBlanks = true
+ }
+ }
+ for i, x := range indices {
+ if i > 0 {
+ if indices[i-1] != nil && needsBlanks {
+ p.print(blank)
+ }
+ p.print(token.COLON)
+ if x != nil && needsBlanks {
+ p.print(blank)
+ }
+ }
+ if x != nil {
+ p.expr0(x, depth+1)
+ }
+ }
+ p.print(x.Rbrack, token.RBRACK)
+
+ case *ast.CallExpr:
+ if len(x.Args) > 1 {
+ depth++
+ }
+ var wasIndented bool
+ if _, ok := x.Fun.(*ast.FuncType); ok {
+ // conversions to literal function types require parentheses around the type
+ p.print(token.LPAREN)
+ wasIndented = p.possibleSelectorExpr(x.Fun, token.HighestPrec, depth)
+ p.print(token.RPAREN)
+ } else {
+ wasIndented = p.possibleSelectorExpr(x.Fun, token.HighestPrec, depth)
+ }
+ p.print(x.Lparen, token.LPAREN)
+ if x.Ellipsis.IsValid() {
+ p.exprList(x.Lparen, x.Args, depth, 0, x.Ellipsis, false)
+ p.print(x.Ellipsis, token.ELLIPSIS)
+ if x.Rparen.IsValid() && p.lineFor(x.Ellipsis) < p.lineFor(x.Rparen) {
+ p.print(token.COMMA, formfeed)
+ }
+ } else {
+ p.exprList(x.Lparen, x.Args, depth, commaTerm, x.Rparen, false)
+ }
+ p.print(x.Rparen, token.RPAREN)
+ if wasIndented {
+ p.print(unindent)
+ }
+
+ case *ast.CompositeLit:
+ // composite literal elements that are composite literals themselves may have the type omitted
+ if x.Type != nil {
+ p.expr1(x.Type, token.HighestPrec, depth)
+ }
+ p.level++
+ p.print(x.Lbrace, token.LBRACE)
+ p.exprList(x.Lbrace, x.Elts, 1, commaTerm, x.Rbrace, x.Incomplete)
+ // do not insert extra line break following a /*-style comment
+ // before the closing '}' as it might break the code if there
+ // is no trailing ','
+ mode := noExtraLinebreak
+ // do not insert extra blank following a /*-style comment
+ // before the closing '}' unless the literal is empty
+ if len(x.Elts) > 0 {
+ mode |= noExtraBlank
+ }
+ // need the initial indent to print lone comments with
+ // the proper level of indentation
+ p.print(indent, unindent, mode, x.Rbrace, token.RBRACE, mode)
+ p.level--
+
+ case *ast.Ellipsis:
+ p.print(token.ELLIPSIS)
+ if x.Elt != nil {
+ p.expr(x.Elt)
+ }
+
+ case *ast.ArrayType:
+ p.print(token.LBRACK)
+ if x.Len != nil {
+ p.expr(x.Len)
+ }
+ p.print(token.RBRACK)
+ p.expr(x.Elt)
+
+ case *ast.StructType:
+ p.print(token.STRUCT)
+ p.fieldList(x.Fields, true, x.Incomplete)
+
+ case *ast.FuncType:
+ p.print(token.FUNC)
+ p.signature(x.Params, x.Results)
+
+ case *ast.InterfaceType:
+ p.print(token.INTERFACE)
+ p.fieldList(x.Methods, false, x.Incomplete)
+
+ case *ast.MapType:
+ p.print(token.MAP, token.LBRACK)
+ p.expr(x.Key)
+ p.print(token.RBRACK)
+ p.expr(x.Value)
+
+ case *ast.ChanType:
+ switch x.Dir {
+ case ast.SEND | ast.RECV:
+ p.print(token.CHAN)
+ case ast.RECV:
+ p.print(token.ARROW, token.CHAN) // x.Arrow and x.Pos() are the same
+ case ast.SEND:
+ p.print(token.CHAN, x.Arrow, token.ARROW)
+ }
+ p.print(blank)
+ p.expr(x.Value)
+
+ default:
+ panic("unreachable")
+ }
+}
+
+// normalizedNumber rewrites base prefixes and exponents
+// of numbers to use lower-case letters (0X123 to 0x123 and 1.2E3 to 1.2e3),
+// and removes leading 0's from integer imaginary literals (0765i to 765i).
+// It leaves hexadecimal digits alone.
+//
+// normalizedNumber doesn't modify the ast.BasicLit value lit points to.
+// If lit is not a number or a number in canonical format already,
+// lit is returned as is. Otherwise a new ast.BasicLit is created.
+func normalizedNumber(lit *ast.BasicLit) *ast.BasicLit {
+ if lit.Kind != token.INT && lit.Kind != token.FLOAT && lit.Kind != token.IMAG {
+ return lit // not a number - nothing to do
+ }
+ if len(lit.Value) < 2 {
+ return lit // only one digit (common case) - nothing to do
+ }
+ // len(lit.Value) >= 2
+
+ // We ignore lit.Kind because for lit.Kind == token.IMAG the literal may be an integer
+ // or floating-point value, decimal or not. Instead, just consider the literal pattern.
+ x := lit.Value
+ switch x[:2] {
+ default:
+ // 0-prefix octal, decimal int, or float (possibly with 'i' suffix)
+ if i := strings.LastIndexByte(x, 'E'); i >= 0 {
+ x = x[:i] + "e" + x[i+1:]
+ break
+ }
+ // remove leading 0's from integer (but not floating-point) imaginary literals
+ if x[len(x)-1] == 'i' && strings.IndexByte(x, '.') < 0 && strings.IndexByte(x, 'e') < 0 {
+ x = strings.TrimLeft(x, "0_")
+ if x == "i" {
+ x = "0i"
+ }
+ }
+ case "0X":
+ x = "0x" + x[2:]
+ // possibly a hexadecimal float
+ if i := strings.LastIndexByte(x, 'P'); i >= 0 {
+ x = x[:i] + "p" + x[i+1:]
+ }
+ case "0x":
+ // possibly a hexadecimal float
+ i := strings.LastIndexByte(x, 'P')
+ if i == -1 {
+ return lit // nothing to do
+ }
+ x = x[:i] + "p" + x[i+1:]
+ case "0O":
+ x = "0o" + x[2:]
+ case "0o":
+ return lit // nothing to do
+ case "0B":
+ x = "0b" + x[2:]
+ case "0b":
+ return lit // nothing to do
+ }
+
+ return &ast.BasicLit{ValuePos: lit.ValuePos, Kind: lit.Kind, Value: x}
+}
+
+func (p *printer) possibleSelectorExpr(expr ast.Expr, prec1, depth int) bool {
+ if x, ok := expr.(*ast.SelectorExpr); ok {
+ return p.selectorExpr(x, depth, true)
+ }
+ p.expr1(expr, prec1, depth)
+ return false
+}
+
+// selectorExpr handles an *ast.SelectorExpr node and reports whether x spans
+// multiple lines.
+func (p *printer) selectorExpr(x *ast.SelectorExpr, depth int, isMethod bool) bool {
+ p.expr1(x.X, token.HighestPrec, depth)
+ p.print(token.PERIOD)
+ if line := p.lineFor(x.Sel.Pos()); p.pos.IsValid() && p.pos.Line < line {
+ p.print(indent, newline, x.Sel.Pos(), x.Sel)
+ if !isMethod {
+ p.print(unindent)
+ }
+ return true
+ }
+ p.print(x.Sel.Pos(), x.Sel)
+ return false
+}
+
+func (p *printer) expr0(x ast.Expr, depth int) {
+ p.expr1(x, token.LowestPrec, depth)
+}
+
+func (p *printer) expr(x ast.Expr) {
+ const depth = 1
+ p.expr1(x, token.LowestPrec, depth)
+}
+
+// ----------------------------------------------------------------------------
+// Statements
+
+// Print the statement list indented, but without a newline after the last statement.
+// Extra line breaks between statements in the source are respected but at most one
+// empty line is printed between statements.
+func (p *printer) stmtList(list []ast.Stmt, nindent int, nextIsRBrace bool) {
+ if nindent > 0 {
+ p.print(indent)
+ }
+ var line int
+ i := 0
+ for _, s := range list {
+ // ignore empty statements (was issue 3466)
+ if _, isEmpty := s.(*ast.EmptyStmt); !isEmpty {
+ // nindent == 0 only for lists of switch/select case clauses;
+ // in those cases each clause is a new section
+ if len(p.output) > 0 {
+ // only print line break if we are not at the beginning of the output
+ // (i.e., we are not printing only a partial program)
+ p.linebreak(p.lineFor(s.Pos()), 1, ignore, i == 0 || nindent == 0 || p.linesFrom(line) > 0)
+ }
+ p.recordLine(&line)
+ p.stmt(s, nextIsRBrace && i == len(list)-1)
+ // labeled statements put labels on a separate line, but here
+ // we only care about the start line of the actual statement
+ // without label - correct line for each label
+ for t := s; ; {
+ lt, _ := t.(*ast.LabeledStmt)
+ if lt == nil {
+ break
+ }
+ line++
+ t = lt.Stmt
+ }
+ i++
+ }
+ }
+ if nindent > 0 {
+ p.print(unindent)
+ }
+}
+
+// block prints an *ast.BlockStmt; it always spans at least two lines.
+func (p *printer) block(b *ast.BlockStmt, nindent int) {
+ p.print(b.Lbrace, token.LBRACE)
+ p.stmtList(b.List, nindent, true)
+ p.linebreak(p.lineFor(b.Rbrace), 1, ignore, true)
+ p.print(b.Rbrace, token.RBRACE)
+}
+
+func isTypeName(x ast.Expr) bool {
+ switch t := x.(type) {
+ case *ast.Ident:
+ return true
+ case *ast.SelectorExpr:
+ return isTypeName(t.X)
+ }
+ return false
+}
+
+func stripParens(x ast.Expr) ast.Expr {
+ if px, strip := x.(*ast.ParenExpr); strip {
+ // parentheses must not be stripped if there are any
+ // unparenthesized composite literals starting with
+ // a type name
+ ast.Inspect(px.X, func(node ast.Node) bool {
+ switch x := node.(type) {
+ case *ast.ParenExpr:
+ // parentheses protect enclosed composite literals
+ return false
+ case *ast.CompositeLit:
+ if isTypeName(x.Type) {
+ strip = false // do not strip parentheses
+ }
+ return false
+ }
+ // in all other cases, keep inspecting
+ return true
+ })
+ if strip {
+ return stripParens(px.X)
+ }
+ }
+ return x
+}
+
+func stripParensAlways(x ast.Expr) ast.Expr {
+ if x, ok := x.(*ast.ParenExpr); ok {
+ return stripParensAlways(x.X)
+ }
+ return x
+}
+
+func (p *printer) controlClause(isForStmt bool, init ast.Stmt, expr ast.Expr, post ast.Stmt) {
+ p.print(blank)
+ needsBlank := false
+ if init == nil && post == nil {
+ // no semicolons required
+ if expr != nil {
+ p.expr(stripParens(expr))
+ needsBlank = true
+ }
+ } else {
+ // all semicolons required
+ // (they are not separators, print them explicitly)
+ if init != nil {
+ p.stmt(init, false)
+ }
+ p.print(token.SEMICOLON, blank)
+ if expr != nil {
+ p.expr(stripParens(expr))
+ needsBlank = true
+ }
+ if isForStmt {
+ p.print(token.SEMICOLON, blank)
+ needsBlank = false
+ if post != nil {
+ p.stmt(post, false)
+ needsBlank = true
+ }
+ }
+ }
+ if needsBlank {
+ p.print(blank)
+ }
+}
+
+// indentList reports whether an expression list would look better if it
+// were indented wholesale (starting with the very first element, rather
+// than starting at the first line break).
+//
+func (p *printer) indentList(list []ast.Expr) bool {
+ // Heuristic: indentList reports whether there are more than one multi-
+ // line element in the list, or if there is any element that is not
+ // starting on the same line as the previous one ends.
+ if len(list) >= 2 {
+ var b = p.lineFor(list[0].Pos())
+ var e = p.lineFor(list[len(list)-1].End())
+ if 0 < b && b < e {
+ // list spans multiple lines
+ n := 0 // multi-line element count
+ line := b
+ for _, x := range list {
+ xb := p.lineFor(x.Pos())
+ xe := p.lineFor(x.End())
+ if line < xb {
+ // x is not starting on the same
+ // line as the previous one ended
+ return true
+ }
+ if xb < xe {
+ // x is a multi-line element
+ n++
+ }
+ line = xe
+ }
+ return n > 1
+ }
+ }
+ return false
+}
+
+func (p *printer) stmt(stmt ast.Stmt, nextIsRBrace bool) {
+ p.print(stmt.Pos())
+
+ switch s := stmt.(type) {
+ case *ast.BadStmt:
+ p.print("BadStmt")
+
+ case *ast.DeclStmt:
+ p.decl(s.Decl)
+
+ case *ast.EmptyStmt:
+ // nothing to do
+
+ case *ast.LabeledStmt:
+ // a "correcting" unindent immediately following a line break
+ // is applied before the line break if there is no comment
+ // between (see writeWhitespace)
+ p.print(unindent)
+ p.expr(s.Label)
+ p.print(s.Colon, token.COLON, indent)
+ if e, isEmpty := s.Stmt.(*ast.EmptyStmt); isEmpty {
+ if !nextIsRBrace {
+ p.print(newline, e.Pos(), token.SEMICOLON)
+ break
+ }
+ } else {
+ p.linebreak(p.lineFor(s.Stmt.Pos()), 1, ignore, true)
+ }
+ p.stmt(s.Stmt, nextIsRBrace)
+
+ case *ast.ExprStmt:
+ const depth = 1
+ p.expr0(s.X, depth)
+
+ case *ast.SendStmt:
+ const depth = 1
+ p.expr0(s.Chan, depth)
+ p.print(blank, s.Arrow, token.ARROW, blank)
+ p.expr0(s.Value, depth)
+
+ case *ast.IncDecStmt:
+ const depth = 1
+ p.expr0(s.X, depth+1)
+ p.print(s.TokPos, s.Tok)
+
+ case *ast.AssignStmt:
+ var depth = 1
+ if len(s.Lhs) > 1 && len(s.Rhs) > 1 {
+ depth++
+ }
+ p.exprList(s.Pos(), s.Lhs, depth, 0, s.TokPos, false)
+ p.print(blank, s.TokPos, s.Tok, blank)
+ p.exprList(s.TokPos, s.Rhs, depth, 0, token.NoPos, false)
+
+ case *ast.GoStmt:
+ p.print(token.GO, blank)
+ p.expr(s.Call)
+
+ case *ast.DeferStmt:
+ p.print(token.DEFER, blank)
+ p.expr(s.Call)
+
+ case *ast.ReturnStmt:
+ p.print(token.RETURN)
+ if s.Results != nil {
+ p.print(blank)
+ // Use indentList heuristic to make corner cases look
+ // better (issue 1207). A more systematic approach would
+ // always indent, but this would cause significant
+ // reformatting of the code base and not necessarily
+ // lead to more nicely formatted code in general.
+ if p.indentList(s.Results) {
+ p.print(indent)
+ // Use NoPos so that a newline never goes before
+ // the results (see issue #32854).
+ p.exprList(token.NoPos, s.Results, 1, noIndent, token.NoPos, false)
+ p.print(unindent)
+ } else {
+ p.exprList(token.NoPos, s.Results, 1, 0, token.NoPos, false)
+ }
+ }
+
+ case *ast.BranchStmt:
+ p.print(s.Tok)
+ if s.Label != nil {
+ p.print(blank)
+ p.expr(s.Label)
+ }
+
+ case *ast.BlockStmt:
+ p.block(s, 1)
+
+ case *ast.IfStmt:
+ p.print(token.IF)
+ p.controlClause(false, s.Init, s.Cond, nil)
+ p.block(s.Body, 1)
+ if s.Else != nil {
+ p.print(blank, token.ELSE, blank)
+ switch s.Else.(type) {
+ case *ast.BlockStmt, *ast.IfStmt:
+ p.stmt(s.Else, nextIsRBrace)
+ default:
+ // This can only happen with an incorrectly
+ // constructed AST. Permit it but print so
+ // that it can be parsed without errors.
+ p.print(token.LBRACE, indent, formfeed)
+ p.stmt(s.Else, true)
+ p.print(unindent, formfeed, token.RBRACE)
+ }
+ }
+
+ case *ast.CaseClause:
+ if s.List != nil {
+ p.print(token.CASE, blank)
+ p.exprList(s.Pos(), s.List, 1, 0, s.Colon, false)
+ } else {
+ p.print(token.DEFAULT)
+ }
+ p.print(s.Colon, token.COLON)
+ p.stmtList(s.Body, 1, nextIsRBrace)
+
+ case *ast.SwitchStmt:
+ p.print(token.SWITCH)
+ p.controlClause(false, s.Init, s.Tag, nil)
+ p.block(s.Body, 0)
+
+ case *ast.TypeSwitchStmt:
+ p.print(token.SWITCH)
+ if s.Init != nil {
+ p.print(blank)
+ p.stmt(s.Init, false)
+ p.print(token.SEMICOLON)
+ }
+ p.print(blank)
+ p.stmt(s.Assign, false)
+ p.print(blank)
+ p.block(s.Body, 0)
+
+ case *ast.CommClause:
+ if s.Comm != nil {
+ p.print(token.CASE, blank)
+ p.stmt(s.Comm, false)
+ } else {
+ p.print(token.DEFAULT)
+ }
+ p.print(s.Colon, token.COLON)
+ p.stmtList(s.Body, 1, nextIsRBrace)
+
+ case *ast.SelectStmt:
+ p.print(token.SELECT, blank)
+ body := s.Body
+ if len(body.List) == 0 && !p.commentBefore(p.posFor(body.Rbrace)) {
+ // print empty select statement w/o comments on one line
+ p.print(body.Lbrace, token.LBRACE, body.Rbrace, token.RBRACE)
+ } else {
+ p.block(body, 0)
+ }
+
+ case *ast.ForStmt:
+ p.print(token.FOR)
+ p.controlClause(true, s.Init, s.Cond, s.Post)
+ p.block(s.Body, 1)
+
+ case *ast.RangeStmt:
+ p.print(token.FOR, blank)
+ if s.Key != nil {
+ p.expr(s.Key)
+ if s.Value != nil {
+ // use position of value following the comma as
+ // comma position for correct comment placement
+ p.print(s.Value.Pos(), token.COMMA, blank)
+ p.expr(s.Value)
+ }
+ p.print(blank, s.TokPos, s.Tok, blank)
+ }
+ p.print(token.RANGE, blank)
+ p.expr(stripParens(s.X))
+ p.print(blank)
+ p.block(s.Body, 1)
+
+ default:
+ panic("unreachable")
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Declarations
+
+// The keepTypeColumn function determines if the type column of a series of
+// consecutive const or var declarations must be kept, or if initialization
+// values (V) can be placed in the type column (T) instead. The i'th entry
+// in the result slice is true if the type column in spec[i] must be kept.
+//
+// For example, the declaration:
+//
+// const (
+// foobar int = 42 // comment
+// x = 7 // comment
+// foo
+// bar = 991
+// )
+//
+// leads to the type/values matrix below. A run of value columns (V) can
+// be moved into the type column if there is no type for any of the values
+// in that column (we only move entire columns so that they align properly).
+//
+// matrix formatted result
+// matrix
+// T V -> T V -> true there is a T and so the type
+// - V - V true column must be kept
+// - - - - false
+// - V V - false V is moved into T column
+//
+func keepTypeColumn(specs []ast.Spec) []bool {
+ m := make([]bool, len(specs))
+
+ populate := func(i, j int, keepType bool) {
+ if keepType {
+ for ; i < j; i++ {
+ m[i] = true
+ }
+ }
+ }
+
+ i0 := -1 // if i0 >= 0 we are in a run and i0 is the start of the run
+ var keepType bool
+ for i, s := range specs {
+ t := s.(*ast.ValueSpec)
+ if t.Values != nil {
+ if i0 < 0 {
+ // start of a run of ValueSpecs with non-nil Values
+ i0 = i
+ keepType = false
+ }
+ } else {
+ if i0 >= 0 {
+ // end of a run
+ populate(i0, i, keepType)
+ i0 = -1
+ }
+ }
+ if t.Type != nil {
+ keepType = true
+ }
+ }
+ if i0 >= 0 {
+ // end of a run
+ populate(i0, len(specs), keepType)
+ }
+
+ return m
+}
+
+func (p *printer) valueSpec(s *ast.ValueSpec, keepType bool) {
+ p.setComment(s.Doc)
+ p.identList(s.Names, false) // always present
+ extraTabs := 3
+ if s.Type != nil || keepType {
+ p.print(vtab)
+ extraTabs--
+ }
+ if s.Type != nil {
+ p.expr(s.Type)
+ }
+ if s.Values != nil {
+ p.print(vtab, token.ASSIGN, blank)
+ p.exprList(token.NoPos, s.Values, 1, 0, token.NoPos, false)
+ extraTabs--
+ }
+ if s.Comment != nil {
+ for ; extraTabs > 0; extraTabs-- {
+ p.print(vtab)
+ }
+ p.setComment(s.Comment)
+ }
+}
+
+func sanitizeImportPath(lit *ast.BasicLit) *ast.BasicLit {
+ // Note: An unmodified AST generated by go/parser will already
+ // contain a backward- or double-quoted path string that does
+ // not contain any invalid characters, and most of the work
+ // here is not needed. However, a modified or generated AST
+ // may possibly contain non-canonical paths. Do the work in
+ // all cases since it's not too hard and not speed-critical.
+
+ // if we don't have a proper string, be conservative and return whatever we have
+ if lit.Kind != token.STRING {
+ return lit
+ }
+ s, err := strconv.Unquote(lit.Value)
+ if err != nil {
+ return lit
+ }
+
+ // if the string is an invalid path, return whatever we have
+ //
+ // spec: "Implementation restriction: A compiler may restrict
+ // ImportPaths to non-empty strings using only characters belonging
+ // to Unicode's L, M, N, P, and S general categories (the Graphic
+ // characters without spaces) and may also exclude the characters
+ // !"#$%&'()*,:;<=>?[\]^`{|} and the Unicode replacement character
+ // U+FFFD."
+ if s == "" {
+ return lit
+ }
+ const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
+ for _, r := range s {
+ if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
+ return lit
+ }
+ }
+
+ // otherwise, return the double-quoted path
+ s = strconv.Quote(s)
+ if s == lit.Value {
+ return lit // nothing wrong with lit
+ }
+ return &ast.BasicLit{ValuePos: lit.ValuePos, Kind: token.STRING, Value: s}
+}
+
+// The parameter n is the number of specs in the group. If doIndent is set,
+// multi-line identifier lists in the spec are indented when the first
+// linebreak is encountered.
+//
+func (p *printer) spec(spec ast.Spec, n int, doIndent bool) {
+ switch s := spec.(type) {
+ case *ast.ImportSpec:
+ p.setComment(s.Doc)
+ if s.Name != nil {
+ p.expr(s.Name)
+ p.print(blank)
+ }
+ p.expr(sanitizeImportPath(s.Path))
+ p.setComment(s.Comment)
+ p.print(s.EndPos)
+
+ case *ast.ValueSpec:
+ if n != 1 {
+ p.internalError("expected n = 1; got", n)
+ }
+ p.setComment(s.Doc)
+ p.identList(s.Names, doIndent) // always present
+ if s.Type != nil {
+ p.print(blank)
+ p.expr(s.Type)
+ }
+ if s.Values != nil {
+ p.print(blank, token.ASSIGN, blank)
+ p.exprList(token.NoPos, s.Values, 1, 0, token.NoPos, false)
+ }
+ p.setComment(s.Comment)
+
+ case *ast.TypeSpec:
+ p.setComment(s.Doc)
+ p.expr(s.Name)
+ if n == 1 {
+ p.print(blank)
+ } else {
+ p.print(vtab)
+ }
+ if s.Assign.IsValid() {
+ p.print(token.ASSIGN, blank)
+ }
+ p.expr(s.Type)
+ p.setComment(s.Comment)
+
+ default:
+ panic("unreachable")
+ }
+}
+
+func (p *printer) genDecl(d *ast.GenDecl) {
+ p.setComment(d.Doc)
+ p.print(d.Pos(), d.Tok, blank)
+
+ if d.Lparen.IsValid() || len(d.Specs) > 1 {
+ // group of parenthesized declarations
+ p.print(d.Lparen, token.LPAREN)
+ if n := len(d.Specs); n > 0 {
+ p.print(indent, formfeed)
+ if n > 1 && (d.Tok == token.CONST || d.Tok == token.VAR) {
+ // two or more grouped const/var declarations:
+ // determine if the type column must be kept
+ keepType := keepTypeColumn(d.Specs)
+ var line int
+ for i, s := range d.Specs {
+ if i > 0 {
+ p.linebreak(p.lineFor(s.Pos()), 1, ignore, p.linesFrom(line) > 0)
+ }
+ p.recordLine(&line)
+ p.valueSpec(s.(*ast.ValueSpec), keepType[i])
+ }
+ } else {
+ var line int
+ for i, s := range d.Specs {
+ if i > 0 {
+ p.linebreak(p.lineFor(s.Pos()), 1, ignore, p.linesFrom(line) > 0)
+ }
+ p.recordLine(&line)
+ p.spec(s, n, false)
+ }
+ }
+ p.print(unindent, formfeed)
+ }
+ p.print(d.Rparen, token.RPAREN)
+
+ } else if len(d.Specs) > 0 {
+ // single declaration
+ p.spec(d.Specs[0], 1, true)
+ }
+}
+
+// nodeSize determines the size of n in chars after formatting.
+// The result is <= maxSize if the node fits on one line with at
+// most maxSize chars and the formatted output doesn't contain
+// any control chars. Otherwise, the result is > maxSize.
+//
+func (p *printer) nodeSize(n ast.Node, maxSize int) (size int) {
+ // nodeSize invokes the printer, which may invoke nodeSize
+ // recursively. For deep composite literal nests, this can
+ // lead to an exponential algorithm. Remember previous
+ // results to prune the recursion (was issue 1628).
+ if size, found := p.nodeSizes[n]; found {
+ return size
+ }
+
+ size = maxSize + 1 // assume n doesn't fit
+ p.nodeSizes[n] = size
+
+ // nodeSize computation must be independent of particular
+ // style so that we always get the same decision; print
+ // in RawFormat
+ cfg := Config{Mode: RawFormat}
+ var buf bytes.Buffer
+ if err := cfg.fprint(&buf, p.fset, n, p.nodeSizes); err != nil {
+ return
+ }
+ if buf.Len() <= maxSize {
+ for _, ch := range buf.Bytes() {
+ if ch < ' ' {
+ return
+ }
+ }
+ size = buf.Len() // n fits
+ p.nodeSizes[n] = size
+ }
+ return
+}
+
+// numLines returns the number of lines spanned by node n in the original source.
+func (p *printer) numLines(n ast.Node) int {
+ if from := n.Pos(); from.IsValid() {
+ if to := n.End(); to.IsValid() {
+ return p.lineFor(to) - p.lineFor(from) + 1
+ }
+ }
+ return infinity
+}
+
+// bodySize is like nodeSize but it is specialized for *ast.BlockStmt's.
+func (p *printer) bodySize(b *ast.BlockStmt, maxSize int) int {
+ pos1 := b.Pos()
+ pos2 := b.Rbrace
+ if pos1.IsValid() && pos2.IsValid() && p.lineFor(pos1) != p.lineFor(pos2) {
+ // opening and closing brace are on different lines - don't make it a one-liner
+ return maxSize + 1
+ }
+ if len(b.List) > 5 {
+ // too many statements - don't make it a one-liner
+ return maxSize + 1
+ }
+ // otherwise, estimate body size
+ bodySize := p.commentSizeBefore(p.posFor(pos2))
+ for i, s := range b.List {
+ if bodySize > maxSize {
+ break // no need to continue
+ }
+ if i > 0 {
+ bodySize += 2 // space for a semicolon and blank
+ }
+ bodySize += p.nodeSize(s, maxSize)
+ }
+ return bodySize
+}
+
+// funcBody prints a function body following a function header of given headerSize.
+// If the header's and block's size are "small enough" and the block is "simple enough",
+// the block is printed on the current line, without line breaks, spaced from the header
+// by sep. Otherwise the block's opening "{" is printed on the current line, followed by
+// lines for the block's statements and its closing "}".
+//
+func (p *printer) funcBody(headerSize int, sep whiteSpace, b *ast.BlockStmt) {
+ if b == nil {
+ return
+ }
+
+ // save/restore composite literal nesting level
+ defer func(level int) {
+ p.level = level
+ }(p.level)
+ p.level = 0
+
+ const maxSize = 100
+ if headerSize+p.bodySize(b, maxSize) <= maxSize {
+ p.print(sep, b.Lbrace, token.LBRACE)
+ if len(b.List) > 0 {
+ p.print(blank)
+ for i, s := range b.List {
+ if i > 0 {
+ p.print(token.SEMICOLON, blank)
+ }
+ p.stmt(s, i == len(b.List)-1)
+ }
+ p.print(blank)
+ }
+ p.print(noExtraLinebreak, b.Rbrace, token.RBRACE, noExtraLinebreak)
+ return
+ }
+
+ if sep != ignore {
+ p.print(blank) // always use blank
+ }
+ p.block(b, 1)
+}
+
+// distanceFrom returns the column difference between p.out (the current output
+// position) and startOutCol. If the start position is on a different line from
+// the current position (or either is unknown), the result is infinity.
+func (p *printer) distanceFrom(startPos token.Pos, startOutCol int) int {
+ if startPos.IsValid() && p.pos.IsValid() && p.posFor(startPos).Line == p.pos.Line {
+ return p.out.Column - startOutCol
+ }
+ return infinity
+}
+
+func (p *printer) funcDecl(d *ast.FuncDecl) {
+ p.setComment(d.Doc)
+ p.print(d.Pos(), token.FUNC, blank)
+ // We have to save startCol only after emitting FUNC; otherwise it can be on a
+ // different line (all whitespace preceding the FUNC is emitted only when the
+ // FUNC is emitted).
+ startCol := p.out.Column - len("func ")
+ if d.Recv != nil {
+ p.parameters(d.Recv) // method: print receiver
+ p.print(blank)
+ }
+ p.expr(d.Name)
+ p.signature(d.Type.Params, d.Type.Results)
+ p.funcBody(p.distanceFrom(d.Pos(), startCol), vtab, d.Body)
+}
+
+func (p *printer) decl(decl ast.Decl) {
+ switch d := decl.(type) {
+ case *ast.BadDecl:
+ p.print(d.Pos(), "BadDecl")
+ case *ast.GenDecl:
+ p.genDecl(d)
+ case *ast.FuncDecl:
+ p.funcDecl(d)
+ default:
+ panic("unreachable")
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Files
+
+func declToken(decl ast.Decl) (tok token.Token) {
+ tok = token.ILLEGAL
+ switch d := decl.(type) {
+ case *ast.GenDecl:
+ tok = d.Tok
+ case *ast.FuncDecl:
+ tok = token.FUNC
+ }
+ return
+}
+
+func (p *printer) declList(list []ast.Decl) {
+ tok := token.ILLEGAL
+ for _, d := range list {
+ prev := tok
+ tok = declToken(d)
+ // If the declaration token changed (e.g., from CONST to TYPE)
+ // or the next declaration has documentation associated with it,
+ // print an empty line between top-level declarations.
+ // (because p.linebreak is called with the position of d, which
+ // is past any documentation, the minimum requirement is satisfied
+ // even w/o the extra getDoc(d) nil-check - leave it in case the
+ // linebreak logic improves - there's already a TODO).
+ if len(p.output) > 0 {
+ // only print line break if we are not at the beginning of the output
+ // (i.e., we are not printing only a partial program)
+ min := 1
+ if prev != tok || getDoc(d) != nil {
+ min = 2
+ }
+ // start a new section if the next declaration is a function
+ // that spans multiple lines (see also issue #19544)
+ p.linebreak(p.lineFor(d.Pos()), min, ignore, tok == token.FUNC && p.numLines(d) > 1)
+ }
+ p.decl(d)
+ }
+}
+
+func (p *printer) file(src *ast.File) {
+ p.setComment(src.Doc)
+ p.print(src.Pos(), token.PACKAGE, blank)
+ p.expr(src.Name)
+ p.declList(src.Decls)
+ p.print(newline)
+}
diff --git a/src/go/printer/performance_test.go b/src/go/printer/performance_test.go
new file mode 100644
index 0000000..e655fa1
--- /dev/null
+++ b/src/go/printer/performance_test.go
@@ -0,0 +1,58 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements a simple printer performance benchmark:
+// go test -bench=BenchmarkPrint
+
+package printer
+
+import (
+ "bytes"
+ "go/ast"
+ "go/parser"
+ "io"
+ "log"
+ "os"
+ "testing"
+)
+
+var testfile *ast.File
+
+func testprint(out io.Writer, file *ast.File) {
+ if err := (&Config{TabIndent | UseSpaces | normalizeNumbers, 8, 0}).Fprint(out, fset, file); err != nil {
+ log.Fatalf("print error: %s", err)
+ }
+}
+
+// cannot initialize in init because (printer) Fprint launches goroutines.
+func initialize() {
+ const filename = "testdata/parser.go"
+
+ src, err := os.ReadFile(filename)
+ if err != nil {
+ log.Fatalf("%s", err)
+ }
+
+ file, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
+ if err != nil {
+ log.Fatalf("%s", err)
+ }
+
+ var buf bytes.Buffer
+ testprint(&buf, file)
+ if !bytes.Equal(buf.Bytes(), src) {
+ log.Fatalf("print error: %s not idempotent", filename)
+ }
+
+ testfile = file
+}
+
+func BenchmarkPrint(b *testing.B) {
+ if testfile == nil {
+ initialize()
+ }
+ for i := 0; i < b.N; i++ {
+ testprint(io.Discard, testfile)
+ }
+}
diff --git a/src/go/printer/printer.go b/src/go/printer/printer.go
new file mode 100644
index 0000000..0077afe
--- /dev/null
+++ b/src/go/printer/printer.go
@@ -0,0 +1,1377 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package printer implements printing of AST nodes.
+package printer
+
+import (
+ "fmt"
+ "go/ast"
+ "go/token"
+ "io"
+ "os"
+ "strings"
+ "text/tabwriter"
+ "unicode"
+)
+
+const (
+ maxNewlines = 2 // max. number of newlines between source text
+ debug = false // enable for debugging
+ infinity = 1 << 30
+)
+
+type whiteSpace byte
+
+const (
+ ignore = whiteSpace(0)
+ blank = whiteSpace(' ')
+ vtab = whiteSpace('\v')
+ newline = whiteSpace('\n')
+ formfeed = whiteSpace('\f')
+ indent = whiteSpace('>')
+ unindent = whiteSpace('<')
+)
+
+// A pmode value represents the current printer mode.
+type pmode int
+
+const (
+ noExtraBlank pmode = 1 << iota // disables extra blank after /*-style comment
+ noExtraLinebreak // disables extra line break after /*-style comment
+)
+
+type commentInfo struct {
+ cindex int // current comment index
+ comment *ast.CommentGroup // = printer.comments[cindex]; or nil
+ commentOffset int // = printer.posFor(printer.comments[cindex].List[0].Pos()).Offset; or infinity
+ commentNewline bool // true if the comment group contains newlines
+}
+
+type printer struct {
+ // Configuration (does not change after initialization)
+ Config
+ fset *token.FileSet
+
+ // Current state
+ output []byte // raw printer result
+ indent int // current indentation
+ level int // level == 0: outside composite literal; level > 0: inside composite literal
+ mode pmode // current printer mode
+ endAlignment bool // if set, terminate alignment immediately
+ impliedSemi bool // if set, a linebreak implies a semicolon
+ lastTok token.Token // last token printed (token.ILLEGAL if it's whitespace)
+ prevOpen token.Token // previous non-brace "open" token (, [, or token.ILLEGAL
+ wsbuf []whiteSpace // delayed white space
+
+ // Positions
+ // The out position differs from the pos position when the result
+ // formatting differs from the source formatting (in the amount of
+ // white space). If there's a difference and SourcePos is set in
+ // ConfigMode, //line directives are used in the output to restore
+ // original source positions for a reader.
+ pos token.Position // current position in AST (source) space
+ out token.Position // current position in output space
+ last token.Position // value of pos after calling writeString
+ linePtr *int // if set, record out.Line for the next token in *linePtr
+
+ // The list of all source comments, in order of appearance.
+ comments []*ast.CommentGroup // may be nil
+ useNodeComments bool // if not set, ignore lead and line comments of nodes
+
+ // Information about p.comments[p.cindex]; set up by nextComment.
+ commentInfo
+
+ // Cache of already computed node sizes.
+ nodeSizes map[ast.Node]int
+
+ // Cache of most recently computed line position.
+ cachedPos token.Pos
+ cachedLine int // line corresponding to cachedPos
+}
+
+func (p *printer) init(cfg *Config, fset *token.FileSet, nodeSizes map[ast.Node]int) {
+ p.Config = *cfg
+ p.fset = fset
+ p.pos = token.Position{Line: 1, Column: 1}
+ p.out = token.Position{Line: 1, Column: 1}
+ p.wsbuf = make([]whiteSpace, 0, 16) // whitespace sequences are short
+ p.nodeSizes = nodeSizes
+ p.cachedPos = -1
+}
+
+func (p *printer) internalError(msg ...interface{}) {
+ if debug {
+ fmt.Print(p.pos.String() + ": ")
+ fmt.Println(msg...)
+ panic("go/printer")
+ }
+}
+
+// commentsHaveNewline reports whether a list of comments belonging to
+// an *ast.CommentGroup contains newlines. Because the position information
+// may only be partially correct, we also have to read the comment text.
+func (p *printer) commentsHaveNewline(list []*ast.Comment) bool {
+ // len(list) > 0
+ line := p.lineFor(list[0].Pos())
+ for i, c := range list {
+ if i > 0 && p.lineFor(list[i].Pos()) != line {
+ // not all comments on the same line
+ return true
+ }
+ if t := c.Text; len(t) >= 2 && (t[1] == '/' || strings.Contains(t, "\n")) {
+ return true
+ }
+ }
+ _ = line
+ return false
+}
+
+func (p *printer) nextComment() {
+ for p.cindex < len(p.comments) {
+ c := p.comments[p.cindex]
+ p.cindex++
+ if list := c.List; len(list) > 0 {
+ p.comment = c
+ p.commentOffset = p.posFor(list[0].Pos()).Offset
+ p.commentNewline = p.commentsHaveNewline(list)
+ return
+ }
+ // we should not reach here (correct ASTs don't have empty
+ // ast.CommentGroup nodes), but be conservative and try again
+ }
+ // no more comments
+ p.commentOffset = infinity
+}
+
+// commentBefore reports whether the current comment group occurs
+// before the next position in the source code and printing it does
+// not introduce implicit semicolons.
+//
+func (p *printer) commentBefore(next token.Position) bool {
+ return p.commentOffset < next.Offset && (!p.impliedSemi || !p.commentNewline)
+}
+
+// commentSizeBefore returns the estimated size of the
+// comments on the same line before the next position.
+//
+func (p *printer) commentSizeBefore(next token.Position) int {
+ // save/restore current p.commentInfo (p.nextComment() modifies it)
+ defer func(info commentInfo) {
+ p.commentInfo = info
+ }(p.commentInfo)
+
+ size := 0
+ for p.commentBefore(next) {
+ for _, c := range p.comment.List {
+ size += len(c.Text)
+ }
+ p.nextComment()
+ }
+ return size
+}
+
+// recordLine records the output line number for the next non-whitespace
+// token in *linePtr. It is used to compute an accurate line number for a
+// formatted construct, independent of pending (not yet emitted) whitespace
+// or comments.
+//
+func (p *printer) recordLine(linePtr *int) {
+ p.linePtr = linePtr
+}
+
+// linesFrom returns the number of output lines between the current
+// output line and the line argument, ignoring any pending (not yet
+// emitted) whitespace or comments. It is used to compute an accurate
+// size (in number of lines) for a formatted construct.
+//
+func (p *printer) linesFrom(line int) int {
+ return p.out.Line - line
+}
+
+func (p *printer) posFor(pos token.Pos) token.Position {
+ // not used frequently enough to cache entire token.Position
+ return p.fset.PositionFor(pos, false /* absolute position */)
+}
+
+func (p *printer) lineFor(pos token.Pos) int {
+ if pos != p.cachedPos {
+ p.cachedPos = pos
+ p.cachedLine = p.fset.PositionFor(pos, false /* absolute position */).Line
+ }
+ return p.cachedLine
+}
+
+// writeLineDirective writes a //line directive if necessary.
+func (p *printer) writeLineDirective(pos token.Position) {
+ if pos.IsValid() && (p.out.Line != pos.Line || p.out.Filename != pos.Filename) {
+ p.output = append(p.output, tabwriter.Escape) // protect '\n' in //line from tabwriter interpretation
+ p.output = append(p.output, fmt.Sprintf("//line %s:%d\n", pos.Filename, pos.Line)...)
+ p.output = append(p.output, tabwriter.Escape)
+ // p.out must match the //line directive
+ p.out.Filename = pos.Filename
+ p.out.Line = pos.Line
+ }
+}
+
+// writeIndent writes indentation.
+func (p *printer) writeIndent() {
+ // use "hard" htabs - indentation columns
+ // must not be discarded by the tabwriter
+ n := p.Config.Indent + p.indent // include base indentation
+ for i := 0; i < n; i++ {
+ p.output = append(p.output, '\t')
+ }
+
+ // update positions
+ p.pos.Offset += n
+ p.pos.Column += n
+ p.out.Column += n
+}
+
+// writeByte writes ch n times to p.output and updates p.pos.
+// Only used to write formatting (white space) characters.
+func (p *printer) writeByte(ch byte, n int) {
+ if p.endAlignment {
+ // Ignore any alignment control character;
+ // and at the end of the line, break with
+ // a formfeed to indicate termination of
+ // existing columns.
+ switch ch {
+ case '\t', '\v':
+ ch = ' '
+ case '\n', '\f':
+ ch = '\f'
+ p.endAlignment = false
+ }
+ }
+
+ if p.out.Column == 1 {
+ // no need to write line directives before white space
+ p.writeIndent()
+ }
+
+ for i := 0; i < n; i++ {
+ p.output = append(p.output, ch)
+ }
+
+ // update positions
+ p.pos.Offset += n
+ if ch == '\n' || ch == '\f' {
+ p.pos.Line += n
+ p.out.Line += n
+ p.pos.Column = 1
+ p.out.Column = 1
+ return
+ }
+ p.pos.Column += n
+ p.out.Column += n
+}
+
+// writeString writes the string s to p.output and updates p.pos, p.out,
+// and p.last. If isLit is set, s is escaped w/ tabwriter.Escape characters
+// to protect s from being interpreted by the tabwriter.
+//
+// Note: writeString is only used to write Go tokens, literals, and
+// comments, all of which must be written literally. Thus, it is correct
+// to always set isLit = true. However, setting it explicitly only when
+// needed (i.e., when we don't know that s contains no tabs or line breaks)
+// avoids processing extra escape characters and reduces run time of the
+// printer benchmark by up to 10%.
+//
+func (p *printer) writeString(pos token.Position, s string, isLit bool) {
+ if p.out.Column == 1 {
+ if p.Config.Mode&SourcePos != 0 {
+ p.writeLineDirective(pos)
+ }
+ p.writeIndent()
+ }
+
+ if pos.IsValid() {
+ // update p.pos (if pos is invalid, continue with existing p.pos)
+ // Note: Must do this after handling line beginnings because
+ // writeIndent updates p.pos if there's indentation, but p.pos
+ // is the position of s.
+ p.pos = pos
+ }
+
+ if isLit {
+ // Protect s such that is passes through the tabwriter
+ // unchanged. Note that valid Go programs cannot contain
+ // tabwriter.Escape bytes since they do not appear in legal
+ // UTF-8 sequences.
+ p.output = append(p.output, tabwriter.Escape)
+ }
+
+ if debug {
+ p.output = append(p.output, fmt.Sprintf("/*%s*/", pos)...) // do not update p.pos!
+ }
+ p.output = append(p.output, s...)
+
+ // update positions
+ nlines := 0
+ var li int // index of last newline; valid if nlines > 0
+ for i := 0; i < len(s); i++ {
+ // Raw string literals may contain any character except back quote (`).
+ if ch := s[i]; ch == '\n' || ch == '\f' {
+ // account for line break
+ nlines++
+ li = i
+ // A line break inside a literal will break whatever column
+ // formatting is in place; ignore any further alignment through
+ // the end of the line.
+ p.endAlignment = true
+ }
+ }
+ p.pos.Offset += len(s)
+ if nlines > 0 {
+ p.pos.Line += nlines
+ p.out.Line += nlines
+ c := len(s) - li
+ p.pos.Column = c
+ p.out.Column = c
+ } else {
+ p.pos.Column += len(s)
+ p.out.Column += len(s)
+ }
+
+ if isLit {
+ p.output = append(p.output, tabwriter.Escape)
+ }
+
+ p.last = p.pos
+}
+
+// writeCommentPrefix writes the whitespace before a comment.
+// If there is any pending whitespace, it consumes as much of
+// it as is likely to help position the comment nicely.
+// pos is the comment position, next the position of the item
+// after all pending comments, prev is the previous comment in
+// a group of comments (or nil), and tok is the next token.
+//
+func (p *printer) writeCommentPrefix(pos, next token.Position, prev *ast.Comment, tok token.Token) {
+ if len(p.output) == 0 {
+ // the comment is the first item to be printed - don't write any whitespace
+ return
+ }
+
+ if pos.IsValid() && pos.Filename != p.last.Filename {
+ // comment in a different file - separate with newlines
+ p.writeByte('\f', maxNewlines)
+ return
+ }
+
+ if pos.Line == p.last.Line && (prev == nil || prev.Text[1] != '/') {
+ // comment on the same line as last item:
+ // separate with at least one separator
+ hasSep := false
+ if prev == nil {
+ // first comment of a comment group
+ j := 0
+ for i, ch := range p.wsbuf {
+ switch ch {
+ case blank:
+ // ignore any blanks before a comment
+ p.wsbuf[i] = ignore
+ continue
+ case vtab:
+ // respect existing tabs - important
+ // for proper formatting of commented structs
+ hasSep = true
+ continue
+ case indent:
+ // apply pending indentation
+ continue
+ }
+ j = i
+ break
+ }
+ p.writeWhitespace(j)
+ }
+ // make sure there is at least one separator
+ if !hasSep {
+ sep := byte('\t')
+ if pos.Line == next.Line {
+ // next item is on the same line as the comment
+ // (which must be a /*-style comment): separate
+ // with a blank instead of a tab
+ sep = ' '
+ }
+ p.writeByte(sep, 1)
+ }
+
+ } else {
+ // comment on a different line:
+ // separate with at least one line break
+ droppedLinebreak := false
+ j := 0
+ for i, ch := range p.wsbuf {
+ switch ch {
+ case blank, vtab:
+ // ignore any horizontal whitespace before line breaks
+ p.wsbuf[i] = ignore
+ continue
+ case indent:
+ // apply pending indentation
+ continue
+ case unindent:
+ // if this is not the last unindent, apply it
+ // as it is (likely) belonging to the last
+ // construct (e.g., a multi-line expression list)
+ // and is not part of closing a block
+ if i+1 < len(p.wsbuf) && p.wsbuf[i+1] == unindent {
+ continue
+ }
+ // if the next token is not a closing }, apply the unindent
+ // if it appears that the comment is aligned with the
+ // token; otherwise assume the unindent is part of a
+ // closing block and stop (this scenario appears with
+ // comments before a case label where the comments
+ // apply to the next case instead of the current one)
+ if tok != token.RBRACE && pos.Column == next.Column {
+ continue
+ }
+ case newline, formfeed:
+ p.wsbuf[i] = ignore
+ droppedLinebreak = prev == nil // record only if first comment of a group
+ }
+ j = i
+ break
+ }
+ p.writeWhitespace(j)
+
+ // determine number of linebreaks before the comment
+ n := 0
+ if pos.IsValid() && p.last.IsValid() {
+ n = pos.Line - p.last.Line
+ if n < 0 { // should never happen
+ n = 0
+ }
+ }
+
+ // at the package scope level only (p.indent == 0),
+ // add an extra newline if we dropped one before:
+ // this preserves a blank line before documentation
+ // comments at the package scope level (issue 2570)
+ if p.indent == 0 && droppedLinebreak {
+ n++
+ }
+
+ // make sure there is at least one line break
+ // if the previous comment was a line comment
+ if n == 0 && prev != nil && prev.Text[1] == '/' {
+ n = 1
+ }
+
+ if n > 0 {
+ // use formfeeds to break columns before a comment;
+ // this is analogous to using formfeeds to separate
+ // individual lines of /*-style comments
+ p.writeByte('\f', nlimit(n))
+ }
+ }
+}
+
+// Returns true if s contains only white space
+// (only tabs and blanks can appear in the printer's context).
+//
+func isBlank(s string) bool {
+ for i := 0; i < len(s); i++ {
+ if s[i] > ' ' {
+ return false
+ }
+ }
+ return true
+}
+
+// commonPrefix returns the common prefix of a and b.
+func commonPrefix(a, b string) string {
+ i := 0
+ for i < len(a) && i < len(b) && a[i] == b[i] && (a[i] <= ' ' || a[i] == '*') {
+ i++
+ }
+ return a[0:i]
+}
+
+// trimRight returns s with trailing whitespace removed.
+func trimRight(s string) string {
+ return strings.TrimRightFunc(s, unicode.IsSpace)
+}
+
+// stripCommonPrefix removes a common prefix from /*-style comment lines (unless no
+// comment line is indented, all but the first line have some form of space prefix).
+// The prefix is computed using heuristics such that is likely that the comment
+// contents are nicely laid out after re-printing each line using the printer's
+// current indentation.
+//
+func stripCommonPrefix(lines []string) {
+ if len(lines) <= 1 {
+ return // at most one line - nothing to do
+ }
+ // len(lines) > 1
+
+ // The heuristic in this function tries to handle a few
+ // common patterns of /*-style comments: Comments where
+ // the opening /* and closing */ are aligned and the
+ // rest of the comment text is aligned and indented with
+ // blanks or tabs, cases with a vertical "line of stars"
+ // on the left, and cases where the closing */ is on the
+ // same line as the last comment text.
+
+ // Compute maximum common white prefix of all but the first,
+ // last, and blank lines, and replace blank lines with empty
+ // lines (the first line starts with /* and has no prefix).
+ // In cases where only the first and last lines are not blank,
+ // such as two-line comments, or comments where all inner lines
+ // are blank, consider the last line for the prefix computation
+ // since otherwise the prefix would be empty.
+ //
+ // Note that the first and last line are never empty (they
+ // contain the opening /* and closing */ respectively) and
+ // thus they can be ignored by the blank line check.
+ prefix := ""
+ prefixSet := false
+ if len(lines) > 2 {
+ for i, line := range lines[1 : len(lines)-1] {
+ if isBlank(line) {
+ lines[1+i] = "" // range starts with lines[1]
+ } else {
+ if !prefixSet {
+ prefix = line
+ prefixSet = true
+ }
+ prefix = commonPrefix(prefix, line)
+ }
+
+ }
+ }
+ // If we don't have a prefix yet, consider the last line.
+ if !prefixSet {
+ line := lines[len(lines)-1]
+ prefix = commonPrefix(line, line)
+ }
+
+ /*
+ * Check for vertical "line of stars" and correct prefix accordingly.
+ */
+ lineOfStars := false
+ if i := strings.Index(prefix, "*"); i >= 0 {
+ // Line of stars present.
+ if i > 0 && prefix[i-1] == ' ' {
+ i-- // remove trailing blank from prefix so stars remain aligned
+ }
+ prefix = prefix[0:i]
+ lineOfStars = true
+ } else {
+ // No line of stars present.
+ // Determine the white space on the first line after the /*
+ // and before the beginning of the comment text, assume two
+ // blanks instead of the /* unless the first character after
+ // the /* is a tab. If the first comment line is empty but
+ // for the opening /*, assume up to 3 blanks or a tab. This
+ // whitespace may be found as suffix in the common prefix.
+ first := lines[0]
+ if isBlank(first[2:]) {
+ // no comment text on the first line:
+ // reduce prefix by up to 3 blanks or a tab
+ // if present - this keeps comment text indented
+ // relative to the /* and */'s if it was indented
+ // in the first place
+ i := len(prefix)
+ for n := 0; n < 3 && i > 0 && prefix[i-1] == ' '; n++ {
+ i--
+ }
+ if i == len(prefix) && i > 0 && prefix[i-1] == '\t' {
+ i--
+ }
+ prefix = prefix[0:i]
+ } else {
+ // comment text on the first line
+ suffix := make([]byte, len(first))
+ n := 2 // start after opening /*
+ for n < len(first) && first[n] <= ' ' {
+ suffix[n] = first[n]
+ n++
+ }
+ if n > 2 && suffix[2] == '\t' {
+ // assume the '\t' compensates for the /*
+ suffix = suffix[2:n]
+ } else {
+ // otherwise assume two blanks
+ suffix[0], suffix[1] = ' ', ' '
+ suffix = suffix[0:n]
+ }
+ // Shorten the computed common prefix by the length of
+ // suffix, if it is found as suffix of the prefix.
+ prefix = strings.TrimSuffix(prefix, string(suffix))
+ }
+ }
+
+ // Handle last line: If it only contains a closing */, align it
+ // with the opening /*, otherwise align the text with the other
+ // lines.
+ last := lines[len(lines)-1]
+ closing := "*/"
+ i := strings.Index(last, closing) // i >= 0 (closing is always present)
+ if isBlank(last[0:i]) {
+ // last line only contains closing */
+ if lineOfStars {
+ closing = " */" // add blank to align final star
+ }
+ lines[len(lines)-1] = prefix + closing
+ } else {
+ // last line contains more comment text - assume
+ // it is aligned like the other lines and include
+ // in prefix computation
+ prefix = commonPrefix(prefix, last)
+ }
+
+ // Remove the common prefix from all but the first and empty lines.
+ for i, line := range lines {
+ if i > 0 && line != "" {
+ lines[i] = line[len(prefix):]
+ }
+ }
+}
+
+func (p *printer) writeComment(comment *ast.Comment) {
+ text := comment.Text
+ pos := p.posFor(comment.Pos())
+
+ const linePrefix = "//line "
+ if strings.HasPrefix(text, linePrefix) && (!pos.IsValid() || pos.Column == 1) {
+ // Possibly a //-style line directive.
+ // Suspend indentation temporarily to keep line directive valid.
+ defer func(indent int) { p.indent = indent }(p.indent)
+ p.indent = 0
+ }
+
+ // shortcut common case of //-style comments
+ if text[1] == '/' {
+ p.writeString(pos, trimRight(text), true)
+ return
+ }
+
+ // for /*-style comments, print line by line and let the
+ // write function take care of the proper indentation
+ lines := strings.Split(text, "\n")
+
+ // The comment started in the first column but is going
+ // to be indented. For an idempotent result, add indentation
+ // to all lines such that they look like they were indented
+ // before - this will make sure the common prefix computation
+ // is the same independent of how many times formatting is
+ // applied (was issue 1835).
+ if pos.IsValid() && pos.Column == 1 && p.indent > 0 {
+ for i, line := range lines[1:] {
+ lines[1+i] = " " + line
+ }
+ }
+
+ stripCommonPrefix(lines)
+
+ // write comment lines, separated by formfeed,
+ // without a line break after the last line
+ for i, line := range lines {
+ if i > 0 {
+ p.writeByte('\f', 1)
+ pos = p.pos
+ }
+ if len(line) > 0 {
+ p.writeString(pos, trimRight(line), true)
+ }
+ }
+}
+
+// writeCommentSuffix writes a line break after a comment if indicated
+// and processes any leftover indentation information. If a line break
+// is needed, the kind of break (newline vs formfeed) depends on the
+// pending whitespace. The writeCommentSuffix result indicates if a
+// newline was written or if a formfeed was dropped from the whitespace
+// buffer.
+//
+func (p *printer) writeCommentSuffix(needsLinebreak bool) (wroteNewline, droppedFF bool) {
+ for i, ch := range p.wsbuf {
+ switch ch {
+ case blank, vtab:
+ // ignore trailing whitespace
+ p.wsbuf[i] = ignore
+ case indent, unindent:
+ // don't lose indentation information
+ case newline, formfeed:
+ // if we need a line break, keep exactly one
+ // but remember if we dropped any formfeeds
+ if needsLinebreak {
+ needsLinebreak = false
+ wroteNewline = true
+ } else {
+ if ch == formfeed {
+ droppedFF = true
+ }
+ p.wsbuf[i] = ignore
+ }
+ }
+ }
+ p.writeWhitespace(len(p.wsbuf))
+
+ // make sure we have a line break
+ if needsLinebreak {
+ p.writeByte('\n', 1)
+ wroteNewline = true
+ }
+
+ return
+}
+
+// containsLinebreak reports whether the whitespace buffer contains any line breaks.
+func (p *printer) containsLinebreak() bool {
+ for _, ch := range p.wsbuf {
+ if ch == newline || ch == formfeed {
+ return true
+ }
+ }
+ return false
+}
+
+// intersperseComments consumes all comments that appear before the next token
+// tok and prints it together with the buffered whitespace (i.e., the whitespace
+// that needs to be written before the next token). A heuristic is used to mix
+// the comments and whitespace. The intersperseComments result indicates if a
+// newline was written or if a formfeed was dropped from the whitespace buffer.
+//
+func (p *printer) intersperseComments(next token.Position, tok token.Token) (wroteNewline, droppedFF bool) {
+ var last *ast.Comment
+ for p.commentBefore(next) {
+ for _, c := range p.comment.List {
+ p.writeCommentPrefix(p.posFor(c.Pos()), next, last, tok)
+ p.writeComment(c)
+ last = c
+ }
+ p.nextComment()
+ }
+
+ if last != nil {
+ // If the last comment is a /*-style comment and the next item
+ // follows on the same line but is not a comma, and not a "closing"
+ // token immediately following its corresponding "opening" token,
+ // add an extra separator unless explicitly disabled. Use a blank
+ // as separator unless we have pending linebreaks, they are not
+ // disabled, and we are outside a composite literal, in which case
+ // we want a linebreak (issue 15137).
+ // TODO(gri) This has become overly complicated. We should be able
+ // to track whether we're inside an expression or statement and
+ // use that information to decide more directly.
+ needsLinebreak := false
+ if p.mode&noExtraBlank == 0 &&
+ last.Text[1] == '*' && p.lineFor(last.Pos()) == next.Line &&
+ tok != token.COMMA &&
+ (tok != token.RPAREN || p.prevOpen == token.LPAREN) &&
+ (tok != token.RBRACK || p.prevOpen == token.LBRACK) {
+ if p.containsLinebreak() && p.mode&noExtraLinebreak == 0 && p.level == 0 {
+ needsLinebreak = true
+ } else {
+ p.writeByte(' ', 1)
+ }
+ }
+ // Ensure that there is a line break after a //-style comment,
+ // before EOF, and before a closing '}' unless explicitly disabled.
+ if last.Text[1] == '/' ||
+ tok == token.EOF ||
+ tok == token.RBRACE && p.mode&noExtraLinebreak == 0 {
+ needsLinebreak = true
+ }
+ return p.writeCommentSuffix(needsLinebreak)
+ }
+
+ // no comment was written - we should never reach here since
+ // intersperseComments should not be called in that case
+ p.internalError("intersperseComments called without pending comments")
+ return
+}
+
+// whiteWhitespace writes the first n whitespace entries.
+func (p *printer) writeWhitespace(n int) {
+ // write entries
+ for i := 0; i < n; i++ {
+ switch ch := p.wsbuf[i]; ch {
+ case ignore:
+ // ignore!
+ case indent:
+ p.indent++
+ case unindent:
+ p.indent--
+ if p.indent < 0 {
+ p.internalError("negative indentation:", p.indent)
+ p.indent = 0
+ }
+ case newline, formfeed:
+ // A line break immediately followed by a "correcting"
+ // unindent is swapped with the unindent - this permits
+ // proper label positioning. If a comment is between
+ // the line break and the label, the unindent is not
+ // part of the comment whitespace prefix and the comment
+ // will be positioned correctly indented.
+ if i+1 < n && p.wsbuf[i+1] == unindent {
+ // Use a formfeed to terminate the current section.
+ // Otherwise, a long label name on the next line leading
+ // to a wide column may increase the indentation column
+ // of lines before the label; effectively leading to wrong
+ // indentation.
+ p.wsbuf[i], p.wsbuf[i+1] = unindent, formfeed
+ i-- // do it again
+ continue
+ }
+ fallthrough
+ default:
+ p.writeByte(byte(ch), 1)
+ }
+ }
+
+ // shift remaining entries down
+ l := copy(p.wsbuf, p.wsbuf[n:])
+ p.wsbuf = p.wsbuf[:l]
+}
+
+// ----------------------------------------------------------------------------
+// Printing interface
+
+// nlines limits n to maxNewlines.
+func nlimit(n int) int {
+ if n > maxNewlines {
+ n = maxNewlines
+ }
+ return n
+}
+
+func mayCombine(prev token.Token, next byte) (b bool) {
+ switch prev {
+ case token.INT:
+ b = next == '.' // 1.
+ case token.ADD:
+ b = next == '+' // ++
+ case token.SUB:
+ b = next == '-' // --
+ case token.QUO:
+ b = next == '*' // /*
+ case token.LSS:
+ b = next == '-' || next == '<' // <- or <<
+ case token.AND:
+ b = next == '&' || next == '^' // && or &^
+ }
+ return
+}
+
+// print prints a list of "items" (roughly corresponding to syntactic
+// tokens, but also including whitespace and formatting information).
+// It is the only print function that should be called directly from
+// any of the AST printing functions in nodes.go.
+//
+// Whitespace is accumulated until a non-whitespace token appears. Any
+// comments that need to appear before that token are printed first,
+// taking into account the amount and structure of any pending white-
+// space for best comment placement. Then, any leftover whitespace is
+// printed, followed by the actual token.
+//
+func (p *printer) print(args ...interface{}) {
+ for _, arg := range args {
+ // information about the current arg
+ var data string
+ var isLit bool
+ var impliedSemi bool // value for p.impliedSemi after this arg
+
+ // record previous opening token, if any
+ switch p.lastTok {
+ case token.ILLEGAL:
+ // ignore (white space)
+ case token.LPAREN, token.LBRACK:
+ p.prevOpen = p.lastTok
+ default:
+ // other tokens followed any opening token
+ p.prevOpen = token.ILLEGAL
+ }
+
+ switch x := arg.(type) {
+ case pmode:
+ // toggle printer mode
+ p.mode ^= x
+ continue
+
+ case whiteSpace:
+ if x == ignore {
+ // don't add ignore's to the buffer; they
+ // may screw up "correcting" unindents (see
+ // LabeledStmt)
+ continue
+ }
+ i := len(p.wsbuf)
+ if i == cap(p.wsbuf) {
+ // Whitespace sequences are very short so this should
+ // never happen. Handle gracefully (but possibly with
+ // bad comment placement) if it does happen.
+ p.writeWhitespace(i)
+ i = 0
+ }
+ p.wsbuf = p.wsbuf[0 : i+1]
+ p.wsbuf[i] = x
+ if x == newline || x == formfeed {
+ // newlines affect the current state (p.impliedSemi)
+ // and not the state after printing arg (impliedSemi)
+ // because comments can be interspersed before the arg
+ // in this case
+ p.impliedSemi = false
+ }
+ p.lastTok = token.ILLEGAL
+ continue
+
+ case *ast.Ident:
+ data = x.Name
+ impliedSemi = true
+ p.lastTok = token.IDENT
+
+ case *ast.BasicLit:
+ data = x.Value
+ isLit = true
+ impliedSemi = true
+ p.lastTok = x.Kind
+
+ case token.Token:
+ s := x.String()
+ if mayCombine(p.lastTok, s[0]) {
+ // the previous and the current token must be
+ // separated by a blank otherwise they combine
+ // into a different incorrect token sequence
+ // (except for token.INT followed by a '.' this
+ // should never happen because it is taken care
+ // of via binary expression formatting)
+ if len(p.wsbuf) != 0 {
+ p.internalError("whitespace buffer not empty")
+ }
+ p.wsbuf = p.wsbuf[0:1]
+ p.wsbuf[0] = ' '
+ }
+ data = s
+ // some keywords followed by a newline imply a semicolon
+ switch x {
+ case token.BREAK, token.CONTINUE, token.FALLTHROUGH, token.RETURN,
+ token.INC, token.DEC, token.RPAREN, token.RBRACK, token.RBRACE:
+ impliedSemi = true
+ }
+ p.lastTok = x
+
+ case token.Pos:
+ if x.IsValid() {
+ p.pos = p.posFor(x) // accurate position of next item
+ }
+ continue
+
+ case string:
+ // incorrect AST - print error message
+ data = x
+ isLit = true
+ impliedSemi = true
+ p.lastTok = token.STRING
+
+ default:
+ fmt.Fprintf(os.Stderr, "print: unsupported argument %v (%T)\n", arg, arg)
+ panic("go/printer type")
+ }
+ // data != ""
+
+ next := p.pos // estimated/accurate position of next item
+ wroteNewline, droppedFF := p.flush(next, p.lastTok)
+
+ // intersperse extra newlines if present in the source and
+ // if they don't cause extra semicolons (don't do this in
+ // flush as it will cause extra newlines at the end of a file)
+ if !p.impliedSemi {
+ n := nlimit(next.Line - p.pos.Line)
+ // don't exceed maxNewlines if we already wrote one
+ if wroteNewline && n == maxNewlines {
+ n = maxNewlines - 1
+ }
+ if n > 0 {
+ ch := byte('\n')
+ if droppedFF {
+ ch = '\f' // use formfeed since we dropped one before
+ }
+ p.writeByte(ch, n)
+ impliedSemi = false
+ }
+ }
+
+ // the next token starts now - record its line number if requested
+ if p.linePtr != nil {
+ *p.linePtr = p.out.Line
+ p.linePtr = nil
+ }
+
+ p.writeString(next, data, isLit)
+ p.impliedSemi = impliedSemi
+ }
+}
+
+// flush prints any pending comments and whitespace occurring textually
+// before the position of the next token tok. The flush result indicates
+// if a newline was written or if a formfeed was dropped from the whitespace
+// buffer.
+//
+func (p *printer) flush(next token.Position, tok token.Token) (wroteNewline, droppedFF bool) {
+ if p.commentBefore(next) {
+ // if there are comments before the next item, intersperse them
+ wroteNewline, droppedFF = p.intersperseComments(next, tok)
+ } else {
+ // otherwise, write any leftover whitespace
+ p.writeWhitespace(len(p.wsbuf))
+ }
+ return
+}
+
+// getNode returns the ast.CommentGroup associated with n, if any.
+func getDoc(n ast.Node) *ast.CommentGroup {
+ switch n := n.(type) {
+ case *ast.Field:
+ return n.Doc
+ case *ast.ImportSpec:
+ return n.Doc
+ case *ast.ValueSpec:
+ return n.Doc
+ case *ast.TypeSpec:
+ return n.Doc
+ case *ast.GenDecl:
+ return n.Doc
+ case *ast.FuncDecl:
+ return n.Doc
+ case *ast.File:
+ return n.Doc
+ }
+ return nil
+}
+
+func getLastComment(n ast.Node) *ast.CommentGroup {
+ switch n := n.(type) {
+ case *ast.Field:
+ return n.Comment
+ case *ast.ImportSpec:
+ return n.Comment
+ case *ast.ValueSpec:
+ return n.Comment
+ case *ast.TypeSpec:
+ return n.Comment
+ case *ast.GenDecl:
+ if len(n.Specs) > 0 {
+ return getLastComment(n.Specs[len(n.Specs)-1])
+ }
+ case *ast.File:
+ if len(n.Comments) > 0 {
+ return n.Comments[len(n.Comments)-1]
+ }
+ }
+ return nil
+}
+
+func (p *printer) printNode(node interface{}) error {
+ // unpack *CommentedNode, if any
+ var comments []*ast.CommentGroup
+ if cnode, ok := node.(*CommentedNode); ok {
+ node = cnode.Node
+ comments = cnode.Comments
+ }
+
+ if comments != nil {
+ // commented node - restrict comment list to relevant range
+ n, ok := node.(ast.Node)
+ if !ok {
+ goto unsupported
+ }
+ beg := n.Pos()
+ end := n.End()
+ // if the node has associated documentation,
+ // include that commentgroup in the range
+ // (the comment list is sorted in the order
+ // of the comment appearance in the source code)
+ if doc := getDoc(n); doc != nil {
+ beg = doc.Pos()
+ }
+ if com := getLastComment(n); com != nil {
+ if e := com.End(); e > end {
+ end = e
+ }
+ }
+ // token.Pos values are global offsets, we can
+ // compare them directly
+ i := 0
+ for i < len(comments) && comments[i].End() < beg {
+ i++
+ }
+ j := i
+ for j < len(comments) && comments[j].Pos() < end {
+ j++
+ }
+ if i < j {
+ p.comments = comments[i:j]
+ }
+ } else if n, ok := node.(*ast.File); ok {
+ // use ast.File comments, if any
+ p.comments = n.Comments
+ }
+
+ // if there are no comments, use node comments
+ p.useNodeComments = p.comments == nil
+
+ // get comments ready for use
+ p.nextComment()
+
+ // format node
+ switch n := node.(type) {
+ case ast.Expr:
+ p.expr(n)
+ case ast.Stmt:
+ // A labeled statement will un-indent to position the label.
+ // Set p.indent to 1 so we don't get indent "underflow".
+ if _, ok := n.(*ast.LabeledStmt); ok {
+ p.indent = 1
+ }
+ p.stmt(n, false)
+ case ast.Decl:
+ p.decl(n)
+ case ast.Spec:
+ p.spec(n, 1, false)
+ case []ast.Stmt:
+ // A labeled statement will un-indent to position the label.
+ // Set p.indent to 1 so we don't get indent "underflow".
+ for _, s := range n {
+ if _, ok := s.(*ast.LabeledStmt); ok {
+ p.indent = 1
+ }
+ }
+ p.stmtList(n, 0, false)
+ case []ast.Decl:
+ p.declList(n)
+ case *ast.File:
+ p.file(n)
+ default:
+ goto unsupported
+ }
+
+ return nil
+
+unsupported:
+ return fmt.Errorf("go/printer: unsupported node type %T", node)
+}
+
+// ----------------------------------------------------------------------------
+// Trimmer
+
+// A trimmer is an io.Writer filter for stripping tabwriter.Escape
+// characters, trailing blanks and tabs, and for converting formfeed
+// and vtab characters into newlines and htabs (in case no tabwriter
+// is used). Text bracketed by tabwriter.Escape characters is passed
+// through unchanged.
+//
+type trimmer struct {
+ output io.Writer
+ state int
+ space []byte
+}
+
+// trimmer is implemented as a state machine.
+// It can be in one of the following states:
+const (
+ inSpace = iota // inside space
+ inEscape // inside text bracketed by tabwriter.Escapes
+ inText // inside text
+)
+
+func (p *trimmer) resetSpace() {
+ p.state = inSpace
+ p.space = p.space[0:0]
+}
+
+// Design note: It is tempting to eliminate extra blanks occurring in
+// whitespace in this function as it could simplify some
+// of the blanks logic in the node printing functions.
+// However, this would mess up any formatting done by
+// the tabwriter.
+
+var aNewline = []byte("\n")
+
+func (p *trimmer) Write(data []byte) (n int, err error) {
+ // invariants:
+ // p.state == inSpace:
+ // p.space is unwritten
+ // p.state == inEscape, inText:
+ // data[m:n] is unwritten
+ m := 0
+ var b byte
+ for n, b = range data {
+ if b == '\v' {
+ b = '\t' // convert to htab
+ }
+ switch p.state {
+ case inSpace:
+ switch b {
+ case '\t', ' ':
+ p.space = append(p.space, b)
+ case '\n', '\f':
+ p.resetSpace() // discard trailing space
+ _, err = p.output.Write(aNewline)
+ case tabwriter.Escape:
+ _, err = p.output.Write(p.space)
+ p.state = inEscape
+ m = n + 1 // +1: skip tabwriter.Escape
+ default:
+ _, err = p.output.Write(p.space)
+ p.state = inText
+ m = n
+ }
+ case inEscape:
+ if b == tabwriter.Escape {
+ _, err = p.output.Write(data[m:n])
+ p.resetSpace()
+ }
+ case inText:
+ switch b {
+ case '\t', ' ':
+ _, err = p.output.Write(data[m:n])
+ p.resetSpace()
+ p.space = append(p.space, b)
+ case '\n', '\f':
+ _, err = p.output.Write(data[m:n])
+ p.resetSpace()
+ if err == nil {
+ _, err = p.output.Write(aNewline)
+ }
+ case tabwriter.Escape:
+ _, err = p.output.Write(data[m:n])
+ p.state = inEscape
+ m = n + 1 // +1: skip tabwriter.Escape
+ }
+ default:
+ panic("unreachable")
+ }
+ if err != nil {
+ return
+ }
+ }
+ n = len(data)
+
+ switch p.state {
+ case inEscape, inText:
+ _, err = p.output.Write(data[m:n])
+ p.resetSpace()
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Public interface
+
+// A Mode value is a set of flags (or 0). They control printing.
+type Mode uint
+
+const (
+ RawFormat Mode = 1 << iota // do not use a tabwriter; if set, UseSpaces is ignored
+ TabIndent // use tabs for indentation independent of UseSpaces
+ UseSpaces // use spaces instead of tabs for alignment
+ SourcePos // emit //line directives to preserve original source positions
+)
+
+// The mode below is not included in printer's public API because
+// editing code text is deemed out of scope. Because this mode is
+// unexported, it's also possible to modify or remove it based on
+// the evolving needs of go/format and cmd/gofmt without breaking
+// users. See discussion in CL 240683.
+const (
+ // normalizeNumbers means to canonicalize number
+ // literal prefixes and exponents while printing.
+ //
+ // This value is known in and used by go/format and cmd/gofmt.
+ // It is currently more convenient and performant for those
+ // packages to apply number normalization during printing,
+ // rather than by modifying the AST in advance.
+ normalizeNumbers Mode = 1 << 30
+)
+
+// A Config node controls the output of Fprint.
+type Config struct {
+ Mode Mode // default: 0
+ Tabwidth int // default: 8
+ Indent int // default: 0 (all code is indented at least by this much)
+}
+
+// fprint implements Fprint and takes a nodesSizes map for setting up the printer state.
+func (cfg *Config) fprint(output io.Writer, fset *token.FileSet, node interface{}, nodeSizes map[ast.Node]int) (err error) {
+ // print node
+ var p printer
+ p.init(cfg, fset, nodeSizes)
+ if err = p.printNode(node); err != nil {
+ return
+ }
+ // print outstanding comments
+ p.impliedSemi = false // EOF acts like a newline
+ p.flush(token.Position{Offset: infinity, Line: infinity}, token.EOF)
+
+ // redirect output through a trimmer to eliminate trailing whitespace
+ // (Input to a tabwriter must be untrimmed since trailing tabs provide
+ // formatting information. The tabwriter could provide trimming
+ // functionality but no tabwriter is used when RawFormat is set.)
+ output = &trimmer{output: output}
+
+ // redirect output through a tabwriter if necessary
+ if cfg.Mode&RawFormat == 0 {
+ minwidth := cfg.Tabwidth
+
+ padchar := byte('\t')
+ if cfg.Mode&UseSpaces != 0 {
+ padchar = ' '
+ }
+
+ twmode := tabwriter.DiscardEmptyColumns
+ if cfg.Mode&TabIndent != 0 {
+ minwidth = 0
+ twmode |= tabwriter.TabIndent
+ }
+
+ output = tabwriter.NewWriter(output, minwidth, cfg.Tabwidth, 1, padchar, twmode)
+ }
+
+ // write printer result via tabwriter/trimmer to output
+ if _, err = output.Write(p.output); err != nil {
+ return
+ }
+
+ // flush tabwriter, if any
+ if tw, _ := output.(*tabwriter.Writer); tw != nil {
+ err = tw.Flush()
+ }
+
+ return
+}
+
+// A CommentedNode bundles an AST node and corresponding comments.
+// It may be provided as argument to any of the Fprint functions.
+//
+type CommentedNode struct {
+ Node interface{} // *ast.File, or ast.Expr, ast.Decl, ast.Spec, or ast.Stmt
+ Comments []*ast.CommentGroup
+}
+
+// Fprint "pretty-prints" an AST node to output for a given configuration cfg.
+// Position information is interpreted relative to the file set fset.
+// The node type must be *ast.File, *CommentedNode, []ast.Decl, []ast.Stmt,
+// or assignment-compatible to ast.Expr, ast.Decl, ast.Spec, or ast.Stmt.
+//
+func (cfg *Config) Fprint(output io.Writer, fset *token.FileSet, node interface{}) error {
+ return cfg.fprint(output, fset, node, make(map[ast.Node]int))
+}
+
+// Fprint "pretty-prints" an AST node to output.
+// It calls Config.Fprint with default settings.
+// Note that gofmt uses tabs for indentation but spaces for alignment;
+// use format.Node (package go/format) for output that matches gofmt.
+//
+func Fprint(output io.Writer, fset *token.FileSet, node interface{}) error {
+ return (&Config{Tabwidth: 8}).Fprint(output, fset, node)
+}
diff --git a/src/go/printer/printer_test.go b/src/go/printer/printer_test.go
new file mode 100644
index 0000000..45e5011
--- /dev/null
+++ b/src/go/printer/printer_test.go
@@ -0,0 +1,814 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package printer
+
+import (
+ "bytes"
+ "errors"
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "io"
+ "os"
+ "path/filepath"
+ "testing"
+ "time"
+)
+
+const (
+ dataDir = "testdata"
+ tabwidth = 8
+)
+
+var update = flag.Bool("update", false, "update golden files")
+
+var fset = token.NewFileSet()
+
+type checkMode uint
+
+const (
+ export checkMode = 1 << iota
+ rawFormat
+ normNumber
+ idempotent
+)
+
+// format parses src, prints the corresponding AST, verifies the resulting
+// src is syntactically correct, and returns the resulting src or an error
+// if any.
+func format(src []byte, mode checkMode) ([]byte, error) {
+ // parse src
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ return nil, fmt.Errorf("parse: %s\n%s", err, src)
+ }
+
+ // filter exports if necessary
+ if mode&export != 0 {
+ ast.FileExports(f) // ignore result
+ f.Comments = nil // don't print comments that are not in AST
+ }
+
+ // determine printer configuration
+ cfg := Config{Tabwidth: tabwidth}
+ if mode&rawFormat != 0 {
+ cfg.Mode |= RawFormat
+ }
+ if mode&normNumber != 0 {
+ cfg.Mode |= normalizeNumbers
+ }
+
+ // print AST
+ var buf bytes.Buffer
+ if err := cfg.Fprint(&buf, fset, f); err != nil {
+ return nil, fmt.Errorf("print: %s", err)
+ }
+
+ // make sure formatted output is syntactically correct
+ res := buf.Bytes()
+ if _, err := parser.ParseFile(fset, "", res, 0); err != nil {
+ return nil, fmt.Errorf("re-parse: %s\n%s", err, buf.Bytes())
+ }
+
+ return res, nil
+}
+
+// lineAt returns the line in text starting at offset offs.
+func lineAt(text []byte, offs int) []byte {
+ i := offs
+ for i < len(text) && text[i] != '\n' {
+ i++
+ }
+ return text[offs:i]
+}
+
+// diff compares a and b.
+func diff(aname, bname string, a, b []byte) error {
+ var buf bytes.Buffer // holding long error message
+
+ // compare lengths
+ if len(a) != len(b) {
+ fmt.Fprintf(&buf, "\nlength changed: len(%s) = %d, len(%s) = %d", aname, len(a), bname, len(b))
+ }
+
+ // compare contents
+ line := 1
+ offs := 1
+ for i := 0; i < len(a) && i < len(b); i++ {
+ ch := a[i]
+ if ch != b[i] {
+ fmt.Fprintf(&buf, "\n%s:%d:%d: %s", aname, line, i-offs+1, lineAt(a, offs))
+ fmt.Fprintf(&buf, "\n%s:%d:%d: %s", bname, line, i-offs+1, lineAt(b, offs))
+ fmt.Fprintf(&buf, "\n\n")
+ break
+ }
+ if ch == '\n' {
+ line++
+ offs = i + 1
+ }
+ }
+
+ if buf.Len() > 0 {
+ return errors.New(buf.String())
+ }
+ return nil
+}
+
+func runcheck(t *testing.T, source, golden string, mode checkMode) {
+ src, err := os.ReadFile(source)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ res, err := format(src, mode)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ // update golden files if necessary
+ if *update {
+ if err := os.WriteFile(golden, res, 0644); err != nil {
+ t.Error(err)
+ }
+ return
+ }
+
+ // get golden
+ gld, err := os.ReadFile(golden)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ // formatted source and golden must be the same
+ if err := diff(source, golden, res, gld); err != nil {
+ t.Error(err)
+ return
+ }
+
+ if mode&idempotent != 0 {
+ // formatting golden must be idempotent
+ // (This is very difficult to achieve in general and for now
+ // it is only checked for files explicitly marked as such.)
+ res, err = format(gld, mode)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+ if err := diff(golden, fmt.Sprintf("format(%s)", golden), gld, res); err != nil {
+ t.Errorf("golden is not idempotent: %s", err)
+ }
+ }
+}
+
+func check(t *testing.T, source, golden string, mode checkMode) {
+ // run the test
+ cc := make(chan int, 1)
+ go func() {
+ runcheck(t, source, golden, mode)
+ cc <- 0
+ }()
+
+ // wait with timeout
+ select {
+ case <-time.After(10 * time.Second): // plenty of a safety margin, even for very slow machines
+ // test running past time out
+ t.Errorf("%s: running too slowly", source)
+ case <-cc:
+ // test finished within allotted time margin
+ }
+}
+
+type entry struct {
+ source, golden string
+ mode checkMode
+}
+
+// Use go test -update to create/update the respective golden files.
+var data = []entry{
+ {"empty.input", "empty.golden", idempotent},
+ {"comments.input", "comments.golden", 0},
+ {"comments.input", "comments.x", export},
+ {"comments2.input", "comments2.golden", idempotent},
+ {"alignment.input", "alignment.golden", idempotent},
+ {"linebreaks.input", "linebreaks.golden", idempotent},
+ {"expressions.input", "expressions.golden", idempotent},
+ {"expressions.input", "expressions.raw", rawFormat | idempotent},
+ {"declarations.input", "declarations.golden", 0},
+ {"statements.input", "statements.golden", 0},
+ {"slow.input", "slow.golden", idempotent},
+ {"complit.input", "complit.x", export},
+ {"go2numbers.input", "go2numbers.golden", idempotent},
+ {"go2numbers.input", "go2numbers.norm", normNumber | idempotent},
+}
+
+func TestFiles(t *testing.T) {
+ t.Parallel()
+ for _, e := range data {
+ source := filepath.Join(dataDir, e.source)
+ golden := filepath.Join(dataDir, e.golden)
+ mode := e.mode
+ t.Run(e.source, func(t *testing.T) {
+ t.Parallel()
+ check(t, source, golden, mode)
+ // TODO(gri) check that golden is idempotent
+ //check(t, golden, golden, e.mode)
+ })
+ }
+}
+
+// TestLineComments, using a simple test case, checks that consecutive line
+// comments are properly terminated with a newline even if the AST position
+// information is incorrect.
+//
+func TestLineComments(t *testing.T) {
+ const src = `// comment 1
+ // comment 2
+ // comment 3
+ package main
+ `
+
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ var buf bytes.Buffer
+ fset = token.NewFileSet() // use the wrong file set
+ Fprint(&buf, fset, f)
+
+ nlines := 0
+ for _, ch := range buf.Bytes() {
+ if ch == '\n' {
+ nlines++
+ }
+ }
+
+ const expected = 3
+ if nlines < expected {
+ t.Errorf("got %d, expected %d\n", nlines, expected)
+ t.Errorf("result:\n%s", buf.Bytes())
+ }
+}
+
+// Verify that the printer can be invoked during initialization.
+func init() {
+ const name = "foobar"
+ var buf bytes.Buffer
+ if err := Fprint(&buf, fset, &ast.Ident{Name: name}); err != nil {
+ panic(err) // error in test
+ }
+ // in debug mode, the result contains additional information;
+ // ignore it
+ if s := buf.String(); !debug && s != name {
+ panic("got " + s + ", want " + name)
+ }
+}
+
+// Verify that the printer doesn't crash if the AST contains BadXXX nodes.
+func TestBadNodes(t *testing.T) {
+ const src = "package p\n("
+ const res = "package p\nBadDecl\n"
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err == nil {
+ t.Error("expected illegal program") // error in test
+ }
+ var buf bytes.Buffer
+ Fprint(&buf, fset, f)
+ if buf.String() != res {
+ t.Errorf("got %q, expected %q", buf.String(), res)
+ }
+}
+
+// testComment verifies that f can be parsed again after printing it
+// with its first comment set to comment at any possible source offset.
+func testComment(t *testing.T, f *ast.File, srclen int, comment *ast.Comment) {
+ f.Comments[0].List[0] = comment
+ var buf bytes.Buffer
+ for offs := 0; offs <= srclen; offs++ {
+ buf.Reset()
+ // Printing f should result in a correct program no
+ // matter what the (incorrect) comment position is.
+ if err := Fprint(&buf, fset, f); err != nil {
+ t.Error(err)
+ }
+ if _, err := parser.ParseFile(fset, "", buf.Bytes(), 0); err != nil {
+ t.Fatalf("incorrect program for pos = %d:\n%s", comment.Slash, buf.String())
+ }
+ // Position information is just an offset.
+ // Move comment one byte down in the source.
+ comment.Slash++
+ }
+}
+
+// Verify that the printer produces a correct program
+// even if the position information of comments introducing newlines
+// is incorrect.
+func TestBadComments(t *testing.T) {
+ t.Parallel()
+ const src = `
+// first comment - text and position changed by test
+package p
+import "fmt"
+const pi = 3.14 // rough circle
+var (
+ x, y, z int = 1, 2, 3
+ u, v float64
+)
+func fibo(n int) {
+ if n < 2 {
+ return n /* seed values */
+ }
+ return fibo(n-1) + fibo(n-2)
+}
+`
+
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ t.Error(err) // error in test
+ }
+
+ comment := f.Comments[0].List[0]
+ pos := comment.Pos()
+ if fset.PositionFor(pos, false /* absolute position */).Offset != 1 {
+ t.Error("expected offset 1") // error in test
+ }
+
+ testComment(t, f, len(src), &ast.Comment{Slash: pos, Text: "//-style comment"})
+ testComment(t, f, len(src), &ast.Comment{Slash: pos, Text: "/*-style comment */"})
+ testComment(t, f, len(src), &ast.Comment{Slash: pos, Text: "/*-style \n comment */"})
+ testComment(t, f, len(src), &ast.Comment{Slash: pos, Text: "/*-style comment \n\n\n */"})
+}
+
+type visitor chan *ast.Ident
+
+func (v visitor) Visit(n ast.Node) (w ast.Visitor) {
+ if ident, ok := n.(*ast.Ident); ok {
+ v <- ident
+ }
+ return v
+}
+
+// idents is an iterator that returns all idents in f via the result channel.
+func idents(f *ast.File) <-chan *ast.Ident {
+ v := make(visitor)
+ go func() {
+ ast.Walk(v, f)
+ close(v)
+ }()
+ return v
+}
+
+// identCount returns the number of identifiers found in f.
+func identCount(f *ast.File) int {
+ n := 0
+ for range idents(f) {
+ n++
+ }
+ return n
+}
+
+// Verify that the SourcePos mode emits correct //line directives
+// by testing that position information for matching identifiers
+// is maintained.
+func TestSourcePos(t *testing.T) {
+ const src = `
+package p
+import ( "go/printer"; "math" )
+const pi = 3.14; var x = 0
+type t struct{ x, y, z int; u, v, w float32 }
+func (t *t) foo(a, b, c int) int {
+ return a*t.x + b*t.y +
+ // two extra lines here
+ // ...
+ c*t.z
+}
+`
+
+ // parse original
+ f1, err := parser.ParseFile(fset, "src", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // pretty-print original
+ var buf bytes.Buffer
+ err = (&Config{Mode: UseSpaces | SourcePos, Tabwidth: 8}).Fprint(&buf, fset, f1)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // parse pretty printed original
+ // (//line directives must be interpreted even w/o parser.ParseComments set)
+ f2, err := parser.ParseFile(fset, "", buf.Bytes(), 0)
+ if err != nil {
+ t.Fatalf("%s\n%s", err, buf.Bytes())
+ }
+
+ // At this point the position information of identifiers in f2 should
+ // match the position information of corresponding identifiers in f1.
+
+ // number of identifiers must be > 0 (test should run) and must match
+ n1 := identCount(f1)
+ n2 := identCount(f2)
+ if n1 == 0 {
+ t.Fatal("got no idents")
+ }
+ if n2 != n1 {
+ t.Errorf("got %d idents; want %d", n2, n1)
+ }
+
+ // verify that all identifiers have correct line information
+ i2range := idents(f2)
+ for i1 := range idents(f1) {
+ i2 := <-i2range
+
+ if i2.Name != i1.Name {
+ t.Errorf("got ident %s; want %s", i2.Name, i1.Name)
+ }
+
+ // here we care about the relative (line-directive adjusted) positions
+ l1 := fset.Position(i1.Pos()).Line
+ l2 := fset.Position(i2.Pos()).Line
+ if l2 != l1 {
+ t.Errorf("got line %d; want %d for %s", l2, l1, i1.Name)
+ }
+ }
+
+ if t.Failed() {
+ t.Logf("\n%s", buf.Bytes())
+ }
+}
+
+// Verify that the SourcePos mode doesn't emit unnecessary //line directives
+// before empty lines.
+func TestIssue5945(t *testing.T) {
+ const orig = `
+package p // line 2
+func f() {} // line 3
+
+var x, y, z int
+
+
+func g() { // line 8
+}
+`
+
+ const want = `//line src.go:2
+package p
+
+//line src.go:3
+func f() {}
+
+var x, y, z int
+
+//line src.go:8
+func g() {
+}
+`
+
+ // parse original
+ f1, err := parser.ParseFile(fset, "src.go", orig, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // pretty-print original
+ var buf bytes.Buffer
+ err = (&Config{Mode: UseSpaces | SourcePos, Tabwidth: 8}).Fprint(&buf, fset, f1)
+ if err != nil {
+ t.Fatal(err)
+ }
+ got := buf.String()
+
+ // compare original with desired output
+ if got != want {
+ t.Errorf("got:\n%s\nwant:\n%s\n", got, want)
+ }
+}
+
+var decls = []string{
+ `import "fmt"`,
+ "const pi = 3.1415\nconst e = 2.71828\n\nvar x = pi",
+ "func sum(x, y int) int\t{ return x + y }",
+}
+
+func TestDeclLists(t *testing.T) {
+ for _, src := range decls {
+ file, err := parser.ParseFile(fset, "", "package p;"+src, parser.ParseComments)
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ var buf bytes.Buffer
+ err = Fprint(&buf, fset, file.Decls) // only print declarations
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ out := buf.String()
+ if out != src {
+ t.Errorf("\ngot : %q\nwant: %q\n", out, src)
+ }
+ }
+}
+
+var stmts = []string{
+ "i := 0",
+ "select {}\nvar a, b = 1, 2\nreturn a + b",
+ "go f()\ndefer func() {}()",
+}
+
+func TestStmtLists(t *testing.T) {
+ for _, src := range stmts {
+ file, err := parser.ParseFile(fset, "", "package p; func _() {"+src+"}", parser.ParseComments)
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ var buf bytes.Buffer
+ err = Fprint(&buf, fset, file.Decls[0].(*ast.FuncDecl).Body.List) // only print statements
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ out := buf.String()
+ if out != src {
+ t.Errorf("\ngot : %q\nwant: %q\n", out, src)
+ }
+ }
+}
+
+func TestBaseIndent(t *testing.T) {
+ t.Parallel()
+ // The testfile must not contain multi-line raw strings since those
+ // are not indented (because their values must not change) and make
+ // this test fail.
+ const filename = "printer.go"
+ src, err := os.ReadFile(filename)
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ file, err := parser.ParseFile(fset, filename, src, 0)
+ if err != nil {
+ panic(err) // error in test
+ }
+
+ for indent := 0; indent < 4; indent++ {
+ indent := indent
+ t.Run(fmt.Sprint(indent), func(t *testing.T) {
+ t.Parallel()
+ var buf bytes.Buffer
+ (&Config{Tabwidth: tabwidth, Indent: indent}).Fprint(&buf, fset, file)
+ // all code must be indented by at least 'indent' tabs
+ lines := bytes.Split(buf.Bytes(), []byte{'\n'})
+ for i, line := range lines {
+ if len(line) == 0 {
+ continue // empty lines don't have indentation
+ }
+ n := 0
+ for j, b := range line {
+ if b != '\t' {
+ // end of indentation
+ n = j
+ break
+ }
+ }
+ if n < indent {
+ t.Errorf("line %d: got only %d tabs; want at least %d: %q", i, n, indent, line)
+ }
+ }
+ })
+ }
+}
+
+// TestFuncType tests that an ast.FuncType with a nil Params field
+// can be printed (per go/ast specification). Test case for issue 3870.
+func TestFuncType(t *testing.T) {
+ src := &ast.File{
+ Name: &ast.Ident{Name: "p"},
+ Decls: []ast.Decl{
+ &ast.FuncDecl{
+ Name: &ast.Ident{Name: "f"},
+ Type: &ast.FuncType{},
+ },
+ },
+ }
+
+ var buf bytes.Buffer
+ if err := Fprint(&buf, fset, src); err != nil {
+ t.Fatal(err)
+ }
+ got := buf.String()
+
+ const want = `package p
+
+func f()
+`
+
+ if got != want {
+ t.Fatalf("got:\n%s\nwant:\n%s\n", got, want)
+ }
+}
+
+type limitWriter struct {
+ remaining int
+ errCount int
+}
+
+func (l *limitWriter) Write(buf []byte) (n int, err error) {
+ n = len(buf)
+ if n >= l.remaining {
+ n = l.remaining
+ err = io.EOF
+ l.errCount++
+ }
+ l.remaining -= n
+ return n, err
+}
+
+// Test whether the printer stops writing after the first error
+func TestWriteErrors(t *testing.T) {
+ t.Parallel()
+ const filename = "printer.go"
+ src, err := os.ReadFile(filename)
+ if err != nil {
+ panic(err) // error in test
+ }
+ file, err := parser.ParseFile(fset, filename, src, 0)
+ if err != nil {
+ panic(err) // error in test
+ }
+ for i := 0; i < 20; i++ {
+ lw := &limitWriter{remaining: i}
+ err := (&Config{Mode: RawFormat}).Fprint(lw, fset, file)
+ if lw.errCount > 1 {
+ t.Fatal("Writes continued after first error returned")
+ }
+ // We expect errCount be 1 iff err is set
+ if (lw.errCount != 0) != (err != nil) {
+ t.Fatal("Expected err when errCount != 0")
+ }
+ }
+}
+
+// TextX is a skeleton test that can be filled in for debugging one-off cases.
+// Do not remove.
+func TestX(t *testing.T) {
+ const src = `
+package p
+func _() {}
+`
+ _, err := format([]byte(src), 0)
+ if err != nil {
+ t.Error(err)
+ }
+}
+
+func TestCommentedNode(t *testing.T) {
+ const (
+ input = `package main
+
+func foo() {
+ // comment inside func
+}
+
+// leading comment
+type bar int // comment2
+
+`
+
+ foo = `func foo() {
+ // comment inside func
+}`
+
+ bar = `// leading comment
+type bar int // comment2
+`
+ )
+
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "input.go", input, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var buf bytes.Buffer
+
+ err = Fprint(&buf, fset, &CommentedNode{Node: f.Decls[0], Comments: f.Comments})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if buf.String() != foo {
+ t.Errorf("got %q, want %q", buf.String(), foo)
+ }
+
+ buf.Reset()
+
+ err = Fprint(&buf, fset, &CommentedNode{Node: f.Decls[1], Comments: f.Comments})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if buf.String() != bar {
+ t.Errorf("got %q, want %q", buf.String(), bar)
+ }
+}
+
+func TestIssue11151(t *testing.T) {
+ const src = "package p\t/*\r/1\r*\r/2*\r\r\r\r/3*\r\r+\r\r/4*/\n"
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var buf bytes.Buffer
+ Fprint(&buf, fset, f)
+ got := buf.String()
+ const want = "package p\t/*/1*\r/2*\r/3*+/4*/\n" // \r following opening /* should be stripped
+ if got != want {
+ t.Errorf("\ngot : %q\nwant: %q", got, want)
+ }
+
+ // the resulting program must be valid
+ _, err = parser.ParseFile(fset, "", got, 0)
+ if err != nil {
+ t.Errorf("%v\norig: %q\ngot : %q", err, src, got)
+ }
+}
+
+// If a declaration has multiple specifications, a parenthesized
+// declaration must be printed even if Lparen is token.NoPos.
+func TestParenthesizedDecl(t *testing.T) {
+ // a package with multiple specs in a single declaration
+ const src = "package p; var ( a float64; b int )"
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // print the original package
+ var buf bytes.Buffer
+ err = Fprint(&buf, fset, f)
+ if err != nil {
+ t.Fatal(err)
+ }
+ original := buf.String()
+
+ // now remove parentheses from the declaration
+ for i := 0; i != len(f.Decls); i++ {
+ f.Decls[i].(*ast.GenDecl).Lparen = token.NoPos
+ }
+ buf.Reset()
+ err = Fprint(&buf, fset, f)
+ if err != nil {
+ t.Fatal(err)
+ }
+ noparen := buf.String()
+
+ if noparen != original {
+ t.Errorf("got %q, want %q", noparen, original)
+ }
+}
+
+// Verify that we don't print a newline between "return" and its results, as
+// that would incorrectly cause a naked return.
+func TestIssue32854(t *testing.T) {
+ src := `package foo
+
+func f() {
+ return Composite{
+ call(),
+ }
+}`
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ panic(err)
+ }
+
+ // Replace the result with call(), which is on the next line.
+ fd := file.Decls[0].(*ast.FuncDecl)
+ ret := fd.Body.List[0].(*ast.ReturnStmt)
+ ret.Results[0] = ret.Results[0].(*ast.CompositeLit).Elts[0]
+
+ var buf bytes.Buffer
+ if err := Fprint(&buf, fset, ret); err != nil {
+ t.Fatal(err)
+ }
+ want := "return call()"
+ if got := buf.String(); got != want {
+ t.Fatalf("got %q, want %q", got, want)
+ }
+}
diff --git a/src/go/printer/testdata/alignment.golden b/src/go/printer/testdata/alignment.golden
new file mode 100644
index 0000000..96086ed
--- /dev/null
+++ b/src/go/printer/testdata/alignment.golden
@@ -0,0 +1,172 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package alignment
+
+// ----------------------------------------------------------------------------
+// Examples from issue #7335.
+
+func main() {
+ z := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ Name: "name",
+ LongName: "longname",
+ Baz: "baz",
+ }
+ y := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ NameXX: "name",
+ LongNameXXXXXXXXXXXXX: "longname",
+ Baz: "baz",
+ }
+ z := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ Name: "name",
+ LongNameXXXXXXXXXXXXX: "longname",
+ Baz: "baz",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #10392.
+
+var kcfg = KubeletConfig{
+ Address: s.Address,
+ AllowPrivileged: s.AllowPrivileged,
+ HostNetworkSources: hostNetworkSources,
+ HostnameOverride: s.HostnameOverride,
+ RootDirectory: s.RootDirectory,
+ ConfigFile: s.Config,
+ ManifestURL: s.ManifestURL,
+ FileCheckFrequency: s.FileCheckFrequency,
+ HTTPCheckFrequency: s.HTTPCheckFrequency,
+ PodInfraContainerImage: s.PodInfraContainerImage,
+ SyncFrequency: s.SyncFrequency,
+ RegistryPullQPS: s.RegistryPullQPS,
+ RegistryBurst: s.RegistryBurst,
+ MinimumGCAge: s.MinimumGCAge,
+ MaxPerPodContainerCount: s.MaxPerPodContainerCount,
+ MaxContainerCount: s.MaxContainerCount,
+ ClusterDomain: s.ClusterDomain,
+ ClusterDNS: s.ClusterDNS,
+ Runonce: s.RunOnce,
+ Port: s.Port,
+ ReadOnlyPort: s.ReadOnlyPort,
+ CadvisorInterface: cadvisorInterface,
+ EnableServer: s.EnableServer,
+ EnableDebuggingHandlers: s.EnableDebuggingHandlers,
+ DockerClient: dockertools.ConnectToDockerOrDie(s.DockerEndpoint),
+ KubeClient: client,
+ MasterServiceNamespace: s.MasterServiceNamespace,
+ VolumePlugins: ProbeVolumePlugins(),
+ NetworkPlugins: ProbeNetworkPlugins(),
+ NetworkPluginName: s.NetworkPluginName,
+ StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout,
+ TLSOptions: tlsOptions,
+ ImageGCPolicy: imageGCPolicy, imageGCPolicy,
+ Cloud: cloud,
+ NodeStatusUpdateFrequency: s.NodeStatusUpdateFrequency,
+}
+
+var a = A{
+ Long: 1,
+ LongLong: 1,
+ LongLongLong: 1,
+ LongLongLongLong: 1,
+ LongLongLongLongLong: 1,
+ LongLongLongLongLongLong: 1,
+ LongLongLongLongLongLongLong: 1,
+ LongLongLongLongLongLongLongLong: 1,
+ Short: 1,
+ LongLongLongLongLongLongLongLongLong: 3,
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #22852.
+
+var fmtMap = map[string]string{
+ "1": "123",
+ "12": "123",
+ "123": "123",
+ "1234": "123",
+ "12345": "123",
+ "123456": "123",
+ "12345678901234567890123456789": "123",
+ "abcde": "123",
+ "123456789012345678901234567890": "123",
+ "1234567": "123",
+ "abcdefghijklmnopqrstuvwxyzabcd": "123",
+ "abcd": "123",
+}
+
+type Fmt struct {
+ abcdefghijklmnopqrstuvwx string
+ abcdefghijklmnopqrstuvwxy string
+ abcdefghijklmnopqrstuvwxyz string
+ abcdefghijklmnopqrstuvwxyza string
+ abcdefghijklmnopqrstuvwxyzab string
+ abcdefghijklmnopqrstuvwxyzabc string
+ abcde string
+ abcdefghijklmnopqrstuvwxyzabcde string
+ abcdefg string
+}
+
+func main() {
+ _ := Fmt{
+ abcdefghijklmnopqrstuvwx: "foo",
+ abcdefghijklmnopqrstuvwxyza: "foo",
+ abcdefghijklmnopqrstuvwxyzab: "foo",
+ abcdefghijklmnopqrstuvwxyzabc: "foo",
+ abcde: "foo",
+ abcdefghijklmnopqrstuvwxyzabcde: "foo",
+ abcdefg: "foo",
+ abcdefghijklmnopqrstuvwxy: "foo",
+ abcdefghijklmnopqrstuvwxyz: "foo",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #26352.
+
+var _ = map[int]string{
+ 1: "",
+
+ 12345678901234567890123456789: "",
+ 12345678901234567890123456789012345678: "",
+}
+
+func f() {
+ _ = map[int]string{
+ 1: "",
+
+ 12345678901234567: "",
+ 12345678901234567890123456789012345678901: "",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #26930.
+
+var _ = S{
+ F1: []string{},
+ F2____: []string{},
+}
+
+var _ = S{
+ F1: []string{},
+ F2____: []string{},
+}
+
+var _ = S{
+ F1____: []string{},
+ F2: []string{},
+}
+
+var _ = S{
+ F1____: []string{},
+ F2: []string{},
+}
diff --git a/src/go/printer/testdata/alignment.input b/src/go/printer/testdata/alignment.input
new file mode 100644
index 0000000..323d268
--- /dev/null
+++ b/src/go/printer/testdata/alignment.input
@@ -0,0 +1,179 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package alignment
+
+// ----------------------------------------------------------------------------
+// Examples from issue #7335.
+
+func main() {
+ z := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ Name: "name",
+ LongName: "longname",
+ Baz: "baz",
+ }
+ y := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ NameXX: "name",
+ LongNameXXXXXXXXXXXXX: "longname",
+ Baz: "baz",
+ }
+ z := MyStruct{
+ Foo: "foo",
+ Bar: "bar",
+ Name: "name",
+ LongNameXXXXXXXXXXXXX: "longname",
+ Baz: "baz",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #10392.
+
+var kcfg = KubeletConfig{
+ Address: s.Address,
+ AllowPrivileged: s.AllowPrivileged,
+ HostNetworkSources: hostNetworkSources,
+ HostnameOverride: s.HostnameOverride,
+ RootDirectory: s.RootDirectory,
+ ConfigFile: s.Config,
+ ManifestURL: s.ManifestURL,
+ FileCheckFrequency: s.FileCheckFrequency,
+ HTTPCheckFrequency: s.HTTPCheckFrequency,
+ PodInfraContainerImage: s.PodInfraContainerImage,
+ SyncFrequency: s.SyncFrequency,
+ RegistryPullQPS: s.RegistryPullQPS,
+ RegistryBurst: s.RegistryBurst,
+ MinimumGCAge: s.MinimumGCAge,
+ MaxPerPodContainerCount: s.MaxPerPodContainerCount,
+ MaxContainerCount: s.MaxContainerCount,
+ ClusterDomain: s.ClusterDomain,
+ ClusterDNS: s.ClusterDNS,
+ Runonce: s.RunOnce,
+ Port: s.Port,
+ ReadOnlyPort: s.ReadOnlyPort,
+ CadvisorInterface: cadvisorInterface,
+ EnableServer: s.EnableServer,
+ EnableDebuggingHandlers: s.EnableDebuggingHandlers,
+ DockerClient: dockertools.ConnectToDockerOrDie(s.DockerEndpoint),
+ KubeClient: client,
+ MasterServiceNamespace: s.MasterServiceNamespace,
+ VolumePlugins: ProbeVolumePlugins(),
+ NetworkPlugins: ProbeNetworkPlugins(),
+ NetworkPluginName: s.NetworkPluginName,
+ StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout,
+ TLSOptions: tlsOptions,
+ ImageGCPolicy: imageGCPolicy,imageGCPolicy,
+ Cloud: cloud,
+ NodeStatusUpdateFrequency: s.NodeStatusUpdateFrequency,
+}
+
+var a = A{
+ Long: 1,
+ LongLong: 1,
+ LongLongLong: 1,
+ LongLongLongLong: 1,
+ LongLongLongLongLong: 1,
+ LongLongLongLongLongLong: 1,
+ LongLongLongLongLongLongLong: 1,
+ LongLongLongLongLongLongLongLong: 1,
+ Short: 1,
+ LongLongLongLongLongLongLongLongLong: 3,
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #22852.
+
+var fmtMap = map[string]string{
+ "1": "123",
+ "12": "123",
+ "123": "123",
+ "1234": "123",
+ "12345": "123",
+ "123456": "123",
+ "12345678901234567890123456789": "123",
+ "abcde": "123",
+ "123456789012345678901234567890": "123",
+ "1234567": "123",
+ "abcdefghijklmnopqrstuvwxyzabcd": "123",
+ "abcd": "123",
+}
+
+type Fmt struct {
+ abcdefghijklmnopqrstuvwx string
+ abcdefghijklmnopqrstuvwxy string
+ abcdefghijklmnopqrstuvwxyz string
+ abcdefghijklmnopqrstuvwxyza string
+ abcdefghijklmnopqrstuvwxyzab string
+ abcdefghijklmnopqrstuvwxyzabc string
+ abcde string
+ abcdefghijklmnopqrstuvwxyzabcde string
+ abcdefg string
+}
+
+func main() {
+ _ := Fmt{
+ abcdefghijklmnopqrstuvwx: "foo",
+ abcdefghijklmnopqrstuvwxyza: "foo",
+ abcdefghijklmnopqrstuvwxyzab: "foo",
+ abcdefghijklmnopqrstuvwxyzabc: "foo",
+ abcde: "foo",
+ abcdefghijklmnopqrstuvwxyzabcde: "foo",
+ abcdefg: "foo",
+ abcdefghijklmnopqrstuvwxy: "foo",
+ abcdefghijklmnopqrstuvwxyz: "foo",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #26352.
+
+var _ = map[int]string{
+ 1: "",
+
+ 12345678901234567890123456789: "",
+ 12345678901234567890123456789012345678: "",
+}
+
+func f() {
+ _ = map[int]string{
+ 1: "",
+
+ 12345678901234567: "",
+ 12345678901234567890123456789012345678901: "",
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Examples from issue #26930.
+
+var _ = S{
+ F1: []string{
+ },
+ F2____: []string{},
+}
+
+var _ = S{
+ F1: []string{
+
+
+ },
+ F2____: []string{},
+}
+
+var _ = S{
+ F1____: []string{
+ },
+ F2: []string{},
+}
+
+var _ = S{
+ F1____: []string{
+
+ },
+ F2: []string{},
+}
diff --git a/src/go/printer/testdata/comments.golden b/src/go/printer/testdata/comments.golden
new file mode 100644
index 0000000..1a21fff
--- /dev/null
+++ b/src/go/printer/testdata/comments.golden
@@ -0,0 +1,759 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a package for testing comment placement by go/printer.
+//
+package main
+
+import "fmt" // fmt
+
+const c0 = 0 // zero
+const (
+ c1 = iota // c1
+ c2 // c2
+)
+
+// Alignment of comments in declarations>
+const (
+ _ T = iota // comment
+ _ // comment
+ _ // comment
+ _ = iota + 10
+ _ // comments
+
+ _ = 10 // comment
+ _ T = 20 // comment
+)
+
+const (
+ _____ = iota // foo
+ _ // bar
+ _ = 0 // bal
+ _ // bat
+)
+
+const (
+ _ T = iota // comment
+ _ // comment
+ _ // comment
+ _ = iota + 10
+ _ // comment
+ _ = 10
+ _ = 20 // comment
+ _ T = 0 // comment
+)
+
+// The SZ struct; it is empty.
+type SZ struct{}
+
+// The S0 struct; no field is exported.
+type S0 struct {
+ int
+ x, y, z int // 3 unexported fields
+}
+
+// The S1 struct; some fields are not exported.
+type S1 struct {
+ S0
+ A, B, C float // 3 exported fields
+ D, b, c int // 2 unexported fields
+}
+
+// The S2 struct; all fields are exported.
+type S2 struct {
+ S1
+ A, B, C float // 3 exported fields
+}
+
+// The IZ interface; it is empty.
+type SZ interface{}
+
+// The I0 interface; no method is exported.
+type I0 interface {
+ f(x int) int // unexported method
+}
+
+// The I1 interface; some methods are not exported.
+type I1 interface {
+ I0
+ F(x float) float // exported methods
+ g(x int) int // unexported method
+}
+
+// The I2 interface; all methods are exported.
+type I2 interface {
+ I0
+ F(x float) float // exported method
+ G(x float) float // exported method
+}
+
+// The S3 struct; all comments except for the last one must appear in the export.
+type S3 struct {
+ // lead comment for F1
+ F1 int // line comment for F1
+ // lead comment for F2
+ F2 int // line comment for F2
+ f3 int // f3 is not exported
+}
+
+// This comment group should be separated
+// with a newline from the next comment
+// group.
+
+// This comment should NOT be associated with the next declaration.
+
+var x int // x
+var ()
+
+// This comment SHOULD be associated with f0.
+func f0() {
+ const pi = 3.14 // pi
+ var s1 struct{} /* an empty struct */ /* foo */
+ // a struct constructor
+ // --------------------
+ var s2 struct{} = struct{}{}
+ x := pi
+}
+
+//
+// This comment should be associated with f1, with one blank line before the comment.
+//
+func f1() {
+ f0()
+ /* 1 */
+ // 2
+ /* 3 */
+ /* 4 */
+ f0()
+}
+
+func _() {
+ // this comment should be properly indented
+}
+
+func _(x int) int {
+ if x < 0 { // the tab printed before this comment's // must not affect the remaining lines
+ return -x // this statement should be properly indented
+ }
+ if x < 0 { /* the tab printed before this comment's /* must not affect the remaining lines */
+ return -x // this statement should be properly indented
+ }
+ return x
+}
+
+func typeswitch(x interface{}) {
+ switch v := x.(type) {
+ case bool, int, float:
+ case string:
+ default:
+ }
+
+ switch x.(type) {
+ }
+
+ switch v0, ok := x.(int); v := x.(type) {
+ }
+
+ switch v0, ok := x.(int); x.(type) {
+ case byte: // this comment should be on the same line as the keyword
+ // this comment should be normally indented
+ _ = 0
+ case bool, int, float:
+ // this comment should be indented
+ case string:
+ default:
+ // this comment should be indented
+ }
+ // this comment should not be indented
+}
+
+//
+// Indentation of comments after possibly indented multi-line constructs
+// (test cases for issue 3147).
+//
+
+func _() {
+ s := 1 +
+ 2
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+
+ // should be indented like s
+ _ = 0
+}
+
+// Test case from issue 3147.
+func f() {
+ templateText := "a" + // A
+ "b" + // B
+ "c" // C
+
+ // should be aligned with f()
+ f()
+}
+
+// Modified test case from issue 3147.
+func f() {
+ templateText := "a" + // A
+ "b" + // B
+ "c" // C
+
+ // may not be aligned with f() (source is not aligned)
+ f()
+}
+
+//
+// Test cases for alignment of lines in general comments.
+//
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line */
+}
+
+// Issue 9751.
+func _() {
+ /*a string
+
+ b string*/
+
+ /*A string
+
+
+
+ Z string*/
+
+ /*a string
+
+ b string
+
+ c string*/
+
+ {
+ /*a string
+ b string*/
+
+ /*a string
+
+ b string*/
+
+ /*a string
+
+ b string
+
+ c string*/
+ }
+
+ {
+ /*a string
+ b string*/
+
+ /*a string
+
+ b string*/
+
+ /*a string
+
+ b string
+
+ c string*/
+ }
+
+ /*
+ */
+
+ /*
+
+ */
+
+ /*
+
+ * line
+
+ */
+}
+
+/*
+ * line
+ * of
+ * stars
+ */
+
+/* another line
+ * of
+ * stars */
+
+/* and another line
+ * of
+ * stars */
+
+/* a line of
+ * stars */
+
+/* and another line of
+ * stars */
+
+/* a line of stars
+ */
+
+/* and another line of
+ */
+
+/* a line of stars
+ */
+
+/* and another line of
+ */
+
+/*
+aligned in middle
+here
+ not here
+*/
+
+/*
+blank line in middle:
+
+with no leading spaces on blank line.
+*/
+
+/*
+ aligned in middle
+ here
+ not here
+*/
+
+/*
+ blank line in middle:
+
+ with no leading spaces on blank line.
+*/
+
+func _() {
+ /*
+ * line
+ * of
+ * stars
+ */
+
+ /*
+ aligned in middle
+ here
+ not here
+ */
+
+ /*
+ blank line in middle:
+
+ with no leading spaces on blank line.
+ */
+}
+
+// Some interesting interspersed comments.
+// See below for more common cases.
+func _( /* this */ x /* is */ /* an */ int) {
+}
+
+func _( /* no params - extra blank before and after comment */ ) {}
+func _(a, b int /* params - no extra blank after comment */) {}
+
+func _() { f( /* no args - extra blank before and after comment */ ) }
+func _() { f(a, b /* args - no extra blank after comment */) }
+
+func _() {
+ f( /* no args - extra blank before and after comment */ )
+ f(a, b /* args - no extra blank after comment */)
+}
+
+func ( /* comment1 */ T /* comment2 */) _() {}
+
+func _() { /* "short-ish one-line functions with comments are formatted as multi-line functions */ }
+func _() { x := 0; /* comment */ y = x /* comment */ }
+
+func _() {
+ _ = 0
+ /* closing curly brace should be on new line */
+}
+
+func _() {
+ _ = []int{0, 1 /* don't introduce a newline after this comment - was issue 1365 */}
+}
+
+// Test cases from issue 1542:
+// Comments must not be placed before commas and cause invalid programs.
+func _() {
+ var a = []int{1, 2 /*jasldf*/}
+ _ = a
+}
+
+func _() {
+ var a = []int{1, 2}/*jasldf
+ */
+
+ _ = a
+}
+
+func _() {
+ var a = []int{1, 2}// jasldf
+
+ _ = a
+}
+
+// Test cases from issues 11274, 15137:
+// Semicolon must not be lost when multiple statements are on the same line with a comment.
+func _() {
+ x := 0 /**/
+ y := 1
+}
+
+func _() {
+ f()
+ f()
+ f() /* comment */
+ f()
+ f() /* comment */
+ f()
+ f() /* a */ /* b */
+ f()
+ f() /* a */ /* b */
+ f()
+ f() /* a */ /* b */
+ f()
+}
+
+func _() {
+ f() /* a */ /* b */
+}
+
+// Comments immediately adjacent to punctuation followed by a newline
+// remain after the punctuation (looks better and permits alignment of
+// comments).
+func _() {
+ _ = T{
+ 1, // comment after comma
+ 2, /* comment after comma */
+ 3, // comment after comma
+ }
+ _ = T{
+ 1, // comment after comma
+ 2, /* comment after comma */
+ 3, // comment after comma
+ }
+ _ = T{
+ /* comment before literal */ 1,
+ 2, /* comment before comma - ok to move after comma */
+ 3, /* comment before comma - ok to move after comma */
+ }
+
+ for i = 0; // comment after semicolon
+ i < 9; /* comment after semicolon */
+ i++ { // comment after opening curly brace
+ }
+
+ // TODO(gri) the last comment in this example should be aligned */
+ for i = 0; // comment after semicolon
+ i < 9; /* comment before semicolon - ok to move after semicolon */
+ i++ /* comment before opening curly brace */ {
+ }
+}
+
+// If there is no newline following punctuation, commas move before the punctuation.
+// This way, commas interspersed in lists stay with the respective expression.
+func f(x /* comment */, y int, z int /* comment */, u, v, w int /* comment */) {
+ f(x /* comment */, y)
+ f(x, /* comment */
+ y)
+ f(
+ x, /* comment */
+ )
+}
+
+func g(
+ x int, /* comment */
+) {
+}
+
+type _ struct {
+ a, b /* comment */, c int
+}
+
+type _ struct {
+ a, b /* comment */, c int
+}
+
+func _() {
+ for a /* comment */, b := range x {
+ }
+}
+
+// Print line directives correctly.
+
+// The following is a legal line directive.
+//line foo:1
+func _() {
+ _ = 0
+ // The following is a legal line directive. It must not be indented:
+//line foo:2
+ _ = 1
+
+ // The following is not a legal line directive (it doesn't start in column 1):
+ //line foo:2
+ _ = 2
+
+ // The following is not a legal line directive (missing colon):
+//line foo -3
+ _ = 3
+}
+
+// Line comments with tabs
+func _() {
+ var finput *bufio.Reader // input file
+ var stderr *bufio.Writer
+ var ftable *bufio.Writer // y.go file
+ var foutput *bufio.Writer // y.output file
+
+ var oflag string // -o [y.go] - y.go file
+ var vflag string // -v [y.output] - y.output file
+ var lflag bool // -l - disable line directives
+}
+
+// Trailing white space in comments should be trimmed
+func _() {
+ // This comment has 4 blanks following that should be trimmed:
+ /* Each line of this comment has blanks or tabs following that should be trimmed:
+ line 2:
+ line 3:
+ */
+}
+
+var _ = []T{ /* lone comment */ }
+
+var _ = []T{
+ /* lone comment */
+}
+
+var _ = []T{
+ // lone comments
+ // in composite lit
+}
+
+var _ = [][]T{
+ {
+ // lone comments
+ // in composite lit
+ },
+}
+
+// TODO: gofmt doesn't add these tabs; make it so that these golden
+// tests run the printer in a way that it's exactly like gofmt.
+
+var _ = []T{ // lone comment
+}
+
+var _ = []T{ // lone comments
+ // in composite lit
+}
+
+/* This comment is the last entry in this file. It must be printed and should be followed by a newline */
diff --git a/src/go/printer/testdata/comments.input b/src/go/printer/testdata/comments.input
new file mode 100644
index 0000000..aa428a2
--- /dev/null
+++ b/src/go/printer/testdata/comments.input
@@ -0,0 +1,756 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a package for testing comment placement by go/printer.
+//
+package main
+
+import "fmt" // fmt
+
+const c0 = 0 // zero
+const (
+ c1 = iota // c1
+ c2 // c2
+)
+
+// Alignment of comments in declarations>
+const (
+ _ T = iota // comment
+ _ // comment
+ _ // comment
+ _ = iota+10
+ _ // comments
+
+ _ = 10 // comment
+ _ T = 20 // comment
+)
+
+const (
+ _____ = iota // foo
+ _ // bar
+ _ = 0 // bal
+ _ // bat
+)
+
+const (
+ _ T = iota // comment
+ _ // comment
+ _ // comment
+ _ = iota + 10
+ _ // comment
+ _ = 10
+ _ = 20 // comment
+ _ T = 0 // comment
+)
+
+// The SZ struct; it is empty.
+type SZ struct {}
+
+// The S0 struct; no field is exported.
+type S0 struct {
+ int
+ x, y, z int // 3 unexported fields
+}
+
+// The S1 struct; some fields are not exported.
+type S1 struct {
+ S0
+ A, B, C float // 3 exported fields
+ D, b, c int // 2 unexported fields
+}
+
+// The S2 struct; all fields are exported.
+type S2 struct {
+ S1
+ A, B, C float // 3 exported fields
+}
+
+// The IZ interface; it is empty.
+type SZ interface {}
+
+// The I0 interface; no method is exported.
+type I0 interface {
+ f(x int) int // unexported method
+}
+
+// The I1 interface; some methods are not exported.
+type I1 interface {
+ I0
+ F(x float) float // exported methods
+ g(x int) int // unexported method
+}
+
+// The I2 interface; all methods are exported.
+type I2 interface {
+ I0
+ F(x float) float // exported method
+ G(x float) float // exported method
+}
+
+// The S3 struct; all comments except for the last one must appear in the export.
+type S3 struct {
+ // lead comment for F1
+ F1 int // line comment for F1
+ // lead comment for F2
+ F2 int // line comment for F2
+ f3 int // f3 is not exported
+}
+
+// This comment group should be separated
+// with a newline from the next comment
+// group.
+
+// This comment should NOT be associated with the next declaration.
+
+var x int // x
+var ()
+
+
+// This comment SHOULD be associated with f0.
+func f0() {
+ const pi = 3.14 // pi
+ var s1 struct {} /* an empty struct */ /* foo */
+ // a struct constructor
+ // --------------------
+ var s2 struct {} = struct {}{}
+ x := pi
+}
+//
+// This comment should be associated with f1, with one blank line before the comment.
+//
+func f1() {
+ f0()
+ /* 1 */
+ // 2
+ /* 3 */
+ /* 4 */
+ f0()
+}
+
+
+func _() {
+// this comment should be properly indented
+}
+
+
+func _(x int) int {
+ if x < 0 { // the tab printed before this comment's // must not affect the remaining lines
+ return -x // this statement should be properly indented
+ }
+ if x < 0 { /* the tab printed before this comment's /* must not affect the remaining lines */
+ return -x // this statement should be properly indented
+ }
+ return x
+}
+
+
+func typeswitch(x interface{}) {
+ switch v := x.(type) {
+ case bool, int, float:
+ case string:
+ default:
+ }
+
+ switch x.(type) {
+ }
+
+ switch v0, ok := x.(int); v := x.(type) {
+ }
+
+ switch v0, ok := x.(int); x.(type) {
+ case byte: // this comment should be on the same line as the keyword
+ // this comment should be normally indented
+ _ = 0
+ case bool, int, float:
+ // this comment should be indented
+ case string:
+ default:
+ // this comment should be indented
+ }
+ // this comment should not be indented
+}
+
+//
+// Indentation of comments after possibly indented multi-line constructs
+// (test cases for issue 3147).
+//
+
+func _() {
+ s := 1 +
+ 2
+// should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+
+// should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+
+ // should be indented like s
+}
+
+func _() {
+ s := 1 +
+ 2 // comment
+
+ // should be indented like s
+ _ = 0
+}
+
+func _() {
+ s := 1 +
+ 2
+
+ // should be indented like s
+ _ = 0
+}
+
+// Test case from issue 3147.
+func f() {
+ templateText := "a" + // A
+ "b" + // B
+ "c" // C
+
+ // should be aligned with f()
+ f()
+}
+
+// Modified test case from issue 3147.
+func f() {
+ templateText := "a" + // A
+ "b" + // B
+ "c" // C
+
+ // may not be aligned with f() (source is not aligned)
+ f()
+}
+
+//
+// Test cases for alignment of lines in general comments.
+//
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ aligned line */
+}
+
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /* freestanding comment
+ aligned line */
+}
+
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line
+ */
+}
+
+func _() {
+ /*
+ freestanding comment
+ aligned line */
+}
+
+// Issue 9751.
+func _() {
+ /*a string
+
+ b string*/
+
+ /*A string
+
+
+
+ Z string*/
+
+ /*a string
+
+ b string
+
+ c string*/
+
+ {
+ /*a string
+b string*/
+
+ /*a string
+
+b string*/
+
+ /*a string
+
+b string
+
+c string*/
+ }
+
+ {
+ /*a string
+ b string*/
+
+ /*a string
+
+ b string*/
+
+ /*a string
+
+ b string
+
+ c string*/
+ }
+
+ /*
+ */
+
+ /*
+
+ */
+
+ /*
+
+ * line
+
+ */
+}
+
+/*
+ * line
+ * of
+ * stars
+ */
+
+/* another line
+ * of
+ * stars */
+
+/* and another line
+ * of
+ * stars */
+
+/* a line of
+ * stars */
+
+/* and another line of
+ * stars */
+
+/* a line of stars
+*/
+
+/* and another line of
+*/
+
+/* a line of stars
+ */
+
+/* and another line of
+ */
+
+/*
+aligned in middle
+here
+ not here
+*/
+
+/*
+blank line in middle:
+
+with no leading spaces on blank line.
+*/
+
+/*
+ aligned in middle
+ here
+ not here
+*/
+
+/*
+ blank line in middle:
+
+ with no leading spaces on blank line.
+*/
+
+func _() {
+ /*
+ * line
+ * of
+ * stars
+ */
+
+ /*
+ aligned in middle
+ here
+ not here
+ */
+
+ /*
+ blank line in middle:
+
+ with no leading spaces on blank line.
+*/
+}
+
+
+// Some interesting interspersed comments.
+// See below for more common cases.
+func _(/* this */x/* is *//* an */ int) {
+}
+
+func _(/* no params - extra blank before and after comment */) {}
+func _(a, b int /* params - no extra blank after comment */) {}
+
+func _() { f(/* no args - extra blank before and after comment */) }
+func _() { f(a, b /* args - no extra blank after comment */) }
+
+func _() {
+ f(/* no args - extra blank before and after comment */)
+ f(a, b /* args - no extra blank after comment */)
+}
+
+func (/* comment1 */ T /* comment2 */) _() {}
+
+func _() { /* "short-ish one-line functions with comments are formatted as multi-line functions */ }
+func _() { x := 0; /* comment */ y = x /* comment */ }
+
+func _() {
+ _ = 0
+ /* closing curly brace should be on new line */ }
+
+func _() {
+ _ = []int{0, 1 /* don't introduce a newline after this comment - was issue 1365 */}
+}
+
+// Test cases from issue 1542:
+// Comments must not be placed before commas and cause invalid programs.
+func _() {
+ var a = []int{1, 2, /*jasldf*/
+ }
+ _ = a
+}
+
+func _() {
+ var a = []int{1, 2, /*jasldf
+ */
+ }
+ _ = a
+}
+
+func _() {
+ var a = []int{1, 2, // jasldf
+ }
+ _ = a
+}
+
+// Test cases from issues 11274, 15137:
+// Semicolon must not be lost when multiple statements are on the same line with a comment.
+func _() {
+ x := 0 /**/; y := 1
+}
+
+func _() {
+ f(); f()
+ f(); /* comment */ f()
+ f() /* comment */; f()
+ f(); /* a */ /* b */ f()
+ f() /* a */ /* b */; f()
+ f() /* a */; /* b */ f()
+}
+
+func _() {
+ f() /* a */ /* b */ }
+
+// Comments immediately adjacent to punctuation followed by a newline
+// remain after the punctuation (looks better and permits alignment of
+// comments).
+func _() {
+ _ = T{
+ 1, // comment after comma
+ 2, /* comment after comma */
+ 3 , // comment after comma
+ }
+ _ = T{
+ 1 ,// comment after comma
+ 2 ,/* comment after comma */
+ 3,// comment after comma
+ }
+ _ = T{
+ /* comment before literal */1,
+ 2/* comment before comma - ok to move after comma */,
+ 3 /* comment before comma - ok to move after comma */ ,
+ }
+
+ for
+ i=0;// comment after semicolon
+ i<9;/* comment after semicolon */
+ i++{// comment after opening curly brace
+ }
+
+ // TODO(gri) the last comment in this example should be aligned */
+ for
+ i=0;// comment after semicolon
+ i<9/* comment before semicolon - ok to move after semicolon */;
+ i++ /* comment before opening curly brace */ {
+ }
+}
+
+// If there is no newline following punctuation, commas move before the punctuation.
+// This way, commas interspersed in lists stay with the respective expression.
+func f(x/* comment */, y int, z int /* comment */, u, v, w int /* comment */) {
+ f(x /* comment */, y)
+ f(x /* comment */,
+ y)
+ f(
+ x /* comment */,
+ )
+}
+
+func g(
+ x int /* comment */,
+) {}
+
+type _ struct {
+ a, b /* comment */, c int
+}
+
+type _ struct { a, b /* comment */, c int }
+
+func _() {
+ for a /* comment */, b := range x {
+ }
+}
+
+// Print line directives correctly.
+
+// The following is a legal line directive.
+//line foo:1
+func _() {
+ _ = 0
+// The following is a legal line directive. It must not be indented:
+//line foo:2
+ _ = 1
+
+// The following is not a legal line directive (it doesn't start in column 1):
+ //line foo:2
+ _ = 2
+
+// The following is not a legal line directive (missing colon):
+//line foo -3
+ _ = 3
+}
+
+// Line comments with tabs
+func _() {
+var finput *bufio.Reader // input file
+var stderr *bufio.Writer
+var ftable *bufio.Writer // y.go file
+var foutput *bufio.Writer // y.output file
+
+var oflag string // -o [y.go] - y.go file
+var vflag string // -v [y.output] - y.output file
+var lflag bool // -l - disable line directives
+}
+
+// Trailing white space in comments should be trimmed
+func _() {
+// This comment has 4 blanks following that should be trimmed:
+/* Each line of this comment has blanks or tabs following that should be trimmed:
+ line 2:
+ line 3:
+*/
+}
+
+var _ = []T{/* lone comment */}
+
+var _ = []T{
+/* lone comment */
+}
+
+var _ = []T{
+// lone comments
+// in composite lit
+}
+
+var _ = [][]T{
+ {
+ // lone comments
+ // in composite lit
+ },
+}
+
+// TODO: gofmt doesn't add these tabs; make it so that these golden
+// tests run the printer in a way that it's exactly like gofmt.
+
+var _ = []T{// lone comment
+}
+
+var _ = []T{// lone comments
+// in composite lit
+}
+
+/* This comment is the last entry in this file. It must be printed and should be followed by a newline */
diff --git a/src/go/printer/testdata/comments.x b/src/go/printer/testdata/comments.x
new file mode 100644
index 0000000..ae77292
--- /dev/null
+++ b/src/go/printer/testdata/comments.x
@@ -0,0 +1,56 @@
+// This is a package for testing comment placement by go/printer.
+//
+package main
+
+// The SZ struct; it is empty.
+type SZ struct{}
+
+// The S0 struct; no field is exported.
+type S0 struct {
+ // contains filtered or unexported fields
+}
+
+// The S1 struct; some fields are not exported.
+type S1 struct {
+ S0
+ A, B, C float // 3 exported fields
+ D int // 2 unexported fields
+ // contains filtered or unexported fields
+}
+
+// The S2 struct; all fields are exported.
+type S2 struct {
+ S1
+ A, B, C float // 3 exported fields
+}
+
+// The IZ interface; it is empty.
+type SZ interface{}
+
+// The I0 interface; no method is exported.
+type I0 interface {
+ // contains filtered or unexported methods
+}
+
+// The I1 interface; some methods are not exported.
+type I1 interface {
+ I0
+ F(x float) float // exported methods
+ // contains filtered or unexported methods
+}
+
+// The I2 interface; all methods are exported.
+type I2 interface {
+ I0
+ F(x float) float // exported method
+ G(x float) float // exported method
+}
+
+// The S3 struct; all comments except for the last one must appear in the export.
+type S3 struct {
+ // lead comment for F1
+ F1 int // line comment for F1
+ // lead comment for F2
+ F2 int // line comment for F2
+ // contains filtered or unexported fields
+}
diff --git a/src/go/printer/testdata/comments2.golden b/src/go/printer/testdata/comments2.golden
new file mode 100644
index 0000000..8b3a94d
--- /dev/null
+++ b/src/go/printer/testdata/comments2.golden
@@ -0,0 +1,164 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a package for testing comment placement by go/printer.
+//
+package main
+
+// Test cases for idempotent comment formatting (was issue 1835).
+/*
+c1a
+*/
+/*
+ c1b
+*/
+/* foo
+c1c
+*/
+/* foo
+ c1d
+*/
+/*
+c1e
+foo */
+/*
+ c1f
+ foo */
+
+func f() {
+ /*
+ c2a
+ */
+ /*
+ c2b
+ */
+ /* foo
+ c2c
+ */
+ /* foo
+ c2d
+ */
+ /*
+ c2e
+ foo */
+ /*
+ c2f
+ foo */
+}
+
+func g() {
+ /*
+ c3a
+ */
+ /*
+ c3b
+ */
+ /* foo
+ c3c
+ */
+ /* foo
+ c3d
+ */
+ /*
+ c3e
+ foo */
+ /*
+ c3f
+ foo */
+}
+
+// Test case taken literally from issue 1835.
+func main() {
+ /*
+ prints test 5 times
+ */
+ for i := 0; i < 5; i++ {
+ println("test")
+ }
+}
+
+func issue5623() {
+L:
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx /* comment */
+
+ _ = yyyyyyyyyyyyyyyy /* comment - should be aligned */
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+
+LLLLLLL:
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+
+LL:
+LLLLL:
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx /* comment */
+ _ = yyyyyyyyyyyyyyyy /* comment - should be aligned */
+
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+
+ // test case from issue
+label:
+ mask := uint64(1)<<c - 1 // Allocation mask
+ used := atomic.LoadUint64(&h.used) // Current allocations
+}
+
+// Test cases for issue 18782
+var _ = [][]int{
+ /* a, b, c, d, e */
+ /* a */ {0, 0, 0, 0, 0},
+ /* b */ {0, 5, 4, 4, 4},
+ /* c */ {0, 4, 5, 4, 4},
+ /* d */ {0, 4, 4, 5, 4},
+ /* e */ {0, 4, 4, 4, 5},
+}
+
+var _ = T{ /* a */ 0}
+
+var _ = T{ /* a */ /* b */ 0}
+
+var _ = T{ /* a */ /* b */
+ /* c */ 0,
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */
+ /* d */ 0,
+}
+
+var _ = T{
+ /* a */
+ /* b */ 0,
+}
+
+var _ = T{ /* a */ {}}
+
+var _ = T{ /* a */ /* b */ {}}
+
+var _ = T{ /* a */ /* b */
+ /* c */ {},
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */
+ /* d */ {},
+}
+
+var _ = T{
+ /* a */
+ /* b */ {},
+}
+
+var _ = []T{
+ func() {
+ var _ = [][]int{
+ /* a, b, c, d, e */
+ /* a */ {0, 0, 0, 0, 0},
+ /* b */ {0, 5, 4, 4, 4},
+ /* c */ {0, 4, 5, 4, 4},
+ /* d */ {0, 4, 4, 5, 4},
+ /* e */ {0, 4, 4, 4, 5},
+ }
+ },
+}
diff --git a/src/go/printer/testdata/comments2.input b/src/go/printer/testdata/comments2.input
new file mode 100644
index 0000000..8d38c41
--- /dev/null
+++ b/src/go/printer/testdata/comments2.input
@@ -0,0 +1,168 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a package for testing comment placement by go/printer.
+//
+package main
+
+// Test cases for idempotent comment formatting (was issue 1835).
+/*
+c1a
+*/
+/*
+ c1b
+*/
+/* foo
+c1c
+*/
+/* foo
+ c1d
+*/
+/*
+c1e
+foo */
+/*
+ c1f
+ foo */
+
+func f() {
+/*
+c2a
+*/
+/*
+ c2b
+*/
+/* foo
+c2c
+*/
+/* foo
+ c2d
+*/
+/*
+c2e
+foo */
+/*
+ c2f
+ foo */
+}
+
+func g() {
+/*
+c3a
+*/
+/*
+ c3b
+*/
+/* foo
+c3c
+*/
+/* foo
+ c3d
+*/
+/*
+c3e
+foo */
+/*
+ c3f
+ foo */
+}
+
+// Test case taken literally from issue 1835.
+func main() {
+/*
+prints test 5 times
+*/
+ for i := 0; i < 5; i++ {
+ println("test")
+ }
+}
+
+func issue5623() {
+L:
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx /* comment */
+
+ _ = yyyyyyyyyyyyyyyy /* comment - should be aligned */
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+
+LLLLLLL:
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+
+LL:
+LLLLL:
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx /* comment */
+ _ = yyyyyyyyyyyyyyyy /* comment - should be aligned */
+
+ _ = xxxxxxxxxxxxxxxxxxxxxxxxxxxx // comment
+ _ = yyyyyyyyyyyyyyyy // comment - should be aligned
+
+// test case from issue
+label:
+ mask := uint64(1)<<c - 1 // Allocation mask
+ used := atomic.LoadUint64(&h.used) // Current allocations
+}
+
+// Test cases for issue 18782
+var _ = [][]int{
+ /* a, b, c, d, e */
+ /* a */ {0, 0, 0, 0, 0},
+ /* b */ {0, 5, 4, 4, 4},
+ /* c */ {0, 4, 5, 4, 4},
+ /* d */ {0, 4, 4, 5, 4},
+ /* e */ {0, 4, 4, 4, 5},
+}
+
+var _ = T{ /* a */ 0,
+}
+
+var _ = T{ /* a */ /* b */ 0,
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */ 0,
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */
+ /* d */ 0,
+}
+
+var _ = T{
+ /* a */
+ /* b */ 0,
+}
+
+var _ = T{ /* a */ {},
+}
+
+var _ = T{ /* a */ /* b */ {},
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */ {},
+}
+
+var _ = T{ /* a */ /* b */
+ /* c */
+ /* d */ {},
+}
+
+var _ = T{
+ /* a */
+ /* b */ {},
+}
+
+var _ = []T{
+ func() {
+ var _ = [][]int{
+ /* a, b, c, d, e */
+ /* a */ {0, 0, 0, 0, 0},
+ /* b */ {0, 5, 4, 4, 4},
+ /* c */ {0, 4, 5, 4, 4},
+ /* d */ {0, 4, 4, 5, 4},
+ /* e */ {0, 4, 4, 4, 5},
+ }
+ },
+}
diff --git a/src/go/printer/testdata/complit.input b/src/go/printer/testdata/complit.input
new file mode 100644
index 0000000..82806a4
--- /dev/null
+++ b/src/go/printer/testdata/complit.input
@@ -0,0 +1,65 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package complit
+
+var (
+ // Multi-line declarations
+ V1 = T{
+ F1: "hello",
+ f2: 1,
+ }
+ V2 = T{
+ f2: 1,
+ F1: "hello",
+ }
+ V3 = T{
+ F1: "hello",
+ F2: T2{
+ A: "world",
+ b: "hidden",
+ },
+ f3: T2{
+ A: "world",
+ },
+ }
+ V4 = T{
+ f2: 1,
+ }
+
+ // Single-line declarations
+ V5 = T{F1: "hello", f2: 1}
+ V6 = T{f2: 1, F1: "hello"}
+ V7 = T{f2: 1}
+
+ // Mixed-mode declarations
+ V8 = T{
+ F1: "hello", f2: 1,
+ F3: "world",
+ f4: 2}
+ V9 = T{
+ f2: 1, F1: "hello",}
+ V10 = T{
+ F1: "hello", f2: 1,
+ f3: 2,
+ F4: "world", f5: 3,
+ }
+
+ // Other miscellaneous declarations
+ V11 = T{
+ t{
+ A: "world",
+ b: "hidden",
+ },
+ f2: t{
+ A: "world",
+ b: "hidden",
+ },
+ }
+ V12 = T{
+ F1: make(chan int),
+ f2: []int{},
+ F3: make(map[int]string), f4: 1,
+ }
+) \ No newline at end of file
diff --git a/src/go/printer/testdata/complit.x b/src/go/printer/testdata/complit.x
new file mode 100644
index 0000000..458ac61
--- /dev/null
+++ b/src/go/printer/testdata/complit.x
@@ -0,0 +1,62 @@
+package complit
+
+var (
+ // Multi-line declarations
+ V1 = T{
+ F1: "hello",
+ // contains filtered or unexported fields
+ }
+ V2 = T{
+
+ F1: "hello",
+ // contains filtered or unexported fields
+ }
+ V3 = T{
+ F1: "hello",
+ F2: T2{
+ A: "world",
+ // contains filtered or unexported fields
+ },
+ // contains filtered or unexported fields
+ }
+ V4 = T{
+ // contains filtered or unexported fields
+ }
+
+ // Single-line declarations
+ V5 = T{F1: "hello", /* contains filtered or unexported fields */}
+ V6 = T{F1: "hello", /* contains filtered or unexported fields */}
+ V7 = T{/* contains filtered or unexported fields */}
+
+ // Mixed-mode declarations
+ V8 = T{
+ F1: "hello",
+ F3: "world",
+ // contains filtered or unexported fields
+ }
+ V9 = T{
+ F1: "hello",
+ // contains filtered or unexported fields
+ }
+ V10 = T{
+ F1: "hello",
+
+ F4: "world",
+ // contains filtered or unexported fields
+ }
+
+ // Other miscellaneous declarations
+ V11 = T{
+ t{
+ A: "world",
+ // contains filtered or unexported fields
+ },
+ // contains filtered or unexported fields
+ }
+ V12 = T{
+ F1: make(chan int),
+
+ F3: make(map[int]string),
+ // contains filtered or unexported fields
+ }
+)
diff --git a/src/go/printer/testdata/declarations.golden b/src/go/printer/testdata/declarations.golden
new file mode 100644
index 0000000..fe0f783
--- /dev/null
+++ b/src/go/printer/testdata/declarations.golden
@@ -0,0 +1,1008 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imports
+
+import "io"
+
+import (
+ _ "io"
+)
+
+import _ "io"
+
+import (
+ "io"
+ "io"
+ "io"
+)
+
+import (
+ "io"
+ aLongRename "io"
+
+ b "io"
+)
+
+import (
+ "unrenamed"
+ renamed "renameMe"
+ . "io"
+ _ "io"
+ "io"
+ . "os"
+)
+
+// no newlines between consecutive single imports, but
+// respect extra line breaks in the source (at most one empty line)
+import _ "io"
+import _ "io"
+import _ "io"
+
+import _ "os"
+import _ "os"
+import _ "os"
+
+import _ "fmt"
+import _ "fmt"
+import _ "fmt"
+
+import "foo" // a comment
+import "bar" // a comment
+
+import (
+ _ "foo"
+ // a comment
+ "bar"
+ "foo" // a comment
+ "bar" // a comment
+)
+
+// comments + renames
+import (
+ "unrenamed" // a comment
+ renamed "renameMe"
+ . "io" /* a comment */
+ _ "io/ioutil" // a comment
+ "io" // testing alignment
+ . "os"
+ // a comment
+)
+
+// a case that caused problems in the past (comment placement)
+import (
+ . "fmt"
+ "io"
+ "malloc" // for the malloc count test only
+ "math"
+ "strings"
+ "testing"
+)
+
+// more import examples
+import (
+ "xxx"
+ "much_longer_name" // comment
+ "short_name" // comment
+)
+
+import (
+ _ "xxx"
+ "much_longer_name" // comment
+)
+
+import (
+ mymath "math"
+ "/foo/bar/long_package_path" // a comment
+)
+
+import (
+ "package_a" // comment
+ "package_b"
+ my_better_c "package_c" // comment
+ "package_d" // comment
+ my_e "package_e" // comment
+
+ "package_a" // comment
+ "package_bb"
+ "package_ccc" // comment
+ "package_dddd" // comment
+)
+
+// print import paths as double-quoted strings
+// (we would like more test cases but the go/parser
+// already excludes most incorrect paths, and we don't
+// bother setting up test-ASTs manually)
+import (
+ "fmt"
+ "math"
+)
+
+// at least one empty line between declarations of different kind
+import _ "io"
+
+var _ int
+
+// at least one empty line between declarations of the same kind
+// if there is associated documentation (was issue 2570)
+type T1 struct{}
+
+// T2 comment
+type T2 struct {
+} // should be a two-line struct
+
+// T3 comment
+type T2 struct {
+} // should be a two-line struct
+
+// printing of constant literals
+const (
+ _ = "foobar"
+ _ = "a۰۱۸"
+ _ = "foo६४"
+ _ = "bar9876"
+ _ = 0
+ _ = 1
+ _ = 123456789012345678890
+ _ = 01234567
+ _ = 0xcafebabe
+ _ = 0.
+ _ = .0
+ _ = 3.14159265
+ _ = 1e0
+ _ = 1e+100
+ _ = 1e-100
+ _ = 2.71828e-1000
+ _ = 0i
+ _ = 1i
+ _ = 012345678901234567889i
+ _ = 123456789012345678890i
+ _ = 0.i
+ _ = .0i
+ _ = 3.14159265i
+ _ = 1e0i
+ _ = 1e+100i
+ _ = 1e-100i
+ _ = 2.71828e-1000i
+ _ = 'a'
+ _ = '\000'
+ _ = '\xFF'
+ _ = '\uff16'
+ _ = '\U0000ff16'
+ _ = `foobar`
+ _ = `foo
+---
+---
+bar`
+)
+
+func _() {
+ type _ int
+ type _ *int
+ type _ []int
+ type _ map[string]int
+ type _ chan int
+ type _ func() int
+
+ var _ int
+ var _ *int
+ var _ []int
+ var _ map[string]int
+ var _ chan int
+ var _ func() int
+
+ type _ struct{}
+ type _ *struct{}
+ type _ []struct{}
+ type _ map[string]struct{}
+ type _ chan struct{}
+ type _ func() struct{}
+
+ type _ interface{}
+ type _ *interface{}
+ type _ []interface{}
+ type _ map[string]interface{}
+ type _ chan interface{}
+ type _ func() interface{}
+
+ var _ struct{}
+ var _ *struct{}
+ var _ []struct{}
+ var _ map[string]struct{}
+ var _ chan struct{}
+ var _ func() struct{}
+
+ var _ interface{}
+ var _ *interface{}
+ var _ []interface{}
+ var _ map[string]interface{}
+ var _ chan interface{}
+ var _ func() interface{}
+}
+
+// don't lose blank lines in grouped declarations
+const (
+ _ int = 0
+ _ float = 1
+
+ _ string = "foo"
+
+ _ = iota
+ _
+
+ // a comment
+ _
+
+ _
+)
+
+type (
+ _ int
+ _ struct{}
+
+ _ interface{}
+
+ // a comment
+ _ map[string]int
+)
+
+var (
+ _ int = 0
+ _ float = 1
+
+ _ string = "foo"
+
+ _ bool
+
+ // a comment
+ _ bool
+)
+
+// don't lose blank lines in this struct
+type _ struct {
+ String struct {
+ Str, Len int
+ }
+ Slice struct {
+ Array, Len, Cap int
+ }
+ Eface struct {
+ Typ, Ptr int
+ }
+
+ UncommonType struct {
+ Name, PkgPath int
+ }
+ CommonType struct {
+ Size, Hash, Alg, Align, FieldAlign, String, UncommonType int
+ }
+ Type struct {
+ Typ, Ptr int
+ }
+ StructField struct {
+ Name, PkgPath, Typ, Tag, Offset int
+ }
+ StructType struct {
+ Fields int
+ }
+ PtrType struct {
+ Elem int
+ }
+ SliceType struct {
+ Elem int
+ }
+ ArrayType struct {
+ Elem, Len int
+ }
+
+ Stktop struct {
+ Stackguard, Stackbase, Gobuf int
+ }
+ Gobuf struct {
+ Sp, Pc, G int
+ }
+ G struct {
+ Stackbase, Sched, Status, Alllink int
+ }
+}
+
+// no blank lines in empty structs and interfaces, but leave 1- or 2-line layout alone
+type _ struct{}
+type _ struct {
+}
+
+type _ interface{}
+type _ interface {
+}
+
+// no tabs for single or ungrouped decls
+func _() {
+ const xxxxxx = 0
+ type x int
+ var xxx int
+ var yyyy float = 3.14
+ var zzzzz = "bar"
+
+ const (
+ xxxxxx = 0
+ )
+ type (
+ x int
+ )
+ var (
+ xxx int
+ )
+ var (
+ yyyy float = 3.14
+ )
+ var (
+ zzzzz = "bar"
+ )
+}
+
+// tabs for multiple or grouped decls
+func _() {
+ // no entry has a type
+ const (
+ zzzzzz = 1
+ z = 2
+ zzz = 3
+ )
+ // some entries have a type
+ const (
+ xxxxxx = 1
+ x = 2
+ xxx = 3
+ yyyyyyyy float = iota
+ yyyy = "bar"
+ yyy
+ yy = 2
+ )
+}
+
+func _() {
+ // no entry has a type
+ var (
+ zzzzzz = 1
+ z = 2
+ zzz = 3
+ )
+ // no entry has a value
+ var (
+ _ int
+ _ float
+ _ string
+
+ _ int // comment
+ _ float // comment
+ _ string // comment
+ )
+ // some entries have a type
+ var (
+ xxxxxx int
+ x float
+ xxx string
+ yyyyyyyy int = 1234
+ y float = 3.14
+ yyyy = "bar"
+ yyy string = "foo"
+ )
+ // mixed entries - all comments should be aligned
+ var (
+ a, b, c int
+ x = 10
+ d int // comment
+ y = 20 // comment
+ f, ff, fff, ffff int = 0, 1, 2, 3 // comment
+ )
+ // respect original line breaks
+ var _ = []T{
+ T{0x20, "Telugu"},
+ }
+ var _ = []T{
+ // respect original line breaks
+ T{0x20, "Telugu"},
+ }
+}
+
+// use the formatted output rather than the input to decide when to align
+// (was issue 4505)
+const (
+ short = 2 * (1 + 2)
+ aMuchLongerName = 3
+)
+
+var (
+ short = X{}
+ aMuchLongerName = X{}
+
+ x1 = X{} // foo
+ x2 = X{} // foo
+)
+
+func _() {
+ type (
+ xxxxxx int
+ x float
+ xxx string
+ xxxxx []x
+ xx struct{}
+ xxxxxxx struct {
+ _, _ int
+ _ float
+ }
+ xxxx chan<- string
+ )
+}
+
+// alignment of "=" in consecutive lines (extended example from issue 1414)
+const (
+ umax uint = ^uint(0) // maximum value for a uint
+ bpu = 1 << (5 + umax>>63) // bits per uint
+ foo
+ bar = -1
+)
+
+// typical enum
+const (
+ a MyType = iota
+ abcd
+ b
+ c
+ def
+)
+
+// excerpt from godoc.go
+var (
+ goroot = flag.String("goroot", runtime.GOROOT(), "Go root directory")
+ testDir = flag.String("testdir", "", "Go root subdirectory - for testing only (faster startups)")
+ pkgPath = flag.String("path", "", "additional package directories (colon-separated)")
+ filter = flag.String("filter", "", "filter file containing permitted package directory paths")
+ filterMin = flag.Int("filter_minutes", 0, "filter file update interval in minutes; disabled if <= 0")
+ filterDelay delayTime // actual filter update interval in minutes; usually filterDelay == filterMin, but filterDelay may back off exponentially
+)
+
+// formatting of structs
+type _ struct{}
+
+type _ struct { /* this comment should be visible */
+}
+
+type _ struct {
+ // this comment should be visible and properly indented
+}
+
+type _ struct { // this comment must not change indentation
+ f int
+ f, ff, fff, ffff int
+}
+
+type _ struct {
+ string
+}
+
+type _ struct {
+ string // comment
+}
+
+type _ struct {
+ string "tag"
+}
+
+type _ struct {
+ string "tag" // comment
+}
+
+type _ struct {
+ f int
+}
+
+type _ struct {
+ f int // comment
+}
+
+type _ struct {
+ f int "tag"
+}
+
+type _ struct {
+ f int "tag" // comment
+}
+
+type _ struct {
+ bool
+ a, b, c int
+ int "tag"
+ ES // comment
+ float "tag" // comment
+ f int // comment
+ f, ff, fff, ffff int // comment
+ g float "tag"
+ h float "tag" // comment
+}
+
+type _ struct {
+ a, b,
+ c, d int // this line should be indented
+ u, v, w, x float // this line should be indented
+ p, q,
+ r, s float // this line should be indented
+}
+
+// difficult cases
+type _ struct {
+ bool // comment
+ text []byte // comment
+}
+
+// formatting of interfaces
+type EI interface{}
+
+type _ interface {
+ EI
+}
+
+type _ interface {
+ f()
+ fffff()
+}
+
+type _ interface {
+ EI
+ f()
+ fffffg()
+}
+
+type _ interface { // this comment must not change indentation
+ EI // here's a comment
+ f() // no blank between identifier and ()
+ fffff() // no blank between identifier and ()
+ gggggggggggg(x, y, z int) // hurray
+}
+
+// formatting of variable declarations
+func _() {
+ type day struct {
+ n int
+ short, long string
+ }
+ var (
+ Sunday = day{0, "SUN", "Sunday"}
+ Monday = day{1, "MON", "Monday"}
+ Tuesday = day{2, "TUE", "Tuesday"}
+ Wednesday = day{3, "WED", "Wednesday"}
+ Thursday = day{4, "THU", "Thursday"}
+ Friday = day{5, "FRI", "Friday"}
+ Saturday = day{6, "SAT", "Saturday"}
+ )
+}
+
+// formatting of multi-line variable declarations
+var a1, b1, c1 int // all on one line
+
+var a2, b2,
+ c2 int // this line should be indented
+
+var (
+ a3, b3,
+ c3, d3 int // this line should be indented
+ a4, b4, c4 int // this line should be indented
+)
+
+// Test case from issue 3304: multi-line declarations must end
+// a formatting section and not influence indentation of the
+// next line.
+var (
+ minRefreshTimeSec = flag.Int64("min_refresh_time_sec", 604800,
+ "minimum time window between two refreshes for a given user.")
+ x = flag.Int64("refresh_user_rollout_percent", 100,
+ "temporary flag to ramp up the refresh user rpc")
+ aVeryLongVariableName = stats.GetVarInt("refresh-user-count")
+)
+
+func _() {
+ var privateKey2 = &Block{Type: "RSA PRIVATE KEY",
+ Headers: map[string]string{},
+ Bytes: []uint8{0x30, 0x82, 0x1, 0x3a, 0x2, 0x1, 0x0, 0x2,
+ 0x41, 0x0, 0xb2, 0x99, 0xf, 0x49, 0xc4, 0x7d, 0xfa, 0x8c,
+ 0xd4, 0x0, 0xae, 0x6a, 0x4d, 0x1b, 0x8a, 0x3b, 0x6a, 0x13,
+ 0x64, 0x2b, 0x23, 0xf2, 0x8b, 0x0, 0x3b, 0xfb, 0x97, 0x79,
+ },
+ }
+}
+
+func _() {
+ var Universe = Scope{
+ Names: map[string]*Ident{
+ // basic types
+ "bool": nil,
+ "byte": nil,
+ "int8": nil,
+ "int16": nil,
+ "int32": nil,
+ "int64": nil,
+ "uint8": nil,
+ "uint16": nil,
+ "uint32": nil,
+ "uint64": nil,
+ "float32": nil,
+ "float64": nil,
+ "string": nil,
+
+ // convenience types
+ "int": nil,
+ "uint": nil,
+ "uintptr": nil,
+ "float": nil,
+
+ // constants
+ "false": nil,
+ "true": nil,
+ "iota": nil,
+ "nil": nil,
+
+ // functions
+ "cap": nil,
+ "len": nil,
+ "new": nil,
+ "make": nil,
+ "panic": nil,
+ "panicln": nil,
+ "print": nil,
+ "println": nil,
+ },
+ }
+}
+
+// alignment of map composite entries
+var _ = map[int]int{
+ // small key sizes: always align even if size ratios are large
+ a: a,
+ abcdefghabcdefgh: a,
+ ab: a,
+ abc: a,
+ abcdefgabcdefg: a,
+ abcd: a,
+ abcde: a,
+ abcdef: a,
+
+ // mixed key sizes: align when key sizes change within accepted ratio
+ abcdefgh: a,
+ abcdefghabcdefg: a,
+ abcdefghij: a,
+ abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij: a, // outlier - do not align with previous line
+ abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij: a, // align with previous line
+
+ ab: a, // do not align with previous line
+ abcde: a, // align with previous line
+}
+
+// alignment of map composite entries: test cases from issue 3965
+// aligned
+var _ = T1{
+ a: x,
+ b: y,
+ cccccccccccccccccccc: z,
+}
+
+// not aligned
+var _ = T2{
+ a: x,
+ b: y,
+ ccccccccccccccccccccc: z,
+}
+
+// aligned
+var _ = T3{
+ aaaaaaaaaaaaaaaaaaaa: x,
+ b: y,
+ c: z,
+}
+
+// not aligned
+var _ = T4{
+ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: x,
+ b: y,
+ c: z,
+}
+
+// no alignment of map composite entries if they are not the first entry on a line
+var _ = T{0: 0} // not aligned
+var _ = T{0: 0, // not aligned
+ 1: 1, // aligned
+ 22: 22, // aligned
+ 333: 333, 1234: 12, 12345: 0, // first on line aligned
+}
+
+// test cases form issue 8685
+// not aligned
+var _ = map[int]string{1: "spring", 2: "summer",
+ 3: "autumn", 4: "winter"}
+
+// not aligned
+var _ = map[string]string{"a": "spring", "b": "summer",
+ "c": "autumn", "d": "winter"}
+
+// aligned
+var _ = map[string]string{"a": "spring",
+ "b": "summer",
+ "c": "autumn",
+ "d": "winter"}
+
+func _() {
+ var _ = T{
+ a, // must introduce trailing comma
+ }
+}
+
+// formatting of function results
+func _() func() {}
+func _() func(int) { return nil }
+func _() func(int) int { return nil }
+func _() func(int) func(int) func() { return nil }
+
+// formatting of consecutive single-line functions
+func _() {}
+func _() {}
+func _() {}
+
+func _() {} // an empty line before this function
+func _() {}
+func _() {}
+
+func _() { f(1, 2, 3) }
+func _(x int) int { y := x; return y + 1 }
+func _() int { type T struct{}; var x T; return x }
+
+// these must remain multi-line since they are multi-line in the source
+func _() {
+ f(1, 2, 3)
+}
+func _(x int) int {
+ y := x
+ return y + 1
+}
+func _() int {
+ type T struct{}
+ var x T
+ return x
+}
+
+// making function declarations safe for new semicolon rules
+func _() { /* single-line function because of "short-ish" comment */ }
+func _() { /* multi-line function because of "long-ish" comment - much more comment text is following here */ /* and more */
+}
+
+func _() {
+ /* multi-line func because block is on multiple lines */
+}
+
+// test case for issue #19544
+func _() {}
+func _longer_name_() { // this comment must not force the {} from above to alignment
+ // multiple lines
+}
+
+// ellipsis parameters
+func _(...int)
+func _(...*int)
+func _(...[]int)
+func _(...struct{})
+func _(bool, ...interface{})
+func _(bool, ...func())
+func _(bool, ...func(...int))
+func _(bool, ...map[string]int)
+func _(bool, ...chan int)
+
+func _(b bool, x ...int)
+func _(b bool, x ...*int)
+func _(b bool, x ...[]int)
+func _(b bool, x ...struct{})
+func _(x ...interface{})
+func _(x ...func())
+func _(x ...func(...int))
+func _(x ...map[string]int)
+func _(x ...chan int)
+
+// these parameter lists must remain multi-line since they are multi-line in the source
+func _(bool,
+ int) {
+}
+func _(x bool,
+ y int) {
+}
+func _(x,
+ y bool) {
+}
+func _(bool, // comment
+ int) {
+}
+func _(x bool, // comment
+ y int) {
+}
+func _(x, // comment
+ y bool) {
+}
+func _(bool, // comment
+ // comment
+ int) {
+}
+func _(x bool, // comment
+ // comment
+ y int) {
+}
+func _(x, // comment
+ // comment
+ y bool) {
+}
+func _(bool,
+ // comment
+ int) {
+}
+func _(x bool,
+ // comment
+ y int) {
+}
+func _(x,
+ // comment
+ y bool) {
+}
+func _(x, // comment
+ y, // comment
+ z bool) {
+}
+func _(x, // comment
+ y, // comment
+ z bool) {
+}
+func _(x int, // comment
+ y float, // comment
+ z bool) {
+}
+
+// properly indent multi-line signatures
+func ManageStatus(in <-chan *Status, req <-chan Request,
+ stat chan<- *TargetInfo,
+ TargetHistorySize int) {
+}
+
+func MultiLineSignature0(
+ a, b, c int,
+) {
+}
+
+func MultiLineSignature1(
+ a, b, c int,
+ u, v, w float,
+) {
+}
+
+func MultiLineSignature2(
+ a, b,
+ c int,
+) {
+}
+
+func MultiLineSignature3(
+ a, b,
+ c int, u, v,
+ w float,
+ x ...int) {
+}
+
+func MultiLineSignature4(
+ a, b, c int,
+ u, v,
+ w float,
+ x ...int) {
+}
+
+func MultiLineSignature5(
+ a, b, c int,
+ u, v, w float,
+ p, q,
+ r string,
+ x ...int) {
+}
+
+// make sure it also works for methods in interfaces
+type _ interface {
+ MultiLineSignature0(
+ a, b, c int,
+ )
+
+ MultiLineSignature1(
+ a, b, c int,
+ u, v, w float,
+ )
+
+ MultiLineSignature2(
+ a, b,
+ c int,
+ )
+
+ MultiLineSignature3(
+ a, b,
+ c int, u, v,
+ w float,
+ x ...int)
+
+ MultiLineSignature4(
+ a, b, c int,
+ u, v,
+ w float,
+ x ...int)
+
+ MultiLineSignature5(
+ a, b, c int,
+ u, v, w float,
+ p, q,
+ r string,
+ x ...int)
+}
+
+// omit superfluous parentheses in parameter lists
+func _(int)
+func _(int)
+func _(x int)
+func _(x int)
+func _(x, y int)
+func _(x, y int)
+
+func _() int
+func _() int
+func _() int
+
+func _() (x int)
+func _() (x int)
+func _() (x int)
+
+// special cases: some channel types require parentheses
+func _(x chan (<-chan int))
+func _(x chan (<-chan int))
+func _(x chan (<-chan int))
+
+func _(x chan<- (chan int))
+func _(x chan<- (chan int))
+func _(x chan<- (chan int))
+
+// don't introduce comma after last parameter if the closing ) is on the same line
+// even if the parameter type itself is multi-line (test cases from issue 4533)
+func _(...interface{})
+func _(...interface {
+ m()
+ n()
+}) // no extra comma between } and )
+
+func (t *T) _(...interface{})
+func (t *T) _(...interface {
+ m()
+ n()
+}) // no extra comma between } and )
+
+func _(interface{})
+func _(interface {
+ m()
+}) // no extra comma between } and )
+
+func _(struct{})
+func _(struct {
+ x int
+ y int
+}) // no extra comma between } and )
+
+// alias declarations
+
+type c0 struct{}
+type c1 = C
+type c2 = struct{ x int }
+type c3 = p.C
+type (
+ s struct{}
+ a = A
+ b = A
+ c = foo
+ d = interface{}
+ ddd = p.Foo
+)
diff --git a/src/go/printer/testdata/declarations.input b/src/go/printer/testdata/declarations.input
new file mode 100644
index 0000000..a858051
--- /dev/null
+++ b/src/go/printer/testdata/declarations.input
@@ -0,0 +1,1021 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imports
+
+import "io"
+
+import (
+ _ "io"
+)
+
+import _ "io"
+
+import (
+ "io"
+ "io"
+ "io"
+)
+
+import (
+ "io"
+ aLongRename "io"
+
+ b "io"
+)
+
+import (
+ "unrenamed"
+ renamed "renameMe"
+ . "io"
+ _ "io"
+ "io"
+ . "os"
+)
+
+// no newlines between consecutive single imports, but
+// respect extra line breaks in the source (at most one empty line)
+import _ "io"
+import _ "io"
+import _ "io"
+
+import _ "os"
+import _ "os"
+import _ "os"
+
+
+import _ "fmt"
+import _ "fmt"
+import _ "fmt"
+
+import "foo" // a comment
+import "bar" // a comment
+
+import (
+ _ "foo"
+ // a comment
+ "bar"
+ "foo" // a comment
+ "bar" // a comment
+)
+
+// comments + renames
+import (
+ "unrenamed" // a comment
+ renamed "renameMe"
+ . "io" /* a comment */
+ _ "io/ioutil" // a comment
+ "io" // testing alignment
+ . "os"
+ // a comment
+)
+
+// a case that caused problems in the past (comment placement)
+import (
+ . "fmt"
+ "io"
+ "malloc" // for the malloc count test only
+ "math"
+ "strings"
+ "testing"
+)
+
+// more import examples
+import (
+ "xxx"
+ "much_longer_name" // comment
+ "short_name" // comment
+)
+
+import (
+ _ "xxx"
+ "much_longer_name" // comment
+)
+
+import (
+ mymath "math"
+ "/foo/bar/long_package_path" // a comment
+)
+
+import (
+ "package_a" // comment
+ "package_b"
+ my_better_c "package_c" // comment
+ "package_d" // comment
+ my_e "package_e" // comment
+
+ "package_a" // comment
+ "package_bb"
+ "package_ccc" // comment
+ "package_dddd" // comment
+)
+
+// print import paths as double-quoted strings
+// (we would like more test cases but the go/parser
+// already excludes most incorrect paths, and we don't
+// bother setting up test-ASTs manually)
+import (
+ `fmt`
+ "math"
+)
+
+// at least one empty line between declarations of different kind
+import _ "io"
+var _ int
+
+// at least one empty line between declarations of the same kind
+// if there is associated documentation (was issue 2570)
+type T1 struct{}
+// T2 comment
+type T2 struct {
+} // should be a two-line struct
+
+
+// T3 comment
+type T2 struct {
+
+
+} // should be a two-line struct
+
+
+// printing of constant literals
+const (
+ _ = "foobar"
+ _ = "a۰۱۸"
+ _ = "foo६४"
+ _ = "bar9876"
+ _ = 0
+ _ = 1
+ _ = 123456789012345678890
+ _ = 01234567
+ _ = 0xcafebabe
+ _ = 0.
+ _ = .0
+ _ = 3.14159265
+ _ = 1e0
+ _ = 1e+100
+ _ = 1e-100
+ _ = 2.71828e-1000
+ _ = 0i
+ _ = 1i
+ _ = 012345678901234567889i
+ _ = 123456789012345678890i
+ _ = 0.i
+ _ = .0i
+ _ = 3.14159265i
+ _ = 1e0i
+ _ = 1e+100i
+ _ = 1e-100i
+ _ = 2.71828e-1000i
+ _ = 'a'
+ _ = '\000'
+ _ = '\xFF'
+ _ = '\uff16'
+ _ = '\U0000ff16'
+ _ = `foobar`
+ _ = `foo
+---
+---
+bar`
+)
+
+
+func _() {
+ type _ int
+ type _ *int
+ type _ []int
+ type _ map[string]int
+ type _ chan int
+ type _ func() int
+
+ var _ int
+ var _ *int
+ var _ []int
+ var _ map[string]int
+ var _ chan int
+ var _ func() int
+
+ type _ struct{}
+ type _ *struct{}
+ type _ []struct{}
+ type _ map[string]struct{}
+ type _ chan struct{}
+ type _ func() struct{}
+
+ type _ interface{}
+ type _ *interface{}
+ type _ []interface{}
+ type _ map[string]interface{}
+ type _ chan interface{}
+ type _ func() interface{}
+
+ var _ struct{}
+ var _ *struct{}
+ var _ []struct{}
+ var _ map[string]struct{}
+ var _ chan struct{}
+ var _ func() struct{}
+
+ var _ interface{}
+ var _ *interface{}
+ var _ []interface{}
+ var _ map[string]interface{}
+ var _ chan interface{}
+ var _ func() interface{}
+}
+
+
+// don't lose blank lines in grouped declarations
+const (
+ _ int = 0
+ _ float = 1
+
+ _ string = "foo"
+
+ _ = iota
+ _
+
+ // a comment
+ _
+
+ _
+)
+
+
+type (
+ _ int
+ _ struct {}
+
+ _ interface{}
+
+ // a comment
+ _ map[string]int
+)
+
+
+var (
+ _ int = 0
+ _ float = 1
+
+ _ string = "foo"
+
+ _ bool
+
+ // a comment
+ _ bool
+)
+
+
+// don't lose blank lines in this struct
+type _ struct {
+ String struct {
+ Str, Len int
+ }
+ Slice struct {
+ Array, Len, Cap int
+ }
+ Eface struct {
+ Typ, Ptr int
+ }
+
+ UncommonType struct {
+ Name, PkgPath int
+ }
+ CommonType struct {
+ Size, Hash, Alg, Align, FieldAlign, String, UncommonType int
+ }
+ Type struct {
+ Typ, Ptr int
+ }
+ StructField struct {
+ Name, PkgPath, Typ, Tag, Offset int
+ }
+ StructType struct {
+ Fields int
+ }
+ PtrType struct {
+ Elem int
+ }
+ SliceType struct {
+ Elem int
+ }
+ ArrayType struct {
+ Elem, Len int
+ }
+
+ Stktop struct {
+ Stackguard, Stackbase, Gobuf int
+ }
+ Gobuf struct {
+ Sp, Pc, G int
+ }
+ G struct {
+ Stackbase, Sched, Status, Alllink int
+ }
+}
+
+
+// no blank lines in empty structs and interfaces, but leave 1- or 2-line layout alone
+type _ struct{ }
+type _ struct {
+
+}
+
+type _ interface{ }
+type _ interface {
+
+}
+
+
+// no tabs for single or ungrouped decls
+func _() {
+ const xxxxxx = 0
+ type x int
+ var xxx int
+ var yyyy float = 3.14
+ var zzzzz = "bar"
+
+ const (
+ xxxxxx = 0
+ )
+ type (
+ x int
+ )
+ var (
+ xxx int
+ )
+ var (
+ yyyy float = 3.14
+ )
+ var (
+ zzzzz = "bar"
+ )
+}
+
+// tabs for multiple or grouped decls
+func _() {
+ // no entry has a type
+ const (
+ zzzzzz = 1
+ z = 2
+ zzz = 3
+ )
+ // some entries have a type
+ const (
+ xxxxxx = 1
+ x = 2
+ xxx = 3
+ yyyyyyyy float = iota
+ yyyy = "bar"
+ yyy
+ yy = 2
+ )
+}
+
+func _() {
+ // no entry has a type
+ var (
+ zzzzzz = 1
+ z = 2
+ zzz = 3
+ )
+ // no entry has a value
+ var (
+ _ int
+ _ float
+ _ string
+
+ _ int // comment
+ _ float // comment
+ _ string // comment
+ )
+ // some entries have a type
+ var (
+ xxxxxx int
+ x float
+ xxx string
+ yyyyyyyy int = 1234
+ y float = 3.14
+ yyyy = "bar"
+ yyy string = "foo"
+ )
+ // mixed entries - all comments should be aligned
+ var (
+ a, b, c int
+ x = 10
+ d int // comment
+ y = 20 // comment
+ f, ff, fff, ffff int = 0, 1, 2, 3 // comment
+ )
+ // respect original line breaks
+ var _ = []T {
+ T{0x20, "Telugu"},
+ }
+ var _ = []T {
+ // respect original line breaks
+ T{0x20, "Telugu"},
+ }
+}
+
+// use the formatted output rather than the input to decide when to align
+// (was issue 4505)
+const (
+ short = 2 * (
+ 1 + 2)
+ aMuchLongerName = 3
+)
+
+var (
+ short = X{
+ }
+ aMuchLongerName = X{}
+
+ x1 = X{} // foo
+ x2 = X{
+ } // foo
+)
+
+func _() {
+ type (
+ xxxxxx int
+ x float
+ xxx string
+ xxxxx []x
+ xx struct{}
+ xxxxxxx struct {
+ _, _ int
+ _ float
+ }
+ xxxx chan<- string
+ )
+}
+
+// alignment of "=" in consecutive lines (extended example from issue 1414)
+const (
+ umax uint = ^uint(0) // maximum value for a uint
+ bpu = 1 << (5 + umax>>63) // bits per uint
+ foo
+ bar = -1
+)
+
+// typical enum
+const (
+ a MyType = iota
+ abcd
+ b
+ c
+ def
+)
+
+// excerpt from godoc.go
+var (
+ goroot = flag.String("goroot", runtime.GOROOT(), "Go root directory")
+ testDir = flag.String("testdir", "", "Go root subdirectory - for testing only (faster startups)")
+ pkgPath = flag.String("path", "", "additional package directories (colon-separated)")
+ filter = flag.String("filter", "", "filter file containing permitted package directory paths")
+ filterMin = flag.Int("filter_minutes", 0, "filter file update interval in minutes; disabled if <= 0")
+ filterDelay delayTime // actual filter update interval in minutes; usually filterDelay == filterMin, but filterDelay may back off exponentially
+)
+
+
+// formatting of structs
+type _ struct{}
+
+type _ struct{ /* this comment should be visible */ }
+
+type _ struct{
+ // this comment should be visible and properly indented
+}
+
+type _ struct { // this comment must not change indentation
+ f int
+ f, ff, fff, ffff int
+}
+
+type _ struct {
+ string
+}
+
+type _ struct {
+ string // comment
+}
+
+type _ struct {
+ string "tag"
+}
+
+type _ struct {
+ string "tag" // comment
+}
+
+type _ struct {
+ f int
+}
+
+type _ struct {
+ f int // comment
+}
+
+type _ struct {
+ f int "tag"
+}
+
+type _ struct {
+ f int "tag" // comment
+}
+
+type _ struct {
+ bool
+ a, b, c int
+ int "tag"
+ ES // comment
+ float "tag" // comment
+ f int // comment
+ f, ff, fff, ffff int // comment
+ g float "tag"
+ h float "tag" // comment
+}
+
+type _ struct { a, b,
+c, d int // this line should be indented
+u, v, w, x float // this line should be indented
+p, q,
+r, s float // this line should be indented
+}
+
+
+// difficult cases
+type _ struct {
+ bool // comment
+ text []byte // comment
+}
+
+
+// formatting of interfaces
+type EI interface{}
+
+type _ interface {
+ EI
+}
+
+type _ interface {
+ f()
+ fffff()
+}
+
+type _ interface {
+ EI
+ f()
+ fffffg()
+}
+
+type _ interface { // this comment must not change indentation
+ EI // here's a comment
+ f() // no blank between identifier and ()
+ fffff() // no blank between identifier and ()
+ gggggggggggg(x, y, z int) () // hurray
+}
+
+
+// formatting of variable declarations
+func _() {
+ type day struct { n int; short, long string }
+ var (
+ Sunday = day{ 0, "SUN", "Sunday" }
+ Monday = day{ 1, "MON", "Monday" }
+ Tuesday = day{ 2, "TUE", "Tuesday" }
+ Wednesday = day{ 3, "WED", "Wednesday" }
+ Thursday = day{ 4, "THU", "Thursday" }
+ Friday = day{ 5, "FRI", "Friday" }
+ Saturday = day{ 6, "SAT", "Saturday" }
+ )
+}
+
+
+// formatting of multi-line variable declarations
+var a1, b1, c1 int // all on one line
+
+var a2, b2,
+c2 int // this line should be indented
+
+var (a3, b3,
+c3, d3 int // this line should be indented
+a4, b4, c4 int // this line should be indented
+)
+
+// Test case from issue 3304: multi-line declarations must end
+// a formatting section and not influence indentation of the
+// next line.
+var (
+ minRefreshTimeSec = flag.Int64("min_refresh_time_sec", 604800,
+ "minimum time window between two refreshes for a given user.")
+ x = flag.Int64("refresh_user_rollout_percent", 100,
+ "temporary flag to ramp up the refresh user rpc")
+ aVeryLongVariableName = stats.GetVarInt("refresh-user-count")
+)
+
+func _() {
+ var privateKey2 = &Block{Type: "RSA PRIVATE KEY",
+ Headers: map[string]string{},
+ Bytes: []uint8{0x30, 0x82, 0x1, 0x3a, 0x2, 0x1, 0x0, 0x2,
+ 0x41, 0x0, 0xb2, 0x99, 0xf, 0x49, 0xc4, 0x7d, 0xfa, 0x8c,
+ 0xd4, 0x0, 0xae, 0x6a, 0x4d, 0x1b, 0x8a, 0x3b, 0x6a, 0x13,
+ 0x64, 0x2b, 0x23, 0xf2, 0x8b, 0x0, 0x3b, 0xfb, 0x97, 0x79,
+ },
+ }
+}
+
+
+func _() {
+ var Universe = Scope {
+ Names: map[string]*Ident {
+ // basic types
+ "bool": nil,
+ "byte": nil,
+ "int8": nil,
+ "int16": nil,
+ "int32": nil,
+ "int64": nil,
+ "uint8": nil,
+ "uint16": nil,
+ "uint32": nil,
+ "uint64": nil,
+ "float32": nil,
+ "float64": nil,
+ "string": nil,
+
+ // convenience types
+ "int": nil,
+ "uint": nil,
+ "uintptr": nil,
+ "float": nil,
+
+ // constants
+ "false": nil,
+ "true": nil,
+ "iota": nil,
+ "nil": nil,
+
+ // functions
+ "cap": nil,
+ "len": nil,
+ "new": nil,
+ "make": nil,
+ "panic": nil,
+ "panicln": nil,
+ "print": nil,
+ "println": nil,
+ },
+ }
+}
+
+
+// alignment of map composite entries
+var _ = map[int]int{
+ // small key sizes: always align even if size ratios are large
+ a: a,
+ abcdefghabcdefgh: a,
+ ab: a,
+ abc: a,
+ abcdefgabcdefg: a,
+ abcd: a,
+ abcde: a,
+ abcdef: a,
+
+ // mixed key sizes: align when key sizes change within accepted ratio
+ abcdefgh: a,
+ abcdefghabcdefg: a,
+ abcdefghij: a,
+ abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij: a, // outlier - do not align with previous line
+ abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij: a, // align with previous line
+
+ ab: a, // do not align with previous line
+ abcde: a, // align with previous line
+}
+
+// alignment of map composite entries: test cases from issue 3965
+// aligned
+var _ = T1{
+ a: x,
+ b: y,
+ cccccccccccccccccccc: z,
+}
+
+// not aligned
+var _ = T2{
+ a: x,
+ b: y,
+ ccccccccccccccccccccc: z,
+}
+
+// aligned
+var _ = T3{
+ aaaaaaaaaaaaaaaaaaaa: x,
+ b: y,
+ c: z,
+}
+
+// not aligned
+var _ = T4{
+ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: x,
+ b: y,
+ c: z,
+}
+
+
+// no alignment of map composite entries if they are not the first entry on a line
+var _ = T{0: 0} // not aligned
+var _ = T{0: 0, // not aligned
+ 1: 1, // aligned
+ 22: 22, // aligned
+ 333: 333, 1234: 12, 12345: 0, // first on line aligned
+}
+
+
+// test cases form issue 8685
+// not aligned
+var _ = map[int]string{1: "spring", 2: "summer",
+ 3: "autumn", 4: "winter"}
+
+// not aligned
+var _ = map[string]string{"a": "spring", "b": "summer",
+ "c": "autumn", "d": "winter"}
+
+// aligned
+var _ = map[string]string{"a": "spring",
+"b": "summer",
+ "c": "autumn",
+"d": "winter"}
+
+
+func _() {
+ var _ = T{
+ a, // must introduce trailing comma
+ }
+}
+
+
+// formatting of function results
+func _() func() {}
+func _() func(int) { return nil }
+func _() func(int) int { return nil }
+func _() func(int) func(int) func() { return nil }
+
+
+// formatting of consecutive single-line functions
+func _() {}
+func _() {}
+func _() {}
+
+func _() {} // an empty line before this function
+func _() {}
+func _() {}
+
+func _() { f(1, 2, 3) }
+func _(x int) int { y := x; return y+1 }
+func _() int { type T struct{}; var x T; return x }
+
+// these must remain multi-line since they are multi-line in the source
+func _() {
+ f(1, 2, 3)
+}
+func _(x int) int {
+ y := x; return y+1
+}
+func _() int {
+ type T struct{}; var x T; return x
+}
+
+
+// making function declarations safe for new semicolon rules
+func _() { /* single-line function because of "short-ish" comment */ }
+func _() { /* multi-line function because of "long-ish" comment - much more comment text is following here */ /* and more */ }
+
+func _() {
+/* multi-line func because block is on multiple lines */ }
+
+// test case for issue #19544
+func _() {}
+func _longer_name_() { // this comment must not force the {} from above to alignment
+ // multiple lines
+}
+
+// ellipsis parameters
+func _(...int)
+func _(...*int)
+func _(...[]int)
+func _(...struct{})
+func _(bool, ...interface{})
+func _(bool, ...func())
+func _(bool, ...func(...int))
+func _(bool, ...map[string]int)
+func _(bool, ...chan int)
+
+func _(b bool, x ...int)
+func _(b bool, x ...*int)
+func _(b bool, x ...[]int)
+func _(b bool, x ...struct{})
+func _(x ...interface{})
+func _(x ...func())
+func _(x ...func(...int))
+func _(x ...map[string]int)
+func _(x ...chan int)
+
+
+// these parameter lists must remain multi-line since they are multi-line in the source
+func _(bool,
+int) {
+}
+func _(x bool,
+y int) {
+}
+func _(x,
+y bool) {
+}
+func _(bool, // comment
+int) {
+}
+func _(x bool, // comment
+y int) {
+}
+func _(x, // comment
+y bool) {
+}
+func _(bool, // comment
+// comment
+int) {
+}
+func _(x bool, // comment
+// comment
+y int) {
+}
+func _(x, // comment
+// comment
+y bool) {
+}
+func _(bool,
+// comment
+int) {
+}
+func _(x bool,
+// comment
+y int) {
+}
+func _(x,
+// comment
+y bool) {
+}
+func _(x, // comment
+y,// comment
+z bool) {
+}
+func _(x, // comment
+ y,// comment
+ z bool) {
+}
+func _(x int, // comment
+ y float, // comment
+ z bool) {
+}
+
+
+// properly indent multi-line signatures
+func ManageStatus(in <-chan *Status, req <-chan Request,
+stat chan<- *TargetInfo,
+TargetHistorySize int) {
+}
+
+func MultiLineSignature0(
+a, b, c int,
+) {}
+
+func MultiLineSignature1(
+a, b, c int,
+u, v, w float,
+) {}
+
+func MultiLineSignature2(
+a, b,
+c int,
+) {}
+
+func MultiLineSignature3(
+a, b,
+c int, u, v,
+w float,
+ x ...int) {}
+
+func MultiLineSignature4(
+a, b, c int,
+u, v,
+w float,
+ x ...int) {}
+
+func MultiLineSignature5(
+a, b, c int,
+u, v, w float,
+p, q,
+r string,
+ x ...int) {}
+
+// make sure it also works for methods in interfaces
+type _ interface {
+MultiLineSignature0(
+a, b, c int,
+)
+
+MultiLineSignature1(
+a, b, c int,
+u, v, w float,
+)
+
+MultiLineSignature2(
+a, b,
+c int,
+)
+
+MultiLineSignature3(
+a, b,
+c int, u, v,
+w float,
+ x ...int)
+
+MultiLineSignature4(
+a, b, c int,
+u, v,
+w float,
+ x ...int)
+
+MultiLineSignature5(
+a, b, c int,
+u, v, w float,
+p, q,
+r string,
+ x ...int)
+}
+
+// omit superfluous parentheses in parameter lists
+func _((int))
+func _((((((int))))))
+func _(x (int))
+func _(x (((((int))))))
+func _(x, y (int))
+func _(x, y (((((int))))))
+
+func _() (int)
+func _() ((int))
+func _() ((((((int))))))
+
+func _() (x int)
+func _() (x (int))
+func _() (x (((((int))))))
+
+// special cases: some channel types require parentheses
+func _(x chan(<-chan int))
+func _(x (chan(<-chan int)))
+func _(x ((((chan(<-chan int))))))
+
+func _(x chan<-(chan int))
+func _(x (chan<-(chan int)))
+func _(x ((((chan<-(chan int))))))
+
+// don't introduce comma after last parameter if the closing ) is on the same line
+// even if the parameter type itself is multi-line (test cases from issue 4533)
+func _(...interface{})
+func _(...interface {
+ m()
+ n()
+}) // no extra comma between } and )
+
+func (t *T) _(...interface{})
+func (t *T) _(...interface {
+ m()
+ n()
+}) // no extra comma between } and )
+
+func _(interface{})
+func _(interface {
+ m()
+}) // no extra comma between } and )
+
+func _(struct{})
+func _(struct {
+ x int
+ y int
+}) // no extra comma between } and )
+
+// alias declarations
+
+type c0 struct{}
+type c1 = C
+type c2 = struct{ x int}
+type c3 = p.C
+type (
+ s struct{}
+ a = A
+ b = A
+ c = foo
+ d = interface{}
+ ddd = p.Foo
+) \ No newline at end of file
diff --git a/src/go/printer/testdata/empty.golden b/src/go/printer/testdata/empty.golden
new file mode 100644
index 0000000..a055f47
--- /dev/null
+++ b/src/go/printer/testdata/empty.golden
@@ -0,0 +1,5 @@
+// a comment at the beginning of the file
+
+package empty
+
+// a comment at the end of the file
diff --git a/src/go/printer/testdata/empty.input b/src/go/printer/testdata/empty.input
new file mode 100644
index 0000000..a055f47
--- /dev/null
+++ b/src/go/printer/testdata/empty.input
@@ -0,0 +1,5 @@
+// a comment at the beginning of the file
+
+package empty
+
+// a comment at the end of the file
diff --git a/src/go/printer/testdata/expressions.golden b/src/go/printer/testdata/expressions.golden
new file mode 100644
index 0000000..16a68c7
--- /dev/null
+++ b/src/go/printer/testdata/expressions.golden
@@ -0,0 +1,743 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package expressions
+
+type T struct {
+ x, y, z int
+}
+
+var (
+ a, b, c, d, e int
+ under_bar int
+ longIdentifier1, longIdentifier2, longIdentifier3 int
+ t0, t1, t2 T
+ s string
+ p *int
+)
+
+func _() {
+ // no spaces around simple or parenthesized expressions
+ _ = (a + 0)
+ _ = a + b
+ _ = a + b + c
+ _ = a + b - c
+ _ = a - b - c
+ _ = a + (b * c)
+ _ = a + (b / c)
+ _ = a - (b % c)
+ _ = 1 + a
+ _ = a + 1
+ _ = a + b + 1
+ _ = s[a]
+ _ = s[a:]
+ _ = s[:b]
+ _ = s[1:2]
+ _ = s[a:b]
+ _ = s[0:len(s)]
+ _ = s[0] << 1
+ _ = (s[0] << 1) & 0xf
+ _ = s[0]<<2 | s[1]>>4
+ _ = "foo" + s
+ _ = s + "foo"
+ _ = 'a' + 'b'
+ _ = len(s) / 2
+ _ = len(t0.x) / a
+
+ // spaces around expressions of different precedence or expressions containing spaces
+ _ = a + -b
+ _ = a - ^b
+ _ = a / *p
+ _ = a + b*c
+ _ = 1 + b*c
+ _ = a + 2*c
+ _ = a + c*2
+ _ = 1 + 2*3
+ _ = s[1 : 2*3]
+ _ = s[a : b-c]
+ _ = s[0:]
+ _ = s[a+b]
+ _ = s[:b-c]
+ _ = s[a+b:]
+ _ = a[a<<b+1]
+ _ = a[a<<b+1:]
+ _ = s[a+b : len(s)]
+ _ = s[len(s):-a]
+ _ = s[a : len(s)+1]
+ _ = s[a:len(s)+1] + s
+
+ // spaces around operators with equal or lower precedence than comparisons
+ _ = a == b
+ _ = a != b
+ _ = a > b
+ _ = a >= b
+ _ = a < b
+ _ = a <= b
+ _ = a < b && c > d
+ _ = a < b || c > d
+
+ // spaces around "long" operands
+ _ = a + longIdentifier1
+ _ = longIdentifier1 + a
+ _ = longIdentifier1 + longIdentifier2*longIdentifier3
+ _ = s + "a longer string"
+
+ // some selected cases
+ _ = a + t0.x
+ _ = a + t0.x + t1.x*t2.x
+ _ = a + b + c + d + e + 2*3
+ _ = a + b + c + 2*3 + d + e
+ _ = (a + b + c) * 2
+ _ = a - b + c - d + (a + b + c) + d&e
+ _ = under_bar - 1
+ _ = Open(dpath+"/file", O_WRONLY|O_CREAT, 0666)
+ _ = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx)
+
+ // test case for issue 8021
+ // want:
+ // ([]bool{})[([]int{})[((1)+(((1)+((((1)*(((1)+(1))+(1)))+(1))*(1)))+(1)))]]
+ _ = ([]bool{})[([]int{})[((1)+(((1)+((((1)*(((1)+(1))+(1)))+(1))*(1)))+(1)))]]
+
+ // the parser does not restrict expressions that may appear as statements
+ true
+ 42
+ "foo"
+ x
+ (x)
+ a + b
+ a + b + c
+ a + (b * c)
+ a + (b / c)
+ 1 + a
+ a + 1
+ s[a]
+ x << 1
+ (s[0] << 1) & 0xf
+ "foo" + s
+ x == y
+ x < y || z > 42
+}
+
+// slice expressions with cap
+func _() {
+ _ = x[a:b:c]
+ _ = x[a : b : c+d]
+ _ = x[a : b+d : c]
+ _ = x[a : b+d : c+d]
+ _ = x[a+d : b : c]
+ _ = x[a+d : b : c+d]
+ _ = x[a+d : b+d : c]
+ _ = x[a+d : b+d : c+d]
+
+ _ = x[:b:c]
+ _ = x[: b : c+d]
+ _ = x[: b+d : c]
+ _ = x[: b+d : c+d]
+}
+
+func issue22111() {
+ _ = x[:]
+
+ _ = x[:b]
+ _ = x[:b+1]
+
+ _ = x[a:]
+ _ = x[a+1:]
+
+ _ = x[a:b]
+ _ = x[a+1 : b]
+ _ = x[a : b+1]
+ _ = x[a+1 : b+1]
+
+ _ = x[:b:c]
+ _ = x[: b+1 : c]
+ _ = x[: b : c+1]
+ _ = x[: b+1 : c+1]
+
+ _ = x[a:b:c]
+ _ = x[a+1 : b : c]
+ _ = x[a : b+1 : c]
+ _ = x[a+1 : b+1 : c]
+ _ = x[a : b : c+1]
+ _ = x[a+1 : b : c+1]
+ _ = x[a : b+1 : c+1]
+ _ = x[a+1 : b+1 : c+1]
+}
+
+func _() {
+ _ = a + b
+ _ = a + b + c
+ _ = a + b*c
+ _ = a + (b * c)
+ _ = (a + b) * c
+ _ = a + (b * c * d)
+ _ = a + (b*c + d)
+
+ _ = 1 << x
+ _ = -1 << x
+ _ = 1<<x - 1
+ _ = -1<<x - 1
+
+ _ = f(a + b)
+ _ = f(a + b + c)
+ _ = f(a + b*c)
+ _ = f(a + (b * c))
+ _ = f(1<<x-1, 1<<x-2)
+
+ _ = 1<<d.logWindowSize - 1
+
+ buf = make(x, 2*cap(b.buf)+n)
+
+ dst[i*3+2] = dbuf[0] << 2
+ dst[i*3+2] = dbuf[0]<<2 | dbuf[1]>>4
+
+ b.buf = b.buf[0 : b.off+m+n]
+ b.buf = b.buf[0 : b.off+m*n]
+ f(b.buf[0 : b.off+m+n])
+
+ signed += ' ' * 8
+ tw.octal(header[148:155], chksum)
+
+ _ = x > 0 && i >= 0
+
+ x1, x0 := x>>w2, x&m2
+ z0 = t1<<w2 + t0
+ z1 = (t1 + t0>>w2) >> w2
+ q1, r1 := x1/d1, x1%d1
+ r1 = r1*b2 | x0>>w2
+ x1 = (x1 << z) | (x0 >> (uint(w) - z))
+ x1 = x1<<z | x0>>(uint(w)-z)
+
+ _ = buf[0 : len(buf)+1]
+ _ = buf[0 : n+1]
+
+ a, b = b, a
+ a = b + c
+ a = b*c + d
+ _ = a*b + c
+ _ = a - b - c
+ _ = a - (b - c)
+ _ = a - b*c
+ _ = a - (b * c)
+ _ = a * b / c
+ _ = a / *b
+ _ = x[a|^b]
+ _ = x[a / *b]
+ _ = a & ^b
+ _ = a + +b
+ _ = a - -b
+ _ = x[a*-b]
+ _ = x[a + +b]
+ _ = x ^ y ^ z
+ _ = b[a>>24] ^ b[(a>>16)&0xFF] ^ b[(a>>8)&0xFF] ^ b[a&0xFF]
+ _ = len(longVariableName) * 2
+
+ _ = token(matchType + xlength<<lengthShift + xoffset)
+}
+
+func f(x int, args ...int) {
+ f(0, args...)
+ f(1, args)
+ f(2, args[0])
+
+ // make sure syntactically legal code remains syntactically legal
+ f(3, 42 ...) // a blank must remain between 42 and ...
+ f(4, 42....)
+ f(5, 42....)
+ f(6, 42.0...)
+ f(7, 42.0...)
+ f(8, .42...)
+ f(9, .42...)
+ f(10, 42e0...)
+ f(11, 42e0...)
+
+ _ = 42 .x // a blank must remain between 42 and .x
+ _ = 42..x
+ _ = 42..x
+ _ = 42.0.x
+ _ = 42.0.x
+ _ = .42.x
+ _ = .42.x
+ _ = 42e0.x
+ _ = 42e0.x
+
+ // a blank must remain between the binary operator and the 2nd operand
+ _ = x / *y
+ _ = x < -1
+ _ = x < <-1
+ _ = x + +1
+ _ = x - -1
+ _ = x & &x
+ _ = x & ^x
+
+ _ = f(x / *y, x < -1, x < <-1, x + +1, x - -1, x & &x, x & ^x)
+}
+
+func _() {
+ _ = T{}
+ _ = struct{}{}
+ _ = [10]T{}
+ _ = [...]T{}
+ _ = []T{}
+ _ = map[int]T{}
+}
+
+// one-line structs/interfaces in composite literals (up to a threshold)
+func _() {
+ _ = struct{}{}
+ _ = struct{ x int }{0}
+ _ = struct{ x, y, z int }{0, 1, 2}
+ _ = struct{ int }{0}
+ _ = struct{ s struct{ int } }{struct{ int }{0}}
+
+ _ = (interface{})(nil)
+ _ = (interface{ String() string })(nil)
+ _ = (interface {
+ String() string
+ })(nil)
+ _ = (interface{ fmt.Stringer })(nil)
+ _ = (interface {
+ fmt.Stringer
+ })(nil)
+}
+
+func _() {
+ // do not modify literals
+ _ = "tab1 tab2 tab3 end" // string contains 3 tabs
+ _ = "tab1 tab2 tab3 end" // same string with 3 blanks - may be unaligned because editors see tabs in strings
+ _ = "" // this comment should be aligned with the one on the previous line
+ _ = ``
+ _ = `
+`
+ _ = `foo
+ bar`
+ _ = `three spaces before the end of the line starting here:
+they must not be removed`
+}
+
+func _() {
+ // smart handling of indentation for multi-line raw strings
+ var _ = ``
+ var _ = `foo`
+ var _ = `foo
+bar`
+
+ var _ = ``
+ var _ = `foo`
+ var _ =
+ // the next line should remain indented
+ `foo
+bar`
+
+ var _ = // comment
+ ``
+ var _ = // comment
+ `foo`
+ var _ = // comment
+ // the next line should remain indented
+ `foo
+bar`
+
+ var _ = /* comment */ ``
+ var _ = /* comment */ `foo`
+ var _ = /* comment */ `foo
+bar`
+
+ var _ = /* comment */
+ ``
+ var _ = /* comment */
+ `foo`
+ var _ = /* comment */
+ // the next line should remain indented
+ `foo
+bar`
+
+ var board = []int(
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`)
+
+ var state = S{
+ "foo",
+ // the next line should remain indented
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`,
+ "bar",
+ }
+}
+
+func _() {
+ // one-line function literals (body is on a single line)
+ _ = func() {}
+ _ = func() int { return 0 }
+ _ = func(x, y int) bool { m := (x + y) / 2; return m < 0 }
+
+ // multi-line function literals (body is not on one line)
+ _ = func() {
+ }
+ _ = func() int {
+ return 0
+ }
+ _ = func(x, y int) bool {
+ m := (x + y) / 2
+ return x < y
+ }
+
+ f(func() {
+ })
+ f(func() int {
+ return 0
+ })
+ f(func(x, y int) bool {
+ m := (x + y) / 2
+ return x < y
+ })
+}
+
+func _() {
+ _ = [][]int{
+ []int{1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int{
+ {1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int{
+ {1},
+ {1, 2},
+ {1, 2, 3},
+ }
+ _ = [][]int{{1}, {1, 2}, {1, 2, 3}}
+}
+
+// various multi-line expressions
+func _() {
+ // do not add extra indentation to multi-line string lists
+ _ = "foo" + "bar"
+ _ = "foo" +
+ "bar" +
+ "bah"
+ _ = []string{
+ "abc" +
+ "def",
+ "foo" +
+ "bar",
+ }
+}
+
+const _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+const _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+const _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+func _() {
+ _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+ _ =
+ `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+ _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+}
+
+func _() {
+ // respect source lines in multi-line expressions
+ _ = a +
+ b +
+ c
+ _ = a < b ||
+ b < a
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+}
+
+// Alignment after overlong lines
+const (
+ _ = "991"
+ _ = "2432902008176640000" // 20!
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+)
+
+// Correct placement of operators and comments in multi-line expressions
+func _() {
+ _ = a + // comment
+ b + // comment
+ c
+ _ = "a" +
+ "b" + // comment
+ "c"
+ _ = "ba0408" + "7265717569726564" // field 71, encoding 2, string "required"
+}
+
+// Correct placement of terminating comma/closing parentheses in multi-line calls.
+func _() {
+ f(1,
+ 2,
+ 3)
+ f(1,
+ 2,
+ 3,
+ )
+ f(1,
+ 2,
+ 3) // comment
+ f(1,
+ 2,
+ 3, // comment
+ )
+ f(1,
+ 2,
+ 3) // comment
+ f(1,
+ 2,
+ 3, // comment
+ )
+}
+
+// Align comments in multi-line lists of single-line expressions.
+var txpix = [NCOL]draw.Color{
+ draw.Yellow, // yellow
+ draw.Cyan, // cyan
+ draw.Green, // lime green
+ draw.GreyBlue, // slate
+ draw.Red, /* red */
+ draw.GreyGreen, /* olive green */
+ draw.Blue, /* blue */
+ draw.Color(0xFF55AAFF), /* pink */
+ draw.Color(0xFFAAFFFF), /* lavender */
+ draw.Color(0xBB005DFF), /* maroon */
+}
+
+func same(t, u *Time) bool {
+ // respect source lines in multi-line expressions
+ return t.Year == u.Year &&
+ t.Month == u.Month &&
+ t.Day == u.Day &&
+ t.Hour == u.Hour &&
+ t.Minute == u.Minute &&
+ t.Second == u.Second &&
+ t.Weekday == u.Weekday &&
+ t.ZoneOffset == u.ZoneOffset &&
+ t.Zone == u.Zone
+}
+
+func (p *parser) charClass() {
+ // respect source lines in multi-line expressions
+ if cc.negate && len(cc.ranges) == 2 &&
+ cc.ranges[0] == '\n' && cc.ranges[1] == '\n' {
+ nl := new(_NotNl)
+ p.re.add(nl)
+ }
+}
+
+func addState(s []state, inst instr, match []int) {
+ // handle comments correctly in multi-line expressions
+ for i := 0; i < l; i++ {
+ if s[i].inst.index() == index && // same instruction
+ s[i].match[0] < pos { // earlier match already going; leftmost wins
+ return s
+ }
+ }
+}
+
+func (self *T) foo(x int) *T { return self }
+
+func _() { module.Func1().Func2() }
+
+func _() {
+ _ = new(T).
+ foo(1).
+ foo(2).
+ foo(3)
+
+ _ = new(T).
+ foo(1).
+ foo(2). // inline comments
+ foo(3)
+
+ _ = new(T).foo(1).foo(2).foo(3)
+
+ // handle multiline argument list correctly
+ _ = new(T).
+ foo(
+ 1).
+ foo(2)
+
+ _ = new(T).foo(
+ 1).foo(2)
+
+ _ = Array[3+
+ 4]
+
+ _ = Method(1, 2,
+ 3)
+
+ _ = new(T).
+ foo().
+ bar().(*Type)
+
+ _ = new(T).
+ foo().
+ bar().(*Type).
+ baz()
+
+ _ = new(T).
+ foo().
+ bar()["idx"]
+
+ _ = new(T).
+ foo().
+ bar()["idx"].
+ baz()
+
+ _ = new(T).
+ foo().
+ bar()[1:2]
+
+ _ = new(T).
+ foo().
+ bar()[1:2].
+ baz()
+
+ _ = new(T).
+ Field.
+ Array[3+
+ 4].
+ Table["foo"].
+ Blob.(*Type).
+ Slices[1:4].
+ Method(1, 2,
+ 3).
+ Thingy
+
+ _ = a.b.c
+ _ = a.
+ b.
+ c
+ _ = a.b().c
+ _ = a.
+ b().
+ c
+ _ = a.b[0].c
+ _ = a.
+ b[0].
+ c
+ _ = a.b[0:].c
+ _ = a.
+ b[0:].
+ c
+ _ = a.b.(T).c
+ _ = a.
+ b.(T).
+ c
+}
+
+// Don't introduce extra newlines in strangely formatted expression lists.
+func f() {
+ // os.Open parameters should remain on two lines
+ if writer, err = os.Open(outfile, s.O_WRONLY|os.O_CREATE|
+ os.O_TRUNC, 0666); err != nil {
+ log.Fatal(err)
+ }
+}
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+ _ = append(s, a...)
+ _ = append(
+ s, a...)
+ _ = append(s,
+ a...)
+ _ = append(
+ s,
+ a...)
+ _ = append(s, a...,
+ )
+ _ = append(s,
+ a...,
+ )
+ _ = append(
+ s,
+ a...,
+ )
+}
+
+// Literal function types in conversions must be parenthesized;
+// for now go/parser accepts the unparenthesized form where it
+// is non-ambiguous.
+func _() {
+ // these conversions should be rewritten to look
+ // the same as the parenthesized conversions below
+ _ = (func())(nil)
+ _ = (func(x int) float)(nil)
+ _ = (func() func() func())(nil)
+
+ _ = (func())(nil)
+ _ = (func(x int) float)(nil)
+ _ = (func() func() func())(nil)
+}
+
+func _() {
+ _ = f().
+ f(func() {
+ f()
+ }).
+ f(map[int]int{
+ 1: 2,
+ 3: 4,
+ })
+
+ _ = f().
+ f(
+ func() {
+ f()
+ },
+ )
+}
diff --git a/src/go/printer/testdata/expressions.input b/src/go/printer/testdata/expressions.input
new file mode 100644
index 0000000..8c523b6
--- /dev/null
+++ b/src/go/printer/testdata/expressions.input
@@ -0,0 +1,771 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package expressions
+
+type T struct {
+ x, y, z int
+}
+
+var (
+ a, b, c, d, e int
+ under_bar int
+ longIdentifier1, longIdentifier2, longIdentifier3 int
+ t0, t1, t2 T
+ s string
+ p *int
+)
+
+
+func _() {
+ // no spaces around simple or parenthesized expressions
+ _ = (a+0)
+ _ = a+b
+ _ = a+b+c
+ _ = a+b-c
+ _ = a-b-c
+ _ = a+(b*c)
+ _ = a+(b/c)
+ _ = a-(b%c)
+ _ = 1+a
+ _ = a+1
+ _ = a+b+1
+ _ = s[a]
+ _ = s[a:]
+ _ = s[:b]
+ _ = s[1:2]
+ _ = s[a:b]
+ _ = s[0:len(s)]
+ _ = s[0]<<1
+ _ = (s[0]<<1)&0xf
+ _ = s[0] << 2 | s[1] >> 4
+ _ = "foo"+s
+ _ = s+"foo"
+ _ = 'a'+'b'
+ _ = len(s)/2
+ _ = len(t0.x)/a
+
+ // spaces around expressions of different precedence or expressions containing spaces
+ _ = a + -b
+ _ = a - ^b
+ _ = a / *p
+ _ = a + b*c
+ _ = 1 + b*c
+ _ = a + 2*c
+ _ = a + c*2
+ _ = 1 + 2*3
+ _ = s[1 : 2*3]
+ _ = s[a : b-c]
+ _ = s[0:]
+ _ = s[a+b]
+ _ = s[: b-c]
+ _ = s[a+b :]
+ _ = a[a<<b+1]
+ _ = a[a<<b+1 :]
+ _ = s[a+b : len(s)]
+ _ = s[len(s) : -a]
+ _ = s[a : len(s)+1]
+ _ = s[a : len(s)+1]+s
+
+ // spaces around operators with equal or lower precedence than comparisons
+ _ = a == b
+ _ = a != b
+ _ = a > b
+ _ = a >= b
+ _ = a < b
+ _ = a <= b
+ _ = a < b && c > d
+ _ = a < b || c > d
+
+ // spaces around "long" operands
+ _ = a + longIdentifier1
+ _ = longIdentifier1 + a
+ _ = longIdentifier1 + longIdentifier2 * longIdentifier3
+ _ = s + "a longer string"
+
+ // some selected cases
+ _ = a + t0.x
+ _ = a + t0.x + t1.x * t2.x
+ _ = a + b + c + d + e + 2*3
+ _ = a + b + c + 2*3 + d + e
+ _ = (a+b+c)*2
+ _ = a - b + c - d + (a+b+c) + d&e
+ _ = under_bar-1
+ _ = Open(dpath + "/file", O_WRONLY | O_CREAT, 0666)
+ _ = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx)
+
+ // test case for issue 8021
+ // want:
+ // ([]bool{})[([]int{})[((1)+(((1)+((((1)*(((1)+(1))+(1)))+(1))*(1)))+(1)))]]
+ _ = ([]bool{})[([]int{})[((1) + (((((1) + (((((((1) * (((((1) + (1))) + (1))))) + (1))) * (1))))) + (1))))]]
+
+ // the parser does not restrict expressions that may appear as statements
+ true
+ 42
+ "foo"
+ x
+ (x)
+ a+b
+ a+b+c
+ a+(b*c)
+ a+(b/c)
+ 1+a
+ a+1
+ s[a]
+ x<<1
+ (s[0]<<1)&0xf
+ "foo"+s
+ x == y
+ x < y || z > 42
+}
+
+
+// slice expressions with cap
+func _() {
+ _ = x[a:b:c]
+ _ = x[a:b:c+d]
+ _ = x[a:b+d:c]
+ _ = x[a:b+d:c+d]
+ _ = x[a+d:b:c]
+ _ = x[a+d:b:c+d]
+ _ = x[a+d:b+d:c]
+ _ = x[a+d:b+d:c+d]
+
+ _ = x[:b:c]
+ _ = x[:b:c+d]
+ _ = x[:b+d:c]
+ _ = x[:b+d:c+d]
+}
+
+func issue22111() {
+ _ = x[:]
+
+ _ = x[:b]
+ _ = x[:b+1]
+
+ _ = x[a:]
+ _ = x[a+1:]
+
+ _ = x[a:b]
+ _ = x[a+1:b]
+ _ = x[a:b+1]
+ _ = x[a+1:b+1]
+
+ _ = x[:b:c]
+ _ = x[:b+1:c]
+ _ = x[:b:c+1]
+ _ = x[:b+1:c+1]
+
+ _ = x[a:b:c]
+ _ = x[a+1:b:c]
+ _ = x[a:b+1:c]
+ _ = x[a+1:b+1:c]
+ _ = x[a:b:c+1]
+ _ = x[a+1:b:c+1]
+ _ = x[a:b+1:c+1]
+ _ = x[a+1:b+1:c+1]
+}
+
+func _() {
+ _ = a+b
+ _ = a+b+c
+ _ = a+b*c
+ _ = a+(b*c)
+ _ = (a+b)*c
+ _ = a+(b*c*d)
+ _ = a+(b*c+d)
+
+ _ = 1<<x
+ _ = -1<<x
+ _ = 1<<x-1
+ _ = -1<<x-1
+
+ _ = f(a+b)
+ _ = f(a+b+c)
+ _ = f(a+b*c)
+ _ = f(a+(b*c))
+ _ = f(1<<x-1, 1<<x-2)
+
+ _ = 1<<d.logWindowSize-1
+
+ buf = make(x, 2*cap(b.buf) + n)
+
+ dst[i*3+2] = dbuf[0]<<2
+ dst[i*3+2] = dbuf[0]<<2 | dbuf[1]>>4
+
+ b.buf = b.buf[0:b.off+m+n]
+ b.buf = b.buf[0:b.off+m*n]
+ f(b.buf[0:b.off+m+n])
+
+ signed += ' '*8
+ tw.octal(header[148:155], chksum)
+
+ _ = x > 0 && i >= 0
+
+ x1, x0 := x>>w2, x&m2
+ z0 = t1<<w2+t0
+ z1 = (t1+t0>>w2)>>w2
+ q1, r1 := x1/d1, x1%d1
+ r1 = r1*b2 | x0>>w2
+ x1 = (x1<<z)|(x0>>(uint(w)-z))
+ x1 = x1<<z | x0>>(uint(w)-z)
+
+ _ = buf[0:len(buf)+1]
+ _ = buf[0:n+1]
+
+ a,b = b,a
+ a = b+c
+ a = b*c+d
+ _ = a*b+c
+ _ = a-b-c
+ _ = a-(b-c)
+ _ = a-b*c
+ _ = a-(b*c)
+ _ = a*b/c
+ _ = a/ *b
+ _ = x[a|^b]
+ _ = x[a/ *b]
+ _ = a& ^b
+ _ = a+ +b
+ _ = a- -b
+ _ = x[a*-b]
+ _ = x[a+ +b]
+ _ = x^y^z
+ _ = b[a>>24] ^ b[(a>>16)&0xFF] ^ b[(a>>8)&0xFF] ^ b[a&0xFF]
+ _ = len(longVariableName)*2
+
+ _ = token(matchType + xlength<<lengthShift + xoffset)
+}
+
+
+func f(x int, args ...int) {
+ f(0, args...)
+ f(1, args)
+ f(2, args[0])
+
+ // make sure syntactically legal code remains syntactically legal
+ f(3, 42 ...) // a blank must remain between 42 and ...
+ f(4, 42. ...)
+ f(5, 42....)
+ f(6, 42.0 ...)
+ f(7, 42.0...)
+ f(8, .42 ...)
+ f(9, .42...)
+ f(10, 42e0 ...)
+ f(11, 42e0...)
+
+ _ = 42 .x // a blank must remain between 42 and .x
+ _ = 42. .x
+ _ = 42..x
+ _ = 42.0 .x
+ _ = 42.0.x
+ _ = .42 .x
+ _ = .42.x
+ _ = 42e0 .x
+ _ = 42e0.x
+
+ // a blank must remain between the binary operator and the 2nd operand
+ _ = x/ *y
+ _ = x< -1
+ _ = x< <-1
+ _ = x+ +1
+ _ = x- -1
+ _ = x& &x
+ _ = x& ^x
+
+ _ = f(x/ *y, x< -1, x< <-1, x+ +1, x- -1, x& &x, x& ^x)
+}
+
+
+func _() {
+ _ = T{}
+ _ = struct{}{}
+ _ = [10]T{}
+ _ = [...]T{}
+ _ = []T{}
+ _ = map[int]T{}
+}
+
+
+// one-line structs/interfaces in composite literals (up to a threshold)
+func _() {
+ _ = struct{}{}
+ _ = struct{ x int }{0}
+ _ = struct{ x, y, z int }{0, 1, 2}
+ _ = struct{ int }{0}
+ _ = struct{ s struct { int } }{struct{ int}{0} }
+
+ _ = (interface{})(nil)
+ _ = (interface{String() string})(nil)
+ _ = (interface{
+ String() string
+ })(nil)
+ _ = (interface{fmt.Stringer})(nil)
+ _ = (interface{
+ fmt.Stringer
+ })(nil)
+}
+
+func _() {
+ // do not modify literals
+ _ = "tab1 tab2 tab3 end" // string contains 3 tabs
+ _ = "tab1 tab2 tab3 end" // same string with 3 blanks - may be unaligned because editors see tabs in strings
+ _ = "" // this comment should be aligned with the one on the previous line
+ _ = ``
+ _ = `
+`
+_ = `foo
+ bar`
+ _ = `three spaces before the end of the line starting here:
+they must not be removed`
+}
+
+
+func _() {
+ // smart handling of indentation for multi-line raw strings
+ var _ = ``
+ var _ = `foo`
+ var _ = `foo
+bar`
+
+
+var _ =
+ ``
+var _ =
+ `foo`
+var _ =
+ // the next line should remain indented
+ `foo
+bar`
+
+
+ var _ = // comment
+ ``
+ var _ = // comment
+ `foo`
+ var _ = // comment
+ // the next line should remain indented
+ `foo
+bar`
+
+
+var _ = /* comment */ ``
+var _ = /* comment */ `foo`
+var _ = /* comment */ `foo
+bar`
+
+
+ var _ = /* comment */
+ ``
+ var _ = /* comment */
+ `foo`
+ var _ = /* comment */
+ // the next line should remain indented
+ `foo
+bar`
+
+
+var board = []int(
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`)
+
+
+ var state = S{
+ "foo",
+ // the next line should remain indented
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`,
+ "bar",
+ }
+}
+
+
+func _() {
+ // one-line function literals (body is on a single line)
+ _ = func() {}
+ _ = func() int { return 0 }
+ _ = func(x, y int) bool { m := (x+y)/2; return m < 0 }
+
+ // multi-line function literals (body is not on one line)
+ _ = func() {
+ }
+ _ = func() int {
+ return 0
+ }
+ _ = func(x, y int) bool {
+ m := (x+y)/2; return x < y }
+
+ f(func() {
+ })
+ f(func() int {
+ return 0
+ })
+ f(func(x, y int) bool {
+ m := (x+y)/2; return x < y })
+}
+
+
+func _() {
+ _ = [][]int {
+ []int{1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int {
+ {1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int {
+ {1},
+ {1, 2},
+ {1, 2, 3},
+ }
+ _ = [][]int {{1}, {1, 2}, {1, 2, 3}}
+}
+
+
+// various multi-line expressions
+func _() {
+ // do not add extra indentation to multi-line string lists
+ _ = "foo" + "bar"
+ _ = "foo" +
+ "bar" +
+ "bah"
+ _ = []string {
+ "abc" +
+ "def",
+ "foo" +
+ "bar",
+ }
+}
+
+
+const _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+
+const _ =
+ `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+
+const _ = `datafmt "datafmt";` +
+`default = "%v";` +
+`array = *;` +
+`datafmt.T3 = s {" " a a / ","};`
+
+
+func _() {
+ _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+ _ =
+ `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+ _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+}
+
+
+func _() {
+ // respect source lines in multi-line expressions
+ _ = a+
+ b+
+ c
+ _ = a < b ||
+ b < a
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+}
+
+
+// Alignment after overlong lines
+const (
+ _ = "991"
+ _ = "2432902008176640000" // 20!
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+)
+
+
+// Correct placement of operators and comments in multi-line expressions
+func _() {
+ _ = a + // comment
+ b + // comment
+ c
+ _ = "a" +
+ "b" + // comment
+ "c"
+ _ = "ba0408" + "7265717569726564" // field 71, encoding 2, string "required"
+}
+
+
+// Correct placement of terminating comma/closing parentheses in multi-line calls.
+func _() {
+ f(1,
+ 2,
+ 3)
+ f(1,
+ 2,
+ 3,
+ )
+ f(1,
+ 2,
+ 3) // comment
+ f(1,
+ 2,
+ 3, // comment
+ )
+ f(1,
+ 2,
+ 3)// comment
+ f(1,
+ 2,
+ 3,// comment
+ )
+}
+
+
+// Align comments in multi-line lists of single-line expressions.
+var txpix = [NCOL]draw.Color{
+ draw.Yellow, // yellow
+ draw.Cyan, // cyan
+ draw.Green, // lime green
+ draw.GreyBlue, // slate
+ draw.Red, /* red */
+ draw.GreyGreen, /* olive green */
+ draw.Blue, /* blue */
+ draw.Color(0xFF55AAFF), /* pink */
+ draw.Color(0xFFAAFFFF), /* lavender */
+ draw.Color(0xBB005DFF), /* maroon */
+}
+
+
+func same(t, u *Time) bool {
+ // respect source lines in multi-line expressions
+ return t.Year == u.Year &&
+ t.Month == u.Month &&
+ t.Day == u.Day &&
+ t.Hour == u.Hour &&
+ t.Minute == u.Minute &&
+ t.Second == u.Second &&
+ t.Weekday == u.Weekday &&
+ t.ZoneOffset == u.ZoneOffset &&
+ t.Zone == u.Zone
+}
+
+
+func (p *parser) charClass() {
+ // respect source lines in multi-line expressions
+ if cc.negate && len(cc.ranges) == 2 &&
+ cc.ranges[0] == '\n' && cc.ranges[1] == '\n' {
+ nl := new(_NotNl)
+ p.re.add(nl)
+ }
+}
+
+
+func addState(s []state, inst instr, match []int) {
+ // handle comments correctly in multi-line expressions
+ for i := 0; i < l; i++ {
+ if s[i].inst.index() == index && // same instruction
+ s[i].match[0] < pos { // earlier match already going; leftmost wins
+ return s
+ }
+ }
+}
+
+func (self *T) foo(x int) *T { return self }
+
+func _() { module.Func1().Func2() }
+
+func _() {
+ _ = new(T).
+ foo(1).
+ foo(2).
+ foo(3)
+
+ _ = new(T).
+ foo(1).
+ foo(2). // inline comments
+ foo(3)
+
+ _ = new(T).foo(1).foo(2).foo(3)
+
+ // handle multiline argument list correctly
+ _ = new(T).
+ foo(
+ 1).
+ foo(2)
+
+ _ = new(T).foo(
+ 1).foo(2)
+
+ _ = Array[3 +
+4]
+
+ _ = Method(1, 2,
+ 3)
+
+ _ = new(T).
+ foo().
+ bar() . (*Type)
+
+ _ = new(T).
+foo().
+bar().(*Type).
+baz()
+
+ _ = new(T).
+ foo().
+ bar()["idx"]
+
+ _ = new(T).
+ foo().
+ bar()["idx"] .
+ baz()
+
+ _ = new(T).
+ foo().
+ bar()[1:2]
+
+ _ = new(T).
+ foo().
+ bar()[1:2].
+ baz()
+
+ _ = new(T).
+ Field.
+ Array[3+
+ 4].
+ Table ["foo"].
+ Blob. (*Type).
+ Slices[1:4].
+ Method(1, 2,
+ 3).
+ Thingy
+
+ _ = a.b.c
+ _ = a.
+ b.
+ c
+ _ = a.b().c
+ _ = a.
+ b().
+ c
+ _ = a.b[0].c
+ _ = a.
+ b[0].
+ c
+ _ = a.b[0:].c
+ _ = a.
+ b[0:].
+ c
+ _ = a.b.(T).c
+ _ = a.
+ b.
+ (T).
+ c
+}
+
+
+// Don't introduce extra newlines in strangely formatted expression lists.
+func f() {
+ // os.Open parameters should remain on two lines
+ if writer, err = os.Open(outfile, s.O_WRONLY|os.O_CREATE|
+ os.O_TRUNC, 0666); err != nil {
+ log.Fatal(err)
+ }
+}
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+ _ = append(s, a...)
+ _ = append(
+ s, a...)
+ _ = append(s,
+ a...)
+ _ = append(
+ s,
+ a...)
+ _ = append(s, a...,
+ )
+ _ = append(s,
+ a...,
+ )
+ _ = append(
+ s,
+ a...,
+ )
+}
+
+// Literal function types in conversions must be parenthesized;
+// for now go/parser accepts the unparenthesized form where it
+// is non-ambiguous.
+func _() {
+ // these conversions should be rewritten to look
+ // the same as the parenthesized conversions below
+ _ = func()()(nil)
+ _ = func(x int)(float)(nil)
+ _ = func() func() func()()(nil)
+
+ _ = (func()())(nil)
+ _ = (func(x int)(float))(nil)
+ _ = (func() func() func()())(nil)
+}
+
+func _() {
+ _ = f().
+ f(func() {
+ f()
+ }).
+ f(map[int]int{
+ 1: 2,
+ 3: 4,
+})
+
+ _ = f().
+ f(
+ func() {
+ f()
+ },
+ )
+}
diff --git a/src/go/printer/testdata/expressions.raw b/src/go/printer/testdata/expressions.raw
new file mode 100644
index 0000000..058fded
--- /dev/null
+++ b/src/go/printer/testdata/expressions.raw
@@ -0,0 +1,743 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package expressions
+
+type T struct {
+ x, y, z int
+}
+
+var (
+ a, b, c, d, e int
+ under_bar int
+ longIdentifier1, longIdentifier2, longIdentifier3 int
+ t0, t1, t2 T
+ s string
+ p *int
+)
+
+func _() {
+ // no spaces around simple or parenthesized expressions
+ _ = (a + 0)
+ _ = a + b
+ _ = a + b + c
+ _ = a + b - c
+ _ = a - b - c
+ _ = a + (b * c)
+ _ = a + (b / c)
+ _ = a - (b % c)
+ _ = 1 + a
+ _ = a + 1
+ _ = a + b + 1
+ _ = s[a]
+ _ = s[a:]
+ _ = s[:b]
+ _ = s[1:2]
+ _ = s[a:b]
+ _ = s[0:len(s)]
+ _ = s[0] << 1
+ _ = (s[0] << 1) & 0xf
+ _ = s[0]<<2 | s[1]>>4
+ _ = "foo" + s
+ _ = s + "foo"
+ _ = 'a' + 'b'
+ _ = len(s) / 2
+ _ = len(t0.x) / a
+
+ // spaces around expressions of different precedence or expressions containing spaces
+ _ = a + -b
+ _ = a - ^b
+ _ = a / *p
+ _ = a + b*c
+ _ = 1 + b*c
+ _ = a + 2*c
+ _ = a + c*2
+ _ = 1 + 2*3
+ _ = s[1 : 2*3]
+ _ = s[a : b-c]
+ _ = s[0:]
+ _ = s[a+b]
+ _ = s[:b-c]
+ _ = s[a+b:]
+ _ = a[a<<b+1]
+ _ = a[a<<b+1:]
+ _ = s[a+b : len(s)]
+ _ = s[len(s):-a]
+ _ = s[a : len(s)+1]
+ _ = s[a:len(s)+1] + s
+
+ // spaces around operators with equal or lower precedence than comparisons
+ _ = a == b
+ _ = a != b
+ _ = a > b
+ _ = a >= b
+ _ = a < b
+ _ = a <= b
+ _ = a < b && c > d
+ _ = a < b || c > d
+
+ // spaces around "long" operands
+ _ = a + longIdentifier1
+ _ = longIdentifier1 + a
+ _ = longIdentifier1 + longIdentifier2*longIdentifier3
+ _ = s + "a longer string"
+
+ // some selected cases
+ _ = a + t0.x
+ _ = a + t0.x + t1.x*t2.x
+ _ = a + b + c + d + e + 2*3
+ _ = a + b + c + 2*3 + d + e
+ _ = (a + b + c) * 2
+ _ = a - b + c - d + (a + b + c) + d&e
+ _ = under_bar - 1
+ _ = Open(dpath+"/file", O_WRONLY|O_CREAT, 0666)
+ _ = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx)
+
+ // test case for issue 8021
+ // want:
+ // ([]bool{})[([]int{})[((1)+(((1)+((((1)*(((1)+(1))+(1)))+(1))*(1)))+(1)))]]
+ _ = ([]bool{})[([]int{})[((1)+(((1)+((((1)*(((1)+(1))+(1)))+(1))*(1)))+(1)))]]
+
+ // the parser does not restrict expressions that may appear as statements
+ true
+ 42
+ "foo"
+ x
+ (x)
+ a + b
+ a + b + c
+ a + (b * c)
+ a + (b / c)
+ 1 + a
+ a + 1
+ s[a]
+ x << 1
+ (s[0] << 1) & 0xf
+ "foo" + s
+ x == y
+ x < y || z > 42
+}
+
+// slice expressions with cap
+func _() {
+ _ = x[a:b:c]
+ _ = x[a : b : c+d]
+ _ = x[a : b+d : c]
+ _ = x[a : b+d : c+d]
+ _ = x[a+d : b : c]
+ _ = x[a+d : b : c+d]
+ _ = x[a+d : b+d : c]
+ _ = x[a+d : b+d : c+d]
+
+ _ = x[:b:c]
+ _ = x[: b : c+d]
+ _ = x[: b+d : c]
+ _ = x[: b+d : c+d]
+}
+
+func issue22111() {
+ _ = x[:]
+
+ _ = x[:b]
+ _ = x[:b+1]
+
+ _ = x[a:]
+ _ = x[a+1:]
+
+ _ = x[a:b]
+ _ = x[a+1 : b]
+ _ = x[a : b+1]
+ _ = x[a+1 : b+1]
+
+ _ = x[:b:c]
+ _ = x[: b+1 : c]
+ _ = x[: b : c+1]
+ _ = x[: b+1 : c+1]
+
+ _ = x[a:b:c]
+ _ = x[a+1 : b : c]
+ _ = x[a : b+1 : c]
+ _ = x[a+1 : b+1 : c]
+ _ = x[a : b : c+1]
+ _ = x[a+1 : b : c+1]
+ _ = x[a : b+1 : c+1]
+ _ = x[a+1 : b+1 : c+1]
+}
+
+func _() {
+ _ = a + b
+ _ = a + b + c
+ _ = a + b*c
+ _ = a + (b * c)
+ _ = (a + b) * c
+ _ = a + (b * c * d)
+ _ = a + (b*c + d)
+
+ _ = 1 << x
+ _ = -1 << x
+ _ = 1<<x - 1
+ _ = -1<<x - 1
+
+ _ = f(a + b)
+ _ = f(a + b + c)
+ _ = f(a + b*c)
+ _ = f(a + (b * c))
+ _ = f(1<<x-1, 1<<x-2)
+
+ _ = 1<<d.logWindowSize - 1
+
+ buf = make(x, 2*cap(b.buf)+n)
+
+ dst[i*3+2] = dbuf[0] << 2
+ dst[i*3+2] = dbuf[0]<<2 | dbuf[1]>>4
+
+ b.buf = b.buf[0 : b.off+m+n]
+ b.buf = b.buf[0 : b.off+m*n]
+ f(b.buf[0 : b.off+m+n])
+
+ signed += ' ' * 8
+ tw.octal(header[148:155], chksum)
+
+ _ = x > 0 && i >= 0
+
+ x1, x0 := x>>w2, x&m2
+ z0 = t1<<w2 + t0
+ z1 = (t1 + t0>>w2) >> w2
+ q1, r1 := x1/d1, x1%d1
+ r1 = r1*b2 | x0>>w2
+ x1 = (x1 << z) | (x0 >> (uint(w) - z))
+ x1 = x1<<z | x0>>(uint(w)-z)
+
+ _ = buf[0 : len(buf)+1]
+ _ = buf[0 : n+1]
+
+ a, b = b, a
+ a = b + c
+ a = b*c + d
+ _ = a*b + c
+ _ = a - b - c
+ _ = a - (b - c)
+ _ = a - b*c
+ _ = a - (b * c)
+ _ = a * b / c
+ _ = a / *b
+ _ = x[a|^b]
+ _ = x[a / *b]
+ _ = a & ^b
+ _ = a + +b
+ _ = a - -b
+ _ = x[a*-b]
+ _ = x[a + +b]
+ _ = x ^ y ^ z
+ _ = b[a>>24] ^ b[(a>>16)&0xFF] ^ b[(a>>8)&0xFF] ^ b[a&0xFF]
+ _ = len(longVariableName) * 2
+
+ _ = token(matchType + xlength<<lengthShift + xoffset)
+}
+
+func f(x int, args ...int) {
+ f(0, args...)
+ f(1, args)
+ f(2, args[0])
+
+ // make sure syntactically legal code remains syntactically legal
+ f(3, 42 ...) // a blank must remain between 42 and ...
+ f(4, 42....)
+ f(5, 42....)
+ f(6, 42.0...)
+ f(7, 42.0...)
+ f(8, .42...)
+ f(9, .42...)
+ f(10, 42e0...)
+ f(11, 42e0...)
+
+ _ = 42 .x // a blank must remain between 42 and .x
+ _ = 42..x
+ _ = 42..x
+ _ = 42.0.x
+ _ = 42.0.x
+ _ = .42.x
+ _ = .42.x
+ _ = 42e0.x
+ _ = 42e0.x
+
+ // a blank must remain between the binary operator and the 2nd operand
+ _ = x / *y
+ _ = x < -1
+ _ = x < <-1
+ _ = x + +1
+ _ = x - -1
+ _ = x & &x
+ _ = x & ^x
+
+ _ = f(x / *y, x < -1, x < <-1, x + +1, x - -1, x & &x, x & ^x)
+}
+
+func _() {
+ _ = T{}
+ _ = struct{}{}
+ _ = [10]T{}
+ _ = [...]T{}
+ _ = []T{}
+ _ = map[int]T{}
+}
+
+// one-line structs/interfaces in composite literals (up to a threshold)
+func _() {
+ _ = struct{}{}
+ _ = struct{ x int }{0}
+ _ = struct{ x, y, z int }{0, 1, 2}
+ _ = struct{ int }{0}
+ _ = struct{ s struct{ int } }{struct{ int }{0}}
+
+ _ = (interface{})(nil)
+ _ = (interface{ String() string })(nil)
+ _ = (interface {
+ String() string
+ })(nil)
+ _ = (interface{ fmt.Stringer })(nil)
+ _ = (interface {
+ fmt.Stringer
+ })(nil)
+}
+
+func _() {
+ // do not modify literals
+ _ = "tab1 tab2 tab3 end" // string contains 3 tabs
+ _ = "tab1 tab2 tab3 end" // same string with 3 blanks - may be unaligned because editors see tabs in strings
+ _ = "" // this comment should be aligned with the one on the previous line
+ _ = ``
+ _ = `
+`
+ _ = `foo
+ bar`
+ _ = `three spaces before the end of the line starting here:
+they must not be removed`
+}
+
+func _() {
+ // smart handling of indentation for multi-line raw strings
+ var _ = ``
+ var _ = `foo`
+ var _ = `foo
+bar`
+
+ var _ = ``
+ var _ = `foo`
+ var _ =
+ // the next line should remain indented
+ `foo
+bar`
+
+ var _ = // comment
+ ``
+ var _ = // comment
+ `foo`
+ var _ = // comment
+ // the next line should remain indented
+ `foo
+bar`
+
+ var _ = /* comment */ ``
+ var _ = /* comment */ `foo`
+ var _ = /* comment */ `foo
+bar`
+
+ var _ = /* comment */
+ ``
+ var _ = /* comment */
+ `foo`
+ var _ = /* comment */
+ // the next line should remain indented
+ `foo
+bar`
+
+ var board = []int(
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`)
+
+ var state = S{
+ "foo",
+ // the next line should remain indented
+ `...........
+...........
+....●●●....
+....●●●....
+..●●●●●●●..
+..●●●○●●●..
+..●●●●●●●..
+....●●●....
+....●●●....
+...........
+...........
+`,
+ "bar",
+ }
+}
+
+func _() {
+ // one-line function literals (body is on a single line)
+ _ = func() {}
+ _ = func() int { return 0 }
+ _ = func(x, y int) bool { m := (x + y) / 2; return m < 0 }
+
+ // multi-line function literals (body is not on one line)
+ _ = func() {
+ }
+ _ = func() int {
+ return 0
+ }
+ _ = func(x, y int) bool {
+ m := (x + y) / 2
+ return x < y
+ }
+
+ f(func() {
+ })
+ f(func() int {
+ return 0
+ })
+ f(func(x, y int) bool {
+ m := (x + y) / 2
+ return x < y
+ })
+}
+
+func _() {
+ _ = [][]int{
+ []int{1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int{
+ {1},
+ []int{1, 2},
+ []int{1, 2, 3},
+ }
+ _ = [][]int{
+ {1},
+ {1, 2},
+ {1, 2, 3},
+ }
+ _ = [][]int{{1}, {1, 2}, {1, 2, 3}}
+}
+
+// various multi-line expressions
+func _() {
+ // do not add extra indentation to multi-line string lists
+ _ = "foo" + "bar"
+ _ = "foo" +
+ "bar" +
+ "bah"
+ _ = []string{
+ "abc" +
+ "def",
+ "foo" +
+ "bar",
+ }
+}
+
+const _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+const _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+const _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+func _() {
+ _ = F1 +
+ `string = "%s";` +
+ `ptr = *;` +
+ `datafmt.T2 = s ["-" p "-"];`
+
+ _ =
+ `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+
+ _ = `datafmt "datafmt";` +
+ `default = "%v";` +
+ `array = *;` +
+ `datafmt.T3 = s {" " a a / ","};`
+}
+
+func _() {
+ // respect source lines in multi-line expressions
+ _ = a +
+ b +
+ c
+ _ = a < b ||
+ b < a
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+}
+
+// Alignment after overlong lines
+const (
+ _ = "991"
+ _ = "2432902008176640000" // 20!
+ _ = "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000" // 100!
+ _ = "170141183460469231731687303715884105727" // prime
+)
+
+// Correct placement of operators and comments in multi-line expressions
+func _() {
+ _ = a + // comment
+ b + // comment
+ c
+ _ = "a" +
+ "b" + // comment
+ "c"
+ _ = "ba0408" + "7265717569726564" // field 71, encoding 2, string "required"
+}
+
+// Correct placement of terminating comma/closing parentheses in multi-line calls.
+func _() {
+ f(1,
+ 2,
+ 3)
+ f(1,
+ 2,
+ 3,
+ )
+ f(1,
+ 2,
+ 3) // comment
+ f(1,
+ 2,
+ 3, // comment
+ )
+ f(1,
+ 2,
+ 3) // comment
+ f(1,
+ 2,
+ 3, // comment
+ )
+}
+
+// Align comments in multi-line lists of single-line expressions.
+var txpix = [NCOL]draw.Color{
+ draw.Yellow, // yellow
+ draw.Cyan, // cyan
+ draw.Green, // lime green
+ draw.GreyBlue, // slate
+ draw.Red, /* red */
+ draw.GreyGreen, /* olive green */
+ draw.Blue, /* blue */
+ draw.Color(0xFF55AAFF), /* pink */
+ draw.Color(0xFFAAFFFF), /* lavender */
+ draw.Color(0xBB005DFF), /* maroon */
+}
+
+func same(t, u *Time) bool {
+ // respect source lines in multi-line expressions
+ return t.Year == u.Year &&
+ t.Month == u.Month &&
+ t.Day == u.Day &&
+ t.Hour == u.Hour &&
+ t.Minute == u.Minute &&
+ t.Second == u.Second &&
+ t.Weekday == u.Weekday &&
+ t.ZoneOffset == u.ZoneOffset &&
+ t.Zone == u.Zone
+}
+
+func (p *parser) charClass() {
+ // respect source lines in multi-line expressions
+ if cc.negate && len(cc.ranges) == 2 &&
+ cc.ranges[0] == '\n' && cc.ranges[1] == '\n' {
+ nl := new(_NotNl)
+ p.re.add(nl)
+ }
+}
+
+func addState(s []state, inst instr, match []int) {
+ // handle comments correctly in multi-line expressions
+ for i := 0; i < l; i++ {
+ if s[i].inst.index() == index && // same instruction
+ s[i].match[0] < pos { // earlier match already going; leftmost wins
+ return s
+ }
+ }
+}
+
+func (self *T) foo(x int) *T { return self }
+
+func _() { module.Func1().Func2() }
+
+func _() {
+ _ = new(T).
+ foo(1).
+ foo(2).
+ foo(3)
+
+ _ = new(T).
+ foo(1).
+ foo(2). // inline comments
+ foo(3)
+
+ _ = new(T).foo(1).foo(2).foo(3)
+
+ // handle multiline argument list correctly
+ _ = new(T).
+ foo(
+ 1).
+ foo(2)
+
+ _ = new(T).foo(
+ 1).foo(2)
+
+ _ = Array[3+
+ 4]
+
+ _ = Method(1, 2,
+ 3)
+
+ _ = new(T).
+ foo().
+ bar().(*Type)
+
+ _ = new(T).
+ foo().
+ bar().(*Type).
+ baz()
+
+ _ = new(T).
+ foo().
+ bar()["idx"]
+
+ _ = new(T).
+ foo().
+ bar()["idx"].
+ baz()
+
+ _ = new(T).
+ foo().
+ bar()[1:2]
+
+ _ = new(T).
+ foo().
+ bar()[1:2].
+ baz()
+
+ _ = new(T).
+ Field.
+ Array[3+
+ 4].
+ Table["foo"].
+ Blob.(*Type).
+ Slices[1:4].
+ Method(1, 2,
+ 3).
+ Thingy
+
+ _ = a.b.c
+ _ = a.
+ b.
+ c
+ _ = a.b().c
+ _ = a.
+ b().
+ c
+ _ = a.b[0].c
+ _ = a.
+ b[0].
+ c
+ _ = a.b[0:].c
+ _ = a.
+ b[0:].
+ c
+ _ = a.b.(T).c
+ _ = a.
+ b.(T).
+ c
+}
+
+// Don't introduce extra newlines in strangely formatted expression lists.
+func f() {
+ // os.Open parameters should remain on two lines
+ if writer, err = os.Open(outfile, s.O_WRONLY|os.O_CREATE|
+ os.O_TRUNC, 0666); err != nil {
+ log.Fatal(err)
+ }
+}
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+ _ = append(s, a...)
+ _ = append(
+ s, a...)
+ _ = append(s,
+ a...)
+ _ = append(
+ s,
+ a...)
+ _ = append(s, a...,
+ )
+ _ = append(s,
+ a...,
+ )
+ _ = append(
+ s,
+ a...,
+ )
+}
+
+// Literal function types in conversions must be parenthesized;
+// for now go/parser accepts the unparenthesized form where it
+// is non-ambiguous.
+func _() {
+ // these conversions should be rewritten to look
+ // the same as the parenthesized conversions below
+ _ = (func())(nil)
+ _ = (func(x int) float)(nil)
+ _ = (func() func() func())(nil)
+
+ _ = (func())(nil)
+ _ = (func(x int) float)(nil)
+ _ = (func() func() func())(nil)
+}
+
+func _() {
+ _ = f().
+ f(func() {
+ f()
+ }).
+ f(map[int]int{
+ 1: 2,
+ 3: 4,
+ })
+
+ _ = f().
+ f(
+ func() {
+ f()
+ },
+ )
+}
diff --git a/src/go/printer/testdata/go2numbers.golden b/src/go/printer/testdata/go2numbers.golden
new file mode 100644
index 0000000..3c12049
--- /dev/null
+++ b/src/go/printer/testdata/go2numbers.golden
@@ -0,0 +1,186 @@
+package p
+
+const (
+ // 0-octals
+ _ = 0
+ _ = 0123
+ _ = 0123456
+
+ _ = 0_123
+ _ = 0123_456
+
+ // decimals
+ _ = 1
+ _ = 1234
+ _ = 1234567
+
+ _ = 1_234
+ _ = 1_234_567
+
+ // hexadecimals
+ _ = 0x0
+ _ = 0x1234
+ _ = 0xcafef00d
+
+ _ = 0X0
+ _ = 0X1234
+ _ = 0XCAFEf00d
+
+ _ = 0X_0
+ _ = 0X_1234
+ _ = 0X_CAFE_f00d
+
+ // octals
+ _ = 0o0
+ _ = 0o1234
+ _ = 0o01234567
+
+ _ = 0O0
+ _ = 0O1234
+ _ = 0O01234567
+
+ _ = 0o_0
+ _ = 0o_1234
+ _ = 0o0123_4567
+
+ _ = 0O_0
+ _ = 0O_1234
+ _ = 0O0123_4567
+
+ // binaries
+ _ = 0b0
+ _ = 0b1011
+ _ = 0b00101101
+
+ _ = 0B0
+ _ = 0B1011
+ _ = 0B00101101
+
+ _ = 0b_0
+ _ = 0b10_11
+ _ = 0b_0010_1101
+
+ // decimal floats
+ _ = 0.
+ _ = 123.
+ _ = 0123.
+
+ _ = .0
+ _ = .123
+ _ = .0123
+
+ _ = 0e0
+ _ = 123e+0
+ _ = 0123E-1
+
+ _ = 0e-0
+ _ = 123E+0
+ _ = 0123E123
+
+ _ = 0.e+1
+ _ = 123.E-10
+ _ = 0123.e123
+
+ _ = .0e-1
+ _ = .123E+10
+ _ = .0123E123
+
+ _ = 0.0
+ _ = 123.123
+ _ = 0123.0123
+
+ _ = 0.0e1
+ _ = 123.123E-10
+ _ = 0123.0123e+456
+
+ _ = 1_2_3.
+ _ = 0_123.
+
+ _ = 0_0e0
+ _ = 1_2_3e0
+ _ = 0_123e0
+
+ _ = 0e-0_0
+ _ = 1_2_3E+0
+ _ = 0123E1_2_3
+
+ _ = 0.e+1
+ _ = 123.E-1_0
+ _ = 01_23.e123
+
+ _ = .0e-1
+ _ = .123E+10
+ _ = .0123E123
+
+ _ = 1_2_3.123
+ _ = 0123.01_23
+
+ // hexadecimal floats
+ _ = 0x0.p+0
+ _ = 0Xdeadcafe.p-10
+ _ = 0x1234.P123
+
+ _ = 0x.1p-0
+ _ = 0X.deadcafep2
+ _ = 0x.1234P+10
+
+ _ = 0x0p0
+ _ = 0Xdeadcafep+1
+ _ = 0x1234P-10
+
+ _ = 0x0.0p0
+ _ = 0Xdead.cafep+1
+ _ = 0x12.34P-10
+
+ _ = 0Xdead_cafep+1
+ _ = 0x_1234P-10
+
+ _ = 0X_dead_cafe.p-10
+ _ = 0x12_34.P1_2_3
+ _ = 0X1_2_3_4.P-1_2_3
+
+ // imaginaries
+ _ = 0i
+ _ = 00i
+ _ = 08i
+ _ = 0000000000i
+ _ = 0123i
+ _ = 0000000123i
+ _ = 0000056789i
+ _ = 1234i
+ _ = 1234567i
+
+ _ = 0i
+ _ = 0_0i
+ _ = 0_8i
+ _ = 0_000_000_000i
+ _ = 0_123i
+ _ = 0_000_000_123i
+ _ = 0_000_056_789i
+ _ = 1_234i
+ _ = 1_234_567i
+
+ _ = 0.i
+ _ = 123.i
+ _ = 0123.i
+ _ = 000123.i
+
+ _ = 0e0i
+ _ = 123e0i
+ _ = 0123E0i
+ _ = 000123E0i
+
+ _ = 0.e+1i
+ _ = 123.E-1_0i
+ _ = 01_23.e123i
+ _ = 00_01_23.e123i
+
+ _ = 0b1010i
+ _ = 0B1010i
+ _ = 0o660i
+ _ = 0O660i
+ _ = 0xabcDEFi
+ _ = 0XabcDEFi
+ _ = 0xabcDEFP0i
+ _ = 0XabcDEFp0i
+)
diff --git a/src/go/printer/testdata/go2numbers.input b/src/go/printer/testdata/go2numbers.input
new file mode 100644
index 0000000..f3e7828
--- /dev/null
+++ b/src/go/printer/testdata/go2numbers.input
@@ -0,0 +1,186 @@
+package p
+
+const (
+ // 0-octals
+ _ = 0
+ _ = 0123
+ _ = 0123456
+
+ _ = 0_123
+ _ = 0123_456
+
+ // decimals
+ _ = 1
+ _ = 1234
+ _ = 1234567
+
+ _ = 1_234
+ _ = 1_234_567
+
+ // hexadecimals
+ _ = 0x0
+ _ = 0x1234
+ _ = 0xcafef00d
+
+ _ = 0X0
+ _ = 0X1234
+ _ = 0XCAFEf00d
+
+ _ = 0X_0
+ _ = 0X_1234
+ _ = 0X_CAFE_f00d
+
+ // octals
+ _ = 0o0
+ _ = 0o1234
+ _ = 0o01234567
+
+ _ = 0O0
+ _ = 0O1234
+ _ = 0O01234567
+
+ _ = 0o_0
+ _ = 0o_1234
+ _ = 0o0123_4567
+
+ _ = 0O_0
+ _ = 0O_1234
+ _ = 0O0123_4567
+
+ // binaries
+ _ = 0b0
+ _ = 0b1011
+ _ = 0b00101101
+
+ _ = 0B0
+ _ = 0B1011
+ _ = 0B00101101
+
+ _ = 0b_0
+ _ = 0b10_11
+ _ = 0b_0010_1101
+
+ // decimal floats
+ _ = 0.
+ _ = 123.
+ _ = 0123.
+
+ _ = .0
+ _ = .123
+ _ = .0123
+
+ _ = 0e0
+ _ = 123e+0
+ _ = 0123E-1
+
+ _ = 0e-0
+ _ = 123E+0
+ _ = 0123E123
+
+ _ = 0.e+1
+ _ = 123.E-10
+ _ = 0123.e123
+
+ _ = .0e-1
+ _ = .123E+10
+ _ = .0123E123
+
+ _ = 0.0
+ _ = 123.123
+ _ = 0123.0123
+
+ _ = 0.0e1
+ _ = 123.123E-10
+ _ = 0123.0123e+456
+
+ _ = 1_2_3.
+ _ = 0_123.
+
+ _ = 0_0e0
+ _ = 1_2_3e0
+ _ = 0_123e0
+
+ _ = 0e-0_0
+ _ = 1_2_3E+0
+ _ = 0123E1_2_3
+
+ _ = 0.e+1
+ _ = 123.E-1_0
+ _ = 01_23.e123
+
+ _ = .0e-1
+ _ = .123E+10
+ _ = .0123E123
+
+ _ = 1_2_3.123
+ _ = 0123.01_23
+
+ // hexadecimal floats
+ _ = 0x0.p+0
+ _ = 0Xdeadcafe.p-10
+ _ = 0x1234.P123
+
+ _ = 0x.1p-0
+ _ = 0X.deadcafep2
+ _ = 0x.1234P+10
+
+ _ = 0x0p0
+ _ = 0Xdeadcafep+1
+ _ = 0x1234P-10
+
+ _ = 0x0.0p0
+ _ = 0Xdead.cafep+1
+ _ = 0x12.34P-10
+
+ _ = 0Xdead_cafep+1
+ _ = 0x_1234P-10
+
+ _ = 0X_dead_cafe.p-10
+ _ = 0x12_34.P1_2_3
+ _ = 0X1_2_3_4.P-1_2_3
+
+ // imaginaries
+ _ = 0i
+ _ = 00i
+ _ = 08i
+ _ = 0000000000i
+ _ = 0123i
+ _ = 0000000123i
+ _ = 0000056789i
+ _ = 1234i
+ _ = 1234567i
+
+ _ = 0i
+ _ = 0_0i
+ _ = 0_8i
+ _ = 0_000_000_000i
+ _ = 0_123i
+ _ = 0_000_000_123i
+ _ = 0_000_056_789i
+ _ = 1_234i
+ _ = 1_234_567i
+
+ _ = 0.i
+ _ = 123.i
+ _ = 0123.i
+ _ = 000123.i
+
+ _ = 0e0i
+ _ = 123e0i
+ _ = 0123E0i
+ _ = 000123E0i
+
+ _ = 0.e+1i
+ _ = 123.E-1_0i
+ _ = 01_23.e123i
+ _ = 00_01_23.e123i
+
+ _ = 0b1010i
+ _ = 0B1010i
+ _ = 0o660i
+ _ = 0O660i
+ _ = 0xabcDEFi
+ _ = 0XabcDEFi
+ _ = 0xabcDEFP0i
+ _ = 0XabcDEFp0i
+)
diff --git a/src/go/printer/testdata/go2numbers.norm b/src/go/printer/testdata/go2numbers.norm
new file mode 100644
index 0000000..855f0fc
--- /dev/null
+++ b/src/go/printer/testdata/go2numbers.norm
@@ -0,0 +1,186 @@
+package p
+
+const (
+ // 0-octals
+ _ = 0
+ _ = 0123
+ _ = 0123456
+
+ _ = 0_123
+ _ = 0123_456
+
+ // decimals
+ _ = 1
+ _ = 1234
+ _ = 1234567
+
+ _ = 1_234
+ _ = 1_234_567
+
+ // hexadecimals
+ _ = 0x0
+ _ = 0x1234
+ _ = 0xcafef00d
+
+ _ = 0x0
+ _ = 0x1234
+ _ = 0xCAFEf00d
+
+ _ = 0x_0
+ _ = 0x_1234
+ _ = 0x_CAFE_f00d
+
+ // octals
+ _ = 0o0
+ _ = 0o1234
+ _ = 0o01234567
+
+ _ = 0o0
+ _ = 0o1234
+ _ = 0o01234567
+
+ _ = 0o_0
+ _ = 0o_1234
+ _ = 0o0123_4567
+
+ _ = 0o_0
+ _ = 0o_1234
+ _ = 0o0123_4567
+
+ // binaries
+ _ = 0b0
+ _ = 0b1011
+ _ = 0b00101101
+
+ _ = 0b0
+ _ = 0b1011
+ _ = 0b00101101
+
+ _ = 0b_0
+ _ = 0b10_11
+ _ = 0b_0010_1101
+
+ // decimal floats
+ _ = 0.
+ _ = 123.
+ _ = 0123.
+
+ _ = .0
+ _ = .123
+ _ = .0123
+
+ _ = 0e0
+ _ = 123e+0
+ _ = 0123e-1
+
+ _ = 0e-0
+ _ = 123e+0
+ _ = 0123e123
+
+ _ = 0.e+1
+ _ = 123.e-10
+ _ = 0123.e123
+
+ _ = .0e-1
+ _ = .123e+10
+ _ = .0123e123
+
+ _ = 0.0
+ _ = 123.123
+ _ = 0123.0123
+
+ _ = 0.0e1
+ _ = 123.123e-10
+ _ = 0123.0123e+456
+
+ _ = 1_2_3.
+ _ = 0_123.
+
+ _ = 0_0e0
+ _ = 1_2_3e0
+ _ = 0_123e0
+
+ _ = 0e-0_0
+ _ = 1_2_3e+0
+ _ = 0123e1_2_3
+
+ _ = 0.e+1
+ _ = 123.e-1_0
+ _ = 01_23.e123
+
+ _ = .0e-1
+ _ = .123e+10
+ _ = .0123e123
+
+ _ = 1_2_3.123
+ _ = 0123.01_23
+
+ // hexadecimal floats
+ _ = 0x0.p+0
+ _ = 0xdeadcafe.p-10
+ _ = 0x1234.p123
+
+ _ = 0x.1p-0
+ _ = 0x.deadcafep2
+ _ = 0x.1234p+10
+
+ _ = 0x0p0
+ _ = 0xdeadcafep+1
+ _ = 0x1234p-10
+
+ _ = 0x0.0p0
+ _ = 0xdead.cafep+1
+ _ = 0x12.34p-10
+
+ _ = 0xdead_cafep+1
+ _ = 0x_1234p-10
+
+ _ = 0x_dead_cafe.p-10
+ _ = 0x12_34.p1_2_3
+ _ = 0x1_2_3_4.p-1_2_3
+
+ // imaginaries
+ _ = 0i
+ _ = 0i
+ _ = 8i
+ _ = 0i
+ _ = 123i
+ _ = 123i
+ _ = 56789i
+ _ = 1234i
+ _ = 1234567i
+
+ _ = 0i
+ _ = 0i
+ _ = 8i
+ _ = 0i
+ _ = 123i
+ _ = 123i
+ _ = 56_789i
+ _ = 1_234i
+ _ = 1_234_567i
+
+ _ = 0.i
+ _ = 123.i
+ _ = 0123.i
+ _ = 000123.i
+
+ _ = 0e0i
+ _ = 123e0i
+ _ = 0123e0i
+ _ = 000123e0i
+
+ _ = 0.e+1i
+ _ = 123.e-1_0i
+ _ = 01_23.e123i
+ _ = 00_01_23.e123i
+
+ _ = 0b1010i
+ _ = 0b1010i
+ _ = 0o660i
+ _ = 0o660i
+ _ = 0xabcDEFi
+ _ = 0xabcDEFi
+ _ = 0xabcDEFp0i
+ _ = 0xabcDEFp0i
+)
diff --git a/src/go/printer/testdata/linebreaks.golden b/src/go/printer/testdata/linebreaks.golden
new file mode 100644
index 0000000..17d2b5c
--- /dev/null
+++ b/src/go/printer/testdata/linebreaks.golden
@@ -0,0 +1,295 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package linebreaks
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "os"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+type writerTestEntry struct {
+ header *Header
+ contents string
+}
+
+type writerTest struct {
+ file string // filename of expected output
+ entries []*writerTestEntry
+}
+
+var writerTests = []*writerTest{
+ &writerTest{
+ file: "testdata/writer.tar",
+ entries: []*writerTestEntry{
+ &writerTestEntry{
+ header: &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1246508266,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ contents: "Kilts",
+ },
+ &writerTestEntry{
+ header: &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1245217492,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ contents: "Google.com\n",
+ },
+ },
+ },
+ // The truncated test file was produced using these commands:
+ // dd if=/dev/zero bs=1048576 count=16384 > /tmp/16gig.txt
+ // tar -b 1 -c -f- /tmp/16gig.txt | dd bs=512 count=8 > writer-big.tar
+ &writerTest{
+ file: "testdata/writer-big.tar",
+ entries: []*writerTestEntry{
+ &writerTestEntry{
+ header: &Header{
+ Name: "tmp/16gig.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 16 << 30,
+ Mtime: 1254699560,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ // no contents
+ },
+ },
+ },
+}
+
+type untarTest struct {
+ file string
+ headers []*Header
+}
+
+var untarTests = []*untarTest{
+ &untarTest{
+ file: "testdata/gnu.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244428340,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244436044,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ },
+ },
+ &untarTest{
+ file: "testdata/star.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244592783,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ Atime: 1244592783,
+ Ctime: 1244592783,
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244592783,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ Atime: 1244592783,
+ Ctime: 1244592783,
+ },
+ },
+ },
+ &untarTest{
+ file: "testdata/v7.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0444,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244593104,
+ Typeflag: '\x00',
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0444,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244593104,
+ Typeflag: '\x00',
+ },
+ },
+ },
+}
+
+var facts = map[int]string{
+ 0: "1",
+ 1: "1",
+ 2: "2",
+ 10: "3628800",
+ 20: "2432902008176640000",
+ 100: "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000",
+}
+
+func usage() {
+ fmt.Fprintf(os.Stderr,
+ // TODO(gri): the 2nd string of this string list should not be indented
+ "usage: godoc package [name ...]\n"+
+ " godoc -http=:6060\n")
+ flag.PrintDefaults()
+ os.Exit(2)
+}
+
+func TestReader(t *testing.T) {
+testLoop:
+ for i, test := range untarTests {
+ f, err := os.Open(test.file, os.O_RDONLY, 0444)
+ if err != nil {
+ t.Errorf("test %d: Unexpected error: %v", i, err)
+ continue
+ }
+ tr := NewReader(f)
+ for j, header := range test.headers {
+ hdr, err := tr.Next()
+ if err != nil || hdr == nil {
+ t.Errorf("test %d, entry %d: Didn't get entry: %v", i, j, err)
+ f.Close()
+ continue testLoop
+ }
+ if !reflect.DeepEqual(hdr, header) {
+ t.Errorf("test %d, entry %d: Incorrect header:\nhave %+v\nwant %+v",
+ i, j, *hdr, *header)
+ }
+ }
+ hdr, err := tr.Next()
+ if hdr != nil || err != nil {
+ t.Errorf("test %d: Unexpected entry or error: hdr=%v err=%v", i, err)
+ }
+ f.Close()
+ }
+}
+
+// Respect line breaks in function calls.
+func _() {
+ f(x)
+ f(x,
+ x)
+ f(x,
+ x,
+ )
+ f(
+ x,
+ x)
+ f(
+ x,
+ x,
+ )
+}
+
+// Respect line breaks in function declarations.
+func _(x T) {}
+func _(x T,
+ y T) {
+}
+func _(x T,
+ y T,
+) {
+}
+func _(
+ x T,
+ y T) {
+}
+func _(
+ x T,
+ y T,
+) {
+}
+
+// Example from issue #2597.
+func ManageStatus0(
+ in <-chan *Status,
+ req <-chan Request,
+ stat chan<- *TargetInfo,
+ TargetHistorySize int) {
+}
+
+func ManageStatus1(
+ in <-chan *Status,
+ req <-chan Request,
+ stat chan<- *TargetInfo,
+ TargetHistorySize int,
+) {
+}
+
+// Example from issue #9064.
+func (y *y) xerrors() error {
+ _ = "xerror.test" //TODO-
+ _ = []byte(`
+foo bar foo bar foo bar
+`) //TODO-
+}
+
+func _() {
+ _ = "abc" // foo
+ _ = `abc_0123456789_` // foo
+}
+
+func _() {
+ _ = "abc" // foo
+ _ = `abc
+0123456789
+` // foo
+}
+
+// There should be exactly one linebreak after this comment.
diff --git a/src/go/printer/testdata/linebreaks.input b/src/go/printer/testdata/linebreaks.input
new file mode 100644
index 0000000..9e714f3
--- /dev/null
+++ b/src/go/printer/testdata/linebreaks.input
@@ -0,0 +1,291 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package linebreaks
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "os"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+type writerTestEntry struct {
+ header *Header
+ contents string
+}
+
+type writerTest struct {
+ file string // filename of expected output
+ entries []*writerTestEntry
+}
+
+var writerTests = []*writerTest{
+ &writerTest{
+ file: "testdata/writer.tar",
+ entries: []*writerTestEntry{
+ &writerTestEntry{
+ header: &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1246508266,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ contents: "Kilts",
+ },
+ &writerTestEntry{
+ header: &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1245217492,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ contents: "Google.com\n",
+ },
+ },
+ },
+ // The truncated test file was produced using these commands:
+ // dd if=/dev/zero bs=1048576 count=16384 > /tmp/16gig.txt
+ // tar -b 1 -c -f- /tmp/16gig.txt | dd bs=512 count=8 > writer-big.tar
+ &writerTest{
+ file: "testdata/writer-big.tar",
+ entries: []*writerTestEntry{
+ &writerTestEntry{
+ header: &Header{
+ Name: "tmp/16gig.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 16 << 30,
+ Mtime: 1254699560,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ // no contents
+ },
+ },
+ },
+}
+
+type untarTest struct {
+ file string
+ headers []*Header
+}
+
+var untarTests = []*untarTest{
+ &untarTest{
+ file: "testdata/gnu.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244428340,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244436044,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ },
+ },
+ },
+ &untarTest{
+ file: "testdata/star.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244592783,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ Atime: 1244592783,
+ Ctime: 1244592783,
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0640,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244592783,
+ Typeflag: '0',
+ Uname: "dsymonds",
+ Gname: "eng",
+ Atime: 1244592783,
+ Ctime: 1244592783,
+ },
+ },
+ },
+ &untarTest{
+ file: "testdata/v7.tar",
+ headers: []*Header{
+ &Header{
+ Name: "small.txt",
+ Mode: 0444,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 5,
+ Mtime: 1244593104,
+ Typeflag: '\x00',
+ },
+ &Header{
+ Name: "small2.txt",
+ Mode: 0444,
+ Uid: 73025,
+ Gid: 5000,
+ Size: 11,
+ Mtime: 1244593104,
+ Typeflag: '\x00',
+ },
+ },
+ },
+}
+
+var facts = map[int] string {
+ 0: "1",
+ 1: "1",
+ 2: "2",
+ 10: "3628800",
+ 20: "2432902008176640000",
+ 100: "933262154439441526816992388562667004907159682643816214685929" +
+ "638952175999932299156089414639761565182862536979208272237582" +
+ "51185210916864000000000000000000000000",
+}
+
+func usage() {
+ fmt.Fprintf(os.Stderr,
+ // TODO(gri): the 2nd string of this string list should not be indented
+ "usage: godoc package [name ...]\n" +
+ " godoc -http=:6060\n")
+ flag.PrintDefaults()
+ os.Exit(2)
+}
+
+func TestReader(t *testing.T) {
+testLoop:
+ for i, test := range untarTests {
+ f, err := os.Open(test.file, os.O_RDONLY, 0444)
+ if err != nil {
+ t.Errorf("test %d: Unexpected error: %v", i, err)
+ continue
+ }
+ tr := NewReader(f)
+ for j, header := range test.headers {
+ hdr, err := tr.Next()
+ if err != nil || hdr == nil {
+ t.Errorf("test %d, entry %d: Didn't get entry: %v", i, j, err)
+ f.Close()
+ continue testLoop
+ }
+ if !reflect.DeepEqual(hdr, header) {
+ t.Errorf("test %d, entry %d: Incorrect header:\nhave %+v\nwant %+v",
+ i, j, *hdr, *header)
+ }
+ }
+ hdr, err := tr.Next()
+ if hdr != nil || err != nil {
+ t.Errorf("test %d: Unexpected entry or error: hdr=%v err=%v", i, err)
+ }
+ f.Close()
+ }
+}
+
+// Respect line breaks in function calls.
+func _() {
+ f(x)
+ f(x,
+ x)
+ f(x,
+ x,
+ )
+ f(
+ x,
+ x)
+ f(
+ x,
+ x,
+ )
+}
+
+// Respect line breaks in function declarations.
+func _(x T) {}
+func _(x T,
+ y T) {}
+func _(x T,
+ y T,
+) {}
+func _(
+ x T,
+ y T) {}
+func _(
+ x T,
+ y T,
+) {}
+
+// Example from issue #2597.
+func ManageStatus0(
+ in <-chan *Status,
+ req <-chan Request,
+ stat chan<- *TargetInfo,
+ TargetHistorySize int) {
+}
+
+func ManageStatus1(
+ in <-chan *Status,
+ req <-chan Request,
+ stat chan<- *TargetInfo,
+ TargetHistorySize int,
+) {
+}
+
+// Example from issue #9064.
+func (y *y) xerrors() error {
+ _ = "xerror.test" //TODO-
+ _ = []byte(`
+foo bar foo bar foo bar
+`) //TODO-
+}
+
+func _() {
+ _ = "abc" // foo
+ _ = `abc_0123456789_` // foo
+}
+
+func _() {
+ _ = "abc" // foo
+ _ = `abc
+0123456789
+` // foo
+}
+
+// There should be exactly one linebreak after this comment.
diff --git a/src/go/printer/testdata/parser.go b/src/go/printer/testdata/parser.go
new file mode 100644
index 0000000..80b476c
--- /dev/null
+++ b/src/go/printer/testdata/parser.go
@@ -0,0 +1,2153 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package parser implements a parser for Go source files. Input may be
+// provided in a variety of forms (see the various Parse* functions); the
+// output is an abstract syntax tree (AST) representing the Go source. The
+// parser is invoked through one of the Parse* functions.
+
+package parser
+
+import (
+ "fmt"
+ "go/ast"
+ "go/scanner"
+ "go/token"
+)
+
+// The mode parameter to the Parse* functions is a set of flags (or 0).
+// They control the amount of source code parsed and other optional
+// parser functionality.
+//
+const (
+ PackageClauseOnly uint = 1 << iota // parsing stops after package clause
+ ImportsOnly // parsing stops after import declarations
+ ParseComments // parse comments and add them to AST
+ Trace // print a trace of parsed productions
+ DeclarationErrors // report declaration errors
+)
+
+// The parser structure holds the parser's internal state.
+type parser struct {
+ file *token.File
+ scanner.ErrorVector
+ scanner scanner.Scanner
+
+ // Tracing/debugging
+ mode uint // parsing mode
+ trace bool // == (mode & Trace != 0)
+ indent uint // indentation used for tracing output
+
+ // Comments
+ comments []*ast.CommentGroup
+ leadComment *ast.CommentGroup // last lead comment
+ lineComment *ast.CommentGroup // last line comment
+
+ // Next token
+ pos token.Pos // token position
+ tok token.Token // one token look-ahead
+ lit string // token literal
+
+ // Non-syntactic parser control
+ exprLev int // < 0: in control clause, >= 0: in expression
+
+ // Ordinary identifier scopes
+ pkgScope *ast.Scope // pkgScope.Outer == nil
+ topScope *ast.Scope // top-most scope; may be pkgScope
+ unresolved []*ast.Ident // unresolved identifiers
+ imports []*ast.ImportSpec // list of imports
+
+ // Label scope
+ // (maintained by open/close LabelScope)
+ labelScope *ast.Scope // label scope for current function
+ targetStack [][]*ast.Ident // stack of unresolved labels
+}
+
+// scannerMode returns the scanner mode bits given the parser's mode bits.
+func scannerMode(mode uint) uint {
+ var m uint = scanner.InsertSemis
+ if mode&ParseComments != 0 {
+ m |= scanner.ScanComments
+ }
+ return m
+}
+
+func (p *parser) init(fset *token.FileSet, filename string, src []byte, mode uint) {
+ p.file = fset.AddFile(filename, fset.Base(), len(src))
+ p.scanner.Init(p.file, src, p, scannerMode(mode))
+
+ p.mode = mode
+ p.trace = mode&Trace != 0 // for convenience (p.trace is used frequently)
+
+ p.next()
+
+ // set up the pkgScope here (as opposed to in parseFile) because
+ // there are other parser entry points (ParseExpr, etc.)
+ p.openScope()
+ p.pkgScope = p.topScope
+
+ // for the same reason, set up a label scope
+ p.openLabelScope()
+}
+
+// ----------------------------------------------------------------------------
+// Scoping support
+
+func (p *parser) openScope() {
+ p.topScope = ast.NewScope(p.topScope)
+}
+
+func (p *parser) closeScope() {
+ p.topScope = p.topScope.Outer
+}
+
+func (p *parser) openLabelScope() {
+ p.labelScope = ast.NewScope(p.labelScope)
+ p.targetStack = append(p.targetStack, nil)
+}
+
+func (p *parser) closeLabelScope() {
+ // resolve labels
+ n := len(p.targetStack) - 1
+ scope := p.labelScope
+ for _, ident := range p.targetStack[n] {
+ ident.Obj = scope.Lookup(ident.Name)
+ if ident.Obj == nil && p.mode&DeclarationErrors != 0 {
+ p.error(ident.Pos(), fmt.Sprintf("label %s undefined", ident.Name))
+ }
+ }
+ // pop label scope
+ p.targetStack = p.targetStack[0:n]
+ p.labelScope = p.labelScope.Outer
+}
+
+func (p *parser) declare(decl interface{}, scope *ast.Scope, kind ast.ObjKind, idents ...*ast.Ident) {
+ for _, ident := range idents {
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ if ident.Name != "_" {
+ obj := ast.NewObj(kind, ident.Name)
+ // remember the corresponding declaration for redeclaration
+ // errors and global variable resolution/typechecking phase
+ obj.Decl = decl
+ if alt := scope.Insert(obj); alt != nil && p.mode&DeclarationErrors != 0 {
+ prevDecl := ""
+ if pos := alt.Pos(); pos.IsValid() {
+ prevDecl = fmt.Sprintf("\n\tprevious declaration at %s", p.file.Position(pos))
+ }
+ p.error(ident.Pos(), fmt.Sprintf("%s redeclared in this block%s", ident.Name, prevDecl))
+ }
+ ident.Obj = obj
+ }
+ }
+}
+
+func (p *parser) shortVarDecl(idents []*ast.Ident) {
+ // Go spec: A short variable declaration may redeclare variables
+ // provided they were originally declared in the same block with
+ // the same type, and at least one of the non-blank variables is new.
+ n := 0 // number of new variables
+ for _, ident := range idents {
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ if ident.Name != "_" {
+ obj := ast.NewObj(ast.Var, ident.Name)
+ // short var declarations cannot have redeclaration errors
+ // and are not global => no need to remember the respective
+ // declaration
+ alt := p.topScope.Insert(obj)
+ if alt == nil {
+ n++ // new declaration
+ alt = obj
+ }
+ ident.Obj = alt
+ }
+ }
+ if n == 0 && p.mode&DeclarationErrors != 0 {
+ p.error(idents[0].Pos(), "no new variables on left side of :=")
+ }
+}
+
+// The unresolved object is a sentinel to mark identifiers that have been added
+// to the list of unresolved identifiers. The sentinel is only used for verifying
+// internal consistency.
+var unresolved = new(ast.Object)
+
+func (p *parser) resolve(x ast.Expr) {
+ // nothing to do if x is not an identifier or the blank identifier
+ ident, _ := x.(*ast.Ident)
+ if ident == nil {
+ return
+ }
+ assert(ident.Obj == nil, "identifier already declared or resolved")
+ if ident.Name == "_" {
+ return
+ }
+ // try to resolve the identifier
+ for s := p.topScope; s != nil; s = s.Outer {
+ if obj := s.Lookup(ident.Name); obj != nil {
+ ident.Obj = obj
+ return
+ }
+ }
+ // all local scopes are known, so any unresolved identifier
+ // must be found either in the file scope, package scope
+ // (perhaps in another file), or universe scope --- collect
+ // them so that they can be resolved later
+ ident.Obj = unresolved
+ p.unresolved = append(p.unresolved, ident)
+}
+
+// ----------------------------------------------------------------------------
+// Parsing support
+
+func (p *parser) printTrace(a ...interface{}) {
+ const dots = ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " +
+ ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "
+ const n = uint(len(dots))
+ pos := p.file.Position(p.pos)
+ fmt.Printf("%5d:%3d: ", pos.Line, pos.Column)
+ i := 2 * p.indent
+ for ; i > n; i -= n {
+ fmt.Print(dots)
+ }
+ fmt.Print(dots[0:i])
+ fmt.Println(a...)
+}
+
+func trace(p *parser, msg string) *parser {
+ p.printTrace(msg, "(")
+ p.indent++
+ return p
+}
+
+// Usage pattern: defer un(trace(p, "..."));
+func un(p *parser) {
+ p.indent--
+ p.printTrace(")")
+}
+
+// Advance to the next token.
+func (p *parser) next0() {
+ // Because of one-token look-ahead, print the previous token
+ // when tracing as it provides a more readable output. The
+ // very first token (!p.pos.IsValid()) is not initialized
+ // (it is token.ILLEGAL), so don't print it .
+ if p.trace && p.pos.IsValid() {
+ s := p.tok.String()
+ switch {
+ case p.tok.IsLiteral():
+ p.printTrace(s, p.lit)
+ case p.tok.IsOperator(), p.tok.IsKeyword():
+ p.printTrace("\"" + s + "\"")
+ default:
+ p.printTrace(s)
+ }
+ }
+
+ p.pos, p.tok, p.lit = p.scanner.Scan()
+}
+
+// Consume a comment and return it and the line on which it ends.
+func (p *parser) consumeComment() (comment *ast.Comment, endline int) {
+ // /*-style comments may end on a different line than where they start.
+ // Scan the comment for '\n' chars and adjust endline accordingly.
+ endline = p.file.Line(p.pos)
+ if p.lit[1] == '*' {
+ // don't use range here - no need to decode Unicode code points
+ for i := 0; i < len(p.lit); i++ {
+ if p.lit[i] == '\n' {
+ endline++
+ }
+ }
+ }
+
+ comment = &ast.Comment{p.pos, p.lit}
+ p.next0()
+
+ return
+}
+
+// Consume a group of adjacent comments, add it to the parser's
+// comments list, and return it together with the line at which
+// the last comment in the group ends. An empty line or non-comment
+// token terminates a comment group.
+//
+func (p *parser) consumeCommentGroup() (comments *ast.CommentGroup, endline int) {
+ var list []*ast.Comment
+ endline = p.file.Line(p.pos)
+ for p.tok == token.COMMENT && endline+1 >= p.file.Line(p.pos) {
+ var comment *ast.Comment
+ comment, endline = p.consumeComment()
+ list = append(list, comment)
+ }
+
+ // add comment group to the comments list
+ comments = &ast.CommentGroup{list}
+ p.comments = append(p.comments, comments)
+
+ return
+}
+
+// Advance to the next non-comment token. In the process, collect
+// any comment groups encountered, and remember the last lead and
+// line comments.
+//
+// A lead comment is a comment group that starts and ends in a
+// line without any other tokens and that is followed by a non-comment
+// token on the line immediately after the comment group.
+//
+// A line comment is a comment group that follows a non-comment
+// token on the same line, and that has no tokens after it on the line
+// where it ends.
+//
+// Lead and line comments may be considered documentation that is
+// stored in the AST.
+//
+func (p *parser) next() {
+ p.leadComment = nil
+ p.lineComment = nil
+ line := p.file.Line(p.pos) // current line
+ p.next0()
+
+ if p.tok == token.COMMENT {
+ var comment *ast.CommentGroup
+ var endline int
+
+ if p.file.Line(p.pos) == line {
+ // The comment is on same line as the previous token; it
+ // cannot be a lead comment but may be a line comment.
+ comment, endline = p.consumeCommentGroup()
+ if p.file.Line(p.pos) != endline {
+ // The next token is on a different line, thus
+ // the last comment group is a line comment.
+ p.lineComment = comment
+ }
+ }
+
+ // consume successor comments, if any
+ endline = -1
+ for p.tok == token.COMMENT {
+ comment, endline = p.consumeCommentGroup()
+ }
+
+ if endline+1 == p.file.Line(p.pos) {
+ // The next token is following on the line immediately after the
+ // comment group, thus the last comment group is a lead comment.
+ p.leadComment = comment
+ }
+ }
+}
+
+func (p *parser) error(pos token.Pos, msg string) {
+ p.Error(p.file.Position(pos), msg)
+}
+
+func (p *parser) errorExpected(pos token.Pos, msg string) {
+ msg = "expected " + msg
+ if pos == p.pos {
+ // the error happened at the current position;
+ // make the error message more specific
+ if p.tok == token.SEMICOLON && p.lit[0] == '\n' {
+ msg += ", found newline"
+ } else {
+ msg += ", found '" + p.tok.String() + "'"
+ if p.tok.IsLiteral() {
+ msg += " " + p.lit
+ }
+ }
+ }
+ p.error(pos, msg)
+}
+
+func (p *parser) expect(tok token.Token) token.Pos {
+ pos := p.pos
+ if p.tok != tok {
+ p.errorExpected(pos, "'"+tok.String()+"'")
+ }
+ p.next() // make progress
+ return pos
+}
+
+func (p *parser) expectSemi() {
+ if p.tok != token.RPAREN && p.tok != token.RBRACE {
+ p.expect(token.SEMICOLON)
+ }
+}
+
+func assert(cond bool, msg string) {
+ if !cond {
+ panic("go/parser internal error: " + msg)
+ }
+}
+
+// ----------------------------------------------------------------------------
+// Identifiers
+
+func (p *parser) parseIdent() *ast.Ident {
+ pos := p.pos
+ name := "_"
+ if p.tok == token.IDENT {
+ name = p.lit
+ p.next()
+ } else {
+ p.expect(token.IDENT) // use expect() error handling
+ }
+ return &ast.Ident{pos, name, nil}
+}
+
+func (p *parser) parseIdentList() (list []*ast.Ident) {
+ if p.trace {
+ defer un(trace(p, "IdentList"))
+ }
+
+ list = append(list, p.parseIdent())
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.parseIdent())
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Common productions
+
+// If lhs is set, result list elements which are identifiers are not resolved.
+func (p *parser) parseExprList(lhs bool) (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "ExpressionList"))
+ }
+
+ list = append(list, p.parseExpr(lhs))
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.parseExpr(lhs))
+ }
+
+ return
+}
+
+func (p *parser) parseLhsList() []ast.Expr {
+ list := p.parseExprList(true)
+ switch p.tok {
+ case token.DEFINE:
+ // lhs of a short variable declaration
+ p.shortVarDecl(p.makeIdentList(list))
+ case token.COLON:
+ // lhs of a label declaration or a communication clause of a select
+ // statement (parseLhsList is not called when parsing the case clause
+ // of a switch statement):
+ // - labels are declared by the caller of parseLhsList
+ // - for communication clauses, if there is a stand-alone identifier
+ // followed by a colon, we have a syntax error; there is no need
+ // to resolve the identifier in that case
+ default:
+ // identifiers must be declared elsewhere
+ for _, x := range list {
+ p.resolve(x)
+ }
+ }
+ return list
+}
+
+func (p *parser) parseRhsList() []ast.Expr {
+ return p.parseExprList(false)
+}
+
+// ----------------------------------------------------------------------------
+// Types
+
+func (p *parser) parseType() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Type"))
+ }
+
+ typ := p.tryType()
+
+ if typ == nil {
+ pos := p.pos
+ p.errorExpected(pos, "type")
+ p.next() // make progress
+ return &ast.BadExpr{pos, p.pos}
+ }
+
+ return typ
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) parseTypeName() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "TypeName"))
+ }
+
+ ident := p.parseIdent()
+ // don't resolve ident yet - it may be a parameter or field name
+
+ if p.tok == token.PERIOD {
+ // ident is a package name
+ p.next()
+ p.resolve(ident)
+ sel := p.parseIdent()
+ return &ast.SelectorExpr{ident, sel}
+ }
+
+ return ident
+}
+
+func (p *parser) parseArrayType(ellipsisOk bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "ArrayType"))
+ }
+
+ lbrack := p.expect(token.LBRACK)
+ var len ast.Expr
+ if ellipsisOk && p.tok == token.ELLIPSIS {
+ len = &ast.Ellipsis{p.pos, nil}
+ p.next()
+ } else if p.tok != token.RBRACK {
+ len = p.parseRhs()
+ }
+ p.expect(token.RBRACK)
+ elt := p.parseType()
+
+ return &ast.ArrayType{lbrack, len, elt}
+}
+
+func (p *parser) makeIdentList(list []ast.Expr) []*ast.Ident {
+ idents := make([]*ast.Ident, len(list))
+ for i, x := range list {
+ ident, isIdent := x.(*ast.Ident)
+ if !isIdent {
+ pos := x.(ast.Expr).Pos()
+ p.errorExpected(pos, "identifier")
+ ident = &ast.Ident{pos, "_", nil}
+ }
+ idents[i] = ident
+ }
+ return idents
+}
+
+func (p *parser) parseFieldDecl(scope *ast.Scope) *ast.Field {
+ if p.trace {
+ defer un(trace(p, "FieldDecl"))
+ }
+
+ doc := p.leadComment
+
+ // fields
+ list, typ := p.parseVarList(false)
+
+ // optional tag
+ var tag *ast.BasicLit
+ if p.tok == token.STRING {
+ tag = &ast.BasicLit{p.pos, p.tok, p.lit}
+ p.next()
+ }
+
+ // analyze case
+ var idents []*ast.Ident
+ if typ != nil {
+ // IdentifierList Type
+ idents = p.makeIdentList(list)
+ } else {
+ // ["*"] TypeName (AnonymousField)
+ typ = list[0] // we always have at least one element
+ p.resolve(typ)
+ if n := len(list); n > 1 || !isTypeName(deref(typ)) {
+ pos := typ.Pos()
+ p.errorExpected(pos, "anonymous field")
+ typ = &ast.BadExpr{pos, list[n-1].End()}
+ }
+ }
+
+ p.expectSemi() // call before accessing p.linecomment
+
+ field := &ast.Field{doc, idents, typ, tag, p.lineComment}
+ p.declare(field, scope, ast.Var, idents...)
+
+ return field
+}
+
+func (p *parser) parseStructType() *ast.StructType {
+ if p.trace {
+ defer un(trace(p, "StructType"))
+ }
+
+ pos := p.expect(token.STRUCT)
+ lbrace := p.expect(token.LBRACE)
+ scope := ast.NewScope(nil) // struct scope
+ var list []*ast.Field
+ for p.tok == token.IDENT || p.tok == token.MUL || p.tok == token.LPAREN {
+ // a field declaration cannot start with a '(' but we accept
+ // it here for more robust parsing and better error messages
+ // (parseFieldDecl will check and complain if necessary)
+ list = append(list, p.parseFieldDecl(scope))
+ }
+ rbrace := p.expect(token.RBRACE)
+
+ // TODO(gri): store struct scope in AST
+ return &ast.StructType{pos, &ast.FieldList{lbrace, list, rbrace}, false}
+}
+
+func (p *parser) parsePointerType() *ast.StarExpr {
+ if p.trace {
+ defer un(trace(p, "PointerType"))
+ }
+
+ star := p.expect(token.MUL)
+ base := p.parseType()
+
+ return &ast.StarExpr{star, base}
+}
+
+func (p *parser) tryVarType(isParam bool) ast.Expr {
+ if isParam && p.tok == token.ELLIPSIS {
+ pos := p.pos
+ p.next()
+ typ := p.tryIdentOrType(isParam) // don't use parseType so we can provide better error message
+ if typ == nil {
+ p.error(pos, "'...' parameter is missing type")
+ typ = &ast.BadExpr{pos, p.pos}
+ }
+ if p.tok != token.RPAREN {
+ p.error(pos, "can use '...' with last parameter type only")
+ }
+ return &ast.Ellipsis{pos, typ}
+ }
+ return p.tryIdentOrType(false)
+}
+
+func (p *parser) parseVarType(isParam bool) ast.Expr {
+ typ := p.tryVarType(isParam)
+ if typ == nil {
+ pos := p.pos
+ p.errorExpected(pos, "type")
+ p.next() // make progress
+ typ = &ast.BadExpr{pos, p.pos}
+ }
+ return typ
+}
+
+func (p *parser) parseVarList(isParam bool) (list []ast.Expr, typ ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "VarList"))
+ }
+
+ // a list of identifiers looks like a list of type names
+ for {
+ // parseVarType accepts any type (including parenthesized ones)
+ // even though the syntax does not permit them here: we
+ // accept them all for more robust parsing and complain
+ // afterwards
+ list = append(list, p.parseVarType(isParam))
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ }
+
+ // if we had a list of identifiers, it must be followed by a type
+ typ = p.tryVarType(isParam)
+ if typ != nil {
+ p.resolve(typ)
+ }
+
+ return
+}
+
+func (p *parser) parseParameterList(scope *ast.Scope, ellipsisOk bool) (params []*ast.Field) {
+ if p.trace {
+ defer un(trace(p, "ParameterList"))
+ }
+
+ list, typ := p.parseVarList(ellipsisOk)
+ if typ != nil {
+ // IdentifierList Type
+ idents := p.makeIdentList(list)
+ field := &ast.Field{nil, idents, typ, nil, nil}
+ params = append(params, field)
+ // Go spec: The scope of an identifier denoting a function
+ // parameter or result variable is the function body.
+ p.declare(field, scope, ast.Var, idents...)
+ if p.tok == token.COMMA {
+ p.next()
+ }
+
+ for p.tok != token.RPAREN && p.tok != token.EOF {
+ idents := p.parseIdentList()
+ typ := p.parseVarType(ellipsisOk)
+ field := &ast.Field{nil, idents, typ, nil, nil}
+ params = append(params, field)
+ // Go spec: The scope of an identifier denoting a function
+ // parameter or result variable is the function body.
+ p.declare(field, scope, ast.Var, idents...)
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ }
+
+ } else {
+ // Type { "," Type } (anonymous parameters)
+ params = make([]*ast.Field, len(list))
+ for i, x := range list {
+ p.resolve(x)
+ params[i] = &ast.Field{Type: x}
+ }
+ }
+
+ return
+}
+
+func (p *parser) parseParameters(scope *ast.Scope, ellipsisOk bool) *ast.FieldList {
+ if p.trace {
+ defer un(trace(p, "Parameters"))
+ }
+
+ var params []*ast.Field
+ lparen := p.expect(token.LPAREN)
+ if p.tok != token.RPAREN {
+ params = p.parseParameterList(scope, ellipsisOk)
+ }
+ rparen := p.expect(token.RPAREN)
+
+ return &ast.FieldList{lparen, params, rparen}
+}
+
+func (p *parser) parseResult(scope *ast.Scope) *ast.FieldList {
+ if p.trace {
+ defer un(trace(p, "Result"))
+ }
+
+ if p.tok == token.LPAREN {
+ return p.parseParameters(scope, false)
+ }
+
+ typ := p.tryType()
+ if typ != nil {
+ list := make([]*ast.Field, 1)
+ list[0] = &ast.Field{Type: typ}
+ return &ast.FieldList{List: list}
+ }
+
+ return nil
+}
+
+func (p *parser) parseSignature(scope *ast.Scope) (params, results *ast.FieldList) {
+ if p.trace {
+ defer un(trace(p, "Signature"))
+ }
+
+ params = p.parseParameters(scope, true)
+ results = p.parseResult(scope)
+
+ return
+}
+
+func (p *parser) parseFuncType() (*ast.FuncType, *ast.Scope) {
+ if p.trace {
+ defer un(trace(p, "FuncType"))
+ }
+
+ pos := p.expect(token.FUNC)
+ scope := ast.NewScope(p.topScope) // function scope
+ params, results := p.parseSignature(scope)
+
+ return &ast.FuncType{pos, params, results}, scope
+}
+
+func (p *parser) parseMethodSpec(scope *ast.Scope) *ast.Field {
+ if p.trace {
+ defer un(trace(p, "MethodSpec"))
+ }
+
+ doc := p.leadComment
+ var idents []*ast.Ident
+ var typ ast.Expr
+ x := p.parseTypeName()
+ if ident, isIdent := x.(*ast.Ident); isIdent && p.tok == token.LPAREN {
+ // method
+ idents = []*ast.Ident{ident}
+ scope := ast.NewScope(nil) // method scope
+ params, results := p.parseSignature(scope)
+ typ = &ast.FuncType{token.NoPos, params, results}
+ } else {
+ // embedded interface
+ typ = x
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ spec := &ast.Field{doc, idents, typ, nil, p.lineComment}
+ p.declare(spec, scope, ast.Fun, idents...)
+
+ return spec
+}
+
+func (p *parser) parseInterfaceType() *ast.InterfaceType {
+ if p.trace {
+ defer un(trace(p, "InterfaceType"))
+ }
+
+ pos := p.expect(token.INTERFACE)
+ lbrace := p.expect(token.LBRACE)
+ scope := ast.NewScope(nil) // interface scope
+ var list []*ast.Field
+ for p.tok == token.IDENT {
+ list = append(list, p.parseMethodSpec(scope))
+ }
+ rbrace := p.expect(token.RBRACE)
+
+ // TODO(gri): store interface scope in AST
+ return &ast.InterfaceType{pos, &ast.FieldList{lbrace, list, rbrace}, false}
+}
+
+func (p *parser) parseMapType() *ast.MapType {
+ if p.trace {
+ defer un(trace(p, "MapType"))
+ }
+
+ pos := p.expect(token.MAP)
+ p.expect(token.LBRACK)
+ key := p.parseType()
+ p.expect(token.RBRACK)
+ value := p.parseType()
+
+ return &ast.MapType{pos, key, value}
+}
+
+func (p *parser) parseChanType() *ast.ChanType {
+ if p.trace {
+ defer un(trace(p, "ChanType"))
+ }
+
+ pos := p.pos
+ dir := ast.SEND | ast.RECV
+ if p.tok == token.CHAN {
+ p.next()
+ if p.tok == token.ARROW {
+ p.next()
+ dir = ast.SEND
+ }
+ } else {
+ p.expect(token.ARROW)
+ p.expect(token.CHAN)
+ dir = ast.RECV
+ }
+ value := p.parseType()
+
+ return &ast.ChanType{pos, dir, value}
+}
+
+// If the result is an identifier, it is not resolved.
+func (p *parser) tryIdentOrType(ellipsisOk bool) ast.Expr {
+ switch p.tok {
+ case token.IDENT:
+ return p.parseTypeName()
+ case token.LBRACK:
+ return p.parseArrayType(ellipsisOk)
+ case token.STRUCT:
+ return p.parseStructType()
+ case token.MUL:
+ return p.parsePointerType()
+ case token.FUNC:
+ typ, _ := p.parseFuncType()
+ return typ
+ case token.INTERFACE:
+ return p.parseInterfaceType()
+ case token.MAP:
+ return p.parseMapType()
+ case token.CHAN, token.ARROW:
+ return p.parseChanType()
+ case token.LPAREN:
+ lparen := p.pos
+ p.next()
+ typ := p.parseType()
+ rparen := p.expect(token.RPAREN)
+ return &ast.ParenExpr{lparen, typ, rparen}
+ }
+
+ // no type found
+ return nil
+}
+
+func (p *parser) tryType() ast.Expr {
+ typ := p.tryIdentOrType(false)
+ if typ != nil {
+ p.resolve(typ)
+ }
+ return typ
+}
+
+// ----------------------------------------------------------------------------
+// Blocks
+
+func (p *parser) parseStmtList() (list []ast.Stmt) {
+ if p.trace {
+ defer un(trace(p, "StatementList"))
+ }
+
+ for p.tok != token.CASE && p.tok != token.DEFAULT && p.tok != token.RBRACE && p.tok != token.EOF {
+ list = append(list, p.parseStmt())
+ }
+
+ return
+}
+
+func (p *parser) parseBody(scope *ast.Scope) *ast.BlockStmt {
+ if p.trace {
+ defer un(trace(p, "Body"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ p.topScope = scope // open function scope
+ p.openLabelScope()
+ list := p.parseStmtList()
+ p.closeLabelScope()
+ p.closeScope()
+ rbrace := p.expect(token.RBRACE)
+
+ return &ast.BlockStmt{lbrace, list, rbrace}
+}
+
+func (p *parser) parseBlockStmt() *ast.BlockStmt {
+ if p.trace {
+ defer un(trace(p, "BlockStmt"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ p.openScope()
+ list := p.parseStmtList()
+ p.closeScope()
+ rbrace := p.expect(token.RBRACE)
+
+ return &ast.BlockStmt{lbrace, list, rbrace}
+}
+
+// ----------------------------------------------------------------------------
+// Expressions
+
+func (p *parser) parseFuncTypeOrLit() ast.Expr {
+ if p.trace {
+ defer un(trace(p, "FuncTypeOrLit"))
+ }
+
+ typ, scope := p.parseFuncType()
+ if p.tok != token.LBRACE {
+ // function type only
+ return typ
+ }
+
+ p.exprLev++
+ body := p.parseBody(scope)
+ p.exprLev--
+
+ return &ast.FuncLit{typ, body}
+}
+
+// parseOperand may return an expression or a raw type (incl. array
+// types of the form [...]T. Callers must verify the result.
+// If lhs is set and the result is an identifier, it is not resolved.
+//
+func (p *parser) parseOperand(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Operand"))
+ }
+
+ switch p.tok {
+ case token.IDENT:
+ x := p.parseIdent()
+ if !lhs {
+ p.resolve(x)
+ }
+ return x
+
+ case token.INT, token.FLOAT, token.IMAG, token.CHAR, token.STRING:
+ x := &ast.BasicLit{p.pos, p.tok, p.lit}
+ p.next()
+ return x
+
+ case token.LPAREN:
+ lparen := p.pos
+ p.next()
+ p.exprLev++
+ x := p.parseRhs()
+ p.exprLev--
+ rparen := p.expect(token.RPAREN)
+ return &ast.ParenExpr{lparen, x, rparen}
+
+ case token.FUNC:
+ return p.parseFuncTypeOrLit()
+
+ default:
+ if typ := p.tryIdentOrType(true); typ != nil {
+ // could be type for composite literal or conversion
+ _, isIdent := typ.(*ast.Ident)
+ assert(!isIdent, "type cannot be identifier")
+ return typ
+ }
+ }
+
+ pos := p.pos
+ p.errorExpected(pos, "operand")
+ p.next() // make progress
+ return &ast.BadExpr{pos, p.pos}
+}
+
+func (p *parser) parseSelector(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Selector"))
+ }
+
+ sel := p.parseIdent()
+
+ return &ast.SelectorExpr{x, sel}
+}
+
+func (p *parser) parseTypeAssertion(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "TypeAssertion"))
+ }
+
+ p.expect(token.LPAREN)
+ var typ ast.Expr
+ if p.tok == token.TYPE {
+ // type switch: typ == nil
+ p.next()
+ } else {
+ typ = p.parseType()
+ }
+ p.expect(token.RPAREN)
+
+ return &ast.TypeAssertExpr{x, typ}
+}
+
+func (p *parser) parseIndexOrSlice(x ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "IndexOrSlice"))
+ }
+
+ lbrack := p.expect(token.LBRACK)
+ p.exprLev++
+ var low, high ast.Expr
+ isSlice := false
+ if p.tok != token.COLON {
+ low = p.parseRhs()
+ }
+ if p.tok == token.COLON {
+ isSlice = true
+ p.next()
+ if p.tok != token.RBRACK {
+ high = p.parseRhs()
+ }
+ }
+ p.exprLev--
+ rbrack := p.expect(token.RBRACK)
+
+ if isSlice {
+ return &ast.SliceExpr{x, lbrack, low, high, rbrack}
+ }
+ return &ast.IndexExpr{x, lbrack, low, rbrack}
+}
+
+func (p *parser) parseCallOrConversion(fun ast.Expr) *ast.CallExpr {
+ if p.trace {
+ defer un(trace(p, "CallOrConversion"))
+ }
+
+ lparen := p.expect(token.LPAREN)
+ p.exprLev++
+ var list []ast.Expr
+ var ellipsis token.Pos
+ for p.tok != token.RPAREN && p.tok != token.EOF && !ellipsis.IsValid() {
+ list = append(list, p.parseRhs())
+ if p.tok == token.ELLIPSIS {
+ ellipsis = p.pos
+ p.next()
+ }
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ }
+ p.exprLev--
+ rparen := p.expect(token.RPAREN)
+
+ return &ast.CallExpr{fun, lparen, list, ellipsis, rparen}
+}
+
+func (p *parser) parseElement(keyOk bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Element"))
+ }
+
+ if p.tok == token.LBRACE {
+ return p.parseLiteralValue(nil)
+ }
+
+ x := p.parseExpr(keyOk) // don't resolve if map key
+ if keyOk {
+ if p.tok == token.COLON {
+ colon := p.pos
+ p.next()
+ return &ast.KeyValueExpr{x, colon, p.parseElement(false)}
+ }
+ p.resolve(x) // not a map key
+ }
+
+ return x
+}
+
+func (p *parser) parseElementList() (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "ElementList"))
+ }
+
+ for p.tok != token.RBRACE && p.tok != token.EOF {
+ list = append(list, p.parseElement(true))
+ if p.tok != token.COMMA {
+ break
+ }
+ p.next()
+ }
+
+ return
+}
+
+func (p *parser) parseLiteralValue(typ ast.Expr) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "LiteralValue"))
+ }
+
+ lbrace := p.expect(token.LBRACE)
+ var elts []ast.Expr
+ p.exprLev++
+ if p.tok != token.RBRACE {
+ elts = p.parseElementList()
+ }
+ p.exprLev--
+ rbrace := p.expect(token.RBRACE)
+ return &ast.CompositeLit{typ, lbrace, elts, rbrace}
+}
+
+// checkExpr checks that x is an expression (and not a type).
+func (p *parser) checkExpr(x ast.Expr) ast.Expr {
+ switch t := unparen(x).(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.BasicLit:
+ case *ast.FuncLit:
+ case *ast.CompositeLit:
+ case *ast.ParenExpr:
+ panic("unreachable")
+ case *ast.SelectorExpr:
+ case *ast.IndexExpr:
+ case *ast.SliceExpr:
+ case *ast.TypeAssertExpr:
+ if t.Type == nil {
+ // the form X.(type) is only allowed in type switch expressions
+ p.errorExpected(x.Pos(), "expression")
+ x = &ast.BadExpr{x.Pos(), x.End()}
+ }
+ case *ast.CallExpr:
+ case *ast.StarExpr:
+ case *ast.UnaryExpr:
+ if t.Op == token.RANGE {
+ // the range operator is only allowed at the top of a for statement
+ p.errorExpected(x.Pos(), "expression")
+ x = &ast.BadExpr{x.Pos(), x.End()}
+ }
+ case *ast.BinaryExpr:
+ default:
+ // all other nodes are not proper expressions
+ p.errorExpected(x.Pos(), "expression")
+ x = &ast.BadExpr{x.Pos(), x.End()}
+ }
+ return x
+}
+
+// isTypeName reports whether x is a (qualified) TypeName.
+func isTypeName(x ast.Expr) bool {
+ switch t := x.(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.SelectorExpr:
+ _, isIdent := t.X.(*ast.Ident)
+ return isIdent
+ default:
+ return false // all other nodes are not type names
+ }
+ return true
+}
+
+// isLiteralType reports whether x is a legal composite literal type.
+func isLiteralType(x ast.Expr) bool {
+ switch t := x.(type) {
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.SelectorExpr:
+ _, isIdent := t.X.(*ast.Ident)
+ return isIdent
+ case *ast.ArrayType:
+ case *ast.StructType:
+ case *ast.MapType:
+ default:
+ return false // all other nodes are not legal composite literal types
+ }
+ return true
+}
+
+// If x is of the form *T, deref returns T, otherwise it returns x.
+func deref(x ast.Expr) ast.Expr {
+ if p, isPtr := x.(*ast.StarExpr); isPtr {
+ x = p.X
+ }
+ return x
+}
+
+// If x is of the form (T), unparen returns unparen(T), otherwise it returns x.
+func unparen(x ast.Expr) ast.Expr {
+ if p, isParen := x.(*ast.ParenExpr); isParen {
+ x = unparen(p.X)
+ }
+ return x
+}
+
+// checkExprOrType checks that x is an expression or a type
+// (and not a raw type such as [...]T).
+//
+func (p *parser) checkExprOrType(x ast.Expr) ast.Expr {
+ switch t := unparen(x).(type) {
+ case *ast.ParenExpr:
+ panic("unreachable")
+ case *ast.UnaryExpr:
+ if t.Op == token.RANGE {
+ // the range operator is only allowed at the top of a for statement
+ p.errorExpected(x.Pos(), "expression")
+ x = &ast.BadExpr{x.Pos(), x.End()}
+ }
+ case *ast.ArrayType:
+ if len, isEllipsis := t.Len.(*ast.Ellipsis); isEllipsis {
+ p.error(len.Pos(), "expected array length, found '...'")
+ x = &ast.BadExpr{x.Pos(), x.End()}
+ }
+ }
+
+ // all other nodes are expressions or types
+ return x
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parsePrimaryExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "PrimaryExpr"))
+ }
+
+ x := p.parseOperand(lhs)
+L:
+ for {
+ switch p.tok {
+ case token.PERIOD:
+ p.next()
+ if lhs {
+ p.resolve(x)
+ }
+ switch p.tok {
+ case token.IDENT:
+ x = p.parseSelector(p.checkExpr(x))
+ case token.LPAREN:
+ x = p.parseTypeAssertion(p.checkExpr(x))
+ default:
+ pos := p.pos
+ p.next() // make progress
+ p.errorExpected(pos, "selector or type assertion")
+ x = &ast.BadExpr{pos, p.pos}
+ }
+ case token.LBRACK:
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseIndexOrSlice(p.checkExpr(x))
+ case token.LPAREN:
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseCallOrConversion(p.checkExprOrType(x))
+ case token.LBRACE:
+ if isLiteralType(x) && (p.exprLev >= 0 || !isTypeName(x)) {
+ if lhs {
+ p.resolve(x)
+ }
+ x = p.parseLiteralValue(x)
+ } else {
+ break L
+ }
+ default:
+ break L
+ }
+ lhs = false // no need to try to resolve again
+ }
+
+ return x
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parseUnaryExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "UnaryExpr"))
+ }
+
+ switch p.tok {
+ case token.ADD, token.SUB, token.NOT, token.XOR, token.AND, token.RANGE:
+ pos, op := p.pos, p.tok
+ p.next()
+ x := p.parseUnaryExpr(false)
+ return &ast.UnaryExpr{pos, op, p.checkExpr(x)}
+
+ case token.ARROW:
+ // channel type or receive expression
+ pos := p.pos
+ p.next()
+ if p.tok == token.CHAN {
+ p.next()
+ value := p.parseType()
+ return &ast.ChanType{pos, ast.RECV, value}
+ }
+
+ x := p.parseUnaryExpr(false)
+ return &ast.UnaryExpr{pos, token.ARROW, p.checkExpr(x)}
+
+ case token.MUL:
+ // pointer type or unary "*" expression
+ pos := p.pos
+ p.next()
+ x := p.parseUnaryExpr(false)
+ return &ast.StarExpr{pos, p.checkExprOrType(x)}
+ }
+
+ return p.parsePrimaryExpr(lhs)
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+func (p *parser) parseBinaryExpr(lhs bool, prec1 int) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "BinaryExpr"))
+ }
+
+ x := p.parseUnaryExpr(lhs)
+ for prec := p.tok.Precedence(); prec >= prec1; prec-- {
+ for p.tok.Precedence() == prec {
+ pos, op := p.pos, p.tok
+ p.next()
+ if lhs {
+ p.resolve(x)
+ lhs = false
+ }
+ y := p.parseBinaryExpr(false, prec+1)
+ x = &ast.BinaryExpr{p.checkExpr(x), pos, op, p.checkExpr(y)}
+ }
+ }
+
+ return x
+}
+
+// If lhs is set and the result is an identifier, it is not resolved.
+// TODO(gri): parseExpr may return a type or even a raw type ([..]int) -
+// should reject when a type/raw type is obviously not allowed
+func (p *parser) parseExpr(lhs bool) ast.Expr {
+ if p.trace {
+ defer un(trace(p, "Expression"))
+ }
+
+ return p.parseBinaryExpr(lhs, token.LowestPrec+1)
+}
+
+func (p *parser) parseRhs() ast.Expr {
+ return p.parseExpr(false)
+}
+
+// ----------------------------------------------------------------------------
+// Statements
+
+func (p *parser) parseSimpleStmt(labelOk bool) ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "SimpleStmt"))
+ }
+
+ x := p.parseLhsList()
+
+ switch p.tok {
+ case
+ token.DEFINE, token.ASSIGN, token.ADD_ASSIGN,
+ token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN,
+ token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN,
+ token.XOR_ASSIGN, token.SHL_ASSIGN, token.SHR_ASSIGN, token.AND_NOT_ASSIGN:
+ // assignment statement
+ pos, tok := p.pos, p.tok
+ p.next()
+ y := p.parseRhsList()
+ return &ast.AssignStmt{x, pos, tok, y}
+ }
+
+ if len(x) > 1 {
+ p.errorExpected(x[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+
+ switch p.tok {
+ case token.COLON:
+ // labeled statement
+ colon := p.pos
+ p.next()
+ if label, isIdent := x[0].(*ast.Ident); labelOk && isIdent {
+ // Go spec: The scope of a label is the body of the function
+ // in which it is declared and excludes the body of any nested
+ // function.
+ stmt := &ast.LabeledStmt{label, colon, p.parseStmt()}
+ p.declare(stmt, p.labelScope, ast.Lbl, label)
+ return stmt
+ }
+ p.error(x[0].Pos(), "illegal label declaration")
+ return &ast.BadStmt{x[0].Pos(), colon + 1}
+
+ case token.ARROW:
+ // send statement
+ arrow := p.pos
+ p.next() // consume "<-"
+ y := p.parseRhs()
+ return &ast.SendStmt{x[0], arrow, y}
+
+ case token.INC, token.DEC:
+ // increment or decrement
+ s := &ast.IncDecStmt{x[0], p.pos, p.tok}
+ p.next() // consume "++" or "--"
+ return s
+ }
+
+ // expression
+ return &ast.ExprStmt{x[0]}
+}
+
+func (p *parser) parseCallExpr() *ast.CallExpr {
+ x := p.parseRhs()
+ if call, isCall := x.(*ast.CallExpr); isCall {
+ return call
+ }
+ p.errorExpected(x.Pos(), "function/method call")
+ return nil
+}
+
+func (p *parser) parseGoStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "GoStmt"))
+ }
+
+ pos := p.expect(token.GO)
+ call := p.parseCallExpr()
+ p.expectSemi()
+ if call == nil {
+ return &ast.BadStmt{pos, pos + 2} // len("go")
+ }
+
+ return &ast.GoStmt{pos, call}
+}
+
+func (p *parser) parseDeferStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "DeferStmt"))
+ }
+
+ pos := p.expect(token.DEFER)
+ call := p.parseCallExpr()
+ p.expectSemi()
+ if call == nil {
+ return &ast.BadStmt{pos, pos + 5} // len("defer")
+ }
+
+ return &ast.DeferStmt{pos, call}
+}
+
+func (p *parser) parseReturnStmt() *ast.ReturnStmt {
+ if p.trace {
+ defer un(trace(p, "ReturnStmt"))
+ }
+
+ pos := p.pos
+ p.expect(token.RETURN)
+ var x []ast.Expr
+ if p.tok != token.SEMICOLON && p.tok != token.RBRACE {
+ x = p.parseRhsList()
+ }
+ p.expectSemi()
+
+ return &ast.ReturnStmt{pos, x}
+}
+
+func (p *parser) parseBranchStmt(tok token.Token) *ast.BranchStmt {
+ if p.trace {
+ defer un(trace(p, "BranchStmt"))
+ }
+
+ pos := p.expect(tok)
+ var label *ast.Ident
+ if tok != token.FALLTHROUGH && p.tok == token.IDENT {
+ label = p.parseIdent()
+ // add to list of unresolved targets
+ n := len(p.targetStack) - 1
+ p.targetStack[n] = append(p.targetStack[n], label)
+ }
+ p.expectSemi()
+
+ return &ast.BranchStmt{pos, tok, label}
+}
+
+func (p *parser) makeExpr(s ast.Stmt) ast.Expr {
+ if s == nil {
+ return nil
+ }
+ if es, isExpr := s.(*ast.ExprStmt); isExpr {
+ return p.checkExpr(es.X)
+ }
+ p.error(s.Pos(), "expected condition, found simple statement")
+ return &ast.BadExpr{s.Pos(), s.End()}
+}
+
+func (p *parser) parseIfStmt() *ast.IfStmt {
+ if p.trace {
+ defer un(trace(p, "IfStmt"))
+ }
+
+ pos := p.expect(token.IF)
+ p.openScope()
+ defer p.closeScope()
+
+ var s ast.Stmt
+ var x ast.Expr
+ {
+ prevLev := p.exprLev
+ p.exprLev = -1
+ if p.tok == token.SEMICOLON {
+ p.next()
+ x = p.parseRhs()
+ } else {
+ s = p.parseSimpleStmt(false)
+ if p.tok == token.SEMICOLON {
+ p.next()
+ x = p.parseRhs()
+ } else {
+ x = p.makeExpr(s)
+ s = nil
+ }
+ }
+ p.exprLev = prevLev
+ }
+
+ body := p.parseBlockStmt()
+ var else_ ast.Stmt
+ if p.tok == token.ELSE {
+ p.next()
+ else_ = p.parseStmt()
+ } else {
+ p.expectSemi()
+ }
+
+ return &ast.IfStmt{pos, s, x, body, else_}
+}
+
+func (p *parser) parseTypeList() (list []ast.Expr) {
+ if p.trace {
+ defer un(trace(p, "TypeList"))
+ }
+
+ list = append(list, p.parseType())
+ for p.tok == token.COMMA {
+ p.next()
+ list = append(list, p.parseType())
+ }
+
+ return
+}
+
+func (p *parser) parseCaseClause(exprSwitch bool) *ast.CaseClause {
+ if p.trace {
+ defer un(trace(p, "CaseClause"))
+ }
+
+ pos := p.pos
+ var list []ast.Expr
+ if p.tok == token.CASE {
+ p.next()
+ if exprSwitch {
+ list = p.parseRhsList()
+ } else {
+ list = p.parseTypeList()
+ }
+ } else {
+ p.expect(token.DEFAULT)
+ }
+
+ colon := p.expect(token.COLON)
+ p.openScope()
+ body := p.parseStmtList()
+ p.closeScope()
+
+ return &ast.CaseClause{pos, list, colon, body}
+}
+
+func isExprSwitch(s ast.Stmt) bool {
+ if s == nil {
+ return true
+ }
+ if e, ok := s.(*ast.ExprStmt); ok {
+ if a, ok := e.X.(*ast.TypeAssertExpr); ok {
+ return a.Type != nil // regular type assertion
+ }
+ return true
+ }
+ return false
+}
+
+func (p *parser) parseSwitchStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "SwitchStmt"))
+ }
+
+ pos := p.expect(token.SWITCH)
+ p.openScope()
+ defer p.closeScope()
+
+ var s1, s2 ast.Stmt
+ if p.tok != token.LBRACE {
+ prevLev := p.exprLev
+ p.exprLev = -1
+ if p.tok != token.SEMICOLON {
+ s2 = p.parseSimpleStmt(false)
+ }
+ if p.tok == token.SEMICOLON {
+ p.next()
+ s1 = s2
+ s2 = nil
+ if p.tok != token.LBRACE {
+ s2 = p.parseSimpleStmt(false)
+ }
+ }
+ p.exprLev = prevLev
+ }
+
+ exprSwitch := isExprSwitch(s2)
+ lbrace := p.expect(token.LBRACE)
+ var list []ast.Stmt
+ for p.tok == token.CASE || p.tok == token.DEFAULT {
+ list = append(list, p.parseCaseClause(exprSwitch))
+ }
+ rbrace := p.expect(token.RBRACE)
+ p.expectSemi()
+ body := &ast.BlockStmt{lbrace, list, rbrace}
+
+ if exprSwitch {
+ return &ast.SwitchStmt{pos, s1, p.makeExpr(s2), body}
+ }
+ // type switch
+ // TODO(gri): do all the checks!
+ return &ast.TypeSwitchStmt{pos, s1, s2, body}
+}
+
+func (p *parser) parseCommClause() *ast.CommClause {
+ if p.trace {
+ defer un(trace(p, "CommClause"))
+ }
+
+ p.openScope()
+ pos := p.pos
+ var comm ast.Stmt
+ if p.tok == token.CASE {
+ p.next()
+ lhs := p.parseLhsList()
+ if p.tok == token.ARROW {
+ // SendStmt
+ if len(lhs) > 1 {
+ p.errorExpected(lhs[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+ arrow := p.pos
+ p.next()
+ rhs := p.parseRhs()
+ comm = &ast.SendStmt{lhs[0], arrow, rhs}
+ } else {
+ // RecvStmt
+ pos := p.pos
+ tok := p.tok
+ var rhs ast.Expr
+ if tok == token.ASSIGN || tok == token.DEFINE {
+ // RecvStmt with assignment
+ if len(lhs) > 2 {
+ p.errorExpected(lhs[0].Pos(), "1 or 2 expressions")
+ // continue with first two expressions
+ lhs = lhs[0:2]
+ }
+ p.next()
+ rhs = p.parseRhs()
+ } else {
+ // rhs must be single receive operation
+ if len(lhs) > 1 {
+ p.errorExpected(lhs[0].Pos(), "1 expression")
+ // continue with first expression
+ }
+ rhs = lhs[0]
+ lhs = nil // there is no lhs
+ }
+ if x, isUnary := rhs.(*ast.UnaryExpr); !isUnary || x.Op != token.ARROW {
+ p.errorExpected(rhs.Pos(), "send or receive operation")
+ rhs = &ast.BadExpr{rhs.Pos(), rhs.End()}
+ }
+ if lhs != nil {
+ comm = &ast.AssignStmt{lhs, pos, tok, []ast.Expr{rhs}}
+ } else {
+ comm = &ast.ExprStmt{rhs}
+ }
+ }
+ } else {
+ p.expect(token.DEFAULT)
+ }
+
+ colon := p.expect(token.COLON)
+ body := p.parseStmtList()
+ p.closeScope()
+
+ return &ast.CommClause{pos, comm, colon, body}
+}
+
+func (p *parser) parseSelectStmt() *ast.SelectStmt {
+ if p.trace {
+ defer un(trace(p, "SelectStmt"))
+ }
+
+ pos := p.expect(token.SELECT)
+ lbrace := p.expect(token.LBRACE)
+ var list []ast.Stmt
+ for p.tok == token.CASE || p.tok == token.DEFAULT {
+ list = append(list, p.parseCommClause())
+ }
+ rbrace := p.expect(token.RBRACE)
+ p.expectSemi()
+ body := &ast.BlockStmt{lbrace, list, rbrace}
+
+ return &ast.SelectStmt{pos, body}
+}
+
+func (p *parser) parseForStmt() ast.Stmt {
+ if p.trace {
+ defer un(trace(p, "ForStmt"))
+ }
+
+ pos := p.expect(token.FOR)
+ p.openScope()
+ defer p.closeScope()
+
+ var s1, s2, s3 ast.Stmt
+ if p.tok != token.LBRACE {
+ prevLev := p.exprLev
+ p.exprLev = -1
+ if p.tok != token.SEMICOLON {
+ s2 = p.parseSimpleStmt(false)
+ }
+ if p.tok == token.SEMICOLON {
+ p.next()
+ s1 = s2
+ s2 = nil
+ if p.tok != token.SEMICOLON {
+ s2 = p.parseSimpleStmt(false)
+ }
+ p.expectSemi()
+ if p.tok != token.LBRACE {
+ s3 = p.parseSimpleStmt(false)
+ }
+ }
+ p.exprLev = prevLev
+ }
+
+ body := p.parseBlockStmt()
+ p.expectSemi()
+
+ if as, isAssign := s2.(*ast.AssignStmt); isAssign {
+ // possibly a for statement with a range clause; check assignment operator
+ if as.Tok != token.ASSIGN && as.Tok != token.DEFINE {
+ p.errorExpected(as.TokPos, "'=' or ':='")
+ return &ast.BadStmt{pos, body.End()}
+ }
+ // check lhs
+ var key, value ast.Expr
+ switch len(as.Lhs) {
+ case 2:
+ key, value = as.Lhs[0], as.Lhs[1]
+ case 1:
+ key = as.Lhs[0]
+ default:
+ p.errorExpected(as.Lhs[0].Pos(), "1 or 2 expressions")
+ return &ast.BadStmt{pos, body.End()}
+ }
+ // check rhs
+ if len(as.Rhs) != 1 {
+ p.errorExpected(as.Rhs[0].Pos(), "1 expression")
+ return &ast.BadStmt{pos, body.End()}
+ }
+ if rhs, isUnary := as.Rhs[0].(*ast.UnaryExpr); isUnary && rhs.Op == token.RANGE {
+ // rhs is range expression
+ // (any short variable declaration was handled by parseSimpleStat above)
+ return &ast.RangeStmt{pos, key, value, as.TokPos, as.Tok, rhs.X, body}
+ }
+ p.errorExpected(s2.Pos(), "range clause")
+ return &ast.BadStmt{pos, body.End()}
+ }
+
+ // regular for statement
+ return &ast.ForStmt{pos, s1, p.makeExpr(s2), s3, body}
+}
+
+func (p *parser) parseStmt() (s ast.Stmt) {
+ if p.trace {
+ defer un(trace(p, "Statement"))
+ }
+
+ switch p.tok {
+ case token.CONST, token.TYPE, token.VAR:
+ s = &ast.DeclStmt{p.parseDecl()}
+ case
+ // tokens that may start a top-level expression
+ token.IDENT, token.INT, token.FLOAT, token.CHAR, token.STRING, token.FUNC, token.LPAREN, // operand
+ token.LBRACK, token.STRUCT, // composite type
+ token.MUL, token.AND, token.ARROW, token.ADD, token.SUB, token.XOR: // unary operators
+ s = p.parseSimpleStmt(true)
+ // because of the required look-ahead, labeled statements are
+ // parsed by parseSimpleStmt - don't expect a semicolon after
+ // them
+ if _, isLabeledStmt := s.(*ast.LabeledStmt); !isLabeledStmt {
+ p.expectSemi()
+ }
+ case token.GO:
+ s = p.parseGoStmt()
+ case token.DEFER:
+ s = p.parseDeferStmt()
+ case token.RETURN:
+ s = p.parseReturnStmt()
+ case token.BREAK, token.CONTINUE, token.GOTO, token.FALLTHROUGH:
+ s = p.parseBranchStmt(p.tok)
+ case token.LBRACE:
+ s = p.parseBlockStmt()
+ p.expectSemi()
+ case token.IF:
+ s = p.parseIfStmt()
+ case token.SWITCH:
+ s = p.parseSwitchStmt()
+ case token.SELECT:
+ s = p.parseSelectStmt()
+ case token.FOR:
+ s = p.parseForStmt()
+ case token.SEMICOLON:
+ s = &ast.EmptyStmt{p.pos}
+ p.next()
+ case token.RBRACE:
+ // a semicolon may be omitted before a closing "}"
+ s = &ast.EmptyStmt{p.pos}
+ default:
+ // no statement found
+ pos := p.pos
+ p.errorExpected(pos, "statement")
+ p.next() // make progress
+ s = &ast.BadStmt{pos, p.pos}
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Declarations
+
+type parseSpecFunction func(p *parser, doc *ast.CommentGroup, iota int) ast.Spec
+
+func parseImportSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "ImportSpec"))
+ }
+
+ var ident *ast.Ident
+ switch p.tok {
+ case token.PERIOD:
+ ident = &ast.Ident{p.pos, ".", nil}
+ p.next()
+ case token.IDENT:
+ ident = p.parseIdent()
+ }
+
+ var path *ast.BasicLit
+ if p.tok == token.STRING {
+ path = &ast.BasicLit{p.pos, p.tok, p.lit}
+ p.next()
+ } else {
+ p.expect(token.STRING) // use expect() error handling
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ // collect imports
+ spec := &ast.ImportSpec{doc, ident, path, p.lineComment}
+ p.imports = append(p.imports, spec)
+
+ return spec
+}
+
+func parseConstSpec(p *parser, doc *ast.CommentGroup, iota int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "ConstSpec"))
+ }
+
+ idents := p.parseIdentList()
+ typ := p.tryType()
+ var values []ast.Expr
+ if typ != nil || p.tok == token.ASSIGN || iota == 0 {
+ p.expect(token.ASSIGN)
+ values = p.parseRhsList()
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ // Go spec: The scope of a constant or variable identifier declared inside
+ // a function begins at the end of the ConstSpec or VarSpec and ends at
+ // the end of the innermost containing block.
+ // (Global identifiers are resolved in a separate phase after parsing.)
+ spec := &ast.ValueSpec{doc, idents, typ, values, p.lineComment}
+ p.declare(spec, p.topScope, ast.Con, idents...)
+
+ return spec
+}
+
+func parseTypeSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "TypeSpec"))
+ }
+
+ ident := p.parseIdent()
+
+ // Go spec: The scope of a type identifier declared inside a function begins
+ // at the identifier in the TypeSpec and ends at the end of the innermost
+ // containing block.
+ // (Global identifiers are resolved in a separate phase after parsing.)
+ spec := &ast.TypeSpec{doc, ident, nil, nil}
+ p.declare(spec, p.topScope, ast.Typ, ident)
+
+ spec.Type = p.parseType()
+ p.expectSemi() // call before accessing p.linecomment
+ spec.Comment = p.lineComment
+
+ return spec
+}
+
+func parseVarSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
+ if p.trace {
+ defer un(trace(p, "VarSpec"))
+ }
+
+ idents := p.parseIdentList()
+ typ := p.tryType()
+ var values []ast.Expr
+ if typ == nil || p.tok == token.ASSIGN {
+ p.expect(token.ASSIGN)
+ values = p.parseRhsList()
+ }
+ p.expectSemi() // call before accessing p.linecomment
+
+ // Go spec: The scope of a constant or variable identifier declared inside
+ // a function begins at the end of the ConstSpec or VarSpec and ends at
+ // the end of the innermost containing block.
+ // (Global identifiers are resolved in a separate phase after parsing.)
+ spec := &ast.ValueSpec{doc, idents, typ, values, p.lineComment}
+ p.declare(spec, p.topScope, ast.Var, idents...)
+
+ return spec
+}
+
+func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction) *ast.GenDecl {
+ if p.trace {
+ defer un(trace(p, "GenDecl("+keyword.String()+")"))
+ }
+
+ doc := p.leadComment
+ pos := p.expect(keyword)
+ var lparen, rparen token.Pos
+ var list []ast.Spec
+ if p.tok == token.LPAREN {
+ lparen = p.pos
+ p.next()
+ for iota := 0; p.tok != token.RPAREN && p.tok != token.EOF; iota++ {
+ list = append(list, f(p, p.leadComment, iota))
+ }
+ rparen = p.expect(token.RPAREN)
+ p.expectSemi()
+ } else {
+ list = append(list, f(p, nil, 0))
+ }
+
+ return &ast.GenDecl{doc, pos, keyword, lparen, list, rparen}
+}
+
+func (p *parser) parseReceiver(scope *ast.Scope) *ast.FieldList {
+ if p.trace {
+ defer un(trace(p, "Receiver"))
+ }
+
+ pos := p.pos
+ par := p.parseParameters(scope, false)
+
+ // must have exactly one receiver
+ if par.NumFields() != 1 {
+ p.errorExpected(pos, "exactly one receiver")
+ // TODO determine a better range for BadExpr below
+ par.List = []*ast.Field{{Type: &ast.BadExpr{pos, pos}}}
+ return par
+ }
+
+ // recv type must be of the form ["*"] identifier
+ recv := par.List[0]
+ base := deref(recv.Type)
+ if _, isIdent := base.(*ast.Ident); !isIdent {
+ p.errorExpected(base.Pos(), "(unqualified) identifier")
+ par.List = []*ast.Field{{Type: &ast.BadExpr{recv.Pos(), recv.End()}}}
+ }
+
+ return par
+}
+
+func (p *parser) parseFuncDecl() *ast.FuncDecl {
+ if p.trace {
+ defer un(trace(p, "FunctionDecl"))
+ }
+
+ doc := p.leadComment
+ pos := p.expect(token.FUNC)
+ scope := ast.NewScope(p.topScope) // function scope
+
+ var recv *ast.FieldList
+ if p.tok == token.LPAREN {
+ recv = p.parseReceiver(scope)
+ }
+
+ ident := p.parseIdent()
+
+ params, results := p.parseSignature(scope)
+
+ var body *ast.BlockStmt
+ if p.tok == token.LBRACE {
+ body = p.parseBody(scope)
+ }
+ p.expectSemi()
+
+ decl := &ast.FuncDecl{doc, recv, ident, &ast.FuncType{pos, params, results}, body}
+ if recv == nil {
+ // Go spec: The scope of an identifier denoting a constant, type,
+ // variable, or function (but not method) declared at top level
+ // (outside any function) is the package block.
+ //
+ // init() functions cannot be referred to and there may
+ // be more than one - don't put them in the pkgScope
+ if ident.Name != "init" {
+ p.declare(decl, p.pkgScope, ast.Fun, ident)
+ }
+ }
+
+ return decl
+}
+
+func (p *parser) parseDecl() ast.Decl {
+ if p.trace {
+ defer un(trace(p, "Declaration"))
+ }
+
+ var f parseSpecFunction
+ switch p.tok {
+ case token.CONST:
+ f = parseConstSpec
+
+ case token.TYPE:
+ f = parseTypeSpec
+
+ case token.VAR:
+ f = parseVarSpec
+
+ case token.FUNC:
+ return p.parseFuncDecl()
+
+ default:
+ pos := p.pos
+ p.errorExpected(pos, "declaration")
+ p.next() // make progress
+ decl := &ast.BadDecl{pos, p.pos}
+ return decl
+ }
+
+ return p.parseGenDecl(p.tok, f)
+}
+
+func (p *parser) parseDeclList() (list []ast.Decl) {
+ if p.trace {
+ defer un(trace(p, "DeclList"))
+ }
+
+ for p.tok != token.EOF {
+ list = append(list, p.parseDecl())
+ }
+
+ return
+}
+
+// ----------------------------------------------------------------------------
+// Source files
+
+func (p *parser) parseFile() *ast.File {
+ if p.trace {
+ defer un(trace(p, "File"))
+ }
+
+ // package clause
+ doc := p.leadComment
+ pos := p.expect(token.PACKAGE)
+ // Go spec: The package clause is not a declaration;
+ // the package name does not appear in any scope.
+ ident := p.parseIdent()
+ if ident.Name == "_" {
+ p.error(p.pos, "invalid package name _")
+ }
+ p.expectSemi()
+
+ var decls []ast.Decl
+
+ // Don't bother parsing the rest if we had errors already.
+ // Likely not a Go source file at all.
+
+ if p.ErrorCount() == 0 && p.mode&PackageClauseOnly == 0 {
+ // import decls
+ for p.tok == token.IMPORT {
+ decls = append(decls, p.parseGenDecl(token.IMPORT, parseImportSpec))
+ }
+
+ if p.mode&ImportsOnly == 0 {
+ // rest of package body
+ for p.tok != token.EOF {
+ decls = append(decls, p.parseDecl())
+ }
+ }
+ }
+
+ assert(p.topScope == p.pkgScope, "imbalanced scopes")
+
+ // resolve global identifiers within the same file
+ i := 0
+ for _, ident := range p.unresolved {
+ // i <= index for current ident
+ assert(ident.Obj == unresolved, "object already resolved")
+ ident.Obj = p.pkgScope.Lookup(ident.Name) // also removes unresolved sentinel
+ if ident.Obj == nil {
+ p.unresolved[i] = ident
+ i++
+ }
+ }
+
+ // TODO(gri): store p.imports in AST
+ return &ast.File{doc, pos, ident, decls, p.pkgScope, p.imports, p.unresolved[0:i], p.comments}
+}
diff --git a/src/go/printer/testdata/slow.golden b/src/go/printer/testdata/slow.golden
new file mode 100644
index 0000000..43a15cb
--- /dev/null
+++ b/src/go/printer/testdata/slow.golden
@@ -0,0 +1,85 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package deepequal_test
+
+import (
+ "testing"
+ "google3/spam/archer/frontend/deepequal"
+)
+
+func TestTwoNilValues(t *testing.T) {
+ if err := deepequal.Check(nil, nil); err != nil {
+ t.Errorf("expected nil, saw %v", err)
+ }
+}
+
+type Foo struct {
+ bar *Bar
+ bang *Bar
+}
+
+type Bar struct {
+ baz *Baz
+ foo []*Foo
+}
+
+type Baz struct {
+ entries map[int]interface{}
+ whatever string
+}
+
+func newFoo() *Foo {
+ return &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ 42: &Foo{},
+ 21: &Bar{},
+ 11: &Baz{whatever: "it's just a test"}}}},
+ bang: &Bar{foo: []*Foo{
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ 43: &Foo{},
+ 22: &Bar{},
+ 13: &Baz{whatever: "this is nuts"}}}},
+ bang: &Bar{foo: []*Foo{
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ 61: &Foo{},
+ 71: &Bar{},
+ 11: &Baz{whatever: "no, it's Go"}}}},
+ bang: &Bar{foo: []*Foo{
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ 0: &Foo{},
+ -2: &Bar{},
+ -11: &Baz{whatever: "we need to go deeper"}}}},
+ bang: &Bar{foo: []*Foo{
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ -2: &Foo{},
+ -5: &Bar{},
+ -7: &Baz{whatever: "are you serious?"}}}},
+ bang: &Bar{foo: []*Foo{}}},
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ -100: &Foo{},
+ 50: &Bar{},
+ 20: &Baz{whatever: "na, not really ..."}}}},
+ bang: &Bar{foo: []*Foo{}}}}}}}}},
+ &Foo{bar: &Bar{baz: &Baz{
+ entries: map[int]interface{}{
+ 2: &Foo{},
+ 1: &Bar{},
+ -1: &Baz{whatever: "... it's just a test."}}}},
+ bang: &Bar{foo: []*Foo{}}}}}}}}}
+}
+
+func TestElaborate(t *testing.T) {
+ a := newFoo()
+ b := newFoo()
+
+ if err := deepequal.Check(a, b); err != nil {
+ t.Errorf("expected nil, saw %v", err)
+ }
+}
diff --git a/src/go/printer/testdata/slow.input b/src/go/printer/testdata/slow.input
new file mode 100644
index 0000000..0e5a23d
--- /dev/null
+++ b/src/go/printer/testdata/slow.input
@@ -0,0 +1,85 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package deepequal_test
+
+import (
+ "testing"
+ "google3/spam/archer/frontend/deepequal"
+)
+
+func TestTwoNilValues(t *testing.T) {
+ if err := deepequal.Check(nil, nil); err != nil {
+ t.Errorf("expected nil, saw %v", err)
+ }
+}
+
+type Foo struct {
+ bar *Bar
+ bang *Bar
+}
+
+type Bar struct {
+ baz *Baz
+ foo []*Foo
+}
+
+type Baz struct {
+ entries map[int]interface{}
+ whatever string
+}
+
+func newFoo() (*Foo) {
+return &Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+42: &Foo{},
+21: &Bar{},
+11: &Baz{ whatever: "it's just a test" }}}},
+ bang: &Bar{foo: []*Foo{
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+43: &Foo{},
+22: &Bar{},
+13: &Baz{ whatever: "this is nuts" }}}},
+ bang: &Bar{foo: []*Foo{
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+61: &Foo{},
+71: &Bar{},
+11: &Baz{ whatever: "no, it's Go" }}}},
+ bang: &Bar{foo: []*Foo{
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+0: &Foo{},
+-2: &Bar{},
+-11: &Baz{ whatever: "we need to go deeper" }}}},
+ bang: &Bar{foo: []*Foo{
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+-2: &Foo{},
+-5: &Bar{},
+-7: &Baz{ whatever: "are you serious?" }}}},
+ bang: &Bar{foo: []*Foo{}}},
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+-100: &Foo{},
+50: &Bar{},
+20: &Baz{ whatever: "na, not really ..." }}}},
+ bang: &Bar{foo: []*Foo{}}}}}}}}},
+&Foo{bar: &Bar{ baz: &Baz{
+entries: map[int]interface{}{
+2: &Foo{},
+1: &Bar{},
+-1: &Baz{ whatever: "... it's just a test." }}}},
+ bang: &Bar{foo: []*Foo{}}}}}}}}}
+}
+
+func TestElaborate(t *testing.T) {
+ a := newFoo()
+ b := newFoo()
+
+ if err := deepequal.Check(a, b); err != nil {
+ t.Errorf("expected nil, saw %v", err)
+ }
+}
diff --git a/src/go/printer/testdata/statements.golden b/src/go/printer/testdata/statements.golden
new file mode 100644
index 0000000..4b13460
--- /dev/null
+++ b/src/go/printer/testdata/statements.golden
@@ -0,0 +1,644 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package statements
+
+var expr bool
+
+func use(x interface{}) {}
+
+// Formatting of multi-line return statements.
+func _f() {
+ return
+ return x, y, z
+ return T{}
+ return T{1, 2, 3},
+ x, y, z
+ return T{1, 2, 3},
+ x, y,
+ z
+ return T{1,
+ 2,
+ 3}
+ return T{1,
+ 2,
+ 3,
+ }
+ return T{
+ 1,
+ 2,
+ 3}
+ return T{
+ 1,
+ 2,
+ 3,
+ }
+ return T{
+ 1,
+ T{1, 2, 3},
+ 3,
+ }
+ return T{
+ 1,
+ T{1,
+ 2, 3},
+ 3,
+ }
+ return T{
+ 1,
+ T{1,
+ 2,
+ 3},
+ 3,
+ }
+ return T{
+ 1,
+ 2,
+ }, nil
+ return T{
+ 1,
+ 2,
+ },
+ T{
+ x: 3,
+ y: 4,
+ }, nil
+ return T{
+ 1,
+ 2,
+ },
+ nil
+ return T{
+ 1,
+ 2,
+ },
+ T{
+ x: 3,
+ y: 4,
+ },
+ nil
+ return x + y +
+ z
+ return func() {}
+ return func() {
+ _ = 0
+ }, T{
+ 1, 2,
+ }
+ return func() {
+ _ = 0
+ }
+ return func() T {
+ return T{
+ 1, 2,
+ }
+ }
+}
+
+// Formatting of multi-line returns: test cases from issue 1207.
+func F() (*T, os.Error) {
+ return &T{
+ X: 1,
+ Y: 2,
+ },
+ nil
+}
+
+func G() (*T, *T, os.Error) {
+ return &T{
+ X: 1,
+ Y: 2,
+ },
+ &T{
+ X: 3,
+ Y: 4,
+ },
+ nil
+}
+
+func _() interface{} {
+ return &fileStat{
+ name: basename(file.name),
+ size: mkSize(d.FileSizeHigh, d.FileSizeLow),
+ modTime: mkModTime(d.LastWriteTime),
+ mode: mkMode(d.FileAttributes),
+ sys: mkSysFromFI(&d),
+ }, nil
+}
+
+// Formatting of if-statement headers.
+func _() {
+ if true {
+ }
+ if true {
+ } // no semicolon printed
+ if expr {
+ }
+ if expr {
+ } // no semicolon printed
+ if expr {
+ } // no parens printed
+ if expr {
+ } // no semicolon and parens printed
+ if x := expr; true {
+ use(x)
+ }
+ if x := expr; expr {
+ use(x)
+ }
+}
+
+// Formatting of switch-statement headers.
+func _() {
+ switch {
+ }
+ switch {
+ } // no semicolon printed
+ switch expr {
+ }
+ switch expr {
+ } // no semicolon printed
+ switch expr {
+ } // no parens printed
+ switch expr {
+ } // no semicolon and parens printed
+ switch x := expr; {
+ default:
+ use(
+ x)
+ }
+ switch x := expr; expr {
+ default:
+ use(x)
+ }
+}
+
+// Formatting of switch statement bodies.
+func _() {
+ switch {
+ }
+
+ switch x := 0; x {
+ case 1:
+ use(x)
+ use(x) // followed by an empty line
+
+ case 2: // followed by an empty line
+
+ use(x) // followed by an empty line
+
+ case 3: // no empty lines
+ use(x)
+ use(x)
+ }
+
+ switch x {
+ case 0:
+ use(x)
+ case 1: // this comment should have no effect on the previous or next line
+ use(x)
+ }
+
+ switch x := 0; x {
+ case 1:
+ x = 0
+ // this comment should be indented
+ case 2:
+ x = 0
+ // this comment should not be indented, it is aligned with the next case
+ case 3:
+ x = 0
+ /* indented comment
+ aligned
+ aligned
+ */
+ // bla
+ /* and more */
+ case 4:
+ x = 0
+ /* not indented comment
+ aligned
+ aligned
+ */
+ // bla
+ /* and more */
+ case 5:
+ }
+}
+
+// Formatting of selected select statements.
+func _() {
+ select {}
+ select { /* this comment should not be tab-aligned because the closing } is on the same line */
+ }
+ select { /* this comment should be tab-aligned */
+ }
+ select { // this comment should be tab-aligned
+ }
+ select {
+ case <-c:
+ }
+}
+
+// Formatting of for-statement headers for single-line for-loops.
+func _() {
+ for {
+ }
+ for expr {
+ }
+ for expr {
+ } // no parens printed
+ for {
+ } // no semicolons printed
+ for x := expr; ; {
+ use(x)
+ }
+ for expr {
+ } // no semicolons printed
+ for expr {
+ } // no semicolons and parens printed
+ for ; ; expr = false {
+ }
+ for x := expr; expr; {
+ use(x)
+ }
+ for x := expr; ; expr = false {
+ use(x)
+ }
+ for ; expr; expr = false {
+ }
+ for x := expr; expr; expr = false {
+ use(x)
+ }
+ for x := range []int{} {
+ use(x)
+ }
+ for x := range []int{} {
+ use(x)
+ } // no parens printed
+}
+
+// Formatting of for-statement headers for multi-line for-loops.
+func _() {
+ for {
+ }
+ for expr {
+ }
+ for expr {
+ } // no parens printed
+ for {
+ } // no semicolons printed
+ for x := expr; ; {
+ use(x)
+ }
+ for expr {
+ } // no semicolons printed
+ for expr {
+ } // no semicolons and parens printed
+ for ; ; expr = false {
+ }
+ for x := expr; expr; {
+ use(x)
+ }
+ for x := expr; ; expr = false {
+ use(x)
+ }
+ for ; expr; expr = false {
+ }
+ for x := expr; expr; expr = false {
+ use(x)
+ }
+ for range []int{} {
+ println("foo")
+ }
+ for x := range []int{} {
+ use(x)
+ }
+ for x := range []int{} {
+ use(x)
+ } // no parens printed
+}
+
+// Formatting of selected short single- and multi-line statements.
+func _() {
+ if cond {
+ }
+ if cond {
+ } // multiple lines
+ if cond {
+ } else {
+ } // else clause always requires multiple lines
+
+ for {
+ }
+ for i := 0; i < len(a); 1++ {
+ }
+ for i := 0; i < len(a); 1++ {
+ a[i] = i
+ }
+ for i := 0; i < len(a); 1++ {
+ a[i] = i
+ } // multiple lines
+
+ for range a {
+ }
+ for _ = range a {
+ }
+ for _, _ = range a {
+ }
+ for i := range a {
+ }
+ for i := range a {
+ a[i] = i
+ }
+ for i := range a {
+ a[i] = i
+ } // multiple lines
+
+ go func() {
+ for {
+ a <- <-b
+ }
+ }()
+ defer func() {
+ if x := recover(); x != nil {
+ err = fmt.Sprintf("error: %s", x.msg)
+ }
+ }()
+}
+
+// Don't remove mandatory parentheses around composite literals in control clauses.
+func _() {
+ // strip parentheses - no composite literals or composite literals don't start with a type name
+ if x {
+ }
+ if x {
+ }
+ if []T{} {
+ }
+ if []T{} {
+ }
+ if []T{} {
+ }
+
+ for x {
+ }
+ for x {
+ }
+ for []T{} {
+ }
+ for []T{} {
+ }
+ for []T{} {
+ }
+
+ switch x {
+ }
+ switch x {
+ }
+ switch []T{} {
+ }
+ switch []T{} {
+ }
+
+ for _ = range []T{T{42}} {
+ }
+
+ // leave parentheses - composite literals start with a type name
+ if (T{}) {
+ }
+ if (T{}) {
+ }
+ if (T{}) {
+ }
+
+ for (T{}) {
+ }
+ for (T{}) {
+ }
+ for (T{}) {
+ }
+
+ switch (T{}) {
+ }
+ switch (T{}) {
+ }
+
+ for _ = range (T1{T{42}}) {
+ }
+
+ if x == (T{42}[0]) {
+ }
+ if (x == T{42}[0]) {
+ }
+ if x == (T{42}[0]) {
+ }
+ if x == (T{42}[0]) {
+ }
+ if x == (T{42}[0]) {
+ }
+ if x == a+b*(T{42}[0]) {
+ }
+ if (x == a+b*T{42}[0]) {
+ }
+ if x == a+b*(T{42}[0]) {
+ }
+ if x == a+(b*(T{42}[0])) {
+ }
+ if x == a+b*(T{42}[0]) {
+ }
+ if (a + b*(T{42}[0])) == x {
+ }
+ if (a + b*(T{42}[0])) == x {
+ }
+
+ if struct{ x bool }{false}.x {
+ }
+ if (struct{ x bool }{false}.x) == false {
+ }
+ if struct{ x bool }{false}.x == false {
+ }
+}
+
+// Extra empty lines inside functions. Do respect source code line
+// breaks between statement boundaries but print at most one empty
+// line at a time.
+func _() {
+
+ const _ = 0
+
+ const _ = 1
+ type _ int
+ type _ float
+
+ var _ = 0
+ var x = 1
+
+ // Each use(x) call below should have at most one empty line before and after.
+ // Known bug: The first use call may have more than one empty line before
+ // (see go/printer/nodes.go, func linebreak).
+
+ use(x)
+
+ if x < x {
+
+ use(x)
+
+ } else {
+
+ use(x)
+
+ }
+}
+
+// Formatting around labels.
+func _() {
+L:
+}
+
+func _() {
+ // this comment should be indented
+L: // no semicolon needed
+}
+
+func _() {
+ switch 0 {
+ case 0:
+ L0:
+ ; // semicolon required
+ case 1:
+ L1:
+ ; // semicolon required
+ default:
+ L2: // no semicolon needed
+ }
+}
+
+func _() {
+ f()
+L1:
+ f()
+L2:
+ ;
+L3:
+}
+
+func _() {
+ // this comment should be indented
+L:
+}
+
+func _() {
+L:
+ _ = 0
+}
+
+func _() {
+ // this comment should be indented
+L:
+ _ = 0
+}
+
+func _() {
+ for {
+ L1:
+ _ = 0
+ L2:
+ _ = 0
+ }
+}
+
+func _() {
+ // this comment should be indented
+ for {
+ L1:
+ _ = 0
+ L2:
+ _ = 0
+ }
+}
+
+func _() {
+ if true {
+ _ = 0
+ }
+ _ = 0 // the indentation here should not be affected by the long label name
+AnOverlongLabel:
+ _ = 0
+
+ if true {
+ _ = 0
+ }
+ _ = 0
+
+L:
+ _ = 0
+}
+
+func _() {
+ for {
+ goto L
+ }
+L:
+
+ MoreCode()
+}
+
+func _() {
+ for {
+ goto L
+ }
+L: // A comment on the same line as the label, followed by a single empty line.
+ // Known bug: There may be more than one empty line before MoreCode()
+ // (see go/printer/nodes.go, func linebreak).
+
+ MoreCode()
+}
+
+func _() {
+ for {
+ goto L
+ }
+L:
+
+ // There should be a single empty line before this comment.
+ MoreCode()
+}
+
+func _() {
+ for {
+ goto AVeryLongLabelThatShouldNotAffectFormatting
+ }
+AVeryLongLabelThatShouldNotAffectFormatting:
+ // There should be a single empty line after this comment.
+
+ // There should be a single empty line before this comment.
+ MoreCode()
+}
+
+// Formatting of empty statements.
+func _() {
+
+}
+
+func _() {
+}
+
+func _() {
+}
+
+func _() {
+ f()
+}
+
+func _() {
+L:
+ ;
+}
+
+func _() {
+L:
+ ;
+ f()
+}
diff --git a/src/go/printer/testdata/statements.input b/src/go/printer/testdata/statements.input
new file mode 100644
index 0000000..cade157
--- /dev/null
+++ b/src/go/printer/testdata/statements.input
@@ -0,0 +1,555 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package statements
+
+var expr bool
+
+func use(x interface{}) {}
+
+// Formatting of multi-line return statements.
+func _f() {
+ return
+ return x, y, z
+ return T{}
+ return T{1, 2, 3},
+ x, y, z
+ return T{1, 2, 3},
+ x, y,
+ z
+ return T{1,
+ 2,
+ 3}
+ return T{1,
+ 2,
+ 3,
+ }
+ return T{
+ 1,
+ 2,
+ 3}
+ return T{
+ 1,
+ 2,
+ 3,
+ }
+ return T{
+ 1,
+ T{1, 2, 3},
+ 3,
+ }
+ return T{
+ 1,
+ T{1,
+ 2, 3},
+ 3,
+ }
+ return T{
+ 1,
+ T{1,
+ 2,
+ 3},
+ 3,
+ }
+ return T{
+ 1,
+ 2,
+ }, nil
+ return T{
+ 1,
+ 2,
+ },
+ T{
+ x: 3,
+ y: 4,
+ }, nil
+ return T{
+ 1,
+ 2,
+ },
+ nil
+ return T{
+ 1,
+ 2,
+ },
+ T{
+ x: 3,
+ y: 4,
+ },
+ nil
+ return x + y +
+ z
+ return func() {}
+ return func() {
+ _ = 0
+ }, T{
+ 1, 2,
+ }
+ return func() {
+ _ = 0
+ }
+ return func() T {
+ return T {
+ 1, 2,
+ }
+ }
+}
+
+// Formatting of multi-line returns: test cases from issue 1207.
+func F() (*T, os.Error) {
+ return &T{
+ X: 1,
+ Y: 2,
+ },
+ nil
+}
+
+func G() (*T, *T, os.Error) {
+ return &T{
+ X: 1,
+ Y: 2,
+ },
+ &T{
+ X: 3,
+ Y: 4,
+ },
+ nil
+}
+
+func _() interface{} {
+ return &fileStat{
+ name: basename(file.name),
+ size: mkSize(d.FileSizeHigh, d.FileSizeLow),
+ modTime: mkModTime(d.LastWriteTime),
+ mode: mkMode(d.FileAttributes),
+ sys: mkSysFromFI(&d),
+ }, nil
+}
+
+// Formatting of if-statement headers.
+func _() {
+ if true {}
+ if; true {} // no semicolon printed
+ if expr{}
+ if;expr{} // no semicolon printed
+ if (expr){} // no parens printed
+ if;((expr)){} // no semicolon and parens printed
+ if x:=expr;true{
+ use(x)}
+ if x:=expr; expr {use(x)}
+}
+
+
+// Formatting of switch-statement headers.
+func _() {
+ switch {}
+ switch;{} // no semicolon printed
+ switch expr {}
+ switch;expr{} // no semicolon printed
+ switch (expr) {} // no parens printed
+ switch;((expr)){} // no semicolon and parens printed
+ switch x := expr; { default:use(
+x)
+ }
+ switch x := expr; expr {default:use(x)}
+}
+
+
+// Formatting of switch statement bodies.
+func _() {
+ switch {
+ }
+
+ switch x := 0; x {
+ case 1:
+ use(x)
+ use(x) // followed by an empty line
+
+ case 2: // followed by an empty line
+
+ use(x) // followed by an empty line
+
+ case 3: // no empty lines
+ use(x)
+ use(x)
+ }
+
+ switch x {
+ case 0:
+ use(x)
+ case 1: // this comment should have no effect on the previous or next line
+ use(x)
+ }
+
+ switch x := 0; x {
+ case 1:
+ x = 0
+ // this comment should be indented
+ case 2:
+ x = 0
+ // this comment should not be indented, it is aligned with the next case
+ case 3:
+ x = 0
+ /* indented comment
+ aligned
+ aligned
+ */
+ // bla
+ /* and more */
+ case 4:
+ x = 0
+ /* not indented comment
+ aligned
+ aligned
+ */
+ // bla
+ /* and more */
+ case 5:
+ }
+}
+
+
+// Formatting of selected select statements.
+func _() {
+ select {
+ }
+ select { /* this comment should not be tab-aligned because the closing } is on the same line */ }
+ select { /* this comment should be tab-aligned */
+ }
+ select { // this comment should be tab-aligned
+ }
+ select { case <-c: }
+}
+
+
+// Formatting of for-statement headers for single-line for-loops.
+func _() {
+ for{}
+ for expr {}
+ for (expr) {} // no parens printed
+ for;;{} // no semicolons printed
+ for x :=expr;; {use( x)}
+ for; expr;{} // no semicolons printed
+ for; ((expr));{} // no semicolons and parens printed
+ for; ; expr = false {}
+ for x :=expr; expr; {use(x)}
+ for x := expr;; expr=false {use(x)}
+ for;expr;expr =false {}
+ for x := expr;expr;expr = false { use(x) }
+ for x := range []int{} { use(x) }
+ for x := range (([]int{})) { use(x) } // no parens printed
+}
+
+
+// Formatting of for-statement headers for multi-line for-loops.
+func _() {
+ for{
+ }
+ for expr {
+ }
+ for (expr) {
+ } // no parens printed
+ for;;{
+ } // no semicolons printed
+ for x :=expr;; {use( x)
+ }
+ for; expr;{
+ } // no semicolons printed
+ for; ((expr));{
+ } // no semicolons and parens printed
+ for; ; expr = false {
+ }
+ for x :=expr; expr; {use(x)
+ }
+ for x := expr;; expr=false {use(x)
+ }
+ for;expr;expr =false {
+ }
+ for x := expr;expr;expr = false {
+ use(x)
+ }
+ for range []int{} {
+ println("foo")}
+ for x := range []int{} {
+ use(x) }
+ for x := range (([]int{})) {
+ use(x) } // no parens printed
+}
+
+
+// Formatting of selected short single- and multi-line statements.
+func _() {
+ if cond {}
+ if cond {
+ } // multiple lines
+ if cond {} else {} // else clause always requires multiple lines
+
+ for {}
+ for i := 0; i < len(a); 1++ {}
+ for i := 0; i < len(a); 1++ { a[i] = i }
+ for i := 0; i < len(a); 1++ { a[i] = i
+ } // multiple lines
+
+ for range a{}
+ for _ = range a{}
+ for _, _ = range a{}
+ for i := range a {}
+ for i := range a { a[i] = i }
+ for i := range a { a[i] = i
+ } // multiple lines
+
+ go func() { for { a <- <-b } }()
+ defer func() { if x := recover(); x != nil { err = fmt.Sprintf("error: %s", x.msg) } }()
+}
+
+
+// Don't remove mandatory parentheses around composite literals in control clauses.
+func _() {
+ // strip parentheses - no composite literals or composite literals don't start with a type name
+ if (x) {}
+ if (((x))) {}
+ if ([]T{}) {}
+ if (([]T{})) {}
+ if ; (((([]T{})))) {}
+
+ for (x) {}
+ for (((x))) {}
+ for ([]T{}) {}
+ for (([]T{})) {}
+ for ; (((([]T{})))) ; {}
+
+ switch (x) {}
+ switch (((x))) {}
+ switch ([]T{}) {}
+ switch ; (((([]T{})))) {}
+
+ for _ = range ((([]T{T{42}}))) {}
+
+ // leave parentheses - composite literals start with a type name
+ if (T{}) {}
+ if ((T{})) {}
+ if ; ((((T{})))) {}
+
+ for (T{}) {}
+ for ((T{})) {}
+ for ; ((((T{})))) ; {}
+
+ switch (T{}) {}
+ switch ; ((((T{})))) {}
+
+ for _ = range (((T1{T{42}}))) {}
+
+ if x == (T{42}[0]) {}
+ if (x == T{42}[0]) {}
+ if (x == (T{42}[0])) {}
+ if (x == (((T{42}[0])))) {}
+ if (((x == (T{42}[0])))) {}
+ if x == a + b*(T{42}[0]) {}
+ if (x == a + b*T{42}[0]) {}
+ if (x == a + b*(T{42}[0])) {}
+ if (x == a + ((b * (T{42}[0])))) {}
+ if (((x == a + b * (T{42}[0])))) {}
+ if (((a + b * (T{42}[0])) == x)) {}
+ if (((a + b * (T{42}[0])))) == x {}
+
+ if (struct{x bool}{false}.x) {}
+ if (struct{x bool}{false}.x) == false {}
+ if (struct{x bool}{false}.x == false) {}
+}
+
+
+// Extra empty lines inside functions. Do respect source code line
+// breaks between statement boundaries but print at most one empty
+// line at a time.
+func _() {
+
+ const _ = 0
+
+ const _ = 1
+ type _ int
+ type _ float
+
+ var _ = 0
+ var x = 1
+
+ // Each use(x) call below should have at most one empty line before and after.
+ // Known bug: The first use call may have more than one empty line before
+ // (see go/printer/nodes.go, func linebreak).
+
+
+
+ use(x)
+
+ if x < x {
+
+ use(x)
+
+ } else {
+
+ use(x)
+
+ }
+}
+
+
+// Formatting around labels.
+func _() {
+ L:
+}
+
+
+func _() {
+ // this comment should be indented
+ L: ; // no semicolon needed
+}
+
+
+func _() {
+ switch 0 {
+ case 0:
+ L0: ; // semicolon required
+ case 1:
+ L1: ; // semicolon required
+ default:
+ L2: ; // no semicolon needed
+ }
+}
+
+
+func _() {
+ f()
+L1:
+ f()
+L2:
+ ;
+L3:
+}
+
+
+func _() {
+ // this comment should be indented
+ L:
+}
+
+
+func _() {
+ L: _ = 0
+}
+
+
+func _() {
+ // this comment should be indented
+ L: _ = 0
+}
+
+
+func _() {
+ for {
+ L1: _ = 0
+ L2:
+ _ = 0
+ }
+}
+
+
+func _() {
+ // this comment should be indented
+ for {
+ L1: _ = 0
+ L2:
+ _ = 0
+ }
+}
+
+
+func _() {
+ if true {
+ _ = 0
+ }
+ _ = 0 // the indentation here should not be affected by the long label name
+AnOverlongLabel:
+ _ = 0
+
+ if true {
+ _ = 0
+ }
+ _ = 0
+
+L: _ = 0
+}
+
+
+func _() {
+ for {
+ goto L
+ }
+L:
+
+ MoreCode()
+}
+
+
+func _() {
+ for {
+ goto L
+ }
+L: // A comment on the same line as the label, followed by a single empty line.
+ // Known bug: There may be more than one empty line before MoreCode()
+ // (see go/printer/nodes.go, func linebreak).
+
+
+
+
+ MoreCode()
+}
+
+
+func _() {
+ for {
+ goto L
+ }
+L:
+
+
+
+
+ // There should be a single empty line before this comment.
+ MoreCode()
+}
+
+
+func _() {
+ for {
+ goto AVeryLongLabelThatShouldNotAffectFormatting
+ }
+AVeryLongLabelThatShouldNotAffectFormatting:
+ // There should be a single empty line after this comment.
+
+ // There should be a single empty line before this comment.
+ MoreCode()
+}
+
+
+// Formatting of empty statements.
+func _() {
+ ;;;;;;;;;;;;;;;;;;;;;;;;;
+}
+
+func _() {;;;;;;;;;;;;;;;;;;;;;;;;;
+}
+
+func _() {;;;;;;;;;;;;;;;;;;;;;;;;;}
+
+func _() {
+f();;;;;;;;;;;;;;;;;;;;;;;;;
+}
+
+func _() {
+L:;;;;;;;;;;;;
+}
+
+func _() {
+L:;;;;;;;;;;;;
+ f()
+}
diff --git a/src/go/scanner/errors.go b/src/go/scanner/errors.go
new file mode 100644
index 0000000..bf7bfa3
--- /dev/null
+++ b/src/go/scanner/errors.go
@@ -0,0 +1,124 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+ "fmt"
+ "go/token"
+ "io"
+ "sort"
+)
+
+// In an ErrorList, an error is represented by an *Error.
+// The position Pos, if valid, points to the beginning of
+// the offending token, and the error condition is described
+// by Msg.
+//
+type Error struct {
+ Pos token.Position
+ Msg string
+}
+
+// Error implements the error interface.
+func (e Error) Error() string {
+ if e.Pos.Filename != "" || e.Pos.IsValid() {
+ // don't print "<unknown position>"
+ // TODO(gri) reconsider the semantics of Position.IsValid
+ return e.Pos.String() + ": " + e.Msg
+ }
+ return e.Msg
+}
+
+// ErrorList is a list of *Errors.
+// The zero value for an ErrorList is an empty ErrorList ready to use.
+//
+type ErrorList []*Error
+
+// Add adds an Error with given position and error message to an ErrorList.
+func (p *ErrorList) Add(pos token.Position, msg string) {
+ *p = append(*p, &Error{pos, msg})
+}
+
+// Reset resets an ErrorList to no errors.
+func (p *ErrorList) Reset() { *p = (*p)[0:0] }
+
+// ErrorList implements the sort Interface.
+func (p ErrorList) Len() int { return len(p) }
+func (p ErrorList) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
+
+func (p ErrorList) Less(i, j int) bool {
+ e := &p[i].Pos
+ f := &p[j].Pos
+ // Note that it is not sufficient to simply compare file offsets because
+ // the offsets do not reflect modified line information (through //line
+ // comments).
+ if e.Filename != f.Filename {
+ return e.Filename < f.Filename
+ }
+ if e.Line != f.Line {
+ return e.Line < f.Line
+ }
+ if e.Column != f.Column {
+ return e.Column < f.Column
+ }
+ return p[i].Msg < p[j].Msg
+}
+
+// Sort sorts an ErrorList. *Error entries are sorted by position,
+// other errors are sorted by error message, and before any *Error
+// entry.
+//
+func (p ErrorList) Sort() {
+ sort.Sort(p)
+}
+
+// RemoveMultiples sorts an ErrorList and removes all but the first error per line.
+func (p *ErrorList) RemoveMultiples() {
+ sort.Sort(p)
+ var last token.Position // initial last.Line is != any legal error line
+ i := 0
+ for _, e := range *p {
+ if e.Pos.Filename != last.Filename || e.Pos.Line != last.Line {
+ last = e.Pos
+ (*p)[i] = e
+ i++
+ }
+ }
+ (*p) = (*p)[0:i]
+}
+
+// An ErrorList implements the error interface.
+func (p ErrorList) Error() string {
+ switch len(p) {
+ case 0:
+ return "no errors"
+ case 1:
+ return p[0].Error()
+ }
+ return fmt.Sprintf("%s (and %d more errors)", p[0], len(p)-1)
+}
+
+// Err returns an error equivalent to this error list.
+// If the list is empty, Err returns nil.
+func (p ErrorList) Err() error {
+ if len(p) == 0 {
+ return nil
+ }
+ return p
+}
+
+// PrintError is a utility function that prints a list of errors to w,
+// one error per line, if the err parameter is an ErrorList. Otherwise
+// it prints the err string.
+//
+func PrintError(w io.Writer, err error) {
+ if list, ok := err.(ErrorList); ok {
+ for _, e := range list {
+ fmt.Fprintf(w, "%s\n", e)
+ }
+ } else if err != nil {
+ fmt.Fprintf(w, "%s\n", err)
+ }
+}
diff --git a/src/go/scanner/example_test.go b/src/go/scanner/example_test.go
new file mode 100644
index 0000000..9004a4a
--- /dev/null
+++ b/src/go/scanner/example_test.go
@@ -0,0 +1,46 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package scanner_test
+
+import (
+ "fmt"
+ "go/scanner"
+ "go/token"
+)
+
+func ExampleScanner_Scan() {
+ // src is the input that we want to tokenize.
+ src := []byte("cos(x) + 1i*sin(x) // Euler")
+
+ // Initialize the scanner.
+ var s scanner.Scanner
+ fset := token.NewFileSet() // positions are relative to fset
+ file := fset.AddFile("", fset.Base(), len(src)) // register input "file"
+ s.Init(file, src, nil /* no error handler */, scanner.ScanComments)
+
+ // Repeated calls to Scan yield the token sequence found in the input.
+ for {
+ pos, tok, lit := s.Scan()
+ if tok == token.EOF {
+ break
+ }
+ fmt.Printf("%s\t%s\t%q\n", fset.Position(pos), tok, lit)
+ }
+
+ // output:
+ // 1:1 IDENT "cos"
+ // 1:4 ( ""
+ // 1:5 IDENT "x"
+ // 1:6 ) ""
+ // 1:8 + ""
+ // 1:10 IMAG "1i"
+ // 1:12 * ""
+ // 1:13 IDENT "sin"
+ // 1:16 ( ""
+ // 1:17 IDENT "x"
+ // 1:18 ) ""
+ // 1:20 ; "\n"
+ // 1:20 COMMENT "// Euler"
+}
diff --git a/src/go/scanner/scanner.go b/src/go/scanner/scanner.go
new file mode 100644
index 0000000..00fe2dc
--- /dev/null
+++ b/src/go/scanner/scanner.go
@@ -0,0 +1,940 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package scanner implements a scanner for Go source text.
+// It takes a []byte as source which can then be tokenized
+// through repeated calls to the Scan method.
+//
+package scanner
+
+import (
+ "bytes"
+ "fmt"
+ "go/token"
+ "path/filepath"
+ "strconv"
+ "unicode"
+ "unicode/utf8"
+)
+
+// An ErrorHandler may be provided to Scanner.Init. If a syntax error is
+// encountered and a handler was installed, the handler is called with a
+// position and an error message. The position points to the beginning of
+// the offending token.
+//
+type ErrorHandler func(pos token.Position, msg string)
+
+// A Scanner holds the scanner's internal state while processing
+// a given text. It can be allocated as part of another data
+// structure but must be initialized via Init before use.
+//
+type Scanner struct {
+ // immutable state
+ file *token.File // source file handle
+ dir string // directory portion of file.Name()
+ src []byte // source
+ err ErrorHandler // error reporting; or nil
+ mode Mode // scanning mode
+
+ // scanning state
+ ch rune // current character
+ offset int // character offset
+ rdOffset int // reading offset (position after current character)
+ lineOffset int // current line offset
+ insertSemi bool // insert a semicolon before next newline
+
+ // public state - ok to modify
+ ErrorCount int // number of errors encountered
+}
+
+const bom = 0xFEFF // byte order mark, only permitted as very first character
+
+// Read the next Unicode char into s.ch.
+// s.ch < 0 means end-of-file.
+//
+func (s *Scanner) next() {
+ if s.rdOffset < len(s.src) {
+ s.offset = s.rdOffset
+ if s.ch == '\n' {
+ s.lineOffset = s.offset
+ s.file.AddLine(s.offset)
+ }
+ r, w := rune(s.src[s.rdOffset]), 1
+ switch {
+ case r == 0:
+ s.error(s.offset, "illegal character NUL")
+ case r >= utf8.RuneSelf:
+ // not ASCII
+ r, w = utf8.DecodeRune(s.src[s.rdOffset:])
+ if r == utf8.RuneError && w == 1 {
+ s.error(s.offset, "illegal UTF-8 encoding")
+ } else if r == bom && s.offset > 0 {
+ s.error(s.offset, "illegal byte order mark")
+ }
+ }
+ s.rdOffset += w
+ s.ch = r
+ } else {
+ s.offset = len(s.src)
+ if s.ch == '\n' {
+ s.lineOffset = s.offset
+ s.file.AddLine(s.offset)
+ }
+ s.ch = -1 // eof
+ }
+}
+
+// peek returns the byte following the most recently read character without
+// advancing the scanner. If the scanner is at EOF, peek returns 0.
+func (s *Scanner) peek() byte {
+ if s.rdOffset < len(s.src) {
+ return s.src[s.rdOffset]
+ }
+ return 0
+}
+
+// A mode value is a set of flags (or 0).
+// They control scanner behavior.
+//
+type Mode uint
+
+const (
+ ScanComments Mode = 1 << iota // return comments as COMMENT tokens
+ dontInsertSemis // do not automatically insert semicolons - for testing only
+)
+
+// Init prepares the scanner s to tokenize the text src by setting the
+// scanner at the beginning of src. The scanner uses the file set file
+// for position information and it adds line information for each line.
+// It is ok to re-use the same file when re-scanning the same file as
+// line information which is already present is ignored. Init causes a
+// panic if the file size does not match the src size.
+//
+// Calls to Scan will invoke the error handler err if they encounter a
+// syntax error and err is not nil. Also, for each error encountered,
+// the Scanner field ErrorCount is incremented by one. The mode parameter
+// determines how comments are handled.
+//
+// Note that Init may call err if there is an error in the first character
+// of the file.
+//
+func (s *Scanner) Init(file *token.File, src []byte, err ErrorHandler, mode Mode) {
+ // Explicitly initialize all fields since a scanner may be reused.
+ if file.Size() != len(src) {
+ panic(fmt.Sprintf("file size (%d) does not match src len (%d)", file.Size(), len(src)))
+ }
+ s.file = file
+ s.dir, _ = filepath.Split(file.Name())
+ s.src = src
+ s.err = err
+ s.mode = mode
+
+ s.ch = ' '
+ s.offset = 0
+ s.rdOffset = 0
+ s.lineOffset = 0
+ s.insertSemi = false
+ s.ErrorCount = 0
+
+ s.next()
+ if s.ch == bom {
+ s.next() // ignore BOM at file beginning
+ }
+}
+
+func (s *Scanner) error(offs int, msg string) {
+ if s.err != nil {
+ s.err(s.file.Position(s.file.Pos(offs)), msg)
+ }
+ s.ErrorCount++
+}
+
+func (s *Scanner) errorf(offs int, format string, args ...interface{}) {
+ s.error(offs, fmt.Sprintf(format, args...))
+}
+
+func (s *Scanner) scanComment() string {
+ // initial '/' already consumed; s.ch == '/' || s.ch == '*'
+ offs := s.offset - 1 // position of initial '/'
+ next := -1 // position immediately following the comment; < 0 means invalid comment
+ numCR := 0
+
+ if s.ch == '/' {
+ //-style comment
+ // (the final '\n' is not considered part of the comment)
+ s.next()
+ for s.ch != '\n' && s.ch >= 0 {
+ if s.ch == '\r' {
+ numCR++
+ }
+ s.next()
+ }
+ // if we are at '\n', the position following the comment is afterwards
+ next = s.offset
+ if s.ch == '\n' {
+ next++
+ }
+ goto exit
+ }
+
+ /*-style comment */
+ s.next()
+ for s.ch >= 0 {
+ ch := s.ch
+ if ch == '\r' {
+ numCR++
+ }
+ s.next()
+ if ch == '*' && s.ch == '/' {
+ s.next()
+ next = s.offset
+ goto exit
+ }
+ }
+
+ s.error(offs, "comment not terminated")
+
+exit:
+ lit := s.src[offs:s.offset]
+
+ // On Windows, a (//-comment) line may end in "\r\n".
+ // Remove the final '\r' before analyzing the text for
+ // line directives (matching the compiler). Remove any
+ // other '\r' afterwards (matching the pre-existing be-
+ // havior of the scanner).
+ if numCR > 0 && len(lit) >= 2 && lit[1] == '/' && lit[len(lit)-1] == '\r' {
+ lit = lit[:len(lit)-1]
+ numCR--
+ }
+
+ // interpret line directives
+ // (//line directives must start at the beginning of the current line)
+ if next >= 0 /* implies valid comment */ && (lit[1] == '*' || offs == s.lineOffset) && bytes.HasPrefix(lit[2:], prefix) {
+ s.updateLineInfo(next, offs, lit)
+ }
+
+ if numCR > 0 {
+ lit = stripCR(lit, lit[1] == '*')
+ }
+
+ return string(lit)
+}
+
+var prefix = []byte("line ")
+
+// updateLineInfo parses the incoming comment text at offset offs
+// as a line directive. If successful, it updates the line info table
+// for the position next per the line directive.
+func (s *Scanner) updateLineInfo(next, offs int, text []byte) {
+ // extract comment text
+ if text[1] == '*' {
+ text = text[:len(text)-2] // lop off trailing "*/"
+ }
+ text = text[7:] // lop off leading "//line " or "/*line "
+ offs += 7
+
+ i, n, ok := trailingDigits(text)
+ if i == 0 {
+ return // ignore (not a line directive)
+ }
+ // i > 0
+
+ if !ok {
+ // text has a suffix :xxx but xxx is not a number
+ s.error(offs+i, "invalid line number: "+string(text[i:]))
+ return
+ }
+
+ var line, col int
+ i2, n2, ok2 := trailingDigits(text[:i-1])
+ if ok2 {
+ //line filename:line:col
+ i, i2 = i2, i
+ line, col = n2, n
+ if col == 0 {
+ s.error(offs+i2, "invalid column number: "+string(text[i2:]))
+ return
+ }
+ text = text[:i2-1] // lop off ":col"
+ } else {
+ //line filename:line
+ line = n
+ }
+
+ if line == 0 {
+ s.error(offs+i, "invalid line number: "+string(text[i:]))
+ return
+ }
+
+ // If we have a column (//line filename:line:col form),
+ // an empty filename means to use the previous filename.
+ filename := string(text[:i-1]) // lop off ":line", and trim white space
+ if filename == "" && ok2 {
+ filename = s.file.Position(s.file.Pos(offs)).Filename
+ } else if filename != "" {
+ // Put a relative filename in the current directory.
+ // This is for compatibility with earlier releases.
+ // See issue 26671.
+ filename = filepath.Clean(filename)
+ if !filepath.IsAbs(filename) {
+ filename = filepath.Join(s.dir, filename)
+ }
+ }
+
+ s.file.AddLineColumnInfo(next, filename, line, col)
+}
+
+func trailingDigits(text []byte) (int, int, bool) {
+ i := bytes.LastIndexByte(text, ':') // look from right (Windows filenames may contain ':')
+ if i < 0 {
+ return 0, 0, false // no ":"
+ }
+ // i >= 0
+ n, err := strconv.ParseUint(string(text[i+1:]), 10, 0)
+ return i + 1, int(n), err == nil
+}
+
+func (s *Scanner) findLineEnd() bool {
+ // initial '/' already consumed
+
+ defer func(offs int) {
+ // reset scanner state to where it was upon calling findLineEnd
+ s.ch = '/'
+ s.offset = offs
+ s.rdOffset = offs + 1
+ s.next() // consume initial '/' again
+ }(s.offset - 1)
+
+ // read ahead until a newline, EOF, or non-comment token is found
+ for s.ch == '/' || s.ch == '*' {
+ if s.ch == '/' {
+ //-style comment always contains a newline
+ return true
+ }
+ /*-style comment: look for newline */
+ s.next()
+ for s.ch >= 0 {
+ ch := s.ch
+ if ch == '\n' {
+ return true
+ }
+ s.next()
+ if ch == '*' && s.ch == '/' {
+ s.next()
+ break
+ }
+ }
+ s.skipWhitespace() // s.insertSemi is set
+ if s.ch < 0 || s.ch == '\n' {
+ return true
+ }
+ if s.ch != '/' {
+ // non-comment token
+ return false
+ }
+ s.next() // consume '/'
+ }
+
+ return false
+}
+
+func isLetter(ch rune) bool {
+ return 'a' <= lower(ch) && lower(ch) <= 'z' || ch == '_' || ch >= utf8.RuneSelf && unicode.IsLetter(ch)
+}
+
+func isDigit(ch rune) bool {
+ return isDecimal(ch) || ch >= utf8.RuneSelf && unicode.IsDigit(ch)
+}
+
+func (s *Scanner) scanIdentifier() string {
+ offs := s.offset
+ for isLetter(s.ch) || isDigit(s.ch) {
+ s.next()
+ }
+ return string(s.src[offs:s.offset])
+}
+
+func digitVal(ch rune) int {
+ switch {
+ case '0' <= ch && ch <= '9':
+ return int(ch - '0')
+ case 'a' <= lower(ch) && lower(ch) <= 'f':
+ return int(lower(ch) - 'a' + 10)
+ }
+ return 16 // larger than any legal digit val
+}
+
+func lower(ch rune) rune { return ('a' - 'A') | ch } // returns lower-case ch iff ch is ASCII letter
+func isDecimal(ch rune) bool { return '0' <= ch && ch <= '9' }
+func isHex(ch rune) bool { return '0' <= ch && ch <= '9' || 'a' <= lower(ch) && lower(ch) <= 'f' }
+
+// digits accepts the sequence { digit | '_' }.
+// If base <= 10, digits accepts any decimal digit but records
+// the offset (relative to the source start) of a digit >= base
+// in *invalid, if *invalid < 0.
+// digits returns a bitset describing whether the sequence contained
+// digits (bit 0 is set), or separators '_' (bit 1 is set).
+func (s *Scanner) digits(base int, invalid *int) (digsep int) {
+ if base <= 10 {
+ max := rune('0' + base)
+ for isDecimal(s.ch) || s.ch == '_' {
+ ds := 1
+ if s.ch == '_' {
+ ds = 2
+ } else if s.ch >= max && *invalid < 0 {
+ *invalid = int(s.offset) // record invalid rune offset
+ }
+ digsep |= ds
+ s.next()
+ }
+ } else {
+ for isHex(s.ch) || s.ch == '_' {
+ ds := 1
+ if s.ch == '_' {
+ ds = 2
+ }
+ digsep |= ds
+ s.next()
+ }
+ }
+ return
+}
+
+func (s *Scanner) scanNumber() (token.Token, string) {
+ offs := s.offset
+ tok := token.ILLEGAL
+
+ base := 10 // number base
+ prefix := rune(0) // one of 0 (decimal), '0' (0-octal), 'x', 'o', or 'b'
+ digsep := 0 // bit 0: digit present, bit 1: '_' present
+ invalid := -1 // index of invalid digit in literal, or < 0
+
+ // integer part
+ if s.ch != '.' {
+ tok = token.INT
+ if s.ch == '0' {
+ s.next()
+ switch lower(s.ch) {
+ case 'x':
+ s.next()
+ base, prefix = 16, 'x'
+ case 'o':
+ s.next()
+ base, prefix = 8, 'o'
+ case 'b':
+ s.next()
+ base, prefix = 2, 'b'
+ default:
+ base, prefix = 8, '0'
+ digsep = 1 // leading 0
+ }
+ }
+ digsep |= s.digits(base, &invalid)
+ }
+
+ // fractional part
+ if s.ch == '.' {
+ tok = token.FLOAT
+ if prefix == 'o' || prefix == 'b' {
+ s.error(s.offset, "invalid radix point in "+litname(prefix))
+ }
+ s.next()
+ digsep |= s.digits(base, &invalid)
+ }
+
+ if digsep&1 == 0 {
+ s.error(s.offset, litname(prefix)+" has no digits")
+ }
+
+ // exponent
+ if e := lower(s.ch); e == 'e' || e == 'p' {
+ switch {
+ case e == 'e' && prefix != 0 && prefix != '0':
+ s.errorf(s.offset, "%q exponent requires decimal mantissa", s.ch)
+ case e == 'p' && prefix != 'x':
+ s.errorf(s.offset, "%q exponent requires hexadecimal mantissa", s.ch)
+ }
+ s.next()
+ tok = token.FLOAT
+ if s.ch == '+' || s.ch == '-' {
+ s.next()
+ }
+ ds := s.digits(10, nil)
+ digsep |= ds
+ if ds&1 == 0 {
+ s.error(s.offset, "exponent has no digits")
+ }
+ } else if prefix == 'x' && tok == token.FLOAT {
+ s.error(s.offset, "hexadecimal mantissa requires a 'p' exponent")
+ }
+
+ // suffix 'i'
+ if s.ch == 'i' {
+ tok = token.IMAG
+ s.next()
+ }
+
+ lit := string(s.src[offs:s.offset])
+ if tok == token.INT && invalid >= 0 {
+ s.errorf(invalid, "invalid digit %q in %s", lit[invalid-offs], litname(prefix))
+ }
+ if digsep&2 != 0 {
+ if i := invalidSep(lit); i >= 0 {
+ s.error(offs+i, "'_' must separate successive digits")
+ }
+ }
+
+ return tok, lit
+}
+
+func litname(prefix rune) string {
+ switch prefix {
+ case 'x':
+ return "hexadecimal literal"
+ case 'o', '0':
+ return "octal literal"
+ case 'b':
+ return "binary literal"
+ }
+ return "decimal literal"
+}
+
+// invalidSep returns the index of the first invalid separator in x, or -1.
+func invalidSep(x string) int {
+ x1 := ' ' // prefix char, we only care if it's 'x'
+ d := '.' // digit, one of '_', '0' (a digit), or '.' (anything else)
+ i := 0
+
+ // a prefix counts as a digit
+ if len(x) >= 2 && x[0] == '0' {
+ x1 = lower(rune(x[1]))
+ if x1 == 'x' || x1 == 'o' || x1 == 'b' {
+ d = '0'
+ i = 2
+ }
+ }
+
+ // mantissa and exponent
+ for ; i < len(x); i++ {
+ p := d // previous digit
+ d = rune(x[i])
+ switch {
+ case d == '_':
+ if p != '0' {
+ return i
+ }
+ case isDecimal(d) || x1 == 'x' && isHex(d):
+ d = '0'
+ default:
+ if p == '_' {
+ return i - 1
+ }
+ d = '.'
+ }
+ }
+ if d == '_' {
+ return len(x) - 1
+ }
+
+ return -1
+}
+
+// scanEscape parses an escape sequence where rune is the accepted
+// escaped quote. In case of a syntax error, it stops at the offending
+// character (without consuming it) and returns false. Otherwise
+// it returns true.
+func (s *Scanner) scanEscape(quote rune) bool {
+ offs := s.offset
+
+ var n int
+ var base, max uint32
+ switch s.ch {
+ case 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', quote:
+ s.next()
+ return true
+ case '0', '1', '2', '3', '4', '5', '6', '7':
+ n, base, max = 3, 8, 255
+ case 'x':
+ s.next()
+ n, base, max = 2, 16, 255
+ case 'u':
+ s.next()
+ n, base, max = 4, 16, unicode.MaxRune
+ case 'U':
+ s.next()
+ n, base, max = 8, 16, unicode.MaxRune
+ default:
+ msg := "unknown escape sequence"
+ if s.ch < 0 {
+ msg = "escape sequence not terminated"
+ }
+ s.error(offs, msg)
+ return false
+ }
+
+ var x uint32
+ for n > 0 {
+ d := uint32(digitVal(s.ch))
+ if d >= base {
+ msg := fmt.Sprintf("illegal character %#U in escape sequence", s.ch)
+ if s.ch < 0 {
+ msg = "escape sequence not terminated"
+ }
+ s.error(s.offset, msg)
+ return false
+ }
+ x = x*base + d
+ s.next()
+ n--
+ }
+
+ if x > max || 0xD800 <= x && x < 0xE000 {
+ s.error(offs, "escape sequence is invalid Unicode code point")
+ return false
+ }
+
+ return true
+}
+
+func (s *Scanner) scanRune() string {
+ // '\'' opening already consumed
+ offs := s.offset - 1
+
+ valid := true
+ n := 0
+ for {
+ ch := s.ch
+ if ch == '\n' || ch < 0 {
+ // only report error if we don't have one already
+ if valid {
+ s.error(offs, "rune literal not terminated")
+ valid = false
+ }
+ break
+ }
+ s.next()
+ if ch == '\'' {
+ break
+ }
+ n++
+ if ch == '\\' {
+ if !s.scanEscape('\'') {
+ valid = false
+ }
+ // continue to read to closing quote
+ }
+ }
+
+ if valid && n != 1 {
+ s.error(offs, "illegal rune literal")
+ }
+
+ return string(s.src[offs:s.offset])
+}
+
+func (s *Scanner) scanString() string {
+ // '"' opening already consumed
+ offs := s.offset - 1
+
+ for {
+ ch := s.ch
+ if ch == '\n' || ch < 0 {
+ s.error(offs, "string literal not terminated")
+ break
+ }
+ s.next()
+ if ch == '"' {
+ break
+ }
+ if ch == '\\' {
+ s.scanEscape('"')
+ }
+ }
+
+ return string(s.src[offs:s.offset])
+}
+
+func stripCR(b []byte, comment bool) []byte {
+ c := make([]byte, len(b))
+ i := 0
+ for j, ch := range b {
+ // In a /*-style comment, don't strip \r from *\r/ (incl.
+ // sequences of \r from *\r\r...\r/) since the resulting
+ // */ would terminate the comment too early unless the \r
+ // is immediately following the opening /* in which case
+ // it's ok because /*/ is not closed yet (issue #11151).
+ if ch != '\r' || comment && i > len("/*") && c[i-1] == '*' && j+1 < len(b) && b[j+1] == '/' {
+ c[i] = ch
+ i++
+ }
+ }
+ return c[:i]
+}
+
+func (s *Scanner) scanRawString() string {
+ // '`' opening already consumed
+ offs := s.offset - 1
+
+ hasCR := false
+ for {
+ ch := s.ch
+ if ch < 0 {
+ s.error(offs, "raw string literal not terminated")
+ break
+ }
+ s.next()
+ if ch == '`' {
+ break
+ }
+ if ch == '\r' {
+ hasCR = true
+ }
+ }
+
+ lit := s.src[offs:s.offset]
+ if hasCR {
+ lit = stripCR(lit, false)
+ }
+
+ return string(lit)
+}
+
+func (s *Scanner) skipWhitespace() {
+ for s.ch == ' ' || s.ch == '\t' || s.ch == '\n' && !s.insertSemi || s.ch == '\r' {
+ s.next()
+ }
+}
+
+// Helper functions for scanning multi-byte tokens such as >> += >>= .
+// Different routines recognize different length tok_i based on matches
+// of ch_i. If a token ends in '=', the result is tok1 or tok3
+// respectively. Otherwise, the result is tok0 if there was no other
+// matching character, or tok2 if the matching character was ch2.
+
+func (s *Scanner) switch2(tok0, tok1 token.Token) token.Token {
+ if s.ch == '=' {
+ s.next()
+ return tok1
+ }
+ return tok0
+}
+
+func (s *Scanner) switch3(tok0, tok1 token.Token, ch2 rune, tok2 token.Token) token.Token {
+ if s.ch == '=' {
+ s.next()
+ return tok1
+ }
+ if s.ch == ch2 {
+ s.next()
+ return tok2
+ }
+ return tok0
+}
+
+func (s *Scanner) switch4(tok0, tok1 token.Token, ch2 rune, tok2, tok3 token.Token) token.Token {
+ if s.ch == '=' {
+ s.next()
+ return tok1
+ }
+ if s.ch == ch2 {
+ s.next()
+ if s.ch == '=' {
+ s.next()
+ return tok3
+ }
+ return tok2
+ }
+ return tok0
+}
+
+// Scan scans the next token and returns the token position, the token,
+// and its literal string if applicable. The source end is indicated by
+// token.EOF.
+//
+// If the returned token is a literal (token.IDENT, token.INT, token.FLOAT,
+// token.IMAG, token.CHAR, token.STRING) or token.COMMENT, the literal string
+// has the corresponding value.
+//
+// If the returned token is a keyword, the literal string is the keyword.
+//
+// If the returned token is token.SEMICOLON, the corresponding
+// literal string is ";" if the semicolon was present in the source,
+// and "\n" if the semicolon was inserted because of a newline or
+// at EOF.
+//
+// If the returned token is token.ILLEGAL, the literal string is the
+// offending character.
+//
+// In all other cases, Scan returns an empty literal string.
+//
+// For more tolerant parsing, Scan will return a valid token if
+// possible even if a syntax error was encountered. Thus, even
+// if the resulting token sequence contains no illegal tokens,
+// a client may not assume that no error occurred. Instead it
+// must check the scanner's ErrorCount or the number of calls
+// of the error handler, if there was one installed.
+//
+// Scan adds line information to the file added to the file
+// set with Init. Token positions are relative to that file
+// and thus relative to the file set.
+//
+func (s *Scanner) Scan() (pos token.Pos, tok token.Token, lit string) {
+scanAgain:
+ s.skipWhitespace()
+
+ // current token start
+ pos = s.file.Pos(s.offset)
+
+ // determine token value
+ insertSemi := false
+ switch ch := s.ch; {
+ case isLetter(ch):
+ lit = s.scanIdentifier()
+ if len(lit) > 1 {
+ // keywords are longer than one letter - avoid lookup otherwise
+ tok = token.Lookup(lit)
+ switch tok {
+ case token.IDENT, token.BREAK, token.CONTINUE, token.FALLTHROUGH, token.RETURN:
+ insertSemi = true
+ }
+ } else {
+ insertSemi = true
+ tok = token.IDENT
+ }
+ case isDecimal(ch) || ch == '.' && isDecimal(rune(s.peek())):
+ insertSemi = true
+ tok, lit = s.scanNumber()
+ default:
+ s.next() // always make progress
+ switch ch {
+ case -1:
+ if s.insertSemi {
+ s.insertSemi = false // EOF consumed
+ return pos, token.SEMICOLON, "\n"
+ }
+ tok = token.EOF
+ case '\n':
+ // we only reach here if s.insertSemi was
+ // set in the first place and exited early
+ // from s.skipWhitespace()
+ s.insertSemi = false // newline consumed
+ return pos, token.SEMICOLON, "\n"
+ case '"':
+ insertSemi = true
+ tok = token.STRING
+ lit = s.scanString()
+ case '\'':
+ insertSemi = true
+ tok = token.CHAR
+ lit = s.scanRune()
+ case '`':
+ insertSemi = true
+ tok = token.STRING
+ lit = s.scanRawString()
+ case ':':
+ tok = s.switch2(token.COLON, token.DEFINE)
+ case '.':
+ // fractions starting with a '.' are handled by outer switch
+ tok = token.PERIOD
+ if s.ch == '.' && s.peek() == '.' {
+ s.next()
+ s.next() // consume last '.'
+ tok = token.ELLIPSIS
+ }
+ case ',':
+ tok = token.COMMA
+ case ';':
+ tok = token.SEMICOLON
+ lit = ";"
+ case '(':
+ tok = token.LPAREN
+ case ')':
+ insertSemi = true
+ tok = token.RPAREN
+ case '[':
+ tok = token.LBRACK
+ case ']':
+ insertSemi = true
+ tok = token.RBRACK
+ case '{':
+ tok = token.LBRACE
+ case '}':
+ insertSemi = true
+ tok = token.RBRACE
+ case '+':
+ tok = s.switch3(token.ADD, token.ADD_ASSIGN, '+', token.INC)
+ if tok == token.INC {
+ insertSemi = true
+ }
+ case '-':
+ tok = s.switch3(token.SUB, token.SUB_ASSIGN, '-', token.DEC)
+ if tok == token.DEC {
+ insertSemi = true
+ }
+ case '*':
+ tok = s.switch2(token.MUL, token.MUL_ASSIGN)
+ case '/':
+ if s.ch == '/' || s.ch == '*' {
+ // comment
+ if s.insertSemi && s.findLineEnd() {
+ // reset position to the beginning of the comment
+ s.ch = '/'
+ s.offset = s.file.Offset(pos)
+ s.rdOffset = s.offset + 1
+ s.insertSemi = false // newline consumed
+ return pos, token.SEMICOLON, "\n"
+ }
+ comment := s.scanComment()
+ if s.mode&ScanComments == 0 {
+ // skip comment
+ s.insertSemi = false // newline consumed
+ goto scanAgain
+ }
+ tok = token.COMMENT
+ lit = comment
+ } else {
+ tok = s.switch2(token.QUO, token.QUO_ASSIGN)
+ }
+ case '%':
+ tok = s.switch2(token.REM, token.REM_ASSIGN)
+ case '^':
+ tok = s.switch2(token.XOR, token.XOR_ASSIGN)
+ case '<':
+ if s.ch == '-' {
+ s.next()
+ tok = token.ARROW
+ } else {
+ tok = s.switch4(token.LSS, token.LEQ, '<', token.SHL, token.SHL_ASSIGN)
+ }
+ case '>':
+ tok = s.switch4(token.GTR, token.GEQ, '>', token.SHR, token.SHR_ASSIGN)
+ case '=':
+ tok = s.switch2(token.ASSIGN, token.EQL)
+ case '!':
+ tok = s.switch2(token.NOT, token.NEQ)
+ case '&':
+ if s.ch == '^' {
+ s.next()
+ tok = s.switch2(token.AND_NOT, token.AND_NOT_ASSIGN)
+ } else {
+ tok = s.switch3(token.AND, token.AND_ASSIGN, '&', token.LAND)
+ }
+ case '|':
+ tok = s.switch3(token.OR, token.OR_ASSIGN, '|', token.LOR)
+ default:
+ // next reports unexpected BOMs - don't repeat
+ if ch != bom {
+ s.errorf(s.file.Offset(pos), "illegal character %#U", ch)
+ }
+ insertSemi = s.insertSemi // preserve insertSemi info
+ tok = token.ILLEGAL
+ lit = string(ch)
+ }
+ }
+ if s.mode&dontInsertSemis == 0 {
+ s.insertSemi = insertSemi
+ }
+
+ return
+}
diff --git a/src/go/scanner/scanner_test.go b/src/go/scanner/scanner_test.go
new file mode 100644
index 0000000..ab4c2dd
--- /dev/null
+++ b/src/go/scanner/scanner_test.go
@@ -0,0 +1,1113 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+ "go/token"
+ "os"
+ "path/filepath"
+ "runtime"
+ "strings"
+ "testing"
+)
+
+var fset = token.NewFileSet()
+
+const /* class */ (
+ special = iota
+ literal
+ operator
+ keyword
+)
+
+func tokenclass(tok token.Token) int {
+ switch {
+ case tok.IsLiteral():
+ return literal
+ case tok.IsOperator():
+ return operator
+ case tok.IsKeyword():
+ return keyword
+ }
+ return special
+}
+
+type elt struct {
+ tok token.Token
+ lit string
+ class int
+}
+
+var tokens = [...]elt{
+ // Special tokens
+ {token.COMMENT, "/* a comment */", special},
+ {token.COMMENT, "// a comment \n", special},
+ {token.COMMENT, "/*\r*/", special},
+ {token.COMMENT, "/**\r/*/", special}, // issue 11151
+ {token.COMMENT, "/**\r\r/*/", special},
+ {token.COMMENT, "//\r\n", special},
+
+ // Identifiers and basic type literals
+ {token.IDENT, "foobar", literal},
+ {token.IDENT, "a۰۱۸", literal},
+ {token.IDENT, "foo६४", literal},
+ {token.IDENT, "bar9876", literal},
+ {token.IDENT, "ŝ", literal}, // was bug (issue 4000)
+ {token.IDENT, "ŝfoo", literal}, // was bug (issue 4000)
+ {token.INT, "0", literal},
+ {token.INT, "1", literal},
+ {token.INT, "123456789012345678890", literal},
+ {token.INT, "01234567", literal},
+ {token.INT, "0xcafebabe", literal},
+ {token.FLOAT, "0.", literal},
+ {token.FLOAT, ".0", literal},
+ {token.FLOAT, "3.14159265", literal},
+ {token.FLOAT, "1e0", literal},
+ {token.FLOAT, "1e+100", literal},
+ {token.FLOAT, "1e-100", literal},
+ {token.FLOAT, "2.71828e-1000", literal},
+ {token.IMAG, "0i", literal},
+ {token.IMAG, "1i", literal},
+ {token.IMAG, "012345678901234567889i", literal},
+ {token.IMAG, "123456789012345678890i", literal},
+ {token.IMAG, "0.i", literal},
+ {token.IMAG, ".0i", literal},
+ {token.IMAG, "3.14159265i", literal},
+ {token.IMAG, "1e0i", literal},
+ {token.IMAG, "1e+100i", literal},
+ {token.IMAG, "1e-100i", literal},
+ {token.IMAG, "2.71828e-1000i", literal},
+ {token.CHAR, "'a'", literal},
+ {token.CHAR, "'\\000'", literal},
+ {token.CHAR, "'\\xFF'", literal},
+ {token.CHAR, "'\\uff16'", literal},
+ {token.CHAR, "'\\U0000ff16'", literal},
+ {token.STRING, "`foobar`", literal},
+ {token.STRING, "`" + `foo
+ bar` +
+ "`",
+ literal,
+ },
+ {token.STRING, "`\r`", literal},
+ {token.STRING, "`foo\r\nbar`", literal},
+
+ // Operators and delimiters
+ {token.ADD, "+", operator},
+ {token.SUB, "-", operator},
+ {token.MUL, "*", operator},
+ {token.QUO, "/", operator},
+ {token.REM, "%", operator},
+
+ {token.AND, "&", operator},
+ {token.OR, "|", operator},
+ {token.XOR, "^", operator},
+ {token.SHL, "<<", operator},
+ {token.SHR, ">>", operator},
+ {token.AND_NOT, "&^", operator},
+
+ {token.ADD_ASSIGN, "+=", operator},
+ {token.SUB_ASSIGN, "-=", operator},
+ {token.MUL_ASSIGN, "*=", operator},
+ {token.QUO_ASSIGN, "/=", operator},
+ {token.REM_ASSIGN, "%=", operator},
+
+ {token.AND_ASSIGN, "&=", operator},
+ {token.OR_ASSIGN, "|=", operator},
+ {token.XOR_ASSIGN, "^=", operator},
+ {token.SHL_ASSIGN, "<<=", operator},
+ {token.SHR_ASSIGN, ">>=", operator},
+ {token.AND_NOT_ASSIGN, "&^=", operator},
+
+ {token.LAND, "&&", operator},
+ {token.LOR, "||", operator},
+ {token.ARROW, "<-", operator},
+ {token.INC, "++", operator},
+ {token.DEC, "--", operator},
+
+ {token.EQL, "==", operator},
+ {token.LSS, "<", operator},
+ {token.GTR, ">", operator},
+ {token.ASSIGN, "=", operator},
+ {token.NOT, "!", operator},
+
+ {token.NEQ, "!=", operator},
+ {token.LEQ, "<=", operator},
+ {token.GEQ, ">=", operator},
+ {token.DEFINE, ":=", operator},
+ {token.ELLIPSIS, "...", operator},
+
+ {token.LPAREN, "(", operator},
+ {token.LBRACK, "[", operator},
+ {token.LBRACE, "{", operator},
+ {token.COMMA, ",", operator},
+ {token.PERIOD, ".", operator},
+
+ {token.RPAREN, ")", operator},
+ {token.RBRACK, "]", operator},
+ {token.RBRACE, "}", operator},
+ {token.SEMICOLON, ";", operator},
+ {token.COLON, ":", operator},
+
+ // Keywords
+ {token.BREAK, "break", keyword},
+ {token.CASE, "case", keyword},
+ {token.CHAN, "chan", keyword},
+ {token.CONST, "const", keyword},
+ {token.CONTINUE, "continue", keyword},
+
+ {token.DEFAULT, "default", keyword},
+ {token.DEFER, "defer", keyword},
+ {token.ELSE, "else", keyword},
+ {token.FALLTHROUGH, "fallthrough", keyword},
+ {token.FOR, "for", keyword},
+
+ {token.FUNC, "func", keyword},
+ {token.GO, "go", keyword},
+ {token.GOTO, "goto", keyword},
+ {token.IF, "if", keyword},
+ {token.IMPORT, "import", keyword},
+
+ {token.INTERFACE, "interface", keyword},
+ {token.MAP, "map", keyword},
+ {token.PACKAGE, "package", keyword},
+ {token.RANGE, "range", keyword},
+ {token.RETURN, "return", keyword},
+
+ {token.SELECT, "select", keyword},
+ {token.STRUCT, "struct", keyword},
+ {token.SWITCH, "switch", keyword},
+ {token.TYPE, "type", keyword},
+ {token.VAR, "var", keyword},
+}
+
+const whitespace = " \t \n\n\n" // to separate tokens
+
+var source = func() []byte {
+ var src []byte
+ for _, t := range tokens {
+ src = append(src, t.lit...)
+ src = append(src, whitespace...)
+ }
+ return src
+}()
+
+func newlineCount(s string) int {
+ n := 0
+ for i := 0; i < len(s); i++ {
+ if s[i] == '\n' {
+ n++
+ }
+ }
+ return n
+}
+
+func checkPos(t *testing.T, lit string, p token.Pos, expected token.Position) {
+ pos := fset.Position(p)
+ // Check cleaned filenames so that we don't have to worry about
+ // different os.PathSeparator values.
+ if pos.Filename != expected.Filename && filepath.Clean(pos.Filename) != filepath.Clean(expected.Filename) {
+ t.Errorf("bad filename for %q: got %s, expected %s", lit, pos.Filename, expected.Filename)
+ }
+ if pos.Offset != expected.Offset {
+ t.Errorf("bad position for %q: got %d, expected %d", lit, pos.Offset, expected.Offset)
+ }
+ if pos.Line != expected.Line {
+ t.Errorf("bad line for %q: got %d, expected %d", lit, pos.Line, expected.Line)
+ }
+ if pos.Column != expected.Column {
+ t.Errorf("bad column for %q: got %d, expected %d", lit, pos.Column, expected.Column)
+ }
+}
+
+// Verify that calling Scan() provides the correct results.
+func TestScan(t *testing.T) {
+ whitespace_linecount := newlineCount(whitespace)
+
+ // error handler
+ eh := func(_ token.Position, msg string) {
+ t.Errorf("error handler called (msg = %s)", msg)
+ }
+
+ // verify scan
+ var s Scanner
+ s.Init(fset.AddFile("", fset.Base(), len(source)), source, eh, ScanComments|dontInsertSemis)
+
+ // set up expected position
+ epos := token.Position{
+ Filename: "",
+ Offset: 0,
+ Line: 1,
+ Column: 1,
+ }
+
+ index := 0
+ for {
+ pos, tok, lit := s.Scan()
+
+ // check position
+ if tok == token.EOF {
+ // correction for EOF
+ epos.Line = newlineCount(string(source))
+ epos.Column = 2
+ }
+ checkPos(t, lit, pos, epos)
+
+ // check token
+ e := elt{token.EOF, "", special}
+ if index < len(tokens) {
+ e = tokens[index]
+ index++
+ }
+ if tok != e.tok {
+ t.Errorf("bad token for %q: got %s, expected %s", lit, tok, e.tok)
+ }
+
+ // check token class
+ if tokenclass(tok) != e.class {
+ t.Errorf("bad class for %q: got %d, expected %d", lit, tokenclass(tok), e.class)
+ }
+
+ // check literal
+ elit := ""
+ switch e.tok {
+ case token.COMMENT:
+ // no CRs in comments
+ elit = string(stripCR([]byte(e.lit), e.lit[1] == '*'))
+ //-style comment literal doesn't contain newline
+ if elit[1] == '/' {
+ elit = elit[0 : len(elit)-1]
+ }
+ case token.IDENT:
+ elit = e.lit
+ case token.SEMICOLON:
+ elit = ";"
+ default:
+ if e.tok.IsLiteral() {
+ // no CRs in raw string literals
+ elit = e.lit
+ if elit[0] == '`' {
+ elit = string(stripCR([]byte(elit), false))
+ }
+ } else if e.tok.IsKeyword() {
+ elit = e.lit
+ }
+ }
+ if lit != elit {
+ t.Errorf("bad literal for %q: got %q, expected %q", lit, lit, elit)
+ }
+
+ if tok == token.EOF {
+ break
+ }
+
+ // update position
+ epos.Offset += len(e.lit) + len(whitespace)
+ epos.Line += newlineCount(e.lit) + whitespace_linecount
+
+ }
+
+ if s.ErrorCount != 0 {
+ t.Errorf("found %d errors", s.ErrorCount)
+ }
+}
+
+func TestStripCR(t *testing.T) {
+ for _, test := range []struct{ have, want string }{
+ {"//\n", "//\n"},
+ {"//\r\n", "//\n"},
+ {"//\r\r\r\n", "//\n"},
+ {"//\r*\r/\r\n", "//*/\n"},
+ {"/**/", "/**/"},
+ {"/*\r/*/", "/*/*/"},
+ {"/*\r*/", "/**/"},
+ {"/**\r/*/", "/**\r/*/"},
+ {"/*\r/\r*\r/*/", "/*/*\r/*/"},
+ {"/*\r\r\r\r*/", "/**/"},
+ } {
+ got := string(stripCR([]byte(test.have), len(test.have) >= 2 && test.have[1] == '*'))
+ if got != test.want {
+ t.Errorf("stripCR(%q) = %q; want %q", test.have, got, test.want)
+ }
+ }
+}
+
+func checkSemi(t *testing.T, line string, mode Mode) {
+ var S Scanner
+ file := fset.AddFile("TestSemis", fset.Base(), len(line))
+ S.Init(file, []byte(line), nil, mode)
+ pos, tok, lit := S.Scan()
+ for tok != token.EOF {
+ if tok == token.ILLEGAL {
+ // the illegal token literal indicates what
+ // kind of semicolon literal to expect
+ semiLit := "\n"
+ if lit[0] == '#' {
+ semiLit = ";"
+ }
+ // next token must be a semicolon
+ semiPos := file.Position(pos)
+ semiPos.Offset++
+ semiPos.Column++
+ pos, tok, lit = S.Scan()
+ if tok == token.SEMICOLON {
+ if lit != semiLit {
+ t.Errorf(`bad literal for %q: got %q, expected %q`, line, lit, semiLit)
+ }
+ checkPos(t, line, pos, semiPos)
+ } else {
+ t.Errorf("bad token for %q: got %s, expected ;", line, tok)
+ }
+ } else if tok == token.SEMICOLON {
+ t.Errorf("bad token for %q: got ;, expected no ;", line)
+ }
+ pos, tok, lit = S.Scan()
+ }
+}
+
+var lines = []string{
+ // # indicates a semicolon present in the source
+ // $ indicates an automatically inserted semicolon
+ "",
+ "\ufeff#;", // first BOM is ignored
+ "#;",
+ "foo$\n",
+ "123$\n",
+ "1.2$\n",
+ "'x'$\n",
+ `"x"` + "$\n",
+ "`x`$\n",
+
+ "+\n",
+ "-\n",
+ "*\n",
+ "/\n",
+ "%\n",
+
+ "&\n",
+ "|\n",
+ "^\n",
+ "<<\n",
+ ">>\n",
+ "&^\n",
+
+ "+=\n",
+ "-=\n",
+ "*=\n",
+ "/=\n",
+ "%=\n",
+
+ "&=\n",
+ "|=\n",
+ "^=\n",
+ "<<=\n",
+ ">>=\n",
+ "&^=\n",
+
+ "&&\n",
+ "||\n",
+ "<-\n",
+ "++$\n",
+ "--$\n",
+
+ "==\n",
+ "<\n",
+ ">\n",
+ "=\n",
+ "!\n",
+
+ "!=\n",
+ "<=\n",
+ ">=\n",
+ ":=\n",
+ "...\n",
+
+ "(\n",
+ "[\n",
+ "{\n",
+ ",\n",
+ ".\n",
+
+ ")$\n",
+ "]$\n",
+ "}$\n",
+ "#;\n",
+ ":\n",
+
+ "break$\n",
+ "case\n",
+ "chan\n",
+ "const\n",
+ "continue$\n",
+
+ "default\n",
+ "defer\n",
+ "else\n",
+ "fallthrough$\n",
+ "for\n",
+
+ "func\n",
+ "go\n",
+ "goto\n",
+ "if\n",
+ "import\n",
+
+ "interface\n",
+ "map\n",
+ "package\n",
+ "range\n",
+ "return$\n",
+
+ "select\n",
+ "struct\n",
+ "switch\n",
+ "type\n",
+ "var\n",
+
+ "foo$//comment\n",
+ "foo$//comment",
+ "foo$/*comment*/\n",
+ "foo$/*\n*/",
+ "foo$/*comment*/ \n",
+ "foo$/*\n*/ ",
+
+ "foo $// comment\n",
+ "foo $// comment",
+ "foo $/*comment*/\n",
+ "foo $/*\n*/",
+ "foo $/* */ /* \n */ bar$/**/\n",
+ "foo $/*0*/ /*1*/ /*2*/\n",
+
+ "foo $/*comment*/ \n",
+ "foo $/*0*/ /*1*/ /*2*/ \n",
+ "foo $/**/ /*-------------*/ /*----\n*/bar $/* \n*/baa$\n",
+ "foo $/* an EOF terminates a line */",
+ "foo $/* an EOF terminates a line */ /*",
+ "foo $/* an EOF terminates a line */ //",
+
+ "package main$\n\nfunc main() {\n\tif {\n\t\treturn /* */ }$\n}$\n",
+ "package main$",
+}
+
+func TestSemis(t *testing.T) {
+ for _, line := range lines {
+ checkSemi(t, line, 0)
+ checkSemi(t, line, ScanComments)
+
+ // if the input ended in newlines, the input must tokenize the
+ // same with or without those newlines
+ for i := len(line) - 1; i >= 0 && line[i] == '\n'; i-- {
+ checkSemi(t, line[0:i], 0)
+ checkSemi(t, line[0:i], ScanComments)
+ }
+ }
+}
+
+type segment struct {
+ srcline string // a line of source text
+ filename string // filename for current token; error message for invalid line directives
+ line, column int // line and column for current token; error position for invalid line directives
+}
+
+var segments = []segment{
+ // exactly one token per line since the test consumes one token per segment
+ {" line1", "TestLineDirectives", 1, 3},
+ {"\nline2", "TestLineDirectives", 2, 1},
+ {"\nline3 //line File1.go:100", "TestLineDirectives", 3, 1}, // bad line comment, ignored
+ {"\nline4", "TestLineDirectives", 4, 1},
+ {"\n//line File1.go:100\n line100", "File1.go", 100, 0},
+ {"\n//line \t :42\n line1", " \t ", 42, 0},
+ {"\n//line File2.go:200\n line200", "File2.go", 200, 0},
+ {"\n//line foo\t:42\n line42", "foo\t", 42, 0},
+ {"\n //line foo:42\n line43", "foo\t", 44, 0}, // bad line comment, ignored (use existing, prior filename)
+ {"\n//line foo 42\n line44", "foo\t", 46, 0}, // bad line comment, ignored (use existing, prior filename)
+ {"\n//line /bar:42\n line45", "/bar", 42, 0},
+ {"\n//line ./foo:42\n line46", "foo", 42, 0},
+ {"\n//line a/b/c/File1.go:100\n line100", "a/b/c/File1.go", 100, 0},
+ {"\n//line c:\\bar:42\n line200", "c:\\bar", 42, 0},
+ {"\n//line c:\\dir\\File1.go:100\n line201", "c:\\dir\\File1.go", 100, 0},
+
+ // tests for new line directive syntax
+ {"\n//line :100\na1", "", 100, 0}, // missing filename means empty filename
+ {"\n//line bar:100\nb1", "bar", 100, 0},
+ {"\n//line :100:10\nc1", "bar", 100, 10}, // missing filename means current filename
+ {"\n//line foo:100:10\nd1", "foo", 100, 10},
+
+ {"\n/*line :100*/a2", "", 100, 0}, // missing filename means empty filename
+ {"\n/*line bar:100*/b2", "bar", 100, 0},
+ {"\n/*line :100:10*/c2", "bar", 100, 10}, // missing filename means current filename
+ {"\n/*line foo:100:10*/d2", "foo", 100, 10},
+ {"\n/*line foo:100:10*/ e2", "foo", 100, 14}, // line-directive relative column
+ {"\n/*line foo:100:10*/\n\nf2", "foo", 102, 1}, // absolute column since on new line
+}
+
+var dirsegments = []segment{
+ // exactly one token per line since the test consumes one token per segment
+ {" line1", "TestLineDir/TestLineDirectives", 1, 3},
+ {"\n//line File1.go:100\n line100", "TestLineDir/File1.go", 100, 0},
+}
+
+var dirUnixSegments = []segment{
+ {"\n//line /bar:42\n line42", "/bar", 42, 0},
+}
+
+var dirWindowsSegments = []segment{
+ {"\n//line c:\\bar:42\n line42", "c:\\bar", 42, 0},
+}
+
+// Verify that line directives are interpreted correctly.
+func TestLineDirectives(t *testing.T) {
+ testSegments(t, segments, "TestLineDirectives")
+ testSegments(t, dirsegments, "TestLineDir/TestLineDirectives")
+ if runtime.GOOS == "windows" {
+ testSegments(t, dirWindowsSegments, "TestLineDir/TestLineDirectives")
+ } else {
+ testSegments(t, dirUnixSegments, "TestLineDir/TestLineDirectives")
+ }
+}
+
+func testSegments(t *testing.T, segments []segment, filename string) {
+ var src string
+ for _, e := range segments {
+ src += e.srcline
+ }
+
+ // verify scan
+ var S Scanner
+ file := fset.AddFile(filename, fset.Base(), len(src))
+ S.Init(file, []byte(src), func(pos token.Position, msg string) { t.Error(Error{pos, msg}) }, dontInsertSemis)
+ for _, s := range segments {
+ p, _, lit := S.Scan()
+ pos := file.Position(p)
+ checkPos(t, lit, p, token.Position{
+ Filename: s.filename,
+ Offset: pos.Offset,
+ Line: s.line,
+ Column: s.column,
+ })
+ }
+
+ if S.ErrorCount != 0 {
+ t.Errorf("got %d errors", S.ErrorCount)
+ }
+}
+
+// The filename is used for the error message in these test cases.
+// The first line directive is valid and used to control the expected error line.
+var invalidSegments = []segment{
+ {"\n//line :1:1\n//line foo:42 extra text\ndummy", "invalid line number: 42 extra text", 1, 12},
+ {"\n//line :2:1\n//line foobar:\ndummy", "invalid line number: ", 2, 15},
+ {"\n//line :5:1\n//line :0\ndummy", "invalid line number: 0", 5, 9},
+ {"\n//line :10:1\n//line :1:0\ndummy", "invalid column number: 0", 10, 11},
+ {"\n//line :1:1\n//line :foo:0\ndummy", "invalid line number: 0", 1, 13}, // foo is considered part of the filename
+}
+
+// Verify that invalid line directives get the correct error message.
+func TestInvalidLineDirectives(t *testing.T) {
+ // make source
+ var src string
+ for _, e := range invalidSegments {
+ src += e.srcline
+ }
+
+ // verify scan
+ var S Scanner
+ var s segment // current segment
+ file := fset.AddFile(filepath.Join("dir", "TestInvalidLineDirectives"), fset.Base(), len(src))
+ S.Init(file, []byte(src), func(pos token.Position, msg string) {
+ if msg != s.filename {
+ t.Errorf("got error %q; want %q", msg, s.filename)
+ }
+ if pos.Line != s.line || pos.Column != s.column {
+ t.Errorf("got position %d:%d; want %d:%d", pos.Line, pos.Column, s.line, s.column)
+ }
+ }, dontInsertSemis)
+ for _, s = range invalidSegments {
+ S.Scan()
+ }
+
+ if S.ErrorCount != len(invalidSegments) {
+ t.Errorf("go %d errors; want %d", S.ErrorCount, len(invalidSegments))
+ }
+}
+
+// Verify that initializing the same scanner more than once works correctly.
+func TestInit(t *testing.T) {
+ var s Scanner
+
+ // 1st init
+ src1 := "if true { }"
+ f1 := fset.AddFile("src1", fset.Base(), len(src1))
+ s.Init(f1, []byte(src1), nil, dontInsertSemis)
+ if f1.Size() != len(src1) {
+ t.Errorf("bad file size: got %d, expected %d", f1.Size(), len(src1))
+ }
+ s.Scan() // if
+ s.Scan() // true
+ _, tok, _ := s.Scan() // {
+ if tok != token.LBRACE {
+ t.Errorf("bad token: got %s, expected %s", tok, token.LBRACE)
+ }
+
+ // 2nd init
+ src2 := "go true { ]"
+ f2 := fset.AddFile("src2", fset.Base(), len(src2))
+ s.Init(f2, []byte(src2), nil, dontInsertSemis)
+ if f2.Size() != len(src2) {
+ t.Errorf("bad file size: got %d, expected %d", f2.Size(), len(src2))
+ }
+ _, tok, _ = s.Scan() // go
+ if tok != token.GO {
+ t.Errorf("bad token: got %s, expected %s", tok, token.GO)
+ }
+
+ if s.ErrorCount != 0 {
+ t.Errorf("found %d errors", s.ErrorCount)
+ }
+}
+
+func TestStdErrorHander(t *testing.T) {
+ const src = "@\n" + // illegal character, cause an error
+ "@ @\n" + // two errors on the same line
+ "//line File2:20\n" +
+ "@\n" + // different file, but same line
+ "//line File2:1\n" +
+ "@ @\n" + // same file, decreasing line number
+ "//line File1:1\n" +
+ "@ @ @" // original file, line 1 again
+
+ var list ErrorList
+ eh := func(pos token.Position, msg string) { list.Add(pos, msg) }
+
+ var s Scanner
+ s.Init(fset.AddFile("File1", fset.Base(), len(src)), []byte(src), eh, dontInsertSemis)
+ for {
+ if _, tok, _ := s.Scan(); tok == token.EOF {
+ break
+ }
+ }
+
+ if len(list) != s.ErrorCount {
+ t.Errorf("found %d errors, expected %d", len(list), s.ErrorCount)
+ }
+
+ if len(list) != 9 {
+ t.Errorf("found %d raw errors, expected 9", len(list))
+ PrintError(os.Stderr, list)
+ }
+
+ list.Sort()
+ if len(list) != 9 {
+ t.Errorf("found %d sorted errors, expected 9", len(list))
+ PrintError(os.Stderr, list)
+ }
+
+ list.RemoveMultiples()
+ if len(list) != 4 {
+ t.Errorf("found %d one-per-line errors, expected 4", len(list))
+ PrintError(os.Stderr, list)
+ }
+}
+
+type errorCollector struct {
+ cnt int // number of errors encountered
+ msg string // last error message encountered
+ pos token.Position // last error position encountered
+}
+
+func checkError(t *testing.T, src string, tok token.Token, pos int, lit, err string) {
+ var s Scanner
+ var h errorCollector
+ eh := func(pos token.Position, msg string) {
+ h.cnt++
+ h.msg = msg
+ h.pos = pos
+ }
+ s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), eh, ScanComments|dontInsertSemis)
+ _, tok0, lit0 := s.Scan()
+ if tok0 != tok {
+ t.Errorf("%q: got %s, expected %s", src, tok0, tok)
+ }
+ if tok0 != token.ILLEGAL && lit0 != lit {
+ t.Errorf("%q: got literal %q, expected %q", src, lit0, lit)
+ }
+ cnt := 0
+ if err != "" {
+ cnt = 1
+ }
+ if h.cnt != cnt {
+ t.Errorf("%q: got cnt %d, expected %d", src, h.cnt, cnt)
+ }
+ if h.msg != err {
+ t.Errorf("%q: got msg %q, expected %q", src, h.msg, err)
+ }
+ if h.pos.Offset != pos {
+ t.Errorf("%q: got offset %d, expected %d", src, h.pos.Offset, pos)
+ }
+}
+
+var errors = []struct {
+ src string
+ tok token.Token
+ pos int
+ lit string
+ err string
+}{
+ {"\a", token.ILLEGAL, 0, "", "illegal character U+0007"},
+ {`#`, token.ILLEGAL, 0, "", "illegal character U+0023 '#'"},
+ {`…`, token.ILLEGAL, 0, "", "illegal character U+2026 '…'"},
+ {"..", token.PERIOD, 0, "", ""}, // two periods, not invalid token (issue #28112)
+ {`' '`, token.CHAR, 0, `' '`, ""},
+ {`''`, token.CHAR, 0, `''`, "illegal rune literal"},
+ {`'12'`, token.CHAR, 0, `'12'`, "illegal rune literal"},
+ {`'123'`, token.CHAR, 0, `'123'`, "illegal rune literal"},
+ {`'\0'`, token.CHAR, 3, `'\0'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\07'`, token.CHAR, 4, `'\07'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\8'`, token.CHAR, 2, `'\8'`, "unknown escape sequence"},
+ {`'\08'`, token.CHAR, 3, `'\08'`, "illegal character U+0038 '8' in escape sequence"},
+ {`'\x'`, token.CHAR, 3, `'\x'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\x0'`, token.CHAR, 4, `'\x0'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\x0g'`, token.CHAR, 4, `'\x0g'`, "illegal character U+0067 'g' in escape sequence"},
+ {`'\u'`, token.CHAR, 3, `'\u'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\u0'`, token.CHAR, 4, `'\u0'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\u00'`, token.CHAR, 5, `'\u00'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\u000'`, token.CHAR, 6, `'\u000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\u000`, token.CHAR, 6, `'\u000`, "escape sequence not terminated"},
+ {`'\u0000'`, token.CHAR, 0, `'\u0000'`, ""},
+ {`'\U'`, token.CHAR, 3, `'\U'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U0'`, token.CHAR, 4, `'\U0'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U00'`, token.CHAR, 5, `'\U00'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U000'`, token.CHAR, 6, `'\U000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U0000'`, token.CHAR, 7, `'\U0000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U00000'`, token.CHAR, 8, `'\U00000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U000000'`, token.CHAR, 9, `'\U000000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U0000000'`, token.CHAR, 10, `'\U0000000'`, "illegal character U+0027 ''' in escape sequence"},
+ {`'\U0000000`, token.CHAR, 10, `'\U0000000`, "escape sequence not terminated"},
+ {`'\U00000000'`, token.CHAR, 0, `'\U00000000'`, ""},
+ {`'\Uffffffff'`, token.CHAR, 2, `'\Uffffffff'`, "escape sequence is invalid Unicode code point"},
+ {`'`, token.CHAR, 0, `'`, "rune literal not terminated"},
+ {`'\`, token.CHAR, 2, `'\`, "escape sequence not terminated"},
+ {"'\n", token.CHAR, 0, "'", "rune literal not terminated"},
+ {"'\n ", token.CHAR, 0, "'", "rune literal not terminated"},
+ {`""`, token.STRING, 0, `""`, ""},
+ {`"abc`, token.STRING, 0, `"abc`, "string literal not terminated"},
+ {"\"abc\n", token.STRING, 0, `"abc`, "string literal not terminated"},
+ {"\"abc\n ", token.STRING, 0, `"abc`, "string literal not terminated"},
+ {"``", token.STRING, 0, "``", ""},
+ {"`", token.STRING, 0, "`", "raw string literal not terminated"},
+ {"/**/", token.COMMENT, 0, "/**/", ""},
+ {"/*", token.COMMENT, 0, "/*", "comment not terminated"},
+ {"077", token.INT, 0, "077", ""},
+ {"078.", token.FLOAT, 0, "078.", ""},
+ {"07801234567.", token.FLOAT, 0, "07801234567.", ""},
+ {"078e0", token.FLOAT, 0, "078e0", ""},
+ {"0E", token.FLOAT, 2, "0E", "exponent has no digits"}, // issue 17621
+ {"078", token.INT, 2, "078", "invalid digit '8' in octal literal"},
+ {"07090000008", token.INT, 3, "07090000008", "invalid digit '9' in octal literal"},
+ {"0x", token.INT, 2, "0x", "hexadecimal literal has no digits"},
+ {"\"abc\x00def\"", token.STRING, 4, "\"abc\x00def\"", "illegal character NUL"},
+ {"\"abc\x80def\"", token.STRING, 4, "\"abc\x80def\"", "illegal UTF-8 encoding"},
+ {"\ufeff\ufeff", token.ILLEGAL, 3, "\ufeff\ufeff", "illegal byte order mark"}, // only first BOM is ignored
+ {"//\ufeff", token.COMMENT, 2, "//\ufeff", "illegal byte order mark"}, // only first BOM is ignored
+ {"'\ufeff" + `'`, token.CHAR, 1, "'\ufeff" + `'`, "illegal byte order mark"}, // only first BOM is ignored
+ {`"` + "abc\ufeffdef" + `"`, token.STRING, 4, `"` + "abc\ufeffdef" + `"`, "illegal byte order mark"}, // only first BOM is ignored
+}
+
+func TestScanErrors(t *testing.T) {
+ for _, e := range errors {
+ checkError(t, e.src, e.tok, e.pos, e.lit, e.err)
+ }
+}
+
+// Verify that no comments show up as literal values when skipping comments.
+func TestIssue10213(t *testing.T) {
+ const src = `
+ var (
+ A = 1 // foo
+ )
+
+ var (
+ B = 2
+ // foo
+ )
+
+ var C = 3 // foo
+
+ var D = 4
+ // foo
+
+ func anycode() {
+ // foo
+ }
+ `
+ var s Scanner
+ s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), nil, 0)
+ for {
+ pos, tok, lit := s.Scan()
+ class := tokenclass(tok)
+ if lit != "" && class != keyword && class != literal && tok != token.SEMICOLON {
+ t.Errorf("%s: tok = %s, lit = %q", fset.Position(pos), tok, lit)
+ }
+ if tok <= token.EOF {
+ break
+ }
+ }
+}
+
+func TestIssue28112(t *testing.T) {
+ const src = "... .. 0.. .." // make sure to have stand-alone ".." immediately before EOF to test EOF behavior
+ tokens := []token.Token{token.ELLIPSIS, token.PERIOD, token.PERIOD, token.FLOAT, token.PERIOD, token.PERIOD, token.PERIOD, token.EOF}
+ var s Scanner
+ s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), nil, 0)
+ for _, want := range tokens {
+ pos, got, lit := s.Scan()
+ if got != want {
+ t.Errorf("%s: got %s, want %s", fset.Position(pos), got, want)
+ }
+ // literals expect to have a (non-empty) literal string and we don't care about other tokens for this test
+ if tokenclass(got) == literal && lit == "" {
+ t.Errorf("%s: for %s got empty literal string", fset.Position(pos), got)
+ }
+ }
+}
+
+func BenchmarkScan(b *testing.B) {
+ b.StopTimer()
+ fset := token.NewFileSet()
+ file := fset.AddFile("", fset.Base(), len(source))
+ var s Scanner
+ b.StartTimer()
+ for i := 0; i < b.N; i++ {
+ s.Init(file, source, nil, ScanComments)
+ for {
+ _, tok, _ := s.Scan()
+ if tok == token.EOF {
+ break
+ }
+ }
+ }
+}
+
+func BenchmarkScanFile(b *testing.B) {
+ b.StopTimer()
+ const filename = "scanner.go"
+ src, err := os.ReadFile(filename)
+ if err != nil {
+ panic(err)
+ }
+ fset := token.NewFileSet()
+ file := fset.AddFile(filename, fset.Base(), len(src))
+ b.SetBytes(int64(len(src)))
+ var s Scanner
+ b.StartTimer()
+ for i := 0; i < b.N; i++ {
+ s.Init(file, src, nil, ScanComments)
+ for {
+ _, tok, _ := s.Scan()
+ if tok == token.EOF {
+ break
+ }
+ }
+ }
+}
+
+func TestNumbers(t *testing.T) {
+ for _, test := range []struct {
+ tok token.Token
+ src, tokens, err string
+ }{
+ // binaries
+ {token.INT, "0b0", "0b0", ""},
+ {token.INT, "0b1010", "0b1010", ""},
+ {token.INT, "0B1110", "0B1110", ""},
+
+ {token.INT, "0b", "0b", "binary literal has no digits"},
+ {token.INT, "0b0190", "0b0190", "invalid digit '9' in binary literal"},
+ {token.INT, "0b01a0", "0b01 a0", ""}, // only accept 0-9
+
+ {token.FLOAT, "0b.", "0b.", "invalid radix point in binary literal"},
+ {token.FLOAT, "0b.1", "0b.1", "invalid radix point in binary literal"},
+ {token.FLOAT, "0b1.0", "0b1.0", "invalid radix point in binary literal"},
+ {token.FLOAT, "0b1e10", "0b1e10", "'e' exponent requires decimal mantissa"},
+ {token.FLOAT, "0b1P-1", "0b1P-1", "'P' exponent requires hexadecimal mantissa"},
+
+ {token.IMAG, "0b10i", "0b10i", ""},
+ {token.IMAG, "0b10.0i", "0b10.0i", "invalid radix point in binary literal"},
+
+ // octals
+ {token.INT, "0o0", "0o0", ""},
+ {token.INT, "0o1234", "0o1234", ""},
+ {token.INT, "0O1234", "0O1234", ""},
+
+ {token.INT, "0o", "0o", "octal literal has no digits"},
+ {token.INT, "0o8123", "0o8123", "invalid digit '8' in octal literal"},
+ {token.INT, "0o1293", "0o1293", "invalid digit '9' in octal literal"},
+ {token.INT, "0o12a3", "0o12 a3", ""}, // only accept 0-9
+
+ {token.FLOAT, "0o.", "0o.", "invalid radix point in octal literal"},
+ {token.FLOAT, "0o.2", "0o.2", "invalid radix point in octal literal"},
+ {token.FLOAT, "0o1.2", "0o1.2", "invalid radix point in octal literal"},
+ {token.FLOAT, "0o1E+2", "0o1E+2", "'E' exponent requires decimal mantissa"},
+ {token.FLOAT, "0o1p10", "0o1p10", "'p' exponent requires hexadecimal mantissa"},
+
+ {token.IMAG, "0o10i", "0o10i", ""},
+ {token.IMAG, "0o10e0i", "0o10e0i", "'e' exponent requires decimal mantissa"},
+
+ // 0-octals
+ {token.INT, "0", "0", ""},
+ {token.INT, "0123", "0123", ""},
+
+ {token.INT, "08123", "08123", "invalid digit '8' in octal literal"},
+ {token.INT, "01293", "01293", "invalid digit '9' in octal literal"},
+ {token.INT, "0F.", "0 F .", ""}, // only accept 0-9
+ {token.INT, "0123F.", "0123 F .", ""},
+ {token.INT, "0123456x", "0123456 x", ""},
+
+ // decimals
+ {token.INT, "1", "1", ""},
+ {token.INT, "1234", "1234", ""},
+
+ {token.INT, "1f", "1 f", ""}, // only accept 0-9
+
+ {token.IMAG, "0i", "0i", ""},
+ {token.IMAG, "0678i", "0678i", ""},
+
+ // decimal floats
+ {token.FLOAT, "0.", "0.", ""},
+ {token.FLOAT, "123.", "123.", ""},
+ {token.FLOAT, "0123.", "0123.", ""},
+
+ {token.FLOAT, ".0", ".0", ""},
+ {token.FLOAT, ".123", ".123", ""},
+ {token.FLOAT, ".0123", ".0123", ""},
+
+ {token.FLOAT, "0.0", "0.0", ""},
+ {token.FLOAT, "123.123", "123.123", ""},
+ {token.FLOAT, "0123.0123", "0123.0123", ""},
+
+ {token.FLOAT, "0e0", "0e0", ""},
+ {token.FLOAT, "123e+0", "123e+0", ""},
+ {token.FLOAT, "0123E-1", "0123E-1", ""},
+
+ {token.FLOAT, "0.e+1", "0.e+1", ""},
+ {token.FLOAT, "123.E-10", "123.E-10", ""},
+ {token.FLOAT, "0123.e123", "0123.e123", ""},
+
+ {token.FLOAT, ".0e-1", ".0e-1", ""},
+ {token.FLOAT, ".123E+10", ".123E+10", ""},
+ {token.FLOAT, ".0123E123", ".0123E123", ""},
+
+ {token.FLOAT, "0.0e1", "0.0e1", ""},
+ {token.FLOAT, "123.123E-10", "123.123E-10", ""},
+ {token.FLOAT, "0123.0123e+456", "0123.0123e+456", ""},
+
+ {token.FLOAT, "0e", "0e", "exponent has no digits"},
+ {token.FLOAT, "0E+", "0E+", "exponent has no digits"},
+ {token.FLOAT, "1e+f", "1e+ f", "exponent has no digits"},
+ {token.FLOAT, "0p0", "0p0", "'p' exponent requires hexadecimal mantissa"},
+ {token.FLOAT, "1.0P-1", "1.0P-1", "'P' exponent requires hexadecimal mantissa"},
+
+ {token.IMAG, "0.i", "0.i", ""},
+ {token.IMAG, ".123i", ".123i", ""},
+ {token.IMAG, "123.123i", "123.123i", ""},
+ {token.IMAG, "123e+0i", "123e+0i", ""},
+ {token.IMAG, "123.E-10i", "123.E-10i", ""},
+ {token.IMAG, ".123E+10i", ".123E+10i", ""},
+
+ // hexadecimals
+ {token.INT, "0x0", "0x0", ""},
+ {token.INT, "0x1234", "0x1234", ""},
+ {token.INT, "0xcafef00d", "0xcafef00d", ""},
+ {token.INT, "0XCAFEF00D", "0XCAFEF00D", ""},
+
+ {token.INT, "0x", "0x", "hexadecimal literal has no digits"},
+ {token.INT, "0x1g", "0x1 g", ""},
+
+ {token.IMAG, "0xf00i", "0xf00i", ""},
+
+ // hexadecimal floats
+ {token.FLOAT, "0x0p0", "0x0p0", ""},
+ {token.FLOAT, "0x12efp-123", "0x12efp-123", ""},
+ {token.FLOAT, "0xABCD.p+0", "0xABCD.p+0", ""},
+ {token.FLOAT, "0x.0189P-0", "0x.0189P-0", ""},
+ {token.FLOAT, "0x1.ffffp+1023", "0x1.ffffp+1023", ""},
+
+ {token.FLOAT, "0x.", "0x.", "hexadecimal literal has no digits"},
+ {token.FLOAT, "0x0.", "0x0.", "hexadecimal mantissa requires a 'p' exponent"},
+ {token.FLOAT, "0x.0", "0x.0", "hexadecimal mantissa requires a 'p' exponent"},
+ {token.FLOAT, "0x1.1", "0x1.1", "hexadecimal mantissa requires a 'p' exponent"},
+ {token.FLOAT, "0x1.1e0", "0x1.1e0", "hexadecimal mantissa requires a 'p' exponent"},
+ {token.FLOAT, "0x1.2gp1a", "0x1.2 gp1a", "hexadecimal mantissa requires a 'p' exponent"},
+ {token.FLOAT, "0x0p", "0x0p", "exponent has no digits"},
+ {token.FLOAT, "0xeP-", "0xeP-", "exponent has no digits"},
+ {token.FLOAT, "0x1234PAB", "0x1234P AB", "exponent has no digits"},
+ {token.FLOAT, "0x1.2p1a", "0x1.2p1 a", ""},
+
+ {token.IMAG, "0xf00.bap+12i", "0xf00.bap+12i", ""},
+
+ // separators
+ {token.INT, "0b_1000_0001", "0b_1000_0001", ""},
+ {token.INT, "0o_600", "0o_600", ""},
+ {token.INT, "0_466", "0_466", ""},
+ {token.INT, "1_000", "1_000", ""},
+ {token.FLOAT, "1_000.000_1", "1_000.000_1", ""},
+ {token.IMAG, "10e+1_2_3i", "10e+1_2_3i", ""},
+ {token.INT, "0x_f00d", "0x_f00d", ""},
+ {token.FLOAT, "0x_f00d.0p1_2", "0x_f00d.0p1_2", ""},
+
+ {token.INT, "0b__1000", "0b__1000", "'_' must separate successive digits"},
+ {token.INT, "0o60___0", "0o60___0", "'_' must separate successive digits"},
+ {token.INT, "0466_", "0466_", "'_' must separate successive digits"},
+ {token.FLOAT, "1_.", "1_.", "'_' must separate successive digits"},
+ {token.FLOAT, "0._1", "0._1", "'_' must separate successive digits"},
+ {token.FLOAT, "2.7_e0", "2.7_e0", "'_' must separate successive digits"},
+ {token.IMAG, "10e+12_i", "10e+12_i", "'_' must separate successive digits"},
+ {token.INT, "0x___0", "0x___0", "'_' must separate successive digits"},
+ {token.FLOAT, "0x1.0_p0", "0x1.0_p0", "'_' must separate successive digits"},
+ } {
+ var s Scanner
+ var err string
+ s.Init(fset.AddFile("", fset.Base(), len(test.src)), []byte(test.src), func(_ token.Position, msg string) {
+ if err == "" {
+ err = msg
+ }
+ }, 0)
+ for i, want := range strings.Split(test.tokens, " ") {
+ err = ""
+ _, tok, lit := s.Scan()
+
+ // compute lit where for tokens where lit is not defined
+ switch tok {
+ case token.PERIOD:
+ lit = "."
+ case token.ADD:
+ lit = "+"
+ case token.SUB:
+ lit = "-"
+ }
+
+ if i == 0 {
+ if tok != test.tok {
+ t.Errorf("%q: got token %s; want %s", test.src, tok, test.tok)
+ }
+ if err != test.err {
+ t.Errorf("%q: got error %q; want %q", test.src, err, test.err)
+ }
+ }
+
+ if lit != want {
+ t.Errorf("%q: got literal %q (%s); want %s", test.src, lit, tok, want)
+ }
+ }
+
+ // make sure we read all
+ _, tok, _ := s.Scan()
+ if tok == token.SEMICOLON {
+ _, tok, _ = s.Scan()
+ }
+ if tok != token.EOF {
+ t.Errorf("%q: got %s; want EOF", test.src, tok)
+ }
+ }
+}
diff --git a/src/go/token/example_test.go b/src/go/token/example_test.go
new file mode 100644
index 0000000..0011703
--- /dev/null
+++ b/src/go/token/example_test.go
@@ -0,0 +1,77 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+)
+
+func Example_retrievePositionInfo() {
+ fset := token.NewFileSet()
+
+ const src = `package main
+
+import "fmt"
+
+import "go/token"
+
+//line :1:5
+type p = token.Pos
+
+const bad = token.NoPos
+
+//line fake.go:42:11
+func ok(pos p) bool {
+ return pos != bad
+}
+
+/*line :7:9*/func main() {
+ fmt.Println(ok(bad) == bad.IsValid())
+}
+`
+
+ f, err := parser.ParseFile(fset, "main.go", src, 0)
+ if err != nil {
+ fmt.Println(err)
+ return
+ }
+
+ // Print the location and kind of each declaration in f.
+ for _, decl := range f.Decls {
+ // Get the filename, line, and column back via the file set.
+ // We get both the relative and absolute position.
+ // The relative position is relative to the last line directive.
+ // The absolute position is the exact position in the source.
+ pos := decl.Pos()
+ relPosition := fset.Position(pos)
+ absPosition := fset.PositionFor(pos, false)
+
+ // Either a FuncDecl or GenDecl, since we exit on error.
+ kind := "func"
+ if gen, ok := decl.(*ast.GenDecl); ok {
+ kind = gen.Tok.String()
+ }
+
+ // If the relative and absolute positions differ, show both.
+ fmtPosition := relPosition.String()
+ if relPosition != absPosition {
+ fmtPosition += "[" + absPosition.String() + "]"
+ }
+
+ fmt.Printf("%s: %s\n", fmtPosition, kind)
+ }
+
+ //Output:
+ //
+ // main.go:3:1: import
+ // main.go:5:1: import
+ // main.go:1:5[main.go:8:1]: type
+ // main.go:3:1[main.go:10:1]: const
+ // fake.go:42:11[main.go:13:1]: func
+ // fake.go:7:9[main.go:17:14]: func
+}
diff --git a/src/go/token/position.go b/src/go/token/position.go
new file mode 100644
index 0000000..a21f5fd
--- /dev/null
+++ b/src/go/token/position.go
@@ -0,0 +1,552 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token
+
+import (
+ "fmt"
+ "sort"
+ "sync"
+)
+
+// -----------------------------------------------------------------------------
+// Positions
+
+// Position describes an arbitrary source position
+// including the file, line, and column location.
+// A Position is valid if the line number is > 0.
+//
+type Position struct {
+ Filename string // filename, if any
+ Offset int // offset, starting at 0
+ Line int // line number, starting at 1
+ Column int // column number, starting at 1 (byte count)
+}
+
+// IsValid reports whether the position is valid.
+func (pos *Position) IsValid() bool { return pos.Line > 0 }
+
+// String returns a string in one of several forms:
+//
+// file:line:column valid position with file name
+// file:line valid position with file name but no column (column == 0)
+// line:column valid position without file name
+// line valid position without file name and no column (column == 0)
+// file invalid position with file name
+// - invalid position without file name
+//
+func (pos Position) String() string {
+ s := pos.Filename
+ if pos.IsValid() {
+ if s != "" {
+ s += ":"
+ }
+ s += fmt.Sprintf("%d", pos.Line)
+ if pos.Column != 0 {
+ s += fmt.Sprintf(":%d", pos.Column)
+ }
+ }
+ if s == "" {
+ s = "-"
+ }
+ return s
+}
+
+// Pos is a compact encoding of a source position within a file set.
+// It can be converted into a Position for a more convenient, but much
+// larger, representation.
+//
+// The Pos value for a given file is a number in the range [base, base+size],
+// where base and size are specified when a file is added to the file set.
+// The difference between a Pos value and the corresponding file base
+// corresponds to the byte offset of that position (represented by the Pos value)
+// from the beginning of the file. Thus, the file base offset is the Pos value
+// representing the first byte in the file.
+//
+// To create the Pos value for a specific source offset (measured in bytes),
+// first add the respective file to the current file set using FileSet.AddFile
+// and then call File.Pos(offset) for that file. Given a Pos value p
+// for a specific file set fset, the corresponding Position value is
+// obtained by calling fset.Position(p).
+//
+// Pos values can be compared directly with the usual comparison operators:
+// If two Pos values p and q are in the same file, comparing p and q is
+// equivalent to comparing the respective source file offsets. If p and q
+// are in different files, p < q is true if the file implied by p was added
+// to the respective file set before the file implied by q.
+//
+type Pos int
+
+// The zero value for Pos is NoPos; there is no file and line information
+// associated with it, and NoPos.IsValid() is false. NoPos is always
+// smaller than any other Pos value. The corresponding Position value
+// for NoPos is the zero value for Position.
+//
+const NoPos Pos = 0
+
+// IsValid reports whether the position is valid.
+func (p Pos) IsValid() bool {
+ return p != NoPos
+}
+
+// -----------------------------------------------------------------------------
+// File
+
+// A File is a handle for a file belonging to a FileSet.
+// A File has a name, size, and line offset table.
+//
+type File struct {
+ set *FileSet
+ name string // file name as provided to AddFile
+ base int // Pos value range for this file is [base...base+size]
+ size int // file size as provided to AddFile
+
+ // lines and infos are protected by mutex
+ mutex sync.Mutex
+ lines []int // lines contains the offset of the first character for each line (the first entry is always 0)
+ infos []lineInfo
+}
+
+// Name returns the file name of file f as registered with AddFile.
+func (f *File) Name() string {
+ return f.name
+}
+
+// Base returns the base offset of file f as registered with AddFile.
+func (f *File) Base() int {
+ return f.base
+}
+
+// Size returns the size of file f as registered with AddFile.
+func (f *File) Size() int {
+ return f.size
+}
+
+// LineCount returns the number of lines in file f.
+func (f *File) LineCount() int {
+ f.mutex.Lock()
+ n := len(f.lines)
+ f.mutex.Unlock()
+ return n
+}
+
+// AddLine adds the line offset for a new line.
+// The line offset must be larger than the offset for the previous line
+// and smaller than the file size; otherwise the line offset is ignored.
+//
+func (f *File) AddLine(offset int) {
+ f.mutex.Lock()
+ if i := len(f.lines); (i == 0 || f.lines[i-1] < offset) && offset < f.size {
+ f.lines = append(f.lines, offset)
+ }
+ f.mutex.Unlock()
+}
+
+// MergeLine merges a line with the following line. It is akin to replacing
+// the newline character at the end of the line with a space (to not change the
+// remaining offsets). To obtain the line number, consult e.g. Position.Line.
+// MergeLine will panic if given an invalid line number.
+//
+func (f *File) MergeLine(line int) {
+ if line < 1 {
+ panic(fmt.Sprintf("invalid line number %d (should be >= 1)", line))
+ }
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ if line >= len(f.lines) {
+ panic(fmt.Sprintf("invalid line number %d (should be < %d)", line, len(f.lines)))
+ }
+ // To merge the line numbered <line> with the line numbered <line+1>,
+ // we need to remove the entry in lines corresponding to the line
+ // numbered <line+1>. The entry in lines corresponding to the line
+ // numbered <line+1> is located at index <line>, since indices in lines
+ // are 0-based and line numbers are 1-based.
+ copy(f.lines[line:], f.lines[line+1:])
+ f.lines = f.lines[:len(f.lines)-1]
+}
+
+// SetLines sets the line offsets for a file and reports whether it succeeded.
+// The line offsets are the offsets of the first character of each line;
+// for instance for the content "ab\nc\n" the line offsets are {0, 3}.
+// An empty file has an empty line offset table.
+// Each line offset must be larger than the offset for the previous line
+// and smaller than the file size; otherwise SetLines fails and returns
+// false.
+// Callers must not mutate the provided slice after SetLines returns.
+//
+func (f *File) SetLines(lines []int) bool {
+ // verify validity of lines table
+ size := f.size
+ for i, offset := range lines {
+ if i > 0 && offset <= lines[i-1] || size <= offset {
+ return false
+ }
+ }
+
+ // set lines table
+ f.mutex.Lock()
+ f.lines = lines
+ f.mutex.Unlock()
+ return true
+}
+
+// SetLinesForContent sets the line offsets for the given file content.
+// It ignores position-altering //line comments.
+func (f *File) SetLinesForContent(content []byte) {
+ var lines []int
+ line := 0
+ for offset, b := range content {
+ if line >= 0 {
+ lines = append(lines, line)
+ }
+ line = -1
+ if b == '\n' {
+ line = offset + 1
+ }
+ }
+
+ // set lines table
+ f.mutex.Lock()
+ f.lines = lines
+ f.mutex.Unlock()
+}
+
+// LineStart returns the Pos value of the start of the specified line.
+// It ignores any alternative positions set using AddLineColumnInfo.
+// LineStart panics if the 1-based line number is invalid.
+func (f *File) LineStart(line int) Pos {
+ if line < 1 {
+ panic(fmt.Sprintf("invalid line number %d (should be >= 1)", line))
+ }
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ if line > len(f.lines) {
+ panic(fmt.Sprintf("invalid line number %d (should be < %d)", line, len(f.lines)))
+ }
+ return Pos(f.base + f.lines[line-1])
+}
+
+// A lineInfo object describes alternative file, line, and column
+// number information (such as provided via a //line directive)
+// for a given file offset.
+type lineInfo struct {
+ // fields are exported to make them accessible to gob
+ Offset int
+ Filename string
+ Line, Column int
+}
+
+// AddLineInfo is like AddLineColumnInfo with a column = 1 argument.
+// It is here for backward-compatibility for code prior to Go 1.11.
+//
+func (f *File) AddLineInfo(offset int, filename string, line int) {
+ f.AddLineColumnInfo(offset, filename, line, 1)
+}
+
+// AddLineColumnInfo adds alternative file, line, and column number
+// information for a given file offset. The offset must be larger
+// than the offset for the previously added alternative line info
+// and smaller than the file size; otherwise the information is
+// ignored.
+//
+// AddLineColumnInfo is typically used to register alternative position
+// information for line directives such as //line filename:line:column.
+//
+func (f *File) AddLineColumnInfo(offset int, filename string, line, column int) {
+ f.mutex.Lock()
+ if i := len(f.infos); i == 0 || f.infos[i-1].Offset < offset && offset < f.size {
+ f.infos = append(f.infos, lineInfo{offset, filename, line, column})
+ }
+ f.mutex.Unlock()
+}
+
+// Pos returns the Pos value for the given file offset;
+// the offset must be <= f.Size().
+// f.Pos(f.Offset(p)) == p.
+//
+func (f *File) Pos(offset int) Pos {
+ if offset > f.size {
+ panic(fmt.Sprintf("invalid file offset %d (should be <= %d)", offset, f.size))
+ }
+ return Pos(f.base + offset)
+}
+
+// Offset returns the offset for the given file position p;
+// p must be a valid Pos value in that file.
+// f.Offset(f.Pos(offset)) == offset.
+//
+func (f *File) Offset(p Pos) int {
+ if int(p) < f.base || int(p) > f.base+f.size {
+ panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+ }
+ return int(p) - f.base
+}
+
+// Line returns the line number for the given file position p;
+// p must be a Pos value in that file or NoPos.
+//
+func (f *File) Line(p Pos) int {
+ return f.Position(p).Line
+}
+
+func searchLineInfos(a []lineInfo, x int) int {
+ return sort.Search(len(a), func(i int) bool { return a[i].Offset > x }) - 1
+}
+
+// unpack returns the filename and line and column number for a file offset.
+// If adjusted is set, unpack will return the filename and line information
+// possibly adjusted by //line comments; otherwise those comments are ignored.
+//
+func (f *File) unpack(offset int, adjusted bool) (filename string, line, column int) {
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ filename = f.name
+ if i := searchInts(f.lines, offset); i >= 0 {
+ line, column = i+1, offset-f.lines[i]+1
+ }
+ if adjusted && len(f.infos) > 0 {
+ // few files have extra line infos
+ if i := searchLineInfos(f.infos, offset); i >= 0 {
+ alt := &f.infos[i]
+ filename = alt.Filename
+ if i := searchInts(f.lines, alt.Offset); i >= 0 {
+ // i+1 is the line at which the alternative position was recorded
+ d := line - (i + 1) // line distance from alternative position base
+ line = alt.Line + d
+ if alt.Column == 0 {
+ // alternative column is unknown => relative column is unknown
+ // (the current specification for line directives requires
+ // this to apply until the next PosBase/line directive,
+ // not just until the new newline)
+ column = 0
+ } else if d == 0 {
+ // the alternative position base is on the current line
+ // => column is relative to alternative column
+ column = alt.Column + (offset - alt.Offset)
+ }
+ }
+ }
+ }
+ return
+}
+
+func (f *File) position(p Pos, adjusted bool) (pos Position) {
+ offset := int(p) - f.base
+ pos.Offset = offset
+ pos.Filename, pos.Line, pos.Column = f.unpack(offset, adjusted)
+ return
+}
+
+// PositionFor returns the Position value for the given file position p.
+// If adjusted is set, the position may be adjusted by position-altering
+// //line comments; otherwise those comments are ignored.
+// p must be a Pos value in f or NoPos.
+//
+func (f *File) PositionFor(p Pos, adjusted bool) (pos Position) {
+ if p != NoPos {
+ if int(p) < f.base || int(p) > f.base+f.size {
+ panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+ }
+ pos = f.position(p, adjusted)
+ }
+ return
+}
+
+// Position returns the Position value for the given file position p.
+// Calling f.Position(p) is equivalent to calling f.PositionFor(p, true).
+//
+func (f *File) Position(p Pos) (pos Position) {
+ return f.PositionFor(p, true)
+}
+
+// -----------------------------------------------------------------------------
+// FileSet
+
+// A FileSet represents a set of source files.
+// Methods of file sets are synchronized; multiple goroutines
+// may invoke them concurrently.
+//
+// The byte offsets for each file in a file set are mapped into
+// distinct (integer) intervals, one interval [base, base+size]
+// per file. Base represents the first byte in the file, and size
+// is the corresponding file size. A Pos value is a value in such
+// an interval. By determining the interval a Pos value belongs
+// to, the file, its file base, and thus the byte offset (position)
+// the Pos value is representing can be computed.
+//
+// When adding a new file, a file base must be provided. That can
+// be any integer value that is past the end of any interval of any
+// file already in the file set. For convenience, FileSet.Base provides
+// such a value, which is simply the end of the Pos interval of the most
+// recently added file, plus one. Unless there is a need to extend an
+// interval later, using the FileSet.Base should be used as argument
+// for FileSet.AddFile.
+//
+type FileSet struct {
+ mutex sync.RWMutex // protects the file set
+ base int // base offset for the next file
+ files []*File // list of files in the order added to the set
+ last *File // cache of last file looked up
+}
+
+// NewFileSet creates a new file set.
+func NewFileSet() *FileSet {
+ return &FileSet{
+ base: 1, // 0 == NoPos
+ }
+}
+
+// Base returns the minimum base offset that must be provided to
+// AddFile when adding the next file.
+//
+func (s *FileSet) Base() int {
+ s.mutex.RLock()
+ b := s.base
+ s.mutex.RUnlock()
+ return b
+
+}
+
+// AddFile adds a new file with a given filename, base offset, and file size
+// to the file set s and returns the file. Multiple files may have the same
+// name. The base offset must not be smaller than the FileSet's Base(), and
+// size must not be negative. As a special case, if a negative base is provided,
+// the current value of the FileSet's Base() is used instead.
+//
+// Adding the file will set the file set's Base() value to base + size + 1
+// as the minimum base value for the next file. The following relationship
+// exists between a Pos value p for a given file offset offs:
+//
+// int(p) = base + offs
+//
+// with offs in the range [0, size] and thus p in the range [base, base+size].
+// For convenience, File.Pos may be used to create file-specific position
+// values from a file offset.
+//
+func (s *FileSet) AddFile(filename string, base, size int) *File {
+ s.mutex.Lock()
+ defer s.mutex.Unlock()
+ if base < 0 {
+ base = s.base
+ }
+ if base < s.base {
+ panic(fmt.Sprintf("invalid base %d (should be >= %d)", base, s.base))
+ }
+ if size < 0 {
+ panic(fmt.Sprintf("invalid size %d (should be >= 0)", size))
+ }
+ // base >= s.base && size >= 0
+ f := &File{set: s, name: filename, base: base, size: size, lines: []int{0}}
+ base += size + 1 // +1 because EOF also has a position
+ if base < 0 {
+ panic("token.Pos offset overflow (> 2G of source code in file set)")
+ }
+ // add the file to the file set
+ s.base = base
+ s.files = append(s.files, f)
+ s.last = f
+ return f
+}
+
+// Iterate calls f for the files in the file set in the order they were added
+// until f returns false.
+//
+func (s *FileSet) Iterate(f func(*File) bool) {
+ for i := 0; ; i++ {
+ var file *File
+ s.mutex.RLock()
+ if i < len(s.files) {
+ file = s.files[i]
+ }
+ s.mutex.RUnlock()
+ if file == nil || !f(file) {
+ break
+ }
+ }
+}
+
+func searchFiles(a []*File, x int) int {
+ return sort.Search(len(a), func(i int) bool { return a[i].base > x }) - 1
+}
+
+func (s *FileSet) file(p Pos) *File {
+ s.mutex.RLock()
+ // common case: p is in last file
+ if f := s.last; f != nil && f.base <= int(p) && int(p) <= f.base+f.size {
+ s.mutex.RUnlock()
+ return f
+ }
+ // p is not in last file - search all files
+ if i := searchFiles(s.files, int(p)); i >= 0 {
+ f := s.files[i]
+ // f.base <= int(p) by definition of searchFiles
+ if int(p) <= f.base+f.size {
+ s.mutex.RUnlock()
+ s.mutex.Lock()
+ s.last = f // race is ok - s.last is only a cache
+ s.mutex.Unlock()
+ return f
+ }
+ }
+ s.mutex.RUnlock()
+ return nil
+}
+
+// File returns the file that contains the position p.
+// If no such file is found (for instance for p == NoPos),
+// the result is nil.
+//
+func (s *FileSet) File(p Pos) (f *File) {
+ if p != NoPos {
+ f = s.file(p)
+ }
+ return
+}
+
+// PositionFor converts a Pos p in the fileset into a Position value.
+// If adjusted is set, the position may be adjusted by position-altering
+// //line comments; otherwise those comments are ignored.
+// p must be a Pos value in s or NoPos.
+//
+func (s *FileSet) PositionFor(p Pos, adjusted bool) (pos Position) {
+ if p != NoPos {
+ if f := s.file(p); f != nil {
+ return f.position(p, adjusted)
+ }
+ }
+ return
+}
+
+// Position converts a Pos p in the fileset into a Position value.
+// Calling s.Position(p) is equivalent to calling s.PositionFor(p, true).
+//
+func (s *FileSet) Position(p Pos) (pos Position) {
+ return s.PositionFor(p, true)
+}
+
+// -----------------------------------------------------------------------------
+// Helper functions
+
+func searchInts(a []int, x int) int {
+ // This function body is a manually inlined version of:
+ //
+ // return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1
+ //
+ // With better compiler optimizations, this may not be needed in the
+ // future, but at the moment this change improves the go/printer
+ // benchmark performance by ~30%. This has a direct impact on the
+ // speed of gofmt and thus seems worthwhile (2011-04-29).
+ // TODO(gri): Remove this when compilers have caught up.
+ i, j := 0, len(a)
+ for i < j {
+ h := i + (j-i)/2 // avoid overflow when computing h
+ // i ≤ h < j
+ if a[h] <= x {
+ i = h + 1
+ } else {
+ j = h
+ }
+ }
+ return i - 1
+}
diff --git a/src/go/token/position_test.go b/src/go/token/position_test.go
new file mode 100644
index 0000000..7d465df
--- /dev/null
+++ b/src/go/token/position_test.go
@@ -0,0 +1,341 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token
+
+import (
+ "fmt"
+ "math/rand"
+ "sync"
+ "testing"
+)
+
+func checkPos(t *testing.T, msg string, got, want Position) {
+ if got.Filename != want.Filename {
+ t.Errorf("%s: got filename = %q; want %q", msg, got.Filename, want.Filename)
+ }
+ if got.Offset != want.Offset {
+ t.Errorf("%s: got offset = %d; want %d", msg, got.Offset, want.Offset)
+ }
+ if got.Line != want.Line {
+ t.Errorf("%s: got line = %d; want %d", msg, got.Line, want.Line)
+ }
+ if got.Column != want.Column {
+ t.Errorf("%s: got column = %d; want %d", msg, got.Column, want.Column)
+ }
+}
+
+func TestNoPos(t *testing.T) {
+ if NoPos.IsValid() {
+ t.Errorf("NoPos should not be valid")
+ }
+ var fset *FileSet
+ checkPos(t, "nil NoPos", fset.Position(NoPos), Position{})
+ fset = NewFileSet()
+ checkPos(t, "fset NoPos", fset.Position(NoPos), Position{})
+}
+
+var tests = []struct {
+ filename string
+ source []byte // may be nil
+ size int
+ lines []int
+}{
+ {"a", []byte{}, 0, []int{}},
+ {"b", []byte("01234"), 5, []int{0}},
+ {"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}},
+ {"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}},
+ {"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}},
+ {"f", []byte("package p\n\nimport \"fmt\""), 23, []int{0, 10, 11}},
+ {"g", []byte("package p\n\nimport \"fmt\"\n"), 24, []int{0, 10, 11}},
+ {"h", []byte("package p\n\nimport \"fmt\"\n "), 25, []int{0, 10, 11, 24}},
+}
+
+func linecol(lines []int, offs int) (int, int) {
+ prevLineOffs := 0
+ for line, lineOffs := range lines {
+ if offs < lineOffs {
+ return line, offs - prevLineOffs + 1
+ }
+ prevLineOffs = lineOffs
+ }
+ return len(lines), offs - prevLineOffs + 1
+}
+
+func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) {
+ for offs := 0; offs < f.Size(); offs++ {
+ p := f.Pos(offs)
+ offs2 := f.Offset(p)
+ if offs2 != offs {
+ t.Errorf("%s, Offset: got offset %d; want %d", f.Name(), offs2, offs)
+ }
+ line, col := linecol(lines, offs)
+ msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
+ checkPos(t, msg, f.Position(f.Pos(offs)), Position{f.Name(), offs, line, col})
+ checkPos(t, msg, fset.Position(p), Position{f.Name(), offs, line, col})
+ }
+}
+
+func makeTestSource(size int, lines []int) []byte {
+ src := make([]byte, size)
+ for _, offs := range lines {
+ if offs > 0 {
+ src[offs-1] = '\n'
+ }
+ }
+ return src
+}
+
+func TestPositions(t *testing.T) {
+ const delta = 7 // a non-zero base offset increment
+ fset := NewFileSet()
+ for _, test := range tests {
+ // verify consistency of test case
+ if test.source != nil && len(test.source) != test.size {
+ t.Errorf("%s: inconsistent test case: got file size %d; want %d", test.filename, len(test.source), test.size)
+ }
+
+ // add file and verify name and size
+ f := fset.AddFile(test.filename, fset.Base()+delta, test.size)
+ if f.Name() != test.filename {
+ t.Errorf("got filename %q; want %q", f.Name(), test.filename)
+ }
+ if f.Size() != test.size {
+ t.Errorf("%s: got file size %d; want %d", f.Name(), f.Size(), test.size)
+ }
+ if fset.File(f.Pos(0)) != f {
+ t.Errorf("%s: f.Pos(0) was not found in f", f.Name())
+ }
+
+ // add lines individually and verify all positions
+ for i, offset := range test.lines {
+ f.AddLine(offset)
+ if f.LineCount() != i+1 {
+ t.Errorf("%s, AddLine: got line count %d; want %d", f.Name(), f.LineCount(), i+1)
+ }
+ // adding the same offset again should be ignored
+ f.AddLine(offset)
+ if f.LineCount() != i+1 {
+ t.Errorf("%s, AddLine: got unchanged line count %d; want %d", f.Name(), f.LineCount(), i+1)
+ }
+ verifyPositions(t, fset, f, test.lines[0:i+1])
+ }
+
+ // add lines with SetLines and verify all positions
+ if ok := f.SetLines(test.lines); !ok {
+ t.Errorf("%s: SetLines failed", f.Name())
+ }
+ if f.LineCount() != len(test.lines) {
+ t.Errorf("%s, SetLines: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
+ }
+ verifyPositions(t, fset, f, test.lines)
+
+ // add lines with SetLinesForContent and verify all positions
+ src := test.source
+ if src == nil {
+ // no test source available - create one from scratch
+ src = makeTestSource(test.size, test.lines)
+ }
+ f.SetLinesForContent(src)
+ if f.LineCount() != len(test.lines) {
+ t.Errorf("%s, SetLinesForContent: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
+ }
+ verifyPositions(t, fset, f, test.lines)
+ }
+}
+
+func TestLineInfo(t *testing.T) {
+ fset := NewFileSet()
+ f := fset.AddFile("foo", fset.Base(), 500)
+ lines := []int{0, 42, 77, 100, 210, 220, 277, 300, 333, 401}
+ // add lines individually and provide alternative line information
+ for _, offs := range lines {
+ f.AddLine(offs)
+ f.AddLineInfo(offs, "bar", 42)
+ }
+ // verify positions for all offsets
+ for offs := 0; offs <= f.Size(); offs++ {
+ p := f.Pos(offs)
+ _, col := linecol(lines, offs)
+ msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
+ checkPos(t, msg, f.Position(f.Pos(offs)), Position{"bar", offs, 42, col})
+ checkPos(t, msg, fset.Position(p), Position{"bar", offs, 42, col})
+ }
+}
+
+func TestFiles(t *testing.T) {
+ fset := NewFileSet()
+ for i, test := range tests {
+ base := fset.Base()
+ if i%2 == 1 {
+ // Setting a negative base is equivalent to
+ // fset.Base(), so test some of each.
+ base = -1
+ }
+ fset.AddFile(test.filename, base, test.size)
+ j := 0
+ fset.Iterate(func(f *File) bool {
+ if f.Name() != tests[j].filename {
+ t.Errorf("got filename = %s; want %s", f.Name(), tests[j].filename)
+ }
+ j++
+ return true
+ })
+ if j != i+1 {
+ t.Errorf("got %d files; want %d", j, i+1)
+ }
+ }
+}
+
+// FileSet.File should return nil if Pos is past the end of the FileSet.
+func TestFileSetPastEnd(t *testing.T) {
+ fset := NewFileSet()
+ for _, test := range tests {
+ fset.AddFile(test.filename, fset.Base(), test.size)
+ }
+ if f := fset.File(Pos(fset.Base())); f != nil {
+ t.Errorf("got %v, want nil", f)
+ }
+}
+
+func TestFileSetCacheUnlikely(t *testing.T) {
+ fset := NewFileSet()
+ offsets := make(map[string]int)
+ for _, test := range tests {
+ offsets[test.filename] = fset.Base()
+ fset.AddFile(test.filename, fset.Base(), test.size)
+ }
+ for file, pos := range offsets {
+ f := fset.File(Pos(pos))
+ if f.Name() != file {
+ t.Errorf("got %q at position %d, want %q", f.Name(), pos, file)
+ }
+ }
+}
+
+// issue 4345. Test that concurrent use of FileSet.Pos does not trigger a
+// race in the FileSet position cache.
+func TestFileSetRace(t *testing.T) {
+ fset := NewFileSet()
+ for i := 0; i < 100; i++ {
+ fset.AddFile(fmt.Sprintf("file-%d", i), fset.Base(), 1031)
+ }
+ max := int32(fset.Base())
+ var stop sync.WaitGroup
+ r := rand.New(rand.NewSource(7))
+ for i := 0; i < 2; i++ {
+ r := rand.New(rand.NewSource(r.Int63()))
+ stop.Add(1)
+ go func() {
+ for i := 0; i < 1000; i++ {
+ fset.Position(Pos(r.Int31n(max)))
+ }
+ stop.Done()
+ }()
+ }
+ stop.Wait()
+}
+
+// issue 16548. Test that concurrent use of File.AddLine and FileSet.PositionFor
+// does not trigger a race in the FileSet position cache.
+func TestFileSetRace2(t *testing.T) {
+ const N = 1e3
+ var (
+ fset = NewFileSet()
+ file = fset.AddFile("", -1, N)
+ ch = make(chan int, 2)
+ )
+
+ go func() {
+ for i := 0; i < N; i++ {
+ file.AddLine(i)
+ }
+ ch <- 1
+ }()
+
+ go func() {
+ pos := file.Pos(0)
+ for i := 0; i < N; i++ {
+ fset.PositionFor(pos, false)
+ }
+ ch <- 1
+ }()
+
+ <-ch
+ <-ch
+}
+
+func TestPositionFor(t *testing.T) {
+ src := []byte(`
+foo
+b
+ar
+//line :100
+foobar
+//line bar:3
+done
+`)
+
+ const filename = "foo"
+ fset := NewFileSet()
+ f := fset.AddFile(filename, fset.Base(), len(src))
+ f.SetLinesForContent(src)
+
+ // verify position info
+ for i, offs := range f.lines {
+ got1 := f.PositionFor(f.Pos(offs), false)
+ got2 := f.PositionFor(f.Pos(offs), true)
+ got3 := f.Position(f.Pos(offs))
+ want := Position{filename, offs, i + 1, 1}
+ checkPos(t, "1. PositionFor unadjusted", got1, want)
+ checkPos(t, "1. PositionFor adjusted", got2, want)
+ checkPos(t, "1. Position", got3, want)
+ }
+
+ // manually add //line info on lines l1, l2
+ const l1, l2 = 5, 7
+ f.AddLineInfo(f.lines[l1-1], "", 100)
+ f.AddLineInfo(f.lines[l2-1], "bar", 3)
+
+ // unadjusted position info must remain unchanged
+ for i, offs := range f.lines {
+ got1 := f.PositionFor(f.Pos(offs), false)
+ want := Position{filename, offs, i + 1, 1}
+ checkPos(t, "2. PositionFor unadjusted", got1, want)
+ }
+
+ // adjusted position info should have changed
+ for i, offs := range f.lines {
+ got2 := f.PositionFor(f.Pos(offs), true)
+ got3 := f.Position(f.Pos(offs))
+ want := Position{filename, offs, i + 1, 1}
+ // manually compute wanted filename and line
+ line := want.Line
+ if i+1 >= l1 {
+ want.Filename = ""
+ want.Line = line - l1 + 100
+ }
+ if i+1 >= l2 {
+ want.Filename = "bar"
+ want.Line = line - l2 + 3
+ }
+ checkPos(t, "3. PositionFor adjusted", got2, want)
+ checkPos(t, "3. Position", got3, want)
+ }
+}
+
+func TestLineStart(t *testing.T) {
+ const src = "one\ntwo\nthree\n"
+ fset := NewFileSet()
+ f := fset.AddFile("input", -1, len(src))
+ f.SetLinesForContent([]byte(src))
+
+ for line := 1; line <= 3; line++ {
+ pos := f.LineStart(line)
+ position := fset.Position(pos)
+ if position.Line != line || position.Column != 1 {
+ t.Errorf("LineStart(%d) returned wrong pos %d: %s", line, pos, position)
+ }
+ }
+}
diff --git a/src/go/token/serialize.go b/src/go/token/serialize.go
new file mode 100644
index 0000000..d0ea345
--- /dev/null
+++ b/src/go/token/serialize.go
@@ -0,0 +1,71 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token
+
+type serializedFile struct {
+ // fields correspond 1:1 to fields with same (lower-case) name in File
+ Name string
+ Base int
+ Size int
+ Lines []int
+ Infos []lineInfo
+}
+
+type serializedFileSet struct {
+ Base int
+ Files []serializedFile
+}
+
+// Read calls decode to deserialize a file set into s; s must not be nil.
+func (s *FileSet) Read(decode func(interface{}) error) error {
+ var ss serializedFileSet
+ if err := decode(&ss); err != nil {
+ return err
+ }
+
+ s.mutex.Lock()
+ s.base = ss.Base
+ files := make([]*File, len(ss.Files))
+ for i := 0; i < len(ss.Files); i++ {
+ f := &ss.Files[i]
+ files[i] = &File{
+ set: s,
+ name: f.Name,
+ base: f.Base,
+ size: f.Size,
+ lines: f.Lines,
+ infos: f.Infos,
+ }
+ }
+ s.files = files
+ s.last = nil
+ s.mutex.Unlock()
+
+ return nil
+}
+
+// Write calls encode to serialize the file set s.
+func (s *FileSet) Write(encode func(interface{}) error) error {
+ var ss serializedFileSet
+
+ s.mutex.Lock()
+ ss.Base = s.base
+ files := make([]serializedFile, len(s.files))
+ for i, f := range s.files {
+ f.mutex.Lock()
+ files[i] = serializedFile{
+ Name: f.name,
+ Base: f.base,
+ Size: f.size,
+ Lines: append([]int(nil), f.lines...),
+ Infos: append([]lineInfo(nil), f.infos...),
+ }
+ f.mutex.Unlock()
+ }
+ ss.Files = files
+ s.mutex.Unlock()
+
+ return encode(ss)
+}
diff --git a/src/go/token/serialize_test.go b/src/go/token/serialize_test.go
new file mode 100644
index 0000000..4e925ad
--- /dev/null
+++ b/src/go/token/serialize_test.go
@@ -0,0 +1,111 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token
+
+import (
+ "bytes"
+ "encoding/gob"
+ "fmt"
+ "testing"
+)
+
+// equal returns nil if p and q describe the same file set;
+// otherwise it returns an error describing the discrepancy.
+func equal(p, q *FileSet) error {
+ if p == q {
+ // avoid deadlock if p == q
+ return nil
+ }
+
+ // not strictly needed for the test
+ p.mutex.Lock()
+ q.mutex.Lock()
+ defer q.mutex.Unlock()
+ defer p.mutex.Unlock()
+
+ if p.base != q.base {
+ return fmt.Errorf("different bases: %d != %d", p.base, q.base)
+ }
+
+ if len(p.files) != len(q.files) {
+ return fmt.Errorf("different number of files: %d != %d", len(p.files), len(q.files))
+ }
+
+ for i, f := range p.files {
+ g := q.files[i]
+ if f.set != p {
+ return fmt.Errorf("wrong fileset for %q", f.name)
+ }
+ if g.set != q {
+ return fmt.Errorf("wrong fileset for %q", g.name)
+ }
+ if f.name != g.name {
+ return fmt.Errorf("different filenames: %q != %q", f.name, g.name)
+ }
+ if f.base != g.base {
+ return fmt.Errorf("different base for %q: %d != %d", f.name, f.base, g.base)
+ }
+ if f.size != g.size {
+ return fmt.Errorf("different size for %q: %d != %d", f.name, f.size, g.size)
+ }
+ for j, l := range f.lines {
+ m := g.lines[j]
+ if l != m {
+ return fmt.Errorf("different offsets for %q", f.name)
+ }
+ }
+ for j, l := range f.infos {
+ m := g.infos[j]
+ if l.Offset != m.Offset || l.Filename != m.Filename || l.Line != m.Line {
+ return fmt.Errorf("different infos for %q", f.name)
+ }
+ }
+ }
+
+ // we don't care about .last - it's just a cache
+ return nil
+}
+
+func checkSerialize(t *testing.T, p *FileSet) {
+ var buf bytes.Buffer
+ encode := func(x interface{}) error {
+ return gob.NewEncoder(&buf).Encode(x)
+ }
+ if err := p.Write(encode); err != nil {
+ t.Errorf("writing fileset failed: %s", err)
+ return
+ }
+ q := NewFileSet()
+ decode := func(x interface{}) error {
+ return gob.NewDecoder(&buf).Decode(x)
+ }
+ if err := q.Read(decode); err != nil {
+ t.Errorf("reading fileset failed: %s", err)
+ return
+ }
+ if err := equal(p, q); err != nil {
+ t.Errorf("filesets not identical: %s", err)
+ }
+}
+
+func TestSerialization(t *testing.T) {
+ p := NewFileSet()
+ checkSerialize(t, p)
+ // add some files
+ for i := 0; i < 10; i++ {
+ f := p.AddFile(fmt.Sprintf("file%d", i), p.Base()+i, i*100)
+ checkSerialize(t, p)
+ // add some lines and alternative file infos
+ line := 1000
+ for offs := 0; offs < f.Size(); offs += 40 + i {
+ f.AddLine(offs)
+ if offs%7 == 0 {
+ f.AddLineInfo(offs, fmt.Sprintf("file%d", offs), line)
+ line += 33
+ }
+ }
+ checkSerialize(t, p)
+ }
+}
diff --git a/src/go/token/token.go b/src/go/token/token.go
new file mode 100644
index 0000000..96a1079
--- /dev/null
+++ b/src/go/token/token.go
@@ -0,0 +1,340 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package token defines constants representing the lexical tokens of the Go
+// programming language and basic operations on tokens (printing, predicates).
+//
+package token
+
+import (
+ "strconv"
+ "unicode"
+ "unicode/utf8"
+)
+
+// Token is the set of lexical tokens of the Go programming language.
+type Token int
+
+// The list of tokens.
+const (
+ // Special tokens
+ ILLEGAL Token = iota
+ EOF
+ COMMENT
+
+ literal_beg
+ // Identifiers and basic type literals
+ // (these tokens stand for classes of literals)
+ IDENT // main
+ INT // 12345
+ FLOAT // 123.45
+ IMAG // 123.45i
+ CHAR // 'a'
+ STRING // "abc"
+ literal_end
+
+ operator_beg
+ // Operators and delimiters
+ ADD // +
+ SUB // -
+ MUL // *
+ QUO // /
+ REM // %
+
+ AND // &
+ OR // |
+ XOR // ^
+ SHL // <<
+ SHR // >>
+ AND_NOT // &^
+
+ ADD_ASSIGN // +=
+ SUB_ASSIGN // -=
+ MUL_ASSIGN // *=
+ QUO_ASSIGN // /=
+ REM_ASSIGN // %=
+
+ AND_ASSIGN // &=
+ OR_ASSIGN // |=
+ XOR_ASSIGN // ^=
+ SHL_ASSIGN // <<=
+ SHR_ASSIGN // >>=
+ AND_NOT_ASSIGN // &^=
+
+ LAND // &&
+ LOR // ||
+ ARROW // <-
+ INC // ++
+ DEC // --
+
+ EQL // ==
+ LSS // <
+ GTR // >
+ ASSIGN // =
+ NOT // !
+
+ NEQ // !=
+ LEQ // <=
+ GEQ // >=
+ DEFINE // :=
+ ELLIPSIS // ...
+
+ LPAREN // (
+ LBRACK // [
+ LBRACE // {
+ COMMA // ,
+ PERIOD // .
+
+ RPAREN // )
+ RBRACK // ]
+ RBRACE // }
+ SEMICOLON // ;
+ COLON // :
+ operator_end
+
+ keyword_beg
+ // Keywords
+ BREAK
+ CASE
+ CHAN
+ CONST
+ CONTINUE
+
+ DEFAULT
+ DEFER
+ ELSE
+ FALLTHROUGH
+ FOR
+
+ FUNC
+ GO
+ GOTO
+ IF
+ IMPORT
+
+ INTERFACE
+ MAP
+ PACKAGE
+ RANGE
+ RETURN
+
+ SELECT
+ STRUCT
+ SWITCH
+ TYPE
+ VAR
+ keyword_end
+)
+
+var tokens = [...]string{
+ ILLEGAL: "ILLEGAL",
+
+ EOF: "EOF",
+ COMMENT: "COMMENT",
+
+ IDENT: "IDENT",
+ INT: "INT",
+ FLOAT: "FLOAT",
+ IMAG: "IMAG",
+ CHAR: "CHAR",
+ STRING: "STRING",
+
+ ADD: "+",
+ SUB: "-",
+ MUL: "*",
+ QUO: "/",
+ REM: "%",
+
+ AND: "&",
+ OR: "|",
+ XOR: "^",
+ SHL: "<<",
+ SHR: ">>",
+ AND_NOT: "&^",
+
+ ADD_ASSIGN: "+=",
+ SUB_ASSIGN: "-=",
+ MUL_ASSIGN: "*=",
+ QUO_ASSIGN: "/=",
+ REM_ASSIGN: "%=",
+
+ AND_ASSIGN: "&=",
+ OR_ASSIGN: "|=",
+ XOR_ASSIGN: "^=",
+ SHL_ASSIGN: "<<=",
+ SHR_ASSIGN: ">>=",
+ AND_NOT_ASSIGN: "&^=",
+
+ LAND: "&&",
+ LOR: "||",
+ ARROW: "<-",
+ INC: "++",
+ DEC: "--",
+
+ EQL: "==",
+ LSS: "<",
+ GTR: ">",
+ ASSIGN: "=",
+ NOT: "!",
+
+ NEQ: "!=",
+ LEQ: "<=",
+ GEQ: ">=",
+ DEFINE: ":=",
+ ELLIPSIS: "...",
+
+ LPAREN: "(",
+ LBRACK: "[",
+ LBRACE: "{",
+ COMMA: ",",
+ PERIOD: ".",
+
+ RPAREN: ")",
+ RBRACK: "]",
+ RBRACE: "}",
+ SEMICOLON: ";",
+ COLON: ":",
+
+ BREAK: "break",
+ CASE: "case",
+ CHAN: "chan",
+ CONST: "const",
+ CONTINUE: "continue",
+
+ DEFAULT: "default",
+ DEFER: "defer",
+ ELSE: "else",
+ FALLTHROUGH: "fallthrough",
+ FOR: "for",
+
+ FUNC: "func",
+ GO: "go",
+ GOTO: "goto",
+ IF: "if",
+ IMPORT: "import",
+
+ INTERFACE: "interface",
+ MAP: "map",
+ PACKAGE: "package",
+ RANGE: "range",
+ RETURN: "return",
+
+ SELECT: "select",
+ STRUCT: "struct",
+ SWITCH: "switch",
+ TYPE: "type",
+ VAR: "var",
+}
+
+// String returns the string corresponding to the token tok.
+// For operators, delimiters, and keywords the string is the actual
+// token character sequence (e.g., for the token ADD, the string is
+// "+"). For all other tokens the string corresponds to the token
+// constant name (e.g. for the token IDENT, the string is "IDENT").
+//
+func (tok Token) String() string {
+ s := ""
+ if 0 <= tok && tok < Token(len(tokens)) {
+ s = tokens[tok]
+ }
+ if s == "" {
+ s = "token(" + strconv.Itoa(int(tok)) + ")"
+ }
+ return s
+}
+
+// A set of constants for precedence-based expression parsing.
+// Non-operators have lowest precedence, followed by operators
+// starting with precedence 1 up to unary operators. The highest
+// precedence serves as "catch-all" precedence for selector,
+// indexing, and other operator and delimiter tokens.
+//
+const (
+ LowestPrec = 0 // non-operators
+ UnaryPrec = 6
+ HighestPrec = 7
+)
+
+// Precedence returns the operator precedence of the binary
+// operator op. If op is not a binary operator, the result
+// is LowestPrecedence.
+//
+func (op Token) Precedence() int {
+ switch op {
+ case LOR:
+ return 1
+ case LAND:
+ return 2
+ case EQL, NEQ, LSS, LEQ, GTR, GEQ:
+ return 3
+ case ADD, SUB, OR, XOR:
+ return 4
+ case MUL, QUO, REM, SHL, SHR, AND, AND_NOT:
+ return 5
+ }
+ return LowestPrec
+}
+
+var keywords map[string]Token
+
+func init() {
+ keywords = make(map[string]Token)
+ for i := keyword_beg + 1; i < keyword_end; i++ {
+ keywords[tokens[i]] = i
+ }
+}
+
+// Lookup maps an identifier to its keyword token or IDENT (if not a keyword).
+//
+func Lookup(ident string) Token {
+ if tok, is_keyword := keywords[ident]; is_keyword {
+ return tok
+ }
+ return IDENT
+}
+
+// Predicates
+
+// IsLiteral returns true for tokens corresponding to identifiers
+// and basic type literals; it returns false otherwise.
+//
+func (tok Token) IsLiteral() bool { return literal_beg < tok && tok < literal_end }
+
+// IsOperator returns true for tokens corresponding to operators and
+// delimiters; it returns false otherwise.
+//
+func (tok Token) IsOperator() bool { return operator_beg < tok && tok < operator_end }
+
+// IsKeyword returns true for tokens corresponding to keywords;
+// it returns false otherwise.
+//
+func (tok Token) IsKeyword() bool { return keyword_beg < tok && tok < keyword_end }
+
+// IsExported reports whether name starts with an upper-case letter.
+//
+func IsExported(name string) bool {
+ ch, _ := utf8.DecodeRuneInString(name)
+ return unicode.IsUpper(ch)
+}
+
+// IsKeyword reports whether name is a Go keyword, such as "func" or "return".
+//
+func IsKeyword(name string) bool {
+ // TODO: opt: use a perfect hash function instead of a global map.
+ _, ok := keywords[name]
+ return ok
+}
+
+// IsIdentifier reports whether name is a Go identifier, that is, a non-empty
+// string made up of letters, digits, and underscores, where the first character
+// is not a digit. Keywords are not identifiers.
+//
+func IsIdentifier(name string) bool {
+ for i, c := range name {
+ if !unicode.IsLetter(c) && c != '_' && (i == 0 || !unicode.IsDigit(c)) {
+ return false
+ }
+ }
+ return name != "" && !IsKeyword(name)
+}
diff --git a/src/go/token/token_test.go b/src/go/token/token_test.go
new file mode 100644
index 0000000..eff38cc
--- /dev/null
+++ b/src/go/token/token_test.go
@@ -0,0 +1,33 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package token
+
+import "testing"
+
+func TestIsIdentifier(t *testing.T) {
+ tests := []struct {
+ name string
+ in string
+ want bool
+ }{
+ {"Empty", "", false},
+ {"Space", " ", false},
+ {"SpaceSuffix", "foo ", false},
+ {"Number", "123", false},
+ {"Keyword", "func", false},
+
+ {"LettersASCII", "foo", true},
+ {"MixedASCII", "_bar123", true},
+ {"UppercaseKeyword", "Func", true},
+ {"LettersUnicode", "fóö", true},
+ }
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ if got := IsIdentifier(test.in); got != test.want {
+ t.Fatalf("IsIdentifier(%q) = %t, want %v", test.in, got, test.want)
+ }
+ })
+ }
+}
diff --git a/src/go/types/api.go b/src/go/types/api.go
new file mode 100644
index 0000000..d625959
--- /dev/null
+++ b/src/go/types/api.go
@@ -0,0 +1,408 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package types declares the data types and implements
+// the algorithms for type-checking of Go packages. Use
+// Config.Check to invoke the type checker for a package.
+// Alternatively, create a new type checker with NewChecker
+// and invoke it incrementally by calling Checker.Files.
+//
+// Type-checking consists of several interdependent phases:
+//
+// Name resolution maps each identifier (ast.Ident) in the program to the
+// language object (Object) it denotes.
+// Use Info.{Defs,Uses,Implicits} for the results of name resolution.
+//
+// Constant folding computes the exact constant value (constant.Value)
+// for every expression (ast.Expr) that is a compile-time constant.
+// Use Info.Types[expr].Value for the results of constant folding.
+//
+// Type inference computes the type (Type) of every expression (ast.Expr)
+// and checks for compliance with the language specification.
+// Use Info.Types[expr].Type for the results of type inference.
+//
+// For a tutorial, see https://golang.org/s/types-tutorial.
+//
+package types
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/constant"
+ "go/token"
+)
+
+// An Error describes a type-checking error; it implements the error interface.
+// A "soft" error is an error that still permits a valid interpretation of a
+// package (such as "unused variable"); "hard" errors may lead to unpredictable
+// behavior if ignored.
+type Error struct {
+ Fset *token.FileSet // file set for interpretation of Pos
+ Pos token.Pos // error position
+ Msg string // error message
+ Soft bool // if set, error is "soft"
+
+ // go116code is a future API, unexported as the set of error codes is large
+ // and likely to change significantly during experimentation. Tools wishing
+ // to preview this feature may read go116code using reflection (see
+ // errorcodes_test.go), but beware that there is no guarantee of future
+ // compatibility.
+ go116code errorCode
+ go116start token.Pos
+ go116end token.Pos
+}
+
+// Error returns an error string formatted as follows:
+// filename:line:column: message
+func (err Error) Error() string {
+ return fmt.Sprintf("%s: %s", err.Fset.Position(err.Pos), err.Msg)
+}
+
+// An Importer resolves import paths to Packages.
+//
+// CAUTION: This interface does not support the import of locally
+// vendored packages. See https://golang.org/s/go15vendor.
+// If possible, external implementations should implement ImporterFrom.
+type Importer interface {
+ // Import returns the imported package for the given import path.
+ // The semantics is like for ImporterFrom.ImportFrom except that
+ // dir and mode are ignored (since they are not present).
+ Import(path string) (*Package, error)
+}
+
+// ImportMode is reserved for future use.
+type ImportMode int
+
+// An ImporterFrom resolves import paths to packages; it
+// supports vendoring per https://golang.org/s/go15vendor.
+// Use go/importer to obtain an ImporterFrom implementation.
+type ImporterFrom interface {
+ // Importer is present for backward-compatibility. Calling
+ // Import(path) is the same as calling ImportFrom(path, "", 0);
+ // i.e., locally vendored packages may not be found.
+ // The types package does not call Import if an ImporterFrom
+ // is present.
+ Importer
+
+ // ImportFrom returns the imported package for the given import
+ // path when imported by a package file located in dir.
+ // If the import failed, besides returning an error, ImportFrom
+ // is encouraged to cache and return a package anyway, if one
+ // was created. This will reduce package inconsistencies and
+ // follow-on type checker errors due to the missing package.
+ // The mode value must be 0; it is reserved for future use.
+ // Two calls to ImportFrom with the same path and dir must
+ // return the same package.
+ ImportFrom(path, dir string, mode ImportMode) (*Package, error)
+}
+
+// A Config specifies the configuration for type checking.
+// The zero value for Config is a ready-to-use default configuration.
+type Config struct {
+ // If IgnoreFuncBodies is set, function bodies are not
+ // type-checked.
+ IgnoreFuncBodies bool
+
+ // If FakeImportC is set, `import "C"` (for packages requiring Cgo)
+ // declares an empty "C" package and errors are omitted for qualified
+ // identifiers referring to package C (which won't find an object).
+ // This feature is intended for the standard library cmd/api tool.
+ //
+ // Caution: Effects may be unpredictable due to follow-on errors.
+ // Do not use casually!
+ FakeImportC bool
+
+ // If go115UsesCgo is set, the type checker expects the
+ // _cgo_gotypes.go file generated by running cmd/cgo to be
+ // provided as a package source file. Qualified identifiers
+ // referring to package C will be resolved to cgo-provided
+ // declarations within _cgo_gotypes.go.
+ //
+ // It is an error to set both FakeImportC and go115UsesCgo.
+ go115UsesCgo bool
+
+ // If Error != nil, it is called with each error found
+ // during type checking; err has dynamic type Error.
+ // Secondary errors (for instance, to enumerate all types
+ // involved in an invalid recursive type declaration) have
+ // error strings that start with a '\t' character.
+ // If Error == nil, type-checking stops with the first
+ // error found.
+ Error func(err error)
+
+ // An importer is used to import packages referred to from
+ // import declarations.
+ // If the installed importer implements ImporterFrom, the type
+ // checker calls ImportFrom instead of Import.
+ // The type checker reports an error if an importer is needed
+ // but none was installed.
+ Importer Importer
+
+ // If Sizes != nil, it provides the sizing functions for package unsafe.
+ // Otherwise SizesFor("gc", "amd64") is used instead.
+ Sizes Sizes
+
+ // If DisableUnusedImportCheck is set, packages are not checked
+ // for unused imports.
+ DisableUnusedImportCheck bool
+}
+
+func srcimporter_setUsesCgo(conf *Config) {
+ conf.go115UsesCgo = true
+}
+
+// Info holds result type information for a type-checked package.
+// Only the information for which a map is provided is collected.
+// If the package has type errors, the collected information may
+// be incomplete.
+type Info struct {
+ // Types maps expressions to their types, and for constant
+ // expressions, also their values. Invalid expressions are
+ // omitted.
+ //
+ // For (possibly parenthesized) identifiers denoting built-in
+ // functions, the recorded signatures are call-site specific:
+ // if the call result is not a constant, the recorded type is
+ // an argument-specific signature. Otherwise, the recorded type
+ // is invalid.
+ //
+ // The Types map does not record the type of every identifier,
+ // only those that appear where an arbitrary expression is
+ // permitted. For instance, the identifier f in a selector
+ // expression x.f is found only in the Selections map, the
+ // identifier z in a variable declaration 'var z int' is found
+ // only in the Defs map, and identifiers denoting packages in
+ // qualified identifiers are collected in the Uses map.
+ Types map[ast.Expr]TypeAndValue
+
+ // Defs maps identifiers to the objects they define (including
+ // package names, dots "." of dot-imports, and blank "_" identifiers).
+ // For identifiers that do not denote objects (e.g., the package name
+ // in package clauses, or symbolic variables t in t := x.(type) of
+ // type switch headers), the corresponding objects are nil.
+ //
+ // For an embedded field, Defs returns the field *Var it defines.
+ //
+ // Invariant: Defs[id] == nil || Defs[id].Pos() == id.Pos()
+ Defs map[*ast.Ident]Object
+
+ // Uses maps identifiers to the objects they denote.
+ //
+ // For an embedded field, Uses returns the *TypeName it denotes.
+ //
+ // Invariant: Uses[id].Pos() != id.Pos()
+ Uses map[*ast.Ident]Object
+
+ // Implicits maps nodes to their implicitly declared objects, if any.
+ // The following node and object types may appear:
+ //
+ // node declared object
+ //
+ // *ast.ImportSpec *PkgName for imports without renames
+ // *ast.CaseClause type-specific *Var for each type switch case clause (incl. default)
+ // *ast.Field anonymous parameter *Var (incl. unnamed results)
+ //
+ Implicits map[ast.Node]Object
+
+ // Selections maps selector expressions (excluding qualified identifiers)
+ // to their corresponding selections.
+ Selections map[*ast.SelectorExpr]*Selection
+
+ // Scopes maps ast.Nodes to the scopes they define. Package scopes are not
+ // associated with a specific node but with all files belonging to a package.
+ // Thus, the package scope can be found in the type-checked Package object.
+ // Scopes nest, with the Universe scope being the outermost scope, enclosing
+ // the package scope, which contains (one or more) files scopes, which enclose
+ // function scopes which in turn enclose statement and function literal scopes.
+ // Note that even though package-level functions are declared in the package
+ // scope, the function scopes are embedded in the file scope of the file
+ // containing the function declaration.
+ //
+ // The following node types may appear in Scopes:
+ //
+ // *ast.File
+ // *ast.FuncType
+ // *ast.BlockStmt
+ // *ast.IfStmt
+ // *ast.SwitchStmt
+ // *ast.TypeSwitchStmt
+ // *ast.CaseClause
+ // *ast.CommClause
+ // *ast.ForStmt
+ // *ast.RangeStmt
+ //
+ Scopes map[ast.Node]*Scope
+
+ // InitOrder is the list of package-level initializers in the order in which
+ // they must be executed. Initializers referring to variables related by an
+ // initialization dependency appear in topological order, the others appear
+ // in source order. Variables without an initialization expression do not
+ // appear in this list.
+ InitOrder []*Initializer
+}
+
+// TypeOf returns the type of expression e, or nil if not found.
+// Precondition: the Types, Uses and Defs maps are populated.
+//
+func (info *Info) TypeOf(e ast.Expr) Type {
+ if t, ok := info.Types[e]; ok {
+ return t.Type
+ }
+ if id, _ := e.(*ast.Ident); id != nil {
+ if obj := info.ObjectOf(id); obj != nil {
+ return obj.Type()
+ }
+ }
+ return nil
+}
+
+// ObjectOf returns the object denoted by the specified id,
+// or nil if not found.
+//
+// If id is an embedded struct field, ObjectOf returns the field (*Var)
+// it defines, not the type (*TypeName) it uses.
+//
+// Precondition: the Uses and Defs maps are populated.
+//
+func (info *Info) ObjectOf(id *ast.Ident) Object {
+ if obj := info.Defs[id]; obj != nil {
+ return obj
+ }
+ return info.Uses[id]
+}
+
+// TypeAndValue reports the type and value (for constants)
+// of the corresponding expression.
+type TypeAndValue struct {
+ mode operandMode
+ Type Type
+ Value constant.Value
+}
+
+// IsVoid reports whether the corresponding expression
+// is a function call without results.
+func (tv TypeAndValue) IsVoid() bool {
+ return tv.mode == novalue
+}
+
+// IsType reports whether the corresponding expression specifies a type.
+func (tv TypeAndValue) IsType() bool {
+ return tv.mode == typexpr
+}
+
+// IsBuiltin reports whether the corresponding expression denotes
+// a (possibly parenthesized) built-in function.
+func (tv TypeAndValue) IsBuiltin() bool {
+ return tv.mode == builtin
+}
+
+// IsValue reports whether the corresponding expression is a value.
+// Builtins are not considered values. Constant values have a non-
+// nil Value.
+func (tv TypeAndValue) IsValue() bool {
+ switch tv.mode {
+ case constant_, variable, mapindex, value, commaok, commaerr:
+ return true
+ }
+ return false
+}
+
+// IsNil reports whether the corresponding expression denotes the
+// predeclared value nil.
+func (tv TypeAndValue) IsNil() bool {
+ return tv.mode == value && tv.Type == Typ[UntypedNil]
+}
+
+// Addressable reports whether the corresponding expression
+// is addressable (https://golang.org/ref/spec#Address_operators).
+func (tv TypeAndValue) Addressable() bool {
+ return tv.mode == variable
+}
+
+// Assignable reports whether the corresponding expression
+// is assignable to (provided a value of the right type).
+func (tv TypeAndValue) Assignable() bool {
+ return tv.mode == variable || tv.mode == mapindex
+}
+
+// HasOk reports whether the corresponding expression may be
+// used on the rhs of a comma-ok assignment.
+func (tv TypeAndValue) HasOk() bool {
+ return tv.mode == commaok || tv.mode == mapindex
+}
+
+// An Initializer describes a package-level variable, or a list of variables in case
+// of a multi-valued initialization expression, and the corresponding initialization
+// expression.
+type Initializer struct {
+ Lhs []*Var // var Lhs = Rhs
+ Rhs ast.Expr
+}
+
+func (init *Initializer) String() string {
+ var buf bytes.Buffer
+ for i, lhs := range init.Lhs {
+ if i > 0 {
+ buf.WriteString(", ")
+ }
+ buf.WriteString(lhs.Name())
+ }
+ buf.WriteString(" = ")
+ WriteExpr(&buf, init.Rhs)
+ return buf.String()
+}
+
+// Check type-checks a package and returns the resulting package object and
+// the first error if any. Additionally, if info != nil, Check populates each
+// of the non-nil maps in the Info struct.
+//
+// The package is marked as complete if no errors occurred, otherwise it is
+// incomplete. See Config.Error for controlling behavior in the presence of
+// errors.
+//
+// The package is specified by a list of *ast.Files and corresponding
+// file set, and the package path the package is identified with.
+// The clean path must not be empty or dot (".").
+func (conf *Config) Check(path string, fset *token.FileSet, files []*ast.File, info *Info) (*Package, error) {
+ pkg := NewPackage(path, "")
+ return pkg, NewChecker(conf, fset, pkg, info).Files(files)
+}
+
+// AssertableTo reports whether a value of type V can be asserted to have type T.
+func AssertableTo(V *Interface, T Type) bool {
+ m, _ := (*Checker)(nil).assertableTo(V, T)
+ return m == nil
+}
+
+// AssignableTo reports whether a value of type V is assignable to a variable of type T.
+func AssignableTo(V, T Type) bool {
+ x := operand{mode: value, typ: V}
+ ok, _ := x.assignableTo(nil, T, nil) // check not needed for non-constant x
+ return ok
+}
+
+// ConvertibleTo reports whether a value of type V is convertible to a value of type T.
+func ConvertibleTo(V, T Type) bool {
+ x := operand{mode: value, typ: V}
+ return x.convertibleTo(nil, T) // check not needed for non-constant x
+}
+
+// Implements reports whether type V implements interface T.
+func Implements(V Type, T *Interface) bool {
+ f, _ := MissingMethod(V, T, true)
+ return f == nil
+}
+
+// Identical reports whether x and y are identical types.
+// Receivers of Signature types are ignored.
+func Identical(x, y Type) bool {
+ return (*Checker)(nil).identical(x, y)
+}
+
+// IdenticalIgnoreTags reports whether x and y are identical types if tags are ignored.
+// Receivers of Signature types are ignored.
+func IdenticalIgnoreTags(x, y Type) bool {
+ return (*Checker)(nil).identicalIgnoreTags(x, y)
+}
diff --git a/src/go/types/api_test.go b/src/go/types/api_test.go
new file mode 100644
index 0000000..75cebc9
--- /dev/null
+++ b/src/go/types/api_test.go
@@ -0,0 +1,1514 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "internal/testenv"
+ "reflect"
+ "regexp"
+ "strings"
+ "testing"
+
+ . "go/types"
+)
+
+func pkgFor(path, source string, info *Info) (*Package, error) {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, path, source, 0)
+ if err != nil {
+ return nil, err
+ }
+ conf := Config{Importer: importer.Default()}
+ return conf.Check(f.Name.Name, fset, []*ast.File{f}, info)
+}
+
+func mustTypecheck(t *testing.T, path, source string, info *Info) string {
+ pkg, err := pkgFor(path, source, info)
+ if err != nil {
+ name := path
+ if pkg != nil {
+ name = "package " + pkg.Name()
+ }
+ t.Fatalf("%s: didn't type-check (%s)", name, err)
+ }
+ return pkg.Name()
+}
+
+func mayTypecheck(t *testing.T, path, source string, info *Info) string {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, path, source, 0)
+ if f == nil { // ignore errors unless f is nil
+ t.Fatalf("%s: unable to parse: %s", path, err)
+ }
+ conf := Config{
+ Error: func(err error) {},
+ Importer: importer.Default(),
+ }
+ pkg, _ := conf.Check(f.Name.Name, fset, []*ast.File{f}, info)
+ return pkg.Name()
+}
+
+func TestValuesInfo(t *testing.T) {
+ var tests = []struct {
+ src string
+ expr string // constant expression
+ typ string // constant type
+ val string // constant value
+ }{
+ {`package a0; const _ = false`, `false`, `untyped bool`, `false`},
+ {`package a1; const _ = 0`, `0`, `untyped int`, `0`},
+ {`package a2; const _ = 'A'`, `'A'`, `untyped rune`, `65`},
+ {`package a3; const _ = 0.`, `0.`, `untyped float`, `0`},
+ {`package a4; const _ = 0i`, `0i`, `untyped complex`, `(0 + 0i)`},
+ {`package a5; const _ = "foo"`, `"foo"`, `untyped string`, `"foo"`},
+
+ {`package b0; var _ = false`, `false`, `bool`, `false`},
+ {`package b1; var _ = 0`, `0`, `int`, `0`},
+ {`package b2; var _ = 'A'`, `'A'`, `rune`, `65`},
+ {`package b3; var _ = 0.`, `0.`, `float64`, `0`},
+ {`package b4; var _ = 0i`, `0i`, `complex128`, `(0 + 0i)`},
+ {`package b5; var _ = "foo"`, `"foo"`, `string`, `"foo"`},
+
+ {`package c0a; var _ = bool(false)`, `false`, `bool`, `false`},
+ {`package c0b; var _ = bool(false)`, `bool(false)`, `bool`, `false`},
+ {`package c0c; type T bool; var _ = T(false)`, `T(false)`, `c0c.T`, `false`},
+
+ {`package c1a; var _ = int(0)`, `0`, `int`, `0`},
+ {`package c1b; var _ = int(0)`, `int(0)`, `int`, `0`},
+ {`package c1c; type T int; var _ = T(0)`, `T(0)`, `c1c.T`, `0`},
+
+ {`package c2a; var _ = rune('A')`, `'A'`, `rune`, `65`},
+ {`package c2b; var _ = rune('A')`, `rune('A')`, `rune`, `65`},
+ {`package c2c; type T rune; var _ = T('A')`, `T('A')`, `c2c.T`, `65`},
+
+ {`package c3a; var _ = float32(0.)`, `0.`, `float32`, `0`},
+ {`package c3b; var _ = float32(0.)`, `float32(0.)`, `float32`, `0`},
+ {`package c3c; type T float32; var _ = T(0.)`, `T(0.)`, `c3c.T`, `0`},
+
+ {`package c4a; var _ = complex64(0i)`, `0i`, `complex64`, `(0 + 0i)`},
+ {`package c4b; var _ = complex64(0i)`, `complex64(0i)`, `complex64`, `(0 + 0i)`},
+ {`package c4c; type T complex64; var _ = T(0i)`, `T(0i)`, `c4c.T`, `(0 + 0i)`},
+
+ {`package c5a; var _ = string("foo")`, `"foo"`, `string`, `"foo"`},
+ {`package c5b; var _ = string("foo")`, `string("foo")`, `string`, `"foo"`},
+ {`package c5c; type T string; var _ = T("foo")`, `T("foo")`, `c5c.T`, `"foo"`},
+ {`package c5d; var _ = string(65)`, `65`, `untyped int`, `65`},
+ {`package c5e; var _ = string('A')`, `'A'`, `untyped rune`, `65`},
+ {`package c5f; type T string; var _ = T('A')`, `'A'`, `untyped rune`, `65`},
+ {`package c5g; var s uint; var _ = string(1 << s)`, `1 << s`, `untyped int`, ``},
+
+ {`package d0; var _ = []byte("foo")`, `"foo"`, `string`, `"foo"`},
+ {`package d1; var _ = []byte(string("foo"))`, `"foo"`, `string`, `"foo"`},
+ {`package d2; var _ = []byte(string("foo"))`, `string("foo")`, `string`, `"foo"`},
+ {`package d3; type T []byte; var _ = T("foo")`, `"foo"`, `string`, `"foo"`},
+
+ {`package e0; const _ = float32( 1e-200)`, `float32(1e-200)`, `float32`, `0`},
+ {`package e1; const _ = float32(-1e-200)`, `float32(-1e-200)`, `float32`, `0`},
+ {`package e2; const _ = float64( 1e-2000)`, `float64(1e-2000)`, `float64`, `0`},
+ {`package e3; const _ = float64(-1e-2000)`, `float64(-1e-2000)`, `float64`, `0`},
+ {`package e4; const _ = complex64( 1e-200)`, `complex64(1e-200)`, `complex64`, `(0 + 0i)`},
+ {`package e5; const _ = complex64(-1e-200)`, `complex64(-1e-200)`, `complex64`, `(0 + 0i)`},
+ {`package e6; const _ = complex128( 1e-2000)`, `complex128(1e-2000)`, `complex128`, `(0 + 0i)`},
+ {`package e7; const _ = complex128(-1e-2000)`, `complex128(-1e-2000)`, `complex128`, `(0 + 0i)`},
+
+ {`package f0 ; var _ float32 = 1e-200`, `1e-200`, `float32`, `0`},
+ {`package f1 ; var _ float32 = -1e-200`, `-1e-200`, `float32`, `0`},
+ {`package f2a; var _ float64 = 1e-2000`, `1e-2000`, `float64`, `0`},
+ {`package f3a; var _ float64 = -1e-2000`, `-1e-2000`, `float64`, `0`},
+ {`package f2b; var _ = 1e-2000`, `1e-2000`, `float64`, `0`},
+ {`package f3b; var _ = -1e-2000`, `-1e-2000`, `float64`, `0`},
+ {`package f4 ; var _ complex64 = 1e-200 `, `1e-200`, `complex64`, `(0 + 0i)`},
+ {`package f5 ; var _ complex64 = -1e-200 `, `-1e-200`, `complex64`, `(0 + 0i)`},
+ {`package f6a; var _ complex128 = 1e-2000i`, `1e-2000i`, `complex128`, `(0 + 0i)`},
+ {`package f7a; var _ complex128 = -1e-2000i`, `-1e-2000i`, `complex128`, `(0 + 0i)`},
+ {`package f6b; var _ = 1e-2000i`, `1e-2000i`, `complex128`, `(0 + 0i)`},
+ {`package f7b; var _ = -1e-2000i`, `-1e-2000i`, `complex128`, `(0 + 0i)`},
+
+ {`package g0; const (a = len([iota]int{}); b; c); const _ = c`, `c`, `int`, `2`}, // issue #22341
+ }
+
+ for _, test := range tests {
+ info := Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ }
+ name := mustTypecheck(t, "ValuesInfo", test.src, &info)
+
+ // look for expression
+ var expr ast.Expr
+ for e := range info.Types {
+ if ExprString(e) == test.expr {
+ expr = e
+ break
+ }
+ }
+ if expr == nil {
+ t.Errorf("package %s: no expression found for %s", name, test.expr)
+ continue
+ }
+ tv := info.Types[expr]
+
+ // check that type is correct
+ if got := tv.Type.String(); got != test.typ {
+ t.Errorf("package %s: got type %s; want %s", name, got, test.typ)
+ continue
+ }
+
+ // if we have a constant, check that value is correct
+ if tv.Value != nil {
+ if got := tv.Value.ExactString(); got != test.val {
+ t.Errorf("package %s: got value %s; want %s", name, got, test.val)
+ }
+ } else {
+ if test.val != "" {
+ t.Errorf("package %s: no constant found; want %s", name, test.val)
+ }
+ }
+ }
+}
+
+func TestTypesInfo(t *testing.T) {
+ var tests = []struct {
+ src string
+ expr string // expression
+ typ string // value type
+ }{
+ // single-valued expressions of untyped constants
+ {`package b0; var x interface{} = false`, `false`, `bool`},
+ {`package b1; var x interface{} = 0`, `0`, `int`},
+ {`package b2; var x interface{} = 0.`, `0.`, `float64`},
+ {`package b3; var x interface{} = 0i`, `0i`, `complex128`},
+ {`package b4; var x interface{} = "foo"`, `"foo"`, `string`},
+
+ // comma-ok expressions
+ {`package p0; var x interface{}; var _, _ = x.(int)`,
+ `x.(int)`,
+ `(int, bool)`,
+ },
+ {`package p1; var x interface{}; func _() { _, _ = x.(int) }`,
+ `x.(int)`,
+ `(int, bool)`,
+ },
+ {`package p2a; type mybool bool; var m map[string]complex128; var b mybool; func _() { _, b = m["foo"] }`,
+ `m["foo"]`,
+ `(complex128, p2a.mybool)`,
+ },
+ {`package p2b; var m map[string]complex128; var b bool; func _() { _, b = m["foo"] }`,
+ `m["foo"]`,
+ `(complex128, bool)`,
+ },
+ {`package p3; var c chan string; var _, _ = <-c`,
+ `<-c`,
+ `(string, bool)`,
+ },
+
+ // issue 6796
+ {`package issue6796_a; var x interface{}; var _, _ = (x.(int))`,
+ `x.(int)`,
+ `(int, bool)`,
+ },
+ {`package issue6796_b; var c chan string; var _, _ = (<-c)`,
+ `(<-c)`,
+ `(string, bool)`,
+ },
+ {`package issue6796_c; var c chan string; var _, _ = (<-c)`,
+ `<-c`,
+ `(string, bool)`,
+ },
+ {`package issue6796_d; var c chan string; var _, _ = ((<-c))`,
+ `(<-c)`,
+ `(string, bool)`,
+ },
+ {`package issue6796_e; func f(c chan string) { _, _ = ((<-c)) }`,
+ `(<-c)`,
+ `(string, bool)`,
+ },
+
+ // issue 7060
+ {`package issue7060_a; var ( m map[int]string; x, ok = m[0] )`,
+ `m[0]`,
+ `(string, bool)`,
+ },
+ {`package issue7060_b; var ( m map[int]string; x, ok interface{} = m[0] )`,
+ `m[0]`,
+ `(string, bool)`,
+ },
+ {`package issue7060_c; func f(x interface{}, ok bool, m map[int]string) { x, ok = m[0] }`,
+ `m[0]`,
+ `(string, bool)`,
+ },
+ {`package issue7060_d; var ( ch chan string; x, ok = <-ch )`,
+ `<-ch`,
+ `(string, bool)`,
+ },
+ {`package issue7060_e; var ( ch chan string; x, ok interface{} = <-ch )`,
+ `<-ch`,
+ `(string, bool)`,
+ },
+ {`package issue7060_f; func f(x interface{}, ok bool, ch chan string) { x, ok = <-ch }`,
+ `<-ch`,
+ `(string, bool)`,
+ },
+
+ // issue 28277
+ {`package issue28277_a; func f(...int)`,
+ `...int`,
+ `[]int`,
+ },
+ {`package issue28277_b; func f(a, b int, c ...[]struct{})`,
+ `...[]struct{}`,
+ `[][]struct{}`,
+ },
+
+ // tests for broken code that doesn't parse or type-check
+ {`package x0; func _() { var x struct {f string}; x.f := 0 }`, `x.f`, `string`},
+ {`package x1; func _() { var z string; type x struct {f string}; y := &x{q: z}}`, `z`, `string`},
+ {`package x2; func _() { var a, b string; type x struct {f string}; z := &x{f: a; f: b;}}`, `b`, `string`},
+ {`package x3; var x = panic("");`, `panic`, `func(interface{})`},
+ {`package x4; func _() { panic("") }`, `panic`, `func(interface{})`},
+ {`package x5; func _() { var x map[string][...]int; x = map[string][...]int{"": {1,2,3}} }`, `x`, `map[string][-1]int`},
+ }
+
+ for _, test := range tests {
+ info := Info{Types: make(map[ast.Expr]TypeAndValue)}
+ name := mayTypecheck(t, "TypesInfo", test.src, &info)
+
+ // look for expression type
+ var typ Type
+ for e, tv := range info.Types {
+ if ExprString(e) == test.expr {
+ typ = tv.Type
+ break
+ }
+ }
+ if typ == nil {
+ t.Errorf("package %s: no type found for %s", name, test.expr)
+ continue
+ }
+
+ // check that type is correct
+ if got := typ.String(); got != test.typ {
+ t.Errorf("package %s: got %s; want %s", name, got, test.typ)
+ }
+ }
+}
+
+func TestImplicitsInfo(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ var tests = []struct {
+ src string
+ want string
+ }{
+ {`package p2; import . "fmt"; var _ = Println`, ""}, // no Implicits entry
+ {`package p0; import local "fmt"; var _ = local.Println`, ""}, // no Implicits entry
+ {`package p1; import "fmt"; var _ = fmt.Println`, "importSpec: package fmt"},
+
+ {`package p3; func f(x interface{}) { switch x.(type) { case int: } }`, ""}, // no Implicits entry
+ {`package p4; func f(x interface{}) { switch t := x.(type) { case int: _ = t } }`, "caseClause: var t int"},
+ {`package p5; func f(x interface{}) { switch t := x.(type) { case int, uint: _ = t } }`, "caseClause: var t interface{}"},
+ {`package p6; func f(x interface{}) { switch t := x.(type) { default: _ = t } }`, "caseClause: var t interface{}"},
+
+ {`package p7; func f(x int) {}`, ""}, // no Implicits entry
+ {`package p8; func f(int) {}`, "field: var int"},
+ {`package p9; func f() (complex64) { return 0 }`, "field: var complex64"},
+ {`package p10; type T struct{}; func (*T) f() {}`, "field: var *p10.T"},
+ }
+
+ for _, test := range tests {
+ info := Info{
+ Implicits: make(map[ast.Node]Object),
+ }
+ name := mustTypecheck(t, "ImplicitsInfo", test.src, &info)
+
+ // the test cases expect at most one Implicits entry
+ if len(info.Implicits) > 1 {
+ t.Errorf("package %s: %d Implicits entries found", name, len(info.Implicits))
+ continue
+ }
+
+ // extract Implicits entry, if any
+ var got string
+ for n, obj := range info.Implicits {
+ switch x := n.(type) {
+ case *ast.ImportSpec:
+ got = "importSpec"
+ case *ast.CaseClause:
+ got = "caseClause"
+ case *ast.Field:
+ got = "field"
+ default:
+ t.Fatalf("package %s: unexpected %T", name, x)
+ }
+ got += ": " + obj.String()
+ }
+
+ // verify entry
+ if got != test.want {
+ t.Errorf("package %s: got %q; want %q", name, got, test.want)
+ }
+ }
+}
+
+func predString(tv TypeAndValue) string {
+ var buf bytes.Buffer
+ pred := func(b bool, s string) {
+ if b {
+ if buf.Len() > 0 {
+ buf.WriteString(", ")
+ }
+ buf.WriteString(s)
+ }
+ }
+
+ pred(tv.IsVoid(), "void")
+ pred(tv.IsType(), "type")
+ pred(tv.IsBuiltin(), "builtin")
+ pred(tv.IsValue() && tv.Value != nil, "const")
+ pred(tv.IsValue() && tv.Value == nil, "value")
+ pred(tv.IsNil(), "nil")
+ pred(tv.Addressable(), "addressable")
+ pred(tv.Assignable(), "assignable")
+ pred(tv.HasOk(), "hasOk")
+
+ if buf.Len() == 0 {
+ return "invalid"
+ }
+ return buf.String()
+}
+
+func TestPredicatesInfo(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ var tests = []struct {
+ src string
+ expr string
+ pred string
+ }{
+ // void
+ {`package n0; func f() { f() }`, `f()`, `void`},
+
+ // types
+ {`package t0; type _ int`, `int`, `type`},
+ {`package t1; type _ []int`, `[]int`, `type`},
+ {`package t2; type _ func()`, `func()`, `type`},
+ {`package t3; type _ func(int)`, `int`, `type`},
+ {`package t3; type _ func(...int)`, `...int`, `type`},
+
+ // built-ins
+ {`package b0; var _ = len("")`, `len`, `builtin`},
+ {`package b1; var _ = (len)("")`, `(len)`, `builtin`},
+
+ // constants
+ {`package c0; var _ = 42`, `42`, `const`},
+ {`package c1; var _ = "foo" + "bar"`, `"foo" + "bar"`, `const`},
+ {`package c2; const (i = 1i; _ = i)`, `i`, `const`},
+
+ // values
+ {`package v0; var (a, b int; _ = a + b)`, `a + b`, `value`},
+ {`package v1; var _ = &[]int{1}`, `([]int literal)`, `value`},
+ {`package v2; var _ = func(){}`, `(func() literal)`, `value`},
+ {`package v4; func f() { _ = f }`, `f`, `value`},
+ {`package v3; var _ *int = nil`, `nil`, `value, nil`},
+ {`package v3; var _ *int = (nil)`, `(nil)`, `value, nil`},
+
+ // addressable (and thus assignable) operands
+ {`package a0; var (x int; _ = x)`, `x`, `value, addressable, assignable`},
+ {`package a1; var (p *int; _ = *p)`, `*p`, `value, addressable, assignable`},
+ {`package a2; var (s []int; _ = s[0])`, `s[0]`, `value, addressable, assignable`},
+ {`package a3; var (s struct{f int}; _ = s.f)`, `s.f`, `value, addressable, assignable`},
+ {`package a4; var (a [10]int; _ = a[0])`, `a[0]`, `value, addressable, assignable`},
+ {`package a5; func _(x int) { _ = x }`, `x`, `value, addressable, assignable`},
+ {`package a6; func _()(x int) { _ = x; return }`, `x`, `value, addressable, assignable`},
+ {`package a7; type T int; func (x T) _() { _ = x }`, `x`, `value, addressable, assignable`},
+ // composite literals are not addressable
+
+ // assignable but not addressable values
+ {`package s0; var (m map[int]int; _ = m[0])`, `m[0]`, `value, assignable, hasOk`},
+ {`package s1; var (m map[int]int; _, _ = m[0])`, `m[0]`, `value, assignable, hasOk`},
+
+ // hasOk expressions
+ {`package k0; var (ch chan int; _ = <-ch)`, `<-ch`, `value, hasOk`},
+ {`package k1; var (ch chan int; _, _ = <-ch)`, `<-ch`, `value, hasOk`},
+
+ // missing entries
+ // - package names are collected in the Uses map
+ // - identifiers being declared are collected in the Defs map
+ {`package m0; import "os"; func _() { _ = os.Stdout }`, `os`, `<missing>`},
+ {`package m1; import p "os"; func _() { _ = p.Stdout }`, `p`, `<missing>`},
+ {`package m2; const c = 0`, `c`, `<missing>`},
+ {`package m3; type T int`, `T`, `<missing>`},
+ {`package m4; var v int`, `v`, `<missing>`},
+ {`package m5; func f() {}`, `f`, `<missing>`},
+ {`package m6; func _(x int) {}`, `x`, `<missing>`},
+ {`package m6; func _()(x int) { return }`, `x`, `<missing>`},
+ {`package m6; type T int; func (x T) _() {}`, `x`, `<missing>`},
+ }
+
+ for _, test := range tests {
+ info := Info{Types: make(map[ast.Expr]TypeAndValue)}
+ name := mustTypecheck(t, "PredicatesInfo", test.src, &info)
+
+ // look for expression predicates
+ got := "<missing>"
+ for e, tv := range info.Types {
+ //println(name, ExprString(e))
+ if ExprString(e) == test.expr {
+ got = predString(tv)
+ break
+ }
+ }
+
+ if got != test.pred {
+ t.Errorf("package %s: got %s; want %s", name, got, test.pred)
+ }
+ }
+}
+
+func TestScopesInfo(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ var tests = []struct {
+ src string
+ scopes []string // list of scope descriptors of the form kind:varlist
+ }{
+ {`package p0`, []string{
+ "file:",
+ }},
+ {`package p1; import ( "fmt"; m "math"; _ "os" ); var ( _ = fmt.Println; _ = m.Pi )`, []string{
+ "file:fmt m",
+ }},
+ {`package p2; func _() {}`, []string{
+ "file:", "func:",
+ }},
+ {`package p3; func _(x, y int) {}`, []string{
+ "file:", "func:x y",
+ }},
+ {`package p4; func _(x, y int) { x, z := 1, 2; _ = z }`, []string{
+ "file:", "func:x y z", // redeclaration of x
+ }},
+ {`package p5; func _(x, y int) (u, _ int) { return }`, []string{
+ "file:", "func:u x y",
+ }},
+ {`package p6; func _() { { var x int; _ = x } }`, []string{
+ "file:", "func:", "block:x",
+ }},
+ {`package p7; func _() { if true {} }`, []string{
+ "file:", "func:", "if:", "block:",
+ }},
+ {`package p8; func _() { if x := 0; x < 0 { y := x; _ = y } }`, []string{
+ "file:", "func:", "if:x", "block:y",
+ }},
+ {`package p9; func _() { switch x := 0; x {} }`, []string{
+ "file:", "func:", "switch:x",
+ }},
+ {`package p10; func _() { switch x := 0; x { case 1: y := x; _ = y; default: }}`, []string{
+ "file:", "func:", "switch:x", "case:y", "case:",
+ }},
+ {`package p11; func _(t interface{}) { switch t.(type) {} }`, []string{
+ "file:", "func:t", "type switch:",
+ }},
+ {`package p12; func _(t interface{}) { switch t := t; t.(type) {} }`, []string{
+ "file:", "func:t", "type switch:t",
+ }},
+ {`package p13; func _(t interface{}) { switch x := t.(type) { case int: _ = x } }`, []string{
+ "file:", "func:t", "type switch:", "case:x", // x implicitly declared
+ }},
+ {`package p14; func _() { select{} }`, []string{
+ "file:", "func:",
+ }},
+ {`package p15; func _(c chan int) { select{ case <-c: } }`, []string{
+ "file:", "func:c", "comm:",
+ }},
+ {`package p16; func _(c chan int) { select{ case i := <-c: x := i; _ = x} }`, []string{
+ "file:", "func:c", "comm:i x",
+ }},
+ {`package p17; func _() { for{} }`, []string{
+ "file:", "func:", "for:", "block:",
+ }},
+ {`package p18; func _(n int) { for i := 0; i < n; i++ { _ = i } }`, []string{
+ "file:", "func:n", "for:i", "block:",
+ }},
+ {`package p19; func _(a []int) { for i := range a { _ = i} }`, []string{
+ "file:", "func:a", "range:i", "block:",
+ }},
+ {`package p20; var s int; func _(a []int) { for i, x := range a { s += x; _ = i } }`, []string{
+ "file:", "func:a", "range:i x", "block:",
+ }},
+ }
+
+ for _, test := range tests {
+ info := Info{Scopes: make(map[ast.Node]*Scope)}
+ name := mustTypecheck(t, "ScopesInfo", test.src, &info)
+
+ // number of scopes must match
+ if len(info.Scopes) != len(test.scopes) {
+ t.Errorf("package %s: got %d scopes; want %d", name, len(info.Scopes), len(test.scopes))
+ }
+
+ // scope descriptions must match
+ for node, scope := range info.Scopes {
+ kind := "<unknown node kind>"
+ switch node.(type) {
+ case *ast.File:
+ kind = "file"
+ case *ast.FuncType:
+ kind = "func"
+ case *ast.BlockStmt:
+ kind = "block"
+ case *ast.IfStmt:
+ kind = "if"
+ case *ast.SwitchStmt:
+ kind = "switch"
+ case *ast.TypeSwitchStmt:
+ kind = "type switch"
+ case *ast.CaseClause:
+ kind = "case"
+ case *ast.CommClause:
+ kind = "comm"
+ case *ast.ForStmt:
+ kind = "for"
+ case *ast.RangeStmt:
+ kind = "range"
+ }
+
+ // look for matching scope description
+ desc := kind + ":" + strings.Join(scope.Names(), " ")
+ found := false
+ for _, d := range test.scopes {
+ if desc == d {
+ found = true
+ break
+ }
+ }
+ if !found {
+ t.Errorf("package %s: no matching scope found for %s", name, desc)
+ }
+ }
+ }
+}
+
+func TestInitOrderInfo(t *testing.T) {
+ var tests = []struct {
+ src string
+ inits []string
+ }{
+ {`package p0; var (x = 1; y = x)`, []string{
+ "x = 1", "y = x",
+ }},
+ {`package p1; var (a = 1; b = 2; c = 3)`, []string{
+ "a = 1", "b = 2", "c = 3",
+ }},
+ {`package p2; var (a, b, c = 1, 2, 3)`, []string{
+ "a = 1", "b = 2", "c = 3",
+ }},
+ {`package p3; var _ = f(); func f() int { return 1 }`, []string{
+ "_ = f()", // blank var
+ }},
+ {`package p4; var (a = 0; x = y; y = z; z = 0)`, []string{
+ "a = 0", "z = 0", "y = z", "x = y",
+ }},
+ {`package p5; var (a, _ = m[0]; m map[int]string)`, []string{
+ "a, _ = m[0]", // blank var
+ }},
+ {`package p6; var a, b = f(); func f() (_, _ int) { return z, z }; var z = 0`, []string{
+ "z = 0", "a, b = f()",
+ }},
+ {`package p7; var (a = func() int { return b }(); b = 1)`, []string{
+ "b = 1", "a = (func() int literal)()",
+ }},
+ {`package p8; var (a, b = func() (_, _ int) { return c, c }(); c = 1)`, []string{
+ "c = 1", "a, b = (func() (_, _ int) literal)()",
+ }},
+ {`package p9; type T struct{}; func (T) m() int { _ = y; return 0 }; var x, y = T.m, 1`, []string{
+ "y = 1", "x = T.m",
+ }},
+ {`package p10; var (d = c + b; a = 0; b = 0; c = 0)`, []string{
+ "a = 0", "b = 0", "c = 0", "d = c + b",
+ }},
+ {`package p11; var (a = e + c; b = d + c; c = 0; d = 0; e = 0)`, []string{
+ "c = 0", "d = 0", "b = d + c", "e = 0", "a = e + c",
+ }},
+ // emit an initializer for n:1 initializations only once (not for each node
+ // on the lhs which may appear in different order in the dependency graph)
+ {`package p12; var (a = x; b = 0; x, y = m[0]; m map[int]int)`, []string{
+ "b = 0", "x, y = m[0]", "a = x",
+ }},
+ // test case from spec section on package initialization
+ {`package p12
+
+ var (
+ a = c + b
+ b = f()
+ c = f()
+ d = 3
+ )
+
+ func f() int {
+ d++
+ return d
+ }`, []string{
+ "d = 3", "b = f()", "c = f()", "a = c + b",
+ }},
+ // test case for issue 7131
+ {`package main
+
+ var counter int
+ func next() int { counter++; return counter }
+
+ var _ = makeOrder()
+ func makeOrder() []int { return []int{f, b, d, e, c, a} }
+
+ var a = next()
+ var b, c = next(), next()
+ var d, e, f = next(), next(), next()
+ `, []string{
+ "a = next()", "b = next()", "c = next()", "d = next()", "e = next()", "f = next()", "_ = makeOrder()",
+ }},
+ // test case for issue 10709
+ {`package p13
+
+ var (
+ v = t.m()
+ t = makeT(0)
+ )
+
+ type T struct{}
+
+ func (T) m() int { return 0 }
+
+ func makeT(n int) T {
+ if n > 0 {
+ return makeT(n-1)
+ }
+ return T{}
+ }`, []string{
+ "t = makeT(0)", "v = t.m()",
+ }},
+ // test case for issue 10709: same as test before, but variable decls swapped
+ {`package p14
+
+ var (
+ t = makeT(0)
+ v = t.m()
+ )
+
+ type T struct{}
+
+ func (T) m() int { return 0 }
+
+ func makeT(n int) T {
+ if n > 0 {
+ return makeT(n-1)
+ }
+ return T{}
+ }`, []string{
+ "t = makeT(0)", "v = t.m()",
+ }},
+ // another candidate possibly causing problems with issue 10709
+ {`package p15
+
+ var y1 = f1()
+
+ func f1() int { return g1() }
+ func g1() int { f1(); return x1 }
+
+ var x1 = 0
+
+ var y2 = f2()
+
+ func f2() int { return g2() }
+ func g2() int { return x2 }
+
+ var x2 = 0`, []string{
+ "x1 = 0", "y1 = f1()", "x2 = 0", "y2 = f2()",
+ }},
+ }
+
+ for _, test := range tests {
+ info := Info{}
+ name := mustTypecheck(t, "InitOrderInfo", test.src, &info)
+
+ // number of initializers must match
+ if len(info.InitOrder) != len(test.inits) {
+ t.Errorf("package %s: got %d initializers; want %d", name, len(info.InitOrder), len(test.inits))
+ continue
+ }
+
+ // initializers must match
+ for i, want := range test.inits {
+ got := info.InitOrder[i].String()
+ if got != want {
+ t.Errorf("package %s, init %d: got %s; want %s", name, i, got, want)
+ continue
+ }
+ }
+ }
+}
+
+func TestMultiFileInitOrder(t *testing.T) {
+ fset := token.NewFileSet()
+ mustParse := func(src string) *ast.File {
+ f, err := parser.ParseFile(fset, "main", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ return f
+ }
+
+ fileA := mustParse(`package main; var a = 1`)
+ fileB := mustParse(`package main; var b = 2`)
+
+ // The initialization order must not depend on the parse
+ // order of the files, only on the presentation order to
+ // the type-checker.
+ for _, test := range []struct {
+ files []*ast.File
+ want string
+ }{
+ {[]*ast.File{fileA, fileB}, "[a = 1 b = 2]"},
+ {[]*ast.File{fileB, fileA}, "[b = 2 a = 1]"},
+ } {
+ var info Info
+ if _, err := new(Config).Check("main", fset, test.files, &info); err != nil {
+ t.Fatal(err)
+ }
+ if got := fmt.Sprint(info.InitOrder); got != test.want {
+ t.Fatalf("got %s; want %s", got, test.want)
+ }
+ }
+}
+
+func TestFiles(t *testing.T) {
+ var sources = []string{
+ "package p; type T struct{}; func (T) m1() {}",
+ "package p; func (T) m2() {}; var x interface{ m1(); m2() } = T{}",
+ "package p; func (T) m3() {}; var y interface{ m1(); m2(); m3() } = T{}",
+ "package p",
+ }
+
+ var conf Config
+ fset := token.NewFileSet()
+ pkg := NewPackage("p", "p")
+ var info Info
+ check := NewChecker(&conf, fset, pkg, &info)
+
+ for i, src := range sources {
+ filename := fmt.Sprintf("sources%d", i)
+ f, err := parser.ParseFile(fset, filename, src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if err := check.Files([]*ast.File{f}); err != nil {
+ t.Error(err)
+ }
+ }
+
+ // check InitOrder is [x y]
+ var vars []string
+ for _, init := range info.InitOrder {
+ for _, v := range init.Lhs {
+ vars = append(vars, v.Name())
+ }
+ }
+ if got, want := fmt.Sprint(vars), "[x y]"; got != want {
+ t.Errorf("InitOrder == %s, want %s", got, want)
+ }
+}
+
+type testImporter map[string]*Package
+
+func (m testImporter) Import(path string) (*Package, error) {
+ if pkg := m[path]; pkg != nil {
+ return pkg, nil
+ }
+ return nil, fmt.Errorf("package %q not found", path)
+}
+
+func TestSelection(t *testing.T) {
+ selections := make(map[*ast.SelectorExpr]*Selection)
+
+ fset := token.NewFileSet()
+ imports := make(testImporter)
+ conf := Config{Importer: imports}
+ makePkg := func(path, src string) {
+ f, err := parser.ParseFile(fset, path+".go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ pkg, err := conf.Check(path, fset, []*ast.File{f}, &Info{Selections: selections})
+ if err != nil {
+ t.Fatal(err)
+ }
+ imports[path] = pkg
+ }
+
+ const libSrc = `
+package lib
+type T float64
+const C T = 3
+var V T
+func F() {}
+func (T) M() {}
+`
+ const mainSrc = `
+package main
+import "lib"
+
+type A struct {
+ *B
+ C
+}
+
+type B struct {
+ b int
+}
+
+func (B) f(int)
+
+type C struct {
+ c int
+}
+
+func (C) g()
+func (*C) h()
+
+func main() {
+ // qualified identifiers
+ var _ lib.T
+ _ = lib.C
+ _ = lib.F
+ _ = lib.V
+ _ = lib.T.M
+
+ // fields
+ _ = A{}.B
+ _ = new(A).B
+
+ _ = A{}.C
+ _ = new(A).C
+
+ _ = A{}.b
+ _ = new(A).b
+
+ _ = A{}.c
+ _ = new(A).c
+
+ // methods
+ _ = A{}.f
+ _ = new(A).f
+ _ = A{}.g
+ _ = new(A).g
+ _ = new(A).h
+
+ _ = B{}.f
+ _ = new(B).f
+
+ _ = C{}.g
+ _ = new(C).g
+ _ = new(C).h
+
+ // method expressions
+ _ = A.f
+ _ = (*A).f
+ _ = B.f
+ _ = (*B).f
+}`
+
+ wantOut := map[string][2]string{
+ "lib.T.M": {"method expr (lib.T) M(lib.T)", ".[0]"},
+
+ "A{}.B": {"field (main.A) B *main.B", ".[0]"},
+ "new(A).B": {"field (*main.A) B *main.B", "->[0]"},
+ "A{}.C": {"field (main.A) C main.C", ".[1]"},
+ "new(A).C": {"field (*main.A) C main.C", "->[1]"},
+ "A{}.b": {"field (main.A) b int", "->[0 0]"},
+ "new(A).b": {"field (*main.A) b int", "->[0 0]"},
+ "A{}.c": {"field (main.A) c int", ".[1 0]"},
+ "new(A).c": {"field (*main.A) c int", "->[1 0]"},
+
+ "A{}.f": {"method (main.A) f(int)", "->[0 0]"},
+ "new(A).f": {"method (*main.A) f(int)", "->[0 0]"},
+ "A{}.g": {"method (main.A) g()", ".[1 0]"},
+ "new(A).g": {"method (*main.A) g()", "->[1 0]"},
+ "new(A).h": {"method (*main.A) h()", "->[1 1]"}, // TODO(gri) should this report .[1 1] ?
+ "B{}.f": {"method (main.B) f(int)", ".[0]"},
+ "new(B).f": {"method (*main.B) f(int)", "->[0]"},
+ "C{}.g": {"method (main.C) g()", ".[0]"},
+ "new(C).g": {"method (*main.C) g()", "->[0]"},
+ "new(C).h": {"method (*main.C) h()", "->[1]"}, // TODO(gri) should this report .[1] ?
+
+ "A.f": {"method expr (main.A) f(main.A, int)", "->[0 0]"},
+ "(*A).f": {"method expr (*main.A) f(*main.A, int)", "->[0 0]"},
+ "B.f": {"method expr (main.B) f(main.B, int)", ".[0]"},
+ "(*B).f": {"method expr (*main.B) f(*main.B, int)", "->[0]"},
+ }
+
+ makePkg("lib", libSrc)
+ makePkg("main", mainSrc)
+
+ for e, sel := range selections {
+ _ = sel.String() // assertion: must not panic
+
+ start := fset.Position(e.Pos()).Offset
+ end := fset.Position(e.End()).Offset
+ syntax := mainSrc[start:end] // (all SelectorExprs are in main, not lib)
+
+ direct := "."
+ if sel.Indirect() {
+ direct = "->"
+ }
+ got := [2]string{
+ sel.String(),
+ fmt.Sprintf("%s%v", direct, sel.Index()),
+ }
+ want := wantOut[syntax]
+ if want != got {
+ t.Errorf("%s: got %q; want %q", syntax, got, want)
+ }
+ delete(wantOut, syntax)
+
+ // We must explicitly assert properties of the
+ // Signature's receiver since it doesn't participate
+ // in Identical() or String().
+ sig, _ := sel.Type().(*Signature)
+ if sel.Kind() == MethodVal {
+ got := sig.Recv().Type()
+ want := sel.Recv()
+ if !Identical(got, want) {
+ t.Errorf("%s: Recv() = %s, want %s", syntax, got, want)
+ }
+ } else if sig != nil && sig.Recv() != nil {
+ t.Errorf("%s: signature has receiver %s", sig, sig.Recv().Type())
+ }
+ }
+ // Assert that all wantOut entries were used exactly once.
+ for syntax := range wantOut {
+ t.Errorf("no ast.Selection found with syntax %q", syntax)
+ }
+}
+
+func TestIssue8518(t *testing.T) {
+ fset := token.NewFileSet()
+ imports := make(testImporter)
+ conf := Config{
+ Error: func(err error) { t.Log(err) }, // don't exit after first error
+ Importer: imports,
+ }
+ makePkg := func(path, src string) {
+ f, err := parser.ParseFile(fset, path, src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ pkg, _ := conf.Check(path, fset, []*ast.File{f}, nil) // errors logged via conf.Error
+ imports[path] = pkg
+ }
+
+ const libSrc = `
+package a
+import "missing"
+const C1 = foo
+const C2 = missing.C
+`
+
+ const mainSrc = `
+package main
+import "a"
+var _ = a.C1
+var _ = a.C2
+`
+
+ makePkg("a", libSrc)
+ makePkg("main", mainSrc) // don't crash when type-checking this package
+}
+
+func TestLookupFieldOrMethod(t *testing.T) {
+ // Test cases assume a lookup of the form a.f or x.f, where a stands for an
+ // addressable value, and x for a non-addressable value (even though a variable
+ // for ease of test case writing).
+ var tests = []struct {
+ src string
+ found bool
+ index []int
+ indirect bool
+ }{
+ // field lookups
+ {"var x T; type T struct{}", false, nil, false},
+ {"var x T; type T struct{ f int }", true, []int{0}, false},
+ {"var x T; type T struct{ a, b, f, c int }", true, []int{2}, false},
+
+ // method lookups
+ {"var a T; type T struct{}; func (T) f() {}", true, []int{0}, false},
+ {"var a *T; type T struct{}; func (T) f() {}", true, []int{0}, true},
+ {"var a T; type T struct{}; func (*T) f() {}", true, []int{0}, false},
+ {"var a *T; type T struct{}; func (*T) f() {}", true, []int{0}, true}, // TODO(gri) should this report indirect = false?
+
+ // collisions
+ {"type ( E1 struct{ f int }; E2 struct{ f int }; x struct{ E1; *E2 })", false, []int{1, 0}, false},
+ {"type ( E1 struct{ f int }; E2 struct{}; x struct{ E1; *E2 }); func (E2) f() {}", false, []int{1, 0}, false},
+
+ // outside methodset
+ // (*T).f method exists, but value of type T is not addressable
+ {"var x T; type T struct{}; func (*T) f() {}", false, nil, true},
+ }
+
+ for _, test := range tests {
+ pkg, err := pkgFor("test", "package p;"+test.src, nil)
+ if err != nil {
+ t.Errorf("%s: incorrect test case: %s", test.src, err)
+ continue
+ }
+
+ obj := pkg.Scope().Lookup("a")
+ if obj == nil {
+ if obj = pkg.Scope().Lookup("x"); obj == nil {
+ t.Errorf("%s: incorrect test case - no object a or x", test.src)
+ continue
+ }
+ }
+
+ f, index, indirect := LookupFieldOrMethod(obj.Type(), obj.Name() == "a", pkg, "f")
+ if (f != nil) != test.found {
+ if f == nil {
+ t.Errorf("%s: got no object; want one", test.src)
+ } else {
+ t.Errorf("%s: got object = %v; want none", test.src, f)
+ }
+ }
+ if !sameSlice(index, test.index) {
+ t.Errorf("%s: got index = %v; want %v", test.src, index, test.index)
+ }
+ if indirect != test.indirect {
+ t.Errorf("%s: got indirect = %v; want %v", test.src, indirect, test.indirect)
+ }
+ }
+}
+
+func sameSlice(a, b []int) bool {
+ if len(a) != len(b) {
+ return false
+ }
+ for i, x := range a {
+ if x != b[i] {
+ return false
+ }
+ }
+ return true
+}
+
+// TestScopeLookupParent ensures that (*Scope).LookupParent returns
+// the correct result at various positions with the source.
+func TestScopeLookupParent(t *testing.T) {
+ fset := token.NewFileSet()
+ imports := make(testImporter)
+ conf := Config{Importer: imports}
+ mustParse := func(src string) *ast.File {
+ f, err := parser.ParseFile(fset, "dummy.go", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+ return f
+ }
+ var info Info
+ makePkg := func(path string, files ...*ast.File) {
+ var err error
+ imports[path], err = conf.Check(path, fset, files, &info)
+ if err != nil {
+ t.Fatal(err)
+ }
+ }
+
+ makePkg("lib", mustParse("package lib; var X int"))
+ // Each /*name=kind:line*/ comment makes the test look up the
+ // name at that point and checks that it resolves to a decl of
+ // the specified kind and line number. "undef" means undefined.
+ mainSrc := `
+/*lib=pkgname:5*/ /*X=var:1*/ /*Pi=const:8*/ /*T=typename:9*/ /*Y=var:10*/ /*F=func:12*/
+package main
+
+import "lib"
+import . "lib"
+
+const Pi = 3.1415
+type T struct{}
+var Y, _ = lib.X, X
+
+func F(){
+ const pi, e = 3.1415, /*pi=undef*/ 2.71828 /*pi=const:13*/ /*e=const:13*/
+ type /*t=undef*/ t /*t=typename:14*/ *t
+ print(Y) /*Y=var:10*/
+ x, Y := Y, /*x=undef*/ /*Y=var:10*/ Pi /*x=var:16*/ /*Y=var:16*/ ; _ = x; _ = Y
+ var F = /*F=func:12*/ F /*F=var:17*/ ; _ = F
+
+ var a []int
+ for i, x := range /*i=undef*/ /*x=var:16*/ a /*i=var:20*/ /*x=var:20*/ { _ = i; _ = x }
+
+ var i interface{}
+ switch y := i.(type) { /*y=undef*/
+ case /*y=undef*/ int /*y=var:23*/ :
+ case float32, /*y=undef*/ float64 /*y=var:23*/ :
+ default /*y=var:23*/:
+ println(y)
+ }
+ /*y=undef*/
+
+ switch int := i.(type) {
+ case /*int=typename:0*/ int /*int=var:31*/ :
+ println(int)
+ default /*int=var:31*/ :
+ }
+}
+/*main=undef*/
+`
+
+ info.Uses = make(map[*ast.Ident]Object)
+ f := mustParse(mainSrc)
+ makePkg("main", f)
+ mainScope := imports["main"].Scope()
+ rx := regexp.MustCompile(`^/\*(\w*)=([\w:]*)\*/$`)
+ for _, group := range f.Comments {
+ for _, comment := range group.List {
+ // Parse the assertion in the comment.
+ m := rx.FindStringSubmatch(comment.Text)
+ if m == nil {
+ t.Errorf("%s: bad comment: %s",
+ fset.Position(comment.Pos()), comment.Text)
+ continue
+ }
+ name, want := m[1], m[2]
+
+ // Look up the name in the innermost enclosing scope.
+ inner := mainScope.Innermost(comment.Pos())
+ if inner == nil {
+ t.Errorf("%s: at %s: can't find innermost scope",
+ fset.Position(comment.Pos()), comment.Text)
+ continue
+ }
+ got := "undef"
+ if _, obj := inner.LookupParent(name, comment.Pos()); obj != nil {
+ kind := strings.ToLower(strings.TrimPrefix(reflect.TypeOf(obj).String(), "*types."))
+ got = fmt.Sprintf("%s:%d", kind, fset.Position(obj.Pos()).Line)
+ }
+ if got != want {
+ t.Errorf("%s: at %s: %s resolved to %s, want %s",
+ fset.Position(comment.Pos()), comment.Text, name, got, want)
+ }
+ }
+ }
+
+ // Check that for each referring identifier,
+ // a lookup of its name on the innermost
+ // enclosing scope returns the correct object.
+
+ for id, wantObj := range info.Uses {
+ inner := mainScope.Innermost(id.Pos())
+ if inner == nil {
+ t.Errorf("%s: can't find innermost scope enclosing %q",
+ fset.Position(id.Pos()), id.Name)
+ continue
+ }
+
+ // Exclude selectors and qualified identifiers---lexical
+ // refs only. (Ideally, we'd see if the AST parent is a
+ // SelectorExpr, but that requires PathEnclosingInterval
+ // from golang.org/x/tools/go/ast/astutil.)
+ if id.Name == "X" {
+ continue
+ }
+
+ _, gotObj := inner.LookupParent(id.Name, id.Pos())
+ if gotObj != wantObj {
+ t.Errorf("%s: got %v, want %v",
+ fset.Position(id.Pos()), gotObj, wantObj)
+ continue
+ }
+ }
+}
+
+func TestConvertibleTo(t *testing.T) {
+ for _, test := range []struct {
+ v, t Type
+ want bool
+ }{
+ {Typ[Int], Typ[Int], true},
+ {Typ[Int], Typ[Float32], true},
+ {newDefined(Typ[Int]), Typ[Int], true},
+ {newDefined(new(Struct)), new(Struct), true},
+ {newDefined(Typ[Int]), new(Struct), false},
+ {Typ[UntypedInt], Typ[Int], true},
+ // Untyped string values are not permitted by the spec, so the below
+ // behavior is undefined.
+ {Typ[UntypedString], Typ[String], true},
+ } {
+ if got := ConvertibleTo(test.v, test.t); got != test.want {
+ t.Errorf("ConvertibleTo(%v, %v) = %t, want %t", test.v, test.t, got, test.want)
+ }
+ }
+}
+
+func TestAssignableTo(t *testing.T) {
+ for _, test := range []struct {
+ v, t Type
+ want bool
+ }{
+ {Typ[Int], Typ[Int], true},
+ {Typ[Int], Typ[Float32], false},
+ {newDefined(Typ[Int]), Typ[Int], false},
+ {newDefined(new(Struct)), new(Struct), true},
+ {Typ[UntypedBool], Typ[Bool], true},
+ {Typ[UntypedString], Typ[Bool], false},
+ // Neither untyped string nor untyped numeric assignments arise during
+ // normal type checking, so the below behavior is technically undefined by
+ // the spec.
+ {Typ[UntypedString], Typ[String], true},
+ {Typ[UntypedInt], Typ[Int], true},
+ } {
+ if got := AssignableTo(test.v, test.t); got != test.want {
+ t.Errorf("AssignableTo(%v, %v) = %t, want %t", test.v, test.t, got, test.want)
+ }
+ }
+}
+
+func TestIdentical_issue15173(t *testing.T) {
+ // Identical should allow nil arguments and be symmetric.
+ for _, test := range []struct {
+ x, y Type
+ want bool
+ }{
+ {Typ[Int], Typ[Int], true},
+ {Typ[Int], nil, false},
+ {nil, Typ[Int], false},
+ {nil, nil, true},
+ } {
+ if got := Identical(test.x, test.y); got != test.want {
+ t.Errorf("Identical(%v, %v) = %t", test.x, test.y, got)
+ }
+ }
+}
+
+func TestIssue15305(t *testing.T) {
+ const src = "package p; func f() int16; var _ = f(undef)"
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "issue15305.go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ conf := Config{
+ Error: func(err error) {}, // allow errors
+ }
+ info := &Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ }
+ conf.Check("p", fset, []*ast.File{f}, info) // ignore result
+ for e, tv := range info.Types {
+ if _, ok := e.(*ast.CallExpr); ok {
+ if tv.Type != Typ[Int16] {
+ t.Errorf("CallExpr has type %v, want int16", tv.Type)
+ }
+ return
+ }
+ }
+ t.Errorf("CallExpr has no type")
+}
+
+// TestCompositeLitTypes verifies that Info.Types registers the correct
+// types for composite literal expressions and composite literal type
+// expressions.
+func TestCompositeLitTypes(t *testing.T) {
+ for _, test := range []struct {
+ lit, typ string
+ }{
+ {`[16]byte{}`, `[16]byte`},
+ {`[...]byte{}`, `[0]byte`}, // test for issue #14092
+ {`[...]int{1, 2, 3}`, `[3]int`}, // test for issue #14092
+ {`[...]int{90: 0, 98: 1, 2}`, `[100]int`}, // test for issue #14092
+ {`[]int{}`, `[]int`},
+ {`map[string]bool{"foo": true}`, `map[string]bool`},
+ {`struct{}{}`, `struct{}`},
+ {`struct{x, y int; z complex128}{}`, `struct{x int; y int; z complex128}`},
+ } {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, test.lit, "package p; var _ = "+test.lit, 0)
+ if err != nil {
+ t.Fatalf("%s: %v", test.lit, err)
+ }
+
+ info := &Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ }
+ if _, err = new(Config).Check("p", fset, []*ast.File{f}, info); err != nil {
+ t.Fatalf("%s: %v", test.lit, err)
+ }
+
+ cmptype := func(x ast.Expr, want string) {
+ tv, ok := info.Types[x]
+ if !ok {
+ t.Errorf("%s: no Types entry found", test.lit)
+ return
+ }
+ if tv.Type == nil {
+ t.Errorf("%s: type is nil", test.lit)
+ return
+ }
+ if got := tv.Type.String(); got != want {
+ t.Errorf("%s: got %v, want %s", test.lit, got, want)
+ }
+ }
+
+ // test type of composite literal expression
+ rhs := f.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0]
+ cmptype(rhs, test.typ)
+
+ // test type of composite literal type expression
+ cmptype(rhs.(*ast.CompositeLit).Type, test.typ)
+ }
+}
+
+// TestObjectParents verifies that objects have parent scopes or not
+// as specified by the Object interface.
+func TestObjectParents(t *testing.T) {
+ const src = `
+package p
+
+const C = 0
+
+type T1 struct {
+ a, b int
+ T2
+}
+
+type T2 interface {
+ im1()
+ im2()
+}
+
+func (T1) m1() {}
+func (*T1) m2() {}
+
+func f(x int) { y := x; print(y) }
+`
+
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "src", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ info := &Info{
+ Defs: make(map[*ast.Ident]Object),
+ }
+ if _, err = new(Config).Check("p", fset, []*ast.File{f}, info); err != nil {
+ t.Fatal(err)
+ }
+
+ for ident, obj := range info.Defs {
+ if obj == nil {
+ // only package names and implicit vars have a nil object
+ // (in this test we only need to handle the package name)
+ if ident.Name != "p" {
+ t.Errorf("%v has nil object", ident)
+ }
+ continue
+ }
+
+ // struct fields, type-associated and interface methods
+ // have no parent scope
+ wantParent := true
+ switch obj := obj.(type) {
+ case *Var:
+ if obj.IsField() {
+ wantParent = false
+ }
+ case *Func:
+ if obj.Type().(*Signature).Recv() != nil { // method
+ wantParent = false
+ }
+ }
+
+ gotParent := obj.Parent() != nil
+ switch {
+ case gotParent && !wantParent:
+ t.Errorf("%v: want no parent, got %s", ident, obj.Parent())
+ case !gotParent && wantParent:
+ t.Errorf("%v: no parent found", ident)
+ }
+ }
+}
+
+// TestFailedImport tests that we don't get follow-on errors
+// elsewhere in a package due to failing to import a package.
+func TestFailedImport(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ const src = `
+package p
+
+import foo "go/types/thisdirectorymustnotexistotherwisethistestmayfail/foo" // should only see an error here
+
+const c = foo.C
+type T = foo.T
+var v T = c
+func f(x T) T { return foo.F(x) }
+`
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "src", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ files := []*ast.File{f}
+
+ // type-check using all possible importers
+ for _, compiler := range []string{"gc", "gccgo", "source"} {
+ errcount := 0
+ conf := Config{
+ Error: func(err error) {
+ // we should only see the import error
+ if errcount > 0 || !strings.Contains(err.Error(), "could not import") {
+ t.Errorf("for %s importer, got unexpected error: %v", compiler, err)
+ }
+ errcount++
+ },
+ Importer: importer.For(compiler, nil),
+ }
+
+ info := &Info{
+ Uses: make(map[*ast.Ident]Object),
+ }
+ pkg, _ := conf.Check("p", fset, files, info)
+ if pkg == nil {
+ t.Errorf("for %s importer, type-checking failed to return a package", compiler)
+ continue
+ }
+
+ imports := pkg.Imports()
+ if len(imports) != 1 {
+ t.Errorf("for %s importer, got %d imports, want 1", compiler, len(imports))
+ continue
+ }
+ imp := imports[0]
+ if imp.Name() != "foo" {
+ t.Errorf(`for %s importer, got %q, want "foo"`, compiler, imp.Name())
+ continue
+ }
+
+ // verify that all uses of foo refer to the imported package foo (imp)
+ for ident, obj := range info.Uses {
+ if ident.Name == "foo" {
+ if obj, ok := obj.(*PkgName); ok {
+ if obj.Imported() != imp {
+ t.Errorf("%s resolved to %v; want %v", ident, obj.Imported(), imp)
+ }
+ } else {
+ t.Errorf("%s resolved to %v; want package name", ident, obj)
+ }
+ }
+ }
+ }
+}
diff --git a/src/go/types/assignments.go b/src/go/types/assignments.go
new file mode 100644
index 0000000..616564b
--- /dev/null
+++ b/src/go/types/assignments.go
@@ -0,0 +1,357 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements initialization and assignment checks.
+
+package types
+
+import (
+ "errors"
+ "go/ast"
+ "go/token"
+)
+
+// assignment reports whether x can be assigned to a variable of type T,
+// if necessary by attempting to convert untyped values to the appropriate
+// type. context describes the context in which the assignment takes place.
+// Use T == nil to indicate assignment to an untyped blank identifier.
+// x.mode is set to invalid if the assignment failed.
+func (check *Checker) assignment(x *operand, T Type, context string) {
+ check.singleValue(x)
+
+ switch x.mode {
+ case invalid:
+ return // error reported before
+ case constant_, variable, mapindex, value, commaok, commaerr:
+ // ok
+ default:
+ unreachable()
+ }
+
+ if isUntyped(x.typ) {
+ target := T
+ // spec: "If an untyped constant is assigned to a variable of interface
+ // type or the blank identifier, the constant is first converted to type
+ // bool, rune, int, float64, complex128 or string respectively, depending
+ // on whether the value is a boolean, rune, integer, floating-point,
+ // complex, or string constant."
+ if T == nil || IsInterface(T) {
+ if T == nil && x.typ == Typ[UntypedNil] {
+ check.errorf(x, _UntypedNil, "use of untyped nil in %s", context)
+ x.mode = invalid
+ return
+ }
+ target = Default(x.typ)
+ }
+ if err := check.canConvertUntyped(x, target); err != nil {
+ msg := check.sprintf("cannot use %s as %s value in %s", x, target, context)
+ code := _IncompatibleAssign
+ var ierr Error
+ if errors.As(err, &ierr) {
+ // Preserve these inner errors, as they are informative.
+ switch ierr.go116code {
+ case _TruncatedFloat:
+ msg += " (truncated)"
+ code = ierr.go116code
+ case _NumericOverflow:
+ msg += " (overflows)"
+ code = ierr.go116code
+ }
+ }
+ check.error(x, code, msg)
+ x.mode = invalid
+ return
+ }
+ }
+ // x.typ is typed
+
+ // spec: "If a left-hand side is the blank identifier, any typed or
+ // non-constant value except for the predeclared identifier nil may
+ // be assigned to it."
+ if T == nil {
+ return
+ }
+
+ reason := ""
+ if ok, code := x.assignableTo(check, T, &reason); !ok {
+ if reason != "" {
+ check.errorf(x, code, "cannot use %s as %s value in %s: %s", x, T, context, reason)
+ } else {
+ check.errorf(x, code, "cannot use %s as %s value in %s", x, T, context)
+ }
+ x.mode = invalid
+ }
+}
+
+func (check *Checker) initConst(lhs *Const, x *operand) {
+ if x.mode == invalid || x.typ == Typ[Invalid] || lhs.typ == Typ[Invalid] {
+ if lhs.typ == nil {
+ lhs.typ = Typ[Invalid]
+ }
+ return
+ }
+
+ // rhs must be a constant
+ if x.mode != constant_ {
+ check.errorf(x, _InvalidConstInit, "%s is not constant", x)
+ if lhs.typ == nil {
+ lhs.typ = Typ[Invalid]
+ }
+ return
+ }
+ assert(isConstType(x.typ))
+
+ // If the lhs doesn't have a type yet, use the type of x.
+ if lhs.typ == nil {
+ lhs.typ = x.typ
+ }
+
+ check.assignment(x, lhs.typ, "constant declaration")
+ if x.mode == invalid {
+ return
+ }
+
+ lhs.val = x.val
+}
+
+func (check *Checker) initVar(lhs *Var, x *operand, context string) Type {
+ if x.mode == invalid || x.typ == Typ[Invalid] || lhs.typ == Typ[Invalid] {
+ if lhs.typ == nil {
+ lhs.typ = Typ[Invalid]
+ }
+ return nil
+ }
+
+ // If the lhs doesn't have a type yet, use the type of x.
+ if lhs.typ == nil {
+ typ := x.typ
+ if isUntyped(typ) {
+ // convert untyped types to default types
+ if typ == Typ[UntypedNil] {
+ check.errorf(x, _UntypedNil, "use of untyped nil in %s", context)
+ lhs.typ = Typ[Invalid]
+ return nil
+ }
+ typ = Default(typ)
+ }
+ lhs.typ = typ
+ }
+
+ check.assignment(x, lhs.typ, context)
+ if x.mode == invalid {
+ return nil
+ }
+
+ return x.typ
+}
+
+func (check *Checker) assignVar(lhs ast.Expr, x *operand) Type {
+ if x.mode == invalid || x.typ == Typ[Invalid] {
+ return nil
+ }
+
+ // Determine if the lhs is a (possibly parenthesized) identifier.
+ ident, _ := unparen(lhs).(*ast.Ident)
+
+ // Don't evaluate lhs if it is the blank identifier.
+ if ident != nil && ident.Name == "_" {
+ check.recordDef(ident, nil)
+ check.assignment(x, nil, "assignment to _ identifier")
+ if x.mode == invalid {
+ return nil
+ }
+ return x.typ
+ }
+
+ // If the lhs is an identifier denoting a variable v, this assignment
+ // is not a 'use' of v. Remember current value of v.used and restore
+ // after evaluating the lhs via check.expr.
+ var v *Var
+ var v_used bool
+ if ident != nil {
+ if obj := check.lookup(ident.Name); obj != nil {
+ // It's ok to mark non-local variables, but ignore variables
+ // from other packages to avoid potential race conditions with
+ // dot-imported variables.
+ if w, _ := obj.(*Var); w != nil && w.pkg == check.pkg {
+ v = w
+ v_used = v.used
+ }
+ }
+ }
+
+ var z operand
+ check.expr(&z, lhs)
+ if v != nil {
+ v.used = v_used // restore v.used
+ }
+
+ if z.mode == invalid || z.typ == Typ[Invalid] {
+ return nil
+ }
+
+ // spec: "Each left-hand side operand must be addressable, a map index
+ // expression, or the blank identifier. Operands may be parenthesized."
+ switch z.mode {
+ case invalid:
+ return nil
+ case variable, mapindex:
+ // ok
+ default:
+ if sel, ok := z.expr.(*ast.SelectorExpr); ok {
+ var op operand
+ check.expr(&op, sel.X)
+ if op.mode == mapindex {
+ check.errorf(&z, _UnaddressableFieldAssign, "cannot assign to struct field %s in map", ExprString(z.expr))
+ return nil
+ }
+ }
+ check.errorf(&z, _UnassignableOperand, "cannot assign to %s", &z)
+ return nil
+ }
+
+ check.assignment(x, z.typ, "assignment")
+ if x.mode == invalid {
+ return nil
+ }
+
+ return x.typ
+}
+
+// If returnPos is valid, initVars is called to type-check the assignment of
+// return expressions, and returnPos is the position of the return statement.
+func (check *Checker) initVars(lhs []*Var, rhs []ast.Expr, returnPos token.Pos) {
+ l := len(lhs)
+ get, r, commaOk := unpack(func(x *operand, i int) { check.multiExpr(x, rhs[i]) }, len(rhs), l == 2 && !returnPos.IsValid())
+ if get == nil || l != r {
+ // invalidate lhs and use rhs
+ for _, obj := range lhs {
+ if obj.typ == nil {
+ obj.typ = Typ[Invalid]
+ }
+ }
+ if get == nil {
+ return // error reported by unpack
+ }
+ check.useGetter(get, r)
+ if returnPos.IsValid() {
+ check.errorf(atPos(returnPos), _WrongResultCount, "wrong number of return values (want %d, got %d)", l, r)
+ return
+ }
+ check.errorf(rhs[0], _WrongAssignCount, "cannot initialize %d variables with %d values", l, r)
+ return
+ }
+
+ context := "assignment"
+ if returnPos.IsValid() {
+ context = "return statement"
+ }
+
+ var x operand
+ if commaOk {
+ var a [2]Type
+ for i := range a {
+ get(&x, i)
+ a[i] = check.initVar(lhs[i], &x, context)
+ }
+ check.recordCommaOkTypes(rhs[0], a)
+ return
+ }
+
+ for i, lhs := range lhs {
+ get(&x, i)
+ check.initVar(lhs, &x, context)
+ }
+}
+
+func (check *Checker) assignVars(lhs, rhs []ast.Expr) {
+ l := len(lhs)
+ get, r, commaOk := unpack(func(x *operand, i int) { check.multiExpr(x, rhs[i]) }, len(rhs), l == 2)
+ if get == nil {
+ check.useLHS(lhs...)
+ return // error reported by unpack
+ }
+ if l != r {
+ check.useGetter(get, r)
+ check.errorf(rhs[0], _WrongAssignCount, "cannot assign %d values to %d variables", r, l)
+ return
+ }
+
+ var x operand
+ if commaOk {
+ var a [2]Type
+ for i := range a {
+ get(&x, i)
+ a[i] = check.assignVar(lhs[i], &x)
+ }
+ check.recordCommaOkTypes(rhs[0], a)
+ return
+ }
+
+ for i, lhs := range lhs {
+ get(&x, i)
+ check.assignVar(lhs, &x)
+ }
+}
+
+func (check *Checker) shortVarDecl(pos positioner, lhs, rhs []ast.Expr) {
+ top := len(check.delayed)
+ scope := check.scope
+
+ // collect lhs variables
+ var newVars []*Var
+ var lhsVars = make([]*Var, len(lhs))
+ for i, lhs := range lhs {
+ var obj *Var
+ if ident, _ := lhs.(*ast.Ident); ident != nil {
+ // Use the correct obj if the ident is redeclared. The
+ // variable's scope starts after the declaration; so we
+ // must use Scope.Lookup here and call Scope.Insert
+ // (via check.declare) later.
+ name := ident.Name
+ if alt := scope.Lookup(name); alt != nil {
+ // redeclared object must be a variable
+ if alt, _ := alt.(*Var); alt != nil {
+ obj = alt
+ } else {
+ check.errorf(lhs, _UnassignableOperand, "cannot assign to %s", lhs)
+ }
+ check.recordUse(ident, alt)
+ } else {
+ // declare new variable, possibly a blank (_) variable
+ obj = NewVar(ident.Pos(), check.pkg, name, nil)
+ if name != "_" {
+ newVars = append(newVars, obj)
+ }
+ check.recordDef(ident, obj)
+ }
+ } else {
+ check.useLHS(lhs)
+ check.invalidAST(lhs, "cannot declare %s", lhs)
+ }
+ if obj == nil {
+ obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable
+ }
+ lhsVars[i] = obj
+ }
+
+ check.initVars(lhsVars, rhs, token.NoPos)
+
+ // process function literals in rhs expressions before scope changes
+ check.processDelayed(top)
+
+ // declare new variables
+ if len(newVars) > 0 {
+ // spec: "The scope of a constant or variable identifier declared inside
+ // a function begins at the end of the ConstSpec or VarSpec (ShortVarDecl
+ // for short variable declarations) and ends at the end of the innermost
+ // containing block."
+ scopePos := rhs[len(rhs)-1].End()
+ for _, obj := range newVars {
+ check.declare(scope, nil, obj, scopePos) // recordObject already called
+ }
+ } else {
+ check.softErrorf(pos, _NoNewVar, "no new variables on left side of :=")
+ }
+}
diff --git a/src/go/types/builtins.go b/src/go/types/builtins.go
new file mode 100644
index 0000000..fd35f78
--- /dev/null
+++ b/src/go/types/builtins.go
@@ -0,0 +1,697 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements typechecking of builtin function calls.
+
+package types
+
+import (
+ "go/ast"
+ "go/constant"
+ "go/token"
+)
+
+// builtin type-checks a call to the built-in specified by id and
+// reports whether the call is valid, with *x holding the result;
+// but x.expr is not set. If the call is invalid, the result is
+// false, and *x is undefined.
+//
+func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ bool) {
+ // append is the only built-in that permits the use of ... for the last argument
+ bin := predeclaredFuncs[id]
+ if call.Ellipsis.IsValid() && id != _Append {
+ check.invalidOp(atPos(call.Ellipsis),
+ _InvalidDotDotDot,
+ "invalid use of ... with built-in %s", bin.name)
+ check.use(call.Args...)
+ return
+ }
+
+ // For len(x) and cap(x) we need to know if x contains any function calls or
+ // receive operations. Save/restore current setting and set hasCallOrRecv to
+ // false for the evaluation of x so that we can check it afterwards.
+ // Note: We must do this _before_ calling unpack because unpack evaluates the
+ // first argument before we even call arg(x, 0)!
+ if id == _Len || id == _Cap {
+ defer func(b bool) {
+ check.hasCallOrRecv = b
+ }(check.hasCallOrRecv)
+ check.hasCallOrRecv = false
+ }
+
+ // determine actual arguments
+ var arg getter
+ nargs := len(call.Args)
+ switch id {
+ default:
+ // make argument getter
+ arg, nargs, _ = unpack(func(x *operand, i int) { check.multiExpr(x, call.Args[i]) }, nargs, false)
+ if arg == nil {
+ return
+ }
+ // evaluate first argument, if present
+ if nargs > 0 {
+ arg(x, 0)
+ if x.mode == invalid {
+ return
+ }
+ }
+ case _Make, _New, _Offsetof, _Trace:
+ // arguments require special handling
+ }
+
+ // check argument count
+ {
+ msg := ""
+ if nargs < bin.nargs {
+ msg = "not enough"
+ } else if !bin.variadic && nargs > bin.nargs {
+ msg = "too many"
+ }
+ if msg != "" {
+ check.invalidOp(inNode(call, call.Rparen), _WrongArgCount, "%s arguments for %s (expected %d, found %d)", msg, call, bin.nargs, nargs)
+ return
+ }
+ }
+
+ switch id {
+ case _Append:
+ // append(s S, x ...T) S, where T is the element type of S
+ // spec: "The variadic function append appends zero or more values x to s of type
+ // S, which must be a slice type, and returns the resulting slice, also of type S.
+ // The values x are passed to a parameter of type ...T where T is the element type
+ // of S and the respective parameter passing rules apply."
+ S := x.typ
+ var T Type
+ if s, _ := S.Underlying().(*Slice); s != nil {
+ T = s.elem
+ } else {
+ check.invalidArg(x, _InvalidAppend, "%s is not a slice", x)
+ return
+ }
+
+ // remember arguments that have been evaluated already
+ alist := []operand{*x}
+
+ // spec: "As a special case, append also accepts a first argument assignable
+ // to type []byte with a second argument of string type followed by ... .
+ // This form appends the bytes of the string.
+ if nargs == 2 && call.Ellipsis.IsValid() {
+ if ok, _ := x.assignableTo(check, NewSlice(universeByte), nil); ok {
+ arg(x, 1)
+ if x.mode == invalid {
+ return
+ }
+ if isString(x.typ) {
+ if check.Types != nil {
+ sig := makeSig(S, S, x.typ)
+ sig.variadic = true
+ check.recordBuiltinType(call.Fun, sig)
+ }
+ x.mode = value
+ x.typ = S
+ break
+ }
+ alist = append(alist, *x)
+ // fallthrough
+ }
+ }
+
+ // check general case by creating custom signature
+ sig := makeSig(S, S, NewSlice(T)) // []T required for variadic signature
+ sig.variadic = true
+ check.arguments(x, call, sig, func(x *operand, i int) {
+ // only evaluate arguments that have not been evaluated before
+ if i < len(alist) {
+ *x = alist[i]
+ return
+ }
+ arg(x, i)
+ }, nargs)
+ // ok to continue even if check.arguments reported errors
+
+ x.mode = value
+ x.typ = S
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, sig)
+ }
+
+ case _Cap, _Len:
+ // cap(x)
+ // len(x)
+ mode := invalid
+ var typ Type
+ var val constant.Value
+ switch typ = implicitArrayDeref(x.typ.Underlying()); t := typ.(type) {
+ case *Basic:
+ if isString(t) && id == _Len {
+ if x.mode == constant_ {
+ mode = constant_
+ val = constant.MakeInt64(int64(len(constant.StringVal(x.val))))
+ } else {
+ mode = value
+ }
+ }
+
+ case *Array:
+ mode = value
+ // spec: "The expressions len(s) and cap(s) are constants
+ // if the type of s is an array or pointer to an array and
+ // the expression s does not contain channel receives or
+ // function calls; in this case s is not evaluated."
+ if !check.hasCallOrRecv {
+ mode = constant_
+ if t.len >= 0 {
+ val = constant.MakeInt64(t.len)
+ } else {
+ val = constant.MakeUnknown()
+ }
+ }
+
+ case *Slice, *Chan:
+ mode = value
+
+ case *Map:
+ if id == _Len {
+ mode = value
+ }
+ }
+
+ if mode == invalid && typ != Typ[Invalid] {
+ code := _InvalidCap
+ if id == _Len {
+ code = _InvalidLen
+ }
+ check.invalidArg(x, code, "%s for %s", x, bin.name)
+ return
+ }
+
+ x.mode = mode
+ x.typ = Typ[Int]
+ x.val = val
+ if check.Types != nil && mode != constant_ {
+ check.recordBuiltinType(call.Fun, makeSig(x.typ, typ))
+ }
+
+ case _Close:
+ // close(c)
+ c, _ := x.typ.Underlying().(*Chan)
+ if c == nil {
+ check.invalidArg(x, _InvalidClose, "%s is not a channel", x)
+ return
+ }
+ if c.dir == RecvOnly {
+ check.invalidArg(x, _InvalidClose, "%s must not be a receive-only channel", x)
+ return
+ }
+
+ x.mode = novalue
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(nil, c))
+ }
+
+ case _Complex:
+ // complex(x, y floatT) complexT
+ var y operand
+ arg(&y, 1)
+ if y.mode == invalid {
+ return
+ }
+
+ // convert or check untyped arguments
+ d := 0
+ if isUntyped(x.typ) {
+ d |= 1
+ }
+ if isUntyped(y.typ) {
+ d |= 2
+ }
+ switch d {
+ case 0:
+ // x and y are typed => nothing to do
+ case 1:
+ // only x is untyped => convert to type of y
+ check.convertUntyped(x, y.typ)
+ case 2:
+ // only y is untyped => convert to type of x
+ check.convertUntyped(&y, x.typ)
+ case 3:
+ // x and y are untyped =>
+ // 1) if both are constants, convert them to untyped
+ // floating-point numbers if possible,
+ // 2) if one of them is not constant (possible because
+ // it contains a shift that is yet untyped), convert
+ // both of them to float64 since they must have the
+ // same type to succeed (this will result in an error
+ // because shifts of floats are not permitted)
+ if x.mode == constant_ && y.mode == constant_ {
+ toFloat := func(x *operand) {
+ if isNumeric(x.typ) && constant.Sign(constant.Imag(x.val)) == 0 {
+ x.typ = Typ[UntypedFloat]
+ }
+ }
+ toFloat(x)
+ toFloat(&y)
+ } else {
+ check.convertUntyped(x, Typ[Float64])
+ check.convertUntyped(&y, Typ[Float64])
+ // x and y should be invalid now, but be conservative
+ // and check below
+ }
+ }
+ if x.mode == invalid || y.mode == invalid {
+ return
+ }
+
+ // both argument types must be identical
+ if !check.identical(x.typ, y.typ) {
+ check.invalidArg(x, _InvalidComplex, "mismatched types %s and %s", x.typ, y.typ)
+ return
+ }
+
+ // the argument types must be of floating-point type
+ if !isFloat(x.typ) {
+ check.invalidArg(x, _InvalidComplex, "arguments have type %s, expected floating-point", x.typ)
+ return
+ }
+
+ // if both arguments are constants, the result is a constant
+ if x.mode == constant_ && y.mode == constant_ {
+ x.val = constant.BinaryOp(constant.ToFloat(x.val), token.ADD, constant.MakeImag(constant.ToFloat(y.val)))
+ } else {
+ x.mode = value
+ }
+
+ // determine result type
+ var res BasicKind
+ switch x.typ.Underlying().(*Basic).kind {
+ case Float32:
+ res = Complex64
+ case Float64:
+ res = Complex128
+ case UntypedFloat:
+ res = UntypedComplex
+ default:
+ unreachable()
+ }
+ resTyp := Typ[res]
+
+ if check.Types != nil && x.mode != constant_ {
+ check.recordBuiltinType(call.Fun, makeSig(resTyp, x.typ, x.typ))
+ }
+
+ x.typ = resTyp
+
+ case _Copy:
+ // copy(x, y []T) int
+ var dst Type
+ if t, _ := x.typ.Underlying().(*Slice); t != nil {
+ dst = t.elem
+ }
+
+ var y operand
+ arg(&y, 1)
+ if y.mode == invalid {
+ return
+ }
+ var src Type
+ switch t := y.typ.Underlying().(type) {
+ case *Basic:
+ if isString(y.typ) {
+ src = universeByte
+ }
+ case *Slice:
+ src = t.elem
+ }
+
+ if dst == nil || src == nil {
+ check.invalidArg(x, _InvalidCopy, "copy expects slice arguments; found %s and %s", x, &y)
+ return
+ }
+
+ if !check.identical(dst, src) {
+ check.invalidArg(x, _InvalidCopy, "arguments to copy %s and %s have different element types %s and %s", x, &y, dst, src)
+ return
+ }
+
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(Typ[Int], x.typ, y.typ))
+ }
+ x.mode = value
+ x.typ = Typ[Int]
+
+ case _Delete:
+ // delete(m, k)
+ m, _ := x.typ.Underlying().(*Map)
+ if m == nil {
+ check.invalidArg(x, _InvalidDelete, "%s is not a map", x)
+ return
+ }
+ arg(x, 1) // k
+ if x.mode == invalid {
+ return
+ }
+
+ if ok, code := x.assignableTo(check, m.key, nil); !ok {
+ check.invalidArg(x, code, "%s is not assignable to %s", x, m.key)
+ return
+ }
+
+ x.mode = novalue
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(nil, m, m.key))
+ }
+
+ case _Imag, _Real:
+ // imag(complexT) floatT
+ // real(complexT) floatT
+
+ // convert or check untyped argument
+ if isUntyped(x.typ) {
+ if x.mode == constant_ {
+ // an untyped constant number can always be considered
+ // as a complex constant
+ if isNumeric(x.typ) {
+ x.typ = Typ[UntypedComplex]
+ }
+ } else {
+ // an untyped non-constant argument may appear if
+ // it contains a (yet untyped non-constant) shift
+ // expression: convert it to complex128 which will
+ // result in an error (shift of complex value)
+ check.convertUntyped(x, Typ[Complex128])
+ // x should be invalid now, but be conservative and check
+ if x.mode == invalid {
+ return
+ }
+ }
+ }
+
+ // the argument must be of complex type
+ if !isComplex(x.typ) {
+ code := _InvalidImag
+ if id == _Real {
+ code = _InvalidReal
+ }
+ check.invalidArg(x, code, "argument has type %s, expected complex type", x.typ)
+ return
+ }
+
+ // if the argument is a constant, the result is a constant
+ if x.mode == constant_ {
+ if id == _Real {
+ x.val = constant.Real(x.val)
+ } else {
+ x.val = constant.Imag(x.val)
+ }
+ } else {
+ x.mode = value
+ }
+
+ // determine result type
+ var res BasicKind
+ switch x.typ.Underlying().(*Basic).kind {
+ case Complex64:
+ res = Float32
+ case Complex128:
+ res = Float64
+ case UntypedComplex:
+ res = UntypedFloat
+ default:
+ unreachable()
+ }
+ resTyp := Typ[res]
+
+ if check.Types != nil && x.mode != constant_ {
+ check.recordBuiltinType(call.Fun, makeSig(resTyp, x.typ))
+ }
+
+ x.typ = resTyp
+
+ case _Make:
+ // make(T, n)
+ // make(T, n, m)
+ // (no argument evaluated yet)
+ arg0 := call.Args[0]
+ T := check.typ(arg0)
+ if T == Typ[Invalid] {
+ return
+ }
+
+ var min int // minimum number of arguments
+ switch T.Underlying().(type) {
+ case *Slice:
+ min = 2
+ case *Map, *Chan:
+ min = 1
+ default:
+ check.invalidArg(arg0, _InvalidMake, "cannot make %s; type must be slice, map, or channel", arg0)
+ return
+ }
+ if nargs < min || min+1 < nargs {
+ check.errorf(call, _WrongArgCount, "%v expects %d or %d arguments; found %d", call, min, min+1, nargs)
+ return
+ }
+ types := []Type{T}
+ var sizes []int64 // constant integer arguments, if any
+ for _, arg := range call.Args[1:] {
+ typ, size := check.index(arg, -1) // ok to continue with typ == Typ[Invalid]
+ types = append(types, typ)
+ if size >= 0 {
+ sizes = append(sizes, size)
+ }
+ }
+ if len(sizes) == 2 && sizes[0] > sizes[1] {
+ check.invalidArg(call.Args[1], _SwappedMakeArgs, "length and capacity swapped")
+ // safe to continue
+ }
+ x.mode = value
+ x.typ = T
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(x.typ, types...))
+ }
+
+ case _New:
+ // new(T)
+ // (no argument evaluated yet)
+ T := check.typ(call.Args[0])
+ if T == Typ[Invalid] {
+ return
+ }
+
+ x.mode = value
+ x.typ = &Pointer{base: T}
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(x.typ, T))
+ }
+
+ case _Panic:
+ // panic(x)
+ // record panic call if inside a function with result parameters
+ // (for use in Checker.isTerminating)
+ if check.sig != nil && check.sig.results.Len() > 0 {
+ // function has result parameters
+ p := check.isPanic
+ if p == nil {
+ // allocate lazily
+ p = make(map[*ast.CallExpr]bool)
+ check.isPanic = p
+ }
+ p[call] = true
+ }
+
+ check.assignment(x, &emptyInterface, "argument to panic")
+ if x.mode == invalid {
+ return
+ }
+
+ x.mode = novalue
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(nil, &emptyInterface))
+ }
+
+ case _Print, _Println:
+ // print(x, y, ...)
+ // println(x, y, ...)
+ var params []Type
+ if nargs > 0 {
+ params = make([]Type, nargs)
+ for i := 0; i < nargs; i++ {
+ if i > 0 {
+ arg(x, i) // first argument already evaluated
+ }
+ check.assignment(x, nil, "argument to "+predeclaredFuncs[id].name)
+ if x.mode == invalid {
+ // TODO(gri) "use" all arguments?
+ return
+ }
+ params[i] = x.typ
+ }
+ }
+
+ x.mode = novalue
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(nil, params...))
+ }
+
+ case _Recover:
+ // recover() interface{}
+ x.mode = value
+ x.typ = &emptyInterface
+ if check.Types != nil {
+ check.recordBuiltinType(call.Fun, makeSig(x.typ))
+ }
+
+ case _Alignof:
+ // unsafe.Alignof(x T) uintptr
+ check.assignment(x, nil, "argument to unsafe.Alignof")
+ if x.mode == invalid {
+ return
+ }
+
+ x.mode = constant_
+ x.val = constant.MakeInt64(check.conf.alignof(x.typ))
+ x.typ = Typ[Uintptr]
+ // result is constant - no need to record signature
+
+ case _Offsetof:
+ // unsafe.Offsetof(x T) uintptr, where x must be a selector
+ // (no argument evaluated yet)
+ arg0 := call.Args[0]
+ selx, _ := unparen(arg0).(*ast.SelectorExpr)
+ if selx == nil {
+ check.invalidArg(arg0, _BadOffsetofSyntax, "%s is not a selector expression", arg0)
+ check.use(arg0)
+ return
+ }
+
+ check.expr(x, selx.X)
+ if x.mode == invalid {
+ return
+ }
+
+ base := derefStructPtr(x.typ)
+ sel := selx.Sel.Name
+ obj, index, indirect := check.lookupFieldOrMethod(base, false, check.pkg, sel)
+ switch obj.(type) {
+ case nil:
+ check.invalidArg(x, _MissingFieldOrMethod, "%s has no single field %s", base, sel)
+ return
+ case *Func:
+ // TODO(gri) Using derefStructPtr may result in methods being found
+ // that don't actually exist. An error either way, but the error
+ // message is confusing. See: https://play.golang.org/p/al75v23kUy ,
+ // but go/types reports: "invalid argument: x.m is a method value".
+ check.invalidArg(arg0, _InvalidOffsetof, "%s is a method value", arg0)
+ return
+ }
+ if indirect {
+ check.invalidArg(x, _InvalidOffsetof, "field %s is embedded via a pointer in %s", sel, base)
+ return
+ }
+
+ // TODO(gri) Should we pass x.typ instead of base (and indirect report if derefStructPtr indirected)?
+ check.recordSelection(selx, FieldVal, base, obj, index, false)
+
+ offs := check.conf.offsetof(base, index)
+ x.mode = constant_
+ x.val = constant.MakeInt64(offs)
+ x.typ = Typ[Uintptr]
+ // result is constant - no need to record signature
+
+ case _Sizeof:
+ // unsafe.Sizeof(x T) uintptr
+ check.assignment(x, nil, "argument to unsafe.Sizeof")
+ if x.mode == invalid {
+ return
+ }
+
+ x.mode = constant_
+ x.val = constant.MakeInt64(check.conf.sizeof(x.typ))
+ x.typ = Typ[Uintptr]
+ // result is constant - no need to record signature
+
+ case _Assert:
+ // assert(pred) causes a typechecker error if pred is false.
+ // The result of assert is the value of pred if there is no error.
+ // Note: assert is only available in self-test mode.
+ if x.mode != constant_ || !isBoolean(x.typ) {
+ check.invalidArg(x, _Test, "%s is not a boolean constant", x)
+ return
+ }
+ if x.val.Kind() != constant.Bool {
+ check.errorf(x, _Test, "internal error: value of %s should be a boolean constant", x)
+ return
+ }
+ if !constant.BoolVal(x.val) {
+ check.errorf(call, _Test, "%v failed", call)
+ // compile-time assertion failure - safe to continue
+ }
+ // result is constant - no need to record signature
+
+ case _Trace:
+ // trace(x, y, z, ...) dumps the positions, expressions, and
+ // values of its arguments. The result of trace is the value
+ // of the first argument.
+ // Note: trace is only available in self-test mode.
+ // (no argument evaluated yet)
+ if nargs == 0 {
+ check.dump("%v: trace() without arguments", call.Pos())
+ x.mode = novalue
+ break
+ }
+ var t operand
+ x1 := x
+ for _, arg := range call.Args {
+ check.rawExpr(x1, arg, nil) // permit trace for types, e.g.: new(trace(T))
+ check.dump("%v: %s", x1.Pos(), x1)
+ x1 = &t // use incoming x only for first argument
+ }
+ // trace is only available in test mode - no need to record signature
+
+ default:
+ unreachable()
+ }
+
+ return true
+}
+
+// makeSig makes a signature for the given argument and result types.
+// Default types are used for untyped arguments, and res may be nil.
+func makeSig(res Type, args ...Type) *Signature {
+ list := make([]*Var, len(args))
+ for i, param := range args {
+ list[i] = NewVar(token.NoPos, nil, "", Default(param))
+ }
+ params := NewTuple(list...)
+ var result *Tuple
+ if res != nil {
+ assert(!isUntyped(res))
+ result = NewTuple(NewVar(token.NoPos, nil, "", res))
+ }
+ return &Signature{params: params, results: result}
+}
+
+// implicitArrayDeref returns A if typ is of the form *A and A is an array;
+// otherwise it returns typ.
+//
+func implicitArrayDeref(typ Type) Type {
+ if p, ok := typ.(*Pointer); ok {
+ if a, ok := p.base.Underlying().(*Array); ok {
+ return a
+ }
+ }
+ return typ
+}
+
+// unparen returns e with any enclosing parentheses stripped.
+func unparen(e ast.Expr) ast.Expr {
+ for {
+ p, ok := e.(*ast.ParenExpr)
+ if !ok {
+ return e
+ }
+ e = p.X
+ }
+}
diff --git a/src/go/types/builtins_test.go b/src/go/types/builtins_test.go
new file mode 100644
index 0000000..cfd19d5
--- /dev/null
+++ b/src/go/types/builtins_test.go
@@ -0,0 +1,220 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "testing"
+
+ . "go/types"
+)
+
+var builtinCalls = []struct {
+ name, src, sig string
+}{
+ {"append", `var s []int; _ = append(s)`, `func([]int, ...int) []int`},
+ {"append", `var s []int; _ = append(s, 0)`, `func([]int, ...int) []int`},
+ {"append", `var s []int; _ = (append)(s, 0)`, `func([]int, ...int) []int`},
+ {"append", `var s []byte; _ = ((append))(s, 0)`, `func([]byte, ...byte) []byte`},
+ {"append", `var s []byte; _ = append(s, "foo"...)`, `func([]byte, string...) []byte`},
+ {"append", `type T []byte; var s T; var str string; _ = append(s, str...)`, `func(p.T, string...) p.T`},
+ {"append", `type T []byte; type U string; var s T; var str U; _ = append(s, str...)`, `func(p.T, p.U...) p.T`},
+
+ {"cap", `var s [10]int; _ = cap(s)`, `invalid type`}, // constant
+ {"cap", `var s [10]int; _ = cap(&s)`, `invalid type`}, // constant
+ {"cap", `var s []int64; _ = cap(s)`, `func([]int64) int`},
+ {"cap", `var c chan<-bool; _ = cap(c)`, `func(chan<- bool) int`},
+
+ {"len", `_ = len("foo")`, `invalid type`}, // constant
+ {"len", `var s string; _ = len(s)`, `func(string) int`},
+ {"len", `var s [10]int; _ = len(s)`, `invalid type`}, // constant
+ {"len", `var s [10]int; _ = len(&s)`, `invalid type`}, // constant
+ {"len", `var s []int64; _ = len(s)`, `func([]int64) int`},
+ {"len", `var c chan<-bool; _ = len(c)`, `func(chan<- bool) int`},
+ {"len", `var m map[string]float32; _ = len(m)`, `func(map[string]float32) int`},
+
+ {"close", `var c chan int; close(c)`, `func(chan int)`},
+ {"close", `var c chan<- chan string; close(c)`, `func(chan<- chan string)`},
+
+ {"complex", `_ = complex(1, 0)`, `invalid type`}, // constant
+ {"complex", `var re float32; _ = complex(re, 1.0)`, `func(float32, float32) complex64`},
+ {"complex", `var im float64; _ = complex(1, im)`, `func(float64, float64) complex128`},
+ {"complex", `type F32 float32; var re, im F32; _ = complex(re, im)`, `func(p.F32, p.F32) complex64`},
+ {"complex", `type F64 float64; var re, im F64; _ = complex(re, im)`, `func(p.F64, p.F64) complex128`},
+
+ {"copy", `var src, dst []byte; copy(dst, src)`, `func([]byte, []byte) int`},
+ {"copy", `type T [][]int; var src, dst T; _ = copy(dst, src)`, `func(p.T, p.T) int`},
+ {"copy", `var src string; var dst []byte; copy(dst, src)`, `func([]byte, string) int`},
+ {"copy", `type T string; type U []byte; var src T; var dst U; copy(dst, src)`, `func(p.U, p.T) int`},
+ {"copy", `var dst []byte; copy(dst, "hello")`, `func([]byte, string) int`},
+
+ {"delete", `var m map[string]bool; delete(m, "foo")`, `func(map[string]bool, string)`},
+ {"delete", `type (K string; V int); var m map[K]V; delete(m, "foo")`, `func(map[p.K]p.V, p.K)`},
+
+ {"imag", `_ = imag(1i)`, `invalid type`}, // constant
+ {"imag", `var c complex64; _ = imag(c)`, `func(complex64) float32`},
+ {"imag", `var c complex128; _ = imag(c)`, `func(complex128) float64`},
+ {"imag", `type C64 complex64; var c C64; _ = imag(c)`, `func(p.C64) float32`},
+ {"imag", `type C128 complex128; var c C128; _ = imag(c)`, `func(p.C128) float64`},
+
+ {"real", `_ = real(1i)`, `invalid type`}, // constant
+ {"real", `var c complex64; _ = real(c)`, `func(complex64) float32`},
+ {"real", `var c complex128; _ = real(c)`, `func(complex128) float64`},
+ {"real", `type C64 complex64; var c C64; _ = real(c)`, `func(p.C64) float32`},
+ {"real", `type C128 complex128; var c C128; _ = real(c)`, `func(p.C128) float64`},
+
+ {"make", `_ = make([]int, 10)`, `func([]int, int) []int`},
+ {"make", `type T []byte; _ = make(T, 10, 20)`, `func(p.T, int, int) p.T`},
+
+ // issue #37349
+ {"make", ` _ = make([]int, 0 )`, `func([]int, int) []int`},
+ {"make", `var l int; _ = make([]int, l )`, `func([]int, int) []int`},
+ {"make", ` _ = make([]int, 0, 0)`, `func([]int, int, int) []int`},
+ {"make", `var l int; _ = make([]int, l, 0)`, `func([]int, int, int) []int`},
+ {"make", `var c int; _ = make([]int, 0, c)`, `func([]int, int, int) []int`},
+ {"make", `var l, c int; _ = make([]int, l, c)`, `func([]int, int, int) []int`},
+
+ // issue #37393
+ {"make", ` _ = make([]int , 0 )`, `func([]int, int) []int`},
+ {"make", `var l byte ; _ = make([]int8 , l )`, `func([]int8, byte) []int8`},
+ {"make", ` _ = make([]int16 , 0, 0)`, `func([]int16, int, int) []int16`},
+ {"make", `var l int16; _ = make([]string , l, 0)`, `func([]string, int16, int) []string`},
+ {"make", `var c int32; _ = make([]float64 , 0, c)`, `func([]float64, int, int32) []float64`},
+ {"make", `var l, c uint ; _ = make([]complex128, l, c)`, `func([]complex128, uint, uint) []complex128`},
+
+ {"new", `_ = new(int)`, `func(int) *int`},
+ {"new", `type T struct{}; _ = new(T)`, `func(p.T) *p.T`},
+
+ {"panic", `panic(0)`, `func(interface{})`},
+ {"panic", `panic("foo")`, `func(interface{})`},
+
+ {"print", `print()`, `func()`},
+ {"print", `print(0)`, `func(int)`},
+ {"print", `print(1, 2.0, "foo", true)`, `func(int, float64, string, bool)`},
+
+ {"println", `println()`, `func()`},
+ {"println", `println(0)`, `func(int)`},
+ {"println", `println(1, 2.0, "foo", true)`, `func(int, float64, string, bool)`},
+
+ {"recover", `recover()`, `func() interface{}`},
+ {"recover", `_ = recover()`, `func() interface{}`},
+
+ {"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`}, // constant
+ {"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
+
+ {"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`}, // constant
+ {"Offsetof", `var x struct{_ int; f bool}; _ = unsafe.Offsetof((&x).f)`, `invalid type`}, // constant
+
+ {"Sizeof", `_ = unsafe.Sizeof(0)`, `invalid type`}, // constant
+ {"Sizeof", `var x struct{}; _ = unsafe.Sizeof(x)`, `invalid type`}, // constant
+
+ {"assert", `assert(true)`, `invalid type`}, // constant
+ {"assert", `type B bool; const pred B = 1 < 2; assert(pred)`, `invalid type`}, // constant
+
+ // no tests for trace since it produces output as a side-effect
+}
+
+func TestBuiltinSignatures(t *testing.T) {
+ DefPredeclaredTestFuncs()
+
+ seen := map[string]bool{"trace": true} // no test for trace built-in; add it manually
+ for _, call := range builtinCalls {
+ testBuiltinSignature(t, call.name, call.src, call.sig)
+ seen[call.name] = true
+ }
+
+ // make sure we didn't miss one
+ for _, name := range Universe.Names() {
+ if _, ok := Universe.Lookup(name).(*Builtin); ok && !seen[name] {
+ t.Errorf("missing test for %s", name)
+ }
+ }
+ for _, name := range Unsafe.Scope().Names() {
+ if _, ok := Unsafe.Scope().Lookup(name).(*Builtin); ok && !seen[name] {
+ t.Errorf("missing test for unsafe.%s", name)
+ }
+ }
+}
+
+func testBuiltinSignature(t *testing.T, name, src0, want string) {
+ src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _() { %s }`, src0)
+ f, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ t.Errorf("%s: %s", src0, err)
+ return
+ }
+
+ conf := Config{Importer: importer.Default()}
+ uses := make(map[*ast.Ident]Object)
+ types := make(map[ast.Expr]TypeAndValue)
+ _, err = conf.Check(f.Name.Name, fset, []*ast.File{f}, &Info{Uses: uses, Types: types})
+ if err != nil {
+ t.Errorf("%s: %s", src0, err)
+ return
+ }
+
+ // find called function
+ n := 0
+ var fun ast.Expr
+ for x := range types {
+ if call, _ := x.(*ast.CallExpr); call != nil {
+ fun = call.Fun
+ n++
+ }
+ }
+ if n != 1 {
+ t.Errorf("%s: got %d CallExprs; want 1", src0, n)
+ return
+ }
+
+ // check recorded types for fun and descendents (may be parenthesized)
+ for {
+ // the recorded type for the built-in must match the wanted signature
+ typ := types[fun].Type
+ if typ == nil {
+ t.Errorf("%s: no type recorded for %s", src0, ExprString(fun))
+ return
+ }
+ if got := typ.String(); got != want {
+ t.Errorf("%s: got type %s; want %s", src0, got, want)
+ return
+ }
+
+ // called function must be a (possibly parenthesized, qualified)
+ // identifier denoting the expected built-in
+ switch p := fun.(type) {
+ case *ast.Ident:
+ obj := uses[p]
+ if obj == nil {
+ t.Errorf("%s: no object found for %s", src0, p)
+ return
+ }
+ bin, _ := obj.(*Builtin)
+ if bin == nil {
+ t.Errorf("%s: %s does not denote a built-in", src0, p)
+ return
+ }
+ if bin.Name() != name {
+ t.Errorf("%s: got built-in %s; want %s", src0, bin.Name(), name)
+ return
+ }
+ return // we're done
+
+ case *ast.ParenExpr:
+ fun = p.X // unpack
+
+ case *ast.SelectorExpr:
+ // built-in from package unsafe - ignore details
+ return // we're done
+
+ default:
+ t.Errorf("%s: invalid function call", src0)
+ return
+ }
+ }
+}
diff --git a/src/go/types/call.go b/src/go/types/call.go
new file mode 100644
index 0000000..6765b17
--- /dev/null
+++ b/src/go/types/call.go
@@ -0,0 +1,569 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements typechecking of call and selector expressions.
+
+package types
+
+import (
+ "go/ast"
+ "go/token"
+ "strings"
+ "unicode"
+)
+
+func (check *Checker) call(x *operand, e *ast.CallExpr) exprKind {
+ check.exprOrType(x, e.Fun)
+
+ switch x.mode {
+ case invalid:
+ check.use(e.Args...)
+ x.mode = invalid
+ x.expr = e
+ return statement
+
+ case typexpr:
+ // conversion
+ T := x.typ
+ x.mode = invalid
+ switch n := len(e.Args); n {
+ case 0:
+ check.errorf(inNode(e, e.Rparen), _WrongArgCount, "missing argument in conversion to %s", T)
+ case 1:
+ check.expr(x, e.Args[0])
+ if x.mode != invalid {
+ if e.Ellipsis.IsValid() {
+ check.errorf(e.Args[0], _BadDotDotDotSyntax, "invalid use of ... in conversion to %s", T)
+ break
+ }
+ check.conversion(x, T)
+ }
+ default:
+ check.use(e.Args...)
+ check.errorf(e.Args[n-1], _WrongArgCount, "too many arguments in conversion to %s", T)
+ }
+ x.expr = e
+ return conversion
+
+ case builtin:
+ id := x.id
+ if !check.builtin(x, e, id) {
+ x.mode = invalid
+ }
+ x.expr = e
+ // a non-constant result implies a function call
+ if x.mode != invalid && x.mode != constant_ {
+ check.hasCallOrRecv = true
+ }
+ return predeclaredFuncs[id].kind
+
+ default:
+ // function/method call
+ cgocall := x.mode == cgofunc
+
+ sig, _ := x.typ.Underlying().(*Signature)
+ if sig == nil {
+ check.invalidOp(x, _InvalidCall, "cannot call non-function %s", x)
+ x.mode = invalid
+ x.expr = e
+ return statement
+ }
+
+ arg, n, _ := unpack(func(x *operand, i int) { check.multiExpr(x, e.Args[i]) }, len(e.Args), false)
+ if arg != nil {
+ check.arguments(x, e, sig, arg, n)
+ } else {
+ x.mode = invalid
+ }
+
+ // determine result
+ switch sig.results.Len() {
+ case 0:
+ x.mode = novalue
+ case 1:
+ if cgocall {
+ x.mode = commaerr
+ } else {
+ x.mode = value
+ }
+ x.typ = sig.results.vars[0].typ // unpack tuple
+ default:
+ x.mode = value
+ x.typ = sig.results
+ }
+
+ x.expr = e
+ check.hasCallOrRecv = true
+
+ return statement
+ }
+}
+
+// use type-checks each argument.
+// Useful to make sure expressions are evaluated
+// (and variables are "used") in the presence of other errors.
+// The arguments may be nil.
+func (check *Checker) use(arg ...ast.Expr) {
+ var x operand
+ for _, e := range arg {
+ // The nil check below is necessary since certain AST fields
+ // may legally be nil (e.g., the ast.SliceExpr.High field).
+ if e != nil {
+ check.rawExpr(&x, e, nil)
+ }
+ }
+}
+
+// useLHS is like use, but doesn't "use" top-level identifiers.
+// It should be called instead of use if the arguments are
+// expressions on the lhs of an assignment.
+// The arguments must not be nil.
+func (check *Checker) useLHS(arg ...ast.Expr) {
+ var x operand
+ for _, e := range arg {
+ // If the lhs is an identifier denoting a variable v, this assignment
+ // is not a 'use' of v. Remember current value of v.used and restore
+ // after evaluating the lhs via check.rawExpr.
+ var v *Var
+ var v_used bool
+ if ident, _ := unparen(e).(*ast.Ident); ident != nil {
+ // never type-check the blank name on the lhs
+ if ident.Name == "_" {
+ continue
+ }
+ if _, obj := check.scope.LookupParent(ident.Name, token.NoPos); obj != nil {
+ // It's ok to mark non-local variables, but ignore variables
+ // from other packages to avoid potential race conditions with
+ // dot-imported variables.
+ if w, _ := obj.(*Var); w != nil && w.pkg == check.pkg {
+ v = w
+ v_used = v.used
+ }
+ }
+ }
+ check.rawExpr(&x, e, nil)
+ if v != nil {
+ v.used = v_used // restore v.used
+ }
+ }
+}
+
+// useGetter is like use, but takes a getter instead of a list of expressions.
+// It should be called instead of use if a getter is present to avoid repeated
+// evaluation of the first argument (since the getter was likely obtained via
+// unpack, which may have evaluated the first argument already).
+func (check *Checker) useGetter(get getter, n int) {
+ var x operand
+ for i := 0; i < n; i++ {
+ get(&x, i)
+ }
+}
+
+// A getter sets x as the i'th operand, where 0 <= i < n and n is the total
+// number of operands (context-specific, and maintained elsewhere). A getter
+// type-checks the i'th operand; the details of the actual check are getter-
+// specific.
+type getter func(x *operand, i int)
+
+// unpack takes a getter get and a number of operands n. If n == 1, unpack
+// calls the incoming getter for the first operand. If that operand is
+// invalid, unpack returns (nil, 0, false). Otherwise, if that operand is a
+// function call, or a comma-ok expression and allowCommaOk is set, the result
+// is a new getter and operand count providing access to the function results,
+// or comma-ok values, respectively. The third result value reports if it
+// is indeed the comma-ok case. In all other cases, the incoming getter and
+// operand count are returned unchanged, and the third result value is false.
+//
+// In other words, if there's exactly one operand that - after type-checking
+// by calling get - stands for multiple operands, the resulting getter provides
+// access to those operands instead.
+//
+// If the returned getter is called at most once for a given operand index i
+// (including i == 0), that operand is guaranteed to cause only one call of
+// the incoming getter with that i.
+//
+func unpack(get getter, n int, allowCommaOk bool) (getter, int, bool) {
+ if n != 1 {
+ // zero or multiple values
+ return get, n, false
+ }
+ // possibly result of an n-valued function call or comma,ok value
+ var x0 operand
+ get(&x0, 0)
+ if x0.mode == invalid {
+ return nil, 0, false
+ }
+
+ if t, ok := x0.typ.(*Tuple); ok {
+ // result of an n-valued function call
+ return func(x *operand, i int) {
+ x.mode = value
+ x.expr = x0.expr
+ x.typ = t.At(i).typ
+ }, t.Len(), false
+ }
+
+ if x0.mode == mapindex || x0.mode == commaok || x0.mode == commaerr {
+ // comma-ok value
+ if allowCommaOk {
+ a := [2]Type{x0.typ, Typ[UntypedBool]}
+ if x0.mode == commaerr {
+ a[1] = universeError
+ }
+ return func(x *operand, i int) {
+ x.mode = value
+ x.expr = x0.expr
+ x.typ = a[i]
+ }, 2, true
+ }
+ x0.mode = value
+ }
+
+ // single value
+ return func(x *operand, i int) {
+ if i != 0 {
+ unreachable()
+ }
+ *x = x0
+ }, 1, false
+}
+
+// arguments checks argument passing for the call with the given signature.
+// The arg function provides the operand for the i'th argument.
+func (check *Checker) arguments(x *operand, call *ast.CallExpr, sig *Signature, arg getter, n int) {
+ if call.Ellipsis.IsValid() {
+ // last argument is of the form x...
+ if !sig.variadic {
+ check.errorf(atPos(call.Ellipsis), _NonVariadicDotDotDot, "cannot use ... in call to non-variadic %s", call.Fun)
+ check.useGetter(arg, n)
+ return
+ }
+ if len(call.Args) == 1 && n > 1 {
+ // f()... is not permitted if f() is multi-valued
+ check.errorf(atPos(call.Ellipsis), _InvalidDotDotDotOperand, "cannot use ... with %d-valued %s", n, call.Args[0])
+ check.useGetter(arg, n)
+ return
+ }
+ }
+
+ // evaluate arguments
+ context := check.sprintf("argument to %s", call.Fun)
+ for i := 0; i < n; i++ {
+ arg(x, i)
+ if x.mode != invalid {
+ var ellipsis token.Pos
+ if i == n-1 && call.Ellipsis.IsValid() {
+ ellipsis = call.Ellipsis
+ }
+ check.argument(sig, i, x, ellipsis, context)
+ }
+ }
+
+ // check argument count
+ if sig.variadic {
+ // a variadic function accepts an "empty"
+ // last argument: count one extra
+ n++
+ }
+ if n < sig.params.Len() {
+ check.errorf(inNode(call, call.Rparen), _WrongArgCount, "too few arguments in call to %s", call.Fun)
+ // ok to continue
+ }
+}
+
+// argument checks passing of argument x to the i'th parameter of the given signature.
+// If ellipsis is valid, the argument is followed by ... at that position in the call.
+func (check *Checker) argument(sig *Signature, i int, x *operand, ellipsis token.Pos, context string) {
+ check.singleValue(x)
+ if x.mode == invalid {
+ return
+ }
+
+ n := sig.params.Len()
+
+ // determine parameter type
+ var typ Type
+ switch {
+ case i < n:
+ typ = sig.params.vars[i].typ
+ case sig.variadic:
+ typ = sig.params.vars[n-1].typ
+ if debug {
+ if _, ok := typ.(*Slice); !ok {
+ check.dump("%v: expected unnamed slice type, got %s", sig.params.vars[n-1].Pos(), typ)
+ }
+ }
+ default:
+ check.errorf(x, _WrongArgCount, "too many arguments")
+ return
+ }
+
+ if ellipsis.IsValid() {
+ if i != n-1 {
+ check.errorf(atPos(ellipsis), _MisplacedDotDotDot, "can only use ... with matching parameter")
+ return
+ }
+ // argument is of the form x... and x is single-valued
+ if _, ok := x.typ.Underlying().(*Slice); !ok && x.typ != Typ[UntypedNil] { // see issue #18268
+ check.errorf(x, _InvalidDotDotDotOperand, "cannot use %s as parameter of type %s", x, typ)
+ return
+ }
+ } else if sig.variadic && i >= n-1 {
+ // use the variadic parameter slice's element type
+ typ = typ.(*Slice).elem
+ }
+
+ check.assignment(x, typ, context)
+}
+
+var cgoPrefixes = [...]string{
+ "_Ciconst_",
+ "_Cfconst_",
+ "_Csconst_",
+ "_Ctype_",
+ "_Cvar_", // actually a pointer to the var
+ "_Cfpvar_fp_",
+ "_Cfunc_",
+ "_Cmacro_", // function to evaluate the expanded expression
+}
+
+func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
+ // these must be declared before the "goto Error" statements
+ var (
+ obj Object
+ index []int
+ indirect bool
+ )
+
+ sel := e.Sel.Name
+ // If the identifier refers to a package, handle everything here
+ // so we don't need a "package" mode for operands: package names
+ // can only appear in qualified identifiers which are mapped to
+ // selector expressions.
+ if ident, ok := e.X.(*ast.Ident); ok {
+ obj := check.lookup(ident.Name)
+ if pname, _ := obj.(*PkgName); pname != nil {
+ assert(pname.pkg == check.pkg)
+ check.recordUse(ident, pname)
+ pname.used = true
+ pkg := pname.imported
+
+ var exp Object
+ funcMode := value
+ if pkg.cgo {
+ // cgo special cases C.malloc: it's
+ // rewritten to _CMalloc and does not
+ // support two-result calls.
+ if sel == "malloc" {
+ sel = "_CMalloc"
+ } else {
+ funcMode = cgofunc
+ }
+ for _, prefix := range cgoPrefixes {
+ // cgo objects are part of the current package (in file
+ // _cgo_gotypes.go). Use regular lookup.
+ _, exp = check.scope.LookupParent(prefix+sel, check.pos)
+ if exp != nil {
+ break
+ }
+ }
+ if exp == nil {
+ check.errorf(e.Sel, _UndeclaredImportedName, "%s not declared by package C", sel)
+ goto Error
+ }
+ check.objDecl(exp, nil)
+ } else {
+ exp = pkg.scope.Lookup(sel)
+ if exp == nil {
+ if !pkg.fake {
+ check.errorf(e.Sel, _UndeclaredImportedName, "%s not declared by package %s", sel, pkg.name)
+ }
+ goto Error
+ }
+ if !exp.Exported() {
+ check.errorf(e.Sel, _UnexportedName, "%s not exported by package %s", sel, pkg.name)
+ // ok to continue
+ }
+ }
+ check.recordUse(e.Sel, exp)
+
+ // Simplified version of the code for *ast.Idents:
+ // - imported objects are always fully initialized
+ switch exp := exp.(type) {
+ case *Const:
+ assert(exp.Val() != nil)
+ x.mode = constant_
+ x.typ = exp.typ
+ x.val = exp.val
+ case *TypeName:
+ x.mode = typexpr
+ x.typ = exp.typ
+ case *Var:
+ x.mode = variable
+ x.typ = exp.typ
+ if pkg.cgo && strings.HasPrefix(exp.name, "_Cvar_") {
+ x.typ = x.typ.(*Pointer).base
+ }
+ case *Func:
+ x.mode = funcMode
+ x.typ = exp.typ
+ if pkg.cgo && strings.HasPrefix(exp.name, "_Cmacro_") {
+ x.mode = value
+ x.typ = x.typ.(*Signature).results.vars[0].typ
+ }
+ case *Builtin:
+ x.mode = builtin
+ x.typ = exp.typ
+ x.id = exp.id
+ default:
+ check.dump("unexpected object %v", exp)
+ unreachable()
+ }
+ x.expr = e
+ return
+ }
+ }
+
+ check.exprOrType(x, e.X)
+ if x.mode == invalid {
+ goto Error
+ }
+
+ obj, index, indirect = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel)
+ if obj == nil {
+ switch {
+ case index != nil:
+ // TODO(gri) should provide actual type where the conflict happens
+ check.errorf(e.Sel, _AmbiguousSelector, "ambiguous selector %s.%s", x.expr, sel)
+ case indirect:
+ check.errorf(e.Sel, _InvalidMethodExpr, "cannot call pointer method %s on %s", sel, x.typ)
+ default:
+ // Check if capitalization of sel matters and provide better error
+ // message in that case.
+ if len(sel) > 0 {
+ var changeCase string
+ if r := rune(sel[0]); unicode.IsUpper(r) {
+ changeCase = string(unicode.ToLower(r)) + sel[1:]
+ } else {
+ changeCase = string(unicode.ToUpper(r)) + sel[1:]
+ }
+ if obj, _, _ = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, changeCase); obj != nil {
+ check.errorf(e.Sel, _MissingFieldOrMethod, "%s.%s undefined (type %s has no field or method %s, but does have %s)", x.expr, sel, x.typ, sel, changeCase)
+ break
+ }
+ }
+ check.errorf(e.Sel, _MissingFieldOrMethod, "%s.%s undefined (type %s has no field or method %s)", x.expr, sel, x.typ, sel)
+ }
+ goto Error
+ }
+
+ // methods may not have a fully set up signature yet
+ if m, _ := obj.(*Func); m != nil {
+ check.objDecl(m, nil)
+ }
+
+ if x.mode == typexpr {
+ // method expression
+ m, _ := obj.(*Func)
+ if m == nil {
+ // TODO(gri) should check if capitalization of sel matters and provide better error message in that case
+ check.errorf(e.Sel, _MissingFieldOrMethod, "%s.%s undefined (type %s has no method %s)", x.expr, sel, x.typ, sel)
+ goto Error
+ }
+
+ check.recordSelection(e, MethodExpr, x.typ, m, index, indirect)
+
+ // the receiver type becomes the type of the first function
+ // argument of the method expression's function type
+ var params []*Var
+ sig := m.typ.(*Signature)
+ if sig.params != nil {
+ params = sig.params.vars
+ }
+ x.mode = value
+ x.typ = &Signature{
+ params: NewTuple(append([]*Var{NewVar(token.NoPos, check.pkg, "", x.typ)}, params...)...),
+ results: sig.results,
+ variadic: sig.variadic,
+ }
+
+ check.addDeclDep(m)
+
+ } else {
+ // regular selector
+ switch obj := obj.(type) {
+ case *Var:
+ check.recordSelection(e, FieldVal, x.typ, obj, index, indirect)
+ if x.mode == variable || indirect {
+ x.mode = variable
+ } else {
+ x.mode = value
+ }
+ x.typ = obj.typ
+
+ case *Func:
+ // TODO(gri) If we needed to take into account the receiver's
+ // addressability, should we report the type &(x.typ) instead?
+ check.recordSelection(e, MethodVal, x.typ, obj, index, indirect)
+
+ if debug {
+ // Verify that LookupFieldOrMethod and MethodSet.Lookup agree.
+ // TODO(gri) This only works because we call LookupFieldOrMethod
+ // _before_ calling NewMethodSet: LookupFieldOrMethod completes
+ // any incomplete interfaces so they are available to NewMethodSet
+ // (which assumes that interfaces have been completed already).
+ typ := x.typ
+ if x.mode == variable {
+ // If typ is not an (unnamed) pointer or an interface,
+ // use *typ instead, because the method set of *typ
+ // includes the methods of typ.
+ // Variables are addressable, so we can always take their
+ // address.
+ if _, ok := typ.(*Pointer); !ok && !IsInterface(typ) {
+ typ = &Pointer{base: typ}
+ }
+ }
+ // If we created a synthetic pointer type above, we will throw
+ // away the method set computed here after use.
+ // TODO(gri) Method set computation should probably always compute
+ // both, the value and the pointer receiver method set and represent
+ // them in a single structure.
+ // TODO(gri) Consider also using a method set cache for the lifetime
+ // of checker once we rely on MethodSet lookup instead of individual
+ // lookup.
+ mset := NewMethodSet(typ)
+ if m := mset.Lookup(check.pkg, sel); m == nil || m.obj != obj {
+ check.dump("%v: (%s).%v -> %s", e.Pos(), typ, obj.name, m)
+ check.dump("%s\n", mset)
+ // Caution: MethodSets are supposed to be used externally
+ // only (after all interface types were completed). It's
+ // now possible that we get here incorrectly. Not urgent
+ // to fix since we only run this code in debug mode.
+ // TODO(gri) fix this eventually.
+ panic("method sets and lookup don't agree")
+ }
+ }
+
+ x.mode = value
+
+ // remove receiver
+ sig := *obj.typ.(*Signature)
+ sig.recv = nil
+ x.typ = &sig
+
+ check.addDeclDep(obj)
+
+ default:
+ unreachable()
+ }
+ }
+
+ // everything went well
+ x.expr = e
+ return
+
+Error:
+ x.mode = invalid
+ x.expr = e
+}
diff --git a/src/go/types/check.go b/src/go/types/check.go
new file mode 100644
index 0000000..280792e
--- /dev/null
+++ b/src/go/types/check.go
@@ -0,0 +1,417 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements the Check function, which drives type-checking.
+
+package types
+
+import (
+ "errors"
+ "go/ast"
+ "go/constant"
+ "go/token"
+)
+
+// debugging/development support
+const (
+ debug = false // leave on during development
+ trace = false // turn on for detailed type resolution traces
+)
+
+// If Strict is set, the type-checker enforces additional
+// rules not specified by the Go 1 spec, but which will
+// catch guaranteed run-time errors if the respective
+// code is executed. In other words, programs passing in
+// Strict mode are Go 1 compliant, but not all Go 1 programs
+// will pass in Strict mode. The additional rules are:
+//
+// - A type assertion x.(T) where T is an interface type
+// is invalid if any (statically known) method that exists
+// for both x and T have different signatures.
+//
+const strict = false
+
+// exprInfo stores information about an untyped expression.
+type exprInfo struct {
+ isLhs bool // expression is lhs operand of a shift with delayed type-check
+ mode operandMode
+ typ *Basic
+ val constant.Value // constant value; or nil (if not a constant)
+}
+
+// A context represents the context within which an object is type-checked.
+type context struct {
+ decl *declInfo // package-level declaration whose init expression/function body is checked
+ scope *Scope // top-most scope for lookups
+ pos token.Pos // if valid, identifiers are looked up as if at position pos (used by Eval)
+ iota constant.Value // value of iota in a constant declaration; nil otherwise
+ errpos positioner // if set, identifier position of a constant with inherited initializer
+ sig *Signature // function signature if inside a function; nil otherwise
+ isPanic map[*ast.CallExpr]bool // set of panic call expressions (used for termination check)
+ hasLabel bool // set if a function makes use of labels (only ~1% of functions); unused outside functions
+ hasCallOrRecv bool // set if an expression contains a function call or channel receive operation
+}
+
+// lookup looks up name in the current context and returns the matching object, or nil.
+func (ctxt *context) lookup(name string) Object {
+ _, obj := ctxt.scope.LookupParent(name, ctxt.pos)
+ return obj
+}
+
+// An importKey identifies an imported package by import path and source directory
+// (directory containing the file containing the import). In practice, the directory
+// may always be the same, or may not matter. Given an (import path, directory), an
+// importer must always return the same package (but given two different import paths,
+// an importer may still return the same package by mapping them to the same package
+// paths).
+type importKey struct {
+ path, dir string
+}
+
+// A Checker maintains the state of the type checker.
+// It must be created with NewChecker.
+type Checker struct {
+ // package information
+ // (initialized by NewChecker, valid for the life-time of checker)
+ conf *Config
+ fset *token.FileSet
+ pkg *Package
+ *Info
+ objMap map[Object]*declInfo // maps package-level objects and (non-interface) methods to declaration info
+ impMap map[importKey]*Package // maps (import path, source directory) to (complete or fake) package
+ posMap map[*Interface][]token.Pos // maps interface types to lists of embedded interface positions
+ pkgCnt map[string]int // counts number of imported packages with a given name (for better error messages)
+
+ // information collected during type-checking of a set of package files
+ // (initialized by Files, valid only for the duration of check.Files;
+ // maps and lists are allocated on demand)
+ files []*ast.File // package files
+ unusedDotImports map[*Scope]map[*Package]*ast.ImportSpec // unused dot-imported packages
+
+ firstErr error // first error encountered
+ methods map[*TypeName][]*Func // maps package scope type names to associated non-blank (non-interface) methods
+ untyped map[ast.Expr]exprInfo // map of expressions without final type
+ delayed []func() // stack of delayed action segments; segments are processed in FIFO order
+ finals []func() // list of final actions; processed at the end of type-checking the current set of files
+ objPath []Object // path of object dependencies during type inference (for cycle reporting)
+
+ // context within which the current object is type-checked
+ // (valid only for the duration of type-checking a specific object)
+ context
+
+ // debugging
+ indent int // indentation for tracing
+}
+
+// addUnusedImport adds the position of a dot-imported package
+// pkg to the map of dot imports for the given file scope.
+func (check *Checker) addUnusedDotImport(scope *Scope, pkg *Package, spec *ast.ImportSpec) {
+ mm := check.unusedDotImports
+ if mm == nil {
+ mm = make(map[*Scope]map[*Package]*ast.ImportSpec)
+ check.unusedDotImports = mm
+ }
+ m := mm[scope]
+ if m == nil {
+ m = make(map[*Package]*ast.ImportSpec)
+ mm[scope] = m
+ }
+ m[pkg] = spec
+}
+
+// addDeclDep adds the dependency edge (check.decl -> to) if check.decl exists
+func (check *Checker) addDeclDep(to Object) {
+ from := check.decl
+ if from == nil {
+ return // not in a package-level init expression
+ }
+ if _, found := check.objMap[to]; !found {
+ return // to is not a package-level object
+ }
+ from.addDep(to)
+}
+
+func (check *Checker) rememberUntyped(e ast.Expr, lhs bool, mode operandMode, typ *Basic, val constant.Value) {
+ m := check.untyped
+ if m == nil {
+ m = make(map[ast.Expr]exprInfo)
+ check.untyped = m
+ }
+ m[e] = exprInfo{lhs, mode, typ, val}
+}
+
+// later pushes f on to the stack of actions that will be processed later;
+// either at the end of the current statement, or in case of a local constant
+// or variable declaration, before the constant or variable is in scope
+// (so that f still sees the scope before any new declarations).
+func (check *Checker) later(f func()) {
+ check.delayed = append(check.delayed, f)
+}
+
+// atEnd adds f to the list of actions processed at the end
+// of type-checking, before initialization order computation.
+// Actions added by atEnd are processed after any actions
+// added by later.
+func (check *Checker) atEnd(f func()) {
+ check.finals = append(check.finals, f)
+}
+
+// push pushes obj onto the object path and returns its index in the path.
+func (check *Checker) push(obj Object) int {
+ check.objPath = append(check.objPath, obj)
+ return len(check.objPath) - 1
+}
+
+// pop pops and returns the topmost object from the object path.
+func (check *Checker) pop() Object {
+ i := len(check.objPath) - 1
+ obj := check.objPath[i]
+ check.objPath[i] = nil
+ check.objPath = check.objPath[:i]
+ return obj
+}
+
+// NewChecker returns a new Checker instance for a given package.
+// Package files may be added incrementally via checker.Files.
+func NewChecker(conf *Config, fset *token.FileSet, pkg *Package, info *Info) *Checker {
+ // make sure we have a configuration
+ if conf == nil {
+ conf = new(Config)
+ }
+
+ // make sure we have an info struct
+ if info == nil {
+ info = new(Info)
+ }
+
+ return &Checker{
+ conf: conf,
+ fset: fset,
+ pkg: pkg,
+ Info: info,
+ objMap: make(map[Object]*declInfo),
+ impMap: make(map[importKey]*Package),
+ posMap: make(map[*Interface][]token.Pos),
+ pkgCnt: make(map[string]int),
+ }
+}
+
+// initFiles initializes the files-specific portion of checker.
+// The provided files must all belong to the same package.
+func (check *Checker) initFiles(files []*ast.File) {
+ // start with a clean slate (check.Files may be called multiple times)
+ check.files = nil
+ check.unusedDotImports = nil
+
+ check.firstErr = nil
+ check.methods = nil
+ check.untyped = nil
+ check.delayed = nil
+ check.finals = nil
+
+ // determine package name and collect valid files
+ pkg := check.pkg
+ for _, file := range files {
+ switch name := file.Name.Name; pkg.name {
+ case "":
+ if name != "_" {
+ pkg.name = name
+ } else {
+ check.errorf(file.Name, _BlankPkgName, "invalid package name _")
+ }
+ fallthrough
+
+ case name:
+ check.files = append(check.files, file)
+
+ default:
+ check.errorf(atPos(file.Package), _MismatchedPkgName, "package %s; expected %s", name, pkg.name)
+ // ignore this file
+ }
+ }
+}
+
+// A bailout panic is used for early termination.
+type bailout struct{}
+
+func (check *Checker) handleBailout(err *error) {
+ switch p := recover().(type) {
+ case nil, bailout:
+ // normal return or early exit
+ *err = check.firstErr
+ default:
+ // re-panic
+ panic(p)
+ }
+}
+
+// Files checks the provided files as part of the checker's package.
+func (check *Checker) Files(files []*ast.File) error { return check.checkFiles(files) }
+
+var errBadCgo = errors.New("cannot use FakeImportC and go115UsesCgo together")
+
+func (check *Checker) checkFiles(files []*ast.File) (err error) {
+ if check.conf.FakeImportC && check.conf.go115UsesCgo {
+ return errBadCgo
+ }
+
+ defer check.handleBailout(&err)
+
+ check.initFiles(files)
+
+ check.collectObjects()
+
+ check.packageObjects()
+
+ check.processDelayed(0) // incl. all functions
+ check.processFinals()
+
+ check.initOrder()
+
+ if !check.conf.DisableUnusedImportCheck {
+ check.unusedImports()
+ }
+
+ check.recordUntyped()
+
+ check.pkg.complete = true
+ return
+}
+
+// processDelayed processes all delayed actions pushed after top.
+func (check *Checker) processDelayed(top int) {
+ // If each delayed action pushes a new action, the
+ // stack will continue to grow during this loop.
+ // However, it is only processing functions (which
+ // are processed in a delayed fashion) that may
+ // add more actions (such as nested functions), so
+ // this is a sufficiently bounded process.
+ for i := top; i < len(check.delayed); i++ {
+ check.delayed[i]() // may append to check.delayed
+ }
+ assert(top <= len(check.delayed)) // stack must not have shrunk
+ check.delayed = check.delayed[:top]
+}
+
+func (check *Checker) processFinals() {
+ n := len(check.finals)
+ for _, f := range check.finals {
+ f() // must not append to check.finals
+ }
+ if len(check.finals) != n {
+ panic("internal error: final action list grew")
+ }
+}
+
+func (check *Checker) recordUntyped() {
+ if !debug && check.Types == nil {
+ return // nothing to do
+ }
+
+ for x, info := range check.untyped {
+ if debug && isTyped(info.typ) {
+ check.dump("%v: %s (type %s) is typed", x.Pos(), x, info.typ)
+ unreachable()
+ }
+ check.recordTypeAndValue(x, info.mode, info.typ, info.val)
+ }
+}
+
+func (check *Checker) recordTypeAndValue(x ast.Expr, mode operandMode, typ Type, val constant.Value) {
+ assert(x != nil)
+ assert(typ != nil)
+ if mode == invalid {
+ return // omit
+ }
+ if mode == constant_ {
+ assert(val != nil)
+ assert(typ == Typ[Invalid] || isConstType(typ))
+ }
+ if m := check.Types; m != nil {
+ m[x] = TypeAndValue{mode, typ, val}
+ }
+}
+
+func (check *Checker) recordBuiltinType(f ast.Expr, sig *Signature) {
+ // f must be a (possibly parenthesized) identifier denoting a built-in
+ // (built-ins in package unsafe always produce a constant result and
+ // we don't record their signatures, so we don't see qualified idents
+ // here): record the signature for f and possible children.
+ for {
+ check.recordTypeAndValue(f, builtin, sig, nil)
+ switch p := f.(type) {
+ case *ast.Ident:
+ return // we're done
+ case *ast.ParenExpr:
+ f = p.X
+ default:
+ unreachable()
+ }
+ }
+}
+
+func (check *Checker) recordCommaOkTypes(x ast.Expr, a [2]Type) {
+ assert(x != nil)
+ if a[0] == nil || a[1] == nil {
+ return
+ }
+ assert(isTyped(a[0]) && isTyped(a[1]) && (isBoolean(a[1]) || a[1] == universeError))
+ if m := check.Types; m != nil {
+ for {
+ tv := m[x]
+ assert(tv.Type != nil) // should have been recorded already
+ pos := x.Pos()
+ tv.Type = NewTuple(
+ NewVar(pos, check.pkg, "", a[0]),
+ NewVar(pos, check.pkg, "", a[1]),
+ )
+ m[x] = tv
+ // if x is a parenthesized expression (p.X), update p.X
+ p, _ := x.(*ast.ParenExpr)
+ if p == nil {
+ break
+ }
+ x = p.X
+ }
+ }
+}
+
+func (check *Checker) recordDef(id *ast.Ident, obj Object) {
+ assert(id != nil)
+ if m := check.Defs; m != nil {
+ m[id] = obj
+ }
+}
+
+func (check *Checker) recordUse(id *ast.Ident, obj Object) {
+ assert(id != nil)
+ assert(obj != nil)
+ if m := check.Uses; m != nil {
+ m[id] = obj
+ }
+}
+
+func (check *Checker) recordImplicit(node ast.Node, obj Object) {
+ assert(node != nil)
+ assert(obj != nil)
+ if m := check.Implicits; m != nil {
+ m[node] = obj
+ }
+}
+
+func (check *Checker) recordSelection(x *ast.SelectorExpr, kind SelectionKind, recv Type, obj Object, index []int, indirect bool) {
+ assert(obj != nil && (recv == nil || len(index) > 0))
+ check.recordUse(x.Sel, obj)
+ if m := check.Selections; m != nil {
+ m[x] = &Selection{kind, recv, obj, index, indirect}
+ }
+}
+
+func (check *Checker) recordScope(node ast.Node, scope *Scope) {
+ assert(node != nil)
+ assert(scope != nil)
+ if m := check.Scopes; m != nil {
+ m[node] = scope
+ }
+}
diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
new file mode 100644
index 0000000..ce31dab
--- /dev/null
+++ b/src/go/types/check_test.go
@@ -0,0 +1,349 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements a typechecker test harness. The packages specified
+// in tests are typechecked. Error messages reported by the typechecker are
+// compared against the error messages expected in the test files.
+//
+// Expected errors are indicated in the test files by putting a comment
+// of the form /* ERROR "rx" */ immediately following an offending token.
+// The harness will verify that an error matching the regular expression
+// rx is reported at that source position. Consecutive comments may be
+// used to indicate multiple errors for the same token position.
+//
+// For instance, the following test file indicates that a "not declared"
+// error should be reported for the undeclared variable x:
+//
+// package p
+// func f() {
+// _ = x /* ERROR "not declared" */ + 1
+// }
+
+// TODO(gri) Also collect strict mode errors of the form /* STRICT ... */
+// and test against strict mode.
+
+package types_test
+
+import (
+ "flag"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/scanner"
+ "go/token"
+ "internal/testenv"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strings"
+ "testing"
+
+ . "go/types"
+)
+
+var (
+ haltOnError = flag.Bool("halt", false, "halt on error")
+ listErrors = flag.Bool("errlist", false, "list errors")
+ testFiles = flag.String("files", "", "space-separated list of test files")
+)
+
+// The test filenames do not end in .go so that they are invisible
+// to gofmt since they contain comments that must not change their
+// positions relative to surrounding tokens.
+
+// Each tests entry is list of files belonging to the same package.
+var tests = [][]string{
+ {"testdata/errors.src"},
+ {"testdata/importdecl0a.src", "testdata/importdecl0b.src"},
+ {"testdata/importdecl1a.src", "testdata/importdecl1b.src"},
+ {"testdata/importC.src"}, // special handling in checkFiles
+ {"testdata/cycles.src"},
+ {"testdata/cycles1.src"},
+ {"testdata/cycles2.src"},
+ {"testdata/cycles3.src"},
+ {"testdata/cycles4.src"},
+ {"testdata/cycles5.src"},
+ {"testdata/init0.src"},
+ {"testdata/init1.src"},
+ {"testdata/init2.src"},
+ {"testdata/decls0.src"},
+ {"testdata/decls1.src"},
+ {"testdata/decls2a.src", "testdata/decls2b.src"},
+ {"testdata/decls3.src"},
+ {"testdata/decls4.src"},
+ {"testdata/decls5.src"},
+ {"testdata/const0.src"},
+ {"testdata/const1.src"},
+ {"testdata/constdecl.src"},
+ {"testdata/vardecl.src"},
+ {"testdata/expr0.src"},
+ {"testdata/expr1.src"},
+ {"testdata/expr2.src"},
+ {"testdata/expr3.src"},
+ {"testdata/methodsets.src"},
+ {"testdata/shifts.src"},
+ {"testdata/builtins.src"},
+ {"testdata/conversions.src"},
+ {"testdata/conversions2.src"},
+ {"testdata/stmt0.src"},
+ {"testdata/stmt1.src"},
+ {"testdata/gotos.src"},
+ {"testdata/labels.src"},
+ {"testdata/literals.src"},
+ {"testdata/issues.src"},
+ {"testdata/blank.src"},
+ {"testdata/issue25008b.src", "testdata/issue25008a.src"}, // order (b before a) is crucial!
+}
+
+var fset = token.NewFileSet()
+
+// Positioned errors are of the form filename:line:column: message .
+var posMsgRx = regexp.MustCompile(`^(.*:[0-9]+:[0-9]+): *(.*)`)
+
+// splitError splits an error's error message into a position string
+// and the actual error message. If there's no position information,
+// pos is the empty string, and msg is the entire error message.
+//
+func splitError(err error) (pos, msg string) {
+ msg = err.Error()
+ if m := posMsgRx.FindStringSubmatch(msg); len(m) == 3 {
+ pos = m[1]
+ msg = m[2]
+ }
+ return
+}
+
+func parseFiles(t *testing.T, filenames []string) ([]*ast.File, []error) {
+ var files []*ast.File
+ var errlist []error
+ for _, filename := range filenames {
+ file, err := parser.ParseFile(fset, filename, nil, parser.AllErrors)
+ if file == nil {
+ t.Fatalf("%s: %s", filename, err)
+ }
+ files = append(files, file)
+ if err != nil {
+ if list, _ := err.(scanner.ErrorList); len(list) > 0 {
+ for _, err := range list {
+ errlist = append(errlist, err)
+ }
+ } else {
+ errlist = append(errlist, err)
+ }
+ }
+ }
+ return files, errlist
+}
+
+// ERROR comments must start with text `ERROR "rx"` or `ERROR rx` where
+// rx is a regular expression that matches the expected error message.
+// Space around "rx" or rx is ignored. Use the form `ERROR HERE "rx"`
+// for error messages that are located immediately after rather than
+// at a token's position.
+//
+var errRx = regexp.MustCompile(`^ *ERROR *(HERE)? *"?([^"]*)"?`)
+
+// errMap collects the regular expressions of ERROR comments found
+// in files and returns them as a map of error positions to error messages.
+//
+func errMap(t *testing.T, testname string, files []*ast.File) map[string][]string {
+ // map of position strings to lists of error message patterns
+ errmap := make(map[string][]string)
+
+ for _, file := range files {
+ filename := fset.Position(file.Package).Filename
+ src, err := os.ReadFile(filename)
+ if err != nil {
+ t.Fatalf("%s: could not read %s", testname, filename)
+ }
+
+ var s scanner.Scanner
+ s.Init(fset.AddFile(filename, -1, len(src)), src, nil, scanner.ScanComments)
+ var prev token.Pos // position of last non-comment, non-semicolon token
+ var here token.Pos // position immediately after the token at position prev
+
+ scanFile:
+ for {
+ pos, tok, lit := s.Scan()
+ switch tok {
+ case token.EOF:
+ break scanFile
+ case token.COMMENT:
+ if lit[1] == '*' {
+ lit = lit[:len(lit)-2] // strip trailing */
+ }
+ if s := errRx.FindStringSubmatch(lit[2:]); len(s) == 3 {
+ pos := prev
+ if s[1] == "HERE" {
+ pos = here
+ }
+ p := fset.Position(pos).String()
+ errmap[p] = append(errmap[p], strings.TrimSpace(s[2]))
+ }
+ case token.SEMICOLON:
+ // ignore automatically inserted semicolon
+ if lit == "\n" {
+ continue scanFile
+ }
+ fallthrough
+ default:
+ prev = pos
+ var l int // token length
+ if tok.IsLiteral() {
+ l = len(lit)
+ } else {
+ l = len(tok.String())
+ }
+ here = prev + token.Pos(l)
+ }
+ }
+ }
+
+ return errmap
+}
+
+func eliminate(t *testing.T, errmap map[string][]string, errlist []error) {
+ for _, err := range errlist {
+ pos, gotMsg := splitError(err)
+ list := errmap[pos]
+ index := -1 // list index of matching message, if any
+ // we expect one of the messages in list to match the error at pos
+ for i, wantRx := range list {
+ rx, err := regexp.Compile(wantRx)
+ if err != nil {
+ t.Errorf("%s: %v", pos, err)
+ continue
+ }
+ if rx.MatchString(gotMsg) {
+ index = i
+ break
+ }
+ }
+ if index >= 0 {
+ // eliminate from list
+ if n := len(list) - 1; n > 0 {
+ // not the last entry - swap in last element and shorten list by 1
+ list[index] = list[n]
+ errmap[pos] = list[:n]
+ } else {
+ // last entry - remove list from map
+ delete(errmap, pos)
+ }
+ } else {
+ t.Errorf("%s: no error expected: %q", pos, gotMsg)
+ }
+ }
+}
+
+func checkFiles(t *testing.T, testfiles []string) {
+ // parse files and collect parser errors
+ files, errlist := parseFiles(t, testfiles)
+
+ pkgName := "<no package>"
+ if len(files) > 0 {
+ pkgName = files[0].Name.Name
+ }
+
+ if *listErrors && len(errlist) > 0 {
+ t.Errorf("--- %s:", pkgName)
+ for _, err := range errlist {
+ t.Error(err)
+ }
+ }
+
+ // typecheck and collect typechecker errors
+ var conf Config
+ // special case for importC.src
+ if len(testfiles) == 1 && strings.HasSuffix(testfiles[0], "importC.src") {
+ conf.FakeImportC = true
+ }
+ conf.Importer = importer.Default()
+ conf.Error = func(err error) {
+ if *haltOnError {
+ defer panic(err)
+ }
+ if *listErrors {
+ t.Error(err)
+ return
+ }
+ // Ignore secondary error messages starting with "\t";
+ // they are clarifying messages for a primary error.
+ if !strings.Contains(err.Error(), ": \t") {
+ errlist = append(errlist, err)
+ }
+ }
+ conf.Check(pkgName, fset, files, nil)
+
+ if *listErrors {
+ return
+ }
+
+ for _, err := range errlist {
+ err, ok := err.(Error)
+ if !ok {
+ continue
+ }
+ code := readCode(err)
+ if code == 0 {
+ t.Errorf("missing error code: %v", err)
+ }
+ }
+
+ // match and eliminate errors;
+ // we are expecting the following errors
+ errmap := errMap(t, pkgName, files)
+ eliminate(t, errmap, errlist)
+
+ // there should be no expected errors left
+ if len(errmap) > 0 {
+ t.Errorf("--- %s: %d source positions with expected (but not reported) errors:", pkgName, len(errmap))
+ for pos, list := range errmap {
+ for _, rx := range list {
+ t.Errorf("%s: %q", pos, rx)
+ }
+ }
+ }
+}
+
+func TestCheck(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ // Declare builtins for testing.
+ DefPredeclaredTestFuncs()
+
+ // If explicit test files are specified, only check those.
+ if files := *testFiles; files != "" {
+ checkFiles(t, strings.Split(files, " "))
+ return
+ }
+
+ // Otherwise, run all the tests.
+ for _, files := range tests {
+ checkFiles(t, files)
+ }
+}
+
+func TestFixedBugs(t *testing.T) { testDir(t, "fixedbugs") }
+
+func testDir(t *testing.T, dir string) {
+ testenv.MustHaveGoBuild(t)
+
+ dirs, err := os.ReadDir(dir)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ for _, d := range dirs {
+ testname := filepath.Base(d.Name())
+ testname = strings.TrimSuffix(testname, filepath.Ext(testname))
+ t.Run(testname, func(t *testing.T) {
+ filename := filepath.Join(dir, d.Name())
+ if d.IsDir() {
+ t.Errorf("skipped directory %q", filename)
+ return
+ }
+ checkFiles(t, []string{filename})
+ })
+ }
+}
diff --git a/src/go/types/conversions.go b/src/go/types/conversions.go
new file mode 100644
index 0000000..1cab1cc
--- /dev/null
+++ b/src/go/types/conversions.go
@@ -0,0 +1,163 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements typechecking of conversions.
+
+package types
+
+import (
+ "go/constant"
+ "unicode"
+)
+
+// Conversion type-checks the conversion T(x).
+// The result is in x.
+func (check *Checker) conversion(x *operand, T Type) {
+ constArg := x.mode == constant_
+
+ var ok bool
+ switch {
+ case constArg && isConstType(T):
+ // constant conversion
+ switch t := T.Underlying().(*Basic); {
+ case representableConst(x.val, check, t, &x.val):
+ ok = true
+ case isInteger(x.typ) && isString(t):
+ codepoint := unicode.ReplacementChar
+ if i, ok := constant.Uint64Val(x.val); ok && i <= unicode.MaxRune {
+ codepoint = rune(i)
+ }
+ x.val = constant.MakeString(string(codepoint))
+ ok = true
+ }
+ case x.convertibleTo(check, T):
+ // non-constant conversion
+ x.mode = value
+ ok = true
+ }
+
+ if !ok {
+ check.errorf(x, _InvalidConversion, "cannot convert %s to %s", x, T)
+ x.mode = invalid
+ return
+ }
+
+ // The conversion argument types are final. For untyped values the
+ // conversion provides the type, per the spec: "A constant may be
+ // given a type explicitly by a constant declaration or conversion,...".
+ if isUntyped(x.typ) {
+ final := T
+ // - For conversions to interfaces, use the argument's default type.
+ // - For conversions of untyped constants to non-constant types, also
+ // use the default type (e.g., []byte("foo") should report string
+ // not []byte as type for the constant "foo").
+ // - Keep untyped nil for untyped nil arguments.
+ // - For integer to string conversions, keep the argument type.
+ // (See also the TODO below.)
+ if IsInterface(T) || constArg && !isConstType(T) {
+ final = Default(x.typ)
+ } else if isInteger(x.typ) && isString(T) {
+ final = x.typ
+ }
+ check.updateExprType(x.expr, final, true)
+ }
+
+ x.typ = T
+}
+
+// TODO(gri) convertibleTo checks if T(x) is valid. It assumes that the type
+// of x is fully known, but that's not the case for say string(1<<s + 1.0):
+// Here, the type of 1<<s + 1.0 will be UntypedFloat which will lead to the
+// (correct!) refusal of the conversion. But the reported error is essentially
+// "cannot convert untyped float value to string", yet the correct error (per
+// the spec) is that we cannot shift a floating-point value: 1 in 1<<s should
+// be converted to UntypedFloat because of the addition of 1.0. Fixing this
+// is tricky because we'd have to run updateExprType on the argument first.
+// (Issue #21982.)
+
+// convertibleTo reports whether T(x) is valid.
+// The check parameter may be nil if convertibleTo is invoked through an
+// exported API call, i.e., when all methods have been type-checked.
+func (x *operand) convertibleTo(check *Checker, T Type) bool {
+ // "x is assignable to T"
+ if ok, _ := x.assignableTo(check, T, nil); ok {
+ return true
+ }
+
+ // "x's type and T have identical underlying types if tags are ignored"
+ V := x.typ
+ Vu := V.Underlying()
+ Tu := T.Underlying()
+ if check.identicalIgnoreTags(Vu, Tu) {
+ return true
+ }
+
+ // "x's type and T are unnamed pointer types and their pointer base types
+ // have identical underlying types if tags are ignored"
+ if V, ok := V.(*Pointer); ok {
+ if T, ok := T.(*Pointer); ok {
+ if check.identicalIgnoreTags(V.base.Underlying(), T.base.Underlying()) {
+ return true
+ }
+ }
+ }
+
+ // "x's type and T are both integer or floating point types"
+ if (isInteger(V) || isFloat(V)) && (isInteger(T) || isFloat(T)) {
+ return true
+ }
+
+ // "x's type and T are both complex types"
+ if isComplex(V) && isComplex(T) {
+ return true
+ }
+
+ // "x is an integer or a slice of bytes or runes and T is a string type"
+ if (isInteger(V) || isBytesOrRunes(Vu)) && isString(T) {
+ return true
+ }
+
+ // "x is a string and T is a slice of bytes or runes"
+ if isString(V) && isBytesOrRunes(Tu) {
+ return true
+ }
+
+ // package unsafe:
+ // "any pointer or value of underlying type uintptr can be converted into a unsafe.Pointer"
+ if (isPointer(Vu) || isUintptr(Vu)) && isUnsafePointer(T) {
+ return true
+ }
+ // "and vice versa"
+ if isUnsafePointer(V) && (isPointer(Tu) || isUintptr(Tu)) {
+ return true
+ }
+
+ return false
+}
+
+func isUintptr(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.kind == Uintptr
+}
+
+func isUnsafePointer(typ Type) bool {
+ // TODO(gri): Is this (typ.Underlying() instead of just typ) correct?
+ // The spec does not say so, but gc claims it is. See also
+ // issue 6326.
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.kind == UnsafePointer
+}
+
+func isPointer(typ Type) bool {
+ _, ok := typ.Underlying().(*Pointer)
+ return ok
+}
+
+func isBytesOrRunes(typ Type) bool {
+ if s, ok := typ.(*Slice); ok {
+ t, ok := s.elem.Underlying().(*Basic)
+ return ok && (t.kind == Byte || t.kind == Rune)
+ }
+ return false
+}
diff --git a/src/go/types/decl.go b/src/go/types/decl.go
new file mode 100644
index 0000000..1f0bc35
--- /dev/null
+++ b/src/go/types/decl.go
@@ -0,0 +1,855 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "go/ast"
+ "go/constant"
+ "go/token"
+)
+
+func (check *Checker) reportAltDecl(obj Object) {
+ if pos := obj.Pos(); pos.IsValid() {
+ // We use "other" rather than "previous" here because
+ // the first declaration seen may not be textually
+ // earlier in the source.
+ check.errorf(obj, _DuplicateDecl, "\tother declaration of %s", obj.Name()) // secondary error, \t indented
+ }
+}
+
+func (check *Checker) declare(scope *Scope, id *ast.Ident, obj Object, pos token.Pos) {
+ // spec: "The blank identifier, represented by the underscore
+ // character _, may be used in a declaration like any other
+ // identifier but the declaration does not introduce a new
+ // binding."
+ if obj.Name() != "_" {
+ if alt := scope.Insert(obj); alt != nil {
+ check.errorf(obj, _DuplicateDecl, "%s redeclared in this block", obj.Name())
+ check.reportAltDecl(alt)
+ return
+ }
+ obj.setScopePos(pos)
+ }
+ if id != nil {
+ check.recordDef(id, obj)
+ }
+}
+
+// pathString returns a string of the form a->b-> ... ->g for a path [a, b, ... g].
+func pathString(path []Object) string {
+ var s string
+ for i, p := range path {
+ if i > 0 {
+ s += "->"
+ }
+ s += p.Name()
+ }
+ return s
+}
+
+// objDecl type-checks the declaration of obj in its respective (file) context.
+// For the meaning of def, see Checker.definedType, in typexpr.go.
+func (check *Checker) objDecl(obj Object, def *Named) {
+ if trace {
+ check.trace(obj.Pos(), "-- checking %s (%s, objPath = %s)", obj, obj.color(), pathString(check.objPath))
+ check.indent++
+ defer func() {
+ check.indent--
+ check.trace(obj.Pos(), "=> %s (%s)", obj, obj.color())
+ }()
+ }
+
+ // Checking the declaration of obj means inferring its type
+ // (and possibly its value, for constants).
+ // An object's type (and thus the object) may be in one of
+ // three states which are expressed by colors:
+ //
+ // - an object whose type is not yet known is painted white (initial color)
+ // - an object whose type is in the process of being inferred is painted grey
+ // - an object whose type is fully inferred is painted black
+ //
+ // During type inference, an object's color changes from white to grey
+ // to black (pre-declared objects are painted black from the start).
+ // A black object (i.e., its type) can only depend on (refer to) other black
+ // ones. White and grey objects may depend on white and black objects.
+ // A dependency on a grey object indicates a cycle which may or may not be
+ // valid.
+ //
+ // When objects turn grey, they are pushed on the object path (a stack);
+ // they are popped again when they turn black. Thus, if a grey object (a
+ // cycle) is encountered, it is on the object path, and all the objects
+ // it depends on are the remaining objects on that path. Color encoding
+ // is such that the color value of a grey object indicates the index of
+ // that object in the object path.
+
+ // During type-checking, white objects may be assigned a type without
+ // traversing through objDecl; e.g., when initializing constants and
+ // variables. Update the colors of those objects here (rather than
+ // everywhere where we set the type) to satisfy the color invariants.
+ if obj.color() == white && obj.Type() != nil {
+ obj.setColor(black)
+ return
+ }
+
+ switch obj.color() {
+ case white:
+ assert(obj.Type() == nil)
+ // All color values other than white and black are considered grey.
+ // Because black and white are < grey, all values >= grey are grey.
+ // Use those values to encode the object's index into the object path.
+ obj.setColor(grey + color(check.push(obj)))
+ defer func() {
+ check.pop().setColor(black)
+ }()
+
+ case black:
+ assert(obj.Type() != nil)
+ return
+
+ default:
+ // Color values other than white or black are considered grey.
+ fallthrough
+
+ case grey:
+ // We have a cycle.
+ // In the existing code, this is marked by a non-nil type
+ // for the object except for constants and variables whose
+ // type may be non-nil (known), or nil if it depends on the
+ // not-yet known initialization value.
+ // In the former case, set the type to Typ[Invalid] because
+ // we have an initialization cycle. The cycle error will be
+ // reported later, when determining initialization order.
+ // TODO(gri) Report cycle here and simplify initialization
+ // order code.
+ switch obj := obj.(type) {
+ case *Const:
+ if check.cycle(obj) || obj.typ == nil {
+ obj.typ = Typ[Invalid]
+ }
+
+ case *Var:
+ if check.cycle(obj) || obj.typ == nil {
+ obj.typ = Typ[Invalid]
+ }
+
+ case *TypeName:
+ if check.cycle(obj) {
+ // break cycle
+ // (without this, calling underlying()
+ // below may lead to an endless loop
+ // if we have a cycle for a defined
+ // (*Named) type)
+ obj.typ = Typ[Invalid]
+ }
+
+ case *Func:
+ if check.cycle(obj) {
+ // Don't set obj.typ to Typ[Invalid] here
+ // because plenty of code type-asserts that
+ // functions have a *Signature type. Grey
+ // functions have their type set to an empty
+ // signature which makes it impossible to
+ // initialize a variable with the function.
+ }
+
+ default:
+ unreachable()
+ }
+ assert(obj.Type() != nil)
+ return
+ }
+
+ d := check.objMap[obj]
+ if d == nil {
+ check.dump("%v: %s should have been declared", obj.Pos(), obj)
+ unreachable()
+ }
+
+ // save/restore current context and setup object context
+ defer func(ctxt context) {
+ check.context = ctxt
+ }(check.context)
+ check.context = context{
+ scope: d.file,
+ }
+
+ // Const and var declarations must not have initialization
+ // cycles. We track them by remembering the current declaration
+ // in check.decl. Initialization expressions depending on other
+ // consts, vars, or functions, add dependencies to the current
+ // check.decl.
+ switch obj := obj.(type) {
+ case *Const:
+ check.decl = d // new package-level const decl
+ check.constDecl(obj, d.typ, d.init, d.inherited)
+ case *Var:
+ check.decl = d // new package-level var decl
+ check.varDecl(obj, d.lhs, d.typ, d.init)
+ case *TypeName:
+ // invalid recursive types are detected via path
+ check.typeDecl(obj, d.typ, def, d.alias)
+ case *Func:
+ // functions may be recursive - no need to track dependencies
+ check.funcDecl(obj, d)
+ default:
+ unreachable()
+ }
+}
+
+// cycle checks if the cycle starting with obj is valid and
+// reports an error if it is not.
+func (check *Checker) cycle(obj Object) (isCycle bool) {
+ // The object map contains the package scope objects and the non-interface methods.
+ if debug {
+ info := check.objMap[obj]
+ inObjMap := info != nil && (info.fdecl == nil || info.fdecl.Recv == nil) // exclude methods
+ isPkgObj := obj.Parent() == check.pkg.scope
+ if isPkgObj != inObjMap {
+ check.dump("%v: inconsistent object map for %s (isPkgObj = %v, inObjMap = %v)", obj.Pos(), obj, isPkgObj, inObjMap)
+ unreachable()
+ }
+ }
+
+ // Count cycle objects.
+ assert(obj.color() >= grey)
+ start := obj.color() - grey // index of obj in objPath
+ cycle := check.objPath[start:]
+ nval := 0 // number of (constant or variable) values in the cycle
+ ndef := 0 // number of type definitions in the cycle
+ for _, obj := range cycle {
+ switch obj := obj.(type) {
+ case *Const, *Var:
+ nval++
+ case *TypeName:
+ // Determine if the type name is an alias or not. For
+ // package-level objects, use the object map which
+ // provides syntactic information (which doesn't rely
+ // on the order in which the objects are set up). For
+ // local objects, we can rely on the order, so use
+ // the object's predicate.
+ // TODO(gri) It would be less fragile to always access
+ // the syntactic information. We should consider storing
+ // this information explicitly in the object.
+ var alias bool
+ if d := check.objMap[obj]; d != nil {
+ alias = d.alias // package-level object
+ } else {
+ alias = obj.IsAlias() // function local object
+ }
+ if !alias {
+ ndef++
+ }
+ case *Func:
+ // ignored for now
+ default:
+ unreachable()
+ }
+ }
+
+ if trace {
+ check.trace(obj.Pos(), "## cycle detected: objPath = %s->%s (len = %d)", pathString(cycle), obj.Name(), len(cycle))
+ check.trace(obj.Pos(), "## cycle contains: %d values, %d type definitions", nval, ndef)
+ defer func() {
+ if isCycle {
+ check.trace(obj.Pos(), "=> error: cycle is invalid")
+ }
+ }()
+ }
+
+ // A cycle involving only constants and variables is invalid but we
+ // ignore them here because they are reported via the initialization
+ // cycle check.
+ if nval == len(cycle) {
+ return false
+ }
+
+ // A cycle involving only types (and possibly functions) must have at least
+ // one type definition to be permitted: If there is no type definition, we
+ // have a sequence of alias type names which will expand ad infinitum.
+ if nval == 0 && ndef > 0 {
+ return false // cycle is permitted
+ }
+
+ check.cycleError(cycle)
+
+ return true
+}
+
+type typeInfo uint
+
+// validType verifies that the given type does not "expand" infinitely
+// producing a cycle in the type graph. Cycles are detected by marking
+// defined types.
+// (Cycles involving alias types, as in "type A = [10]A" are detected
+// earlier, via the objDecl cycle detection mechanism.)
+func (check *Checker) validType(typ Type, path []Object) typeInfo {
+ const (
+ unknown typeInfo = iota
+ marked
+ valid
+ invalid
+ )
+
+ switch t := typ.(type) {
+ case *Array:
+ return check.validType(t.elem, path)
+
+ case *Struct:
+ for _, f := range t.fields {
+ if check.validType(f.typ, path) == invalid {
+ return invalid
+ }
+ }
+
+ case *Interface:
+ for _, etyp := range t.embeddeds {
+ if check.validType(etyp, path) == invalid {
+ return invalid
+ }
+ }
+
+ case *Named:
+ // don't touch the type if it is from a different package or the Universe scope
+ // (doing so would lead to a race condition - was issue #35049)
+ if t.obj.pkg != check.pkg {
+ return valid
+ }
+
+ // don't report a 2nd error if we already know the type is invalid
+ // (e.g., if a cycle was detected earlier, via Checker.underlying).
+ if t.underlying == Typ[Invalid] {
+ t.info = invalid
+ return invalid
+ }
+
+ switch t.info {
+ case unknown:
+ t.info = marked
+ t.info = check.validType(t.orig, append(path, t.obj)) // only types of current package added to path
+ case marked:
+ // cycle detected
+ for i, tn := range path {
+ if t.obj.pkg != check.pkg {
+ panic("internal error: type cycle via package-external type")
+ }
+ if tn == t.obj {
+ check.cycleError(path[i:])
+ t.info = invalid
+ t.underlying = Typ[Invalid]
+ return t.info
+ }
+ }
+ panic("internal error: cycle start not found")
+ }
+ return t.info
+ }
+
+ return valid
+}
+
+// cycleError reports a declaration cycle starting with
+// the object in cycle that is "first" in the source.
+func (check *Checker) cycleError(cycle []Object) {
+ // TODO(gri) Should we start with the last (rather than the first) object in the cycle
+ // since that is the earliest point in the source where we start seeing the
+ // cycle? That would be more consistent with other error messages.
+ i := firstInSrc(cycle)
+ obj := cycle[i]
+ check.errorf(obj, _InvalidDeclCycle, "illegal cycle in declaration of %s", obj.Name())
+ for range cycle {
+ check.errorf(obj, _InvalidDeclCycle, "\t%s refers to", obj.Name()) // secondary error, \t indented
+ i++
+ if i >= len(cycle) {
+ i = 0
+ }
+ obj = cycle[i]
+ }
+ check.errorf(obj, _InvalidDeclCycle, "\t%s", obj.Name())
+}
+
+// firstInSrc reports the index of the object with the "smallest"
+// source position in path. path must not be empty.
+func firstInSrc(path []Object) int {
+ fst, pos := 0, path[0].Pos()
+ for i, t := range path[1:] {
+ if t.Pos() < pos {
+ fst, pos = i+1, t.Pos()
+ }
+ }
+ return fst
+}
+
+type (
+ decl interface {
+ node() ast.Node
+ }
+
+ importDecl struct{ spec *ast.ImportSpec }
+ constDecl struct {
+ spec *ast.ValueSpec
+ iota int
+ typ ast.Expr
+ init []ast.Expr
+ inherited bool
+ }
+ varDecl struct{ spec *ast.ValueSpec }
+ typeDecl struct{ spec *ast.TypeSpec }
+ funcDecl struct{ decl *ast.FuncDecl }
+)
+
+func (d importDecl) node() ast.Node { return d.spec }
+func (d constDecl) node() ast.Node { return d.spec }
+func (d varDecl) node() ast.Node { return d.spec }
+func (d typeDecl) node() ast.Node { return d.spec }
+func (d funcDecl) node() ast.Node { return d.decl }
+
+func (check *Checker) walkDecls(decls []ast.Decl, f func(decl)) {
+ for _, d := range decls {
+ check.walkDecl(d, f)
+ }
+}
+
+func (check *Checker) walkDecl(d ast.Decl, f func(decl)) {
+ switch d := d.(type) {
+ case *ast.BadDecl:
+ // ignore
+ case *ast.GenDecl:
+ var last *ast.ValueSpec // last ValueSpec with type or init exprs seen
+ for iota, s := range d.Specs {
+ switch s := s.(type) {
+ case *ast.ImportSpec:
+ f(importDecl{s})
+ case *ast.ValueSpec:
+ switch d.Tok {
+ case token.CONST:
+ // determine which initialization expressions to use
+ inherited := true
+ switch {
+ case s.Type != nil || len(s.Values) > 0:
+ last = s
+ inherited = false
+ case last == nil:
+ last = new(ast.ValueSpec) // make sure last exists
+ inherited = false
+ }
+ check.arityMatch(s, last)
+ f(constDecl{spec: s, iota: iota, typ: last.Type, init: last.Values, inherited: inherited})
+ case token.VAR:
+ check.arityMatch(s, nil)
+ f(varDecl{s})
+ default:
+ check.invalidAST(s, "invalid token %s", d.Tok)
+ }
+ case *ast.TypeSpec:
+ f(typeDecl{s})
+ default:
+ check.invalidAST(s, "unknown ast.Spec node %T", s)
+ }
+ }
+ case *ast.FuncDecl:
+ f(funcDecl{d})
+ default:
+ check.invalidAST(d, "unknown ast.Decl node %T", d)
+ }
+}
+
+func (check *Checker) constDecl(obj *Const, typ, init ast.Expr, inherited bool) {
+ assert(obj.typ == nil)
+
+ // use the correct value of iota
+ defer func(iota constant.Value, errpos positioner) {
+ check.iota = iota
+ check.errpos = errpos
+ }(check.iota, check.errpos)
+ check.iota = obj.val
+ check.errpos = nil
+
+ // provide valid constant value under all circumstances
+ obj.val = constant.MakeUnknown()
+
+ // determine type, if any
+ if typ != nil {
+ t := check.typ(typ)
+ if !isConstType(t) {
+ // don't report an error if the type is an invalid C (defined) type
+ // (issue #22090)
+ if t.Underlying() != Typ[Invalid] {
+ check.errorf(typ, _InvalidConstType, "invalid constant type %s", t)
+ }
+ obj.typ = Typ[Invalid]
+ return
+ }
+ obj.typ = t
+ }
+
+ // check initialization
+ var x operand
+ if init != nil {
+ if inherited {
+ // The initialization expression is inherited from a previous
+ // constant declaration, and (error) positions refer to that
+ // expression and not the current constant declaration. Use
+ // the constant identifier position for any errors during
+ // init expression evaluation since that is all we have
+ // (see issues #42991, #42992).
+ check.errpos = atPos(obj.pos)
+ }
+ check.expr(&x, init)
+ }
+ check.initConst(obj, &x)
+}
+
+func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init ast.Expr) {
+ assert(obj.typ == nil)
+
+ // determine type, if any
+ if typ != nil {
+ obj.typ = check.typ(typ)
+ // We cannot spread the type to all lhs variables if there
+ // are more than one since that would mark them as checked
+ // (see Checker.objDecl) and the assignment of init exprs,
+ // if any, would not be checked.
+ //
+ // TODO(gri) If we have no init expr, we should distribute
+ // a given type otherwise we need to re-evalate the type
+ // expr for each lhs variable, leading to duplicate work.
+ }
+
+ // check initialization
+ if init == nil {
+ if typ == nil {
+ // error reported before by arityMatch
+ obj.typ = Typ[Invalid]
+ }
+ return
+ }
+
+ if lhs == nil || len(lhs) == 1 {
+ assert(lhs == nil || lhs[0] == obj)
+ var x operand
+ check.expr(&x, init)
+ check.initVar(obj, &x, "variable declaration")
+ return
+ }
+
+ if debug {
+ // obj must be one of lhs
+ found := false
+ for _, lhs := range lhs {
+ if obj == lhs {
+ found = true
+ break
+ }
+ }
+ if !found {
+ panic("inconsistent lhs")
+ }
+ }
+
+ // We have multiple variables on the lhs and one init expr.
+ // Make sure all variables have been given the same type if
+ // one was specified, otherwise they assume the type of the
+ // init expression values (was issue #15755).
+ if typ != nil {
+ for _, lhs := range lhs {
+ lhs.typ = obj.typ
+ }
+ }
+
+ check.initVars(lhs, []ast.Expr{init}, token.NoPos)
+}
+
+// underlying returns the underlying type of typ; possibly by following
+// forward chains of named types. Such chains only exist while named types
+// are incomplete. If an underlying type is found, resolve the chain by
+// setting the underlying type for each defined type in the chain before
+// returning it.
+//
+// If no underlying type is found, a cycle error is reported and Typ[Invalid]
+// is used as underlying type for each defined type in the chain and returned
+// as result.
+func (check *Checker) underlying(typ Type) Type {
+ // If typ is not a defined type, its underlying type is itself.
+ n0, _ := typ.(*Named)
+ if n0 == nil {
+ return typ // nothing to do
+ }
+
+ // If the underlying type of a defined type is not a defined
+ // type, then that is the desired underlying type.
+ typ = n0.underlying
+ n, _ := typ.(*Named)
+ if n == nil {
+ return typ // common case
+ }
+
+ // Otherwise, follow the forward chain.
+ seen := map[*Named]int{n0: 0}
+ path := []Object{n0.obj}
+ for {
+ typ = n.underlying
+ n1, _ := typ.(*Named)
+ if n1 == nil {
+ break // end of chain
+ }
+
+ seen[n] = len(seen)
+ path = append(path, n.obj)
+ n = n1
+
+ if i, ok := seen[n]; ok {
+ // cycle
+ check.cycleError(path[i:])
+ typ = Typ[Invalid]
+ break
+ }
+ }
+
+ for n := range seen {
+ // We should never have to update the underlying type of an imported type;
+ // those underlying types should have been resolved during the import.
+ // Also, doing so would lead to a race condition (was issue #31749).
+ if n.obj.pkg != check.pkg {
+ panic("internal error: imported type with unresolved underlying type")
+ }
+ n.underlying = typ
+ }
+
+ return typ
+}
+
+func (n *Named) setUnderlying(typ Type) {
+ if n != nil {
+ n.underlying = typ
+ }
+}
+
+func (check *Checker) typeDecl(obj *TypeName, typ ast.Expr, def *Named, alias bool) {
+ assert(obj.typ == nil)
+
+ check.later(func() {
+ check.validType(obj.typ, nil)
+ })
+
+ if alias {
+
+ obj.typ = Typ[Invalid]
+ obj.typ = check.typ(typ)
+
+ } else {
+
+ named := &Named{obj: obj}
+ def.setUnderlying(named)
+ obj.typ = named // make sure recursive type declarations terminate
+
+ // determine underlying type of named
+ named.orig = check.definedType(typ, named)
+
+ // The underlying type of named may be itself a named type that is
+ // incomplete:
+ //
+ // type (
+ // A B
+ // B *C
+ // C A
+ // )
+ //
+ // The type of C is the (named) type of A which is incomplete,
+ // and which has as its underlying type the named type B.
+ // Determine the (final, unnamed) underlying type by resolving
+ // any forward chain.
+ named.underlying = check.underlying(named)
+
+ }
+
+ check.addMethodDecls(obj)
+}
+
+func (check *Checker) addMethodDecls(obj *TypeName) {
+ // get associated methods
+ // (Checker.collectObjects only collects methods with non-blank names;
+ // Checker.resolveBaseTypeName ensures that obj is not an alias name
+ // if it has attached methods.)
+ methods := check.methods[obj]
+ if methods == nil {
+ return
+ }
+ delete(check.methods, obj)
+ assert(!check.objMap[obj].alias) // don't use TypeName.IsAlias (requires fully set up object)
+
+ // use an objset to check for name conflicts
+ var mset objset
+
+ // spec: "If the base type is a struct type, the non-blank method
+ // and field names must be distinct."
+ base, _ := obj.typ.(*Named) // shouldn't fail but be conservative
+ if base != nil {
+ if t, _ := base.underlying.(*Struct); t != nil {
+ for _, fld := range t.fields {
+ if fld.name != "_" {
+ assert(mset.insert(fld) == nil)
+ }
+ }
+ }
+
+ // Checker.Files may be called multiple times; additional package files
+ // may add methods to already type-checked types. Add pre-existing methods
+ // so that we can detect redeclarations.
+ for _, m := range base.methods {
+ assert(m.name != "_")
+ assert(mset.insert(m) == nil)
+ }
+ }
+
+ // add valid methods
+ for _, m := range methods {
+ // spec: "For a base type, the non-blank names of methods bound
+ // to it must be unique."
+ assert(m.name != "_")
+ if alt := mset.insert(m); alt != nil {
+ switch alt.(type) {
+ case *Var:
+ check.errorf(m, _DuplicateFieldAndMethod, "field and method with the same name %s", m.name)
+ case *Func:
+ check.errorf(m, _DuplicateMethod, "method %s already declared for %s", m.name, obj)
+ default:
+ unreachable()
+ }
+ check.reportAltDecl(alt)
+ continue
+ }
+
+ if base != nil {
+ base.methods = append(base.methods, m)
+ }
+ }
+}
+
+func (check *Checker) funcDecl(obj *Func, decl *declInfo) {
+ assert(obj.typ == nil)
+
+ // func declarations cannot use iota
+ assert(check.iota == nil)
+
+ sig := new(Signature)
+ obj.typ = sig // guard against cycles
+ fdecl := decl.fdecl
+ check.funcType(sig, fdecl.Recv, fdecl.Type)
+ if sig.recv == nil && obj.name == "init" && (sig.params.Len() > 0 || sig.results.Len() > 0) {
+ check.errorf(fdecl, _InvalidInitSig, "func init must have no arguments and no return values")
+ // ok to continue
+ }
+
+ // function body must be type-checked after global declarations
+ // (functions implemented elsewhere have no body)
+ if !check.conf.IgnoreFuncBodies && fdecl.Body != nil {
+ check.later(func() {
+ check.funcBody(decl, obj.name, sig, fdecl.Body, nil)
+ })
+ }
+}
+
+func (check *Checker) declStmt(d ast.Decl) {
+ pkg := check.pkg
+
+ check.walkDecl(d, func(d decl) {
+ switch d := d.(type) {
+ case constDecl:
+ top := len(check.delayed)
+
+ // declare all constants
+ lhs := make([]*Const, len(d.spec.Names))
+ for i, name := range d.spec.Names {
+ obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(d.iota)))
+ lhs[i] = obj
+
+ var init ast.Expr
+ if i < len(d.init) {
+ init = d.init[i]
+ }
+
+ check.constDecl(obj, d.typ, init, d.inherited)
+ }
+
+ // process function literals in init expressions before scope changes
+ check.processDelayed(top)
+
+ // spec: "The scope of a constant or variable identifier declared
+ // inside a function begins at the end of the ConstSpec or VarSpec
+ // (ShortVarDecl for short variable declarations) and ends at the
+ // end of the innermost containing block."
+ scopePos := d.spec.End()
+ for i, name := range d.spec.Names {
+ check.declare(check.scope, name, lhs[i], scopePos)
+ }
+
+ case varDecl:
+ top := len(check.delayed)
+
+ lhs0 := make([]*Var, len(d.spec.Names))
+ for i, name := range d.spec.Names {
+ lhs0[i] = NewVar(name.Pos(), pkg, name.Name, nil)
+ }
+
+ // initialize all variables
+ for i, obj := range lhs0 {
+ var lhs []*Var
+ var init ast.Expr
+ switch len(d.spec.Values) {
+ case len(d.spec.Names):
+ // lhs and rhs match
+ init = d.spec.Values[i]
+ case 1:
+ // rhs is expected to be a multi-valued expression
+ lhs = lhs0
+ init = d.spec.Values[0]
+ default:
+ if i < len(d.spec.Values) {
+ init = d.spec.Values[i]
+ }
+ }
+ check.varDecl(obj, lhs, d.spec.Type, init)
+ if len(d.spec.Values) == 1 {
+ // If we have a single lhs variable we are done either way.
+ // If we have a single rhs expression, it must be a multi-
+ // valued expression, in which case handling the first lhs
+ // variable will cause all lhs variables to have a type
+ // assigned, and we are done as well.
+ if debug {
+ for _, obj := range lhs0 {
+ assert(obj.typ != nil)
+ }
+ }
+ break
+ }
+ }
+
+ // process function literals in init expressions before scope changes
+ check.processDelayed(top)
+
+ // declare all variables
+ // (only at this point are the variable scopes (parents) set)
+ scopePos := d.spec.End() // see constant declarations
+ for i, name := range d.spec.Names {
+ // see constant declarations
+ check.declare(check.scope, name, lhs0[i], scopePos)
+ }
+
+ case typeDecl:
+ obj := NewTypeName(d.spec.Name.Pos(), pkg, d.spec.Name.Name, nil)
+ // spec: "The scope of a type identifier declared inside a function
+ // begins at the identifier in the TypeSpec and ends at the end of
+ // the innermost containing block."
+ scopePos := d.spec.Name.Pos()
+ check.declare(check.scope, d.spec.Name, obj, scopePos)
+ // mark and unmark type before calling typeDecl; its type is still nil (see Checker.objDecl)
+ obj.setColor(grey + color(check.push(obj)))
+ check.typeDecl(obj, d.spec.Type, nil, d.spec.Assign.IsValid())
+ check.pop().setColor(black)
+ default:
+ check.invalidAST(d.node(), "unknown ast.Decl node %T", d.node())
+ }
+ })
+}
diff --git a/src/go/types/errorcodes.go b/src/go/types/errorcodes.go
new file mode 100644
index 0000000..c01a12c
--- /dev/null
+++ b/src/go/types/errorcodes.go
@@ -0,0 +1,1366 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+type errorCode int
+
+// This file defines the error codes that can be produced during type-checking.
+// Collectively, these codes provide an identifier that may be used to
+// implement special handling for certain types of errors.
+//
+// Error codes should be fine-grained enough that the exact nature of the error
+// can be easily determined, but coarse enough that they are not an
+// implementation detail of the type checking algorithm. As a rule-of-thumb,
+// errors should be considered equivalent if there is a theoretical refactoring
+// of the type checker in which they are emitted in exactly one place. For
+// example, the type checker emits different error messages for "too many
+// arguments" and "too few arguments", but one can imagine an alternative type
+// checker where this check instead just emits a single "wrong number of
+// arguments", so these errors should have the same code.
+//
+// Error code names should be as brief as possible while retaining accuracy and
+// distinctiveness. In most cases names should start with an adjective
+// describing the nature of the error (e.g. "invalid", "unused", "misplaced"),
+// and end with a noun identifying the relevant language object. For example,
+// "_DuplicateDecl" or "_InvalidSliceExpr". For brevity, naming follows the
+// convention that "bad" implies a problem with syntax, and "invalid" implies a
+// problem with types.
+
+const (
+ _ errorCode = iota
+
+ // _Test is reserved for errors that only apply while in self-test mode.
+ _Test
+
+ /* package names */
+
+ // _BlankPkgName occurs when a package name is the blank identifier "_".
+ //
+ // Per the spec:
+ // "The PackageName must not be the blank identifier."
+ _BlankPkgName
+
+ // _MismatchedPkgName occurs when a file's package name doesn't match the
+ // package name already established by other files.
+ _MismatchedPkgName
+
+ // _InvalidPkgUse occurs when a package identifier is used outside of a
+ // selector expression.
+ //
+ // Example:
+ // import "fmt"
+ //
+ // var _ = fmt
+ _InvalidPkgUse
+
+ /* imports */
+
+ // _BadImportPath occurs when an import path is not valid.
+ _BadImportPath
+
+ // _BrokenImport occurs when importing a package fails.
+ //
+ // Example:
+ // import "amissingpackage"
+ _BrokenImport
+
+ // _ImportCRenamed occurs when the special import "C" is renamed. "C" is a
+ // pseudo-package, and must not be renamed.
+ //
+ // Example:
+ // import _ "C"
+ _ImportCRenamed
+
+ // _UnusedImport occurs when an import is unused.
+ //
+ // Example:
+ // import "fmt"
+ //
+ // func main() {}
+ _UnusedImport
+
+ /* initialization */
+
+ // _InvalidInitCycle occurs when an invalid cycle is detected within the
+ // initialization graph.
+ //
+ // Example:
+ // var x int = f()
+ //
+ // func f() int { return x }
+ _InvalidInitCycle
+
+ /* decls */
+
+ // _DuplicateDecl occurs when an identifier is declared multiple times.
+ //
+ // Example:
+ // var x = 1
+ // var x = 2
+ _DuplicateDecl
+
+ // _InvalidDeclCycle occurs when a declaration cycle is not valid.
+ //
+ // Example:
+ // import "unsafe"
+ //
+ // type T struct {
+ // a [n]int
+ // }
+ //
+ // var n = unsafe.Sizeof(T{})
+ _InvalidDeclCycle
+
+ // _InvalidTypeCycle occurs when a cycle in type definitions results in a
+ // type that is not well-defined.
+ //
+ // Example:
+ // import "unsafe"
+ //
+ // type T [unsafe.Sizeof(T{})]int
+ _InvalidTypeCycle
+
+ /* decls > const */
+
+ // _InvalidConstInit occurs when a const declaration has a non-constant
+ // initializer.
+ //
+ // Example:
+ // var x int
+ // const _ = x
+ _InvalidConstInit
+
+ // _InvalidConstVal occurs when a const value cannot be converted to its
+ // target type.
+ //
+ // TODO(findleyr): this error code and example are not very clear. Consider
+ // removing it.
+ //
+ // Example:
+ // const _ = 1 << "hello"
+ _InvalidConstVal
+
+ // _InvalidConstType occurs when the underlying type in a const declaration
+ // is not a valid constant type.
+ //
+ // Example:
+ // const c *int = 4
+ _InvalidConstType
+
+ /* decls > var (+ other variable assignment codes) */
+
+ // _UntypedNil occurs when the predeclared (untyped) value nil is used to
+ // initialize a variable declared without an explicit type.
+ //
+ // Example:
+ // var x = nil
+ _UntypedNil
+
+ // _WrongAssignCount occurs when the number of values on the right-hand side
+ // of an assignment or or initialization expression does not match the number
+ // of variables on the left-hand side.
+ //
+ // Example:
+ // var x = 1, 2
+ _WrongAssignCount
+
+ // _UnassignableOperand occurs when the left-hand side of an assignment is
+ // not assignable.
+ //
+ // Example:
+ // func f() {
+ // const c = 1
+ // c = 2
+ // }
+ _UnassignableOperand
+
+ // _NoNewVar occurs when a short variable declaration (':=') does not declare
+ // new variables.
+ //
+ // Example:
+ // func f() {
+ // x := 1
+ // x := 2
+ // }
+ _NoNewVar
+
+ // _MultiValAssignOp occurs when an assignment operation (+=, *=, etc) does
+ // not have single-valued left-hand or right-hand side.
+ //
+ // Per the spec:
+ // "In assignment operations, both the left- and right-hand expression lists
+ // must contain exactly one single-valued expression"
+ //
+ // Example:
+ // func f() int {
+ // x, y := 1, 2
+ // x, y += 1
+ // return x + y
+ // }
+ _MultiValAssignOp
+
+ // _InvalidIfaceAssign occurs when a value of type T is used as an
+ // interface, but T does not implement a method of the expected interface.
+ //
+ // Example:
+ // type I interface {
+ // f()
+ // }
+ //
+ // type T int
+ //
+ // var x I = T(1)
+ _InvalidIfaceAssign
+
+ // _InvalidChanAssign occurs when a chan assignment is invalid.
+ //
+ // Per the spec, a value x is assignable to a channel type T if:
+ // "x is a bidirectional channel value, T is a channel type, x's type V and
+ // T have identical element types, and at least one of V or T is not a
+ // defined type."
+ //
+ // Example:
+ // type T1 chan int
+ // type T2 chan int
+ //
+ // var x T1
+ // // Invalid assignment because both types are named
+ // var _ T2 = x
+ _InvalidChanAssign
+
+ // _IncompatibleAssign occurs when the type of the right-hand side expression
+ // in an assignment cannot be assigned to the type of the variable being
+ // assigned.
+ //
+ // Example:
+ // var x []int
+ // var _ int = x
+ _IncompatibleAssign
+
+ // _UnaddressableFieldAssign occurs when trying to assign to a struct field
+ // in a map value.
+ //
+ // Example:
+ // func f() {
+ // m := make(map[string]struct{i int})
+ // m["foo"].i = 42
+ // }
+ _UnaddressableFieldAssign
+
+ /* decls > type (+ other type expression codes) */
+
+ // _NotAType occurs when the identifier used as the underlying type in a type
+ // declaration or the right-hand side of a type alias does not denote a type.
+ //
+ // Example:
+ // var S = 2
+ //
+ // type T S
+ _NotAType
+
+ // _InvalidArrayLen occurs when an array length is not a constant value.
+ //
+ // Example:
+ // var n = 3
+ // var _ = [n]int{}
+ _InvalidArrayLen
+
+ // _BlankIfaceMethod occurs when a method name is '_'.
+ //
+ // Per the spec:
+ // "The name of each explicitly specified method must be unique and not
+ // blank."
+ //
+ // Example:
+ // type T interface {
+ // _(int)
+ // }
+ _BlankIfaceMethod
+
+ // _IncomparableMapKey occurs when a map key type does not support the == and
+ // != operators.
+ //
+ // Per the spec:
+ // "The comparison operators == and != must be fully defined for operands of
+ // the key type; thus the key type must not be a function, map, or slice."
+ //
+ // Example:
+ // var x map[T]int
+ //
+ // type T []int
+ _IncomparableMapKey
+
+ // _InvalidIfaceEmbed occurs when a non-interface type is embedded in an
+ // interface.
+ //
+ // Example:
+ // type T struct {}
+ //
+ // func (T) m()
+ //
+ // type I interface {
+ // T
+ // }
+ _InvalidIfaceEmbed
+
+ // _InvalidPtrEmbed occurs when an embedded field is of the pointer form *T,
+ // and T itself is itself a pointer, an unsafe.Pointer, or an interface.
+ //
+ // Per the spec:
+ // "An embedded field must be specified as a type name T or as a pointer to
+ // a non-interface type name *T, and T itself may not be a pointer type."
+ //
+ // Example:
+ // type T *int
+ //
+ // type S struct {
+ // *T
+ // }
+ _InvalidPtrEmbed
+
+ /* decls > func and method */
+
+ // _BadRecv occurs when a method declaration does not have exactly one
+ // receiver parameter.
+ //
+ // Example:
+ // func () _() {}
+ _BadRecv
+
+ // _InvalidRecv occurs when a receiver type expression is not of the form T
+ // or *T, or T is a pointer type.
+ //
+ // Example:
+ // type T struct {}
+ //
+ // func (**T) m() {}
+ _InvalidRecv
+
+ // _DuplicateFieldAndMethod occurs when an identifier appears as both a field
+ // and method name.
+ //
+ // Example:
+ // type T struct {
+ // m int
+ // }
+ //
+ // func (T) m() {}
+ _DuplicateFieldAndMethod
+
+ // _DuplicateMethod occurs when two methods on the same receiver type have
+ // the same name.
+ //
+ // Example:
+ // type T struct {}
+ // func (T) m() {}
+ // func (T) m(i int) int { return i }
+ _DuplicateMethod
+
+ /* decls > special */
+
+ // _InvalidBlank occurs when a blank identifier is used as a value or type.
+ //
+ // Per the spec:
+ // "The blank identifier may appear as an operand only on the left-hand side
+ // of an assignment."
+ //
+ // Example:
+ // var x = _
+ _InvalidBlank
+
+ // _InvalidIota occurs when the predeclared identifier iota is used outside
+ // of a constant declaration.
+ //
+ // Example:
+ // var x = iota
+ _InvalidIota
+
+ // _MissingInitBody occurs when an init function is missing its body.
+ //
+ // Example:
+ // func init()
+ _MissingInitBody
+
+ // _InvalidInitSig occurs when an init function declares parameters or
+ // results.
+ //
+ // Example:
+ // func init() int { return 1 }
+ _InvalidInitSig
+
+ // _InvalidInitDecl occurs when init is declared as anything other than a
+ // function.
+ //
+ // Example:
+ // var init = 1
+ _InvalidInitDecl
+
+ // _InvalidMainDecl occurs when main is declared as anything other than a
+ // function, in a main package.
+ _InvalidMainDecl
+
+ /* exprs */
+
+ // _TooManyValues occurs when a function returns too many values for the
+ // expression context in which it is used.
+ //
+ // Example:
+ // func ReturnTwo() (int, int) {
+ // return 1, 2
+ // }
+ //
+ // var x = ReturnTwo()
+ _TooManyValues
+
+ // _NotAnExpr occurs when a type expression is used where a value expression
+ // is expected.
+ //
+ // Example:
+ // type T struct {}
+ //
+ // func f() {
+ // T
+ // }
+ _NotAnExpr
+
+ /* exprs > const */
+
+ // _TruncatedFloat occurs when a float constant is truncated to an integer
+ // value.
+ //
+ // Example:
+ // var _ int = 98.6
+ _TruncatedFloat
+
+ // _NumericOverflow occurs when a numeric constant overflows its target type.
+ //
+ // Example:
+ // var x int8 = 1000
+ _NumericOverflow
+
+ /* exprs > operation */
+
+ // _UndefinedOp occurs when an operator is not defined for the type(s) used
+ // in an operation.
+ //
+ // Example:
+ // var c = "a" - "b"
+ _UndefinedOp
+
+ // _MismatchedTypes occurs when operand types are incompatible in a binary
+ // operation.
+ //
+ // Example:
+ // var a = "hello"
+ // var b = 1
+ // var c = a - b
+ _MismatchedTypes
+
+ // _DivByZero occurs when a division operation is provable at compile
+ // time to be a division by zero.
+ //
+ // Example:
+ // const divisor = 0
+ // var x int = 1/divisor
+ _DivByZero
+
+ // _NonNumericIncDec occurs when an increment or decrement operator is
+ // applied to a non-numeric value.
+ //
+ // Example:
+ // func f() {
+ // var c = "c"
+ // c++
+ // }
+ _NonNumericIncDec
+
+ /* exprs > ptr */
+
+ // _UnaddressableOperand occurs when the & operator is applied to an
+ // unaddressable expression.
+ //
+ // Example:
+ // var x = &1
+ _UnaddressableOperand
+
+ // _InvalidIndirection occurs when a non-pointer value is indirected via the
+ // '*' operator.
+ //
+ // Example:
+ // var x int
+ // var y = *x
+ _InvalidIndirection
+
+ /* exprs > [] */
+
+ // _NonIndexableOperand occurs when an index operation is applied to a value
+ // that cannot be indexed.
+ //
+ // Example:
+ // var x = 1
+ // var y = x[1]
+ _NonIndexableOperand
+
+ // _InvalidIndex occurs when an index argument is not of integer type,
+ // negative, or out-of-bounds.
+ //
+ // Example:
+ // var s = [...]int{1,2,3}
+ // var x = s[5]
+ //
+ // Example:
+ // var s = []int{1,2,3}
+ // var _ = s[-1]
+ //
+ // Example:
+ // var s = []int{1,2,3}
+ // var i string
+ // var _ = s[i]
+ _InvalidIndex
+
+ // _SwappedSliceIndices occurs when constant indices in a slice expression
+ // are decreasing in value.
+ //
+ // Example:
+ // var _ = []int{1,2,3}[2:1]
+ _SwappedSliceIndices
+
+ /* operators > slice */
+
+ // _NonSliceableOperand occurs when a slice operation is applied to a value
+ // whose type is not sliceable, or is unaddressable.
+ //
+ // Example:
+ // var x = [...]int{1, 2, 3}[:1]
+ //
+ // Example:
+ // var x = 1
+ // var y = 1[:1]
+ _NonSliceableOperand
+
+ // _InvalidSliceExpr occurs when a three-index slice expression (a[x:y:z]) is
+ // applied to a string.
+ //
+ // Example:
+ // var s = "hello"
+ // var x = s[1:2:3]
+ _InvalidSliceExpr
+
+ /* exprs > shift */
+
+ // _InvalidShiftCount occurs when the right-hand side of a shift operation is
+ // either non-integer, negative, or too large.
+ //
+ // Example:
+ // var (
+ // x string
+ // y int = 1 << x
+ // )
+ _InvalidShiftCount
+
+ // _InvalidShiftOperand occurs when the shifted operand is not an integer.
+ //
+ // Example:
+ // var s = "hello"
+ // var x = s << 2
+ _InvalidShiftOperand
+
+ /* exprs > chan */
+
+ // _InvalidReceive occurs when there is a channel receive from a value that
+ // is either not a channel, or is a send-only channel.
+ //
+ // Example:
+ // func f() {
+ // var x = 1
+ // <-x
+ // }
+ _InvalidReceive
+
+ // _InvalidSend occurs when there is a channel send to a value that is not a
+ // channel, or is a receive-only channel.
+ //
+ // Example:
+ // func f() {
+ // var x = 1
+ // x <- "hello!"
+ // }
+ _InvalidSend
+
+ /* exprs > literal */
+
+ // _DuplicateLitKey occurs when an index is duplicated in a slice, array, or
+ // map literal.
+ //
+ // Example:
+ // var _ = []int{0:1, 0:2}
+ //
+ // Example:
+ // var _ = map[string]int{"a": 1, "a": 2}
+ _DuplicateLitKey
+
+ // _MissingLitKey occurs when a map literal is missing a key expression.
+ //
+ // Example:
+ // var _ = map[string]int{1}
+ _MissingLitKey
+
+ // _InvalidLitIndex occurs when the key in a key-value element of a slice or
+ // array literal is not an integer constant.
+ //
+ // Example:
+ // var i = 0
+ // var x = []string{i: "world"}
+ _InvalidLitIndex
+
+ // _OversizeArrayLit occurs when an array literal exceeds its length.
+ //
+ // Example:
+ // var _ = [2]int{1,2,3}
+ _OversizeArrayLit
+
+ // _MixedStructLit occurs when a struct literal contains a mix of positional
+ // and named elements.
+ //
+ // Example:
+ // var _ = struct{i, j int}{i: 1, 2}
+ _MixedStructLit
+
+ // _InvalidStructLit occurs when a positional struct literal has an incorrect
+ // number of values.
+ //
+ // Example:
+ // var _ = struct{i, j int}{1,2,3}
+ _InvalidStructLit
+
+ // _MissingLitField occurs when a struct literal refers to a field that does
+ // not exist on the struct type.
+ //
+ // Example:
+ // var _ = struct{i int}{j: 2}
+ _MissingLitField
+
+ // _DuplicateLitField occurs when a struct literal contains duplicated
+ // fields.
+ //
+ // Example:
+ // var _ = struct{i int}{i: 1, i: 2}
+ _DuplicateLitField
+
+ // _UnexportedLitField occurs when a positional struct literal implicitly
+ // assigns an unexported field of an imported type.
+ _UnexportedLitField
+
+ // _InvalidLitField occurs when a field name is not a valid identifier.
+ //
+ // Example:
+ // var _ = struct{i int}{1: 1}
+ _InvalidLitField
+
+ // _UntypedLit occurs when a composite literal omits a required type
+ // identifier.
+ //
+ // Example:
+ // type outer struct{
+ // inner struct { i int }
+ // }
+ //
+ // var _ = outer{inner: {1}}
+ _UntypedLit
+
+ // _InvalidLit occurs when a composite literal expression does not match its
+ // type.
+ //
+ // Example:
+ // type P *struct{
+ // x int
+ // }
+ // var _ = P {}
+ _InvalidLit
+
+ /* exprs > selector */
+
+ // _AmbiguousSelector occurs when a selector is ambiguous.
+ //
+ // Example:
+ // type E1 struct { i int }
+ // type E2 struct { i int }
+ // type T struct { E1; E2 }
+ //
+ // var x T
+ // var _ = x.i
+ _AmbiguousSelector
+
+ // _UndeclaredImportedName occurs when a package-qualified identifier is
+ // undeclared by the imported package.
+ //
+ // Example:
+ // import "go/types"
+ //
+ // var _ = types.NotAnActualIdentifier
+ _UndeclaredImportedName
+
+ // _UnexportedName occurs when a selector refers to an unexported identifier
+ // of an imported package.
+ //
+ // Example:
+ // import "reflect"
+ //
+ // type _ reflect.flag
+ _UnexportedName
+
+ // _UndeclaredName occurs when an identifier is not declared in the current
+ // scope.
+ //
+ // Example:
+ // var x T
+ _UndeclaredName
+
+ // _MissingFieldOrMethod occurs when a selector references a field or method
+ // that does not exist.
+ //
+ // Example:
+ // type T struct {}
+ //
+ // var x = T{}.f
+ _MissingFieldOrMethod
+
+ /* exprs > ... */
+
+ // _BadDotDotDotSyntax occurs when a "..." occurs in a context where it is
+ // not valid.
+ //
+ // Example:
+ // var _ = map[int][...]int{0: {}}
+ _BadDotDotDotSyntax
+
+ // _NonVariadicDotDotDot occurs when a "..." is used on the final argument to
+ // a non-variadic function.
+ //
+ // Example:
+ // func printArgs(s []string) {
+ // for _, a := range s {
+ // println(a)
+ // }
+ // }
+ //
+ // func f() {
+ // s := []string{"a", "b", "c"}
+ // printArgs(s...)
+ // }
+ _NonVariadicDotDotDot
+
+ // _MisplacedDotDotDot occurs when a "..." is used somewhere other than the
+ // final argument to a function call.
+ //
+ // Example:
+ // func printArgs(args ...int) {
+ // for _, a := range args {
+ // println(a)
+ // }
+ // }
+ //
+ // func f() {
+ // a := []int{1,2,3}
+ // printArgs(0, a...)
+ // }
+ _MisplacedDotDotDot
+
+ // _InvalidDotDotDotOperand occurs when a "..." operator is applied to a
+ // single-valued operand.
+ //
+ // Example:
+ // func printArgs(args ...int) {
+ // for _, a := range args {
+ // println(a)
+ // }
+ // }
+ //
+ // func f() {
+ // a := 1
+ // printArgs(a...)
+ // }
+ //
+ // Example:
+ // func args() (int, int) {
+ // return 1, 2
+ // }
+ //
+ // func printArgs(args ...int) {
+ // for _, a := range args {
+ // println(a)
+ // }
+ // }
+ //
+ // func g() {
+ // printArgs(args()...)
+ // }
+ _InvalidDotDotDotOperand
+
+ // _InvalidDotDotDot occurs when a "..." is used in a non-variadic built-in
+ // function.
+ //
+ // Example:
+ // var s = []int{1, 2, 3}
+ // var l = len(s...)
+ _InvalidDotDotDot
+
+ /* exprs > built-in */
+
+ // _UncalledBuiltin occurs when a built-in function is used as a
+ // function-valued expression, instead of being called.
+ //
+ // Per the spec:
+ // "The built-in functions do not have standard Go types, so they can only
+ // appear in call expressions; they cannot be used as function values."
+ //
+ // Example:
+ // var _ = copy
+ _UncalledBuiltin
+
+ // _InvalidAppend occurs when append is called with a first argument that is
+ // not a slice.
+ //
+ // Example:
+ // var _ = append(1, 2)
+ _InvalidAppend
+
+ // _InvalidCap occurs when an argument to the cap built-in function is not of
+ // supported type.
+ //
+ // See https://golang.org/ref/spec#Length_and_capacity for information on
+ // which underlying types are supported as arguments to cap and len.
+ //
+ // Example:
+ // var s = 2
+ // var x = cap(s)
+ _InvalidCap
+
+ // _InvalidClose occurs when close(...) is called with an argument that is
+ // not of channel type, or that is a receive-only channel.
+ //
+ // Example:
+ // func f() {
+ // var x int
+ // close(x)
+ // }
+ _InvalidClose
+
+ // _InvalidCopy occurs when the arguments are not of slice type or do not
+ // have compatible type.
+ //
+ // See https://golang.org/ref/spec#Appending_and_copying_slices for more
+ // information on the type requirements for the copy built-in.
+ //
+ // Example:
+ // func f() {
+ // var x []int
+ // y := []int64{1,2,3}
+ // copy(x, y)
+ // }
+ _InvalidCopy
+
+ // _InvalidComplex occurs when the complex built-in function is called with
+ // arguments with incompatible types.
+ //
+ // Example:
+ // var _ = complex(float32(1), float64(2))
+ _InvalidComplex
+
+ // _InvalidDelete occurs when the delete built-in function is called with a
+ // first argument that is not a map.
+ //
+ // Example:
+ // func f() {
+ // m := "hello"
+ // delete(m, "e")
+ // }
+ _InvalidDelete
+
+ // _InvalidImag occurs when the imag built-in function is called with an
+ // argument that does not have complex type.
+ //
+ // Example:
+ // var _ = imag(int(1))
+ _InvalidImag
+
+ // _InvalidLen occurs when an argument to the len built-in function is not of
+ // supported type.
+ //
+ // See https://golang.org/ref/spec#Length_and_capacity for information on
+ // which underlying types are supported as arguments to cap and len.
+ //
+ // Example:
+ // var s = 2
+ // var x = len(s)
+ _InvalidLen
+
+ // _SwappedMakeArgs occurs when make is called with three arguments, and its
+ // length argument is larger than its capacity argument.
+ //
+ // Example:
+ // var x = make([]int, 3, 2)
+ _SwappedMakeArgs
+
+ // _InvalidMake occurs when make is called with an unsupported type argument.
+ //
+ // See https://golang.org/ref/spec#Making_slices_maps_and_channels for
+ // information on the types that may be created using make.
+ //
+ // Example:
+ // var x = make(int)
+ _InvalidMake
+
+ // _InvalidReal occurs when the real built-in function is called with an
+ // argument that does not have complex type.
+ //
+ // Example:
+ // var _ = real(int(1))
+ _InvalidReal
+
+ /* exprs > assertion */
+
+ // _InvalidAssert occurs when a type assertion is applied to a
+ // value that is not of interface type.
+ //
+ // Example:
+ // var x = 1
+ // var _ = x.(float64)
+ _InvalidAssert
+
+ // _ImpossibleAssert occurs for a type assertion x.(T) when the value x of
+ // interface cannot have dynamic type T, due to a missing or mismatching
+ // method on T.
+ //
+ // Example:
+ // type T int
+ //
+ // func (t *T) m() int { return int(*t) }
+ //
+ // type I interface { m() int }
+ //
+ // var x I
+ // var _ = x.(T)
+ _ImpossibleAssert
+
+ /* exprs > conversion */
+
+ // _InvalidConversion occurs when the argument type cannot be converted to the
+ // target.
+ //
+ // See https://golang.org/ref/spec#Conversions for the rules of
+ // convertibility.
+ //
+ // Example:
+ // var x float64
+ // var _ = string(x)
+ _InvalidConversion
+
+ // _InvalidUntypedConversion occurs when an there is no valid implicit
+ // conversion from an untyped value satisfying the type constraints of the
+ // context in which it is used.
+ //
+ // Example:
+ // var _ = 1 + ""
+ _InvalidUntypedConversion
+
+ /* offsetof */
+
+ // _BadOffsetofSyntax occurs when unsafe.Offsetof is called with an argument
+ // that is not a selector expression.
+ //
+ // Example:
+ // import "unsafe"
+ //
+ // var x int
+ // var _ = unsafe.Offsetof(x)
+ _BadOffsetofSyntax
+
+ // _InvalidOffsetof occurs when unsafe.Offsetof is called with a method
+ // selector, rather than a field selector, or when the field is embedded via
+ // a pointer.
+ //
+ // Per the spec:
+ //
+ // "If f is an embedded field, it must be reachable without pointer
+ // indirections through fields of the struct. "
+ //
+ // Example:
+ // import "unsafe"
+ //
+ // type T struct { f int }
+ // type S struct { *T }
+ // var s S
+ // var _ = unsafe.Offsetof(s.f)
+ //
+ // Example:
+ // import "unsafe"
+ //
+ // type S struct{}
+ //
+ // func (S) m() {}
+ //
+ // var s S
+ // var _ = unsafe.Offsetof(s.m)
+ _InvalidOffsetof
+
+ /* control flow > scope */
+
+ // _UnusedExpr occurs when a side-effect free expression is used as a
+ // statement. Such a statement has no effect.
+ //
+ // Example:
+ // func f(i int) {
+ // i*i
+ // }
+ _UnusedExpr
+
+ // _UnusedVar occurs when a variable is declared but unused.
+ //
+ // Example:
+ // func f() {
+ // x := 1
+ // }
+ _UnusedVar
+
+ // _MissingReturn occurs when a function with results is missing a return
+ // statement.
+ //
+ // Example:
+ // func f() int {}
+ _MissingReturn
+
+ // _WrongResultCount occurs when a return statement returns an incorrect
+ // number of values.
+ //
+ // Example:
+ // func ReturnOne() int {
+ // return 1, 2
+ // }
+ _WrongResultCount
+
+ // _OutOfScopeResult occurs when the name of a value implicitly returned by
+ // an empty return statement is shadowed in a nested scope.
+ //
+ // Example:
+ // func factor(n int) (i int) {
+ // for i := 2; i < n; i++ {
+ // if n%i == 0 {
+ // return
+ // }
+ // }
+ // return 0
+ // }
+ _OutOfScopeResult
+
+ /* control flow > if */
+
+ // _InvalidCond occurs when an if condition is not a boolean expression.
+ //
+ // Example:
+ // func checkReturn(i int) {
+ // if i {
+ // panic("non-zero return")
+ // }
+ // }
+ _InvalidCond
+
+ /* control flow > for */
+
+ // _InvalidPostDecl occurs when there is a declaration in a for-loop post
+ // statement.
+ //
+ // Example:
+ // func f() {
+ // for i := 0; i < 10; j := 0 {}
+ // }
+ _InvalidPostDecl
+
+ // _InvalidChanRange occurs when a send-only channel used in a range
+ // expression.
+ //
+ // Example:
+ // func sum(c chan<- int) {
+ // s := 0
+ // for i := range c {
+ // s += i
+ // }
+ // }
+ _InvalidChanRange
+
+ // _InvalidIterVar occurs when two iteration variables are used while ranging
+ // over a channel.
+ //
+ // Example:
+ // func f(c chan int) {
+ // for k, v := range c {
+ // println(k, v)
+ // }
+ // }
+ _InvalidIterVar
+
+ // _InvalidRangeExpr occurs when the type of a range expression is not array,
+ // slice, string, map, or channel.
+ //
+ // Example:
+ // func f(i int) {
+ // for j := range i {
+ // println(j)
+ // }
+ // }
+ _InvalidRangeExpr
+
+ /* control flow > switch */
+
+ // _MisplacedBreak occurs when a break statement is not within a for, switch,
+ // or select statement of the innermost function definition.
+ //
+ // Example:
+ // func f() {
+ // break
+ // }
+ _MisplacedBreak
+
+ // _MisplacedContinue occurs when a continue statement is not within a for
+ // loop of the innermost function definition.
+ //
+ // Example:
+ // func sumeven(n int) int {
+ // proceed := func() {
+ // continue
+ // }
+ // sum := 0
+ // for i := 1; i <= n; i++ {
+ // if i % 2 != 0 {
+ // proceed()
+ // }
+ // sum += i
+ // }
+ // return sum
+ // }
+ _MisplacedContinue
+
+ // _MisplacedFallthrough occurs when a fallthrough statement is not within an
+ // expression switch.
+ //
+ // Example:
+ // func typename(i interface{}) string {
+ // switch i.(type) {
+ // case int64:
+ // fallthrough
+ // case int:
+ // return "int"
+ // }
+ // return "unsupported"
+ // }
+ _MisplacedFallthrough
+
+ // _DuplicateCase occurs when a type or expression switch has duplicate
+ // cases.
+ //
+ // Example:
+ // func printInt(i int) {
+ // switch i {
+ // case 1:
+ // println("one")
+ // case 1:
+ // println("One")
+ // }
+ // }
+ _DuplicateCase
+
+ // _DuplicateDefault occurs when a type or expression switch has multiple
+ // default clauses.
+ //
+ // Example:
+ // func printInt(i int) {
+ // switch i {
+ // case 1:
+ // println("one")
+ // default:
+ // println("One")
+ // default:
+ // println("1")
+ // }
+ // }
+ _DuplicateDefault
+
+ // _BadTypeKeyword occurs when a .(type) expression is used anywhere other
+ // than a type switch.
+ //
+ // Example:
+ // type I interface {
+ // m()
+ // }
+ // var t I
+ // var _ = t.(type)
+ _BadTypeKeyword
+
+ // _InvalidTypeSwitch occurs when .(type) is used on an expression that is
+ // not of interface type.
+ //
+ // Example:
+ // func f(i int) {
+ // switch x := i.(type) {}
+ // }
+ _InvalidTypeSwitch
+
+ // _InvalidExprSwitch occurs when a switch expression is not comparable.
+ //
+ // Example:
+ // func _() {
+ // var a struct{ _ func() }
+ // switch a /* ERROR cannot switch on a */ {
+ // }
+ // }
+ _InvalidExprSwitch
+
+ /* control flow > select */
+
+ // _InvalidSelectCase occurs when a select case is not a channel send or
+ // receive.
+ //
+ // Example:
+ // func checkChan(c <-chan int) bool {
+ // select {
+ // case c:
+ // return true
+ // default:
+ // return false
+ // }
+ // }
+ _InvalidSelectCase
+
+ /* control flow > labels and jumps */
+
+ // _UndeclaredLabel occurs when an undeclared label is jumped to.
+ //
+ // Example:
+ // func f() {
+ // goto L
+ // }
+ _UndeclaredLabel
+
+ // _DuplicateLabel occurs when a label is declared more than once.
+ //
+ // Example:
+ // func f() int {
+ // L:
+ // L:
+ // return 1
+ // }
+ _DuplicateLabel
+
+ // _MisplacedLabel occurs when a break or continue label is not on a for,
+ // switch, or select statement.
+ //
+ // Example:
+ // func f() {
+ // L:
+ // a := []int{1,2,3}
+ // for _, e := range a {
+ // if e > 10 {
+ // break L
+ // }
+ // println(a)
+ // }
+ // }
+ _MisplacedLabel
+
+ // _UnusedLabel occurs when a label is declared but not used.
+ //
+ // Example:
+ // func f() {
+ // L:
+ // }
+ _UnusedLabel
+
+ // _JumpOverDecl occurs when a label jumps over a variable declaration.
+ //
+ // Example:
+ // func f() int {
+ // goto L
+ // x := 2
+ // L:
+ // x++
+ // return x
+ // }
+ _JumpOverDecl
+
+ // _JumpIntoBlock occurs when a forward jump goes to a label inside a nested
+ // block.
+ //
+ // Example:
+ // func f(x int) {
+ // goto L
+ // if x > 0 {
+ // L:
+ // print("inside block")
+ // }
+ // }
+ _JumpIntoBlock
+
+ /* control flow > calls */
+
+ // _InvalidMethodExpr occurs when a pointer method is called but the argument
+ // is not addressable.
+ //
+ // Example:
+ // type T struct {}
+ //
+ // func (*T) m() int { return 1 }
+ //
+ // var _ = T.m(T{})
+ _InvalidMethodExpr
+
+ // _WrongArgCount occurs when too few or too many arguments are passed by a
+ // function call.
+ //
+ // Example:
+ // func f(i int) {}
+ // var x = f()
+ _WrongArgCount
+
+ // _InvalidCall occurs when an expression is called that is not of function
+ // type.
+ //
+ // Example:
+ // var x = "x"
+ // var y = x()
+ _InvalidCall
+
+ /* control flow > suspended */
+
+ // _UnusedResults occurs when a restricted expression-only built-in function
+ // is suspended via go or defer. Such a suspension discards the results of
+ // these side-effect free built-in functions, and therefore is ineffectual.
+ //
+ // Example:
+ // func f(a []int) int {
+ // defer len(a)
+ // return i
+ // }
+ _UnusedResults
+
+ // _InvalidDefer occurs when a deferred expression is not a function call,
+ // for example if the expression is a type conversion.
+ //
+ // Example:
+ // func f(i int) int {
+ // defer int32(i)
+ // return i
+ // }
+ _InvalidDefer
+
+ // _InvalidGo occurs when a go expression is not a function call, for example
+ // if the expression is a type conversion.
+ //
+ // Example:
+ // func f(i int) int {
+ // go int32(i)
+ // return i
+ // }
+ _InvalidGo
+)
diff --git a/src/go/types/errorcodes_test.go b/src/go/types/errorcodes_test.go
new file mode 100644
index 0000000..5da1cda
--- /dev/null
+++ b/src/go/types/errorcodes_test.go
@@ -0,0 +1,197 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/constant"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "reflect"
+ "strings"
+ "testing"
+
+ . "go/types"
+)
+
+func TestErrorCodeExamples(t *testing.T) {
+ walkCodes(t, func(name string, value int, spec *ast.ValueSpec) {
+ t.Run(name, func(t *testing.T) {
+ doc := spec.Doc.Text()
+ examples := strings.Split(doc, "Example:")
+ for i := 1; i < len(examples); i++ {
+ example := examples[i]
+ err := checkExample(t, example)
+ if err == nil {
+ t.Fatalf("no error in example #%d", i)
+ }
+ typerr, ok := err.(Error)
+ if !ok {
+ t.Fatalf("not a types.Error: %v", err)
+ }
+ if got := readCode(typerr); got != value {
+ t.Errorf("%s: example #%d returned code %d (%s), want %d", name, i, got, err, value)
+ }
+ }
+ })
+ })
+}
+
+func walkCodes(t *testing.T, f func(string, int, *ast.ValueSpec)) {
+ t.Helper()
+ fset := token.NewFileSet()
+ files, err := pkgFiles(fset, ".", parser.ParseComments) // from self_test.go
+ if err != nil {
+ t.Fatal(err)
+ }
+ conf := Config{Importer: importer.Default()}
+ info := &Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ Defs: make(map[*ast.Ident]Object),
+ Uses: make(map[*ast.Ident]Object),
+ }
+ _, err = conf.Check("types", fset, files, info)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for _, file := range files {
+ for _, decl := range file.Decls {
+ decl, ok := decl.(*ast.GenDecl)
+ if !ok || decl.Tok != token.CONST {
+ continue
+ }
+ for _, spec := range decl.Specs {
+ spec, ok := spec.(*ast.ValueSpec)
+ if !ok || len(spec.Names) == 0 {
+ continue
+ }
+ obj := info.ObjectOf(spec.Names[0])
+ if named, ok := obj.Type().(*Named); ok && named.Obj().Name() == "errorCode" {
+ if len(spec.Names) != 1 {
+ t.Fatalf("bad Code declaration for %q: got %d names, want exactly 1", spec.Names[0].Name, len(spec.Names))
+ }
+ codename := spec.Names[0].Name
+ value := int(constant.Val(obj.(*Const).Val()).(int64))
+ f(codename, value, spec)
+ }
+ }
+ }
+ }
+}
+
+func readCode(err Error) int {
+ v := reflect.ValueOf(err)
+ return int(v.FieldByName("go116code").Int())
+}
+
+func checkExample(t *testing.T, example string) error {
+ t.Helper()
+ fset := token.NewFileSet()
+ src := fmt.Sprintf("package p\n\n%s", example)
+ file, err := parser.ParseFile(fset, "example.go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ conf := Config{
+ FakeImportC: true,
+ Importer: importer.Default(),
+ }
+ _, err = conf.Check("example", fset, []*ast.File{file}, nil)
+ return err
+}
+
+func TestErrorCodeStyle(t *testing.T) {
+ // The set of error codes is large and intended to be self-documenting, so
+ // this test enforces some style conventions.
+ forbiddenInIdent := []string{
+ // use invalid instead
+ "illegal",
+ // words with a common short-form
+ "argument",
+ "assertion",
+ "assignment",
+ "boolean",
+ "channel",
+ "condition",
+ "declaration",
+ "expression",
+ "function",
+ "initial", // use init for initializer, initialization, etc.
+ "integer",
+ "interface",
+ "iterat", // use iter for iterator, iteration, etc.
+ "literal",
+ "operation",
+ "package",
+ "pointer",
+ "receiver",
+ "signature",
+ "statement",
+ "variable",
+ }
+ forbiddenInComment := []string{
+ // lhs and rhs should be spelled-out.
+ "lhs", "rhs",
+ // builtin should be hyphenated.
+ "builtin",
+ // Use dot-dot-dot.
+ "ellipsis",
+ }
+ nameHist := make(map[int]int)
+ longestName := ""
+ maxValue := 0
+
+ walkCodes(t, func(name string, value int, spec *ast.ValueSpec) {
+ if name == "_" {
+ return
+ }
+ nameHist[len(name)]++
+ if value > maxValue {
+ maxValue = value
+ }
+ if len(name) > len(longestName) {
+ longestName = name
+ }
+ if token.IsExported(name) {
+ // This is an experimental API, and errorCode values should not be
+ // exported.
+ t.Errorf("%q is exported", name)
+ }
+ if name[0] != '_' || !token.IsExported(name[1:]) {
+ t.Errorf("%q should start with _, followed by an exported identifier", name)
+ }
+ lower := strings.ToLower(name)
+ for _, bad := range forbiddenInIdent {
+ if strings.Contains(lower, bad) {
+ t.Errorf("%q contains forbidden word %q", name, bad)
+ }
+ }
+ doc := spec.Doc.Text()
+ if !strings.HasPrefix(doc, name) {
+ t.Errorf("doc for %q does not start with identifier", name)
+ }
+ lowerComment := strings.ToLower(strings.TrimPrefix(doc, name))
+ for _, bad := range forbiddenInComment {
+ if strings.Contains(lowerComment, bad) {
+ t.Errorf("doc for %q contains forbidden word %q", name, bad)
+ }
+ }
+ })
+
+ if testing.Verbose() {
+ var totChars, totCount int
+ for chars, count := range nameHist {
+ totChars += chars * count
+ totCount += count
+ }
+ avg := float64(totChars) / float64(totCount)
+ fmt.Println()
+ fmt.Printf("%d error codes\n", totCount)
+ fmt.Printf("average length: %.2f chars\n", avg)
+ fmt.Printf("max length: %d (%s)\n", len(longestName), longestName)
+ }
+}
diff --git a/src/go/types/errors.go b/src/go/types/errors.go
new file mode 100644
index 0000000..a219501
--- /dev/null
+++ b/src/go/types/errors.go
@@ -0,0 +1,227 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements various error reporters.
+
+package types
+
+import (
+ "errors"
+ "fmt"
+ "go/ast"
+ "go/token"
+ "strconv"
+ "strings"
+)
+
+func assert(p bool) {
+ if !p {
+ panic("assertion failed")
+ }
+}
+
+func unreachable() {
+ panic("unreachable")
+}
+
+func (check *Checker) qualifier(pkg *Package) string {
+ // Qualify the package unless it's the package being type-checked.
+ if pkg != check.pkg {
+ // If the same package name was used by multiple packages, display the full path.
+ if check.pkgCnt[pkg.name] > 1 {
+ return strconv.Quote(pkg.path)
+ }
+ return pkg.name
+ }
+ return ""
+}
+
+func (check *Checker) sprintf(format string, args ...interface{}) string {
+ for i, arg := range args {
+ switch a := arg.(type) {
+ case nil:
+ arg = "<nil>"
+ case operand:
+ panic("internal error: should always pass *operand")
+ case *operand:
+ arg = operandString(a, check.qualifier)
+ case token.Pos:
+ arg = check.fset.Position(a).String()
+ case ast.Expr:
+ arg = ExprString(a)
+ case Object:
+ arg = ObjectString(a, check.qualifier)
+ case Type:
+ arg = TypeString(a, check.qualifier)
+ }
+ args[i] = arg
+ }
+ return fmt.Sprintf(format, args...)
+}
+
+func (check *Checker) trace(pos token.Pos, format string, args ...interface{}) {
+ fmt.Printf("%s:\t%s%s\n",
+ check.fset.Position(pos),
+ strings.Repeat(". ", check.indent),
+ check.sprintf(format, args...),
+ )
+}
+
+// dump is only needed for debugging
+func (check *Checker) dump(format string, args ...interface{}) {
+ fmt.Println(check.sprintf(format, args...))
+}
+
+func (check *Checker) err(err error) {
+ if err == nil {
+ return
+ }
+ var e Error
+ isInternal := errors.As(err, &e)
+ // Cheap trick: Don't report errors with messages containing
+ // "invalid operand" or "invalid type" as those tend to be
+ // follow-on errors which don't add useful information. Only
+ // exclude them if these strings are not at the beginning,
+ // and only if we have at least one error already reported.
+ isInvalidErr := isInternal && (strings.Index(e.Msg, "invalid operand") > 0 || strings.Index(e.Msg, "invalid type") > 0)
+ if check.firstErr != nil && isInvalidErr {
+ return
+ }
+
+ if check.errpos != nil && isInternal {
+ // If we have an internal error and the errpos override is set, use it to
+ // augment our error positioning.
+ // TODO(rFindley) we may also want to augment the error message and refer
+ // to the position (pos) in the original expression.
+ span := spanOf(check.errpos)
+ e.Pos = span.pos
+ e.go116start = span.start
+ e.go116end = span.end
+ err = e
+ }
+
+ if check.firstErr == nil {
+ check.firstErr = err
+ }
+
+ if trace {
+ pos := e.Pos
+ msg := e.Msg
+ if !isInternal {
+ msg = err.Error()
+ pos = token.NoPos
+ }
+ check.trace(pos, "ERROR: %s", msg)
+ }
+
+ f := check.conf.Error
+ if f == nil {
+ panic(bailout{}) // report only first error
+ }
+ f(err)
+}
+
+func (check *Checker) newError(at positioner, code errorCode, soft bool, msg string) error {
+ span := spanOf(at)
+ return Error{
+ Fset: check.fset,
+ Pos: span.pos,
+ Msg: msg,
+ Soft: soft,
+ go116code: code,
+ go116start: span.start,
+ go116end: span.end,
+ }
+}
+
+// newErrorf creates a new Error, but does not handle it.
+func (check *Checker) newErrorf(at positioner, code errorCode, soft bool, format string, args ...interface{}) error {
+ msg := check.sprintf(format, args...)
+ return check.newError(at, code, soft, msg)
+}
+
+func (check *Checker) error(at positioner, code errorCode, msg string) {
+ check.err(check.newError(at, code, false, msg))
+}
+
+func (check *Checker) errorf(at positioner, code errorCode, format string, args ...interface{}) {
+ check.error(at, code, check.sprintf(format, args...))
+}
+
+func (check *Checker) softErrorf(at positioner, code errorCode, format string, args ...interface{}) {
+ check.err(check.newErrorf(at, code, true, format, args...))
+}
+
+func (check *Checker) invalidAST(at positioner, format string, args ...interface{}) {
+ check.errorf(at, 0, "invalid AST: "+format, args...)
+}
+
+func (check *Checker) invalidArg(at positioner, code errorCode, format string, args ...interface{}) {
+ check.errorf(at, code, "invalid argument: "+format, args...)
+}
+
+func (check *Checker) invalidOp(at positioner, code errorCode, format string, args ...interface{}) {
+ check.errorf(at, code, "invalid operation: "+format, args...)
+}
+
+// The positioner interface is used to extract the position of type-checker
+// errors.
+type positioner interface {
+ Pos() token.Pos
+}
+
+// posSpan holds a position range along with a highlighted position within that
+// range. This is used for positioning errors, with pos by convention being the
+// first position in the source where the error is known to exist, and start
+// and end defining the full span of syntax being considered when the error was
+// detected. Invariant: start <= pos < end || start == pos == end.
+type posSpan struct {
+ start, pos, end token.Pos
+}
+
+func (e posSpan) Pos() token.Pos {
+ return e.pos
+}
+
+// inNode creates a posSpan for the given node.
+// Invariant: node.Pos() <= pos < node.End() (node.End() is the position of the
+// first byte after node within the source).
+func inNode(node ast.Node, pos token.Pos) posSpan {
+ start, end := node.Pos(), node.End()
+ if debug {
+ assert(start <= pos && pos < end)
+ }
+ return posSpan{start, pos, end}
+}
+
+// atPos wraps a token.Pos to implement the positioner interface.
+type atPos token.Pos
+
+func (s atPos) Pos() token.Pos {
+ return token.Pos(s)
+}
+
+// spanOf extracts an error span from the given positioner. By default this is
+// the trivial span starting and ending at pos, but this span is expanded when
+// the argument naturally corresponds to a span of source code.
+func spanOf(at positioner) posSpan {
+ switch x := at.(type) {
+ case nil:
+ panic("internal error: nil")
+ case posSpan:
+ return x
+ case ast.Node:
+ pos := x.Pos()
+ return posSpan{pos, pos, x.End()}
+ case *operand:
+ if x.expr != nil {
+ pos := x.Pos()
+ return posSpan{pos, pos, x.expr.End()}
+ }
+ return posSpan{token.NoPos, token.NoPos, token.NoPos}
+ default:
+ pos := at.Pos()
+ return posSpan{pos, pos, pos}
+ }
+}
diff --git a/src/go/types/eval.go b/src/go/types/eval.go
new file mode 100644
index 0000000..5125960
--- /dev/null
+++ b/src/go/types/eval.go
@@ -0,0 +1,99 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+)
+
+// Eval returns the type and, if constant, the value for the
+// expression expr, evaluated at position pos of package pkg,
+// which must have been derived from type-checking an AST with
+// complete position information relative to the provided file
+// set.
+//
+// The meaning of the parameters fset, pkg, and pos is the
+// same as in CheckExpr. An error is returned if expr cannot
+// be parsed successfully, or the resulting expr AST cannot be
+// type-checked.
+func Eval(fset *token.FileSet, pkg *Package, pos token.Pos, expr string) (_ TypeAndValue, err error) {
+ // parse expressions
+ node, err := parser.ParseExprFrom(fset, "eval", expr, 0)
+ if err != nil {
+ return TypeAndValue{}, err
+ }
+
+ info := &Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ }
+ err = CheckExpr(fset, pkg, pos, node, info)
+ return info.Types[node], err
+}
+
+// CheckExpr type checks the expression expr as if it had appeared at
+// position pos of package pkg. Type information about the expression
+// is recorded in info.
+//
+// If pkg == nil, the Universe scope is used and the provided
+// position pos is ignored. If pkg != nil, and pos is invalid,
+// the package scope is used. Otherwise, pos must belong to the
+// package.
+//
+// An error is returned if pos is not within the package or
+// if the node cannot be type-checked.
+//
+// Note: Eval and CheckExpr should not be used instead of running Check
+// to compute types and values, but in addition to Check, as these
+// functions ignore the context in which an expression is used (e.g., an
+// assignment). Thus, top-level untyped constants will return an
+// untyped type rather then the respective context-specific type.
+//
+func CheckExpr(fset *token.FileSet, pkg *Package, pos token.Pos, expr ast.Expr, info *Info) (err error) {
+ // determine scope
+ var scope *Scope
+ if pkg == nil {
+ scope = Universe
+ pos = token.NoPos
+ } else if !pos.IsValid() {
+ scope = pkg.scope
+ } else {
+ // The package scope extent (position information) may be
+ // incorrect (files spread across a wide range of fset
+ // positions) - ignore it and just consider its children
+ // (file scopes).
+ for _, fscope := range pkg.scope.children {
+ if scope = fscope.Innermost(pos); scope != nil {
+ break
+ }
+ }
+ if scope == nil || debug {
+ s := scope
+ for s != nil && s != pkg.scope {
+ s = s.parent
+ }
+ // s == nil || s == pkg.scope
+ if s == nil {
+ return fmt.Errorf("no position %s found in package %s", fset.Position(pos), pkg.name)
+ }
+ }
+ }
+
+ // initialize checker
+ check := NewChecker(nil, fset, pkg, info)
+ check.scope = scope
+ check.pos = pos
+ defer check.handleBailout(&err)
+
+ // evaluate node
+ var x operand
+ check.rawExpr(&x, expr, nil)
+ check.processDelayed(0) // incl. all functions
+ check.recordUntyped()
+
+ return nil
+}
diff --git a/src/go/types/eval_test.go b/src/go/types/eval_test.go
new file mode 100644
index 0000000..d940bf0
--- /dev/null
+++ b/src/go/types/eval_test.go
@@ -0,0 +1,297 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains tests for Eval.
+
+package types_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "internal/testenv"
+ "strings"
+ "testing"
+
+ . "go/types"
+)
+
+func testEval(t *testing.T, fset *token.FileSet, pkg *Package, pos token.Pos, expr string, typ Type, typStr, valStr string) {
+ gotTv, err := Eval(fset, pkg, pos, expr)
+ if err != nil {
+ t.Errorf("Eval(%q) failed: %s", expr, err)
+ return
+ }
+ if gotTv.Type == nil {
+ t.Errorf("Eval(%q) got nil type but no error", expr)
+ return
+ }
+
+ // compare types
+ if typ != nil {
+ // we have a type, check identity
+ if !Identical(gotTv.Type, typ) {
+ t.Errorf("Eval(%q) got type %s, want %s", expr, gotTv.Type, typ)
+ return
+ }
+ } else {
+ // we have a string, compare type string
+ gotStr := gotTv.Type.String()
+ if gotStr != typStr {
+ t.Errorf("Eval(%q) got type %s, want %s", expr, gotStr, typStr)
+ return
+ }
+ }
+
+ // compare values
+ gotStr := ""
+ if gotTv.Value != nil {
+ gotStr = gotTv.Value.ExactString()
+ }
+ if gotStr != valStr {
+ t.Errorf("Eval(%q) got value %s, want %s", expr, gotStr, valStr)
+ }
+}
+
+func TestEvalBasic(t *testing.T) {
+ fset := token.NewFileSet()
+ for _, typ := range Typ[Bool : String+1] {
+ testEval(t, fset, nil, token.NoPos, typ.Name(), typ, "", "")
+ }
+}
+
+func TestEvalComposite(t *testing.T) {
+ fset := token.NewFileSet()
+ for _, test := range independentTestTypes {
+ testEval(t, fset, nil, token.NoPos, test.src, nil, test.str, "")
+ }
+}
+
+func TestEvalArith(t *testing.T) {
+ var tests = []string{
+ `true`,
+ `false == false`,
+ `12345678 + 87654321 == 99999999`,
+ `10 * 20 == 200`,
+ `(1<<1000)*2 >> 100 == 2<<900`,
+ `"foo" + "bar" == "foobar"`,
+ `"abc" <= "bcd"`,
+ `len([10]struct{}{}) == 2*5`,
+ }
+ fset := token.NewFileSet()
+ for _, test := range tests {
+ testEval(t, fset, nil, token.NoPos, test, Typ[UntypedBool], "", "true")
+ }
+}
+
+func TestEvalPos(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ // The contents of /*-style comments are of the form
+ // expr => value, type
+ // where value may be the empty string.
+ // Each expr is evaluated at the position of the comment
+ // and the result is compared with the expected value
+ // and type.
+ var sources = []string{
+ `
+ package p
+ import "fmt"
+ import m "math"
+ const c = 3.0
+ type T []int
+ func f(a int, s string) float64 {
+ fmt.Println("calling f")
+ _ = m.Pi // use package math
+ const d int = c + 1
+ var x int
+ x = a + len(s)
+ return float64(x)
+ /* true => true, untyped bool */
+ /* fmt.Println => , func(a ...interface{}) (n int, err error) */
+ /* c => 3, untyped float */
+ /* T => , p.T */
+ /* a => , int */
+ /* s => , string */
+ /* d => 4, int */
+ /* x => , int */
+ /* d/c => 1, int */
+ /* c/2 => 3/2, untyped float */
+ /* m.Pi < m.E => false, untyped bool */
+ }
+ `,
+ `
+ package p
+ /* c => 3, untyped float */
+ type T1 /* T1 => , p.T1 */ struct {}
+ var v1 /* v1 => , int */ = 42
+ func /* f1 => , func(v1 float64) */ f1(v1 float64) {
+ /* f1 => , func(v1 float64) */
+ /* v1 => , float64 */
+ var c /* c => 3, untyped float */ = "foo" /* c => , string */
+ {
+ var c struct {
+ c /* c => , string */ int
+ }
+ /* c => , struct{c int} */
+ _ = c
+ }
+ _ = func(a, b, c int) /* c => , string */ {
+ /* c => , int */
+ }
+ _ = c
+ type FT /* FT => , p.FT */ interface{}
+ }
+ `,
+ `
+ package p
+ /* T => , p.T */
+ `,
+ `
+ package p
+ import "io"
+ type R = io.Reader
+ func _() {
+ /* interface{R}.Read => , func(interface{io.Reader}, p []byte) (n int, err error) */
+ _ = func() {
+ /* interface{io.Writer}.Write => , func(interface{io.Writer}, p []byte) (n int, err error) */
+ type io interface {} // must not shadow io in line above
+ }
+ type R interface {} // must not shadow R in first line of this function body
+ }
+ `,
+ }
+
+ fset := token.NewFileSet()
+ var files []*ast.File
+ for i, src := range sources {
+ file, err := parser.ParseFile(fset, "p", src, parser.ParseComments)
+ if err != nil {
+ t.Fatalf("could not parse file %d: %s", i, err)
+ }
+ files = append(files, file)
+ }
+
+ conf := Config{Importer: importer.Default()}
+ pkg, err := conf.Check("p", fset, files, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ for _, file := range files {
+ for _, group := range file.Comments {
+ for _, comment := range group.List {
+ s := comment.Text
+ if len(s) >= 4 && s[:2] == "/*" && s[len(s)-2:] == "*/" {
+ str, typ := split(s[2:len(s)-2], ", ")
+ str, val := split(str, "=>")
+ testEval(t, fset, pkg, comment.Pos(), str, nil, typ, val)
+ }
+ }
+ }
+ }
+}
+
+// split splits string s at the first occurrence of s.
+func split(s, sep string) (string, string) {
+ i := strings.Index(s, sep)
+ return strings.TrimSpace(s[:i]), strings.TrimSpace(s[i+len(sep):])
+}
+
+func TestCheckExpr(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ // Each comment has the form /* expr => object */:
+ // expr is an identifier or selector expression that is passed
+ // to CheckExpr at the position of the comment, and object is
+ // the string form of the object it denotes.
+ const src = `
+package p
+
+import "fmt"
+
+const c = 3.0
+type T []int
+type S struct{ X int }
+
+func f(a int, s string) S {
+ /* fmt.Println => func fmt.Println(a ...interface{}) (n int, err error) */
+ /* fmt.Stringer.String => func (fmt.Stringer).String() string */
+ fmt.Println("calling f")
+
+ var fmt struct{ Println int }
+ /* fmt => var fmt struct{Println int} */
+ /* fmt.Println => field Println int */
+ /* f(1, "").X => field X int */
+ fmt.Println = 1
+
+ /* append => builtin append */
+
+ /* new(S).X => field X int */
+
+ return S{}
+}`
+
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "p", src, parser.ParseComments)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ conf := Config{Importer: importer.Default()}
+ pkg, err := conf.Check("p", fset, []*ast.File{f}, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ checkExpr := func(pos token.Pos, str string) (Object, error) {
+ expr, err := parser.ParseExprFrom(fset, "eval", str, 0)
+ if err != nil {
+ return nil, err
+ }
+
+ info := &Info{
+ Uses: make(map[*ast.Ident]Object),
+ Selections: make(map[*ast.SelectorExpr]*Selection),
+ }
+ if err := CheckExpr(fset, pkg, pos, expr, info); err != nil {
+ return nil, fmt.Errorf("CheckExpr(%q) failed: %s", str, err)
+ }
+ switch expr := expr.(type) {
+ case *ast.Ident:
+ if obj, ok := info.Uses[expr]; ok {
+ return obj, nil
+ }
+ case *ast.SelectorExpr:
+ if sel, ok := info.Selections[expr]; ok {
+ return sel.Obj(), nil
+ }
+ if obj, ok := info.Uses[expr.Sel]; ok {
+ return obj, nil // qualified identifier
+ }
+ }
+ return nil, fmt.Errorf("no object for %s", str)
+ }
+
+ for _, group := range f.Comments {
+ for _, comment := range group.List {
+ s := comment.Text
+ if len(s) >= 4 && strings.HasPrefix(s, "/*") && strings.HasSuffix(s, "*/") {
+ pos := comment.Pos()
+ expr, wantObj := split(s[2:len(s)-2], "=>")
+ obj, err := checkExpr(pos, expr)
+ if err != nil {
+ t.Errorf("%s: %s", fset.Position(pos), err)
+ continue
+ }
+ if obj.String() != wantObj {
+ t.Errorf("%s: checkExpr(%s) = %s, want %v",
+ fset.Position(pos), expr, obj, wantObj)
+ }
+ }
+ }
+ }
+}
diff --git a/src/go/types/example_test.go b/src/go/types/example_test.go
new file mode 100644
index 0000000..3747f3b
--- /dev/null
+++ b/src/go/types/example_test.go
@@ -0,0 +1,334 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Only run where builders (build.golang.org) have
+// access to compiled packages for import.
+//
+// +build !arm,!arm64
+
+package types_test
+
+// This file shows examples of basic usage of the go/types API.
+//
+// To locate a Go package, use (*go/build.Context).Import.
+// To load, parse, and type-check a complete Go program
+// from source, use golang.org/x/tools/go/loader.
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/format"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "go/types"
+ "log"
+ "regexp"
+ "sort"
+ "strings"
+)
+
+// ExampleScope prints the tree of Scopes of a package created from a
+// set of parsed files.
+func ExampleScope() {
+ // Parse the source files for a package.
+ fset := token.NewFileSet()
+ var files []*ast.File
+ for _, file := range []struct{ name, input string }{
+ {"main.go", `
+package main
+import "fmt"
+func main() {
+ freezing := FToC(-18)
+ fmt.Println(freezing, Boiling) }
+`},
+ {"celsius.go", `
+package main
+import "fmt"
+type Celsius float64
+func (c Celsius) String() string { return fmt.Sprintf("%g°C", c) }
+func FToC(f float64) Celsius { return Celsius(f - 32 / 9 * 5) }
+const Boiling Celsius = 100
+func Unused() { {}; {{ var x int; _ = x }} } // make sure empty block scopes get printed
+`},
+ } {
+ f, err := parser.ParseFile(fset, file.name, file.input, 0)
+ if err != nil {
+ log.Fatal(err)
+ }
+ files = append(files, f)
+ }
+
+ // Type-check a package consisting of these files.
+ // Type information for the imported "fmt" package
+ // comes from $GOROOT/pkg/$GOOS_$GOOARCH/fmt.a.
+ conf := types.Config{Importer: importer.Default()}
+ pkg, err := conf.Check("temperature", fset, files, nil)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Print the tree of scopes.
+ // For determinism, we redact addresses.
+ var buf bytes.Buffer
+ pkg.Scope().WriteTo(&buf, 0, true)
+ rx := regexp.MustCompile(` 0x[a-fA-F0-9]*`)
+ fmt.Println(rx.ReplaceAllString(buf.String(), ""))
+
+ // Output:
+ // package "temperature" scope {
+ // . const temperature.Boiling temperature.Celsius
+ // . type temperature.Celsius float64
+ // . func temperature.FToC(f float64) temperature.Celsius
+ // . func temperature.Unused()
+ // . func temperature.main()
+ // . main.go scope {
+ // . . package fmt
+ // . . function scope {
+ // . . . var freezing temperature.Celsius
+ // . . }
+ // . }
+ // . celsius.go scope {
+ // . . package fmt
+ // . . function scope {
+ // . . . var c temperature.Celsius
+ // . . }
+ // . . function scope {
+ // . . . var f float64
+ // . . }
+ // . . function scope {
+ // . . . block scope {
+ // . . . }
+ // . . . block scope {
+ // . . . . block scope {
+ // . . . . . var x int
+ // . . . . }
+ // . . . }
+ // . . }
+ // . }
+ // }
+}
+
+// ExampleMethodSet prints the method sets of various types.
+func ExampleMethodSet() {
+ // Parse a single source file.
+ const input = `
+package temperature
+import "fmt"
+type Celsius float64
+func (c Celsius) String() string { return fmt.Sprintf("%g°C", c) }
+func (c *Celsius) SetF(f float64) { *c = Celsius(f - 32 / 9 * 5) }
+
+type S struct { I; m int }
+type I interface { m() byte }
+`
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "celsius.go", input, 0)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Type-check a package consisting of this file.
+ // Type information for the imported packages
+ // comes from $GOROOT/pkg/$GOOS_$GOOARCH/fmt.a.
+ conf := types.Config{Importer: importer.Default()}
+ pkg, err := conf.Check("temperature", fset, []*ast.File{f}, nil)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Print the method sets of Celsius and *Celsius.
+ celsius := pkg.Scope().Lookup("Celsius").Type()
+ for _, t := range []types.Type{celsius, types.NewPointer(celsius)} {
+ fmt.Printf("Method set of %s:\n", t)
+ mset := types.NewMethodSet(t)
+ for i := 0; i < mset.Len(); i++ {
+ fmt.Println(mset.At(i))
+ }
+ fmt.Println()
+ }
+
+ // Print the method set of S.
+ styp := pkg.Scope().Lookup("S").Type()
+ fmt.Printf("Method set of %s:\n", styp)
+ fmt.Println(types.NewMethodSet(styp))
+
+ // Output:
+ // Method set of temperature.Celsius:
+ // method (temperature.Celsius) String() string
+ //
+ // Method set of *temperature.Celsius:
+ // method (*temperature.Celsius) SetF(f float64)
+ // method (*temperature.Celsius) String() string
+ //
+ // Method set of temperature.S:
+ // MethodSet {}
+}
+
+// ExampleInfo prints various facts recorded by the type checker in a
+// types.Info struct: definitions of and references to each named object,
+// and the type, value, and mode of every expression in the package.
+func ExampleInfo() {
+ // Parse a single source file.
+ const input = `
+package fib
+
+type S string
+
+var a, b, c = len(b), S(c), "hello"
+
+func fib(x int) int {
+ if x < 2 {
+ return x
+ }
+ return fib(x-1) - fib(x-2)
+}`
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "fib.go", input, 0)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Type-check the package.
+ // We create an empty map for each kind of input
+ // we're interested in, and Check populates them.
+ info := types.Info{
+ Types: make(map[ast.Expr]types.TypeAndValue),
+ Defs: make(map[*ast.Ident]types.Object),
+ Uses: make(map[*ast.Ident]types.Object),
+ }
+ var conf types.Config
+ pkg, err := conf.Check("fib", fset, []*ast.File{f}, &info)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // Print package-level variables in initialization order.
+ fmt.Printf("InitOrder: %v\n\n", info.InitOrder)
+
+ // For each named object, print the line and
+ // column of its definition and each of its uses.
+ fmt.Println("Defs and Uses of each named object:")
+ usesByObj := make(map[types.Object][]string)
+ for id, obj := range info.Uses {
+ posn := fset.Position(id.Pos())
+ lineCol := fmt.Sprintf("%d:%d", posn.Line, posn.Column)
+ usesByObj[obj] = append(usesByObj[obj], lineCol)
+ }
+ var items []string
+ for obj, uses := range usesByObj {
+ sort.Strings(uses)
+ item := fmt.Sprintf("%s:\n defined at %s\n used at %s",
+ types.ObjectString(obj, types.RelativeTo(pkg)),
+ fset.Position(obj.Pos()),
+ strings.Join(uses, ", "))
+ items = append(items, item)
+ }
+ sort.Strings(items) // sort by line:col, in effect
+ fmt.Println(strings.Join(items, "\n"))
+ fmt.Println()
+
+ fmt.Println("Types and Values of each expression:")
+ items = nil
+ for expr, tv := range info.Types {
+ var buf bytes.Buffer
+ posn := fset.Position(expr.Pos())
+ tvstr := tv.Type.String()
+ if tv.Value != nil {
+ tvstr += " = " + tv.Value.String()
+ }
+ // line:col | expr | mode : type = value
+ fmt.Fprintf(&buf, "%2d:%2d | %-19s | %-7s : %s",
+ posn.Line, posn.Column, exprString(fset, expr),
+ mode(tv), tvstr)
+ items = append(items, buf.String())
+ }
+ sort.Strings(items)
+ fmt.Println(strings.Join(items, "\n"))
+
+ // Output:
+ // InitOrder: [c = "hello" b = S(c) a = len(b)]
+ //
+ // Defs and Uses of each named object:
+ // builtin len:
+ // defined at -
+ // used at 6:15
+ // func fib(x int) int:
+ // defined at fib.go:8:6
+ // used at 12:20, 12:9
+ // type S string:
+ // defined at fib.go:4:6
+ // used at 6:23
+ // type int:
+ // defined at -
+ // used at 8:12, 8:17
+ // type string:
+ // defined at -
+ // used at 4:8
+ // var b S:
+ // defined at fib.go:6:8
+ // used at 6:19
+ // var c string:
+ // defined at fib.go:6:11
+ // used at 6:25
+ // var x int:
+ // defined at fib.go:8:10
+ // used at 10:10, 12:13, 12:24, 9:5
+ //
+ // Types and Values of each expression:
+ // 4: 8 | string | type : string
+ // 6:15 | len | builtin : func(string) int
+ // 6:15 | len(b) | value : int
+ // 6:19 | b | var : fib.S
+ // 6:23 | S | type : fib.S
+ // 6:23 | S(c) | value : fib.S
+ // 6:25 | c | var : string
+ // 6:29 | "hello" | value : string = "hello"
+ // 8:12 | int | type : int
+ // 8:17 | int | type : int
+ // 9: 5 | x | var : int
+ // 9: 5 | x < 2 | value : untyped bool
+ // 9: 9 | 2 | value : int = 2
+ // 10:10 | x | var : int
+ // 12: 9 | fib | value : func(x int) int
+ // 12: 9 | fib(x - 1) | value : int
+ // 12: 9 | fib(x-1) - fib(x-2) | value : int
+ // 12:13 | x | var : int
+ // 12:13 | x - 1 | value : int
+ // 12:15 | 1 | value : int = 1
+ // 12:20 | fib | value : func(x int) int
+ // 12:20 | fib(x - 2) | value : int
+ // 12:24 | x | var : int
+ // 12:24 | x - 2 | value : int
+ // 12:26 | 2 | value : int = 2
+}
+
+func mode(tv types.TypeAndValue) string {
+ switch {
+ case tv.IsVoid():
+ return "void"
+ case tv.IsType():
+ return "type"
+ case tv.IsBuiltin():
+ return "builtin"
+ case tv.IsNil():
+ return "nil"
+ case tv.Assignable():
+ if tv.Addressable() {
+ return "var"
+ }
+ return "mapindex"
+ case tv.IsValue():
+ return "value"
+ default:
+ return "unknown"
+ }
+}
+
+func exprString(fset *token.FileSet, expr ast.Expr) string {
+ var buf bytes.Buffer
+ format.Node(&buf, fset, expr)
+ return buf.String()
+}
diff --git a/src/go/types/expr.go b/src/go/types/expr.go
new file mode 100644
index 0000000..eb20561
--- /dev/null
+++ b/src/go/types/expr.go
@@ -0,0 +1,1709 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements typechecking of expressions.
+
+package types
+
+import (
+ "fmt"
+ "go/ast"
+ "go/constant"
+ "go/token"
+ "math"
+)
+
+/*
+Basic algorithm:
+
+Expressions are checked recursively, top down. Expression checker functions
+are generally of the form:
+
+ func f(x *operand, e *ast.Expr, ...)
+
+where e is the expression to be checked, and x is the result of the check.
+The check performed by f may fail in which case x.mode == invalid, and
+related error messages will have been issued by f.
+
+If a hint argument is present, it is the composite literal element type
+of an outer composite literal; it is used to type-check composite literal
+elements that have no explicit type specification in the source
+(e.g.: []T{{...}, {...}}, the hint is the type T in this case).
+
+All expressions are checked via rawExpr, which dispatches according
+to expression kind. Upon returning, rawExpr is recording the types and
+constant values for all expressions that have an untyped type (those types
+may change on the way up in the expression tree). Usually these are constants,
+but the results of comparisons or non-constant shifts of untyped constants
+may also be untyped, but not constant.
+
+Untyped expressions may eventually become fully typed (i.e., not untyped),
+typically when the value is assigned to a variable, or is used otherwise.
+The updateExprType method is used to record this final type and update
+the recorded types: the type-checked expression tree is again traversed down,
+and the new type is propagated as needed. Untyped constant expression values
+that become fully typed must now be representable by the full type (constant
+sub-expression trees are left alone except for their roots). This mechanism
+ensures that a client sees the actual (run-time) type an untyped value would
+have. It also permits type-checking of lhs shift operands "as if the shift
+were not present": when updateExprType visits an untyped lhs shift operand
+and assigns it it's final type, that type must be an integer type, and a
+constant lhs must be representable as an integer.
+
+When an expression gets its final type, either on the way out from rawExpr,
+on the way down in updateExprType, or at the end of the type checker run,
+the type (and constant value, if any) is recorded via Info.Types, if present.
+*/
+
+type opPredicates map[token.Token]func(Type) bool
+
+var unaryOpPredicates = opPredicates{
+ token.ADD: isNumeric,
+ token.SUB: isNumeric,
+ token.XOR: isInteger,
+ token.NOT: isBoolean,
+}
+
+func (check *Checker) op(m opPredicates, x *operand, op token.Token) bool {
+ if pred := m[op]; pred != nil {
+ if !pred(x.typ) {
+ check.invalidOp(x, _UndefinedOp, "operator %s not defined for %s", op, x)
+ return false
+ }
+ } else {
+ check.invalidAST(x, "unknown operator %s", op)
+ return false
+ }
+ return true
+}
+
+// The unary expression e may be nil. It's passed in for better error messages only.
+func (check *Checker) unary(x *operand, e *ast.UnaryExpr, op token.Token) {
+ switch op {
+ case token.AND:
+ // spec: "As an exception to the addressability
+ // requirement x may also be a composite literal."
+ if _, ok := unparen(x.expr).(*ast.CompositeLit); !ok && x.mode != variable {
+ check.invalidOp(x, _UnaddressableOperand, "cannot take address of %s", x)
+ x.mode = invalid
+ return
+ }
+ x.mode = value
+ x.typ = &Pointer{base: x.typ}
+ return
+
+ case token.ARROW:
+ typ, ok := x.typ.Underlying().(*Chan)
+ if !ok {
+ check.invalidOp(x, _InvalidReceive, "cannot receive from non-channel %s", x)
+ x.mode = invalid
+ return
+ }
+ if typ.dir == SendOnly {
+ check.invalidOp(x, _InvalidReceive, "cannot receive from send-only channel %s", x)
+ x.mode = invalid
+ return
+ }
+ x.mode = commaok
+ x.typ = typ.elem
+ check.hasCallOrRecv = true
+ return
+ }
+
+ if !check.op(unaryOpPredicates, x, op) {
+ x.mode = invalid
+ return
+ }
+
+ if x.mode == constant_ {
+ typ := x.typ.Underlying().(*Basic)
+ var prec uint
+ if isUnsigned(typ) {
+ prec = uint(check.conf.sizeof(typ) * 8)
+ }
+ x.val = constant.UnaryOp(op, x.val, prec)
+ // Typed constants must be representable in
+ // their type after each constant operation.
+ if isTyped(typ) {
+ if e != nil {
+ x.expr = e // for better error message
+ }
+ check.representable(x, typ)
+ }
+ return
+ }
+
+ x.mode = value
+ // x.typ remains unchanged
+}
+
+func isShift(op token.Token) bool {
+ return op == token.SHL || op == token.SHR
+}
+
+func isComparison(op token.Token) bool {
+ // Note: tokens are not ordered well to make this much easier
+ switch op {
+ case token.EQL, token.NEQ, token.LSS, token.LEQ, token.GTR, token.GEQ:
+ return true
+ }
+ return false
+}
+
+func fitsFloat32(x constant.Value) bool {
+ f32, _ := constant.Float32Val(x)
+ f := float64(f32)
+ return !math.IsInf(f, 0)
+}
+
+func roundFloat32(x constant.Value) constant.Value {
+ f32, _ := constant.Float32Val(x)
+ f := float64(f32)
+ if !math.IsInf(f, 0) {
+ return constant.MakeFloat64(f)
+ }
+ return nil
+}
+
+func fitsFloat64(x constant.Value) bool {
+ f, _ := constant.Float64Val(x)
+ return !math.IsInf(f, 0)
+}
+
+func roundFloat64(x constant.Value) constant.Value {
+ f, _ := constant.Float64Val(x)
+ if !math.IsInf(f, 0) {
+ return constant.MakeFloat64(f)
+ }
+ return nil
+}
+
+// representableConst reports whether x can be represented as
+// value of the given basic type and for the configuration
+// provided (only needed for int/uint sizes).
+//
+// If rounded != nil, *rounded is set to the rounded value of x for
+// representable floating-point and complex values, and to an Int
+// value for integer values; it is left alone otherwise.
+// It is ok to provide the addressof the first argument for rounded.
+//
+// The check parameter may be nil if representableConst is invoked
+// (indirectly) through an exported API call (AssignableTo, ConvertibleTo)
+// because we don't need the Checker's config for those calls.
+func representableConst(x constant.Value, check *Checker, typ *Basic, rounded *constant.Value) bool {
+ if x.Kind() == constant.Unknown {
+ return true // avoid follow-up errors
+ }
+
+ var conf *Config
+ if check != nil {
+ conf = check.conf
+ }
+
+ switch {
+ case isInteger(typ):
+ x := constant.ToInt(x)
+ if x.Kind() != constant.Int {
+ return false
+ }
+ if rounded != nil {
+ *rounded = x
+ }
+ if x, ok := constant.Int64Val(x); ok {
+ switch typ.kind {
+ case Int:
+ var s = uint(conf.sizeof(typ)) * 8
+ return int64(-1)<<(s-1) <= x && x <= int64(1)<<(s-1)-1
+ case Int8:
+ const s = 8
+ return -1<<(s-1) <= x && x <= 1<<(s-1)-1
+ case Int16:
+ const s = 16
+ return -1<<(s-1) <= x && x <= 1<<(s-1)-1
+ case Int32:
+ const s = 32
+ return -1<<(s-1) <= x && x <= 1<<(s-1)-1
+ case Int64, UntypedInt:
+ return true
+ case Uint, Uintptr:
+ if s := uint(conf.sizeof(typ)) * 8; s < 64 {
+ return 0 <= x && x <= int64(1)<<s-1
+ }
+ return 0 <= x
+ case Uint8:
+ const s = 8
+ return 0 <= x && x <= 1<<s-1
+ case Uint16:
+ const s = 16
+ return 0 <= x && x <= 1<<s-1
+ case Uint32:
+ const s = 32
+ return 0 <= x && x <= 1<<s-1
+ case Uint64:
+ return 0 <= x
+ default:
+ unreachable()
+ }
+ }
+ // x does not fit into int64
+ switch n := constant.BitLen(x); typ.kind {
+ case Uint, Uintptr:
+ var s = uint(conf.sizeof(typ)) * 8
+ return constant.Sign(x) >= 0 && n <= int(s)
+ case Uint64:
+ return constant.Sign(x) >= 0 && n <= 64
+ case UntypedInt:
+ return true
+ }
+
+ case isFloat(typ):
+ x := constant.ToFloat(x)
+ if x.Kind() != constant.Float {
+ return false
+ }
+ switch typ.kind {
+ case Float32:
+ if rounded == nil {
+ return fitsFloat32(x)
+ }
+ r := roundFloat32(x)
+ if r != nil {
+ *rounded = r
+ return true
+ }
+ case Float64:
+ if rounded == nil {
+ return fitsFloat64(x)
+ }
+ r := roundFloat64(x)
+ if r != nil {
+ *rounded = r
+ return true
+ }
+ case UntypedFloat:
+ return true
+ default:
+ unreachable()
+ }
+
+ case isComplex(typ):
+ x := constant.ToComplex(x)
+ if x.Kind() != constant.Complex {
+ return false
+ }
+ switch typ.kind {
+ case Complex64:
+ if rounded == nil {
+ return fitsFloat32(constant.Real(x)) && fitsFloat32(constant.Imag(x))
+ }
+ re := roundFloat32(constant.Real(x))
+ im := roundFloat32(constant.Imag(x))
+ if re != nil && im != nil {
+ *rounded = constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
+ return true
+ }
+ case Complex128:
+ if rounded == nil {
+ return fitsFloat64(constant.Real(x)) && fitsFloat64(constant.Imag(x))
+ }
+ re := roundFloat64(constant.Real(x))
+ im := roundFloat64(constant.Imag(x))
+ if re != nil && im != nil {
+ *rounded = constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
+ return true
+ }
+ case UntypedComplex:
+ return true
+ default:
+ unreachable()
+ }
+
+ case isString(typ):
+ return x.Kind() == constant.String
+
+ case isBoolean(typ):
+ return x.Kind() == constant.Bool
+ }
+
+ return false
+}
+
+// representable checks that a constant operand is representable in the given
+// basic type.
+func (check *Checker) representable(x *operand, typ *Basic) {
+ if err := check.isRepresentable(x, typ); err != nil {
+ x.mode = invalid
+ check.err(err)
+ }
+}
+
+func (check *Checker) isRepresentable(x *operand, typ *Basic) error {
+ assert(x.mode == constant_)
+ if !representableConst(x.val, check, typ, &x.val) {
+ var msg string
+ var code errorCode
+ if isNumeric(x.typ) && isNumeric(typ) {
+ // numeric conversion : error msg
+ //
+ // integer -> integer : overflows
+ // integer -> float : overflows (actually not possible)
+ // float -> integer : truncated
+ // float -> float : overflows
+ //
+ if !isInteger(x.typ) && isInteger(typ) {
+ msg = "%s truncated to %s"
+ code = _TruncatedFloat
+ } else {
+ msg = "%s overflows %s"
+ code = _NumericOverflow
+ }
+ } else {
+ msg = "cannot convert %s to %s"
+ code = _InvalidConstVal
+ }
+ return check.newErrorf(x, code, false, msg, x, typ)
+ }
+ return nil
+}
+
+// updateExprType updates the type of x to typ and invokes itself
+// recursively for the operands of x, depending on expression kind.
+// If typ is still an untyped and not the final type, updateExprType
+// only updates the recorded untyped type for x and possibly its
+// operands. Otherwise (i.e., typ is not an untyped type anymore,
+// or it is the final type for x), the type and value are recorded.
+// Also, if x is a constant, it must be representable as a value of typ,
+// and if x is the (formerly untyped) lhs operand of a non-constant
+// shift, it must be an integer value.
+//
+func (check *Checker) updateExprType(x ast.Expr, typ Type, final bool) {
+ old, found := check.untyped[x]
+ if !found {
+ return // nothing to do
+ }
+
+ // update operands of x if necessary
+ switch x := x.(type) {
+ case *ast.BadExpr,
+ *ast.FuncLit,
+ *ast.CompositeLit,
+ *ast.IndexExpr,
+ *ast.SliceExpr,
+ *ast.TypeAssertExpr,
+ *ast.StarExpr,
+ *ast.KeyValueExpr,
+ *ast.ArrayType,
+ *ast.StructType,
+ *ast.FuncType,
+ *ast.InterfaceType,
+ *ast.MapType,
+ *ast.ChanType:
+ // These expression are never untyped - nothing to do.
+ // The respective sub-expressions got their final types
+ // upon assignment or use.
+ if debug {
+ check.dump("%v: found old type(%s): %s (new: %s)", x.Pos(), x, old.typ, typ)
+ unreachable()
+ }
+ return
+
+ case *ast.CallExpr:
+ // Resulting in an untyped constant (e.g., built-in complex).
+ // The respective calls take care of calling updateExprType
+ // for the arguments if necessary.
+
+ case *ast.Ident, *ast.BasicLit, *ast.SelectorExpr:
+ // An identifier denoting a constant, a constant literal,
+ // or a qualified identifier (imported untyped constant).
+ // No operands to take care of.
+
+ case *ast.ParenExpr:
+ check.updateExprType(x.X, typ, final)
+
+ case *ast.UnaryExpr:
+ // If x is a constant, the operands were constants.
+ // The operands don't need to be updated since they
+ // never get "materialized" into a typed value. If
+ // left in the untyped map, they will be processed
+ // at the end of the type check.
+ if old.val != nil {
+ break
+ }
+ check.updateExprType(x.X, typ, final)
+
+ case *ast.BinaryExpr:
+ if old.val != nil {
+ break // see comment for unary expressions
+ }
+ if isComparison(x.Op) {
+ // The result type is independent of operand types
+ // and the operand types must have final types.
+ } else if isShift(x.Op) {
+ // The result type depends only on lhs operand.
+ // The rhs type was updated when checking the shift.
+ check.updateExprType(x.X, typ, final)
+ } else {
+ // The operand types match the result type.
+ check.updateExprType(x.X, typ, final)
+ check.updateExprType(x.Y, typ, final)
+ }
+
+ default:
+ unreachable()
+ }
+
+ // If the new type is not final and still untyped, just
+ // update the recorded type.
+ if !final && isUntyped(typ) {
+ old.typ = typ.Underlying().(*Basic)
+ check.untyped[x] = old
+ return
+ }
+
+ // Otherwise we have the final (typed or untyped type).
+ // Remove it from the map of yet untyped expressions.
+ delete(check.untyped, x)
+
+ if old.isLhs {
+ // If x is the lhs of a shift, its final type must be integer.
+ // We already know from the shift check that it is representable
+ // as an integer if it is a constant.
+ if !isInteger(typ) {
+ check.invalidOp(x, _InvalidShiftOperand, "shifted operand %s (type %s) must be integer", x, typ)
+ return
+ }
+ // Even if we have an integer, if the value is a constant we
+ // still must check that it is representable as the specific
+ // int type requested (was issue #22969). Fall through here.
+ }
+ if old.val != nil {
+ // If x is a constant, it must be representable as a value of typ.
+ c := operand{old.mode, x, old.typ, old.val, 0}
+ check.convertUntyped(&c, typ)
+ if c.mode == invalid {
+ return
+ }
+ }
+
+ // Everything's fine, record final type and value for x.
+ check.recordTypeAndValue(x, old.mode, typ, old.val)
+}
+
+// updateExprVal updates the value of x to val.
+func (check *Checker) updateExprVal(x ast.Expr, val constant.Value) {
+ if info, ok := check.untyped[x]; ok {
+ info.val = val
+ check.untyped[x] = info
+ }
+}
+
+// convertUntyped attempts to set the type of an untyped value to the target type.
+func (check *Checker) convertUntyped(x *operand, target Type) {
+ if err := check.canConvertUntyped(x, target); err != nil {
+ x.mode = invalid
+ check.err(err)
+ }
+}
+
+func (check *Checker) canConvertUntyped(x *operand, target Type) error {
+ if x.mode == invalid || isTyped(x.typ) || target == Typ[Invalid] {
+ return nil
+ }
+
+ if isUntyped(target) {
+ // both x and target are untyped
+ xkind := x.typ.(*Basic).kind
+ tkind := target.(*Basic).kind
+ if isNumeric(x.typ) && isNumeric(target) {
+ if xkind < tkind {
+ x.typ = target
+ check.updateExprType(x.expr, target, false)
+ }
+ } else if xkind != tkind {
+ return check.newErrorf(x, _InvalidUntypedConversion, false, "cannot convert %s to %s", x, target)
+ }
+ return nil
+ }
+
+ if t, ok := target.Underlying().(*Basic); ok && x.mode == constant_ {
+ if err := check.isRepresentable(x, t); err != nil {
+ return err
+ }
+ // Expression value may have been rounded - update if needed.
+ check.updateExprVal(x.expr, x.val)
+ } else {
+ newTarget := check.implicitType(x, target)
+ if newTarget == nil {
+ return check.newErrorf(x, _InvalidUntypedConversion, false, "cannot convert %s to %s", x, target)
+ }
+ target = newTarget
+ }
+ x.typ = target
+ // Even though implicitType can return UntypedNil, this value is final: the
+ // predeclared identifier nil has no type.
+ check.updateExprType(x.expr, target, true)
+ return nil
+}
+
+// implicitType returns the implicit type of x when used in a context where the
+// target type is expected. If no such implicit conversion is possible, it
+// returns nil.
+func (check *Checker) implicitType(x *operand, target Type) Type {
+ assert(isUntyped(x.typ))
+ switch t := target.Underlying().(type) {
+ case *Basic:
+ assert(x.mode != constant_)
+ // Non-constant untyped values may appear as the
+ // result of comparisons (untyped bool), intermediate
+ // (delayed-checked) rhs operands of shifts, and as
+ // the value nil.
+ switch x.typ.(*Basic).kind {
+ case UntypedBool:
+ if !isBoolean(target) {
+ return nil
+ }
+ case UntypedInt, UntypedRune, UntypedFloat, UntypedComplex:
+ if !isNumeric(target) {
+ return nil
+ }
+ case UntypedString:
+ // Non-constant untyped string values are not permitted by the spec and
+ // should not occur during normal typechecking passes, but this path is
+ // reachable via the AssignableTo API.
+ if !isString(target) {
+ return nil
+ }
+ case UntypedNil:
+ // Unsafe.Pointer is a basic type that includes nil.
+ if !hasNil(target) {
+ return nil
+ }
+ default:
+ return nil
+ }
+ case *Interface:
+ // Values must have concrete dynamic types. If the value is nil,
+ // keep it untyped (this is important for tools such as go vet which
+ // need the dynamic type for argument checking of say, print
+ // functions)
+ if x.isNil() {
+ return Typ[UntypedNil]
+ }
+ // cannot assign untyped values to non-empty interfaces
+ check.completeInterface(t)
+ if !t.Empty() {
+ return nil
+ }
+ return Default(x.typ)
+ case *Pointer, *Signature, *Slice, *Map, *Chan:
+ if !x.isNil() {
+ return nil
+ }
+ // Keep nil untyped - see comment for interfaces, above.
+ return Typ[UntypedNil]
+ default:
+ return nil
+ }
+ return target
+}
+
+func (check *Checker) comparison(x, y *operand, op token.Token) {
+ // spec: "In any comparison, the first operand must be assignable
+ // to the type of the second operand, or vice versa."
+ err := ""
+ var code errorCode
+ xok, _ := x.assignableTo(check, y.typ, nil)
+ yok, _ := y.assignableTo(check, x.typ, nil)
+ if xok || yok {
+ defined := false
+ switch op {
+ case token.EQL, token.NEQ:
+ // spec: "The equality operators == and != apply to operands that are comparable."
+ defined = Comparable(x.typ) && Comparable(y.typ) || x.isNil() && hasNil(y.typ) || y.isNil() && hasNil(x.typ)
+ case token.LSS, token.LEQ, token.GTR, token.GEQ:
+ // spec: The ordering operators <, <=, >, and >= apply to operands that are ordered."
+ defined = isOrdered(x.typ) && isOrdered(y.typ)
+ default:
+ unreachable()
+ }
+ if !defined {
+ typ := x.typ
+ if x.isNil() {
+ typ = y.typ
+ }
+ err = check.sprintf("operator %s not defined for %s", op, typ)
+ code = _UndefinedOp
+ }
+ } else {
+ err = check.sprintf("mismatched types %s and %s", x.typ, y.typ)
+ code = _MismatchedTypes
+ }
+
+ if err != "" {
+ check.errorf(x, code, "cannot compare %s %s %s (%s)", x.expr, op, y.expr, err)
+ x.mode = invalid
+ return
+ }
+
+ if x.mode == constant_ && y.mode == constant_ {
+ x.val = constant.MakeBool(constant.Compare(x.val, op, y.val))
+ // The operands are never materialized; no need to update
+ // their types.
+ } else {
+ x.mode = value
+ // The operands have now their final types, which at run-
+ // time will be materialized. Update the expression trees.
+ // If the current types are untyped, the materialized type
+ // is the respective default type.
+ check.updateExprType(x.expr, Default(x.typ), true)
+ check.updateExprType(y.expr, Default(y.typ), true)
+ }
+
+ // spec: "Comparison operators compare two operands and yield
+ // an untyped boolean value."
+ x.typ = Typ[UntypedBool]
+}
+
+func (check *Checker) shift(x, y *operand, e *ast.BinaryExpr, op token.Token) {
+ untypedx := isUntyped(x.typ)
+
+ var xval constant.Value
+ if x.mode == constant_ {
+ xval = constant.ToInt(x.val)
+ }
+
+ if isInteger(x.typ) || untypedx && xval != nil && xval.Kind() == constant.Int {
+ // The lhs is of integer type or an untyped constant representable
+ // as an integer. Nothing to do.
+ } else {
+ // shift has no chance
+ check.invalidOp(x, _InvalidShiftOperand, "shifted operand %s must be integer", x)
+ x.mode = invalid
+ return
+ }
+
+ // spec: "The right operand in a shift expression must have integer type
+ // or be an untyped constant representable by a value of type uint."
+ switch {
+ case isInteger(y.typ):
+ // nothing to do
+ case isUntyped(y.typ):
+ check.convertUntyped(y, Typ[Uint])
+ if y.mode == invalid {
+ x.mode = invalid
+ return
+ }
+ default:
+ check.invalidOp(y, _InvalidShiftCount, "shift count %s must be integer", y)
+ x.mode = invalid
+ return
+ }
+
+ var yval constant.Value
+ if y.mode == constant_ {
+ // rhs must be an integer value
+ // (Either it was of an integer type already, or it was
+ // untyped and successfully converted to a uint above.)
+ yval = constant.ToInt(y.val)
+ assert(yval.Kind() == constant.Int)
+ if constant.Sign(yval) < 0 {
+ check.invalidOp(y, _InvalidShiftCount, "negative shift count %s", y)
+ x.mode = invalid
+ return
+ }
+ }
+
+ if x.mode == constant_ {
+ if y.mode == constant_ {
+ // rhs must be within reasonable bounds in constant shifts
+ const shiftBound = 1023 - 1 + 52 // so we can express smallestFloat64
+ s, ok := constant.Uint64Val(yval)
+ if !ok || s > shiftBound {
+ check.invalidOp(y, _InvalidShiftCount, "invalid shift count %s", y)
+ x.mode = invalid
+ return
+ }
+ // The lhs is representable as an integer but may not be an integer
+ // (e.g., 2.0, an untyped float) - this can only happen for untyped
+ // non-integer numeric constants. Correct the type so that the shift
+ // result is of integer type.
+ if !isInteger(x.typ) {
+ x.typ = Typ[UntypedInt]
+ }
+ // x is a constant so xval != nil and it must be of Int kind.
+ x.val = constant.Shift(xval, op, uint(s))
+ // Typed constants must be representable in
+ // their type after each constant operation.
+ if isTyped(x.typ) {
+ if e != nil {
+ x.expr = e // for better error message
+ }
+ check.representable(x, x.typ.Underlying().(*Basic))
+ }
+ return
+ }
+
+ // non-constant shift with constant lhs
+ if untypedx {
+ // spec: "If the left operand of a non-constant shift
+ // expression is an untyped constant, the type of the
+ // constant is what it would be if the shift expression
+ // were replaced by its left operand alone.".
+ //
+ // Delay operand checking until we know the final type
+ // by marking the lhs expression as lhs shift operand.
+ //
+ // Usually (in correct programs), the lhs expression
+ // is in the untyped map. However, it is possible to
+ // create incorrect programs where the same expression
+ // is evaluated twice (via a declaration cycle) such
+ // that the lhs expression type is determined in the
+ // first round and thus deleted from the map, and then
+ // not found in the second round (double insertion of
+ // the same expr node still just leads to one entry for
+ // that node, and it can only be deleted once).
+ // Be cautious and check for presence of entry.
+ // Example: var e, f = int(1<<""[f]) // issue 11347
+ if info, found := check.untyped[x.expr]; found {
+ info.isLhs = true
+ check.untyped[x.expr] = info
+ }
+ // keep x's type
+ x.mode = value
+ return
+ }
+ }
+
+ // non-constant shift - lhs must be an integer
+ if !isInteger(x.typ) {
+ check.invalidOp(x, _InvalidShiftOperand, "shifted operand %s must be integer", x)
+ x.mode = invalid
+ return
+ }
+
+ x.mode = value
+}
+
+var binaryOpPredicates = opPredicates{
+ token.ADD: func(typ Type) bool { return isNumeric(typ) || isString(typ) },
+ token.SUB: isNumeric,
+ token.MUL: isNumeric,
+ token.QUO: isNumeric,
+ token.REM: isInteger,
+
+ token.AND: isInteger,
+ token.OR: isInteger,
+ token.XOR: isInteger,
+ token.AND_NOT: isInteger,
+
+ token.LAND: isBoolean,
+ token.LOR: isBoolean,
+}
+
+// The binary expression e may be nil. It's passed in for better error messages only.
+func (check *Checker) binary(x *operand, e *ast.BinaryExpr, lhs, rhs ast.Expr, op token.Token, opPos token.Pos) {
+ var y operand
+
+ check.expr(x, lhs)
+ check.expr(&y, rhs)
+
+ if x.mode == invalid {
+ return
+ }
+ if y.mode == invalid {
+ x.mode = invalid
+ x.expr = y.expr
+ return
+ }
+
+ if isShift(op) {
+ check.shift(x, &y, e, op)
+ return
+ }
+
+ check.convertUntyped(x, y.typ)
+ if x.mode == invalid {
+ return
+ }
+ check.convertUntyped(&y, x.typ)
+ if y.mode == invalid {
+ x.mode = invalid
+ return
+ }
+
+ if isComparison(op) {
+ check.comparison(x, &y, op)
+ return
+ }
+
+ if !check.identical(x.typ, y.typ) {
+ // only report an error if we have valid types
+ // (otherwise we had an error reported elsewhere already)
+ if x.typ != Typ[Invalid] && y.typ != Typ[Invalid] {
+ var posn positioner = x
+ if e != nil {
+ posn = e
+ }
+ check.invalidOp(posn, _MismatchedTypes, "mismatched types %s and %s", x.typ, y.typ)
+ }
+ x.mode = invalid
+ return
+ }
+
+ if !check.op(binaryOpPredicates, x, op) {
+ x.mode = invalid
+ return
+ }
+
+ if op == token.QUO || op == token.REM {
+ // check for zero divisor
+ if (x.mode == constant_ || isInteger(x.typ)) && y.mode == constant_ && constant.Sign(y.val) == 0 {
+ check.invalidOp(&y, _DivByZero, "division by zero")
+ x.mode = invalid
+ return
+ }
+
+ // check for divisor underflow in complex division (see issue 20227)
+ if x.mode == constant_ && y.mode == constant_ && isComplex(x.typ) {
+ re, im := constant.Real(y.val), constant.Imag(y.val)
+ re2, im2 := constant.BinaryOp(re, token.MUL, re), constant.BinaryOp(im, token.MUL, im)
+ if constant.Sign(re2) == 0 && constant.Sign(im2) == 0 {
+ check.invalidOp(&y, _DivByZero, "division by zero")
+ x.mode = invalid
+ return
+ }
+ }
+ }
+
+ if x.mode == constant_ && y.mode == constant_ {
+ xval := x.val
+ yval := y.val
+ typ := x.typ.Underlying().(*Basic)
+ // force integer division of integer operands
+ if op == token.QUO && isInteger(typ) {
+ op = token.QUO_ASSIGN
+ }
+ x.val = constant.BinaryOp(xval, op, yval)
+ // report error if valid operands lead to an invalid result
+ if xval.Kind() != constant.Unknown && yval.Kind() != constant.Unknown && x.val.Kind() == constant.Unknown {
+ // TODO(gri) We should report exactly what went wrong. At the
+ // moment we don't have the (go/constant) API for that.
+ // See also TODO in go/constant/value.go.
+ check.errorf(atPos(opPos), _InvalidConstVal, "constant result is not representable")
+ // TODO(gri) Should we mark operands with unknown values as invalid?
+ }
+ // Typed constants must be representable in
+ // their type after each constant operation.
+ if isTyped(typ) {
+ if e != nil {
+ x.expr = e // for better error message
+ }
+ check.representable(x, typ)
+ }
+ return
+ }
+
+ x.mode = value
+ // x.typ is unchanged
+}
+
+// index checks an index expression for validity.
+// If max >= 0, it is the upper bound for index.
+// If the result typ is != Typ[Invalid], index is valid and typ is its (possibly named) integer type.
+// If the result val >= 0, index is valid and val is its constant int value.
+func (check *Checker) index(index ast.Expr, max int64) (typ Type, val int64) {
+ typ = Typ[Invalid]
+ val = -1
+
+ var x operand
+ check.expr(&x, index)
+ if x.mode == invalid {
+ return
+ }
+
+ // an untyped constant must be representable as Int
+ check.convertUntyped(&x, Typ[Int])
+ if x.mode == invalid {
+ return
+ }
+
+ // the index must be of integer type
+ if !isInteger(x.typ) {
+ check.invalidArg(&x, _InvalidIndex, "index %s must be integer", &x)
+ return
+ }
+
+ if x.mode != constant_ {
+ return x.typ, -1
+ }
+
+ // a constant index i must be in bounds
+ if constant.Sign(x.val) < 0 {
+ check.invalidArg(&x, _InvalidIndex, "index %s must not be negative", &x)
+ return
+ }
+
+ v, valid := constant.Int64Val(constant.ToInt(x.val))
+ if !valid || max >= 0 && v >= max {
+ check.errorf(&x, _InvalidIndex, "index %s is out of bounds", &x)
+ return
+ }
+
+ // 0 <= v [ && v < max ]
+ return Typ[Int], v
+}
+
+// indexElts checks the elements (elts) of an array or slice composite literal
+// against the literal's element type (typ), and the element indices against
+// the literal length if known (length >= 0). It returns the length of the
+// literal (maximum index value + 1).
+//
+func (check *Checker) indexedElts(elts []ast.Expr, typ Type, length int64) int64 {
+ visited := make(map[int64]bool, len(elts))
+ var index, max int64
+ for _, e := range elts {
+ // determine and check index
+ validIndex := false
+ eval := e
+ if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
+ if typ, i := check.index(kv.Key, length); typ != Typ[Invalid] {
+ if i >= 0 {
+ index = i
+ validIndex = true
+ } else {
+ check.errorf(e, _InvalidLitIndex, "index %s must be integer constant", kv.Key)
+ }
+ }
+ eval = kv.Value
+ } else if length >= 0 && index >= length {
+ check.errorf(e, _OversizeArrayLit, "index %d is out of bounds (>= %d)", index, length)
+ } else {
+ validIndex = true
+ }
+
+ // if we have a valid index, check for duplicate entries
+ if validIndex {
+ if visited[index] {
+ check.errorf(e, _DuplicateLitKey, "duplicate index %d in array or slice literal", index)
+ }
+ visited[index] = true
+ }
+ index++
+ if index > max {
+ max = index
+ }
+
+ // check element against composite literal element type
+ var x operand
+ check.exprWithHint(&x, eval, typ)
+ check.assignment(&x, typ, "array or slice literal")
+ }
+ return max
+}
+
+// exprKind describes the kind of an expression; the kind
+// determines if an expression is valid in 'statement context'.
+type exprKind int
+
+const (
+ conversion exprKind = iota
+ expression
+ statement
+)
+
+// rawExpr typechecks expression e and initializes x with the expression
+// value or type. If an error occurred, x.mode is set to invalid.
+// If hint != nil, it is the type of a composite literal element.
+//
+func (check *Checker) rawExpr(x *operand, e ast.Expr, hint Type) exprKind {
+ if trace {
+ check.trace(e.Pos(), "%s", e)
+ check.indent++
+ defer func() {
+ check.indent--
+ check.trace(e.Pos(), "=> %s", x)
+ }()
+ }
+
+ kind := check.exprInternal(x, e, hint)
+
+ // convert x into a user-friendly set of values
+ // TODO(gri) this code can be simplified
+ var typ Type
+ var val constant.Value
+ switch x.mode {
+ case invalid:
+ typ = Typ[Invalid]
+ case novalue:
+ typ = (*Tuple)(nil)
+ case constant_:
+ typ = x.typ
+ val = x.val
+ default:
+ typ = x.typ
+ }
+ assert(x.expr != nil && typ != nil)
+
+ if isUntyped(typ) {
+ // delay type and value recording until we know the type
+ // or until the end of type checking
+ check.rememberUntyped(x.expr, false, x.mode, typ.(*Basic), val)
+ } else {
+ check.recordTypeAndValue(e, x.mode, typ, val)
+ }
+
+ return kind
+}
+
+// exprInternal contains the core of type checking of expressions.
+// Must only be called by rawExpr.
+//
+func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
+ // make sure x has a valid state in case of bailout
+ // (was issue 5770)
+ x.mode = invalid
+ x.typ = Typ[Invalid]
+
+ switch e := e.(type) {
+ case *ast.BadExpr:
+ goto Error // error was reported before
+
+ case *ast.Ident:
+ check.ident(x, e, nil, false)
+
+ case *ast.Ellipsis:
+ // ellipses are handled explicitly where they are legal
+ // (array composite literals and parameter lists)
+ check.error(e, _BadDotDotDotSyntax, "invalid use of '...'")
+ goto Error
+
+ case *ast.BasicLit:
+ x.setConst(e.Kind, e.Value)
+ if x.mode == invalid {
+ // The parser already establishes syntactic correctness.
+ // If we reach here it's because of number under-/overflow.
+ // TODO(gri) setConst (and in turn the go/constant package)
+ // should return an error describing the issue.
+ check.errorf(e, _InvalidConstVal, "malformed constant: %s", e.Value)
+ goto Error
+ }
+
+ case *ast.FuncLit:
+ if sig, ok := check.typ(e.Type).(*Signature); ok {
+ // Anonymous functions are considered part of the
+ // init expression/func declaration which contains
+ // them: use existing package-level declaration info.
+ decl := check.decl // capture for use in closure below
+ iota := check.iota // capture for use in closure below (#22345)
+ // Don't type-check right away because the function may
+ // be part of a type definition to which the function
+ // body refers. Instead, type-check as soon as possible,
+ // but before the enclosing scope contents changes (#22992).
+ check.later(func() {
+ check.funcBody(decl, "<function literal>", sig, e.Body, iota)
+ })
+ x.mode = value
+ x.typ = sig
+ } else {
+ check.invalidAST(e, "invalid function literal %s", e)
+ goto Error
+ }
+
+ case *ast.CompositeLit:
+ var typ, base Type
+
+ switch {
+ case e.Type != nil:
+ // composite literal type present - use it
+ // [...]T array types may only appear with composite literals.
+ // Check for them here so we don't have to handle ... in general.
+ if atyp, _ := e.Type.(*ast.ArrayType); atyp != nil && atyp.Len != nil {
+ if ellip, _ := atyp.Len.(*ast.Ellipsis); ellip != nil && ellip.Elt == nil {
+ // We have an "open" [...]T array type.
+ // Create a new ArrayType with unknown length (-1)
+ // and finish setting it up after analyzing the literal.
+ typ = &Array{len: -1, elem: check.typ(atyp.Elt)}
+ base = typ
+ break
+ }
+ }
+ typ = check.typ(e.Type)
+ base = typ
+
+ case hint != nil:
+ // no composite literal type present - use hint (element type of enclosing type)
+ typ = hint
+ base, _ = deref(typ.Underlying()) // *T implies &T{}
+
+ default:
+ // TODO(gri) provide better error messages depending on context
+ check.error(e, _UntypedLit, "missing type in composite literal")
+ goto Error
+ }
+
+ switch utyp := base.Underlying().(type) {
+ case *Struct:
+ if len(e.Elts) == 0 {
+ break
+ }
+ fields := utyp.fields
+ if _, ok := e.Elts[0].(*ast.KeyValueExpr); ok {
+ // all elements must have keys
+ visited := make([]bool, len(fields))
+ for _, e := range e.Elts {
+ kv, _ := e.(*ast.KeyValueExpr)
+ if kv == nil {
+ check.error(e, _MixedStructLit, "mixture of field:value and value elements in struct literal")
+ continue
+ }
+ key, _ := kv.Key.(*ast.Ident)
+ // do all possible checks early (before exiting due to errors)
+ // so we don't drop information on the floor
+ check.expr(x, kv.Value)
+ if key == nil {
+ check.errorf(kv, _InvalidLitField, "invalid field name %s in struct literal", kv.Key)
+ continue
+ }
+ i := fieldIndex(utyp.fields, check.pkg, key.Name)
+ if i < 0 {
+ check.errorf(kv, _MissingLitField, "unknown field %s in struct literal", key.Name)
+ continue
+ }
+ fld := fields[i]
+ check.recordUse(key, fld)
+ etyp := fld.typ
+ check.assignment(x, etyp, "struct literal")
+ // 0 <= i < len(fields)
+ if visited[i] {
+ check.errorf(kv, _DuplicateLitField, "duplicate field name %s in struct literal", key.Name)
+ continue
+ }
+ visited[i] = true
+ }
+ } else {
+ // no element must have a key
+ for i, e := range e.Elts {
+ if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
+ check.error(kv, _MixedStructLit, "mixture of field:value and value elements in struct literal")
+ continue
+ }
+ check.expr(x, e)
+ if i >= len(fields) {
+ check.error(x, _InvalidStructLit, "too many values in struct literal")
+ break // cannot continue
+ }
+ // i < len(fields)
+ fld := fields[i]
+ if !fld.Exported() && fld.pkg != check.pkg {
+ check.errorf(x,
+ _UnexportedLitField,
+ "implicit assignment to unexported field %s in %s literal", fld.name, typ)
+ continue
+ }
+ etyp := fld.typ
+ check.assignment(x, etyp, "struct literal")
+ }
+ if len(e.Elts) < len(fields) {
+ check.error(inNode(e, e.Rbrace), _InvalidStructLit, "too few values in struct literal")
+ // ok to continue
+ }
+ }
+
+ case *Array:
+ // Prevent crash if the array referred to is not yet set up. Was issue #18643.
+ // This is a stop-gap solution. Should use Checker.objPath to report entire
+ // path starting with earliest declaration in the source. TODO(gri) fix this.
+ if utyp.elem == nil {
+ check.error(e, _InvalidTypeCycle, "illegal cycle in type declaration")
+ goto Error
+ }
+ n := check.indexedElts(e.Elts, utyp.elem, utyp.len)
+ // If we have an array of unknown length (usually [...]T arrays, but also
+ // arrays [n]T where n is invalid) set the length now that we know it and
+ // record the type for the array (usually done by check.typ which is not
+ // called for [...]T). We handle [...]T arrays and arrays with invalid
+ // length the same here because it makes sense to "guess" the length for
+ // the latter if we have a composite literal; e.g. for [n]int{1, 2, 3}
+ // where n is invalid for some reason, it seems fair to assume it should
+ // be 3 (see also Checked.arrayLength and issue #27346).
+ if utyp.len < 0 {
+ utyp.len = n
+ // e.Type is missing if we have a composite literal element
+ // that is itself a composite literal with omitted type. In
+ // that case there is nothing to record (there is no type in
+ // the source at that point).
+ if e.Type != nil {
+ check.recordTypeAndValue(e.Type, typexpr, utyp, nil)
+ }
+ }
+
+ case *Slice:
+ // Prevent crash if the slice referred to is not yet set up.
+ // See analogous comment for *Array.
+ if utyp.elem == nil {
+ check.error(e, _InvalidTypeCycle, "illegal cycle in type declaration")
+ goto Error
+ }
+ check.indexedElts(e.Elts, utyp.elem, -1)
+
+ case *Map:
+ // Prevent crash if the map referred to is not yet set up.
+ // See analogous comment for *Array.
+ if utyp.key == nil || utyp.elem == nil {
+ check.error(e, _InvalidTypeCycle, "illegal cycle in type declaration")
+ goto Error
+ }
+ visited := make(map[interface{}][]Type, len(e.Elts))
+ for _, e := range e.Elts {
+ kv, _ := e.(*ast.KeyValueExpr)
+ if kv == nil {
+ check.error(e, _MissingLitKey, "missing key in map literal")
+ continue
+ }
+ check.exprWithHint(x, kv.Key, utyp.key)
+ check.assignment(x, utyp.key, "map literal")
+ if x.mode == invalid {
+ continue
+ }
+ if x.mode == constant_ {
+ duplicate := false
+ // if the key is of interface type, the type is also significant when checking for duplicates
+ xkey := keyVal(x.val)
+ if _, ok := utyp.key.Underlying().(*Interface); ok {
+ for _, vtyp := range visited[xkey] {
+ if check.identical(vtyp, x.typ) {
+ duplicate = true
+ break
+ }
+ }
+ visited[xkey] = append(visited[xkey], x.typ)
+ } else {
+ _, duplicate = visited[xkey]
+ visited[xkey] = nil
+ }
+ if duplicate {
+ check.errorf(x, _DuplicateLitKey, "duplicate key %s in map literal", x.val)
+ continue
+ }
+ }
+ check.exprWithHint(x, kv.Value, utyp.elem)
+ check.assignment(x, utyp.elem, "map literal")
+ }
+
+ default:
+ // when "using" all elements unpack KeyValueExpr
+ // explicitly because check.use doesn't accept them
+ for _, e := range e.Elts {
+ if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
+ // Ideally, we should also "use" kv.Key but we can't know
+ // if it's an externally defined struct key or not. Going
+ // forward anyway can lead to other errors. Give up instead.
+ e = kv.Value
+ }
+ check.use(e)
+ }
+ // if utyp is invalid, an error was reported before
+ if utyp != Typ[Invalid] {
+ check.errorf(e, _InvalidLit, "invalid composite literal type %s", typ)
+ goto Error
+ }
+ }
+
+ x.mode = value
+ x.typ = typ
+
+ case *ast.ParenExpr:
+ kind := check.rawExpr(x, e.X, nil)
+ x.expr = e
+ return kind
+
+ case *ast.SelectorExpr:
+ check.selector(x, e)
+
+ case *ast.IndexExpr:
+ check.expr(x, e.X)
+ if x.mode == invalid {
+ check.use(e.Index)
+ goto Error
+ }
+
+ valid := false
+ length := int64(-1) // valid if >= 0
+ switch typ := x.typ.Underlying().(type) {
+ case *Basic:
+ if isString(typ) {
+ valid = true
+ if x.mode == constant_ {
+ length = int64(len(constant.StringVal(x.val)))
+ }
+ // an indexed string always yields a byte value
+ // (not a constant) even if the string and the
+ // index are constant
+ x.mode = value
+ x.typ = universeByte // use 'byte' name
+ }
+
+ case *Array:
+ valid = true
+ length = typ.len
+ if x.mode != variable {
+ x.mode = value
+ }
+ x.typ = typ.elem
+
+ case *Pointer:
+ if typ, _ := typ.base.Underlying().(*Array); typ != nil {
+ valid = true
+ length = typ.len
+ x.mode = variable
+ x.typ = typ.elem
+ }
+
+ case *Slice:
+ valid = true
+ x.mode = variable
+ x.typ = typ.elem
+
+ case *Map:
+ var key operand
+ check.expr(&key, e.Index)
+ check.assignment(&key, typ.key, "map index")
+ // ok to continue even if indexing failed - map element type is known
+ x.mode = mapindex
+ x.typ = typ.elem
+ x.expr = e
+ return expression
+ }
+
+ if !valid {
+ check.invalidOp(x, _NonIndexableOperand, "cannot index %s", x)
+ goto Error
+ }
+
+ if e.Index == nil {
+ check.invalidAST(e, "missing index for %s", x)
+ goto Error
+ }
+
+ check.index(e.Index, length)
+ // ok to continue
+
+ case *ast.SliceExpr:
+ check.expr(x, e.X)
+ if x.mode == invalid {
+ check.use(e.Low, e.High, e.Max)
+ goto Error
+ }
+
+ valid := false
+ length := int64(-1) // valid if >= 0
+ switch typ := x.typ.Underlying().(type) {
+ case *Basic:
+ if isString(typ) {
+ if e.Slice3 {
+ check.invalidOp(x, _InvalidSliceExpr, "3-index slice of string")
+ goto Error
+ }
+ valid = true
+ if x.mode == constant_ {
+ length = int64(len(constant.StringVal(x.val)))
+ }
+ // spec: "For untyped string operands the result
+ // is a non-constant value of type string."
+ if typ.kind == UntypedString {
+ x.typ = Typ[String]
+ }
+ }
+
+ case *Array:
+ valid = true
+ length = typ.len
+ if x.mode != variable {
+ check.invalidOp(x, _NonSliceableOperand, "cannot slice %s (value not addressable)", x)
+ goto Error
+ }
+ x.typ = &Slice{elem: typ.elem}
+
+ case *Pointer:
+ if typ, _ := typ.base.Underlying().(*Array); typ != nil {
+ valid = true
+ length = typ.len
+ x.typ = &Slice{elem: typ.elem}
+ }
+
+ case *Slice:
+ valid = true
+ // x.typ doesn't change
+ }
+
+ if !valid {
+ check.invalidOp(x, _NonSliceableOperand, "cannot slice %s", x)
+ goto Error
+ }
+
+ x.mode = value
+
+ // spec: "Only the first index may be omitted; it defaults to 0."
+ if e.Slice3 && (e.High == nil || e.Max == nil) {
+ check.invalidAST(inNode(e, e.Rbrack), "2nd and 3rd index required in 3-index slice")
+ goto Error
+ }
+
+ // check indices
+ var ind [3]int64
+ for i, expr := range []ast.Expr{e.Low, e.High, e.Max} {
+ x := int64(-1)
+ switch {
+ case expr != nil:
+ // The "capacity" is only known statically for strings, arrays,
+ // and pointers to arrays, and it is the same as the length for
+ // those types.
+ max := int64(-1)
+ if length >= 0 {
+ max = length + 1
+ }
+ if _, v := check.index(expr, max); v >= 0 {
+ x = v
+ }
+ case i == 0:
+ // default is 0 for the first index
+ x = 0
+ case length >= 0:
+ // default is length (== capacity) otherwise
+ x = length
+ }
+ ind[i] = x
+ }
+
+ // constant indices must be in range
+ // (check.index already checks that existing indices >= 0)
+ L:
+ for i, x := range ind[:len(ind)-1] {
+ if x > 0 {
+ for _, y := range ind[i+1:] {
+ if y >= 0 && x > y {
+ check.errorf(inNode(e, e.Rbrack), _SwappedSliceIndices, "swapped slice indices: %d > %d", x, y)
+ break L // only report one error, ok to continue
+ }
+ }
+ }
+ }
+
+ case *ast.TypeAssertExpr:
+ check.expr(x, e.X)
+ if x.mode == invalid {
+ goto Error
+ }
+ xtyp, _ := x.typ.Underlying().(*Interface)
+ if xtyp == nil {
+ check.invalidOp(x, _InvalidAssert, "%s is not an interface", x)
+ goto Error
+ }
+ // x.(type) expressions are handled explicitly in type switches
+ if e.Type == nil {
+ // Don't use invalidAST because this can occur in the AST produced by
+ // go/parser.
+ check.error(e, _BadTypeKeyword, "use of .(type) outside type switch")
+ goto Error
+ }
+ T := check.typ(e.Type)
+ if T == Typ[Invalid] {
+ goto Error
+ }
+ check.typeAssertion(x, x, xtyp, T)
+ x.mode = commaok
+ x.typ = T
+
+ case *ast.CallExpr:
+ return check.call(x, e)
+
+ case *ast.StarExpr:
+ check.exprOrType(x, e.X)
+ switch x.mode {
+ case invalid:
+ goto Error
+ case typexpr:
+ x.typ = &Pointer{base: x.typ}
+ default:
+ if typ, ok := x.typ.Underlying().(*Pointer); ok {
+ x.mode = variable
+ x.typ = typ.base
+ } else {
+ check.invalidOp(x, _InvalidIndirection, "cannot indirect %s", x)
+ goto Error
+ }
+ }
+
+ case *ast.UnaryExpr:
+ check.expr(x, e.X)
+ if x.mode == invalid {
+ goto Error
+ }
+ check.unary(x, e, e.Op)
+ if x.mode == invalid {
+ goto Error
+ }
+ if e.Op == token.ARROW {
+ x.expr = e
+ return statement // receive operations may appear in statement context
+ }
+
+ case *ast.BinaryExpr:
+ check.binary(x, e, e.X, e.Y, e.Op, e.OpPos)
+ if x.mode == invalid {
+ goto Error
+ }
+
+ case *ast.KeyValueExpr:
+ // key:value expressions are handled in composite literals
+ check.invalidAST(e, "no key:value expected")
+ goto Error
+
+ case *ast.ArrayType, *ast.StructType, *ast.FuncType,
+ *ast.InterfaceType, *ast.MapType, *ast.ChanType:
+ x.mode = typexpr
+ x.typ = check.typ(e)
+ // Note: rawExpr (caller of exprInternal) will call check.recordTypeAndValue
+ // even though check.typ has already called it. This is fine as both
+ // times the same expression and type are recorded. It is also not a
+ // performance issue because we only reach here for composite literal
+ // types, which are comparatively rare.
+
+ default:
+ panic(fmt.Sprintf("%s: unknown expression type %T", check.fset.Position(e.Pos()), e))
+ }
+
+ // everything went well
+ x.expr = e
+ return expression
+
+Error:
+ x.mode = invalid
+ x.expr = e
+ return statement // avoid follow-up errors
+}
+
+func keyVal(x constant.Value) interface{} {
+ switch x.Kind() {
+ case constant.Bool:
+ return constant.BoolVal(x)
+ case constant.String:
+ return constant.StringVal(x)
+ case constant.Int:
+ if v, ok := constant.Int64Val(x); ok {
+ return v
+ }
+ if v, ok := constant.Uint64Val(x); ok {
+ return v
+ }
+ case constant.Float:
+ v, _ := constant.Float64Val(x)
+ return v
+ case constant.Complex:
+ r, _ := constant.Float64Val(constant.Real(x))
+ i, _ := constant.Float64Val(constant.Imag(x))
+ return complex(r, i)
+ }
+ return x
+}
+
+// typeAssertion checks that x.(T) is legal; xtyp must be the type of x.
+func (check *Checker) typeAssertion(at positioner, x *operand, xtyp *Interface, T Type) {
+ method, wrongType := check.assertableTo(xtyp, T)
+ if method == nil {
+ return
+ }
+ var msg string
+ if wrongType != nil {
+ if check.identical(method.typ, wrongType.typ) {
+ msg = fmt.Sprintf("missing method %s (%s has pointer receiver)", method.name, method.name)
+ } else {
+ msg = fmt.Sprintf("wrong type for method %s (have %s, want %s)", method.name, wrongType.typ, method.typ)
+ }
+ } else {
+ msg = "missing method " + method.name
+ }
+ check.errorf(at, _ImpossibleAssert, "%s cannot have dynamic type %s (%s)", x, T, msg)
+}
+
+func (check *Checker) singleValue(x *operand) {
+ if x.mode == value {
+ // tuple types are never named - no need for underlying type below
+ if t, ok := x.typ.(*Tuple); ok {
+ assert(t.Len() != 1)
+ check.errorf(x, _TooManyValues, "%d-valued %s where single value is expected", t.Len(), x)
+ x.mode = invalid
+ }
+ }
+}
+
+// expr typechecks expression e and initializes x with the expression value.
+// The result must be a single value.
+// If an error occurred, x.mode is set to invalid.
+//
+func (check *Checker) expr(x *operand, e ast.Expr) {
+ check.multiExpr(x, e)
+ check.singleValue(x)
+}
+
+// multiExpr is like expr but the result may be a multi-value.
+func (check *Checker) multiExpr(x *operand, e ast.Expr) {
+ check.rawExpr(x, e, nil)
+ var msg string
+ var code errorCode
+ switch x.mode {
+ default:
+ return
+ case novalue:
+ msg = "%s used as value"
+ code = _TooManyValues
+ case builtin:
+ msg = "%s must be called"
+ code = _UncalledBuiltin
+ case typexpr:
+ msg = "%s is not an expression"
+ code = _NotAnExpr
+ }
+ check.errorf(x, code, msg, x)
+ x.mode = invalid
+}
+
+// exprWithHint typechecks expression e and initializes x with the expression value;
+// hint is the type of a composite literal element.
+// If an error occurred, x.mode is set to invalid.
+//
+func (check *Checker) exprWithHint(x *operand, e ast.Expr, hint Type) {
+ assert(hint != nil)
+ check.rawExpr(x, e, hint)
+ check.singleValue(x)
+ var msg string
+ var code errorCode
+ switch x.mode {
+ default:
+ return
+ case novalue:
+ msg = "%s used as value"
+ code = _TooManyValues
+ case builtin:
+ msg = "%s must be called"
+ code = _UncalledBuiltin
+ case typexpr:
+ msg = "%s is not an expression"
+ code = _NotAnExpr
+ }
+ check.errorf(x, code, msg, x)
+ x.mode = invalid
+}
+
+// exprOrType typechecks expression or type e and initializes x with the expression value or type.
+// If an error occurred, x.mode is set to invalid.
+//
+func (check *Checker) exprOrType(x *operand, e ast.Expr) {
+ check.rawExpr(x, e, nil)
+ check.singleValue(x)
+ if x.mode == novalue {
+ check.errorf(x, _NotAnExpr, "%s used as value or type", x)
+ x.mode = invalid
+ }
+}
diff --git a/src/go/types/exprstring.go b/src/go/types/exprstring.go
new file mode 100644
index 0000000..28d605f
--- /dev/null
+++ b/src/go/types/exprstring.go
@@ -0,0 +1,224 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements printing of expressions.
+
+package types
+
+import (
+ "bytes"
+ "go/ast"
+)
+
+// ExprString returns the (possibly shortened) string representation for x.
+// Shortened representations are suitable for user interfaces but may not
+// necessarily follow Go syntax.
+func ExprString(x ast.Expr) string {
+ var buf bytes.Buffer
+ WriteExpr(&buf, x)
+ return buf.String()
+}
+
+// WriteExpr writes the (possibly shortened) string representation for x to buf.
+// Shortened representations are suitable for user interfaces but may not
+// necessarily follow Go syntax.
+func WriteExpr(buf *bytes.Buffer, x ast.Expr) {
+ // The AST preserves source-level parentheses so there is
+ // no need to introduce them here to correct for different
+ // operator precedences. (This assumes that the AST was
+ // generated by a Go parser.)
+
+ switch x := x.(type) {
+ default:
+ buf.WriteString("(bad expr)") // nil, ast.BadExpr, ast.KeyValueExpr
+
+ case *ast.Ident:
+ buf.WriteString(x.Name)
+
+ case *ast.Ellipsis:
+ buf.WriteString("...")
+ if x.Elt != nil {
+ WriteExpr(buf, x.Elt)
+ }
+
+ case *ast.BasicLit:
+ buf.WriteString(x.Value)
+
+ case *ast.FuncLit:
+ buf.WriteByte('(')
+ WriteExpr(buf, x.Type)
+ buf.WriteString(" literal)") // shortened
+
+ case *ast.CompositeLit:
+ buf.WriteByte('(')
+ WriteExpr(buf, x.Type)
+ buf.WriteString(" literal)") // shortened
+
+ case *ast.ParenExpr:
+ buf.WriteByte('(')
+ WriteExpr(buf, x.X)
+ buf.WriteByte(')')
+
+ case *ast.SelectorExpr:
+ WriteExpr(buf, x.X)
+ buf.WriteByte('.')
+ buf.WriteString(x.Sel.Name)
+
+ case *ast.IndexExpr:
+ WriteExpr(buf, x.X)
+ buf.WriteByte('[')
+ WriteExpr(buf, x.Index)
+ buf.WriteByte(']')
+
+ case *ast.SliceExpr:
+ WriteExpr(buf, x.X)
+ buf.WriteByte('[')
+ if x.Low != nil {
+ WriteExpr(buf, x.Low)
+ }
+ buf.WriteByte(':')
+ if x.High != nil {
+ WriteExpr(buf, x.High)
+ }
+ if x.Slice3 {
+ buf.WriteByte(':')
+ if x.Max != nil {
+ WriteExpr(buf, x.Max)
+ }
+ }
+ buf.WriteByte(']')
+
+ case *ast.TypeAssertExpr:
+ WriteExpr(buf, x.X)
+ buf.WriteString(".(")
+ WriteExpr(buf, x.Type)
+ buf.WriteByte(')')
+
+ case *ast.CallExpr:
+ WriteExpr(buf, x.Fun)
+ buf.WriteByte('(')
+ for i, arg := range x.Args {
+ if i > 0 {
+ buf.WriteString(", ")
+ }
+ WriteExpr(buf, arg)
+ }
+ if x.Ellipsis.IsValid() {
+ buf.WriteString("...")
+ }
+ buf.WriteByte(')')
+
+ case *ast.StarExpr:
+ buf.WriteByte('*')
+ WriteExpr(buf, x.X)
+
+ case *ast.UnaryExpr:
+ buf.WriteString(x.Op.String())
+ WriteExpr(buf, x.X)
+
+ case *ast.BinaryExpr:
+ WriteExpr(buf, x.X)
+ buf.WriteByte(' ')
+ buf.WriteString(x.Op.String())
+ buf.WriteByte(' ')
+ WriteExpr(buf, x.Y)
+
+ case *ast.ArrayType:
+ buf.WriteByte('[')
+ if x.Len != nil {
+ WriteExpr(buf, x.Len)
+ }
+ buf.WriteByte(']')
+ WriteExpr(buf, x.Elt)
+
+ case *ast.StructType:
+ buf.WriteString("struct{")
+ writeFieldList(buf, x.Fields, "; ", false)
+ buf.WriteByte('}')
+
+ case *ast.FuncType:
+ buf.WriteString("func")
+ writeSigExpr(buf, x)
+
+ case *ast.InterfaceType:
+ buf.WriteString("interface{")
+ writeFieldList(buf, x.Methods, "; ", true)
+ buf.WriteByte('}')
+
+ case *ast.MapType:
+ buf.WriteString("map[")
+ WriteExpr(buf, x.Key)
+ buf.WriteByte(']')
+ WriteExpr(buf, x.Value)
+
+ case *ast.ChanType:
+ var s string
+ switch x.Dir {
+ case ast.SEND:
+ s = "chan<- "
+ case ast.RECV:
+ s = "<-chan "
+ default:
+ s = "chan "
+ }
+ buf.WriteString(s)
+ WriteExpr(buf, x.Value)
+ }
+}
+
+func writeSigExpr(buf *bytes.Buffer, sig *ast.FuncType) {
+ buf.WriteByte('(')
+ writeFieldList(buf, sig.Params, ", ", false)
+ buf.WriteByte(')')
+
+ res := sig.Results
+ n := res.NumFields()
+ if n == 0 {
+ // no result
+ return
+ }
+
+ buf.WriteByte(' ')
+ if n == 1 && len(res.List[0].Names) == 0 {
+ // single unnamed result
+ WriteExpr(buf, res.List[0].Type)
+ return
+ }
+
+ // multiple or named result(s)
+ buf.WriteByte('(')
+ writeFieldList(buf, res, ", ", false)
+ buf.WriteByte(')')
+}
+
+func writeFieldList(buf *bytes.Buffer, fields *ast.FieldList, sep string, iface bool) {
+ for i, f := range fields.List {
+ if i > 0 {
+ buf.WriteString(sep)
+ }
+
+ // field list names
+ for i, name := range f.Names {
+ if i > 0 {
+ buf.WriteString(", ")
+ }
+ buf.WriteString(name.Name)
+ }
+
+ // types of interface methods consist of signatures only
+ if sig, _ := f.Type.(*ast.FuncType); sig != nil && iface {
+ writeSigExpr(buf, sig)
+ continue
+ }
+
+ // named fields are separated with a blank from the field type
+ if len(f.Names) > 0 {
+ buf.WriteByte(' ')
+ }
+
+ WriteExpr(buf, f.Type)
+
+ // ignore tag
+ }
+}
diff --git a/src/go/types/exprstring_test.go b/src/go/types/exprstring_test.go
new file mode 100644
index 0000000..5110288
--- /dev/null
+++ b/src/go/types/exprstring_test.go
@@ -0,0 +1,94 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "go/parser"
+ "testing"
+
+ . "go/types"
+)
+
+var testExprs = []testEntry{
+ // basic type literals
+ dup("x"),
+ dup("true"),
+ dup("42"),
+ dup("3.1415"),
+ dup("2.71828i"),
+ dup(`'a'`),
+ dup(`"foo"`),
+ dup("`bar`"),
+
+ // func and composite literals
+ {"func(){}", "(func() literal)"},
+ {"func(x int) complex128 {}", "(func(x int) complex128 literal)"},
+ {"[]int{1, 2, 3}", "([]int literal)"},
+
+ // non-type expressions
+ dup("(x)"),
+ dup("x.f"),
+ dup("a[i]"),
+
+ dup("s[:]"),
+ dup("s[i:]"),
+ dup("s[:j]"),
+ dup("s[i:j]"),
+ dup("s[:j:k]"),
+ dup("s[i:j:k]"),
+
+ dup("x.(T)"),
+
+ dup("x.([10]int)"),
+ dup("x.([...]int)"),
+
+ dup("x.(struct{})"),
+ dup("x.(struct{x int; y, z float32; E})"),
+
+ dup("x.(func())"),
+ dup("x.(func(x int))"),
+ dup("x.(func() int)"),
+ dup("x.(func(x, y int, z float32) (r int))"),
+ dup("x.(func(a, b, c int))"),
+ dup("x.(func(x ...T))"),
+
+ dup("x.(interface{})"),
+ dup("x.(interface{m(); n(x int); E})"),
+ dup("x.(interface{m(); n(x int) T; E; F})"),
+
+ dup("x.(map[K]V)"),
+
+ dup("x.(chan E)"),
+ dup("x.(<-chan E)"),
+ dup("x.(chan<- chan int)"),
+ dup("x.(chan<- <-chan int)"),
+ dup("x.(<-chan chan int)"),
+ dup("x.(chan (<-chan int))"),
+
+ dup("f()"),
+ dup("f(x)"),
+ dup("int(x)"),
+ dup("f(x, x + y)"),
+ dup("f(s...)"),
+ dup("f(a, s...)"),
+
+ dup("*x"),
+ dup("&x"),
+ dup("x + y"),
+ dup("x + y << (2 * s)"),
+}
+
+func TestExprString(t *testing.T) {
+ for _, test := range testExprs {
+ x, err := parser.ParseExpr(test.src)
+ if err != nil {
+ t.Errorf("%s: %s", test.src, err)
+ continue
+ }
+ if got := ExprString(x); got != test.str {
+ t.Errorf("%s: got %s, want %s", test.src, got, test.str)
+ }
+ }
+}
diff --git a/src/go/types/fixedbugs/issue20583.src b/src/go/types/fixedbugs/issue20583.src
new file mode 100644
index 0000000..d26dbad
--- /dev/null
+++ b/src/go/types/fixedbugs/issue20583.src
@@ -0,0 +1,14 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue20583
+
+const (
+ _ = 6e886451608 /* ERROR malformed constant */ /2
+ _ = 6e886451608i /* ERROR malformed constant */ /2
+ _ = 0 * 1e+1000000000 // ERROR malformed constant
+
+ x = 1e100000000
+ _ = x*x*x*x*x*x* /* ERROR not representable */ x
+)
diff --git a/src/go/types/fixedbugs/issue23203a.src b/src/go/types/fixedbugs/issue23203a.src
new file mode 100644
index 0000000..48cb588
--- /dev/null
+++ b/src/go/types/fixedbugs/issue23203a.src
@@ -0,0 +1,14 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "unsafe"
+
+type T struct{}
+
+func (T) m1() {}
+func (T) m2([unsafe.Sizeof(T.m1)]int) {}
+
+func main() {}
diff --git a/src/go/types/fixedbugs/issue23203b.src b/src/go/types/fixedbugs/issue23203b.src
new file mode 100644
index 0000000..638ec6c
--- /dev/null
+++ b/src/go/types/fixedbugs/issue23203b.src
@@ -0,0 +1,14 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "unsafe"
+
+type T struct{}
+
+func (T) m2([unsafe.Sizeof(T.m1)]int) {}
+func (T) m1() {}
+
+func main() {}
diff --git a/src/go/types/fixedbugs/issue26390.src b/src/go/types/fixedbugs/issue26390.src
new file mode 100644
index 0000000..9e0101f
--- /dev/null
+++ b/src/go/types/fixedbugs/issue26390.src
@@ -0,0 +1,13 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// stand-alone test to ensure case is triggered
+
+package issue26390
+
+type A = T
+
+func (t *T) m() *A { return t }
+
+type T struct{}
diff --git a/src/go/types/fixedbugs/issue28251.src b/src/go/types/fixedbugs/issue28251.src
new file mode 100644
index 0000000..cd79e0e
--- /dev/null
+++ b/src/go/types/fixedbugs/issue28251.src
@@ -0,0 +1,65 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains test cases for various forms of
+// method receiver declarations, per the spec clarification
+// https://golang.org/cl/142757.
+
+package issue28251
+
+// test case from issue28251
+type T struct{}
+
+type T0 = *T
+
+func (T0) m() {}
+
+func _() { (&T{}).m() }
+
+// various alternative forms
+type (
+ T1 = (((T)))
+)
+
+func ((*(T1))) m1() {}
+func _() { (T{}).m2() }
+func _() { (&T{}).m2() }
+
+type (
+ T2 = (((T3)))
+ T3 = T
+)
+
+func (T2) m2() {}
+func _() { (T{}).m2() }
+func _() { (&T{}).m2() }
+
+type (
+ T4 = ((*(T5)))
+ T5 = T
+)
+
+func (T4) m4() {}
+func _() { (T{}).m4 /* ERROR "cannot call pointer method m4 on T" */ () }
+func _() { (&T{}).m4() }
+
+type (
+ T6 = (((T7)))
+ T7 = (*(T8))
+ T8 = T
+)
+
+func (T6) m6() {}
+func _() { (T{}).m6 /* ERROR "cannot call pointer method m6 on T" */ () }
+func _() { (&T{}).m6() }
+
+type (
+ T9 = *T10
+ T10 = *T11
+ T11 = T
+)
+
+func (T9 /* ERROR invalid receiver \*\*T */ ) m9() {}
+func _() { (T{}).m9 /* ERROR has no field or method m9 */ () }
+func _() { (&T{}).m9 /* ERROR has no field or method m9 */ () }
diff --git a/src/go/types/fixedbugs/issue42695.src b/src/go/types/fixedbugs/issue42695.src
new file mode 100644
index 0000000..d0d6200
--- /dev/null
+++ b/src/go/types/fixedbugs/issue42695.src
@@ -0,0 +1,17 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue42695
+
+const _ = 6e5518446744 // ERROR malformed constant
+const _ uint8 = 6e5518446744 // ERROR malformed constant
+
+var _ = 6e5518446744 // ERROR malformed constant
+var _ uint8 = 6e5518446744 // ERROR malformed constant
+
+func f(x int) int {
+ return x + 6e5518446744 // ERROR malformed constant
+}
+
+var _ = f(6e5518446744 /* ERROR malformed constant */ )
diff --git a/src/go/types/fixedbugs/issue43110.src b/src/go/types/fixedbugs/issue43110.src
new file mode 100644
index 0000000..4a46945
--- /dev/null
+++ b/src/go/types/fixedbugs/issue43110.src
@@ -0,0 +1,43 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type P *struct{}
+
+func _() {
+ // want an error even if the switch is empty
+ var a struct{ _ func() }
+ switch a /* ERROR cannot switch on a */ {
+ }
+
+ switch a /* ERROR cannot switch on a */ {
+ case a: // no follow-on error here
+ }
+
+ // this is ok because f can be compared to nil
+ var f func()
+ switch f {
+ }
+
+ switch f {
+ case nil:
+ }
+
+ switch (func())(nil) {
+ case nil:
+ }
+
+ switch (func())(nil) {
+ case f /* ERROR cannot compare */ :
+ }
+
+ switch nil /* ERROR use of untyped nil in switch expression */ {
+ }
+
+ // this is ok
+ switch P(nil) {
+ case P(nil):
+ }
+}
diff --git a/src/go/types/fixedbugs/issue43124.src b/src/go/types/fixedbugs/issue43124.src
new file mode 100644
index 0000000..f429f74
--- /dev/null
+++ b/src/go/types/fixedbugs/issue43124.src
@@ -0,0 +1,16 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+var _ = int(0 /* ERROR invalid use of \.\.\. in conversion to int */ ...)
+
+// test case from issue
+
+type M []string
+
+var (
+ x = []string{"a", "b"}
+ _ = M(x /* ERROR invalid use of \.\.\. in conversion to M */ ...)
+)
diff --git a/src/go/types/fixedbugs/issue6977.src b/src/go/types/fixedbugs/issue6977.src
new file mode 100644
index 0000000..8f4e9ba
--- /dev/null
+++ b/src/go/types/fixedbugs/issue6977.src
@@ -0,0 +1,82 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "io"
+
+// Alan's initial report.
+
+type I interface { f(); String() string }
+type J interface { g(); String() string }
+
+type IJ1 = interface { I; J }
+type IJ2 = interface { f(); g(); String() string }
+
+var _ = (*IJ1)(nil) == (*IJ2)(nil) // static assert that IJ1 and IJ2 are identical types
+
+// The canonical example.
+
+type ReadWriteCloser interface { io.ReadCloser; io.WriteCloser }
+
+// Some more cases.
+
+type M interface { m() }
+type M32 interface { m() int32 }
+type M64 interface { m() int64 }
+
+type U1 interface { m() }
+type U2 interface { m(); M }
+type U3 interface { M; m() }
+type U4 interface { M; M; M }
+type U5 interface { U1; U2; U3; U4 }
+
+type U6 interface { m(); m /* ERROR duplicate method */ () }
+type U7 interface { M32 /* ERROR duplicate method */ ; m() }
+type U8 interface { m(); M32 /* ERROR duplicate method */ }
+type U9 interface { M32; M64 /* ERROR duplicate method */ }
+
+// Verify that repeated embedding of the same interface(s)
+// eliminates duplicate methods early (rather than at the
+// end) to prevent exponential memory and time use.
+// Without early elimination, computing T29 may take dozens
+// of minutes.
+type (
+ T0 interface { m() }
+ T1 interface { T0; T0 }
+ T2 interface { T1; T1 }
+ T3 interface { T2; T2 }
+ T4 interface { T3; T3 }
+ T5 interface { T4; T4 }
+ T6 interface { T5; T5 }
+ T7 interface { T6; T6 }
+ T8 interface { T7; T7 }
+ T9 interface { T8; T8 }
+
+ T10 interface { T9; T9 }
+ T11 interface { T10; T10 }
+ T12 interface { T11; T11 }
+ T13 interface { T12; T12 }
+ T14 interface { T13; T13 }
+ T15 interface { T14; T14 }
+ T16 interface { T15; T15 }
+ T17 interface { T16; T16 }
+ T18 interface { T17; T17 }
+ T19 interface { T18; T18 }
+
+ T20 interface { T19; T19 }
+ T21 interface { T20; T20 }
+ T22 interface { T21; T21 }
+ T23 interface { T22; T22 }
+ T24 interface { T23; T23 }
+ T25 interface { T24; T24 }
+ T26 interface { T25; T25 }
+ T27 interface { T26; T26 }
+ T28 interface { T27; T27 }
+ T29 interface { T28; T28 }
+)
+
+// Verify that m is present.
+var x T29
+var _ = x.m
diff --git a/src/go/types/gccgosizes.go b/src/go/types/gccgosizes.go
new file mode 100644
index 0000000..d5c92c6
--- /dev/null
+++ b/src/go/types/gccgosizes.go
@@ -0,0 +1,40 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a copy of the file generated during the gccgo build process.
+// Last update 2019-01-22.
+
+package types
+
+var gccgoArchSizes = map[string]*StdSizes{
+ "386": {4, 4},
+ "alpha": {8, 8},
+ "amd64": {8, 8},
+ "amd64p32": {4, 8},
+ "arm": {4, 8},
+ "armbe": {4, 8},
+ "arm64": {8, 8},
+ "arm64be": {8, 8},
+ "ia64": {8, 8},
+ "m68k": {4, 2},
+ "mips": {4, 8},
+ "mipsle": {4, 8},
+ "mips64": {8, 8},
+ "mips64le": {8, 8},
+ "mips64p32": {4, 8},
+ "mips64p32le": {4, 8},
+ "nios2": {4, 8},
+ "ppc": {4, 8},
+ "ppc64": {8, 8},
+ "ppc64le": {8, 8},
+ "riscv": {4, 8},
+ "riscv64": {8, 8},
+ "s390": {4, 8},
+ "s390x": {8, 8},
+ "sh": {4, 8},
+ "shbe": {4, 8},
+ "sparc": {4, 8},
+ "sparc64": {8, 8},
+ "wasm": {8, 8},
+}
diff --git a/src/go/types/gotype.go b/src/go/types/gotype.go
new file mode 100644
index 0000000..52709df
--- /dev/null
+++ b/src/go/types/gotype.go
@@ -0,0 +1,354 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+// Build this command explicitly: go build gotype.go
+
+/*
+The gotype command, like the front-end of a Go compiler, parses and
+type-checks a single Go package. Errors are reported if the analysis
+fails; otherwise gotype is quiet (unless -v is set).
+
+Without a list of paths, gotype reads from standard input, which
+must provide a single Go source file defining a complete package.
+
+With a single directory argument, gotype checks the Go files in
+that directory, comprising a single package. Use -t to include the
+(in-package) _test.go files. Use -x to type check only external
+test files.
+
+Otherwise, each path must be the filename of a Go file belonging
+to the same package.
+
+Imports are processed by importing directly from the source of
+imported packages (default), or by importing from compiled and
+installed packages (by setting -c to the respective compiler).
+
+The -c flag must be set to a compiler ("gc", "gccgo") when type-
+checking packages containing imports with relative import paths
+(import "./mypkg") because the source importer cannot know which
+files to include for such packages.
+
+Usage:
+ gotype [flags] [path...]
+
+The flags are:
+ -t
+ include local test files in a directory (ignored if -x is provided)
+ -x
+ consider only external test files in a directory
+ -e
+ report all errors (not just the first 10)
+ -v
+ verbose mode
+ -c
+ compiler used for installed packages (gc, gccgo, or source); default: source
+
+Flags controlling additional output:
+ -ast
+ print AST
+ -trace
+ print parse trace
+ -comments
+ parse comments (ignored unless -ast or -trace is provided)
+ -panic
+ panic on first error
+
+Examples:
+
+To check the files a.go, b.go, and c.go:
+
+ gotype a.go b.go c.go
+
+To check an entire package including (in-package) tests in the directory dir and print the processed files:
+
+ gotype -t -v dir
+
+To check the external test package (if any) in the current directory, based on installed packages compiled with
+cmd/compile:
+
+ gotype -c=gc -x .
+
+To verify the output of a pipe:
+
+ echo "package foo" | gotype
+
+*/
+package main
+
+import (
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/importer"
+ "go/parser"
+ "go/scanner"
+ "go/token"
+ "go/types"
+ "io"
+ "os"
+ "path/filepath"
+ "sync"
+ "time"
+)
+
+var (
+ // main operation modes
+ testFiles = flag.Bool("t", false, "include in-package test files in a directory")
+ xtestFiles = flag.Bool("x", false, "consider only external test files in a directory")
+ allErrors = flag.Bool("e", false, "report all errors, not just the first 10")
+ verbose = flag.Bool("v", false, "verbose mode")
+ compiler = flag.String("c", "source", "compiler used for installed packages (gc, gccgo, or source)")
+
+ // additional output control
+ printAST = flag.Bool("ast", false, "print AST")
+ printTrace = flag.Bool("trace", false, "print parse trace")
+ parseComments = flag.Bool("comments", false, "parse comments (ignored unless -ast or -trace is provided)")
+ panicOnError = flag.Bool("panic", false, "panic on first error")
+)
+
+var (
+ fset = token.NewFileSet()
+ errorCount = 0
+ sequential = false
+ parserMode parser.Mode
+)
+
+func initParserMode() {
+ if *allErrors {
+ parserMode |= parser.AllErrors
+ }
+ if *printAST {
+ sequential = true
+ }
+ if *printTrace {
+ parserMode |= parser.Trace
+ sequential = true
+ }
+ if *parseComments && (*printAST || *printTrace) {
+ parserMode |= parser.ParseComments
+ }
+}
+
+const usageString = `usage: gotype [flags] [path ...]
+
+The gotype command, like the front-end of a Go compiler, parses and
+type-checks a single Go package. Errors are reported if the analysis
+fails; otherwise gotype is quiet (unless -v is set).
+
+Without a list of paths, gotype reads from standard input, which
+must provide a single Go source file defining a complete package.
+
+With a single directory argument, gotype checks the Go files in
+that directory, comprising a single package. Use -t to include the
+(in-package) _test.go files. Use -x to type check only external
+test files.
+
+Otherwise, each path must be the filename of a Go file belonging
+to the same package.
+
+Imports are processed by importing directly from the source of
+imported packages (default), or by importing from compiled and
+installed packages (by setting -c to the respective compiler).
+
+The -c flag must be set to a compiler ("gc", "gccgo") when type-
+checking packages containing imports with relative import paths
+(import "./mypkg") because the source importer cannot know which
+files to include for such packages.
+`
+
+func usage() {
+ fmt.Fprintln(os.Stderr, usageString)
+ flag.PrintDefaults()
+ os.Exit(2)
+}
+
+func report(err error) {
+ if *panicOnError {
+ panic(err)
+ }
+ scanner.PrintError(os.Stderr, err)
+ if list, ok := err.(scanner.ErrorList); ok {
+ errorCount += len(list)
+ return
+ }
+ errorCount++
+}
+
+// parse may be called concurrently
+func parse(filename string, src interface{}) (*ast.File, error) {
+ if *verbose {
+ fmt.Println(filename)
+ }
+ file, err := parser.ParseFile(fset, filename, src, parserMode) // ok to access fset concurrently
+ if *printAST {
+ ast.Print(fset, file)
+ }
+ return file, err
+}
+
+func parseStdin() (*ast.File, error) {
+ src, err := io.ReadAll(os.Stdin)
+ if err != nil {
+ return nil, err
+ }
+ return parse("<standard input>", src)
+}
+
+func parseFiles(dir string, filenames []string) ([]*ast.File, error) {
+ files := make([]*ast.File, len(filenames))
+ errors := make([]error, len(filenames))
+
+ var wg sync.WaitGroup
+ for i, filename := range filenames {
+ wg.Add(1)
+ go func(i int, filepath string) {
+ defer wg.Done()
+ files[i], errors[i] = parse(filepath, nil)
+ }(i, filepath.Join(dir, filename))
+ if sequential {
+ wg.Wait()
+ }
+ }
+ wg.Wait()
+
+ // If there are errors, return the first one for deterministic results.
+ var first error
+ for _, err := range errors {
+ if err != nil {
+ first = err
+ // If we have an error, some files may be nil.
+ // Remove them. (The go/parser always returns
+ // a possibly partial AST even in the presence
+ // of errors, except if the file doesn't exist
+ // in the first place, in which case it cannot
+ // matter.)
+ i := 0
+ for _, f := range files {
+ if f != nil {
+ files[i] = f
+ i++
+ }
+ }
+ files = files[:i]
+ break
+ }
+ }
+
+ return files, first
+}
+
+func parseDir(dir string) ([]*ast.File, error) {
+ ctxt := build.Default
+ pkginfo, err := ctxt.ImportDir(dir, 0)
+ if _, nogo := err.(*build.NoGoError); err != nil && !nogo {
+ return nil, err
+ }
+
+ if *xtestFiles {
+ return parseFiles(dir, pkginfo.XTestGoFiles)
+ }
+
+ filenames := append(pkginfo.GoFiles, pkginfo.CgoFiles...)
+ if *testFiles {
+ filenames = append(filenames, pkginfo.TestGoFiles...)
+ }
+ return parseFiles(dir, filenames)
+}
+
+func getPkgFiles(args []string) ([]*ast.File, error) {
+ if len(args) == 0 {
+ // stdin
+ file, err := parseStdin()
+ if err != nil {
+ return nil, err
+ }
+ return []*ast.File{file}, nil
+ }
+
+ if len(args) == 1 {
+ // possibly a directory
+ path := args[0]
+ info, err := os.Stat(path)
+ if err != nil {
+ return nil, err
+ }
+ if info.IsDir() {
+ return parseDir(path)
+ }
+ }
+
+ // list of files
+ return parseFiles("", args)
+}
+
+func checkPkgFiles(files []*ast.File) {
+ type bailout struct{}
+
+ // if checkPkgFiles is called multiple times, set up conf only once
+ conf := types.Config{
+ FakeImportC: true,
+ Error: func(err error) {
+ if !*allErrors && errorCount >= 10 {
+ panic(bailout{})
+ }
+ report(err)
+ },
+ Importer: importer.ForCompiler(fset, *compiler, nil),
+ Sizes: types.SizesFor(build.Default.Compiler, build.Default.GOARCH),
+ }
+
+ defer func() {
+ switch p := recover().(type) {
+ case nil, bailout:
+ // normal return or early exit
+ default:
+ // re-panic
+ panic(p)
+ }
+ }()
+
+ const path = "pkg" // any non-empty string will do for now
+ conf.Check(path, fset, files, nil)
+}
+
+func printStats(d time.Duration) {
+ fileCount := 0
+ lineCount := 0
+ fset.Iterate(func(f *token.File) bool {
+ fileCount++
+ lineCount += f.LineCount()
+ return true
+ })
+
+ fmt.Printf(
+ "%s (%d files, %d lines, %d lines/s)\n",
+ d, fileCount, lineCount, int64(float64(lineCount)/d.Seconds()),
+ )
+}
+
+func main() {
+ flag.Usage = usage
+ flag.Parse()
+ initParserMode()
+
+ start := time.Now()
+
+ files, err := getPkgFiles(flag.Args())
+ if err != nil {
+ report(err)
+ // ok to continue (files may be empty, but not nil)
+ }
+
+ checkPkgFiles(files)
+ if errorCount > 0 {
+ os.Exit(2)
+ }
+
+ if *verbose {
+ printStats(time.Since(start))
+ }
+}
diff --git a/src/go/types/hilbert_test.go b/src/go/types/hilbert_test.go
new file mode 100644
index 0000000..77954d2
--- /dev/null
+++ b/src/go/types/hilbert_test.go
@@ -0,0 +1,222 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "bytes"
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "os"
+ "testing"
+
+ . "go/types"
+)
+
+var (
+ H = flag.Int("H", 5, "Hilbert matrix size")
+ out = flag.String("out", "", "write generated program to out")
+)
+
+func TestHilbert(t *testing.T) {
+ // generate source
+ src := program(*H, *out)
+ if *out != "" {
+ os.WriteFile(*out, src, 0666)
+ return
+ }
+
+ // parse source
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "hilbert.go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // type-check file
+ DefPredeclaredTestFuncs() // define assert built-in
+ conf := Config{Importer: importer.Default()}
+ _, err = conf.Check(f.Name.Name, fset, []*ast.File{f}, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+}
+
+func program(n int, out string) []byte {
+ var g gen
+
+ g.p(`// Code generated by: go test -run=Hilbert -H=%d -out=%q. DO NOT EDIT.
+
+// +`+`build ignore
+
+// This program tests arbitrary precision constant arithmetic
+// by generating the constant elements of a Hilbert matrix H,
+// its inverse I, and the product P = H*I. The product should
+// be the identity matrix.
+package main
+
+func main() {
+ if !ok {
+ printProduct()
+ return
+ }
+ println("PASS")
+}
+
+`, n, out)
+ g.hilbert(n)
+ g.inverse(n)
+ g.product(n)
+ g.verify(n)
+ g.printProduct(n)
+ g.binomials(2*n - 1)
+ g.factorials(2*n - 1)
+
+ return g.Bytes()
+}
+
+type gen struct {
+ bytes.Buffer
+}
+
+func (g *gen) p(format string, args ...interface{}) {
+ fmt.Fprintf(&g.Buffer, format, args...)
+}
+
+func (g *gen) hilbert(n int) {
+ g.p(`// Hilbert matrix, n = %d
+const (
+`, n)
+ for i := 0; i < n; i++ {
+ g.p("\t")
+ for j := 0; j < n; j++ {
+ if j > 0 {
+ g.p(", ")
+ }
+ g.p("h%d_%d", i, j)
+ }
+ if i == 0 {
+ g.p(" = ")
+ for j := 0; j < n; j++ {
+ if j > 0 {
+ g.p(", ")
+ }
+ g.p("1.0/(iota + %d)", j+1)
+ }
+ }
+ g.p("\n")
+ }
+ g.p(")\n\n")
+}
+
+func (g *gen) inverse(n int) {
+ g.p(`// Inverse Hilbert matrix
+const (
+`)
+ for i := 0; i < n; i++ {
+ for j := 0; j < n; j++ {
+ s := "+"
+ if (i+j)&1 != 0 {
+ s = "-"
+ }
+ g.p("\ti%d_%d = %s%d * b%d_%d * b%d_%d * b%d_%d * b%d_%d\n",
+ i, j, s, i+j+1, n+i, n-j-1, n+j, n-i-1, i+j, i, i+j, i)
+ }
+ g.p("\n")
+ }
+ g.p(")\n\n")
+}
+
+func (g *gen) product(n int) {
+ g.p(`// Product matrix
+const (
+`)
+ for i := 0; i < n; i++ {
+ for j := 0; j < n; j++ {
+ g.p("\tp%d_%d = ", i, j)
+ for k := 0; k < n; k++ {
+ if k > 0 {
+ g.p(" + ")
+ }
+ g.p("h%d_%d*i%d_%d", i, k, k, j)
+ }
+ g.p("\n")
+ }
+ g.p("\n")
+ }
+ g.p(")\n\n")
+}
+
+func (g *gen) verify(n int) {
+ g.p(`// Verify that product is the identity matrix
+const ok =
+`)
+ for i := 0; i < n; i++ {
+ for j := 0; j < n; j++ {
+ if j == 0 {
+ g.p("\t")
+ } else {
+ g.p(" && ")
+ }
+ v := 0
+ if i == j {
+ v = 1
+ }
+ g.p("p%d_%d == %d", i, j, v)
+ }
+ g.p(" &&\n")
+ }
+ g.p("\ttrue\n\n")
+
+ // verify ok at type-check time
+ if *out == "" {
+ g.p("const _ = assert(ok)\n\n")
+ }
+}
+
+func (g *gen) printProduct(n int) {
+ g.p("func printProduct() {\n")
+ for i := 0; i < n; i++ {
+ g.p("\tprintln(")
+ for j := 0; j < n; j++ {
+ if j > 0 {
+ g.p(", ")
+ }
+ g.p("p%d_%d", i, j)
+ }
+ g.p(")\n")
+ }
+ g.p("}\n\n")
+}
+
+func (g *gen) binomials(n int) {
+ g.p(`// Binomials
+const (
+`)
+ for j := 0; j <= n; j++ {
+ if j > 0 {
+ g.p("\n")
+ }
+ for k := 0; k <= j; k++ {
+ g.p("\tb%d_%d = f%d / (f%d*f%d)\n", j, k, j, k, j-k)
+ }
+ }
+ g.p(")\n\n")
+}
+
+func (g *gen) factorials(n int) {
+ g.p(`// Factorials
+const (
+ f0 = 1
+ f1 = 1
+`)
+ for i := 2; i <= n; i++ {
+ g.p("\tf%d = f%d * %d\n", i, i-1, i)
+ }
+ g.p(")\n\n")
+}
diff --git a/src/go/types/initorder.go b/src/go/types/initorder.go
new file mode 100644
index 0000000..77a739c
--- /dev/null
+++ b/src/go/types/initorder.go
@@ -0,0 +1,297 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "container/heap"
+ "fmt"
+)
+
+// initOrder computes the Info.InitOrder for package variables.
+func (check *Checker) initOrder() {
+ // An InitOrder may already have been computed if a package is
+ // built from several calls to (*Checker).Files. Clear it.
+ check.Info.InitOrder = check.Info.InitOrder[:0]
+
+ // Compute the object dependency graph and initialize
+ // a priority queue with the list of graph nodes.
+ pq := nodeQueue(dependencyGraph(check.objMap))
+ heap.Init(&pq)
+
+ const debug = false
+ if debug {
+ fmt.Printf("Computing initialization order for %s\n\n", check.pkg)
+ fmt.Println("Object dependency graph:")
+ for obj, d := range check.objMap {
+ // only print objects that may appear in the dependency graph
+ if obj, _ := obj.(dependency); obj != nil {
+ if len(d.deps) > 0 {
+ fmt.Printf("\t%s depends on\n", obj.Name())
+ for dep := range d.deps {
+ fmt.Printf("\t\t%s\n", dep.Name())
+ }
+ } else {
+ fmt.Printf("\t%s has no dependencies\n", obj.Name())
+ }
+ }
+ }
+ fmt.Println()
+
+ fmt.Println("Transposed object dependency graph (functions eliminated):")
+ for _, n := range pq {
+ fmt.Printf("\t%s depends on %d nodes\n", n.obj.Name(), n.ndeps)
+ for p := range n.pred {
+ fmt.Printf("\t\t%s is dependent\n", p.obj.Name())
+ }
+ }
+ fmt.Println()
+
+ fmt.Println("Processing nodes:")
+ }
+
+ // Determine initialization order by removing the highest priority node
+ // (the one with the fewest dependencies) and its edges from the graph,
+ // repeatedly, until there are no nodes left.
+ // In a valid Go program, those nodes always have zero dependencies (after
+ // removing all incoming dependencies), otherwise there are initialization
+ // cycles.
+ emitted := make(map[*declInfo]bool)
+ for len(pq) > 0 {
+ // get the next node
+ n := heap.Pop(&pq).(*graphNode)
+
+ if debug {
+ fmt.Printf("\t%s (src pos %d) depends on %d nodes now\n",
+ n.obj.Name(), n.obj.order(), n.ndeps)
+ }
+
+ // if n still depends on other nodes, we have a cycle
+ if n.ndeps > 0 {
+ cycle := findPath(check.objMap, n.obj, n.obj, make(map[Object]bool))
+ // If n.obj is not part of the cycle (e.g., n.obj->b->c->d->c),
+ // cycle will be nil. Don't report anything in that case since
+ // the cycle is reported when the algorithm gets to an object
+ // in the cycle.
+ // Furthermore, once an object in the cycle is encountered,
+ // the cycle will be broken (dependency count will be reduced
+ // below), and so the remaining nodes in the cycle don't trigger
+ // another error (unless they are part of multiple cycles).
+ if cycle != nil {
+ check.reportCycle(cycle)
+ }
+ // Ok to continue, but the variable initialization order
+ // will be incorrect at this point since it assumes no
+ // cycle errors.
+ }
+
+ // reduce dependency count of all dependent nodes
+ // and update priority queue
+ for p := range n.pred {
+ p.ndeps--
+ heap.Fix(&pq, p.index)
+ }
+
+ // record the init order for variables with initializers only
+ v, _ := n.obj.(*Var)
+ info := check.objMap[v]
+ if v == nil || !info.hasInitializer() {
+ continue
+ }
+
+ // n:1 variable declarations such as: a, b = f()
+ // introduce a node for each lhs variable (here: a, b);
+ // but they all have the same initializer - emit only
+ // one, for the first variable seen
+ if emitted[info] {
+ continue // initializer already emitted, if any
+ }
+ emitted[info] = true
+
+ infoLhs := info.lhs // possibly nil (see declInfo.lhs field comment)
+ if infoLhs == nil {
+ infoLhs = []*Var{v}
+ }
+ init := &Initializer{infoLhs, info.init}
+ check.Info.InitOrder = append(check.Info.InitOrder, init)
+ }
+
+ if debug {
+ fmt.Println()
+ fmt.Println("Initialization order:")
+ for _, init := range check.Info.InitOrder {
+ fmt.Printf("\t%s\n", init)
+ }
+ fmt.Println()
+ }
+}
+
+// findPath returns the (reversed) list of objects []Object{to, ... from}
+// such that there is a path of object dependencies from 'from' to 'to'.
+// If there is no such path, the result is nil.
+func findPath(objMap map[Object]*declInfo, from, to Object, seen map[Object]bool) []Object {
+ if seen[from] {
+ return nil
+ }
+ seen[from] = true
+
+ for d := range objMap[from].deps {
+ if d == to {
+ return []Object{d}
+ }
+ if P := findPath(objMap, d, to, seen); P != nil {
+ return append(P, d)
+ }
+ }
+
+ return nil
+}
+
+// reportCycle reports an error for the given cycle.
+func (check *Checker) reportCycle(cycle []Object) {
+ obj := cycle[0]
+ check.errorf(obj, _InvalidInitCycle, "initialization cycle for %s", obj.Name())
+ // subtle loop: print cycle[i] for i = 0, n-1, n-2, ... 1 for len(cycle) = n
+ for i := len(cycle) - 1; i >= 0; i-- {
+ check.errorf(obj, _InvalidInitCycle, "\t%s refers to", obj.Name()) // secondary error, \t indented
+ obj = cycle[i]
+ }
+ // print cycle[0] again to close the cycle
+ check.errorf(obj, _InvalidInitCycle, "\t%s", obj.Name())
+}
+
+// ----------------------------------------------------------------------------
+// Object dependency graph
+
+// A dependency is an object that may be a dependency in an initialization
+// expression. Only constants, variables, and functions can be dependencies.
+// Constants are here because constant expression cycles are reported during
+// initialization order computation.
+type dependency interface {
+ Object
+ isDependency()
+}
+
+// A graphNode represents a node in the object dependency graph.
+// Each node p in n.pred represents an edge p->n, and each node
+// s in n.succ represents an edge n->s; with a->b indicating that
+// a depends on b.
+type graphNode struct {
+ obj dependency // object represented by this node
+ pred, succ nodeSet // consumers and dependencies of this node (lazily initialized)
+ index int // node index in graph slice/priority queue
+ ndeps int // number of outstanding dependencies before this object can be initialized
+}
+
+type nodeSet map[*graphNode]bool
+
+func (s *nodeSet) add(p *graphNode) {
+ if *s == nil {
+ *s = make(nodeSet)
+ }
+ (*s)[p] = true
+}
+
+// dependencyGraph computes the object dependency graph from the given objMap,
+// with any function nodes removed. The resulting graph contains only constants
+// and variables.
+func dependencyGraph(objMap map[Object]*declInfo) []*graphNode {
+ // M is the dependency (Object) -> graphNode mapping
+ M := make(map[dependency]*graphNode)
+ for obj := range objMap {
+ // only consider nodes that may be an initialization dependency
+ if obj, _ := obj.(dependency); obj != nil {
+ M[obj] = &graphNode{obj: obj}
+ }
+ }
+
+ // compute edges for graph M
+ // (We need to include all nodes, even isolated ones, because they still need
+ // to be scheduled for initialization in correct order relative to other nodes.)
+ for obj, n := range M {
+ // for each dependency obj -> d (= deps[i]), create graph edges n->s and s->n
+ for d := range objMap[obj].deps {
+ // only consider nodes that may be an initialization dependency
+ if d, _ := d.(dependency); d != nil {
+ d := M[d]
+ n.succ.add(d)
+ d.pred.add(n)
+ }
+ }
+ }
+
+ // remove function nodes and collect remaining graph nodes in G
+ // (Mutually recursive functions may introduce cycles among themselves
+ // which are permitted. Yet such cycles may incorrectly inflate the dependency
+ // count for variables which in turn may not get scheduled for initialization
+ // in correct order.)
+ var G []*graphNode
+ for obj, n := range M {
+ if _, ok := obj.(*Func); ok {
+ // connect each predecessor p of n with each successor s
+ // and drop the function node (don't collect it in G)
+ for p := range n.pred {
+ // ignore self-cycles
+ if p != n {
+ // Each successor s of n becomes a successor of p, and
+ // each predecessor p of n becomes a predecessor of s.
+ for s := range n.succ {
+ // ignore self-cycles
+ if s != n {
+ p.succ.add(s)
+ s.pred.add(p)
+ delete(s.pred, n) // remove edge to n
+ }
+ }
+ delete(p.succ, n) // remove edge to n
+ }
+ }
+ } else {
+ // collect non-function nodes
+ G = append(G, n)
+ }
+ }
+
+ // fill in index and ndeps fields
+ for i, n := range G {
+ n.index = i
+ n.ndeps = len(n.succ)
+ }
+
+ return G
+}
+
+// ----------------------------------------------------------------------------
+// Priority queue
+
+// nodeQueue implements the container/heap interface;
+// a nodeQueue may be used as a priority queue.
+type nodeQueue []*graphNode
+
+func (a nodeQueue) Len() int { return len(a) }
+
+func (a nodeQueue) Swap(i, j int) {
+ x, y := a[i], a[j]
+ a[i], a[j] = y, x
+ x.index, y.index = j, i
+}
+
+func (a nodeQueue) Less(i, j int) bool {
+ x, y := a[i], a[j]
+ // nodes are prioritized by number of incoming dependencies (1st key)
+ // and source order (2nd key)
+ return x.ndeps < y.ndeps || x.ndeps == y.ndeps && x.obj.order() < y.obj.order()
+}
+
+func (a *nodeQueue) Push(x interface{}) {
+ panic("unreachable")
+}
+
+func (a *nodeQueue) Pop() interface{} {
+ n := len(*a)
+ x := (*a)[n-1]
+ x.index = -1 // for safety
+ *a = (*a)[:n-1]
+ return x
+}
diff --git a/src/go/types/issues_test.go b/src/go/types/issues_test.go
new file mode 100644
index 0000000..34850eb
--- /dev/null
+++ b/src/go/types/issues_test.go
@@ -0,0 +1,551 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements tests for various issues.
+
+package types_test
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "internal/testenv"
+ "sort"
+ "strings"
+ "testing"
+
+ . "go/types"
+)
+
+func mustParse(t *testing.T, src string) *ast.File {
+ f, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ return f
+}
+func TestIssue5770(t *testing.T) {
+ f := mustParse(t, `package p; type S struct{T}`)
+ conf := Config{Importer: importer.Default()}
+ _, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, nil) // do not crash
+ want := "undeclared name: T"
+ if err == nil || !strings.Contains(err.Error(), want) {
+ t.Errorf("got: %v; want: %s", err, want)
+ }
+}
+
+func TestIssue5849(t *testing.T) {
+ src := `
+package p
+var (
+ s uint
+ _ = uint8(8)
+ _ = uint16(16) << s
+ _ = uint32(32 << s)
+ _ = uint64(64 << s + s)
+ _ = (interface{})("foo")
+ _ = (interface{})(nil)
+)`
+ f := mustParse(t, src)
+
+ var conf Config
+ types := make(map[ast.Expr]TypeAndValue)
+ _, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, &Info{Types: types})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ for x, tv := range types {
+ var want Type
+ switch x := x.(type) {
+ case *ast.BasicLit:
+ switch x.Value {
+ case `8`:
+ want = Typ[Uint8]
+ case `16`:
+ want = Typ[Uint16]
+ case `32`:
+ want = Typ[Uint32]
+ case `64`:
+ want = Typ[Uint] // because of "+ s", s is of type uint
+ case `"foo"`:
+ want = Typ[String]
+ }
+ case *ast.Ident:
+ if x.Name == "nil" {
+ want = Typ[UntypedNil]
+ }
+ }
+ if want != nil && !Identical(tv.Type, want) {
+ t.Errorf("got %s; want %s", tv.Type, want)
+ }
+ }
+}
+
+func TestIssue6413(t *testing.T) {
+ src := `
+package p
+func f() int {
+ defer f()
+ go f()
+ return 0
+}
+`
+ f := mustParse(t, src)
+
+ var conf Config
+ types := make(map[ast.Expr]TypeAndValue)
+ _, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, &Info{Types: types})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ want := Typ[Int]
+ n := 0
+ for x, tv := range types {
+ if _, ok := x.(*ast.CallExpr); ok {
+ if tv.Type != want {
+ t.Errorf("%s: got %s; want %s", fset.Position(x.Pos()), tv.Type, want)
+ }
+ n++
+ }
+ }
+
+ if n != 2 {
+ t.Errorf("got %d CallExprs; want 2", n)
+ }
+}
+
+func TestIssue7245(t *testing.T) {
+ src := `
+package p
+func (T) m() (res bool) { return }
+type T struct{} // receiver type after method declaration
+`
+ f := mustParse(t, src)
+
+ var conf Config
+ defs := make(map[*ast.Ident]Object)
+ _, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, &Info{Defs: defs})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ m := f.Decls[0].(*ast.FuncDecl)
+ res1 := defs[m.Name].(*Func).Type().(*Signature).Results().At(0)
+ res2 := defs[m.Type.Results.List[0].Names[0]].(*Var)
+
+ if res1 != res2 {
+ t.Errorf("got %s (%p) != %s (%p)", res1, res2, res1, res2)
+ }
+}
+
+// This tests that uses of existing vars on the LHS of an assignment
+// are Uses, not Defs; and also that the (illegal) use of a non-var on
+// the LHS of an assignment is a Use nonetheless.
+func TestIssue7827(t *testing.T) {
+ const src = `
+package p
+func _() {
+ const w = 1 // defs w
+ x, y := 2, 3 // defs x, y
+ w, x, z := 4, 5, 6 // uses w, x, defs z; error: cannot assign to w
+ _, _, _ = x, y, z // uses x, y, z
+}
+`
+ f := mustParse(t, src)
+
+ const want = `L3 defs func p._()
+L4 defs const w untyped int
+L5 defs var x int
+L5 defs var y int
+L6 defs var z int
+L6 uses const w untyped int
+L6 uses var x int
+L7 uses var x int
+L7 uses var y int
+L7 uses var z int`
+
+ // don't abort at the first error
+ conf := Config{Error: func(err error) { t.Log(err) }}
+ defs := make(map[*ast.Ident]Object)
+ uses := make(map[*ast.Ident]Object)
+ _, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, &Info{Defs: defs, Uses: uses})
+ if s := fmt.Sprint(err); !strings.HasSuffix(s, "cannot assign to w") {
+ t.Errorf("Check: unexpected error: %s", s)
+ }
+
+ var facts []string
+ for id, obj := range defs {
+ if obj != nil {
+ fact := fmt.Sprintf("L%d defs %s", fset.Position(id.Pos()).Line, obj)
+ facts = append(facts, fact)
+ }
+ }
+ for id, obj := range uses {
+ fact := fmt.Sprintf("L%d uses %s", fset.Position(id.Pos()).Line, obj)
+ facts = append(facts, fact)
+ }
+ sort.Strings(facts)
+
+ got := strings.Join(facts, "\n")
+ if got != want {
+ t.Errorf("Unexpected defs/uses\ngot:\n%s\nwant:\n%s", got, want)
+ }
+}
+
+// This tests that the package associated with the types.Object.Pkg method
+// is the type's package independent of the order in which the imports are
+// listed in the sources src1, src2 below.
+// The actual issue is in go/internal/gcimporter which has a corresponding
+// test; we leave this test here to verify correct behavior at the go/types
+// level.
+func TestIssue13898(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ const src0 = `
+package main
+
+import "go/types"
+
+func main() {
+ var info types.Info
+ for _, obj := range info.Uses {
+ _ = obj.Pkg()
+ }
+}
+`
+ // like src0, but also imports go/importer
+ const src1 = `
+package main
+
+import (
+ "go/types"
+ _ "go/importer"
+)
+
+func main() {
+ var info types.Info
+ for _, obj := range info.Uses {
+ _ = obj.Pkg()
+ }
+}
+`
+ // like src1 but with different import order
+ // (used to fail with this issue)
+ const src2 = `
+package main
+
+import (
+ _ "go/importer"
+ "go/types"
+)
+
+func main() {
+ var info types.Info
+ for _, obj := range info.Uses {
+ _ = obj.Pkg()
+ }
+}
+`
+ f := func(test, src string) {
+ f := mustParse(t, src)
+ cfg := Config{Importer: importer.Default()}
+ info := Info{Uses: make(map[*ast.Ident]Object)}
+ _, err := cfg.Check("main", fset, []*ast.File{f}, &info)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var pkg *Package
+ count := 0
+ for id, obj := range info.Uses {
+ if id.Name == "Pkg" {
+ pkg = obj.Pkg()
+ count++
+ }
+ }
+ if count != 1 {
+ t.Fatalf("%s: got %d entries named Pkg; want 1", test, count)
+ }
+ if pkg.Name() != "types" {
+ t.Fatalf("%s: got %v; want package types", test, pkg)
+ }
+ }
+
+ f("src0", src0)
+ f("src1", src1)
+ f("src2", src2)
+}
+
+func TestIssue22525(t *testing.T) {
+ f := mustParse(t, `package p; func f() { var a, b, c, d, e int }`)
+
+ got := "\n"
+ conf := Config{Error: func(err error) { got += err.Error() + "\n" }}
+ conf.Check(f.Name.Name, fset, []*ast.File{f}, nil) // do not crash
+ want := `
+1:27: a declared but not used
+1:30: b declared but not used
+1:33: c declared but not used
+1:36: d declared but not used
+1:39: e declared but not used
+`
+ if got != want {
+ t.Errorf("got: %swant: %s", got, want)
+ }
+}
+
+func TestIssue25627(t *testing.T) {
+ const prefix = `package p; import "unsafe"; type P *struct{}; type I interface{}; type T `
+ // The src strings (without prefix) are constructed such that the number of semicolons
+ // plus one corresponds to the number of fields expected in the respective struct.
+ for _, src := range []string{
+ `struct { x Missing }`,
+ `struct { Missing }`,
+ `struct { *Missing }`,
+ `struct { unsafe.Pointer }`,
+ `struct { P }`,
+ `struct { *I }`,
+ `struct { a int; b Missing; *Missing }`,
+ } {
+ f := mustParse(t, prefix+src)
+
+ cfg := Config{Importer: importer.Default(), Error: func(err error) {}}
+ info := &Info{Types: make(map[ast.Expr]TypeAndValue)}
+ _, err := cfg.Check(f.Name.Name, fset, []*ast.File{f}, info)
+ if err != nil {
+ if _, ok := err.(Error); !ok {
+ t.Fatal(err)
+ }
+ }
+
+ ast.Inspect(f, func(n ast.Node) bool {
+ if spec, _ := n.(*ast.TypeSpec); spec != nil {
+ if tv, ok := info.Types[spec.Type]; ok && spec.Name.Name == "T" {
+ want := strings.Count(src, ";") + 1
+ if got := tv.Type.(*Struct).NumFields(); got != want {
+ t.Errorf("%s: got %d fields; want %d", src, got, want)
+ }
+ }
+ }
+ return true
+ })
+ }
+}
+
+func TestIssue28005(t *testing.T) {
+ // method names must match defining interface name for this test
+ // (see last comment in this function)
+ sources := [...]string{
+ "package p; type A interface{ A() }",
+ "package p; type B interface{ B() }",
+ "package p; type X interface{ A; B }",
+ }
+
+ // compute original file ASTs
+ var orig [len(sources)]*ast.File
+ for i, src := range sources {
+ orig[i] = mustParse(t, src)
+ }
+
+ // run the test for all order permutations of the incoming files
+ for _, perm := range [][len(sources)]int{
+ {0, 1, 2},
+ {0, 2, 1},
+ {1, 0, 2},
+ {1, 2, 0},
+ {2, 0, 1},
+ {2, 1, 0},
+ } {
+ // create file order permutation
+ files := make([]*ast.File, len(sources))
+ for i := range perm {
+ files[i] = orig[perm[i]]
+ }
+
+ // type-check package with given file order permutation
+ var conf Config
+ info := &Info{Defs: make(map[*ast.Ident]Object)}
+ _, err := conf.Check("", fset, files, info)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // look for interface object X
+ var obj Object
+ for name, def := range info.Defs {
+ if name.Name == "X" {
+ obj = def
+ break
+ }
+ }
+ if obj == nil {
+ t.Fatal("interface not found")
+ }
+ iface := obj.Type().Underlying().(*Interface) // I must be an interface
+
+ // Each iface method m is embedded; and m's receiver base type name
+ // must match the method's name per the choice in the source file.
+ for i := 0; i < iface.NumMethods(); i++ {
+ m := iface.Method(i)
+ recvName := m.Type().(*Signature).Recv().Type().(*Named).Obj().Name()
+ if recvName != m.Name() {
+ t.Errorf("perm %v: got recv %s; want %s", perm, recvName, m.Name())
+ }
+ }
+ }
+}
+
+func TestIssue28282(t *testing.T) {
+ // create type interface { error }
+ et := Universe.Lookup("error").Type()
+ it := NewInterfaceType(nil, []Type{et})
+ it.Complete()
+ // verify that after completing the interface, the embedded method remains unchanged
+ want := et.Underlying().(*Interface).Method(0)
+ got := it.Method(0)
+ if got != want {
+ t.Fatalf("%s.Method(0): got %q (%p); want %q (%p)", it, got, got, want, want)
+ }
+ // verify that lookup finds the same method in both interfaces (redundant check)
+ obj, _, _ := LookupFieldOrMethod(et, false, nil, "Error")
+ if obj != want {
+ t.Fatalf("%s.Lookup: got %q (%p); want %q (%p)", et, obj, obj, want, want)
+ }
+ obj, _, _ = LookupFieldOrMethod(it, false, nil, "Error")
+ if obj != want {
+ t.Fatalf("%s.Lookup: got %q (%p); want %q (%p)", it, obj, obj, want, want)
+ }
+}
+
+func TestIssue29029(t *testing.T) {
+ f1 := mustParse(t, `package p; type A interface { M() }`)
+ f2 := mustParse(t, `package p; var B interface { A }`)
+
+ // printInfo prints the *Func definitions recorded in info, one *Func per line.
+ printInfo := func(info *Info) string {
+ var buf bytes.Buffer
+ for _, obj := range info.Defs {
+ if fn, ok := obj.(*Func); ok {
+ fmt.Fprintln(&buf, fn)
+ }
+ }
+ return buf.String()
+ }
+
+ // The *Func (method) definitions for package p must be the same
+ // independent on whether f1 and f2 are type-checked together, or
+ // incrementally.
+
+ // type-check together
+ var conf Config
+ info := &Info{Defs: make(map[*ast.Ident]Object)}
+ check := NewChecker(&conf, fset, NewPackage("", "p"), info)
+ if err := check.Files([]*ast.File{f1, f2}); err != nil {
+ t.Fatal(err)
+ }
+ want := printInfo(info)
+
+ // type-check incrementally
+ info = &Info{Defs: make(map[*ast.Ident]Object)}
+ check = NewChecker(&conf, fset, NewPackage("", "p"), info)
+ if err := check.Files([]*ast.File{f1}); err != nil {
+ t.Fatal(err)
+ }
+ if err := check.Files([]*ast.File{f2}); err != nil {
+ t.Fatal(err)
+ }
+ got := printInfo(info)
+
+ if got != want {
+ t.Errorf("\ngot : %swant: %s", got, want)
+ }
+}
+
+func TestIssue34151(t *testing.T) {
+ const asrc = `package a; type I interface{ M() }; type T struct { F interface { I } }`
+ const bsrc = `package b; import "a"; type T struct { F interface { a.I } }; var _ = a.T(T{})`
+
+ a, err := pkgFor("a", asrc, nil)
+ if err != nil {
+ t.Fatalf("package %s failed to typecheck: %v", a.Name(), err)
+ }
+
+ bast := mustParse(t, bsrc)
+ conf := Config{Importer: importHelper{a}}
+ b, err := conf.Check(bast.Name.Name, fset, []*ast.File{bast}, nil)
+ if err != nil {
+ t.Errorf("package %s failed to typecheck: %v", b.Name(), err)
+ }
+}
+
+type importHelper struct {
+ pkg *Package
+}
+
+func (h importHelper) Import(path string) (*Package, error) {
+ if path != h.pkg.Path() {
+ return nil, fmt.Errorf("got package path %q; want %q", path, h.pkg.Path())
+ }
+ return h.pkg, nil
+}
+
+// TestIssue34921 verifies that we don't update an imported type's underlying
+// type when resolving an underlying type. Specifically, when determining the
+// underlying type of b.T (which is the underlying type of a.T, which is int)
+// we must not set the underlying type of a.T again since that would lead to
+// a race condition if package b is imported elsewhere, in a package that is
+// concurrently type-checked.
+func TestIssue34921(t *testing.T) {
+ defer func() {
+ if r := recover(); r != nil {
+ t.Error(r)
+ }
+ }()
+
+ var sources = []string{
+ `package a; type T int`,
+ `package b; import "a"; type T a.T`,
+ }
+
+ var pkg *Package
+ for _, src := range sources {
+ f := mustParse(t, src)
+ conf := Config{Importer: importHelper{pkg}}
+ res, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, nil)
+ if err != nil {
+ t.Errorf("%q failed to typecheck: %v", src, err)
+ }
+ pkg = res // res is imported by the next package in this test
+ }
+}
+
+func TestIssue43088(t *testing.T) {
+ // type T1 struct {
+ // _ T2
+ // }
+ //
+ // type T2 struct {
+ // _ struct {
+ // _ T2
+ // }
+ // }
+ n1 := NewTypeName(token.NoPos, nil, "T1", nil)
+ T1 := NewNamed(n1, nil, nil)
+ n2 := NewTypeName(token.NoPos, nil, "T2", nil)
+ T2 := NewNamed(n2, nil, nil)
+ s1 := NewStruct([]*Var{NewField(token.NoPos, nil, "_", T2, false)}, nil)
+ T1.SetUnderlying(s1)
+ s2 := NewStruct([]*Var{NewField(token.NoPos, nil, "_", T2, false)}, nil)
+ s3 := NewStruct([]*Var{NewField(token.NoPos, nil, "_", s2, false)}, nil)
+ T2.SetUnderlying(s3)
+
+ // These calls must terminate (no endless recursion).
+ Comparable(T1)
+ Comparable(T2)
+}
diff --git a/src/go/types/labels.go b/src/go/types/labels.go
new file mode 100644
index 0000000..8cf6e63
--- /dev/null
+++ b/src/go/types/labels.go
@@ -0,0 +1,272 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "go/ast"
+ "go/token"
+)
+
+// labels checks correct label use in body.
+func (check *Checker) labels(body *ast.BlockStmt) {
+ // set of all labels in this body
+ all := NewScope(nil, body.Pos(), body.End(), "label")
+
+ fwdJumps := check.blockBranches(all, nil, nil, body.List)
+
+ // If there are any forward jumps left, no label was found for
+ // the corresponding goto statements. Either those labels were
+ // never defined, or they are inside blocks and not reachable
+ // for the respective gotos.
+ for _, jmp := range fwdJumps {
+ var msg string
+ var code errorCode
+ name := jmp.Label.Name
+ if alt := all.Lookup(name); alt != nil {
+ msg = "goto %s jumps into block"
+ alt.(*Label).used = true // avoid another error
+ code = _JumpIntoBlock
+ } else {
+ msg = "label %s not declared"
+ code = _UndeclaredLabel
+ }
+ check.errorf(jmp.Label, code, msg, name)
+ }
+
+ // spec: "It is illegal to define a label that is never used."
+ for _, obj := range all.elems {
+ if lbl := obj.(*Label); !lbl.used {
+ check.softErrorf(lbl, _UnusedLabel, "label %s declared but not used", lbl.name)
+ }
+ }
+}
+
+// A block tracks label declarations in a block and its enclosing blocks.
+type block struct {
+ parent *block // enclosing block
+ lstmt *ast.LabeledStmt // labeled statement to which this block belongs, or nil
+ labels map[string]*ast.LabeledStmt // allocated lazily
+}
+
+// insert records a new label declaration for the current block.
+// The label must not have been declared before in any block.
+func (b *block) insert(s *ast.LabeledStmt) {
+ name := s.Label.Name
+ if debug {
+ assert(b.gotoTarget(name) == nil)
+ }
+ labels := b.labels
+ if labels == nil {
+ labels = make(map[string]*ast.LabeledStmt)
+ b.labels = labels
+ }
+ labels[name] = s
+}
+
+// gotoTarget returns the labeled statement in the current
+// or an enclosing block with the given label name, or nil.
+func (b *block) gotoTarget(name string) *ast.LabeledStmt {
+ for s := b; s != nil; s = s.parent {
+ if t := s.labels[name]; t != nil {
+ return t
+ }
+ }
+ return nil
+}
+
+// enclosingTarget returns the innermost enclosing labeled
+// statement with the given label name, or nil.
+func (b *block) enclosingTarget(name string) *ast.LabeledStmt {
+ for s := b; s != nil; s = s.parent {
+ if t := s.lstmt; t != nil && t.Label.Name == name {
+ return t
+ }
+ }
+ return nil
+}
+
+// blockBranches processes a block's statement list and returns the set of outgoing forward jumps.
+// all is the scope of all declared labels, parent the set of labels declared in the immediately
+// enclosing block, and lstmt is the labeled statement this block is associated with (or nil).
+func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *ast.LabeledStmt, list []ast.Stmt) []*ast.BranchStmt {
+ b := &block{parent: parent, lstmt: lstmt}
+
+ var (
+ varDeclPos token.Pos
+ fwdJumps, badJumps []*ast.BranchStmt
+ )
+
+ // All forward jumps jumping over a variable declaration are possibly
+ // invalid (they may still jump out of the block and be ok).
+ // recordVarDecl records them for the given position.
+ recordVarDecl := func(pos token.Pos) {
+ varDeclPos = pos
+ badJumps = append(badJumps[:0], fwdJumps...) // copy fwdJumps to badJumps
+ }
+
+ jumpsOverVarDecl := func(jmp *ast.BranchStmt) bool {
+ if varDeclPos.IsValid() {
+ for _, bad := range badJumps {
+ if jmp == bad {
+ return true
+ }
+ }
+ }
+ return false
+ }
+
+ blockBranches := func(lstmt *ast.LabeledStmt, list []ast.Stmt) {
+ // Unresolved forward jumps inside the nested block
+ // become forward jumps in the current block.
+ fwdJumps = append(fwdJumps, check.blockBranches(all, b, lstmt, list)...)
+ }
+
+ var stmtBranches func(ast.Stmt)
+ stmtBranches = func(s ast.Stmt) {
+ switch s := s.(type) {
+ case *ast.DeclStmt:
+ if d, _ := s.Decl.(*ast.GenDecl); d != nil && d.Tok == token.VAR {
+ recordVarDecl(d.Pos())
+ }
+
+ case *ast.LabeledStmt:
+ // declare non-blank label
+ if name := s.Label.Name; name != "_" {
+ lbl := NewLabel(s.Label.Pos(), check.pkg, name)
+ if alt := all.Insert(lbl); alt != nil {
+ check.softErrorf(lbl, _DuplicateLabel, "label %s already declared", name)
+ check.reportAltDecl(alt)
+ // ok to continue
+ } else {
+ b.insert(s)
+ check.recordDef(s.Label, lbl)
+ }
+ // resolve matching forward jumps and remove them from fwdJumps
+ i := 0
+ for _, jmp := range fwdJumps {
+ if jmp.Label.Name == name {
+ // match
+ lbl.used = true
+ check.recordUse(jmp.Label, lbl)
+ if jumpsOverVarDecl(jmp) {
+ check.softErrorf(
+ jmp.Label,
+ _JumpOverDecl,
+ "goto %s jumps over variable declaration at line %d",
+ name,
+ check.fset.Position(varDeclPos).Line,
+ )
+ // ok to continue
+ }
+ } else {
+ // no match - record new forward jump
+ fwdJumps[i] = jmp
+ i++
+ }
+ }
+ fwdJumps = fwdJumps[:i]
+ lstmt = s
+ }
+ stmtBranches(s.Stmt)
+
+ case *ast.BranchStmt:
+ if s.Label == nil {
+ return // checked in 1st pass (check.stmt)
+ }
+
+ // determine and validate target
+ name := s.Label.Name
+ switch s.Tok {
+ case token.BREAK:
+ // spec: "If there is a label, it must be that of an enclosing
+ // "for", "switch", or "select" statement, and that is the one
+ // whose execution terminates."
+ valid := false
+ if t := b.enclosingTarget(name); t != nil {
+ switch t.Stmt.(type) {
+ case *ast.SwitchStmt, *ast.TypeSwitchStmt, *ast.SelectStmt, *ast.ForStmt, *ast.RangeStmt:
+ valid = true
+ }
+ }
+ if !valid {
+ check.errorf(s.Label, _MisplacedLabel, "invalid break label %s", name)
+ return
+ }
+
+ case token.CONTINUE:
+ // spec: "If there is a label, it must be that of an enclosing
+ // "for" statement, and that is the one whose execution advances."
+ valid := false
+ if t := b.enclosingTarget(name); t != nil {
+ switch t.Stmt.(type) {
+ case *ast.ForStmt, *ast.RangeStmt:
+ valid = true
+ }
+ }
+ if !valid {
+ check.errorf(s.Label, _MisplacedLabel, "invalid continue label %s", name)
+ return
+ }
+
+ case token.GOTO:
+ if b.gotoTarget(name) == nil {
+ // label may be declared later - add branch to forward jumps
+ fwdJumps = append(fwdJumps, s)
+ return
+ }
+
+ default:
+ check.invalidAST(s, "branch statement: %s %s", s.Tok, name)
+ return
+ }
+
+ // record label use
+ obj := all.Lookup(name)
+ obj.(*Label).used = true
+ check.recordUse(s.Label, obj)
+
+ case *ast.AssignStmt:
+ if s.Tok == token.DEFINE {
+ recordVarDecl(s.Pos())
+ }
+
+ case *ast.BlockStmt:
+ blockBranches(lstmt, s.List)
+
+ case *ast.IfStmt:
+ stmtBranches(s.Body)
+ if s.Else != nil {
+ stmtBranches(s.Else)
+ }
+
+ case *ast.CaseClause:
+ blockBranches(nil, s.Body)
+
+ case *ast.SwitchStmt:
+ stmtBranches(s.Body)
+
+ case *ast.TypeSwitchStmt:
+ stmtBranches(s.Body)
+
+ case *ast.CommClause:
+ blockBranches(nil, s.Body)
+
+ case *ast.SelectStmt:
+ stmtBranches(s.Body)
+
+ case *ast.ForStmt:
+ stmtBranches(s.Body)
+
+ case *ast.RangeStmt:
+ stmtBranches(s.Body)
+ }
+ }
+
+ for _, s := range list {
+ stmtBranches(s)
+ }
+
+ return fwdJumps
+}
diff --git a/src/go/types/lookup.go b/src/go/types/lookup.go
new file mode 100644
index 0000000..3c9ff18
--- /dev/null
+++ b/src/go/types/lookup.go
@@ -0,0 +1,400 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements various field and method lookup functions.
+
+package types
+
+// LookupFieldOrMethod looks up a field or method with given package and name
+// in T and returns the corresponding *Var or *Func, an index sequence, and a
+// bool indicating if there were any pointer indirections on the path to the
+// field or method. If addressable is set, T is the type of an addressable
+// variable (only matters for method lookups).
+//
+// The last index entry is the field or method index in the (possibly embedded)
+// type where the entry was found, either:
+//
+// 1) the list of declared methods of a named type; or
+// 2) the list of all methods (method set) of an interface type; or
+// 3) the list of fields of a struct type.
+//
+// The earlier index entries are the indices of the embedded struct fields
+// traversed to get to the found entry, starting at depth 0.
+//
+// If no entry is found, a nil object is returned. In this case, the returned
+// index and indirect values have the following meaning:
+//
+// - If index != nil, the index sequence points to an ambiguous entry
+// (the same name appeared more than once at the same embedding level).
+//
+// - If indirect is set, a method with a pointer receiver type was found
+// but there was no pointer on the path from the actual receiver type to
+// the method's formal receiver base type, nor was the receiver addressable.
+//
+func LookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
+ return (*Checker)(nil).lookupFieldOrMethod(T, addressable, pkg, name)
+}
+
+// Internal use of Checker.lookupFieldOrMethod: If the obj result is a method
+// associated with a concrete (non-interface) type, the method's signature
+// may not be fully set up. Call Checker.objDecl(obj, nil) before accessing
+// the method's type.
+// TODO(gri) Now that we provide the *Checker, we can probably remove this
+// caveat by calling Checker.objDecl from lookupFieldOrMethod. Investigate.
+
+// lookupFieldOrMethod is like the external version but completes interfaces
+// as necessary.
+func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
+ // Methods cannot be associated to a named pointer type
+ // (spec: "The type denoted by T is called the receiver base type;
+ // it must not be a pointer or interface type and it must be declared
+ // in the same package as the method.").
+ // Thus, if we have a named pointer type, proceed with the underlying
+ // pointer type but discard the result if it is a method since we would
+ // not have found it for T (see also issue 8590).
+ if t, _ := T.(*Named); t != nil {
+ if p, _ := t.underlying.(*Pointer); p != nil {
+ obj, index, indirect = check.rawLookupFieldOrMethod(p, false, pkg, name)
+ if _, ok := obj.(*Func); ok {
+ return nil, nil, false
+ }
+ return
+ }
+ }
+
+ return check.rawLookupFieldOrMethod(T, addressable, pkg, name)
+}
+
+// TODO(gri) The named type consolidation and seen maps below must be
+// indexed by unique keys for a given type. Verify that named
+// types always have only one representation (even when imported
+// indirectly via different packages.)
+
+// rawLookupFieldOrMethod should only be called by lookupFieldOrMethod and missingMethod.
+func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
+ // WARNING: The code in this function is extremely subtle - do not modify casually!
+ // This function and NewMethodSet should be kept in sync.
+
+ if name == "_" {
+ return // blank fields/methods are never found
+ }
+
+ typ, isPtr := deref(T)
+
+ // *typ where typ is an interface has no methods.
+ if isPtr && IsInterface(typ) {
+ return
+ }
+
+ // Start with typ as single entry at shallowest depth.
+ current := []embeddedType{{typ, nil, isPtr, false}}
+
+ // Named types that we have seen already, allocated lazily.
+ // Used to avoid endless searches in case of recursive types.
+ // Since only Named types can be used for recursive types, we
+ // only need to track those.
+ // (If we ever allow type aliases to construct recursive types,
+ // we must use type identity rather than pointer equality for
+ // the map key comparison, as we do in consolidateMultiples.)
+ var seen map[*Named]bool
+
+ // search current depth
+ for len(current) > 0 {
+ var next []embeddedType // embedded types found at current depth
+
+ // look for (pkg, name) in all types at current depth
+ for _, e := range current {
+ typ := e.typ
+
+ // If we have a named type, we may have associated methods.
+ // Look for those first.
+ if named, _ := typ.(*Named); named != nil {
+ if seen[named] {
+ // We have seen this type before, at a more shallow depth
+ // (note that multiples of this type at the current depth
+ // were consolidated before). The type at that depth shadows
+ // this same type at the current depth, so we can ignore
+ // this one.
+ continue
+ }
+ if seen == nil {
+ seen = make(map[*Named]bool)
+ }
+ seen[named] = true
+
+ // look for a matching attached method
+ if i, m := lookupMethod(named.methods, pkg, name); m != nil {
+ // potential match
+ // caution: method may not have a proper signature yet
+ index = concat(e.index, i)
+ if obj != nil || e.multiples {
+ return nil, index, false // collision
+ }
+ obj = m
+ indirect = e.indirect
+ continue // we can't have a matching field or interface method
+ }
+
+ // continue with underlying type
+ typ = named.underlying
+ }
+
+ switch t := typ.(type) {
+ case *Struct:
+ // look for a matching field and collect embedded types
+ for i, f := range t.fields {
+ if f.sameId(pkg, name) {
+ assert(f.typ != nil)
+ index = concat(e.index, i)
+ if obj != nil || e.multiples {
+ return nil, index, false // collision
+ }
+ obj = f
+ indirect = e.indirect
+ continue // we can't have a matching interface method
+ }
+ // Collect embedded struct fields for searching the next
+ // lower depth, but only if we have not seen a match yet
+ // (if we have a match it is either the desired field or
+ // we have a name collision on the same depth; in either
+ // case we don't need to look further).
+ // Embedded fields are always of the form T or *T where
+ // T is a type name. If e.typ appeared multiple times at
+ // this depth, f.typ appears multiple times at the next
+ // depth.
+ if obj == nil && f.embedded {
+ typ, isPtr := deref(f.typ)
+ // TODO(gri) optimization: ignore types that can't
+ // have fields or methods (only Named, Struct, and
+ // Interface types need to be considered).
+ next = append(next, embeddedType{typ, concat(e.index, i), e.indirect || isPtr, e.multiples})
+ }
+ }
+
+ case *Interface:
+ // look for a matching method
+ // TODO(gri) t.allMethods is sorted - use binary search
+ check.completeInterface(t)
+ if i, m := lookupMethod(t.allMethods, pkg, name); m != nil {
+ assert(m.typ != nil)
+ index = concat(e.index, i)
+ if obj != nil || e.multiples {
+ return nil, index, false // collision
+ }
+ obj = m
+ indirect = e.indirect
+ }
+ }
+ }
+
+ if obj != nil {
+ // found a potential match
+ // spec: "A method call x.m() is valid if the method set of (the type of) x
+ // contains m and the argument list can be assigned to the parameter
+ // list of m. If x is addressable and &x's method set contains m, x.m()
+ // is shorthand for (&x).m()".
+ if f, _ := obj.(*Func); f != nil && ptrRecv(f) && !indirect && !addressable {
+ return nil, nil, true // pointer/addressable receiver required
+ }
+ return
+ }
+
+ current = check.consolidateMultiples(next)
+ }
+
+ return nil, nil, false // not found
+}
+
+// embeddedType represents an embedded type
+type embeddedType struct {
+ typ Type
+ index []int // embedded field indices, starting with index at depth 0
+ indirect bool // if set, there was a pointer indirection on the path to this field
+ multiples bool // if set, typ appears multiple times at this depth
+}
+
+// consolidateMultiples collects multiple list entries with the same type
+// into a single entry marked as containing multiples. The result is the
+// consolidated list.
+func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
+ if len(list) <= 1 {
+ return list // at most one entry - nothing to do
+ }
+
+ n := 0 // number of entries w/ unique type
+ prev := make(map[Type]int) // index at which type was previously seen
+ for _, e := range list {
+ if i, found := check.lookupType(prev, e.typ); found {
+ list[i].multiples = true
+ // ignore this entry
+ } else {
+ prev[e.typ] = n
+ list[n] = e
+ n++
+ }
+ }
+ return list[:n]
+}
+
+func (check *Checker) lookupType(m map[Type]int, typ Type) (int, bool) {
+ // fast path: maybe the types are equal
+ if i, found := m[typ]; found {
+ return i, true
+ }
+
+ for t, i := range m {
+ if check.identical(t, typ) {
+ return i, true
+ }
+ }
+
+ return 0, false
+}
+
+// MissingMethod returns (nil, false) if V implements T, otherwise it
+// returns a missing method required by T and whether it is missing or
+// just has the wrong type.
+//
+// For non-interface types V, or if static is set, V implements T if all
+// methods of T are present in V. Otherwise (V is an interface and static
+// is not set), MissingMethod only checks that methods of T which are also
+// present in V have matching types (e.g., for a type assertion x.(T) where
+// x is of interface type V).
+//
+func MissingMethod(V Type, T *Interface, static bool) (method *Func, wrongType bool) {
+ m, typ := (*Checker)(nil).missingMethod(V, T, static)
+ return m, typ != nil
+}
+
+// missingMethod is like MissingMethod but accepts a receiver.
+// The receiver may be nil if missingMethod is invoked through
+// an exported API call (such as MissingMethod), i.e., when all
+// methods have been type-checked.
+// If the type has the correctly named method, but with the wrong
+// signature, the existing method is returned as well.
+// To improve error messages, also report the wrong signature
+// when the method exists on *V instead of V.
+func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method, wrongType *Func) {
+ check.completeInterface(T)
+
+ // fast path for common case
+ if T.Empty() {
+ return
+ }
+
+ if ityp, _ := V.Underlying().(*Interface); ityp != nil {
+ check.completeInterface(ityp)
+ // TODO(gri) allMethods is sorted - can do this more efficiently
+ for _, m := range T.allMethods {
+ _, obj := lookupMethod(ityp.allMethods, m.pkg, m.name)
+ switch {
+ case obj == nil:
+ if static {
+ return m, nil
+ }
+ case !check.identical(obj.Type(), m.typ):
+ return m, obj
+ }
+ }
+ return
+ }
+
+ // A concrete type implements T if it implements all methods of T.
+ for _, m := range T.allMethods {
+ obj, _, _ := check.rawLookupFieldOrMethod(V, false, m.pkg, m.name)
+
+ // Check if *V implements this method of T.
+ if obj == nil {
+ ptr := NewPointer(V)
+ obj, _, _ = check.rawLookupFieldOrMethod(ptr, false, m.pkg, m.name)
+ if obj != nil {
+ return m, obj.(*Func)
+ }
+ }
+
+ // we must have a method (not a field of matching function type)
+ f, _ := obj.(*Func)
+ if f == nil {
+ return m, nil
+ }
+
+ // methods may not have a fully set up signature yet
+ if check != nil {
+ check.objDecl(f, nil)
+ }
+
+ if !check.identical(f.typ, m.typ) {
+ return m, f
+ }
+ }
+
+ return
+}
+
+// assertableTo reports whether a value of type V can be asserted to have type T.
+// It returns (nil, false) as affirmative answer. Otherwise it returns a missing
+// method required by V and whether it is missing or just has the wrong type.
+// The receiver may be nil if assertableTo is invoked through an exported API call
+// (such as AssertableTo), i.e., when all methods have been type-checked.
+func (check *Checker) assertableTo(V *Interface, T Type) (method, wrongType *Func) {
+ // no static check is required if T is an interface
+ // spec: "If T is an interface type, x.(T) asserts that the
+ // dynamic type of x implements the interface T."
+ if _, ok := T.Underlying().(*Interface); ok && !strict {
+ return
+ }
+ return check.missingMethod(T, V, false)
+}
+
+// deref dereferences typ if it is a *Pointer and returns its base and true.
+// Otherwise it returns (typ, false).
+func deref(typ Type) (Type, bool) {
+ if p, _ := typ.(*Pointer); p != nil {
+ return p.base, true
+ }
+ return typ, false
+}
+
+// derefStructPtr dereferences typ if it is a (named or unnamed) pointer to a
+// (named or unnamed) struct and returns its base. Otherwise it returns typ.
+func derefStructPtr(typ Type) Type {
+ if p, _ := typ.Underlying().(*Pointer); p != nil {
+ if _, ok := p.base.Underlying().(*Struct); ok {
+ return p.base
+ }
+ }
+ return typ
+}
+
+// concat returns the result of concatenating list and i.
+// The result does not share its underlying array with list.
+func concat(list []int, i int) []int {
+ var t []int
+ t = append(t, list...)
+ return append(t, i)
+}
+
+// fieldIndex returns the index for the field with matching package and name, or a value < 0.
+func fieldIndex(fields []*Var, pkg *Package, name string) int {
+ if name != "_" {
+ for i, f := range fields {
+ if f.sameId(pkg, name) {
+ return i
+ }
+ }
+ }
+ return -1
+}
+
+// lookupMethod returns the index of and method with matching package and name, or (-1, nil).
+func lookupMethod(methods []*Func, pkg *Package, name string) (int, *Func) {
+ if name != "_" {
+ for i, m := range methods {
+ if m.sameId(pkg, name) {
+ return i, m
+ }
+ }
+ }
+ return -1, nil
+}
diff --git a/src/go/types/methodset.go b/src/go/types/methodset.go
new file mode 100644
index 0000000..c34d732
--- /dev/null
+++ b/src/go/types/methodset.go
@@ -0,0 +1,260 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements method sets.
+
+package types
+
+import (
+ "fmt"
+ "sort"
+ "strings"
+)
+
+// A MethodSet is an ordered set of concrete or abstract (interface) methods;
+// a method is a MethodVal selection, and they are ordered by ascending m.Obj().Id().
+// The zero value for a MethodSet is a ready-to-use empty method set.
+type MethodSet struct {
+ list []*Selection
+}
+
+func (s *MethodSet) String() string {
+ if s.Len() == 0 {
+ return "MethodSet {}"
+ }
+
+ var buf strings.Builder
+ fmt.Fprintln(&buf, "MethodSet {")
+ for _, f := range s.list {
+ fmt.Fprintf(&buf, "\t%s\n", f)
+ }
+ fmt.Fprintln(&buf, "}")
+ return buf.String()
+}
+
+// Len returns the number of methods in s.
+func (s *MethodSet) Len() int { return len(s.list) }
+
+// At returns the i'th method in s for 0 <= i < s.Len().
+func (s *MethodSet) At(i int) *Selection { return s.list[i] }
+
+// Lookup returns the method with matching package and name, or nil if not found.
+func (s *MethodSet) Lookup(pkg *Package, name string) *Selection {
+ if s.Len() == 0 {
+ return nil
+ }
+
+ key := Id(pkg, name)
+ i := sort.Search(len(s.list), func(i int) bool {
+ m := s.list[i]
+ return m.obj.Id() >= key
+ })
+ if i < len(s.list) {
+ m := s.list[i]
+ if m.obj.Id() == key {
+ return m
+ }
+ }
+ return nil
+}
+
+// Shared empty method set.
+var emptyMethodSet MethodSet
+
+// Note: NewMethodSet is intended for external use only as it
+// requires interfaces to be complete. If may be used
+// internally if LookupFieldOrMethod completed the same
+// interfaces beforehand.
+
+// NewMethodSet returns the method set for the given type T.
+// It always returns a non-nil method set, even if it is empty.
+func NewMethodSet(T Type) *MethodSet {
+ // WARNING: The code in this function is extremely subtle - do not modify casually!
+ // This function and lookupFieldOrMethod should be kept in sync.
+
+ // method set up to the current depth, allocated lazily
+ var base methodSet
+
+ typ, isPtr := deref(T)
+
+ // *typ where typ is an interface has no methods.
+ if isPtr && IsInterface(typ) {
+ return &emptyMethodSet
+ }
+
+ // Start with typ as single entry at shallowest depth.
+ current := []embeddedType{{typ, nil, isPtr, false}}
+
+ // Named types that we have seen already, allocated lazily.
+ // Used to avoid endless searches in case of recursive types.
+ // Since only Named types can be used for recursive types, we
+ // only need to track those.
+ // (If we ever allow type aliases to construct recursive types,
+ // we must use type identity rather than pointer equality for
+ // the map key comparison, as we do in consolidateMultiples.)
+ var seen map[*Named]bool
+
+ // collect methods at current depth
+ for len(current) > 0 {
+ var next []embeddedType // embedded types found at current depth
+
+ // field and method sets at current depth, indexed by names (Id's), and allocated lazily
+ var fset map[string]bool // we only care about the field names
+ var mset methodSet
+
+ for _, e := range current {
+ typ := e.typ
+
+ // If we have a named type, we may have associated methods.
+ // Look for those first.
+ if named, _ := typ.(*Named); named != nil {
+ if seen[named] {
+ // We have seen this type before, at a more shallow depth
+ // (note that multiples of this type at the current depth
+ // were consolidated before). The type at that depth shadows
+ // this same type at the current depth, so we can ignore
+ // this one.
+ continue
+ }
+ if seen == nil {
+ seen = make(map[*Named]bool)
+ }
+ seen[named] = true
+
+ mset = mset.add(named.methods, e.index, e.indirect, e.multiples)
+
+ // continue with underlying type
+ typ = named.underlying
+ }
+
+ switch t := typ.(type) {
+ case *Struct:
+ for i, f := range t.fields {
+ if fset == nil {
+ fset = make(map[string]bool)
+ }
+ fset[f.Id()] = true
+
+ // Embedded fields are always of the form T or *T where
+ // T is a type name. If typ appeared multiple times at
+ // this depth, f.Type appears multiple times at the next
+ // depth.
+ if f.embedded {
+ typ, isPtr := deref(f.typ)
+ // TODO(gri) optimization: ignore types that can't
+ // have fields or methods (only Named, Struct, and
+ // Interface types need to be considered).
+ next = append(next, embeddedType{typ, concat(e.index, i), e.indirect || isPtr, e.multiples})
+ }
+ }
+
+ case *Interface:
+ mset = mset.add(t.allMethods, e.index, true, e.multiples)
+ }
+ }
+
+ // Add methods and collisions at this depth to base if no entries with matching
+ // names exist already.
+ for k, m := range mset {
+ if _, found := base[k]; !found {
+ // Fields collide with methods of the same name at this depth.
+ if fset[k] {
+ m = nil // collision
+ }
+ if base == nil {
+ base = make(methodSet)
+ }
+ base[k] = m
+ }
+ }
+
+ // Add all (remaining) fields at this depth as collisions (since they will
+ // hide any method further down) if no entries with matching names exist already.
+ for k := range fset {
+ if _, found := base[k]; !found {
+ if base == nil {
+ base = make(methodSet)
+ }
+ base[k] = nil // collision
+ }
+ }
+
+ // It's ok to call consolidateMultiples with a nil *Checker because
+ // MethodSets are not used internally (outside debug mode). When used
+ // externally, interfaces are expected to be completed and then we do
+ // not need a *Checker to complete them when (indirectly) calling
+ // Checker.identical via consolidateMultiples.
+ current = (*Checker)(nil).consolidateMultiples(next)
+ }
+
+ if len(base) == 0 {
+ return &emptyMethodSet
+ }
+
+ // collect methods
+ var list []*Selection
+ for _, m := range base {
+ if m != nil {
+ m.recv = T
+ list = append(list, m)
+ }
+ }
+ // sort by unique name
+ sort.Slice(list, func(i, j int) bool {
+ return list[i].obj.Id() < list[j].obj.Id()
+ })
+ return &MethodSet{list}
+}
+
+// A methodSet is a set of methods and name collisions.
+// A collision indicates that multiple methods with the
+// same unique id, or a field with that id appeared.
+type methodSet map[string]*Selection // a nil entry indicates a name collision
+
+// Add adds all functions in list to the method set s.
+// If multiples is set, every function in list appears multiple times
+// and is treated as a collision.
+func (s methodSet) add(list []*Func, index []int, indirect bool, multiples bool) methodSet {
+ if len(list) == 0 {
+ return s
+ }
+ if s == nil {
+ s = make(methodSet)
+ }
+ for i, f := range list {
+ key := f.Id()
+ // if f is not in the set, add it
+ if !multiples {
+ // TODO(gri) A found method may not be added because it's not in the method set
+ // (!indirect && ptrRecv(f)). A 2nd method on the same level may be in the method
+ // set and may not collide with the first one, thus leading to a false positive.
+ // Is that possible? Investigate.
+ if _, found := s[key]; !found && (indirect || !ptrRecv(f)) {
+ s[key] = &Selection{MethodVal, nil, f, concat(index, i), indirect}
+ continue
+ }
+ }
+ s[key] = nil // collision
+ }
+ return s
+}
+
+// ptrRecv reports whether the receiver is of the form *T.
+func ptrRecv(f *Func) bool {
+ // If a method's receiver type is set, use that as the source of truth for the receiver.
+ // Caution: Checker.funcDecl (decl.go) marks a function by setting its type to an empty
+ // signature. We may reach here before the signature is fully set up: we must explicitly
+ // check if the receiver is set (we cannot just look for non-nil f.typ).
+ if sig, _ := f.typ.(*Signature); sig != nil && sig.recv != nil {
+ _, isPtr := deref(sig.recv.typ)
+ return isPtr
+ }
+
+ // If a method's type is not set it may be a method/function that is:
+ // 1) client-supplied (via NewFunc with no signature), or
+ // 2) internally created but not yet type-checked.
+ // For case 1) we can't do anything; the client must know what they are doing.
+ // For case 2) we can use the information gathered by the resolver.
+ return f.hasPtrRecv
+}
diff --git a/src/go/types/object.go b/src/go/types/object.go
new file mode 100644
index 0000000..374b24d
--- /dev/null
+++ b/src/go/types/object.go
@@ -0,0 +1,486 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "bytes"
+ "fmt"
+ "go/constant"
+ "go/token"
+)
+
+// An Object describes a named language entity such as a package,
+// constant, type, variable, function (incl. methods), or label.
+// All objects implement the Object interface.
+//
+type Object interface {
+ Parent() *Scope // scope in which this object is declared; nil for methods and struct fields
+ Pos() token.Pos // position of object identifier in declaration
+ Pkg() *Package // package to which this object belongs; nil for labels and objects in the Universe scope
+ Name() string // package local object name
+ Type() Type // object type
+ Exported() bool // reports whether the name starts with a capital letter
+ Id() string // object name if exported, qualified name if not exported (see func Id)
+
+ // String returns a human-readable string of the object.
+ String() string
+
+ // order reflects a package-level object's source order: if object
+ // a is before object b in the source, then a.order() < b.order().
+ // order returns a value > 0 for package-level objects; it returns
+ // 0 for all other objects (including objects in file scopes).
+ order() uint32
+
+ // color returns the object's color.
+ color() color
+
+ // setOrder sets the order number of the object. It must be > 0.
+ setOrder(uint32)
+
+ // setColor sets the object's color. It must not be white.
+ setColor(color color)
+
+ // setParent sets the parent scope of the object.
+ setParent(*Scope)
+
+ // sameId reports whether obj.Id() and Id(pkg, name) are the same.
+ sameId(pkg *Package, name string) bool
+
+ // scopePos returns the start position of the scope of this Object
+ scopePos() token.Pos
+
+ // setScopePos sets the start position of the scope for this Object.
+ setScopePos(pos token.Pos)
+}
+
+// Id returns name if it is exported, otherwise it
+// returns the name qualified with the package path.
+func Id(pkg *Package, name string) string {
+ if token.IsExported(name) {
+ return name
+ }
+ // unexported names need the package path for differentiation
+ // (if there's no package, make sure we don't start with '.'
+ // as that may change the order of methods between a setup
+ // inside a package and outside a package - which breaks some
+ // tests)
+ path := "_"
+ // pkg is nil for objects in Universe scope and possibly types
+ // introduced via Eval (see also comment in object.sameId)
+ if pkg != nil && pkg.path != "" {
+ path = pkg.path
+ }
+ return path + "." + name
+}
+
+// An object implements the common parts of an Object.
+type object struct {
+ parent *Scope
+ pos token.Pos
+ pkg *Package
+ name string
+ typ Type
+ order_ uint32
+ color_ color
+ scopePos_ token.Pos
+}
+
+// color encodes the color of an object (see Checker.objDecl for details).
+type color uint32
+
+// An object may be painted in one of three colors.
+// Color values other than white or black are considered grey.
+const (
+ white color = iota
+ black
+ grey // must be > white and black
+)
+
+func (c color) String() string {
+ switch c {
+ case white:
+ return "white"
+ case black:
+ return "black"
+ default:
+ return "grey"
+ }
+}
+
+// colorFor returns the (initial) color for an object depending on
+// whether its type t is known or not.
+func colorFor(t Type) color {
+ if t != nil {
+ return black
+ }
+ return white
+}
+
+// Parent returns the scope in which the object is declared.
+// The result is nil for methods and struct fields.
+func (obj *object) Parent() *Scope { return obj.parent }
+
+// Pos returns the declaration position of the object's identifier.
+func (obj *object) Pos() token.Pos { return obj.pos }
+
+// Pkg returns the package to which the object belongs.
+// The result is nil for labels and objects in the Universe scope.
+func (obj *object) Pkg() *Package { return obj.pkg }
+
+// Name returns the object's (package-local, unqualified) name.
+func (obj *object) Name() string { return obj.name }
+
+// Type returns the object's type.
+func (obj *object) Type() Type { return obj.typ }
+
+// Exported reports whether the object is exported (starts with a capital letter).
+// It doesn't take into account whether the object is in a local (function) scope
+// or not.
+func (obj *object) Exported() bool { return token.IsExported(obj.name) }
+
+// Id is a wrapper for Id(obj.Pkg(), obj.Name()).
+func (obj *object) Id() string { return Id(obj.pkg, obj.name) }
+
+func (obj *object) String() string { panic("abstract") }
+func (obj *object) order() uint32 { return obj.order_ }
+func (obj *object) color() color { return obj.color_ }
+func (obj *object) scopePos() token.Pos { return obj.scopePos_ }
+
+func (obj *object) setParent(parent *Scope) { obj.parent = parent }
+func (obj *object) setOrder(order uint32) { assert(order > 0); obj.order_ = order }
+func (obj *object) setColor(color color) { assert(color != white); obj.color_ = color }
+func (obj *object) setScopePos(pos token.Pos) { obj.scopePos_ = pos }
+
+func (obj *object) sameId(pkg *Package, name string) bool {
+ // spec:
+ // "Two identifiers are different if they are spelled differently,
+ // or if they appear in different packages and are not exported.
+ // Otherwise, they are the same."
+ if name != obj.name {
+ return false
+ }
+ // obj.Name == name
+ if obj.Exported() {
+ return true
+ }
+ // not exported, so packages must be the same (pkg == nil for
+ // fields in Universe scope; this can only happen for types
+ // introduced via Eval)
+ if pkg == nil || obj.pkg == nil {
+ return pkg == obj.pkg
+ }
+ // pkg != nil && obj.pkg != nil
+ return pkg.path == obj.pkg.path
+}
+
+// A PkgName represents an imported Go package.
+// PkgNames don't have a type.
+type PkgName struct {
+ object
+ imported *Package
+ used bool // set if the package was used
+}
+
+// NewPkgName returns a new PkgName object representing an imported package.
+// The remaining arguments set the attributes found with all Objects.
+func NewPkgName(pos token.Pos, pkg *Package, name string, imported *Package) *PkgName {
+ return &PkgName{object{nil, pos, pkg, name, Typ[Invalid], 0, black, token.NoPos}, imported, false}
+}
+
+// Imported returns the package that was imported.
+// It is distinct from Pkg(), which is the package containing the import statement.
+func (obj *PkgName) Imported() *Package { return obj.imported }
+
+// A Const represents a declared constant.
+type Const struct {
+ object
+ val constant.Value
+}
+
+// NewConst returns a new constant with value val.
+// The remaining arguments set the attributes found with all Objects.
+func NewConst(pos token.Pos, pkg *Package, name string, typ Type, val constant.Value) *Const {
+ return &Const{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, val}
+}
+
+// Val returns the constant's value.
+func (obj *Const) Val() constant.Value { return obj.val }
+
+func (*Const) isDependency() {} // a constant may be a dependency of an initialization expression
+
+// A TypeName represents a name for a (defined or alias) type.
+type TypeName struct {
+ object
+}
+
+// NewTypeName returns a new type name denoting the given typ.
+// The remaining arguments set the attributes found with all Objects.
+//
+// The typ argument may be a defined (Named) type or an alias type.
+// It may also be nil such that the returned TypeName can be used as
+// argument for NewNamed, which will set the TypeName's type as a side-
+// effect.
+func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeName {
+ return &TypeName{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}}
+}
+
+// IsAlias reports whether obj is an alias name for a type.
+func (obj *TypeName) IsAlias() bool {
+ switch t := obj.typ.(type) {
+ case nil:
+ return false
+ case *Basic:
+ // unsafe.Pointer is not an alias.
+ if obj.pkg == Unsafe {
+ return false
+ }
+ // Any user-defined type name for a basic type is an alias for a
+ // basic type (because basic types are pre-declared in the Universe
+ // scope, outside any package scope), and so is any type name with
+ // a different name than the name of the basic type it refers to.
+ // Additionally, we need to look for "byte" and "rune" because they
+ // are aliases but have the same names (for better error messages).
+ return obj.pkg != nil || t.name != obj.name || t == universeByte || t == universeRune
+ case *Named:
+ return obj != t.obj
+ default:
+ return true
+ }
+}
+
+// A Variable represents a declared variable (including function parameters and results, and struct fields).
+type Var struct {
+ object
+ embedded bool // if set, the variable is an embedded struct field, and name is the type name
+ isField bool // var is struct field
+ used bool // set if the variable was used
+}
+
+// NewVar returns a new variable.
+// The arguments set the attributes found with all Objects.
+func NewVar(pos token.Pos, pkg *Package, name string, typ Type) *Var {
+ return &Var{object: object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}}
+}
+
+// NewParam returns a new variable representing a function parameter.
+func NewParam(pos token.Pos, pkg *Package, name string, typ Type) *Var {
+ return &Var{object: object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, used: true} // parameters are always 'used'
+}
+
+// NewField returns a new variable representing a struct field.
+// For embedded fields, the name is the unqualified type name
+/// under which the field is accessible.
+func NewField(pos token.Pos, pkg *Package, name string, typ Type, embedded bool) *Var {
+ return &Var{object: object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, embedded: embedded, isField: true}
+}
+
+// Anonymous reports whether the variable is an embedded field.
+// Same as Embedded; only present for backward-compatibility.
+func (obj *Var) Anonymous() bool { return obj.embedded }
+
+// Embedded reports whether the variable is an embedded field.
+func (obj *Var) Embedded() bool { return obj.embedded }
+
+// IsField reports whether the variable is a struct field.
+func (obj *Var) IsField() bool { return obj.isField }
+
+func (*Var) isDependency() {} // a variable may be a dependency of an initialization expression
+
+// A Func represents a declared function, concrete method, or abstract
+// (interface) method. Its Type() is always a *Signature.
+// An abstract method may belong to many interfaces due to embedding.
+type Func struct {
+ object
+ hasPtrRecv bool // only valid for methods that don't have a type yet
+}
+
+// NewFunc returns a new function with the given signature, representing
+// the function's type.
+func NewFunc(pos token.Pos, pkg *Package, name string, sig *Signature) *Func {
+ // don't store a nil signature
+ var typ Type
+ if sig != nil {
+ typ = sig
+ }
+ return &Func{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, false}
+}
+
+// FullName returns the package- or receiver-type-qualified name of
+// function or method obj.
+func (obj *Func) FullName() string {
+ var buf bytes.Buffer
+ writeFuncName(&buf, obj, nil)
+ return buf.String()
+}
+
+// Scope returns the scope of the function's body block.
+func (obj *Func) Scope() *Scope { return obj.typ.(*Signature).scope }
+
+func (*Func) isDependency() {} // a function may be a dependency of an initialization expression
+
+// A Label represents a declared label.
+// Labels don't have a type.
+type Label struct {
+ object
+ used bool // set if the label was used
+}
+
+// NewLabel returns a new label.
+func NewLabel(pos token.Pos, pkg *Package, name string) *Label {
+ return &Label{object{pos: pos, pkg: pkg, name: name, typ: Typ[Invalid], color_: black}, false}
+}
+
+// A Builtin represents a built-in function.
+// Builtins don't have a valid type.
+type Builtin struct {
+ object
+ id builtinId
+}
+
+func newBuiltin(id builtinId) *Builtin {
+ return &Builtin{object{name: predeclaredFuncs[id].name, typ: Typ[Invalid], color_: black}, id}
+}
+
+// Nil represents the predeclared value nil.
+type Nil struct {
+ object
+}
+
+func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) {
+ var tname *TypeName
+ typ := obj.Type()
+
+ switch obj := obj.(type) {
+ case *PkgName:
+ fmt.Fprintf(buf, "package %s", obj.Name())
+ if path := obj.imported.path; path != "" && path != obj.name {
+ fmt.Fprintf(buf, " (%q)", path)
+ }
+ return
+
+ case *Const:
+ buf.WriteString("const")
+
+ case *TypeName:
+ tname = obj
+ buf.WriteString("type")
+
+ case *Var:
+ if obj.isField {
+ buf.WriteString("field")
+ } else {
+ buf.WriteString("var")
+ }
+
+ case *Func:
+ buf.WriteString("func ")
+ writeFuncName(buf, obj, qf)
+ if typ != nil {
+ WriteSignature(buf, typ.(*Signature), qf)
+ }
+ return
+
+ case *Label:
+ buf.WriteString("label")
+ typ = nil
+
+ case *Builtin:
+ buf.WriteString("builtin")
+ typ = nil
+
+ case *Nil:
+ buf.WriteString("nil")
+ return
+
+ default:
+ panic(fmt.Sprintf("writeObject(%T)", obj))
+ }
+
+ buf.WriteByte(' ')
+
+ // For package-level objects, qualify the name.
+ if obj.Pkg() != nil && obj.Pkg().scope.Lookup(obj.Name()) == obj {
+ writePackage(buf, obj.Pkg(), qf)
+ }
+ buf.WriteString(obj.Name())
+
+ if typ == nil {
+ return
+ }
+
+ if tname != nil {
+ // We have a type object: Don't print anything more for
+ // basic types since there's no more information (names
+ // are the same; see also comment in TypeName.IsAlias).
+ if _, ok := typ.(*Basic); ok {
+ return
+ }
+ if tname.IsAlias() {
+ buf.WriteString(" =")
+ } else {
+ typ = typ.Underlying()
+ }
+ }
+
+ buf.WriteByte(' ')
+ WriteType(buf, typ, qf)
+}
+
+func writePackage(buf *bytes.Buffer, pkg *Package, qf Qualifier) {
+ if pkg == nil {
+ return
+ }
+ var s string
+ if qf != nil {
+ s = qf(pkg)
+ } else {
+ s = pkg.Path()
+ }
+ if s != "" {
+ buf.WriteString(s)
+ buf.WriteByte('.')
+ }
+}
+
+// ObjectString returns the string form of obj.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func ObjectString(obj Object, qf Qualifier) string {
+ var buf bytes.Buffer
+ writeObject(&buf, obj, qf)
+ return buf.String()
+}
+
+func (obj *PkgName) String() string { return ObjectString(obj, nil) }
+func (obj *Const) String() string { return ObjectString(obj, nil) }
+func (obj *TypeName) String() string { return ObjectString(obj, nil) }
+func (obj *Var) String() string { return ObjectString(obj, nil) }
+func (obj *Func) String() string { return ObjectString(obj, nil) }
+func (obj *Label) String() string { return ObjectString(obj, nil) }
+func (obj *Builtin) String() string { return ObjectString(obj, nil) }
+func (obj *Nil) String() string { return ObjectString(obj, nil) }
+
+func writeFuncName(buf *bytes.Buffer, f *Func, qf Qualifier) {
+ if f.typ != nil {
+ sig := f.typ.(*Signature)
+ if recv := sig.Recv(); recv != nil {
+ buf.WriteByte('(')
+ if _, ok := recv.Type().(*Interface); ok {
+ // gcimporter creates abstract methods of
+ // named interfaces using the interface type
+ // (not the named type) as the receiver.
+ // Don't print it in full.
+ buf.WriteString("interface")
+ } else {
+ WriteType(buf, recv.Type(), qf)
+ }
+ buf.WriteByte(')')
+ buf.WriteByte('.')
+ } else if f.pkg != nil {
+ writePackage(buf, f.pkg, qf)
+ }
+ }
+ buf.WriteString(f.name)
+}
diff --git a/src/go/types/object_test.go b/src/go/types/object_test.go
new file mode 100644
index 0000000..2b6057b
--- /dev/null
+++ b/src/go/types/object_test.go
@@ -0,0 +1,86 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "testing"
+)
+
+func TestIsAlias(t *testing.T) {
+ check := func(obj *TypeName, want bool) {
+ if got := obj.IsAlias(); got != want {
+ t.Errorf("%v: got IsAlias = %v; want %v", obj, got, want)
+ }
+ }
+
+ // predeclared types
+ check(Unsafe.Scope().Lookup("Pointer").(*TypeName), false)
+ for _, name := range Universe.Names() {
+ if obj, _ := Universe.Lookup(name).(*TypeName); obj != nil {
+ check(obj, name == "byte" || name == "rune")
+ }
+ }
+
+ // various other types
+ pkg := NewPackage("p", "p")
+ t1 := NewTypeName(0, pkg, "t1", nil)
+ n1 := NewNamed(t1, new(Struct), nil)
+ for _, test := range []struct {
+ name *TypeName
+ alias bool
+ }{
+ {NewTypeName(0, nil, "t0", nil), false}, // no type yet
+ {NewTypeName(0, pkg, "t0", nil), false}, // no type yet
+ {t1, false}, // type name refers to named type and vice versa
+ {NewTypeName(0, nil, "t2", &emptyInterface), true}, // type name refers to unnamed type
+ {NewTypeName(0, pkg, "t3", n1), true}, // type name refers to named type with different type name
+ {NewTypeName(0, nil, "t4", Typ[Int32]), true}, // type name refers to basic type with different name
+ {NewTypeName(0, nil, "int32", Typ[Int32]), false}, // type name refers to basic type with same name
+ {NewTypeName(0, pkg, "int32", Typ[Int32]), true}, // type name is declared in user-defined package (outside Universe)
+ {NewTypeName(0, nil, "rune", Typ[Rune]), true}, // type name refers to basic type rune which is an alias already
+ } {
+ check(test.name, test.alias)
+ }
+}
+
+// TestEmbeddedMethod checks that an embedded method is represented by
+// the same Func Object as the original method. See also issue #34421.
+func TestEmbeddedMethod(t *testing.T) {
+ const src = `package p; type I interface { error }`
+
+ // type-check src
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "", src, 0)
+ if err != nil {
+ t.Fatalf("parse failed: %s", err)
+ }
+ var conf Config
+ pkg, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, nil)
+ if err != nil {
+ t.Fatalf("typecheck failed: %s", err)
+ }
+
+ // get original error.Error method
+ eface := Universe.Lookup("error")
+ orig, _, _ := LookupFieldOrMethod(eface.Type(), false, nil, "Error")
+ if orig == nil {
+ t.Fatalf("original error.Error not found")
+ }
+
+ // get embedded error.Error method
+ iface := pkg.Scope().Lookup("I")
+ embed, _, _ := LookupFieldOrMethod(iface.Type(), false, nil, "Error")
+ if embed == nil {
+ t.Fatalf("embedded error.Error not found")
+ }
+
+ // original and embedded Error object should be identical
+ if orig != embed {
+ t.Fatalf("%s (%p) != %s (%p)", orig, orig, embed, embed)
+ }
+}
diff --git a/src/go/types/objset.go b/src/go/types/objset.go
new file mode 100644
index 0000000..55eb74a
--- /dev/null
+++ b/src/go/types/objset.go
@@ -0,0 +1,31 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements objsets.
+//
+// An objset is similar to a Scope but objset elements
+// are identified by their unique id, instead of their
+// object name.
+
+package types
+
+// An objset is a set of objects identified by their unique id.
+// The zero value for objset is a ready-to-use empty objset.
+type objset map[string]Object // initialized lazily
+
+// insert attempts to insert an object obj into objset s.
+// If s already contains an alternative object alt with
+// the same name, insert leaves s unchanged and returns alt.
+// Otherwise it inserts obj and returns nil.
+func (s *objset) insert(obj Object) Object {
+ id := obj.Id()
+ if alt := (*s)[id]; alt != nil {
+ return alt
+ }
+ if *s == nil {
+ *s = make(map[string]Object)
+ }
+ (*s)[id] = obj
+ return nil
+}
diff --git a/src/go/types/operand.go b/src/go/types/operand.go
new file mode 100644
index 0000000..3e1ac31
--- /dev/null
+++ b/src/go/types/operand.go
@@ -0,0 +1,283 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file defines operands and associated operations.
+
+package types
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/constant"
+ "go/token"
+)
+
+// An operandMode specifies the (addressing) mode of an operand.
+type operandMode byte
+
+const (
+ invalid operandMode = iota // operand is invalid
+ novalue // operand represents no value (result of a function call w/o result)
+ builtin // operand is a built-in function
+ typexpr // operand is a type
+ constant_ // operand is a constant; the operand's typ is a Basic type
+ variable // operand is an addressable variable
+ mapindex // operand is a map index expression (acts like a variable on lhs, commaok on rhs of an assignment)
+ value // operand is a computed value
+ commaok // like value, but operand may be used in a comma,ok expression
+ commaerr // like commaok, but second value is error, not boolean
+ cgofunc // operand is a cgo function
+)
+
+var operandModeString = [...]string{
+ invalid: "invalid operand",
+ novalue: "no value",
+ builtin: "built-in",
+ typexpr: "type",
+ constant_: "constant",
+ variable: "variable",
+ mapindex: "map index expression",
+ value: "value",
+ commaok: "comma, ok expression",
+ commaerr: "comma, error expression",
+ cgofunc: "cgo function",
+}
+
+// An operand represents an intermediate value during type checking.
+// Operands have an (addressing) mode, the expression evaluating to
+// the operand, the operand's type, a value for constants, and an id
+// for built-in functions.
+// The zero value of operand is a ready to use invalid operand.
+//
+type operand struct {
+ mode operandMode
+ expr ast.Expr
+ typ Type
+ val constant.Value
+ id builtinId
+}
+
+// Pos returns the position of the expression corresponding to x.
+// If x is invalid the position is token.NoPos.
+//
+func (x *operand) Pos() token.Pos {
+ // x.expr may not be set if x is invalid
+ if x.expr == nil {
+ return token.NoPos
+ }
+ return x.expr.Pos()
+}
+
+// Operand string formats
+// (not all "untyped" cases can appear due to the type system,
+// but they fall out naturally here)
+//
+// mode format
+//
+// invalid <expr> ( <mode> )
+// novalue <expr> ( <mode> )
+// builtin <expr> ( <mode> )
+// typexpr <expr> ( <mode> )
+//
+// constant <expr> (<untyped kind> <mode> )
+// constant <expr> ( <mode> of type <typ>)
+// constant <expr> (<untyped kind> <mode> <val> )
+// constant <expr> ( <mode> <val> of type <typ>)
+//
+// variable <expr> (<untyped kind> <mode> )
+// variable <expr> ( <mode> of type <typ>)
+//
+// mapindex <expr> (<untyped kind> <mode> )
+// mapindex <expr> ( <mode> of type <typ>)
+//
+// value <expr> (<untyped kind> <mode> )
+// value <expr> ( <mode> of type <typ>)
+//
+// commaok <expr> (<untyped kind> <mode> )
+// commaok <expr> ( <mode> of type <typ>)
+//
+// commaerr <expr> (<untyped kind> <mode> )
+// commaerr <expr> ( <mode> of type <typ>)
+//
+// cgofunc <expr> (<untyped kind> <mode> )
+// cgofunc <expr> ( <mode> of type <typ>)
+//
+func operandString(x *operand, qf Qualifier) string {
+ var buf bytes.Buffer
+
+ var expr string
+ if x.expr != nil {
+ expr = ExprString(x.expr)
+ } else {
+ switch x.mode {
+ case builtin:
+ expr = predeclaredFuncs[x.id].name
+ case typexpr:
+ expr = TypeString(x.typ, qf)
+ case constant_:
+ expr = x.val.String()
+ }
+ }
+
+ // <expr> (
+ if expr != "" {
+ buf.WriteString(expr)
+ buf.WriteString(" (")
+ }
+
+ // <untyped kind>
+ hasType := false
+ switch x.mode {
+ case invalid, novalue, builtin, typexpr:
+ // no type
+ default:
+ // should have a type, but be cautious (don't crash during printing)
+ if x.typ != nil {
+ if isUntyped(x.typ) {
+ buf.WriteString(x.typ.(*Basic).name)
+ buf.WriteByte(' ')
+ break
+ }
+ hasType = true
+ }
+ }
+
+ // <mode>
+ buf.WriteString(operandModeString[x.mode])
+
+ // <val>
+ if x.mode == constant_ {
+ if s := x.val.String(); s != expr {
+ buf.WriteByte(' ')
+ buf.WriteString(s)
+ }
+ }
+
+ // <typ>
+ if hasType {
+ if x.typ != Typ[Invalid] {
+ buf.WriteString(" of type ")
+ WriteType(&buf, x.typ, qf)
+ } else {
+ buf.WriteString(" with invalid type")
+ }
+ }
+
+ // )
+ if expr != "" {
+ buf.WriteByte(')')
+ }
+
+ return buf.String()
+}
+
+func (x *operand) String() string {
+ return operandString(x, nil)
+}
+
+// setConst sets x to the untyped constant for literal lit.
+func (x *operand) setConst(tok token.Token, lit string) {
+ var kind BasicKind
+ switch tok {
+ case token.INT:
+ kind = UntypedInt
+ case token.FLOAT:
+ kind = UntypedFloat
+ case token.IMAG:
+ kind = UntypedComplex
+ case token.CHAR:
+ kind = UntypedRune
+ case token.STRING:
+ kind = UntypedString
+ default:
+ unreachable()
+ }
+
+ val := constant.MakeFromLiteral(lit, tok, 0)
+ if val.Kind() == constant.Unknown {
+ x.mode = invalid
+ x.typ = Typ[Invalid]
+ return
+ }
+ x.mode = constant_
+ x.typ = Typ[kind]
+ x.val = val
+}
+
+// isNil reports whether x is the nil value.
+func (x *operand) isNil() bool {
+ return x.mode == value && x.typ == Typ[UntypedNil]
+}
+
+// assignableTo reports whether x is assignable to a variable of type T. If the
+// result is false and a non-nil reason is provided, it may be set to a more
+// detailed explanation of the failure (result != ""). The check parameter may
+// be nil if assignableTo is invoked through an exported API call, i.e., when
+// all methods have been type-checked.
+func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, errorCode) {
+ if x.mode == invalid || T == Typ[Invalid] {
+ return true, 0 // avoid spurious errors
+ }
+
+ V := x.typ
+
+ // x's type is identical to T
+ if check.identical(V, T) {
+ return true, 0
+ }
+
+ Vu := V.Underlying()
+ Tu := T.Underlying()
+
+ // x is an untyped value representable by a value of type T.
+ if isUntyped(Vu) {
+ if t, ok := Tu.(*Basic); ok && x.mode == constant_ {
+ return representableConst(x.val, check, t, nil), _IncompatibleAssign
+ }
+ return check.implicitType(x, Tu) != nil, _IncompatibleAssign
+ }
+ // Vu is typed
+
+ // x's type V and T have identical underlying types and at least one of V or
+ // T is not a named type.
+ if check.identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) {
+ return true, 0
+ }
+
+ // T is an interface type and x implements T
+ if Ti, ok := Tu.(*Interface); ok {
+ if m, wrongType := check.missingMethod(V, Ti, true); m != nil /* Implements(V, Ti) */ {
+ if reason != nil {
+ if wrongType != nil {
+ if check.identical(m.typ, wrongType.typ) {
+ *reason = fmt.Sprintf("missing method %s (%s has pointer receiver)", m.name, m.name)
+ } else {
+ *reason = fmt.Sprintf("wrong type for method %s (have %s, want %s)", m.Name(), wrongType.typ, m.typ)
+ }
+
+ } else {
+ *reason = "missing method " + m.Name()
+ }
+ }
+ return false, _InvalidIfaceAssign
+ }
+ return true, 0
+ }
+
+ // x is a bidirectional channel value, T is a channel
+ // type, x's type V and T have identical element types,
+ // and at least one of V or T is not a named type
+ if Vc, ok := Vu.(*Chan); ok && Vc.dir == SendRecv {
+ if Tc, ok := Tu.(*Chan); ok && check.identical(Vc.elem, Tc.elem) {
+ if !isNamed(V) || !isNamed(T) {
+ return true, 0
+ } else {
+ return false, _InvalidChanAssign
+ }
+ }
+ }
+
+ return false, _IncompatibleAssign
+}
diff --git a/src/go/types/package.go b/src/go/types/package.go
new file mode 100644
index 0000000..7b89def
--- /dev/null
+++ b/src/go/types/package.go
@@ -0,0 +1,65 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "fmt"
+ "go/token"
+)
+
+// A Package describes a Go package.
+type Package struct {
+ path string
+ name string
+ scope *Scope
+ complete bool
+ imports []*Package
+ fake bool // scope lookup errors are silently dropped if package is fake (internal use only)
+ cgo bool // uses of this package will be rewritten into uses of declarations from _cgo_gotypes.go
+}
+
+// NewPackage returns a new Package for the given package path and name.
+// The package is not complete and contains no explicit imports.
+func NewPackage(path, name string) *Package {
+ scope := NewScope(Universe, token.NoPos, token.NoPos, fmt.Sprintf("package %q", path))
+ return &Package{path: path, name: name, scope: scope}
+}
+
+// Path returns the package path.
+func (pkg *Package) Path() string { return pkg.path }
+
+// Name returns the package name.
+func (pkg *Package) Name() string { return pkg.name }
+
+// SetName sets the package name.
+func (pkg *Package) SetName(name string) { pkg.name = name }
+
+// Scope returns the (complete or incomplete) package scope
+// holding the objects declared at package level (TypeNames,
+// Consts, Vars, and Funcs).
+func (pkg *Package) Scope() *Scope { return pkg.scope }
+
+// A package is complete if its scope contains (at least) all
+// exported objects; otherwise it is incomplete.
+func (pkg *Package) Complete() bool { return pkg.complete }
+
+// MarkComplete marks a package as complete.
+func (pkg *Package) MarkComplete() { pkg.complete = true }
+
+// Imports returns the list of packages directly imported by
+// pkg; the list is in source order.
+//
+// If pkg was loaded from export data, Imports includes packages that
+// provide package-level objects referenced by pkg. This may be more or
+// less than the set of packages directly imported by pkg's source code.
+func (pkg *Package) Imports() []*Package { return pkg.imports }
+
+// SetImports sets the list of explicitly imported packages to list.
+// It is the caller's responsibility to make sure list elements are unique.
+func (pkg *Package) SetImports(list []*Package) { pkg.imports = list }
+
+func (pkg *Package) String() string {
+ return fmt.Sprintf("package %s (%q)", pkg.name, pkg.path)
+}
diff --git a/src/go/types/predicates.go b/src/go/types/predicates.go
new file mode 100644
index 0000000..148edbf
--- /dev/null
+++ b/src/go/types/predicates.go
@@ -0,0 +1,340 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements commonly used type predicates.
+
+package types
+
+import "sort"
+
+func isNamed(typ Type) bool {
+ if _, ok := typ.(*Basic); ok {
+ return ok
+ }
+ _, ok := typ.(*Named)
+ return ok
+}
+
+func isBoolean(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsBoolean != 0
+}
+
+func isInteger(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsInteger != 0
+}
+
+func isUnsigned(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsUnsigned != 0
+}
+
+func isFloat(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsFloat != 0
+}
+
+func isComplex(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsComplex != 0
+}
+
+func isNumeric(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsNumeric != 0
+}
+
+func isString(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsString != 0
+}
+
+func isTyped(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return !ok || t.info&IsUntyped == 0
+}
+
+func isUntyped(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsUntyped != 0
+}
+
+func isOrdered(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsOrdered != 0
+}
+
+func isConstType(typ Type) bool {
+ t, ok := typ.Underlying().(*Basic)
+ return ok && t.info&IsConstType != 0
+}
+
+// IsInterface reports whether typ is an interface type.
+func IsInterface(typ Type) bool {
+ _, ok := typ.Underlying().(*Interface)
+ return ok
+}
+
+// Comparable reports whether values of type T are comparable.
+func Comparable(T Type) bool {
+ return comparable(T, nil)
+}
+
+func comparable(T Type, seen map[Type]bool) bool {
+ if seen[T] {
+ return true
+ }
+ if seen == nil {
+ seen = make(map[Type]bool)
+ }
+ seen[T] = true
+
+ switch t := T.Underlying().(type) {
+ case *Basic:
+ // assume invalid types to be comparable
+ // to avoid follow-up errors
+ return t.kind != UntypedNil
+ case *Pointer, *Interface, *Chan:
+ return true
+ case *Struct:
+ for _, f := range t.fields {
+ if !comparable(f.typ, seen) {
+ return false
+ }
+ }
+ return true
+ case *Array:
+ return comparable(t.elem, seen)
+ }
+ return false
+}
+
+// hasNil reports whether a type includes the nil value.
+func hasNil(typ Type) bool {
+ switch t := typ.Underlying().(type) {
+ case *Basic:
+ return t.kind == UnsafePointer
+ case *Slice, *Pointer, *Signature, *Interface, *Map, *Chan:
+ return true
+ }
+ return false
+}
+
+// identical reports whether x and y are identical types.
+// Receivers of Signature types are ignored.
+func (check *Checker) identical(x, y Type) bool {
+ return check.identical0(x, y, true, nil)
+}
+
+// identicalIgnoreTags reports whether x and y are identical types if tags are ignored.
+// Receivers of Signature types are ignored.
+func (check *Checker) identicalIgnoreTags(x, y Type) bool {
+ return check.identical0(x, y, false, nil)
+}
+
+// An ifacePair is a node in a stack of interface type pairs compared for identity.
+type ifacePair struct {
+ x, y *Interface
+ prev *ifacePair
+}
+
+func (p *ifacePair) identical(q *ifacePair) bool {
+ return p.x == q.x && p.y == q.y || p.x == q.y && p.y == q.x
+}
+
+func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
+ if x == y {
+ return true
+ }
+
+ switch x := x.(type) {
+ case *Basic:
+ // Basic types are singletons except for the rune and byte
+ // aliases, thus we cannot solely rely on the x == y check
+ // above. See also comment in TypeName.IsAlias.
+ if y, ok := y.(*Basic); ok {
+ return x.kind == y.kind
+ }
+
+ case *Array:
+ // Two array types are identical if they have identical element types
+ // and the same array length.
+ if y, ok := y.(*Array); ok {
+ // If one or both array lengths are unknown (< 0) due to some error,
+ // assume they are the same to avoid spurious follow-on errors.
+ return (x.len < 0 || y.len < 0 || x.len == y.len) && check.identical0(x.elem, y.elem, cmpTags, p)
+ }
+
+ case *Slice:
+ // Two slice types are identical if they have identical element types.
+ if y, ok := y.(*Slice); ok {
+ return check.identical0(x.elem, y.elem, cmpTags, p)
+ }
+
+ case *Struct:
+ // Two struct types are identical if they have the same sequence of fields,
+ // and if corresponding fields have the same names, and identical types,
+ // and identical tags. Two embedded fields are considered to have the same
+ // name. Lower-case field names from different packages are always different.
+ if y, ok := y.(*Struct); ok {
+ if x.NumFields() == y.NumFields() {
+ for i, f := range x.fields {
+ g := y.fields[i]
+ if f.embedded != g.embedded ||
+ cmpTags && x.Tag(i) != y.Tag(i) ||
+ !f.sameId(g.pkg, g.name) ||
+ !check.identical0(f.typ, g.typ, cmpTags, p) {
+ return false
+ }
+ }
+ return true
+ }
+ }
+
+ case *Pointer:
+ // Two pointer types are identical if they have identical base types.
+ if y, ok := y.(*Pointer); ok {
+ return check.identical0(x.base, y.base, cmpTags, p)
+ }
+
+ case *Tuple:
+ // Two tuples types are identical if they have the same number of elements
+ // and corresponding elements have identical types.
+ if y, ok := y.(*Tuple); ok {
+ if x.Len() == y.Len() {
+ if x != nil {
+ for i, v := range x.vars {
+ w := y.vars[i]
+ if !check.identical0(v.typ, w.typ, cmpTags, p) {
+ return false
+ }
+ }
+ }
+ return true
+ }
+ }
+
+ case *Signature:
+ // Two function types are identical if they have the same number of parameters
+ // and result values, corresponding parameter and result types are identical,
+ // and either both functions are variadic or neither is. Parameter and result
+ // names are not required to match.
+ if y, ok := y.(*Signature); ok {
+ return x.variadic == y.variadic &&
+ check.identical0(x.params, y.params, cmpTags, p) &&
+ check.identical0(x.results, y.results, cmpTags, p)
+ }
+
+ case *Interface:
+ // Two interface types are identical if they have the same set of methods with
+ // the same names and identical function types. Lower-case method names from
+ // different packages are always different. The order of the methods is irrelevant.
+ if y, ok := y.(*Interface); ok {
+ // If identical0 is called (indirectly) via an external API entry point
+ // (such as Identical, IdenticalIgnoreTags, etc.), check is nil. But in
+ // that case, interfaces are expected to be complete and lazy completion
+ // here is not needed.
+ if check != nil {
+ check.completeInterface(x)
+ check.completeInterface(y)
+ }
+ a := x.allMethods
+ b := y.allMethods
+ if len(a) == len(b) {
+ // Interface types are the only types where cycles can occur
+ // that are not "terminated" via named types; and such cycles
+ // can only be created via method parameter types that are
+ // anonymous interfaces (directly or indirectly) embedding
+ // the current interface. Example:
+ //
+ // type T interface {
+ // m() interface{T}
+ // }
+ //
+ // If two such (differently named) interfaces are compared,
+ // endless recursion occurs if the cycle is not detected.
+ //
+ // If x and y were compared before, they must be equal
+ // (if they were not, the recursion would have stopped);
+ // search the ifacePair stack for the same pair.
+ //
+ // This is a quadratic algorithm, but in practice these stacks
+ // are extremely short (bounded by the nesting depth of interface
+ // type declarations that recur via parameter types, an extremely
+ // rare occurrence). An alternative implementation might use a
+ // "visited" map, but that is probably less efficient overall.
+ q := &ifacePair{x, y, p}
+ for p != nil {
+ if p.identical(q) {
+ return true // same pair was compared before
+ }
+ p = p.prev
+ }
+ if debug {
+ assert(sort.IsSorted(byUniqueMethodName(a)))
+ assert(sort.IsSorted(byUniqueMethodName(b)))
+ }
+ for i, f := range a {
+ g := b[i]
+ if f.Id() != g.Id() || !check.identical0(f.typ, g.typ, cmpTags, q) {
+ return false
+ }
+ }
+ return true
+ }
+ }
+
+ case *Map:
+ // Two map types are identical if they have identical key and value types.
+ if y, ok := y.(*Map); ok {
+ return check.identical0(x.key, y.key, cmpTags, p) && check.identical0(x.elem, y.elem, cmpTags, p)
+ }
+
+ case *Chan:
+ // Two channel types are identical if they have identical value types
+ // and the same direction.
+ if y, ok := y.(*Chan); ok {
+ return x.dir == y.dir && check.identical0(x.elem, y.elem, cmpTags, p)
+ }
+
+ case *Named:
+ // Two named types are identical if their type names originate
+ // in the same type declaration.
+ if y, ok := y.(*Named); ok {
+ return x.obj == y.obj
+ }
+
+ case nil:
+
+ default:
+ unreachable()
+ }
+
+ return false
+}
+
+// Default returns the default "typed" type for an "untyped" type;
+// it returns the incoming type for all other types. The default type
+// for untyped nil is untyped nil.
+//
+func Default(typ Type) Type {
+ if t, ok := typ.(*Basic); ok {
+ switch t.kind {
+ case UntypedBool:
+ return Typ[Bool]
+ case UntypedInt:
+ return Typ[Int]
+ case UntypedRune:
+ return universeRune // use 'rune' name
+ case UntypedFloat:
+ return Typ[Float64]
+ case UntypedComplex:
+ return Typ[Complex128]
+ case UntypedString:
+ return Typ[String]
+ }
+ }
+ return typ
+}
diff --git a/src/go/types/resolver.go b/src/go/types/resolver.go
new file mode 100644
index 0000000..b637f8b
--- /dev/null
+++ b/src/go/types/resolver.go
@@ -0,0 +1,614 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+ "fmt"
+ "go/ast"
+ "go/constant"
+ "go/token"
+ "sort"
+ "strconv"
+ "strings"
+ "unicode"
+)
+
+// A declInfo describes a package-level const, type, var, or func declaration.
+type declInfo struct {
+ file *Scope // scope of file containing this declaration
+ lhs []*Var // lhs of n:1 variable declarations, or nil
+ typ ast.Expr // type, or nil
+ init ast.Expr // init/orig expression, or nil
+ inherited bool // if set, the init expression is inherited from a previous constant declaration
+ fdecl *ast.FuncDecl // func declaration, or nil
+ alias bool // type alias declaration
+
+ // The deps field tracks initialization expression dependencies.
+ deps map[Object]bool // lazily initialized
+}
+
+// hasInitializer reports whether the declared object has an initialization
+// expression or function body.
+func (d *declInfo) hasInitializer() bool {
+ return d.init != nil || d.fdecl != nil && d.fdecl.Body != nil
+}
+
+// addDep adds obj to the set of objects d's init expression depends on.
+func (d *declInfo) addDep(obj Object) {
+ m := d.deps
+ if m == nil {
+ m = make(map[Object]bool)
+ d.deps = m
+ }
+ m[obj] = true
+}
+
+// arityMatch checks that the lhs and rhs of a const or var decl
+// have the appropriate number of names and init exprs. For const
+// decls, init is the value spec providing the init exprs; for
+// var decls, init is nil (the init exprs are in s in this case).
+func (check *Checker) arityMatch(s, init *ast.ValueSpec) {
+ l := len(s.Names)
+ r := len(s.Values)
+ if init != nil {
+ r = len(init.Values)
+ }
+
+ const code = _WrongAssignCount
+ switch {
+ case init == nil && r == 0:
+ // var decl w/o init expr
+ if s.Type == nil {
+ check.errorf(s, code, "missing type or init expr")
+ }
+ case l < r:
+ if l < len(s.Values) {
+ // init exprs from s
+ n := s.Values[l]
+ check.errorf(n, code, "extra init expr %s", n)
+ // TODO(gri) avoid declared but not used error here
+ } else {
+ // init exprs "inherited"
+ check.errorf(s, code, "extra init expr at %s", check.fset.Position(init.Pos()))
+ // TODO(gri) avoid declared but not used error here
+ }
+ case l > r && (init != nil || r != 1):
+ n := s.Names[r]
+ check.errorf(n, code, "missing init expr for %s", n)
+ }
+}
+
+func validatedImportPath(path string) (string, error) {
+ s, err := strconv.Unquote(path)
+ if err != nil {
+ return "", err
+ }
+ if s == "" {
+ return "", fmt.Errorf("empty string")
+ }
+ const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
+ for _, r := range s {
+ if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
+ return s, fmt.Errorf("invalid character %#U", r)
+ }
+ }
+ return s, nil
+}
+
+// declarePkgObj declares obj in the package scope, records its ident -> obj mapping,
+// and updates check.objMap. The object must not be a function or method.
+func (check *Checker) declarePkgObj(ident *ast.Ident, obj Object, d *declInfo) {
+ assert(ident.Name == obj.Name())
+
+ // spec: "A package-scope or file-scope identifier with name init
+ // may only be declared to be a function with this (func()) signature."
+ if ident.Name == "init" {
+ check.errorf(ident, _InvalidInitDecl, "cannot declare init - must be func")
+ return
+ }
+
+ // spec: "The main package must have package name main and declare
+ // a function main that takes no arguments and returns no value."
+ if ident.Name == "main" && check.pkg.name == "main" {
+ check.errorf(ident, _InvalidMainDecl, "cannot declare main - must be func")
+ return
+ }
+
+ check.declare(check.pkg.scope, ident, obj, token.NoPos)
+ check.objMap[obj] = d
+ obj.setOrder(uint32(len(check.objMap)))
+}
+
+// filename returns a filename suitable for debugging output.
+func (check *Checker) filename(fileNo int) string {
+ file := check.files[fileNo]
+ if pos := file.Pos(); pos.IsValid() {
+ return check.fset.File(pos).Name()
+ }
+ return fmt.Sprintf("file[%d]", fileNo)
+}
+
+func (check *Checker) importPackage(pos token.Pos, path, dir string) *Package {
+ // If we already have a package for the given (path, dir)
+ // pair, use it instead of doing a full import.
+ // Checker.impMap only caches packages that are marked Complete
+ // or fake (dummy packages for failed imports). Incomplete but
+ // non-fake packages do require an import to complete them.
+ key := importKey{path, dir}
+ imp := check.impMap[key]
+ if imp != nil {
+ return imp
+ }
+
+ // no package yet => import it
+ if path == "C" && (check.conf.FakeImportC || check.conf.go115UsesCgo) {
+ imp = NewPackage("C", "C")
+ imp.fake = true // package scope is not populated
+ imp.cgo = check.conf.go115UsesCgo
+ } else {
+ // ordinary import
+ var err error
+ if importer := check.conf.Importer; importer == nil {
+ err = fmt.Errorf("Config.Importer not installed")
+ } else if importerFrom, ok := importer.(ImporterFrom); ok {
+ imp, err = importerFrom.ImportFrom(path, dir, 0)
+ if imp == nil && err == nil {
+ err = fmt.Errorf("Config.Importer.ImportFrom(%s, %s, 0) returned nil but no error", path, dir)
+ }
+ } else {
+ imp, err = importer.Import(path)
+ if imp == nil && err == nil {
+ err = fmt.Errorf("Config.Importer.Import(%s) returned nil but no error", path)
+ }
+ }
+ // make sure we have a valid package name
+ // (errors here can only happen through manipulation of packages after creation)
+ if err == nil && imp != nil && (imp.name == "_" || imp.name == "") {
+ err = fmt.Errorf("invalid package name: %q", imp.name)
+ imp = nil // create fake package below
+ }
+ if err != nil {
+ check.errorf(atPos(pos), _BrokenImport, "could not import %s (%s)", path, err)
+ if imp == nil {
+ // create a new fake package
+ // come up with a sensible package name (heuristic)
+ name := path
+ if i := len(name); i > 0 && name[i-1] == '/' {
+ name = name[:i-1]
+ }
+ if i := strings.LastIndex(name, "/"); i >= 0 {
+ name = name[i+1:]
+ }
+ imp = NewPackage(path, name)
+ }
+ // continue to use the package as best as we can
+ imp.fake = true // avoid follow-up lookup failures
+ }
+ }
+
+ // package should be complete or marked fake, but be cautious
+ if imp.complete || imp.fake {
+ check.impMap[key] = imp
+ check.pkgCnt[imp.name]++
+ return imp
+ }
+
+ // something went wrong (importer may have returned incomplete package without error)
+ return nil
+}
+
+// collectObjects collects all file and package objects and inserts them
+// into their respective scopes. It also performs imports and associates
+// methods with receiver base type names.
+func (check *Checker) collectObjects() {
+ pkg := check.pkg
+
+ // pkgImports is the set of packages already imported by any package file seen
+ // so far. Used to avoid duplicate entries in pkg.imports. Allocate and populate
+ // it (pkg.imports may not be empty if we are checking test files incrementally).
+ // Note that pkgImports is keyed by package (and thus package path), not by an
+ // importKey value. Two different importKey values may map to the same package
+ // which is why we cannot use the check.impMap here.
+ var pkgImports = make(map[*Package]bool)
+ for _, imp := range pkg.imports {
+ pkgImports[imp] = true
+ }
+
+ var methods []*Func // list of methods with non-blank _ names
+ for fileNo, file := range check.files {
+ // The package identifier denotes the current package,
+ // but there is no corresponding package object.
+ check.recordDef(file.Name, nil)
+
+ // Use the actual source file extent rather than *ast.File extent since the
+ // latter doesn't include comments which appear at the start or end of the file.
+ // Be conservative and use the *ast.File extent if we don't have a *token.File.
+ pos, end := file.Pos(), file.End()
+ if f := check.fset.File(file.Pos()); f != nil {
+ pos, end = token.Pos(f.Base()), token.Pos(f.Base()+f.Size())
+ }
+ fileScope := NewScope(check.pkg.scope, pos, end, check.filename(fileNo))
+ check.recordScope(file, fileScope)
+
+ // determine file directory, necessary to resolve imports
+ // FileName may be "" (typically for tests) in which case
+ // we get "." as the directory which is what we would want.
+ fileDir := dir(check.fset.Position(file.Name.Pos()).Filename)
+
+ check.walkDecls(file.Decls, func(d decl) {
+ switch d := d.(type) {
+ case importDecl:
+ // import package
+ path, err := validatedImportPath(d.spec.Path.Value)
+ if err != nil {
+ check.errorf(d.spec.Path, _BadImportPath, "invalid import path (%s)", err)
+ return
+ }
+
+ imp := check.importPackage(d.spec.Path.Pos(), path, fileDir)
+ if imp == nil {
+ return
+ }
+
+ // add package to list of explicit imports
+ // (this functionality is provided as a convenience
+ // for clients; it is not needed for type-checking)
+ if !pkgImports[imp] {
+ pkgImports[imp] = true
+ pkg.imports = append(pkg.imports, imp)
+ }
+
+ // local name overrides imported package name
+ name := imp.name
+ if d.spec.Name != nil {
+ name = d.spec.Name.Name
+ if path == "C" {
+ // match cmd/compile (not prescribed by spec)
+ check.errorf(d.spec.Name, _ImportCRenamed, `cannot rename import "C"`)
+ return
+ }
+ if name == "init" {
+ check.errorf(d.spec.Name, _InvalidInitDecl, "cannot declare init - must be func")
+ return
+ }
+ }
+
+ obj := NewPkgName(d.spec.Pos(), pkg, name, imp)
+ if d.spec.Name != nil {
+ // in a dot-import, the dot represents the package
+ check.recordDef(d.spec.Name, obj)
+ } else {
+ check.recordImplicit(d.spec, obj)
+ }
+
+ if path == "C" {
+ // match cmd/compile (not prescribed by spec)
+ obj.used = true
+ }
+
+ // add import to file scope
+ if name == "." {
+ // merge imported scope with file scope
+ for _, obj := range imp.scope.elems {
+ // A package scope may contain non-exported objects,
+ // do not import them!
+ if obj.Exported() {
+ // declare dot-imported object
+ // (Do not use check.declare because it modifies the object
+ // via Object.setScopePos, which leads to a race condition;
+ // the object may be imported into more than one file scope
+ // concurrently. See issue #32154.)
+ if alt := fileScope.Insert(obj); alt != nil {
+ check.errorf(d.spec.Name, _DuplicateDecl, "%s redeclared in this block", obj.Name())
+ check.reportAltDecl(alt)
+ }
+ }
+ }
+ // add position to set of dot-import positions for this file
+ // (this is only needed for "imported but not used" errors)
+ check.addUnusedDotImport(fileScope, imp, d.spec)
+ } else {
+ // declare imported package object in file scope
+ // (no need to provide s.Name since we called check.recordDef earlier)
+ check.declare(fileScope, nil, obj, token.NoPos)
+ }
+ case constDecl:
+ // declare all constants
+ for i, name := range d.spec.Names {
+ obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(d.iota)))
+
+ var init ast.Expr
+ if i < len(d.init) {
+ init = d.init[i]
+ }
+
+ d := &declInfo{file: fileScope, typ: d.typ, init: init, inherited: d.inherited}
+ check.declarePkgObj(name, obj, d)
+ }
+
+ case varDecl:
+ lhs := make([]*Var, len(d.spec.Names))
+ // If there's exactly one rhs initializer, use
+ // the same declInfo d1 for all lhs variables
+ // so that each lhs variable depends on the same
+ // rhs initializer (n:1 var declaration).
+ var d1 *declInfo
+ if len(d.spec.Values) == 1 {
+ // The lhs elements are only set up after the for loop below,
+ // but that's ok because declareVar only collects the declInfo
+ // for a later phase.
+ d1 = &declInfo{file: fileScope, lhs: lhs, typ: d.spec.Type, init: d.spec.Values[0]}
+ }
+
+ // declare all variables
+ for i, name := range d.spec.Names {
+ obj := NewVar(name.Pos(), pkg, name.Name, nil)
+ lhs[i] = obj
+
+ di := d1
+ if di == nil {
+ // individual assignments
+ var init ast.Expr
+ if i < len(d.spec.Values) {
+ init = d.spec.Values[i]
+ }
+ di = &declInfo{file: fileScope, typ: d.spec.Type, init: init}
+ }
+
+ check.declarePkgObj(name, obj, di)
+ }
+ case typeDecl:
+ obj := NewTypeName(d.spec.Name.Pos(), pkg, d.spec.Name.Name, nil)
+ check.declarePkgObj(d.spec.Name, obj, &declInfo{file: fileScope, typ: d.spec.Type, alias: d.spec.Assign.IsValid()})
+ case funcDecl:
+ info := &declInfo{file: fileScope, fdecl: d.decl}
+ name := d.decl.Name.Name
+ obj := NewFunc(d.decl.Name.Pos(), pkg, name, nil)
+ if d.decl.Recv == nil {
+ // regular function
+ if name == "init" {
+ // don't declare init functions in the package scope - they are invisible
+ obj.parent = pkg.scope
+ check.recordDef(d.decl.Name, obj)
+ // init functions must have a body
+ if d.decl.Body == nil {
+ check.softErrorf(obj, _MissingInitBody, "missing function body")
+ }
+ } else {
+ check.declare(pkg.scope, d.decl.Name, obj, token.NoPos)
+ }
+ } else {
+ // method
+ // (Methods with blank _ names are never found; no need to collect
+ // them for later type association. They will still be type-checked
+ // with all the other functions.)
+ if name != "_" {
+ methods = append(methods, obj)
+ }
+ check.recordDef(d.decl.Name, obj)
+ }
+ // Methods are not package-level objects but we still track them in the
+ // object map so that we can handle them like regular functions (if the
+ // receiver is invalid); also we need their fdecl info when associating
+ // them with their receiver base type, below.
+ check.objMap[obj] = info
+ obj.setOrder(uint32(len(check.objMap)))
+ }
+ })
+ }
+
+ // verify that objects in package and file scopes have different names
+ for _, scope := range check.pkg.scope.children /* file scopes */ {
+ for _, obj := range scope.elems {
+ if alt := pkg.scope.Lookup(obj.Name()); alt != nil {
+ if pkg, ok := obj.(*PkgName); ok {
+ check.errorf(alt, _DuplicateDecl, "%s already declared through import of %s", alt.Name(), pkg.Imported())
+ check.reportAltDecl(pkg)
+ } else {
+ check.errorf(alt, _DuplicateDecl, "%s already declared through dot-import of %s", alt.Name(), obj.Pkg())
+ // TODO(gri) dot-imported objects don't have a position; reportAltDecl won't print anything
+ check.reportAltDecl(obj)
+ }
+ }
+ }
+ }
+
+ // Now that we have all package scope objects and all methods,
+ // associate methods with receiver base type name where possible.
+ // Ignore methods that have an invalid receiver. They will be
+ // type-checked later, with regular functions.
+ if methods == nil {
+ return // nothing to do
+ }
+ check.methods = make(map[*TypeName][]*Func)
+ for _, f := range methods {
+ fdecl := check.objMap[f].fdecl
+ if list := fdecl.Recv.List; len(list) > 0 {
+ // f is a method.
+ // Determine the receiver base type and associate f with it.
+ ptr, base := check.resolveBaseTypeName(list[0].Type)
+ if base != nil {
+ f.hasPtrRecv = ptr
+ check.methods[base] = append(check.methods[base], f)
+ }
+ }
+ }
+}
+
+// resolveBaseTypeName returns the non-alias base type name for typ, and whether
+// there was a pointer indirection to get to it. The base type name must be declared
+// in package scope, and there can be at most one pointer indirection. If no such type
+// name exists, the returned base is nil.
+func (check *Checker) resolveBaseTypeName(typ ast.Expr) (ptr bool, base *TypeName) {
+ // Algorithm: Starting from a type expression, which may be a name,
+ // we follow that type through alias declarations until we reach a
+ // non-alias type name. If we encounter anything but pointer types or
+ // parentheses we're done. If we encounter more than one pointer type
+ // we're done.
+ var seen map[*TypeName]bool
+ for {
+ typ = unparen(typ)
+
+ // check if we have a pointer type
+ if pexpr, _ := typ.(*ast.StarExpr); pexpr != nil {
+ // if we've already seen a pointer, we're done
+ if ptr {
+ return false, nil
+ }
+ ptr = true
+ typ = unparen(pexpr.X) // continue with pointer base type
+ }
+
+ // typ must be a name
+ name, _ := typ.(*ast.Ident)
+ if name == nil {
+ return false, nil
+ }
+
+ // name must denote an object found in the current package scope
+ // (note that dot-imported objects are not in the package scope!)
+ obj := check.pkg.scope.Lookup(name.Name)
+ if obj == nil {
+ return false, nil
+ }
+
+ // the object must be a type name...
+ tname, _ := obj.(*TypeName)
+ if tname == nil {
+ return false, nil
+ }
+
+ // ... which we have not seen before
+ if seen[tname] {
+ return false, nil
+ }
+
+ // we're done if tdecl defined tname as a new type
+ // (rather than an alias)
+ tdecl := check.objMap[tname] // must exist for objects in package scope
+ if !tdecl.alias {
+ return ptr, tname
+ }
+
+ // otherwise, continue resolving
+ typ = tdecl.typ
+ if seen == nil {
+ seen = make(map[*TypeName]bool)
+ }
+ seen[tname] = true
+ }
+}
+
+// packageObjects typechecks all package objects, but not function bodies.
+func (check *Checker) packageObjects() {
+ // process package objects in source order for reproducible results
+ objList := make([]Object, len(check.objMap))
+ i := 0
+ for obj := range check.objMap {
+ objList[i] = obj
+ i++
+ }
+ sort.Sort(inSourceOrder(objList))
+
+ // add new methods to already type-checked types (from a prior Checker.Files call)
+ for _, obj := range objList {
+ if obj, _ := obj.(*TypeName); obj != nil && obj.typ != nil {
+ check.addMethodDecls(obj)
+ }
+ }
+
+ // We process non-alias declarations first, in order to avoid situations where
+ // the type of an alias declaration is needed before it is available. In general
+ // this is still not enough, as it is possible to create sufficiently convoluted
+ // recursive type definitions that will cause a type alias to be needed before it
+ // is available (see issue #25838 for examples).
+ // As an aside, the cmd/compiler suffers from the same problem (#25838).
+ var aliasList []*TypeName
+ // phase 1
+ for _, obj := range objList {
+ // If we have a type alias, collect it for the 2nd phase.
+ if tname, _ := obj.(*TypeName); tname != nil && check.objMap[tname].alias {
+ aliasList = append(aliasList, tname)
+ continue
+ }
+
+ check.objDecl(obj, nil)
+ }
+ // phase 2
+ for _, obj := range aliasList {
+ check.objDecl(obj, nil)
+ }
+
+ // At this point we may have a non-empty check.methods map; this means that not all
+ // entries were deleted at the end of typeDecl because the respective receiver base
+ // types were not found. In that case, an error was reported when declaring those
+ // methods. We can now safely discard this map.
+ check.methods = nil
+}
+
+// inSourceOrder implements the sort.Sort interface.
+type inSourceOrder []Object
+
+func (a inSourceOrder) Len() int { return len(a) }
+func (a inSourceOrder) Less(i, j int) bool { return a[i].order() < a[j].order() }
+func (a inSourceOrder) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// unusedImports checks for unused imports.
+func (check *Checker) unusedImports() {
+ // if function bodies are not checked, packages' uses are likely missing - don't check
+ if check.conf.IgnoreFuncBodies {
+ return
+ }
+
+ // spec: "It is illegal (...) to directly import a package without referring to
+ // any of its exported identifiers. To import a package solely for its side-effects
+ // (initialization), use the blank identifier as explicit package name."
+
+ // check use of regular imported packages
+ for _, scope := range check.pkg.scope.children /* file scopes */ {
+ for _, obj := range scope.elems {
+ if obj, ok := obj.(*PkgName); ok {
+ // Unused "blank imports" are automatically ignored
+ // since _ identifiers are not entered into scopes.
+ if !obj.used {
+ path := obj.imported.path
+ base := pkgName(path)
+ if obj.name == base {
+ check.softErrorf(obj, _UnusedImport, "%q imported but not used", path)
+ } else {
+ check.softErrorf(obj, _UnusedImport, "%q imported but not used as %s", path, obj.name)
+ }
+ }
+ }
+ }
+ }
+
+ // check use of dot-imported packages
+ for _, unusedDotImports := range check.unusedDotImports {
+ for pkg, pos := range unusedDotImports {
+ check.softErrorf(pos, _UnusedImport, "%q imported but not used", pkg.path)
+ }
+ }
+}
+
+// pkgName returns the package name (last element) of an import path.
+func pkgName(path string) string {
+ if i := strings.LastIndex(path, "/"); i >= 0 {
+ path = path[i+1:]
+ }
+ return path
+}
+
+// dir makes a good-faith attempt to return the directory
+// portion of path. If path is empty, the result is ".".
+// (Per the go/build package dependency tests, we cannot import
+// path/filepath and simply use filepath.Dir.)
+func dir(path string) string {
+ if i := strings.LastIndexAny(path, `/\`); i > 0 {
+ return path[:i]
+ }
+ // i <= 0
+ return "."
+}
diff --git a/src/go/types/resolver_test.go b/src/go/types/resolver_test.go
new file mode 100644
index 0000000..4bb63b6
--- /dev/null
+++ b/src/go/types/resolver_test.go
@@ -0,0 +1,216 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "internal/testenv"
+ "sort"
+ "testing"
+
+ . "go/types"
+)
+
+type resolveTestImporter struct {
+ importer ImporterFrom
+ imported map[string]bool
+}
+
+func (imp *resolveTestImporter) Import(string) (*Package, error) {
+ panic("should not be called")
+}
+
+func (imp *resolveTestImporter) ImportFrom(path, srcDir string, mode ImportMode) (*Package, error) {
+ if mode != 0 {
+ panic("mode must be 0")
+ }
+ if imp.importer == nil {
+ imp.importer = importer.Default().(ImporterFrom)
+ imp.imported = make(map[string]bool)
+ }
+ pkg, err := imp.importer.ImportFrom(path, srcDir, mode)
+ if err != nil {
+ return nil, err
+ }
+ imp.imported[path] = true
+ return pkg, nil
+}
+
+func TestResolveIdents(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ sources := []string{
+ `
+ package p
+ import "fmt"
+ import "math"
+ const pi = math.Pi
+ func sin(x float64) float64 {
+ return math.Sin(x)
+ }
+ var Println = fmt.Println
+ `,
+ `
+ package p
+ import "fmt"
+ type errorStringer struct { fmt.Stringer; error }
+ func f() string {
+ _ = "foo"
+ return fmt.Sprintf("%d", g())
+ }
+ func g() (x int) { return }
+ `,
+ `
+ package p
+ import . "go/parser"
+ import "sync"
+ func h() Mode { return ImportsOnly }
+ var _, x int = 1, 2
+ func init() {}
+ type T struct{ *sync.Mutex; a, b, c int}
+ type I interface{ m() }
+ var _ = T{a: 1, b: 2, c: 3}
+ func (_ T) m() {}
+ func (T) _() {}
+ var i I
+ var _ = i.m
+ func _(s []int) { for i, x := range s { _, _ = i, x } }
+ func _(x interface{}) {
+ switch x := x.(type) {
+ case int:
+ _ = x
+ }
+ switch {} // implicit 'true' tag
+ }
+ `,
+ `
+ package p
+ type S struct{}
+ func (T) _() {}
+ func (T) _() {}
+ `,
+ `
+ package p
+ func _() {
+ L0:
+ L1:
+ goto L0
+ for {
+ goto L1
+ }
+ if true {
+ goto L2
+ }
+ L2:
+ }
+ `,
+ }
+
+ pkgnames := []string{
+ "fmt",
+ "math",
+ }
+
+ // parse package files
+ fset := token.NewFileSet()
+ var files []*ast.File
+ for i, src := range sources {
+ f, err := parser.ParseFile(fset, fmt.Sprintf("sources[%d]", i), src, parser.DeclarationErrors)
+ if err != nil {
+ t.Fatal(err)
+ }
+ files = append(files, f)
+ }
+
+ // resolve and type-check package AST
+ importer := new(resolveTestImporter)
+ conf := Config{Importer: importer}
+ uses := make(map[*ast.Ident]Object)
+ defs := make(map[*ast.Ident]Object)
+ _, err := conf.Check("testResolveIdents", fset, files, &Info{Defs: defs, Uses: uses})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // check that all packages were imported
+ for _, name := range pkgnames {
+ if !importer.imported[name] {
+ t.Errorf("package %s not imported", name)
+ }
+ }
+
+ // check that qualified identifiers are resolved
+ for _, f := range files {
+ ast.Inspect(f, func(n ast.Node) bool {
+ if s, ok := n.(*ast.SelectorExpr); ok {
+ if x, ok := s.X.(*ast.Ident); ok {
+ obj := uses[x]
+ if obj == nil {
+ t.Errorf("%s: unresolved qualified identifier %s", fset.Position(x.Pos()), x.Name)
+ return false
+ }
+ if _, ok := obj.(*PkgName); ok && uses[s.Sel] == nil {
+ t.Errorf("%s: unresolved selector %s", fset.Position(s.Sel.Pos()), s.Sel.Name)
+ return false
+ }
+ return false
+ }
+ return false
+ }
+ return true
+ })
+ }
+
+ for id, obj := range uses {
+ if obj == nil {
+ t.Errorf("%s: Uses[%s] == nil", fset.Position(id.Pos()), id.Name)
+ }
+ }
+
+ // check that each identifier in the source is found in uses or defs or both
+ var both []string
+ for _, f := range files {
+ ast.Inspect(f, func(n ast.Node) bool {
+ if x, ok := n.(*ast.Ident); ok {
+ var objects int
+ if _, found := uses[x]; found {
+ objects |= 1
+ delete(uses, x)
+ }
+ if _, found := defs[x]; found {
+ objects |= 2
+ delete(defs, x)
+ }
+ if objects == 0 {
+ t.Errorf("%s: unresolved identifier %s", fset.Position(x.Pos()), x.Name)
+ } else if objects == 3 {
+ both = append(both, x.Name)
+ }
+ return false
+ }
+ return true
+ })
+ }
+
+ // check the expected set of idents that are simultaneously uses and defs
+ sort.Strings(both)
+ if got, want := fmt.Sprint(both), "[Mutex Stringer error]"; got != want {
+ t.Errorf("simultaneous uses/defs = %s, want %s", got, want)
+ }
+
+ // any left-over identifiers didn't exist in the source
+ for x := range uses {
+ t.Errorf("%s: identifier %s not present in source", fset.Position(x.Pos()), x.Name)
+ }
+ for x := range defs {
+ t.Errorf("%s: identifier %s not present in source", fset.Position(x.Pos()), x.Name)
+ }
+
+ // TODO(gri) add tests to check ImplicitObj callbacks
+}
diff --git a/src/go/types/return.go b/src/go/types/return.go
new file mode 100644
index 0000000..2d34a70
--- /dev/null
+++ b/src/go/types/return.go
@@ -0,0 +1,184 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements isTerminating.
+
+package types
+
+import (
+ "go/ast"
+ "go/token"
+)
+
+// isTerminating reports if s is a terminating statement.
+// If s is labeled, label is the label name; otherwise s
+// is "".
+func (check *Checker) isTerminating(s ast.Stmt, label string) bool {
+ switch s := s.(type) {
+ default:
+ unreachable()
+
+ case *ast.BadStmt, *ast.DeclStmt, *ast.EmptyStmt, *ast.SendStmt,
+ *ast.IncDecStmt, *ast.AssignStmt, *ast.GoStmt, *ast.DeferStmt,
+ *ast.RangeStmt:
+ // no chance
+
+ case *ast.LabeledStmt:
+ return check.isTerminating(s.Stmt, s.Label.Name)
+
+ case *ast.ExprStmt:
+ // calling the predeclared (possibly parenthesized) panic() function is terminating
+ if call, ok := unparen(s.X).(*ast.CallExpr); ok && check.isPanic[call] {
+ return true
+ }
+
+ case *ast.ReturnStmt:
+ return true
+
+ case *ast.BranchStmt:
+ if s.Tok == token.GOTO || s.Tok == token.FALLTHROUGH {
+ return true
+ }
+
+ case *ast.BlockStmt:
+ return check.isTerminatingList(s.List, "")
+
+ case *ast.IfStmt:
+ if s.Else != nil &&
+ check.isTerminating(s.Body, "") &&
+ check.isTerminating(s.Else, "") {
+ return true
+ }
+
+ case *ast.SwitchStmt:
+ return check.isTerminatingSwitch(s.Body, label)
+
+ case *ast.TypeSwitchStmt:
+ return check.isTerminatingSwitch(s.Body, label)
+
+ case *ast.SelectStmt:
+ for _, s := range s.Body.List {
+ cc := s.(*ast.CommClause)
+ if !check.isTerminatingList(cc.Body, "") || hasBreakList(cc.Body, label, true) {
+ return false
+ }
+
+ }
+ return true
+
+ case *ast.ForStmt:
+ if s.Cond == nil && !hasBreak(s.Body, label, true) {
+ return true
+ }
+ }
+
+ return false
+}
+
+func (check *Checker) isTerminatingList(list []ast.Stmt, label string) bool {
+ // trailing empty statements are permitted - skip them
+ for i := len(list) - 1; i >= 0; i-- {
+ if _, ok := list[i].(*ast.EmptyStmt); !ok {
+ return check.isTerminating(list[i], label)
+ }
+ }
+ return false // all statements are empty
+}
+
+func (check *Checker) isTerminatingSwitch(body *ast.BlockStmt, label string) bool {
+ hasDefault := false
+ for _, s := range body.List {
+ cc := s.(*ast.CaseClause)
+ if cc.List == nil {
+ hasDefault = true
+ }
+ if !check.isTerminatingList(cc.Body, "") || hasBreakList(cc.Body, label, true) {
+ return false
+ }
+ }
+ return hasDefault
+}
+
+// TODO(gri) For nested breakable statements, the current implementation of hasBreak
+// will traverse the same subtree repeatedly, once for each label. Replace
+// with a single-pass label/break matching phase.
+
+// hasBreak reports if s is or contains a break statement
+// referring to the label-ed statement or implicit-ly the
+// closest outer breakable statement.
+func hasBreak(s ast.Stmt, label string, implicit bool) bool {
+ switch s := s.(type) {
+ default:
+ unreachable()
+
+ case *ast.BadStmt, *ast.DeclStmt, *ast.EmptyStmt, *ast.ExprStmt,
+ *ast.SendStmt, *ast.IncDecStmt, *ast.AssignStmt, *ast.GoStmt,
+ *ast.DeferStmt, *ast.ReturnStmt:
+ // no chance
+
+ case *ast.LabeledStmt:
+ return hasBreak(s.Stmt, label, implicit)
+
+ case *ast.BranchStmt:
+ if s.Tok == token.BREAK {
+ if s.Label == nil {
+ return implicit
+ }
+ if s.Label.Name == label {
+ return true
+ }
+ }
+
+ case *ast.BlockStmt:
+ return hasBreakList(s.List, label, implicit)
+
+ case *ast.IfStmt:
+ if hasBreak(s.Body, label, implicit) ||
+ s.Else != nil && hasBreak(s.Else, label, implicit) {
+ return true
+ }
+
+ case *ast.CaseClause:
+ return hasBreakList(s.Body, label, implicit)
+
+ case *ast.SwitchStmt:
+ if label != "" && hasBreak(s.Body, label, false) {
+ return true
+ }
+
+ case *ast.TypeSwitchStmt:
+ if label != "" && hasBreak(s.Body, label, false) {
+ return true
+ }
+
+ case *ast.CommClause:
+ return hasBreakList(s.Body, label, implicit)
+
+ case *ast.SelectStmt:
+ if label != "" && hasBreak(s.Body, label, false) {
+ return true
+ }
+
+ case *ast.ForStmt:
+ if label != "" && hasBreak(s.Body, label, false) {
+ return true
+ }
+
+ case *ast.RangeStmt:
+ if label != "" && hasBreak(s.Body, label, false) {
+ return true
+ }
+ }
+
+ return false
+}
+
+func hasBreakList(list []ast.Stmt, label string, implicit bool) bool {
+ for _, s := range list {
+ if hasBreak(s, label, implicit) {
+ return true
+ }
+ }
+ return false
+}
diff --git a/src/go/types/scope.go b/src/go/types/scope.go
new file mode 100644
index 0000000..8c9d9ab
--- /dev/null
+++ b/src/go/types/scope.go
@@ -0,0 +1,182 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements Scopes.
+
+package types
+
+import (
+ "bytes"
+ "fmt"
+ "go/token"
+ "io"
+ "sort"
+ "strings"
+)
+
+// A Scope maintains a set of objects and links to its containing
+// (parent) and contained (children) scopes. Objects may be inserted
+// and looked up by name. The zero value for Scope is a ready-to-use
+// empty scope.
+type Scope struct {
+ parent *Scope
+ children []*Scope
+ elems map[string]Object // lazily allocated
+ pos, end token.Pos // scope extent; may be invalid
+ comment string // for debugging only
+ isFunc bool // set if this is a function scope (internal use only)
+}
+
+// NewScope returns a new, empty scope contained in the given parent
+// scope, if any. The comment is for debugging only.
+func NewScope(parent *Scope, pos, end token.Pos, comment string) *Scope {
+ s := &Scope{parent, nil, nil, pos, end, comment, false}
+ // don't add children to Universe scope!
+ if parent != nil && parent != Universe {
+ parent.children = append(parent.children, s)
+ }
+ return s
+}
+
+// Parent returns the scope's containing (parent) scope.
+func (s *Scope) Parent() *Scope { return s.parent }
+
+// Len returns the number of scope elements.
+func (s *Scope) Len() int { return len(s.elems) }
+
+// Names returns the scope's element names in sorted order.
+func (s *Scope) Names() []string {
+ names := make([]string, len(s.elems))
+ i := 0
+ for name := range s.elems {
+ names[i] = name
+ i++
+ }
+ sort.Strings(names)
+ return names
+}
+
+// NumChildren returns the number of scopes nested in s.
+func (s *Scope) NumChildren() int { return len(s.children) }
+
+// Child returns the i'th child scope for 0 <= i < NumChildren().
+func (s *Scope) Child(i int) *Scope { return s.children[i] }
+
+// Lookup returns the object in scope s with the given name if such an
+// object exists; otherwise the result is nil.
+func (s *Scope) Lookup(name string) Object {
+ return s.elems[name]
+}
+
+// LookupParent follows the parent chain of scopes starting with s until
+// it finds a scope where Lookup(name) returns a non-nil object, and then
+// returns that scope and object. If a valid position pos is provided,
+// only objects that were declared at or before pos are considered.
+// If no such scope and object exists, the result is (nil, nil).
+//
+// Note that obj.Parent() may be different from the returned scope if the
+// object was inserted into the scope and already had a parent at that
+// time (see Insert). This can only happen for dot-imported objects
+// whose scope is the scope of the package that exported them.
+func (s *Scope) LookupParent(name string, pos token.Pos) (*Scope, Object) {
+ for ; s != nil; s = s.parent {
+ if obj := s.elems[name]; obj != nil && (!pos.IsValid() || obj.scopePos() <= pos) {
+ return s, obj
+ }
+ }
+ return nil, nil
+}
+
+// Insert attempts to insert an object obj into scope s.
+// If s already contains an alternative object alt with
+// the same name, Insert leaves s unchanged and returns alt.
+// Otherwise it inserts obj, sets the object's parent scope
+// if not already set, and returns nil.
+func (s *Scope) Insert(obj Object) Object {
+ name := obj.Name()
+ if alt := s.elems[name]; alt != nil {
+ return alt
+ }
+ if s.elems == nil {
+ s.elems = make(map[string]Object)
+ }
+ s.elems[name] = obj
+ if obj.Parent() == nil {
+ obj.setParent(s)
+ }
+ return nil
+}
+
+// Pos and End describe the scope's source code extent [pos, end).
+// The results are guaranteed to be valid only if the type-checked
+// AST has complete position information. The extent is undefined
+// for Universe and package scopes.
+func (s *Scope) Pos() token.Pos { return s.pos }
+func (s *Scope) End() token.Pos { return s.end }
+
+// Contains reports whether pos is within the scope's extent.
+// The result is guaranteed to be valid only if the type-checked
+// AST has complete position information.
+func (s *Scope) Contains(pos token.Pos) bool {
+ return s.pos <= pos && pos < s.end
+}
+
+// Innermost returns the innermost (child) scope containing
+// pos. If pos is not within any scope, the result is nil.
+// The result is also nil for the Universe scope.
+// The result is guaranteed to be valid only if the type-checked
+// AST has complete position information.
+func (s *Scope) Innermost(pos token.Pos) *Scope {
+ // Package scopes do not have extents since they may be
+ // discontiguous, so iterate over the package's files.
+ if s.parent == Universe {
+ for _, s := range s.children {
+ if inner := s.Innermost(pos); inner != nil {
+ return inner
+ }
+ }
+ }
+
+ if s.Contains(pos) {
+ for _, s := range s.children {
+ if s.Contains(pos) {
+ return s.Innermost(pos)
+ }
+ }
+ return s
+ }
+ return nil
+}
+
+// WriteTo writes a string representation of the scope to w,
+// with the scope elements sorted by name.
+// The level of indentation is controlled by n >= 0, with
+// n == 0 for no indentation.
+// If recurse is set, it also writes nested (children) scopes.
+func (s *Scope) WriteTo(w io.Writer, n int, recurse bool) {
+ const ind = ". "
+ indn := strings.Repeat(ind, n)
+
+ fmt.Fprintf(w, "%s%s scope %p {\n", indn, s.comment, s)
+
+ indn1 := indn + ind
+ for _, name := range s.Names() {
+ fmt.Fprintf(w, "%s%s\n", indn1, s.elems[name])
+ }
+
+ if recurse {
+ for _, s := range s.children {
+ s.WriteTo(w, n+1, recurse)
+ }
+ }
+
+ fmt.Fprintf(w, "%s}\n", indn)
+}
+
+// String returns a string representation of the scope, for debugging.
+func (s *Scope) String() string {
+ var buf bytes.Buffer
+ s.WriteTo(&buf, 0, false)
+ return buf.String()
+}
diff --git a/src/go/types/selection.go b/src/go/types/selection.go
new file mode 100644
index 0000000..6ec69d2
--- /dev/null
+++ b/src/go/types/selection.go
@@ -0,0 +1,143 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements Selections.
+
+package types
+
+import (
+ "bytes"
+ "fmt"
+)
+
+// SelectionKind describes the kind of a selector expression x.f
+// (excluding qualified identifiers).
+type SelectionKind int
+
+const (
+ FieldVal SelectionKind = iota // x.f is a struct field selector
+ MethodVal // x.f is a method selector
+ MethodExpr // x.f is a method expression
+)
+
+// A Selection describes a selector expression x.f.
+// For the declarations:
+//
+// type T struct{ x int; E }
+// type E struct{}
+// func (e E) m() {}
+// var p *T
+//
+// the following relations exist:
+//
+// Selector Kind Recv Obj Type Index Indirect
+//
+// p.x FieldVal T x int {0} true
+// p.m MethodVal *T m func() {1, 0} true
+// T.m MethodExpr T m func(T) {1, 0} false
+//
+type Selection struct {
+ kind SelectionKind
+ recv Type // type of x
+ obj Object // object denoted by x.f
+ index []int // path from x to x.f
+ indirect bool // set if there was any pointer indirection on the path
+}
+
+// Kind returns the selection kind.
+func (s *Selection) Kind() SelectionKind { return s.kind }
+
+// Recv returns the type of x in x.f.
+func (s *Selection) Recv() Type { return s.recv }
+
+// Obj returns the object denoted by x.f; a *Var for
+// a field selection, and a *Func in all other cases.
+func (s *Selection) Obj() Object { return s.obj }
+
+// Type returns the type of x.f, which may be different from the type of f.
+// See Selection for more information.
+func (s *Selection) Type() Type {
+ switch s.kind {
+ case MethodVal:
+ // The type of x.f is a method with its receiver type set
+ // to the type of x.
+ sig := *s.obj.(*Func).typ.(*Signature)
+ recv := *sig.recv
+ recv.typ = s.recv
+ sig.recv = &recv
+ return &sig
+
+ case MethodExpr:
+ // The type of x.f is a function (without receiver)
+ // and an additional first argument with the same type as x.
+ // TODO(gri) Similar code is already in call.go - factor!
+ // TODO(gri) Compute this eagerly to avoid allocations.
+ sig := *s.obj.(*Func).typ.(*Signature)
+ arg0 := *sig.recv
+ sig.recv = nil
+ arg0.typ = s.recv
+ var params []*Var
+ if sig.params != nil {
+ params = sig.params.vars
+ }
+ sig.params = NewTuple(append([]*Var{&arg0}, params...)...)
+ return &sig
+ }
+
+ // In all other cases, the type of x.f is the type of x.
+ return s.obj.Type()
+}
+
+// Index describes the path from x to f in x.f.
+// The last index entry is the field or method index of the type declaring f;
+// either:
+//
+// 1) the list of declared methods of a named type; or
+// 2) the list of methods of an interface type; or
+// 3) the list of fields of a struct type.
+//
+// The earlier index entries are the indices of the embedded fields implicitly
+// traversed to get from (the type of) x to f, starting at embedding depth 0.
+func (s *Selection) Index() []int { return s.index }
+
+// Indirect reports whether any pointer indirection was required to get from
+// x to f in x.f.
+func (s *Selection) Indirect() bool { return s.indirect }
+
+func (s *Selection) String() string { return SelectionString(s, nil) }
+
+// SelectionString returns the string form of s.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+//
+// Examples:
+// "field (T) f int"
+// "method (T) f(X) Y"
+// "method expr (T) f(X) Y"
+//
+func SelectionString(s *Selection, qf Qualifier) string {
+ var k string
+ switch s.kind {
+ case FieldVal:
+ k = "field "
+ case MethodVal:
+ k = "method "
+ case MethodExpr:
+ k = "method expr "
+ default:
+ unreachable()
+ }
+ var buf bytes.Buffer
+ buf.WriteString(k)
+ buf.WriteByte('(')
+ WriteType(&buf, s.Recv(), qf)
+ fmt.Fprintf(&buf, ") %s", s.obj.Name())
+ if T := s.Type(); s.kind == FieldVal {
+ buf.WriteByte(' ')
+ WriteType(&buf, T, qf)
+ } else {
+ WriteSignature(&buf, T.(*Signature), qf)
+ }
+ return buf.String()
+}
diff --git a/src/go/types/self_test.go b/src/go/types/self_test.go
new file mode 100644
index 0000000..262dc7b
--- /dev/null
+++ b/src/go/types/self_test.go
@@ -0,0 +1,121 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "path"
+ "path/filepath"
+ "testing"
+ "time"
+
+ . "go/types"
+)
+
+func TestSelf(t *testing.T) {
+ fset := token.NewFileSet()
+ files, err := pkgFiles(fset, ".", 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ conf := Config{Importer: importer.Default()}
+ _, err = conf.Check("go/types", fset, files, nil)
+ if err != nil {
+ // Importing go/constant doesn't work in the
+ // build dashboard environment. Don't report an error
+ // for now so that the build remains green.
+ // TODO(gri) fix this
+ t.Log(err) // replace w/ t.Fatal eventually
+ return
+ }
+}
+
+func BenchmarkCheck(b *testing.B) {
+ for _, p := range []string{
+ "net/http",
+ "go/parser",
+ "go/constant",
+ filepath.Join("go", "internal", "gcimporter"),
+ } {
+ b.Run(path.Base(p), func(b *testing.B) {
+ path := filepath.Join("..", "..", p)
+ for _, ignoreFuncBodies := range []bool{false, true} {
+ name := "funcbodies"
+ if ignoreFuncBodies {
+ name = "nofuncbodies"
+ }
+ b.Run(name, func(b *testing.B) {
+ b.Run("info", func(b *testing.B) {
+ runbench(b, path, ignoreFuncBodies, true)
+ })
+ b.Run("noinfo", func(b *testing.B) {
+ runbench(b, path, ignoreFuncBodies, false)
+ })
+ })
+ }
+ })
+ }
+}
+
+func runbench(b *testing.B, path string, ignoreFuncBodies, writeInfo bool) {
+ fset := token.NewFileSet()
+ files, err := pkgFiles(fset, path, 0)
+ if err != nil {
+ b.Fatal(err)
+ }
+ // determine line count
+ lines := 0
+ fset.Iterate(func(f *token.File) bool {
+ lines += f.LineCount()
+ return true
+ })
+
+ b.ResetTimer()
+ start := time.Now()
+ for i := 0; i < b.N; i++ {
+ conf := Config{
+ IgnoreFuncBodies: ignoreFuncBodies,
+ Importer: importer.Default(),
+ }
+ var info *Info
+ if writeInfo {
+ info = &Info{
+ Types: make(map[ast.Expr]TypeAndValue),
+ Defs: make(map[*ast.Ident]Object),
+ Uses: make(map[*ast.Ident]Object),
+ Implicits: make(map[ast.Node]Object),
+ Selections: make(map[*ast.SelectorExpr]*Selection),
+ Scopes: make(map[ast.Node]*Scope),
+ }
+ }
+ if _, err := conf.Check(path, fset, files, info); err != nil {
+ b.Fatal(err)
+ }
+ }
+ b.StopTimer()
+ b.ReportMetric(float64(lines)*float64(b.N)/time.Since(start).Seconds(), "lines/s")
+}
+
+func pkgFiles(fset *token.FileSet, path string, mode parser.Mode) ([]*ast.File, error) {
+ filenames, err := pkgFilenames(path) // from stdlib_test.go
+ if err != nil {
+ return nil, err
+ }
+
+ var files []*ast.File
+ for _, filename := range filenames {
+ file, err := parser.ParseFile(fset, filename, nil, mode)
+ if err != nil {
+ return nil, err
+ }
+ files = append(files, file)
+ }
+
+ return files, nil
+}
diff --git a/src/go/types/sizes.go b/src/go/types/sizes.go
new file mode 100644
index 0000000..6ab6157
--- /dev/null
+++ b/src/go/types/sizes.go
@@ -0,0 +1,263 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements Sizes.
+
+package types
+
+// Sizes defines the sizing functions for package unsafe.
+type Sizes interface {
+ // Alignof returns the alignment of a variable of type T.
+ // Alignof must implement the alignment guarantees required by the spec.
+ Alignof(T Type) int64
+
+ // Offsetsof returns the offsets of the given struct fields, in bytes.
+ // Offsetsof must implement the offset guarantees required by the spec.
+ Offsetsof(fields []*Var) []int64
+
+ // Sizeof returns the size of a variable of type T.
+ // Sizeof must implement the size guarantees required by the spec.
+ Sizeof(T Type) int64
+}
+
+// StdSizes is a convenience type for creating commonly used Sizes.
+// It makes the following simplifying assumptions:
+//
+// - The size of explicitly sized basic types (int16, etc.) is the
+// specified size.
+// - The size of strings and interfaces is 2*WordSize.
+// - The size of slices is 3*WordSize.
+// - The size of an array of n elements corresponds to the size of
+// a struct of n consecutive fields of the array's element type.
+// - The size of a struct is the offset of the last field plus that
+// field's size. As with all element types, if the struct is used
+// in an array its size must first be aligned to a multiple of the
+// struct's alignment.
+// - All other types have size WordSize.
+// - Arrays and structs are aligned per spec definition; all other
+// types are naturally aligned with a maximum alignment MaxAlign.
+//
+// *StdSizes implements Sizes.
+//
+type StdSizes struct {
+ WordSize int64 // word size in bytes - must be >= 4 (32bits)
+ MaxAlign int64 // maximum alignment in bytes - must be >= 1
+}
+
+func (s *StdSizes) Alignof(T Type) int64 {
+ // For arrays and structs, alignment is defined in terms
+ // of alignment of the elements and fields, respectively.
+ switch t := T.Underlying().(type) {
+ case *Array:
+ // spec: "For a variable x of array type: unsafe.Alignof(x)
+ // is the same as unsafe.Alignof(x[0]), but at least 1."
+ return s.Alignof(t.elem)
+ case *Struct:
+ // spec: "For a variable x of struct type: unsafe.Alignof(x)
+ // is the largest of the values unsafe.Alignof(x.f) for each
+ // field f of x, but at least 1."
+ max := int64(1)
+ for _, f := range t.fields {
+ if a := s.Alignof(f.typ); a > max {
+ max = a
+ }
+ }
+ return max
+ case *Slice, *Interface:
+ // Multiword data structures are effectively structs
+ // in which each element has size WordSize.
+ return s.WordSize
+ case *Basic:
+ // Strings are like slices and interfaces.
+ if t.Info()&IsString != 0 {
+ return s.WordSize
+ }
+ }
+ a := s.Sizeof(T) // may be 0
+ // spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1."
+ if a < 1 {
+ return 1
+ }
+ // complex{64,128} are aligned like [2]float{32,64}.
+ if isComplex(T) {
+ a /= 2
+ }
+ if a > s.MaxAlign {
+ return s.MaxAlign
+ }
+ return a
+}
+
+func (s *StdSizes) Offsetsof(fields []*Var) []int64 {
+ offsets := make([]int64, len(fields))
+ var o int64
+ for i, f := range fields {
+ a := s.Alignof(f.typ)
+ o = align(o, a)
+ offsets[i] = o
+ o += s.Sizeof(f.typ)
+ }
+ return offsets
+}
+
+var basicSizes = [...]byte{
+ Bool: 1,
+ Int8: 1,
+ Int16: 2,
+ Int32: 4,
+ Int64: 8,
+ Uint8: 1,
+ Uint16: 2,
+ Uint32: 4,
+ Uint64: 8,
+ Float32: 4,
+ Float64: 8,
+ Complex64: 8,
+ Complex128: 16,
+}
+
+func (s *StdSizes) Sizeof(T Type) int64 {
+ switch t := T.Underlying().(type) {
+ case *Basic:
+ assert(isTyped(T))
+ k := t.kind
+ if int(k) < len(basicSizes) {
+ if s := basicSizes[k]; s > 0 {
+ return int64(s)
+ }
+ }
+ if k == String {
+ return s.WordSize * 2
+ }
+ case *Array:
+ n := t.len
+ if n <= 0 {
+ return 0
+ }
+ // n > 0
+ a := s.Alignof(t.elem)
+ z := s.Sizeof(t.elem)
+ return align(z, a)*(n-1) + z
+ case *Slice:
+ return s.WordSize * 3
+ case *Struct:
+ n := t.NumFields()
+ if n == 0 {
+ return 0
+ }
+ offsets := s.Offsetsof(t.fields)
+ return offsets[n-1] + s.Sizeof(t.fields[n-1].typ)
+ case *Interface:
+ return s.WordSize * 2
+ }
+ return s.WordSize // catch-all
+}
+
+// common architecture word sizes and alignments
+var gcArchSizes = map[string]*StdSizes{
+ "386": {4, 4},
+ "arm": {4, 4},
+ "arm64": {8, 8},
+ "amd64": {8, 8},
+ "amd64p32": {4, 8},
+ "mips": {4, 4},
+ "mipsle": {4, 4},
+ "mips64": {8, 8},
+ "mips64le": {8, 8},
+ "ppc64": {8, 8},
+ "ppc64le": {8, 8},
+ "riscv64": {8, 8},
+ "s390x": {8, 8},
+ "sparc64": {8, 8},
+ "wasm": {8, 8},
+ // When adding more architectures here,
+ // update the doc string of SizesFor below.
+}
+
+// SizesFor returns the Sizes used by a compiler for an architecture.
+// The result is nil if a compiler/architecture pair is not known.
+//
+// Supported architectures for compiler "gc":
+// "386", "arm", "arm64", "amd64", "amd64p32", "mips", "mipsle",
+// "mips64", "mips64le", "ppc64", "ppc64le", "riscv64", "s390x", "sparc64", "wasm".
+func SizesFor(compiler, arch string) Sizes {
+ var m map[string]*StdSizes
+ switch compiler {
+ case "gc":
+ m = gcArchSizes
+ case "gccgo":
+ m = gccgoArchSizes
+ default:
+ return nil
+ }
+ s, ok := m[arch]
+ if !ok {
+ return nil
+ }
+ return s
+}
+
+// stdSizes is used if Config.Sizes == nil.
+var stdSizes = SizesFor("gc", "amd64")
+
+func (conf *Config) alignof(T Type) int64 {
+ if s := conf.Sizes; s != nil {
+ if a := s.Alignof(T); a >= 1 {
+ return a
+ }
+ panic("Config.Sizes.Alignof returned an alignment < 1")
+ }
+ return stdSizes.Alignof(T)
+}
+
+func (conf *Config) offsetsof(T *Struct) []int64 {
+ var offsets []int64
+ if T.NumFields() > 0 {
+ // compute offsets on demand
+ if s := conf.Sizes; s != nil {
+ offsets = s.Offsetsof(T.fields)
+ // sanity checks
+ if len(offsets) != T.NumFields() {
+ panic("Config.Sizes.Offsetsof returned the wrong number of offsets")
+ }
+ for _, o := range offsets {
+ if o < 0 {
+ panic("Config.Sizes.Offsetsof returned an offset < 0")
+ }
+ }
+ } else {
+ offsets = stdSizes.Offsetsof(T.fields)
+ }
+ }
+ return offsets
+}
+
+// offsetof returns the offset of the field specified via
+// the index sequence relative to typ. All embedded fields
+// must be structs (rather than pointer to structs).
+func (conf *Config) offsetof(typ Type, index []int) int64 {
+ var o int64
+ for _, i := range index {
+ s := typ.Underlying().(*Struct)
+ o += conf.offsetsof(s)[i]
+ typ = s.fields[i].typ
+ }
+ return o
+}
+
+func (conf *Config) sizeof(T Type) int64 {
+ if s := conf.Sizes; s != nil {
+ if z := s.Sizeof(T); z >= 0 {
+ return z
+ }
+ panic("Config.Sizes.Sizeof returned a size < 0")
+ }
+ return stdSizes.Sizeof(T)
+}
+
+// align returns the smallest y >= x such that y % a == 0.
+func align(x, a int64) int64 {
+ y := x + a - 1
+ return y - y%a
+}
diff --git a/src/go/types/sizes_test.go b/src/go/types/sizes_test.go
new file mode 100644
index 0000000..539b4e3
--- /dev/null
+++ b/src/go/types/sizes_test.go
@@ -0,0 +1,112 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains tests for sizes.
+
+package types_test
+
+import (
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "go/types"
+ "testing"
+)
+
+// findStructType typechecks src and returns the first struct type encountered.
+func findStructType(t *testing.T, src string) *types.Struct {
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "x.go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ info := types.Info{Types: make(map[ast.Expr]types.TypeAndValue)}
+ var conf types.Config
+ _, err = conf.Check("x", fset, []*ast.File{f}, &info)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for _, tv := range info.Types {
+ if ts, ok := tv.Type.(*types.Struct); ok {
+ return ts
+ }
+ }
+ t.Fatalf("failed to find a struct type in src:\n%s\n", src)
+ return nil
+}
+
+// Issue 16316
+func TestMultipleSizeUse(t *testing.T) {
+ const src = `
+package main
+
+type S struct {
+ i int
+ b bool
+ s string
+ n int
+}
+`
+ ts := findStructType(t, src)
+ sizes := types.StdSizes{WordSize: 4, MaxAlign: 4}
+ if got := sizes.Sizeof(ts); got != 20 {
+ t.Errorf("Sizeof(%v) with WordSize 4 = %d want 20", ts, got)
+ }
+ sizes = types.StdSizes{WordSize: 8, MaxAlign: 8}
+ if got := sizes.Sizeof(ts); got != 40 {
+ t.Errorf("Sizeof(%v) with WordSize 8 = %d want 40", ts, got)
+ }
+}
+
+// Issue 16464
+func TestAlignofNaclSlice(t *testing.T) {
+ const src = `
+package main
+
+var s struct {
+ x *int
+ y []byte
+}
+`
+ ts := findStructType(t, src)
+ sizes := &types.StdSizes{WordSize: 4, MaxAlign: 8}
+ var fields []*types.Var
+ // Make a copy manually :(
+ for i := 0; i < ts.NumFields(); i++ {
+ fields = append(fields, ts.Field(i))
+ }
+ offsets := sizes.Offsetsof(fields)
+ if offsets[0] != 0 || offsets[1] != 4 {
+ t.Errorf("OffsetsOf(%v) = %v want %v", ts, offsets, []int{0, 4})
+ }
+}
+
+func TestIssue16902(t *testing.T) {
+ const src = `
+package a
+
+import "unsafe"
+
+const _ = unsafe.Offsetof(struct{ x int64 }{}.x)
+`
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, "x.go", src, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+ info := types.Info{Types: make(map[ast.Expr]types.TypeAndValue)}
+ conf := types.Config{
+ Importer: importer.Default(),
+ Sizes: &types.StdSizes{WordSize: 8, MaxAlign: 8},
+ }
+ _, err = conf.Check("x", fset, []*ast.File{f}, &info)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for _, tv := range info.Types {
+ _ = conf.Sizes.Sizeof(tv.Type)
+ _ = conf.Sizes.Alignof(tv.Type)
+ }
+}
diff --git a/src/go/types/stdlib_test.go b/src/go/types/stdlib_test.go
new file mode 100644
index 0000000..5ca4493
--- /dev/null
+++ b/src/go/types/stdlib_test.go
@@ -0,0 +1,326 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file tests types.Check by using it to
+// typecheck the standard library and tests.
+
+package types_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/importer"
+ "go/parser"
+ "go/scanner"
+ "go/token"
+ "internal/testenv"
+ "os"
+ "path/filepath"
+ "runtime"
+ "strings"
+ "testing"
+ "time"
+
+ . "go/types"
+)
+
+// Use the same importer for all std lib tests to
+// avoid repeated importing of the same packages.
+var stdLibImporter = importer.Default()
+
+func TestStdlib(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ pkgCount := 0
+ duration := walkPkgDirs(filepath.Join(runtime.GOROOT(), "src"), func(dir string, filenames []string) {
+ typecheck(t, dir, filenames)
+ pkgCount++
+ }, t.Error)
+
+ if testing.Verbose() {
+ fmt.Println(pkgCount, "packages typechecked in", duration)
+ }
+}
+
+// firstComment returns the contents of the first non-empty comment in
+// the given file, "skip", or the empty string. No matter the present
+// comments, if any of them contains a build tag, the result is always
+// "skip". Only comments before the "package" token and within the first
+// 4K of the file are considered.
+func firstComment(filename string) string {
+ f, err := os.Open(filename)
+ if err != nil {
+ return ""
+ }
+ defer f.Close()
+
+ var src [4 << 10]byte // read at most 4KB
+ n, _ := f.Read(src[:])
+
+ var first string
+ var s scanner.Scanner
+ s.Init(fset.AddFile("", fset.Base(), n), src[:n], nil /* ignore errors */, scanner.ScanComments)
+ for {
+ _, tok, lit := s.Scan()
+ switch tok {
+ case token.COMMENT:
+ // remove trailing */ of multi-line comment
+ if lit[1] == '*' {
+ lit = lit[:len(lit)-2]
+ }
+ contents := strings.TrimSpace(lit[2:])
+ if strings.HasPrefix(contents, "+build ") {
+ return "skip"
+ }
+ if first == "" {
+ first = contents // contents may be "" but that's ok
+ }
+ // continue as we may still see build tags
+
+ case token.PACKAGE, token.EOF:
+ return first
+ }
+ }
+}
+
+func testTestDir(t *testing.T, path string, ignore ...string) {
+ files, err := os.ReadDir(path)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ excluded := make(map[string]bool)
+ for _, filename := range ignore {
+ excluded[filename] = true
+ }
+
+ fset := token.NewFileSet()
+ for _, f := range files {
+ // filter directory contents
+ if f.IsDir() || !strings.HasSuffix(f.Name(), ".go") || excluded[f.Name()] {
+ continue
+ }
+
+ // get per-file instructions
+ expectErrors := false
+ filename := filepath.Join(path, f.Name())
+ if comment := firstComment(filename); comment != "" {
+ fields := strings.Fields(comment)
+ switch fields[0] {
+ case "skip", "compiledir":
+ continue // ignore this file
+ case "errorcheck":
+ expectErrors = true
+ for _, arg := range fields[1:] {
+ if arg == "-0" || arg == "-+" || arg == "-std" {
+ // Marked explicitly as not expected errors (-0),
+ // or marked as compiling runtime/stdlib, which is only done
+ // to trigger runtime/stdlib-only error output.
+ // In both cases, the code should typecheck.
+ expectErrors = false
+ break
+ }
+ }
+ }
+ }
+
+ // parse and type-check file
+ file, err := parser.ParseFile(fset, filename, nil, 0)
+ if err == nil {
+ conf := Config{Importer: stdLibImporter}
+ _, err = conf.Check(filename, fset, []*ast.File{file}, nil)
+ }
+
+ if expectErrors {
+ if err == nil {
+ t.Errorf("expected errors but found none in %s", filename)
+ }
+ } else {
+ if err != nil {
+ t.Error(err)
+ }
+ }
+ }
+}
+
+func TestStdTest(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ if testing.Short() && testenv.Builder() == "" {
+ t.Skip("skipping in short mode")
+ }
+
+ testTestDir(t, filepath.Join(runtime.GOROOT(), "test"),
+ "cmplxdivide.go", // also needs file cmplxdivide1.go - ignore
+ "directive.go", // tests compiler rejection of bad directive placement - ignore
+ "embedfunc.go", // tests //go:embed
+ "embedvers.go", // tests //go:embed
+ )
+}
+
+func TestStdFixed(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ if testing.Short() && testenv.Builder() == "" {
+ t.Skip("skipping in short mode")
+ }
+
+ testTestDir(t, filepath.Join(runtime.GOROOT(), "test", "fixedbugs"),
+ "bug248.go", "bug302.go", "bug369.go", // complex test instructions - ignore
+ "issue6889.go", // gc-specific test
+ "issue7746.go", // large constants - consumes too much memory
+ "issue11362.go", // canonical import path check
+ "issue16369.go", // go/types handles this correctly - not an issue
+ "issue18459.go", // go/types doesn't check validity of //go:xxx directives
+ "issue18882.go", // go/types doesn't check validity of //go:xxx directives
+ "issue20232.go", // go/types handles larger constants than gc
+ "issue20529.go", // go/types does not have constraints on stack size
+ "issue22200.go", // go/types does not have constraints on stack size
+ "issue22200b.go", // go/types does not have constraints on stack size
+ "issue25507.go", // go/types does not have constraints on stack size
+ "issue20780.go", // go/types does not have constraints on stack size
+ "issue31747.go", // go/types does not have constraints on language level (-lang=go1.12) (see #31793)
+ "issue34329.go", // go/types does not have constraints on language level (-lang=go1.13) (see #31793)
+ "bug251.go", // issue #34333 which was exposed with fix for #34151
+ "issue42058a.go", // go/types does not have constraints on channel element size
+ "issue42058b.go", // go/types does not have constraints on channel element size
+ )
+}
+
+func TestStdKen(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ testTestDir(t, filepath.Join(runtime.GOROOT(), "test", "ken"))
+}
+
+// Package paths of excluded packages.
+var excluded = map[string]bool{
+ "builtin": true,
+}
+
+// typecheck typechecks the given package files.
+func typecheck(t *testing.T, path string, filenames []string) {
+ fset := token.NewFileSet()
+
+ // parse package files
+ var files []*ast.File
+ for _, filename := range filenames {
+ file, err := parser.ParseFile(fset, filename, nil, parser.AllErrors)
+ if err != nil {
+ // the parser error may be a list of individual errors; report them all
+ if list, ok := err.(scanner.ErrorList); ok {
+ for _, err := range list {
+ t.Error(err)
+ }
+ return
+ }
+ t.Error(err)
+ return
+ }
+
+ if testing.Verbose() {
+ if len(files) == 0 {
+ fmt.Println("package", file.Name.Name)
+ }
+ fmt.Println("\t", filename)
+ }
+
+ files = append(files, file)
+ }
+
+ // typecheck package files
+ conf := Config{
+ Error: func(err error) { t.Error(err) },
+ Importer: stdLibImporter,
+ }
+ info := Info{Uses: make(map[*ast.Ident]Object)}
+ conf.Check(path, fset, files, &info)
+
+ // Perform checks of API invariants.
+
+ // All Objects have a package, except predeclared ones.
+ errorError := Universe.Lookup("error").Type().Underlying().(*Interface).ExplicitMethod(0) // (error).Error
+ for id, obj := range info.Uses {
+ predeclared := obj == Universe.Lookup(obj.Name()) || obj == errorError
+ if predeclared == (obj.Pkg() != nil) {
+ posn := fset.Position(id.Pos())
+ if predeclared {
+ t.Errorf("%s: predeclared object with package: %s", posn, obj)
+ } else {
+ t.Errorf("%s: user-defined object without package: %s", posn, obj)
+ }
+ }
+ }
+}
+
+// pkgFilenames returns the list of package filenames for the given directory.
+func pkgFilenames(dir string) ([]string, error) {
+ ctxt := build.Default
+ ctxt.CgoEnabled = false
+ pkg, err := ctxt.ImportDir(dir, 0)
+ if err != nil {
+ if _, nogo := err.(*build.NoGoError); nogo {
+ return nil, nil // no *.go files, not an error
+ }
+ return nil, err
+ }
+ if excluded[pkg.ImportPath] {
+ return nil, nil
+ }
+ var filenames []string
+ for _, name := range pkg.GoFiles {
+ filenames = append(filenames, filepath.Join(pkg.Dir, name))
+ }
+ for _, name := range pkg.TestGoFiles {
+ filenames = append(filenames, filepath.Join(pkg.Dir, name))
+ }
+ return filenames, nil
+}
+
+func walkPkgDirs(dir string, pkgh func(dir string, filenames []string), errh func(args ...interface{})) time.Duration {
+ w := walker{time.Now(), 10 * time.Millisecond, pkgh, errh}
+ w.walk(dir)
+ return time.Since(w.start)
+}
+
+type walker struct {
+ start time.Time
+ dmax time.Duration
+ pkgh func(dir string, filenames []string)
+ errh func(args ...interface{})
+}
+
+func (w *walker) walk(dir string) {
+ // limit run time for short tests
+ if testing.Short() && time.Since(w.start) >= w.dmax {
+ return
+ }
+
+ files, err := os.ReadDir(dir)
+ if err != nil {
+ w.errh(err)
+ return
+ }
+
+ // apply pkgh to the files in directory dir
+ // but ignore files directly under $GOROOT/src (might be temporary test files).
+ if dir != filepath.Join(runtime.GOROOT(), "src") {
+ files, err := pkgFilenames(dir)
+ if err != nil {
+ w.errh(err)
+ return
+ }
+ if files != nil {
+ w.pkgh(dir, files)
+ }
+ }
+
+ // traverse subdirectories, but don't walk into testdata
+ for _, f := range files {
+ if f.IsDir() && f.Name() != "testdata" {
+ w.walk(filepath.Join(dir, f.Name()))
+ }
+ }
+}
diff --git a/src/go/types/stmt.go b/src/go/types/stmt.go
new file mode 100644
index 0000000..d88e471
--- /dev/null
+++ b/src/go/types/stmt.go
@@ -0,0 +1,881 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements typechecking of statements.
+
+package types
+
+import (
+ "go/ast"
+ "go/constant"
+ "go/token"
+ "sort"
+)
+
+func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body *ast.BlockStmt, iota constant.Value) {
+ if trace {
+ check.trace(body.Pos(), "--- %s: %s", name, sig)
+ defer func() {
+ check.trace(body.End(), "--- <end>")
+ }()
+ }
+
+ // set function scope extent
+ sig.scope.pos = body.Pos()
+ sig.scope.end = body.End()
+
+ // save/restore current context and setup function context
+ // (and use 0 indentation at function start)
+ defer func(ctxt context, indent int) {
+ check.context = ctxt
+ check.indent = indent
+ }(check.context, check.indent)
+ check.context = context{
+ decl: decl,
+ scope: sig.scope,
+ iota: iota,
+ sig: sig,
+ }
+ check.indent = 0
+
+ check.stmtList(0, body.List)
+
+ if check.hasLabel {
+ check.labels(body)
+ }
+
+ if sig.results.Len() > 0 && !check.isTerminating(body, "") {
+ check.error(atPos(body.Rbrace), _MissingReturn, "missing return")
+ }
+
+ // spec: "Implementation restriction: A compiler may make it illegal to
+ // declare a variable inside a function body if the variable is never used."
+ check.usage(sig.scope)
+}
+
+func (check *Checker) usage(scope *Scope) {
+ var unused []*Var
+ for _, elem := range scope.elems {
+ if v, _ := elem.(*Var); v != nil && !v.used {
+ unused = append(unused, v)
+ }
+ }
+ sort.Slice(unused, func(i, j int) bool {
+ return unused[i].pos < unused[j].pos
+ })
+ for _, v := range unused {
+ check.softErrorf(v, _UnusedVar, "%s declared but not used", v.name)
+ }
+
+ for _, scope := range scope.children {
+ // Don't go inside function literal scopes a second time;
+ // they are handled explicitly by funcBody.
+ if !scope.isFunc {
+ check.usage(scope)
+ }
+ }
+}
+
+// stmtContext is a bitset describing which
+// control-flow statements are permissible,
+// and provides additional context information
+// for better error messages.
+type stmtContext uint
+
+const (
+ // permissible control-flow statements
+ breakOk stmtContext = 1 << iota
+ continueOk
+ fallthroughOk
+
+ // additional context information
+ finalSwitchCase
+)
+
+func (check *Checker) simpleStmt(s ast.Stmt) {
+ if s != nil {
+ check.stmt(0, s)
+ }
+}
+
+func trimTrailingEmptyStmts(list []ast.Stmt) []ast.Stmt {
+ for i := len(list); i > 0; i-- {
+ if _, ok := list[i-1].(*ast.EmptyStmt); !ok {
+ return list[:i]
+ }
+ }
+ return nil
+}
+
+func (check *Checker) stmtList(ctxt stmtContext, list []ast.Stmt) {
+ ok := ctxt&fallthroughOk != 0
+ inner := ctxt &^ fallthroughOk
+ list = trimTrailingEmptyStmts(list) // trailing empty statements are "invisible" to fallthrough analysis
+ for i, s := range list {
+ inner := inner
+ if ok && i+1 == len(list) {
+ inner |= fallthroughOk
+ }
+ check.stmt(inner, s)
+ }
+}
+
+func (check *Checker) multipleDefaults(list []ast.Stmt) {
+ var first ast.Stmt
+ for _, s := range list {
+ var d ast.Stmt
+ switch c := s.(type) {
+ case *ast.CaseClause:
+ if len(c.List) == 0 {
+ d = s
+ }
+ case *ast.CommClause:
+ if c.Comm == nil {
+ d = s
+ }
+ default:
+ check.invalidAST(s, "case/communication clause expected")
+ }
+ if d != nil {
+ if first != nil {
+ check.errorf(d, _DuplicateDefault, "multiple defaults (first at %s)", check.fset.Position(first.Pos()))
+ } else {
+ first = d
+ }
+ }
+ }
+}
+
+func (check *Checker) openScope(s ast.Stmt, comment string) {
+ scope := NewScope(check.scope, s.Pos(), s.End(), comment)
+ check.recordScope(s, scope)
+ check.scope = scope
+}
+
+func (check *Checker) closeScope() {
+ check.scope = check.scope.Parent()
+}
+
+func assignOp(op token.Token) token.Token {
+ // token_test.go verifies the token ordering this function relies on
+ if token.ADD_ASSIGN <= op && op <= token.AND_NOT_ASSIGN {
+ return op + (token.ADD - token.ADD_ASSIGN)
+ }
+ return token.ILLEGAL
+}
+
+func (check *Checker) suspendedCall(keyword string, call *ast.CallExpr) {
+ var x operand
+ var msg string
+ var code errorCode
+ switch check.rawExpr(&x, call, nil) {
+ case conversion:
+ msg = "requires function call, not conversion"
+ code = _InvalidDefer
+ if keyword == "go" {
+ code = _InvalidGo
+ }
+ case expression:
+ msg = "discards result of"
+ code = _UnusedResults
+ case statement:
+ return
+ default:
+ unreachable()
+ }
+ check.errorf(&x, code, "%s %s %s", keyword, msg, &x)
+}
+
+// goVal returns the Go value for val, or nil.
+func goVal(val constant.Value) interface{} {
+ // val should exist, but be conservative and check
+ if val == nil {
+ return nil
+ }
+ // Match implementation restriction of other compilers.
+ // gc only checks duplicates for integer, floating-point
+ // and string values, so only create Go values for these
+ // types.
+ switch val.Kind() {
+ case constant.Int:
+ if x, ok := constant.Int64Val(val); ok {
+ return x
+ }
+ if x, ok := constant.Uint64Val(val); ok {
+ return x
+ }
+ case constant.Float:
+ if x, ok := constant.Float64Val(val); ok {
+ return x
+ }
+ case constant.String:
+ return constant.StringVal(val)
+ }
+ return nil
+}
+
+// A valueMap maps a case value (of a basic Go type) to a list of positions
+// where the same case value appeared, together with the corresponding case
+// types.
+// Since two case values may have the same "underlying" value but different
+// types we need to also check the value's types (e.g., byte(1) vs myByte(1))
+// when the switch expression is of interface type.
+type (
+ valueMap map[interface{}][]valueType // underlying Go value -> valueType
+ valueType struct {
+ pos token.Pos
+ typ Type
+ }
+)
+
+func (check *Checker) caseValues(x *operand, values []ast.Expr, seen valueMap) {
+L:
+ for _, e := range values {
+ var v operand
+ check.expr(&v, e)
+ if x.mode == invalid || v.mode == invalid {
+ continue L
+ }
+ check.convertUntyped(&v, x.typ)
+ if v.mode == invalid {
+ continue L
+ }
+ // Order matters: By comparing v against x, error positions are at the case values.
+ res := v // keep original v unchanged
+ check.comparison(&res, x, token.EQL)
+ if res.mode == invalid {
+ continue L
+ }
+ if v.mode != constant_ {
+ continue L // we're done
+ }
+ // look for duplicate values
+ if val := goVal(v.val); val != nil {
+ // look for duplicate types for a given value
+ // (quadratic algorithm, but these lists tend to be very short)
+ for _, vt := range seen[val] {
+ if check.identical(v.typ, vt.typ) {
+ check.errorf(&v, _DuplicateCase, "duplicate case %s in expression switch", &v)
+ check.error(atPos(vt.pos), _DuplicateCase, "\tprevious case") // secondary error, \t indented
+ continue L
+ }
+ }
+ seen[val] = append(seen[val], valueType{v.Pos(), v.typ})
+ }
+ }
+}
+
+func (check *Checker) caseTypes(x *operand, xtyp *Interface, types []ast.Expr, seen map[Type]ast.Expr) (T Type) {
+L:
+ for _, e := range types {
+ T = check.typOrNil(e)
+ if T == Typ[Invalid] {
+ continue L
+ }
+ // look for duplicate types
+ // (quadratic algorithm, but type switches tend to be reasonably small)
+ for t, other := range seen {
+ if T == nil && t == nil || T != nil && t != nil && check.identical(T, t) {
+ // talk about "case" rather than "type" because of nil case
+ Ts := "nil"
+ if T != nil {
+ Ts = T.String()
+ }
+ check.errorf(e, _DuplicateCase, "duplicate case %s in type switch", Ts)
+ check.error(other, _DuplicateCase, "\tprevious case") // secondary error, \t indented
+ continue L
+ }
+ }
+ seen[T] = e
+ if T != nil {
+ check.typeAssertion(e, x, xtyp, T)
+ }
+ }
+ return
+}
+
+// stmt typechecks statement s.
+func (check *Checker) stmt(ctxt stmtContext, s ast.Stmt) {
+ // statements must end with the same top scope as they started with
+ if debug {
+ defer func(scope *Scope) {
+ // don't check if code is panicking
+ if p := recover(); p != nil {
+ panic(p)
+ }
+ assert(scope == check.scope)
+ }(check.scope)
+ }
+
+ // process collected function literals before scope changes
+ defer check.processDelayed(len(check.delayed))
+
+ inner := ctxt &^ (fallthroughOk | finalSwitchCase)
+ switch s := s.(type) {
+ case *ast.BadStmt, *ast.EmptyStmt:
+ // ignore
+
+ case *ast.DeclStmt:
+ check.declStmt(s.Decl)
+
+ case *ast.LabeledStmt:
+ check.hasLabel = true
+ check.stmt(ctxt, s.Stmt)
+
+ case *ast.ExprStmt:
+ // spec: "With the exception of specific built-in functions,
+ // function and method calls and receive operations can appear
+ // in statement context. Such statements may be parenthesized."
+ var x operand
+ kind := check.rawExpr(&x, s.X, nil)
+ var msg string
+ var code errorCode
+ switch x.mode {
+ default:
+ if kind == statement {
+ return
+ }
+ msg = "is not used"
+ code = _UnusedExpr
+ case builtin:
+ msg = "must be called"
+ code = _UncalledBuiltin
+ case typexpr:
+ msg = "is not an expression"
+ code = _NotAnExpr
+ }
+ check.errorf(&x, code, "%s %s", &x, msg)
+
+ case *ast.SendStmt:
+ var ch, x operand
+ check.expr(&ch, s.Chan)
+ check.expr(&x, s.Value)
+ if ch.mode == invalid || x.mode == invalid {
+ return
+ }
+
+ tch, ok := ch.typ.Underlying().(*Chan)
+ if !ok {
+ check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to non-chan type %s", ch.typ)
+ return
+ }
+
+ if tch.dir == RecvOnly {
+ check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to receive-only type %s", tch)
+ return
+ }
+
+ check.assignment(&x, tch.elem, "send")
+
+ case *ast.IncDecStmt:
+ var op token.Token
+ switch s.Tok {
+ case token.INC:
+ op = token.ADD
+ case token.DEC:
+ op = token.SUB
+ default:
+ check.invalidAST(inNode(s, s.TokPos), "unknown inc/dec operation %s", s.Tok)
+ return
+ }
+
+ var x operand
+ check.expr(&x, s.X)
+ if x.mode == invalid {
+ return
+ }
+ if !isNumeric(x.typ) {
+ check.invalidOp(s.X, _NonNumericIncDec, "%s%s (non-numeric type %s)", s.X, s.Tok, x.typ)
+ return
+ }
+
+ Y := &ast.BasicLit{ValuePos: s.X.Pos(), Kind: token.INT, Value: "1"} // use x's position
+ check.binary(&x, nil, s.X, Y, op, s.TokPos)
+ if x.mode == invalid {
+ return
+ }
+ check.assignVar(s.X, &x)
+
+ case *ast.AssignStmt:
+ switch s.Tok {
+ case token.ASSIGN, token.DEFINE:
+ if len(s.Lhs) == 0 {
+ check.invalidAST(s, "missing lhs in assignment")
+ return
+ }
+ if s.Tok == token.DEFINE {
+ check.shortVarDecl(inNode(s, s.TokPos), s.Lhs, s.Rhs)
+ } else {
+ // regular assignment
+ check.assignVars(s.Lhs, s.Rhs)
+ }
+
+ default:
+ // assignment operations
+ if len(s.Lhs) != 1 || len(s.Rhs) != 1 {
+ check.errorf(inNode(s, s.TokPos), _MultiValAssignOp, "assignment operation %s requires single-valued expressions", s.Tok)
+ return
+ }
+ op := assignOp(s.Tok)
+ if op == token.ILLEGAL {
+ check.invalidAST(atPos(s.TokPos), "unknown assignment operation %s", s.Tok)
+ return
+ }
+ var x operand
+ check.binary(&x, nil, s.Lhs[0], s.Rhs[0], op, s.TokPos)
+ if x.mode == invalid {
+ return
+ }
+ check.assignVar(s.Lhs[0], &x)
+ }
+
+ case *ast.GoStmt:
+ check.suspendedCall("go", s.Call)
+
+ case *ast.DeferStmt:
+ check.suspendedCall("defer", s.Call)
+
+ case *ast.ReturnStmt:
+ res := check.sig.results
+ if res.Len() > 0 {
+ // function returns results
+ // (if one, say the first, result parameter is named, all of them are named)
+ if len(s.Results) == 0 && res.vars[0].name != "" {
+ // spec: "Implementation restriction: A compiler may disallow an empty expression
+ // list in a "return" statement if a different entity (constant, type, or variable)
+ // with the same name as a result parameter is in scope at the place of the return."
+ for _, obj := range res.vars {
+ if alt := check.lookup(obj.name); alt != nil && alt != obj {
+ check.errorf(s, _OutOfScopeResult, "result parameter %s not in scope at return", obj.name)
+ check.errorf(alt, _OutOfScopeResult, "\tinner declaration of %s", obj)
+ // ok to continue
+ }
+ }
+ } else {
+ // return has results or result parameters are unnamed
+ check.initVars(res.vars, s.Results, s.Return)
+ }
+ } else if len(s.Results) > 0 {
+ check.error(s.Results[0], _WrongResultCount, "no result values expected")
+ check.use(s.Results...)
+ }
+
+ case *ast.BranchStmt:
+ if s.Label != nil {
+ check.hasLabel = true
+ return // checked in 2nd pass (check.labels)
+ }
+ switch s.Tok {
+ case token.BREAK:
+ if ctxt&breakOk == 0 {
+ check.error(s, _MisplacedBreak, "break not in for, switch, or select statement")
+ }
+ case token.CONTINUE:
+ if ctxt&continueOk == 0 {
+ check.error(s, _MisplacedContinue, "continue not in for statement")
+ }
+ case token.FALLTHROUGH:
+ if ctxt&fallthroughOk == 0 {
+ msg := "fallthrough statement out of place"
+ code := _MisplacedFallthrough
+ if ctxt&finalSwitchCase != 0 {
+ msg = "cannot fallthrough final case in switch"
+ }
+ check.error(s, code, msg)
+ }
+ default:
+ check.invalidAST(s, "branch statement: %s", s.Tok)
+ }
+
+ case *ast.BlockStmt:
+ check.openScope(s, "block")
+ defer check.closeScope()
+
+ check.stmtList(inner, s.List)
+
+ case *ast.IfStmt:
+ check.openScope(s, "if")
+ defer check.closeScope()
+
+ check.simpleStmt(s.Init)
+ var x operand
+ check.expr(&x, s.Cond)
+ if x.mode != invalid && !isBoolean(x.typ) {
+ check.error(s.Cond, _InvalidCond, "non-boolean condition in if statement")
+ }
+ check.stmt(inner, s.Body)
+ // The parser produces a correct AST but if it was modified
+ // elsewhere the else branch may be invalid. Check again.
+ switch s.Else.(type) {
+ case nil, *ast.BadStmt:
+ // valid or error already reported
+ case *ast.IfStmt, *ast.BlockStmt:
+ check.stmt(inner, s.Else)
+ default:
+ check.invalidAST(s.Else, "invalid else branch in if statement")
+ }
+
+ case *ast.SwitchStmt:
+ inner |= breakOk
+ check.openScope(s, "switch")
+ defer check.closeScope()
+
+ check.simpleStmt(s.Init)
+ var x operand
+ if s.Tag != nil {
+ check.expr(&x, s.Tag)
+ // By checking assignment of x to an invisible temporary
+ // (as a compiler would), we get all the relevant checks.
+ check.assignment(&x, nil, "switch expression")
+ if x.mode != invalid && !Comparable(x.typ) && !hasNil(x.typ) {
+ check.errorf(&x, _InvalidExprSwitch, "cannot switch on %s (%s is not comparable)", &x, x.typ)
+ x.mode = invalid
+ }
+ } else {
+ // spec: "A missing switch expression is
+ // equivalent to the boolean value true."
+ x.mode = constant_
+ x.typ = Typ[Bool]
+ x.val = constant.MakeBool(true)
+ x.expr = &ast.Ident{NamePos: s.Body.Lbrace, Name: "true"}
+ }
+
+ check.multipleDefaults(s.Body.List)
+
+ seen := make(valueMap) // map of seen case values to positions and types
+ for i, c := range s.Body.List {
+ clause, _ := c.(*ast.CaseClause)
+ if clause == nil {
+ check.invalidAST(c, "incorrect expression switch case")
+ continue
+ }
+ check.caseValues(&x, clause.List, seen)
+ check.openScope(clause, "case")
+ inner := inner
+ if i+1 < len(s.Body.List) {
+ inner |= fallthroughOk
+ } else {
+ inner |= finalSwitchCase
+ }
+ check.stmtList(inner, clause.Body)
+ check.closeScope()
+ }
+
+ case *ast.TypeSwitchStmt:
+ inner |= breakOk
+ check.openScope(s, "type switch")
+ defer check.closeScope()
+
+ check.simpleStmt(s.Init)
+
+ // A type switch guard must be of the form:
+ //
+ // TypeSwitchGuard = [ identifier ":=" ] PrimaryExpr "." "(" "type" ")" .
+ //
+ // The parser is checking syntactic correctness;
+ // remaining syntactic errors are considered AST errors here.
+ // TODO(gri) better factoring of error handling (invalid ASTs)
+ //
+ var lhs *ast.Ident // lhs identifier or nil
+ var rhs ast.Expr
+ switch guard := s.Assign.(type) {
+ case *ast.ExprStmt:
+ rhs = guard.X
+ case *ast.AssignStmt:
+ if len(guard.Lhs) != 1 || guard.Tok != token.DEFINE || len(guard.Rhs) != 1 {
+ check.invalidAST(s, "incorrect form of type switch guard")
+ return
+ }
+
+ lhs, _ = guard.Lhs[0].(*ast.Ident)
+ if lhs == nil {
+ check.invalidAST(s, "incorrect form of type switch guard")
+ return
+ }
+
+ if lhs.Name == "_" {
+ // _ := x.(type) is an invalid short variable declaration
+ check.softErrorf(lhs, _NoNewVar, "no new variable on left side of :=")
+ lhs = nil // avoid declared but not used error below
+ } else {
+ check.recordDef(lhs, nil) // lhs variable is implicitly declared in each cause clause
+ }
+
+ rhs = guard.Rhs[0]
+
+ default:
+ check.invalidAST(s, "incorrect form of type switch guard")
+ return
+ }
+
+ // rhs must be of the form: expr.(type) and expr must be an interface
+ expr, _ := rhs.(*ast.TypeAssertExpr)
+ if expr == nil || expr.Type != nil {
+ check.invalidAST(s, "incorrect form of type switch guard")
+ return
+ }
+ var x operand
+ check.expr(&x, expr.X)
+ if x.mode == invalid {
+ return
+ }
+ xtyp, _ := x.typ.Underlying().(*Interface)
+ if xtyp == nil {
+ check.errorf(&x, _InvalidTypeSwitch, "%s is not an interface", &x)
+ return
+ }
+
+ check.multipleDefaults(s.Body.List)
+
+ var lhsVars []*Var // list of implicitly declared lhs variables
+ seen := make(map[Type]ast.Expr) // map of seen types to positions
+ for _, s := range s.Body.List {
+ clause, _ := s.(*ast.CaseClause)
+ if clause == nil {
+ check.invalidAST(s, "incorrect type switch case")
+ continue
+ }
+ // Check each type in this type switch case.
+ T := check.caseTypes(&x, xtyp, clause.List, seen)
+ check.openScope(clause, "case")
+ // If lhs exists, declare a corresponding variable in the case-local scope.
+ if lhs != nil {
+ // spec: "The TypeSwitchGuard may include a short variable declaration.
+ // When that form is used, the variable is declared at the beginning of
+ // the implicit block in each clause. In clauses with a case listing
+ // exactly one type, the variable has that type; otherwise, the variable
+ // has the type of the expression in the TypeSwitchGuard."
+ if len(clause.List) != 1 || T == nil {
+ T = x.typ
+ }
+ obj := NewVar(lhs.Pos(), check.pkg, lhs.Name, T)
+ scopePos := clause.Pos() + token.Pos(len("default")) // for default clause (len(List) == 0)
+ if n := len(clause.List); n > 0 {
+ scopePos = clause.List[n-1].End()
+ }
+ check.declare(check.scope, nil, obj, scopePos)
+ check.recordImplicit(clause, obj)
+ // For the "declared but not used" error, all lhs variables act as
+ // one; i.e., if any one of them is 'used', all of them are 'used'.
+ // Collect them for later analysis.
+ lhsVars = append(lhsVars, obj)
+ }
+ check.stmtList(inner, clause.Body)
+ check.closeScope()
+ }
+
+ // If lhs exists, we must have at least one lhs variable that was used.
+ if lhs != nil {
+ var used bool
+ for _, v := range lhsVars {
+ if v.used {
+ used = true
+ }
+ v.used = true // avoid usage error when checking entire function
+ }
+ if !used {
+ check.softErrorf(lhs, _UnusedVar, "%s declared but not used", lhs.Name)
+ }
+ }
+
+ case *ast.SelectStmt:
+ inner |= breakOk
+
+ check.multipleDefaults(s.Body.List)
+
+ for _, s := range s.Body.List {
+ clause, _ := s.(*ast.CommClause)
+ if clause == nil {
+ continue // error reported before
+ }
+
+ // clause.Comm must be a SendStmt, RecvStmt, or default case
+ valid := false
+ var rhs ast.Expr // rhs of RecvStmt, or nil
+ switch s := clause.Comm.(type) {
+ case nil, *ast.SendStmt:
+ valid = true
+ case *ast.AssignStmt:
+ if len(s.Rhs) == 1 {
+ rhs = s.Rhs[0]
+ }
+ case *ast.ExprStmt:
+ rhs = s.X
+ }
+
+ // if present, rhs must be a receive operation
+ if rhs != nil {
+ if x, _ := unparen(rhs).(*ast.UnaryExpr); x != nil && x.Op == token.ARROW {
+ valid = true
+ }
+ }
+
+ if !valid {
+ check.error(clause.Comm, _InvalidSelectCase, "select case must be send or receive (possibly with assignment)")
+ continue
+ }
+
+ check.openScope(s, "case")
+ if clause.Comm != nil {
+ check.stmt(inner, clause.Comm)
+ }
+ check.stmtList(inner, clause.Body)
+ check.closeScope()
+ }
+
+ case *ast.ForStmt:
+ inner |= breakOk | continueOk
+ check.openScope(s, "for")
+ defer check.closeScope()
+
+ check.simpleStmt(s.Init)
+ if s.Cond != nil {
+ var x operand
+ check.expr(&x, s.Cond)
+ if x.mode != invalid && !isBoolean(x.typ) {
+ check.error(s.Cond, _InvalidCond, "non-boolean condition in for statement")
+ }
+ }
+ check.simpleStmt(s.Post)
+ // spec: "The init statement may be a short variable
+ // declaration, but the post statement must not."
+ if s, _ := s.Post.(*ast.AssignStmt); s != nil && s.Tok == token.DEFINE {
+ check.softErrorf(s, _InvalidPostDecl, "cannot declare in post statement")
+ // Don't call useLHS here because we want to use the lhs in
+ // this erroneous statement so that we don't get errors about
+ // these lhs variables being declared but not used.
+ check.use(s.Lhs...) // avoid follow-up errors
+ }
+ check.stmt(inner, s.Body)
+
+ case *ast.RangeStmt:
+ inner |= breakOk | continueOk
+ check.openScope(s, "for")
+ defer check.closeScope()
+
+ // check expression to iterate over
+ var x operand
+ check.expr(&x, s.X)
+
+ // determine key/value types
+ var key, val Type
+ if x.mode != invalid {
+ switch typ := x.typ.Underlying().(type) {
+ case *Basic:
+ if isString(typ) {
+ key = Typ[Int]
+ val = universeRune // use 'rune' name
+ }
+ case *Array:
+ key = Typ[Int]
+ val = typ.elem
+ case *Slice:
+ key = Typ[Int]
+ val = typ.elem
+ case *Pointer:
+ if typ, _ := typ.base.Underlying().(*Array); typ != nil {
+ key = Typ[Int]
+ val = typ.elem
+ }
+ case *Map:
+ key = typ.key
+ val = typ.elem
+ case *Chan:
+ key = typ.elem
+ val = Typ[Invalid]
+ if typ.dir == SendOnly {
+ check.errorf(&x, _InvalidChanRange, "cannot range over send-only channel %s", &x)
+ // ok to continue
+ }
+ if s.Value != nil {
+ check.errorf(atPos(s.Value.Pos()), _InvalidIterVar, "iteration over %s permits only one iteration variable", &x)
+ // ok to continue
+ }
+ }
+ }
+
+ if key == nil {
+ check.errorf(&x, _InvalidRangeExpr, "cannot range over %s", &x)
+ // ok to continue
+ }
+
+ // check assignment to/declaration of iteration variables
+ // (irregular assignment, cannot easily map to existing assignment checks)
+
+ // lhs expressions and initialization value (rhs) types
+ lhs := [2]ast.Expr{s.Key, s.Value}
+ rhs := [2]Type{key, val} // key, val may be nil
+
+ if s.Tok == token.DEFINE {
+ // short variable declaration; variable scope starts after the range clause
+ // (the for loop opens a new scope, so variables on the lhs never redeclare
+ // previously declared variables)
+ var vars []*Var
+ for i, lhs := range lhs {
+ if lhs == nil {
+ continue
+ }
+
+ // determine lhs variable
+ var obj *Var
+ if ident, _ := lhs.(*ast.Ident); ident != nil {
+ // declare new variable
+ name := ident.Name
+ obj = NewVar(ident.Pos(), check.pkg, name, nil)
+ check.recordDef(ident, obj)
+ // _ variables don't count as new variables
+ if name != "_" {
+ vars = append(vars, obj)
+ }
+ } else {
+ check.invalidAST(lhs, "cannot declare %s", lhs)
+ obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable
+ }
+
+ // initialize lhs variable
+ if typ := rhs[i]; typ != nil {
+ x.mode = value
+ x.expr = lhs // we don't have a better rhs expression to use here
+ x.typ = typ
+ check.initVar(obj, &x, "range clause")
+ } else {
+ obj.typ = Typ[Invalid]
+ obj.used = true // don't complain about unused variable
+ }
+ }
+
+ // declare variables
+ if len(vars) > 0 {
+ scopePos := s.X.End()
+ for _, obj := range vars {
+ // spec: "The scope of a constant or variable identifier declared inside
+ // a function begins at the end of the ConstSpec or VarSpec (ShortVarDecl
+ // for short variable declarations) and ends at the end of the innermost
+ // containing block."
+ check.declare(check.scope, nil /* recordDef already called */, obj, scopePos)
+ }
+ } else {
+ check.error(inNode(s, s.TokPos), _NoNewVar, "no new variables on left side of :=")
+ }
+ } else {
+ // ordinary assignment
+ for i, lhs := range lhs {
+ if lhs == nil {
+ continue
+ }
+ if typ := rhs[i]; typ != nil {
+ x.mode = value
+ x.expr = lhs // we don't have a better rhs expression to use here
+ x.typ = typ
+ check.assignVar(lhs, &x)
+ }
+ }
+ }
+
+ check.stmt(inner, s.Body)
+
+ default:
+ check.invalidAST(s, "invalid statement")
+ }
+}
diff --git a/src/go/types/testdata/blank.src b/src/go/types/testdata/blank.src
new file mode 100644
index 0000000..6a2507f
--- /dev/null
+++ b/src/go/types/testdata/blank.src
@@ -0,0 +1,5 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package _ /* ERROR invalid package name */
diff --git a/src/go/types/testdata/builtins.src b/src/go/types/testdata/builtins.src
new file mode 100644
index 0000000..98830eb
--- /dev/null
+++ b/src/go/types/testdata/builtins.src
@@ -0,0 +1,902 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// builtin calls
+
+package builtins
+
+import "unsafe"
+
+func f0() {}
+
+func append1() {
+ var b byte
+ var x int
+ var s []byte
+ _ = append() // ERROR not enough arguments
+ _ = append("foo" /* ERROR not a slice */ )
+ _ = append(nil /* ERROR not a slice */ , s)
+ _ = append(x /* ERROR not a slice */ , s)
+ _ = append(s)
+ _ = append(s, nil...)
+ append /* ERROR not used */ (s)
+
+ _ = append(s, b)
+ _ = append(s, x /* ERROR cannot use x */ )
+ _ = append(s, s /* ERROR cannot use s */ )
+ _ = append(s... /* ERROR can only use ... with matching parameter */ )
+ _ = append(s, b, s... /* ERROR can only use ... with matching parameter */ )
+ _ = append(s, 1, 2, 3)
+ _ = append(s, 1, 2, 3, x /* ERROR cannot use x */ , 5, 6, 6)
+ _ = append(s, 1, 2, s... /* ERROR can only use ... with matching parameter */ )
+ _ = append([]interface{}(nil), 1, 2, "foo", x, 3.1425, false)
+
+ type S []byte
+ type T string
+ var t T
+ _ = append(s, "foo" /* ERROR cannot use .* in argument to append */ )
+ _ = append(s, "foo"...)
+ _ = append(S(s), "foo" /* ERROR cannot use .* in argument to append */ )
+ _ = append(S(s), "foo"...)
+ _ = append(s, t /* ERROR cannot use t */ )
+ _ = append(s, t...)
+ _ = append(s, T("foo")...)
+ _ = append(S(s), t /* ERROR cannot use t */ )
+ _ = append(S(s), t...)
+ _ = append(S(s), T("foo")...)
+ _ = append([]string{}, t /* ERROR cannot use t */ , "foo")
+ _ = append([]T{}, t, "foo")
+}
+
+// from the spec
+func append2() {
+ s0 := []int{0, 0}
+ s1 := append(s0, 2) // append a single element s1 == []int{0, 0, 2}
+ s2 := append(s1, 3, 5, 7) // append multiple elements s2 == []int{0, 0, 2, 3, 5, 7}
+ s3 := append(s2, s0...) // append a slice s3 == []int{0, 0, 2, 3, 5, 7, 0, 0}
+ s4 := append(s3[3:6], s3[2:]...) // append overlapping slice s4 == []int{3, 5, 7, 2, 3, 5, 7, 0, 0}
+
+ var t []interface{}
+ t = append(t, 42, 3.1415, "foo") // t == []interface{}{42, 3.1415, "foo"}
+
+ var b []byte
+ b = append(b, "bar"...) // append string contents b == []byte{'b', 'a', 'r' }
+
+ _ = s4
+}
+
+func append3() {
+ f1 := func() (s []int) { return }
+ f2 := func() (s []int, x int) { return }
+ f3 := func() (s []int, x, y int) { return }
+ f5 := func() (s []interface{}, x int, y float32, z string, b bool) { return }
+ ff := func() (int, float32) { return 0, 0 }
+ _ = append(f0 /* ERROR used as value */ ())
+ _ = append(f1())
+ _ = append(f2())
+ _ = append(f3())
+ _ = append(f5())
+ _ = append(ff /* ERROR not a slice */ ()) // TODO(gri) better error message
+}
+
+func cap1() {
+ var a [10]bool
+ var p *[20]int
+ var c chan string
+ _ = cap() // ERROR not enough arguments
+ _ = cap(1, 2) // ERROR too many arguments
+ _ = cap(42 /* ERROR invalid */)
+ const _3 = cap(a)
+ assert(_3 == 10)
+ const _4 = cap(p)
+ assert(_4 == 20)
+ _ = cap(c)
+ cap /* ERROR not used */ (c)
+
+ // issue 4744
+ type T struct{ a [10]int }
+ const _ = cap(((*T)(nil)).a)
+
+ var s [][]byte
+ _ = cap(s)
+ _ = cap(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func cap2() {
+ f1a := func() (a [10]int) { return }
+ f1s := func() (s []int) { return }
+ f2 := func() (s []int, x int) { return }
+ _ = cap(f0 /* ERROR used as value */ ())
+ _ = cap(f1a())
+ _ = cap(f1s())
+ _ = cap(f2()) // ERROR too many arguments
+}
+
+// test cases for issue 7387
+func cap3() {
+ var f = func() int { return 0 }
+ var x = f()
+ const (
+ _ = cap([4]int{})
+ _ = cap([4]int{x})
+ _ = cap /* ERROR not constant */ ([4]int{f()})
+ _ = cap /* ERROR not constant */ ([4]int{cap([]int{})})
+ _ = cap([4]int{cap([4]int{})})
+ )
+ var y float64
+ var z complex128
+ const (
+ _ = cap([4]float64{})
+ _ = cap([4]float64{y})
+ _ = cap([4]float64{real(2i)})
+ _ = cap /* ERROR not constant */ ([4]float64{real(z)})
+ )
+ var ch chan [10]int
+ const (
+ _ = cap /* ERROR not constant */ (<-ch)
+ _ = cap /* ERROR not constant */ ([4]int{(<-ch)[0]})
+ )
+}
+
+func close1() {
+ var c chan int
+ var r <-chan int
+ close() // ERROR not enough arguments
+ close(1, 2) // ERROR too many arguments
+ close(42 /* ERROR not a channel */)
+ close(r /* ERROR receive-only channel */)
+ close(c)
+ _ = close /* ERROR used as value */ (c)
+
+ var s []chan int
+ close(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func close2() {
+ f1 := func() (ch chan int) { return }
+ f2 := func() (ch chan int, x int) { return }
+ close(f0 /* ERROR used as value */ ())
+ close(f1())
+ close(f2()) // ERROR too many arguments
+}
+
+func complex1() {
+ var i32 int32
+ var f32 float32
+ var f64 float64
+ var c64 complex64
+ var c128 complex128
+ _ = complex() // ERROR not enough arguments
+ _ = complex(1) // ERROR not enough arguments
+ _ = complex(true /* ERROR mismatched types */ , 0)
+ _ = complex(i32 /* ERROR expected floating-point */ , 0)
+ _ = complex("foo" /* ERROR mismatched types */ , 0)
+ _ = complex(c64 /* ERROR expected floating-point */ , 0)
+ _ = complex(0 /* ERROR mismatched types */ , true)
+ _ = complex(0 /* ERROR expected floating-point */ , i32)
+ _ = complex(0 /* ERROR mismatched types */ , "foo")
+ _ = complex(0 /* ERROR expected floating-point */ , c64)
+ _ = complex(f32, f32)
+ _ = complex(f32, 1)
+ _ = complex(f32, 1.0)
+ _ = complex(f32, 'a')
+ _ = complex(f64, f64)
+ _ = complex(f64, 1)
+ _ = complex(f64, 1.0)
+ _ = complex(f64, 'a')
+ _ = complex(f32 /* ERROR mismatched types */ , f64)
+ _ = complex(f64 /* ERROR mismatched types */ , f32)
+ _ = complex(1, 1)
+ _ = complex(1, 1.1)
+ _ = complex(1, 'a')
+ complex /* ERROR not used */ (1, 2)
+
+ var _ complex64 = complex(f32, f32)
+ var _ complex64 = complex /* ERROR cannot use .* in variable declaration */ (f64, f64)
+
+ var _ complex128 = complex /* ERROR cannot use .* in variable declaration */ (f32, f32)
+ var _ complex128 = complex(f64, f64)
+
+ // untyped constants
+ const _ int = complex(1, 0)
+ const _ float32 = complex(1, 0)
+ const _ complex64 = complex(1, 0)
+ const _ complex128 = complex(1, 0)
+ const _ = complex(0i, 0i)
+ const _ = complex(0i, 0)
+ const _ int = 1.0 + complex(1, 0i)
+
+ const _ int = complex /* ERROR int */ (1.1, 0)
+ const _ float32 = complex /* ERROR float32 */ (1, 2)
+
+ // untyped values
+ var s uint
+ _ = complex(1 /* ERROR integer */ <<s, 0)
+ const _ = complex /* ERROR not constant */ (1 /* ERROR integer */ <<s, 0)
+ var _ int = complex /* ERROR cannot use .* in variable declaration */ (1 /* ERROR integer */ <<s, 0)
+
+ // floating-point argument types must be identical
+ type F32 float32
+ type F64 float64
+ var x32 F32
+ var x64 F64
+ c64 = complex(x32, x32)
+ _ = complex(x32 /* ERROR mismatched types */ , f32)
+ _ = complex(f32 /* ERROR mismatched types */ , x32)
+ c128 = complex(x64, x64)
+ _ = c128
+ _ = complex(x64 /* ERROR mismatched types */ , f64)
+ _ = complex(f64 /* ERROR mismatched types */ , x64)
+
+ var t []float32
+ _ = complex(t... /* ERROR invalid use of \.\.\. */ )
+}
+
+func complex2() {
+ f1 := func() (x float32) { return }
+ f2 := func() (x, y float32) { return }
+ f3 := func() (x, y, z float32) { return }
+ _ = complex(f0 /* ERROR used as value */ ())
+ _ = complex(f1()) // ERROR not enough arguments
+ _ = complex(f2())
+ _ = complex(f3()) // ERROR too many arguments
+}
+
+func copy1() {
+ copy() // ERROR not enough arguments
+ copy("foo") // ERROR not enough arguments
+ copy([ /* ERROR copy expects slice arguments */ ...]int{}, []int{})
+ copy([ /* ERROR copy expects slice arguments */ ]int{}, [...]int{})
+ copy([ /* ERROR different element types */ ]int8{}, "foo")
+
+ // spec examples
+ var a = [...]int{0, 1, 2, 3, 4, 5, 6, 7}
+ var s = make([]int, 6)
+ var b = make([]byte, 5)
+ n1 := copy(s, a[0:]) // n1 == 6, s == []int{0, 1, 2, 3, 4, 5}
+ n2 := copy(s, s[2:]) // n2 == 4, s == []int{2, 3, 4, 5, 4, 5}
+ n3 := copy(b, "Hello, World!") // n3 == 5, b == []byte("Hello")
+ _, _, _ = n1, n2, n3
+
+ var t [][]int
+ copy(t, t)
+ copy(t /* ERROR copy expects slice arguments */ , nil)
+ copy(nil /* ERROR copy expects slice arguments */ , t)
+ copy(nil /* ERROR copy expects slice arguments */ , nil)
+ copy(t... /* ERROR invalid use of \.\.\. */ )
+}
+
+func copy2() {
+ f1 := func() (a []int) { return }
+ f2 := func() (a, b []int) { return }
+ f3 := func() (a, b, c []int) { return }
+ copy(f0 /* ERROR used as value */ ())
+ copy(f1()) // ERROR not enough arguments
+ copy(f2())
+ copy(f3()) // ERROR too many arguments
+}
+
+func delete1() {
+ var m map[string]int
+ var s string
+ delete() // ERROR not enough arguments
+ delete(1) // ERROR not enough arguments
+ delete(1, 2, 3) // ERROR too many arguments
+ delete(m, 0 /* ERROR not assignable */)
+ delete(m, s)
+ _ = delete /* ERROR used as value */ (m, s)
+
+ var t []map[string]string
+ delete(t... /* ERROR invalid use of \.\.\. */ )
+}
+
+func delete2() {
+ f1 := func() (m map[string]int) { return }
+ f2 := func() (m map[string]int, k string) { return }
+ f3 := func() (m map[string]int, k string, x float32) { return }
+ delete(f0 /* ERROR used as value */ ())
+ delete(f1()) // ERROR not enough arguments
+ delete(f2())
+ delete(f3()) // ERROR too many arguments
+}
+
+func imag1() {
+ var f32 float32
+ var f64 float64
+ var c64 complex64
+ var c128 complex128
+ _ = imag() // ERROR not enough arguments
+ _ = imag(1, 2) // ERROR too many arguments
+ _ = imag(10)
+ _ = imag(2.7182818)
+ _ = imag("foo" /* ERROR expected complex */)
+ _ = imag('a')
+ const _5 = imag(1 + 2i)
+ assert(_5 == 2)
+ f32 = _5
+ f64 = _5
+ const _6 = imag(0i)
+ assert(_6 == 0)
+ f32 = imag(c64)
+ f64 = imag(c128)
+ f32 = imag /* ERROR cannot use .* in assignment */ (c128)
+ f64 = imag /* ERROR cannot use .* in assignment */ (c64)
+ imag /* ERROR not used */ (c64)
+ _, _ = f32, f64
+
+ // complex type may not be predeclared
+ type C64 complex64
+ type C128 complex128
+ var x64 C64
+ var x128 C128
+ f32 = imag(x64)
+ f64 = imag(x128)
+
+ var a []complex64
+ _ = imag(a... /* ERROR invalid use of \.\.\. */ )
+
+ // if argument is untyped, result is untyped
+ const _ byte = imag(1.2 + 3i)
+ const _ complex128 = imag(1.2 + 3i)
+
+ // lhs constant shift operands are typed as complex128
+ var s uint
+ _ = imag(1 /* ERROR must be integer */ << s)
+}
+
+func imag2() {
+ f1 := func() (x complex128) { return }
+ f2 := func() (x, y complex128) { return }
+ _ = imag(f0 /* ERROR used as value */ ())
+ _ = imag(f1())
+ _ = imag(f2()) // ERROR too many arguments
+}
+
+func len1() {
+ const c = "foobar"
+ var a [10]bool
+ var p *[20]int
+ var m map[string]complex128
+ _ = len() // ERROR not enough arguments
+ _ = len(1, 2) // ERROR too many arguments
+ _ = len(42 /* ERROR invalid */)
+ const _3 = len(c)
+ assert(_3 == 6)
+ const _4 = len(a)
+ assert(_4 == 10)
+ const _5 = len(p)
+ assert(_5 == 20)
+ _ = len(m)
+ len /* ERROR not used */ (c)
+
+ // esoteric case
+ var t string
+ var hash map[interface{}][]*[10]int
+ const n = len /* ERROR not constant */ (hash[recover()][len(t)])
+ assert(n == 10) // ok because n has unknown value and no error is reported
+ var ch <-chan int
+ const nn = len /* ERROR not constant */ (hash[<-ch][len(t)])
+
+ // issue 4744
+ type T struct{ a [10]int }
+ const _ = len(((*T)(nil)).a)
+
+ var s [][]byte
+ _ = len(s)
+ _ = len(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func len2() {
+ f1 := func() (x []int) { return }
+ f2 := func() (x, y []int) { return }
+ _ = len(f0 /* ERROR used as value */ ())
+ _ = len(f1())
+ _ = len(f2()) // ERROR too many arguments
+}
+
+// test cases for issue 7387
+func len3() {
+ var f = func() int { return 0 }
+ var x = f()
+ const (
+ _ = len([4]int{})
+ _ = len([4]int{x})
+ _ = len /* ERROR not constant */ ([4]int{f()})
+ _ = len /* ERROR not constant */ ([4]int{len([]int{})})
+ _ = len([4]int{len([4]int{})})
+ )
+ var y float64
+ var z complex128
+ const (
+ _ = len([4]float64{})
+ _ = len([4]float64{y})
+ _ = len([4]float64{real(2i)})
+ _ = len /* ERROR not constant */ ([4]float64{real(z)})
+ )
+ var ch chan [10]int
+ const (
+ _ = len /* ERROR not constant */ (<-ch)
+ _ = len /* ERROR not constant */ ([4]int{(<-ch)[0]})
+ )
+}
+
+func make1() {
+ var n int
+ var m float32
+ var s uint
+
+ _ = make() // ERROR not enough arguments
+ _ = make(1 /* ERROR not a type */)
+ _ = make(int /* ERROR cannot make */)
+
+ // slices
+ _ = make/* ERROR arguments */ ([]int)
+ _ = make/* ERROR arguments */ ([]int, 2, 3, 4)
+ _ = make([]int, int /* ERROR not an expression */)
+ _ = make([]int, 10, float32 /* ERROR not an expression */)
+ _ = make([]int, "foo" /* ERROR cannot convert */)
+ _ = make([]int, 10, 2.3 /* ERROR truncated */)
+ _ = make([]int, 5, 10.0)
+ _ = make([]int, 0i)
+ _ = make([]int, 1.0)
+ _ = make([]int, 1.0<<s)
+ _ = make([]int, 1.1 /* ERROR int */ <<s)
+ _ = make([]int, - /* ERROR must not be negative */ 1, 10)
+ _ = make([]int, 0, - /* ERROR must not be negative */ 1)
+ _ = make([]int, - /* ERROR must not be negative */ 1, - /* ERROR must not be negative */ 1)
+ _ = make([]int, 1 /* ERROR overflows */ <<100, 1 /* ERROR overflows */ <<100)
+ _ = make([]int, 10 /* ERROR length and capacity swapped */ , 9)
+ _ = make([]int, 1 /* ERROR overflows */ <<100, 12345)
+ _ = make([]int, m /* ERROR must be integer */ )
+ _ = &make /* ERROR cannot take address */ ([]int, 0)
+
+ // maps
+ _ = make /* ERROR arguments */ (map[int]string, 10, 20)
+ _ = make(map[int]float32, int /* ERROR not an expression */)
+ _ = make(map[int]float32, "foo" /* ERROR cannot convert */)
+ _ = make(map[int]float32, 10)
+ _ = make(map[int]float32, n)
+ _ = make(map[int]float32, int64(n))
+ _ = make(map[string]bool, 10.0)
+ _ = make(map[string]bool, 10.0<<s)
+ _ = &make /* ERROR cannot take address */ (map[string]bool)
+
+ // channels
+ _ = make /* ERROR arguments */ (chan int, 10, 20)
+ _ = make(chan int, int /* ERROR not an expression */)
+ _ = make(chan<- int, "foo" /* ERROR cannot convert */)
+ _ = make(chan int, - /* ERROR must not be negative */ 10)
+ _ = make(<-chan float64, 10)
+ _ = make(chan chan int, n)
+ _ = make(chan string, int64(n))
+ _ = make(chan bool, 10.0)
+ _ = make(chan bool, 10.0<<s)
+ _ = &make /* ERROR cannot take address */ (chan bool)
+
+ make /* ERROR not used */ ([]int, 10)
+
+ var t []int
+ _ = make([]int, t[0], t[1])
+ _ = make([]int, t... /* ERROR invalid use of \.\.\. */ )
+}
+
+func make2() {
+ f1 /* ERROR not used */ := func() (x []int) { return }
+ _ = make(f0 /* ERROR not a type */ ())
+ _ = make(f1 /* ERROR not a type */ ())
+}
+
+func new1() {
+ _ = new() // ERROR not enough arguments
+ _ = new(1, 2) // ERROR too many arguments
+ _ = new("foo" /* ERROR not a type */)
+ p := new(float64)
+ _ = new(struct{ x, y int })
+ q := new(*float64)
+ _ = *p == **q
+ new /* ERROR not used */ (int)
+ _ = &new /* ERROR cannot take address */ (int)
+
+ _ = new(int... /* ERROR invalid use of \.\.\. */ )
+}
+
+func new2() {
+ f1 /* ERROR not used */ := func() (x []int) { return }
+ _ = new(f0 /* ERROR not a type */ ())
+ _ = new(f1 /* ERROR not a type */ ())
+}
+
+func panic1() {
+ panic() // ERROR not enough arguments
+ panic(1, 2) // ERROR too many arguments
+ panic(0)
+ panic("foo")
+ panic(false)
+ panic(1<<10)
+ panic(1 /* ERROR overflows */ <<1000)
+ _ = panic /* ERROR used as value */ (0)
+
+ var s []byte
+ panic(s)
+ panic(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func panic2() {
+ f1 := func() (x int) { return }
+ f2 := func() (x, y int) { return }
+ panic(f0 /* ERROR used as value */ ())
+ panic(f1())
+ panic(f2()) // ERROR too many arguments
+}
+
+func print1() {
+ print()
+ print(1)
+ print(1, 2)
+ print("foo")
+ print(2.718281828)
+ print(false)
+ print(1<<10)
+ print(1 /* ERROR overflows */ <<1000)
+ println(nil /* ERROR untyped nil */ )
+
+ var s []int
+ print(s... /* ERROR invalid use of \.\.\. */ )
+ _ = print /* ERROR used as value */ ()
+}
+
+func print2() {
+ f1 := func() (x int) { return }
+ f2 := func() (x, y int) { return }
+ f3 := func() (x int, y float32, z string) { return }
+ print(f0 /* ERROR used as value */ ())
+ print(f1())
+ print(f2())
+ print(f3())
+}
+
+func println1() {
+ println()
+ println(1)
+ println(1, 2)
+ println("foo")
+ println(2.718281828)
+ println(false)
+ println(1<<10)
+ println(1 /* ERROR overflows */ <<1000)
+ println(nil /* ERROR untyped nil */ )
+
+ var s []int
+ println(s... /* ERROR invalid use of \.\.\. */ )
+ _ = println /* ERROR used as value */ ()
+}
+
+func println2() {
+ f1 := func() (x int) { return }
+ f2 := func() (x, y int) { return }
+ f3 := func() (x int, y float32, z string) { return }
+ println(f0 /* ERROR used as value */ ())
+ println(f1())
+ println(f2())
+ println(f3())
+}
+
+func real1() {
+ var f32 float32
+ var f64 float64
+ var c64 complex64
+ var c128 complex128
+ _ = real() // ERROR not enough arguments
+ _ = real(1, 2) // ERROR too many arguments
+ _ = real(10)
+ _ = real(2.7182818)
+ _ = real("foo" /* ERROR expected complex */)
+ const _5 = real(1 + 2i)
+ assert(_5 == 1)
+ f32 = _5
+ f64 = _5
+ const _6 = real(0i)
+ assert(_6 == 0)
+ f32 = real(c64)
+ f64 = real(c128)
+ f32 = real /* ERROR cannot use .* in assignment */ (c128)
+ f64 = real /* ERROR cannot use .* in assignment */ (c64)
+ real /* ERROR not used */ (c64)
+
+ // complex type may not be predeclared
+ type C64 complex64
+ type C128 complex128
+ var x64 C64
+ var x128 C128
+ f32 = imag(x64)
+ f64 = imag(x128)
+ _, _ = f32, f64
+
+ var a []complex64
+ _ = real(a... /* ERROR invalid use of \.\.\. */ )
+
+ // if argument is untyped, result is untyped
+ const _ byte = real(1 + 2.3i)
+ const _ complex128 = real(1 + 2.3i)
+
+ // lhs constant shift operands are typed as complex128
+ var s uint
+ _ = real(1 /* ERROR must be integer */ << s)
+}
+
+func real2() {
+ f1 := func() (x complex128) { return }
+ f2 := func() (x, y complex128) { return }
+ _ = real(f0 /* ERROR used as value */ ())
+ _ = real(f1())
+ _ = real(f2()) // ERROR too many arguments
+}
+
+func recover1() {
+ _ = recover()
+ _ = recover(10) // ERROR too many arguments
+ recover()
+
+ var s []int
+ recover(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func recover2() {
+ f1 := func() (x int) { return }
+ f2 := func() (x, y int) { return }
+ _ = recover(f0 /* ERROR used as value */ ())
+ _ = recover(f1()) // ERROR too many arguments
+ _ = recover(f2()) // ERROR too many arguments
+}
+
+// assuming types.DefaultPtrSize == 8
+type S0 struct{ // offset
+ a bool // 0
+ b rune // 4
+ c *int // 8
+ d bool // 16
+ e complex128 // 24
+} // 40
+
+type S1 struct{ // offset
+ x float32 // 0
+ y string // 8
+ z *S1 // 24
+ S0 // 32
+} // 72
+
+type S2 struct{ // offset
+ *S1 // 0
+} // 8
+
+type S3 struct { // offset
+ a int64 // 0
+ b int32 // 8
+} // 12
+
+type S4 struct { // offset
+ S3 // 0
+ int32 // 12
+} // 16
+
+type S5 struct { // offset
+ a [3]int32 // 0
+ b int32 // 12
+} // 16
+
+func (S2) m() {}
+
+func Alignof1() {
+ var x int
+ _ = unsafe.Alignof() // ERROR not enough arguments
+ _ = unsafe.Alignof(1, 2) // ERROR too many arguments
+ _ = unsafe.Alignof(int /* ERROR not an expression */)
+ _ = unsafe.Alignof(42)
+ _ = unsafe.Alignof(new(struct{}))
+ _ = unsafe.Alignof(1<<10)
+ _ = unsafe.Alignof(1 /* ERROR overflows */ <<1000)
+ _ = unsafe.Alignof(nil /* ERROR "untyped nil */ )
+ unsafe /* ERROR not used */ .Alignof(x)
+
+ var y S0
+ assert(unsafe.Alignof(y.a) == 1)
+ assert(unsafe.Alignof(y.b) == 4)
+ assert(unsafe.Alignof(y.c) == 8)
+ assert(unsafe.Alignof(y.d) == 1)
+ assert(unsafe.Alignof(y.e) == 8)
+
+ var s []byte
+ _ = unsafe.Alignof(s)
+ _ = unsafe.Alignof(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func Alignof2() {
+ f1 := func() (x int32) { return }
+ f2 := func() (x, y int32) { return }
+ _ = unsafe.Alignof(f0 /* ERROR used as value */ ())
+ assert(unsafe.Alignof(f1()) == 4)
+ _ = unsafe.Alignof(f2()) // ERROR too many arguments
+}
+
+func Offsetof1() {
+ var x struct{ f int }
+ _ = unsafe.Offsetof() // ERROR not enough arguments
+ _ = unsafe.Offsetof(1, 2) // ERROR too many arguments
+ _ = unsafe.Offsetof(int /* ERROR not a selector expression */ )
+ _ = unsafe.Offsetof(x /* ERROR not a selector expression */ )
+ _ = unsafe.Offsetof(nil /* ERROR not a selector expression */ )
+ _ = unsafe.Offsetof(x.f)
+ _ = unsafe.Offsetof((x.f))
+ _ = unsafe.Offsetof((((((((x))).f)))))
+ unsafe /* ERROR not used */ .Offsetof(x.f)
+
+ var y0 S0
+ assert(unsafe.Offsetof(y0.a) == 0)
+ assert(unsafe.Offsetof(y0.b) == 4)
+ assert(unsafe.Offsetof(y0.c) == 8)
+ assert(unsafe.Offsetof(y0.d) == 16)
+ assert(unsafe.Offsetof(y0.e) == 24)
+
+ var y1 S1
+ assert(unsafe.Offsetof(y1.x) == 0)
+ assert(unsafe.Offsetof(y1.y) == 8)
+ assert(unsafe.Offsetof(y1.z) == 24)
+ assert(unsafe.Offsetof(y1.S0) == 32)
+
+ assert(unsafe.Offsetof(y1.S0.a) == 0) // relative to S0
+ assert(unsafe.Offsetof(y1.a) == 32) // relative to S1
+ assert(unsafe.Offsetof(y1.b) == 36) // relative to S1
+ assert(unsafe.Offsetof(y1.c) == 40) // relative to S1
+ assert(unsafe.Offsetof(y1.d) == 48) // relative to S1
+ assert(unsafe.Offsetof(y1.e) == 56) // relative to S1
+
+ var y1p *S1
+ assert(unsafe.Offsetof(y1p.S0) == 32)
+
+ type P *S1
+ var p P = y1p
+ assert(unsafe.Offsetof(p.S0) == 32)
+
+ var y2 S2
+ assert(unsafe.Offsetof(y2.S1) == 0)
+ _ = unsafe.Offsetof(y2 /* ERROR embedded via a pointer */ .x)
+ _ = unsafe.Offsetof(y2 /* ERROR method value */ .m)
+
+ var s []byte
+ _ = unsafe.Offsetof(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func Offsetof2() {
+ f1 := func() (x int32) { return }
+ f2 := func() (x, y int32) { return }
+ _ = unsafe.Offsetof(f0 /* ERROR not a selector expression */ ())
+ _ = unsafe.Offsetof(f1 /* ERROR not a selector expression */ ())
+ _ = unsafe.Offsetof(f2 /* ERROR not a selector expression */ ())
+}
+
+func Sizeof1() {
+ var x int
+ _ = unsafe.Sizeof() // ERROR not enough arguments
+ _ = unsafe.Sizeof(1, 2) // ERROR too many arguments
+ _ = unsafe.Sizeof(int /* ERROR not an expression */)
+ _ = unsafe.Sizeof(42)
+ _ = unsafe.Sizeof(new(complex128))
+ _ = unsafe.Sizeof(1<<10)
+ _ = unsafe.Sizeof(1 /* ERROR overflows */ <<1000)
+ _ = unsafe.Sizeof(nil /* ERROR untyped nil */ )
+ unsafe /* ERROR not used */ .Sizeof(x)
+
+ // basic types have size guarantees
+ assert(unsafe.Sizeof(byte(0)) == 1)
+ assert(unsafe.Sizeof(uint8(0)) == 1)
+ assert(unsafe.Sizeof(int8(0)) == 1)
+ assert(unsafe.Sizeof(uint16(0)) == 2)
+ assert(unsafe.Sizeof(int16(0)) == 2)
+ assert(unsafe.Sizeof(uint32(0)) == 4)
+ assert(unsafe.Sizeof(int32(0)) == 4)
+ assert(unsafe.Sizeof(float32(0)) == 4)
+ assert(unsafe.Sizeof(uint64(0)) == 8)
+ assert(unsafe.Sizeof(int64(0)) == 8)
+ assert(unsafe.Sizeof(float64(0)) == 8)
+ assert(unsafe.Sizeof(complex64(0)) == 8)
+ assert(unsafe.Sizeof(complex128(0)) == 16)
+
+ var y0 S0
+ assert(unsafe.Sizeof(y0.a) == 1)
+ assert(unsafe.Sizeof(y0.b) == 4)
+ assert(unsafe.Sizeof(y0.c) == 8)
+ assert(unsafe.Sizeof(y0.d) == 1)
+ assert(unsafe.Sizeof(y0.e) == 16)
+ assert(unsafe.Sizeof(y0) == 40)
+
+ var y1 S1
+ assert(unsafe.Sizeof(y1) == 72)
+
+ var y2 S2
+ assert(unsafe.Sizeof(y2) == 8)
+
+ var y3 S3
+ assert(unsafe.Sizeof(y3) == 12)
+
+ var y4 S4
+ assert(unsafe.Sizeof(y4) == 16)
+
+ var y5 S5
+ assert(unsafe.Sizeof(y5) == 16)
+
+ var a3 [10]S3
+ assert(unsafe.Sizeof(a3) == 156)
+
+ // test case for issue 5670
+ type T struct {
+ a int32
+ _ int32
+ c int32
+ }
+ assert(unsafe.Sizeof(T{}) == 12)
+
+ var s []byte
+ _ = unsafe.Sizeof(s)
+ _ = unsafe.Sizeof(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func Sizeof2() {
+ f1 := func() (x int64) { return }
+ f2 := func() (x, y int64) { return }
+ _ = unsafe.Sizeof(f0 /* ERROR used as value */ ())
+ assert(unsafe.Sizeof(f1()) == 8)
+ _ = unsafe.Sizeof(f2()) // ERROR too many arguments
+}
+
+// self-testing only
+func assert1() {
+ var x int
+ assert() /* ERROR not enough arguments */
+ assert(1, 2) /* ERROR too many arguments */
+ assert("foo" /* ERROR boolean constant */ )
+ assert(x /* ERROR boolean constant */)
+ assert(true)
+ assert /* ERROR failed */ (false)
+ _ = assert(true)
+
+ var s []byte
+ assert(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func assert2() {
+ f1 := func() (x bool) { return }
+ f2 := func() (x bool) { return }
+ assert(f0 /* ERROR used as value */ ())
+ assert(f1 /* ERROR boolean constant */ ())
+ assert(f2 /* ERROR boolean constant */ ())
+}
+
+// self-testing only
+func trace1() {
+ // Uncomment the code below to test trace - will produce console output
+ // _ = trace /* ERROR no value */ ()
+ // _ = trace(1)
+ // _ = trace(true, 1.2, '\'', "foo", 42i, "foo" <= "bar")
+
+ var s []byte
+ trace(s... /* ERROR invalid use of \.\.\. */ )
+}
+
+func trace2() {
+ f1 := func() (x int) { return }
+ f2 := func() (x int, y string) { return }
+ f3 := func() (x int, y string, z []int) { return }
+ _ = f1
+ _ = f2
+ _ = f3
+ // Uncomment the code below to test trace - will produce console output
+ // trace(f0())
+ // trace(f1())
+ // trace(f2())
+ // trace(f3())
+ // trace(f0(), 1)
+ // trace(f1(), 1, 2)
+ // trace(f2(), 1, 2, 3)
+ // trace(f3(), 1, 2, 3, 4)
+}
diff --git a/src/go/types/testdata/const0.src b/src/go/types/testdata/const0.src
new file mode 100644
index 0000000..adbbf28
--- /dev/null
+++ b/src/go/types/testdata/const0.src
@@ -0,0 +1,350 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// constant declarations
+
+package const0
+
+import "unsafe"
+
+// constants declarations must be initialized by constants
+var x = 0
+const c0 = x /* ERROR "not constant" */
+
+// typed constants must have constant types
+const _ interface /* ERROR invalid constant type */ {} = 0
+
+func _ () {
+ const _ interface /* ERROR invalid constant type */ {} = 0
+ for i := 0; i < 10; i++ {} // don't crash with non-nil iota here
+}
+
+// untyped constants
+const (
+ // boolean values
+ ub0 = false
+ ub1 = true
+ ub2 = 2 < 1
+ ub3 = ui1 == uf1
+ ub4 = true /* ERROR "cannot convert" */ == 0
+
+ // integer values
+ ui0 = 0
+ ui1 = 1
+ ui2 = 42
+ ui3 = 3141592653589793238462643383279502884197169399375105820974944592307816406286
+ ui4 = -10
+
+ ui5 = ui0 + ui1
+ ui6 = ui1 - ui1
+ ui7 = ui2 * ui1
+ ui8 = ui3 / ui3
+ ui9 = ui3 % ui3
+
+ ui10 = 1 / 0 /* ERROR "division by zero" */
+ ui11 = ui1 / 0 /* ERROR "division by zero" */
+ ui12 = ui3 / ui0 /* ERROR "division by zero" */
+ ui13 = 1 % 0 /* ERROR "division by zero" */
+ ui14 = ui1 % 0 /* ERROR "division by zero" */
+ ui15 = ui3 % ui0 /* ERROR "division by zero" */
+
+ ui16 = ui2 & ui3
+ ui17 = ui2 | ui3
+ ui18 = ui2 ^ ui3
+ ui19 = 1 /* ERROR "invalid operation" */ % 1.0
+
+ // floating point values
+ uf0 = 0.
+ uf1 = 1.
+ uf2 = 4.2e1
+ uf3 = 3.141592653589793238462643383279502884197169399375105820974944592307816406286
+ uf4 = 1e-1
+
+ uf5 = uf0 + uf1
+ uf6 = uf1 - uf1
+ uf7 = uf2 * uf1
+ uf8 = uf3 / uf3
+ uf9 = uf3 /* ERROR "not defined" */ % uf3
+
+ uf10 = 1 / 0 /* ERROR "division by zero" */
+ uf11 = uf1 / 0 /* ERROR "division by zero" */
+ uf12 = uf3 / uf0 /* ERROR "division by zero" */
+
+ uf16 = uf2 /* ERROR "not defined" */ & uf3
+ uf17 = uf2 /* ERROR "not defined" */ | uf3
+ uf18 = uf2 /* ERROR "not defined" */ ^ uf3
+
+ // complex values
+ uc0 = 0.i
+ uc1 = 1.i
+ uc2 = 4.2e1i
+ uc3 = 3.141592653589793238462643383279502884197169399375105820974944592307816406286i
+ uc4 = 1e-1i
+
+ uc5 = uc0 + uc1
+ uc6 = uc1 - uc1
+ uc7 = uc2 * uc1
+ uc8 = uc3 / uc3
+ uc9 = uc3 /* ERROR "not defined" */ % uc3
+
+ uc10 = 1 / 0 /* ERROR "division by zero" */
+ uc11 = uc1 / 0 /* ERROR "division by zero" */
+ uc12 = uc3 / uc0 /* ERROR "division by zero" */
+
+ uc16 = uc2 /* ERROR "not defined" */ & uc3
+ uc17 = uc2 /* ERROR "not defined" */ | uc3
+ uc18 = uc2 /* ERROR "not defined" */ ^ uc3
+)
+
+type (
+ mybool bool
+ myint int
+ myfloat float64
+ mycomplex complex128
+)
+
+// typed constants
+const (
+ // boolean values
+ tb0 bool = false
+ tb1 bool = true
+ tb2 mybool = 2 < 1
+ tb3 mybool = ti1 /* ERROR "mismatched types" */ == tf1
+
+ // integer values
+ ti0 int8 = ui0
+ ti1 int32 = ui1
+ ti2 int64 = ui2
+ ti3 myint = ui3 /* ERROR "overflows" */
+ ti4 myint = ui4
+
+ ti5 = ti0 /* ERROR "mismatched types" */ + ti1
+ ti6 = ti1 - ti1
+ ti7 = ti2 /* ERROR "mismatched types" */ * ti1
+ ti8 = ti3 / ti3
+ ti9 = ti3 % ti3
+
+ ti10 = 1 / 0 /* ERROR "division by zero" */
+ ti11 = ti1 / 0 /* ERROR "division by zero" */
+ ti12 = ti3 /* ERROR "mismatched types" */ / ti0
+ ti13 = 1 % 0 /* ERROR "division by zero" */
+ ti14 = ti1 % 0 /* ERROR "division by zero" */
+ ti15 = ti3 /* ERROR "mismatched types" */ % ti0
+
+ ti16 = ti2 /* ERROR "mismatched types" */ & ti3
+ ti17 = ti2 /* ERROR "mismatched types" */ | ti4
+ ti18 = ti2 ^ ti5 // no mismatched types error because the type of ti5 is unknown
+
+ // floating point values
+ tf0 float32 = 0.
+ tf1 float32 = 1.
+ tf2 float64 = 4.2e1
+ tf3 myfloat = 3.141592653589793238462643383279502884197169399375105820974944592307816406286
+ tf4 myfloat = 1e-1
+
+ tf5 = tf0 + tf1
+ tf6 = tf1 - tf1
+ tf7 = tf2 /* ERROR "mismatched types" */ * tf1
+ tf8 = tf3 / tf3
+ tf9 = tf3 /* ERROR "not defined" */ % tf3
+
+ tf10 = 1 / 0 /* ERROR "division by zero" */
+ tf11 = tf1 / 0 /* ERROR "division by zero" */
+ tf12 = tf3 /* ERROR "mismatched types" */ / tf0
+
+ tf16 = tf2 /* ERROR "mismatched types" */ & tf3
+ tf17 = tf2 /* ERROR "mismatched types" */ | tf3
+ tf18 = tf2 /* ERROR "mismatched types" */ ^ tf3
+
+ // complex values
+ tc0 = 0.i
+ tc1 = 1.i
+ tc2 = 4.2e1i
+ tc3 = 3.141592653589793238462643383279502884197169399375105820974944592307816406286i
+ tc4 = 1e-1i
+
+ tc5 = tc0 + tc1
+ tc6 = tc1 - tc1
+ tc7 = tc2 * tc1
+ tc8 = tc3 / tc3
+ tc9 = tc3 /* ERROR "not defined" */ % tc3
+
+ tc10 = 1 / 0 /* ERROR "division by zero" */
+ tc11 = tc1 / 0 /* ERROR "division by zero" */
+ tc12 = tc3 / tc0 /* ERROR "division by zero" */
+
+ tc16 = tc2 /* ERROR "not defined" */ & tc3
+ tc17 = tc2 /* ERROR "not defined" */ | tc3
+ tc18 = tc2 /* ERROR "not defined" */ ^ tc3
+)
+
+// initialization cycles
+const (
+ a /* ERROR "initialization cycle" */ = a
+ b /* ERROR "initialization cycle" */ , c /* ERROR "initialization cycle" */, d, e = e, d, c, b // TODO(gri) should only have one cycle error
+ f float64 = d
+)
+
+// multiple initialization
+const (
+ a1, a2, a3 = 7, 3.1415926, "foo"
+ b1, b2, b3 = b3, b1, 42
+ c1, c2, c3 /* ERROR "missing init expr for c3" */ = 1, 2
+ d1, d2, d3 = 1, 2, 3, 4 /* ERROR "extra init expr 4" */
+ _p0 = assert(a1 == 7)
+ _p1 = assert(a2 == 3.1415926)
+ _p2 = assert(a3 == "foo")
+ _p3 = assert(b1 == 42)
+ _p4 = assert(b2 == 42)
+ _p5 = assert(b3 == 42)
+)
+
+func _() {
+ const (
+ a1, a2, a3 = 7, 3.1415926, "foo"
+ b1, b2, b3 = b3, b1, 42
+ c1, c2, c3 /* ERROR "missing init expr for c3" */ = 1, 2
+ d1, d2, d3 = 1, 2, 3, 4 /* ERROR "extra init expr 4" */
+ _p0 = assert(a1 == 7)
+ _p1 = assert(a2 == 3.1415926)
+ _p2 = assert(a3 == "foo")
+ _p3 = assert(b1 == 42)
+ _p4 = assert(b2 == 42)
+ _p5 = assert(b3 == 42)
+ )
+}
+
+// iota
+const (
+ iota0 = iota
+ iota1 = iota
+ iota2 = iota*2
+ _a0 = assert(iota0 == 0)
+ _a1 = assert(iota1 == 1)
+ _a2 = assert(iota2 == 4)
+ iota6 = iota*3
+
+ iota7
+ iota8
+ _a3 = assert(iota7 == 21)
+ _a4 = assert(iota8 == 24)
+)
+
+const (
+ _b0 = iota
+ _b1 = assert(iota + iota2 == 5)
+ _b2 = len([iota]int{}) // iota may appear in a type!
+ _b3 = assert(_b2 == 2)
+ _b4 = len(A{})
+)
+
+type A [iota /* ERROR "cannot use iota" */ ]int
+
+// constant expressions with operands across different
+// constant declarations must use the right iota values
+const (
+ _c0 = iota
+ _c1
+ _c2
+ _x = _c2 + _d1 + _e0 // 3
+)
+
+const (
+ _d0 = iota
+ _d1
+)
+
+const (
+ _e0 = iota
+)
+
+var _ = assert(_x == 3)
+
+// special cases
+const (
+ _n0 = nil /* ERROR "not constant" */
+ _n1 = [ /* ERROR "not constant" */ ]int{}
+)
+
+// iotas must not be usable in expressions outside constant declarations
+type _ [iota /* ERROR "iota outside constant decl" */ ]byte
+var _ = iota /* ERROR "iota outside constant decl" */
+func _() {
+ _ = iota /* ERROR "iota outside constant decl" */
+ const _ = iota
+ _ = iota /* ERROR "iota outside constant decl" */
+}
+
+func _() {
+ iota := 123
+ const x = iota /* ERROR "is not constant" */
+ var y = iota
+ _ = y
+}
+
+// iotas are usable inside closures in constant declarations (#22345)
+const (
+ _ = iota
+ _ = len([iota]byte{})
+ _ = unsafe.Sizeof(iota)
+ _ = unsafe.Sizeof(func() { _ = iota })
+ _ = unsafe.Sizeof(func() { var _ = iota })
+ _ = unsafe.Sizeof(func() { const _ = iota })
+ _ = unsafe.Sizeof(func() { type _ [iota]byte })
+ _ = unsafe.Sizeof(func() { func() int { return iota }() })
+)
+
+// verify inner and outer const declarations have distinct iotas
+const (
+ zero = iota
+ one = iota
+ _ = unsafe.Sizeof(func() {
+ var x [iota]int // [2]int
+ const (
+ Zero = iota
+ One
+ Two
+ _ = unsafe.Sizeof([iota-1]int{} == x) // assert types are equal
+ _ = unsafe.Sizeof([Two]int{} == x) // assert types are equal
+ )
+ var z [iota]int // [2]int
+ _ = unsafe.Sizeof([2]int{} == z) // assert types are equal
+ })
+ three = iota // the sequence continues
+)
+var _ [three]int = [3]int{} // assert 'three' has correct value
+
+var (
+ _ = iota /* ERROR "iota outside constant decl" */
+ _ = unsafe.Sizeof(iota /* ERROR "iota outside constant decl" */ )
+ _ = unsafe.Sizeof(func() { _ = iota /* ERROR "iota outside constant decl" */ })
+ _ = unsafe.Sizeof(func() { var _ = iota /* ERROR "iota outside constant decl" */ })
+ _ = unsafe.Sizeof(func() { type _ [iota /* ERROR "iota outside constant decl" */ ]byte })
+ _ = unsafe.Sizeof(func() { func() int { return iota /* ERROR "iota outside constant decl" */ }() })
+)
+
+// constant arithmetic precision and rounding must lead to expected (integer) results
+var _ = []int64{
+ 0.0005 * 1e9,
+ 0.001 * 1e9,
+ 0.005 * 1e9,
+ 0.01 * 1e9,
+ 0.05 * 1e9,
+ 0.1 * 1e9,
+ 0.5 * 1e9,
+ 1 * 1e9,
+ 5 * 1e9,
+}
+
+const _ = unsafe.Sizeof(func() {
+ const _ = 0
+ _ = iota
+
+ const (
+ zero = iota
+ one
+ )
+ assert(one == 1)
+ assert(iota == 0)
+})
diff --git a/src/go/types/testdata/const1.src b/src/go/types/testdata/const1.src
new file mode 100644
index 0000000..d827704
--- /dev/null
+++ b/src/go/types/testdata/const1.src
@@ -0,0 +1,322 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// constant conversions
+
+package const1
+
+const(
+ mi = ^int(0)
+ mu = ^uint(0)
+ mp = ^uintptr(0)
+
+ logSizeofInt = uint(mi>>8&1 + mi>>16&1 + mi>>32&1)
+ logSizeofUint = uint(mu>>8&1 + mu>>16&1 + mu>>32&1)
+ logSizeofUintptr = uint(mp>>8&1 + mp>>16&1 + mp>>32&1)
+)
+
+const (
+ minInt8 = -1<<(8<<iota - 1)
+ minInt16
+ minInt32
+ minInt64
+ minInt = -1<<(8<<logSizeofInt - 1)
+)
+
+const (
+ maxInt8 = 1<<(8<<iota - 1) - 1
+ maxInt16
+ maxInt32
+ maxInt64
+ maxInt = 1<<(8<<logSizeofInt - 1) - 1
+)
+
+const (
+ maxUint8 = 1<<(8<<iota) - 1
+ maxUint16
+ maxUint32
+ maxUint64
+ maxUint = 1<<(8<<logSizeofUint) - 1
+ maxUintptr = 1<<(8<<logSizeofUintptr) - 1
+)
+
+const (
+ smallestFloat32 = 1.0 / (1<<(127 - 1 + 23))
+ smallestFloat64 = 1.0 / (1<<(1023 - 1 + 52))
+)
+
+const (
+ _ = assert(smallestFloat32 > 0)
+ _ = assert(smallestFloat64 > 0)
+)
+
+const (
+ maxFloat32 = 1<<127 * (1<<24 - 1) / (1.0<<23)
+ maxFloat64 = 1<<1023 * (1<<53 - 1) / (1.0<<52)
+)
+
+const (
+ _ int8 = minInt8 /* ERROR "overflows" */ - 1
+ _ int8 = minInt8
+ _ int8 = maxInt8
+ _ int8 = maxInt8 /* ERROR "overflows" */ + 1
+ _ int8 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = int8(minInt8 /* ERROR "cannot convert" */ - 1)
+ _ = int8(minInt8)
+ _ = int8(maxInt8)
+ _ = int8(maxInt8 /* ERROR "cannot convert" */ + 1)
+ _ = int8(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ int16 = minInt16 /* ERROR "overflows" */ - 1
+ _ int16 = minInt16
+ _ int16 = maxInt16
+ _ int16 = maxInt16 /* ERROR "overflows" */ + 1
+ _ int16 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = int16(minInt16 /* ERROR "cannot convert" */ - 1)
+ _ = int16(minInt16)
+ _ = int16(maxInt16)
+ _ = int16(maxInt16 /* ERROR "cannot convert" */ + 1)
+ _ = int16(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ int32 = minInt32 /* ERROR "overflows" */ - 1
+ _ int32 = minInt32
+ _ int32 = maxInt32
+ _ int32 = maxInt32 /* ERROR "overflows" */ + 1
+ _ int32 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = int32(minInt32 /* ERROR "cannot convert" */ - 1)
+ _ = int32(minInt32)
+ _ = int32(maxInt32)
+ _ = int32(maxInt32 /* ERROR "cannot convert" */ + 1)
+ _ = int32(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ int64 = minInt64 /* ERROR "overflows" */ - 1
+ _ int64 = minInt64
+ _ int64 = maxInt64
+ _ int64 = maxInt64 /* ERROR "overflows" */ + 1
+ _ int64 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = int64(minInt64 /* ERROR "cannot convert" */ - 1)
+ _ = int64(minInt64)
+ _ = int64(maxInt64)
+ _ = int64(maxInt64 /* ERROR "cannot convert" */ + 1)
+ _ = int64(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ int = minInt /* ERROR "overflows" */ - 1
+ _ int = minInt
+ _ int = maxInt
+ _ int = maxInt /* ERROR "overflows" */ + 1
+ _ int = smallestFloat64 /* ERROR "truncated" */
+
+ _ = int(minInt /* ERROR "cannot convert" */ - 1)
+ _ = int(minInt)
+ _ = int(maxInt)
+ _ = int(maxInt /* ERROR "cannot convert" */ + 1)
+ _ = int(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uint8 = 0 /* ERROR "overflows" */ - 1
+ _ uint8 = 0
+ _ uint8 = maxUint8
+ _ uint8 = maxUint8 /* ERROR "overflows" */ + 1
+ _ uint8 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uint8(0 /* ERROR "cannot convert" */ - 1)
+ _ = uint8(0)
+ _ = uint8(maxUint8)
+ _ = uint8(maxUint8 /* ERROR "cannot convert" */ + 1)
+ _ = uint8(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uint16 = 0 /* ERROR "overflows" */ - 1
+ _ uint16 = 0
+ _ uint16 = maxUint16
+ _ uint16 = maxUint16 /* ERROR "overflows" */ + 1
+ _ uint16 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uint16(0 /* ERROR "cannot convert" */ - 1)
+ _ = uint16(0)
+ _ = uint16(maxUint16)
+ _ = uint16(maxUint16 /* ERROR "cannot convert" */ + 1)
+ _ = uint16(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uint32 = 0 /* ERROR "overflows" */ - 1
+ _ uint32 = 0
+ _ uint32 = maxUint32
+ _ uint32 = maxUint32 /* ERROR "overflows" */ + 1
+ _ uint32 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uint32(0 /* ERROR "cannot convert" */ - 1)
+ _ = uint32(0)
+ _ = uint32(maxUint32)
+ _ = uint32(maxUint32 /* ERROR "cannot convert" */ + 1)
+ _ = uint32(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uint64 = 0 /* ERROR "overflows" */ - 1
+ _ uint64 = 0
+ _ uint64 = maxUint64
+ _ uint64 = maxUint64 /* ERROR "overflows" */ + 1
+ _ uint64 = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uint64(0 /* ERROR "cannot convert" */ - 1)
+ _ = uint64(0)
+ _ = uint64(maxUint64)
+ _ = uint64(maxUint64 /* ERROR "cannot convert" */ + 1)
+ _ = uint64(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uint = 0 /* ERROR "overflows" */ - 1
+ _ uint = 0
+ _ uint = maxUint
+ _ uint = maxUint /* ERROR "overflows" */ + 1
+ _ uint = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uint(0 /* ERROR "cannot convert" */ - 1)
+ _ = uint(0)
+ _ = uint(maxUint)
+ _ = uint(maxUint /* ERROR "cannot convert" */ + 1)
+ _ = uint(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ uintptr = 0 /* ERROR "overflows" */ - 1
+ _ uintptr = 0
+ _ uintptr = maxUintptr
+ _ uintptr = maxUintptr /* ERROR "overflows" */ + 1
+ _ uintptr = smallestFloat64 /* ERROR "truncated" */
+
+ _ = uintptr(0 /* ERROR "cannot convert" */ - 1)
+ _ = uintptr(0)
+ _ = uintptr(maxUintptr)
+ _ = uintptr(maxUintptr /* ERROR "cannot convert" */ + 1)
+ _ = uintptr(smallestFloat64 /* ERROR "cannot convert" */)
+)
+
+const (
+ _ float32 = minInt64
+ _ float64 = minInt64
+ _ complex64 = minInt64
+ _ complex128 = minInt64
+
+ _ = float32(minInt64)
+ _ = float64(minInt64)
+ _ = complex64(minInt64)
+ _ = complex128(minInt64)
+)
+
+const (
+ _ float32 = maxUint64
+ _ float64 = maxUint64
+ _ complex64 = maxUint64
+ _ complex128 = maxUint64
+
+ _ = float32(maxUint64)
+ _ = float64(maxUint64)
+ _ = complex64(maxUint64)
+ _ = complex128(maxUint64)
+)
+
+// TODO(gri) find smaller deltas below
+
+const delta32 = maxFloat32/(1 << 23)
+
+const (
+ _ float32 = - /* ERROR "overflow" */ (maxFloat32 + delta32)
+ _ float32 = -maxFloat32
+ _ float32 = maxFloat32
+ _ float32 = maxFloat32 /* ERROR "overflow" */ + delta32
+
+ _ = float32(- /* ERROR "cannot convert" */ (maxFloat32 + delta32))
+ _ = float32(-maxFloat32)
+ _ = float32(maxFloat32)
+ _ = float32(maxFloat32 /* ERROR "cannot convert" */ + delta32)
+
+ _ = assert(float32(smallestFloat32) == smallestFloat32)
+ _ = assert(float32(smallestFloat32/2) == 0)
+ _ = assert(float32(smallestFloat64) == 0)
+ _ = assert(float32(smallestFloat64/2) == 0)
+)
+
+const delta64 = maxFloat64/(1 << 52)
+
+const (
+ _ float64 = - /* ERROR "overflow" */ (maxFloat64 + delta64)
+ _ float64 = -maxFloat64
+ _ float64 = maxFloat64
+ _ float64 = maxFloat64 /* ERROR "overflow" */ + delta64
+
+ _ = float64(- /* ERROR "cannot convert" */ (maxFloat64 + delta64))
+ _ = float64(-maxFloat64)
+ _ = float64(maxFloat64)
+ _ = float64(maxFloat64 /* ERROR "cannot convert" */ + delta64)
+
+ _ = assert(float64(smallestFloat32) == smallestFloat32)
+ _ = assert(float64(smallestFloat32/2) == smallestFloat32/2)
+ _ = assert(float64(smallestFloat64) == smallestFloat64)
+ _ = assert(float64(smallestFloat64/2) == 0)
+)
+
+const (
+ _ complex64 = - /* ERROR "overflow" */ (maxFloat32 + delta32)
+ _ complex64 = -maxFloat32
+ _ complex64 = maxFloat32
+ _ complex64 = maxFloat32 /* ERROR "overflow" */ + delta32
+
+ _ = complex64(- /* ERROR "cannot convert" */ (maxFloat32 + delta32))
+ _ = complex64(-maxFloat32)
+ _ = complex64(maxFloat32)
+ _ = complex64(maxFloat32 /* ERROR "cannot convert" */ + delta32)
+)
+
+const (
+ _ complex128 = - /* ERROR "overflow" */ (maxFloat64 + delta64)
+ _ complex128 = -maxFloat64
+ _ complex128 = maxFloat64
+ _ complex128 = maxFloat64 /* ERROR "overflow" */ + delta64
+
+ _ = complex128(- /* ERROR "cannot convert" */ (maxFloat64 + delta64))
+ _ = complex128(-maxFloat64)
+ _ = complex128(maxFloat64)
+ _ = complex128(maxFloat64 /* ERROR "cannot convert" */ + delta64)
+)
+
+// Initialization of typed constant and conversion are the same:
+const (
+ f32 = 1 + smallestFloat32
+ x32 float32 = f32
+ y32 = float32(f32)
+ _ = assert(x32 - y32 == 0)
+)
+
+const (
+ f64 = 1 + smallestFloat64
+ x64 float64 = f64
+ y64 = float64(f64)
+ _ = assert(x64 - y64 == 0)
+)
+
+const (
+ _ = int8(-1) << 7
+ _ = int8 /* ERROR "overflows" */ (-1) << 8
+
+ _ = uint32(1) << 31
+ _ = uint32 /* ERROR "overflows" */ (1) << 32
+)
diff --git a/src/go/types/testdata/constdecl.src b/src/go/types/testdata/constdecl.src
new file mode 100644
index 0000000..680c85a
--- /dev/null
+++ b/src/go/types/testdata/constdecl.src
@@ -0,0 +1,141 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package constdecl
+
+import "math"
+import "unsafe"
+
+var v int
+
+// Const decls must be initialized by constants.
+const _ = v /* ERROR "not constant" */
+const _ = math /* ERROR "not constant" */ .Sin(0)
+const _ = int /* ERROR "not an expression" */
+
+func _() {
+ const _ = v /* ERROR "not constant" */
+ const _ = math /* ERROR "not constant" */ .Sin(0)
+ const _ = int /* ERROR "not an expression" */
+}
+
+// Identifier and expression arity must match.
+// The first error message is produced by the parser.
+// In a real-world scenario, the type-checker would not be run
+// in this case and the 2nd error message would not appear.
+const _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */
+const _ = 1, 2 /* ERROR "extra init expr 2" */
+
+const _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */ int
+const _ int = 1, 2 /* ERROR "extra init expr 2" */
+
+const (
+ _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */
+ _ = 1, 2 /* ERROR "extra init expr 2" */
+
+ _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */ int
+ _ int = 1, 2 /* ERROR "extra init expr 2" */
+)
+
+const (
+ _ = 1
+ _
+ _, _ /* ERROR "missing init expr for _" */
+ _
+)
+
+const (
+ _, _ = 1, 2
+ _, _
+ _ /* ERROR "extra init expr at" */
+ _, _
+ _, _, _ /* ERROR "missing init expr for _" */
+ _, _
+)
+
+func _() {
+ const _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */
+ const _ = 1, 2 /* ERROR "extra init expr 2" */
+
+ const _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */ int
+ const _ int = 1, 2 /* ERROR "extra init expr 2" */
+
+ const (
+ _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */
+ _ = 1, 2 /* ERROR "extra init expr 2" */
+
+ _ /* ERROR "missing constant value" */ /* ERROR "missing init expr for _" */ int
+ _ int = 1, 2 /* ERROR "extra init expr 2" */
+ )
+
+ const (
+ _ = 1
+ _
+ _, _ /* ERROR "missing init expr for _" */
+ _
+ )
+
+ const (
+ _, _ = 1, 2
+ _, _
+ _ /* ERROR "extra init expr at" */
+ _, _
+ _, _, _ /* ERROR "missing init expr for _" */
+ _, _
+ )
+}
+
+// Test case for constant with invalid initialization.
+// Caused panic because the constant value was not set up (gri - 7/8/2014).
+func _() {
+ const (
+ x string = missing /* ERROR "undeclared name" */
+ y = x + ""
+ )
+}
+
+// Test case for constants depending on function literals (see also #22992).
+const A /* ERROR initialization cycle */ = unsafe.Sizeof(func() { _ = A })
+
+func _() {
+ // The function literal below must not see a.
+ const a = unsafe.Sizeof(func() { _ = a /* ERROR "undeclared name" */ })
+ const b = unsafe.Sizeof(func() { _ = a })
+
+ // The function literal below must not see x, y, or z.
+ const x, y, z = 0, 1, unsafe.Sizeof(func() { _ = x /* ERROR "undeclared name" */ + y /* ERROR "undeclared name" */ + z /* ERROR "undeclared name" */ })
+}
+
+// Test cases for errors in inherited constant initialization expressions.
+// Errors related to inherited initialization expressions must appear at
+// the constant identifier being declared, not at the original expression
+// (issues #42991, #42992).
+const (
+ _ byte = 255 + iota
+ /* some gap */
+ _ // ERROR overflows
+ /* some gap */
+ /* some gap */ _ /* ERROR overflows */; _ /* ERROR overflows */
+ /* some gap */
+ _ = 255 + iota
+ _ = byte /* ERROR overflows */ (255) + iota
+ _ /* ERROR overflows */
+)
+
+// Test cases from issue.
+const (
+ ok = byte(iota + 253)
+ bad
+ barn
+ bard // ERROR cannot convert
+)
+
+const (
+ c = len([1 - iota]int{})
+ d
+ e // ERROR invalid array length
+ f // ERROR invalid array length
+)
+
+// TODO(gri) move extra tests from testdata/const0.src into here
diff --git a/src/go/types/testdata/conversions.src b/src/go/types/testdata/conversions.src
new file mode 100644
index 0000000..e1336c0
--- /dev/null
+++ b/src/go/types/testdata/conversions.src
@@ -0,0 +1,93 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// conversions
+
+package conversions
+
+import "unsafe"
+
+// argument count
+var (
+ _ = int() /* ERROR "missing argument" */
+ _ = int(1, 2 /* ERROR "too many arguments" */ )
+)
+
+// numeric constant conversions are in const1.src.
+
+func string_conversions() {
+ const A = string(65)
+ assert(A == "A")
+ const E = string(-1)
+ assert(E == "\uFFFD")
+ assert(E == string(1234567890))
+
+ type myint int
+ assert(A == string(myint(65)))
+
+ type mystring string
+ const _ mystring = mystring("foo")
+
+ const _ = string(true /* ERROR "cannot convert" */ )
+ const _ = string(1.2 /* ERROR "cannot convert" */ )
+ const _ = string(nil /* ERROR "cannot convert" */ )
+
+ // issues 11357, 11353: argument must be of integer type
+ _ = string(0.0 /* ERROR "cannot convert" */ )
+ _ = string(0i /* ERROR "cannot convert" */ )
+ _ = string(1 /* ERROR "cannot convert" */ + 2i)
+}
+
+func interface_conversions() {
+ type E interface{}
+
+ type I1 interface{
+ m1()
+ }
+
+ type I2 interface{
+ m1()
+ m2(x int)
+ }
+
+ type I3 interface{
+ m1()
+ m2() int
+ }
+
+ var e E
+ var i1 I1
+ var i2 I2
+ var i3 I3
+
+ _ = E(0)
+ _ = E(nil)
+ _ = E(e)
+ _ = E(i1)
+ _ = E(i2)
+
+ _ = I1(0 /* ERROR "cannot convert" */ )
+ _ = I1(nil)
+ _ = I1(i1)
+ _ = I1(e /* ERROR "cannot convert" */ )
+ _ = I1(i2)
+
+ _ = I2(nil)
+ _ = I2(i1 /* ERROR "cannot convert" */ )
+ _ = I2(i2)
+ _ = I2(i3 /* ERROR "cannot convert" */ )
+
+ _ = I3(nil)
+ _ = I3(i1 /* ERROR "cannot convert" */ )
+ _ = I3(i2 /* ERROR "cannot convert" */ )
+ _ = I3(i3)
+
+ // TODO(gri) add more tests, improve error message
+}
+
+func issue6326() {
+ type T unsafe.Pointer
+ var x T
+ _ = uintptr(x) // see issue 6326
+}
diff --git a/src/go/types/testdata/conversions2.src b/src/go/types/testdata/conversions2.src
new file mode 100644
index 0000000..93a5f18
--- /dev/null
+++ b/src/go/types/testdata/conversions2.src
@@ -0,0 +1,313 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test various valid and invalid struct assignments and conversions.
+// Does not compile.
+
+package conversions2
+
+type I interface {
+ m()
+}
+
+// conversions between structs
+
+func _() {
+ type S struct{}
+ type T struct{}
+ var s S
+ var t T
+ var u struct{}
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u
+ s = S(s)
+ s = S(t)
+ s = S(u)
+ t = u
+ t = T(u)
+}
+
+func _() {
+ type S struct{ x int }
+ type T struct {
+ x int "foo"
+ }
+ var s S
+ var t T
+ var u struct {
+ x int "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = S(s)
+ s = S(t)
+ s = S(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = T(u)
+}
+
+func _() {
+ type E struct{ x int }
+ type S struct{ x E }
+ type T struct {
+ x E "foo"
+ }
+ var s S
+ var t T
+ var u struct {
+ x E "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = S(s)
+ s = S(t)
+ s = S(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = T(u)
+}
+
+func _() {
+ type S struct {
+ x struct {
+ x int "foo"
+ }
+ }
+ type T struct {
+ x struct {
+ x int "bar"
+ } "foo"
+ }
+ var s S
+ var t T
+ var u struct {
+ x struct {
+ x int "bar"
+ } "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = S(s)
+ s = S(t)
+ s = S(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = T(u)
+}
+
+func _() {
+ type E1 struct {
+ x int "foo"
+ }
+ type E2 struct {
+ x int "bar"
+ }
+ type S struct{ x E1 }
+ type T struct {
+ x E2 "foo"
+ }
+ var s S
+ var t T
+ var u struct {
+ x E2 "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = S(s)
+ s = S(t /* ERROR "cannot convert" */ )
+ s = S(u /* ERROR "cannot convert" */ )
+ t = u // ERROR "cannot use .* in assignment"
+ t = T(u)
+}
+
+func _() {
+ type E struct{ x int }
+ type S struct {
+ f func(struct {
+ x int "foo"
+ })
+ }
+ type T struct {
+ f func(struct {
+ x int "bar"
+ })
+ }
+ var s S
+ var t T
+ var u struct{ f func(E) }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = S(s)
+ s = S(t)
+ s = S(u /* ERROR "cannot convert" */ )
+ t = u // ERROR "cannot use .* in assignment"
+ t = T(u /* ERROR "cannot convert" */ )
+}
+
+// conversions between pointers to structs
+
+func _() {
+ type S struct{}
+ type T struct{}
+ var s *S
+ var t *T
+ var u *struct{}
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u)
+}
+
+func _() {
+ type S struct{ x int }
+ type T struct {
+ x int "foo"
+ }
+ var s *S
+ var t *T
+ var u *struct {
+ x int "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u)
+}
+
+func _() {
+ type E struct{ x int }
+ type S struct{ x E }
+ type T struct {
+ x E "foo"
+ }
+ var s *S
+ var t *T
+ var u *struct {
+ x E "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u)
+}
+
+func _() {
+ type S struct {
+ x struct {
+ x int "foo"
+ }
+ }
+ type T struct {
+ x struct {
+ x int "bar"
+ } "foo"
+ }
+ var s *S
+ var t *T
+ var u *struct {
+ x struct {
+ x int "bar"
+ } "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u)
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u)
+}
+
+func _() {
+ type E1 struct {
+ x int "foo"
+ }
+ type E2 struct {
+ x int "bar"
+ }
+ type S struct{ x E1 }
+ type T struct {
+ x E2 "foo"
+ }
+ var s *S
+ var t *T
+ var u *struct {
+ x E2 "bar"
+ }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t /* ERROR "cannot convert" */ )
+ s = (*S)(u /* ERROR "cannot convert" */ )
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u)
+}
+
+func _() {
+ type E struct{ x int }
+ type S struct {
+ f func(struct {
+ x int "foo"
+ })
+ }
+ type T struct {
+ f func(struct {
+ x int "bar"
+ })
+ }
+ var s *S
+ var t *T
+ var u *struct{ f func(E) }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u /* ERROR "cannot convert" */ )
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u /* ERROR "cannot convert" */ )
+}
+
+func _() {
+ type E struct{ x int }
+ type S struct {
+ f func(*struct {
+ x int "foo"
+ })
+ }
+ type T struct {
+ f func(*struct {
+ x int "bar"
+ })
+ }
+ var s *S
+ var t *T
+ var u *struct{ f func(E) }
+ s = s
+ s = t // ERROR "cannot use .* in assignment"
+ s = u // ERROR "cannot use .* in assignment"
+ s = (*S)(s)
+ s = (*S)(t)
+ s = (*S)(u /* ERROR "cannot convert" */ )
+ t = u // ERROR "cannot use .* in assignment"
+ t = (*T)(u /* ERROR "cannot convert" */ )
+}
diff --git a/src/go/types/testdata/cycles.src b/src/go/types/testdata/cycles.src
new file mode 100644
index 0000000..218b4ca
--- /dev/null
+++ b/src/go/types/testdata/cycles.src
@@ -0,0 +1,174 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cycles
+
+import "unsafe"
+
+type (
+ T0 int
+ T1 /* ERROR cycle */ T1
+ T2 *T2
+
+ T3 /* ERROR cycle */ T4
+ T4 T5
+ T5 T3
+
+ T6 T7
+ T7 *T8
+ T8 T6
+
+ // arrays
+ A0 /* ERROR cycle */ [10]A0
+ A1 [10]*A1
+
+ A2 /* ERROR cycle */ [10]A3
+ A3 [10]A4
+ A4 A2
+
+ A5 [10]A6
+ A6 *A5
+
+ // slices
+ L0 []L0
+
+ // structs
+ S0 /* ERROR cycle */ struct{ _ S0 }
+ S1 /* ERROR cycle */ struct{ S1 }
+ S2 struct{ _ *S2 }
+ S3 struct{ *S3 }
+
+ S4 /* ERROR cycle */ struct{ S5 }
+ S5 struct{ S6 }
+ S6 S4
+
+ // pointers
+ P0 *P0
+
+ // functions
+ F0 func(F0)
+ F1 func() F1
+ F2 func(F2) F2
+
+ // interfaces
+ I0 /* ERROR cycle */ interface{ I0 }
+
+ I1 /* ERROR cycle */ interface{ I2 }
+ I2 interface{ I3 }
+ I3 interface{ I1 }
+
+ I4 interface{ f(I4) }
+
+ // testcase for issue 5090
+ I5 interface{ f(I6) }
+ I6 interface{ I5 }
+
+ // maps
+ M0 map[M0 /* ERROR incomparable map key */ ]M0
+
+ // channels
+ C0 chan C0
+)
+
+// test case for issue #34771
+type (
+ AA /* ERROR cycle */ B
+ B C
+ C [10]D
+ D E
+ E AA
+)
+
+func _() {
+ type (
+ t1 /* ERROR cycle */ t1
+ t2 *t2
+
+ t3 t4 /* ERROR undeclared */
+ t4 t5 /* ERROR undeclared */
+ t5 t3
+
+ // arrays
+ a0 /* ERROR cycle */ [10]a0
+ a1 [10]*a1
+
+ // slices
+ l0 []l0
+
+ // structs
+ s0 /* ERROR cycle */ struct{ _ s0 }
+ s1 /* ERROR cycle */ struct{ s1 }
+ s2 struct{ _ *s2 }
+ s3 struct{ *s3 }
+
+ // pointers
+ p0 *p0
+
+ // functions
+ f0 func(f0)
+ f1 func() f1
+ f2 func(f2) f2
+
+ // interfaces
+ i0 /* ERROR cycle */ interface{ i0 }
+
+ // maps
+ m0 map[m0 /* ERROR incomparable map key */ ]m0
+
+ // channels
+ c0 chan c0
+ )
+}
+
+// test cases for issue 6667
+
+type A [10]map[A /* ERROR incomparable map key */ ]bool
+
+type S struct {
+ m map[S /* ERROR incomparable map key */ ]bool
+}
+
+// test cases for issue 7236
+// (cycle detection must not be dependent on starting point of resolution)
+
+type (
+ P1 *T9
+ T9 /* ERROR cycle */ T9
+
+ T10 /* ERROR cycle */ T10
+ P2 *T10
+)
+
+func (T11) m() {}
+
+type T11 /* ERROR cycle */ struct{ T11 }
+
+type T12 /* ERROR cycle */ struct{ T12 }
+
+func (*T12) m() {}
+
+type (
+ P3 *T13
+ T13 /* ERROR cycle */ T13
+)
+
+// test cases for issue 18643
+// (type cycle detection when non-type expressions are involved)
+type (
+ T14 [len(T14 /* ERROR cycle */ {})]int
+ T15 [][len(T15 /* ERROR cycle */ {})]int
+ T16 map[[len(T16 /* ERROR cycle */ {1:2})]int]int
+ T17 map[int][len(T17 /* ERROR cycle */ {1:2})]int
+)
+
+// Test case for types depending on function literals (see also #22992).
+type T20 chan [unsafe.Sizeof(func(ch T20){ _ = <-ch })]byte
+type T22 = chan [unsafe.Sizeof(func(ch T20){ _ = <-ch })]byte
+
+func _() {
+ type T0 func(T0)
+ type T1 /* ERROR cycle */ = func(T1)
+ type T2 chan [unsafe.Sizeof(func(ch T2){ _ = <-ch })]byte
+ type T3 /* ERROR cycle */ = chan [unsafe.Sizeof(func(ch T3){ _ = <-ch })]byte
+}
diff --git a/src/go/types/testdata/cycles1.src b/src/go/types/testdata/cycles1.src
new file mode 100644
index 0000000..ae2b38e
--- /dev/null
+++ b/src/go/types/testdata/cycles1.src
@@ -0,0 +1,77 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type (
+ A interface {
+ a() interface {
+ ABC1
+ }
+ }
+ B interface {
+ b() interface {
+ ABC2
+ }
+ }
+ C interface {
+ c() interface {
+ ABC3
+ }
+ }
+
+ AB interface {
+ A
+ B
+ }
+ BC interface {
+ B
+ C
+ }
+
+ ABC1 interface {
+ A
+ B
+ C
+ }
+ ABC2 interface {
+ AB
+ C
+ }
+ ABC3 interface {
+ A
+ BC
+ }
+)
+
+var (
+ x1 ABC1
+ x2 ABC2
+ x3 ABC3
+)
+
+func _() {
+ // all types have the same method set
+ x1 = x2
+ x2 = x1
+
+ x1 = x3
+ x3 = x1
+
+ x2 = x3
+ x3 = x2
+
+ // all methods return the same type again
+ x1 = x1.a()
+ x1 = x1.b()
+ x1 = x1.c()
+
+ x2 = x2.a()
+ x2 = x2.b()
+ x2 = x2.c()
+
+ x3 = x3.a()
+ x3 = x3.b()
+ x3 = x3.c()
+}
diff --git a/src/go/types/testdata/cycles2.src b/src/go/types/testdata/cycles2.src
new file mode 100644
index 0000000..1a7f40a
--- /dev/null
+++ b/src/go/types/testdata/cycles2.src
@@ -0,0 +1,98 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "unsafe"
+
+// Test case for issue 5090
+
+type t interface {
+ f(u)
+}
+
+type u interface {
+ t
+}
+
+func _() {
+ var t t
+ var u u
+
+ t.f(t)
+ t.f(u)
+
+ u.f(t)
+ u.f(u)
+}
+
+
+// Test case for issues #6589, #33656.
+
+type A interface {
+ a() interface {
+ AB
+ }
+}
+
+type B interface {
+ b() interface {
+ AB
+ }
+}
+
+type AB interface {
+ a() interface {
+ A
+ B
+ }
+ b() interface {
+ A
+ B
+ }
+}
+
+var x AB
+var y interface {
+ A
+ B
+}
+
+var _ = x == y
+
+
+// Test case for issue 6638.
+
+type T interface {
+ m() [T(nil).m /* ERROR undefined */ ()[0]]int
+}
+
+// Variations of this test case.
+
+type T1 /* ERROR cycle */ interface {
+ m() [x1.m()[0]]int
+}
+
+var x1 T1
+
+type T2 /* ERROR cycle */ interface {
+ m() [len(x2.m())]int
+}
+
+var x2 T2
+
+type T3 /* ERROR cycle */ interface {
+ m() [unsafe.Sizeof(x3.m)]int
+}
+
+var x3 T3
+
+type T4 /* ERROR cycle */ interface {
+ m() [unsafe.Sizeof(cast4(x4.m))]int // cast is invalid but we have a cycle, so all bets are off
+}
+
+var x4 T4
+var _ = cast4(x4.m)
+
+type cast4 func()
diff --git a/src/go/types/testdata/cycles3.src b/src/go/types/testdata/cycles3.src
new file mode 100644
index 0000000..5e89b62
--- /dev/null
+++ b/src/go/types/testdata/cycles3.src
@@ -0,0 +1,60 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "unsafe"
+
+var (
+ _ A = A(nil).a().b().c().d().e().f()
+ _ A = A(nil).b().c().d().e().f()
+ _ A = A(nil).c().d().e().f()
+ _ A = A(nil).d().e().f()
+ _ A = A(nil).e().f()
+ _ A = A(nil).f()
+ _ A = A(nil)
+)
+
+type (
+ A interface {
+ a() B
+ B
+ }
+
+ B interface {
+ b() C
+ C
+ }
+
+ C interface {
+ c() D
+ D
+ }
+
+ D interface {
+ d() E
+ E
+ }
+
+ E interface {
+ e() F
+ F
+ }
+
+ F interface {
+ f() A
+ }
+)
+
+type (
+ U /* ERROR cycle */ interface {
+ V
+ }
+
+ V interface {
+ v() [unsafe.Sizeof(u)]int
+ }
+)
+
+var u U
diff --git a/src/go/types/testdata/cycles4.src b/src/go/types/testdata/cycles4.src
new file mode 100644
index 0000000..445babc
--- /dev/null
+++ b/src/go/types/testdata/cycles4.src
@@ -0,0 +1,110 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// Check that all methods of T are collected before
+// determining the result type of m (which embeds
+// all methods of T).
+
+type T interface {
+ m() interface {T}
+ E
+}
+
+var _ = T.m(nil).m().e()
+
+type E interface {
+ e() int
+}
+
+// Check that unresolved forward chains are followed
+// (see also comment in resolver.go, checker.typeDecl).
+
+var _ = C.m(nil).m().e()
+
+type A B
+
+type B interface {
+ m() interface{C}
+ E
+}
+
+type C A
+
+// Check that interface type comparison for identity
+// does not recur endlessly.
+
+type T1 interface {
+ m() interface{T1}
+}
+
+type T2 interface {
+ m() interface{T2}
+}
+
+func _(x T1, y T2) {
+ // Checking for assignability of interfaces must check
+ // if all methods of x are present in y, and that they
+ // have identical signatures. The signatures recur via
+ // the result type, which is an interface that embeds
+ // a single method m that refers to the very interface
+ // that contains it. This requires cycle detection in
+ // identity checks for interface types.
+ x = y
+}
+
+type T3 interface {
+ m() interface{T4}
+}
+
+type T4 interface {
+ m() interface{T3}
+}
+
+func _(x T1, y T3) {
+ x = y
+}
+
+// Check that interfaces are type-checked in order of
+// (embedded interface) dependencies (was issue 7158).
+
+var x1 T5 = T7(nil)
+
+type T5 interface {
+ T6
+}
+
+type T6 interface {
+ m() T7
+}
+type T7 interface {
+ T5
+}
+
+// Actual test case from issue 7158.
+
+func wrapNode() Node {
+ return wrapElement()
+}
+
+func wrapElement() Element {
+ return nil
+}
+
+type EventTarget interface {
+ AddEventListener(Event)
+}
+
+type Node interface {
+ EventTarget
+}
+
+type Element interface {
+ Node
+}
+
+type Event interface {
+ Target() Element
+}
diff --git a/src/go/types/testdata/cycles5.src b/src/go/types/testdata/cycles5.src
new file mode 100644
index 0000000..397adcc
--- /dev/null
+++ b/src/go/types/testdata/cycles5.src
@@ -0,0 +1,200 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "unsafe"
+
+// test case from issue #18395
+
+type (
+ A interface { B }
+ B interface { C }
+ C interface { D; F() A }
+ D interface { G() B }
+)
+
+var _ = A(nil).G // G must be found
+
+
+// test case from issue #21804
+
+type sourceBridge interface {
+ listVersions() ([]Version, error)
+}
+
+type Constraint interface {
+ copyTo(*ConstraintMsg)
+}
+
+type ConstraintMsg struct{}
+
+func (m *ConstraintMsg) asUnpairedVersion() UnpairedVersion {
+ return nil
+}
+
+type Version interface {
+ Constraint
+}
+
+type UnpairedVersion interface {
+ Version
+}
+
+var _ Constraint = UnpairedVersion(nil)
+
+
+// derived test case from issue #21804
+
+type (
+ _ interface{ m(B1) }
+ A1 interface{ a(D1) }
+ B1 interface{ A1 }
+ C1 interface{ B1 }
+ D1 interface{ C1 }
+)
+
+var _ A1 = C1(nil)
+
+
+// derived test case from issue #22701
+
+func F(x I4) interface{} {
+ return x.Method()
+}
+
+type Unused interface {
+ RefersToI1(a I1)
+}
+
+type I1 interface {
+ I2
+ I3
+}
+
+type I2 interface {
+ RefersToI4() I4
+}
+
+type I3 interface {
+ Method() interface{}
+}
+
+type I4 interface {
+ I1
+}
+
+
+// check embedding of error interface
+
+type Error interface{ error }
+
+var err Error
+var _ = err.Error()
+
+
+// more esoteric cases
+
+type (
+ T1 interface { T2 }
+ T2 /* ERROR cycle */ T2
+)
+
+type (
+ T3 interface { T4 }
+ T4 /* ERROR cycle */ T5
+ T5 = T6
+ T6 = T7
+ T7 = T4
+)
+
+
+// arbitrary code may appear inside an interface
+
+const n = unsafe.Sizeof(func(){})
+
+type I interface {
+ m([unsafe.Sizeof(func() { I.m(nil, [n]byte{}) })]byte)
+}
+
+
+// test cases for varias alias cycles
+
+type T10 /* ERROR cycle */ = *T10 // issue #25141
+type T11 /* ERROR cycle */ = interface{ f(T11) } // issue #23139
+
+// issue #18640
+type (
+ aa = bb
+ bb struct {
+ *aa
+ }
+)
+
+type (
+ a struct{ *b }
+ b = c
+ c struct{ *b }
+)
+
+// issue #24939
+type (
+ _ interface {
+ M(P)
+ }
+
+ M interface {
+ F() P
+ }
+
+ P = interface {
+ I() M
+ }
+)
+
+// issue #8699
+type T12 /* ERROR cycle */ [len(a12)]int
+var a12 = makeArray()
+func makeArray() (res T12) { return }
+
+// issue #20770
+var r /* ERROR cycle */ = newReader()
+func newReader() r
+
+// variations of the theme of #8699 and #20770
+var arr /* ERROR cycle */ = f()
+func f() [len(arr)]int
+
+// issue #25790
+func ff(ff /* ERROR not a type */ )
+func gg((gg /* ERROR not a type */ ))
+
+type T13 /* ERROR cycle */ [len(b13)]int
+var b13 T13
+
+func g1() [unsafe.Sizeof(g1)]int
+func g2() [unsafe.Sizeof(x2)]int
+var x2 = g2
+
+// verify that we get the correct sizes for the functions above
+// (note: assert is statically evaluated in go/types test mode)
+func init() {
+ assert(unsafe.Sizeof(g1) == 8)
+ assert(unsafe.Sizeof(x2) == 8)
+}
+
+func h() [h /* ERROR no value */ ()[0]]int { panic(0) }
+
+var c14 /* ERROR cycle */ T14
+type T14 [uintptr(unsafe.Sizeof(&c14))]byte
+
+// issue #34333
+type T15 /* ERROR cycle */ struct {
+ f func() T16
+ b T16
+}
+
+type T16 struct {
+ T15
+} \ No newline at end of file
diff --git a/src/go/types/testdata/decls0.src b/src/go/types/testdata/decls0.src
new file mode 100644
index 0000000..5501b65
--- /dev/null
+++ b/src/go/types/testdata/decls0.src
@@ -0,0 +1,206 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// type declarations
+
+package decls0
+
+import "unsafe"
+
+const pi = 3.1415
+
+type (
+ N undeclared /* ERROR "undeclared" */
+ B bool
+ I int32
+ A [10]P
+ T struct {
+ x, y P
+ }
+ P *T
+ R (*R)
+ F func(A) I
+ Y interface {
+ f(A) I
+ }
+ S [](((P)))
+ M map[I]F
+ C chan<- I
+
+ // blank types must be typechecked
+ _ pi /* ERROR "not a type" */
+ _ struct{}
+ _ struct{ pi /* ERROR "not a type" */ }
+)
+
+
+// declarations of init
+const _, init /* ERROR "cannot declare init" */ , _ = 0, 1, 2
+type init /* ERROR "cannot declare init" */ struct{}
+var _, init /* ERROR "cannot declare init" */ int
+
+func init() {}
+func init /* ERROR "missing function body" */ ()
+
+func _() { const init = 0 }
+func _() { type init int }
+func _() { var init int; _ = init }
+
+// invalid array types
+type (
+ iA0 [... /* ERROR "invalid use of '...'" */ ]byte
+ // The error message below could be better. At the moment
+ // we believe an integer that is too large is not an integer.
+ // But at least we get an error.
+ iA1 [1 /* ERROR "must be integer" */ <<100]int
+ iA2 [- /* ERROR "invalid array length" */ 1]complex128
+ iA3 ["foo" /* ERROR "must be integer" */ ]string
+ iA4 [float64 /* ERROR "must be integer" */ (0)]int
+)
+
+
+type (
+ p1 pi.foo /* ERROR "no field or method foo" */
+ p2 unsafe.Pointer
+)
+
+
+type (
+ Pi pi /* ERROR "not a type" */
+
+ a /* ERROR "illegal cycle" */ a
+ a /* ERROR "redeclared" */ int
+
+ b /* ERROR "illegal cycle" */ c
+ c d
+ d e
+ e b
+
+ t *t
+
+ U V
+ V *W
+ W U
+
+ P1 *S2
+ P2 P1
+
+ S0 struct {
+ }
+ S1 struct {
+ a, b, c int
+ u, v, a /* ERROR "redeclared" */ float32
+ }
+ S2 struct {
+ S0 // embedded field
+ S0 /* ERROR "redeclared" */ int
+ }
+ S3 struct {
+ x S2
+ }
+ S4/* ERROR "illegal cycle" */ struct {
+ S4
+ }
+ S5 /* ERROR "illegal cycle" */ struct {
+ S6
+ }
+ S6 struct {
+ field S7
+ }
+ S7 struct {
+ S5
+ }
+
+ L1 []L1
+ L2 []int
+
+ A1 [10.0]int
+ A2 /* ERROR "illegal cycle" */ [10]A2
+ A3 /* ERROR "illegal cycle" */ [10]struct {
+ x A4
+ }
+ A4 [10]A3
+
+ F1 func()
+ F2 func(x, y, z float32)
+ F3 func(x, y, x /* ERROR "redeclared" */ float32)
+ F4 func() (x, y, x /* ERROR "redeclared" */ float32)
+ F5 func(x int) (x /* ERROR "redeclared" */ float32)
+ F6 func(x ...int)
+
+ I1 interface{}
+ I2 interface {
+ m1()
+ }
+ I3 interface {
+ m1()
+ m1 /* ERROR "duplicate method" */ ()
+ }
+ I4 interface {
+ m1(x, y, x /* ERROR "redeclared" */ float32)
+ m2() (x, y, x /* ERROR "redeclared" */ float32)
+ m3(x int) (x /* ERROR "redeclared" */ float32)
+ }
+ I5 interface {
+ m1(I5)
+ }
+ I6 interface {
+ S0 /* ERROR "not an interface" */
+ }
+ I7 interface {
+ I1
+ I1
+ }
+ I8 /* ERROR "illegal cycle" */ interface {
+ I8
+ }
+ I9 /* ERROR "illegal cycle" */ interface {
+ I10
+ }
+ I10 interface {
+ I11
+ }
+ I11 interface {
+ I9
+ }
+
+ C1 chan int
+ C2 <-chan int
+ C3 chan<- C3
+ C4 chan C5
+ C5 chan C6
+ C6 chan C4
+
+ M1 map[Last]string
+ M2 map[string]M2
+
+ Last int
+)
+
+// cycles in function/method declarations
+// (test cases for issues #5217, #25790 and variants)
+func f1(x f1 /* ERROR "not a type" */ ) {}
+func f2(x *f2 /* ERROR "not a type" */ ) {}
+func f3() (x f3 /* ERROR "not a type" */ ) { return }
+func f4() (x *f4 /* ERROR "not a type" */ ) { return }
+
+func (S0) m1 /* ERROR illegal cycle */ (x S0 /* ERROR value .* is not a type */ .m1) {}
+func (S0) m2 /* ERROR illegal cycle */ (x *S0 /* ERROR value .* is not a type */ .m2) {}
+func (S0) m3 /* ERROR illegal cycle */ () (x S0 /* ERROR value .* is not a type */ .m3) { return }
+func (S0) m4 /* ERROR illegal cycle */ () (x *S0 /* ERROR value .* is not a type */ .m4) { return }
+
+// interfaces may not have any blank methods
+type BlankI interface {
+ _ /* ERROR "invalid method name" */ ()
+ _ /* ERROR "invalid method name" */ (float32) int
+ m()
+}
+
+// non-interface types may have multiple blank methods
+type BlankT struct{}
+
+func (BlankT) _() {}
+func (BlankT) _(int) {}
+func (BlankT) _() int { return 0 }
+func (BlankT) _(int) int { return 0}
diff --git a/src/go/types/testdata/decls1.src b/src/go/types/testdata/decls1.src
new file mode 100644
index 0000000..f4d2eab
--- /dev/null
+++ b/src/go/types/testdata/decls1.src
@@ -0,0 +1,146 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// variable declarations
+
+package decls1
+
+import (
+ "math"
+)
+
+// Global variables without initialization
+var (
+ a, b bool
+ c byte
+ d uint8
+ r rune
+ i int
+ j, k, l int
+ x, y float32
+ xx, yy float64
+ u, v complex64
+ uu, vv complex128
+ s, t string
+ array []byte
+ iface interface{}
+
+ blank _ /* ERROR "cannot use _" */
+)
+
+// Global variables with initialization
+var (
+ s1 = i + j
+ s2 = i /* ERROR "mismatched types" */ + x
+ s3 = c + d
+ s4 = s + t
+ s5 = s /* ERROR "invalid operation" */ / t
+ s6 = array[t1]
+ s7 = array[x /* ERROR "integer" */]
+ s8 = &a
+ s10 = &42 /* ERROR "cannot take address" */
+ s11 = &v
+ s12 = -(u + *t11) / *&v
+ s13 = a /* ERROR "shifted operand" */ << d
+ s14 = i << j
+ s18 = math.Pi * 10.0
+ s19 = s1 /* ERROR "cannot call" */ ()
+ s20 = f0 /* ERROR "no value" */ ()
+ s21 = f6(1, s1, i)
+ s22 = f6(1, s1, uu /* ERROR "cannot use .* in argument" */ )
+
+ t1 int = i + j
+ t2 int = i /* ERROR "mismatched types" */ + x
+ t3 int = c /* ERROR "cannot use .* variable declaration" */ + d
+ t4 string = s + t
+ t5 string = s /* ERROR "invalid operation" */ / t
+ t6 byte = array[t1]
+ t7 byte = array[x /* ERROR "must be integer" */]
+ t8 *int = & /* ERROR "cannot use .* variable declaration" */ a
+ t10 *int = &42 /* ERROR "cannot take address" */
+ t11 *complex64 = &v
+ t12 complex64 = -(u + *t11) / *&v
+ t13 int = a /* ERROR "shifted operand" */ << d
+ t14 int = i << j
+ t15 math /* ERROR "not in selector" */
+ t16 math.xxx /* ERROR "not declared" */
+ t17 math /* ERROR "not a type" */ .Pi
+ t18 float64 = math.Pi * 10.0
+ t19 int = t1 /* ERROR "cannot call" */ ()
+ t20 int = f0 /* ERROR "no value" */ ()
+ t21 int = a /* ERROR "cannot use .* variable declaration" */
+)
+
+// Various more complex expressions
+var (
+ u1 = x /* ERROR "not an interface" */ .(int)
+ u2 = iface.([]int)
+ u3 = iface.(a /* ERROR "not a type" */ )
+ u4, ok = iface.(int)
+ u5, ok2, ok3 = iface /* ERROR "cannot initialize" */ .(int)
+)
+
+// Constant expression initializations
+var (
+ v1 = 1 /* ERROR "cannot convert" */ + "foo"
+ v2 = c + 255
+ v3 = c + 256 /* ERROR "overflows" */
+ v4 = r + 2147483647
+ v5 = r + 2147483648 /* ERROR "overflows" */
+ v6 = 42
+ v7 = v6 + 9223372036854775807
+ v8 = v6 + 9223372036854775808 /* ERROR "overflows" */
+ v9 = i + 1 << 10
+ v10 byte = 1024 /* ERROR "overflows" */
+ v11 = xx/yy*yy - xx
+ v12 = true && false
+ v13 = nil /* ERROR "use of untyped nil" */
+ v14 string = 257 // ERROR cannot use 257 .* as string value in variable declaration$
+ v15 int8 = 257 // ERROR cannot use 257 .* as int8 value in variable declaration .*overflows
+)
+
+// Multiple assignment expressions
+var (
+ m1a, m1b = 1, 2
+ m2a, m2b, m2c /* ERROR "missing init expr for m2c" */ = 1, 2
+ m3a, m3b = 1, 2, 3 /* ERROR "extra init expr 3" */
+)
+
+func _() {
+ var (
+ m1a, m1b = 1, 2
+ m2a, m2b, m2c /* ERROR "missing init expr for m2c" */ = 1, 2
+ m3a, m3b = 1, 2, 3 /* ERROR "extra init expr 3" */
+ )
+
+ _, _ = m1a, m1b
+ _, _, _ = m2a, m2b, m2c
+ _, _ = m3a, m3b
+}
+
+// Declaration of parameters and results
+func f0() {}
+func f1(a /* ERROR "not a type" */) {}
+func f2(a, b, c d /* ERROR "not a type" */) {}
+
+func f3() int { return 0 }
+func f4() a /* ERROR "not a type" */ { return 0 }
+func f5() (a, b, c d /* ERROR "not a type" */) { return }
+
+func f6(a, b, c int) complex128 { return 0 }
+
+// Declaration of receivers
+type T struct{}
+
+func (T) m0() {}
+func (*T) m1() {}
+func (x T) m2() {}
+func (x *T) m3() {}
+
+// Initialization functions
+func init() {}
+func /* ERROR "no arguments and no return values" */ init(int) {}
+func /* ERROR "no arguments and no return values" */ init() int { return 0 }
+func /* ERROR "no arguments and no return values" */ init(int) int { return 0 }
+func (T) init(int) int { return 0 }
diff --git a/src/go/types/testdata/decls2a.src b/src/go/types/testdata/decls2a.src
new file mode 100644
index 0000000..bdbecd9
--- /dev/null
+++ b/src/go/types/testdata/decls2a.src
@@ -0,0 +1,111 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// method declarations
+
+package decls2
+
+import "time"
+import "unsafe"
+
+// T1 declared before its methods.
+type T1 struct{
+ f int
+}
+
+func (T1) m() {}
+func (T1) m /* ERROR "already declared" */ () {}
+func (x *T1) f /* ERROR "field and method" */ () {}
+
+// Conflict between embedded field and method name,
+// with the embedded field being a basic type.
+type T1b struct {
+ int
+}
+
+func (T1b) int /* ERROR "field and method" */ () {}
+
+type T1c struct {
+ time.Time
+}
+
+func (T1c) Time /* ERROR "field and method" */ () int { return 0 }
+
+// Disabled for now: LookupFieldOrMethod will find Pointer even though
+// it's double-declared (it would cost extra in the common case to verify
+// this). But the MethodSet computation will not find it due to the name
+// collision caused by the double-declaration, leading to an internal
+// inconsistency while we are verifying one computation against the other.
+// var _ = T1c{}.Pointer
+
+// T2's method declared before the type.
+func (*T2) f /* ERROR "field and method" */ () {}
+
+type T2 struct {
+ f int
+}
+
+// Methods declared without a declared type.
+func (undeclared /* ERROR "undeclared" */) m() {}
+func (x *undeclared /* ERROR "undeclared" */) m() {}
+
+func (pi /* ERROR "not a type" */) m1() {}
+func (x pi /* ERROR "not a type" */) m2() {}
+func (x *pi /* ERROR "not a type" */ ) m3() {}
+
+// Blank types.
+type _ struct { m int }
+type _ struct { m int }
+
+func (_ /* ERROR "cannot use _" */) m() {}
+func m(_ /* ERROR "cannot use _" */) {}
+
+// Methods with receiver base type declared in another file.
+func (T3) m1() {}
+func (*T3) m2() {}
+func (x T3) m3() {}
+func (x *T3) f /* ERROR "field and method" */ () {}
+
+// Methods of non-struct type.
+type T4 func()
+
+func (self T4) m() func() { return self }
+
+// Methods associated with an interface.
+type T5 interface {
+ m() int
+}
+
+func (T5 /* ERROR "invalid receiver" */ ) m1() {}
+func (T5 /* ERROR "invalid receiver" */ ) m2() {}
+
+// Methods associated with a named pointer type.
+type ptr *int
+func (ptr /* ERROR "invalid receiver" */ ) _() {}
+func (* /* ERROR "invalid receiver" */ ptr) _() {}
+
+// Methods with zero or multiple receivers.
+func ( /* ERROR "missing receiver" */ ) _() {}
+func (T3, * /* ERROR "exactly one receiver" */ T3) _() {}
+func (T3, T3, T3 /* ERROR "exactly one receiver" */ ) _() {}
+func (a, b /* ERROR "exactly one receiver" */ T3) _() {}
+func (a, b, c /* ERROR "exactly one receiver" */ T3) _() {}
+
+// Methods associated with non-local or unnamed types.
+func (int /* ERROR "invalid receiver" */ ) m() {}
+func ([ /* ERROR "invalid receiver" */ ]int) m() {}
+func (time /* ERROR "invalid receiver" */ .Time) m() {}
+func (* /* ERROR "invalid receiver" */ time.Time) m() {}
+func (x /* ERROR "invalid receiver" */ interface{}) m() {}
+
+// Unsafe.Pointer is treated like a pointer when used as receiver type.
+type UP unsafe.Pointer
+func (UP /* ERROR "invalid" */ ) m1() {}
+func (* /* ERROR "invalid" */ UP) m2() {}
+
+// Double declarations across package files
+const c_double = 0
+type t_double int
+var v_double int
+func f_double() {}
diff --git a/src/go/types/testdata/decls2b.src b/src/go/types/testdata/decls2b.src
new file mode 100644
index 0000000..5c55750
--- /dev/null
+++ b/src/go/types/testdata/decls2b.src
@@ -0,0 +1,75 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// method declarations
+
+package decls2
+
+import "io"
+
+const pi = 3.1415
+
+func (T1) m /* ERROR "already declared" */ () {}
+func (T2) m(io.Writer) {}
+
+type T3 struct {
+ f *T3
+}
+
+type T6 struct {
+ x int
+}
+
+func (t *T6) m1() int {
+ return t.x
+}
+
+func f() {
+ var t *T6
+ t.m1()
+}
+
+// Double declarations across package files
+const c_double /* ERROR "redeclared" */ = 0
+type t_double /* ERROR "redeclared" */ int
+var v_double /* ERROR "redeclared" */ int
+func f_double /* ERROR "redeclared" */ () {}
+
+// Blank methods need to be type-checked.
+// Verify by checking that errors are reported.
+func (T /* ERROR "undeclared" */ ) _() {}
+func (T1) _(undeclared /* ERROR "undeclared" */ ) {}
+func (T1) _() int { return "foo" /* ERROR "cannot use .* in return statement" */ }
+
+// Methods with undeclared receiver type can still be checked.
+// Verify by checking that errors are reported.
+func (Foo /* ERROR "undeclared" */ ) m() {}
+func (Foo /* ERROR "undeclared" */ ) m(undeclared /* ERROR "undeclared" */ ) {}
+func (Foo /* ERROR "undeclared" */ ) m() int { return "foo" /* ERROR "cannot use .* in return statement" */ }
+
+func (Foo /* ERROR "undeclared" */ ) _() {}
+func (Foo /* ERROR "undeclared" */ ) _(undeclared /* ERROR "undeclared" */ ) {}
+func (Foo /* ERROR "undeclared" */ ) _() int { return "foo" /* ERROR "cannot use .* in return statement" */ }
+
+// Receiver declarations are regular parameter lists;
+// receiver types may use parentheses, and the list
+// may have a trailing comma.
+type T7 struct {}
+
+func (T7) m1() {}
+func ((T7)) m2() {}
+func ((*T7)) m3() {}
+func (x *(T7),) m4() {}
+func (x (*(T7)),) m5() {}
+func (x ((*((T7)))),) m6() {}
+
+// Check that methods with parenthesized receiver are actually present (issue #23130).
+var (
+ _ = T7.m1
+ _ = T7.m2
+ _ = (*T7).m3
+ _ = (*T7).m4
+ _ = (*T7).m5
+ _ = (*T7).m6
+)
diff --git a/src/go/types/testdata/decls3.src b/src/go/types/testdata/decls3.src
new file mode 100644
index 0000000..745175c
--- /dev/null
+++ b/src/go/types/testdata/decls3.src
@@ -0,0 +1,309 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// embedded types
+
+package decls3
+
+import "unsafe"
+import "fmt"
+
+// fields with the same name at the same level cancel each other out
+
+func _() {
+ type (
+ T1 struct { X int }
+ T2 struct { X int }
+ T3 struct { T1; T2 } // X is embedded twice at the same level via T1->X, T2->X
+ )
+
+ var t T3
+ _ = t.X /* ERROR "ambiguous selector t.X" */
+}
+
+func _() {
+ type (
+ T1 struct { X int }
+ T2 struct { T1 }
+ T3 struct { T1 }
+ T4 struct { T2; T3 } // X is embedded twice at the same level via T2->T1->X, T3->T1->X
+ )
+
+ var t T4
+ _ = t.X /* ERROR "ambiguous selector t.X" */
+}
+
+func issue4355() {
+ type (
+ T1 struct {X int}
+ T2 struct {T1}
+ T3 struct {T2}
+ T4 struct {T2}
+ T5 struct {T3; T4} // X is embedded twice at the same level via T3->T2->T1->X, T4->T2->T1->X
+ )
+
+ var t T5
+ _ = t.X /* ERROR "ambiguous selector t.X" */
+}
+
+func _() {
+ type State int
+ type A struct{ State }
+ type B struct{ fmt.State }
+ type T struct{ A; B }
+
+ var t T
+ _ = t.State /* ERROR "ambiguous selector t.State" */
+}
+
+// Embedded fields can be predeclared types.
+
+func _() {
+ type T0 struct{
+ int
+ float32
+ f int
+ }
+ var x T0
+ _ = x.int
+ _ = x.float32
+ _ = x.f
+
+ type T1 struct{
+ T0
+ }
+ var y T1
+ _ = y.int
+ _ = y.float32
+ _ = y.f
+}
+
+// Restrictions on embedded field types.
+
+func _() {
+ type I1 interface{}
+ type I2 interface{}
+ type P1 *int
+ type P2 *int
+ type UP unsafe.Pointer
+
+ type T1 struct {
+ I1
+ * /* ERROR "cannot be a pointer to an interface" */ I2
+ * /* ERROR "cannot be a pointer to an interface" */ error
+ P1 /* ERROR "cannot be a pointer" */
+ * /* ERROR "cannot be a pointer" */ P2
+ }
+
+ // unsafe.Pointers are treated like regular pointers when embedded
+ type T2 struct {
+ unsafe /* ERROR "cannot be unsafe.Pointer" */ .Pointer
+ */* ERROR "cannot be unsafe.Pointer" */ /* ERROR "Pointer redeclared" */ unsafe.Pointer
+ UP /* ERROR "cannot be unsafe.Pointer" */
+ * /* ERROR "cannot be unsafe.Pointer" */ /* ERROR "UP redeclared" */ UP
+ }
+}
+
+// Named types that are pointers.
+
+type S struct{ x int }
+func (*S) m() {}
+type P *S
+
+func _() {
+ var s *S
+ _ = s.x
+ _ = s.m
+
+ var p P
+ _ = p.x
+ _ = p.m /* ERROR "no field or method" */
+ _ = P.m /* ERROR "no field or method" */
+}
+
+// Borrowed from the FieldByName test cases in reflect/all_test.go.
+
+type D1 struct {
+ d int
+}
+type D2 struct {
+ d int
+}
+
+type S0 struct {
+ A, B, C int
+ D1
+ D2
+}
+
+type S1 struct {
+ B int
+ S0
+}
+
+type S2 struct {
+ A int
+ *S1
+}
+
+type S1x struct {
+ S1
+}
+
+type S1y struct {
+ S1
+}
+
+type S3 struct {
+ S1x
+ S2
+ D, E int
+ *S1y
+}
+
+type S4 struct {
+ *S4
+ A int
+}
+
+// The X in S6 and S7 annihilate, but they also block the X in S8.S9.
+type S5 struct {
+ S6
+ S7
+ S8
+}
+
+type S6 struct {
+ X int
+}
+
+type S7 S6
+
+type S8 struct {
+ S9
+}
+
+type S9 struct {
+ X int
+ Y int
+}
+
+// The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9.
+type S10 struct {
+ S11
+ S12
+ S13
+}
+
+type S11 struct {
+ S6
+}
+
+type S12 struct {
+ S6
+}
+
+type S13 struct {
+ S8
+}
+
+func _() {
+ _ = struct{}{}.Foo /* ERROR "no field or method" */
+ _ = S0{}.A
+ _ = S0{}.D /* ERROR "no field or method" */
+ _ = S1{}.A
+ _ = S1{}.B
+ _ = S1{}.S0
+ _ = S1{}.C
+ _ = S2{}.A
+ _ = S2{}.S1
+ _ = S2{}.B
+ _ = S2{}.C
+ _ = S2{}.D /* ERROR "no field or method" */
+ _ = S3{}.S1 /* ERROR "ambiguous selector \(S3 literal\).S1" */
+ _ = S3{}.A
+ _ = S3{}.B /* ERROR "ambiguous selector" \(S3 literal\).B */
+ _ = S3{}.D
+ _ = S3{}.E
+ _ = S4{}.A
+ _ = S4{}.B /* ERROR "no field or method" */
+ _ = S5{}.X /* ERROR "ambiguous selector \(S5 literal\).X" */
+ _ = S5{}.Y
+ _ = S10{}.X /* ERROR "ambiguous selector \(S10 literal\).X" */
+ _ = S10{}.Y
+}
+
+// Borrowed from the FieldByName benchmark in reflect/all_test.go.
+
+type R0 struct {
+ *R1
+ *R2
+ *R3
+ *R4
+}
+
+type R1 struct {
+ *R5
+ *R6
+ *R7
+ *R8
+}
+
+type R2 R1
+type R3 R1
+type R4 R1
+
+type R5 struct {
+ *R9
+ *R10
+ *R11
+ *R12
+}
+
+type R6 R5
+type R7 R5
+type R8 R5
+
+type R9 struct {
+ *R13
+ *R14
+ *R15
+ *R16
+}
+
+type R10 R9
+type R11 R9
+type R12 R9
+
+type R13 struct {
+ *R17
+ *R18
+ *R19
+ *R20
+}
+
+type R14 R13
+type R15 R13
+type R16 R13
+
+type R17 struct {
+ *R21
+ *R22
+ *R23
+ *R24
+}
+
+type R18 R17
+type R19 R17
+type R20 R17
+
+type R21 struct {
+ X int
+}
+
+type R22 R21
+type R23 R21
+type R24 R21
+
+var _ = R0{}.X /* ERROR "ambiguous selector \(R0 literal\).X" */ \ No newline at end of file
diff --git a/src/go/types/testdata/decls4.src b/src/go/types/testdata/decls4.src
new file mode 100644
index 0000000..140bbfd
--- /dev/null
+++ b/src/go/types/testdata/decls4.src
@@ -0,0 +1,199 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// type aliases
+
+package decls4
+
+type (
+ T0 [10]int
+ T1 []byte
+ T2 struct {
+ x int
+ }
+ T3 interface{
+ m() T2
+ }
+ T4 func(int, T0) chan T2
+)
+
+type (
+ Ai = int
+ A0 = T0
+ A1 = T1
+ A2 = T2
+ A3 = T3
+ A4 = T4
+
+ A10 = [10]int
+ A11 = []byte
+ A12 = struct {
+ x int
+ }
+ A13 = interface{
+ m() A2
+ }
+ A14 = func(int, A0) chan A2
+)
+
+// check assignment compatibility due to equality of types
+var (
+ xi_ int
+ ai Ai = xi_
+
+ x0 T0
+ a0 A0 = x0
+
+ x1 T1
+ a1 A1 = x1
+
+ x2 T2
+ a2 A2 = x2
+
+ x3 T3
+ a3 A3 = x3
+
+ x4 T4
+ a4 A4 = x4
+)
+
+// alias receiver types
+func (Ai /* ERROR "invalid receiver" */) m1() {}
+func (T0) m1() {}
+func (A0) m1 /* ERROR already declared */ () {}
+func (A0) m2 () {}
+func (A3 /* ERROR invalid receiver */ ) m1 () {}
+func (A10 /* ERROR invalid receiver */ ) m1() {}
+
+// x0 has methods m1, m2 declared via receiver type names T0 and A0
+var _ interface{ m1(); m2() } = x0
+
+// alias receiver types (test case for issue #23042)
+type T struct{}
+
+var (
+ _ = T.m
+ _ = T{}.m
+ _ interface{m()} = T{}
+)
+
+var (
+ _ = T.n
+ _ = T{}.n
+ _ interface{m(); n()} = T{}
+)
+
+type U = T
+func (U) m() {}
+
+// alias receiver types (long type declaration chains)
+type (
+ V0 = V1
+ V1 = (V2)
+ V2 = ((V3))
+ V3 = T
+)
+
+func (V0) m /* ERROR already declared */ () {}
+func (V1) n() {}
+
+// alias receiver types (invalid due to cycles)
+type (
+ W0 /* ERROR illegal cycle */ = W1
+ W1 = (W2)
+ W2 = ((W0))
+)
+
+func (W0) m() {} // no error expected (due to above cycle error)
+func (W1) n() {}
+
+// alias receiver types (invalid due to builtin underlying type)
+type (
+ B0 = B1
+ B1 = B2
+ B2 = int
+)
+
+func (B0 /* ERROR invalid receiver */ ) m() {}
+func (B1 /* ERROR invalid receiver */ ) n() {}
+
+// cycles
+type (
+ C2 /* ERROR illegal cycle */ = C2
+ C3 /* ERROR illegal cycle */ = C4
+ C4 = C3
+ C5 struct {
+ f *C6
+ }
+ C6 = C5
+ C7 /* ERROR illegal cycle */ struct {
+ f C8
+ }
+ C8 = C7
+)
+
+// embedded fields
+var (
+ s0 struct { T0 }
+ s1 struct { A0 } = s0 /* ERROR cannot use */ // embedded field names are different
+)
+
+// embedding and lookup of fields and methods
+func _(s struct{A0}) { s.A0 = x0 }
+
+type eX struct{xf int}
+
+func (eX) xm()
+
+type eY = struct{eX} // field/method set of eY includes xf, xm
+
+type eZ = *struct{eX} // field/method set of eZ includes xf, xm
+
+type eA struct {
+ eX // eX contributes xf, xm to eA
+}
+
+type eA2 struct {
+ *eX // *eX contributes xf, xm to eA
+}
+
+type eB struct {
+ eY // eY contributes xf, xm to eB
+}
+
+type eB2 struct {
+ *eY // *eY contributes xf, xm to eB
+}
+
+type eC struct {
+ eZ // eZ contributes xf, xm to eC
+}
+
+var (
+ _ = eA{}.xf
+ _ = eA{}.xm
+ _ = eA2{}.xf
+ _ = eA2{}.xm
+ _ = eB{}.xf
+ _ = eB{}.xm
+ _ = eB2{}.xf
+ _ = eB2{}.xm
+ _ = eC{}.xf
+ _ = eC{}.xm
+)
+
+// ambiguous selectors due to embedding via type aliases
+type eD struct {
+ eY
+ eZ
+}
+
+var (
+ _ = eD{}.xf /* ERROR ambiguous selector \(eD literal\).xf */
+ _ = eD{}.xm /* ERROR ambiguous selector \(eD literal\).xm */
+)
+
+var (
+ _ interface{ xm() } = eD /* ERROR missing method xm */ {}
+) \ No newline at end of file
diff --git a/src/go/types/testdata/decls5.src b/src/go/types/testdata/decls5.src
new file mode 100644
index 0000000..88d3194
--- /dev/null
+++ b/src/go/types/testdata/decls5.src
@@ -0,0 +1,10 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// declarations of main
+const _, main /* ERROR "cannot declare main" */ , _ = 0, 1, 2
+type main /* ERROR "cannot declare main" */ struct{}
+var _, main /* ERROR "cannot declare main" */ int
diff --git a/src/go/types/testdata/errors.src b/src/go/types/testdata/errors.src
new file mode 100644
index 0000000..ff92921
--- /dev/null
+++ b/src/go/types/testdata/errors.src
@@ -0,0 +1,60 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package errors
+
+// Testing precise operand formatting in error messages
+// (matching messages are regular expressions, hence the \'s).
+func f(x int, m map[string]int) {
+ // no values
+ _ = f /* ERROR "f\(0, m\) \(no value\) used as value" */ (0, m)
+
+ // built-ins
+ _ = println /* ERROR "println \(built-in\) must be called" */
+
+ // types
+ _ = complex128 /* ERROR "complex128 \(type\) is not an expression" */
+
+ // constants
+ const c1 = 991
+ const c2 float32 = 0.5
+ 0 /* ERROR "0 \(untyped int constant\) is not used" */
+ c1 /* ERROR "c1 \(untyped int constant 991\) is not used" */
+ c2 /* ERROR "c2 \(constant 0.5 of type float32\) is not used" */
+ c1 /* ERROR "c1 \+ c2 \(constant 991.5 of type float32\) is not used" */ + c2
+
+ // variables
+ x /* ERROR "x \(variable of type int\) is not used" */
+
+ // values
+ x /* ERROR "x != x \(untyped bool value\) is not used" */ != x
+ x /* ERROR "x \+ x \(value of type int\) is not used" */ + x
+
+ // value, ok's
+ const s = "foo"
+ m /* ERROR "m\[s\] \(map index expression of type int\) is not used" */ [s]
+}
+
+// Valid ERROR comments can have a variety of forms.
+func _() {
+ 0 /* ERROR "0 .* is not used" */
+ 0 /* ERROR 0 .* is not used */
+ 0 // ERROR "0 .* is not used"
+ 0 // ERROR 0 .* is not used
+}
+
+// Don't report spurious errors as a consequence of earlier errors.
+// Add more tests as needed.
+func _() {
+ if err := foo /* ERROR undeclared */ (); err != nil /* no error here */ {}
+}
+
+// Use unqualified names for package-local objects.
+type T struct{}
+var _ int = T /* ERROR value of type T */ {} // use T in error message rather then errors.T
+
+// Don't report errors containing "invalid type" (issue #24182).
+func _(x *missing /* ERROR undeclared name: missing */ ) {
+ x.m() // there shouldn't be an error here referring to *invalid type
+}
diff --git a/src/go/types/testdata/expr0.src b/src/go/types/testdata/expr0.src
new file mode 100644
index 0000000..1aac726
--- /dev/null
+++ b/src/go/types/testdata/expr0.src
@@ -0,0 +1,180 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// unary expressions
+
+package expr0
+
+type mybool bool
+
+var (
+ // bool
+ b0 = true
+ b1 bool = b0
+ b2 = !true
+ b3 = !b1
+ b4 bool = !true
+ b5 bool = !b4
+ b6 = +b0 /* ERROR "not defined" */
+ b7 = -b0 /* ERROR "not defined" */
+ b8 = ^b0 /* ERROR "not defined" */
+ b9 = *b0 /* ERROR "cannot indirect" */
+ b10 = &true /* ERROR "cannot take address" */
+ b11 = &b0
+ b12 = <-b0 /* ERROR "cannot receive" */
+ b13 = & & /* ERROR "cannot take address" */ b0
+
+ // byte
+ _ = byte(0)
+ _ = byte(- /* ERROR "cannot convert" */ 1)
+ _ = - /* ERROR "-byte\(1\) \(constant -1 of type byte\) overflows byte" */ byte(1) // test for issue 11367
+ _ = byte /* ERROR "overflows byte" */ (0) - byte(1)
+
+ // int
+ i0 = 1
+ i1 int = i0
+ i2 = +1
+ i3 = +i0
+ i4 int = +1
+ i5 int = +i4
+ i6 = -1
+ i7 = -i0
+ i8 int = -1
+ i9 int = -i4
+ i10 = !i0 /* ERROR "not defined" */
+ i11 = ^1
+ i12 = ^i0
+ i13 int = ^1
+ i14 int = ^i4
+ i15 = *i0 /* ERROR "cannot indirect" */
+ i16 = &i0
+ i17 = *i16
+ i18 = <-i16 /* ERROR "cannot receive" */
+
+ // uint
+ u0 = uint(1)
+ u1 uint = u0
+ u2 = +1
+ u3 = +u0
+ u4 uint = +1
+ u5 uint = +u4
+ u6 = -1
+ u7 = -u0
+ u8 uint = - /* ERROR "overflows" */ 1
+ u9 uint = -u4
+ u10 = !u0 /* ERROR "not defined" */
+ u11 = ^1
+ u12 = ^i0
+ u13 uint = ^ /* ERROR "overflows" */ 1
+ u14 uint = ^u4
+ u15 = *u0 /* ERROR "cannot indirect" */
+ u16 = &u0
+ u17 = *u16
+ u18 = <-u16 /* ERROR "cannot receive" */
+ u19 = ^uint(0)
+
+ // float64
+ f0 = float64(1)
+ f1 float64 = f0
+ f2 = +1
+ f3 = +f0
+ f4 float64 = +1
+ f5 float64 = +f4
+ f6 = -1
+ f7 = -f0
+ f8 float64 = -1
+ f9 float64 = -f4
+ f10 = !f0 /* ERROR "not defined" */
+ f11 = ^1
+ f12 = ^i0
+ f13 float64 = ^1
+ f14 float64 = ^f4 /* ERROR "not defined" */
+ f15 = *f0 /* ERROR "cannot indirect" */
+ f16 = &f0
+ f17 = *u16
+ f18 = <-u16 /* ERROR "cannot receive" */
+
+ // complex128
+ c0 = complex128(1)
+ c1 complex128 = c0
+ c2 = +1
+ c3 = +c0
+ c4 complex128 = +1
+ c5 complex128 = +c4
+ c6 = -1
+ c7 = -c0
+ c8 complex128 = -1
+ c9 complex128 = -c4
+ c10 = !c0 /* ERROR "not defined" */
+ c11 = ^1
+ c12 = ^i0
+ c13 complex128 = ^1
+ c14 complex128 = ^c4 /* ERROR "not defined" */
+ c15 = *c0 /* ERROR "cannot indirect" */
+ c16 = &c0
+ c17 = *u16
+ c18 = <-u16 /* ERROR "cannot receive" */
+
+ // string
+ s0 = "foo"
+ s1 = +"foo" /* ERROR "not defined" */
+ s2 = -s0 /* ERROR "not defined" */
+ s3 = !s0 /* ERROR "not defined" */
+ s4 = ^s0 /* ERROR "not defined" */
+ s5 = *s4
+ s6 = &s4
+ s7 = *s6
+ s8 = <-s7
+
+ // channel
+ ch chan int
+ rc <-chan float64
+ sc chan <- string
+ ch0 = +ch /* ERROR "not defined" */
+ ch1 = -ch /* ERROR "not defined" */
+ ch2 = !ch /* ERROR "not defined" */
+ ch3 = ^ch /* ERROR "not defined" */
+ ch4 = *ch /* ERROR "cannot indirect" */
+ ch5 = &ch
+ ch6 = *ch5
+ ch7 = <-ch
+ ch8 = <-rc
+ ch9 = <-sc /* ERROR "cannot receive" */
+ ch10, ok = <-ch
+ // ok is of type bool
+ ch11, myok = <-ch
+ _ mybool = myok /* ERROR "cannot use .* in variable declaration" */
+)
+
+// address of composite literals
+type T struct{x, y int}
+
+func f() T { return T{} }
+
+var (
+ _ = &T{1, 2}
+ _ = &[...]int{}
+ _ = &[]int{}
+ _ = &[]int{}
+ _ = &map[string]T{}
+ _ = &(T{1, 2})
+ _ = &((((T{1, 2}))))
+ _ = &f /* ERROR "cannot take address" */ ()
+)
+
+// recursive pointer types
+type P *P
+
+var (
+ p1 P = new(P)
+ p2 P = *p1
+ p3 P = &p2
+)
+
+func g() (a, b int) { return }
+
+func _() {
+ _ = -g /* ERROR 2-valued g */ ()
+ _ = <-g /* ERROR 2-valued g */ ()
+}
diff --git a/src/go/types/testdata/expr1.src b/src/go/types/testdata/expr1.src
new file mode 100644
index 0000000..4ead815
--- /dev/null
+++ b/src/go/types/testdata/expr1.src
@@ -0,0 +1,127 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// binary expressions
+
+package expr1
+
+type mybool bool
+
+func _(x, y bool, z mybool) {
+ x = x || y
+ x = x || true
+ x = x || false
+ x = x && y
+ x = x && true
+ x = x && false
+
+ z = z /* ERROR mismatched types */ || y
+ z = z || true
+ z = z || false
+ z = z /* ERROR mismatched types */ && y
+ z = z && true
+ z = z && false
+}
+
+type myint int
+
+func _(x, y int, z myint) {
+ x = x + 1
+ x = x + 1.0
+ x = x + 1.1 // ERROR truncated to int
+ x = x + y
+ x = x - y
+ x = x * y
+ x = x / y
+ x = x % y
+ x = x << y
+ x = x >> y
+
+ z = z + 1
+ z = z + 1.0
+ z = z + 1.1 // ERROR truncated to int
+ z = z /* ERROR mismatched types */ + y
+ z = z /* ERROR mismatched types */ - y
+ z = z /* ERROR mismatched types */ * y
+ z = z /* ERROR mismatched types */ / y
+ z = z /* ERROR mismatched types */ % y
+ z = z << y
+ z = z >> y
+}
+
+type myuint uint
+
+func _(x, y uint, z myuint) {
+ x = x + 1
+ x = x + - /* ERROR overflows uint */ 1
+ x = x + 1.0
+ x = x + 1.1 // ERROR truncated to uint
+ x = x + y
+ x = x - y
+ x = x * y
+ x = x / y
+ x = x % y
+ x = x << y
+ x = x >> y
+
+ z = z + 1
+ z = x + - /* ERROR overflows uint */ 1
+ z = z + 1.0
+ z = z + 1.1 // ERROR truncated to uint
+ z = z /* ERROR mismatched types */ + y
+ z = z /* ERROR mismatched types */ - y
+ z = z /* ERROR mismatched types */ * y
+ z = z /* ERROR mismatched types */ / y
+ z = z /* ERROR mismatched types */ % y
+ z = z << y
+ z = z >> y
+}
+
+type myfloat64 float64
+
+func _(x, y float64, z myfloat64) {
+ x = x + 1
+ x = x + -1
+ x = x + 1.0
+ x = x + 1.1
+ x = x + y
+ x = x - y
+ x = x * y
+ x = x / y
+ x = x /* ERROR not defined */ % y
+ x = x /* ERROR operand x .* must be integer */ << y
+ x = x /* ERROR operand x .* must be integer */ >> y
+
+ z = z + 1
+ z = z + -1
+ z = z + 1.0
+ z = z + 1.1
+ z = z /* ERROR mismatched types */ + y
+ z = z /* ERROR mismatched types */ - y
+ z = z /* ERROR mismatched types */ * y
+ z = z /* ERROR mismatched types */ / y
+ z = z /* ERROR mismatched types */ % y
+ z = z /* ERROR operand z .* must be integer */ << y
+ z = z /* ERROR operand z .* must be integer */ >> y
+}
+
+type mystring string
+
+func _(x, y string, z mystring) {
+ x = x + "foo"
+ x = x /* ERROR not defined */ - "foo"
+ x = x + 1 // ERROR cannot convert
+ x = x + y
+ x = x /* ERROR not defined */ - y
+ x = x * 10 // ERROR cannot convert
+}
+
+func f() (a, b int) { return }
+
+func _(x int) {
+ _ = f /* ERROR 2-valued f */ () + 1
+ _ = x + f /* ERROR 2-valued f */ ()
+ _ = f /* ERROR 2-valued f */ () + f
+ _ = f /* ERROR 2-valued f */ () + f /* ERROR 2-valued f */ ()
+}
diff --git a/src/go/types/testdata/expr2.src b/src/go/types/testdata/expr2.src
new file mode 100644
index 0000000..0c959e8
--- /dev/null
+++ b/src/go/types/testdata/expr2.src
@@ -0,0 +1,260 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// comparisons
+
+package expr2
+
+func _bool() {
+ const t = true == true
+ const f = true == false
+ _ = t /* ERROR "cannot compare" */ < f
+ _ = 0 /* ERROR "cannot convert" */ == t
+ var b bool
+ var x, y float32
+ b = x < y
+ _ = b
+ _ = struct{b bool}{x < y}
+}
+
+// corner cases
+var (
+ v0 = nil /* ERROR "cannot compare" */ == nil
+)
+
+func arrays() {
+ // basics
+ var a, b [10]int
+ _ = a == b
+ _ = a != b
+ _ = a /* ERROR < not defined */ < b
+ _ = a == nil /* ERROR cannot convert */
+
+ type C [10]int
+ var c C
+ _ = a == c
+
+ type D [10]int
+ var d D
+ _ = c /* ERROR mismatched types */ == d
+
+ var e [10]func() int
+ _ = e /* ERROR == not defined */ == e
+}
+
+func structs() {
+ // basics
+ var s, t struct {
+ x int
+ a [10]float32
+ _ bool
+ }
+ _ = s == t
+ _ = s != t
+ _ = s /* ERROR < not defined */ < t
+ _ = s == nil /* ERROR cannot convert */
+
+ type S struct {
+ x int
+ a [10]float32
+ _ bool
+ }
+ type T struct {
+ x int
+ a [10]float32
+ _ bool
+ }
+ var ss S
+ var tt T
+ _ = s == ss
+ _ = ss /* ERROR mismatched types */ == tt
+
+ var u struct {
+ x int
+ a [10]map[string]int
+ }
+ _ = u /* ERROR cannot compare */ == u
+}
+
+func pointers() {
+ // nil
+ _ = nil /* ERROR == not defined */ == nil
+ _ = nil /* ERROR != not defined */ != nil
+ _ = nil /* ERROR < not defined */ < nil
+ _ = nil /* ERROR <= not defined */ <= nil
+ _ = nil /* ERROR > not defined */ > nil
+ _ = nil /* ERROR >= not defined */ >= nil
+
+ // basics
+ var p, q *int
+ _ = p == q
+ _ = p != q
+
+ _ = p == nil
+ _ = p != nil
+ _ = nil == q
+ _ = nil != q
+
+ _ = p /* ERROR < not defined */ < q
+ _ = p /* ERROR <= not defined */ <= q
+ _ = p /* ERROR > not defined */ > q
+ _ = p /* ERROR >= not defined */ >= q
+
+ // various element types
+ type (
+ S1 struct{}
+ S2 struct{}
+ P1 *S1
+ P2 *S2
+ )
+ var (
+ ps1 *S1
+ ps2 *S2
+ p1 P1
+ p2 P2
+ )
+ _ = ps1 == ps1
+ _ = ps1 /* ERROR mismatched types */ == ps2
+ _ = ps2 /* ERROR mismatched types */ == ps1
+
+ _ = p1 == p1
+ _ = p1 /* ERROR mismatched types */ == p2
+
+ _ = p1 == ps1
+}
+
+func channels() {
+ // basics
+ var c, d chan int
+ _ = c == d
+ _ = c != d
+ _ = c == nil
+ _ = c /* ERROR < not defined */ < d
+
+ // various element types (named types)
+ type (
+ C1 chan int
+ C1r <-chan int
+ C1s chan<- int
+ C2 chan float32
+ )
+ var (
+ c1 C1
+ c1r C1r
+ c1s C1s
+ c1a chan int
+ c2 C2
+ )
+ _ = c1 == c1
+ _ = c1 /* ERROR mismatched types */ == c1r
+ _ = c1 /* ERROR mismatched types */ == c1s
+ _ = c1r /* ERROR mismatched types */ == c1s
+ _ = c1 == c1a
+ _ = c1a == c1
+ _ = c1 /* ERROR mismatched types */ == c2
+ _ = c1a /* ERROR mismatched types */ == c2
+
+ // various element types (unnamed types)
+ var (
+ d1 chan int
+ d1r <-chan int
+ d1s chan<- int
+ d1a chan<- int
+ d2 chan float32
+ )
+ _ = d1 == d1
+ _ = d1 == d1r
+ _ = d1 == d1s
+ _ = d1r /* ERROR mismatched types */ == d1s
+ _ = d1 == d1a
+ _ = d1a == d1
+ _ = d1 /* ERROR mismatched types */ == d2
+ _ = d1a /* ERROR mismatched types */ == d2
+}
+
+// for interfaces test
+type S1 struct{}
+type S11 struct{}
+type S2 struct{}
+func (*S1) m() int
+func (*S11) m() int
+func (*S11) n()
+func (*S2) m() float32
+
+func interfaces() {
+ // basics
+ var i, j interface{ m() int }
+ _ = i == j
+ _ = i != j
+ _ = i == nil
+ _ = i /* ERROR < not defined */ < j
+
+ // various interfaces
+ var ii interface { m() int; n() }
+ var k interface { m() float32 }
+ _ = i == ii
+ _ = i /* ERROR mismatched types */ == k
+
+ // interfaces vs values
+ var s1 S1
+ var s11 S11
+ var s2 S2
+
+ _ = i == 0 /* ERROR cannot convert */
+ _ = i /* ERROR mismatched types */ == s1
+ _ = i == &s1
+ _ = i == &s11
+
+ _ = i /* ERROR mismatched types */ == s2
+ _ = i /* ERROR mismatched types */ == &s2
+
+ // issue #28164
+ // testcase from issue
+ _ = interface /* ERROR cannot compare */ {}(nil) == []int(nil)
+
+ // related cases
+ var e interface{}
+ var s []int
+ var x int
+ _ = e /* ERROR cannot compare */ == s
+ _ = s /* ERROR cannot compare */ == e
+ _ = e /* ERROR cannot compare */ < x
+ _ = x /* ERROR cannot compare */ < e
+}
+
+func slices() {
+ // basics
+ var s []int
+ _ = s == nil
+ _ = s != nil
+ _ = s /* ERROR < not defined */ < nil
+
+ // slices are not otherwise comparable
+ _ = s /* ERROR == not defined */ == s
+ _ = s /* ERROR < not defined */ < s
+}
+
+func maps() {
+ // basics
+ var m map[string]int
+ _ = m == nil
+ _ = m != nil
+ _ = m /* ERROR < not defined */ < nil
+
+ // maps are not otherwise comparable
+ _ = m /* ERROR == not defined */ == m
+ _ = m /* ERROR < not defined */ < m
+}
+
+func funcs() {
+ // basics
+ var f func(int) float32
+ _ = f == nil
+ _ = f != nil
+ _ = f /* ERROR < not defined */ < nil
+
+ // funcs are not otherwise comparable
+ _ = f /* ERROR == not defined */ == f
+ _ = f /* ERROR < not defined */ < f
+}
diff --git a/src/go/types/testdata/expr3.src b/src/go/types/testdata/expr3.src
new file mode 100644
index 0000000..e6777aa
--- /dev/null
+++ b/src/go/types/testdata/expr3.src
@@ -0,0 +1,563 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package expr3
+
+import "time"
+
+func indexes() {
+ _ = 1 /* ERROR "cannot index" */ [0]
+ _ = indexes /* ERROR "cannot index" */ [0]
+ _ = ( /* ERROR "cannot slice" */ 12 + 3)[1:2]
+
+ var a [10]int
+ _ = a[true /* ERROR "cannot convert" */ ]
+ _ = a["foo" /* ERROR "cannot convert" */ ]
+ _ = a[1.1 /* ERROR "truncated" */ ]
+ _ = a[1.0]
+ _ = a[- /* ERROR "negative" */ 1]
+ _ = a[- /* ERROR "negative" */ 1 :]
+ _ = a[: - /* ERROR "negative" */ 1]
+ _ = a[: /* ERROR "2nd index required" */ : /* ERROR "3rd index required" */ ]
+ _ = a[0: /* ERROR "2nd index required" */ : /* ERROR "3rd index required" */ ]
+ _ = a[0: /* ERROR "2nd index required" */ :10]
+ _ = a[:10:10]
+
+ var a0 int
+ a0 = a[0]
+ _ = a0
+ var a1 int32
+ a1 = a /* ERROR "cannot use .* in assignment" */ [1]
+ _ = a1
+
+ _ = a[9]
+ _ = a[10 /* ERROR "index .* out of bounds" */ ]
+ _ = a[1 /* ERROR "overflows" */ <<100]
+ _ = a[10:]
+ _ = a[:10]
+ _ = a[10:10]
+ _ = a[11 /* ERROR "index .* out of bounds" */ :]
+ _ = a[: 11 /* ERROR "index .* out of bounds" */ ]
+ _ = a[: 1 /* ERROR "overflows" */ <<100]
+ _ = a[:10:10]
+ _ = a[:11 /* ERROR "index .* out of bounds" */ :10]
+ _ = a[:10:11 /* ERROR "index .* out of bounds" */ ]
+ _ = a[10:0:10] /* ERROR swapped slice indices" */
+ _ = a[0:10:0] /* ERROR "swapped slice indices" */
+ _ = a[10:0:0] /* ERROR "swapped slice indices" */
+ _ = &a /* ERROR "cannot take address" */ [:10]
+
+ pa := &a
+ _ = pa[9]
+ _ = pa[10 /* ERROR "index .* out of bounds" */ ]
+ _ = pa[1 /* ERROR "overflows" */ <<100]
+ _ = pa[10:]
+ _ = pa[:10]
+ _ = pa[10:10]
+ _ = pa[11 /* ERROR "index .* out of bounds" */ :]
+ _ = pa[: 11 /* ERROR "index .* out of bounds" */ ]
+ _ = pa[: 1 /* ERROR "overflows" */ <<100]
+ _ = pa[:10:10]
+ _ = pa[:11 /* ERROR "index .* out of bounds" */ :10]
+ _ = pa[:10:11 /* ERROR "index .* out of bounds" */ ]
+ _ = pa[10:0:10] /* ERROR "swapped slice indices" */
+ _ = pa[0:10:0] /* ERROR "swapped slice indices" */
+ _ = pa[10:0:0] /* ERROR "swapped slice indices" */
+ _ = &pa /* ERROR "cannot take address" */ [:10]
+
+ var b [0]int
+ _ = b[0 /* ERROR "index .* out of bounds" */ ]
+ _ = b[:]
+ _ = b[0:]
+ _ = b[:0]
+ _ = b[0:0]
+ _ = b[0:0:0]
+ _ = b[1 /* ERROR "index .* out of bounds" */ :0:0]
+
+ var s []int
+ _ = s[- /* ERROR "negative" */ 1]
+ _ = s[- /* ERROR "negative" */ 1 :]
+ _ = s[: - /* ERROR "negative" */ 1]
+ _ = s[0]
+ _ = s[1:2]
+ _ = s[2:1] /* ERROR "swapped slice indices" */
+ _ = s[2:]
+ _ = s[: 1 /* ERROR "overflows" */ <<100]
+ _ = s[1 /* ERROR "overflows" */ <<100 :]
+ _ = s[1 /* ERROR "overflows" */ <<100 : 1 /* ERROR "overflows" */ <<100]
+ _ = s[: /* ERROR "2nd index required" */ : /* ERROR "3rd index required" */ ]
+ _ = s[:10:10]
+ _ = s[10:0:10] /* ERROR "swapped slice indices" */
+ _ = s[0:10:0] /* ERROR "swapped slice indices" */
+ _ = s[10:0:0] /* ERROR "swapped slice indices" */
+ _ = &s /* ERROR "cannot take address" */ [:10]
+
+ var m map[string]int
+ _ = m[0 /* ERROR "cannot use .* in map index" */ ]
+ _ = m /* ERROR "cannot slice" */ ["foo" : "bar"]
+ _ = m["foo"]
+ // ok is of type bool
+ type mybool bool
+ var ok mybool
+ _, ok = m["bar"]
+ _ = ok
+ _ = m[0 /* ERROR "cannot use 0" */ ] + "foo" // ERROR "cannot convert"
+
+ var t string
+ _ = t[- /* ERROR "negative" */ 1]
+ _ = t[- /* ERROR "negative" */ 1 :]
+ _ = t[: - /* ERROR "negative" */ 1]
+ _ = t /* ERROR "3-index slice of string" */ [1:2:3]
+ _ = "foo" /* ERROR "3-index slice of string" */ [1:2:3]
+ var t0 byte
+ t0 = t[0]
+ _ = t0
+ var t1 rune
+ t1 = t /* ERROR "cannot use .* in assignment" */ [2]
+ _ = t1
+ _ = ("foo" + "bar")[5]
+ _ = ("foo" + "bar")[6 /* ERROR "index .* out of bounds" */ ]
+
+ const c = "foo"
+ _ = c[- /* ERROR "negative" */ 1]
+ _ = c[- /* ERROR "negative" */ 1 :]
+ _ = c[: - /* ERROR "negative" */ 1]
+ var c0 byte
+ c0 = c[0]
+ _ = c0
+ var c2 float32
+ c2 = c /* ERROR "cannot use .* in assignment" */ [2]
+ _ = c[3 /* ERROR "index .* out of bounds" */ ]
+ _ = ""[0 /* ERROR "index .* out of bounds" */ ]
+ _ = c2
+
+ _ = s[1<<30] // no compile-time error here
+
+ // issue 4913
+ type mystring string
+ var ss string
+ var ms mystring
+ var i, j int
+ ss = "foo"[1:2]
+ ss = "foo"[i:j]
+ ms = "foo" /* ERROR "cannot use .* in assignment" */ [1:2]
+ ms = "foo" /* ERROR "cannot use .* in assignment" */ [i:j]
+ _, _ = ss, ms
+}
+
+type T struct {
+ x int
+ y func()
+}
+
+func (*T) m() {}
+
+func method_expressions() {
+ _ = T.a /* ERROR "no field or method" */
+ _ = T.x /* ERROR "has no method" */
+ _ = T.m /* ERROR "cannot call pointer method m on T" */
+ _ = (*T).m
+
+ var f func(*T) = T.m /* ERROR "cannot call pointer method m on T" */
+ var g func(*T) = (*T).m
+ _, _ = f, g
+
+ _ = T.y /* ERROR "has no method" */
+ _ = (*T).y /* ERROR "has no method" */
+}
+
+func struct_literals() {
+ type T0 struct {
+ a, b, c int
+ }
+
+ type T1 struct {
+ T0
+ a, b int
+ u float64
+ s string
+ }
+
+ // keyed elements
+ _ = T1{}
+ _ = T1{a: 0, 1 /* ERROR "mixture of .* elements" */ }
+ _ = T1{aa /* ERROR "unknown field" */ : 0}
+ _ = T1{1 /* ERROR "invalid field name" */ : 0}
+ _ = T1{a: 0, s: "foo", u: 0, a /* ERROR "duplicate field" */: 10}
+ _ = T1{a: "foo" /* ERROR "cannot use .* in struct literal" */ }
+ _ = T1{c /* ERROR "unknown field" */ : 0}
+ _ = T1{T0: { /* ERROR "missing type" */ }} // struct literal element type may not be elided
+ _ = T1{T0: T0{}}
+ _ = T1{T0 /* ERROR "invalid field name" */ .a: 0}
+
+ // unkeyed elements
+ _ = T0{1, 2, 3}
+ _ = T0{1, b /* ERROR "mixture" */ : 2, 3}
+ _ = T0{1, 2} /* ERROR "too few values" */
+ _ = T0{1, 2, 3, 4 /* ERROR "too many values" */ }
+ _ = T0{1, "foo" /* ERROR "cannot use .* in struct literal" */, 3.4 /* ERROR "cannot use .*\(truncated\)" */}
+
+ // invalid type
+ type P *struct{
+ x int
+ }
+ _ = P /* ERROR "invalid composite literal type" */ {}
+
+ // unexported fields
+ _ = time.Time{}
+ _ = time.Time{sec /* ERROR "unknown field" */ : 0}
+ _ = time.Time{
+ 0 /* ERROR implicit assignment to unexported field wall in time.Time literal */,
+ 0 /* ERROR implicit assignment */ ,
+ nil /* ERROR implicit assignment */ ,
+ }
+}
+
+func array_literals() {
+ type A0 [0]int
+ _ = A0{}
+ _ = A0{0 /* ERROR "index .* out of bounds" */}
+ _ = A0{0 /* ERROR "index .* out of bounds" */ : 0}
+
+ type A1 [10]int
+ _ = A1{}
+ _ = A1{0, 1, 2}
+ _ = A1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+ _ = A1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 /* ERROR "index .* out of bounds" */ }
+ _ = A1{- /* ERROR "negative" */ 1: 0}
+ _ = A1{8: 8, 9}
+ _ = A1{8: 8, 9, 10 /* ERROR "index .* out of bounds" */ }
+ _ = A1{0, 1, 2, 0 /* ERROR "duplicate index" */ : 0, 3: 3, 4}
+ _ = A1{5: 5, 6, 7, 3: 3, 4}
+ _ = A1{5: 5, 6, 7, 3: 3, 4, 5 /* ERROR "duplicate index" */ }
+ _ = A1{10 /* ERROR "index .* out of bounds" */ : 10, 10 /* ERROR "index .* out of bounds" */ : 10}
+ _ = A1{5: 5, 6, 7, 3: 3, 1 /* ERROR "overflows" */ <<100: 4, 5 /* ERROR "duplicate index" */ }
+ _ = A1{5: 5, 6, 7, 4: 4, 1 /* ERROR "overflows" */ <<100: 4}
+ _ = A1{2.0}
+ _ = A1{2.1 /* ERROR "truncated" */ }
+ _ = A1{"foo" /* ERROR "cannot use .* in array or slice literal" */ }
+
+ // indices must be integer constants
+ i := 1
+ const f = 2.1
+ const s = "foo"
+ _ = A1{i /* ERROR "index i must be integer constant" */ : 0}
+ _ = A1{f /* ERROR "truncated" */ : 0}
+ _ = A1{s /* ERROR "cannot convert" */ : 0}
+
+ a0 := [...]int{}
+ assert(len(a0) == 0)
+
+ a1 := [...]int{0, 1, 2}
+ assert(len(a1) == 3)
+ var a13 [3]int
+ var a14 [4]int
+ a13 = a1
+ a14 = a1 /* ERROR "cannot use .* in assignment" */
+ _, _ = a13, a14
+
+ a2 := [...]int{- /* ERROR "negative" */ 1: 0}
+ _ = a2
+
+ a3 := [...]int{0, 1, 2, 0 /* ERROR "duplicate index" */ : 0, 3: 3, 4}
+ assert(len(a3) == 5) // somewhat arbitrary
+
+ a4 := [...]complex128{0, 1, 2, 1<<10-2: -1i, 1i, 400: 10, 12, 14}
+ assert(len(a4) == 1024)
+
+ // composite literal element types may be elided
+ type T []int
+ _ = [10]T{T{}, {}, 5: T{1, 2, 3}, 7: {1, 2, 3}}
+ a6 := [...]T{T{}, {}, 5: T{1, 2, 3}, 7: {1, 2, 3}}
+ assert(len(a6) == 8)
+
+ // recursively so
+ _ = [10][10]T{{}, [10]T{{}}, {{1, 2, 3}}}
+
+ // from the spec
+ type Point struct { x, y float32 }
+ _ = [...]Point{Point{1.5, -3.5}, Point{0, 0}}
+ _ = [...]Point{{1.5, -3.5}, {0, 0}}
+ _ = [][]int{[]int{1, 2, 3}, []int{4, 5}}
+ _ = [][]int{{1, 2, 3}, {4, 5}}
+ _ = [...]*Point{&Point{1.5, -3.5}, &Point{0, 0}}
+ _ = [...]*Point{{1.5, -3.5}, {0, 0}}
+}
+
+func slice_literals() {
+ type S0 []int
+ _ = S0{}
+ _ = S0{0, 1, 2}
+ _ = S0{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+ _ = S0{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+ _ = S0{- /* ERROR "negative" */ 1: 0}
+ _ = S0{8: 8, 9}
+ _ = S0{8: 8, 9, 10}
+ _ = S0{0, 1, 2, 0 /* ERROR "duplicate index" */ : 0, 3: 3, 4}
+ _ = S0{5: 5, 6, 7, 3: 3, 4}
+ _ = S0{5: 5, 6, 7, 3: 3, 4, 5 /* ERROR "duplicate index" */ }
+ _ = S0{10: 10, 10 /* ERROR "duplicate index" */ : 10}
+ _ = S0{5: 5, 6, 7, 3: 3, 1 /* ERROR "overflows" */ <<100: 4, 5 /* ERROR "duplicate index" */ }
+ _ = S0{5: 5, 6, 7, 4: 4, 1 /* ERROR "overflows" */ <<100: 4}
+ _ = S0{2.0}
+ _ = S0{2.1 /* ERROR "truncated" */ }
+ _ = S0{"foo" /* ERROR "cannot use .* in array or slice literal" */ }
+
+ // indices must be resolved correctly
+ const index1 = 1
+ _ = S0{index1: 1}
+ _ = S0{index2: 2}
+ _ = S0{index3 /* ERROR "undeclared name" */ : 3}
+
+ // indices must be integer constants
+ i := 1
+ const f = 2.1
+ const s = "foo"
+ _ = S0{i /* ERROR "index i must be integer constant" */ : 0}
+ _ = S0{f /* ERROR "truncated" */ : 0}
+ _ = S0{s /* ERROR "cannot convert" */ : 0}
+
+ // composite literal element types may be elided
+ type T []int
+ _ = []T{T{}, {}, 5: T{1, 2, 3}, 7: {1, 2, 3}}
+ _ = [][]int{{1, 2, 3}, {4, 5}}
+
+ // recursively so
+ _ = [][]T{{}, []T{{}}, {{1, 2, 3}}}
+
+ // issue 17954
+ type T0 *struct { s string }
+ _ = []T0{{}}
+ _ = []T0{{"foo"}}
+
+ type T1 *struct{ int }
+ _ = []T1{}
+ _ = []T1{{0}, {1}, {2}}
+
+ type T2 T1
+ _ = []T2{}
+ _ = []T2{{0}, {1}, {2}}
+
+ _ = map[T0]T2{}
+ _ = map[T0]T2{{}: {}}
+}
+
+const index2 int = 2
+
+type N int
+func (N) f() {}
+
+func map_literals() {
+ type M0 map[string]int
+ type M1 map[bool]int
+ type M2 map[*int]int
+
+ _ = M0{}
+ _ = M0{1 /* ERROR "missing key" */ }
+ _ = M0{1 /* ERROR "cannot use .* in map literal" */ : 2}
+ _ = M0{"foo": "bar" /* ERROR "cannot use .* in map literal" */ }
+ _ = M0{"foo": 1, "bar": 2, "foo" /* ERROR "duplicate key" */ : 3 }
+
+ _ = map[interface{}]int{2: 1, 2 /* ERROR "duplicate key" */ : 1}
+ _ = map[interface{}]int{int(2): 1, int16(2): 1}
+ _ = map[interface{}]int{int16(2): 1, int16 /* ERROR "duplicate key" */ (2): 1}
+
+ type S string
+
+ _ = map[interface{}]int{"a": 1, "a" /* ERROR "duplicate key" */ : 1}
+ _ = map[interface{}]int{"a": 1, S("a"): 1}
+ _ = map[interface{}]int{S("a"): 1, S /* ERROR "duplicate key" */ ("a"): 1}
+ _ = map[interface{}]int{1.0: 1, 1.0 /* ERROR "duplicate key" */: 1}
+ _ = map[interface{}]int{int64(-1): 1, int64 /* ERROR "duplicate key" */ (-1) : 1}
+ _ = map[interface{}]int{^uint64(0): 1, ^ /* ERROR "duplicate key" */ uint64(0): 1}
+ _ = map[interface{}]int{complex(1,2): 1, complex /* ERROR "duplicate key" */ (1,2) : 1}
+
+ type I interface {
+ f()
+ }
+
+ _ = map[I]int{N(0): 1, N(2): 1}
+ _ = map[I]int{N(2): 1, N /* ERROR "duplicate key" */ (2): 1}
+
+ // map keys must be resolved correctly
+ key1 := "foo"
+ _ = M0{key1: 1}
+ _ = M0{key2: 2}
+ _ = M0{key3 /* ERROR "undeclared name" */ : 2}
+
+ var value int
+ _ = M1{true: 1, false: 0}
+ _ = M2{nil: 0, &value: 1}
+
+ // composite literal element types may be elided
+ type T [2]int
+ _ = map[int]T{0: T{3, 4}, 1: {5, 6}}
+
+ // recursively so
+ _ = map[int][]T{0: {}, 1: {{}, T{1, 2}}}
+
+ // composite literal key types may be elided
+ _ = map[T]int{T{3, 4}: 0, {5, 6}: 1}
+
+ // recursively so
+ _ = map[[2]T]int{{}: 0, {{}}: 1, [2]T{{}}: 2, {T{1, 2}}: 3}
+
+ // composite literal element and key types may be elided
+ _ = map[T]T{{}: {}, {1, 2}: T{3, 4}, T{4, 5}: {}}
+ _ = map[T]M0{{} : {}, T{1, 2}: M0{"foo": 0}, {1, 3}: {"foo": 1}}
+
+ // recursively so
+ _ = map[[2]T][]T{{}: {}, {{}}: {{}, T{1, 2}}, [2]T{{}}: nil, {T{1, 2}}: {{}, {}}}
+
+ // from the spec
+ type Point struct { x, y float32 }
+ _ = map[string]Point{"orig": {0, 0}}
+ _ = map[*Point]string{{0, 0}: "orig"}
+
+ // issue 17954
+ type T0 *struct{ s string }
+ type T1 *struct{ int }
+ type T2 T1
+
+ _ = map[T0]T2{}
+ _ = map[T0]T2{{}: {}}
+}
+
+var key2 string = "bar"
+
+type I interface {
+ m()
+}
+
+type I2 interface {
+ m(int)
+}
+
+type T1 struct{}
+type T2 struct{}
+
+func (T2) m(int) {}
+
+type mybool bool
+
+func type_asserts() {
+ var x int
+ _ = x /* ERROR "not an interface" */ .(int)
+
+ var e interface{}
+ var ok bool
+ x, ok = e.(int)
+ _ = ok
+
+ // ok value is of type bool
+ var myok mybool
+ _, myok = e.(int)
+ _ = myok
+
+ var t I
+ _ = t /* ERROR "use of .* outside type switch" */ .(type)
+ _ = t /* ERROR "missing method m" */ .(T)
+ _ = t.(*T)
+ _ = t /* ERROR "missing method m" */ .(T1)
+ _ = t /* ERROR "wrong type for method m" */ .(T2)
+ _ = t /* STRICT "wrong type for method m" */ .(I2) // only an error in strict mode (issue 8561)
+
+ // e doesn't statically have an m, but may have one dynamically.
+ _ = e.(I2)
+}
+
+func f0() {}
+func f1(x int) {}
+func f2(u float32, s string) {}
+func fs(s []byte) {}
+func fv(x ...int) {}
+func fi(x ... interface{}) {}
+func (T) fm(x ...int)
+
+func g0() {}
+func g1() int { return 0}
+func g2() (u float32, s string) { return }
+func gs() []byte { return nil }
+
+func _calls() {
+ var x int
+ var y float32
+ var s []int
+
+ f0()
+ _ = f0 /* ERROR "used as value" */ ()
+ f0(g0 /* ERROR "too many arguments" */ )
+
+ f1(0)
+ f1(x)
+ f1(10.0)
+ f1() /* ERROR "too few arguments" */
+ f1(x, y /* ERROR "too many arguments" */ )
+ f1(s /* ERROR "cannot use .* in argument" */ )
+ f1(x ... /* ERROR "cannot use ..." */ )
+ f1(g0 /* ERROR "used as value" */ ())
+ f1(g1())
+ f1(g2 /* ERROR "cannot use g2" */ /* ERROR "too many arguments" */ ())
+
+ f2() /* ERROR "too few arguments" */
+ f2(3.14) /* ERROR "too few arguments" */
+ f2(3.14, "foo")
+ f2(x /* ERROR "cannot use .* in argument" */ , "foo")
+ f2(g0 /* ERROR "used as value" */ ())
+ f2(g1 /* ERROR "cannot use .* in argument" */ ()) /* ERROR "too few arguments" */
+ f2(g2())
+
+ fs() /* ERROR "too few arguments" */
+ fs(g0 /* ERROR "used as value" */ ())
+ fs(g1 /* ERROR "cannot use .* in argument" */ ())
+ fs(g2 /* ERROR "cannot use .* in argument" */ /* ERROR "too many arguments" */ ())
+ fs(gs())
+
+ fv()
+ fv(1, 2.0, x)
+ fv(s /* ERROR "cannot use .* in argument" */ )
+ fv(s...)
+ fv(x /* ERROR "cannot use" */ ...)
+ fv(1, s... /* ERROR "can only use ... with matching parameter" */ )
+ fv(gs /* ERROR "cannot use .* in argument" */ ())
+ fv(gs /* ERROR "cannot use .* in argument" */ ()...)
+
+ var t T
+ t.fm()
+ t.fm(1, 2.0, x)
+ t.fm(s /* ERROR "cannot use .* in argument" */ )
+ t.fm(g1())
+ t.fm(1, s... /* ERROR "can only use ... with matching parameter" */ )
+ t.fm(gs /* ERROR "cannot use .* in argument" */ ())
+ t.fm(gs /* ERROR "cannot use .* in argument" */ ()...)
+
+ T.fm(t, )
+ T.fm(t, 1, 2.0, x)
+ T.fm(t, s /* ERROR "cannot use .* in argument" */ )
+ T.fm(t, g1())
+ T.fm(t, 1, s... /* ERROR "can only use ... with matching parameter" */ )
+ T.fm(t, gs /* ERROR "cannot use .* in argument" */ ())
+ T.fm(t, gs /* ERROR "cannot use .* in argument" */ ()...)
+
+ var i interface{ fm(x ...int) } = t
+ i.fm()
+ i.fm(1, 2.0, x)
+ i.fm(s /* ERROR "cannot use .* in argument" */ )
+ i.fm(g1())
+ i.fm(1, s... /* ERROR "can only use ... with matching parameter" */ )
+ i.fm(gs /* ERROR "cannot use .* in argument" */ ())
+ i.fm(gs /* ERROR "cannot use .* in argument" */ ()...)
+
+ fi()
+ fi(1, 2.0, x, 3.14, "foo")
+ fi(g2())
+ fi(0, g2)
+ fi(0, g2 /* ERROR "2-valued g2" */ ())
+}
+
+func issue6344() {
+ type T []interface{}
+ var x T
+ fi(x...) // ... applies also to named slices
+}
diff --git a/src/go/types/testdata/gotos.src b/src/go/types/testdata/gotos.src
new file mode 100644
index 0000000..069a94b
--- /dev/null
+++ b/src/go/types/testdata/gotos.src
@@ -0,0 +1,560 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is a modified copy of $GOROOT/test/goto.go.
+
+package gotos
+
+var (
+ i, n int
+ x []int
+ c chan int
+ m map[int]int
+ s string
+)
+
+// goto after declaration okay
+func _() {
+ x := 1
+ goto L
+L:
+ _ = x
+}
+
+// goto before declaration okay
+func _() {
+ goto L
+L:
+ x := 1
+ _ = x
+}
+
+// goto across declaration not okay
+func _() {
+ goto L /* ERROR "goto L jumps over variable declaration at line 36" */
+ x := 1
+ _ = x
+L:
+}
+
+// goto across declaration in inner scope okay
+func _() {
+ goto L
+ {
+ x := 1
+ _ = x
+ }
+L:
+}
+
+// goto across declaration after inner scope not okay
+func _() {
+ goto L /* ERROR "goto L jumps over variable declaration at line 58" */
+ {
+ x := 1
+ _ = x
+ }
+ x := 1
+ _ = x
+L:
+}
+
+// goto across declaration in reverse okay
+func _() {
+L:
+ x := 1
+ _ = x
+ goto L
+}
+
+func _() {
+L: L1:
+ x := 1
+ _ = x
+ goto L
+ goto L1
+}
+
+// error shows first offending variable
+func _() {
+ goto L /* ERROR "goto L jumps over variable declaration at line 84" */
+ x := 1
+ _ = x
+ y := 1
+ _ = y
+L:
+}
+
+// goto not okay even if code path is dead
+func _() {
+ goto L /* ERROR "goto L jumps over variable declaration" */
+ x := 1
+ _ = x
+ y := 1
+ _ = y
+ return
+L:
+}
+
+// goto into outer block okay
+func _() {
+ {
+ goto L
+ }
+L:
+}
+
+func _() {
+ {
+ goto L
+ goto L1
+ }
+L: L1:
+}
+
+// goto backward into outer block okay
+func _() {
+L:
+ {
+ goto L
+ }
+}
+
+func _() {
+L: L1:
+ {
+ goto L
+ goto L1
+ }
+}
+
+// goto into inner block not okay
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ {
+ L:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ goto L1 /* ERROR "goto L1 jumps into block" */
+ {
+ L: L1:
+ }
+}
+
+// goto backward into inner block still not okay
+func _() {
+ {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ {
+ L: L1:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+ goto L1 /* ERROR "goto L1 jumps into block" */
+}
+
+// error shows first (outermost) offending block
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ {
+ {
+ {
+ L:
+ }
+ }
+ }
+}
+
+// error prefers block diagnostic over declaration diagnostic
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ x := 1
+ _ = x
+ {
+ L:
+ }
+}
+
+// many kinds of blocks, all invalid to jump into or among,
+// but valid to jump out of
+
+// if
+
+func _() {
+L:
+ if true {
+ goto L
+ }
+}
+
+func _() {
+L:
+ if true {
+ goto L
+ } else {
+ }
+}
+
+func _() {
+L:
+ if false {
+ } else {
+ goto L
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ if true {
+ L:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ if true {
+ L:
+ } else {
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ if true {
+ } else {
+ L:
+ }
+}
+
+func _() {
+ if false {
+ L:
+ } else {
+ goto L /* ERROR "goto L jumps into block" */
+ }
+}
+
+func _() {
+ if true {
+ goto L /* ERROR "goto L jumps into block" */
+ } else {
+ L:
+ }
+}
+
+func _() {
+ if true {
+ goto L /* ERROR "goto L jumps into block" */
+ } else if false {
+ L:
+ }
+}
+
+func _() {
+ if true {
+ goto L /* ERROR "goto L jumps into block" */
+ } else if false {
+ L:
+ } else {
+ }
+}
+
+func _() {
+ if true {
+ goto L /* ERROR "goto L jumps into block" */
+ } else if false {
+ } else {
+ L:
+ }
+}
+
+func _() {
+ if true {
+ goto L /* ERROR "goto L jumps into block" */
+ } else {
+ L:
+ }
+}
+
+func _() {
+ if true {
+ L:
+ } else {
+ goto L /* ERROR "goto L jumps into block" */
+ }
+}
+
+// for
+
+func _() {
+ for {
+ goto L
+ }
+L:
+}
+
+func _() {
+ for {
+ goto L
+ L:
+ }
+}
+
+func _() {
+ for {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for {
+ goto L
+ L1:
+ }
+L:
+ goto L1 /* ERROR "goto L1 jumps into block" */
+}
+
+func _() {
+ for i < n {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for i = 0; i < n; i++ {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for i = range x {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for i = range c {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for i = range m {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+func _() {
+ for i = range s {
+ L:
+ }
+ goto L /* ERROR "goto L jumps into block" */
+}
+
+// switch
+
+func _() {
+L:
+ switch i {
+ case 0:
+ goto L
+ }
+}
+
+func _() {
+L:
+ switch i {
+ case 0:
+
+ default:
+ goto L
+ }
+}
+
+func _() {
+ switch i {
+ case 0:
+
+ default:
+ L:
+ goto L
+ }
+}
+
+func _() {
+ switch i {
+ case 0:
+
+ default:
+ goto L
+ L:
+ }
+}
+
+func _() {
+ switch i {
+ case 0:
+ goto L
+ L:
+ ;
+ default:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ switch i {
+ case 0:
+ L:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ switch i {
+ case 0:
+ L:
+ ;
+ default:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ switch i {
+ case 0:
+ default:
+ L:
+ }
+}
+
+func _() {
+ switch i {
+ default:
+ goto L /* ERROR "goto L jumps into block" */
+ case 0:
+ L:
+ }
+}
+
+func _() {
+ switch i {
+ case 0:
+ L:
+ ;
+ default:
+ goto L /* ERROR "goto L jumps into block" */
+ }
+}
+
+// select
+// different from switch. the statement has no implicit block around it.
+
+func _() {
+L:
+ select {
+ case <-c:
+ goto L
+ }
+}
+
+func _() {
+L:
+ select {
+ case c <- 1:
+
+ default:
+ goto L
+ }
+}
+
+func _() {
+ select {
+ case <-c:
+
+ default:
+ L:
+ goto L
+ }
+}
+
+func _() {
+ select {
+ case c <- 1:
+
+ default:
+ goto L
+ L:
+ }
+}
+
+func _() {
+ select {
+ case <-c:
+ goto L
+ L:
+ ;
+ default:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ select {
+ case c <- 1:
+ L:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ select {
+ case c <- 1:
+ L:
+ ;
+ default:
+ }
+}
+
+func _() {
+ goto L /* ERROR "goto L jumps into block" */
+ select {
+ case <-c:
+ default:
+ L:
+ }
+}
+
+func _() {
+ select {
+ default:
+ goto L /* ERROR "goto L jumps into block" */
+ case <-c:
+ L:
+ }
+}
+
+func _() {
+ select {
+ case <-c:
+ L:
+ ;
+ default:
+ goto L /* ERROR "goto L jumps into block" */
+ }
+}
diff --git a/src/go/types/testdata/importC.src b/src/go/types/testdata/importC.src
new file mode 100644
index 0000000..f55be2d
--- /dev/null
+++ b/src/go/types/testdata/importC.src
@@ -0,0 +1,54 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package importC
+
+import "C"
+import _ /* ERROR cannot rename import "C" */ "C"
+import foo /* ERROR cannot rename import "C" */ "C"
+import . /* ERROR cannot rename import "C" */ "C"
+
+// Test cases extracted from issue #22090.
+
+import "unsafe"
+
+const _ C.int = 0xff // no error due to invalid constant type
+
+type T struct {
+ Name string
+ Ordinal int
+}
+
+func _(args []T) {
+ var s string
+ for i, v := range args {
+ cname := C.CString(v.Name)
+ args[i].Ordinal = int(C.sqlite3_bind_parameter_index(s, cname)) // no error due to i not being "used"
+ C.free(unsafe.Pointer(cname))
+ }
+}
+
+type CType C.Type
+
+const _ CType = C.X // no error due to invalid constant type
+const _ = C.X
+
+// Test cases extracted from issue #23712.
+
+func _() {
+ var a [C.ArrayLength]byte
+ _ = a[0] // no index out of bounds error here
+}
+
+// Additional tests to verify fix for #23712.
+
+func _() {
+ var a [C.ArrayLength1]byte
+ _ = 1 / len(a) // no division by zero error here and below
+ _ = 1 / cap(a)
+ _ = uint(unsafe.Sizeof(a)) // must not be negative
+
+ var b [C.ArrayLength2]byte
+ a = b // should be valid
+}
diff --git a/src/go/types/testdata/importdecl0a.src b/src/go/types/testdata/importdecl0a.src
new file mode 100644
index 0000000..e96fca3
--- /dev/null
+++ b/src/go/types/testdata/importdecl0a.src
@@ -0,0 +1,53 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package importdecl0
+
+import ()
+
+import (
+ // we can have multiple blank imports (was bug)
+ _ "math"
+ _ "net/rpc"
+ init /* ERROR "cannot declare init" */ "fmt"
+ // reflect defines a type "flag" which shows up in the gc export data
+ "reflect"
+ . /* ERROR "imported but not used" */ "reflect"
+)
+
+import "math" /* ERROR "imported but not used" */
+import m /* ERROR "imported but not used as m" */ "math"
+import _ "math"
+
+import (
+ "math/big" /* ERROR "imported but not used" */
+ b /* ERROR "imported but not used" */ "math/big"
+ _ "math/big"
+)
+
+import "fmt"
+import f1 "fmt"
+import f2 "fmt"
+
+// reflect.flag must not be visible in this package
+type flag int
+type _ reflect.flag /* ERROR "not exported" */
+
+// imported package name may conflict with local objects
+type reflect /* ERROR "reflect already declared" */ int
+
+// dot-imported exported objects may conflict with local objects
+type Value /* ERROR "Value already declared through dot-import of package reflect" */ struct{}
+
+var _ = fmt.Println // use "fmt"
+
+func _() {
+ f1.Println() // use "fmt"
+}
+
+func _() {
+ _ = func() {
+ f2.Println() // use "fmt"
+ }
+}
diff --git a/src/go/types/testdata/importdecl0b.src b/src/go/types/testdata/importdecl0b.src
new file mode 100644
index 0000000..6844e70
--- /dev/null
+++ b/src/go/types/testdata/importdecl0b.src
@@ -0,0 +1,33 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package importdecl0
+
+import "math"
+import m "math"
+
+import . "testing" // declares T in file scope
+import . /* ERROR "imported but not used" */ "unsafe"
+import . "fmt" // declares Println in file scope
+
+import (
+ // TODO(gri) At the moment, 2 errors are reported because both go/parser
+ // and the type checker report it. Eventually, this test should not be
+ // done by the parser anymore.
+ "" /* ERROR invalid import path */ /* ERROR invalid import path */
+ "a!b" /* ERROR invalid import path */ /* ERROR invalid import path */
+ "abc\xffdef" /* ERROR invalid import path */ /* ERROR invalid import path */
+)
+
+// using "math" in this file doesn't affect its use in other files
+const Pi0 = math.Pi
+const Pi1 = m.Pi
+
+type _ T // use "testing"
+
+func _() func() interface{} {
+ return func() interface{} {
+ return Println // use "fmt"
+ }
+}
diff --git a/src/go/types/testdata/importdecl1a.src b/src/go/types/testdata/importdecl1a.src
new file mode 100644
index 0000000..d377c01
--- /dev/null
+++ b/src/go/types/testdata/importdecl1a.src
@@ -0,0 +1,22 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test case for issue 8969.
+
+package importdecl1
+
+import "go/ast"
+import . "unsafe"
+
+var _ Pointer // use dot-imported package unsafe
+
+// Test cases for issue 23914.
+
+type A interface {
+ // Methods m1, m2 must be type-checked in this file scope
+ // even when embedded in an interface in a different
+ // file of the same package.
+ m1() ast.Node
+ m2() Pointer
+}
diff --git a/src/go/types/testdata/importdecl1b.src b/src/go/types/testdata/importdecl1b.src
new file mode 100644
index 0000000..ee70bbd
--- /dev/null
+++ b/src/go/types/testdata/importdecl1b.src
@@ -0,0 +1,11 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package importdecl1
+
+import . /* ERROR "imported but not used" */ "unsafe"
+
+type B interface {
+ A
+}
diff --git a/src/go/types/testdata/init0.src b/src/go/types/testdata/init0.src
new file mode 100644
index 0000000..6e8746a
--- /dev/null
+++ b/src/go/types/testdata/init0.src
@@ -0,0 +1,106 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// initialization cycles
+
+package init0
+
+// initialization cycles (we don't know the types)
+const (
+ s0 /* ERROR initialization cycle */ = s0
+
+ x0 /* ERROR initialization cycle */ = y0
+ y0 = x0
+
+ a0 = b0
+ b0 /* ERROR initialization cycle */ = c0
+ c0 = d0
+ d0 = b0
+)
+
+var (
+ s1 /* ERROR initialization cycle */ = s1
+
+ x1 /* ERROR initialization cycle */ = y1
+ y1 = x1
+
+ a1 = b1
+ b1 /* ERROR initialization cycle */ = c1
+ c1 = d1
+ d1 = b1
+)
+
+// initialization cycles (we know the types)
+const (
+ s2 /* ERROR initialization cycle */ int = s2
+
+ x2 /* ERROR initialization cycle */ int = y2
+ y2 = x2
+
+ a2 = b2
+ b2 /* ERROR initialization cycle */ int = c2
+ c2 = d2
+ d2 = b2
+)
+
+var (
+ s3 /* ERROR initialization cycle */ int = s3
+
+ x3 /* ERROR initialization cycle */ int = y3
+ y3 = x3
+
+ a3 = b3
+ b3 /* ERROR initialization cycle */ int = c3
+ c3 = d3
+ d3 = b3
+)
+
+// cycles via struct fields
+
+type S1 struct {
+ f int
+}
+const cx3 S1 /* ERROR invalid constant type */ = S1{cx3.f}
+var vx3 /* ERROR initialization cycle */ S1 = S1{vx3.f}
+
+// cycles via functions
+
+var x4 = x5
+var x5 /* ERROR initialization cycle */ = f1()
+func f1() int { return x5*10 }
+
+var x6, x7 /* ERROR initialization cycle */ = f2()
+var x8 = x7
+func f2() (int, int) { return f3() + f3(), 0 }
+func f3() int { return x8 }
+
+// cycles via function literals
+
+var x9 /* ERROR initialization cycle */ = func() int { return x9 }()
+
+var x10 /* ERROR initialization cycle */ = f4()
+
+func f4() int {
+ _ = func() {
+ _ = x10
+ }
+ return 0
+}
+
+// cycles via method expressions
+
+type T1 struct{}
+
+func (T1) m() bool { _ = x11; return false }
+
+var x11 /* ERROR initialization cycle */ = T1.m(T1{})
+
+// cycles via method values
+
+type T2 struct{}
+
+func (T2) m() bool { _ = x12; return false }
+
+var t1 T2
+var x12 /* ERROR initialization cycle */ = t1.m
diff --git a/src/go/types/testdata/init1.src b/src/go/types/testdata/init1.src
new file mode 100644
index 0000000..39ca314
--- /dev/null
+++ b/src/go/types/testdata/init1.src
@@ -0,0 +1,97 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// initialization cycles
+
+package init1
+
+// issue 6683 (marked as WorkingAsIntended)
+
+type T0 struct{}
+
+func (T0) m() int { return y0 }
+
+var x0 = T0{}
+
+var y0 /* ERROR initialization cycle */ = x0.m()
+
+type T1 struct{}
+
+func (T1) m() int { return y1 }
+
+var x1 interface {
+ m() int
+} = T1{}
+
+var y1 = x1.m() // no cycle reported, x1 is of interface type
+
+// issue 6703 (modified)
+
+var x2 /* ERROR initialization cycle */ = T2.m
+
+var y2 = x2
+
+type T2 struct{}
+
+func (T2) m() int {
+ _ = y2
+ return 0
+}
+
+var x3 /* ERROR initialization cycle */ = T3.m(T3{}) // <<<< added (T3{})
+
+var y3 = x3
+
+type T3 struct{}
+
+func (T3) m() int {
+ _ = y3
+ return 0
+}
+
+var x4 /* ERROR initialization cycle */ = T4{}.m // <<<< added {}
+
+var y4 = x4
+
+type T4 struct{}
+
+func (T4) m() int {
+ _ = y4
+ return 0
+}
+
+var x5 /* ERROR initialization cycle */ = T5{}.m() // <<<< added ()
+
+var y5 = x5
+
+type T5 struct{}
+
+func (T5) m() int {
+ _ = y5
+ return 0
+}
+
+// issue 4847
+// simplified test case
+
+var x6 = f6
+var y6 /* ERROR initialization cycle */ = f6
+func f6() { _ = y6 }
+
+// full test case
+
+type (
+ E int
+ S int
+)
+
+type matcher func(s *S) E
+
+func matchList(s *S) E { return matcher(matchAnyFn)(s) }
+
+var foo = matcher(matchList)
+
+var matchAny /* ERROR initialization cycle */ = matcher(matchList)
+
+func matchAnyFn(s *S) (err E) { return matchAny(s) } \ No newline at end of file
diff --git a/src/go/types/testdata/init2.src b/src/go/types/testdata/init2.src
new file mode 100644
index 0000000..614db6c
--- /dev/null
+++ b/src/go/types/testdata/init2.src
@@ -0,0 +1,139 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// initialization cycles
+
+package init2
+
+// cycles through functions
+
+func f1() int { _ = x1; return 0 }
+var x1 /* ERROR initialization cycle */ = f1
+
+func f2() int { _ = x2; return 0 }
+var x2 /* ERROR initialization cycle */ = f2()
+
+// cycles through method expressions
+
+type T3 int
+func (T3) m() int { _ = x3; return 0 }
+var x3 /* ERROR initialization cycle */ = T3.m
+
+type T4 int
+func (T4) m() int { _ = x4; return 0 }
+var x4 /* ERROR initialization cycle */ = T4.m(0)
+
+type T3p int
+func (*T3p) m() int { _ = x3p; return 0 }
+var x3p /* ERROR initialization cycle */ = (*T3p).m
+
+type T4p int
+func (*T4p) m() int { _ = x4p; return 0 }
+var x4p /* ERROR initialization cycle */ = (*T4p).m(nil)
+
+// cycles through method expressions of embedded methods
+
+type T5 struct { E5 }
+type E5 int
+func (E5) m() int { _ = x5; return 0 }
+var x5 /* ERROR initialization cycle */ = T5.m
+
+type T6 struct { E6 }
+type E6 int
+func (E6) m() int { _ = x6; return 0 }
+var x6 /* ERROR initialization cycle */ = T6.m(T6{0})
+
+type T5p struct { E5p }
+type E5p int
+func (*E5p) m() int { _ = x5p; return 0 }
+var x5p /* ERROR initialization cycle */ = (*T5p).m
+
+type T6p struct { E6p }
+type E6p int
+func (*E6p) m() int { _ = x6p; return 0 }
+var x6p /* ERROR initialization cycle */ = (*T6p).m(nil)
+
+// cycles through method values
+
+type T7 int
+func (T7) m() int { _ = x7; return 0 }
+var x7 /* ERROR initialization cycle */ = T7(0).m
+
+type T8 int
+func (T8) m() int { _ = x8; return 0 }
+var x8 /* ERROR initialization cycle */ = T8(0).m()
+
+type T7p int
+func (*T7p) m() int { _ = x7p; return 0 }
+var x7p /* ERROR initialization cycle */ = new(T7p).m
+
+type T8p int
+func (*T8p) m() int { _ = x8p; return 0 }
+var x8p /* ERROR initialization cycle */ = new(T8p).m()
+
+type T7v int
+func (T7v) m() int { _ = x7v; return 0 }
+var x7var T7v
+var x7v /* ERROR initialization cycle */ = x7var.m
+
+type T8v int
+func (T8v) m() int { _ = x8v; return 0 }
+var x8var T8v
+var x8v /* ERROR initialization cycle */ = x8var.m()
+
+type T7pv int
+func (*T7pv) m() int { _ = x7pv; return 0 }
+var x7pvar *T7pv
+var x7pv /* ERROR initialization cycle */ = x7pvar.m
+
+type T8pv int
+func (*T8pv) m() int { _ = x8pv; return 0 }
+var x8pvar *T8pv
+var x8pv /* ERROR initialization cycle */ = x8pvar.m()
+
+// cycles through method values of embedded methods
+
+type T9 struct { E9 }
+type E9 int
+func (E9) m() int { _ = x9; return 0 }
+var x9 /* ERROR initialization cycle */ = T9{0}.m
+
+type T10 struct { E10 }
+type E10 int
+func (E10) m() int { _ = x10; return 0 }
+var x10 /* ERROR initialization cycle */ = T10{0}.m()
+
+type T9p struct { E9p }
+type E9p int
+func (*E9p) m() int { _ = x9p; return 0 }
+var x9p /* ERROR initialization cycle */ = new(T9p).m
+
+type T10p struct { E10p }
+type E10p int
+func (*E10p) m() int { _ = x10p; return 0 }
+var x10p /* ERROR initialization cycle */ = new(T10p).m()
+
+type T9v struct { E9v }
+type E9v int
+func (E9v) m() int { _ = x9v; return 0 }
+var x9var T9v
+var x9v /* ERROR initialization cycle */ = x9var.m
+
+type T10v struct { E10v }
+type E10v int
+func (E10v) m() int { _ = x10v; return 0 }
+var x10var T10v
+var x10v /* ERROR initialization cycle */ = x10var.m()
+
+type T9pv struct { E9pv }
+type E9pv int
+func (*E9pv) m() int { _ = x9pv; return 0 }
+var x9pvar *T9pv
+var x9pv /* ERROR initialization cycle */ = x9pvar.m
+
+type T10pv struct { E10pv }
+type E10pv int
+func (*E10pv) m() int { _ = x10pv; return 0 }
+var x10pvar *T10pv
+var x10pv /* ERROR initialization cycle */ = x10pvar.m()
diff --git a/src/go/types/testdata/issue25008a.src b/src/go/types/testdata/issue25008a.src
new file mode 100644
index 0000000..cf71ca1
--- /dev/null
+++ b/src/go/types/testdata/issue25008a.src
@@ -0,0 +1,15 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "io"
+
+type A interface {
+ io.Reader
+}
+
+func f(a A) {
+ a.Read(nil)
+}
diff --git a/src/go/types/testdata/issue25008b.src b/src/go/types/testdata/issue25008b.src
new file mode 100644
index 0000000..f132b7f
--- /dev/null
+++ b/src/go/types/testdata/issue25008b.src
@@ -0,0 +1,9 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type B interface {
+ A
+}
diff --git a/src/go/types/testdata/issues.src b/src/go/types/testdata/issues.src
new file mode 100644
index 0000000..e0c5d7a
--- /dev/null
+++ b/src/go/types/testdata/issues.src
@@ -0,0 +1,365 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issues
+
+import (
+ "fmt"
+ syn "cmd/compile/internal/syntax"
+ t1 "text/template"
+ t2 "html/template"
+)
+
+func issue7035() {
+ type T struct{ X int }
+ _ = func() {
+ fmt.Println() // must refer to imported fmt rather than the fmt below
+ }
+ fmt := new(T)
+ _ = fmt.X
+}
+
+func issue8066() {
+ const (
+ _ = float32(340282356779733661637539395458142568447)
+ _ = float32(340282356779733661637539395458142568448 /* ERROR cannot convert */ )
+ )
+}
+
+// Check that a missing identifier doesn't lead to a spurious error cascade.
+func issue8799a() {
+ x, ok := missing /* ERROR undeclared */ ()
+ _ = !ok
+ _ = x
+}
+
+func issue8799b(x int, ok bool) {
+ x, ok = missing /* ERROR undeclared */ ()
+ _ = !ok
+ _ = x
+}
+
+func issue9182() {
+ type Point C /* ERROR undeclared */ .Point
+ // no error for composite literal based on unknown type
+ _ = Point{x: 1, y: 2}
+}
+
+func f0() (a []int) { return }
+func f1() (a []int, b int) { return }
+func f2() (a, b []int) { return }
+
+func append_([]int, ...int) {}
+
+func issue9473(a []int, b ...int) {
+ // variadic builtin function
+ _ = append(f0())
+ _ = append(f0(), f0()...)
+ _ = append(f1())
+ _ = append(f2 /* ERROR cannot use .* in argument */ ())
+ _ = append(f2()... /* ERROR cannot use ... */ )
+ _ = append(f0(), f1 /* ERROR 2-valued f1 */ ())
+ _ = append(f0(), f2 /* ERROR 2-valued f2 */ ())
+ _ = append(f0(), f1 /* ERROR 2-valued f1 */ ()...)
+ _ = append(f0(), f2 /* ERROR 2-valued f2 */ ()...)
+
+ // variadic user-defined function
+ append_(f0())
+ append_(f0(), f0()...)
+ append_(f1())
+ append_(f2 /* ERROR cannot use .* in argument */ ())
+ append_(f2()... /* ERROR cannot use ... */ )
+ append_(f0(), f1 /* ERROR 2-valued f1 */ ())
+ append_(f0(), f2 /* ERROR 2-valued f2 */ ())
+ append_(f0(), f1 /* ERROR 2-valued f1 */ ()...)
+ append_(f0(), f2 /* ERROR 2-valued f2 */ ()...)
+}
+
+// Check that embedding a non-interface type in an interface results in a good error message.
+func issue10979() {
+ type _ interface {
+ int /* ERROR int is not an interface */
+ }
+ type T struct{}
+ type _ interface {
+ T /* ERROR T is not an interface */
+ }
+ type _ interface {
+ nosuchtype /* ERROR undeclared name: nosuchtype */
+ }
+ type _ interface {
+ fmt.Nosuchtype /* ERROR Nosuchtype not declared by package fmt */
+ }
+ type _ interface {
+ nosuchpkg /* ERROR undeclared name: nosuchpkg */ .Nosuchtype
+ }
+ type I interface {
+ I.m /* ERROR no field or method m */
+ m()
+ }
+}
+
+// issue11347
+// These should not crash.
+var a1, b1 /* ERROR cycle */ , c1 /* ERROR cycle */ b1 = 0 > 0<<""[""[c1]]>c1
+var a2, b2 /* ERROR cycle */ = 0 /* ERROR cannot initialize */ /* ERROR cannot initialize */ > 0<<""[b2]
+var a3, b3 /* ERROR cycle */ = int /* ERROR cannot initialize */ /* ERROR cannot initialize */ (1<<""[b3])
+
+// issue10260
+// Check that error messages explain reason for interface assignment failures.
+type (
+ I0 interface{}
+ I1 interface{ foo() }
+ I2 interface{ foo(x int) }
+ T0 struct{}
+ T1 struct{}
+ T2 struct{}
+)
+
+func (*T1) foo() {}
+func (*T2) foo(x int) {}
+
+func issue10260() {
+ var (
+ i0 I0
+ i1 I1
+ i2 I2
+ t0 *T0
+ t1 *T1
+ t2 *T2
+ )
+
+ var x I1
+ x = T1 /* ERROR cannot use .*: missing method foo \(foo has pointer receiver\) */ {}
+ _ = x /* ERROR .* cannot have dynamic type T1 \(missing method foo \(foo has pointer receiver\)\) */ .(T1)
+
+ T1{}.foo /* ERROR cannot call pointer method foo on T1 */ ()
+ x.Foo /* ERROR "x.Foo undefined \(type I1 has no field or method Foo, but does have foo\)" */ ()
+
+ _ = i2 /* ERROR i2 .* cannot have dynamic type \*T1 \(wrong type for method foo \(have func\(\), want func\(x int\)\)\) */ .(*T1)
+
+ i1 = i0 /* ERROR cannot use .* missing method foo */
+ i1 = t0 /* ERROR cannot use .* missing method foo */
+ i1 = i2 /* ERROR cannot use .* wrong type for method foo */
+ i1 = t2 /* ERROR cannot use .* wrong type for method foo */
+ i2 = i1 /* ERROR cannot use .* wrong type for method foo */
+ i2 = t1 /* ERROR cannot use .* wrong type for method foo */
+
+ _ = func() I1 { return i0 /* ERROR cannot use .* missing method foo */ }
+ _ = func() I1 { return t0 /* ERROR cannot use .* missing method foo */ }
+ _ = func() I1 { return i2 /* ERROR cannot use .* wrong type for method foo */ }
+ _ = func() I1 { return t2 /* ERROR cannot use .* wrong type for method foo */ }
+ _ = func() I2 { return i1 /* ERROR cannot use .* wrong type for method foo */ }
+ _ = func() I2 { return t1 /* ERROR cannot use .* wrong type for method foo */ }
+
+ // a few more - less exhaustive now
+
+ f := func(I1, I2){}
+ f(i0 /* ERROR cannot use .* missing method foo */ , i1 /* ERROR cannot use .* wrong type for method foo \(have func\(\), want func\(x int\)\) */ )
+
+ _ = [...]I1{i0 /* ERROR cannot use .* missing method foo */ }
+ _ = [...]I1{i2 /* ERROR cannot use .* wrong type for method foo */ }
+ _ = []I1{i0 /* ERROR cannot use .* missing method foo */ }
+ _ = []I1{i2 /* ERROR cannot use .* wrong type for method foo */ }
+ _ = map[int]I1{0: i0 /* ERROR cannot use .* missing method foo */ }
+ _ = map[int]I1{0: i2 /* ERROR cannot use .* wrong type for method foo */ }
+
+ make(chan I1) <- i0 /* ERROR cannot use .* in send: missing method foo */
+ make(chan I1) <- i2 /* ERROR cannot use .* in send: wrong type for method foo */
+}
+
+// Check that constants representable as integers are in integer form
+// before being used in operations that are only defined on integers.
+func issue14229() {
+ // from the issue
+ const _ = int64(-1<<63) % 1e6
+
+ // related
+ const (
+ a int = 3
+ b = 4.0
+ _ = a / b
+ _ = a % b
+ _ = b / a
+ _ = b % a
+ )
+}
+
+// Check that in a n:1 variable declaration with type and initialization
+// expression the type is distributed to all variables of the lhs before
+// the initialization expression assignment is checked.
+func issue15755() {
+ // from issue
+ var i interface{}
+ type b bool
+ var x, y b = i.(b)
+ _ = x == y
+
+ // related: we should see an error since the result of f1 is ([]int, int)
+ var u, v []int = f1 /* ERROR cannot use f1 */ ()
+ _ = u
+ _ = v
+}
+
+// Test that we don't get "declared but not used"
+// errors in the context of invalid/C objects.
+func issue20358() {
+ var F C /* ERROR "undeclared" */ .F
+ var A C /* ERROR "undeclared" */ .A
+ var S C /* ERROR "undeclared" */ .S
+ type T C /* ERROR "undeclared" */ .T
+ type P C /* ERROR "undeclared" */ .P
+
+ // these variables must be "used" even though
+ // the LHS expressions/types below in which
+ // context they are used are unknown/invalid
+ var f, a, s1, s2, s3, t, p int
+
+ _ = F(f)
+ _ = A[a]
+ _ = S[s1:s2:s3]
+ _ = T{t}
+ _ = P{f: p}
+}
+
+// Test that we don't declare lhs variables in short variable
+// declarations before we type-check function literals on the
+// rhs.
+func issue24026() {
+ f := func() int { f(0) /* must refer to outer f */; return 0 }
+ _ = f
+
+ _ = func() {
+ f := func() { _ = f() /* must refer to outer f */ }
+ _ = f
+ }
+
+ // b and c must not be visible inside function literal
+ a := 0
+ a, b, c := func() (int, int, int) {
+ return a, b /* ERROR undeclared */ , c /* ERROR undeclared */
+ }()
+ _, _ = b, c
+}
+
+func f(int) {} // for issue24026
+
+// Test that we don't report a "missing return statement" error
+// (due to incorrect context when type-checking interfaces).
+func issue24140(x interface{}) int {
+ switch x.(type) {
+ case interface{}:
+ return 0
+ default:
+ panic(0)
+ }
+}
+
+// Test that we don't crash when the 'if' condition is missing.
+func issue25438() {
+ if { /* ERROR missing condition */ }
+ if x := 0; /* ERROR missing condition */ { _ = x }
+ if
+ { /* ERROR missing condition */ }
+}
+
+// Test that we can embed alias type names in interfaces.
+type issue25301 interface {
+ E
+}
+
+type E = interface {
+ m()
+}
+
+// Test case from issue.
+// cmd/compile reports a cycle as well.
+type issue25301b /* ERROR cycle */ = interface {
+ m() interface{ issue25301b }
+}
+
+type issue25301c interface {
+ notE // ERROR struct\{\} is not an interface
+}
+
+type notE = struct{}
+
+// Test that method declarations don't introduce artificial cycles
+// (issue #26124).
+const CC TT = 1
+type TT int
+func (TT) MM() [CC]TT
+
+// Reduced test case from issue #26124.
+const preloadLimit LNumber = 128
+type LNumber float64
+func (LNumber) assertFunction() *LFunction
+type LFunction struct {
+ GFunction LGFunction
+}
+type LGFunction func(*LState)
+type LState struct {
+ reg *registry
+}
+type registry struct {
+ alloc *allocator
+}
+type allocator struct {
+ _ [int(preloadLimit)]int
+}
+
+// Test that we don't crash when type-checking composite literals
+// containing errors in the type.
+var issue27346 = [][n /* ERROR undeclared */ ]int{
+ 0: {},
+}
+
+var issue22467 = map[int][... /* ERROR invalid use of ... */ ]int{0: {}}
+
+// Test that invalid use of ... in parameter lists is recognized
+// (issue #28281).
+func issue28281a(int, int, ...int)
+func issue28281b(a, b int, c ...int)
+func issue28281c(a, b, c ... /* ERROR can only use ... with final parameter */ int)
+func issue28281d(... /* ERROR can only use ... with final parameter */ int, int)
+func issue28281e(a, b, c ... /* ERROR can only use ... with final parameter */ int, d int)
+func issue28281f(... /* ERROR can only use ... with final parameter */ int, ... /* ERROR can only use ... with final parameter */ int, int)
+func (... /* ERROR expected type */ TT) f()
+func issue28281g() (... /* ERROR expected type */ TT)
+
+// Issue #26234: Make various field/method lookup errors easier to read by matching cmd/compile's output
+func issue26234a(f *syn.File) {
+ // The error message below should refer to the actual package name (syntax)
+ // not the local package name (syn).
+ f.foo /* ERROR f.foo undefined \(type \*syntax.File has no field or method foo\) */
+}
+
+type T struct {
+ x int
+ E1
+ E2
+}
+
+type E1 struct{ f int }
+type E2 struct{ f int }
+
+func issue26234b(x T) {
+ _ = x.f /* ERROR ambiguous selector x.f */
+}
+
+func issue26234c() {
+ T.x /* ERROR T.x undefined \(type T has no method x\) */ ()
+}
+
+func issue35895() {
+ // T is defined in this package, don't qualify its name with the package name.
+ var _ T = 0 // ERROR cannot use 0 \(untyped int constant\) as T
+
+ // There is only one package with name syntax imported, only use the (global) package name in error messages.
+ var _ *syn.File = 0 // ERROR cannot use 0 \(untyped int constant\) as \*syntax.File
+
+ // Because both t1 and t2 have the same global package name (template),
+ // qualify packages with full path name in this case.
+ var _ t1.Template = t2 /* ERROR cannot use .* \(value of type "html/template".Template\) as "text/template".Template */ .Template{}
+}
diff --git a/src/go/types/testdata/labels.src b/src/go/types/testdata/labels.src
new file mode 100644
index 0000000..9f42406
--- /dev/null
+++ b/src/go/types/testdata/labels.src
@@ -0,0 +1,207 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is a modified concatenation of the files
+// $GOROOT/test/label.go and $GOROOT/test/label1.go.
+
+package labels
+
+var x int
+
+func f0() {
+L1 /* ERROR "label L1 declared but not used" */ :
+ for {
+ }
+L2 /* ERROR "label L2 declared but not used" */ :
+ select {
+ }
+L3 /* ERROR "label L3 declared but not used" */ :
+ switch {
+ }
+L4 /* ERROR "label L4 declared but not used" */ :
+ if true {
+ }
+L5 /* ERROR "label L5 declared but not used" */ :
+ f0()
+L6:
+ f0()
+L6 /* ERROR "label L6 already declared" */ :
+ f0()
+ if x == 20 {
+ goto L6
+ }
+
+L7:
+ for {
+ break L7
+ break L8 /* ERROR "invalid break label L8" */
+ }
+
+// A label must be directly associated with a switch, select, or
+// for statement; it cannot be the label of a labeled statement.
+
+L7a /* ERROR "declared but not used" */ : L7b:
+ for {
+ break L7a /* ERROR "invalid break label L7a" */
+ continue L7a /* ERROR "invalid continue label L7a" */
+ continue L7b
+ }
+
+L8:
+ for {
+ if x == 21 {
+ continue L8
+ continue L7 /* ERROR "invalid continue label L7" */
+ }
+ }
+
+L9:
+ switch {
+ case true:
+ break L9
+ defalt /* ERROR "label defalt declared but not used" */ :
+ }
+
+L10:
+ select {
+ default:
+ break L10
+ break L9 /* ERROR "invalid break label L9" */
+ }
+
+ goto L10a
+L10a: L10b:
+ select {
+ default:
+ break L10a /* ERROR "invalid break label L10a" */
+ break L10b
+ continue L10b /* ERROR "invalid continue label L10b" */
+ }
+}
+
+func f1() {
+L1:
+ for {
+ if x == 0 {
+ break L1
+ }
+ if x == 1 {
+ continue L1
+ }
+ goto L1
+ }
+
+L2:
+ select {
+ default:
+ if x == 0 {
+ break L2
+ }
+ if x == 1 {
+ continue L2 /* ERROR "invalid continue label L2" */
+ }
+ goto L2
+ }
+
+L3:
+ switch {
+ case x > 10:
+ if x == 11 {
+ break L3
+ }
+ if x == 12 {
+ continue L3 /* ERROR "invalid continue label L3" */
+ }
+ goto L3
+ }
+
+L4:
+ if true {
+ if x == 13 {
+ break L4 /* ERROR "invalid break label L4" */
+ }
+ if x == 14 {
+ continue L4 /* ERROR "invalid continue label L4" */
+ }
+ if x == 15 {
+ goto L4
+ }
+ }
+
+L5:
+ f1()
+ if x == 16 {
+ break L5 /* ERROR "invalid break label L5" */
+ }
+ if x == 17 {
+ continue L5 /* ERROR "invalid continue label L5" */
+ }
+ if x == 18 {
+ goto L5
+ }
+
+ for {
+ if x == 19 {
+ break L1 /* ERROR "invalid break label L1" */
+ }
+ if x == 20 {
+ continue L1 /* ERROR "invalid continue label L1" */
+ }
+ if x == 21 {
+ goto L1
+ }
+ }
+}
+
+// Additional tests not in the original files.
+
+func f2() {
+L1 /* ERROR "label L1 declared but not used" */ :
+ if x == 0 {
+ for {
+ continue L1 /* ERROR "invalid continue label L1" */
+ }
+ }
+}
+
+func f3() {
+L1:
+L2:
+L3:
+ for {
+ break L1 /* ERROR "invalid break label L1" */
+ break L2 /* ERROR "invalid break label L2" */
+ break L3
+ continue L1 /* ERROR "invalid continue label L1" */
+ continue L2 /* ERROR "invalid continue label L2" */
+ continue L3
+ goto L1
+ goto L2
+ goto L3
+ }
+}
+
+// Blank labels are never declared.
+
+func f4() {
+_:
+_: // multiple blank labels are ok
+ goto _ /* ERROR "label _ not declared" */
+}
+
+func f5() {
+_:
+ for {
+ break _ /* ERROR "invalid break label _" */
+ continue _ /* ERROR "invalid continue label _" */
+ }
+}
+
+func f6() {
+_:
+ switch {
+ default:
+ break _ /* ERROR "invalid break label _" */
+ }
+}
diff --git a/src/go/types/testdata/literals.src b/src/go/types/testdata/literals.src
new file mode 100644
index 0000000..494a465
--- /dev/null
+++ b/src/go/types/testdata/literals.src
@@ -0,0 +1,111 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file tests various representations of literals
+// and compares them with literals or constant expressions
+// of equal values.
+
+package literals
+
+func _() {
+ // 0-octals
+ assert(0_123 == 0123)
+ assert(0123_456 == 0123456)
+
+ // decimals
+ assert(1_234 == 1234)
+ assert(1_234_567 == 1234567)
+
+ // hexadecimals
+ assert(0X_0 == 0)
+ assert(0X_1234 == 0x1234)
+ assert(0X_CAFE_f00d == 0xcafef00d)
+
+ // octals
+ assert(0o0 == 0)
+ assert(0o1234 == 01234)
+ assert(0o01234567 == 01234567)
+
+ assert(0O0 == 0)
+ assert(0O1234 == 01234)
+ assert(0O01234567 == 01234567)
+
+ assert(0o_0 == 0)
+ assert(0o_1234 == 01234)
+ assert(0o0123_4567 == 01234567)
+
+ assert(0O_0 == 0)
+ assert(0O_1234 == 01234)
+ assert(0O0123_4567 == 01234567)
+
+ // binaries
+ assert(0b0 == 0)
+ assert(0b1011 == 0xb)
+ assert(0b00101101 == 0x2d)
+
+ assert(0B0 == 0)
+ assert(0B1011 == 0xb)
+ assert(0B00101101 == 0x2d)
+
+ assert(0b_0 == 0)
+ assert(0b10_11 == 0xb)
+ assert(0b_0010_1101 == 0x2d)
+
+ // decimal floats
+ assert(1_2_3. == 123.)
+ assert(0_123. == 123.)
+
+ assert(0_0e0 == 0.)
+ assert(1_2_3e0 == 123.)
+ assert(0_123e0 == 123.)
+
+ assert(0e-0_0 == 0.)
+ assert(1_2_3E+0 == 123.)
+ assert(0123E1_2_3 == 123e123)
+
+ assert(0.e+1 == 0.)
+ assert(123.E-1_0 == 123e-10)
+ assert(01_23.e123 == 123e123)
+
+ assert(.0e-1 == .0)
+ assert(.123E+10 == .123e10)
+ assert(.0123E123 == .0123e123)
+
+ assert(1_2_3.123 == 123.123)
+ assert(0123.01_23 == 123.0123)
+
+ // hexadecimal floats
+ assert(0x0.p+0 == 0.)
+ assert(0Xdeadcafe.p-10 == 0xdeadcafe/1024.0)
+ assert(0x1234.P84 == 0x1234000000000000000000000)
+
+ assert(0x.1p-0 == 1./16)
+ assert(0X.deadcafep4 == 1.0*0xdeadcafe/0x10000000)
+ assert(0x.1234P+12 == 1.0*0x1234/0x10)
+
+ assert(0x0p0 == 0.)
+ assert(0Xdeadcafep+1 == 0x1bd5b95fc)
+ assert(0x1234P-10 == 0x1234/1024.0)
+
+ assert(0x0.0p0 == 0.)
+ assert(0Xdead.cafep+1 == 1.0*0x1bd5b95fc/0x10000)
+ assert(0x12.34P-10 == 1.0*0x1234/0x40000)
+
+ assert(0Xdead_cafep+1 == 0xdeadcafep+1)
+ assert(0x_1234P-10 == 0x1234p-10)
+
+ assert(0X_dead_cafe.p-10 == 0xdeadcafe.p-10)
+ assert(0x12_34.P1_2_3 == 0x1234.p123)
+
+ assert(1_234i == 1234i)
+ assert(1_234_567i == 1234567i)
+
+ assert(0.i == 0i)
+ assert(123.i == 123i)
+ assert(0123.i == 123i)
+
+ assert(0.e+1i == 0i)
+ assert(123.E-1_0i == 123e-10i)
+ assert(01_23.e123i == 123e123i)
+}
diff --git a/src/go/types/testdata/methodsets.src b/src/go/types/testdata/methodsets.src
new file mode 100644
index 0000000..9fb10de
--- /dev/null
+++ b/src/go/types/testdata/methodsets.src
@@ -0,0 +1,214 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package methodsets
+
+type T0 struct {}
+
+func (T0) v0() {}
+func (*T0) p0() {}
+
+type T1 struct {} // like T0 with different method names
+
+func (T1) v1() {}
+func (*T1) p1() {}
+
+type T2 interface {
+ v2()
+ p2()
+}
+
+type T3 struct {
+ T0
+ *T1
+ T2
+}
+
+// Method expressions
+func _() {
+ var (
+ _ func(T0) = T0.v0
+ _ = T0.p0 /* ERROR "cannot call pointer method p0 on T0" */
+
+ _ func (*T0) = (*T0).v0
+ _ func (*T0) = (*T0).p0
+
+ // T1 is like T0
+
+ _ func(T2) = T2.v2
+ _ func(T2) = T2.p2
+
+ _ func(T3) = T3.v0
+ _ func(T3) = T3.p0 /* ERROR "cannot call pointer method p0 on T3" */
+ _ func(T3) = T3.v1
+ _ func(T3) = T3.p1
+ _ func(T3) = T3.v2
+ _ func(T3) = T3.p2
+
+ _ func(*T3) = (*T3).v0
+ _ func(*T3) = (*T3).p0
+ _ func(*T3) = (*T3).v1
+ _ func(*T3) = (*T3).p1
+ _ func(*T3) = (*T3).v2
+ _ func(*T3) = (*T3).p2
+ )
+}
+
+// Method values with addressable receivers
+func _() {
+ var (
+ v0 T0
+ _ func() = v0.v0
+ _ func() = v0.p0
+ )
+
+ var (
+ p0 *T0
+ _ func() = p0.v0
+ _ func() = p0.p0
+ )
+
+ // T1 is like T0
+
+ var (
+ v2 T2
+ _ func() = v2.v2
+ _ func() = v2.p2
+ )
+
+ var (
+ v4 T3
+ _ func() = v4.v0
+ _ func() = v4.p0
+ _ func() = v4.v1
+ _ func() = v4.p1
+ _ func() = v4.v2
+ _ func() = v4.p2
+ )
+
+ var (
+ p4 *T3
+ _ func() = p4.v0
+ _ func() = p4.p0
+ _ func() = p4.v1
+ _ func() = p4.p1
+ _ func() = p4.v2
+ _ func() = p4.p2
+ )
+}
+
+// Method calls with addressable receivers
+func _() {
+ var v0 T0
+ v0.v0()
+ v0.p0()
+
+ var p0 *T0
+ p0.v0()
+ p0.p0()
+
+ // T1 is like T0
+
+ var v2 T2
+ v2.v2()
+ v2.p2()
+
+ var v4 T3
+ v4.v0()
+ v4.p0()
+ v4.v1()
+ v4.p1()
+ v4.v2()
+ v4.p2()
+
+ var p4 *T3
+ p4.v0()
+ p4.p0()
+ p4.v1()
+ p4.p1()
+ p4.v2()
+ p4.p2()
+}
+
+// Method values with value receivers
+func _() {
+ var (
+ _ func() = T0{}.v0
+ _ func() = T0{}.p0 /* ERROR "cannot call pointer method p0 on T0" */
+
+ _ func() = (&T0{}).v0
+ _ func() = (&T0{}).p0
+
+ // T1 is like T0
+
+ // no values for T2
+
+ _ func() = T3{}.v0
+ _ func() = T3{}.p0 /* ERROR "cannot call pointer method p0 on T3" */
+ _ func() = T3{}.v1
+ _ func() = T3{}.p1
+ _ func() = T3{}.v2
+ _ func() = T3{}.p2
+
+ _ func() = (&T3{}).v0
+ _ func() = (&T3{}).p0
+ _ func() = (&T3{}).v1
+ _ func() = (&T3{}).p1
+ _ func() = (&T3{}).v2
+ _ func() = (&T3{}).p2
+ )
+}
+
+// Method calls with value receivers
+func _() {
+ T0{}.v0()
+ T0{}.p0 /* ERROR "cannot call pointer method p0 on T0" */ ()
+
+ (&T0{}).v0()
+ (&T0{}).p0()
+
+ // T1 is like T0
+
+ // no values for T2
+
+ T3{}.v0()
+ T3{}.p0 /* ERROR "cannot call pointer method p0 on T3" */ ()
+ T3{}.v1()
+ T3{}.p1()
+ T3{}.v2()
+ T3{}.p2()
+
+ (&T3{}).v0()
+ (&T3{}).p0()
+ (&T3{}).v1()
+ (&T3{}).p1()
+ (&T3{}).v2()
+ (&T3{}).p2()
+}
+
+// *T has no methods if T is an interface type
+func issue5918() {
+ var (
+ err error
+ _ = err.Error()
+ _ func() string = err.Error
+ _ func(error) string = error.Error
+
+ perr = &err
+ _ = perr.Error /* ERROR "no field or method" */ ()
+ _ func() string = perr.Error /* ERROR "no field or method" */
+ _ func(*error) string = (*error).Error /* ERROR "no field or method" */
+ )
+
+ type T *interface{ m() int }
+ var (
+ x T
+ _ = (*x).m()
+ _ = (*x).m
+
+ _ = x.m /* ERROR "no field or method" */ ()
+ _ = x.m /* ERROR "no field or method" */
+ _ = T.m /* ERROR "no field or method" */
+ )
+}
diff --git a/src/go/types/testdata/shifts.src b/src/go/types/testdata/shifts.src
new file mode 100644
index 0000000..c9a38ae
--- /dev/null
+++ b/src/go/types/testdata/shifts.src
@@ -0,0 +1,395 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package shifts
+
+func shifts0() {
+ // basic constant shifts
+ const (
+ s = 10
+ _ = 0<<0
+ _ = 1<<s
+ _ = 1<<- /* ERROR "negative shift count" */ 1
+ // For the test below we may decide to convert to int
+ // rather than uint and then report a negative shift
+ // count instead, which might be a better error. The
+ // (minor) difference is that this would restrict the
+ // shift count range by half (from all uint values to
+ // the positive int values).
+ // This depends on the exact spec wording which is not
+ // done yet.
+ // TODO(gri) revisit and adjust when spec change is done
+ _ = 1<<- /* ERROR "truncated to uint" */ 1.0
+ _ = 1<<1075 /* ERROR "invalid shift" */
+ _ = 2.0<<1
+ _ = 1<<1.0
+ _ = 1<<(1+0i)
+
+ _ int = 2<<s
+ _ float32 = 2<<s
+ _ complex64 = 2<<s
+
+ _ int = 2.0<<s
+ _ float32 = 2.0<<s
+ _ complex64 = 2.0<<s
+
+ _ int = 'a'<<s
+ _ float32 = 'a'<<s
+ _ complex64 = 'a'<<s
+ )
+}
+
+func shifts1() {
+ // basic non-constant shifts
+ var (
+ i int
+ u uint
+
+ _ = 1<<0
+ _ = 1<<i
+ _ = 1<<u
+ _ = 1<<"foo" /* ERROR "cannot convert" */
+ _ = i<<0
+ _ = i<<- /* ERROR "negative shift count" */ 1
+ _ = i<<1.0
+ _ = 1<<(1+0i)
+ _ = 1 /* ERROR "overflows" */ <<100
+
+ _ uint = 1 << 0
+ _ uint = 1 << u
+ _ float32 = 1 /* ERROR "must be integer" */ << u
+
+ // for issue 14822
+ _ = 1<<( /* ERROR "invalid shift count" */ 1<<64-1)
+ _ = 1<<( /* ERROR "invalid shift count" */ 1<<64)
+ _ = u<<(1<<63) // valid
+ _ = u<<(1<<64) // valid
+ )
+}
+
+func shifts2() {
+ // from the spec
+ var (
+ s uint = 33
+ i = 1<<s // 1 has type int
+ j int32 = 1<<s // 1 has type int32; j == 0
+ k = uint64(1<<s) // 1 has type uint64; k == 1<<33
+ m int = 1.0<<s // 1.0 has type int
+ n = 1.0<<s != i // 1.0 has type int; n == false if ints are 32bits in size
+ o = 1<<s == 2<<s // 1 and 2 have type int; o == true if ints are 32bits in size
+ p = 1<<s == 1<<33 // illegal if ints are 32bits in size: 1 has type int, but 1<<33 overflows int
+ u = 1.0 /* ERROR "must be integer" */ <<s // illegal: 1.0 has type float64, cannot shift
+ u1 = 1.0 /* ERROR "must be integer" */ <<s != 0 // illegal: 1.0 has type float64, cannot shift
+ u2 = 1 /* ERROR "must be integer" */ <<s != 1.0 // illegal: 1 has type float64, cannot shift
+ v float32 = 1 /* ERROR "must be integer" */ <<s // illegal: 1 has type float32, cannot shift
+ w int64 = 1.0<<33 // 1.0<<33 is a constant shift expression
+ )
+ _, _, _, _, _, _, _, _, _, _, _, _ = i, j, k, m, n, o, p, u, u1, u2, v, w
+}
+
+func shifts3(a int16, b float32) {
+ // random tests
+ var (
+ s uint = 11
+ u = 1 /* ERROR "must be integer" */ <<s + 1.0
+ v complex128 = 1 /* ERROR "must be integer" */ << s + 1.0 /* ERROR "must be integer" */ << s + 1
+ )
+ x := 1.0 /* ERROR "must be integer" */ <<s + 1
+ shifts3(1.0 << s, 1 /* ERROR "must be integer" */ >> s)
+ _, _, _ = u, v, x
+}
+
+func shifts4() {
+ // shifts in comparisons w/ untyped operands
+ var s uint
+
+ _ = 1<<s == 1
+ _ = 1 /* ERROR "integer" */ <<s == 1.
+ _ = 1. /* ERROR "integer" */ <<s == 1
+ _ = 1. /* ERROR "integer" */ <<s == 1.
+
+ _ = 1<<s + 1 == 1
+ _ = 1 /* ERROR "integer" */ <<s + 1 == 1.
+ _ = 1 /* ERROR "integer" */ <<s + 1. == 1
+ _ = 1 /* ERROR "integer" */ <<s + 1. == 1.
+ _ = 1. /* ERROR "integer" */ <<s + 1 == 1
+ _ = 1. /* ERROR "integer" */ <<s + 1 == 1.
+ _ = 1. /* ERROR "integer" */ <<s + 1. == 1
+ _ = 1. /* ERROR "integer" */ <<s + 1. == 1.
+
+ _ = 1<<s == 1<<s
+ _ = 1 /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s
+
+ _ = 1<<s + 1<<s == 1
+ _ = 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1.
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1.
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1.
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1.
+
+ _ = 1<<s + 1<<s == 1<<s + 1<<s
+ _ = 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1 /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1 /* ERROR "integer" */ <<s
+ _ = 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s == 1. /* ERROR "integer" */ <<s + 1. /* ERROR "integer" */ <<s
+}
+
+func shifts5() {
+ // shifts in comparisons w/ typed operands
+ var s uint
+ var x int
+
+ _ = 1<<s == x
+ _ = 1.<<s == x
+ _ = 1.1 /* ERROR "int" */ <<s == x
+
+ _ = 1<<s + x == 1
+ _ = 1<<s + x == 1.
+ _ = 1<<s + x == 1.1 /* ERROR "int" */
+ _ = 1.<<s + x == 1
+ _ = 1.<<s + x == 1.
+ _ = 1.<<s + x == 1.1 /* ERROR "int" */
+ _ = 1.1 /* ERROR "int" */ <<s + x == 1
+ _ = 1.1 /* ERROR "int" */ <<s + x == 1.
+ _ = 1.1 /* ERROR "int" */ <<s + x == 1.1
+
+ _ = 1<<s == x<<s
+ _ = 1.<<s == x<<s
+ _ = 1.1 /* ERROR "int" */ <<s == x<<s
+}
+
+func shifts6() {
+ // shifts as operands in non-arithmetic operations and as arguments
+ var a [10]int
+ var s uint
+
+ _ = a[1<<s]
+ _ = a[1.0]
+ _ = a[1.0<<s]
+
+ _ = make([]int, 1.0)
+ _ = make([]int, 1.0<<s)
+ _ = make([]int, 1.1 /* ERROR "must be integer" */ <<s)
+
+ _ = float32(1)
+ _ = float32(1 /* ERROR "must be integer" */ <<s)
+ _ = float32(1.0)
+ _ = float32(1.0 /* ERROR "must be integer" */ <<s)
+ _ = float32(1.1 /* ERROR "must be integer" */ <<s)
+
+ _ = int32(0x80000000 /* ERROR "overflows int32" */ << s)
+ // TODO(rfindley) Eliminate the redundant error here.
+ _ = int32(( /* ERROR "truncated to int32" */ 0x80000000 /* ERROR "truncated to int32" */ + 0i) << s)
+
+ _ = int(1+0i<<0)
+ _ = int((1+0i)<<s)
+ _ = int(1.0<<s)
+ _ = int(complex(1, 0)<<s)
+ _ = int(float32/* ERROR "must be integer" */(1.0) <<s)
+ _ = int(1.1 /* ERROR must be integer */ <<s)
+ _ = int(( /* ERROR "must be integer" */ 1+1i) <<s)
+
+ _ = complex(1 /* ERROR "must be integer" */ <<s, 0)
+
+ var b []int
+ _ = append(b, 1<<s)
+ _ = append(b, 1.0<<s)
+ _ = append(b, (1+0i)<<s)
+ _ = append(b, 1.1 /* ERROR "must be integer" */ <<s)
+ _ = append(b, (1 + 0i) <<s)
+ _ = append(b, ( /* ERROR "must be integer" */ 1 + 1i) <<s)
+
+ _ = complex(1.0 /* ERROR "must be integer" */ <<s, 0)
+ _ = complex(1.1 /* ERROR "must be integer" */ <<s, 0)
+ _ = complex(0, 1.0 /* ERROR "must be integer" */ <<s)
+ _ = complex(0, 1.1 /* ERROR "must be integer" */ <<s)
+
+ // TODO(gri) The delete below is not type-checked correctly yet.
+ // var m1 map[int]string
+ // delete(m1, 1<<s)
+}
+
+func shifts7() {
+ // shifts of shifts
+ var s uint
+ var x int
+ _ = x
+
+ _ = 1<<(1<<s)
+ _ = 1<<(1.<<s)
+ _ = 1. /* ERROR "integer" */ <<(1<<s)
+ _ = 1. /* ERROR "integer" */ <<(1.<<s)
+
+ x = 1<<(1<<s)
+ x = 1<<(1.<<s)
+ x = 1.<<(1<<s)
+ x = 1.<<(1.<<s)
+
+ _ = (1<<s)<<(1<<s)
+ _ = (1<<s)<<(1.<<s)
+ _ = ( /* ERROR "integer" */ 1.<<s)<<(1<<s)
+ _ = ( /* ERROR "integer" */ 1.<<s)<<(1.<<s)
+
+ x = (1<<s)<<(1<<s)
+ x = (1<<s)<<(1.<<s)
+ x = ( /* ERROR "integer" */ 1.<<s)<<(1<<s)
+ x = ( /* ERROR "integer" */ 1.<<s)<<(1.<<s)
+}
+
+func shifts8() {
+ // shift examples from shift discussion: better error messages
+ var s uint
+ _ = 1.0 /* ERROR "shifted operand 1.0 \(type float64\) must be integer" */ <<s == 1
+ _ = 1.0 /* ERROR "shifted operand 1.0 \(type float64\) must be integer" */ <<s == 1.0
+ _ = 1 /* ERROR "shifted operand 1 \(type float64\) must be integer" */ <<s == 1.0
+ _ = 1 /* ERROR "shifted operand 1 \(type float64\) must be integer" */ <<s + 1.0 == 1
+ _ = 1 /* ERROR "shifted operand 1 \(type float64\) must be integer" */ <<s + 1.1 == 1
+ _ = 1 /* ERROR "shifted operand 1 \(type float64\) must be integer" */ <<s + 1 == 1.0
+
+ // additional cases
+ _ = complex(1.0 /* ERROR "shifted operand 1.0 \(type float64\) must be integer" */ <<s, 1)
+ _ = complex(1.0, 1 /* ERROR "shifted operand 1 \(type float64\) must be integer" */ <<s)
+
+ _ = int(1.<<s)
+ _ = int(1.1 /* ERROR "shifted operand .* must be integer" */ <<s)
+ _ = float32(1 /* ERROR "shifted operand .* must be integer" */ <<s)
+ _ = float32(1. /* ERROR "shifted operand .* must be integer" */ <<s)
+ _ = float32(1.1 /* ERROR "shifted operand .* must be integer" */ <<s)
+ // TODO(gri) the error messages for these two are incorrect - disabled for now
+ // _ = complex64(1<<s)
+ // _ = complex64(1.<<s)
+ _ = complex64(1.1 /* ERROR "shifted operand .* must be integer" */ <<s)
+}
+
+func shifts9() {
+ // various originally failing snippets of code from the std library
+ // from src/compress/lzw/reader.go:90
+ {
+ var d struct {
+ bits uint32
+ width uint
+ }
+ _ = uint16(d.bits & (1<<d.width - 1))
+ }
+
+ // from src/debug/dwarf/buf.go:116
+ {
+ var ux uint64
+ var bits uint
+ x := int64(ux)
+ if x&(1<<(bits-1)) != 0 {}
+ }
+
+ // from src/encoding/asn1/asn1.go:160
+ {
+ var bytes []byte
+ if bytes[len(bytes)-1]&((1<<bytes[0])-1) != 0 {}
+ }
+
+ // from src/math/big/rat.go:140
+ {
+ var exp int
+ var mantissa uint64
+ shift := uint64(-1022 - (exp - 1)) // [1..53)
+ _ = mantissa & (1<<shift - 1)
+ }
+
+ // from src/net/interface.go:51
+ {
+ type Flags uint
+ var f Flags
+ var i int
+ if f&(1<<uint(i)) != 0 {}
+ }
+
+ // from src/runtime/softfloat64.go:234
+ {
+ var gm uint64
+ var shift uint
+ _ = gm & (1<<shift - 1)
+ }
+
+ // from src/strconv/atof.go:326
+ {
+ var mant uint64
+ var mantbits uint
+ if mant == 2<<mantbits {}
+ }
+
+ // from src/route_bsd.go:82
+ {
+ var Addrs int32
+ const rtaRtMask = 1
+ var i uint
+ if Addrs&rtaRtMask&(1<<i) == 0 {}
+ }
+
+ // from src/text/scanner/scanner.go:540
+ {
+ var s struct { Whitespace uint64 }
+ var ch rune
+ for s.Whitespace&(1<<uint(ch)) != 0 {}
+ }
+}
+
+func issue5895() {
+ var x = 'a' << 1 // type of x must be rune
+ var _ rune = x
+}
+
+func issue11325() {
+ var _ = 0 >> 1.1 /* ERROR "truncated to uint" */ // example from issue 11325
+ _ = 0 >> 1.1 /* ERROR "truncated to uint" */
+ _ = 0 << 1.1 /* ERROR "truncated to uint" */
+ _ = 0 >> 1.
+ _ = 1 >> 1.1 /* ERROR "truncated to uint" */
+ _ = 1 >> 1.
+ _ = 1. >> 1
+ _ = 1. >> 1.
+ _ = 1.1 /* ERROR "must be integer" */ >> 1
+}
+
+func issue11594() {
+ var _ = complex64 /* ERROR "must be integer" */ (1) << 2 // example from issue 11594
+ _ = float32 /* ERROR "must be integer" */ (0) << 1
+ _ = float64 /* ERROR "must be integer" */ (0) >> 2
+ _ = complex64 /* ERROR "must be integer" */ (0) << 3
+ _ = complex64 /* ERROR "must be integer" */ (0) >> 4
+}
+
+func issue21727() {
+ var s uint
+ var a = make([]int, 1<<s + 1.2 /* ERROR "truncated to int" */ )
+ var _ = a[1<<s - 2.3 /* ERROR "truncated to int" */ ]
+ var _ int = 1<<s + 3.4 /* ERROR "truncated to int" */
+ var _ = string(1 << s)
+ var _ = string(1.0 /* ERROR "cannot convert" */ << s)
+}
+
+func issue22969() {
+ var s uint
+ var a []byte
+ _ = a[0xffffffffffffffff /* ERROR "overflows int" */ <<s] // example from issue 22969
+ _ = make([]int, 0xffffffffffffffff /* ERROR "overflows int" */ << s)
+ _ = make([]int, 0, 0xffffffffffffffff /* ERROR "overflows int" */ << s)
+ var _ byte = 0x100 /* ERROR "overflows byte" */ << s
+ var _ int8 = 0xff /* ERROR "overflows int8" */ << s
+ var _ int16 = 0xffff /* ERROR "overflows int16" */ << s
+ var _ int32 = 0x80000000 /* ERROR "overflows int32" */ << s
+}
diff --git a/src/go/types/testdata/stmt0.src b/src/go/types/testdata/stmt0.src
new file mode 100644
index 0000000..1377729
--- /dev/null
+++ b/src/go/types/testdata/stmt0.src
@@ -0,0 +1,980 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// statements
+
+package stmt0
+
+func assignments0() (int, int) {
+ var a, b, c int
+ var ch chan int
+ f0 := func() {}
+ f1 := func() int { return 1 }
+ f2 := func() (int, int) { return 1, 2 }
+ f3 := func() (int, int, int) { return 1, 2, 3 }
+
+ a, b, c = 1, 2, 3
+ a, b, c = 1 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ , 2
+ a, b, c = 1 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ , 2, 3, 4
+ _, _, _ = a, b, c
+
+ a = f0 /* ERROR "used as value" */ ()
+ a = f1()
+ a = f2 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
+ a, b = f2()
+ a, b, c = f2 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
+ a, b, c = f3()
+ a, b = f3 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
+
+ a, b, c = <- /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ch
+
+ return /* ERROR "wrong number of return values" */
+ return /* ERROR "wrong number of return values" */ 1
+ return 1, 2
+ return /* ERROR "wrong number of return values" */ 1, 2, 3
+}
+
+func assignments1() {
+ b, i, f, c, s := false, 1, 1.0, 1i, "foo"
+ b = i /* ERROR "cannot use .* in assignment" */
+ i = f /* ERROR "cannot use .* in assignment" */
+ f = c /* ERROR "cannot use .* in assignment" */
+ c = s /* ERROR "cannot use .* in assignment" */
+ s = b /* ERROR "cannot use .* in assignment" */
+
+ v0, v1, v2 := 1 /* ERROR "cannot initialize" */ , 2, 3, 4
+ _, _, _ = v0, v1, v2
+
+ b = true
+
+ i += 1
+ i += "foo" /* ERROR "cannot convert.*int" */
+
+ f -= 1
+ f /= 0
+ f = float32(0)/0 /* ERROR "division by zero" */
+ f -= "foo" /* ERROR "cannot convert.*float64" */
+
+ c *= 1
+ c /= 0
+
+ s += "bar"
+ s += 1 /* ERROR "cannot convert.*string" */
+
+ var u64 uint64
+ u64 += 1<<u64
+
+ undeclared /* ERROR "undeclared" */ = 991
+
+ // test cases for issue 5800
+ var (
+ _ int = nil /* ERROR "untyped nil value" */
+ _ [10]int = nil /* ERROR "untyped nil value" */
+ _ []byte = nil
+ _ struct{} = nil /* ERROR "untyped nil value" */
+ _ func() = nil
+ _ map[int]string = nil
+ _ chan int = nil
+ )
+
+ // test cases for issue 5500
+ _ = func() (int, bool) {
+ var m map[int]int
+ return /* ERROR "wrong number of return values" */ m[0]
+ }
+
+ g := func(int, bool){}
+ var m map[int]int
+ g(m[0]) /* ERROR "too few arguments" */
+
+ // assignments to _
+ _ = nil /* ERROR "use of untyped nil" */
+ _ = 1 /* ERROR overflow */ <<1000
+ (_) = 0
+}
+
+func assignments2() {
+ type mybool bool
+ var m map[string][]bool
+ var s []bool
+ var b bool
+ var d mybool
+ _ = s
+ _ = b
+ _ = d
+
+ // assignments to map index expressions are ok
+ s, b = m["foo"]
+ _, d = m["bar"]
+ m["foo"] = nil
+ m["foo"] = nil /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
+ _ = append(m["foo"])
+ _ = append(m["foo"], true)
+
+ var c chan int
+ _, b = <-c
+ _, d = <-c
+ <- /* ERROR cannot assign */ c = 0
+ <-c = 0 /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
+
+ var x interface{}
+ _, b = x.(int)
+ x /* ERROR cannot assign */ .(int) = 0
+ x.(int) = 0 /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
+
+ assignments2 /* ERROR used as value */ () = nil
+ int /* ERROR not an expression */ = 0
+}
+
+func issue6487() {
+ type S struct{x int}
+ _ = &S /* ERROR "cannot take address" */ {}.x
+ _ = &( /* ERROR "cannot take address" */ S{}.x)
+ _ = (&S{}).x
+ S /* ERROR "cannot assign" */ {}.x = 0
+ (&S{}).x = 0
+
+ type M map[string]S
+ var m M
+ m /* ERROR "cannot assign to struct field" */ ["foo"].x = 0
+ _ = &( /* ERROR "cannot take address" */ m["foo"].x)
+ _ = &m /* ERROR "cannot take address" */ ["foo"].x
+}
+
+func issue6766a() {
+ a, a /* ERROR redeclared */ := 1, 2
+ _ = a
+ a, b, b /* ERROR redeclared */ := 1, 2, 3
+ _ = b
+ c, c /* ERROR redeclared */, b := 1, 2, 3
+ _ = c
+ a, b := /* ERROR no new variables */ 1, 2
+}
+
+func shortVarDecls1() {
+ const c = 0
+ type d int
+ a, b, c /* ERROR "cannot assign" */ , d /* ERROR "cannot assign" */ := 1, "zwei", 3.0, 4
+ var _ int = a // a is of type int
+ var _ string = b // b is of type string
+}
+
+func incdecs() {
+ const c = 3.14
+ c /* ERROR "cannot assign" */ ++
+ s := "foo"
+ s /* ERROR "invalid operation" */ --
+ 3.14 /* ERROR "cannot assign" */ ++
+ var (
+ x int
+ y float32
+ z complex128
+ )
+ x++
+ y--
+ z++
+}
+
+func sends() {
+ var ch chan int
+ var rch <-chan int
+ var x int
+ x <- /* ERROR "cannot send" */ x
+ rch <- /* ERROR "cannot send" */ x
+ ch <- "foo" /* ERROR "cannot use .* in send" */
+ ch <- x
+}
+
+func selects() {
+ select {}
+ var (
+ ch chan int
+ sc chan <- bool
+ )
+ select {
+ case <-ch:
+ case (<-ch):
+ case t := <-ch:
+ _ = t
+ case t := (<-ch):
+ _ = t
+ case t, ok := <-ch:
+ _, _ = t, ok
+ case t, ok := (<-ch):
+ _, _ = t, ok
+ case <-sc /* ERROR "cannot receive from send-only channel" */ :
+ }
+ select {
+ default:
+ default /* ERROR "multiple defaults" */ :
+ }
+ select {
+ case a, b := <-ch:
+ _, b = a, b
+ case x /* ERROR send or receive */ :
+ case a /* ERROR send or receive */ := ch:
+ }
+
+ // test for issue 9570: ch2 in second case falsely resolved to
+ // ch2 declared in body of first case
+ ch1 := make(chan int)
+ ch2 := make(chan int)
+ select {
+ case <-ch1:
+ var ch2 /* ERROR ch2 declared but not used */ chan bool
+ case i := <-ch2:
+ print(i + 1)
+ }
+}
+
+func gos() {
+ go 1 /* ERROR HERE "function must be invoked" */
+ go int /* ERROR "go requires function call, not conversion" */ (0)
+ go gos()
+ var c chan int
+ go close(c)
+ go len /* ERROR "go discards result" */ (c)
+}
+
+func defers() {
+ defer 1 /* ERROR HERE "function must be invoked" */
+ defer int /* ERROR "defer requires function call, not conversion" */ (0)
+ defer defers()
+ var c chan int
+ defer close(c)
+ defer len /* ERROR "defer discards result" */ (c)
+}
+
+func breaks() {
+ var x, y int
+
+ break /* ERROR "break" */
+ {
+ break /* ERROR "break" */
+ }
+ if x < y {
+ break /* ERROR "break" */
+ }
+
+ switch x {
+ case 0:
+ break
+ case 1:
+ if x == y {
+ break
+ }
+ default:
+ break
+ break
+ }
+
+ var z interface{}
+ switch z.(type) {
+ case int:
+ break
+ }
+
+ for {
+ break
+ }
+
+ var a []int
+ for _ = range a {
+ break
+ }
+
+ for {
+ if x == y {
+ break
+ }
+ }
+
+ var ch chan int
+ select {
+ case <-ch:
+ break
+ }
+
+ select {
+ case <-ch:
+ if x == y {
+ break
+ }
+ default:
+ break
+ }
+}
+
+func continues() {
+ var x, y int
+
+ continue /* ERROR "continue" */
+ {
+ continue /* ERROR "continue" */
+ }
+
+ if x < y {
+ continue /* ERROR "continue" */
+ }
+
+ switch x {
+ case 0:
+ continue /* ERROR "continue" */
+ }
+
+ var z interface{}
+ switch z.(type) {
+ case int:
+ continue /* ERROR "continue" */
+ }
+
+ var ch chan int
+ select {
+ case <-ch:
+ continue /* ERROR "continue" */
+ }
+
+ for i := 0; i < 10; i++ {
+ continue
+ if x < y {
+ continue
+ break
+ }
+ switch x {
+ case y:
+ continue
+ default:
+ break
+ }
+ select {
+ case <-ch:
+ continue
+ }
+ }
+
+ var a []int
+ for _ = range a {
+ continue
+ if x < y {
+ continue
+ break
+ }
+ switch x {
+ case y:
+ continue
+ default:
+ break
+ }
+ select {
+ case <-ch:
+ continue
+ }
+ }
+}
+
+func returns0() {
+ return
+ return 0 /* ERROR no result values expected */
+}
+
+func returns1(x float64) (int, *float64) {
+ return 0, &x
+ return /* ERROR wrong number of return values */
+ return "foo" /* ERROR "cannot .* in return statement" */, x /* ERROR "cannot use .* in return statement" */
+ return /* ERROR wrong number of return values */ 0, &x, 1
+}
+
+func returns2() (a, b int) {
+ return
+ return 1, "foo" /* ERROR cannot use .* in return statement */
+ return /* ERROR wrong number of return values */ 1, 2, 3
+ {
+ type a int
+ return 1, 2
+ return /* ERROR a not in scope at return */
+ }
+}
+
+func returns3() (_ int) {
+ return
+ {
+ var _ int // blank (_) identifiers never shadow since they are in no scope
+ return
+ }
+}
+
+func switches0() {
+ var x int
+
+ switch x {
+ }
+
+ switch x {
+ default:
+ default /* ERROR "multiple defaults" */ :
+ }
+
+ switch {
+ case 1 /* ERROR "cannot convert" */ :
+ }
+
+ true := "false"
+ _ = true
+ // A tagless switch is equivalent to the bool
+ // constant true, not the identifier 'true'.
+ switch {
+ case "false" /* ERROR "cannot convert" */:
+ }
+
+ switch int32(x) {
+ case 1, 2:
+ case x /* ERROR "cannot compare" */ :
+ }
+
+ switch x {
+ case 1 /* ERROR "overflows" */ << 100:
+ }
+
+ switch x {
+ case 1:
+ case 1 /* ERROR "duplicate case" */ :
+ case ( /* ERROR "duplicate case" */ 1):
+ case 2, 3, 4:
+ case 5, 1 /* ERROR "duplicate case" */ :
+ }
+
+ switch uint64(x) {
+ case 1<<64 - 1:
+ case 1 /* ERROR duplicate case */ <<64 - 1:
+ case 2, 3, 4:
+ case 5, 1 /* ERROR duplicate case */ <<64 - 1:
+ }
+
+ var y32 float32
+ switch y32 {
+ case 1.1:
+ case 11/10: // integer division!
+ case 11. /* ERROR duplicate case */ /10:
+ case 2, 3.0, 4.1:
+ case 5.2, 1.10 /* ERROR duplicate case */ :
+ }
+
+ var y64 float64
+ switch y64 {
+ case 1.1:
+ case 11/10: // integer division!
+ case 11. /* ERROR duplicate case */ /10:
+ case 2, 3.0, 4.1:
+ case 5.2, 1.10 /* ERROR duplicate case */ :
+ }
+
+ var s string
+ switch s {
+ case "foo":
+ case "foo" /* ERROR duplicate case */ :
+ case "f" /* ERROR duplicate case */ + "oo":
+ case "abc", "def", "ghi":
+ case "jkl", "foo" /* ERROR duplicate case */ :
+ }
+
+ type T int
+ type F float64
+ type S string
+ type B bool
+ var i interface{}
+ switch i {
+ case nil:
+ case nil: // no duplicate detection
+ case (*int)(nil):
+ case (*int)(nil): // do duplicate detection
+ case 1:
+ case byte(1):
+ case int /* ERROR duplicate case */ (1):
+ case T(1):
+ case 1.0:
+ case F(1.0):
+ case F /* ERROR duplicate case */ (1.0):
+ case "hello":
+ case S("hello"):
+ case S /* ERROR duplicate case */ ("hello"):
+ case 1==1, B(false):
+ case false, B(2==2):
+ }
+
+ // switch on array
+ var a [3]int
+ switch a {
+ case [3]int{1, 2, 3}:
+ case [3]int{1, 2, 3}: // no duplicate detection
+ case [ /* ERROR "mismatched types */ 4]int{4, 5, 6}:
+ }
+
+ // switch on channel
+ var c1, c2 chan int
+ switch c1 {
+ case nil:
+ case c1:
+ case c2:
+ case c1, c2: // no duplicate detection
+ }
+}
+
+func switches1() {
+ fallthrough /* ERROR "fallthrough statement out of place" */
+
+ var x int
+ switch x {
+ case 0:
+ fallthrough /* ERROR "fallthrough statement out of place" */
+ break
+ case 1:
+ fallthrough
+ case 2:
+ fallthrough; ; ; // trailing empty statements are ok
+ case 3:
+ default:
+ fallthrough; ;
+ case 4:
+ fallthrough /* ERROR "cannot fallthrough final case in switch" */
+ }
+
+ var y interface{}
+ switch y.(type) {
+ case int:
+ fallthrough /* ERROR "fallthrough statement out of place" */ ; ; ;
+ default:
+ }
+
+ switch x {
+ case 0:
+ if x == 0 {
+ fallthrough /* ERROR "fallthrough statement out of place" */
+ }
+ }
+
+ switch x {
+ case 0:
+ goto L1
+ L1: fallthrough; ;
+ case 1:
+ goto L2
+ goto L3
+ goto L4
+ L2: L3: L4: fallthrough
+ default:
+ }
+
+ switch x {
+ case 0:
+ goto L5
+ L5: fallthrough
+ default:
+ goto L6
+ goto L7
+ goto L8
+ L6: L7: L8: fallthrough /* ERROR "cannot fallthrough final case in switch" */
+ }
+
+ switch x {
+ case 0:
+ fallthrough; ;
+ case 1:
+ {
+ fallthrough /* ERROR "fallthrough statement out of place" */
+ }
+ case 2:
+ fallthrough
+ case 3:
+ fallthrough /* ERROR "fallthrough statement out of place" */
+ { /* empty block is not an empty statement */ }; ;
+ default:
+ fallthrough /* ERROR "cannot fallthrough final case in switch" */
+ }
+
+ switch x {
+ case 0:
+ {
+ fallthrough /* ERROR "fallthrough statement out of place" */
+ }
+ }
+}
+
+func switches2() {
+ // untyped nil is not permitted as switch expression
+ switch nil /* ERROR "use of untyped nil" */ {
+ case 1, 2, "foo": // don't report additional errors here
+ }
+
+ // untyped constants are converted to default types
+ switch 1<<63-1 {
+ }
+ switch 1 /* ERROR "cannot use .* as int value.*\(overflows\)" */ << 63 {
+ }
+ var x int
+ switch 1.0 {
+ case 1.0, 2.0, x /* ERROR "mismatched types int and float64" */ :
+ }
+ switch x {
+ case 1.0:
+ }
+
+ // untyped bools become of type bool
+ type B bool
+ var b B = true
+ switch x == x {
+ case b /* ERROR "mismatched types B and bool" */ :
+ }
+ switch {
+ case b /* ERROR "mismatched types B and bool" */ :
+ }
+}
+
+func issue11667() {
+ switch 9223372036854775808 /* ERROR "cannot use .* as int value.*\(overflows\)" */ {
+ }
+ switch 9223372036854775808 /* ERROR "cannot use .* as int value.*\(overflows\)" */ {
+ case 9223372036854775808:
+ }
+ var x int
+ switch x {
+ case 9223372036854775808 /* ERROR "overflows int" */ :
+ }
+ var y float64
+ switch y {
+ case 9223372036854775808:
+ }
+}
+
+func issue11687() {
+ f := func() (_, _ int) { return }
+ switch f /* ERROR "2-valued f" */ () {
+ }
+ var x int
+ switch f /* ERROR "2-valued f" */ () {
+ case x:
+ }
+ switch x {
+ case f /* ERROR "2-valued f" */ ():
+ }
+}
+
+type I interface {
+ m()
+}
+
+type I2 interface {
+ m(int)
+}
+
+type T struct{}
+type T1 struct{}
+type T2 struct{}
+
+func (T) m() {}
+func (T2) m(int) {}
+
+func typeswitches() {
+ var i int
+ var x interface{}
+
+ switch x.(type) {}
+ switch (x /* ERROR "outside type switch" */ .(type)) {}
+
+ switch x.(type) {
+ default:
+ default /* ERROR "multiple defaults" */ :
+ }
+
+ switch x /* ERROR "declared but not used" */ := x.(type) {}
+ switch _ /* ERROR "no new variable on left side of :=" */ := x.(type) {}
+
+ switch x := x.(type) {
+ case int:
+ var y int = x
+ _ = y
+ }
+
+ switch x := i /* ERROR "not an interface" */ .(type) {}
+
+ switch t := x.(type) {
+ case nil:
+ var v bool = t /* ERROR "cannot use .* in variable declaration" */
+ _ = v
+ case int:
+ var v int = t
+ _ = v
+ case float32, complex64:
+ var v float32 = t /* ERROR "cannot use .* in variable declaration" */
+ _ = v
+ default:
+ var v float32 = t /* ERROR "cannot use .* in variable declaration" */
+ _ = v
+ }
+
+ var t I
+ switch t.(type) {
+ case T:
+ case T1 /* ERROR "missing method m" */ :
+ case T2 /* ERROR "wrong type for method m" */ :
+ case I2 /* STRICT "wrong type for method m" */ : // only an error in strict mode (issue 8561)
+ }
+}
+
+// Test that each case clause uses the correct type of the variable
+// declared by the type switch (issue 5504).
+func typeswitch0() {
+ switch y := interface{}(nil).(type) {
+ case int:
+ func() int { return y + 0 }()
+ case float32:
+ func() float32 { return y }()
+ }
+}
+
+// Test correct scope setup.
+// (no redeclaration errors expected in the type switch)
+func typeswitch1() {
+ var t I
+ switch t := t; t := t.(type) {
+ case nil:
+ var _ I = t
+ case T:
+ var _ T = t
+ default:
+ var _ I = t
+ }
+}
+
+// Test correct typeswitch against interface types.
+type A interface { a() }
+type B interface { b() }
+type C interface { a(int) }
+
+func typeswitch2() {
+ switch A(nil).(type) {
+ case A:
+ case B:
+ case C /* STRICT "cannot have dynamic type" */: // only an error in strict mode (issue 8561)
+ }
+}
+
+func typeswitch3(x interface{}) {
+ switch x.(type) {
+ case int:
+ case float64:
+ case int /* ERROR duplicate case */ :
+ }
+
+ switch x.(type) {
+ case nil:
+ case int:
+ case nil /* ERROR duplicate case */ , nil /* ERROR duplicate case */ :
+ }
+
+ type F func(int)
+ switch x.(type) {
+ case nil:
+ case int, func(int):
+ case float32, func /* ERROR duplicate case */ (x int):
+ case F:
+ }
+}
+
+func fors1() {
+ for {}
+ var i string
+ _ = i
+ for i := 0; i < 10; i++ {}
+ for i := 0; i < 10; j /* ERROR cannot declare */ := 0 {}
+}
+
+func rangeloops1() {
+ var (
+ x int
+ a [10]float32
+ b []string
+ p *[10]complex128
+ pp **[10]complex128
+ s string
+ m map[int]bool
+ c chan int
+ sc chan<- int
+ rc <-chan int
+ )
+
+ for range x /* ERROR "cannot range over" */ {}
+ for _ = range x /* ERROR "cannot range over" */ {}
+ for i := range x /* ERROR "cannot range over" */ {}
+
+ for range a {}
+ for i := range a {
+ var ii int
+ ii = i
+ _ = ii
+ }
+ for i, x := range a {
+ var ii int
+ ii = i
+ _ = ii
+ var xx float64
+ xx = x /* ERROR "cannot use .* in assignment" */
+ _ = xx
+ }
+ var ii int
+ var xx float32
+ for ii, xx = range a {}
+ _, _ = ii, xx
+
+ for range b {}
+ for i := range b {
+ var ii int
+ ii = i
+ _ = ii
+ }
+ for i, x := range b {
+ var ii int
+ ii = i
+ _ = ii
+ var xx string
+ xx = x
+ _ = xx
+ }
+
+ for range s {}
+ for i := range s {
+ var ii int
+ ii = i
+ _ = ii
+ }
+ for i, x := range s {
+ var ii int
+ ii = i
+ _ = ii
+ var xx rune
+ xx = x
+ _ = xx
+ }
+
+ for range p {}
+ for _, x := range p {
+ var xx complex128
+ xx = x
+ _ = xx
+ }
+
+ for range pp /* ERROR "cannot range over" */ {}
+ for _, x := range pp /* ERROR "cannot range over" */ {}
+
+ for range m {}
+ for k := range m {
+ var kk int32
+ kk = k /* ERROR "cannot use .* in assignment" */
+ _ = kk
+ }
+ for k, v := range m {
+ var kk int
+ kk = k
+ _ = kk
+ if v {}
+ }
+
+ for range c {}
+ for _, _ /* ERROR "only one iteration variable" */ = range c {}
+ for e := range c {
+ var ee int
+ ee = e
+ _ = ee
+ }
+ for _ = range sc /* ERROR "cannot range over send-only channel" */ {}
+ for _ = range rc {}
+
+ // constant strings
+ const cs = "foo"
+ for range cs {}
+ for range "" {}
+ for i, x := range cs { _, _ = i, x }
+ for i, x := range "" {
+ var ii int
+ ii = i
+ _ = ii
+ var xx rune
+ xx = x
+ _ = xx
+ }
+}
+
+func rangeloops2() {
+ type I int
+ type R rune
+
+ var a [10]int
+ var i I
+ _ = i
+ for i /* ERROR cannot use .* in assignment */ = range a {}
+ for i /* ERROR cannot use .* in assignment */ = range &a {}
+ for i /* ERROR cannot use .* in assignment */ = range a[:] {}
+
+ var s string
+ var r R
+ _ = r
+ for i /* ERROR cannot use .* in assignment */ = range s {}
+ for i /* ERROR cannot use .* in assignment */ = range "foo" {}
+ for _, r /* ERROR cannot use .* in assignment */ = range s {}
+ for _, r /* ERROR cannot use .* in assignment */ = range "foo" {}
+}
+
+func issue6766b() {
+ for _ := /* ERROR no new variables */ range "" {}
+ for a, a /* ERROR redeclared */ := range "" { _ = a }
+ var a int
+ _ = a
+ for a, a /* ERROR redeclared */ := range []int{1, 2, 3} { _ = a }
+}
+
+// Test that despite errors in the range clause,
+// the loop body is still type-checked (and thus
+// errors reported).
+func issue10148() {
+ for y /* ERROR declared but not used */ := range "" {
+ _ = "" /* ERROR cannot convert */ + 1
+ }
+ for range 1 /* ERROR cannot range over 1 */ {
+ _ = "" /* ERROR cannot convert */ + 1
+ }
+ for y := range 1 /* ERROR cannot range over 1 */ {
+ _ = "" /* ERROR cannot convert */ + 1
+ }
+}
+
+func labels0() {
+ goto L0
+ goto L1
+ L0:
+ L1:
+ L1 /* ERROR "already declared" */ :
+ if true {
+ goto L2
+ L2:
+ L0 /* ERROR "already declared" */ :
+ }
+ _ = func() {
+ goto L0
+ goto L1
+ goto L2
+ L0:
+ L1:
+ L2:
+ }
+}
+
+func expression_statements(ch chan int) {
+ expression_statements(ch)
+ <-ch
+ println()
+
+ 0 /* ERROR "not used" */
+ 1 /* ERROR "not used" */ +2
+ cap /* ERROR "not used" */ (ch)
+ println /* ERROR "must be called" */
+}
diff --git a/src/go/types/testdata/stmt1.src b/src/go/types/testdata/stmt1.src
new file mode 100644
index 0000000..f79f920
--- /dev/null
+++ b/src/go/types/testdata/stmt1.src
@@ -0,0 +1,259 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// terminating statements
+
+package stmt1
+
+func _() {}
+
+func _() int {} /* ERROR "missing return" */
+
+func _() int { panic(0) }
+func _() int { (panic(0)) }
+
+// block statements
+func _(x, y int) (z int) {
+ {
+ return
+ }
+}
+
+func _(x, y int) (z int) {
+ {
+ return; ; ; // trailing empty statements are ok
+ }
+ ; ; ;
+}
+
+func _(x, y int) (z int) {
+ {
+ }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ {
+ ; ; ;
+ }
+ ; ; ;
+} /* ERROR "missing return" */
+
+// if statements
+func _(x, y int) (z int) {
+ if x < y { return }
+ return 1
+}
+
+func _(x, y int) (z int) {
+ if x < y { return; ; ; ; }
+ return 1
+}
+
+func _(x, y int) (z int) {
+ if x < y { return }
+ return 1; ;
+}
+
+func _(x, y int) (z int) {
+ if x < y { return }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ if x < y {
+ } else { return 1
+ }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ if x < y { return
+ } else { return
+ }
+}
+
+// for statements
+func _(x, y int) (z int) {
+ for x < y {
+ return
+ }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ for {
+ return
+ }
+}
+
+func _(x, y int) (z int) {
+ for {
+ return; ; ; ;
+ }
+}
+
+func _(x, y int) (z int) {
+ for {
+ return
+ break
+ }
+ ; ; ;
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ for {
+ for { break }
+ return
+ }
+}
+
+func _(x, y int) (z int) {
+ for {
+ for { break }
+ return ; ;
+ }
+ ;
+}
+
+func _(x, y int) (z int) {
+L: for {
+ for { break L }
+ return
+ }
+} /* ERROR "missing return" */
+
+// switch statements
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return
+ default: return
+ }
+}
+
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return;
+ default: return; ; ;
+ }
+}
+
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return
+ }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return
+ case 1: break
+ }
+} /* ERROR "missing return" */
+
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return
+ default:
+ switch y {
+ case 0: break
+ }
+ panic(0)
+ }
+}
+
+func _(x, y int) (z int) {
+ switch x {
+ case 0: return
+ default:
+ switch y {
+ case 0: break
+ }
+ panic(0); ; ;
+ }
+ ;
+}
+
+func _(x, y int) (z int) {
+L: switch x {
+ case 0: return
+ default:
+ switch y {
+ case 0: break L
+ }
+ panic(0)
+ }
+} /* ERROR "missing return" */
+
+// select statements
+func _(ch chan int) (z int) {
+ select {}
+} // nice!
+
+func _(ch chan int) (z int) {
+ select {}
+ ; ;
+}
+
+func _(ch chan int) (z int) {
+ select {
+ default: break
+ }
+} /* ERROR "missing return" */
+
+func _(ch chan int) (z int) {
+ select {
+ case <-ch: return
+ default: break
+ }
+} /* ERROR "missing return" */
+
+func _(ch chan int) (z int) {
+ select {
+ case <-ch: return
+ default:
+ for i := 0; i < 10; i++ {
+ break
+ }
+ return
+ }
+}
+
+func _(ch chan int) (z int) {
+ select {
+ case <-ch: return; ; ;
+ default:
+ for i := 0; i < 10; i++ {
+ break
+ }
+ return; ; ;
+ }
+ ; ; ;
+}
+
+func _(ch chan int) (z int) {
+L: select {
+ case <-ch: return
+ default:
+ for i := 0; i < 10; i++ {
+ break L
+ }
+ return
+ }
+ ; ; ;
+} /* ERROR "missing return" */
+
+func parenPanic() int {
+ ((((((panic)))(0))))
+}
+
+func issue23218a() int {
+ {
+ panic := func(interface{}){}
+ panic(0)
+ }
+} /* ERROR "missing return" */
+
+func issue23218b() int {
+ {
+ panic := func(interface{}){}
+ ((((panic))))(0)
+ }
+} /* ERROR "missing return" */
diff --git a/src/go/types/testdata/vardecl.src b/src/go/types/testdata/vardecl.src
new file mode 100644
index 0000000..54f5ef1
--- /dev/null
+++ b/src/go/types/testdata/vardecl.src
@@ -0,0 +1,206 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vardecl
+
+// Prerequisites.
+import "math"
+func f() {}
+func g() (x, y int) { return }
+var m map[string]int
+
+// Var decls must have a type or an initializer.
+var _ int
+var _, _ int
+
+// The first error message is produced by the parser.
+// In a real-world scenario, the type-checker would not be run
+// in this case and the 2nd error message would not appear.
+var _ /* ERROR "missing variable type" */ /* ERROR "missing type or init expr" */
+var _ /* ERROR "missing variable type" */ /* ERROR "missing type or init expr" */, _
+var _ /* ERROR "missing variable type" */ /* ERROR "missing type or init expr" */, _, _
+
+// The initializer must be an expression.
+var _ = int /* ERROR "not an expression" */
+var _ = f /* ERROR "used as value" */ ()
+
+// Identifier and expression arity must match.
+var _, _ = 1, 2
+var _ = 1, 2 /* ERROR "extra init expr 2" */
+var _, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
+var _, _, _ /* ERROR "missing init expr for _" */ = 1, 2
+
+var _ = g /* ERROR "2-valued g" */ ()
+var _, _ = g()
+var _, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()
+
+var _ = m["foo"]
+var _, _ = m["foo"]
+var _, _, _ = m /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ["foo"]
+
+var _, _ int = 1, 2
+var _ int = 1, 2 /* ERROR "extra init expr 2" */
+var _, _ int = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
+var _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2
+
+var (
+ _, _ = 1, 2
+ _ = 1, 2 /* ERROR "extra init expr 2" */
+ _, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
+ _, _, _ /* ERROR "missing init expr for _" */ = 1, 2
+
+ _ = g /* ERROR "2-valued g" */ ()
+ _, _ = g()
+ _, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()
+
+ _ = m["foo"]
+ _, _ = m["foo"]
+ _, _, _ = m /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ["foo"]
+
+ _, _ int = 1, 2
+ _ int = 1, 2 /* ERROR "extra init expr 2" */
+ _, _ int = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
+ _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2
+)
+
+// Variables declared in function bodies must be 'used'.
+type T struct{}
+func (r T) _(a, b, c int) (u, v, w int) {
+ var x1 /* ERROR "declared but not used" */ int
+ var x2 /* ERROR "declared but not used" */ int
+ x1 = 1
+ (x2) = 2
+
+ y1 /* ERROR "declared but not used" */ := 1
+ y2 /* ERROR "declared but not used" */ := 2
+ y1 = 1
+ (y1) = 2
+
+ {
+ var x1 /* ERROR "declared but not used" */ int
+ var x2 /* ERROR "declared but not used" */ int
+ x1 = 1
+ (x2) = 2
+
+ y1 /* ERROR "declared but not used" */ := 1
+ y2 /* ERROR "declared but not used" */ := 2
+ y1 = 1
+ (y1) = 2
+ }
+
+ if x /* ERROR "declared but not used" */ := 0; a < b {}
+
+ switch x /* ERROR "declared but not used" */, y := 0, 1; a {
+ case 0:
+ _ = y
+ case 1:
+ x /* ERROR "declared but not used" */ := 0
+ }
+
+ var t interface{}
+ switch t /* ERROR "declared but not used" */ := t.(type) {}
+
+ switch t /* ERROR "declared but not used" */ := t.(type) {
+ case int:
+ }
+
+ switch t /* ERROR "declared but not used" */ := t.(type) {
+ case int:
+ case float32, complex64:
+ t = nil
+ }
+
+ switch t := t.(type) {
+ case int:
+ case float32, complex64:
+ _ = t
+ }
+
+ switch t := t.(type) {
+ case int:
+ case float32:
+ case string:
+ _ = func() string {
+ return t
+ }
+ }
+
+ switch t := t; t /* ERROR "declared but not used" */ := t.(type) {}
+
+ var z1 /* ERROR "declared but not used" */ int
+ var z2 int
+ _ = func(a, b, c int) (u, v, w int) {
+ z1 = a
+ (z1) = b
+ a = z2
+ return
+ }
+
+ var s []int
+ var i /* ERROR "declared but not used" */ , j int
+ for i, j = range s {
+ _ = j
+ }
+
+ for i, j /* ERROR "declared but not used" */ := range s {
+ _ = func() int {
+ return i
+ }
+ }
+ return
+}
+
+// Unused variables in function literals must lead to only one error (issue #22524).
+func _() {
+ _ = func() {
+ var x /* ERROR declared but not used */ int
+ }
+}
+
+// Invalid (unused) expressions must not lead to spurious "declared but not used errors"
+func _() {
+ var a, b, c int
+ var x, y int
+ x, y = a /* ERROR cannot assign [0-9]+ values to [0-9]+ variables */ , b, c
+ _ = x
+ _ = y
+}
+
+func _() {
+ var x int
+ return x /* ERROR no result values expected */
+ return math /* ERROR no result values expected */ .Sin(0)
+}
+
+func _() int {
+ var x, y int
+ return /* ERROR wrong number of return values */ x, y
+}
+
+// Short variable declarations must declare at least one new non-blank variable.
+func _() {
+ _ := /* ERROR no new variables */ 0
+ _, a := 0, 1
+ _, a := /* ERROR no new variables */ 0, 1
+ _, a, b := 0, 1, 2
+ _, _, _ := /* ERROR no new variables */ 0, 1, 2
+
+ _ = a
+ _ = b
+}
+
+// Test case for variables depending on function literals (see also #22992).
+var A /* ERROR initialization cycle */ = func() int { return A }()
+
+func _() {
+ // The function literal below must not see a.
+ var a = func() int { return a /* ERROR "undeclared name" */ }()
+ var _ = func() int { return a }()
+
+ // The function literal below must not see x, y, or z.
+ var x, y, z = 0, 1, func() int { return x /* ERROR "undeclared name" */ + y /* ERROR "undeclared name" */ + z /* ERROR "undeclared name" */ }()
+ _, _, _ = x, y, z
+}
+
+// TODO(gri) consolidate other var decl checks in this file \ No newline at end of file
diff --git a/src/go/types/token_test.go b/src/go/types/token_test.go
new file mode 100644
index 0000000..705bb29
--- /dev/null
+++ b/src/go/types/token_test.go
@@ -0,0 +1,47 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file checks invariants of token.Token ordering that we rely on
+// since package go/token doesn't provide any guarantees at the moment.
+
+package types
+
+import (
+ "go/token"
+ "testing"
+)
+
+var assignOps = map[token.Token]token.Token{
+ token.ADD_ASSIGN: token.ADD,
+ token.SUB_ASSIGN: token.SUB,
+ token.MUL_ASSIGN: token.MUL,
+ token.QUO_ASSIGN: token.QUO,
+ token.REM_ASSIGN: token.REM,
+ token.AND_ASSIGN: token.AND,
+ token.OR_ASSIGN: token.OR,
+ token.XOR_ASSIGN: token.XOR,
+ token.SHL_ASSIGN: token.SHL,
+ token.SHR_ASSIGN: token.SHR,
+ token.AND_NOT_ASSIGN: token.AND_NOT,
+}
+
+func TestZeroTok(t *testing.T) {
+ // zero value for token.Token must be token.ILLEGAL
+ var zero token.Token
+ if token.ILLEGAL != zero {
+ t.Errorf("%s == %d; want 0", token.ILLEGAL, zero)
+ }
+}
+
+func TestAssignOp(t *testing.T) {
+ // there are fewer than 256 tokens
+ for i := 0; i < 256; i++ {
+ tok := token.Token(i)
+ got := assignOp(tok)
+ want := assignOps[tok]
+ if got != want {
+ t.Errorf("for assignOp(%s): got %s; want %s", tok, got, want)
+ }
+ }
+}
diff --git a/src/go/types/type.go b/src/go/types/type.go
new file mode 100644
index 0000000..087cda4
--- /dev/null
+++ b/src/go/types/type.go
@@ -0,0 +1,523 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import "sort"
+
+// A Type represents a type of Go.
+// All types implement the Type interface.
+type Type interface {
+ // Underlying returns the underlying type of a type.
+ Underlying() Type
+
+ // String returns a string representation of a type.
+ String() string
+}
+
+// BasicKind describes the kind of basic type.
+type BasicKind int
+
+const (
+ Invalid BasicKind = iota // type is invalid
+
+ // predeclared types
+ Bool
+ Int
+ Int8
+ Int16
+ Int32
+ Int64
+ Uint
+ Uint8
+ Uint16
+ Uint32
+ Uint64
+ Uintptr
+ Float32
+ Float64
+ Complex64
+ Complex128
+ String
+ UnsafePointer
+
+ // types for untyped values
+ UntypedBool
+ UntypedInt
+ UntypedRune
+ UntypedFloat
+ UntypedComplex
+ UntypedString
+ UntypedNil
+
+ // aliases
+ Byte = Uint8
+ Rune = Int32
+)
+
+// BasicInfo is a set of flags describing properties of a basic type.
+type BasicInfo int
+
+// Properties of basic types.
+const (
+ IsBoolean BasicInfo = 1 << iota
+ IsInteger
+ IsUnsigned
+ IsFloat
+ IsComplex
+ IsString
+ IsUntyped
+
+ IsOrdered = IsInteger | IsFloat | IsString
+ IsNumeric = IsInteger | IsFloat | IsComplex
+ IsConstType = IsBoolean | IsNumeric | IsString
+)
+
+// A Basic represents a basic type.
+type Basic struct {
+ kind BasicKind
+ info BasicInfo
+ name string
+}
+
+// Kind returns the kind of basic type b.
+func (b *Basic) Kind() BasicKind { return b.kind }
+
+// Info returns information about properties of basic type b.
+func (b *Basic) Info() BasicInfo { return b.info }
+
+// Name returns the name of basic type b.
+func (b *Basic) Name() string { return b.name }
+
+// An Array represents an array type.
+type Array struct {
+ len int64
+ elem Type
+}
+
+// NewArray returns a new array type for the given element type and length.
+// A negative length indicates an unknown length.
+func NewArray(elem Type, len int64) *Array { return &Array{len, elem} }
+
+// Len returns the length of array a.
+// A negative result indicates an unknown length.
+func (a *Array) Len() int64 { return a.len }
+
+// Elem returns element type of array a.
+func (a *Array) Elem() Type { return a.elem }
+
+// A Slice represents a slice type.
+type Slice struct {
+ elem Type
+}
+
+// NewSlice returns a new slice type for the given element type.
+func NewSlice(elem Type) *Slice { return &Slice{elem} }
+
+// Elem returns the element type of slice s.
+func (s *Slice) Elem() Type { return s.elem }
+
+// A Struct represents a struct type.
+type Struct struct {
+ fields []*Var
+ tags []string // field tags; nil if there are no tags
+}
+
+// NewStruct returns a new struct with the given fields and corresponding field tags.
+// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be
+// only as long as required to hold the tag with the largest index i. Consequently,
+// if no field has a tag, tags may be nil.
+func NewStruct(fields []*Var, tags []string) *Struct {
+ var fset objset
+ for _, f := range fields {
+ if f.name != "_" && fset.insert(f) != nil {
+ panic("multiple fields with the same name")
+ }
+ }
+ if len(tags) > len(fields) {
+ panic("more tags than fields")
+ }
+ return &Struct{fields: fields, tags: tags}
+}
+
+// NumFields returns the number of fields in the struct (including blank and embedded fields).
+func (s *Struct) NumFields() int { return len(s.fields) }
+
+// Field returns the i'th field for 0 <= i < NumFields().
+func (s *Struct) Field(i int) *Var { return s.fields[i] }
+
+// Tag returns the i'th field tag for 0 <= i < NumFields().
+func (s *Struct) Tag(i int) string {
+ if i < len(s.tags) {
+ return s.tags[i]
+ }
+ return ""
+}
+
+// A Pointer represents a pointer type.
+type Pointer struct {
+ base Type // element type
+}
+
+// NewPointer returns a new pointer type for the given element (base) type.
+func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} }
+
+// Elem returns the element type for the given pointer p.
+func (p *Pointer) Elem() Type { return p.base }
+
+// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple.
+// Tuples are used as components of signatures and to represent the type of multiple
+// assignments; they are not first class types of Go.
+type Tuple struct {
+ vars []*Var
+}
+
+// NewTuple returns a new tuple for the given variables.
+func NewTuple(x ...*Var) *Tuple {
+ if len(x) > 0 {
+ return &Tuple{x}
+ }
+ return nil
+}
+
+// Len returns the number variables of tuple t.
+func (t *Tuple) Len() int {
+ if t != nil {
+ return len(t.vars)
+ }
+ return 0
+}
+
+// At returns the i'th variable of tuple t.
+func (t *Tuple) At(i int) *Var { return t.vars[i] }
+
+// A Signature represents a (non-builtin) function or method type.
+// The receiver is ignored when comparing signatures for identity.
+type Signature struct {
+ // We need to keep the scope in Signature (rather than passing it around
+ // and store it in the Func Object) because when type-checking a function
+ // literal we call the general type checker which returns a general Type.
+ // We then unpack the *Signature and use the scope for the literal body.
+ scope *Scope // function scope, present for package-local signatures
+ recv *Var // nil if not a method
+ params *Tuple // (incoming) parameters from left to right; or nil
+ results *Tuple // (outgoing) results from left to right; or nil
+ variadic bool // true if the last parameter's type is of the form ...T (or string, for append built-in only)
+}
+
+// NewSignature returns a new function type for the given receiver, parameters,
+// and results, either of which may be nil. If variadic is set, the function
+// is variadic, it must have at least one parameter, and the last parameter
+// must be of unnamed slice type.
+func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature {
+ if variadic {
+ n := params.Len()
+ if n == 0 {
+ panic("types.NewSignature: variadic function must have at least one parameter")
+ }
+ if _, ok := params.At(n - 1).typ.(*Slice); !ok {
+ panic("types.NewSignature: variadic parameter must be of unnamed slice type")
+ }
+ }
+ return &Signature{nil, recv, params, results, variadic}
+}
+
+// Recv returns the receiver of signature s (if a method), or nil if a
+// function. It is ignored when comparing signatures for identity.
+//
+// For an abstract method, Recv returns the enclosing interface either
+// as a *Named or an *Interface. Due to embedding, an interface may
+// contain methods whose receiver type is a different interface.
+func (s *Signature) Recv() *Var { return s.recv }
+
+// Params returns the parameters of signature s, or nil.
+func (s *Signature) Params() *Tuple { return s.params }
+
+// Results returns the results of signature s, or nil.
+func (s *Signature) Results() *Tuple { return s.results }
+
+// Variadic reports whether the signature s is variadic.
+func (s *Signature) Variadic() bool { return s.variadic }
+
+// An Interface represents an interface type.
+type Interface struct {
+ methods []*Func // ordered list of explicitly declared methods
+ embeddeds []Type // ordered list of explicitly embedded types
+
+ allMethods []*Func // ordered list of methods declared with or embedded in this interface (TODO(gri): replace with mset)
+}
+
+// emptyInterface represents the empty (completed) interface
+var emptyInterface = Interface{allMethods: markComplete}
+
+// markComplete is used to mark an empty interface as completely
+// set up by setting the allMethods field to a non-nil empty slice.
+var markComplete = make([]*Func, 0)
+
+// NewInterface returns a new (incomplete) interface for the given methods and embedded types.
+// Each embedded type must have an underlying type of interface type.
+// NewInterface takes ownership of the provided methods and may modify their types by setting
+// missing receivers. To compute the method set of the interface, Complete must be called.
+//
+// Deprecated: Use NewInterfaceType instead which allows any (even non-defined) interface types
+// to be embedded. This is necessary for interfaces that embed alias type names referring to
+// non-defined (literal) interface types.
+func NewInterface(methods []*Func, embeddeds []*Named) *Interface {
+ tnames := make([]Type, len(embeddeds))
+ for i, t := range embeddeds {
+ tnames[i] = t
+ }
+ return NewInterfaceType(methods, tnames)
+}
+
+// NewInterfaceType returns a new (incomplete) interface for the given methods and embedded types.
+// Each embedded type must have an underlying type of interface type (this property is not
+// verified for defined types, which may be in the process of being set up and which don't
+// have a valid underlying type yet).
+// NewInterfaceType takes ownership of the provided methods and may modify their types by setting
+// missing receivers. To compute the method set of the interface, Complete must be called.
+func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
+ if len(methods) == 0 && len(embeddeds) == 0 {
+ return &emptyInterface
+ }
+
+ // set method receivers if necessary
+ typ := new(Interface)
+ for _, m := range methods {
+ if sig := m.typ.(*Signature); sig.recv == nil {
+ sig.recv = NewVar(m.pos, m.pkg, "", typ)
+ }
+ }
+
+ // All embedded types should be interfaces; however, defined types
+ // may not yet be fully resolved. Only verify that non-defined types
+ // are interfaces. This matches the behavior of the code before the
+ // fix for #25301 (issue #25596).
+ for _, t := range embeddeds {
+ if _, ok := t.(*Named); !ok && !IsInterface(t) {
+ panic("embedded type is not an interface")
+ }
+ }
+
+ // sort for API stability
+ sort.Sort(byUniqueMethodName(methods))
+ sort.Stable(byUniqueTypeName(embeddeds))
+
+ typ.methods = methods
+ typ.embeddeds = embeddeds
+ return typ
+}
+
+// NumExplicitMethods returns the number of explicitly declared methods of interface t.
+func (t *Interface) NumExplicitMethods() int { return len(t.methods) }
+
+// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods().
+// The methods are ordered by their unique Id.
+func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] }
+
+// NumEmbeddeds returns the number of embedded types in interface t.
+func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) }
+
+// Embedded returns the i'th embedded defined (*Named) type of interface t for 0 <= i < t.NumEmbeddeds().
+// The result is nil if the i'th embedded type is not a defined type.
+//
+// Deprecated: Use EmbeddedType which is not restricted to defined (*Named) types.
+func (t *Interface) Embedded(i int) *Named { tname, _ := t.embeddeds[i].(*Named); return tname }
+
+// EmbeddedType returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds().
+func (t *Interface) EmbeddedType(i int) Type { return t.embeddeds[i] }
+
+// NumMethods returns the total number of methods of interface t.
+// The interface must have been completed.
+func (t *Interface) NumMethods() int { t.assertCompleteness(); return len(t.allMethods) }
+
+func (t *Interface) assertCompleteness() {
+ if t.allMethods == nil {
+ panic("interface is incomplete")
+ }
+}
+
+// Method returns the i'th method of interface t for 0 <= i < t.NumMethods().
+// The methods are ordered by their unique Id.
+// The interface must have been completed.
+func (t *Interface) Method(i int) *Func { t.assertCompleteness(); return t.allMethods[i] }
+
+// Empty reports whether t is the empty interface.
+// The interface must have been completed.
+func (t *Interface) Empty() bool { t.assertCompleteness(); return len(t.allMethods) == 0 }
+
+// Complete computes the interface's method set. It must be called by users of
+// NewInterfaceType and NewInterface after the interface's embedded types are
+// fully defined and before using the interface type in any way other than to
+// form other types. The interface must not contain duplicate methods or a
+// panic occurs. Complete returns the receiver.
+func (t *Interface) Complete() *Interface {
+ // TODO(gri) consolidate this method with Checker.completeInterface
+ if t.allMethods != nil {
+ return t
+ }
+
+ t.allMethods = markComplete // avoid infinite recursion
+
+ var todo []*Func
+ var methods []*Func
+ var seen objset
+ addMethod := func(m *Func, explicit bool) {
+ switch other := seen.insert(m); {
+ case other == nil:
+ methods = append(methods, m)
+ case explicit:
+ panic("duplicate method " + m.name)
+ default:
+ // check method signatures after all locally embedded interfaces are computed
+ todo = append(todo, m, other.(*Func))
+ }
+ }
+
+ for _, m := range t.methods {
+ addMethod(m, true)
+ }
+
+ for _, typ := range t.embeddeds {
+ typ := typ.Underlying().(*Interface)
+ typ.Complete()
+ for _, m := range typ.allMethods {
+ addMethod(m, false)
+ }
+ }
+
+ for i := 0; i < len(todo); i += 2 {
+ m := todo[i]
+ other := todo[i+1]
+ if !Identical(m.typ, other.typ) {
+ panic("duplicate method " + m.name)
+ }
+ }
+
+ if methods != nil {
+ sort.Sort(byUniqueMethodName(methods))
+ t.allMethods = methods
+ }
+
+ return t
+}
+
+// A Map represents a map type.
+type Map struct {
+ key, elem Type
+}
+
+// NewMap returns a new map for the given key and element types.
+func NewMap(key, elem Type) *Map {
+ return &Map{key, elem}
+}
+
+// Key returns the key type of map m.
+func (m *Map) Key() Type { return m.key }
+
+// Elem returns the element type of map m.
+func (m *Map) Elem() Type { return m.elem }
+
+// A Chan represents a channel type.
+type Chan struct {
+ dir ChanDir
+ elem Type
+}
+
+// A ChanDir value indicates a channel direction.
+type ChanDir int
+
+// The direction of a channel is indicated by one of these constants.
+const (
+ SendRecv ChanDir = iota
+ SendOnly
+ RecvOnly
+)
+
+// NewChan returns a new channel type for the given direction and element type.
+func NewChan(dir ChanDir, elem Type) *Chan {
+ return &Chan{dir, elem}
+}
+
+// Dir returns the direction of channel c.
+func (c *Chan) Dir() ChanDir { return c.dir }
+
+// Elem returns the element type of channel c.
+func (c *Chan) Elem() Type { return c.elem }
+
+// A Named represents a named type.
+type Named struct {
+ info typeInfo // for cycle detection
+ obj *TypeName // corresponding declared object
+ orig Type // type (on RHS of declaration) this *Named type is derived of (for cycle reporting)
+ underlying Type // possibly a *Named during setup; never a *Named once set up completely
+ methods []*Func // methods declared for this type (not the method set of this type); signatures are type-checked lazily
+}
+
+// NewNamed returns a new named type for the given type name, underlying type, and associated methods.
+// If the given type name obj doesn't have a type yet, its type is set to the returned named type.
+// The underlying type must not be a *Named.
+func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
+ if _, ok := underlying.(*Named); ok {
+ panic("types.NewNamed: underlying type must not be *Named")
+ }
+ typ := &Named{obj: obj, orig: underlying, underlying: underlying, methods: methods}
+ if obj.typ == nil {
+ obj.typ = typ
+ }
+ return typ
+}
+
+// Obj returns the type name for the named type t.
+func (t *Named) Obj() *TypeName { return t.obj }
+
+// NumMethods returns the number of explicit methods whose receiver is named type t.
+func (t *Named) NumMethods() int { return len(t.methods) }
+
+// Method returns the i'th method of named type t for 0 <= i < t.NumMethods().
+func (t *Named) Method(i int) *Func { return t.methods[i] }
+
+// SetUnderlying sets the underlying type and marks t as complete.
+func (t *Named) SetUnderlying(underlying Type) {
+ if underlying == nil {
+ panic("types.Named.SetUnderlying: underlying type must not be nil")
+ }
+ if _, ok := underlying.(*Named); ok {
+ panic("types.Named.SetUnderlying: underlying type must not be *Named")
+ }
+ t.underlying = underlying
+}
+
+// AddMethod adds method m unless it is already in the method list.
+func (t *Named) AddMethod(m *Func) {
+ if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 {
+ t.methods = append(t.methods, m)
+ }
+}
+
+// Implementations for Type methods.
+
+func (b *Basic) Underlying() Type { return b }
+func (a *Array) Underlying() Type { return a }
+func (s *Slice) Underlying() Type { return s }
+func (s *Struct) Underlying() Type { return s }
+func (p *Pointer) Underlying() Type { return p }
+func (t *Tuple) Underlying() Type { return t }
+func (s *Signature) Underlying() Type { return s }
+func (t *Interface) Underlying() Type { return t }
+func (m *Map) Underlying() Type { return m }
+func (c *Chan) Underlying() Type { return c }
+func (t *Named) Underlying() Type { return t.underlying }
+
+func (b *Basic) String() string { return TypeString(b, nil) }
+func (a *Array) String() string { return TypeString(a, nil) }
+func (s *Slice) String() string { return TypeString(s, nil) }
+func (s *Struct) String() string { return TypeString(s, nil) }
+func (p *Pointer) String() string { return TypeString(p, nil) }
+func (t *Tuple) String() string { return TypeString(t, nil) }
+func (s *Signature) String() string { return TypeString(s, nil) }
+func (t *Interface) String() string { return TypeString(t, nil) }
+func (m *Map) String() string { return TypeString(m, nil) }
+func (c *Chan) String() string { return TypeString(c, nil) }
+func (t *Named) String() string { return TypeString(t, nil) }
diff --git a/src/go/types/typestring.go b/src/go/types/typestring.go
new file mode 100644
index 0000000..31c572f
--- /dev/null
+++ b/src/go/types/typestring.go
@@ -0,0 +1,307 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements printing of types.
+
+package types
+
+import (
+ "bytes"
+ "fmt"
+)
+
+// A Qualifier controls how named package-level objects are printed in
+// calls to TypeString, ObjectString, and SelectionString.
+//
+// These three formatting routines call the Qualifier for each
+// package-level object O, and if the Qualifier returns a non-empty
+// string p, the object is printed in the form p.O.
+// If it returns an empty string, only the object name O is printed.
+//
+// Using a nil Qualifier is equivalent to using (*Package).Path: the
+// object is qualified by the import path, e.g., "encoding/json.Marshal".
+//
+type Qualifier func(*Package) string
+
+// RelativeTo returns a Qualifier that fully qualifies members of
+// all packages other than pkg.
+func RelativeTo(pkg *Package) Qualifier {
+ if pkg == nil {
+ return nil
+ }
+ return func(other *Package) string {
+ if pkg == other {
+ return "" // same package; unqualified
+ }
+ return other.Path()
+ }
+}
+
+// If gcCompatibilityMode is set, printing of types is modified
+// to match the representation of some types in the gc compiler:
+//
+// - byte and rune lose their alias name and simply stand for
+// uint8 and int32 respectively
+// - embedded interfaces get flattened (the embedding info is lost,
+// and certain recursive interface types cannot be printed anymore)
+//
+// This makes it easier to compare packages computed with the type-
+// checker vs packages imported from gc export data.
+//
+// Caution: This flag affects all uses of WriteType, globally.
+// It is only provided for testing in conjunction with
+// gc-generated data.
+//
+// This flag is exported in the x/tools/go/types package. We don't
+// need it at the moment in the std repo and so we don't export it
+// anymore. We should eventually try to remove it altogether.
+// TODO(gri) remove this
+var gcCompatibilityMode bool
+
+// TypeString returns the string representation of typ.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func TypeString(typ Type, qf Qualifier) string {
+ var buf bytes.Buffer
+ WriteType(&buf, typ, qf)
+ return buf.String()
+}
+
+// WriteType writes the string representation of typ to buf.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func WriteType(buf *bytes.Buffer, typ Type, qf Qualifier) {
+ writeType(buf, typ, qf, make([]Type, 0, 8))
+}
+
+func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
+ // Theoretically, this is a quadratic lookup algorithm, but in
+ // practice deeply nested composite types with unnamed component
+ // types are uncommon. This code is likely more efficient than
+ // using a map.
+ for _, t := range visited {
+ if t == typ {
+ fmt.Fprintf(buf, "○%T", typ) // cycle to typ
+ return
+ }
+ }
+ visited = append(visited, typ)
+
+ switch t := typ.(type) {
+ case nil:
+ buf.WriteString("<nil>")
+
+ case *Basic:
+ if t.kind == UnsafePointer {
+ buf.WriteString("unsafe.")
+ }
+ if gcCompatibilityMode {
+ // forget the alias names
+ switch t.kind {
+ case Byte:
+ t = Typ[Uint8]
+ case Rune:
+ t = Typ[Int32]
+ }
+ }
+ buf.WriteString(t.name)
+
+ case *Array:
+ fmt.Fprintf(buf, "[%d]", t.len)
+ writeType(buf, t.elem, qf, visited)
+
+ case *Slice:
+ buf.WriteString("[]")
+ writeType(buf, t.elem, qf, visited)
+
+ case *Struct:
+ buf.WriteString("struct{")
+ for i, f := range t.fields {
+ if i > 0 {
+ buf.WriteString("; ")
+ }
+ if !f.embedded {
+ buf.WriteString(f.name)
+ buf.WriteByte(' ')
+ }
+ writeType(buf, f.typ, qf, visited)
+ if tag := t.Tag(i); tag != "" {
+ fmt.Fprintf(buf, " %q", tag)
+ }
+ }
+ buf.WriteByte('}')
+
+ case *Pointer:
+ buf.WriteByte('*')
+ writeType(buf, t.base, qf, visited)
+
+ case *Tuple:
+ writeTuple(buf, t, false, qf, visited)
+
+ case *Signature:
+ buf.WriteString("func")
+ writeSignature(buf, t, qf, visited)
+
+ case *Interface:
+ // We write the source-level methods and embedded types rather
+ // than the actual method set since resolved method signatures
+ // may have non-printable cycles if parameters have embedded
+ // interface types that (directly or indirectly) embed the
+ // current interface. For instance, consider the result type
+ // of m:
+ //
+ // type T interface{
+ // m() interface{ T }
+ // }
+ //
+ buf.WriteString("interface{")
+ empty := true
+ if gcCompatibilityMode {
+ // print flattened interface
+ // (useful to compare against gc-generated interfaces)
+ for i, m := range t.allMethods {
+ if i > 0 {
+ buf.WriteString("; ")
+ }
+ buf.WriteString(m.name)
+ writeSignature(buf, m.typ.(*Signature), qf, visited)
+ empty = false
+ }
+ } else {
+ // print explicit interface methods and embedded types
+ for i, m := range t.methods {
+ if i > 0 {
+ buf.WriteString("; ")
+ }
+ buf.WriteString(m.name)
+ writeSignature(buf, m.typ.(*Signature), qf, visited)
+ empty = false
+ }
+ for i, typ := range t.embeddeds {
+ if i > 0 || len(t.methods) > 0 {
+ buf.WriteString("; ")
+ }
+ writeType(buf, typ, qf, visited)
+ empty = false
+ }
+ }
+ if t.allMethods == nil || len(t.methods) > len(t.allMethods) {
+ if !empty {
+ buf.WriteByte(' ')
+ }
+ buf.WriteString("/* incomplete */")
+ }
+ buf.WriteByte('}')
+
+ case *Map:
+ buf.WriteString("map[")
+ writeType(buf, t.key, qf, visited)
+ buf.WriteByte(']')
+ writeType(buf, t.elem, qf, visited)
+
+ case *Chan:
+ var s string
+ var parens bool
+ switch t.dir {
+ case SendRecv:
+ s = "chan "
+ // chan (<-chan T) requires parentheses
+ if c, _ := t.elem.(*Chan); c != nil && c.dir == RecvOnly {
+ parens = true
+ }
+ case SendOnly:
+ s = "chan<- "
+ case RecvOnly:
+ s = "<-chan "
+ default:
+ panic("unreachable")
+ }
+ buf.WriteString(s)
+ if parens {
+ buf.WriteByte('(')
+ }
+ writeType(buf, t.elem, qf, visited)
+ if parens {
+ buf.WriteByte(')')
+ }
+
+ case *Named:
+ s := "<Named w/o object>"
+ if obj := t.obj; obj != nil {
+ if obj.pkg != nil {
+ writePackage(buf, obj.pkg, qf)
+ }
+ // TODO(gri): function-local named types should be displayed
+ // differently from named types at package level to avoid
+ // ambiguity.
+ s = obj.name
+ }
+ buf.WriteString(s)
+
+ default:
+ // For externally defined implementations of Type.
+ buf.WriteString(t.String())
+ }
+}
+
+func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visited []Type) {
+ buf.WriteByte('(')
+ if tup != nil {
+ for i, v := range tup.vars {
+ if i > 0 {
+ buf.WriteString(", ")
+ }
+ if v.name != "" {
+ buf.WriteString(v.name)
+ buf.WriteByte(' ')
+ }
+ typ := v.typ
+ if variadic && i == len(tup.vars)-1 {
+ if s, ok := typ.(*Slice); ok {
+ buf.WriteString("...")
+ typ = s.elem
+ } else {
+ // special case:
+ // append(s, "foo"...) leads to signature func([]byte, string...)
+ if t, ok := typ.Underlying().(*Basic); !ok || t.kind != String {
+ panic("internal error: string type expected")
+ }
+ writeType(buf, typ, qf, visited)
+ buf.WriteString("...")
+ continue
+ }
+ }
+ writeType(buf, typ, qf, visited)
+ }
+ }
+ buf.WriteByte(')')
+}
+
+// WriteSignature writes the representation of the signature sig to buf,
+// without a leading "func" keyword.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func WriteSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier) {
+ writeSignature(buf, sig, qf, make([]Type, 0, 8))
+}
+
+func writeSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier, visited []Type) {
+ writeTuple(buf, sig.params, sig.variadic, qf, visited)
+
+ n := sig.results.Len()
+ if n == 0 {
+ // no result
+ return
+ }
+
+ buf.WriteByte(' ')
+ if n == 1 && sig.results.vars[0].name == "" {
+ // single unnamed result
+ writeType(buf, sig.results.vars[0].typ, qf, visited)
+ return
+ }
+
+ // multiple or named result(s)
+ writeTuple(buf, sig.results, false, qf, visited)
+}
diff --git a/src/go/types/typestring_test.go b/src/go/types/typestring_test.go
new file mode 100644
index 0000000..5d9db39
--- /dev/null
+++ b/src/go/types/typestring_test.go
@@ -0,0 +1,221 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types_test
+
+import (
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "internal/testenv"
+ "testing"
+
+ . "go/types"
+)
+
+const filename = "<src>"
+
+func makePkg(src string) (*Package, error) {
+ fset := token.NewFileSet()
+ file, err := parser.ParseFile(fset, filename, src, parser.DeclarationErrors)
+ if err != nil {
+ return nil, err
+ }
+ // use the package name as package path
+ conf := Config{Importer: importer.Default()}
+ return conf.Check(file.Name.Name, fset, []*ast.File{file}, nil)
+}
+
+type testEntry struct {
+ src, str string
+}
+
+// dup returns a testEntry where both src and str are the same.
+func dup(s string) testEntry {
+ return testEntry{s, s}
+}
+
+// types that don't depend on any other type declarations
+var independentTestTypes = []testEntry{
+ // basic types
+ dup("int"),
+ dup("float32"),
+ dup("string"),
+
+ // arrays
+ dup("[10]int"),
+
+ // slices
+ dup("[]int"),
+ dup("[][]int"),
+
+ // structs
+ dup("struct{}"),
+ dup("struct{x int}"),
+ {`struct {
+ x, y int
+ z float32 "foo"
+ }`, `struct{x int; y int; z float32 "foo"}`},
+ {`struct {
+ string
+ elems []complex128
+ }`, `struct{string; elems []complex128}`},
+
+ // pointers
+ dup("*int"),
+ dup("***struct{}"),
+ dup("*struct{a int; b float32}"),
+
+ // functions
+ dup("func()"),
+ dup("func(x int)"),
+ {"func(x, y int)", "func(x int, y int)"},
+ {"func(x, y int, z string)", "func(x int, y int, z string)"},
+ dup("func(int)"),
+ {"func(int, string, byte)", "func(int, string, byte)"},
+
+ dup("func() int"),
+ {"func() (string)", "func() string"},
+ dup("func() (u int)"),
+ {"func() (u, v int, w string)", "func() (u int, v int, w string)"},
+
+ dup("func(int) string"),
+ dup("func(x int) string"),
+ dup("func(x int) (u string)"),
+ {"func(x, y int) (u string)", "func(x int, y int) (u string)"},
+
+ dup("func(...int) string"),
+ dup("func(x ...int) string"),
+ dup("func(x ...int) (u string)"),
+ {"func(x int, y ...int) (u string)", "func(x int, y ...int) (u string)"},
+
+ // interfaces
+ dup("interface{}"),
+ dup("interface{m()}"),
+ dup(`interface{String() string; m(int) float32}`),
+
+ // maps
+ dup("map[string]int"),
+ {"map[struct{x, y int}][]byte", "map[struct{x int; y int}][]byte"},
+
+ // channels
+ dup("chan<- chan int"),
+ dup("chan<- <-chan int"),
+ dup("<-chan <-chan int"),
+ dup("chan (<-chan int)"),
+ dup("chan<- func()"),
+ dup("<-chan []func() int"),
+}
+
+// types that depend on other type declarations (src in TestTypes)
+var dependentTestTypes = []testEntry{
+ // interfaces
+ dup(`interface{io.Reader; io.Writer}`),
+ dup(`interface{m() int; io.Writer}`),
+ {`interface{m() interface{T}}`, `interface{m() interface{p.T}}`},
+}
+
+func TestTypeString(t *testing.T) {
+ testenv.MustHaveGoBuild(t)
+
+ var tests []testEntry
+ tests = append(tests, independentTestTypes...)
+ tests = append(tests, dependentTestTypes...)
+
+ for _, test := range tests {
+ src := `package p; import "io"; type _ io.Writer; type T ` + test.src
+ pkg, err := makePkg(src)
+ if err != nil {
+ t.Errorf("%s: %s", src, err)
+ continue
+ }
+ typ := pkg.Scope().Lookup("T").Type().Underlying()
+ if got := typ.String(); got != test.str {
+ t.Errorf("%s: got %s, want %s", test.src, got, test.str)
+ }
+ }
+}
+
+func TestIncompleteInterfaces(t *testing.T) {
+ sig := NewSignature(nil, nil, nil, false)
+ m := NewFunc(token.NoPos, nil, "m", sig)
+ for _, test := range []struct {
+ typ *Interface
+ want string
+ }{
+ {new(Interface), "interface{/* incomplete */}"},
+ {new(Interface).Complete(), "interface{}"},
+
+ {NewInterface(nil, nil), "interface{}"},
+ {NewInterface(nil, nil).Complete(), "interface{}"},
+ {NewInterface([]*Func{}, nil), "interface{}"},
+ {NewInterface([]*Func{}, nil).Complete(), "interface{}"},
+ {NewInterface(nil, []*Named{}), "interface{}"},
+ {NewInterface(nil, []*Named{}).Complete(), "interface{}"},
+ {NewInterface([]*Func{m}, nil), "interface{m() /* incomplete */}"},
+ {NewInterface([]*Func{m}, nil).Complete(), "interface{m()}"},
+ {NewInterface(nil, []*Named{newDefined(new(Interface).Complete())}), "interface{T /* incomplete */}"},
+ {NewInterface(nil, []*Named{newDefined(new(Interface).Complete())}).Complete(), "interface{T}"},
+ {NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil))}), "interface{T /* incomplete */}"},
+ {NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil).Complete())}), "interface{T /* incomplete */}"},
+ {NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil).Complete())}).Complete(), "interface{T}"},
+
+ {NewInterfaceType(nil, nil), "interface{}"},
+ {NewInterfaceType(nil, nil).Complete(), "interface{}"},
+ {NewInterfaceType([]*Func{}, nil), "interface{}"},
+ {NewInterfaceType([]*Func{}, nil).Complete(), "interface{}"},
+ {NewInterfaceType(nil, []Type{}), "interface{}"},
+ {NewInterfaceType(nil, []Type{}).Complete(), "interface{}"},
+ {NewInterfaceType([]*Func{m}, nil), "interface{m() /* incomplete */}"},
+ {NewInterfaceType([]*Func{m}, nil).Complete(), "interface{m()}"},
+ {NewInterfaceType(nil, []Type{new(Interface).Complete()}), "interface{interface{} /* incomplete */}"},
+ {NewInterfaceType(nil, []Type{new(Interface).Complete()}).Complete(), "interface{interface{}}"},
+ {NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil)}), "interface{interface{m() /* incomplete */} /* incomplete */}"},
+ {NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil).Complete()}), "interface{interface{m()} /* incomplete */}"},
+ {NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil).Complete()}).Complete(), "interface{interface{m()}}"},
+ } {
+ got := test.typ.String()
+ if got != test.want {
+ t.Errorf("got: %s, want: %s", got, test.want)
+ }
+ }
+}
+
+// newDefined creates a new defined type named T with the given underlying type.
+// Helper function for use with TestIncompleteInterfaces only.
+func newDefined(underlying Type) *Named {
+ tname := NewTypeName(token.NoPos, nil, "T", nil)
+ return NewNamed(tname, underlying, nil)
+}
+
+func TestQualifiedTypeString(t *testing.T) {
+ p, _ := pkgFor("p.go", "package p; type T int", nil)
+ q, _ := pkgFor("q.go", "package q", nil)
+
+ pT := p.Scope().Lookup("T").Type()
+ for _, test := range []struct {
+ typ Type
+ this *Package
+ want string
+ }{
+ {nil, nil, "<nil>"},
+ {pT, nil, "p.T"},
+ {pT, p, "T"},
+ {pT, q, "p.T"},
+ {NewPointer(pT), p, "*T"},
+ {NewPointer(pT), q, "*p.T"},
+ } {
+ qualifier := func(pkg *Package) string {
+ if pkg != test.this {
+ return pkg.Name()
+ }
+ return ""
+ }
+ if got := TypeString(test.typ, qualifier); got != test.want {
+ t.Errorf("TypeString(%s, %s) = %s, want %s",
+ test.this, test.typ, got, test.want)
+ }
+ }
+}
diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
new file mode 100644
index 0000000..2b39801
--- /dev/null
+++ b/src/go/types/typexpr.go
@@ -0,0 +1,764 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements type-checking of identifiers and type expressions.
+
+package types
+
+import (
+ "go/ast"
+ "go/constant"
+ "go/token"
+ "sort"
+ "strconv"
+)
+
+// ident type-checks identifier e and initializes x with the value or type of e.
+// If an error occurred, x.mode is set to invalid.
+// For the meaning of def, see Checker.definedType, below.
+// If wantType is set, the identifier e is expected to denote a type.
+//
+func (check *Checker) ident(x *operand, e *ast.Ident, def *Named, wantType bool) {
+ x.mode = invalid
+ x.expr = e
+
+ // Note that we cannot use check.lookup here because the returned scope
+ // may be different from obj.Parent(). See also Scope.LookupParent doc.
+ scope, obj := check.scope.LookupParent(e.Name, check.pos)
+ if obj == nil {
+ if e.Name == "_" {
+ check.errorf(e, _InvalidBlank, "cannot use _ as value or type")
+ } else {
+ check.errorf(e, _UndeclaredName, "undeclared name: %s", e.Name)
+ }
+ return
+ }
+ check.recordUse(e, obj)
+
+ // Type-check the object.
+ // Only call Checker.objDecl if the object doesn't have a type yet
+ // (in which case we must actually determine it) or the object is a
+ // TypeName and we also want a type (in which case we might detect
+ // a cycle which needs to be reported). Otherwise we can skip the
+ // call and avoid a possible cycle error in favor of the more
+ // informative "not a type/value" error that this function's caller
+ // will issue (see issue #25790).
+ typ := obj.Type()
+ if _, gotType := obj.(*TypeName); typ == nil || gotType && wantType {
+ check.objDecl(obj, def)
+ typ = obj.Type() // type must have been assigned by Checker.objDecl
+ }
+ assert(typ != nil)
+
+ // The object may be dot-imported: If so, remove its package from
+ // the map of unused dot imports for the respective file scope.
+ // (This code is only needed for dot-imports. Without them,
+ // we only have to mark variables, see *Var case below).
+ if pkg := obj.Pkg(); pkg != check.pkg && pkg != nil {
+ delete(check.unusedDotImports[scope], pkg)
+ }
+
+ switch obj := obj.(type) {
+ case *PkgName:
+ check.errorf(e, _InvalidPkgUse, "use of package %s not in selector", obj.name)
+ return
+
+ case *Const:
+ check.addDeclDep(obj)
+ if typ == Typ[Invalid] {
+ return
+ }
+ if obj == universeIota {
+ if check.iota == nil {
+ check.errorf(e, _InvalidIota, "cannot use iota outside constant declaration")
+ return
+ }
+ x.val = check.iota
+ } else {
+ x.val = obj.val
+ }
+ assert(x.val != nil)
+ x.mode = constant_
+
+ case *TypeName:
+ x.mode = typexpr
+
+ case *Var:
+ // It's ok to mark non-local variables, but ignore variables
+ // from other packages to avoid potential race conditions with
+ // dot-imported variables.
+ if obj.pkg == check.pkg {
+ obj.used = true
+ }
+ check.addDeclDep(obj)
+ if typ == Typ[Invalid] {
+ return
+ }
+ x.mode = variable
+
+ case *Func:
+ check.addDeclDep(obj)
+ x.mode = value
+
+ case *Builtin:
+ x.id = obj.id
+ x.mode = builtin
+
+ case *Nil:
+ x.mode = value
+
+ default:
+ unreachable()
+ }
+
+ x.typ = typ
+}
+
+// typ type-checks the type expression e and returns its type, or Typ[Invalid].
+func (check *Checker) typ(e ast.Expr) Type {
+ return check.definedType(e, nil)
+}
+
+// definedType is like typ but also accepts a type name def.
+// If def != nil, e is the type specification for the defined type def, declared
+// in a type declaration, and def.underlying will be set to the type of e before
+// any components of e are type-checked.
+//
+func (check *Checker) definedType(e ast.Expr, def *Named) (T Type) {
+ if trace {
+ check.trace(e.Pos(), "%s", e)
+ check.indent++
+ defer func() {
+ check.indent--
+ check.trace(e.Pos(), "=> %s", T)
+ }()
+ }
+
+ T = check.typInternal(e, def)
+ assert(isTyped(T))
+ check.recordTypeAndValue(e, typexpr, T, nil)
+
+ return
+}
+
+// funcType type-checks a function or method type.
+func (check *Checker) funcType(sig *Signature, recvPar *ast.FieldList, ftyp *ast.FuncType) {
+ scope := NewScope(check.scope, token.NoPos, token.NoPos, "function")
+ scope.isFunc = true
+ check.recordScope(ftyp, scope)
+
+ recvList, _ := check.collectParams(scope, recvPar, false)
+ params, variadic := check.collectParams(scope, ftyp.Params, true)
+ results, _ := check.collectParams(scope, ftyp.Results, false)
+
+ if recvPar != nil {
+ // recv parameter list present (may be empty)
+ // spec: "The receiver is specified via an extra parameter section preceding the
+ // method name. That parameter section must declare a single parameter, the receiver."
+ var recv *Var
+ switch len(recvList) {
+ case 0:
+ check.error(recvPar, _BadRecv, "method is missing receiver")
+ recv = NewParam(0, nil, "", Typ[Invalid]) // ignore recv below
+ default:
+ // more than one receiver
+ check.error(recvList[len(recvList)-1], _BadRecv, "method must have exactly one receiver")
+ fallthrough // continue with first receiver
+ case 1:
+ recv = recvList[0]
+ }
+ // spec: "The receiver type must be of the form T or *T where T is a type name."
+ // (ignore invalid types - error was reported before)
+ if t, _ := deref(recv.typ); t != Typ[Invalid] {
+ var err string
+ if T, _ := t.(*Named); T != nil {
+ // spec: "The type denoted by T is called the receiver base type; it must not
+ // be a pointer or interface type and it must be declared in the same package
+ // as the method."
+ if T.obj.pkg != check.pkg {
+ err = "type not defined in this package"
+ } else {
+ // TODO(gri) This is not correct if the underlying type is unknown yet.
+ switch u := T.underlying.(type) {
+ case *Basic:
+ // unsafe.Pointer is treated like a regular pointer
+ if u.kind == UnsafePointer {
+ err = "unsafe.Pointer"
+ }
+ case *Pointer, *Interface:
+ err = "pointer or interface type"
+ }
+ }
+ } else {
+ err = "basic or unnamed type"
+ }
+ if err != "" {
+ check.errorf(recv, _InvalidRecv, "invalid receiver %s (%s)", recv.typ, err)
+ // ok to continue
+ }
+ }
+ sig.recv = recv
+ }
+
+ sig.scope = scope
+ sig.params = NewTuple(params...)
+ sig.results = NewTuple(results...)
+ sig.variadic = variadic
+}
+
+// typInternal drives type checking of types.
+// Must only be called by definedType.
+//
+func (check *Checker) typInternal(e ast.Expr, def *Named) Type {
+ switch e := e.(type) {
+ case *ast.BadExpr:
+ // ignore - error reported before
+
+ case *ast.Ident:
+ var x operand
+ check.ident(&x, e, def, true)
+
+ switch x.mode {
+ case typexpr:
+ typ := x.typ
+ def.setUnderlying(typ)
+ return typ
+ case invalid:
+ // ignore - error reported before
+ case novalue:
+ check.errorf(&x, _NotAType, "%s used as type", &x)
+ default:
+ check.errorf(&x, _NotAType, "%s is not a type", &x)
+ }
+
+ case *ast.SelectorExpr:
+ var x operand
+ check.selector(&x, e)
+
+ switch x.mode {
+ case typexpr:
+ typ := x.typ
+ def.setUnderlying(typ)
+ return typ
+ case invalid:
+ // ignore - error reported before
+ case novalue:
+ check.errorf(&x, _NotAType, "%s used as type", &x)
+ default:
+ check.errorf(&x, _NotAType, "%s is not a type", &x)
+ }
+
+ case *ast.ParenExpr:
+ return check.definedType(e.X, def)
+
+ case *ast.ArrayType:
+ if e.Len != nil {
+ typ := new(Array)
+ def.setUnderlying(typ)
+ typ.len = check.arrayLength(e.Len)
+ typ.elem = check.typ(e.Elt)
+ return typ
+
+ } else {
+ typ := new(Slice)
+ def.setUnderlying(typ)
+ typ.elem = check.typ(e.Elt)
+ return typ
+ }
+
+ case *ast.StructType:
+ typ := new(Struct)
+ def.setUnderlying(typ)
+ check.structType(typ, e)
+ return typ
+
+ case *ast.StarExpr:
+ typ := new(Pointer)
+ def.setUnderlying(typ)
+ typ.base = check.typ(e.X)
+ return typ
+
+ case *ast.FuncType:
+ typ := new(Signature)
+ def.setUnderlying(typ)
+ check.funcType(typ, nil, e)
+ return typ
+
+ case *ast.InterfaceType:
+ typ := new(Interface)
+ def.setUnderlying(typ)
+ check.interfaceType(typ, e, def)
+ return typ
+
+ case *ast.MapType:
+ typ := new(Map)
+ def.setUnderlying(typ)
+
+ typ.key = check.typ(e.Key)
+ typ.elem = check.typ(e.Value)
+
+ // spec: "The comparison operators == and != must be fully defined
+ // for operands of the key type; thus the key type must not be a
+ // function, map, or slice."
+ //
+ // Delay this check because it requires fully setup types;
+ // it is safe to continue in any case (was issue 6667).
+ check.atEnd(func() {
+ if !Comparable(typ.key) {
+ check.errorf(e.Key, _IncomparableMapKey, "incomparable map key type %s", typ.key)
+ }
+ })
+
+ return typ
+
+ case *ast.ChanType:
+ typ := new(Chan)
+ def.setUnderlying(typ)
+
+ dir := SendRecv
+ switch e.Dir {
+ case ast.SEND | ast.RECV:
+ // nothing to do
+ case ast.SEND:
+ dir = SendOnly
+ case ast.RECV:
+ dir = RecvOnly
+ default:
+ check.invalidAST(e, "unknown channel direction %d", e.Dir)
+ // ok to continue
+ }
+
+ typ.dir = dir
+ typ.elem = check.typ(e.Value)
+ return typ
+
+ default:
+ check.errorf(e, _NotAType, "%s is not a type", e)
+ }
+
+ typ := Typ[Invalid]
+ def.setUnderlying(typ)
+ return typ
+}
+
+// typeOrNil type-checks the type expression (or nil value) e
+// and returns the typ of e, or nil.
+// If e is neither a type nor nil, typOrNil returns Typ[Invalid].
+//
+func (check *Checker) typOrNil(e ast.Expr) Type {
+ var x operand
+ check.rawExpr(&x, e, nil)
+ switch x.mode {
+ case invalid:
+ // ignore - error reported before
+ case novalue:
+ check.errorf(&x, _NotAType, "%s used as type", &x)
+ case typexpr:
+ return x.typ
+ case value:
+ if x.isNil() {
+ return nil
+ }
+ fallthrough
+ default:
+ check.errorf(&x, _NotAType, "%s is not a type", &x)
+ }
+ return Typ[Invalid]
+}
+
+// arrayLength type-checks the array length expression e
+// and returns the constant length >= 0, or a value < 0
+// to indicate an error (and thus an unknown length).
+func (check *Checker) arrayLength(e ast.Expr) int64 {
+ var x operand
+ check.expr(&x, e)
+ if x.mode != constant_ {
+ if x.mode != invalid {
+ check.errorf(&x, _InvalidArrayLen, "array length %s must be constant", &x)
+ }
+ return -1
+ }
+ if isUntyped(x.typ) || isInteger(x.typ) {
+ if val := constant.ToInt(x.val); val.Kind() == constant.Int {
+ if representableConst(val, check, Typ[Int], nil) {
+ if n, ok := constant.Int64Val(val); ok && n >= 0 {
+ return n
+ }
+ check.errorf(&x, _InvalidArrayLen, "invalid array length %s", &x)
+ return -1
+ }
+ }
+ }
+ check.errorf(&x, _InvalidArrayLen, "array length %s must be integer", &x)
+ return -1
+}
+
+func (check *Checker) collectParams(scope *Scope, list *ast.FieldList, variadicOk bool) (params []*Var, variadic bool) {
+ if list == nil {
+ return
+ }
+
+ var named, anonymous bool
+ for i, field := range list.List {
+ ftype := field.Type
+ if t, _ := ftype.(*ast.Ellipsis); t != nil {
+ ftype = t.Elt
+ if variadicOk && i == len(list.List)-1 && len(field.Names) <= 1 {
+ variadic = true
+ } else {
+ check.softErrorf(t, _MisplacedDotDotDot, "can only use ... with final parameter in list")
+ // ignore ... and continue
+ }
+ }
+ typ := check.typ(ftype)
+ // The parser ensures that f.Tag is nil and we don't
+ // care if a constructed AST contains a non-nil tag.
+ if len(field.Names) > 0 {
+ // named parameter
+ for _, name := range field.Names {
+ if name.Name == "" {
+ check.invalidAST(name, "anonymous parameter")
+ // ok to continue
+ }
+ par := NewParam(name.Pos(), check.pkg, name.Name, typ)
+ check.declare(scope, name, par, scope.pos)
+ params = append(params, par)
+ }
+ named = true
+ } else {
+ // anonymous parameter
+ par := NewParam(ftype.Pos(), check.pkg, "", typ)
+ check.recordImplicit(field, par)
+ params = append(params, par)
+ anonymous = true
+ }
+ }
+
+ if named && anonymous {
+ check.invalidAST(list, "list contains both named and anonymous parameters")
+ // ok to continue
+ }
+
+ // For a variadic function, change the last parameter's type from T to []T.
+ // Since we type-checked T rather than ...T, we also need to retro-actively
+ // record the type for ...T.
+ if variadic {
+ last := params[len(params)-1]
+ last.typ = &Slice{elem: last.typ}
+ check.recordTypeAndValue(list.List[len(list.List)-1].Type, typexpr, last.typ, nil)
+ }
+
+ return
+}
+
+func (check *Checker) declareInSet(oset *objset, pos token.Pos, obj Object) bool {
+ if alt := oset.insert(obj); alt != nil {
+ check.errorf(atPos(pos), _DuplicateDecl, "%s redeclared", obj.Name())
+ check.reportAltDecl(alt)
+ return false
+ }
+ return true
+}
+
+func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, def *Named) {
+ for _, f := range iface.Methods.List {
+ if len(f.Names) > 0 {
+ // We have a method with name f.Names[0].
+ // (The parser ensures that there's only one method
+ // and we don't care if a constructed AST has more.)
+ name := f.Names[0]
+ if name.Name == "_" {
+ check.errorf(name, _BlankIfaceMethod, "invalid method name _")
+ continue // ignore
+ }
+
+ typ := check.typ(f.Type)
+ sig, _ := typ.(*Signature)
+ if sig == nil {
+ if typ != Typ[Invalid] {
+ check.invalidAST(f.Type, "%s is not a method signature", typ)
+ }
+ continue // ignore
+ }
+
+ // use named receiver type if available (for better error messages)
+ var recvTyp Type = ityp
+ if def != nil {
+ recvTyp = def
+ }
+ sig.recv = NewVar(name.Pos(), check.pkg, "", recvTyp)
+
+ m := NewFunc(name.Pos(), check.pkg, name.Name, sig)
+ check.recordDef(name, m)
+ ityp.methods = append(ityp.methods, m)
+ } else {
+ // We have an embedded interface and f.Type is its
+ // (possibly qualified) embedded type name. Collect
+ // it if it's a valid interface.
+ typ := check.typ(f.Type)
+
+ utyp := check.underlying(typ)
+ if _, ok := utyp.(*Interface); !ok {
+ if utyp != Typ[Invalid] {
+ check.errorf(f.Type, _InvalidIfaceEmbed, "%s is not an interface", typ)
+ }
+ continue
+ }
+
+ ityp.embeddeds = append(ityp.embeddeds, typ)
+ check.posMap[ityp] = append(check.posMap[ityp], f.Type.Pos())
+ }
+ }
+
+ if len(ityp.methods) == 0 && len(ityp.embeddeds) == 0 {
+ // empty interface
+ ityp.allMethods = markComplete
+ return
+ }
+
+ // sort for API stability
+ sort.Sort(byUniqueMethodName(ityp.methods))
+ sort.Stable(byUniqueTypeName(ityp.embeddeds))
+
+ check.later(func() { check.completeInterface(ityp) })
+}
+
+func (check *Checker) completeInterface(ityp *Interface) {
+ if ityp.allMethods != nil {
+ return
+ }
+
+ // completeInterface may be called via the LookupFieldOrMethod,
+ // MissingMethod, Identical, or IdenticalIgnoreTags external API
+ // in which case check will be nil. In this case, type-checking
+ // must be finished and all interfaces should have been completed.
+ if check == nil {
+ panic("internal error: incomplete interface")
+ }
+
+ if trace {
+ check.trace(token.NoPos, "complete %s", ityp)
+ check.indent++
+ defer func() {
+ check.indent--
+ check.trace(token.NoPos, "=> %s", ityp)
+ }()
+ }
+
+ // An infinitely expanding interface (due to a cycle) is detected
+ // elsewhere (Checker.validType), so here we simply assume we only
+ // have valid interfaces. Mark the interface as complete to avoid
+ // infinite recursion if the validType check occurs later for some
+ // reason.
+ ityp.allMethods = markComplete
+
+ // Methods of embedded interfaces are collected unchanged; i.e., the identity
+ // of a method I.m's Func Object of an interface I is the same as that of
+ // the method m in an interface that embeds interface I. On the other hand,
+ // if a method is embedded via multiple overlapping embedded interfaces, we
+ // don't provide a guarantee which "original m" got chosen for the embedding
+ // interface. See also issue #34421.
+ //
+ // If we don't care to provide this identity guarantee anymore, instead of
+ // reusing the original method in embeddings, we can clone the method's Func
+ // Object and give it the position of a corresponding embedded interface. Then
+ // we can get rid of the mpos map below and simply use the cloned method's
+ // position.
+
+ var seen objset
+ var methods []*Func
+ mpos := make(map[*Func]token.Pos) // method specification or method embedding position, for good error messages
+ addMethod := func(pos token.Pos, m *Func, explicit bool) {
+ switch other := seen.insert(m); {
+ case other == nil:
+ methods = append(methods, m)
+ mpos[m] = pos
+ case explicit:
+ check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
+ check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
+ default:
+ // check method signatures after all types are computed (issue #33656)
+ check.atEnd(func() {
+ if !check.identical(m.typ, other.Type()) {
+ check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
+ check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
+ }
+ })
+ }
+ }
+
+ for _, m := range ityp.methods {
+ addMethod(m.pos, m, true)
+ }
+
+ posList := check.posMap[ityp]
+ for i, typ := range ityp.embeddeds {
+ pos := posList[i] // embedding position
+ typ, ok := check.underlying(typ).(*Interface)
+ if !ok {
+ // An error was reported when collecting the embedded types.
+ // Ignore it.
+ continue
+ }
+ check.completeInterface(typ)
+ for _, m := range typ.allMethods {
+ addMethod(pos, m, false) // use embedding position pos rather than m.pos
+ }
+ }
+
+ if methods != nil {
+ sort.Sort(byUniqueMethodName(methods))
+ ityp.allMethods = methods
+ }
+}
+
+// byUniqueTypeName named type lists can be sorted by their unique type names.
+type byUniqueTypeName []Type
+
+func (a byUniqueTypeName) Len() int { return len(a) }
+func (a byUniqueTypeName) Less(i, j int) bool { return sortName(a[i]) < sortName(a[j]) }
+func (a byUniqueTypeName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+func sortName(t Type) string {
+ if named, _ := t.(*Named); named != nil {
+ return named.obj.Id()
+ }
+ return ""
+}
+
+// byUniqueMethodName method lists can be sorted by their unique method names.
+type byUniqueMethodName []*Func
+
+func (a byUniqueMethodName) Len() int { return len(a) }
+func (a byUniqueMethodName) Less(i, j int) bool { return a[i].Id() < a[j].Id() }
+func (a byUniqueMethodName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+func (check *Checker) tag(t *ast.BasicLit) string {
+ if t != nil {
+ if t.Kind == token.STRING {
+ if val, err := strconv.Unquote(t.Value); err == nil {
+ return val
+ }
+ }
+ check.invalidAST(t, "incorrect tag syntax: %q", t.Value)
+ }
+ return ""
+}
+
+func (check *Checker) structType(styp *Struct, e *ast.StructType) {
+ list := e.Fields
+ if list == nil {
+ return
+ }
+
+ // struct fields and tags
+ var fields []*Var
+ var tags []string
+
+ // for double-declaration checks
+ var fset objset
+
+ // current field typ and tag
+ var typ Type
+ var tag string
+ add := func(ident *ast.Ident, embedded bool, pos token.Pos) {
+ if tag != "" && tags == nil {
+ tags = make([]string, len(fields))
+ }
+ if tags != nil {
+ tags = append(tags, tag)
+ }
+
+ name := ident.Name
+ fld := NewField(pos, check.pkg, name, typ, embedded)
+ // spec: "Within a struct, non-blank field names must be unique."
+ if name == "_" || check.declareInSet(&fset, pos, fld) {
+ fields = append(fields, fld)
+ check.recordDef(ident, fld)
+ }
+ }
+
+ // addInvalid adds an embedded field of invalid type to the struct for
+ // fields with errors; this keeps the number of struct fields in sync
+ // with the source as long as the fields are _ or have different names
+ // (issue #25627).
+ addInvalid := func(ident *ast.Ident, pos token.Pos) {
+ typ = Typ[Invalid]
+ tag = ""
+ add(ident, true, pos)
+ }
+
+ for _, f := range list.List {
+ typ = check.typ(f.Type)
+ tag = check.tag(f.Tag)
+ if len(f.Names) > 0 {
+ // named fields
+ for _, name := range f.Names {
+ add(name, false, name.Pos())
+ }
+ } else {
+ // embedded field
+ // spec: "An embedded type must be specified as a type name T or as a pointer
+ // to a non-interface type name *T, and T itself may not be a pointer type."
+ pos := f.Type.Pos()
+ name := embeddedFieldIdent(f.Type)
+ if name == nil {
+ check.invalidAST(f.Type, "embedded field type %s has no name", f.Type)
+ name = ast.NewIdent("_")
+ name.NamePos = pos
+ addInvalid(name, pos)
+ continue
+ }
+ t, isPtr := deref(typ)
+ // Because we have a name, typ must be of the form T or *T, where T is the name
+ // of a (named or alias) type, and t (= deref(typ)) must be the type of T.
+ switch t := t.Underlying().(type) {
+ case *Basic:
+ if t == Typ[Invalid] {
+ // error was reported before
+ addInvalid(name, pos)
+ continue
+ }
+
+ // unsafe.Pointer is treated like a regular pointer
+ if t.kind == UnsafePointer {
+ check.errorf(f.Type, _InvalidPtrEmbed, "embedded field type cannot be unsafe.Pointer")
+ addInvalid(name, pos)
+ continue
+ }
+
+ case *Pointer:
+ check.errorf(f.Type, _InvalidPtrEmbed, "embedded field type cannot be a pointer")
+ addInvalid(name, pos)
+ continue
+
+ case *Interface:
+ if isPtr {
+ check.errorf(f.Type, _InvalidPtrEmbed, "embedded field type cannot be a pointer to an interface")
+ addInvalid(name, pos)
+ continue
+ }
+ }
+ add(name, true, pos)
+ }
+ }
+
+ styp.fields = fields
+ styp.tags = tags
+}
+
+func embeddedFieldIdent(e ast.Expr) *ast.Ident {
+ switch e := e.(type) {
+ case *ast.Ident:
+ return e
+ case *ast.StarExpr:
+ // *T is valid, but **T is not
+ if _, ok := e.X.(*ast.StarExpr); !ok {
+ return embeddedFieldIdent(e.X)
+ }
+ case *ast.SelectorExpr:
+ return e.Sel
+ }
+ return nil // invalid embedded field
+}
diff --git a/src/go/types/universe.go b/src/go/types/universe.go
new file mode 100644
index 0000000..ff5b891
--- /dev/null
+++ b/src/go/types/universe.go
@@ -0,0 +1,238 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file sets up the universe scope and the unsafe package.
+
+package types
+
+import (
+ "go/constant"
+ "go/token"
+ "strings"
+)
+
+// The Universe scope contains all predeclared objects of Go.
+// It is the outermost scope of any chain of nested scopes.
+var Universe *Scope
+
+// The Unsafe package is the package returned by an importer
+// for the import path "unsafe".
+var Unsafe *Package
+
+var (
+ universeIota *Const
+ universeByte *Basic // uint8 alias, but has name "byte"
+ universeRune *Basic // int32 alias, but has name "rune"
+ universeError *Named
+)
+
+// Typ contains the predeclared *Basic types indexed by their
+// corresponding BasicKind.
+//
+// The *Basic type for Typ[Byte] will have the name "uint8".
+// Use Universe.Lookup("byte").Type() to obtain the specific
+// alias basic type named "byte" (and analogous for "rune").
+var Typ = []*Basic{
+ Invalid: {Invalid, 0, "invalid type"},
+
+ Bool: {Bool, IsBoolean, "bool"},
+ Int: {Int, IsInteger, "int"},
+ Int8: {Int8, IsInteger, "int8"},
+ Int16: {Int16, IsInteger, "int16"},
+ Int32: {Int32, IsInteger, "int32"},
+ Int64: {Int64, IsInteger, "int64"},
+ Uint: {Uint, IsInteger | IsUnsigned, "uint"},
+ Uint8: {Uint8, IsInteger | IsUnsigned, "uint8"},
+ Uint16: {Uint16, IsInteger | IsUnsigned, "uint16"},
+ Uint32: {Uint32, IsInteger | IsUnsigned, "uint32"},
+ Uint64: {Uint64, IsInteger | IsUnsigned, "uint64"},
+ Uintptr: {Uintptr, IsInteger | IsUnsigned, "uintptr"},
+ Float32: {Float32, IsFloat, "float32"},
+ Float64: {Float64, IsFloat, "float64"},
+ Complex64: {Complex64, IsComplex, "complex64"},
+ Complex128: {Complex128, IsComplex, "complex128"},
+ String: {String, IsString, "string"},
+ UnsafePointer: {UnsafePointer, 0, "Pointer"},
+
+ UntypedBool: {UntypedBool, IsBoolean | IsUntyped, "untyped bool"},
+ UntypedInt: {UntypedInt, IsInteger | IsUntyped, "untyped int"},
+ UntypedRune: {UntypedRune, IsInteger | IsUntyped, "untyped rune"},
+ UntypedFloat: {UntypedFloat, IsFloat | IsUntyped, "untyped float"},
+ UntypedComplex: {UntypedComplex, IsComplex | IsUntyped, "untyped complex"},
+ UntypedString: {UntypedString, IsString | IsUntyped, "untyped string"},
+ UntypedNil: {UntypedNil, IsUntyped, "untyped nil"},
+}
+
+var aliases = [...]*Basic{
+ {Byte, IsInteger | IsUnsigned, "byte"},
+ {Rune, IsInteger, "rune"},
+}
+
+func defPredeclaredTypes() {
+ for _, t := range Typ {
+ def(NewTypeName(token.NoPos, nil, t.name, t))
+ }
+ for _, t := range aliases {
+ def(NewTypeName(token.NoPos, nil, t.name, t))
+ }
+
+ // Error has a nil package in its qualified name since it is in no package
+ res := NewVar(token.NoPos, nil, "", Typ[String])
+ sig := &Signature{results: NewTuple(res)}
+ err := NewFunc(token.NoPos, nil, "Error", sig)
+ typ := &Named{underlying: NewInterfaceType([]*Func{err}, nil).Complete()}
+ sig.recv = NewVar(token.NoPos, nil, "", typ)
+ def(NewTypeName(token.NoPos, nil, "error", typ))
+}
+
+var predeclaredConsts = [...]struct {
+ name string
+ kind BasicKind
+ val constant.Value
+}{
+ {"true", UntypedBool, constant.MakeBool(true)},
+ {"false", UntypedBool, constant.MakeBool(false)},
+ {"iota", UntypedInt, constant.MakeInt64(0)},
+}
+
+func defPredeclaredConsts() {
+ for _, c := range predeclaredConsts {
+ def(NewConst(token.NoPos, nil, c.name, Typ[c.kind], c.val))
+ }
+}
+
+func defPredeclaredNil() {
+ def(&Nil{object{name: "nil", typ: Typ[UntypedNil], color_: black}})
+}
+
+// A builtinId is the id of a builtin function.
+type builtinId int
+
+const (
+ // universe scope
+ _Append builtinId = iota
+ _Cap
+ _Close
+ _Complex
+ _Copy
+ _Delete
+ _Imag
+ _Len
+ _Make
+ _New
+ _Panic
+ _Print
+ _Println
+ _Real
+ _Recover
+
+ // package unsafe
+ _Alignof
+ _Offsetof
+ _Sizeof
+
+ // testing support
+ _Assert
+ _Trace
+)
+
+var predeclaredFuncs = [...]struct {
+ name string
+ nargs int
+ variadic bool
+ kind exprKind
+}{
+ _Append: {"append", 1, true, expression},
+ _Cap: {"cap", 1, false, expression},
+ _Close: {"close", 1, false, statement},
+ _Complex: {"complex", 2, false, expression},
+ _Copy: {"copy", 2, false, statement},
+ _Delete: {"delete", 2, false, statement},
+ _Imag: {"imag", 1, false, expression},
+ _Len: {"len", 1, false, expression},
+ _Make: {"make", 1, true, expression},
+ _New: {"new", 1, false, expression},
+ _Panic: {"panic", 1, false, statement},
+ _Print: {"print", 0, true, statement},
+ _Println: {"println", 0, true, statement},
+ _Real: {"real", 1, false, expression},
+ _Recover: {"recover", 0, false, statement},
+
+ _Alignof: {"Alignof", 1, false, expression},
+ _Offsetof: {"Offsetof", 1, false, expression},
+ _Sizeof: {"Sizeof", 1, false, expression},
+
+ _Assert: {"assert", 1, false, statement},
+ _Trace: {"trace", 0, true, statement},
+}
+
+func defPredeclaredFuncs() {
+ for i := range predeclaredFuncs {
+ id := builtinId(i)
+ if id == _Assert || id == _Trace {
+ continue // only define these in testing environment
+ }
+ def(newBuiltin(id))
+ }
+}
+
+// DefPredeclaredTestFuncs defines the assert and trace built-ins.
+// These built-ins are intended for debugging and testing of this
+// package only.
+func DefPredeclaredTestFuncs() {
+ if Universe.Lookup("assert") != nil {
+ return // already defined
+ }
+ def(newBuiltin(_Assert))
+ def(newBuiltin(_Trace))
+}
+
+func init() {
+ Universe = NewScope(nil, token.NoPos, token.NoPos, "universe")
+ Unsafe = NewPackage("unsafe", "unsafe")
+ Unsafe.complete = true
+
+ defPredeclaredTypes()
+ defPredeclaredConsts()
+ defPredeclaredNil()
+ defPredeclaredFuncs()
+
+ universeIota = Universe.Lookup("iota").(*Const)
+ universeByte = Universe.Lookup("byte").(*TypeName).typ.(*Basic)
+ universeRune = Universe.Lookup("rune").(*TypeName).typ.(*Basic)
+ universeError = Universe.Lookup("error").(*TypeName).typ.(*Named)
+}
+
+// Objects with names containing blanks are internal and not entered into
+// a scope. Objects with exported names are inserted in the unsafe package
+// scope; other objects are inserted in the universe scope.
+//
+func def(obj Object) {
+ assert(obj.color() == black)
+ name := obj.Name()
+ if strings.Contains(name, " ") {
+ return // nothing to do
+ }
+ // fix Obj link for named types
+ if typ, ok := obj.Type().(*Named); ok {
+ typ.obj = obj.(*TypeName)
+ }
+ // exported identifiers go into package unsafe
+ scope := Universe
+ if obj.Exported() {
+ scope = Unsafe.scope
+ // set Pkg field
+ switch obj := obj.(type) {
+ case *TypeName:
+ obj.pkg = Unsafe
+ case *Builtin:
+ obj.pkg = Unsafe
+ default:
+ unreachable()
+ }
+ }
+ if scope.Insert(obj) != nil {
+ panic("internal error: double declaration")
+ }
+}