diff options
Diffstat (limited to 'src/reflect')
-rw-r--r-- | src/reflect/all_test.go | 7181 | ||||
-rw-r--r-- | src/reflect/asm_386.s | 36 | ||||
-rw-r--r-- | src/reflect/asm_amd64.s | 40 | ||||
-rw-r--r-- | src/reflect/asm_arm.s | 38 | ||||
-rw-r--r-- | src/reflect/asm_arm64.s | 36 | ||||
-rw-r--r-- | src/reflect/asm_mips64x.s | 40 | ||||
-rw-r--r-- | src/reflect/asm_mipsx.s | 40 | ||||
-rw-r--r-- | src/reflect/asm_ppc64x.s | 39 | ||||
-rw-r--r-- | src/reflect/asm_riscv64.s | 36 | ||||
-rw-r--r-- | src/reflect/asm_s390x.s | 36 | ||||
-rw-r--r-- | src/reflect/asm_wasm.s | 50 | ||||
-rw-r--r-- | src/reflect/deepequal.go | 219 | ||||
-rw-r--r-- | src/reflect/example_test.go | 168 | ||||
-rw-r--r-- | src/reflect/export_test.go | 122 | ||||
-rw-r--r-- | src/reflect/makefunc.go | 138 | ||||
-rw-r--r-- | src/reflect/set_test.go | 226 | ||||
-rw-r--r-- | src/reflect/swapper.go | 77 | ||||
-rw-r--r-- | src/reflect/tostring_test.go | 95 | ||||
-rw-r--r-- | src/reflect/type.go | 3132 | ||||
-rw-r--r-- | src/reflect/value.go | 2858 |
20 files changed, 14607 insertions, 0 deletions
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go new file mode 100644 index 0000000..1225d61 --- /dev/null +++ b/src/reflect/all_test.go @@ -0,0 +1,7181 @@ +// 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 reflect_test + +import ( + "bytes" + "encoding/base64" + "flag" + "fmt" + "go/token" + "io" + "math" + "math/rand" + "os" + . "reflect" + "runtime" + "sort" + "strconv" + "strings" + "sync" + "sync/atomic" + "testing" + "time" + "unsafe" +) + +var sink interface{} + +func TestBool(t *testing.T) { + v := ValueOf(true) + if v.Bool() != true { + t.Fatal("ValueOf(true).Bool() = false") + } +} + +type integer int +type T struct { + a int + b float64 + c string + d *int +} + +type pair struct { + i interface{} + s string +} + +func assert(t *testing.T, s, want string) { + if s != want { + t.Errorf("have %#q want %#q", s, want) + } +} + +var typeTests = []pair{ + {struct{ x int }{}, "int"}, + {struct{ x int8 }{}, "int8"}, + {struct{ x int16 }{}, "int16"}, + {struct{ x int32 }{}, "int32"}, + {struct{ x int64 }{}, "int64"}, + {struct{ x uint }{}, "uint"}, + {struct{ x uint8 }{}, "uint8"}, + {struct{ x uint16 }{}, "uint16"}, + {struct{ x uint32 }{}, "uint32"}, + {struct{ x uint64 }{}, "uint64"}, + {struct{ x float32 }{}, "float32"}, + {struct{ x float64 }{}, "float64"}, + {struct{ x int8 }{}, "int8"}, + {struct{ x (**int8) }{}, "**int8"}, + {struct{ x (**integer) }{}, "**reflect_test.integer"}, + {struct{ x ([32]int32) }{}, "[32]int32"}, + {struct{ x ([]int8) }{}, "[]int8"}, + {struct{ x (map[string]int32) }{}, "map[string]int32"}, + {struct{ x (chan<- string) }{}, "chan<- string"}, + {struct{ x (chan<- chan string) }{}, "chan<- chan string"}, + {struct{ x (chan<- <-chan string) }{}, "chan<- <-chan string"}, + {struct{ x (<-chan <-chan string) }{}, "<-chan <-chan string"}, + {struct{ x (chan (<-chan string)) }{}, "chan (<-chan string)"}, + {struct { + x struct { + c chan *int32 + d float32 + } + }{}, + "struct { c chan *int32; d float32 }", + }, + {struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"}, + {struct { + x struct { + c func(chan *integer, *int8) + } + }{}, + "struct { c func(chan *reflect_test.integer, *int8) }", + }, + {struct { + x struct { + a int8 + b int32 + } + }{}, + "struct { a int8; b int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int32 + } + }{}, + "struct { a int8; b int8; c int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int32 + } + }{}, + "struct { a int8; b int8; c int8; d int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int8 + e int32 + } + }{}, + "struct { a int8; b int8; c int8; d int8; e int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int8 + e int8 + f int32 + } + }{}, + "struct { a int8; b int8; c int8; d int8; e int8; f int32 }", + }, + {struct { + x struct { + a int8 `reflect:"hi there"` + } + }{}, + `struct { a int8 "reflect:\"hi there\"" }`, + }, + {struct { + x struct { + a int8 `reflect:"hi \x00there\t\n\"\\"` + } + }{}, + `struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`, + }, + {struct { + x struct { + f func(args ...int) + } + }{}, + "struct { f func(...int) }", + }, + {struct { + x (interface { + a(func(func(int) int) func(func(int)) int) + b() + }) + }{}, + "interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }", + }, + {struct { + x struct { + int32 + int64 + } + }{}, + "struct { int32; int64 }", + }, +} + +var valueTests = []pair{ + {new(int), "132"}, + {new(int8), "8"}, + {new(int16), "16"}, + {new(int32), "32"}, + {new(int64), "64"}, + {new(uint), "132"}, + {new(uint8), "8"}, + {new(uint16), "16"}, + {new(uint32), "32"}, + {new(uint64), "64"}, + {new(float32), "256.25"}, + {new(float64), "512.125"}, + {new(complex64), "532.125+10i"}, + {new(complex128), "564.25+1i"}, + {new(string), "stringy cheese"}, + {new(bool), "true"}, + {new(*int8), "*int8(0)"}, + {new(**int8), "**int8(0)"}, + {new([5]int32), "[5]int32{0, 0, 0, 0, 0}"}, + {new(**integer), "**reflect_test.integer(0)"}, + {new(map[string]int32), "map[string]int32{<can't iterate on maps>}"}, + {new(chan<- string), "chan<- string"}, + {new(func(a int8, b int32)), "func(int8, int32)(0)"}, + {new(struct { + c chan *int32 + d float32 + }), + "struct { c chan *int32; d float32 }{chan *int32, 0}", + }, + {new(struct{ c func(chan *integer, *int8) }), + "struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}", + }, + {new(struct { + a int8 + b int32 + }), + "struct { a int8; b int32 }{0, 0}", + }, + {new(struct { + a int8 + b int8 + c int32 + }), + "struct { a int8; b int8; c int32 }{0, 0, 0}", + }, +} + +func testType(t *testing.T, i int, typ Type, want string) { + s := typ.String() + if s != want { + t.Errorf("#%d: have %#q, want %#q", i, s, want) + } +} + +func TestTypes(t *testing.T) { + for i, tt := range typeTests { + testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s) + } +} + +func TestSet(t *testing.T) { + for i, tt := range valueTests { + v := ValueOf(tt.i) + v = v.Elem() + switch v.Kind() { + case Int: + v.SetInt(132) + case Int8: + v.SetInt(8) + case Int16: + v.SetInt(16) + case Int32: + v.SetInt(32) + case Int64: + v.SetInt(64) + case Uint: + v.SetUint(132) + case Uint8: + v.SetUint(8) + case Uint16: + v.SetUint(16) + case Uint32: + v.SetUint(32) + case Uint64: + v.SetUint(64) + case Float32: + v.SetFloat(256.25) + case Float64: + v.SetFloat(512.125) + case Complex64: + v.SetComplex(532.125 + 10i) + case Complex128: + v.SetComplex(564.25 + 1i) + case String: + v.SetString("stringy cheese") + case Bool: + v.SetBool(true) + } + s := valueToString(v) + if s != tt.s { + t.Errorf("#%d: have %#q, want %#q", i, s, tt.s) + } + } +} + +func TestSetValue(t *testing.T) { + for i, tt := range valueTests { + v := ValueOf(tt.i).Elem() + switch v.Kind() { + case Int: + v.Set(ValueOf(int(132))) + case Int8: + v.Set(ValueOf(int8(8))) + case Int16: + v.Set(ValueOf(int16(16))) + case Int32: + v.Set(ValueOf(int32(32))) + case Int64: + v.Set(ValueOf(int64(64))) + case Uint: + v.Set(ValueOf(uint(132))) + case Uint8: + v.Set(ValueOf(uint8(8))) + case Uint16: + v.Set(ValueOf(uint16(16))) + case Uint32: + v.Set(ValueOf(uint32(32))) + case Uint64: + v.Set(ValueOf(uint64(64))) + case Float32: + v.Set(ValueOf(float32(256.25))) + case Float64: + v.Set(ValueOf(512.125)) + case Complex64: + v.Set(ValueOf(complex64(532.125 + 10i))) + case Complex128: + v.Set(ValueOf(complex128(564.25 + 1i))) + case String: + v.Set(ValueOf("stringy cheese")) + case Bool: + v.Set(ValueOf(true)) + } + s := valueToString(v) + if s != tt.s { + t.Errorf("#%d: have %#q, want %#q", i, s, tt.s) + } + } +} + +func TestCanSetField(t *testing.T) { + type embed struct{ x, X int } + type Embed struct{ x, X int } + type S1 struct { + embed + x, X int + } + type S2 struct { + *embed + x, X int + } + type S3 struct { + Embed + x, X int + } + type S4 struct { + *Embed + x, X int + } + + type testCase struct { + // -1 means Addr().Elem() of current value + index []int + canSet bool + } + tests := []struct { + val Value + cases []testCase + }{{ + val: ValueOf(&S1{}), + cases: []testCase{ + {[]int{0}, false}, + {[]int{0, -1}, false}, + {[]int{0, 0}, false}, + {[]int{0, 0, -1}, false}, + {[]int{0, -1, 0}, false}, + {[]int{0, -1, 0, -1}, false}, + {[]int{0, 1}, true}, + {[]int{0, 1, -1}, true}, + {[]int{0, -1, 1}, true}, + {[]int{0, -1, 1, -1}, true}, + {[]int{1}, false}, + {[]int{1, -1}, false}, + {[]int{2}, true}, + {[]int{2, -1}, true}, + }, + }, { + val: ValueOf(&S2{embed: &embed{}}), + cases: []testCase{ + {[]int{0}, false}, + {[]int{0, -1}, false}, + {[]int{0, 0}, false}, + {[]int{0, 0, -1}, false}, + {[]int{0, -1, 0}, false}, + {[]int{0, -1, 0, -1}, false}, + {[]int{0, 1}, true}, + {[]int{0, 1, -1}, true}, + {[]int{0, -1, 1}, true}, + {[]int{0, -1, 1, -1}, true}, + {[]int{1}, false}, + {[]int{2}, true}, + }, + }, { + val: ValueOf(&S3{}), + cases: []testCase{ + {[]int{0}, true}, + {[]int{0, -1}, true}, + {[]int{0, 0}, false}, + {[]int{0, 0, -1}, false}, + {[]int{0, -1, 0}, false}, + {[]int{0, -1, 0, -1}, false}, + {[]int{0, 1}, true}, + {[]int{0, 1, -1}, true}, + {[]int{0, -1, 1}, true}, + {[]int{0, -1, 1, -1}, true}, + {[]int{1}, false}, + {[]int{2}, true}, + }, + }, { + val: ValueOf(&S4{Embed: &Embed{}}), + cases: []testCase{ + {[]int{0}, true}, + {[]int{0, -1}, true}, + {[]int{0, 0}, false}, + {[]int{0, 0, -1}, false}, + {[]int{0, -1, 0}, false}, + {[]int{0, -1, 0, -1}, false}, + {[]int{0, 1}, true}, + {[]int{0, 1, -1}, true}, + {[]int{0, -1, 1}, true}, + {[]int{0, -1, 1, -1}, true}, + {[]int{1}, false}, + {[]int{2}, true}, + }, + }} + + for _, tt := range tests { + t.Run(tt.val.Type().Name(), func(t *testing.T) { + for _, tc := range tt.cases { + f := tt.val + for _, i := range tc.index { + if f.Kind() == Ptr { + f = f.Elem() + } + if i == -1 { + f = f.Addr().Elem() + } else { + f = f.Field(i) + } + } + if got := f.CanSet(); got != tc.canSet { + t.Errorf("CanSet() = %v, want %v", got, tc.canSet) + } + } + }) + } +} + +var _i = 7 + +var valueToStringTests = []pair{ + {123, "123"}, + {123.5, "123.5"}, + {byte(123), "123"}, + {"abc", "abc"}, + {T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"}, + {new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"}, + {[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"}, + {&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[10]int(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"}, + {[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"}, + {&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"}, +} + +func TestValueToString(t *testing.T) { + for i, test := range valueToStringTests { + s := valueToString(ValueOf(test.i)) + if s != test.s { + t.Errorf("#%d: have %#q, want %#q", i, s, test.s) + } + } +} + +func TestArrayElemSet(t *testing.T) { + v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem() + v.Index(4).SetInt(123) + s := valueToString(v) + const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}" + if s != want { + t.Errorf("[10]int: have %#q want %#q", s, want) + } + + v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}) + v.Index(4).SetInt(123) + s = valueToString(v) + const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}" + if s != want1 { + t.Errorf("[]int: have %#q want %#q", s, want1) + } +} + +func TestPtrPointTo(t *testing.T) { + var ip *int32 + var i int32 = 1234 + vip := ValueOf(&ip) + vi := ValueOf(&i).Elem() + vip.Elem().Set(vi.Addr()) + if *ip != 1234 { + t.Errorf("got %d, want 1234", *ip) + } + + ip = nil + vp := ValueOf(&ip).Elem() + vp.Set(Zero(vp.Type())) + if ip != nil { + t.Errorf("got non-nil (%p), want nil", ip) + } +} + +func TestPtrSetNil(t *testing.T) { + var i int32 = 1234 + ip := &i + vip := ValueOf(&ip) + vip.Elem().Set(Zero(vip.Elem().Type())) + if ip != nil { + t.Errorf("got non-nil (%d), want nil", *ip) + } +} + +func TestMapSetNil(t *testing.T) { + m := make(map[string]int) + vm := ValueOf(&m) + vm.Elem().Set(Zero(vm.Elem().Type())) + if m != nil { + t.Errorf("got non-nil (%p), want nil", m) + } +} + +func TestAll(t *testing.T) { + testType(t, 1, TypeOf((int8)(0)), "int8") + testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8") + + typ := TypeOf((*struct { + c chan *int32 + d float32 + })(nil)) + testType(t, 3, typ, "*struct { c chan *int32; d float32 }") + etyp := typ.Elem() + testType(t, 4, etyp, "struct { c chan *int32; d float32 }") + styp := etyp + f := styp.Field(0) + testType(t, 5, f.Type, "chan *int32") + + f, present := styp.FieldByName("d") + if !present { + t.Errorf("FieldByName says present field is absent") + } + testType(t, 6, f.Type, "float32") + + f, present = styp.FieldByName("absent") + if present { + t.Errorf("FieldByName says absent field is present") + } + + typ = TypeOf([32]int32{}) + testType(t, 7, typ, "[32]int32") + testType(t, 8, typ.Elem(), "int32") + + typ = TypeOf((map[string]*int32)(nil)) + testType(t, 9, typ, "map[string]*int32") + mtyp := typ + testType(t, 10, mtyp.Key(), "string") + testType(t, 11, mtyp.Elem(), "*int32") + + typ = TypeOf((chan<- string)(nil)) + testType(t, 12, typ, "chan<- string") + testType(t, 13, typ.Elem(), "string") + + // make sure tag strings are not part of element type + typ = TypeOf(struct { + d []uint32 `reflect:"TAG"` + }{}).Field(0).Type + testType(t, 14, typ, "[]uint32") +} + +func TestInterfaceGet(t *testing.T) { + var inter struct { + E interface{} + } + inter.E = 123.456 + v1 := ValueOf(&inter) + v2 := v1.Elem().Field(0) + assert(t, v2.Type().String(), "interface {}") + i2 := v2.Interface() + v3 := ValueOf(i2) + assert(t, v3.Type().String(), "float64") +} + +func TestInterfaceValue(t *testing.T) { + var inter struct { + E interface{} + } + inter.E = 123.456 + v1 := ValueOf(&inter) + v2 := v1.Elem().Field(0) + assert(t, v2.Type().String(), "interface {}") + v3 := v2.Elem() + assert(t, v3.Type().String(), "float64") + + i3 := v2.Interface() + if _, ok := i3.(float64); !ok { + t.Error("v2.Interface() did not return float64, got ", TypeOf(i3)) + } +} + +func TestFunctionValue(t *testing.T) { + var x interface{} = func() {} + v := ValueOf(x) + if fmt.Sprint(v.Interface()) != fmt.Sprint(x) { + t.Fatalf("TestFunction returned wrong pointer") + } + assert(t, v.Type().String(), "func()") +} + +var appendTests = []struct { + orig, extra []int +}{ + {make([]int, 2, 4), []int{22}}, + {make([]int, 2, 4), []int{22, 33, 44}}, +} + +func sameInts(x, y []int) bool { + if len(x) != len(y) { + return false + } + for i, xx := range x { + if xx != y[i] { + return false + } + } + return true +} + +func TestAppend(t *testing.T) { + for i, test := range appendTests { + origLen, extraLen := len(test.orig), len(test.extra) + want := append(test.orig, test.extra...) + // Convert extra from []int to []Value. + e0 := make([]Value, len(test.extra)) + for j, e := range test.extra { + e0[j] = ValueOf(e) + } + // Convert extra from []int to *SliceValue. + e1 := ValueOf(test.extra) + // Test Append. + a0 := ValueOf(test.orig) + have0 := Append(a0, e0...).Interface().([]int) + if !sameInts(have0, want) { + t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0) + } + // Check that the orig and extra slices were not modified. + if len(test.orig) != origLen { + t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen) + } + if len(test.extra) != extraLen { + t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen) + } + // Test AppendSlice. + a1 := ValueOf(test.orig) + have1 := AppendSlice(a1, e1).Interface().([]int) + if !sameInts(have1, want) { + t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want) + } + // Check that the orig and extra slices were not modified. + if len(test.orig) != origLen { + t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen) + } + if len(test.extra) != extraLen { + t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen) + } + } +} + +func TestCopy(t *testing.T) { + a := []int{1, 2, 3, 4, 10, 9, 8, 7} + b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + for i := 0; i < len(b); i++ { + if b[i] != c[i] { + t.Fatalf("b != c before test") + } + } + a1 := a + b1 := b + aa := ValueOf(&a1).Elem() + ab := ValueOf(&b1).Elem() + for tocopy := 1; tocopy <= 7; tocopy++ { + aa.SetLen(tocopy) + Copy(ab, aa) + aa.SetLen(8) + for i := 0; i < tocopy; i++ { + if a[i] != b[i] { + t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d", + tocopy, i, a[i], i, b[i]) + } + } + for i := tocopy; i < len(b); i++ { + if b[i] != c[i] { + if i < len(a) { + t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d", + tocopy, i, a[i], i, b[i], i, c[i]) + } else { + t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d", + tocopy, i, b[i], i, c[i]) + } + } else { + t.Logf("tocopy=%d elem %d is okay\n", tocopy, i) + } + } + } +} + +func TestCopyString(t *testing.T) { + t.Run("Slice", func(t *testing.T) { + s := bytes.Repeat([]byte{'_'}, 8) + val := ValueOf(s) + + n := Copy(val, ValueOf("")) + if expecting := []byte("________"); n != 0 || !bytes.Equal(s, expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s, expecting) + } + + n = Copy(val, ValueOf("hello")) + if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s, expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s, expecting) + } + + n = Copy(val, ValueOf("helloworld")) + if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s, expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s, expecting) + } + }) + t.Run("Array", func(t *testing.T) { + s := [...]byte{'_', '_', '_', '_', '_', '_', '_', '_'} + val := ValueOf(&s).Elem() + + n := Copy(val, ValueOf("")) + if expecting := []byte("________"); n != 0 || !bytes.Equal(s[:], expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s[:], expecting) + } + + n = Copy(val, ValueOf("hello")) + if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s[:], expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s[:], expecting) + } + + n = Copy(val, ValueOf("helloworld")) + if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s[:], expecting) { + t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s[:], expecting) + } + }) +} + +func TestCopyArray(t *testing.T) { + a := [8]int{1, 2, 3, 4, 10, 9, 8, 7} + b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + c := b + aa := ValueOf(&a).Elem() + ab := ValueOf(&b).Elem() + Copy(ab, aa) + for i := 0; i < len(a); i++ { + if a[i] != b[i] { + t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i]) + } + } + for i := len(a); i < len(b); i++ { + if b[i] != c[i] { + t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i]) + } else { + t.Logf("elem %d is okay\n", i) + } + } +} + +func TestBigUnnamedStruct(t *testing.T) { + b := struct{ a, b, c, d int64 }{1, 2, 3, 4} + v := ValueOf(b) + b1 := v.Interface().(struct { + a, b, c, d int64 + }) + if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d { + t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1) + } +} + +type big struct { + a, b, c, d, e int64 +} + +func TestBigStruct(t *testing.T) { + b := big{1, 2, 3, 4, 5} + v := ValueOf(b) + b1 := v.Interface().(big) + if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e { + t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1) + } +} + +type Basic struct { + x int + y float32 +} + +type NotBasic Basic + +type DeepEqualTest struct { + a, b interface{} + eq bool +} + +// Simple functions for DeepEqual tests. +var ( + fn1 func() // nil. + fn2 func() // nil. + fn3 = func() { fn1() } // Not nil. +) + +type self struct{} + +type Loop *Loop +type Loopy interface{} + +var loop1, loop2 Loop +var loopy1, loopy2 Loopy +var cycleMap1, cycleMap2, cycleMap3 map[string]interface{} + +type structWithSelfPtr struct { + p *structWithSelfPtr + s string +} + +func init() { + loop1 = &loop2 + loop2 = &loop1 + + loopy1 = &loopy2 + loopy2 = &loopy1 + + cycleMap1 = map[string]interface{}{} + cycleMap1["cycle"] = cycleMap1 + cycleMap2 = map[string]interface{}{} + cycleMap2["cycle"] = cycleMap2 + cycleMap3 = map[string]interface{}{} + cycleMap3["different"] = cycleMap3 +} + +var deepEqualTests = []DeepEqualTest{ + // Equalities + {nil, nil, true}, + {1, 1, true}, + {int32(1), int32(1), true}, + {0.5, 0.5, true}, + {float32(0.5), float32(0.5), true}, + {"hello", "hello", true}, + {make([]int, 10), make([]int, 10), true}, + {&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true}, + {Basic{1, 0.5}, Basic{1, 0.5}, true}, + {error(nil), error(nil), true}, + {map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true}, + {fn1, fn2, true}, + + // Inequalities + {1, 2, false}, + {int32(1), int32(2), false}, + {0.5, 0.6, false}, + {float32(0.5), float32(0.6), false}, + {"hello", "hey", false}, + {make([]int, 10), make([]int, 11), false}, + {&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false}, + {Basic{1, 0.5}, Basic{1, 0.6}, false}, + {Basic{1, 0}, Basic{2, 0}, false}, + {map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false}, + {nil, 1, false}, + {1, nil, false}, + {fn1, fn3, false}, + {fn3, fn3, false}, + {[][]int{{1}}, [][]int{{2}}, false}, + {math.NaN(), math.NaN(), false}, + {&[1]float64{math.NaN()}, &[1]float64{math.NaN()}, false}, + {&[1]float64{math.NaN()}, self{}, true}, + {[]float64{math.NaN()}, []float64{math.NaN()}, false}, + {[]float64{math.NaN()}, self{}, true}, + {map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false}, + {map[float64]float64{math.NaN(): 1}, self{}, true}, + {&structWithSelfPtr{p: &structWithSelfPtr{s: "a"}}, &structWithSelfPtr{p: &structWithSelfPtr{s: "b"}}, false}, + + // Nil vs empty: not the same. + {[]int{}, []int(nil), false}, + {[]int{}, []int{}, true}, + {[]int(nil), []int(nil), true}, + {map[int]int{}, map[int]int(nil), false}, + {map[int]int{}, map[int]int{}, true}, + {map[int]int(nil), map[int]int(nil), true}, + + // Mismatched types + {1, 1.0, false}, + {int32(1), int64(1), false}, + {0.5, "hello", false}, + {[]int{1, 2, 3}, [3]int{1, 2, 3}, false}, + {&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false}, + {Basic{1, 0.5}, NotBasic{1, 0.5}, false}, + {map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false}, + + // Possible loops. + {&loop1, &loop1, true}, + {&loop1, &loop2, true}, + {&loopy1, &loopy1, true}, + {&loopy1, &loopy2, true}, + {&cycleMap1, &cycleMap2, true}, + {&cycleMap1, &cycleMap3, false}, +} + +func TestDeepEqual(t *testing.T) { + for _, test := range deepEqualTests { + if test.b == (self{}) { + test.b = test.a + } + if r := DeepEqual(test.a, test.b); r != test.eq { + t.Errorf("DeepEqual(%#v, %#v) = %v, want %v", test.a, test.b, r, test.eq) + } + } +} + +func TestTypeOf(t *testing.T) { + // Special case for nil + if typ := TypeOf(nil); typ != nil { + t.Errorf("expected nil type for nil value; got %v", typ) + } + for _, test := range deepEqualTests { + v := ValueOf(test.a) + if !v.IsValid() { + continue + } + typ := TypeOf(test.a) + if typ != v.Type() { + t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type()) + } + } +} + +type Recursive struct { + x int + r *Recursive +} + +func TestDeepEqualRecursiveStruct(t *testing.T) { + a, b := new(Recursive), new(Recursive) + *a = Recursive{12, a} + *b = Recursive{12, b} + if !DeepEqual(a, b) { + t.Error("DeepEqual(recursive same) = false, want true") + } +} + +type _Complex struct { + a int + b [3]*_Complex + c *string + d map[float64]float64 +} + +func TestDeepEqualComplexStruct(t *testing.T) { + m := make(map[float64]float64) + stra, strb := "hello", "hello" + a, b := new(_Complex), new(_Complex) + *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m} + *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m} + if !DeepEqual(a, b) { + t.Error("DeepEqual(complex same) = false, want true") + } +} + +func TestDeepEqualComplexStructInequality(t *testing.T) { + m := make(map[float64]float64) + stra, strb := "hello", "helloo" // Difference is here + a, b := new(_Complex), new(_Complex) + *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m} + *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m} + if DeepEqual(a, b) { + t.Error("DeepEqual(complex different) = true, want false") + } +} + +type UnexpT struct { + m map[int]int +} + +func TestDeepEqualUnexportedMap(t *testing.T) { + // Check that DeepEqual can look at unexported fields. + x1 := UnexpT{map[int]int{1: 2}} + x2 := UnexpT{map[int]int{1: 2}} + if !DeepEqual(&x1, &x2) { + t.Error("DeepEqual(x1, x2) = false, want true") + } + + y1 := UnexpT{map[int]int{2: 3}} + if DeepEqual(&x1, &y1) { + t.Error("DeepEqual(x1, y1) = true, want false") + } +} + +func check2ndField(x interface{}, offs uintptr, t *testing.T) { + s := ValueOf(x) + f := s.Type().Field(1) + if f.Offset != offs { + t.Error("mismatched offsets in structure alignment:", f.Offset, offs) + } +} + +// Check that structure alignment & offsets viewed through reflect agree with those +// from the compiler itself. +func TestAlignment(t *testing.T) { + type T1inner struct { + a int + } + type T1 struct { + T1inner + f int + } + type T2inner struct { + a, b int + } + type T2 struct { + T2inner + f int + } + + x := T1{T1inner{2}, 17} + check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t) + + x1 := T2{T2inner{2, 3}, 17} + check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t) +} + +func Nil(a interface{}, t *testing.T) { + n := ValueOf(a).Field(0) + if !n.IsNil() { + t.Errorf("%v should be nil", a) + } +} + +func NotNil(a interface{}, t *testing.T) { + n := ValueOf(a).Field(0) + if n.IsNil() { + t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String()) + } +} + +func TestIsNil(t *testing.T) { + // These implement IsNil. + // Wrap in extra struct to hide interface type. + doNil := []interface{}{ + struct{ x *int }{}, + struct{ x interface{} }{}, + struct{ x map[string]int }{}, + struct{ x func() bool }{}, + struct{ x chan int }{}, + struct{ x []string }{}, + struct{ x unsafe.Pointer }{}, + } + for _, ts := range doNil { + ty := TypeOf(ts).Field(0).Type + v := Zero(ty) + v.IsNil() // panics if not okay to call + } + + // Check the implementations + var pi struct { + x *int + } + Nil(pi, t) + pi.x = new(int) + NotNil(pi, t) + + var si struct { + x []int + } + Nil(si, t) + si.x = make([]int, 10) + NotNil(si, t) + + var ci struct { + x chan int + } + Nil(ci, t) + ci.x = make(chan int) + NotNil(ci, t) + + var mi struct { + x map[int]int + } + Nil(mi, t) + mi.x = make(map[int]int) + NotNil(mi, t) + + var ii struct { + x interface{} + } + Nil(ii, t) + ii.x = 2 + NotNil(ii, t) + + var fi struct { + x func(t *testing.T) + } + Nil(fi, t) + fi.x = TestIsNil + NotNil(fi, t) +} + +func TestIsZero(t *testing.T) { + for i, tt := range []struct { + x interface{} + want bool + }{ + // Booleans + {true, false}, + {false, true}, + // Numeric types + {int(0), true}, + {int(1), false}, + {int8(0), true}, + {int8(1), false}, + {int16(0), true}, + {int16(1), false}, + {int32(0), true}, + {int32(1), false}, + {int64(0), true}, + {int64(1), false}, + {uint(0), true}, + {uint(1), false}, + {uint8(0), true}, + {uint8(1), false}, + {uint16(0), true}, + {uint16(1), false}, + {uint32(0), true}, + {uint32(1), false}, + {uint64(0), true}, + {uint64(1), false}, + {float32(0), true}, + {float32(1.2), false}, + {float64(0), true}, + {float64(1.2), false}, + {math.Copysign(0, -1), false}, + {complex64(0), true}, + {complex64(1.2), false}, + {complex128(0), true}, + {complex128(1.2), false}, + {complex(math.Copysign(0, -1), 0), false}, + {complex(0, math.Copysign(0, -1)), false}, + {complex(math.Copysign(0, -1), math.Copysign(0, -1)), false}, + {uintptr(0), true}, + {uintptr(128), false}, + // Array + {Zero(TypeOf([5]string{})).Interface(), true}, + {[5]string{"", "", "", "", ""}, true}, + {[5]string{}, true}, + {[5]string{"", "", "", "a", ""}, false}, + // Chan + {(chan string)(nil), true}, + {make(chan string), false}, + {time.After(1), false}, + // Func + {(func())(nil), true}, + {New, false}, + // Interface + {New(TypeOf(new(error)).Elem()).Elem(), true}, + {(io.Reader)(strings.NewReader("")), false}, + // Map + {(map[string]string)(nil), true}, + {map[string]string{}, false}, + {make(map[string]string), false}, + // Ptr + {(*func())(nil), true}, + {(*int)(nil), true}, + {new(int), false}, + // Slice + {[]string{}, false}, + {([]string)(nil), true}, + {make([]string, 0), false}, + // Strings + {"", true}, + {"not-zero", false}, + // Structs + {T{}, true}, + {T{123, 456.75, "hello", &_i}, false}, + // UnsafePointer + {(unsafe.Pointer)(nil), true}, + {(unsafe.Pointer)(new(int)), false}, + } { + var x Value + if v, ok := tt.x.(Value); ok { + x = v + } else { + x = ValueOf(tt.x) + } + + b := x.IsZero() + if b != tt.want { + t.Errorf("%d: IsZero((%s)(%+v)) = %t, want %t", i, x.Kind(), tt.x, b, tt.want) + } + + if !Zero(TypeOf(tt.x)).IsZero() { + t.Errorf("%d: IsZero(Zero(TypeOf((%s)(%+v)))) is false", i, x.Kind(), tt.x) + } + } + + func() { + defer func() { + if r := recover(); r == nil { + t.Error("should panic for invalid value") + } + }() + (Value{}).IsZero() + }() +} + +func TestInterfaceExtraction(t *testing.T) { + var s struct { + W io.Writer + } + + s.W = os.Stdout + v := Indirect(ValueOf(&s)).Field(0).Interface() + if v != s.W.(interface{}) { + t.Error("Interface() on interface: ", v, s.W) + } +} + +func TestNilPtrValueSub(t *testing.T) { + var pi *int + if pv := ValueOf(pi); pv.Elem().IsValid() { + t.Error("ValueOf((*int)(nil)).Elem().IsValid()") + } +} + +func TestMap(t *testing.T) { + m := map[string]int{"a": 1, "b": 2} + mv := ValueOf(m) + if n := mv.Len(); n != len(m) { + t.Errorf("Len = %d, want %d", n, len(m)) + } + keys := mv.MapKeys() + newmap := MakeMap(mv.Type()) + for k, v := range m { + // Check that returned Keys match keys in range. + // These aren't required to be in the same order. + seen := false + for _, kv := range keys { + if kv.String() == k { + seen = true + break + } + } + if !seen { + t.Errorf("Missing key %q", k) + } + + // Check that value lookup is correct. + vv := mv.MapIndex(ValueOf(k)) + if vi := vv.Int(); vi != int64(v) { + t.Errorf("Key %q: have value %d, want %d", k, vi, v) + } + + // Copy into new map. + newmap.SetMapIndex(ValueOf(k), ValueOf(v)) + } + vv := mv.MapIndex(ValueOf("not-present")) + if vv.IsValid() { + t.Errorf("Invalid key: got non-nil value %s", valueToString(vv)) + } + + newm := newmap.Interface().(map[string]int) + if len(newm) != len(m) { + t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m)) + } + + for k, v := range newm { + mv, ok := m[k] + if mv != v { + t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok) + } + } + + newmap.SetMapIndex(ValueOf("a"), Value{}) + v, ok := newm["a"] + if ok { + t.Errorf("newm[\"a\"] = %d after delete", v) + } + + mv = ValueOf(&m).Elem() + mv.Set(Zero(mv.Type())) + if m != nil { + t.Errorf("mv.Set(nil) failed") + } +} + +func TestNilMap(t *testing.T) { + var m map[string]int + mv := ValueOf(m) + keys := mv.MapKeys() + if len(keys) != 0 { + t.Errorf(">0 keys for nil map: %v", keys) + } + + // Check that value for missing key is zero. + x := mv.MapIndex(ValueOf("hello")) + if x.Kind() != Invalid { + t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x) + } + + // Check big value too. + var mbig map[string][10 << 20]byte + x = ValueOf(mbig).MapIndex(ValueOf("hello")) + if x.Kind() != Invalid { + t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x) + } + + // Test that deletes from a nil map succeed. + mv.SetMapIndex(ValueOf("hi"), Value{}) +} + +func TestChan(t *testing.T) { + for loop := 0; loop < 2; loop++ { + var c chan int + var cv Value + + // check both ways to allocate channels + switch loop { + case 1: + c = make(chan int, 1) + cv = ValueOf(c) + case 0: + cv = MakeChan(TypeOf(c), 1) + c = cv.Interface().(chan int) + } + + // Send + cv.Send(ValueOf(2)) + if i := <-c; i != 2 { + t.Errorf("reflect Send 2, native recv %d", i) + } + + // Recv + c <- 3 + if i, ok := cv.Recv(); i.Int() != 3 || !ok { + t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok) + } + + // TryRecv fail + val, ok := cv.TryRecv() + if val.IsValid() || ok { + t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok) + } + + // TryRecv success + c <- 4 + val, ok = cv.TryRecv() + if !val.IsValid() { + t.Errorf("TryRecv on ready chan got nil") + } else if i := val.Int(); i != 4 || !ok { + t.Errorf("native send 4, TryRecv %d, %t", i, ok) + } + + // TrySend fail + c <- 100 + ok = cv.TrySend(ValueOf(5)) + i := <-c + if ok { + t.Errorf("TrySend on full chan succeeded: value %d", i) + } + + // TrySend success + ok = cv.TrySend(ValueOf(6)) + if !ok { + t.Errorf("TrySend on empty chan failed") + select { + case x := <-c: + t.Errorf("TrySend failed but it did send %d", x) + default: + } + } else { + if i = <-c; i != 6 { + t.Errorf("TrySend 6, recv %d", i) + } + } + + // Close + c <- 123 + cv.Close() + if i, ok := cv.Recv(); i.Int() != 123 || !ok { + t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok) + } + if i, ok := cv.Recv(); i.Int() != 0 || ok { + t.Errorf("after close Recv %d, %t", i.Int(), ok) + } + } + + // check creation of unbuffered channel + var c chan int + cv := MakeChan(TypeOf(c), 0) + c = cv.Interface().(chan int) + if cv.TrySend(ValueOf(7)) { + t.Errorf("TrySend on sync chan succeeded") + } + if v, ok := cv.TryRecv(); v.IsValid() || ok { + t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok) + } + + // len/cap + cv = MakeChan(TypeOf(c), 10) + c = cv.Interface().(chan int) + for i := 0; i < 3; i++ { + c <- i + } + if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) { + t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c)) + } +} + +// caseInfo describes a single case in a select test. +type caseInfo struct { + desc string + canSelect bool + recv Value + closed bool + helper func() + panic bool +} + +var allselect = flag.Bool("allselect", false, "exhaustive select test") + +func TestSelect(t *testing.T) { + selectWatch.once.Do(func() { go selectWatcher() }) + + var x exhaustive + nch := 0 + newop := func(n int, cap int) (ch, val Value) { + nch++ + if nch%101%2 == 1 { + c := make(chan int, cap) + ch = ValueOf(c) + val = ValueOf(n) + } else { + c := make(chan string, cap) + ch = ValueOf(c) + val = ValueOf(fmt.Sprint(n)) + } + return + } + + for n := 0; x.Next(); n++ { + if testing.Short() && n >= 1000 { + break + } + if n >= 100000 && !*allselect { + break + } + if n%100000 == 0 && testing.Verbose() { + println("TestSelect", n) + } + var cases []SelectCase + var info []caseInfo + + // Ready send. + if x.Maybe() { + ch, val := newop(len(cases), 1) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ch, + Send: val, + }) + info = append(info, caseInfo{desc: "ready send", canSelect: true}) + } + + // Ready recv. + if x.Maybe() { + ch, val := newop(len(cases), 1) + ch.Send(val) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val}) + } + + // Blocking send. + if x.Maybe() { + ch, val := newop(len(cases), 0) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ch, + Send: val, + }) + // Let it execute? + if x.Maybe() { + f := func() { ch.Recv() } + info = append(info, caseInfo{desc: "blocking send", helper: f}) + } else { + info = append(info, caseInfo{desc: "blocking send"}) + } + } + + // Blocking recv. + if x.Maybe() { + ch, val := newop(len(cases), 0) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + // Let it execute? + if x.Maybe() { + f := func() { ch.Send(val) } + info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f}) + } else { + info = append(info, caseInfo{desc: "blocking recv"}) + } + } + + // Zero Chan send. + if x.Maybe() { + // Maybe include value to send. + var val Value + if x.Maybe() { + val = ValueOf(100) + } + cases = append(cases, SelectCase{ + Dir: SelectSend, + Send: val, + }) + info = append(info, caseInfo{desc: "zero Chan send"}) + } + + // Zero Chan receive. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectRecv, + }) + info = append(info, caseInfo{desc: "zero Chan recv"}) + } + + // nil Chan send. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ValueOf((chan int)(nil)), + Send: ValueOf(101), + }) + info = append(info, caseInfo{desc: "nil Chan send"}) + } + + // nil Chan recv. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ValueOf((chan int)(nil)), + }) + info = append(info, caseInfo{desc: "nil Chan recv"}) + } + + // closed Chan send. + if x.Maybe() { + ch := make(chan int) + close(ch) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ValueOf(ch), + Send: ValueOf(101), + }) + info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true}) + } + + // closed Chan recv. + if x.Maybe() { + ch, val := newop(len(cases), 0) + ch.Close() + val = Zero(val.Type()) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val}) + } + + var helper func() // goroutine to help the select complete + + // Add default? Must be last case here, but will permute. + // Add the default if the select would otherwise + // block forever, and maybe add it anyway. + numCanSelect := 0 + canProceed := false + canBlock := true + canPanic := false + helpers := []int{} + for i, c := range info { + if c.canSelect { + canProceed = true + canBlock = false + numCanSelect++ + if c.panic { + canPanic = true + } + } else if c.helper != nil { + canProceed = true + helpers = append(helpers, i) + } + } + if !canProceed || x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectDefault, + }) + info = append(info, caseInfo{desc: "default", canSelect: canBlock}) + numCanSelect++ + } else if canBlock { + // Select needs to communicate with another goroutine. + cas := &info[helpers[x.Choose(len(helpers))]] + helper = cas.helper + cas.canSelect = true + numCanSelect++ + } + + // Permute cases and case info. + // Doing too much here makes the exhaustive loop + // too exhausting, so just do two swaps. + for loop := 0; loop < 2; loop++ { + i := x.Choose(len(cases)) + j := x.Choose(len(cases)) + cases[i], cases[j] = cases[j], cases[i] + info[i], info[j] = info[j], info[i] + } + + if helper != nil { + // We wait before kicking off a goroutine to satisfy a blocked select. + // The pause needs to be big enough to let the select block before + // we run the helper, but if we lose that race once in a while it's okay: the + // select will just proceed immediately. Not a big deal. + // For short tests we can grow [sic] the timeout a bit without fear of taking too long + pause := 10 * time.Microsecond + if testing.Short() { + pause = 100 * time.Microsecond + } + time.AfterFunc(pause, helper) + } + + // Run select. + i, recv, recvOK, panicErr := runSelect(cases, info) + if panicErr != nil && !canPanic { + t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr) + } + if panicErr == nil && canPanic && numCanSelect == 1 { + t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i) + } + if panicErr != nil { + continue + } + + cas := info[i] + if !cas.canSelect { + recvStr := "" + if recv.IsValid() { + recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK) + } + t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr) + continue + } + if cas.panic { + t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i) + continue + } + + if cases[i].Dir == SelectRecv { + if !recv.IsValid() { + t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed) + } + if !cas.recv.IsValid() { + t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i) + } + if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed { + if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed { + t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface()) + } + t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed) + } + } else { + if recv.IsValid() || recvOK { + t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false) + } + } + } +} + +func TestSelectMaxCases(t *testing.T) { + var sCases []SelectCase + channel := make(chan int) + close(channel) + for i := 0; i < 65536; i++ { + sCases = append(sCases, SelectCase{ + Dir: SelectRecv, + Chan: ValueOf(channel), + }) + } + // Should not panic + _, _, _ = Select(sCases) + sCases = append(sCases, SelectCase{ + Dir: SelectRecv, + Chan: ValueOf(channel), + }) + defer func() { + if err := recover(); err != nil { + if err.(string) != "reflect.Select: too many cases (max 65536)" { + t.Fatalf("unexpected error from select call with greater than max supported cases") + } + } else { + t.Fatalf("expected select call to panic with greater than max supported cases") + } + }() + // Should panic + _, _, _ = Select(sCases) +} + +func TestSelectNop(t *testing.T) { + // "select { default: }" should always return the default case. + chosen, _, _ := Select([]SelectCase{{Dir: SelectDefault}}) + if chosen != 0 { + t.Fatalf("expected Select to return 0, but got %#v", chosen) + } +} + +func BenchmarkSelect(b *testing.B) { + channel := make(chan int) + close(channel) + var cases []SelectCase + for i := 0; i < 8; i++ { + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ValueOf(channel), + }) + } + for _, numCases := range []int{1, 4, 8} { + b.Run(strconv.Itoa(numCases), func(b *testing.B) { + b.ReportAllocs() + for i := 0; i < b.N; i++ { + _, _, _ = Select(cases[:numCases]) + } + }) + } +} + +// selectWatch and the selectWatcher are a watchdog mechanism for running Select. +// If the selectWatcher notices that the select has been blocked for >1 second, it prints +// an error describing the select and panics the entire test binary. +var selectWatch struct { + sync.Mutex + once sync.Once + now time.Time + info []caseInfo +} + +func selectWatcher() { + for { + time.Sleep(1 * time.Second) + selectWatch.Lock() + if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second { + fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info)) + panic("select stuck") + } + selectWatch.Unlock() + } +} + +// runSelect runs a single select test. +// It returns the values returned by Select but also returns +// a panic value if the Select panics. +func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr interface{}) { + defer func() { + panicErr = recover() + + selectWatch.Lock() + selectWatch.info = nil + selectWatch.Unlock() + }() + + selectWatch.Lock() + selectWatch.now = time.Now() + selectWatch.info = info + selectWatch.Unlock() + + chosen, recv, recvOK = Select(cases) + return +} + +// fmtSelect formats the information about a single select test. +func fmtSelect(info []caseInfo) string { + var buf bytes.Buffer + fmt.Fprintf(&buf, "\nselect {\n") + for i, cas := range info { + fmt.Fprintf(&buf, "%d: %s", i, cas.desc) + if cas.recv.IsValid() { + fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface()) + } + if cas.canSelect { + fmt.Fprintf(&buf, " canselect") + } + if cas.panic { + fmt.Fprintf(&buf, " panic") + } + fmt.Fprintf(&buf, "\n") + } + fmt.Fprintf(&buf, "}") + return buf.String() +} + +type two [2]uintptr + +// Difficult test for function call because of +// implicit padding between arguments. +func dummy(b byte, c int, d byte, e two, f byte, g float32, h byte) (i byte, j int, k byte, l two, m byte, n float32, o byte) { + return b, c, d, e, f, g, h +} + +func TestFunc(t *testing.T) { + ret := ValueOf(dummy).Call([]Value{ + ValueOf(byte(10)), + ValueOf(20), + ValueOf(byte(30)), + ValueOf(two{40, 50}), + ValueOf(byte(60)), + ValueOf(float32(70)), + ValueOf(byte(80)), + }) + if len(ret) != 7 { + t.Fatalf("Call returned %d values, want 7", len(ret)) + } + + i := byte(ret[0].Uint()) + j := int(ret[1].Int()) + k := byte(ret[2].Uint()) + l := ret[3].Interface().(two) + m := byte(ret[4].Uint()) + n := float32(ret[5].Float()) + o := byte(ret[6].Uint()) + + if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 { + t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o) + } + + for i, v := range ret { + if v.CanAddr() { + t.Errorf("result %d is addressable", i) + } + } +} + +func TestCallConvert(t *testing.T) { + v := ValueOf(new(io.ReadWriter)).Elem() + f := ValueOf(func(r io.Reader) io.Reader { return r }) + out := f.Call([]Value{v}) + if len(out) != 1 || out[0].Type() != TypeOf(new(io.Reader)).Elem() || !out[0].IsNil() { + t.Errorf("expected [nil], got %v", out) + } +} + +type emptyStruct struct{} + +type nonEmptyStruct struct { + member int +} + +func returnEmpty() emptyStruct { + return emptyStruct{} +} + +func takesEmpty(e emptyStruct) { +} + +func returnNonEmpty(i int) nonEmptyStruct { + return nonEmptyStruct{member: i} +} + +func takesNonEmpty(n nonEmptyStruct) int { + return n.member +} + +func TestCallWithStruct(t *testing.T) { + r := ValueOf(returnEmpty).Call(nil) + if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) { + t.Errorf("returning empty struct returned %#v instead", r) + } + r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})}) + if len(r) != 0 { + t.Errorf("takesEmpty returned values: %#v", r) + } + r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)}) + if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 { + t.Errorf("returnNonEmpty returned %#v", r) + } + r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})}) + if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 { + t.Errorf("takesNonEmpty returned %#v", r) + } +} + +func TestCallReturnsEmpty(t *testing.T) { + // Issue 21717: past-the-end pointer write in Call with + // nonzero-sized frame and zero-sized return value. + runtime.GC() + var finalized uint32 + f := func() (emptyStruct, *[2]int64) { + i := new([2]int64) // big enough to not be tinyalloc'd, so finalizer always runs when i dies + runtime.SetFinalizer(i, func(*[2]int64) { atomic.StoreUint32(&finalized, 1) }) + return emptyStruct{}, i + } + v := ValueOf(f).Call(nil)[0] // out[0] should not alias out[1]'s memory, so the finalizer should run. + timeout := time.After(5 * time.Second) + for atomic.LoadUint32(&finalized) == 0 { + select { + case <-timeout: + t.Fatal("finalizer did not run") + default: + } + runtime.Gosched() + runtime.GC() + } + runtime.KeepAlive(v) +} + +func BenchmarkCall(b *testing.B) { + fv := ValueOf(func(a, b string) {}) + b.ReportAllocs() + b.RunParallel(func(pb *testing.PB) { + args := []Value{ValueOf("a"), ValueOf("b")} + for pb.Next() { + fv.Call(args) + } + }) +} + +func BenchmarkCallArgCopy(b *testing.B) { + byteArray := func(n int) Value { + return Zero(ArrayOf(n, TypeOf(byte(0)))) + } + sizes := [...]struct { + fv Value + arg Value + }{ + {ValueOf(func(a [128]byte) {}), byteArray(128)}, + {ValueOf(func(a [256]byte) {}), byteArray(256)}, + {ValueOf(func(a [1024]byte) {}), byteArray(1024)}, + {ValueOf(func(a [4096]byte) {}), byteArray(4096)}, + {ValueOf(func(a [65536]byte) {}), byteArray(65536)}, + } + for _, size := range sizes { + bench := func(b *testing.B) { + args := []Value{size.arg} + b.SetBytes(int64(size.arg.Len())) + b.ResetTimer() + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + size.fv.Call(args) + } + }) + } + name := fmt.Sprintf("size=%v", size.arg.Len()) + b.Run(name, bench) + } +} + +func TestMakeFunc(t *testing.T) { + f := dummy + fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in }) + ValueOf(&f).Elem().Set(fv) + + // Call g with small arguments so that there is + // something predictable (and different from the + // correct results) in those positions on the stack. + g := dummy + g(1, 2, 3, two{4, 5}, 6, 7, 8) + + // Call constructed function f. + i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80) + if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 { + t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o) + } +} + +func TestMakeFuncInterface(t *testing.T) { + fn := func(i int) int { return i } + incr := func(in []Value) []Value { + return []Value{ValueOf(int(in[0].Int() + 1))} + } + fv := MakeFunc(TypeOf(fn), incr) + ValueOf(&fn).Elem().Set(fv) + if r := fn(2); r != 3 { + t.Errorf("Call returned %d, want 3", r) + } + if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 { + t.Errorf("Call returned %d, want 15", r) + } + if r := fv.Interface().(func(int) int)(26); r != 27 { + t.Errorf("Call returned %d, want 27", r) + } +} + +func TestMakeFuncVariadic(t *testing.T) { + // Test that variadic arguments are packed into a slice and passed as last arg + fn := func(_ int, is ...int) []int { return nil } + fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] }) + ValueOf(&fn).Elem().Set(fv) + + r := fn(1, 2, 3) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fn(1, []int{2, 3}...) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + f := fv.Interface().(func(int, ...int) []int) + + r = f(1, 2, 3) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + r = f(1, []int{2, 3}...) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } +} + +// Dummy type that implements io.WriteCloser +type WC struct { +} + +func (w *WC) Write(p []byte) (n int, err error) { + return 0, nil +} +func (w *WC) Close() error { + return nil +} + +func TestMakeFuncValidReturnAssignments(t *testing.T) { + // reflect.Values returned from the wrapped function should be assignment-converted + // to the types returned by the result of MakeFunc. + + // Concrete types should be promotable to interfaces they implement. + var f func() error + f = MakeFunc(TypeOf(f), func([]Value) []Value { + return []Value{ValueOf(io.EOF)} + }).Interface().(func() error) + f() + + // Super-interfaces should be promotable to simpler interfaces. + var g func() io.Writer + g = MakeFunc(TypeOf(g), func([]Value) []Value { + var w io.WriteCloser = &WC{} + return []Value{ValueOf(&w).Elem()} + }).Interface().(func() io.Writer) + g() + + // Channels should be promotable to directional channels. + var h func() <-chan int + h = MakeFunc(TypeOf(h), func([]Value) []Value { + return []Value{ValueOf(make(chan int))} + }).Interface().(func() <-chan int) + h() + + // Unnamed types should be promotable to named types. + type T struct{ a, b, c int } + var i func() T + i = MakeFunc(TypeOf(i), func([]Value) []Value { + return []Value{ValueOf(struct{ a, b, c int }{a: 1, b: 2, c: 3})} + }).Interface().(func() T) + i() +} + +func TestMakeFuncInvalidReturnAssignments(t *testing.T) { + // Type doesn't implement the required interface. + shouldPanic("", func() { + var f func() error + f = MakeFunc(TypeOf(f), func([]Value) []Value { + return []Value{ValueOf(int(7))} + }).Interface().(func() error) + f() + }) + // Assigning to an interface with additional methods. + shouldPanic("", func() { + var f func() io.ReadWriteCloser + f = MakeFunc(TypeOf(f), func([]Value) []Value { + var w io.WriteCloser = &WC{} + return []Value{ValueOf(&w).Elem()} + }).Interface().(func() io.ReadWriteCloser) + f() + }) + // Directional channels can't be assigned to bidirectional ones. + shouldPanic("", func() { + var f func() chan int + f = MakeFunc(TypeOf(f), func([]Value) []Value { + var c <-chan int = make(chan int) + return []Value{ValueOf(c)} + }).Interface().(func() chan int) + f() + }) + // Two named types which are otherwise identical. + shouldPanic("", func() { + type T struct{ a, b, c int } + type U struct{ a, b, c int } + var f func() T + f = MakeFunc(TypeOf(f), func([]Value) []Value { + return []Value{ValueOf(U{a: 1, b: 2, c: 3})} + }).Interface().(func() T) + f() + }) +} + +type Point struct { + x, y int +} + +// This will be index 0. +func (p Point) AnotherMethod(scale int) int { + return -1 +} + +// This will be index 1. +func (p Point) Dist(scale int) int { + //println("Point.Dist", p.x, p.y, scale) + return p.x*p.x*scale + p.y*p.y*scale +} + +// This will be index 2. +func (p Point) GCMethod(k int) int { + runtime.GC() + return k + p.x +} + +// This will be index 3. +func (p Point) NoArgs() { + // Exercise no-argument/no-result paths. +} + +// This will be index 4. +func (p Point) TotalDist(points ...Point) int { + tot := 0 + for _, q := range points { + dx := q.x - p.x + dy := q.y - p.y + tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test. + + } + return tot +} + +// This will be index 5. +func (p *Point) Int64Method(x int64) int64 { + return x +} + +// This will be index 6. +func (p *Point) Int32Method(x int32) int32 { + return x +} + +func TestMethod(t *testing.T) { + // Non-curried method of type. + p := Point{3, 4} + i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Type Method returned %d; want 250", i) + } + + m, ok := TypeOf(p).MethodByName("Dist") + if !ok { + t.Fatalf("method by name failed") + } + i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int() + if i != 275 { + t.Errorf("Type MethodByName returned %d; want 275", i) + } + + m, ok = TypeOf(p).MethodByName("NoArgs") + if !ok { + t.Fatalf("method by name failed") + } + n := len(m.Func.Call([]Value{ValueOf(p)})) + if n != 0 { + t.Errorf("NoArgs returned %d values; want 0", n) + } + + i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int() + if i != 300 { + t.Errorf("Pointer Type Method returned %d; want 300", i) + } + + m, ok = TypeOf(&p).MethodByName("Dist") + if !ok { + t.Fatalf("ptr method by name failed") + } + i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int() + if i != 325 { + t.Errorf("Pointer Type MethodByName returned %d; want 325", i) + } + + m, ok = TypeOf(&p).MethodByName("NoArgs") + if !ok { + t.Fatalf("method by name failed") + } + n = len(m.Func.Call([]Value{ValueOf(&p)})) + if n != 0 { + t.Errorf("NoArgs returned %d values; want 0", n) + } + + // Curried method of value. + tfunc := TypeOf((func(int) int)(nil)) + v := ValueOf(p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Value Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(14)})[0].Int() + if i != 350 { + t.Errorf("Value Method returned %d; want 350", i) + } + v = ValueOf(p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(15)})[0].Int() + if i != 375 { + t.Errorf("Value MethodByName returned %d; want 375", i) + } + v = ValueOf(p).MethodByName("NoArgs") + v.Call(nil) + + // Curried method of pointer. + v = ValueOf(&p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(16)})[0].Int() + if i != 400 { + t.Errorf("Pointer Value Method returned %d; want 400", i) + } + v = ValueOf(&p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(17)})[0].Int() + if i != 425 { + t.Errorf("Pointer Value MethodByName returned %d; want 425", i) + } + v = ValueOf(&p).MethodByName("NoArgs") + v.Call(nil) + + // Curried method of interface value. + // Have to wrap interface value in a struct to get at it. + // Passing it to ValueOf directly would + // access the underlying Point, not the interface. + var x interface { + Dist(int) int + } = p + pv := ValueOf(&x).Elem() + v = pv.Method(0) + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(18)})[0].Int() + if i != 450 { + t.Errorf("Interface Method returned %d; want 450", i) + } + v = pv.MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(19)})[0].Int() + if i != 475 { + t.Errorf("Interface MethodByName returned %d; want 475", i) + } +} + +func TestMethodValue(t *testing.T) { + p := Point{3, 4} + var i int64 + + // Curried method of value. + tfunc := TypeOf((func(int) int)(nil)) + v := ValueOf(p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Value Method returned %d; want 250", i) + } + v = ValueOf(p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int() + if i != 275 { + t.Errorf("Value MethodByName returned %d; want 275", i) + } + v = ValueOf(p).MethodByName("NoArgs") + ValueOf(v.Interface()).Call(nil) + v.Interface().(func())() + + // Curried method of pointer. + v = ValueOf(&p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int() + if i != 300 { + t.Errorf("Pointer Value Method returned %d; want 300", i) + } + v = ValueOf(&p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int() + if i != 325 { + t.Errorf("Pointer Value MethodByName returned %d; want 325", i) + } + v = ValueOf(&p).MethodByName("NoArgs") + ValueOf(v.Interface()).Call(nil) + v.Interface().(func())() + + // Curried method of pointer to pointer. + pp := &p + v = ValueOf(&pp).Elem().Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int() + if i != 350 { + t.Errorf("Pointer Pointer Value Method returned %d; want 350", i) + } + v = ValueOf(&pp).Elem().MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int() + if i != 375 { + t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i) + } + + // Curried method of interface value. + // Have to wrap interface value in a struct to get at it. + // Passing it to ValueOf directly would + // access the underlying Point, not the interface. + var s = struct { + X interface { + Dist(int) int + } + }{p} + pv := ValueOf(s).Field(0) + v = pv.Method(0) + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int() + if i != 400 { + t.Errorf("Interface Method returned %d; want 400", i) + } + v = pv.MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int() + if i != 425 { + t.Errorf("Interface MethodByName returned %d; want 425", i) + } + + // For issue #33628: method args are not stored at the right offset + // on amd64p32. + m64 := ValueOf(&p).MethodByName("Int64Method").Interface().(func(int64) int64) + if x := m64(123); x != 123 { + t.Errorf("Int64Method returned %d; want 123", x) + } + m32 := ValueOf(&p).MethodByName("Int32Method").Interface().(func(int32) int32) + if x := m32(456); x != 456 { + t.Errorf("Int32Method returned %d; want 456", x) + } +} + +func TestVariadicMethodValue(t *testing.T) { + p := Point{3, 4} + points := []Point{{20, 21}, {22, 23}, {24, 25}} + want := int64(p.TotalDist(points[0], points[1], points[2])) + + // Variadic method of type. + tfunc := TypeOf((func(Point, ...Point) int)(nil)) + if tt := TypeOf(p).Method(4).Type; tt != tfunc { + t.Errorf("Variadic Method Type from TypeOf is %s; want %s", tt, tfunc) + } + + // Curried method of value. + tfunc = TypeOf((func(...Point) int)(nil)) + v := ValueOf(p).Method(4) + if tt := v.Type(); tt != tfunc { + t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc) + } + i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int() + if i != want { + t.Errorf("Variadic Method returned %d; want %d", i, want) + } + i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int() + if i != want { + t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want) + } + + f := v.Interface().(func(...Point) int) + i = int64(f(points[0], points[1], points[2])) + if i != want { + t.Errorf("Variadic Method Interface returned %d; want %d", i, want) + } + i = int64(f(points...)) + if i != want { + t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want) + } +} + +type DirectIfaceT struct { + p *int +} + +func (d DirectIfaceT) M() int { return *d.p } + +func TestDirectIfaceMethod(t *testing.T) { + x := 42 + v := DirectIfaceT{&x} + typ := TypeOf(v) + m, ok := typ.MethodByName("M") + if !ok { + t.Fatalf("cannot find method M") + } + in := []Value{ValueOf(v)} + out := m.Func.Call(in) + if got := out[0].Int(); got != 42 { + t.Errorf("Call with value receiver got %d, want 42", got) + } + + pv := &v + typ = TypeOf(pv) + m, ok = typ.MethodByName("M") + if !ok { + t.Fatalf("cannot find method M") + } + in = []Value{ValueOf(pv)} + out = m.Func.Call(in) + if got := out[0].Int(); got != 42 { + t.Errorf("Call with pointer receiver got %d, want 42", got) + } +} + +// Reflect version of $GOROOT/test/method5.go + +// Concrete types implementing M method. +// Smaller than a word, word-sized, larger than a word. +// Value and pointer receivers. + +type Tinter interface { + M(int, byte) (byte, int) +} + +type Tsmallv byte + +func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) } + +type Tsmallp byte + +func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) } + +type Twordv uintptr + +func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) } + +type Twordp uintptr + +func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) } + +type Tbigv [2]uintptr + +func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) } + +type Tbigp [2]uintptr + +func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) } + +type tinter interface { + m(int, byte) (byte, int) +} + +// Embedding via pointer. + +type Tm1 struct { + Tm2 +} + +type Tm2 struct { + *Tm3 +} + +type Tm3 struct { + *Tm4 +} + +type Tm4 struct { +} + +func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 } + +func TestMethod5(t *testing.T) { + CheckF := func(name string, f func(int, byte) (byte, int), inc int) { + b, x := f(1000, 99) + if b != 99 || x != 1000+inc { + t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc) + } + } + + CheckV := func(name string, i Value, inc int) { + bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))}) + b := bx[0].Interface() + x := bx[1].Interface() + if b != byte(99) || x != 1000+inc { + t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc) + } + + CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc) + } + + var TinterType = TypeOf(new(Tinter)).Elem() + + CheckI := func(name string, i interface{}, inc int) { + v := ValueOf(i) + CheckV(name, v, inc) + CheckV("(i="+name+")", v.Convert(TinterType), inc) + } + + sv := Tsmallv(1) + CheckI("sv", sv, 1) + CheckI("&sv", &sv, 1) + + sp := Tsmallp(2) + CheckI("&sp", &sp, 2) + + wv := Twordv(3) + CheckI("wv", wv, 3) + CheckI("&wv", &wv, 3) + + wp := Twordp(4) + CheckI("&wp", &wp, 4) + + bv := Tbigv([2]uintptr{5, 6}) + CheckI("bv", bv, 11) + CheckI("&bv", &bv, 11) + + bp := Tbigp([2]uintptr{7, 8}) + CheckI("&bp", &bp, 15) + + t4 := Tm4{} + t3 := Tm3{&t4} + t2 := Tm2{&t3} + t1 := Tm1{t2} + CheckI("t4", t4, 40) + CheckI("&t4", &t4, 40) + CheckI("t3", t3, 40) + CheckI("&t3", &t3, 40) + CheckI("t2", t2, 40) + CheckI("&t2", &t2, 40) + CheckI("t1", t1, 40) + CheckI("&t1", &t1, 40) + + var tnil Tinter + vnil := ValueOf(&tnil).Elem() + shouldPanic("Method", func() { vnil.Method(0) }) +} + +func TestInterfaceSet(t *testing.T) { + p := &Point{3, 4} + + var s struct { + I interface{} + P interface { + Dist(int) int + } + } + sv := ValueOf(&s).Elem() + sv.Field(0).Set(ValueOf(p)) + if q := s.I.(*Point); q != p { + t.Errorf("i: have %p want %p", q, p) + } + + pv := sv.Field(1) + pv.Set(ValueOf(p)) + if q := s.P.(*Point); q != p { + t.Errorf("i: have %p want %p", q, p) + } + + i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Interface Method returned %d; want 250", i) + } +} + +type T1 struct { + a string + int +} + +func TestAnonymousFields(t *testing.T) { + var field StructField + var ok bool + var t1 T1 + type1 := TypeOf(t1) + if field, ok = type1.FieldByName("int"); !ok { + t.Fatal("no field 'int'") + } + if field.Index[0] != 1 { + t.Error("field index should be 1; is", field.Index) + } +} + +type FTest struct { + s interface{} + name string + index []int + value int +} + +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 +} + +// The X in S15.S11.S1 and S16.S11.S1 annihilate. +type S14 struct { + S15 + S16 +} + +type S15 struct { + S11 +} + +type S16 struct { + S11 +} + +var fieldTests = []FTest{ + {struct{}{}, "", nil, 0}, + {struct{}{}, "Foo", nil, 0}, + {S0{A: 'a'}, "A", []int{0}, 'a'}, + {S0{}, "D", nil, 0}, + {S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'}, + {S1{B: 'b'}, "B", []int{0}, 'b'}, + {S1{}, "S0", []int{1}, 0}, + {S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'}, + {S2{A: 'a'}, "A", []int{0}, 'a'}, + {S2{}, "S1", []int{1}, 0}, + {S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'}, + {S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'}, + {S2{}, "D", nil, 0}, + {S3{}, "S1", nil, 0}, + {S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'}, + {S3{}, "B", nil, 0}, + {S3{D: 'd'}, "D", []int{2}, 0}, + {S3{E: 'e'}, "E", []int{3}, 'e'}, + {S4{A: 'a'}, "A", []int{1}, 'a'}, + {S4{}, "B", nil, 0}, + {S5{}, "X", nil, 0}, + {S5{}, "Y", []int{2, 0, 1}, 0}, + {S10{}, "X", nil, 0}, + {S10{}, "Y", []int{2, 0, 0, 1}, 0}, + {S14{}, "X", nil, 0}, +} + +func TestFieldByIndex(t *testing.T) { + for _, test := range fieldTests { + s := TypeOf(test.s) + f := s.FieldByIndex(test.index) + if f.Name != "" { + if test.index != nil { + if f.Name != test.name { + t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name) + } + } else { + t.Errorf("%s.%s found", s.Name(), f.Name) + } + } else if len(test.index) > 0 { + t.Errorf("%s.%s not found", s.Name(), test.name) + } + + if test.value != 0 { + v := ValueOf(test.s).FieldByIndex(test.index) + if v.IsValid() { + if x, ok := v.Interface().(int); ok { + if x != test.value { + t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value) + } + } else { + t.Errorf("%s%v value not an int", s.Name(), test.index) + } + } else { + t.Errorf("%s%v value not found", s.Name(), test.index) + } + } + } +} + +func TestFieldByName(t *testing.T) { + for _, test := range fieldTests { + s := TypeOf(test.s) + f, found := s.FieldByName(test.name) + if found { + if test.index != nil { + // Verify field depth and index. + if len(f.Index) != len(test.index) { + t.Errorf("%s.%s depth %d; want %d: %v vs %v", s.Name(), test.name, len(f.Index), len(test.index), f.Index, test.index) + } else { + for i, x := range f.Index { + if x != test.index[i] { + t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i]) + } + } + } + } else { + t.Errorf("%s.%s found", s.Name(), f.Name) + } + } else if len(test.index) > 0 { + t.Errorf("%s.%s not found", s.Name(), test.name) + } + + if test.value != 0 { + v := ValueOf(test.s).FieldByName(test.name) + if v.IsValid() { + if x, ok := v.Interface().(int); ok { + if x != test.value { + t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value) + } + } else { + t.Errorf("%s.%s value not an int", s.Name(), test.name) + } + } else { + t.Errorf("%s.%s value not found", s.Name(), test.name) + } + } + } +} + +func TestImportPath(t *testing.T) { + tests := []struct { + t Type + path string + }{ + {TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"}, + {TypeOf(int(0)), ""}, + {TypeOf(int8(0)), ""}, + {TypeOf(int16(0)), ""}, + {TypeOf(int32(0)), ""}, + {TypeOf(int64(0)), ""}, + {TypeOf(uint(0)), ""}, + {TypeOf(uint8(0)), ""}, + {TypeOf(uint16(0)), ""}, + {TypeOf(uint32(0)), ""}, + {TypeOf(uint64(0)), ""}, + {TypeOf(uintptr(0)), ""}, + {TypeOf(float32(0)), ""}, + {TypeOf(float64(0)), ""}, + {TypeOf(complex64(0)), ""}, + {TypeOf(complex128(0)), ""}, + {TypeOf(byte(0)), ""}, + {TypeOf(rune(0)), ""}, + {TypeOf([]byte(nil)), ""}, + {TypeOf([]rune(nil)), ""}, + {TypeOf(string("")), ""}, + {TypeOf((*interface{})(nil)).Elem(), ""}, + {TypeOf((*byte)(nil)), ""}, + {TypeOf((*rune)(nil)), ""}, + {TypeOf((*int64)(nil)), ""}, + {TypeOf(map[string]int{}), ""}, + {TypeOf((*error)(nil)).Elem(), ""}, + {TypeOf((*Point)(nil)), ""}, + {TypeOf((*Point)(nil)).Elem(), "reflect_test"}, + } + for _, test := range tests { + if path := test.t.PkgPath(); path != test.path { + t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path) + } + } +} + +func TestFieldPkgPath(t *testing.T) { + type x int + typ := TypeOf(struct { + Exported string + unexported string + OtherPkgFields + int // issue 21702 + *x // issue 21122 + }{}) + + type pkgpathTest struct { + index []int + pkgPath string + embedded bool + } + + checkPkgPath := func(name string, s []pkgpathTest) { + for _, test := range s { + f := typ.FieldByIndex(test.index) + if got, want := f.PkgPath, test.pkgPath; got != want { + t.Errorf("%s: Field(%d).PkgPath = %q, want %q", name, test.index, got, want) + } + if got, want := f.Anonymous, test.embedded; got != want { + t.Errorf("%s: Field(%d).Anonymous = %v, want %v", name, test.index, got, want) + } + } + } + + checkPkgPath("testStruct", []pkgpathTest{ + {[]int{0}, "", false}, // Exported + {[]int{1}, "reflect_test", false}, // unexported + {[]int{2}, "", true}, // OtherPkgFields + {[]int{2, 0}, "", false}, // OtherExported + {[]int{2, 1}, "reflect", false}, // otherUnexported + {[]int{3}, "reflect_test", true}, // int + {[]int{4}, "reflect_test", true}, // *x + }) + + type localOtherPkgFields OtherPkgFields + typ = TypeOf(localOtherPkgFields{}) + checkPkgPath("localOtherPkgFields", []pkgpathTest{ + {[]int{0}, "", false}, // OtherExported + {[]int{1}, "reflect", false}, // otherUnexported + }) +} + +func TestVariadicType(t *testing.T) { + // Test example from Type documentation. + var f func(x int, y ...float64) + typ := TypeOf(f) + if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) { + sl := typ.In(1) + if sl.Kind() == Slice { + if sl.Elem() == TypeOf(0.0) { + // ok + return + } + } + } + + // Failed + t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64") + s := fmt.Sprintf("have NumIn() = %d", typ.NumIn()) + for i := 0; i < typ.NumIn(); i++ { + s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i)) + } + t.Error(s) +} + +type inner struct { + x int +} + +type outer struct { + y int + inner +} + +func (*inner) M() {} +func (*outer) M() {} + +func TestNestedMethods(t *testing.T) { + typ := TypeOf((*outer)(nil)) + if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*outer).M).Pointer() { + t.Errorf("Wrong method table for outer: (M=%p)", (*outer).M) + for i := 0; i < typ.NumMethod(); i++ { + m := typ.Method(i) + t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer()) + } + } +} + +type unexp struct{} + +func (*unexp) f() (int32, int8) { return 7, 7 } +func (*unexp) g() (int64, int8) { return 8, 8 } + +type unexpI interface { + f() (int32, int8) +} + +var unexpi unexpI = new(unexp) + +func TestUnexportedMethods(t *testing.T) { + typ := TypeOf(unexpi) + + if got := typ.NumMethod(); got != 0 { + t.Errorf("NumMethod=%d, want 0 satisfied methods", got) + } +} + +type InnerInt struct { + X int +} + +type OuterInt struct { + Y int + InnerInt +} + +func (i *InnerInt) M() int { + return i.X +} + +func TestEmbeddedMethods(t *testing.T) { + typ := TypeOf((*OuterInt)(nil)) + if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*OuterInt).M).Pointer() { + t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M) + for i := 0; i < typ.NumMethod(); i++ { + m := typ.Method(i) + t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer()) + } + } + + i := &InnerInt{3} + if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 { + t.Errorf("i.M() = %d, want 3", v) + } + + o := &OuterInt{1, InnerInt{2}} + if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 { + t.Errorf("i.M() = %d, want 2", v) + } + + f := (*OuterInt).M + if v := f(o); v != 2 { + t.Errorf("f(o) = %d, want 2", v) + } +} + +type FuncDDD func(...interface{}) error + +func (f FuncDDD) M() {} + +func TestNumMethodOnDDD(t *testing.T) { + rv := ValueOf((FuncDDD)(nil)) + if n := rv.NumMethod(); n != 1 { + t.Fatalf("NumMethod()=%d, want 1", n) + } +} + +func TestPtrTo(t *testing.T) { + // This block of code means that the ptrToThis field of the + // reflect data for *unsafe.Pointer is non zero, see + // https://golang.org/issue/19003 + var x unsafe.Pointer + var y = &x + var z = &y + + var i int + + typ := TypeOf(z) + for i = 0; i < 100; i++ { + typ = PtrTo(typ) + } + for i = 0; i < 100; i++ { + typ = typ.Elem() + } + if typ != TypeOf(z) { + t.Errorf("after 100 PtrTo and Elem, have %s, want %s", typ, TypeOf(z)) + } +} + +func TestPtrToGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + pt := PtrTo(tt) + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := New(pt) + p := new(*uintptr) + *p = new(uintptr) + **p = uintptr(i) + v.Elem().Set(ValueOf(p).Convert(pt)) + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr) + if k != uintptr(i) { + t.Errorf("lost x[%d] = %d, want %d", i, k, i) + } + } +} + +func BenchmarkPtrTo(b *testing.B) { + // Construct a type with a zero ptrToThis. + type T struct{ int } + t := SliceOf(TypeOf(T{})) + ptrToThis := ValueOf(t).Elem().FieldByName("ptrToThis") + if !ptrToThis.IsValid() { + b.Fatalf("%v has no ptrToThis field; was it removed from rtype?", t) + } + if ptrToThis.Int() != 0 { + b.Fatalf("%v.ptrToThis unexpectedly nonzero", t) + } + b.ResetTimer() + + // Now benchmark calling PtrTo on it: we'll have to hit the ptrMap cache on + // every call. + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + PtrTo(t) + } + }) +} + +func TestAddr(t *testing.T) { + var p struct { + X, Y int + } + + v := ValueOf(&p) + v = v.Elem() + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(2) + if p.X != 2 { + t.Errorf("Addr.Elem.Set failed to set value") + } + + // Again but take address of the ValueOf value. + // Exercises generation of PtrTypes not present in the binary. + q := &p + v = ValueOf(&q).Elem() + v = v.Addr() + v = v.Elem() + v = v.Elem() + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(3) + if p.X != 3 { + t.Errorf("Addr.Elem.Set failed to set value") + } + + // Starting without pointer we should get changed value + // in interface. + qq := p + v = ValueOf(&qq).Elem() + v0 := v + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(4) + if p.X != 3 { // should be unchanged from last time + t.Errorf("somehow value Set changed original p") + } + p = v0.Interface().(struct { + X, Y int + }) + if p.X != 4 { + t.Errorf("Addr.Elem.Set valued to set value in top value") + } + + // Verify that taking the address of a type gives us a pointer + // which we can convert back using the usual interface + // notation. + var s struct { + B *bool + } + ps := ValueOf(&s).Elem().Field(0).Addr().Interface() + *(ps.(**bool)) = new(bool) + if s.B == nil { + t.Errorf("Addr.Interface direct assignment failed") + } +} + +func noAlloc(t *testing.T, n int, f func(int)) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + if runtime.GOMAXPROCS(0) > 1 { + t.Skip("skipping; GOMAXPROCS>1") + } + i := -1 + allocs := testing.AllocsPerRun(n, func() { + f(i) + i++ + }) + if allocs > 0 { + t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs) + } +} + +func TestAllocations(t *testing.T) { + noAlloc(t, 100, func(j int) { + var i interface{} + var v Value + + // We can uncomment this when compiler escape analysis + // is good enough to see that the integer assigned to i + // does not escape and therefore need not be allocated. + // + // i = 42 + j + // v = ValueOf(i) + // if int(v.Int()) != 42+j { + // panic("wrong int") + // } + + i = func(j int) int { return j } + v = ValueOf(i) + if v.Interface().(func(int) int)(j) != j { + panic("wrong result") + } + }) +} + +func TestSmallNegativeInt(t *testing.T) { + i := int16(-1) + v := ValueOf(i) + if v.Int() != -1 { + t.Errorf("int16(-1).Int() returned %v", v.Int()) + } +} + +func TestIndex(t *testing.T) { + xs := []byte{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Index(3).Interface().(byte) + if v != xs[3] { + t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3]) + } + xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(xa).Index(2).Interface().(byte) + if v != xa[2] { + t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2]) + } + s := "0123456789" + v = ValueOf(s).Index(3).Interface().(byte) + if v != s[3] { + t.Errorf("s.Index(3) = %v; expected %v", v, s[3]) + } +} + +func TestSlice(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Slice(3, 5).Interface().([]int) + if len(v) != 2 { + t.Errorf("len(xs.Slice(3, 5)) = %d", len(v)) + } + if cap(v) != 5 { + t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v)) + } + if !DeepEqual(v[0:5], xs[3:]) { + t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5]) + } + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int) + if len(v) != 3 { + t.Errorf("len(xa.Slice(2, 5)) = %d", len(v)) + } + if cap(v) != 6 { + t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v)) + } + if !DeepEqual(v[0:6], xa[2:]) { + t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6]) + } + s := "0123456789" + vs := ValueOf(s).Slice(3, 5).Interface().(string) + if vs != s[3:5] { + t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5]) + } + + rv := ValueOf(&xs).Elem() + rv = rv.Slice(3, 4) + ptr2 := rv.Pointer() + rv = rv.Slice(5, 5) + ptr3 := rv.Pointer() + if ptr3 != ptr2 { + t.Errorf("xs.Slice(3,4).Slice3(5,5).Pointer() = %#x, want %#x", ptr3, ptr2) + } +} + +func TestSlice3(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int) + if len(v) != 2 { + t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v)) + } + if cap(v) != 4 { + t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v)) + } + if !DeepEqual(v[0:4], xs[3:7:7]) { + t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4]) + } + rv := ValueOf(&xs).Elem() + shouldPanic("Slice3", func() { rv.Slice3(1, 2, 1) }) + shouldPanic("Slice3", func() { rv.Slice3(1, 1, 11) }) + shouldPanic("Slice3", func() { rv.Slice3(2, 2, 1) }) + + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int) + if len(v) != 3 { + t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v)) + } + if cap(v) != 4 { + t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v)) + } + if !DeepEqual(v[0:4], xa[2:6:6]) { + t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4]) + } + rv = ValueOf(&xa).Elem() + shouldPanic("Slice3", func() { rv.Slice3(1, 2, 1) }) + shouldPanic("Slice3", func() { rv.Slice3(1, 1, 11) }) + shouldPanic("Slice3", func() { rv.Slice3(2, 2, 1) }) + + s := "hello world" + rv = ValueOf(&s).Elem() + shouldPanic("Slice3", func() { rv.Slice3(1, 2, 3) }) + + rv = ValueOf(&xs).Elem() + rv = rv.Slice3(3, 5, 7) + ptr2 := rv.Pointer() + rv = rv.Slice3(4, 4, 4) + ptr3 := rv.Pointer() + if ptr3 != ptr2 { + t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).Pointer() = %#x, want %#x", ptr3, ptr2) + } +} + +func TestSetLenCap(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + + vs := ValueOf(&xs).Elem() + shouldPanic("SetLen", func() { vs.SetLen(10) }) + shouldPanic("SetCap", func() { vs.SetCap(10) }) + shouldPanic("SetLen", func() { vs.SetLen(-1) }) + shouldPanic("SetCap", func() { vs.SetCap(-1) }) + shouldPanic("SetCap", func() { vs.SetCap(6) }) // smaller than len + vs.SetLen(5) + if len(xs) != 5 || cap(xs) != 8 { + t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs)) + } + vs.SetCap(6) + if len(xs) != 5 || cap(xs) != 6 { + t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs)) + } + vs.SetCap(5) + if len(xs) != 5 || cap(xs) != 5 { + t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs)) + } + shouldPanic("SetCap", func() { vs.SetCap(4) }) // smaller than len + shouldPanic("SetLen", func() { vs.SetLen(6) }) // bigger than cap + + va := ValueOf(&xa).Elem() + shouldPanic("SetLen", func() { va.SetLen(8) }) + shouldPanic("SetCap", func() { va.SetCap(8) }) +} + +func TestVariadic(t *testing.T) { + var b bytes.Buffer + V := ValueOf + + b.Reset() + V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)}) + if b.String() != "hello, 42 world" { + t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world") + } + + b.Reset() + V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]interface{}{"hello", 42})}) + if b.String() != "hello, 42 world" { + t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world") + } +} + +func TestFuncArg(t *testing.T) { + f1 := func(i int, f func(int) int) int { return f(i) } + f2 := func(i int) int { return i + 1 } + r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)}) + if r[0].Int() != 101 { + t.Errorf("function returned %d, want 101", r[0].Int()) + } +} + +func TestStructArg(t *testing.T) { + type padded struct { + B string + C int32 + } + var ( + gotA padded + gotB uint32 + wantA = padded{"3", 4} + wantB = uint32(5) + ) + f := func(a padded, b uint32) { + gotA, gotB = a, b + } + ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)}) + if gotA != wantA || gotB != wantB { + t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB) + } +} + +var tagGetTests = []struct { + Tag StructTag + Key string + Value string +}{ + {`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`}, + {`protobuf:"PB(1,2)"`, `foo`, ``}, + {`protobuf:"PB(1,2)"`, `rotobuf`, ``}, + {`protobuf:"PB(1,2)" json:"name"`, `json`, `name`}, + {`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`}, + {`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"}, + {`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"}, +} + +func TestTagGet(t *testing.T) { + for _, tt := range tagGetTests { + if v := tt.Tag.Get(tt.Key); v != tt.Value { + t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value) + } + } +} + +func TestBytes(t *testing.T) { + type B []byte + x := B{1, 2, 3, 4} + y := ValueOf(x).Bytes() + if !bytes.Equal(x, y) { + t.Fatalf("ValueOf(%v).Bytes() = %v", x, y) + } + if &x[0] != &y[0] { + t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0]) + } +} + +func TestSetBytes(t *testing.T) { + type B []byte + var x B + y := []byte{1, 2, 3, 4} + ValueOf(&x).Elem().SetBytes(y) + if !bytes.Equal(x, y) { + t.Fatalf("ValueOf(%v).Bytes() = %v", x, y) + } + if &x[0] != &y[0] { + t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0]) + } +} + +type Private struct { + x int + y **int + Z int +} + +func (p *Private) m() { +} + +type private struct { + Z int + z int + S string + A [1]Private + T []Private +} + +func (p *private) P() { +} + +type Public struct { + X int + Y **int + private +} + +func (p *Public) M() { +} + +func TestUnexported(t *testing.T) { + var pub Public + pub.S = "S" + pub.T = pub.A[:] + v := ValueOf(&pub) + isValid(v.Elem().Field(0)) + isValid(v.Elem().Field(1)) + isValid(v.Elem().Field(2)) + isValid(v.Elem().FieldByName("X")) + isValid(v.Elem().FieldByName("Y")) + isValid(v.Elem().FieldByName("Z")) + isValid(v.Type().Method(0).Func) + m, _ := v.Type().MethodByName("M") + isValid(m.Func) + m, _ = v.Type().MethodByName("P") + isValid(m.Func) + isNonNil(v.Elem().Field(0).Interface()) + isNonNil(v.Elem().Field(1).Interface()) + isNonNil(v.Elem().Field(2).Field(2).Index(0)) + isNonNil(v.Elem().FieldByName("X").Interface()) + isNonNil(v.Elem().FieldByName("Y").Interface()) + isNonNil(v.Elem().FieldByName("Z").Interface()) + isNonNil(v.Elem().FieldByName("S").Index(0).Interface()) + isNonNil(v.Type().Method(0).Func.Interface()) + m, _ = v.Type().MethodByName("P") + isNonNil(m.Func.Interface()) + + var priv Private + v = ValueOf(&priv) + isValid(v.Elem().Field(0)) + isValid(v.Elem().Field(1)) + isValid(v.Elem().FieldByName("x")) + isValid(v.Elem().FieldByName("y")) + shouldPanic("Interface", func() { v.Elem().Field(0).Interface() }) + shouldPanic("Interface", func() { v.Elem().Field(1).Interface() }) + shouldPanic("Interface", func() { v.Elem().FieldByName("x").Interface() }) + shouldPanic("Interface", func() { v.Elem().FieldByName("y").Interface() }) + shouldPanic("Method", func() { v.Type().Method(0) }) +} + +func TestSetPanic(t *testing.T) { + ok := func(f func()) { f() } + bad := func(f func()) { shouldPanic("Set", f) } + clear := func(v Value) { v.Set(Zero(v.Type())) } + + type t0 struct { + W int + } + + type t1 struct { + Y int + t0 + } + + type T2 struct { + Z int + namedT0 t0 + } + + type T struct { + X int + t1 + T2 + NamedT1 t1 + NamedT2 T2 + namedT1 t1 + namedT2 T2 + } + + // not addressable + v := ValueOf(T{}) + bad(func() { clear(v.Field(0)) }) // .X + bad(func() { clear(v.Field(1)) }) // .t1 + bad(func() { clear(v.Field(1).Field(0)) }) // .t1.Y + bad(func() { clear(v.Field(1).Field(1)) }) // .t1.t0 + bad(func() { clear(v.Field(1).Field(1).Field(0)) }) // .t1.t0.W + bad(func() { clear(v.Field(2)) }) // .T2 + bad(func() { clear(v.Field(2).Field(0)) }) // .T2.Z + bad(func() { clear(v.Field(2).Field(1)) }) // .T2.namedT0 + bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W + bad(func() { clear(v.Field(3)) }) // .NamedT1 + bad(func() { clear(v.Field(3).Field(0)) }) // .NamedT1.Y + bad(func() { clear(v.Field(3).Field(1)) }) // .NamedT1.t0 + bad(func() { clear(v.Field(3).Field(1).Field(0)) }) // .NamedT1.t0.W + bad(func() { clear(v.Field(4)) }) // .NamedT2 + bad(func() { clear(v.Field(4).Field(0)) }) // .NamedT2.Z + bad(func() { clear(v.Field(4).Field(1)) }) // .NamedT2.namedT0 + bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W + bad(func() { clear(v.Field(5)) }) // .namedT1 + bad(func() { clear(v.Field(5).Field(0)) }) // .namedT1.Y + bad(func() { clear(v.Field(5).Field(1)) }) // .namedT1.t0 + bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W + bad(func() { clear(v.Field(6)) }) // .namedT2 + bad(func() { clear(v.Field(6).Field(0)) }) // .namedT2.Z + bad(func() { clear(v.Field(6).Field(1)) }) // .namedT2.namedT0 + bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W + + // addressable + v = ValueOf(&T{}).Elem() + ok(func() { clear(v.Field(0)) }) // .X + bad(func() { clear(v.Field(1)) }) // .t1 + ok(func() { clear(v.Field(1).Field(0)) }) // .t1.Y + bad(func() { clear(v.Field(1).Field(1)) }) // .t1.t0 + ok(func() { clear(v.Field(1).Field(1).Field(0)) }) // .t1.t0.W + ok(func() { clear(v.Field(2)) }) // .T2 + ok(func() { clear(v.Field(2).Field(0)) }) // .T2.Z + bad(func() { clear(v.Field(2).Field(1)) }) // .T2.namedT0 + bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W + ok(func() { clear(v.Field(3)) }) // .NamedT1 + ok(func() { clear(v.Field(3).Field(0)) }) // .NamedT1.Y + bad(func() { clear(v.Field(3).Field(1)) }) // .NamedT1.t0 + ok(func() { clear(v.Field(3).Field(1).Field(0)) }) // .NamedT1.t0.W + ok(func() { clear(v.Field(4)) }) // .NamedT2 + ok(func() { clear(v.Field(4).Field(0)) }) // .NamedT2.Z + bad(func() { clear(v.Field(4).Field(1)) }) // .NamedT2.namedT0 + bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W + bad(func() { clear(v.Field(5)) }) // .namedT1 + bad(func() { clear(v.Field(5).Field(0)) }) // .namedT1.Y + bad(func() { clear(v.Field(5).Field(1)) }) // .namedT1.t0 + bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W + bad(func() { clear(v.Field(6)) }) // .namedT2 + bad(func() { clear(v.Field(6).Field(0)) }) // .namedT2.Z + bad(func() { clear(v.Field(6).Field(1)) }) // .namedT2.namedT0 + bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W +} + +type timp int + +func (t timp) W() {} +func (t timp) Y() {} +func (t timp) w() {} +func (t timp) y() {} + +func TestCallPanic(t *testing.T) { + type t0 interface { + W() + w() + } + type T1 interface { + Y() + y() + } + type T2 struct { + T1 + t0 + } + type T struct { + t0 // 0 + T1 // 1 + + NamedT0 t0 // 2 + NamedT1 T1 // 3 + NamedT2 T2 // 4 + + namedT0 t0 // 5 + namedT1 T1 // 6 + namedT2 T2 // 7 + } + ok := func(f func()) { f() } + badCall := func(f func()) { shouldPanic("Call", f) } + badMethod := func(f func()) { shouldPanic("Method", f) } + call := func(v Value) { v.Call(nil) } + + i := timp(0) + v := ValueOf(T{i, i, i, i, T2{i, i}, i, i, T2{i, i}}) + badCall(func() { call(v.Field(0).Method(0)) }) // .t0.W + badCall(func() { call(v.Field(0).Elem().Method(0)) }) // .t0.W + badCall(func() { call(v.Field(0).Method(1)) }) // .t0.w + badMethod(func() { call(v.Field(0).Elem().Method(2)) }) // .t0.w + ok(func() { call(v.Field(1).Method(0)) }) // .T1.Y + ok(func() { call(v.Field(1).Elem().Method(0)) }) // .T1.Y + badCall(func() { call(v.Field(1).Method(1)) }) // .T1.y + badMethod(func() { call(v.Field(1).Elem().Method(2)) }) // .T1.y + + ok(func() { call(v.Field(2).Method(0)) }) // .NamedT0.W + ok(func() { call(v.Field(2).Elem().Method(0)) }) // .NamedT0.W + badCall(func() { call(v.Field(2).Method(1)) }) // .NamedT0.w + badMethod(func() { call(v.Field(2).Elem().Method(2)) }) // .NamedT0.w + + ok(func() { call(v.Field(3).Method(0)) }) // .NamedT1.Y + ok(func() { call(v.Field(3).Elem().Method(0)) }) // .NamedT1.Y + badCall(func() { call(v.Field(3).Method(1)) }) // .NamedT1.y + badMethod(func() { call(v.Field(3).Elem().Method(3)) }) // .NamedT1.y + + ok(func() { call(v.Field(4).Field(0).Method(0)) }) // .NamedT2.T1.Y + ok(func() { call(v.Field(4).Field(0).Elem().Method(0)) }) // .NamedT2.T1.W + badCall(func() { call(v.Field(4).Field(1).Method(0)) }) // .NamedT2.t0.W + badCall(func() { call(v.Field(4).Field(1).Elem().Method(0)) }) // .NamedT2.t0.W + + badCall(func() { call(v.Field(5).Method(0)) }) // .namedT0.W + badCall(func() { call(v.Field(5).Elem().Method(0)) }) // .namedT0.W + badCall(func() { call(v.Field(5).Method(1)) }) // .namedT0.w + badMethod(func() { call(v.Field(5).Elem().Method(2)) }) // .namedT0.w + + badCall(func() { call(v.Field(6).Method(0)) }) // .namedT1.Y + badCall(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.Y + badCall(func() { call(v.Field(6).Method(0)) }) // .namedT1.y + badCall(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.y + + badCall(func() { call(v.Field(7).Field(0).Method(0)) }) // .namedT2.T1.Y + badCall(func() { call(v.Field(7).Field(0).Elem().Method(0)) }) // .namedT2.T1.W + badCall(func() { call(v.Field(7).Field(1).Method(0)) }) // .namedT2.t0.W + badCall(func() { call(v.Field(7).Field(1).Elem().Method(0)) }) // .namedT2.t0.W +} + +func shouldPanic(expect string, f func()) { + defer func() { + r := recover() + if r == nil { + panic("did not panic") + } + if expect != "" { + var s string + switch r := r.(type) { + case string: + s = r + case *ValueError: + s = r.Error() + default: + panic(fmt.Sprintf("panicked with unexpected type %T", r)) + } + if !strings.HasPrefix(s, "reflect") { + panic(`panic string does not start with "reflect": ` + s) + } + if !strings.Contains(s, expect) { + panic(`panic string does not contain "` + expect + `": ` + s) + } + } + }() + f() +} + +func isNonNil(x interface{}) { + if x == nil { + panic("nil interface") + } +} + +func isValid(v Value) { + if !v.IsValid() { + panic("zero Value") + } +} + +func TestAlias(t *testing.T) { + x := string("hello") + v := ValueOf(&x).Elem() + oldvalue := v.Interface() + v.SetString("world") + newvalue := v.Interface() + + if oldvalue != "hello" || newvalue != "world" { + t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue) + } +} + +var V = ValueOf + +func EmptyInterfaceV(x interface{}) Value { + return ValueOf(&x).Elem() +} + +func ReaderV(x io.Reader) Value { + return ValueOf(&x).Elem() +} + +func ReadWriterV(x io.ReadWriter) Value { + return ValueOf(&x).Elem() +} + +type Empty struct{} +type MyStruct struct { + x int `some:"tag"` +} +type MyString string +type MyBytes []byte +type MyRunes []int32 +type MyFunc func() +type MyByte byte + +type IntChan chan int +type IntChanRecv <-chan int +type IntChanSend chan<- int +type BytesChan chan []byte +type BytesChanRecv <-chan []byte +type BytesChanSend chan<- []byte + +var convertTests = []struct { + in Value + out Value +}{ + // numbers + /* + Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go + + package main + + import "fmt" + + var numbers = []string{ + "int8", "uint8", "int16", "uint16", + "int32", "uint32", "int64", "uint64", + "int", "uint", "uintptr", + "float32", "float64", + } + + func main() { + // all pairs but in an unusual order, + // to emit all the int8, uint8 cases + // before n grows too big. + n := 1 + for i, f := range numbers { + for _, g := range numbers[i:] { + fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n) + n++ + if f != g { + fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n) + n++ + } + } + } + } + */ + {V(int8(1)), V(int8(1))}, + {V(int8(2)), V(uint8(2))}, + {V(uint8(3)), V(int8(3))}, + {V(int8(4)), V(int16(4))}, + {V(int16(5)), V(int8(5))}, + {V(int8(6)), V(uint16(6))}, + {V(uint16(7)), V(int8(7))}, + {V(int8(8)), V(int32(8))}, + {V(int32(9)), V(int8(9))}, + {V(int8(10)), V(uint32(10))}, + {V(uint32(11)), V(int8(11))}, + {V(int8(12)), V(int64(12))}, + {V(int64(13)), V(int8(13))}, + {V(int8(14)), V(uint64(14))}, + {V(uint64(15)), V(int8(15))}, + {V(int8(16)), V(int(16))}, + {V(int(17)), V(int8(17))}, + {V(int8(18)), V(uint(18))}, + {V(uint(19)), V(int8(19))}, + {V(int8(20)), V(uintptr(20))}, + {V(uintptr(21)), V(int8(21))}, + {V(int8(22)), V(float32(22))}, + {V(float32(23)), V(int8(23))}, + {V(int8(24)), V(float64(24))}, + {V(float64(25)), V(int8(25))}, + {V(uint8(26)), V(uint8(26))}, + {V(uint8(27)), V(int16(27))}, + {V(int16(28)), V(uint8(28))}, + {V(uint8(29)), V(uint16(29))}, + {V(uint16(30)), V(uint8(30))}, + {V(uint8(31)), V(int32(31))}, + {V(int32(32)), V(uint8(32))}, + {V(uint8(33)), V(uint32(33))}, + {V(uint32(34)), V(uint8(34))}, + {V(uint8(35)), V(int64(35))}, + {V(int64(36)), V(uint8(36))}, + {V(uint8(37)), V(uint64(37))}, + {V(uint64(38)), V(uint8(38))}, + {V(uint8(39)), V(int(39))}, + {V(int(40)), V(uint8(40))}, + {V(uint8(41)), V(uint(41))}, + {V(uint(42)), V(uint8(42))}, + {V(uint8(43)), V(uintptr(43))}, + {V(uintptr(44)), V(uint8(44))}, + {V(uint8(45)), V(float32(45))}, + {V(float32(46)), V(uint8(46))}, + {V(uint8(47)), V(float64(47))}, + {V(float64(48)), V(uint8(48))}, + {V(int16(49)), V(int16(49))}, + {V(int16(50)), V(uint16(50))}, + {V(uint16(51)), V(int16(51))}, + {V(int16(52)), V(int32(52))}, + {V(int32(53)), V(int16(53))}, + {V(int16(54)), V(uint32(54))}, + {V(uint32(55)), V(int16(55))}, + {V(int16(56)), V(int64(56))}, + {V(int64(57)), V(int16(57))}, + {V(int16(58)), V(uint64(58))}, + {V(uint64(59)), V(int16(59))}, + {V(int16(60)), V(int(60))}, + {V(int(61)), V(int16(61))}, + {V(int16(62)), V(uint(62))}, + {V(uint(63)), V(int16(63))}, + {V(int16(64)), V(uintptr(64))}, + {V(uintptr(65)), V(int16(65))}, + {V(int16(66)), V(float32(66))}, + {V(float32(67)), V(int16(67))}, + {V(int16(68)), V(float64(68))}, + {V(float64(69)), V(int16(69))}, + {V(uint16(70)), V(uint16(70))}, + {V(uint16(71)), V(int32(71))}, + {V(int32(72)), V(uint16(72))}, + {V(uint16(73)), V(uint32(73))}, + {V(uint32(74)), V(uint16(74))}, + {V(uint16(75)), V(int64(75))}, + {V(int64(76)), V(uint16(76))}, + {V(uint16(77)), V(uint64(77))}, + {V(uint64(78)), V(uint16(78))}, + {V(uint16(79)), V(int(79))}, + {V(int(80)), V(uint16(80))}, + {V(uint16(81)), V(uint(81))}, + {V(uint(82)), V(uint16(82))}, + {V(uint16(83)), V(uintptr(83))}, + {V(uintptr(84)), V(uint16(84))}, + {V(uint16(85)), V(float32(85))}, + {V(float32(86)), V(uint16(86))}, + {V(uint16(87)), V(float64(87))}, + {V(float64(88)), V(uint16(88))}, + {V(int32(89)), V(int32(89))}, + {V(int32(90)), V(uint32(90))}, + {V(uint32(91)), V(int32(91))}, + {V(int32(92)), V(int64(92))}, + {V(int64(93)), V(int32(93))}, + {V(int32(94)), V(uint64(94))}, + {V(uint64(95)), V(int32(95))}, + {V(int32(96)), V(int(96))}, + {V(int(97)), V(int32(97))}, + {V(int32(98)), V(uint(98))}, + {V(uint(99)), V(int32(99))}, + {V(int32(100)), V(uintptr(100))}, + {V(uintptr(101)), V(int32(101))}, + {V(int32(102)), V(float32(102))}, + {V(float32(103)), V(int32(103))}, + {V(int32(104)), V(float64(104))}, + {V(float64(105)), V(int32(105))}, + {V(uint32(106)), V(uint32(106))}, + {V(uint32(107)), V(int64(107))}, + {V(int64(108)), V(uint32(108))}, + {V(uint32(109)), V(uint64(109))}, + {V(uint64(110)), V(uint32(110))}, + {V(uint32(111)), V(int(111))}, + {V(int(112)), V(uint32(112))}, + {V(uint32(113)), V(uint(113))}, + {V(uint(114)), V(uint32(114))}, + {V(uint32(115)), V(uintptr(115))}, + {V(uintptr(116)), V(uint32(116))}, + {V(uint32(117)), V(float32(117))}, + {V(float32(118)), V(uint32(118))}, + {V(uint32(119)), V(float64(119))}, + {V(float64(120)), V(uint32(120))}, + {V(int64(121)), V(int64(121))}, + {V(int64(122)), V(uint64(122))}, + {V(uint64(123)), V(int64(123))}, + {V(int64(124)), V(int(124))}, + {V(int(125)), V(int64(125))}, + {V(int64(126)), V(uint(126))}, + {V(uint(127)), V(int64(127))}, + {V(int64(128)), V(uintptr(128))}, + {V(uintptr(129)), V(int64(129))}, + {V(int64(130)), V(float32(130))}, + {V(float32(131)), V(int64(131))}, + {V(int64(132)), V(float64(132))}, + {V(float64(133)), V(int64(133))}, + {V(uint64(134)), V(uint64(134))}, + {V(uint64(135)), V(int(135))}, + {V(int(136)), V(uint64(136))}, + {V(uint64(137)), V(uint(137))}, + {V(uint(138)), V(uint64(138))}, + {V(uint64(139)), V(uintptr(139))}, + {V(uintptr(140)), V(uint64(140))}, + {V(uint64(141)), V(float32(141))}, + {V(float32(142)), V(uint64(142))}, + {V(uint64(143)), V(float64(143))}, + {V(float64(144)), V(uint64(144))}, + {V(int(145)), V(int(145))}, + {V(int(146)), V(uint(146))}, + {V(uint(147)), V(int(147))}, + {V(int(148)), V(uintptr(148))}, + {V(uintptr(149)), V(int(149))}, + {V(int(150)), V(float32(150))}, + {V(float32(151)), V(int(151))}, + {V(int(152)), V(float64(152))}, + {V(float64(153)), V(int(153))}, + {V(uint(154)), V(uint(154))}, + {V(uint(155)), V(uintptr(155))}, + {V(uintptr(156)), V(uint(156))}, + {V(uint(157)), V(float32(157))}, + {V(float32(158)), V(uint(158))}, + {V(uint(159)), V(float64(159))}, + {V(float64(160)), V(uint(160))}, + {V(uintptr(161)), V(uintptr(161))}, + {V(uintptr(162)), V(float32(162))}, + {V(float32(163)), V(uintptr(163))}, + {V(uintptr(164)), V(float64(164))}, + {V(float64(165)), V(uintptr(165))}, + {V(float32(166)), V(float32(166))}, + {V(float32(167)), V(float64(167))}, + {V(float64(168)), V(float32(168))}, + {V(float64(169)), V(float64(169))}, + + // truncation + {V(float64(1.5)), V(int(1))}, + + // complex + {V(complex64(1i)), V(complex64(1i))}, + {V(complex64(2i)), V(complex128(2i))}, + {V(complex128(3i)), V(complex64(3i))}, + {V(complex128(4i)), V(complex128(4i))}, + + // string + {V(string("hello")), V(string("hello"))}, + {V(string("bytes1")), V([]byte("bytes1"))}, + {V([]byte("bytes2")), V(string("bytes2"))}, + {V([]byte("bytes3")), V([]byte("bytes3"))}, + {V(string("runes♝")), V([]rune("runes♝"))}, + {V([]rune("runes♕")), V(string("runes♕"))}, + {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V(int('a')), V(string("a"))}, + {V(int8('a')), V(string("a"))}, + {V(int16('a')), V(string("a"))}, + {V(int32('a')), V(string("a"))}, + {V(int64('a')), V(string("a"))}, + {V(uint('a')), V(string("a"))}, + {V(uint8('a')), V(string("a"))}, + {V(uint16('a')), V(string("a"))}, + {V(uint32('a')), V(string("a"))}, + {V(uint64('a')), V(string("a"))}, + {V(uintptr('a')), V(string("a"))}, + {V(int(-1)), V(string("\uFFFD"))}, + {V(int8(-2)), V(string("\uFFFD"))}, + {V(int16(-3)), V(string("\uFFFD"))}, + {V(int32(-4)), V(string("\uFFFD"))}, + {V(int64(-5)), V(string("\uFFFD"))}, + {V(int64(-1 << 32)), V(string("\uFFFD"))}, + {V(int64(1 << 32)), V(string("\uFFFD"))}, + {V(uint(0x110001)), V(string("\uFFFD"))}, + {V(uint32(0x110002)), V(string("\uFFFD"))}, + {V(uint64(0x110003)), V(string("\uFFFD"))}, + {V(uint64(1 << 32)), V(string("\uFFFD"))}, + {V(uintptr(0x110004)), V(string("\uFFFD"))}, + + // named string + {V(MyString("hello")), V(string("hello"))}, + {V(string("hello")), V(MyString("hello"))}, + {V(string("hello")), V(string("hello"))}, + {V(MyString("hello")), V(MyString("hello"))}, + {V(MyString("bytes1")), V([]byte("bytes1"))}, + {V([]byte("bytes2")), V(MyString("bytes2"))}, + {V([]byte("bytes3")), V([]byte("bytes3"))}, + {V(MyString("runes♝")), V([]rune("runes♝"))}, + {V([]rune("runes♕")), V(MyString("runes♕"))}, + {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, + {V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V(int('a')), V(MyString("a"))}, + {V(int8('a')), V(MyString("a"))}, + {V(int16('a')), V(MyString("a"))}, + {V(int32('a')), V(MyString("a"))}, + {V(int64('a')), V(MyString("a"))}, + {V(uint('a')), V(MyString("a"))}, + {V(uint8('a')), V(MyString("a"))}, + {V(uint16('a')), V(MyString("a"))}, + {V(uint32('a')), V(MyString("a"))}, + {V(uint64('a')), V(MyString("a"))}, + {V(uintptr('a')), V(MyString("a"))}, + {V(int(-1)), V(MyString("\uFFFD"))}, + {V(int8(-2)), V(MyString("\uFFFD"))}, + {V(int16(-3)), V(MyString("\uFFFD"))}, + {V(int32(-4)), V(MyString("\uFFFD"))}, + {V(int64(-5)), V(MyString("\uFFFD"))}, + {V(uint(0x110001)), V(MyString("\uFFFD"))}, + {V(uint32(0x110002)), V(MyString("\uFFFD"))}, + {V(uint64(0x110003)), V(MyString("\uFFFD"))}, + {V(uintptr(0x110004)), V(MyString("\uFFFD"))}, + + // named []byte + {V(string("bytes1")), V(MyBytes("bytes1"))}, + {V(MyBytes("bytes2")), V(string("bytes2"))}, + {V(MyBytes("bytes3")), V(MyBytes("bytes3"))}, + {V(MyString("bytes1")), V(MyBytes("bytes1"))}, + {V(MyBytes("bytes2")), V(MyString("bytes2"))}, + + // named []rune + {V(string("runes♝")), V(MyRunes("runes♝"))}, + {V(MyRunes("runes♕")), V(string("runes♕"))}, + {V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, + {V(MyString("runes♝")), V(MyRunes("runes♝"))}, + {V(MyRunes("runes♕")), V(MyString("runes♕"))}, + + // named types and equal underlying types + {V(new(int)), V(new(integer))}, + {V(new(integer)), V(new(int))}, + {V(Empty{}), V(struct{}{})}, + {V(new(Empty)), V(new(struct{}))}, + {V(struct{}{}), V(Empty{})}, + {V(new(struct{})), V(new(Empty))}, + {V(Empty{}), V(Empty{})}, + {V(MyBytes{}), V([]byte{})}, + {V([]byte{}), V(MyBytes{})}, + {V((func())(nil)), V(MyFunc(nil))}, + {V((MyFunc)(nil)), V((func())(nil))}, + + // structs with different tags + {V(struct { + x int `some:"foo"` + }{}), V(struct { + x int `some:"bar"` + }{})}, + + {V(struct { + x int `some:"bar"` + }{}), V(struct { + x int `some:"foo"` + }{})}, + + {V(MyStruct{}), V(struct { + x int `some:"foo"` + }{})}, + + {V(struct { + x int `some:"foo"` + }{}), V(MyStruct{})}, + + {V(MyStruct{}), V(struct { + x int `some:"bar"` + }{})}, + + {V(struct { + x int `some:"bar"` + }{}), V(MyStruct{})}, + + // can convert *byte and *MyByte + {V((*byte)(nil)), V((*MyByte)(nil))}, + {V((*MyByte)(nil)), V((*byte)(nil))}, + + // cannot convert mismatched array sizes + {V([2]byte{}), V([2]byte{})}, + {V([3]byte{}), V([3]byte{})}, + + // cannot convert other instances + {V((**byte)(nil)), V((**byte)(nil))}, + {V((**MyByte)(nil)), V((**MyByte)(nil))}, + {V((chan byte)(nil)), V((chan byte)(nil))}, + {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, + {V(([]byte)(nil)), V(([]byte)(nil))}, + {V(([]MyByte)(nil)), V(([]MyByte)(nil))}, + {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, + {V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))}, + {V((map[byte]int)(nil)), V((map[byte]int)(nil))}, + {V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))}, + {V([2]byte{}), V([2]byte{})}, + {V([2]MyByte{}), V([2]MyByte{})}, + + // other + {V((***int)(nil)), V((***int)(nil))}, + {V((***byte)(nil)), V((***byte)(nil))}, + {V((***int32)(nil)), V((***int32)(nil))}, + {V((***int64)(nil)), V((***int64)(nil))}, + {V((chan byte)(nil)), V((chan byte)(nil))}, + {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, + {V((map[int]bool)(nil)), V((map[int]bool)(nil))}, + {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, + {V((map[uint]bool)(nil)), V((map[uint]bool)(nil))}, + {V([]uint(nil)), V([]uint(nil))}, + {V([]int(nil)), V([]int(nil))}, + {V(new(interface{})), V(new(interface{}))}, + {V(new(io.Reader)), V(new(io.Reader))}, + {V(new(io.Writer)), V(new(io.Writer))}, + + // channels + {V(IntChan(nil)), V((chan<- int)(nil))}, + {V(IntChan(nil)), V((<-chan int)(nil))}, + {V((chan int)(nil)), V(IntChanRecv(nil))}, + {V((chan int)(nil)), V(IntChanSend(nil))}, + {V(IntChanRecv(nil)), V((<-chan int)(nil))}, + {V((<-chan int)(nil)), V(IntChanRecv(nil))}, + {V(IntChanSend(nil)), V((chan<- int)(nil))}, + {V((chan<- int)(nil)), V(IntChanSend(nil))}, + {V(IntChan(nil)), V((chan int)(nil))}, + {V((chan int)(nil)), V(IntChan(nil))}, + {V((chan int)(nil)), V((<-chan int)(nil))}, + {V((chan int)(nil)), V((chan<- int)(nil))}, + {V(BytesChan(nil)), V((chan<- []byte)(nil))}, + {V(BytesChan(nil)), V((<-chan []byte)(nil))}, + {V((chan []byte)(nil)), V(BytesChanRecv(nil))}, + {V((chan []byte)(nil)), V(BytesChanSend(nil))}, + {V(BytesChanRecv(nil)), V((<-chan []byte)(nil))}, + {V((<-chan []byte)(nil)), V(BytesChanRecv(nil))}, + {V(BytesChanSend(nil)), V((chan<- []byte)(nil))}, + {V((chan<- []byte)(nil)), V(BytesChanSend(nil))}, + {V(BytesChan(nil)), V((chan []byte)(nil))}, + {V((chan []byte)(nil)), V(BytesChan(nil))}, + {V((chan []byte)(nil)), V((<-chan []byte)(nil))}, + {V((chan []byte)(nil)), V((chan<- []byte)(nil))}, + + // cannot convert other instances (channels) + {V(IntChan(nil)), V(IntChan(nil))}, + {V(IntChanRecv(nil)), V(IntChanRecv(nil))}, + {V(IntChanSend(nil)), V(IntChanSend(nil))}, + {V(BytesChan(nil)), V(BytesChan(nil))}, + {V(BytesChanRecv(nil)), V(BytesChanRecv(nil))}, + {V(BytesChanSend(nil)), V(BytesChanSend(nil))}, + + // interfaces + {V(int(1)), EmptyInterfaceV(int(1))}, + {V(string("hello")), EmptyInterfaceV(string("hello"))}, + {V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, + {ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, + {V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))}, +} + +func TestConvert(t *testing.T) { + canConvert := map[[2]Type]bool{} + all := map[Type]bool{} + + for _, tt := range convertTests { + t1 := tt.in.Type() + if !t1.ConvertibleTo(t1) { + t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1) + continue + } + + t2 := tt.out.Type() + if !t1.ConvertibleTo(t2) { + t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2) + continue + } + + all[t1] = true + all[t2] = true + canConvert[[2]Type{t1, t2}] = true + + // vout1 represents the in value converted to the in type. + v1 := tt.in + vout1 := v1.Convert(t1) + out1 := vout1.Interface() + if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) { + t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface()) + } + + // vout2 represents the in value converted to the out type. + vout2 := v1.Convert(t2) + out2 := vout2.Interface() + if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) { + t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface()) + } + + // vout3 represents a new value of the out type, set to vout2. This makes + // sure the converted value vout2 is really usable as a regular value. + vout3 := New(t2).Elem() + vout3.Set(vout2) + out3 := vout3.Interface() + if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) { + t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface()) + } + + if IsRO(v1) { + t.Errorf("table entry %v is RO, should not be", v1) + } + if IsRO(vout1) { + t.Errorf("self-conversion output %v is RO, should not be", vout1) + } + if IsRO(vout2) { + t.Errorf("conversion output %v is RO, should not be", vout2) + } + if IsRO(vout3) { + t.Errorf("set(conversion output) %v is RO, should not be", vout3) + } + if !IsRO(MakeRO(v1).Convert(t1)) { + t.Errorf("RO self-conversion output %v is not RO, should be", v1) + } + if !IsRO(MakeRO(v1).Convert(t2)) { + t.Errorf("RO conversion output %v is not RO, should be", v1) + } + } + + // Assume that of all the types we saw during the tests, + // if there wasn't an explicit entry for a conversion between + // a pair of types, then it's not to be allowed. This checks for + // things like 'int64' converting to '*int'. + for t1 := range all { + for t2 := range all { + expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0 + if ok := t1.ConvertibleTo(t2); ok != expectOK { + t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK) + } + } + } +} + +var gFloat32 float32 + +func TestConvertNaNs(t *testing.T) { + const snan uint32 = 0x7f800001 + type myFloat32 float32 + x := V(myFloat32(math.Float32frombits(snan))) + y := x.Convert(TypeOf(float32(0))) + z := y.Interface().(float32) + if got := math.Float32bits(z); got != snan { + t.Errorf("signaling nan conversion got %x, want %x", got, snan) + } +} + +type ComparableStruct struct { + X int +} + +type NonComparableStruct struct { + X int + Y map[string]int +} + +var comparableTests = []struct { + typ Type + ok bool +}{ + {TypeOf(1), true}, + {TypeOf("hello"), true}, + {TypeOf(new(byte)), true}, + {TypeOf((func())(nil)), false}, + {TypeOf([]byte{}), false}, + {TypeOf(map[string]int{}), false}, + {TypeOf(make(chan int)), true}, + {TypeOf(1.5), true}, + {TypeOf(false), true}, + {TypeOf(1i), true}, + {TypeOf(ComparableStruct{}), true}, + {TypeOf(NonComparableStruct{}), false}, + {TypeOf([10]map[string]int{}), false}, + {TypeOf([10]string{}), true}, + {TypeOf(new(interface{})).Elem(), true}, +} + +func TestComparable(t *testing.T) { + for _, tt := range comparableTests { + if ok := tt.typ.Comparable(); ok != tt.ok { + t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok) + } + } +} + +func TestOverflow(t *testing.T) { + if ovf := V(float64(0)).OverflowFloat(1e300); ovf { + t.Errorf("%v wrongly overflows float64", 1e300) + } + + maxFloat32 := float64((1<<24 - 1) << (127 - 23)) + if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf { + t.Errorf("%v wrongly overflows float32", maxFloat32) + } + ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52)) + if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", ovfFloat32) + } + if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", -ovfFloat32) + } + + maxInt32 := int64(0x7fffffff) + if ovf := V(int32(0)).OverflowInt(maxInt32); ovf { + t.Errorf("%v wrongly overflows int32", maxInt32) + } + if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf { + t.Errorf("%v wrongly overflows int32", -int64(1)<<31) + } + ovfInt32 := int64(1 << 31) + if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf { + t.Errorf("%v should overflow int32", ovfInt32) + } + + maxUint32 := uint64(0xffffffff) + if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf { + t.Errorf("%v wrongly overflows uint32", maxUint32) + } + ovfUint32 := uint64(1 << 32) + if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf { + t.Errorf("%v should overflow uint32", ovfUint32) + } +} + +func checkSameType(t *testing.T, x Type, y interface{}) { + if x != TypeOf(y) || TypeOf(Zero(x).Interface()) != TypeOf(y) { + t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y)) + } +} + +func TestArrayOf(t *testing.T) { + // check construction and use of type not in binary + tests := []struct { + n int + value func(i int) interface{} + comparable bool + want string + }{ + { + n: 0, + value: func(i int) interface{} { type Tint int; return Tint(i) }, + comparable: true, + want: "[]", + }, + { + n: 10, + value: func(i int) interface{} { type Tint int; return Tint(i) }, + comparable: true, + want: "[0 1 2 3 4 5 6 7 8 9]", + }, + { + n: 10, + value: func(i int) interface{} { type Tfloat float64; return Tfloat(i) }, + comparable: true, + want: "[0 1 2 3 4 5 6 7 8 9]", + }, + { + n: 10, + value: func(i int) interface{} { type Tstring string; return Tstring(strconv.Itoa(i)) }, + comparable: true, + want: "[0 1 2 3 4 5 6 7 8 9]", + }, + { + n: 10, + value: func(i int) interface{} { type Tstruct struct{ V int }; return Tstruct{i} }, + comparable: true, + want: "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]", + }, + { + n: 10, + value: func(i int) interface{} { type Tint int; return []Tint{Tint(i)} }, + comparable: false, + want: "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]", + }, + { + n: 10, + value: func(i int) interface{} { type Tint int; return [1]Tint{Tint(i)} }, + comparable: true, + want: "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]", + }, + { + n: 10, + value: func(i int) interface{} { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} }, + comparable: true, + want: "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]", + }, + { + n: 10, + value: func(i int) interface{} { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} }, + comparable: false, + want: "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]", + }, + { + n: 10, + value: func(i int) interface{} { type TstructUV struct{ U, V int }; return TstructUV{i, i} }, + comparable: true, + want: "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]", + }, + { + n: 10, + value: func(i int) interface{} { + type TstructUV struct { + U int + V float64 + } + return TstructUV{i, float64(i)} + }, + comparable: true, + want: "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]", + }, + } + + for _, table := range tests { + at := ArrayOf(table.n, TypeOf(table.value(0))) + v := New(at).Elem() + vok := New(at).Elem() + vnot := New(at).Elem() + for i := 0; i < v.Len(); i++ { + v.Index(i).Set(ValueOf(table.value(i))) + vok.Index(i).Set(ValueOf(table.value(i))) + j := i + if i+1 == v.Len() { + j = i + 1 + } + vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element + } + s := fmt.Sprint(v.Interface()) + if s != table.want { + t.Errorf("constructed array = %s, want %s", s, table.want) + } + + if table.comparable != at.Comparable() { + t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable) + } + if table.comparable { + if table.n > 0 { + if DeepEqual(vnot.Interface(), v.Interface()) { + t.Errorf( + "arrays (%#v) compare ok (but should not)", + v.Interface(), + ) + } + } + if !DeepEqual(vok.Interface(), v.Interface()) { + t.Errorf( + "arrays (%#v) compare NOT-ok (but should)", + v.Interface(), + ) + } + } + } + + // check that type already in binary is found + type T int + checkSameType(t, ArrayOf(5, TypeOf(T(1))), [5]T{}) +} + +func TestArrayOfGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := New(ArrayOf(n, tt)).Elem() + for j := 0; j < v.Len(); j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Index(j).Set(ValueOf(p).Convert(tt)) + } + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi) + for j := 0; j < v.Len(); j++ { + k := v.Index(j).Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestArrayOfAlg(t *testing.T) { + at := ArrayOf(6, TypeOf(byte(0))) + v1 := New(at).Elem() + v2 := New(at).Elem() + if v1.Interface() != v1.Interface() { + t.Errorf("constructed array %v not equal to itself", v1.Interface()) + } + v1.Index(5).Set(ValueOf(byte(1))) + if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 { + t.Errorf("constructed arrays %v and %v should not be equal", i1, i2) + } + + at = ArrayOf(6, TypeOf([]int(nil))) + v1 = New(at).Elem() + shouldPanic("", func() { _ = v1.Interface() == v1.Interface() }) +} + +func TestArrayOfGenericAlg(t *testing.T) { + at1 := ArrayOf(5, TypeOf(string(""))) + at := ArrayOf(6, at1) + v1 := New(at).Elem() + v2 := New(at).Elem() + if v1.Interface() != v1.Interface() { + t.Errorf("constructed array %v not equal to itself", v1.Interface()) + } + + v1.Index(0).Index(0).Set(ValueOf("abc")) + v2.Index(0).Index(0).Set(ValueOf("efg")) + if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 { + t.Errorf("constructed arrays %v and %v should not be equal", i1, i2) + } + + v1.Index(0).Index(0).Set(ValueOf("abc")) + v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3])) + if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 { + t.Errorf("constructed arrays %v and %v should be equal", i1, i2) + } + + // Test hash + m := MakeMap(MapOf(at, TypeOf(int(0)))) + m.SetMapIndex(v1, ValueOf(1)) + if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() { + t.Errorf("constructed arrays %v and %v have different hashes", i1, i2) + } +} + +func TestArrayOfDirectIface(t *testing.T) { + { + type T [1]*byte + i1 := Zero(TypeOf(T{})).Interface() + v1 := ValueOf(&i1).Elem() + p1 := v1.InterfaceData()[1] + + i2 := Zero(ArrayOf(1, PtrTo(TypeOf(int8(0))))).Interface() + v2 := ValueOf(&i2).Elem() + p2 := v2.InterfaceData()[1] + + if p1 != 0 { + t.Errorf("got p1=%v. want=%v", p1, nil) + } + + if p2 != 0 { + t.Errorf("got p2=%v. want=%v", p2, nil) + } + } + { + type T [0]*byte + i1 := Zero(TypeOf(T{})).Interface() + v1 := ValueOf(&i1).Elem() + p1 := v1.InterfaceData()[1] + + i2 := Zero(ArrayOf(0, PtrTo(TypeOf(int8(0))))).Interface() + v2 := ValueOf(&i2).Elem() + p2 := v2.InterfaceData()[1] + + if p1 == 0 { + t.Errorf("got p1=%v. want=not-%v", p1, nil) + } + + if p2 == 0 { + t.Errorf("got p2=%v. want=not-%v", p2, nil) + } + } +} + +func TestSliceOf(t *testing.T) { + // check construction and use of type not in binary + type T int + st := SliceOf(TypeOf(T(1))) + if got, want := st.String(), "[]reflect_test.T"; got != want { + t.Errorf("SliceOf(T(1)).String()=%q, want %q", got, want) + } + v := MakeSlice(st, 10, 10) + runtime.GC() + for i := 0; i < v.Len(); i++ { + v.Index(i).Set(ValueOf(T(i))) + runtime.GC() + } + s := fmt.Sprint(v.Interface()) + want := "[0 1 2 3 4 5 6 7 8 9]" + if s != want { + t.Errorf("constructed slice = %s, want %s", s, want) + } + + // check that type already in binary is found + type T1 int + checkSameType(t, SliceOf(TypeOf(T1(1))), []T1{}) +} + +func TestSliceOverflow(t *testing.T) { + // check that MakeSlice panics when size of slice overflows uint + const S = 1e6 + s := uint(S) + l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1 + if l*s >= s { + t.Fatal("slice size does not overflow") + } + var x [S]byte + st := SliceOf(TypeOf(x)) + defer func() { + err := recover() + if err == nil { + t.Fatal("slice overflow does not panic") + } + }() + MakeSlice(st, int(l), int(l)) +} + +func TestSliceOfGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + st := SliceOf(tt) + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeSlice(st, n, n) + for j := 0; j < v.Len(); j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Index(j).Set(ValueOf(p).Convert(tt)) + } + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi) + for j := 0; j < v.Len(); j++ { + k := v.Index(j).Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestStructOfFieldName(t *testing.T) { + // invalid field name "1nvalid" + shouldPanic("has invalid name", func() { + StructOf([]StructField{ + {Name: "Valid", Type: TypeOf("")}, + {Name: "1nvalid", Type: TypeOf("")}, + }) + }) + + // invalid field name "+" + shouldPanic("has invalid name", func() { + StructOf([]StructField{ + {Name: "Val1d", Type: TypeOf("")}, + {Name: "+", Type: TypeOf("")}, + }) + }) + + // no field name + shouldPanic("has no name", func() { + StructOf([]StructField{ + {Name: "", Type: TypeOf("")}, + }) + }) + + // verify creation of a struct with valid struct fields + validFields := []StructField{ + { + Name: "φ", + Type: TypeOf(""), + }, + { + Name: "ValidName", + Type: TypeOf(""), + }, + { + Name: "Val1dNam5", + Type: TypeOf(""), + }, + } + + validStruct := StructOf(validFields) + + const structStr = `struct { φ string; ValidName string; Val1dNam5 string }` + if got, want := validStruct.String(), structStr; got != want { + t.Errorf("StructOf(validFields).String()=%q, want %q", got, want) + } +} + +func TestStructOf(t *testing.T) { + // check construction and use of type not in binary + fields := []StructField{ + { + Name: "S", + Tag: "s", + Type: TypeOf(""), + }, + { + Name: "X", + Tag: "x", + Type: TypeOf(byte(0)), + }, + { + Name: "Y", + Type: TypeOf(uint64(0)), + }, + { + Name: "Z", + Type: TypeOf([3]uint16{}), + }, + } + + st := StructOf(fields) + v := New(st).Elem() + runtime.GC() + v.FieldByName("X").Set(ValueOf(byte(2))) + v.FieldByIndex([]int{1}).Set(ValueOf(byte(1))) + runtime.GC() + + s := fmt.Sprint(v.Interface()) + want := `{ 1 0 [0 0 0]}` + if s != want { + t.Errorf("constructed struct = %s, want %s", s, want) + } + const stStr = `struct { S string "s"; X uint8 "x"; Y uint64; Z [3]uint16 }` + if got, want := st.String(), stStr; got != want { + t.Errorf("StructOf(fields).String()=%q, want %q", got, want) + } + + // check the size, alignment and field offsets + stt := TypeOf(struct { + String string + X byte + Y uint64 + Z [3]uint16 + }{}) + if st.Size() != stt.Size() { + t.Errorf("constructed struct size = %v, want %v", st.Size(), stt.Size()) + } + if st.Align() != stt.Align() { + t.Errorf("constructed struct align = %v, want %v", st.Align(), stt.Align()) + } + if st.FieldAlign() != stt.FieldAlign() { + t.Errorf("constructed struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign()) + } + for i := 0; i < st.NumField(); i++ { + o1 := st.Field(i).Offset + o2 := stt.Field(i).Offset + if o1 != o2 { + t.Errorf("constructed struct field %v offset = %v, want %v", i, o1, o2) + } + } + + // Check size and alignment with a trailing zero-sized field. + st = StructOf([]StructField{ + { + Name: "F1", + Type: TypeOf(byte(0)), + }, + { + Name: "F2", + Type: TypeOf([0]*byte{}), + }, + }) + stt = TypeOf(struct { + G1 byte + G2 [0]*byte + }{}) + if st.Size() != stt.Size() { + t.Errorf("constructed zero-padded struct size = %v, want %v", st.Size(), stt.Size()) + } + if st.Align() != stt.Align() { + t.Errorf("constructed zero-padded struct align = %v, want %v", st.Align(), stt.Align()) + } + if st.FieldAlign() != stt.FieldAlign() { + t.Errorf("constructed zero-padded struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign()) + } + for i := 0; i < st.NumField(); i++ { + o1 := st.Field(i).Offset + o2 := stt.Field(i).Offset + if o1 != o2 { + t.Errorf("constructed zero-padded struct field %v offset = %v, want %v", i, o1, o2) + } + } + + // check duplicate names + shouldPanic("duplicate field", func() { + StructOf([]StructField{ + {Name: "string", PkgPath: "p", Type: TypeOf("")}, + {Name: "string", PkgPath: "p", Type: TypeOf("")}, + }) + }) + shouldPanic("has no name", func() { + StructOf([]StructField{ + {Type: TypeOf("")}, + {Name: "string", PkgPath: "p", Type: TypeOf("")}, + }) + }) + shouldPanic("has no name", func() { + StructOf([]StructField{ + {Type: TypeOf("")}, + {Type: TypeOf("")}, + }) + }) + // check that type already in binary is found + checkSameType(t, StructOf(fields[2:3]), struct{ Y uint64 }{}) + + // gccgo used to fail this test. + type structFieldType interface{} + checkSameType(t, + StructOf([]StructField{ + { + Name: "F", + Type: TypeOf((*structFieldType)(nil)).Elem(), + }, + }), + struct{ F structFieldType }{}) +} + +func TestStructOfExportRules(t *testing.T) { + type S1 struct{} + type s2 struct{} + type ΦType struct{} + type φType struct{} + + testPanic := func(i int, mustPanic bool, f func()) { + defer func() { + err := recover() + if err == nil && mustPanic { + t.Errorf("test-%d did not panic", i) + } + if err != nil && !mustPanic { + t.Errorf("test-%d panicked: %v\n", i, err) + } + }() + f() + } + + tests := []struct { + field StructField + mustPanic bool + exported bool + }{ + { + field: StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{})}, + exported: true, + }, + { + field: StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil))}, + exported: true, + }, + { + field: StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{})}, + mustPanic: true, + }, + { + field: StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil))}, + mustPanic: true, + }, + { + field: StructField{Name: "Name", Type: nil, PkgPath: ""}, + mustPanic: true, + }, + { + field: StructField{Name: "", Type: TypeOf(S1{}), PkgPath: ""}, + mustPanic: true, + }, + { + field: StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{}), PkgPath: "other/pkg"}, + mustPanic: true, + }, + { + field: StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"}, + mustPanic: true, + }, + { + field: StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{}), PkgPath: "other/pkg"}, + mustPanic: true, + }, + { + field: StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"}, + mustPanic: true, + }, + { + field: StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "S", Type: TypeOf(S1{})}, + exported: true, + }, + { + field: StructField{Name: "S", Type: TypeOf((*S1)(nil))}, + exported: true, + }, + { + field: StructField{Name: "S", Type: TypeOf(s2{})}, + exported: true, + }, + { + field: StructField{Name: "S", Type: TypeOf((*s2)(nil))}, + exported: true, + }, + { + field: StructField{Name: "s", Type: TypeOf(S1{})}, + mustPanic: true, + }, + { + field: StructField{Name: "s", Type: TypeOf((*S1)(nil))}, + mustPanic: true, + }, + { + field: StructField{Name: "s", Type: TypeOf(s2{})}, + mustPanic: true, + }, + { + field: StructField{Name: "s", Type: TypeOf((*s2)(nil))}, + mustPanic: true, + }, + { + field: StructField{Name: "s", Type: TypeOf(S1{}), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "s", Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "s", Type: TypeOf(s2{}), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "s", Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"}, + }, + { + field: StructField{Name: "", Type: TypeOf(ΦType{})}, + mustPanic: true, + }, + { + field: StructField{Name: "", Type: TypeOf(φType{})}, + mustPanic: true, + }, + { + field: StructField{Name: "Φ", Type: TypeOf(0)}, + exported: true, + }, + { + field: StructField{Name: "φ", Type: TypeOf(0)}, + exported: false, + }, + } + + for i, test := range tests { + testPanic(i, test.mustPanic, func() { + typ := StructOf([]StructField{test.field}) + if typ == nil { + t.Errorf("test-%d: error creating struct type", i) + return + } + field := typ.Field(0) + n := field.Name + if n == "" { + panic("field.Name must not be empty") + } + exported := token.IsExported(n) + if exported != test.exported { + t.Errorf("test-%d: got exported=%v want exported=%v", i, exported, test.exported) + } + if field.PkgPath != test.field.PkgPath { + t.Errorf("test-%d: got PkgPath=%q want pkgPath=%q", i, field.PkgPath, test.field.PkgPath) + } + }) + } +} + +func TestStructOfGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + fields := []StructField{ + {Name: "X", Type: tt}, + {Name: "Y", Type: tt}, + } + st := StructOf(fields) + + const n = 10000 + var x []interface{} + for i := 0; i < n; i++ { + v := New(st).Elem() + for j := 0; j < v.NumField(); j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Field(j).Set(ValueOf(p).Convert(tt)) + } + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi) + for j := 0; j < v.NumField(); j++ { + k := v.Field(j).Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d].%c = %d, want %d", i, "XY"[j], k, i*n+j) + } + } + } +} + +func TestStructOfAlg(t *testing.T) { + st := StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf(int(0))}}) + v1 := New(st).Elem() + v2 := New(st).Elem() + if !DeepEqual(v1.Interface(), v1.Interface()) { + t.Errorf("constructed struct %v not equal to itself", v1.Interface()) + } + v1.FieldByName("X").Set(ValueOf(int(1))) + if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) { + t.Errorf("constructed structs %v and %v should not be equal", i1, i2) + } + + st = StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf([]int(nil))}}) + v1 = New(st).Elem() + shouldPanic("", func() { _ = v1.Interface() == v1.Interface() }) +} + +func TestStructOfGenericAlg(t *testing.T) { + st1 := StructOf([]StructField{ + {Name: "X", Tag: "x", Type: TypeOf(int64(0))}, + {Name: "Y", Type: TypeOf(string(""))}, + }) + st := StructOf([]StructField{ + {Name: "S0", Type: st1}, + {Name: "S1", Type: st1}, + }) + + tests := []struct { + rt Type + idx []int + }{ + { + rt: st, + idx: []int{0, 1}, + }, + { + rt: st1, + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf([0]int{})}, + {Name: "YY", Type: TypeOf("")}, + }, + ), + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf([0]int{})}, + {Name: "YY", Type: TypeOf("")}, + {Name: "ZZ", Type: TypeOf([2]int{})}, + }, + ), + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf([1]int{})}, + {Name: "YY", Type: TypeOf("")}, + }, + ), + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf([1]int{})}, + {Name: "YY", Type: TypeOf("")}, + {Name: "ZZ", Type: TypeOf([1]int{})}, + }, + ), + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf([2]int{})}, + {Name: "YY", Type: TypeOf("")}, + {Name: "ZZ", Type: TypeOf([2]int{})}, + }, + ), + idx: []int{1}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf(int64(0))}, + {Name: "YY", Type: TypeOf(byte(0))}, + {Name: "ZZ", Type: TypeOf("")}, + }, + ), + idx: []int{2}, + }, + { + rt: StructOf( + []StructField{ + {Name: "XX", Type: TypeOf(int64(0))}, + {Name: "YY", Type: TypeOf(int64(0))}, + {Name: "ZZ", Type: TypeOf("")}, + {Name: "AA", Type: TypeOf([1]int64{})}, + }, + ), + idx: []int{2}, + }, + } + + for _, table := range tests { + v1 := New(table.rt).Elem() + v2 := New(table.rt).Elem() + + if !DeepEqual(v1.Interface(), v1.Interface()) { + t.Errorf("constructed struct %v not equal to itself", v1.Interface()) + } + + v1.FieldByIndex(table.idx).Set(ValueOf("abc")) + v2.FieldByIndex(table.idx).Set(ValueOf("def")) + if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) { + t.Errorf("constructed structs %v and %v should not be equal", i1, i2) + } + + abc := "abc" + v1.FieldByIndex(table.idx).Set(ValueOf(abc)) + val := "+" + abc + "-" + v2.FieldByIndex(table.idx).Set(ValueOf(val[1:4])) + if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) { + t.Errorf("constructed structs %v and %v should be equal", i1, i2) + } + + // Test hash + m := MakeMap(MapOf(table.rt, TypeOf(int(0)))) + m.SetMapIndex(v1, ValueOf(1)) + if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() { + t.Errorf("constructed structs %#v and %#v have different hashes", i1, i2) + } + + v2.FieldByIndex(table.idx).Set(ValueOf("abc")) + if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) { + t.Errorf("constructed structs %v and %v should be equal", i1, i2) + } + + if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() { + t.Errorf("constructed structs %v and %v have different hashes", i1, i2) + } + } +} + +func TestStructOfDirectIface(t *testing.T) { + { + type T struct{ X [1]*byte } + i1 := Zero(TypeOf(T{})).Interface() + v1 := ValueOf(&i1).Elem() + p1 := v1.InterfaceData()[1] + + i2 := Zero(StructOf([]StructField{ + { + Name: "X", + Type: ArrayOf(1, TypeOf((*int8)(nil))), + }, + })).Interface() + v2 := ValueOf(&i2).Elem() + p2 := v2.InterfaceData()[1] + + if p1 != 0 { + t.Errorf("got p1=%v. want=%v", p1, nil) + } + + if p2 != 0 { + t.Errorf("got p2=%v. want=%v", p2, nil) + } + } + { + type T struct{ X [0]*byte } + i1 := Zero(TypeOf(T{})).Interface() + v1 := ValueOf(&i1).Elem() + p1 := v1.InterfaceData()[1] + + i2 := Zero(StructOf([]StructField{ + { + Name: "X", + Type: ArrayOf(0, TypeOf((*int8)(nil))), + }, + })).Interface() + v2 := ValueOf(&i2).Elem() + p2 := v2.InterfaceData()[1] + + if p1 == 0 { + t.Errorf("got p1=%v. want=not-%v", p1, nil) + } + + if p2 == 0 { + t.Errorf("got p2=%v. want=not-%v", p2, nil) + } + } +} + +type StructI int + +func (i StructI) Get() int { return int(i) } + +type StructIPtr int + +func (i *StructIPtr) Get() int { return int(*i) } +func (i *StructIPtr) Set(v int) { *(*int)(i) = v } + +type SettableStruct struct { + SettableField int +} + +func (p *SettableStruct) Set(v int) { p.SettableField = v } + +type SettablePointer struct { + SettableField *int +} + +func (p *SettablePointer) Set(v int) { *p.SettableField = v } + +func TestStructOfWithInterface(t *testing.T) { + const want = 42 + type Iface interface { + Get() int + } + type IfaceSet interface { + Set(int) + } + tests := []struct { + name string + typ Type + val Value + impl bool + }{ + { + name: "StructI", + typ: TypeOf(StructI(want)), + val: ValueOf(StructI(want)), + impl: true, + }, + { + name: "StructI", + typ: PtrTo(TypeOf(StructI(want))), + val: ValueOf(func() interface{} { + v := StructI(want) + return &v + }()), + impl: true, + }, + { + name: "StructIPtr", + typ: PtrTo(TypeOf(StructIPtr(want))), + val: ValueOf(func() interface{} { + v := StructIPtr(want) + return &v + }()), + impl: true, + }, + { + name: "StructIPtr", + typ: TypeOf(StructIPtr(want)), + val: ValueOf(StructIPtr(want)), + impl: false, + }, + // { + // typ: TypeOf((*Iface)(nil)).Elem(), // FIXME(sbinet): fix method.ifn/tfn + // val: ValueOf(StructI(want)), + // impl: true, + // }, + } + + for i, table := range tests { + for j := 0; j < 2; j++ { + var fields []StructField + if j == 1 { + fields = append(fields, StructField{ + Name: "Dummy", + PkgPath: "", + Type: TypeOf(int(0)), + }) + } + fields = append(fields, StructField{ + Name: table.name, + Anonymous: true, + PkgPath: "", + Type: table.typ, + }) + + // We currently do not correctly implement methods + // for embedded fields other than the first. + // Therefore, for now, we expect those methods + // to not exist. See issues 15924 and 20824. + // When those issues are fixed, this test of panic + // should be removed. + if j == 1 && table.impl { + func() { + defer func() { + if err := recover(); err == nil { + t.Errorf("test-%d-%d did not panic", i, j) + } + }() + _ = StructOf(fields) + }() + continue + } + + rt := StructOf(fields) + rv := New(rt).Elem() + rv.Field(j).Set(table.val) + + if _, ok := rv.Interface().(Iface); ok != table.impl { + if table.impl { + t.Errorf("test-%d-%d: type=%v fails to implement Iface.\n", i, j, table.typ) + } else { + t.Errorf("test-%d-%d: type=%v should NOT implement Iface\n", i, j, table.typ) + } + continue + } + + if !table.impl { + continue + } + + v := rv.Interface().(Iface).Get() + if v != want { + t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, v, want) + } + + fct := rv.MethodByName("Get") + out := fct.Call(nil) + if !DeepEqual(out[0].Interface(), want) { + t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, out[0].Interface(), want) + } + } + } + + // Test an embedded nil pointer with pointer methods. + fields := []StructField{{ + Name: "StructIPtr", + Anonymous: true, + Type: PtrTo(TypeOf(StructIPtr(want))), + }} + rt := StructOf(fields) + rv := New(rt).Elem() + // This should panic since the pointer is nil. + shouldPanic("", func() { + rv.Interface().(IfaceSet).Set(want) + }) + + // Test an embedded nil pointer to a struct with pointer methods. + + fields = []StructField{{ + Name: "SettableStruct", + Anonymous: true, + Type: PtrTo(TypeOf(SettableStruct{})), + }} + rt = StructOf(fields) + rv = New(rt).Elem() + // This should panic since the pointer is nil. + shouldPanic("", func() { + rv.Interface().(IfaceSet).Set(want) + }) + + // The behavior is different if there is a second field, + // since now an interface value holds a pointer to the struct + // rather than just holding a copy of the struct. + fields = []StructField{ + { + Name: "SettableStruct", + Anonymous: true, + Type: PtrTo(TypeOf(SettableStruct{})), + }, + { + Name: "EmptyStruct", + Anonymous: true, + Type: StructOf(nil), + }, + } + // With the current implementation this is expected to panic. + // Ideally it should work and we should be able to see a panic + // if we call the Set method. + shouldPanic("", func() { + StructOf(fields) + }) + + // Embed a field that can be stored directly in an interface, + // with a second field. + fields = []StructField{ + { + Name: "SettablePointer", + Anonymous: true, + Type: TypeOf(SettablePointer{}), + }, + { + Name: "EmptyStruct", + Anonymous: true, + Type: StructOf(nil), + }, + } + // With the current implementation this is expected to panic. + // Ideally it should work and we should be able to call the + // Set and Get methods. + shouldPanic("", func() { + StructOf(fields) + }) +} + +func TestStructOfTooManyFields(t *testing.T) { + // Bug Fix: #25402 - this should not panic + tt := StructOf([]StructField{ + {Name: "Time", Type: TypeOf(time.Time{}), Anonymous: true}, + }) + + if _, present := tt.MethodByName("After"); !present { + t.Errorf("Expected method `After` to be found") + } +} + +func TestStructOfDifferentPkgPath(t *testing.T) { + fields := []StructField{ + { + Name: "f1", + PkgPath: "p1", + Type: TypeOf(int(0)), + }, + { + Name: "f2", + PkgPath: "p2", + Type: TypeOf(int(0)), + }, + } + shouldPanic("different PkgPath", func() { + StructOf(fields) + }) +} + +func TestChanOf(t *testing.T) { + // check construction and use of type not in binary + type T string + ct := ChanOf(BothDir, TypeOf(T(""))) + v := MakeChan(ct, 2) + runtime.GC() + v.Send(ValueOf(T("hello"))) + runtime.GC() + v.Send(ValueOf(T("world"))) + runtime.GC() + + sv1, _ := v.Recv() + sv2, _ := v.Recv() + s1 := sv1.String() + s2 := sv2.String() + if s1 != "hello" || s2 != "world" { + t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world") + } + + // check that type already in binary is found + type T1 int + checkSameType(t, ChanOf(BothDir, TypeOf(T1(1))), (chan T1)(nil)) + + // Check arrow token association in undefined chan types. + var left chan<- chan T + var right chan (<-chan T) + tLeft := ChanOf(SendDir, ChanOf(BothDir, TypeOf(T("")))) + tRight := ChanOf(BothDir, ChanOf(RecvDir, TypeOf(T("")))) + if tLeft != TypeOf(left) { + t.Errorf("chan<-chan: have %s, want %T", tLeft, left) + } + if tRight != TypeOf(right) { + t.Errorf("chan<-chan: have %s, want %T", tRight, right) + } +} + +func TestChanOfDir(t *testing.T) { + // check construction and use of type not in binary + type T string + crt := ChanOf(RecvDir, TypeOf(T(""))) + cst := ChanOf(SendDir, TypeOf(T(""))) + + // check that type already in binary is found + type T1 int + checkSameType(t, ChanOf(RecvDir, TypeOf(T1(1))), (<-chan T1)(nil)) + checkSameType(t, ChanOf(SendDir, TypeOf(T1(1))), (chan<- T1)(nil)) + + // check String form of ChanDir + if crt.ChanDir().String() != "<-chan" { + t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan") + } + if cst.ChanDir().String() != "chan<-" { + t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-") + } +} + +func TestChanOfGC(t *testing.T) { + done := make(chan bool, 1) + go func() { + select { + case <-done: + case <-time.After(5 * time.Second): + panic("deadlock in TestChanOfGC") + } + }() + + defer func() { + done <- true + }() + + type T *uintptr + tt := TypeOf(T(nil)) + ct := ChanOf(BothDir, tt) + + // NOTE: The garbage collector handles allocated channels specially, + // so we have to save pointers to channels in x; the pointer code will + // use the gc info in the newly constructed chan type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeChan(ct, n) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Send(ValueOf(p).Convert(tt)) + } + pv := New(ct) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + for j := 0; j < n; j++ { + pv, _ := v.Recv() + k := pv.Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestMapOf(t *testing.T) { + // check construction and use of type not in binary + type K string + type V float64 + + v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0)))) + runtime.GC() + v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1))) + runtime.GC() + + s := fmt.Sprint(v.Interface()) + want := "map[a:1]" + if s != want { + t.Errorf("constructed map = %s, want %s", s, want) + } + + // check that type already in binary is found + checkSameType(t, MapOf(TypeOf(V(0)), TypeOf(K(""))), map[V]K(nil)) + + // check that invalid key type panics + shouldPanic("invalid key type", func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) }) +} + +func TestMapOfGCKeys(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + mt := MapOf(tt, TypeOf(false)) + + // NOTE: The garbage collector handles allocated maps specially, + // so we have to save pointers to maps in x; the pointer code will + // use the gc info in the newly constructed map type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeMap(mt) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true)) + } + pv := New(mt) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + var out []int + for _, kv := range v.MapKeys() { + out = append(out, int(kv.Elem().Interface().(uintptr))) + } + sort.Ints(out) + for j, k := range out { + if k != i*n+j { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestMapOfGCValues(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + mt := MapOf(TypeOf(1), tt) + + // NOTE: The garbage collector handles allocated maps specially, + // so we have to save pointers to maps in x; the pointer code will + // use the gc info in the newly constructed map type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeMap(mt) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt)) + } + pv := New(mt) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + for j := 0; j < n; j++ { + k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr) + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestTypelinksSorted(t *testing.T) { + var last string + for i, n := range TypeLinks() { + if n < last { + t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i) + } + last = n + } +} + +func TestFuncOf(t *testing.T) { + // check construction and use of type not in binary + type K string + type V float64 + + fn := func(args []Value) []Value { + if len(args) != 1 { + t.Errorf("args == %v, want exactly one arg", args) + } else if args[0].Type() != TypeOf(K("")) { + t.Errorf("args[0] is type %v, want %v", args[0].Type(), TypeOf(K(""))) + } else if args[0].String() != "gopher" { + t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher") + } + return []Value{ValueOf(V(3.14))} + } + v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn) + + outs := v.Call([]Value{ValueOf(K("gopher"))}) + if len(outs) != 1 { + t.Fatalf("v.Call returned %v, want exactly one result", outs) + } else if outs[0].Type() != TypeOf(V(0)) { + t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type(), TypeOf(V(0))) + } + f := outs[0].Float() + if f != 3.14 { + t.Errorf("constructed func returned %f, want %f", f, 3.14) + } + + // check that types already in binary are found + type T1 int + testCases := []struct { + in, out []Type + variadic bool + want interface{} + }{ + {in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)}, + {in: []Type{TypeOf(int(0))}, want: (func(int))(nil)}, + {in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)}, + {in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)}, + {in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)}, + } + for _, tt := range testCases { + checkSameType(t, FuncOf(tt.in, tt.out, tt.variadic), tt.want) + } + + // check that variadic requires last element be a slice. + FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true) + shouldPanic("must be slice", func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) }) + shouldPanic("must be slice", func() { FuncOf(nil, nil, true) }) +} + +type B1 struct { + X int + Y int + Z int +} + +func BenchmarkFieldByName1(b *testing.B) { + t := TypeOf(B1{}) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + t.FieldByName("Z") + } + }) +} + +func BenchmarkFieldByName2(b *testing.B) { + t := TypeOf(S3{}) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + t.FieldByName("B") + } + }) +} + +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 + +func TestEmbed(t *testing.T) { + typ := TypeOf(R0{}) + f, ok := typ.FieldByName("X") + if ok { + t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index) + } +} + +func BenchmarkFieldByName3(b *testing.B) { + t := TypeOf(R0{}) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + t.FieldByName("X") + } + }) +} + +type S struct { + i1 int64 + i2 int64 +} + +func BenchmarkInterfaceBig(b *testing.B) { + v := ValueOf(S{}) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + v.Interface() + } + }) + b.StopTimer() +} + +func TestAllocsInterfaceBig(t *testing.T) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + v := ValueOf(S{}) + if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 { + t.Error("allocs:", allocs) + } +} + +func BenchmarkInterfaceSmall(b *testing.B) { + v := ValueOf(int64(0)) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + v.Interface() + } + }) +} + +func TestAllocsInterfaceSmall(t *testing.T) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + v := ValueOf(int64(0)) + if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 { + t.Error("allocs:", allocs) + } +} + +// An exhaustive is a mechanism for writing exhaustive or stochastic tests. +// The basic usage is: +// +// for x.Next() { +// ... code using x.Maybe() or x.Choice(n) to create test cases ... +// } +// +// Each iteration of the loop returns a different set of results, until all +// possible result sets have been explored. It is okay for different code paths +// to make different method call sequences on x, but there must be no +// other source of non-determinism in the call sequences. +// +// When faced with a new decision, x chooses randomly. Future explorations +// of that path will choose successive values for the result. Thus, stopping +// the loop after a fixed number of iterations gives somewhat stochastic +// testing. +// +// Example: +// +// for x.Next() { +// v := make([]bool, x.Choose(4)) +// for i := range v { +// v[i] = x.Maybe() +// } +// fmt.Println(v) +// } +// +// prints (in some order): +// +// [] +// [false] +// [true] +// [false false] +// [false true] +// ... +// [true true] +// [false false false] +// ... +// [true true true] +// [false false false false] +// ... +// [true true true true] +// +type exhaustive struct { + r *rand.Rand + pos int + last []choice +} + +type choice struct { + off int + n int + max int +} + +func (x *exhaustive) Next() bool { + if x.r == nil { + x.r = rand.New(rand.NewSource(time.Now().UnixNano())) + } + x.pos = 0 + if x.last == nil { + x.last = []choice{} + return true + } + for i := len(x.last) - 1; i >= 0; i-- { + c := &x.last[i] + if c.n+1 < c.max { + c.n++ + x.last = x.last[:i+1] + return true + } + } + return false +} + +func (x *exhaustive) Choose(max int) int { + if x.pos >= len(x.last) { + x.last = append(x.last, choice{x.r.Intn(max), 0, max}) + } + c := &x.last[x.pos] + x.pos++ + if c.max != max { + panic("inconsistent use of exhaustive tester") + } + return (c.n + c.off) % max +} + +func (x *exhaustive) Maybe() bool { + return x.Choose(2) == 1 +} + +func GCFunc(args []Value) []Value { + runtime.GC() + return []Value{} +} + +func TestReflectFuncTraceback(t *testing.T) { + f := MakeFunc(TypeOf(func() {}), GCFunc) + f.Call([]Value{}) +} + +func TestReflectMethodTraceback(t *testing.T) { + p := Point{3, 4} + m := ValueOf(p).MethodByName("GCMethod") + i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int() + if i != 8 { + t.Errorf("Call returned %d; want 8", i) + } +} + +func TestSmallZero(t *testing.T) { + type T [10]byte + typ := TypeOf(T{}) + if allocs := testing.AllocsPerRun(100, func() { Zero(typ) }); allocs > 0 { + t.Errorf("Creating small zero values caused %f allocs, want 0", allocs) + } +} + +func TestBigZero(t *testing.T) { + const size = 1 << 10 + var v [size]byte + z := Zero(ValueOf(v).Type()).Interface().([size]byte) + for i := 0; i < size; i++ { + if z[i] != 0 { + t.Fatalf("Zero object not all zero, index %d", i) + } + } +} + +func TestZeroSet(t *testing.T) { + type T [16]byte + type S struct { + a uint64 + T T + b uint64 + } + v := S{ + a: 0xaaaaaaaaaaaaaaaa, + T: T{9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9}, + b: 0xbbbbbbbbbbbbbbbb, + } + ValueOf(&v).Elem().Field(1).Set(Zero(TypeOf(T{}))) + if v != (S{ + a: 0xaaaaaaaaaaaaaaaa, + b: 0xbbbbbbbbbbbbbbbb, + }) { + t.Fatalf("Setting a field to a Zero value didn't work") + } +} + +func TestFieldByIndexNil(t *testing.T) { + type P struct { + F int + } + type T struct { + *P + } + v := ValueOf(T{}) + + v.FieldByName("P") // should be fine + + defer func() { + if err := recover(); err == nil { + t.Fatalf("no error") + } else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") { + t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err) + } + }() + v.FieldByName("F") // should panic + + t.Fatalf("did not panic") +} + +// Given +// type Outer struct { +// *Inner +// ... +// } +// the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner. +// The implementation is logically: +// func (p *Outer) M() { +// (p.Inner).M() +// } +// but since the only change here is the replacement of one pointer receiver with another, +// the actual generated code overwrites the original receiver with the p.Inner pointer and +// then jumps to the M method expecting the *Inner receiver. +// +// During reflect.Value.Call, we create an argument frame and the associated data structures +// to describe it to the garbage collector, populate the frame, call reflect.call to +// run a function call using that frame, and then copy the results back out of the frame. +// The reflect.call function does a memmove of the frame structure onto the +// stack (to set up the inputs), runs the call, and the memmoves the stack back to +// the frame structure (to preserve the outputs). +// +// Originally reflect.call did not distinguish inputs from outputs: both memmoves +// were for the full stack frame. However, in the case where the called function was +// one of these wrappers, the rewritten receiver is almost certainly a different type +// than the original receiver. This is not a problem on the stack, where we use the +// program counter to determine the type information and understand that +// during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same +// memory word is now an *Inner. But in the statically typed argument frame created +// by reflect, the receiver is always an *Outer. Copying the modified receiver pointer +// off the stack into the frame will store an *Inner there, and then if a garbage collection +// happens to scan that argument frame before it is discarded, it will scan the *Inner +// memory as if it were an *Outer. If the two have different memory layouts, the +// collection will interpret the memory incorrectly. +// +// One such possible incorrect interpretation is to treat two arbitrary memory words +// (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting +// an interface requires dereferencing the itab word, the misinterpretation will try to +// deference Inner.P1, causing a crash during garbage collection. +// +// This came up in a real program in issue 7725. + +type Outer struct { + *Inner + R io.Reader +} + +type Inner struct { + X *Outer + P1 uintptr + P2 uintptr +} + +func (pi *Inner) M() { + // Clear references to pi so that the only way the + // garbage collection will find the pointer is in the + // argument frame, typed as a *Outer. + pi.X.Inner = nil + + // Set up an interface value that will cause a crash. + // P1 = 1 is a non-zero, so the interface looks non-nil. + // P2 = pi ensures that the data word points into the + // allocated heap; if not the collection skips the interface + // value as irrelevant, without dereferencing P1. + pi.P1 = 1 + pi.P2 = uintptr(unsafe.Pointer(pi)) +} + +func TestCallMethodJump(t *testing.T) { + // In reflect.Value.Call, trigger a garbage collection after reflect.call + // returns but before the args frame has been discarded. + // This is a little clumsy but makes the failure repeatable. + *CallGC = true + + p := &Outer{Inner: new(Inner)} + p.Inner.X = p + ValueOf(p).Method(0).Call(nil) + + // Stop garbage collecting during reflect.call. + *CallGC = false +} + +func TestMakeFuncStackCopy(t *testing.T) { + target := func(in []Value) []Value { + runtime.GC() + useStack(16) + return []Value{ValueOf(9)} + } + + var concrete func(*int, int) int + fn := MakeFunc(ValueOf(concrete).Type(), target) + ValueOf(&concrete).Elem().Set(fn) + x := concrete(nil, 7) + if x != 9 { + t.Errorf("have %#q want 9", x) + } +} + +// use about n KB of stack +func useStack(n int) { + if n == 0 { + return + } + var b [1024]byte // makes frame about 1KB + useStack(n - 1 + int(b[99])) +} + +type Impl struct{} + +func (Impl) F() {} + +func TestValueString(t *testing.T) { + rv := ValueOf(Impl{}) + if rv.String() != "<reflect_test.Impl Value>" { + t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>") + } + + method := rv.Method(0) + if method.String() != "<func() Value>" { + t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>") + } +} + +func TestInvalid(t *testing.T) { + // Used to have inconsistency between IsValid() and Kind() != Invalid. + type T struct{ v interface{} } + + v := ValueOf(T{}).Field(0) + if v.IsValid() != true || v.Kind() != Interface { + t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind()) + } + v = v.Elem() + if v.IsValid() != false || v.Kind() != Invalid { + t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind()) + } +} + +// Issue 8917. +func TestLargeGCProg(t *testing.T) { + fv := ValueOf(func([256]*byte) {}) + fv.Call([]Value{ValueOf([256]*byte{})}) +} + +func fieldIndexRecover(t Type, i int) (recovered interface{}) { + defer func() { + recovered = recover() + }() + + t.Field(i) + return +} + +// Issue 15046. +func TestTypeFieldOutOfRangePanic(t *testing.T) { + typ := TypeOf(struct{ X int }{10}) + testIndices := [...]struct { + i int + mustPanic bool + }{ + 0: {-2, true}, + 1: {0, false}, + 2: {1, true}, + 3: {1 << 10, true}, + } + for i, tt := range testIndices { + recoveredErr := fieldIndexRecover(typ, tt.i) + if tt.mustPanic { + if recoveredErr == nil { + t.Errorf("#%d: fieldIndex %d expected to panic", i, tt.i) + } + } else { + if recoveredErr != nil { + t.Errorf("#%d: got err=%v, expected no panic", i, recoveredErr) + } + } + } +} + +// Issue 9179. +func TestCallGC(t *testing.T) { + f := func(a, b, c, d, e string) { + } + g := func(in []Value) []Value { + runtime.GC() + return nil + } + typ := ValueOf(f).Type() + f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string)) + f2("four", "five5", "six666", "seven77", "eight888") +} + +// Issue 18635 (function version). +func TestKeepFuncLive(t *testing.T) { + // Test that we keep makeFuncImpl live as long as it is + // referenced on the stack. + typ := TypeOf(func(i int) {}) + var f, g func(in []Value) []Value + f = func(in []Value) []Value { + clobber() + i := int(in[0].Int()) + if i > 0 { + // We can't use Value.Call here because + // runtime.call* will keep the makeFuncImpl + // alive. However, by converting it to an + // interface value and calling that, + // reflect.callReflect is the only thing that + // can keep the makeFuncImpl live. + // + // Alternate between f and g so that if we do + // reuse the memory prematurely it's more + // likely to get obviously corrupted. + MakeFunc(typ, g).Interface().(func(i int))(i - 1) + } + return nil + } + g = func(in []Value) []Value { + clobber() + i := int(in[0].Int()) + MakeFunc(typ, f).Interface().(func(i int))(i) + return nil + } + MakeFunc(typ, f).Call([]Value{ValueOf(10)}) +} + +type UnExportedFirst int + +func (i UnExportedFirst) ΦExported() {} +func (i UnExportedFirst) unexported() {} + +// Issue 21177 +func TestMethodByNameUnExportedFirst(t *testing.T) { + defer func() { + if recover() != nil { + t.Errorf("should not panic") + } + }() + typ := TypeOf(UnExportedFirst(0)) + m, _ := typ.MethodByName("ΦExported") + if m.Name != "ΦExported" { + t.Errorf("got %s, expected ΦExported", m.Name) + } +} + +// Issue 18635 (method version). +type KeepMethodLive struct{} + +func (k KeepMethodLive) Method1(i int) { + clobber() + if i > 0 { + ValueOf(k).MethodByName("Method2").Interface().(func(i int))(i - 1) + } +} + +func (k KeepMethodLive) Method2(i int) { + clobber() + ValueOf(k).MethodByName("Method1").Interface().(func(i int))(i) +} + +func TestKeepMethodLive(t *testing.T) { + // Test that we keep methodValue live as long as it is + // referenced on the stack. + KeepMethodLive{}.Method1(10) +} + +// clobber tries to clobber unreachable memory. +func clobber() { + runtime.GC() + for i := 1; i < 32; i++ { + for j := 0; j < 10; j++ { + obj := make([]*byte, i) + sink = obj + } + } + runtime.GC() +} + +type funcLayoutTest struct { + rcvr, t Type + size, argsize, retOffset uintptr + stack []byte // pointer bitmap: 1 is pointer, 0 is scalar + gc []byte +} + +var funcLayoutTests []funcLayoutTest + +func init() { + var argAlign uintptr = PtrSize + roundup := func(x uintptr, a uintptr) uintptr { + return (x + a - 1) / a * a + } + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a, b string) string { return "" }).Type(), + 6 * PtrSize, + 4 * PtrSize, + 4 * PtrSize, + []byte{1, 0, 1, 0, 1}, + []byte{1, 0, 1, 0, 1}, + }) + + var r []byte + if PtrSize == 4 { + r = []byte{0, 0, 0, 1} + } else { + r = []byte{0, 0, 1} + } + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(), + roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign), + roundup(3*4, PtrSize) + PtrSize + 2, + roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign), + r, + r, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(), + 4 * PtrSize, + 4 * PtrSize, + 4 * PtrSize, + []byte{1, 0, 1, 1}, + []byte{1, 0, 1, 1}, + }) + + type S struct { + a, b uintptr + c, d *byte + } + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a S) {}).Type(), + 4 * PtrSize, + 4 * PtrSize, + 4 * PtrSize, + []byte{0, 0, 1, 1}, + []byte{0, 0, 1, 1}, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + ValueOf((*byte)(nil)).Type(), + ValueOf(func(a uintptr, b *int) {}).Type(), + roundup(3*PtrSize, argAlign), + 3 * PtrSize, + roundup(3*PtrSize, argAlign), + []byte{1, 0, 1}, + []byte{1, 0, 1}, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a uintptr) {}).Type(), + roundup(PtrSize, argAlign), + PtrSize, + roundup(PtrSize, argAlign), + []byte{}, + []byte{}, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func() uintptr { return 0 }).Type(), + PtrSize, + 0, + 0, + []byte{}, + []byte{}, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + ValueOf(uintptr(0)).Type(), + ValueOf(func(a uintptr) {}).Type(), + 2 * PtrSize, + 2 * PtrSize, + 2 * PtrSize, + []byte{1}, + []byte{1}, + // Note: this one is tricky, as the receiver is not a pointer. But we + // pass the receiver by reference to the autogenerated pointer-receiver + // version of the function. + }) +} + +func TestFuncLayout(t *testing.T) { + for _, lt := range funcLayoutTests { + typ, argsize, retOffset, stack, gc, ptrs := FuncLayout(lt.t, lt.rcvr) + if typ.Size() != lt.size { + t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.t, lt.rcvr, typ.Size(), lt.size) + } + if argsize != lt.argsize { + t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize) + } + if retOffset != lt.retOffset { + t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.t, lt.rcvr, retOffset, lt.retOffset) + } + if !bytes.Equal(stack, lt.stack) { + t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack) + } + if !bytes.Equal(gc, lt.gc) { + t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.t, lt.rcvr, gc, lt.gc) + } + if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 { + t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.t, lt.rcvr, ptrs, !ptrs) + } + } +} + +func verifyGCBits(t *testing.T, typ Type, bits []byte) { + heapBits := GCBits(New(typ).Interface()) + if !bytes.Equal(heapBits, bits) { + _, _, line, _ := runtime.Caller(1) + t.Errorf("line %d: heapBits incorrect for %v\nhave %v\nwant %v", line, typ, heapBits, bits) + } +} + +func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) { + // Creating a slice causes the runtime to repeat a bitmap, + // which exercises a different path from making the compiler + // repeat a bitmap for a small array or executing a repeat in + // a GC program. + val := MakeSlice(typ, 0, cap) + data := NewAt(ArrayOf(cap, typ), unsafe.Pointer(val.Pointer())) + heapBits := GCBits(data.Interface()) + // Repeat the bitmap for the slice size, trimming scalars in + // the last element. + bits = rep(cap, bits) + for len(bits) > 0 && bits[len(bits)-1] == 0 { + bits = bits[:len(bits)-1] + } + if !bytes.Equal(heapBits, bits) { + t.Errorf("heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", typ, cap, heapBits, bits) + } +} + +func TestGCBits(t *testing.T) { + verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1}) + + // Building blocks for types seen by the compiler (like [2]Xscalar). + // The compiler will create the type structures for the derived types, + // including their GC metadata. + type Xscalar struct{ x uintptr } + type Xptr struct{ x *byte } + type Xptrscalar struct { + *byte + uintptr + } + type Xscalarptr struct { + uintptr + *byte + } + type Xbigptrscalar struct { + _ [100]*byte + _ [100]uintptr + } + + var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type + { + // Building blocks for types constructed by reflect. + // This code is in a separate block so that code below + // cannot accidentally refer to these. + // The compiler must NOT see types derived from these + // (for example, [2]Scalar must NOT appear in the program), + // or else reflect will use it instead of having to construct one. + // The goal is to test the construction. + type Scalar struct{ x uintptr } + type Ptr struct{ x *byte } + type Ptrscalar struct { + *byte + uintptr + } + type Scalarptr struct { + uintptr + *byte + } + type Bigptrscalar struct { + _ [100]*byte + _ [100]uintptr + } + type Int64 int64 + Tscalar = TypeOf(Scalar{}) + Tint64 = TypeOf(Int64(0)) + Tptr = TypeOf(Ptr{}) + Tscalarptr = TypeOf(Scalarptr{}) + Tptrscalar = TypeOf(Ptrscalar{}) + Tbigptrscalar = TypeOf(Bigptrscalar{}) + } + + empty := []byte{} + + verifyGCBits(t, TypeOf(Xscalar{}), empty) + verifyGCBits(t, Tscalar, empty) + verifyGCBits(t, TypeOf(Xptr{}), lit(1)) + verifyGCBits(t, Tptr, lit(1)) + verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1)) + verifyGCBits(t, Tscalarptr, lit(0, 1)) + verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1)) + verifyGCBits(t, Tptrscalar, lit(1)) + + verifyGCBits(t, TypeOf([0]Xptr{}), empty) + verifyGCBits(t, ArrayOf(0, Tptr), empty) + verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1)) + verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1)) + verifyGCBits(t, TypeOf([2]Xscalar{}), empty) + verifyGCBits(t, ArrayOf(2, Tscalar), empty) + verifyGCBits(t, TypeOf([10000]Xscalar{}), empty) + verifyGCBits(t, ArrayOf(10000, Tscalar), empty) + verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1)) + verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1)) + verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1))) + verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1))) + verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1)) + verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1)) + verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1))) + verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1))) + verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1)) + verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1)) + verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0))) + verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0))) + verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0))) + verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0))) + verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0))) + verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0))) + verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1)))) + verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1)))) + + verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty) + verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty) + verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1)) + verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1)) + verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0)) + verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0)) + verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0)) + verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0)) + verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1)) + verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1)) + verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1)) + verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1)) + verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1)) + verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1)) + verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1)) + verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1)) + verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0)) + verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0)) + verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0)) + verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0)) + verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0))) + verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0))) + verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0))) + verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0))) + verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0)))) + verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0)))) + + verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1)) + verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1)) + + verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1)) + verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1)) + + verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1)) + verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1)) + + verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1)) + verifyGCBits(t, PtrTo(ArrayOf(10000, Tscalar)), lit(1)) + + verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1)) + verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1)) + + hdr := make([]byte, 8/PtrSize) + + verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) { + verifyGCBits(t, MapBucketOf(k, e), want) + verifyGCBits(t, CachedBucketOf(TypeOf(m)), want) + } + verifyMapBucket(t, + Tscalar, Tptr, + map[Xscalar]Xptr(nil), + join(hdr, rep(8, lit(0)), rep(8, lit(1)), lit(1))) + verifyMapBucket(t, + Tscalarptr, Tptr, + map[Xscalarptr]Xptr(nil), + join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1))) + verifyMapBucket(t, Tint64, Tptr, + map[int64]Xptr(nil), + join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), lit(1))) + verifyMapBucket(t, + Tscalar, Tscalar, + map[Xscalar]Xscalar(nil), + empty) + verifyMapBucket(t, + ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar), + map[[2]Xscalarptr][3]Xptrscalar(nil), + join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1))) + verifyMapBucket(t, + ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar), + map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil), + join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1))) + verifyMapBucket(t, + ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar), + map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil), + join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1))) + verifyMapBucket(t, + ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar), + map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil), + join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1))) + verifyMapBucket(t, + ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar), + map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil), + join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1))) +} + +func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) } +func join(b ...[]byte) []byte { return bytes.Join(b, nil) } +func lit(x ...byte) []byte { return x } + +func TestTypeOfTypeOf(t *testing.T) { + // Check that all the type constructors return concrete *rtype implementations. + // It's difficult to test directly because the reflect package is only at arm's length. + // The easiest thing to do is just call a function that crashes if it doesn't get an *rtype. + check := func(name string, typ Type) { + if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" { + t.Errorf("%v returned %v, not *reflect.rtype", name, underlying) + } + } + + type T struct{ int } + check("TypeOf", TypeOf(T{})) + + check("ArrayOf", ArrayOf(10, TypeOf(T{}))) + check("ChanOf", ChanOf(BothDir, TypeOf(T{}))) + check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false)) + check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{}))) + check("PtrTo", PtrTo(TypeOf(T{}))) + check("SliceOf", SliceOf(TypeOf(T{}))) +} + +type XM struct{ _ bool } + +func (*XM) String() string { return "" } + +func TestPtrToMethods(t *testing.T) { + var y struct{ XM } + yp := New(TypeOf(y)).Interface() + _, ok := yp.(fmt.Stringer) + if !ok { + t.Fatal("does not implement Stringer, but should") + } +} + +func TestMapAlloc(t *testing.T) { + m := ValueOf(make(map[int]int, 10)) + k := ValueOf(5) + v := ValueOf(7) + allocs := testing.AllocsPerRun(100, func() { + m.SetMapIndex(k, v) + }) + if allocs > 0.5 { + t.Errorf("allocs per map assignment: want 0 got %f", allocs) + } + + const size = 1000 + tmp := 0 + val := ValueOf(&tmp).Elem() + allocs = testing.AllocsPerRun(100, func() { + mv := MakeMapWithSize(TypeOf(map[int]int{}), size) + // Only adding half of the capacity to not trigger re-allocations due too many overloaded buckets. + for i := 0; i < size/2; i++ { + val.SetInt(int64(i)) + mv.SetMapIndex(val, val) + } + }) + if allocs > 10 { + t.Errorf("allocs per map assignment: want at most 10 got %f", allocs) + } + // Empirical testing shows that with capacity hint single run will trigger 3 allocations and without 91. I set + // the threshold to 10, to not make it overly brittle if something changes in the initial allocation of the + // map, but to still catch a regression where we keep re-allocating in the hashmap as new entries are added. +} + +func TestChanAlloc(t *testing.T) { + // Note: for a chan int, the return Value must be allocated, so we + // use a chan *int instead. + c := ValueOf(make(chan *int, 1)) + v := ValueOf(new(int)) + allocs := testing.AllocsPerRun(100, func() { + c.Send(v) + _, _ = c.Recv() + }) + if allocs < 0.5 || allocs > 1.5 { + t.Errorf("allocs per chan send/recv: want 1 got %f", allocs) + } + // Note: there is one allocation in reflect.recv which seems to be + // a limitation of escape analysis. If that is ever fixed the + // allocs < 0.5 condition will trigger and this test should be fixed. +} + +type TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678 int + +type nameTest struct { + v interface{} + want string +} + +var nameTests = []nameTest{ + {(*int32)(nil), "int32"}, + {(*D1)(nil), "D1"}, + {(*[]D1)(nil), ""}, + {(*chan D1)(nil), ""}, + {(*func() D1)(nil), ""}, + {(*<-chan D1)(nil), ""}, + {(*chan<- D1)(nil), ""}, + {(*interface{})(nil), ""}, + {(*interface { + F() + })(nil), ""}, + {(*TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678)(nil), "TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678"}, +} + +func TestNames(t *testing.T) { + for _, test := range nameTests { + typ := TypeOf(test.v).Elem() + if got := typ.Name(); got != test.want { + t.Errorf("%v Name()=%q, want %q", typ, got, test.want) + } + } +} + +func TestExported(t *testing.T) { + type ΦExported struct{} + type φUnexported struct{} + type BigP *big + type P int + type p *P + type P2 p + type p3 p + + type exportTest struct { + v interface{} + want bool + } + exportTests := []exportTest{ + {D1{}, true}, + {(*D1)(nil), true}, + {big{}, false}, + {(*big)(nil), false}, + {(BigP)(nil), true}, + {(*BigP)(nil), true}, + {ΦExported{}, true}, + {φUnexported{}, false}, + {P(0), true}, + {(p)(nil), false}, + {(P2)(nil), true}, + {(p3)(nil), false}, + } + + for i, test := range exportTests { + typ := TypeOf(test.v) + if got := IsExported(typ); got != test.want { + t.Errorf("%d: %s exported=%v, want %v", i, typ.Name(), got, test.want) + } + } +} + +type embed struct { + EmbedWithUnexpMeth +} + +func TestNameBytesAreAligned(t *testing.T) { + typ := TypeOf(embed{}) + b := FirstMethodNameBytes(typ) + v := uintptr(unsafe.Pointer(b)) + if v%unsafe.Alignof((*byte)(nil)) != 0 { + t.Errorf("reflect.name.bytes pointer is not aligned: %x", v) + } +} + +func TestTypeStrings(t *testing.T) { + type stringTest struct { + typ Type + want string + } + stringTests := []stringTest{ + {TypeOf(func(int) {}), "func(int)"}, + {FuncOf([]Type{TypeOf(int(0))}, nil, false), "func(int)"}, + {TypeOf(XM{}), "reflect_test.XM"}, + {TypeOf(new(XM)), "*reflect_test.XM"}, + {TypeOf(new(XM).String), "func() string"}, + {TypeOf(new(XM)).Method(0).Type, "func(*reflect_test.XM) string"}, + {ChanOf(3, TypeOf(XM{})), "chan reflect_test.XM"}, + {MapOf(TypeOf(int(0)), TypeOf(XM{})), "map[int]reflect_test.XM"}, + {ArrayOf(3, TypeOf(XM{})), "[3]reflect_test.XM"}, + {ArrayOf(3, TypeOf(struct{}{})), "[3]struct {}"}, + } + + for i, test := range stringTests { + if got, want := test.typ.String(), test.want; got != want { + t.Errorf("type %d String()=%q, want %q", i, got, want) + } + } +} + +func TestOffsetLock(t *testing.T) { + var wg sync.WaitGroup + for i := 0; i < 4; i++ { + i := i + wg.Add(1) + go func() { + for j := 0; j < 50; j++ { + ResolveReflectName(fmt.Sprintf("OffsetLockName:%d:%d", i, j)) + } + wg.Done() + }() + } + wg.Wait() +} + +func BenchmarkNew(b *testing.B) { + v := TypeOf(XM{}) + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + New(v) + } + }) +} + +func TestSwapper(t *testing.T) { + type I int + var a, b, c I + type pair struct { + x, y int + } + type pairPtr struct { + x, y int + p *I + } + type S string + + tests := []struct { + in interface{} + i, j int + want interface{} + }{ + { + in: []int{1, 20, 300}, + i: 0, + j: 2, + want: []int{300, 20, 1}, + }, + { + in: []uintptr{1, 20, 300}, + i: 0, + j: 2, + want: []uintptr{300, 20, 1}, + }, + { + in: []int16{1, 20, 300}, + i: 0, + j: 2, + want: []int16{300, 20, 1}, + }, + { + in: []int8{1, 20, 100}, + i: 0, + j: 2, + want: []int8{100, 20, 1}, + }, + { + in: []*I{&a, &b, &c}, + i: 0, + j: 2, + want: []*I{&c, &b, &a}, + }, + { + in: []string{"eric", "sergey", "larry"}, + i: 0, + j: 2, + want: []string{"larry", "sergey", "eric"}, + }, + { + in: []S{"eric", "sergey", "larry"}, + i: 0, + j: 2, + want: []S{"larry", "sergey", "eric"}, + }, + { + in: []pair{{1, 2}, {3, 4}, {5, 6}}, + i: 0, + j: 2, + want: []pair{{5, 6}, {3, 4}, {1, 2}}, + }, + { + in: []pairPtr{{1, 2, &a}, {3, 4, &b}, {5, 6, &c}}, + i: 0, + j: 2, + want: []pairPtr{{5, 6, &c}, {3, 4, &b}, {1, 2, &a}}, + }, + } + + for i, tt := range tests { + inStr := fmt.Sprint(tt.in) + Swapper(tt.in)(tt.i, tt.j) + if !DeepEqual(tt.in, tt.want) { + t.Errorf("%d. swapping %v and %v of %v = %v; want %v", i, tt.i, tt.j, inStr, tt.in, tt.want) + } + } +} + +// TestUnaddressableField tests that the reflect package will not allow +// a type from another package to be used as a named type with an +// unexported field. +// +// This ensures that unexported fields cannot be modified by other packages. +func TestUnaddressableField(t *testing.T) { + var b Buffer // type defined in reflect, a different package + var localBuffer struct { + buf []byte + } + lv := ValueOf(&localBuffer).Elem() + rv := ValueOf(b) + shouldPanic("Set", func() { + lv.Set(rv) + }) +} + +type Tint int + +type Tint2 = Tint + +type Talias1 struct { + byte + uint8 + int + int32 + rune +} + +type Talias2 struct { + Tint + Tint2 +} + +func TestAliasNames(t *testing.T) { + t1 := Talias1{byte: 1, uint8: 2, int: 3, int32: 4, rune: 5} + out := fmt.Sprintf("%#v", t1) + want := "reflect_test.Talias1{byte:0x1, uint8:0x2, int:3, int32:4, rune:5}" + if out != want { + t.Errorf("Talias1 print:\nhave: %s\nwant: %s", out, want) + } + + t2 := Talias2{Tint: 1, Tint2: 2} + out = fmt.Sprintf("%#v", t2) + want = "reflect_test.Talias2{Tint:1, Tint2:2}" + if out != want { + t.Errorf("Talias2 print:\nhave: %s\nwant: %s", out, want) + } +} + +func TestIssue22031(t *testing.T) { + type s []struct{ C int } + + type t1 struct{ s } + type t2 struct{ f s } + + tests := []Value{ + ValueOf(t1{s{{}}}).Field(0).Index(0).Field(0), + ValueOf(t2{s{{}}}).Field(0).Index(0).Field(0), + } + + for i, test := range tests { + if test.CanSet() { + t.Errorf("%d: CanSet: got true, want false", i) + } + } +} + +type NonExportedFirst int + +func (i NonExportedFirst) ΦExported() {} +func (i NonExportedFirst) nonexported() int { panic("wrong") } + +func TestIssue22073(t *testing.T) { + m := ValueOf(NonExportedFirst(0)).Method(0) + + if got := m.Type().NumOut(); got != 0 { + t.Errorf("NumOut: got %v, want 0", got) + } + + // Shouldn't panic. + m.Call(nil) +} + +func TestMapIterNonEmptyMap(t *testing.T) { + m := map[string]int{"one": 1, "two": 2, "three": 3} + iter := ValueOf(m).MapRange() + if got, want := iterateToString(iter), `[one: 1, three: 3, two: 2]`; got != want { + t.Errorf("iterator returned %s (after sorting), want %s", got, want) + } +} + +func TestMapIterNilMap(t *testing.T) { + var m map[string]int + iter := ValueOf(m).MapRange() + if got, want := iterateToString(iter), `[]`; got != want { + t.Errorf("non-empty result iteratoring nil map: %s", got) + } +} + +func TestMapIterSafety(t *testing.T) { + // Using a zero MapIter causes a panic, but not a crash. + func() { + defer func() { recover() }() + new(MapIter).Key() + t.Fatal("Key did not panic") + }() + func() { + defer func() { recover() }() + new(MapIter).Value() + t.Fatal("Value did not panic") + }() + func() { + defer func() { recover() }() + new(MapIter).Next() + t.Fatal("Next did not panic") + }() + + // Calling Key/Value on a MapIter before Next + // causes a panic, but not a crash. + var m map[string]int + iter := ValueOf(m).MapRange() + + func() { + defer func() { recover() }() + iter.Key() + t.Fatal("Key did not panic") + }() + func() { + defer func() { recover() }() + iter.Value() + t.Fatal("Value did not panic") + }() + + // Calling Next, Key, or Value on an exhausted iterator + // causes a panic, but not a crash. + iter.Next() // -> false + func() { + defer func() { recover() }() + iter.Key() + t.Fatal("Key did not panic") + }() + func() { + defer func() { recover() }() + iter.Value() + t.Fatal("Value did not panic") + }() + func() { + defer func() { recover() }() + iter.Next() + t.Fatal("Next did not panic") + }() +} + +func TestMapIterNext(t *testing.T) { + // The first call to Next should reflect any + // insertions to the map since the iterator was created. + m := map[string]int{} + iter := ValueOf(m).MapRange() + m["one"] = 1 + if got, want := iterateToString(iter), `[one: 1]`; got != want { + t.Errorf("iterator returned deleted elements: got %s, want %s", got, want) + } +} + +func TestMapIterDelete0(t *testing.T) { + // Delete all elements before first iteration. + m := map[string]int{"one": 1, "two": 2, "three": 3} + iter := ValueOf(m).MapRange() + delete(m, "one") + delete(m, "two") + delete(m, "three") + if got, want := iterateToString(iter), `[]`; got != want { + t.Errorf("iterator returned deleted elements: got %s, want %s", got, want) + } +} + +func TestMapIterDelete1(t *testing.T) { + // Delete all elements after first iteration. + m := map[string]int{"one": 1, "two": 2, "three": 3} + iter := ValueOf(m).MapRange() + var got []string + for iter.Next() { + got = append(got, fmt.Sprint(iter.Key(), iter.Value())) + delete(m, "one") + delete(m, "two") + delete(m, "three") + } + if len(got) != 1 { + t.Errorf("iterator returned wrong number of elements: got %d, want 1", len(got)) + } +} + +// iterateToString returns the set of elements +// returned by an iterator in readable form. +func iterateToString(it *MapIter) string { + var got []string + for it.Next() { + line := fmt.Sprintf("%v: %v", it.Key(), it.Value()) + got = append(got, line) + } + sort.Strings(got) + return "[" + strings.Join(got, ", ") + "]" +} diff --git a/src/reflect/asm_386.s b/src/reflect/asm_386.s new file mode 100644 index 0000000..e79beb6 --- /dev/null +++ b/src/reflect/asm_386.s @@ -0,0 +1,36 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + MOVB $0, 12(SP) + LEAL 12(SP), AX + MOVL AX, 8(SP) + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + MOVB $0, 12(SP) + LEAL 12(SP), AX + MOVL AX, 8(SP) + CALL ·callMethod(SB) + RET diff --git a/src/reflect/asm_amd64.s b/src/reflect/asm_amd64.s new file mode 100644 index 0000000..5c8e565 --- /dev/null +++ b/src/reflect/asm_amd64.s @@ -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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +// makeFuncStub must be ABIInternal because it is placed directly +// in function values. +TEXT ·makeFuncStub<ABIInternal>(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVQ DX, 0(SP) + LEAQ argframe+0(FP), CX + MOVQ CX, 8(SP) + MOVB $0, 24(SP) + LEAQ 24(SP), AX + MOVQ AX, 16(SP) + CALL ·callReflect<ABIInternal>(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +// methodValueCall must be ABIInternal because it is placed directly +// in function values. +TEXT ·methodValueCall<ABIInternal>(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVQ DX, 0(SP) + LEAQ argframe+0(FP), CX + MOVQ CX, 8(SP) + MOVB $0, 24(SP) + LEAQ 24(SP), AX + MOVQ AX, 16(SP) + CALL ·callMethod<ABIInternal>(SB) + RET diff --git a/src/reflect/asm_arm.s b/src/reflect/asm_arm.s new file mode 100644 index 0000000..cd50d33 --- /dev/null +++ b/src/reflect/asm_arm.s @@ -0,0 +1,38 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is jumped to by the code generated by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVW R7, 4(R13) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R13) + MOVW $0, R1 + MOVB R1, 16(R13) + ADD $16, R13, R1 + MOVW R1, 12(R13) + BL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVW R7, 4(R13) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R13) + MOVW $0, R1 + MOVB R1, 16(R13) + ADD $16, R13, R1 + MOVW R1, 12(R13) + BL ·callMethod(SB) + RET diff --git a/src/reflect/asm_arm64.s b/src/reflect/asm_arm64.s new file mode 100644 index 0000000..28bb86c --- /dev/null +++ b/src/reflect/asm_arm64.s @@ -0,0 +1,36 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$40 + NO_LOCAL_POINTERS + MOVD R26, 8(RSP) + MOVD $argframe+0(FP), R3 + MOVD R3, 16(RSP) + MOVB $0, 32(RSP) + ADD $32, RSP, R3 + MOVD R3, 24(RSP) + BL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$40 + NO_LOCAL_POINTERS + MOVD R26, 8(RSP) + MOVD $argframe+0(FP), R3 + MOVD R3, 16(RSP) + MOVB $0, 32(RSP) + ADD $32, RSP, R3 + MOVD R3, 24(RSP) + BL ·callMethod(SB) + RET diff --git a/src/reflect/asm_mips64x.s b/src/reflect/asm_mips64x.s new file mode 100644 index 0000000..6f76685 --- /dev/null +++ b/src/reflect/asm_mips64x.s @@ -0,0 +1,40 @@ +// 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. + +// +build mips64 mips64le + +#include "textflag.h" +#include "funcdata.h" + +#define REGCTXT R22 + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVV REGCTXT, 8(R29) + MOVV $argframe+0(FP), R1 + MOVV R1, 16(R29) + MOVB R0, 32(R29) + ADDV $32, R29, R1 + MOVV R1, 24(R29) + JAL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVV REGCTXT, 8(R29) + MOVV $argframe+0(FP), R1 + MOVV R1, 16(R29) + MOVB R0, 32(R29) + ADDV $32, R29, R1 + MOVV R1, 24(R29) + JAL ·callMethod(SB) + RET diff --git a/src/reflect/asm_mipsx.s b/src/reflect/asm_mipsx.s new file mode 100644 index 0000000..5a5c53e --- /dev/null +++ b/src/reflect/asm_mipsx.s @@ -0,0 +1,40 @@ +// 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. + +// +build mips mipsle + +#include "textflag.h" +#include "funcdata.h" + +#define REGCTXT R22 + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVW REGCTXT, 4(R29) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R29) + MOVB R0, 16(R29) + ADD $16, R29, R1 + MOVW R1, 12(R29) + JAL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVW REGCTXT, 4(R29) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R29) + MOVB R0, 16(R29) + ADD $16, R29, R1 + MOVW R1, 12(R29) + JAL ·callMethod(SB) + RET diff --git a/src/reflect/asm_ppc64x.s b/src/reflect/asm_ppc64x.s new file mode 100644 index 0000000..4609f6b --- /dev/null +++ b/src/reflect/asm_ppc64x.s @@ -0,0 +1,39 @@ +// 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. + +// +build ppc64 ppc64le + +#include "textflag.h" +#include "funcdata.h" +#include "asm_ppc64x.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVD R11, FIXED_FRAME+0(R1) + MOVD $argframe+0(FP), R3 + MOVD R3, FIXED_FRAME+8(R1) + MOVB R0, FIXED_FRAME+24(R1) + ADD $FIXED_FRAME+24, R1, R3 + MOVD R3, FIXED_FRAME+16(R1) + BL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVD R11, FIXED_FRAME+0(R1) + MOVD $argframe+0(FP), R3 + MOVD R3, FIXED_FRAME+8(R1) + MOVB R0, FIXED_FRAME+24(R1) + ADD $FIXED_FRAME+24, R1, R3 + MOVD R3, FIXED_FRAME+16(R1) + BL ·callMethod(SB) + RET diff --git a/src/reflect/asm_riscv64.s b/src/reflect/asm_riscv64.s new file mode 100644 index 0000000..e6fab39 --- /dev/null +++ b/src/reflect/asm_riscv64.s @@ -0,0 +1,36 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOV CTXT, 8(SP) + MOV $argframe+0(FP), T0 + MOV T0, 16(SP) + ADD $32, SP, T1 + MOV T1, 24(SP) + MOVB ZERO, 32(SP) + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOV CTXT, 8(SP) + MOV $argframe+0(FP), T0 + MOV T0, 16(SP) + ADD $32, SP, T1 + MOV T1, 24(SP) + MOVB ZERO, 32(SP) + CALL ·callMethod(SB) + RET diff --git a/src/reflect/asm_s390x.s b/src/reflect/asm_s390x.s new file mode 100644 index 0000000..cb7954c --- /dev/null +++ b/src/reflect/asm_s390x.s @@ -0,0 +1,36 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here, runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVD R12, 8(R15) + MOVD $argframe+0(FP), R3 + MOVD R3, 16(R15) + MOVB $0, 32(R15) + ADD $32, R15, R3 + MOVD R3, 24(R15) + BL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + MOVD R12, 8(R15) + MOVD $argframe+0(FP), R3 + MOVD R3, 16(R15) + MOVB $0, 32(R15) + ADD $32, R15, R3 + MOVD R3, 24(R15) + BL ·callMethod(SB) + RET diff --git a/src/reflect/asm_wasm.s b/src/reflect/asm_wasm.s new file mode 100644 index 0000000..63b4d94 --- /dev/null +++ b/src/reflect/asm_wasm.s @@ -0,0 +1,50 @@ +// 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. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + + MOVD CTXT, 0(SP) + + Get SP + Get SP + I64ExtendI32U + I64Const $argframe+0(FP) + I64Add + I64Store $8 + + MOVB $0, 24(SP) + MOVD $24(SP), 16(SP) + + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32 + NO_LOCAL_POINTERS + + MOVD CTXT, 0(SP) + + Get SP + Get SP + I64ExtendI32U + I64Const $argframe+0(FP) + I64Add + I64Store $8 + + MOVB $0, 24(SP) + MOVD $24(SP), 16(SP) + + CALL ·callMethod(SB) + RET diff --git a/src/reflect/deepequal.go b/src/reflect/deepequal.go new file mode 100644 index 0000000..d951d8d --- /dev/null +++ b/src/reflect/deepequal.go @@ -0,0 +1,219 @@ +// 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. + +// Deep equality test via reflection + +package reflect + +import "unsafe" + +// During deepValueEqual, must keep track of checks that are +// in progress. The comparison algorithm assumes that all +// checks in progress are true when it reencounters them. +// Visited comparisons are stored in a map indexed by visit. +type visit struct { + a1 unsafe.Pointer + a2 unsafe.Pointer + typ Type +} + +// Tests for deep equality using reflected types. The map argument tracks +// comparisons that have already been seen, which allows short circuiting on +// recursive types. +func deepValueEqual(v1, v2 Value, visited map[visit]bool) bool { + if !v1.IsValid() || !v2.IsValid() { + return v1.IsValid() == v2.IsValid() + } + if v1.Type() != v2.Type() { + return false + } + + // We want to avoid putting more in the visited map than we need to. + // For any possible reference cycle that might be encountered, + // hard(v1, v2) needs to return true for at least one of the types in the cycle, + // and it's safe and valid to get Value's internal pointer. + hard := func(v1, v2 Value) bool { + switch v1.Kind() { + case Ptr: + if v1.typ.ptrdata == 0 { + // go:notinheap pointers can't be cyclic. + // At least, all of our current uses of go:notinheap have + // that property. The runtime ones aren't cyclic (and we don't use + // DeepEqual on them anyway), and the cgo-generated ones are + // all empty structs. + return false + } + fallthrough + case Map, Slice, Interface: + // Nil pointers cannot be cyclic. Avoid putting them in the visited map. + return !v1.IsNil() && !v2.IsNil() + } + return false + } + + if hard(v1, v2) { + // For a Ptr or Map value, we need to check flagIndir, + // which we do by calling the pointer method. + // For Slice or Interface, flagIndir is always set, + // and using v.ptr suffices. + ptrval := func(v Value) unsafe.Pointer { + switch v.Kind() { + case Ptr, Map: + return v.pointer() + default: + return v.ptr + } + } + addr1 := ptrval(v1) + addr2 := ptrval(v2) + if uintptr(addr1) > uintptr(addr2) { + // Canonicalize order to reduce number of entries in visited. + // Assumes non-moving garbage collector. + addr1, addr2 = addr2, addr1 + } + + // Short circuit if references are already seen. + typ := v1.Type() + v := visit{addr1, addr2, typ} + if visited[v] { + return true + } + + // Remember for later. + visited[v] = true + } + + switch v1.Kind() { + case Array: + for i := 0; i < v1.Len(); i++ { + if !deepValueEqual(v1.Index(i), v2.Index(i), visited) { + return false + } + } + return true + case Slice: + if v1.IsNil() != v2.IsNil() { + return false + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for i := 0; i < v1.Len(); i++ { + if !deepValueEqual(v1.Index(i), v2.Index(i), visited) { + return false + } + } + return true + case Interface: + if v1.IsNil() || v2.IsNil() { + return v1.IsNil() == v2.IsNil() + } + return deepValueEqual(v1.Elem(), v2.Elem(), visited) + case Ptr: + if v1.Pointer() == v2.Pointer() { + return true + } + return deepValueEqual(v1.Elem(), v2.Elem(), visited) + case Struct: + for i, n := 0, v1.NumField(); i < n; i++ { + if !deepValueEqual(v1.Field(i), v2.Field(i), visited) { + return false + } + } + return true + case Map: + if v1.IsNil() != v2.IsNil() { + return false + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for _, k := range v1.MapKeys() { + val1 := v1.MapIndex(k) + val2 := v2.MapIndex(k) + if !val1.IsValid() || !val2.IsValid() || !deepValueEqual(val1, val2, visited) { + return false + } + } + return true + case Func: + if v1.IsNil() && v2.IsNil() { + return true + } + // Can't do better than this: + return false + default: + // Normal equality suffices + return valueInterface(v1, false) == valueInterface(v2, false) + } +} + +// DeepEqual reports whether x and y are ``deeply equal,'' defined as follows. +// Two values of identical type are deeply equal if one of the following cases applies. +// Values of distinct types are never deeply equal. +// +// Array values are deeply equal when their corresponding elements are deeply equal. +// +// Struct values are deeply equal if their corresponding fields, +// both exported and unexported, are deeply equal. +// +// Func values are deeply equal if both are nil; otherwise they are not deeply equal. +// +// Interface values are deeply equal if they hold deeply equal concrete values. +// +// Map values are deeply equal when all of the following are true: +// they are both nil or both non-nil, they have the same length, +// and either they are the same map object or their corresponding keys +// (matched using Go equality) map to deeply equal values. +// +// Pointer values are deeply equal if they are equal using Go's == operator +// or if they point to deeply equal values. +// +// Slice values are deeply equal when all of the following are true: +// they are both nil or both non-nil, they have the same length, +// and either they point to the same initial entry of the same underlying array +// (that is, &x[0] == &y[0]) or their corresponding elements (up to length) are deeply equal. +// Note that a non-nil empty slice and a nil slice (for example, []byte{} and []byte(nil)) +// are not deeply equal. +// +// Other values - numbers, bools, strings, and channels - are deeply equal +// if they are equal using Go's == operator. +// +// In general DeepEqual is a recursive relaxation of Go's == operator. +// However, this idea is impossible to implement without some inconsistency. +// Specifically, it is possible for a value to be unequal to itself, +// either because it is of func type (uncomparable in general) +// or because it is a floating-point NaN value (not equal to itself in floating-point comparison), +// or because it is an array, struct, or interface containing +// such a value. +// On the other hand, pointer values are always equal to themselves, +// even if they point at or contain such problematic values, +// because they compare equal using Go's == operator, and that +// is a sufficient condition to be deeply equal, regardless of content. +// DeepEqual has been defined so that the same short-cut applies +// to slices and maps: if x and y are the same slice or the same map, +// they are deeply equal regardless of content. +// +// As DeepEqual traverses the data values it may find a cycle. The +// second and subsequent times that DeepEqual compares two pointer +// values that have been compared before, it treats the values as +// equal rather than examining the values to which they point. +// This ensures that DeepEqual terminates. +func DeepEqual(x, y interface{}) bool { + if x == nil || y == nil { + return x == y + } + v1 := ValueOf(x) + v2 := ValueOf(y) + if v1.Type() != v2.Type() { + return false + } + return deepValueEqual(v1, v2, make(map[visit]bool)) +} diff --git a/src/reflect/example_test.go b/src/reflect/example_test.go new file mode 100644 index 0000000..23c08e4 --- /dev/null +++ b/src/reflect/example_test.go @@ -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. + +package reflect_test + +import ( + "bytes" + "encoding/json" + "fmt" + "io" + "os" + "reflect" +) + +func ExampleKind() { + for _, v := range []interface{}{"hi", 42, func() {}} { + switch v := reflect.ValueOf(v); v.Kind() { + case reflect.String: + fmt.Println(v.String()) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + fmt.Println(v.Int()) + default: + fmt.Printf("unhandled kind %s", v.Kind()) + } + } + + // Output: + // hi + // 42 + // unhandled kind func +} + +func ExampleMakeFunc() { + // swap is the implementation passed to MakeFunc. + // It must work in terms of reflect.Values so that it is possible + // to write code without knowing beforehand what the types + // will be. + swap := func(in []reflect.Value) []reflect.Value { + return []reflect.Value{in[1], in[0]} + } + + // makeSwap expects fptr to be a pointer to a nil function. + // It sets that pointer to a new function created with MakeFunc. + // When the function is invoked, reflect turns the arguments + // into Values, calls swap, and then turns swap's result slice + // into the values returned by the new function. + makeSwap := func(fptr interface{}) { + // fptr is a pointer to a function. + // Obtain the function value itself (likely nil) as a reflect.Value + // so that we can query its type and then set the value. + fn := reflect.ValueOf(fptr).Elem() + + // Make a function of the right type. + v := reflect.MakeFunc(fn.Type(), swap) + + // Assign it to the value fn represents. + fn.Set(v) + } + + // Make and call a swap function for ints. + var intSwap func(int, int) (int, int) + makeSwap(&intSwap) + fmt.Println(intSwap(0, 1)) + + // Make and call a swap function for float64s. + var floatSwap func(float64, float64) (float64, float64) + makeSwap(&floatSwap) + fmt.Println(floatSwap(2.72, 3.14)) + + // Output: + // 1 0 + // 3.14 2.72 +} + +func ExampleStructTag() { + type S struct { + F string `species:"gopher" color:"blue"` + } + + s := S{} + st := reflect.TypeOf(s) + field := st.Field(0) + fmt.Println(field.Tag.Get("color"), field.Tag.Get("species")) + + // Output: + // blue gopher +} + +func ExampleStructTag_Lookup() { + type S struct { + F0 string `alias:"field_0"` + F1 string `alias:""` + F2 string + } + + s := S{} + st := reflect.TypeOf(s) + for i := 0; i < st.NumField(); i++ { + field := st.Field(i) + if alias, ok := field.Tag.Lookup("alias"); ok { + if alias == "" { + fmt.Println("(blank)") + } else { + fmt.Println(alias) + } + } else { + fmt.Println("(not specified)") + } + } + + // Output: + // field_0 + // (blank) + // (not specified) +} + +func ExampleTypeOf() { + // As interface types are only used for static typing, a + // common idiom to find the reflection Type for an interface + // type Foo is to use a *Foo value. + writerType := reflect.TypeOf((*io.Writer)(nil)).Elem() + + fileType := reflect.TypeOf((*os.File)(nil)) + fmt.Println(fileType.Implements(writerType)) + + // Output: + // true +} + +func ExampleStructOf() { + typ := reflect.StructOf([]reflect.StructField{ + { + Name: "Height", + Type: reflect.TypeOf(float64(0)), + Tag: `json:"height"`, + }, + { + Name: "Age", + Type: reflect.TypeOf(int(0)), + Tag: `json:"age"`, + }, + }) + + v := reflect.New(typ).Elem() + v.Field(0).SetFloat(0.4) + v.Field(1).SetInt(2) + s := v.Addr().Interface() + + w := new(bytes.Buffer) + if err := json.NewEncoder(w).Encode(s); err != nil { + panic(err) + } + + fmt.Printf("value: %+v\n", s) + fmt.Printf("json: %s", w.Bytes()) + + r := bytes.NewReader([]byte(`{"height":1.5,"age":10}`)) + if err := json.NewDecoder(r).Decode(s); err != nil { + panic(err) + } + fmt.Printf("value: %+v\n", s) + + // Output: + // value: &{Height:0.4 Age:2} + // json: {"height":0.4,"age":2} + // value: &{Height:1.5 Age:10} +} diff --git a/src/reflect/export_test.go b/src/reflect/export_test.go new file mode 100644 index 0000000..de426b5 --- /dev/null +++ b/src/reflect/export_test.go @@ -0,0 +1,122 @@ +// 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 reflect + +import "unsafe" + +// MakeRO returns a copy of v with the read-only flag set. +func MakeRO(v Value) Value { + v.flag |= flagStickyRO + return v +} + +// IsRO reports whether v's read-only flag is set. +func IsRO(v Value) bool { + return v.flag&flagStickyRO != 0 +} + +var CallGC = &callGC + +const PtrSize = ptrSize + +func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr, stack []byte, gc []byte, ptrs bool) { + var ft *rtype + var s *bitVector + if rcvr != nil { + ft, argSize, retOffset, s, _ = funcLayout((*funcType)(unsafe.Pointer(t.(*rtype))), rcvr.(*rtype)) + } else { + ft, argSize, retOffset, s, _ = funcLayout((*funcType)(unsafe.Pointer(t.(*rtype))), nil) + } + frametype = ft + for i := uint32(0); i < s.n; i++ { + stack = append(stack, s.data[i/8]>>(i%8)&1) + } + if ft.kind&kindGCProg != 0 { + panic("can't handle gc programs") + } + ptrs = ft.ptrdata != 0 + if ptrs { + nptrs := ft.ptrdata / ptrSize + gcdata := ft.gcSlice(0, (nptrs+7)/8) + for i := uintptr(0); i < nptrs; i++ { + gc = append(gc, gcdata[i/8]>>(i%8)&1) + } + } + return +} + +func TypeLinks() []string { + var r []string + sections, offset := typelinks() + for i, offs := range offset { + rodata := sections[i] + for _, off := range offs { + typ := (*rtype)(resolveTypeOff(unsafe.Pointer(rodata), off)) + r = append(r, typ.String()) + } + } + return r +} + +var GCBits = gcbits + +func gcbits(interface{}) []byte // provided by runtime + +func MapBucketOf(x, y Type) Type { + return bucketOf(x.(*rtype), y.(*rtype)) +} + +func CachedBucketOf(m Type) Type { + t := m.(*rtype) + if Kind(t.kind&kindMask) != Map { + panic("not map") + } + tt := (*mapType)(unsafe.Pointer(t)) + return tt.bucket +} + +type EmbedWithUnexpMeth struct{} + +func (EmbedWithUnexpMeth) f() {} + +type pinUnexpMeth interface { + f() +} + +var pinUnexpMethI = pinUnexpMeth(EmbedWithUnexpMeth{}) + +func FirstMethodNameBytes(t Type) *byte { + _ = pinUnexpMethI + + ut := t.uncommon() + if ut == nil { + panic("type has no methods") + } + m := ut.methods()[0] + mname := t.(*rtype).nameOff(m.name) + if *mname.data(0, "name flag field")&(1<<2) == 0 { + panic("method name does not have pkgPath *string") + } + return mname.bytes +} + +type OtherPkgFields struct { + OtherExported int + otherUnexported int +} + +func IsExported(t Type) bool { + typ := t.(*rtype) + n := typ.nameOff(typ.str) + return n.isExported() +} + +func ResolveReflectName(s string) { + resolveReflectName(newName(s, "", false)) +} + +type Buffer struct { + buf []byte +} diff --git a/src/reflect/makefunc.go b/src/reflect/makefunc.go new file mode 100644 index 0000000..67dc485 --- /dev/null +++ b/src/reflect/makefunc.go @@ -0,0 +1,138 @@ +// 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. + +// MakeFunc implementation. + +package reflect + +import ( + "unsafe" +) + +// makeFuncImpl is the closure value implementing the function +// returned by MakeFunc. +// The first three words of this type must be kept in sync with +// methodValue and runtime.reflectMethodValue. +// Any changes should be reflected in all three. +type makeFuncImpl struct { + code uintptr + stack *bitVector // ptrmap for both args and results + argLen uintptr // just args + ftyp *funcType + fn func([]Value) []Value +} + +// MakeFunc returns a new function of the given Type +// that wraps the function fn. When called, that new function +// does the following: +// +// - converts its arguments to a slice of Values. +// - runs results := fn(args). +// - returns the results as a slice of Values, one per formal result. +// +// The implementation fn can assume that the argument Value slice +// has the number and type of arguments given by typ. +// If typ describes a variadic function, the final Value is itself +// a slice representing the variadic arguments, as in the +// body of a variadic function. The result Value slice returned by fn +// must have the number and type of results given by typ. +// +// The Value.Call method allows the caller to invoke a typed function +// in terms of Values; in contrast, MakeFunc allows the caller to implement +// a typed function in terms of Values. +// +// The Examples section of the documentation includes an illustration +// of how to use MakeFunc to build a swap function for different types. +// +func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value { + if typ.Kind() != Func { + panic("reflect: call of MakeFunc with non-Func type") + } + + t := typ.common() + ftyp := (*funcType)(unsafe.Pointer(t)) + + // Indirect Go func value (dummy) to obtain + // actual code address. (A Go func value is a pointer + // to a C function pointer. https://golang.org/s/go11func.) + dummy := makeFuncStub + code := **(**uintptr)(unsafe.Pointer(&dummy)) + + // makeFuncImpl contains a stack map for use by the runtime + _, argLen, _, stack, _ := funcLayout(ftyp, nil) + + impl := &makeFuncImpl{code: code, stack: stack, argLen: argLen, ftyp: ftyp, fn: fn} + + return Value{t, unsafe.Pointer(impl), flag(Func)} +} + +// makeFuncStub is an assembly function that is the code half of +// the function returned from MakeFunc. It expects a *callReflectFunc +// as its context register, and its job is to invoke callReflect(ctxt, frame) +// where ctxt is the context register and frame is a pointer to the first +// word in the passed-in argument frame. +func makeFuncStub() + +// The first 3 words of this type must be kept in sync with +// makeFuncImpl and runtime.reflectMethodValue. +// Any changes should be reflected in all three. +type methodValue struct { + fn uintptr + stack *bitVector // ptrmap for both args and results + argLen uintptr // just args + method int + rcvr Value +} + +// makeMethodValue converts v from the rcvr+method index representation +// of a method value to an actual method func value, which is +// basically the receiver value with a special bit set, into a true +// func value - a value holding an actual func. The output is +// semantically equivalent to the input as far as the user of package +// reflect can tell, but the true func representation can be handled +// by code like Convert and Interface and Assign. +func makeMethodValue(op string, v Value) Value { + if v.flag&flagMethod == 0 { + panic("reflect: internal error: invalid use of makeMethodValue") + } + + // Ignoring the flagMethod bit, v describes the receiver, not the method type. + fl := v.flag & (flagRO | flagAddr | flagIndir) + fl |= flag(v.typ.Kind()) + rcvr := Value{v.typ, v.ptr, fl} + + // v.Type returns the actual type of the method value. + ftyp := (*funcType)(unsafe.Pointer(v.Type().(*rtype))) + + // Indirect Go func value (dummy) to obtain + // actual code address. (A Go func value is a pointer + // to a C function pointer. https://golang.org/s/go11func.) + dummy := methodValueCall + code := **(**uintptr)(unsafe.Pointer(&dummy)) + + // methodValue contains a stack map for use by the runtime + _, argLen, _, stack, _ := funcLayout(ftyp, nil) + + fv := &methodValue{ + fn: code, + stack: stack, + argLen: argLen, + method: int(v.flag) >> flagMethodShift, + rcvr: rcvr, + } + + // Cause panic if method is not appropriate. + // The panic would still happen during the call if we omit this, + // but we want Interface() and other operations to fail early. + methodReceiver(op, fv.rcvr, fv.method) + + return Value{&ftyp.rtype, unsafe.Pointer(fv), v.flag&flagRO | flag(Func)} +} + +// methodValueCall is an assembly function that is the code half of +// the function returned from makeMethodValue. It expects a *methodValue +// as its context register, and its job is to invoke callMethod(ctxt, frame) +// where ctxt is the context register and frame is a pointer to the first +// word in the passed-in argument frame. +func methodValueCall() diff --git a/src/reflect/set_test.go b/src/reflect/set_test.go new file mode 100644 index 0000000..a633e6e --- /dev/null +++ b/src/reflect/set_test.go @@ -0,0 +1,226 @@ +// 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 reflect_test + +import ( + "bytes" + "go/ast" + "go/token" + "io" + . "reflect" + "testing" + "unsafe" +) + +func TestImplicitMapConversion(t *testing.T) { + // Test implicit conversions in MapIndex and SetMapIndex. + { + // direct + m := make(map[int]int) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#1 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#1 MapIndex(1) = %d", n) + } + } + { + // convert interface key + m := make(map[interface{}]int) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#2 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#2 MapIndex(1) = %d", n) + } + } + { + // convert interface value + m := make(map[int]interface{}) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#3 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#3 MapIndex(1) = %d", n) + } + } + { + // convert both interface key and interface value + m := make(map[interface{}]interface{}) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#4 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#4 MapIndex(1) = %d", n) + } + } + { + // convert both, with non-empty interfaces + m := make(map[io.Reader]io.Writer) + mv := ValueOf(m) + b1 := new(bytes.Buffer) + b2 := new(bytes.Buffer) + mv.SetMapIndex(ValueOf(b1), ValueOf(b2)) + x, ok := m[b1] + if x != b2 { + t.Errorf("#5 after SetMapIndex(b1, b2): %p (!= %p), %t (map=%v)", x, b2, ok, m) + } + if p := mv.MapIndex(ValueOf(b1)).Elem().Pointer(); p != uintptr(unsafe.Pointer(b2)) { + t.Errorf("#5 MapIndex(b1) = %#x want %p", p, b2) + } + } + { + // convert channel direction + m := make(map[<-chan int]chan int) + mv := ValueOf(m) + c1 := make(chan int) + c2 := make(chan int) + mv.SetMapIndex(ValueOf(c1), ValueOf(c2)) + x, ok := m[c1] + if x != c2 { + t.Errorf("#6 after SetMapIndex(c1, c2): %p (!= %p), %t (map=%v)", x, c2, ok, m) + } + if p := mv.MapIndex(ValueOf(c1)).Pointer(); p != ValueOf(c2).Pointer() { + t.Errorf("#6 MapIndex(c1) = %#x want %p", p, c2) + } + } + { + // convert identical underlying types + type MyBuffer bytes.Buffer + m := make(map[*MyBuffer]*bytes.Buffer) + mv := ValueOf(m) + b1 := new(MyBuffer) + b2 := new(bytes.Buffer) + mv.SetMapIndex(ValueOf(b1), ValueOf(b2)) + x, ok := m[b1] + if x != b2 { + t.Errorf("#7 after SetMapIndex(b1, b2): %p (!= %p), %t (map=%v)", x, b2, ok, m) + } + if p := mv.MapIndex(ValueOf(b1)).Pointer(); p != uintptr(unsafe.Pointer(b2)) { + t.Errorf("#7 MapIndex(b1) = %#x want %p", p, b2) + } + } + +} + +func TestImplicitSetConversion(t *testing.T) { + // Assume TestImplicitMapConversion covered the basics. + // Just make sure conversions are being applied at all. + var r io.Reader + b := new(bytes.Buffer) + rv := ValueOf(&r).Elem() + rv.Set(ValueOf(b)) + if r != b { + t.Errorf("after Set: r=%T(%v)", r, r) + } +} + +func TestImplicitSendConversion(t *testing.T) { + c := make(chan io.Reader, 10) + b := new(bytes.Buffer) + ValueOf(c).Send(ValueOf(b)) + if bb := <-c; bb != b { + t.Errorf("Received %p != %p", bb, b) + } +} + +func TestImplicitCallConversion(t *testing.T) { + // Arguments must be assignable to parameter types. + fv := ValueOf(io.WriteString) + b := new(bytes.Buffer) + fv.Call([]Value{ValueOf(b), ValueOf("hello world")}) + if b.String() != "hello world" { + t.Errorf("After call: string=%q want %q", b.String(), "hello world") + } +} + +func TestImplicitAppendConversion(t *testing.T) { + // Arguments must be assignable to the slice's element type. + s := []io.Reader{} + sv := ValueOf(&s).Elem() + b := new(bytes.Buffer) + sv.Set(Append(sv, ValueOf(b))) + if len(s) != 1 || s[0] != b { + t.Errorf("after append: s=%v want [%p]", s, b) + } +} + +var implementsTests = []struct { + x interface{} + t interface{} + b bool +}{ + {new(*bytes.Buffer), new(io.Reader), true}, + {new(bytes.Buffer), new(io.Reader), false}, + {new(*bytes.Buffer), new(io.ReaderAt), false}, + {new(*ast.Ident), new(ast.Expr), true}, + {new(*notAnExpr), new(ast.Expr), false}, + {new(*ast.Ident), new(notASTExpr), false}, + {new(notASTExpr), new(ast.Expr), false}, + {new(ast.Expr), new(notASTExpr), false}, + {new(*notAnExpr), new(notASTExpr), true}, +} + +type notAnExpr struct{} + +func (notAnExpr) Pos() token.Pos { return token.NoPos } +func (notAnExpr) End() token.Pos { return token.NoPos } +func (notAnExpr) exprNode() {} + +type notASTExpr interface { + Pos() token.Pos + End() token.Pos + exprNode() +} + +func TestImplements(t *testing.T) { + for _, tt := range implementsTests { + xv := TypeOf(tt.x).Elem() + xt := TypeOf(tt.t).Elem() + if b := xv.Implements(xt); b != tt.b { + t.Errorf("(%s).Implements(%s) = %v, want %v", xv.String(), xt.String(), b, tt.b) + } + } +} + +var assignableTests = []struct { + x interface{} + t interface{} + b bool +}{ + {new(chan int), new(<-chan int), true}, + {new(<-chan int), new(chan int), false}, + {new(*int), new(IntPtr), true}, + {new(IntPtr), new(*int), true}, + {new(IntPtr), new(IntPtr1), false}, + {new(Ch), new(<-chan interface{}), true}, + // test runs implementsTests too +} + +type IntPtr *int +type IntPtr1 *int +type Ch <-chan interface{} + +func TestAssignableTo(t *testing.T) { + for _, tt := range append(assignableTests, implementsTests...) { + xv := TypeOf(tt.x).Elem() + xt := TypeOf(tt.t).Elem() + if b := xv.AssignableTo(xt); b != tt.b { + t.Errorf("(%s).AssignableTo(%s) = %v, want %v", xv.String(), xt.String(), b, tt.b) + } + } +} diff --git a/src/reflect/swapper.go b/src/reflect/swapper.go new file mode 100644 index 0000000..0cf4066 --- /dev/null +++ b/src/reflect/swapper.go @@ -0,0 +1,77 @@ +// 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 reflect + +import ( + "internal/unsafeheader" + "unsafe" +) + +// Swapper returns a function that swaps the elements in the provided +// slice. +// +// Swapper panics if the provided interface is not a slice. +func Swapper(slice interface{}) func(i, j int) { + v := ValueOf(slice) + if v.Kind() != Slice { + panic(&ValueError{Method: "Swapper", Kind: v.Kind()}) + } + // Fast path for slices of size 0 and 1. Nothing to swap. + switch v.Len() { + case 0: + return func(i, j int) { panic("reflect: slice index out of range") } + case 1: + return func(i, j int) { + if i != 0 || j != 0 { + panic("reflect: slice index out of range") + } + } + } + + typ := v.Type().Elem().(*rtype) + size := typ.Size() + hasPtr := typ.ptrdata != 0 + + // Some common & small cases, without using memmove: + if hasPtr { + if size == ptrSize { + ps := *(*[]unsafe.Pointer)(v.ptr) + return func(i, j int) { ps[i], ps[j] = ps[j], ps[i] } + } + if typ.Kind() == String { + ss := *(*[]string)(v.ptr) + return func(i, j int) { ss[i], ss[j] = ss[j], ss[i] } + } + } else { + switch size { + case 8: + is := *(*[]int64)(v.ptr) + return func(i, j int) { is[i], is[j] = is[j], is[i] } + case 4: + is := *(*[]int32)(v.ptr) + return func(i, j int) { is[i], is[j] = is[j], is[i] } + case 2: + is := *(*[]int16)(v.ptr) + return func(i, j int) { is[i], is[j] = is[j], is[i] } + case 1: + is := *(*[]int8)(v.ptr) + return func(i, j int) { is[i], is[j] = is[j], is[i] } + } + } + + s := (*unsafeheader.Slice)(v.ptr) + tmp := unsafe_New(typ) // swap scratch space + + return func(i, j int) { + if uint(i) >= uint(s.Len) || uint(j) >= uint(s.Len) { + panic("reflect: slice index out of range") + } + val1 := arrayAt(s.Data, i, size, "i < s.Len") + val2 := arrayAt(s.Data, j, size, "j < s.Len") + typedmemmove(typ, tmp, val1) + typedmemmove(typ, val1, val2) + typedmemmove(typ, val2, tmp) + } +} diff --git a/src/reflect/tostring_test.go b/src/reflect/tostring_test.go new file mode 100644 index 0000000..e416fd8 --- /dev/null +++ b/src/reflect/tostring_test.go @@ -0,0 +1,95 @@ +// 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. + +// Formatting of reflection types and values for debugging. +// Not defined as methods so they do not need to be linked into most binaries; +// the functions are not used by the library itself, only in tests. + +package reflect_test + +import ( + . "reflect" + "strconv" +) + +// valueToString returns a textual representation of the reflection value val. +// For debugging only. +func valueToString(val Value) string { + var str string + if !val.IsValid() { + return "<zero Value>" + } + typ := val.Type() + switch val.Kind() { + case Int, Int8, Int16, Int32, Int64: + return strconv.FormatInt(val.Int(), 10) + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return strconv.FormatUint(val.Uint(), 10) + case Float32, Float64: + return strconv.FormatFloat(val.Float(), 'g', -1, 64) + case Complex64, Complex128: + c := val.Complex() + return strconv.FormatFloat(real(c), 'g', -1, 64) + "+" + strconv.FormatFloat(imag(c), 'g', -1, 64) + "i" + case String: + return val.String() + case Bool: + if val.Bool() { + return "true" + } else { + return "false" + } + case Ptr: + v := val + str = typ.String() + "(" + if v.IsNil() { + str += "0" + } else { + str += "&" + valueToString(v.Elem()) + } + str += ")" + return str + case Array, Slice: + v := val + str += typ.String() + str += "{" + for i := 0; i < v.Len(); i++ { + if i > 0 { + str += ", " + } + str += valueToString(v.Index(i)) + } + str += "}" + return str + case Map: + t := typ + str = t.String() + str += "{" + str += "<can't iterate on maps>" + str += "}" + return str + case Chan: + str = typ.String() + return str + case Struct: + t := typ + v := val + str += t.String() + str += "{" + for i, n := 0, v.NumField(); i < n; i++ { + if i > 0 { + str += ", " + } + str += valueToString(v.Field(i)) + } + str += "}" + return str + case Interface: + return typ.String() + "(" + valueToString(val.Elem()) + ")" + case Func: + v := val + return typ.String() + "(" + strconv.FormatUint(uint64(v.Pointer()), 10) + ")" + default: + panic("valueToString: can't print type " + typ.String()) + } +} diff --git a/src/reflect/type.go b/src/reflect/type.go new file mode 100644 index 0000000..a1cdf45 --- /dev/null +++ b/src/reflect/type.go @@ -0,0 +1,3132 @@ +// 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 reflect implements run-time reflection, allowing a program to +// manipulate objects with arbitrary types. The typical use is to take a value +// with static type interface{} and extract its dynamic type information by +// calling TypeOf, which returns a Type. +// +// A call to ValueOf returns a Value representing the run-time data. +// Zero takes a Type and returns a Value representing a zero value +// for that type. +// +// See "The Laws of Reflection" for an introduction to reflection in Go: +// https://golang.org/doc/articles/laws_of_reflection.html +package reflect + +import ( + "internal/unsafeheader" + "strconv" + "sync" + "unicode" + "unicode/utf8" + "unsafe" +) + +// Type is the representation of a Go type. +// +// Not all methods apply to all kinds of types. Restrictions, +// if any, are noted in the documentation for each method. +// Use the Kind method to find out the kind of type before +// calling kind-specific methods. Calling a method +// inappropriate to the kind of type causes a run-time panic. +// +// Type values are comparable, such as with the == operator, +// so they can be used as map keys. +// Two Type values are equal if they represent identical types. +type Type interface { + // Methods applicable to all types. + + // Align returns the alignment in bytes of a value of + // this type when allocated in memory. + Align() int + + // FieldAlign returns the alignment in bytes of a value of + // this type when used as a field in a struct. + FieldAlign() int + + // Method returns the i'th method in the type's method set. + // It panics if i is not in the range [0, NumMethod()). + // + // For a non-interface type T or *T, the returned Method's Type and Func + // fields describe a function whose first argument is the receiver, + // and only exported methods are accessible. + // + // For an interface type, the returned Method's Type field gives the + // method signature, without a receiver, and the Func field is nil. + // + // Methods are sorted in lexicographic order. + Method(int) Method + + // MethodByName returns the method with that name in the type's + // method set and a boolean indicating if the method was found. + // + // For a non-interface type T or *T, the returned Method's Type and Func + // fields describe a function whose first argument is the receiver. + // + // For an interface type, the returned Method's Type field gives the + // method signature, without a receiver, and the Func field is nil. + MethodByName(string) (Method, bool) + + // NumMethod returns the number of methods accessible using Method. + // + // Note that NumMethod counts unexported methods only for interface types. + NumMethod() int + + // Name returns the type's name within its package for a defined type. + // For other (non-defined) types it returns the empty string. + Name() string + + // PkgPath returns a defined type's package path, that is, the import path + // that uniquely identifies the package, such as "encoding/base64". + // If the type was predeclared (string, error) or not defined (*T, struct{}, + // []int, or A where A is an alias for a non-defined type), the package path + // will be the empty string. + PkgPath() string + + // Size returns the number of bytes needed to store + // a value of the given type; it is analogous to unsafe.Sizeof. + Size() uintptr + + // String returns a string representation of the type. + // The string representation may use shortened package names + // (e.g., base64 instead of "encoding/base64") and is not + // guaranteed to be unique among types. To test for type identity, + // compare the Types directly. + String() string + + // Kind returns the specific kind of this type. + Kind() Kind + + // Implements reports whether the type implements the interface type u. + Implements(u Type) bool + + // AssignableTo reports whether a value of the type is assignable to type u. + AssignableTo(u Type) bool + + // ConvertibleTo reports whether a value of the type is convertible to type u. + ConvertibleTo(u Type) bool + + // Comparable reports whether values of this type are comparable. + Comparable() bool + + // Methods applicable only to some types, depending on Kind. + // The methods allowed for each kind are: + // + // Int*, Uint*, Float*, Complex*: Bits + // Array: Elem, Len + // Chan: ChanDir, Elem + // Func: In, NumIn, Out, NumOut, IsVariadic. + // Map: Key, Elem + // Ptr: Elem + // Slice: Elem + // Struct: Field, FieldByIndex, FieldByName, FieldByNameFunc, NumField + + // Bits returns the size of the type in bits. + // It panics if the type's Kind is not one of the + // sized or unsized Int, Uint, Float, or Complex kinds. + Bits() int + + // ChanDir returns a channel type's direction. + // It panics if the type's Kind is not Chan. + ChanDir() ChanDir + + // IsVariadic reports whether a function type's final input parameter + // is a "..." parameter. If so, t.In(t.NumIn() - 1) returns the parameter's + // implicit actual type []T. + // + // For concreteness, if t represents func(x int, y ... float64), then + // + // t.NumIn() == 2 + // t.In(0) is the reflect.Type for "int" + // t.In(1) is the reflect.Type for "[]float64" + // t.IsVariadic() == true + // + // IsVariadic panics if the type's Kind is not Func. + IsVariadic() bool + + // Elem returns a type's element type. + // It panics if the type's Kind is not Array, Chan, Map, Ptr, or Slice. + Elem() Type + + // Field returns a struct type's i'th field. + // It panics if the type's Kind is not Struct. + // It panics if i is not in the range [0, NumField()). + Field(i int) StructField + + // FieldByIndex returns the nested field corresponding + // to the index sequence. It is equivalent to calling Field + // successively for each index i. + // It panics if the type's Kind is not Struct. + FieldByIndex(index []int) StructField + + // FieldByName returns the struct field with the given name + // and a boolean indicating if the field was found. + FieldByName(name string) (StructField, bool) + + // FieldByNameFunc returns the struct field with a name + // that satisfies the match function and a boolean indicating if + // the field was found. + // + // FieldByNameFunc considers the fields in the struct itself + // and then the fields in any embedded structs, in breadth first order, + // stopping at the shallowest nesting depth containing one or more + // fields satisfying the match function. If multiple fields at that depth + // satisfy the match function, they cancel each other + // and FieldByNameFunc returns no match. + // This behavior mirrors Go's handling of name lookup in + // structs containing embedded fields. + FieldByNameFunc(match func(string) bool) (StructField, bool) + + // In returns the type of a function type's i'th input parameter. + // It panics if the type's Kind is not Func. + // It panics if i is not in the range [0, NumIn()). + In(i int) Type + + // Key returns a map type's key type. + // It panics if the type's Kind is not Map. + Key() Type + + // Len returns an array type's length. + // It panics if the type's Kind is not Array. + Len() int + + // NumField returns a struct type's field count. + // It panics if the type's Kind is not Struct. + NumField() int + + // NumIn returns a function type's input parameter count. + // It panics if the type's Kind is not Func. + NumIn() int + + // NumOut returns a function type's output parameter count. + // It panics if the type's Kind is not Func. + NumOut() int + + // Out returns the type of a function type's i'th output parameter. + // It panics if the type's Kind is not Func. + // It panics if i is not in the range [0, NumOut()). + Out(i int) Type + + common() *rtype + uncommon() *uncommonType +} + +// BUG(rsc): FieldByName and related functions consider struct field names to be equal +// if the names are equal, even if they are unexported names originating +// in different packages. The practical effect of this is that the result of +// t.FieldByName("x") is not well defined if the struct type t contains +// multiple fields named x (embedded from different packages). +// FieldByName may return one of the fields named x or may report that there are none. +// See https://golang.org/issue/4876 for more details. + +/* + * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go). + * A few are known to ../runtime/type.go to convey to debuggers. + * They are also known to ../runtime/type.go. + */ + +// A Kind represents the specific kind of type that a Type represents. +// The zero Kind is not a valid kind. +type Kind uint + +const ( + Invalid Kind = iota + Bool + Int + Int8 + Int16 + Int32 + Int64 + Uint + Uint8 + Uint16 + Uint32 + Uint64 + Uintptr + Float32 + Float64 + Complex64 + Complex128 + Array + Chan + Func + Interface + Map + Ptr + Slice + String + Struct + UnsafePointer +) + +// tflag is used by an rtype to signal what extra type information is +// available in the memory directly following the rtype value. +// +// tflag values must be kept in sync with copies in: +// cmd/compile/internal/gc/reflect.go +// cmd/link/internal/ld/decodesym.go +// runtime/type.go +type tflag uint8 + +const ( + // tflagUncommon means that there is a pointer, *uncommonType, + // just beyond the outer type structure. + // + // For example, if t.Kind() == Struct and t.tflag&tflagUncommon != 0, + // then t has uncommonType data and it can be accessed as: + // + // type tUncommon struct { + // structType + // u uncommonType + // } + // u := &(*tUncommon)(unsafe.Pointer(t)).u + tflagUncommon tflag = 1 << 0 + + // tflagExtraStar means the name in the str field has an + // extraneous '*' prefix. This is because for most types T in + // a program, the type *T also exists and reusing the str data + // saves binary size. + tflagExtraStar tflag = 1 << 1 + + // tflagNamed means the type has a name. + tflagNamed tflag = 1 << 2 + + // tflagRegularMemory means that equal and hash functions can treat + // this type as a single region of t.size bytes. + tflagRegularMemory tflag = 1 << 3 +) + +// rtype is the common implementation of most values. +// It is embedded in other struct types. +// +// rtype must be kept in sync with ../runtime/type.go:/^type._type. +type rtype struct { + size uintptr + ptrdata uintptr // number of bytes in the type that can contain pointers + hash uint32 // hash of type; avoids computation in hash tables + tflag tflag // extra type information flags + align uint8 // alignment of variable with this type + fieldAlign uint8 // alignment of struct field with this type + kind uint8 // enumeration for C + // function for comparing objects of this type + // (ptr to object A, ptr to object B) -> ==? + equal func(unsafe.Pointer, unsafe.Pointer) bool + gcdata *byte // garbage collection data + str nameOff // string form + ptrToThis typeOff // type for pointer to this type, may be zero +} + +// Method on non-interface type +type method struct { + name nameOff // name of method + mtyp typeOff // method type (without receiver) + ifn textOff // fn used in interface call (one-word receiver) + tfn textOff // fn used for normal method call +} + +// uncommonType is present only for defined types or types with methods +// (if T is a defined type, the uncommonTypes for T and *T have methods). +// Using a pointer to this struct reduces the overall size required +// to describe a non-defined type with no methods. +type uncommonType struct { + pkgPath nameOff // import path; empty for built-in types like int, string + mcount uint16 // number of methods + xcount uint16 // number of exported methods + moff uint32 // offset from this uncommontype to [mcount]method + _ uint32 // unused +} + +// ChanDir represents a channel type's direction. +type ChanDir int + +const ( + RecvDir ChanDir = 1 << iota // <-chan + SendDir // chan<- + BothDir = RecvDir | SendDir // chan +) + +// arrayType represents a fixed array type. +type arrayType struct { + rtype + elem *rtype // array element type + slice *rtype // slice type + len uintptr +} + +// chanType represents a channel type. +type chanType struct { + rtype + elem *rtype // channel element type + dir uintptr // channel direction (ChanDir) +} + +// funcType represents a function type. +// +// A *rtype for each in and out parameter is stored in an array that +// directly follows the funcType (and possibly its uncommonType). So +// a function type with one method, one input, and one output is: +// +// struct { +// funcType +// uncommonType +// [2]*rtype // [0] is in, [1] is out +// } +type funcType struct { + rtype + inCount uint16 + outCount uint16 // top bit is set if last input parameter is ... +} + +// imethod represents a method on an interface type +type imethod struct { + name nameOff // name of method + typ typeOff // .(*FuncType) underneath +} + +// interfaceType represents an interface type. +type interfaceType struct { + rtype + pkgPath name // import path + methods []imethod // sorted by hash +} + +// mapType represents a map type. +type mapType struct { + rtype + key *rtype // map key type + elem *rtype // map element (value) type + bucket *rtype // internal bucket structure + // function for hashing keys (ptr to key, seed) -> hash + hasher func(unsafe.Pointer, uintptr) uintptr + keysize uint8 // size of key slot + valuesize uint8 // size of value slot + bucketsize uint16 // size of bucket + flags uint32 +} + +// ptrType represents a pointer type. +type ptrType struct { + rtype + elem *rtype // pointer element (pointed at) type +} + +// sliceType represents a slice type. +type sliceType struct { + rtype + elem *rtype // slice element type +} + +// Struct field +type structField struct { + name name // name is always non-empty + typ *rtype // type of field + offsetEmbed uintptr // byte offset of field<<1 | isEmbedded +} + +func (f *structField) offset() uintptr { + return f.offsetEmbed >> 1 +} + +func (f *structField) embedded() bool { + return f.offsetEmbed&1 != 0 +} + +// structType represents a struct type. +type structType struct { + rtype + pkgPath name + fields []structField // sorted by offset +} + +// name is an encoded type name with optional extra data. +// +// The first byte is a bit field containing: +// +// 1<<0 the name is exported +// 1<<1 tag data follows the name +// 1<<2 pkgPath nameOff follows the name and tag +// +// The next two bytes are the data length: +// +// l := uint16(data[1])<<8 | uint16(data[2]) +// +// Bytes [3:3+l] are the string data. +// +// If tag data follows then bytes 3+l and 3+l+1 are the tag length, +// with the data following. +// +// If the import path follows, then 4 bytes at the end of +// the data form a nameOff. The import path is only set for concrete +// methods that are defined in a different package than their type. +// +// If a name starts with "*", then the exported bit represents +// whether the pointed to type is exported. +type name struct { + bytes *byte +} + +func (n name) data(off int, whySafe string) *byte { + return (*byte)(add(unsafe.Pointer(n.bytes), uintptr(off), whySafe)) +} + +func (n name) isExported() bool { + return (*n.bytes)&(1<<0) != 0 +} + +func (n name) nameLen() int { + return int(uint16(*n.data(1, "name len field"))<<8 | uint16(*n.data(2, "name len field"))) +} + +func (n name) tagLen() int { + if *n.data(0, "name flag field")&(1<<1) == 0 { + return 0 + } + off := 3 + n.nameLen() + return int(uint16(*n.data(off, "name taglen field"))<<8 | uint16(*n.data(off+1, "name taglen field"))) +} + +func (n name) name() (s string) { + if n.bytes == nil { + return + } + b := (*[4]byte)(unsafe.Pointer(n.bytes)) + + hdr := (*unsafeheader.String)(unsafe.Pointer(&s)) + hdr.Data = unsafe.Pointer(&b[3]) + hdr.Len = int(b[1])<<8 | int(b[2]) + return s +} + +func (n name) tag() (s string) { + tl := n.tagLen() + if tl == 0 { + return "" + } + nl := n.nameLen() + hdr := (*unsafeheader.String)(unsafe.Pointer(&s)) + hdr.Data = unsafe.Pointer(n.data(3+nl+2, "non-empty string")) + hdr.Len = tl + return s +} + +func (n name) pkgPath() string { + if n.bytes == nil || *n.data(0, "name flag field")&(1<<2) == 0 { + return "" + } + off := 3 + n.nameLen() + if tl := n.tagLen(); tl > 0 { + off += 2 + tl + } + var nameOff int32 + // Note that this field may not be aligned in memory, + // so we cannot use a direct int32 assignment here. + copy((*[4]byte)(unsafe.Pointer(&nameOff))[:], (*[4]byte)(unsafe.Pointer(n.data(off, "name offset field")))[:]) + pkgPathName := name{(*byte)(resolveTypeOff(unsafe.Pointer(n.bytes), nameOff))} + return pkgPathName.name() +} + +func newName(n, tag string, exported bool) name { + if len(n) > 1<<16-1 { + panic("reflect.nameFrom: name too long: " + n) + } + if len(tag) > 1<<16-1 { + panic("reflect.nameFrom: tag too long: " + tag) + } + + var bits byte + l := 1 + 2 + len(n) + if exported { + bits |= 1 << 0 + } + if len(tag) > 0 { + l += 2 + len(tag) + bits |= 1 << 1 + } + + b := make([]byte, l) + b[0] = bits + b[1] = uint8(len(n) >> 8) + b[2] = uint8(len(n)) + copy(b[3:], n) + if len(tag) > 0 { + tb := b[3+len(n):] + tb[0] = uint8(len(tag) >> 8) + tb[1] = uint8(len(tag)) + copy(tb[2:], tag) + } + + return name{bytes: &b[0]} +} + +/* + * The compiler knows the exact layout of all the data structures above. + * The compiler does not know about the data structures and methods below. + */ + +// Method represents a single method. +type Method struct { + // Name is the method name. + // PkgPath is the package path that qualifies a lower case (unexported) + // method name. It is empty for upper case (exported) method names. + // The combination of PkgPath and Name uniquely identifies a method + // in a method set. + // See https://golang.org/ref/spec#Uniqueness_of_identifiers + Name string + PkgPath string + + Type Type // method type + Func Value // func with receiver as first argument + Index int // index for Type.Method +} + +const ( + kindDirectIface = 1 << 5 + kindGCProg = 1 << 6 // Type.gc points to GC program + kindMask = (1 << 5) - 1 +) + +// String returns the name of k. +func (k Kind) String() string { + if int(k) < len(kindNames) { + return kindNames[k] + } + return "kind" + strconv.Itoa(int(k)) +} + +var kindNames = []string{ + Invalid: "invalid", + Bool: "bool", + Int: "int", + Int8: "int8", + Int16: "int16", + Int32: "int32", + Int64: "int64", + Uint: "uint", + Uint8: "uint8", + Uint16: "uint16", + Uint32: "uint32", + Uint64: "uint64", + Uintptr: "uintptr", + Float32: "float32", + Float64: "float64", + Complex64: "complex64", + Complex128: "complex128", + Array: "array", + Chan: "chan", + Func: "func", + Interface: "interface", + Map: "map", + Ptr: "ptr", + Slice: "slice", + String: "string", + Struct: "struct", + UnsafePointer: "unsafe.Pointer", +} + +func (t *uncommonType) methods() []method { + if t.mcount == 0 { + return nil + } + return (*[1 << 16]method)(add(unsafe.Pointer(t), uintptr(t.moff), "t.mcount > 0"))[:t.mcount:t.mcount] +} + +func (t *uncommonType) exportedMethods() []method { + if t.xcount == 0 { + return nil + } + return (*[1 << 16]method)(add(unsafe.Pointer(t), uintptr(t.moff), "t.xcount > 0"))[:t.xcount:t.xcount] +} + +// resolveNameOff resolves a name offset from a base pointer. +// The (*rtype).nameOff method is a convenience wrapper for this function. +// Implemented in the runtime package. +func resolveNameOff(ptrInModule unsafe.Pointer, off int32) unsafe.Pointer + +// resolveTypeOff resolves an *rtype offset from a base type. +// The (*rtype).typeOff method is a convenience wrapper for this function. +// Implemented in the runtime package. +func resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer + +// resolveTextOff resolves a function pointer offset from a base type. +// The (*rtype).textOff method is a convenience wrapper for this function. +// Implemented in the runtime package. +func resolveTextOff(rtype unsafe.Pointer, off int32) unsafe.Pointer + +// addReflectOff adds a pointer to the reflection lookup map in the runtime. +// It returns a new ID that can be used as a typeOff or textOff, and will +// be resolved correctly. Implemented in the runtime package. +func addReflectOff(ptr unsafe.Pointer) int32 + +// resolveReflectName adds a name to the reflection lookup map in the runtime. +// It returns a new nameOff that can be used to refer to the pointer. +func resolveReflectName(n name) nameOff { + return nameOff(addReflectOff(unsafe.Pointer(n.bytes))) +} + +// resolveReflectType adds a *rtype to the reflection lookup map in the runtime. +// It returns a new typeOff that can be used to refer to the pointer. +func resolveReflectType(t *rtype) typeOff { + return typeOff(addReflectOff(unsafe.Pointer(t))) +} + +// resolveReflectText adds a function pointer to the reflection lookup map in +// the runtime. It returns a new textOff that can be used to refer to the +// pointer. +func resolveReflectText(ptr unsafe.Pointer) textOff { + return textOff(addReflectOff(ptr)) +} + +type nameOff int32 // offset to a name +type typeOff int32 // offset to an *rtype +type textOff int32 // offset from top of text section + +func (t *rtype) nameOff(off nameOff) name { + return name{(*byte)(resolveNameOff(unsafe.Pointer(t), int32(off)))} +} + +func (t *rtype) typeOff(off typeOff) *rtype { + return (*rtype)(resolveTypeOff(unsafe.Pointer(t), int32(off))) +} + +func (t *rtype) textOff(off textOff) unsafe.Pointer { + return resolveTextOff(unsafe.Pointer(t), int32(off)) +} + +func (t *rtype) uncommon() *uncommonType { + if t.tflag&tflagUncommon == 0 { + return nil + } + switch t.Kind() { + case Struct: + return &(*structTypeUncommon)(unsafe.Pointer(t)).u + case Ptr: + type u struct { + ptrType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Func: + type u struct { + funcType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Slice: + type u struct { + sliceType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Array: + type u struct { + arrayType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Chan: + type u struct { + chanType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Map: + type u struct { + mapType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + case Interface: + type u struct { + interfaceType + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + default: + type u struct { + rtype + u uncommonType + } + return &(*u)(unsafe.Pointer(t)).u + } +} + +func (t *rtype) String() string { + s := t.nameOff(t.str).name() + if t.tflag&tflagExtraStar != 0 { + return s[1:] + } + return s +} + +func (t *rtype) Size() uintptr { return t.size } + +func (t *rtype) Bits() int { + if t == nil { + panic("reflect: Bits of nil Type") + } + k := t.Kind() + if k < Int || k > Complex128 { + panic("reflect: Bits of non-arithmetic Type " + t.String()) + } + return int(t.size) * 8 +} + +func (t *rtype) Align() int { return int(t.align) } + +func (t *rtype) FieldAlign() int { return int(t.fieldAlign) } + +func (t *rtype) Kind() Kind { return Kind(t.kind & kindMask) } + +func (t *rtype) pointers() bool { return t.ptrdata != 0 } + +func (t *rtype) common() *rtype { return t } + +func (t *rtype) exportedMethods() []method { + ut := t.uncommon() + if ut == nil { + return nil + } + return ut.exportedMethods() +} + +func (t *rtype) NumMethod() int { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.NumMethod() + } + return len(t.exportedMethods()) +} + +func (t *rtype) Method(i int) (m Method) { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.Method(i) + } + methods := t.exportedMethods() + if i < 0 || i >= len(methods) { + panic("reflect: Method index out of range") + } + p := methods[i] + pname := t.nameOff(p.name) + m.Name = pname.name() + fl := flag(Func) + mtyp := t.typeOff(p.mtyp) + ft := (*funcType)(unsafe.Pointer(mtyp)) + in := make([]Type, 0, 1+len(ft.in())) + in = append(in, t) + for _, arg := range ft.in() { + in = append(in, arg) + } + out := make([]Type, 0, len(ft.out())) + for _, ret := range ft.out() { + out = append(out, ret) + } + mt := FuncOf(in, out, ft.IsVariadic()) + m.Type = mt + tfn := t.textOff(p.tfn) + fn := unsafe.Pointer(&tfn) + m.Func = Value{mt.(*rtype), fn, fl} + + m.Index = i + return m +} + +func (t *rtype) MethodByName(name string) (m Method, ok bool) { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.MethodByName(name) + } + ut := t.uncommon() + if ut == nil { + return Method{}, false + } + // TODO(mdempsky): Binary search. + for i, p := range ut.exportedMethods() { + if t.nameOff(p.name).name() == name { + return t.Method(i), true + } + } + return Method{}, false +} + +func (t *rtype) PkgPath() string { + if t.tflag&tflagNamed == 0 { + return "" + } + ut := t.uncommon() + if ut == nil { + return "" + } + return t.nameOff(ut.pkgPath).name() +} + +func (t *rtype) hasName() bool { + return t.tflag&tflagNamed != 0 +} + +func (t *rtype) Name() string { + if !t.hasName() { + return "" + } + s := t.String() + i := len(s) - 1 + for i >= 0 && s[i] != '.' { + i-- + } + return s[i+1:] +} + +func (t *rtype) ChanDir() ChanDir { + if t.Kind() != Chan { + panic("reflect: ChanDir of non-chan type " + t.String()) + } + tt := (*chanType)(unsafe.Pointer(t)) + return ChanDir(tt.dir) +} + +func (t *rtype) IsVariadic() bool { + if t.Kind() != Func { + panic("reflect: IsVariadic of non-func type " + t.String()) + } + tt := (*funcType)(unsafe.Pointer(t)) + return tt.outCount&(1<<15) != 0 +} + +func (t *rtype) Elem() Type { + switch t.Kind() { + case Array: + tt := (*arrayType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Chan: + tt := (*chanType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Map: + tt := (*mapType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Ptr: + tt := (*ptrType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Slice: + tt := (*sliceType)(unsafe.Pointer(t)) + return toType(tt.elem) + } + panic("reflect: Elem of invalid type " + t.String()) +} + +func (t *rtype) Field(i int) StructField { + if t.Kind() != Struct { + panic("reflect: Field of non-struct type " + t.String()) + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.Field(i) +} + +func (t *rtype) FieldByIndex(index []int) StructField { + if t.Kind() != Struct { + panic("reflect: FieldByIndex of non-struct type " + t.String()) + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByIndex(index) +} + +func (t *rtype) FieldByName(name string) (StructField, bool) { + if t.Kind() != Struct { + panic("reflect: FieldByName of non-struct type " + t.String()) + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByName(name) +} + +func (t *rtype) FieldByNameFunc(match func(string) bool) (StructField, bool) { + if t.Kind() != Struct { + panic("reflect: FieldByNameFunc of non-struct type " + t.String()) + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByNameFunc(match) +} + +func (t *rtype) In(i int) Type { + if t.Kind() != Func { + panic("reflect: In of non-func type " + t.String()) + } + tt := (*funcType)(unsafe.Pointer(t)) + return toType(tt.in()[i]) +} + +func (t *rtype) Key() Type { + if t.Kind() != Map { + panic("reflect: Key of non-map type " + t.String()) + } + tt := (*mapType)(unsafe.Pointer(t)) + return toType(tt.key) +} + +func (t *rtype) Len() int { + if t.Kind() != Array { + panic("reflect: Len of non-array type " + t.String()) + } + tt := (*arrayType)(unsafe.Pointer(t)) + return int(tt.len) +} + +func (t *rtype) NumField() int { + if t.Kind() != Struct { + panic("reflect: NumField of non-struct type " + t.String()) + } + tt := (*structType)(unsafe.Pointer(t)) + return len(tt.fields) +} + +func (t *rtype) NumIn() int { + if t.Kind() != Func { + panic("reflect: NumIn of non-func type " + t.String()) + } + tt := (*funcType)(unsafe.Pointer(t)) + return int(tt.inCount) +} + +func (t *rtype) NumOut() int { + if t.Kind() != Func { + panic("reflect: NumOut of non-func type " + t.String()) + } + tt := (*funcType)(unsafe.Pointer(t)) + return len(tt.out()) +} + +func (t *rtype) Out(i int) Type { + if t.Kind() != Func { + panic("reflect: Out of non-func type " + t.String()) + } + tt := (*funcType)(unsafe.Pointer(t)) + return toType(tt.out()[i]) +} + +func (t *funcType) in() []*rtype { + uadd := unsafe.Sizeof(*t) + if t.tflag&tflagUncommon != 0 { + uadd += unsafe.Sizeof(uncommonType{}) + } + if t.inCount == 0 { + return nil + } + return (*[1 << 20]*rtype)(add(unsafe.Pointer(t), uadd, "t.inCount > 0"))[:t.inCount:t.inCount] +} + +func (t *funcType) out() []*rtype { + uadd := unsafe.Sizeof(*t) + if t.tflag&tflagUncommon != 0 { + uadd += unsafe.Sizeof(uncommonType{}) + } + outCount := t.outCount & (1<<15 - 1) + if outCount == 0 { + return nil + } + return (*[1 << 20]*rtype)(add(unsafe.Pointer(t), uadd, "outCount > 0"))[t.inCount : t.inCount+outCount : t.inCount+outCount] +} + +// add returns p+x. +// +// The whySafe string is ignored, so that the function still inlines +// as efficiently as p+x, but all call sites should use the string to +// record why the addition is safe, which is to say why the addition +// does not cause x to advance to the very end of p's allocation +// and therefore point incorrectly at the next block in memory. +func add(p unsafe.Pointer, x uintptr, whySafe string) unsafe.Pointer { + return unsafe.Pointer(uintptr(p) + x) +} + +func (d ChanDir) String() string { + switch d { + case SendDir: + return "chan<-" + case RecvDir: + return "<-chan" + case BothDir: + return "chan" + } + return "ChanDir" + strconv.Itoa(int(d)) +} + +// Method returns the i'th method in the type's method set. +func (t *interfaceType) Method(i int) (m Method) { + if i < 0 || i >= len(t.methods) { + return + } + p := &t.methods[i] + pname := t.nameOff(p.name) + m.Name = pname.name() + if !pname.isExported() { + m.PkgPath = pname.pkgPath() + if m.PkgPath == "" { + m.PkgPath = t.pkgPath.name() + } + } + m.Type = toType(t.typeOff(p.typ)) + m.Index = i + return +} + +// NumMethod returns the number of interface methods in the type's method set. +func (t *interfaceType) NumMethod() int { return len(t.methods) } + +// MethodByName method with the given name in the type's method set. +func (t *interfaceType) MethodByName(name string) (m Method, ok bool) { + if t == nil { + return + } + var p *imethod + for i := range t.methods { + p = &t.methods[i] + if t.nameOff(p.name).name() == name { + return t.Method(i), true + } + } + return +} + +// A StructField describes a single field in a struct. +type StructField struct { + // Name is the field name. + Name string + // PkgPath is the package path that qualifies a lower case (unexported) + // field name. It is empty for upper case (exported) field names. + // See https://golang.org/ref/spec#Uniqueness_of_identifiers + PkgPath string + + Type Type // field type + Tag StructTag // field tag string + Offset uintptr // offset within struct, in bytes + Index []int // index sequence for Type.FieldByIndex + Anonymous bool // is an embedded field +} + +// A StructTag is the tag string in a struct field. +// +// By convention, tag strings are a concatenation of +// optionally space-separated key:"value" pairs. +// Each key is a non-empty string consisting of non-control +// characters other than space (U+0020 ' '), quote (U+0022 '"'), +// and colon (U+003A ':'). Each value is quoted using U+0022 '"' +// characters and Go string literal syntax. +type StructTag string + +// Get returns the value associated with key in the tag string. +// If there is no such key in the tag, Get returns the empty string. +// If the tag does not have the conventional format, the value +// returned by Get is unspecified. To determine whether a tag is +// explicitly set to the empty string, use Lookup. +func (tag StructTag) Get(key string) string { + v, _ := tag.Lookup(key) + return v +} + +// Lookup returns the value associated with key in the tag string. +// If the key is present in the tag the value (which may be empty) +// is returned. Otherwise the returned value will be the empty string. +// The ok return value reports whether the value was explicitly set in +// the tag string. If the tag does not have the conventional format, +// the value returned by Lookup is unspecified. +func (tag StructTag) Lookup(key string) (value string, ok bool) { + // When modifying this code, also update the validateStructTag code + // in cmd/vet/structtag.go. + + for tag != "" { + // Skip leading space. + i := 0 + for i < len(tag) && tag[i] == ' ' { + i++ + } + tag = tag[i:] + if tag == "" { + break + } + + // Scan to colon. A space, a quote or a control character is a syntax error. + // Strictly speaking, control chars include the range [0x7f, 0x9f], not just + // [0x00, 0x1f], but in practice, we ignore the multi-byte control characters + // as it is simpler to inspect the tag's bytes than the tag's runes. + i = 0 + for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f { + i++ + } + if i == 0 || i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' { + break + } + name := string(tag[:i]) + tag = tag[i+1:] + + // Scan quoted string to find value. + i = 1 + for i < len(tag) && tag[i] != '"' { + if tag[i] == '\\' { + i++ + } + i++ + } + if i >= len(tag) { + break + } + qvalue := string(tag[:i+1]) + tag = tag[i+1:] + + if key == name { + value, err := strconv.Unquote(qvalue) + if err != nil { + break + } + return value, true + } + } + return "", false +} + +// Field returns the i'th struct field. +func (t *structType) Field(i int) (f StructField) { + if i < 0 || i >= len(t.fields) { + panic("reflect: Field index out of bounds") + } + p := &t.fields[i] + f.Type = toType(p.typ) + f.Name = p.name.name() + f.Anonymous = p.embedded() + if !p.name.isExported() { + f.PkgPath = t.pkgPath.name() + } + if tag := p.name.tag(); tag != "" { + f.Tag = StructTag(tag) + } + f.Offset = p.offset() + + // NOTE(rsc): This is the only allocation in the interface + // presented by a reflect.Type. It would be nice to avoid, + // at least in the common cases, but we need to make sure + // that misbehaving clients of reflect cannot affect other + // uses of reflect. One possibility is CL 5371098, but we + // postponed that ugliness until there is a demonstrated + // need for the performance. This is issue 2320. + f.Index = []int{i} + return +} + +// TODO(gri): Should there be an error/bool indicator if the index +// is wrong for FieldByIndex? + +// FieldByIndex returns the nested field corresponding to index. +func (t *structType) FieldByIndex(index []int) (f StructField) { + f.Type = toType(&t.rtype) + for i, x := range index { + if i > 0 { + ft := f.Type + if ft.Kind() == Ptr && ft.Elem().Kind() == Struct { + ft = ft.Elem() + } + f.Type = ft + } + f = f.Type.Field(x) + } + return +} + +// A fieldScan represents an item on the fieldByNameFunc scan work list. +type fieldScan struct { + typ *structType + index []int +} + +// FieldByNameFunc returns the struct field with a name that satisfies the +// match function and a boolean to indicate if the field was found. +func (t *structType) FieldByNameFunc(match func(string) bool) (result StructField, ok bool) { + // This uses the same condition that the Go language does: there must be a unique instance + // of the match at a given depth level. If there are multiple instances of a match at the + // same depth, they annihilate each other and inhibit any possible match at a lower level. + // The algorithm is breadth first search, one depth level at a time. + + // The current and next slices are work queues: + // current lists the fields to visit on this depth level, + // and next lists the fields on the next lower level. + current := []fieldScan{} + next := []fieldScan{{typ: t}} + + // nextCount records the number of times an embedded type has been + // encountered and considered for queueing in the 'next' slice. + // We only queue the first one, but we increment the count on each. + // If a struct type T can be reached more than once at a given depth level, + // then it annihilates itself and need not be considered at all when we + // process that next depth level. + var nextCount map[*structType]int + + // visited records the structs that have been considered already. + // Embedded pointer fields can create cycles in the graph of + // reachable embedded types; visited avoids following those cycles. + // It also avoids duplicated effort: if we didn't find the field in an + // embedded type T at level 2, we won't find it in one at level 4 either. + visited := map[*structType]bool{} + + for len(next) > 0 { + current, next = next, current[:0] + count := nextCount + nextCount = nil + + // Process all the fields at this depth, now listed in 'current'. + // The loop queues embedded fields found in 'next', for processing during the next + // iteration. The multiplicity of the 'current' field counts is recorded + // in 'count'; the multiplicity of the 'next' field counts is recorded in 'nextCount'. + for _, scan := range current { + t := scan.typ + if visited[t] { + // We've looked through this type before, at a higher level. + // That higher level would shadow the lower level we're now at, + // so this one can't be useful to us. Ignore it. + continue + } + visited[t] = true + for i := range t.fields { + f := &t.fields[i] + // Find name and (for embedded field) type for field f. + fname := f.name.name() + var ntyp *rtype + if f.embedded() { + // Embedded field of type T or *T. + ntyp = f.typ + if ntyp.Kind() == Ptr { + ntyp = ntyp.Elem().common() + } + } + + // Does it match? + if match(fname) { + // Potential match + if count[t] > 1 || ok { + // Name appeared multiple times at this level: annihilate. + return StructField{}, false + } + result = t.Field(i) + result.Index = nil + result.Index = append(result.Index, scan.index...) + result.Index = append(result.Index, i) + ok = true + continue + } + + // Queue embedded struct fields for processing with next level, + // but only if we haven't seen a match yet at this level and only + // if the embedded types haven't already been queued. + if ok || ntyp == nil || ntyp.Kind() != Struct { + continue + } + styp := (*structType)(unsafe.Pointer(ntyp)) + if nextCount[styp] > 0 { + nextCount[styp] = 2 // exact multiple doesn't matter + continue + } + if nextCount == nil { + nextCount = map[*structType]int{} + } + nextCount[styp] = 1 + if count[t] > 1 { + nextCount[styp] = 2 // exact multiple doesn't matter + } + var index []int + index = append(index, scan.index...) + index = append(index, i) + next = append(next, fieldScan{styp, index}) + } + } + if ok { + break + } + } + return +} + +// FieldByName returns the struct field with the given name +// and a boolean to indicate if the field was found. +func (t *structType) FieldByName(name string) (f StructField, present bool) { + // Quick check for top-level name, or struct without embedded fields. + hasEmbeds := false + if name != "" { + for i := range t.fields { + tf := &t.fields[i] + if tf.name.name() == name { + return t.Field(i), true + } + if tf.embedded() { + hasEmbeds = true + } + } + } + if !hasEmbeds { + return + } + return t.FieldByNameFunc(func(s string) bool { return s == name }) +} + +// TypeOf returns the reflection Type that represents the dynamic type of i. +// If i is a nil interface value, TypeOf returns nil. +func TypeOf(i interface{}) Type { + eface := *(*emptyInterface)(unsafe.Pointer(&i)) + return toType(eface.typ) +} + +// ptrMap is the cache for PtrTo. +var ptrMap sync.Map // map[*rtype]*ptrType + +// PtrTo returns the pointer type with element t. +// For example, if t represents type Foo, PtrTo(t) represents *Foo. +func PtrTo(t Type) Type { + return t.(*rtype).ptrTo() +} + +func (t *rtype) ptrTo() *rtype { + if t.ptrToThis != 0 { + return t.typeOff(t.ptrToThis) + } + + // Check the cache. + if pi, ok := ptrMap.Load(t); ok { + return &pi.(*ptrType).rtype + } + + // Look in known types. + s := "*" + t.String() + for _, tt := range typesByString(s) { + p := (*ptrType)(unsafe.Pointer(tt)) + if p.elem != t { + continue + } + pi, _ := ptrMap.LoadOrStore(t, p) + return &pi.(*ptrType).rtype + } + + // Create a new ptrType starting with the description + // of an *unsafe.Pointer. + var iptr interface{} = (*unsafe.Pointer)(nil) + prototype := *(**ptrType)(unsafe.Pointer(&iptr)) + pp := *prototype + + pp.str = resolveReflectName(newName(s, "", false)) + pp.ptrToThis = 0 + + // For the type structures linked into the binary, the + // compiler provides a good hash of the string. + // Create a good hash for the new string by using + // the FNV-1 hash's mixing function to combine the + // old hash and the new "*". + pp.hash = fnv1(t.hash, '*') + + pp.elem = t + + pi, _ := ptrMap.LoadOrStore(t, &pp) + return &pi.(*ptrType).rtype +} + +// fnv1 incorporates the list of bytes into the hash x using the FNV-1 hash function. +func fnv1(x uint32, list ...byte) uint32 { + for _, b := range list { + x = x*16777619 ^ uint32(b) + } + return x +} + +func (t *rtype) Implements(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.Implements") + } + if u.Kind() != Interface { + panic("reflect: non-interface type passed to Type.Implements") + } + return implements(u.(*rtype), t) +} + +func (t *rtype) AssignableTo(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.AssignableTo") + } + uu := u.(*rtype) + return directlyAssignable(uu, t) || implements(uu, t) +} + +func (t *rtype) ConvertibleTo(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.ConvertibleTo") + } + uu := u.(*rtype) + return convertOp(uu, t) != nil +} + +func (t *rtype) Comparable() bool { + return t.equal != nil +} + +// implements reports whether the type V implements the interface type T. +func implements(T, V *rtype) bool { + if T.Kind() != Interface { + return false + } + t := (*interfaceType)(unsafe.Pointer(T)) + if len(t.methods) == 0 { + return true + } + + // The same algorithm applies in both cases, but the + // method tables for an interface type and a concrete type + // are different, so the code is duplicated. + // In both cases the algorithm is a linear scan over the two + // lists - T's methods and V's methods - simultaneously. + // Since method tables are stored in a unique sorted order + // (alphabetical, with no duplicate method names), the scan + // through V's methods must hit a match for each of T's + // methods along the way, or else V does not implement T. + // This lets us run the scan in overall linear time instead of + // the quadratic time a naive search would require. + // See also ../runtime/iface.go. + if V.Kind() == Interface { + v := (*interfaceType)(unsafe.Pointer(V)) + i := 0 + for j := 0; j < len(v.methods); j++ { + tm := &t.methods[i] + tmName := t.nameOff(tm.name) + vm := &v.methods[j] + vmName := V.nameOff(vm.name) + if vmName.name() == tmName.name() && V.typeOff(vm.typ) == t.typeOff(tm.typ) { + if !tmName.isExported() { + tmPkgPath := tmName.pkgPath() + if tmPkgPath == "" { + tmPkgPath = t.pkgPath.name() + } + vmPkgPath := vmName.pkgPath() + if vmPkgPath == "" { + vmPkgPath = v.pkgPath.name() + } + if tmPkgPath != vmPkgPath { + continue + } + } + if i++; i >= len(t.methods) { + return true + } + } + } + return false + } + + v := V.uncommon() + if v == nil { + return false + } + i := 0 + vmethods := v.methods() + for j := 0; j < int(v.mcount); j++ { + tm := &t.methods[i] + tmName := t.nameOff(tm.name) + vm := vmethods[j] + vmName := V.nameOff(vm.name) + if vmName.name() == tmName.name() && V.typeOff(vm.mtyp) == t.typeOff(tm.typ) { + if !tmName.isExported() { + tmPkgPath := tmName.pkgPath() + if tmPkgPath == "" { + tmPkgPath = t.pkgPath.name() + } + vmPkgPath := vmName.pkgPath() + if vmPkgPath == "" { + vmPkgPath = V.nameOff(v.pkgPath).name() + } + if tmPkgPath != vmPkgPath { + continue + } + } + if i++; i >= len(t.methods) { + return true + } + } + } + return false +} + +// specialChannelAssignability reports whether a value x of channel type V +// can be directly assigned (using memmove) to another channel type T. +// https://golang.org/doc/go_spec.html#Assignability +// T and V must be both of Chan kind. +func specialChannelAssignability(T, V *rtype) bool { + // Special case: + // 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. + return V.ChanDir() == BothDir && (T.Name() == "" || V.Name() == "") && haveIdenticalType(T.Elem(), V.Elem(), true) +} + +// directlyAssignable reports whether a value x of type V can be directly +// assigned (using memmove) to a value of type T. +// https://golang.org/doc/go_spec.html#Assignability +// Ignoring the interface rules (implemented elsewhere) +// and the ideal constant rules (no ideal constants at run time). +func directlyAssignable(T, V *rtype) bool { + // x's type V is identical to T? + if T == V { + return true + } + + // Otherwise at least one of T and V must not be defined + // and they must have the same kind. + if T.hasName() && V.hasName() || T.Kind() != V.Kind() { + return false + } + + if T.Kind() == Chan && specialChannelAssignability(T, V) { + return true + } + + // x's type T and V must have identical underlying types. + return haveIdenticalUnderlyingType(T, V, true) +} + +func haveIdenticalType(T, V Type, cmpTags bool) bool { + if cmpTags { + return T == V + } + + if T.Name() != V.Name() || T.Kind() != V.Kind() { + return false + } + + return haveIdenticalUnderlyingType(T.common(), V.common(), false) +} + +func haveIdenticalUnderlyingType(T, V *rtype, cmpTags bool) bool { + if T == V { + return true + } + + kind := T.Kind() + if kind != V.Kind() { + return false + } + + // Non-composite types of equal kind have same underlying type + // (the predefined instance of the type). + if Bool <= kind && kind <= Complex128 || kind == String || kind == UnsafePointer { + return true + } + + // Composite types. + switch kind { + case Array: + return T.Len() == V.Len() && haveIdenticalType(T.Elem(), V.Elem(), cmpTags) + + case Chan: + return V.ChanDir() == T.ChanDir() && haveIdenticalType(T.Elem(), V.Elem(), cmpTags) + + case Func: + t := (*funcType)(unsafe.Pointer(T)) + v := (*funcType)(unsafe.Pointer(V)) + if t.outCount != v.outCount || t.inCount != v.inCount { + return false + } + for i := 0; i < t.NumIn(); i++ { + if !haveIdenticalType(t.In(i), v.In(i), cmpTags) { + return false + } + } + for i := 0; i < t.NumOut(); i++ { + if !haveIdenticalType(t.Out(i), v.Out(i), cmpTags) { + return false + } + } + return true + + case Interface: + t := (*interfaceType)(unsafe.Pointer(T)) + v := (*interfaceType)(unsafe.Pointer(V)) + if len(t.methods) == 0 && len(v.methods) == 0 { + return true + } + // Might have the same methods but still + // need a run time conversion. + return false + + case Map: + return haveIdenticalType(T.Key(), V.Key(), cmpTags) && haveIdenticalType(T.Elem(), V.Elem(), cmpTags) + + case Ptr, Slice: + return haveIdenticalType(T.Elem(), V.Elem(), cmpTags) + + case Struct: + t := (*structType)(unsafe.Pointer(T)) + v := (*structType)(unsafe.Pointer(V)) + if len(t.fields) != len(v.fields) { + return false + } + if t.pkgPath.name() != v.pkgPath.name() { + return false + } + for i := range t.fields { + tf := &t.fields[i] + vf := &v.fields[i] + if tf.name.name() != vf.name.name() { + return false + } + if !haveIdenticalType(tf.typ, vf.typ, cmpTags) { + return false + } + if cmpTags && tf.name.tag() != vf.name.tag() { + return false + } + if tf.offsetEmbed != vf.offsetEmbed { + return false + } + } + return true + } + + return false +} + +// typelinks is implemented in package runtime. +// It returns a slice of the sections in each module, +// and a slice of *rtype offsets in each module. +// +// The types in each module are sorted by string. That is, the first +// two linked types of the first module are: +// +// d0 := sections[0] +// t1 := (*rtype)(add(d0, offset[0][0])) +// t2 := (*rtype)(add(d0, offset[0][1])) +// +// and +// +// t1.String() < t2.String() +// +// Note that strings are not unique identifiers for types: +// there can be more than one with a given string. +// Only types we might want to look up are included: +// pointers, channels, maps, slices, and arrays. +func typelinks() (sections []unsafe.Pointer, offset [][]int32) + +func rtypeOff(section unsafe.Pointer, off int32) *rtype { + return (*rtype)(add(section, uintptr(off), "sizeof(rtype) > 0")) +} + +// typesByString returns the subslice of typelinks() whose elements have +// the given string representation. +// It may be empty (no known types with that string) or may have +// multiple elements (multiple types with that string). +func typesByString(s string) []*rtype { + sections, offset := typelinks() + var ret []*rtype + + for offsI, offs := range offset { + section := sections[offsI] + + // We are looking for the first index i where the string becomes >= s. + // This is a copy of sort.Search, with f(h) replaced by (*typ[h].String() >= s). + i, j := 0, len(offs) + for i < j { + h := i + (j-i)/2 // avoid overflow when computing h + // i ≤ h < j + if !(rtypeOff(section, offs[h]).String() >= s) { + i = h + 1 // preserves f(i-1) == false + } else { + j = h // preserves f(j) == true + } + } + // i == j, f(i-1) == false, and f(j) (= f(i)) == true => answer is i. + + // Having found the first, linear scan forward to find the last. + // We could do a second binary search, but the caller is going + // to do a linear scan anyway. + for j := i; j < len(offs); j++ { + typ := rtypeOff(section, offs[j]) + if typ.String() != s { + break + } + ret = append(ret, typ) + } + } + return ret +} + +// The lookupCache caches ArrayOf, ChanOf, MapOf and SliceOf lookups. +var lookupCache sync.Map // map[cacheKey]*rtype + +// A cacheKey is the key for use in the lookupCache. +// Four values describe any of the types we are looking for: +// type kind, one or two subtypes, and an extra integer. +type cacheKey struct { + kind Kind + t1 *rtype + t2 *rtype + extra uintptr +} + +// The funcLookupCache caches FuncOf lookups. +// FuncOf does not share the common lookupCache since cacheKey is not +// sufficient to represent functions unambiguously. +var funcLookupCache struct { + sync.Mutex // Guards stores (but not loads) on m. + + // m is a map[uint32][]*rtype keyed by the hash calculated in FuncOf. + // Elements of m are append-only and thus safe for concurrent reading. + m sync.Map +} + +// ChanOf returns the channel type with the given direction and element type. +// For example, if t represents int, ChanOf(RecvDir, t) represents <-chan int. +// +// The gc runtime imposes a limit of 64 kB on channel element types. +// If t's size is equal to or exceeds this limit, ChanOf panics. +func ChanOf(dir ChanDir, t Type) Type { + typ := t.(*rtype) + + // Look in cache. + ckey := cacheKey{Chan, typ, nil, uintptr(dir)} + if ch, ok := lookupCache.Load(ckey); ok { + return ch.(*rtype) + } + + // This restriction is imposed by the gc compiler and the runtime. + if typ.size >= 1<<16 { + panic("reflect.ChanOf: element size too large") + } + + // Look in known types. + var s string + switch dir { + default: + panic("reflect.ChanOf: invalid dir") + case SendDir: + s = "chan<- " + typ.String() + case RecvDir: + s = "<-chan " + typ.String() + case BothDir: + typeStr := typ.String() + if typeStr[0] == '<' { + // typ is recv chan, need parentheses as "<-" associates with leftmost + // chan possible, see: + // * https://golang.org/ref/spec#Channel_types + // * https://github.com/golang/go/issues/39897 + s = "chan (" + typeStr + ")" + } else { + s = "chan " + typeStr + } + } + for _, tt := range typesByString(s) { + ch := (*chanType)(unsafe.Pointer(tt)) + if ch.elem == typ && ch.dir == uintptr(dir) { + ti, _ := lookupCache.LoadOrStore(ckey, tt) + return ti.(Type) + } + } + + // Make a channel type. + var ichan interface{} = (chan unsafe.Pointer)(nil) + prototype := *(**chanType)(unsafe.Pointer(&ichan)) + ch := *prototype + ch.tflag = tflagRegularMemory + ch.dir = uintptr(dir) + ch.str = resolveReflectName(newName(s, "", false)) + ch.hash = fnv1(typ.hash, 'c', byte(dir)) + ch.elem = typ + + ti, _ := lookupCache.LoadOrStore(ckey, &ch.rtype) + return ti.(Type) +} + +// MapOf returns the map type with the given key and element types. +// For example, if k represents int and e represents string, +// MapOf(k, e) represents map[int]string. +// +// If the key type is not a valid map key type (that is, if it does +// not implement Go's == operator), MapOf panics. +func MapOf(key, elem Type) Type { + ktyp := key.(*rtype) + etyp := elem.(*rtype) + + if ktyp.equal == nil { + panic("reflect.MapOf: invalid key type " + ktyp.String()) + } + + // Look in cache. + ckey := cacheKey{Map, ktyp, etyp, 0} + if mt, ok := lookupCache.Load(ckey); ok { + return mt.(Type) + } + + // Look in known types. + s := "map[" + ktyp.String() + "]" + etyp.String() + for _, tt := range typesByString(s) { + mt := (*mapType)(unsafe.Pointer(tt)) + if mt.key == ktyp && mt.elem == etyp { + ti, _ := lookupCache.LoadOrStore(ckey, tt) + return ti.(Type) + } + } + + // Make a map type. + // Note: flag values must match those used in the TMAP case + // in ../cmd/compile/internal/gc/reflect.go:dtypesym. + var imap interface{} = (map[unsafe.Pointer]unsafe.Pointer)(nil) + mt := **(**mapType)(unsafe.Pointer(&imap)) + mt.str = resolveReflectName(newName(s, "", false)) + mt.tflag = 0 + mt.hash = fnv1(etyp.hash, 'm', byte(ktyp.hash>>24), byte(ktyp.hash>>16), byte(ktyp.hash>>8), byte(ktyp.hash)) + mt.key = ktyp + mt.elem = etyp + mt.bucket = bucketOf(ktyp, etyp) + mt.hasher = func(p unsafe.Pointer, seed uintptr) uintptr { + return typehash(ktyp, p, seed) + } + mt.flags = 0 + if ktyp.size > maxKeySize { + mt.keysize = uint8(ptrSize) + mt.flags |= 1 // indirect key + } else { + mt.keysize = uint8(ktyp.size) + } + if etyp.size > maxValSize { + mt.valuesize = uint8(ptrSize) + mt.flags |= 2 // indirect value + } else { + mt.valuesize = uint8(etyp.size) + } + mt.bucketsize = uint16(mt.bucket.size) + if isReflexive(ktyp) { + mt.flags |= 4 + } + if needKeyUpdate(ktyp) { + mt.flags |= 8 + } + if hashMightPanic(ktyp) { + mt.flags |= 16 + } + mt.ptrToThis = 0 + + ti, _ := lookupCache.LoadOrStore(ckey, &mt.rtype) + return ti.(Type) +} + +// TODO(crawshaw): as these funcTypeFixedN structs have no methods, +// they could be defined at runtime using the StructOf function. +type funcTypeFixed4 struct { + funcType + args [4]*rtype +} +type funcTypeFixed8 struct { + funcType + args [8]*rtype +} +type funcTypeFixed16 struct { + funcType + args [16]*rtype +} +type funcTypeFixed32 struct { + funcType + args [32]*rtype +} +type funcTypeFixed64 struct { + funcType + args [64]*rtype +} +type funcTypeFixed128 struct { + funcType + args [128]*rtype +} + +// FuncOf returns the function type with the given argument and result types. +// For example if k represents int and e represents string, +// FuncOf([]Type{k}, []Type{e}, false) represents func(int) string. +// +// The variadic argument controls whether the function is variadic. FuncOf +// panics if the in[len(in)-1] does not represent a slice and variadic is +// true. +func FuncOf(in, out []Type, variadic bool) Type { + if variadic && (len(in) == 0 || in[len(in)-1].Kind() != Slice) { + panic("reflect.FuncOf: last arg of variadic func must be slice") + } + + // Make a func type. + var ifunc interface{} = (func())(nil) + prototype := *(**funcType)(unsafe.Pointer(&ifunc)) + n := len(in) + len(out) + + var ft *funcType + var args []*rtype + switch { + case n <= 4: + fixed := new(funcTypeFixed4) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + case n <= 8: + fixed := new(funcTypeFixed8) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + case n <= 16: + fixed := new(funcTypeFixed16) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + case n <= 32: + fixed := new(funcTypeFixed32) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + case n <= 64: + fixed := new(funcTypeFixed64) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + case n <= 128: + fixed := new(funcTypeFixed128) + args = fixed.args[:0:len(fixed.args)] + ft = &fixed.funcType + default: + panic("reflect.FuncOf: too many arguments") + } + *ft = *prototype + + // Build a hash and minimally populate ft. + var hash uint32 + for _, in := range in { + t := in.(*rtype) + args = append(args, t) + hash = fnv1(hash, byte(t.hash>>24), byte(t.hash>>16), byte(t.hash>>8), byte(t.hash)) + } + if variadic { + hash = fnv1(hash, 'v') + } + hash = fnv1(hash, '.') + for _, out := range out { + t := out.(*rtype) + args = append(args, t) + hash = fnv1(hash, byte(t.hash>>24), byte(t.hash>>16), byte(t.hash>>8), byte(t.hash)) + } + if len(args) > 50 { + panic("reflect.FuncOf does not support more than 50 arguments") + } + ft.tflag = 0 + ft.hash = hash + ft.inCount = uint16(len(in)) + ft.outCount = uint16(len(out)) + if variadic { + ft.outCount |= 1 << 15 + } + + // Look in cache. + if ts, ok := funcLookupCache.m.Load(hash); ok { + for _, t := range ts.([]*rtype) { + if haveIdenticalUnderlyingType(&ft.rtype, t, true) { + return t + } + } + } + + // Not in cache, lock and retry. + funcLookupCache.Lock() + defer funcLookupCache.Unlock() + if ts, ok := funcLookupCache.m.Load(hash); ok { + for _, t := range ts.([]*rtype) { + if haveIdenticalUnderlyingType(&ft.rtype, t, true) { + return t + } + } + } + + addToCache := func(tt *rtype) Type { + var rts []*rtype + if rti, ok := funcLookupCache.m.Load(hash); ok { + rts = rti.([]*rtype) + } + funcLookupCache.m.Store(hash, append(rts, tt)) + return tt + } + + // Look in known types for the same string representation. + str := funcStr(ft) + for _, tt := range typesByString(str) { + if haveIdenticalUnderlyingType(&ft.rtype, tt, true) { + return addToCache(tt) + } + } + + // Populate the remaining fields of ft and store in cache. + ft.str = resolveReflectName(newName(str, "", false)) + ft.ptrToThis = 0 + return addToCache(&ft.rtype) +} + +// funcStr builds a string representation of a funcType. +func funcStr(ft *funcType) string { + repr := make([]byte, 0, 64) + repr = append(repr, "func("...) + for i, t := range ft.in() { + if i > 0 { + repr = append(repr, ", "...) + } + if ft.IsVariadic() && i == int(ft.inCount)-1 { + repr = append(repr, "..."...) + repr = append(repr, (*sliceType)(unsafe.Pointer(t)).elem.String()...) + } else { + repr = append(repr, t.String()...) + } + } + repr = append(repr, ')') + out := ft.out() + if len(out) == 1 { + repr = append(repr, ' ') + } else if len(out) > 1 { + repr = append(repr, " ("...) + } + for i, t := range out { + if i > 0 { + repr = append(repr, ", "...) + } + repr = append(repr, t.String()...) + } + if len(out) > 1 { + repr = append(repr, ')') + } + return string(repr) +} + +// isReflexive reports whether the == operation on the type is reflexive. +// That is, x == x for all values x of type t. +func isReflexive(t *rtype) bool { + switch t.Kind() { + case Bool, Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr, Chan, Ptr, String, UnsafePointer: + return true + case Float32, Float64, Complex64, Complex128, Interface: + return false + case Array: + tt := (*arrayType)(unsafe.Pointer(t)) + return isReflexive(tt.elem) + case Struct: + tt := (*structType)(unsafe.Pointer(t)) + for _, f := range tt.fields { + if !isReflexive(f.typ) { + return false + } + } + return true + default: + // Func, Map, Slice, Invalid + panic("isReflexive called on non-key type " + t.String()) + } +} + +// needKeyUpdate reports whether map overwrites require the key to be copied. +func needKeyUpdate(t *rtype) bool { + switch t.Kind() { + case Bool, Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr, Chan, Ptr, UnsafePointer: + return false + case Float32, Float64, Complex64, Complex128, Interface, String: + // Float keys can be updated from +0 to -0. + // String keys can be updated to use a smaller backing store. + // Interfaces might have floats of strings in them. + return true + case Array: + tt := (*arrayType)(unsafe.Pointer(t)) + return needKeyUpdate(tt.elem) + case Struct: + tt := (*structType)(unsafe.Pointer(t)) + for _, f := range tt.fields { + if needKeyUpdate(f.typ) { + return true + } + } + return false + default: + // Func, Map, Slice, Invalid + panic("needKeyUpdate called on non-key type " + t.String()) + } +} + +// hashMightPanic reports whether the hash of a map key of type t might panic. +func hashMightPanic(t *rtype) bool { + switch t.Kind() { + case Interface: + return true + case Array: + tt := (*arrayType)(unsafe.Pointer(t)) + return hashMightPanic(tt.elem) + case Struct: + tt := (*structType)(unsafe.Pointer(t)) + for _, f := range tt.fields { + if hashMightPanic(f.typ) { + return true + } + } + return false + default: + return false + } +} + +// Make sure these routines stay in sync with ../../runtime/map.go! +// These types exist only for GC, so we only fill out GC relevant info. +// Currently, that's just size and the GC program. We also fill in string +// for possible debugging use. +const ( + bucketSize uintptr = 8 + maxKeySize uintptr = 128 + maxValSize uintptr = 128 +) + +func bucketOf(ktyp, etyp *rtype) *rtype { + if ktyp.size > maxKeySize { + ktyp = PtrTo(ktyp).(*rtype) + } + if etyp.size > maxValSize { + etyp = PtrTo(etyp).(*rtype) + } + + // Prepare GC data if any. + // A bucket is at most bucketSize*(1+maxKeySize+maxValSize)+2*ptrSize bytes, + // or 2072 bytes, or 259 pointer-size words, or 33 bytes of pointer bitmap. + // Note that since the key and value are known to be <= 128 bytes, + // they're guaranteed to have bitmaps instead of GC programs. + var gcdata *byte + var ptrdata uintptr + var overflowPad uintptr + + size := bucketSize*(1+ktyp.size+etyp.size) + overflowPad + ptrSize + if size&uintptr(ktyp.align-1) != 0 || size&uintptr(etyp.align-1) != 0 { + panic("reflect: bad size computation in MapOf") + } + + if ktyp.ptrdata != 0 || etyp.ptrdata != 0 { + nptr := (bucketSize*(1+ktyp.size+etyp.size) + ptrSize) / ptrSize + mask := make([]byte, (nptr+7)/8) + base := bucketSize / ptrSize + + if ktyp.ptrdata != 0 { + emitGCMask(mask, base, ktyp, bucketSize) + } + base += bucketSize * ktyp.size / ptrSize + + if etyp.ptrdata != 0 { + emitGCMask(mask, base, etyp, bucketSize) + } + base += bucketSize * etyp.size / ptrSize + base += overflowPad / ptrSize + + word := base + mask[word/8] |= 1 << (word % 8) + gcdata = &mask[0] + ptrdata = (word + 1) * ptrSize + + // overflow word must be last + if ptrdata != size { + panic("reflect: bad layout computation in MapOf") + } + } + + b := &rtype{ + align: ptrSize, + size: size, + kind: uint8(Struct), + ptrdata: ptrdata, + gcdata: gcdata, + } + if overflowPad > 0 { + b.align = 8 + } + s := "bucket(" + ktyp.String() + "," + etyp.String() + ")" + b.str = resolveReflectName(newName(s, "", false)) + return b +} + +func (t *rtype) gcSlice(begin, end uintptr) []byte { + return (*[1 << 30]byte)(unsafe.Pointer(t.gcdata))[begin:end:end] +} + +// emitGCMask writes the GC mask for [n]typ into out, starting at bit +// offset base. +func emitGCMask(out []byte, base uintptr, typ *rtype, n uintptr) { + if typ.kind&kindGCProg != 0 { + panic("reflect: unexpected GC program") + } + ptrs := typ.ptrdata / ptrSize + words := typ.size / ptrSize + mask := typ.gcSlice(0, (ptrs+7)/8) + for j := uintptr(0); j < ptrs; j++ { + if (mask[j/8]>>(j%8))&1 != 0 { + for i := uintptr(0); i < n; i++ { + k := base + i*words + j + out[k/8] |= 1 << (k % 8) + } + } + } +} + +// appendGCProg appends the GC program for the first ptrdata bytes of +// typ to dst and returns the extended slice. +func appendGCProg(dst []byte, typ *rtype) []byte { + if typ.kind&kindGCProg != 0 { + // Element has GC program; emit one element. + n := uintptr(*(*uint32)(unsafe.Pointer(typ.gcdata))) + prog := typ.gcSlice(4, 4+n-1) + return append(dst, prog...) + } + + // Element is small with pointer mask; use as literal bits. + ptrs := typ.ptrdata / ptrSize + mask := typ.gcSlice(0, (ptrs+7)/8) + + // Emit 120-bit chunks of full bytes (max is 127 but we avoid using partial bytes). + for ; ptrs > 120; ptrs -= 120 { + dst = append(dst, 120) + dst = append(dst, mask[:15]...) + mask = mask[15:] + } + + dst = append(dst, byte(ptrs)) + dst = append(dst, mask...) + return dst +} + +// SliceOf returns the slice type with element type t. +// For example, if t represents int, SliceOf(t) represents []int. +func SliceOf(t Type) Type { + typ := t.(*rtype) + + // Look in cache. + ckey := cacheKey{Slice, typ, nil, 0} + if slice, ok := lookupCache.Load(ckey); ok { + return slice.(Type) + } + + // Look in known types. + s := "[]" + typ.String() + for _, tt := range typesByString(s) { + slice := (*sliceType)(unsafe.Pointer(tt)) + if slice.elem == typ { + ti, _ := lookupCache.LoadOrStore(ckey, tt) + return ti.(Type) + } + } + + // Make a slice type. + var islice interface{} = ([]unsafe.Pointer)(nil) + prototype := *(**sliceType)(unsafe.Pointer(&islice)) + slice := *prototype + slice.tflag = 0 + slice.str = resolveReflectName(newName(s, "", false)) + slice.hash = fnv1(typ.hash, '[') + slice.elem = typ + slice.ptrToThis = 0 + + ti, _ := lookupCache.LoadOrStore(ckey, &slice.rtype) + return ti.(Type) +} + +// The structLookupCache caches StructOf lookups. +// StructOf does not share the common lookupCache since we need to pin +// the memory associated with *structTypeFixedN. +var structLookupCache struct { + sync.Mutex // Guards stores (but not loads) on m. + + // m is a map[uint32][]Type keyed by the hash calculated in StructOf. + // Elements in m are append-only and thus safe for concurrent reading. + m sync.Map +} + +type structTypeUncommon struct { + structType + u uncommonType +} + +// isLetter reports whether a given 'rune' is classified as a Letter. +func isLetter(ch rune) bool { + return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch == '_' || ch >= utf8.RuneSelf && unicode.IsLetter(ch) +} + +// isValidFieldName checks if a string is a valid (struct) field name or not. +// +// According to the language spec, a field name should be an identifier. +// +// identifier = letter { letter | unicode_digit } . +// letter = unicode_letter | "_" . +func isValidFieldName(fieldName string) bool { + for i, c := range fieldName { + if i == 0 && !isLetter(c) { + return false + } + + if !(isLetter(c) || unicode.IsDigit(c)) { + return false + } + } + + return len(fieldName) > 0 +} + +// StructOf returns the struct type containing fields. +// The Offset and Index fields are ignored and computed as they would be +// by the compiler. +// +// StructOf currently does not generate wrapper methods for embedded +// fields and panics if passed unexported StructFields. +// These limitations may be lifted in a future version. +func StructOf(fields []StructField) Type { + var ( + hash = fnv1(0, []byte("struct {")...) + size uintptr + typalign uint8 + comparable = true + methods []method + + fs = make([]structField, len(fields)) + repr = make([]byte, 0, 64) + fset = map[string]struct{}{} // fields' names + + hasGCProg = false // records whether a struct-field type has a GCProg + ) + + lastzero := uintptr(0) + repr = append(repr, "struct {"...) + pkgpath := "" + for i, field := range fields { + if field.Name == "" { + panic("reflect.StructOf: field " + strconv.Itoa(i) + " has no name") + } + if !isValidFieldName(field.Name) { + panic("reflect.StructOf: field " + strconv.Itoa(i) + " has invalid name") + } + if field.Type == nil { + panic("reflect.StructOf: field " + strconv.Itoa(i) + " has no type") + } + f, fpkgpath := runtimeStructField(field) + ft := f.typ + if ft.kind&kindGCProg != 0 { + hasGCProg = true + } + if fpkgpath != "" { + if pkgpath == "" { + pkgpath = fpkgpath + } else if pkgpath != fpkgpath { + panic("reflect.Struct: fields with different PkgPath " + pkgpath + " and " + fpkgpath) + } + } + + // Update string and hash + name := f.name.name() + hash = fnv1(hash, []byte(name)...) + repr = append(repr, (" " + name)...) + if f.embedded() { + // Embedded field + if f.typ.Kind() == Ptr { + // Embedded ** and *interface{} are illegal + elem := ft.Elem() + if k := elem.Kind(); k == Ptr || k == Interface { + panic("reflect.StructOf: illegal embedded field type " + ft.String()) + } + } + + switch f.typ.Kind() { + case Interface: + ift := (*interfaceType)(unsafe.Pointer(ft)) + for im, m := range ift.methods { + if ift.nameOff(m.name).pkgPath() != "" { + // TODO(sbinet). Issue 15924. + panic("reflect: embedded interface with unexported method(s) not implemented") + } + + var ( + mtyp = ift.typeOff(m.typ) + ifield = i + imethod = im + ifn Value + tfn Value + ) + + if ft.kind&kindDirectIface != 0 { + tfn = MakeFunc(mtyp, func(in []Value) []Value { + var args []Value + var recv = in[0] + if len(in) > 1 { + args = in[1:] + } + return recv.Field(ifield).Method(imethod).Call(args) + }) + ifn = MakeFunc(mtyp, func(in []Value) []Value { + var args []Value + var recv = in[0] + if len(in) > 1 { + args = in[1:] + } + return recv.Field(ifield).Method(imethod).Call(args) + }) + } else { + tfn = MakeFunc(mtyp, func(in []Value) []Value { + var args []Value + var recv = in[0] + if len(in) > 1 { + args = in[1:] + } + return recv.Field(ifield).Method(imethod).Call(args) + }) + ifn = MakeFunc(mtyp, func(in []Value) []Value { + var args []Value + var recv = Indirect(in[0]) + if len(in) > 1 { + args = in[1:] + } + return recv.Field(ifield).Method(imethod).Call(args) + }) + } + + methods = append(methods, method{ + name: resolveReflectName(ift.nameOff(m.name)), + mtyp: resolveReflectType(mtyp), + ifn: resolveReflectText(unsafe.Pointer(&ifn)), + tfn: resolveReflectText(unsafe.Pointer(&tfn)), + }) + } + case Ptr: + ptr := (*ptrType)(unsafe.Pointer(ft)) + if unt := ptr.uncommon(); unt != nil { + if i > 0 && unt.mcount > 0 { + // Issue 15924. + panic("reflect: embedded type with methods not implemented if type is not first field") + } + if len(fields) > 1 { + panic("reflect: embedded type with methods not implemented if there is more than one field") + } + for _, m := range unt.methods() { + mname := ptr.nameOff(m.name) + if mname.pkgPath() != "" { + // TODO(sbinet). + // Issue 15924. + panic("reflect: embedded interface with unexported method(s) not implemented") + } + methods = append(methods, method{ + name: resolveReflectName(mname), + mtyp: resolveReflectType(ptr.typeOff(m.mtyp)), + ifn: resolveReflectText(ptr.textOff(m.ifn)), + tfn: resolveReflectText(ptr.textOff(m.tfn)), + }) + } + } + if unt := ptr.elem.uncommon(); unt != nil { + for _, m := range unt.methods() { + mname := ptr.nameOff(m.name) + if mname.pkgPath() != "" { + // TODO(sbinet) + // Issue 15924. + panic("reflect: embedded interface with unexported method(s) not implemented") + } + methods = append(methods, method{ + name: resolveReflectName(mname), + mtyp: resolveReflectType(ptr.elem.typeOff(m.mtyp)), + ifn: resolveReflectText(ptr.elem.textOff(m.ifn)), + tfn: resolveReflectText(ptr.elem.textOff(m.tfn)), + }) + } + } + default: + if unt := ft.uncommon(); unt != nil { + if i > 0 && unt.mcount > 0 { + // Issue 15924. + panic("reflect: embedded type with methods not implemented if type is not first field") + } + if len(fields) > 1 && ft.kind&kindDirectIface != 0 { + panic("reflect: embedded type with methods not implemented for non-pointer type") + } + for _, m := range unt.methods() { + mname := ft.nameOff(m.name) + if mname.pkgPath() != "" { + // TODO(sbinet) + // Issue 15924. + panic("reflect: embedded interface with unexported method(s) not implemented") + } + methods = append(methods, method{ + name: resolveReflectName(mname), + mtyp: resolveReflectType(ft.typeOff(m.mtyp)), + ifn: resolveReflectText(ft.textOff(m.ifn)), + tfn: resolveReflectText(ft.textOff(m.tfn)), + }) + + } + } + } + } + if _, dup := fset[name]; dup { + panic("reflect.StructOf: duplicate field " + name) + } + fset[name] = struct{}{} + + hash = fnv1(hash, byte(ft.hash>>24), byte(ft.hash>>16), byte(ft.hash>>8), byte(ft.hash)) + + repr = append(repr, (" " + ft.String())...) + if f.name.tagLen() > 0 { + hash = fnv1(hash, []byte(f.name.tag())...) + repr = append(repr, (" " + strconv.Quote(f.name.tag()))...) + } + if i < len(fields)-1 { + repr = append(repr, ';') + } + + comparable = comparable && (ft.equal != nil) + + offset := align(size, uintptr(ft.align)) + if ft.align > typalign { + typalign = ft.align + } + size = offset + ft.size + f.offsetEmbed |= offset << 1 + + if ft.size == 0 { + lastzero = size + } + + fs[i] = f + } + + if size > 0 && lastzero == size { + // This is a non-zero sized struct that ends in a + // zero-sized field. We add an extra byte of padding, + // to ensure that taking the address of the final + // zero-sized field can't manufacture a pointer to the + // next object in the heap. See issue 9401. + size++ + } + + var typ *structType + var ut *uncommonType + + if len(methods) == 0 { + t := new(structTypeUncommon) + typ = &t.structType + ut = &t.u + } else { + // A *rtype representing a struct is followed directly in memory by an + // array of method objects representing the methods attached to the + // struct. To get the same layout for a run time generated type, we + // need an array directly following the uncommonType memory. + // A similar strategy is used for funcTypeFixed4, ...funcTypeFixedN. + tt := New(StructOf([]StructField{ + {Name: "S", Type: TypeOf(structType{})}, + {Name: "U", Type: TypeOf(uncommonType{})}, + {Name: "M", Type: ArrayOf(len(methods), TypeOf(methods[0]))}, + })) + + typ = (*structType)(unsafe.Pointer(tt.Elem().Field(0).UnsafeAddr())) + ut = (*uncommonType)(unsafe.Pointer(tt.Elem().Field(1).UnsafeAddr())) + + copy(tt.Elem().Field(2).Slice(0, len(methods)).Interface().([]method), methods) + } + // TODO(sbinet): Once we allow embedding multiple types, + // methods will need to be sorted like the compiler does. + // TODO(sbinet): Once we allow non-exported methods, we will + // need to compute xcount as the number of exported methods. + ut.mcount = uint16(len(methods)) + ut.xcount = ut.mcount + ut.moff = uint32(unsafe.Sizeof(uncommonType{})) + + if len(fs) > 0 { + repr = append(repr, ' ') + } + repr = append(repr, '}') + hash = fnv1(hash, '}') + str := string(repr) + + // Round the size up to be a multiple of the alignment. + size = align(size, uintptr(typalign)) + + // Make the struct type. + var istruct interface{} = struct{}{} + prototype := *(**structType)(unsafe.Pointer(&istruct)) + *typ = *prototype + typ.fields = fs + if pkgpath != "" { + typ.pkgPath = newName(pkgpath, "", false) + } + + // Look in cache. + if ts, ok := structLookupCache.m.Load(hash); ok { + for _, st := range ts.([]Type) { + t := st.common() + if haveIdenticalUnderlyingType(&typ.rtype, t, true) { + return t + } + } + } + + // Not in cache, lock and retry. + structLookupCache.Lock() + defer structLookupCache.Unlock() + if ts, ok := structLookupCache.m.Load(hash); ok { + for _, st := range ts.([]Type) { + t := st.common() + if haveIdenticalUnderlyingType(&typ.rtype, t, true) { + return t + } + } + } + + addToCache := func(t Type) Type { + var ts []Type + if ti, ok := structLookupCache.m.Load(hash); ok { + ts = ti.([]Type) + } + structLookupCache.m.Store(hash, append(ts, t)) + return t + } + + // Look in known types. + for _, t := range typesByString(str) { + if haveIdenticalUnderlyingType(&typ.rtype, t, true) { + // even if 't' wasn't a structType with methods, we should be ok + // as the 'u uncommonType' field won't be accessed except when + // tflag&tflagUncommon is set. + return addToCache(t) + } + } + + typ.str = resolveReflectName(newName(str, "", false)) + typ.tflag = 0 // TODO: set tflagRegularMemory + typ.hash = hash + typ.size = size + typ.ptrdata = typeptrdata(typ.common()) + typ.align = typalign + typ.fieldAlign = typalign + typ.ptrToThis = 0 + if len(methods) > 0 { + typ.tflag |= tflagUncommon + } + + if hasGCProg { + lastPtrField := 0 + for i, ft := range fs { + if ft.typ.pointers() { + lastPtrField = i + } + } + prog := []byte{0, 0, 0, 0} // will be length of prog + var off uintptr + for i, ft := range fs { + if i > lastPtrField { + // gcprog should not include anything for any field after + // the last field that contains pointer data + break + } + if !ft.typ.pointers() { + // Ignore pointerless fields. + continue + } + // Pad to start of this field with zeros. + if ft.offset() > off { + n := (ft.offset() - off) / ptrSize + prog = append(prog, 0x01, 0x00) // emit a 0 bit + if n > 1 { + prog = append(prog, 0x81) // repeat previous bit + prog = appendVarint(prog, n-1) // n-1 times + } + off = ft.offset() + } + + prog = appendGCProg(prog, ft.typ) + off += ft.typ.ptrdata + } + prog = append(prog, 0) + *(*uint32)(unsafe.Pointer(&prog[0])) = uint32(len(prog) - 4) + typ.kind |= kindGCProg + typ.gcdata = &prog[0] + } else { + typ.kind &^= kindGCProg + bv := new(bitVector) + addTypeBits(bv, 0, typ.common()) + if len(bv.data) > 0 { + typ.gcdata = &bv.data[0] + } + } + typ.equal = nil + if comparable { + typ.equal = func(p, q unsafe.Pointer) bool { + for _, ft := range typ.fields { + pi := add(p, ft.offset(), "&x.field safe") + qi := add(q, ft.offset(), "&x.field safe") + if !ft.typ.equal(pi, qi) { + return false + } + } + return true + } + } + + switch { + case len(fs) == 1 && !ifaceIndir(fs[0].typ): + // structs of 1 direct iface type can be direct + typ.kind |= kindDirectIface + default: + typ.kind &^= kindDirectIface + } + + return addToCache(&typ.rtype) +} + +// runtimeStructField takes a StructField value passed to StructOf and +// returns both the corresponding internal representation, of type +// structField, and the pkgpath value to use for this field. +func runtimeStructField(field StructField) (structField, string) { + if field.Anonymous && field.PkgPath != "" { + panic("reflect.StructOf: field \"" + field.Name + "\" is anonymous but has PkgPath set") + } + + exported := field.PkgPath == "" + if exported { + // Best-effort check for misuse. + // Since this field will be treated as exported, not much harm done if Unicode lowercase slips through. + c := field.Name[0] + if 'a' <= c && c <= 'z' || c == '_' { + panic("reflect.StructOf: field \"" + field.Name + "\" is unexported but missing PkgPath") + } + } + + offsetEmbed := uintptr(0) + if field.Anonymous { + offsetEmbed |= 1 + } + + resolveReflectType(field.Type.common()) // install in runtime + f := structField{ + name: newName(field.Name, string(field.Tag), exported), + typ: field.Type.common(), + offsetEmbed: offsetEmbed, + } + return f, field.PkgPath +} + +// typeptrdata returns the length in bytes of the prefix of t +// containing pointer data. Anything after this offset is scalar data. +// keep in sync with ../cmd/compile/internal/gc/reflect.go +func typeptrdata(t *rtype) uintptr { + switch t.Kind() { + case Struct: + st := (*structType)(unsafe.Pointer(t)) + // find the last field that has pointers. + field := -1 + for i := range st.fields { + ft := st.fields[i].typ + if ft.pointers() { + field = i + } + } + if field == -1 { + return 0 + } + f := st.fields[field] + return f.offset() + f.typ.ptrdata + + default: + panic("reflect.typeptrdata: unexpected type, " + t.String()) + } +} + +// See cmd/compile/internal/gc/reflect.go for derivation of constant. +const maxPtrmaskBytes = 2048 + +// ArrayOf returns the array type with the given count and element type. +// For example, if t represents int, ArrayOf(5, t) represents [5]int. +// +// If the resulting type would be larger than the available address space, +// ArrayOf panics. +func ArrayOf(count int, elem Type) Type { + typ := elem.(*rtype) + + // Look in cache. + ckey := cacheKey{Array, typ, nil, uintptr(count)} + if array, ok := lookupCache.Load(ckey); ok { + return array.(Type) + } + + // Look in known types. + s := "[" + strconv.Itoa(count) + "]" + typ.String() + for _, tt := range typesByString(s) { + array := (*arrayType)(unsafe.Pointer(tt)) + if array.elem == typ { + ti, _ := lookupCache.LoadOrStore(ckey, tt) + return ti.(Type) + } + } + + // Make an array type. + var iarray interface{} = [1]unsafe.Pointer{} + prototype := *(**arrayType)(unsafe.Pointer(&iarray)) + array := *prototype + array.tflag = typ.tflag & tflagRegularMemory + array.str = resolveReflectName(newName(s, "", false)) + array.hash = fnv1(typ.hash, '[') + for n := uint32(count); n > 0; n >>= 8 { + array.hash = fnv1(array.hash, byte(n)) + } + array.hash = fnv1(array.hash, ']') + array.elem = typ + array.ptrToThis = 0 + if typ.size > 0 { + max := ^uintptr(0) / typ.size + if uintptr(count) > max { + panic("reflect.ArrayOf: array size would exceed virtual address space") + } + } + array.size = typ.size * uintptr(count) + if count > 0 && typ.ptrdata != 0 { + array.ptrdata = typ.size*uintptr(count-1) + typ.ptrdata + } + array.align = typ.align + array.fieldAlign = typ.fieldAlign + array.len = uintptr(count) + array.slice = SliceOf(elem).(*rtype) + + switch { + case typ.ptrdata == 0 || array.size == 0: + // No pointers. + array.gcdata = nil + array.ptrdata = 0 + + case count == 1: + // In memory, 1-element array looks just like the element. + array.kind |= typ.kind & kindGCProg + array.gcdata = typ.gcdata + array.ptrdata = typ.ptrdata + + case typ.kind&kindGCProg == 0 && array.size <= maxPtrmaskBytes*8*ptrSize: + // Element is small with pointer mask; array is still small. + // Create direct pointer mask by turning each 1 bit in elem + // into count 1 bits in larger mask. + mask := make([]byte, (array.ptrdata/ptrSize+7)/8) + emitGCMask(mask, 0, typ, array.len) + array.gcdata = &mask[0] + + default: + // Create program that emits one element + // and then repeats to make the array. + prog := []byte{0, 0, 0, 0} // will be length of prog + prog = appendGCProg(prog, typ) + // Pad from ptrdata to size. + elemPtrs := typ.ptrdata / ptrSize + elemWords := typ.size / ptrSize + if elemPtrs < elemWords { + // Emit literal 0 bit, then repeat as needed. + prog = append(prog, 0x01, 0x00) + if elemPtrs+1 < elemWords { + prog = append(prog, 0x81) + prog = appendVarint(prog, elemWords-elemPtrs-1) + } + } + // Repeat count-1 times. + if elemWords < 0x80 { + prog = append(prog, byte(elemWords|0x80)) + } else { + prog = append(prog, 0x80) + prog = appendVarint(prog, elemWords) + } + prog = appendVarint(prog, uintptr(count)-1) + prog = append(prog, 0) + *(*uint32)(unsafe.Pointer(&prog[0])) = uint32(len(prog) - 4) + array.kind |= kindGCProg + array.gcdata = &prog[0] + array.ptrdata = array.size // overestimate but ok; must match program + } + + etyp := typ.common() + esize := etyp.Size() + + array.equal = nil + if eequal := etyp.equal; eequal != nil { + array.equal = func(p, q unsafe.Pointer) bool { + for i := 0; i < count; i++ { + pi := arrayAt(p, i, esize, "i < count") + qi := arrayAt(q, i, esize, "i < count") + if !eequal(pi, qi) { + return false + } + + } + return true + } + } + + switch { + case count == 1 && !ifaceIndir(typ): + // array of 1 direct iface type can be direct + array.kind |= kindDirectIface + default: + array.kind &^= kindDirectIface + } + + ti, _ := lookupCache.LoadOrStore(ckey, &array.rtype) + return ti.(Type) +} + +func appendVarint(x []byte, v uintptr) []byte { + for ; v >= 0x80; v >>= 7 { + x = append(x, byte(v|0x80)) + } + x = append(x, byte(v)) + return x +} + +// toType converts from a *rtype to a Type that can be returned +// to the client of package reflect. In gc, the only concern is that +// a nil *rtype must be replaced by a nil Type, but in gccgo this +// function takes care of ensuring that multiple *rtype for the same +// type are coalesced into a single Type. +func toType(t *rtype) Type { + if t == nil { + return nil + } + return t +} + +type layoutKey struct { + ftyp *funcType // function signature + rcvr *rtype // receiver type, or nil if none +} + +type layoutType struct { + t *rtype + argSize uintptr // size of arguments + retOffset uintptr // offset of return values. + stack *bitVector + framePool *sync.Pool +} + +var layoutCache sync.Map // map[layoutKey]layoutType + +// funcLayout computes a struct type representing the layout of the +// function arguments and return values for the function type t. +// If rcvr != nil, rcvr specifies the type of the receiver. +// The returned type exists only for GC, so we only fill out GC relevant info. +// Currently, that's just size and the GC program. We also fill in +// the name for possible debugging use. +func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, argSize, retOffset uintptr, stk *bitVector, framePool *sync.Pool) { + if t.Kind() != Func { + panic("reflect: funcLayout of non-func type " + t.String()) + } + if rcvr != nil && rcvr.Kind() == Interface { + panic("reflect: funcLayout with interface receiver " + rcvr.String()) + } + k := layoutKey{t, rcvr} + if lti, ok := layoutCache.Load(k); ok { + lt := lti.(layoutType) + return lt.t, lt.argSize, lt.retOffset, lt.stack, lt.framePool + } + + // compute gc program & stack bitmap for arguments + ptrmap := new(bitVector) + var offset uintptr + if rcvr != nil { + // Reflect uses the "interface" calling convention for + // methods, where receivers take one word of argument + // space no matter how big they actually are. + if ifaceIndir(rcvr) || rcvr.pointers() { + ptrmap.append(1) + } else { + ptrmap.append(0) + } + offset += ptrSize + } + for _, arg := range t.in() { + offset += -offset & uintptr(arg.align-1) + addTypeBits(ptrmap, offset, arg) + offset += arg.size + } + argSize = offset + offset += -offset & (ptrSize - 1) + retOffset = offset + for _, res := range t.out() { + offset += -offset & uintptr(res.align-1) + addTypeBits(ptrmap, offset, res) + offset += res.size + } + offset += -offset & (ptrSize - 1) + + // build dummy rtype holding gc program + x := &rtype{ + align: ptrSize, + size: offset, + ptrdata: uintptr(ptrmap.n) * ptrSize, + } + if ptrmap.n > 0 { + x.gcdata = &ptrmap.data[0] + } + + var s string + if rcvr != nil { + s = "methodargs(" + rcvr.String() + ")(" + t.String() + ")" + } else { + s = "funcargs(" + t.String() + ")" + } + x.str = resolveReflectName(newName(s, "", false)) + + // cache result for future callers + framePool = &sync.Pool{New: func() interface{} { + return unsafe_New(x) + }} + lti, _ := layoutCache.LoadOrStore(k, layoutType{ + t: x, + argSize: argSize, + retOffset: retOffset, + stack: ptrmap, + framePool: framePool, + }) + lt := lti.(layoutType) + return lt.t, lt.argSize, lt.retOffset, lt.stack, lt.framePool +} + +// ifaceIndir reports whether t is stored indirectly in an interface value. +func ifaceIndir(t *rtype) bool { + return t.kind&kindDirectIface == 0 +} + +// Note: this type must agree with runtime.bitvector. +type bitVector struct { + n uint32 // number of bits + data []byte +} + +// append a bit to the bitmap. +func (bv *bitVector) append(bit uint8) { + if bv.n%8 == 0 { + bv.data = append(bv.data, 0) + } + bv.data[bv.n/8] |= bit << (bv.n % 8) + bv.n++ +} + +func addTypeBits(bv *bitVector, offset uintptr, t *rtype) { + if t.ptrdata == 0 { + return + } + + switch Kind(t.kind & kindMask) { + case Chan, Func, Map, Ptr, Slice, String, UnsafePointer: + // 1 pointer at start of representation + for bv.n < uint32(offset/uintptr(ptrSize)) { + bv.append(0) + } + bv.append(1) + + case Interface: + // 2 pointers + for bv.n < uint32(offset/uintptr(ptrSize)) { + bv.append(0) + } + bv.append(1) + bv.append(1) + + case Array: + // repeat inner type + tt := (*arrayType)(unsafe.Pointer(t)) + for i := 0; i < int(tt.len); i++ { + addTypeBits(bv, offset+uintptr(i)*tt.elem.size, tt.elem) + } + + case Struct: + // apply fields + tt := (*structType)(unsafe.Pointer(t)) + for i := range tt.fields { + f := &tt.fields[i] + addTypeBits(bv, offset+f.offset(), f.typ) + } + } +} diff --git a/src/reflect/value.go b/src/reflect/value.go new file mode 100644 index 0000000..1f185b5 --- /dev/null +++ b/src/reflect/value.go @@ -0,0 +1,2858 @@ +// 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 reflect + +import ( + "internal/unsafeheader" + "math" + "runtime" + "unsafe" +) + +const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const + +// Value is the reflection interface to a Go value. +// +// Not all methods apply to all kinds of values. Restrictions, +// if any, are noted in the documentation for each method. +// Use the Kind method to find out the kind of value before +// calling kind-specific methods. Calling a method +// inappropriate to the kind of type causes a run time panic. +// +// The zero Value represents no value. +// Its IsValid method returns false, its Kind method returns Invalid, +// its String method returns "<invalid Value>", and all other methods panic. +// Most functions and methods never return an invalid value. +// If one does, its documentation states the conditions explicitly. +// +// A Value can be used concurrently by multiple goroutines provided that +// the underlying Go value can be used concurrently for the equivalent +// direct operations. +// +// To compare two Values, compare the results of the Interface method. +// Using == on two Values does not compare the underlying values +// they represent. +type Value struct { + // typ holds the type of the value represented by a Value. + typ *rtype + + // Pointer-valued data or, if flagIndir is set, pointer to data. + // Valid when either flagIndir is set or typ.pointers() is true. + ptr unsafe.Pointer + + // flag holds metadata about the value. + // The lowest bits are flag bits: + // - flagStickyRO: obtained via unexported not embedded field, so read-only + // - flagEmbedRO: obtained via unexported embedded field, so read-only + // - flagIndir: val holds a pointer to the data + // - flagAddr: v.CanAddr is true (implies flagIndir) + // - flagMethod: v is a method value. + // The next five bits give the Kind of the value. + // This repeats typ.Kind() except for method values. + // The remaining 23+ bits give a method number for method values. + // If flag.kind() != Func, code can assume that flagMethod is unset. + // If ifaceIndir(typ), code can assume that flagIndir is set. + flag + + // A method value represents a curried method invocation + // like r.Read for some receiver r. The typ+val+flag bits describe + // the receiver r, but the flag's Kind bits say Func (methods are + // functions), and the top bits of the flag give the method number + // in r's type's method table. +} + +type flag uintptr + +const ( + flagKindWidth = 5 // there are 27 kinds + flagKindMask flag = 1<<flagKindWidth - 1 + flagStickyRO flag = 1 << 5 + flagEmbedRO flag = 1 << 6 + flagIndir flag = 1 << 7 + flagAddr flag = 1 << 8 + flagMethod flag = 1 << 9 + flagMethodShift = 10 + flagRO flag = flagStickyRO | flagEmbedRO +) + +func (f flag) kind() Kind { + return Kind(f & flagKindMask) +} + +func (f flag) ro() flag { + if f&flagRO != 0 { + return flagStickyRO + } + return 0 +} + +// pointer returns the underlying pointer represented by v. +// v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer +// if v.Kind() == Ptr, the base type must not be go:notinheap. +func (v Value) pointer() unsafe.Pointer { + if v.typ.size != ptrSize || !v.typ.pointers() { + panic("can't call pointer on a non-pointer Value") + } + if v.flag&flagIndir != 0 { + return *(*unsafe.Pointer)(v.ptr) + } + return v.ptr +} + +// packEface converts v to the empty interface. +func packEface(v Value) interface{} { + t := v.typ + var i interface{} + e := (*emptyInterface)(unsafe.Pointer(&i)) + // First, fill in the data portion of the interface. + switch { + case ifaceIndir(t): + if v.flag&flagIndir == 0 { + panic("bad indir") + } + // Value is indirect, and so is the interface we're making. + ptr := v.ptr + if v.flag&flagAddr != 0 { + // TODO: pass safe boolean from valueInterface so + // we don't need to copy if safe==true? + c := unsafe_New(t) + typedmemmove(t, c, ptr) + ptr = c + } + e.word = ptr + case v.flag&flagIndir != 0: + // Value is indirect, but interface is direct. We need + // to load the data at v.ptr into the interface data word. + e.word = *(*unsafe.Pointer)(v.ptr) + default: + // Value is direct, and so is the interface. + e.word = v.ptr + } + // Now, fill in the type portion. We're very careful here not + // to have any operation between the e.word and e.typ assignments + // that would let the garbage collector observe the partially-built + // interface value. + e.typ = t + return i +} + +// unpackEface converts the empty interface i to a Value. +func unpackEface(i interface{}) Value { + e := (*emptyInterface)(unsafe.Pointer(&i)) + // NOTE: don't read e.word until we know whether it is really a pointer or not. + t := e.typ + if t == nil { + return Value{} + } + f := flag(t.Kind()) + if ifaceIndir(t) { + f |= flagIndir + } + return Value{t, e.word, f} +} + +// A ValueError occurs when a Value method is invoked on +// a Value that does not support it. Such cases are documented +// in the description of each method. +type ValueError struct { + Method string + Kind Kind +} + +func (e *ValueError) Error() string { + if e.Kind == 0 { + return "reflect: call of " + e.Method + " on zero Value" + } + return "reflect: call of " + e.Method + " on " + e.Kind.String() + " Value" +} + +// methodName returns the name of the calling method, +// assumed to be two stack frames above. +func methodName() string { + pc, _, _, _ := runtime.Caller(2) + f := runtime.FuncForPC(pc) + if f == nil { + return "unknown method" + } + return f.Name() +} + +// methodNameSkip is like methodName, but skips another stack frame. +// This is a separate function so that reflect.flag.mustBe will be inlined. +func methodNameSkip() string { + pc, _, _, _ := runtime.Caller(3) + f := runtime.FuncForPC(pc) + if f == nil { + return "unknown method" + } + return f.Name() +} + +// emptyInterface is the header for an interface{} value. +type emptyInterface struct { + typ *rtype + word unsafe.Pointer +} + +// nonEmptyInterface is the header for an interface value with methods. +type nonEmptyInterface struct { + // see ../runtime/iface.go:/Itab + itab *struct { + ityp *rtype // static interface type + typ *rtype // dynamic concrete type + hash uint32 // copy of typ.hash + _ [4]byte + fun [100000]unsafe.Pointer // method table + } + word unsafe.Pointer +} + +// mustBe panics if f's kind is not expected. +// Making this a method on flag instead of on Value +// (and embedding flag in Value) means that we can write +// the very clear v.mustBe(Bool) and have it compile into +// v.flag.mustBe(Bool), which will only bother to copy the +// single important word for the receiver. +func (f flag) mustBe(expected Kind) { + // TODO(mvdan): use f.kind() again once mid-stack inlining gets better + if Kind(f&flagKindMask) != expected { + panic(&ValueError{methodName(), f.kind()}) + } +} + +// mustBeExported panics if f records that the value was obtained using +// an unexported field. +func (f flag) mustBeExported() { + if f == 0 || f&flagRO != 0 { + f.mustBeExportedSlow() + } +} + +func (f flag) mustBeExportedSlow() { + if f == 0 { + panic(&ValueError{methodNameSkip(), Invalid}) + } + if f&flagRO != 0 { + panic("reflect: " + methodNameSkip() + " using value obtained using unexported field") + } +} + +// mustBeAssignable panics if f records that the value is not assignable, +// which is to say that either it was obtained using an unexported field +// or it is not addressable. +func (f flag) mustBeAssignable() { + if f&flagRO != 0 || f&flagAddr == 0 { + f.mustBeAssignableSlow() + } +} + +func (f flag) mustBeAssignableSlow() { + if f == 0 { + panic(&ValueError{methodNameSkip(), Invalid}) + } + // Assignable if addressable and not read-only. + if f&flagRO != 0 { + panic("reflect: " + methodNameSkip() + " using value obtained using unexported field") + } + if f&flagAddr == 0 { + panic("reflect: " + methodNameSkip() + " using unaddressable value") + } +} + +// Addr returns a pointer value representing the address of v. +// It panics if CanAddr() returns false. +// Addr is typically used to obtain a pointer to a struct field +// or slice element in order to call a method that requires a +// pointer receiver. +func (v Value) Addr() Value { + if v.flag&flagAddr == 0 { + panic("reflect.Value.Addr of unaddressable value") + } + // Preserve flagRO instead of using v.flag.ro() so that + // v.Addr().Elem() is equivalent to v (#32772) + fl := v.flag & flagRO + return Value{v.typ.ptrTo(), v.ptr, fl | flag(Ptr)} +} + +// Bool returns v's underlying value. +// It panics if v's kind is not Bool. +func (v Value) Bool() bool { + v.mustBe(Bool) + return *(*bool)(v.ptr) +} + +// Bytes returns v's underlying value. +// It panics if v's underlying value is not a slice of bytes. +func (v Value) Bytes() []byte { + v.mustBe(Slice) + if v.typ.Elem().Kind() != Uint8 { + panic("reflect.Value.Bytes of non-byte slice") + } + // Slice is always bigger than a word; assume flagIndir. + return *(*[]byte)(v.ptr) +} + +// runes returns v's underlying value. +// It panics if v's underlying value is not a slice of runes (int32s). +func (v Value) runes() []rune { + v.mustBe(Slice) + if v.typ.Elem().Kind() != Int32 { + panic("reflect.Value.Bytes of non-rune slice") + } + // Slice is always bigger than a word; assume flagIndir. + return *(*[]rune)(v.ptr) +} + +// CanAddr reports whether the value's address can be obtained with Addr. +// Such values are called addressable. A value is addressable if it is +// an element of a slice, an element of an addressable array, +// a field of an addressable struct, or the result of dereferencing a pointer. +// If CanAddr returns false, calling Addr will panic. +func (v Value) CanAddr() bool { + return v.flag&flagAddr != 0 +} + +// CanSet reports whether the value of v can be changed. +// A Value can be changed only if it is addressable and was not +// obtained by the use of unexported struct fields. +// If CanSet returns false, calling Set or any type-specific +// setter (e.g., SetBool, SetInt) will panic. +func (v Value) CanSet() bool { + return v.flag&(flagAddr|flagRO) == flagAddr +} + +// Call calls the function v with the input arguments in. +// For example, if len(in) == 3, v.Call(in) represents the Go call v(in[0], in[1], in[2]). +// Call panics if v's Kind is not Func. +// It returns the output results as Values. +// As in Go, each input argument must be assignable to the +// type of the function's corresponding input parameter. +// If v is a variadic function, Call creates the variadic slice parameter +// itself, copying in the corresponding values. +func (v Value) Call(in []Value) []Value { + v.mustBe(Func) + v.mustBeExported() + return v.call("Call", in) +} + +// CallSlice calls the variadic function v with the input arguments in, +// assigning the slice in[len(in)-1] to v's final variadic argument. +// For example, if len(in) == 3, v.CallSlice(in) represents the Go call v(in[0], in[1], in[2]...). +// CallSlice panics if v's Kind is not Func or if v is not variadic. +// It returns the output results as Values. +// As in Go, each input argument must be assignable to the +// type of the function's corresponding input parameter. +func (v Value) CallSlice(in []Value) []Value { + v.mustBe(Func) + v.mustBeExported() + return v.call("CallSlice", in) +} + +var callGC bool // for testing; see TestCallMethodJump + +func (v Value) call(op string, in []Value) []Value { + // Get function pointer, type. + t := (*funcType)(unsafe.Pointer(v.typ)) + var ( + fn unsafe.Pointer + rcvr Value + rcvrtype *rtype + ) + if v.flag&flagMethod != 0 { + rcvr = v + rcvrtype, t, fn = methodReceiver(op, v, int(v.flag)>>flagMethodShift) + } else if v.flag&flagIndir != 0 { + fn = *(*unsafe.Pointer)(v.ptr) + } else { + fn = v.ptr + } + + if fn == nil { + panic("reflect.Value.Call: call of nil function") + } + + isSlice := op == "CallSlice" + n := t.NumIn() + if isSlice { + if !t.IsVariadic() { + panic("reflect: CallSlice of non-variadic function") + } + if len(in) < n { + panic("reflect: CallSlice with too few input arguments") + } + if len(in) > n { + panic("reflect: CallSlice with too many input arguments") + } + } else { + if t.IsVariadic() { + n-- + } + if len(in) < n { + panic("reflect: Call with too few input arguments") + } + if !t.IsVariadic() && len(in) > n { + panic("reflect: Call with too many input arguments") + } + } + for _, x := range in { + if x.Kind() == Invalid { + panic("reflect: " + op + " using zero Value argument") + } + } + for i := 0; i < n; i++ { + if xt, targ := in[i].Type(), t.In(i); !xt.AssignableTo(targ) { + panic("reflect: " + op + " using " + xt.String() + " as type " + targ.String()) + } + } + if !isSlice && t.IsVariadic() { + // prepare slice for remaining values + m := len(in) - n + slice := MakeSlice(t.In(n), m, m) + elem := t.In(n).Elem() + for i := 0; i < m; i++ { + x := in[n+i] + if xt := x.Type(); !xt.AssignableTo(elem) { + panic("reflect: cannot use " + xt.String() + " as type " + elem.String() + " in " + op) + } + slice.Index(i).Set(x) + } + origIn := in + in = make([]Value, n+1) + copy(in[:n], origIn) + in[n] = slice + } + + nin := len(in) + if nin != t.NumIn() { + panic("reflect.Value.Call: wrong argument count") + } + nout := t.NumOut() + + // Compute frame type. + frametype, _, retOffset, _, framePool := funcLayout(t, rcvrtype) + + // Allocate a chunk of memory for frame. + var args unsafe.Pointer + if nout == 0 { + args = framePool.Get().(unsafe.Pointer) + } else { + // Can't use pool if the function has return values. + // We will leak pointer to args in ret, so its lifetime is not scoped. + args = unsafe_New(frametype) + } + off := uintptr(0) + + // Copy inputs into args. + if rcvrtype != nil { + storeRcvr(rcvr, args) + off = ptrSize + } + for i, v := range in { + v.mustBeExported() + targ := t.In(i).(*rtype) + a := uintptr(targ.align) + off = (off + a - 1) &^ (a - 1) + n := targ.size + if n == 0 { + // Not safe to compute args+off pointing at 0 bytes, + // because that might point beyond the end of the frame, + // but we still need to call assignTo to check assignability. + v.assignTo("reflect.Value.Call", targ, nil) + continue + } + addr := add(args, off, "n > 0") + v = v.assignTo("reflect.Value.Call", targ, addr) + if v.flag&flagIndir != 0 { + typedmemmove(targ, addr, v.ptr) + } else { + *(*unsafe.Pointer)(addr) = v.ptr + } + off += n + } + + // Call. + call(frametype, fn, args, uint32(frametype.size), uint32(retOffset)) + + // For testing; see TestCallMethodJump. + if callGC { + runtime.GC() + } + + var ret []Value + if nout == 0 { + typedmemclr(frametype, args) + framePool.Put(args) + } else { + // Zero the now unused input area of args, + // because the Values returned by this function contain pointers to the args object, + // and will thus keep the args object alive indefinitely. + typedmemclrpartial(frametype, args, 0, retOffset) + + // Wrap Values around return values in args. + ret = make([]Value, nout) + off = retOffset + for i := 0; i < nout; i++ { + tv := t.Out(i) + a := uintptr(tv.Align()) + off = (off + a - 1) &^ (a - 1) + if tv.Size() != 0 { + fl := flagIndir | flag(tv.Kind()) + ret[i] = Value{tv.common(), add(args, off, "tv.Size() != 0"), fl} + // Note: this does introduce false sharing between results - + // if any result is live, they are all live. + // (And the space for the args is live as well, but as we've + // cleared that space it isn't as big a deal.) + } else { + // For zero-sized return value, args+off may point to the next object. + // In this case, return the zero value instead. + ret[i] = Zero(tv) + } + off += tv.Size() + } + } + + return ret +} + +// callReflect is the call implementation used by a function +// returned by MakeFunc. In many ways it is the opposite of the +// method Value.call above. The method above converts a call using Values +// into a call of a function with a concrete argument frame, while +// callReflect converts a call of a function with a concrete argument +// frame into a call using Values. +// It is in this file so that it can be next to the call method above. +// The remainder of the MakeFunc implementation is in makefunc.go. +// +// NOTE: This function must be marked as a "wrapper" in the generated code, +// so that the linker can make it work correctly for panic and recover. +// The gc compilers know to do that for the name "reflect.callReflect". +// +// ctxt is the "closure" generated by MakeFunc. +// frame is a pointer to the arguments to that closure on the stack. +// retValid points to a boolean which should be set when the results +// section of frame is set. +func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer, retValid *bool) { + ftyp := ctxt.ftyp + f := ctxt.fn + + // Copy argument frame into Values. + ptr := frame + off := uintptr(0) + in := make([]Value, 0, int(ftyp.inCount)) + for _, typ := range ftyp.in() { + off += -off & uintptr(typ.align-1) + v := Value{typ, nil, flag(typ.Kind())} + if ifaceIndir(typ) { + // value cannot be inlined in interface data. + // Must make a copy, because f might keep a reference to it, + // and we cannot let f keep a reference to the stack frame + // after this function returns, not even a read-only reference. + v.ptr = unsafe_New(typ) + if typ.size > 0 { + typedmemmove(typ, v.ptr, add(ptr, off, "typ.size > 0")) + } + v.flag |= flagIndir + } else { + v.ptr = *(*unsafe.Pointer)(add(ptr, off, "1-ptr")) + } + in = append(in, v) + off += typ.size + } + + // Call underlying function. + out := f(in) + numOut := ftyp.NumOut() + if len(out) != numOut { + panic("reflect: wrong return count from function created by MakeFunc") + } + + // Copy results back into argument frame. + if numOut > 0 { + off += -off & (ptrSize - 1) + for i, typ := range ftyp.out() { + v := out[i] + if v.typ == nil { + panic("reflect: function created by MakeFunc using " + funcName(f) + + " returned zero Value") + } + if v.flag&flagRO != 0 { + panic("reflect: function created by MakeFunc using " + funcName(f) + + " returned value obtained from unexported field") + } + off += -off & uintptr(typ.align-1) + if typ.size == 0 { + continue + } + addr := add(ptr, off, "typ.size > 0") + + // Convert v to type typ if v is assignable to a variable + // of type t in the language spec. + // See issue 28761. + if typ.Kind() == Interface { + // We must clear the destination before calling assignTo, + // in case assignTo writes (with memory barriers) to the + // target location used as scratch space. See issue 39541. + *(*uintptr)(addr) = 0 + *(*uintptr)(add(addr, ptrSize, "typ.size == 2*ptrSize")) = 0 + } + v = v.assignTo("reflect.MakeFunc", typ, addr) + + // We are writing to stack. No write barrier. + if v.flag&flagIndir != 0 { + memmove(addr, v.ptr, typ.size) + } else { + *(*uintptr)(addr) = uintptr(v.ptr) + } + off += typ.size + } + } + + // Announce that the return values are valid. + // After this point the runtime can depend on the return values being valid. + *retValid = true + + // We have to make sure that the out slice lives at least until + // the runtime knows the return values are valid. Otherwise, the + // return values might not be scanned by anyone during a GC. + // (out would be dead, and the return slots not yet alive.) + runtime.KeepAlive(out) + + // runtime.getArgInfo expects to be able to find ctxt on the + // stack when it finds our caller, makeFuncStub. Make sure it + // doesn't get garbage collected. + runtime.KeepAlive(ctxt) +} + +// methodReceiver returns information about the receiver +// described by v. The Value v may or may not have the +// flagMethod bit set, so the kind cached in v.flag should +// not be used. +// The return value rcvrtype gives the method's actual receiver type. +// The return value t gives the method type signature (without the receiver). +// The return value fn is a pointer to the method code. +func methodReceiver(op string, v Value, methodIndex int) (rcvrtype *rtype, t *funcType, fn unsafe.Pointer) { + i := methodIndex + if v.typ.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &tt.methods[i] + if !tt.nameOff(m.name).isExported() { + panic("reflect: " + op + " of unexported method") + } + iface := (*nonEmptyInterface)(v.ptr) + if iface.itab == nil { + panic("reflect: " + op + " of method on nil interface value") + } + rcvrtype = iface.itab.typ + fn = unsafe.Pointer(&iface.itab.fun[i]) + t = (*funcType)(unsafe.Pointer(tt.typeOff(m.typ))) + } else { + rcvrtype = v.typ + ms := v.typ.exportedMethods() + if uint(i) >= uint(len(ms)) { + panic("reflect: internal error: invalid method index") + } + m := ms[i] + if !v.typ.nameOff(m.name).isExported() { + panic("reflect: " + op + " of unexported method") + } + ifn := v.typ.textOff(m.ifn) + fn = unsafe.Pointer(&ifn) + t = (*funcType)(unsafe.Pointer(v.typ.typeOff(m.mtyp))) + } + return +} + +// v is a method receiver. Store at p the word which is used to +// encode that receiver at the start of the argument list. +// Reflect uses the "interface" calling convention for +// methods, which always uses one word to record the receiver. +func storeRcvr(v Value, p unsafe.Pointer) { + t := v.typ + if t.Kind() == Interface { + // the interface data word becomes the receiver word + iface := (*nonEmptyInterface)(v.ptr) + *(*unsafe.Pointer)(p) = iface.word + } else if v.flag&flagIndir != 0 && !ifaceIndir(t) { + *(*unsafe.Pointer)(p) = *(*unsafe.Pointer)(v.ptr) + } else { + *(*unsafe.Pointer)(p) = v.ptr + } +} + +// align returns the result of rounding x up to a multiple of n. +// n must be a power of two. +func align(x, n uintptr) uintptr { + return (x + n - 1) &^ (n - 1) +} + +// callMethod is the call implementation used by a function returned +// by makeMethodValue (used by v.Method(i).Interface()). +// It is a streamlined version of the usual reflect call: the caller has +// already laid out the argument frame for us, so we don't have +// to deal with individual Values for each argument. +// It is in this file so that it can be next to the two similar functions above. +// The remainder of the makeMethodValue implementation is in makefunc.go. +// +// NOTE: This function must be marked as a "wrapper" in the generated code, +// so that the linker can make it work correctly for panic and recover. +// The gc compilers know to do that for the name "reflect.callMethod". +// +// ctxt is the "closure" generated by makeVethodValue. +// frame is a pointer to the arguments to that closure on the stack. +// retValid points to a boolean which should be set when the results +// section of frame is set. +func callMethod(ctxt *methodValue, frame unsafe.Pointer, retValid *bool) { + rcvr := ctxt.rcvr + rcvrtype, t, fn := methodReceiver("call", rcvr, ctxt.method) + frametype, argSize, retOffset, _, framePool := funcLayout(t, rcvrtype) + + // Make a new frame that is one word bigger so we can store the receiver. + // This space is used for both arguments and return values. + scratch := framePool.Get().(unsafe.Pointer) + + // Copy in receiver and rest of args. + storeRcvr(rcvr, scratch) + // Align the first arg. The alignment can't be larger than ptrSize. + argOffset := uintptr(ptrSize) + if len(t.in()) > 0 { + argOffset = align(argOffset, uintptr(t.in()[0].align)) + } + // Avoid constructing out-of-bounds pointers if there are no args. + if argSize-argOffset > 0 { + typedmemmovepartial(frametype, add(scratch, argOffset, "argSize > argOffset"), frame, argOffset, argSize-argOffset) + } + + // Call. + // Call copies the arguments from scratch to the stack, calls fn, + // and then copies the results back into scratch. + call(frametype, fn, scratch, uint32(frametype.size), uint32(retOffset)) + + // Copy return values. + // Ignore any changes to args and just copy return values. + // Avoid constructing out-of-bounds pointers if there are no return values. + if frametype.size-retOffset > 0 { + callerRetOffset := retOffset - argOffset + // This copies to the stack. Write barriers are not needed. + memmove(add(frame, callerRetOffset, "frametype.size > retOffset"), + add(scratch, retOffset, "frametype.size > retOffset"), + frametype.size-retOffset) + } + + // Tell the runtime it can now depend on the return values + // being properly initialized. + *retValid = true + + // Clear the scratch space and put it back in the pool. + // This must happen after the statement above, so that the return + // values will always be scanned by someone. + typedmemclr(frametype, scratch) + framePool.Put(scratch) + + // See the comment in callReflect. + runtime.KeepAlive(ctxt) +} + +// funcName returns the name of f, for use in error messages. +func funcName(f func([]Value) []Value) string { + pc := *(*uintptr)(unsafe.Pointer(&f)) + rf := runtime.FuncForPC(pc) + if rf != nil { + return rf.Name() + } + return "closure" +} + +// Cap returns v's capacity. +// It panics if v's Kind is not Array, Chan, or Slice. +func (v Value) Cap() int { + k := v.kind() + switch k { + case Array: + return v.typ.Len() + case Chan: + return chancap(v.pointer()) + case Slice: + // Slice is always bigger than a word; assume flagIndir. + return (*unsafeheader.Slice)(v.ptr).Cap + } + panic(&ValueError{"reflect.Value.Cap", v.kind()}) +} + +// Close closes the channel v. +// It panics if v's Kind is not Chan. +func (v Value) Close() { + v.mustBe(Chan) + v.mustBeExported() + chanclose(v.pointer()) +} + +// Complex returns v's underlying value, as a complex128. +// It panics if v's Kind is not Complex64 or Complex128 +func (v Value) Complex() complex128 { + k := v.kind() + switch k { + case Complex64: + return complex128(*(*complex64)(v.ptr)) + case Complex128: + return *(*complex128)(v.ptr) + } + panic(&ValueError{"reflect.Value.Complex", v.kind()}) +} + +// Elem returns the value that the interface v contains +// or that the pointer v points to. +// It panics if v's Kind is not Interface or Ptr. +// It returns the zero Value if v is nil. +func (v Value) Elem() Value { + k := v.kind() + switch k { + case Interface: + var eface interface{} + if v.typ.NumMethod() == 0 { + eface = *(*interface{})(v.ptr) + } else { + eface = (interface{})(*(*interface { + M() + })(v.ptr)) + } + x := unpackEface(eface) + if x.flag != 0 { + x.flag |= v.flag.ro() + } + return x + case Ptr: + ptr := v.ptr + if v.flag&flagIndir != 0 { + ptr = *(*unsafe.Pointer)(ptr) + } + // The returned value's address is v's value. + if ptr == nil { + return Value{} + } + tt := (*ptrType)(unsafe.Pointer(v.typ)) + typ := tt.elem + fl := v.flag&flagRO | flagIndir | flagAddr + fl |= flag(typ.Kind()) + return Value{typ, ptr, fl} + } + panic(&ValueError{"reflect.Value.Elem", v.kind()}) +} + +// Field returns the i'th field of the struct v. +// It panics if v's Kind is not Struct or i is out of range. +func (v Value) Field(i int) Value { + if v.kind() != Struct { + panic(&ValueError{"reflect.Value.Field", v.kind()}) + } + tt := (*structType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.fields)) { + panic("reflect: Field index out of range") + } + field := &tt.fields[i] + typ := field.typ + + // Inherit permission bits from v, but clear flagEmbedRO. + fl := v.flag&(flagStickyRO|flagIndir|flagAddr) | flag(typ.Kind()) + // Using an unexported field forces flagRO. + if !field.name.isExported() { + if field.embedded() { + fl |= flagEmbedRO + } else { + fl |= flagStickyRO + } + } + // Either flagIndir is set and v.ptr points at struct, + // or flagIndir is not set and v.ptr is the actual struct data. + // In the former case, we want v.ptr + offset. + // In the latter case, we must have field.offset = 0, + // so v.ptr + field.offset is still the correct address. + ptr := add(v.ptr, field.offset(), "same as non-reflect &v.field") + return Value{typ, ptr, fl} +} + +// FieldByIndex returns the nested field corresponding to index. +// It panics if v's Kind is not struct. +func (v Value) FieldByIndex(index []int) Value { + if len(index) == 1 { + return v.Field(index[0]) + } + v.mustBe(Struct) + for i, x := range index { + if i > 0 { + if v.Kind() == Ptr && v.typ.Elem().Kind() == Struct { + if v.IsNil() { + panic("reflect: indirection through nil pointer to embedded struct") + } + v = v.Elem() + } + } + v = v.Field(x) + } + return v +} + +// FieldByName returns the struct field with the given name. +// It returns the zero Value if no field was found. +// It panics if v's Kind is not struct. +func (v Value) FieldByName(name string) Value { + v.mustBe(Struct) + if f, ok := v.typ.FieldByName(name); ok { + return v.FieldByIndex(f.Index) + } + return Value{} +} + +// FieldByNameFunc returns the struct field with a name +// that satisfies the match function. +// It panics if v's Kind is not struct. +// It returns the zero Value if no field was found. +func (v Value) FieldByNameFunc(match func(string) bool) Value { + if f, ok := v.typ.FieldByNameFunc(match); ok { + return v.FieldByIndex(f.Index) + } + return Value{} +} + +// Float returns v's underlying value, as a float64. +// It panics if v's Kind is not Float32 or Float64 +func (v Value) Float() float64 { + k := v.kind() + switch k { + case Float32: + return float64(*(*float32)(v.ptr)) + case Float64: + return *(*float64)(v.ptr) + } + panic(&ValueError{"reflect.Value.Float", v.kind()}) +} + +var uint8Type = TypeOf(uint8(0)).(*rtype) + +// Index returns v's i'th element. +// It panics if v's Kind is not Array, Slice, or String or i is out of range. +func (v Value) Index(i int) Value { + switch v.kind() { + case Array: + tt := (*arrayType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(tt.len) { + panic("reflect: array index out of range") + } + typ := tt.elem + offset := uintptr(i) * typ.size + + // Either flagIndir is set and v.ptr points at array, + // or flagIndir is not set and v.ptr is the actual array data. + // In the former case, we want v.ptr + offset. + // In the latter case, we must be doing Index(0), so offset = 0, + // so v.ptr + offset is still the correct address. + val := add(v.ptr, offset, "same as &v[i], i < tt.len") + fl := v.flag&(flagIndir|flagAddr) | v.flag.ro() | flag(typ.Kind()) // bits same as overall array + return Value{typ, val, fl} + + case Slice: + // Element flag same as Elem of Ptr. + // Addressable, indirect, possibly read-only. + s := (*unsafeheader.Slice)(v.ptr) + if uint(i) >= uint(s.Len) { + panic("reflect: slice index out of range") + } + tt := (*sliceType)(unsafe.Pointer(v.typ)) + typ := tt.elem + val := arrayAt(s.Data, i, typ.size, "i < s.Len") + fl := flagAddr | flagIndir | v.flag.ro() | flag(typ.Kind()) + return Value{typ, val, fl} + + case String: + s := (*unsafeheader.String)(v.ptr) + if uint(i) >= uint(s.Len) { + panic("reflect: string index out of range") + } + p := arrayAt(s.Data, i, 1, "i < s.Len") + fl := v.flag.ro() | flag(Uint8) | flagIndir + return Value{uint8Type, p, fl} + } + panic(&ValueError{"reflect.Value.Index", v.kind()}) +} + +// Int returns v's underlying value, as an int64. +// It panics if v's Kind is not Int, Int8, Int16, Int32, or Int64. +func (v Value) Int() int64 { + k := v.kind() + p := v.ptr + switch k { + case Int: + return int64(*(*int)(p)) + case Int8: + return int64(*(*int8)(p)) + case Int16: + return int64(*(*int16)(p)) + case Int32: + return int64(*(*int32)(p)) + case Int64: + return *(*int64)(p) + } + panic(&ValueError{"reflect.Value.Int", v.kind()}) +} + +// CanInterface reports whether Interface can be used without panicking. +func (v Value) CanInterface() bool { + if v.flag == 0 { + panic(&ValueError{"reflect.Value.CanInterface", Invalid}) + } + return v.flag&flagRO == 0 +} + +// Interface returns v's current value as an interface{}. +// It is equivalent to: +// var i interface{} = (v's underlying value) +// It panics if the Value was obtained by accessing +// unexported struct fields. +func (v Value) Interface() (i interface{}) { + return valueInterface(v, true) +} + +func valueInterface(v Value, safe bool) interface{} { + if v.flag == 0 { + panic(&ValueError{"reflect.Value.Interface", Invalid}) + } + if safe && v.flag&flagRO != 0 { + // Do not allow access to unexported values via Interface, + // because they might be pointers that should not be + // writable or methods or function that should not be callable. + panic("reflect.Value.Interface: cannot return value obtained from unexported field or method") + } + if v.flag&flagMethod != 0 { + v = makeMethodValue("Interface", v) + } + + if v.kind() == Interface { + // Special case: return the element inside the interface. + // Empty interface has one layout, all interfaces with + // methods have a second layout. + if v.NumMethod() == 0 { + return *(*interface{})(v.ptr) + } + return *(*interface { + M() + })(v.ptr) + } + + // TODO: pass safe to packEface so we don't need to copy if safe==true? + return packEface(v) +} + +// InterfaceData returns the interface v's value as a uintptr pair. +// It panics if v's Kind is not Interface. +func (v Value) InterfaceData() [2]uintptr { + // TODO: deprecate this + v.mustBe(Interface) + // We treat this as a read operation, so we allow + // it even for unexported data, because the caller + // has to import "unsafe" to turn it into something + // that can be abused. + // Interface value is always bigger than a word; assume flagIndir. + return *(*[2]uintptr)(v.ptr) +} + +// IsNil reports whether its argument v is nil. The argument must be +// a chan, func, interface, map, pointer, or slice value; if it is +// not, IsNil panics. Note that IsNil is not always equivalent to a +// regular comparison with nil in Go. For example, if v was created +// by calling ValueOf with an uninitialized interface variable i, +// i==nil will be true but v.IsNil will panic as v will be the zero +// Value. +func (v Value) IsNil() bool { + k := v.kind() + switch k { + case Chan, Func, Map, Ptr, UnsafePointer: + if v.flag&flagMethod != 0 { + return false + } + ptr := v.ptr + if v.flag&flagIndir != 0 { + ptr = *(*unsafe.Pointer)(ptr) + } + return ptr == nil + case Interface, Slice: + // Both interface and slice are nil if first word is 0. + // Both are always bigger than a word; assume flagIndir. + return *(*unsafe.Pointer)(v.ptr) == nil + } + panic(&ValueError{"reflect.Value.IsNil", v.kind()}) +} + +// IsValid reports whether v represents a value. +// It returns false if v is the zero Value. +// If IsValid returns false, all other methods except String panic. +// Most functions and methods never return an invalid Value. +// If one does, its documentation states the conditions explicitly. +func (v Value) IsValid() bool { + return v.flag != 0 +} + +// IsZero reports whether v is the zero value for its type. +// It panics if the argument is invalid. +func (v Value) IsZero() bool { + switch v.kind() { + case Bool: + return !v.Bool() + case Int, Int8, Int16, Int32, Int64: + return v.Int() == 0 + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return v.Uint() == 0 + case Float32, Float64: + return math.Float64bits(v.Float()) == 0 + case Complex64, Complex128: + c := v.Complex() + return math.Float64bits(real(c)) == 0 && math.Float64bits(imag(c)) == 0 + case Array: + for i := 0; i < v.Len(); i++ { + if !v.Index(i).IsZero() { + return false + } + } + return true + case Chan, Func, Interface, Map, Ptr, Slice, UnsafePointer: + return v.IsNil() + case String: + return v.Len() == 0 + case Struct: + for i := 0; i < v.NumField(); i++ { + if !v.Field(i).IsZero() { + return false + } + } + return true + default: + // This should never happens, but will act as a safeguard for + // later, as a default value doesn't makes sense here. + panic(&ValueError{"reflect.Value.IsZero", v.Kind()}) + } +} + +// Kind returns v's Kind. +// If v is the zero Value (IsValid returns false), Kind returns Invalid. +func (v Value) Kind() Kind { + return v.kind() +} + +// Len returns v's length. +// It panics if v's Kind is not Array, Chan, Map, Slice, or String. +func (v Value) Len() int { + k := v.kind() + switch k { + case Array: + tt := (*arrayType)(unsafe.Pointer(v.typ)) + return int(tt.len) + case Chan: + return chanlen(v.pointer()) + case Map: + return maplen(v.pointer()) + case Slice: + // Slice is bigger than a word; assume flagIndir. + return (*unsafeheader.Slice)(v.ptr).Len + case String: + // String is bigger than a word; assume flagIndir. + return (*unsafeheader.String)(v.ptr).Len + } + panic(&ValueError{"reflect.Value.Len", v.kind()}) +} + +// MapIndex returns the value associated with key in the map v. +// It panics if v's Kind is not Map. +// It returns the zero Value if key is not found in the map or if v represents a nil map. +// As in Go, the key's value must be assignable to the map's key type. +func (v Value) MapIndex(key Value) Value { + v.mustBe(Map) + tt := (*mapType)(unsafe.Pointer(v.typ)) + + // Do not require key to be exported, so that DeepEqual + // and other programs can use all the keys returned by + // MapKeys as arguments to MapIndex. If either the map + // or the key is unexported, though, the result will be + // considered unexported. This is consistent with the + // behavior for structs, which allow read but not write + // of unexported fields. + key = key.assignTo("reflect.Value.MapIndex", tt.key, nil) + + var k unsafe.Pointer + if key.flag&flagIndir != 0 { + k = key.ptr + } else { + k = unsafe.Pointer(&key.ptr) + } + e := mapaccess(v.typ, v.pointer(), k) + if e == nil { + return Value{} + } + typ := tt.elem + fl := (v.flag | key.flag).ro() + fl |= flag(typ.Kind()) + return copyVal(typ, fl, e) +} + +// MapKeys returns a slice containing all the keys present in the map, +// in unspecified order. +// It panics if v's Kind is not Map. +// It returns an empty slice if v represents a nil map. +func (v Value) MapKeys() []Value { + v.mustBe(Map) + tt := (*mapType)(unsafe.Pointer(v.typ)) + keyType := tt.key + + fl := v.flag.ro() | flag(keyType.Kind()) + + m := v.pointer() + mlen := int(0) + if m != nil { + mlen = maplen(m) + } + it := mapiterinit(v.typ, m) + a := make([]Value, mlen) + var i int + for i = 0; i < len(a); i++ { + key := mapiterkey(it) + if key == nil { + // Someone deleted an entry from the map since we + // called maplen above. It's a data race, but nothing + // we can do about it. + break + } + a[i] = copyVal(keyType, fl, key) + mapiternext(it) + } + return a[:i] +} + +// A MapIter is an iterator for ranging over a map. +// See Value.MapRange. +type MapIter struct { + m Value + it unsafe.Pointer +} + +// Key returns the key of the iterator's current map entry. +func (it *MapIter) Key() Value { + if it.it == nil { + panic("MapIter.Key called before Next") + } + if mapiterkey(it.it) == nil { + panic("MapIter.Key called on exhausted iterator") + } + + t := (*mapType)(unsafe.Pointer(it.m.typ)) + ktype := t.key + return copyVal(ktype, it.m.flag.ro()|flag(ktype.Kind()), mapiterkey(it.it)) +} + +// Value returns the value of the iterator's current map entry. +func (it *MapIter) Value() Value { + if it.it == nil { + panic("MapIter.Value called before Next") + } + if mapiterkey(it.it) == nil { + panic("MapIter.Value called on exhausted iterator") + } + + t := (*mapType)(unsafe.Pointer(it.m.typ)) + vtype := t.elem + return copyVal(vtype, it.m.flag.ro()|flag(vtype.Kind()), mapiterelem(it.it)) +} + +// Next advances the map iterator and reports whether there is another +// entry. It returns false when the iterator is exhausted; subsequent +// calls to Key, Value, or Next will panic. +func (it *MapIter) Next() bool { + if it.it == nil { + it.it = mapiterinit(it.m.typ, it.m.pointer()) + } else { + if mapiterkey(it.it) == nil { + panic("MapIter.Next called on exhausted iterator") + } + mapiternext(it.it) + } + return mapiterkey(it.it) != nil +} + +// MapRange returns a range iterator for a map. +// It panics if v's Kind is not Map. +// +// Call Next to advance the iterator, and Key/Value to access each entry. +// Next returns false when the iterator is exhausted. +// MapRange follows the same iteration semantics as a range statement. +// +// Example: +// +// iter := reflect.ValueOf(m).MapRange() +// for iter.Next() { +// k := iter.Key() +// v := iter.Value() +// ... +// } +// +func (v Value) MapRange() *MapIter { + v.mustBe(Map) + return &MapIter{m: v} +} + +// copyVal returns a Value containing the map key or value at ptr, +// allocating a new variable as needed. +func copyVal(typ *rtype, fl flag, ptr unsafe.Pointer) Value { + if ifaceIndir(typ) { + // Copy result so future changes to the map + // won't change the underlying value. + c := unsafe_New(typ) + typedmemmove(typ, c, ptr) + return Value{typ, c, fl | flagIndir} + } + return Value{typ, *(*unsafe.Pointer)(ptr), fl} +} + +// Method returns a function value corresponding to v's i'th method. +// The arguments to a Call on the returned function should not include +// a receiver; the returned function will always use v as the receiver. +// Method panics if i is out of range or if v is a nil interface value. +func (v Value) Method(i int) Value { + if v.typ == nil { + panic(&ValueError{"reflect.Value.Method", Invalid}) + } + if v.flag&flagMethod != 0 || uint(i) >= uint(v.typ.NumMethod()) { + panic("reflect: Method index out of range") + } + if v.typ.Kind() == Interface && v.IsNil() { + panic("reflect: Method on nil interface value") + } + fl := v.flag.ro() | (v.flag & flagIndir) + fl |= flag(Func) + fl |= flag(i)<<flagMethodShift | flagMethod + return Value{v.typ, v.ptr, fl} +} + +// NumMethod returns the number of exported methods in the value's method set. +func (v Value) NumMethod() int { + if v.typ == nil { + panic(&ValueError{"reflect.Value.NumMethod", Invalid}) + } + if v.flag&flagMethod != 0 { + return 0 + } + return v.typ.NumMethod() +} + +// MethodByName returns a function value corresponding to the method +// of v with the given name. +// The arguments to a Call on the returned function should not include +// a receiver; the returned function will always use v as the receiver. +// It returns the zero Value if no method was found. +func (v Value) MethodByName(name string) Value { + if v.typ == nil { + panic(&ValueError{"reflect.Value.MethodByName", Invalid}) + } + if v.flag&flagMethod != 0 { + return Value{} + } + m, ok := v.typ.MethodByName(name) + if !ok { + return Value{} + } + return v.Method(m.Index) +} + +// NumField returns the number of fields in the struct v. +// It panics if v's Kind is not Struct. +func (v Value) NumField() int { + v.mustBe(Struct) + tt := (*structType)(unsafe.Pointer(v.typ)) + return len(tt.fields) +} + +// OverflowComplex reports whether the complex128 x cannot be represented by v's type. +// It panics if v's Kind is not Complex64 or Complex128. +func (v Value) OverflowComplex(x complex128) bool { + k := v.kind() + switch k { + case Complex64: + return overflowFloat32(real(x)) || overflowFloat32(imag(x)) + case Complex128: + return false + } + panic(&ValueError{"reflect.Value.OverflowComplex", v.kind()}) +} + +// OverflowFloat reports whether the float64 x cannot be represented by v's type. +// It panics if v's Kind is not Float32 or Float64. +func (v Value) OverflowFloat(x float64) bool { + k := v.kind() + switch k { + case Float32: + return overflowFloat32(x) + case Float64: + return false + } + panic(&ValueError{"reflect.Value.OverflowFloat", v.kind()}) +} + +func overflowFloat32(x float64) bool { + if x < 0 { + x = -x + } + return math.MaxFloat32 < x && x <= math.MaxFloat64 +} + +// OverflowInt reports whether the int64 x cannot be represented by v's type. +// It panics if v's Kind is not Int, Int8, Int16, Int32, or Int64. +func (v Value) OverflowInt(x int64) bool { + k := v.kind() + switch k { + case Int, Int8, Int16, Int32, Int64: + bitSize := v.typ.size * 8 + trunc := (x << (64 - bitSize)) >> (64 - bitSize) + return x != trunc + } + panic(&ValueError{"reflect.Value.OverflowInt", v.kind()}) +} + +// OverflowUint reports whether the uint64 x cannot be represented by v's type. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64. +func (v Value) OverflowUint(x uint64) bool { + k := v.kind() + switch k { + case Uint, Uintptr, Uint8, Uint16, Uint32, Uint64: + bitSize := v.typ.size * 8 + trunc := (x << (64 - bitSize)) >> (64 - bitSize) + return x != trunc + } + panic(&ValueError{"reflect.Value.OverflowUint", v.kind()}) +} + +//go:nocheckptr +// This prevents inlining Value.Pointer when -d=checkptr is enabled, +// which ensures cmd/compile can recognize unsafe.Pointer(v.Pointer()) +// and make an exception. + +// Pointer returns v's value as a uintptr. +// It returns uintptr instead of unsafe.Pointer so that +// code using reflect cannot obtain unsafe.Pointers +// without importing the unsafe package explicitly. +// It panics if v's Kind is not Chan, Func, Map, Ptr, Slice, or UnsafePointer. +// +// If v's Kind is Func, the returned pointer is an underlying +// code pointer, but not necessarily enough to identify a +// single function uniquely. The only guarantee is that the +// result is zero if and only if v is a nil func Value. +// +// If v's Kind is Slice, the returned pointer is to the first +// element of the slice. If the slice is nil the returned value +// is 0. If the slice is empty but non-nil the return value is non-zero. +func (v Value) Pointer() uintptr { + // TODO: deprecate + k := v.kind() + switch k { + case Ptr: + if v.typ.ptrdata == 0 { + // Handle pointers to go:notinheap types directly, + // so we never materialize such pointers as an + // unsafe.Pointer. (Such pointers are always indirect.) + // See issue 42076. + return *(*uintptr)(v.ptr) + } + fallthrough + case Chan, Map, UnsafePointer: + return uintptr(v.pointer()) + case Func: + if v.flag&flagMethod != 0 { + // As the doc comment says, the returned pointer is an + // underlying code pointer but not necessarily enough to + // identify a single function uniquely. All method expressions + // created via reflect have the same underlying code pointer, + // so their Pointers are equal. The function used here must + // match the one used in makeMethodValue. + f := methodValueCall + return **(**uintptr)(unsafe.Pointer(&f)) + } + p := v.pointer() + // Non-nil func value points at data block. + // First word of data block is actual code. + if p != nil { + p = *(*unsafe.Pointer)(p) + } + return uintptr(p) + + case Slice: + return (*SliceHeader)(v.ptr).Data + } + panic(&ValueError{"reflect.Value.Pointer", v.kind()}) +} + +// Recv receives and returns a value from the channel v. +// It panics if v's Kind is not Chan. +// The receive blocks until a value is ready. +// The boolean value ok is true if the value x corresponds to a send +// on the channel, false if it is a zero value received because the channel is closed. +func (v Value) Recv() (x Value, ok bool) { + v.mustBe(Chan) + v.mustBeExported() + return v.recv(false) +} + +// internal recv, possibly non-blocking (nb). +// v is known to be a channel. +func (v Value) recv(nb bool) (val Value, ok bool) { + tt := (*chanType)(unsafe.Pointer(v.typ)) + if ChanDir(tt.dir)&RecvDir == 0 { + panic("reflect: recv on send-only channel") + } + t := tt.elem + val = Value{t, nil, flag(t.Kind())} + var p unsafe.Pointer + if ifaceIndir(t) { + p = unsafe_New(t) + val.ptr = p + val.flag |= flagIndir + } else { + p = unsafe.Pointer(&val.ptr) + } + selected, ok := chanrecv(v.pointer(), nb, p) + if !selected { + val = Value{} + } + return +} + +// Send sends x on the channel v. +// It panics if v's kind is not Chan or if x's type is not the same type as v's element type. +// As in Go, x's value must be assignable to the channel's element type. +func (v Value) Send(x Value) { + v.mustBe(Chan) + v.mustBeExported() + v.send(x, false) +} + +// internal send, possibly non-blocking. +// v is known to be a channel. +func (v Value) send(x Value, nb bool) (selected bool) { + tt := (*chanType)(unsafe.Pointer(v.typ)) + if ChanDir(tt.dir)&SendDir == 0 { + panic("reflect: send on recv-only channel") + } + x.mustBeExported() + x = x.assignTo("reflect.Value.Send", tt.elem, nil) + var p unsafe.Pointer + if x.flag&flagIndir != 0 { + p = x.ptr + } else { + p = unsafe.Pointer(&x.ptr) + } + return chansend(v.pointer(), p, nb) +} + +// Set assigns x to the value v. +// It panics if CanSet returns false. +// As in Go, x's value must be assignable to v's type. +func (v Value) Set(x Value) { + v.mustBeAssignable() + x.mustBeExported() // do not let unexported x leak + var target unsafe.Pointer + if v.kind() == Interface { + target = v.ptr + } + x = x.assignTo("reflect.Set", v.typ, target) + if x.flag&flagIndir != 0 { + if x.ptr == unsafe.Pointer(&zeroVal[0]) { + typedmemclr(v.typ, v.ptr) + } else { + typedmemmove(v.typ, v.ptr, x.ptr) + } + } else { + *(*unsafe.Pointer)(v.ptr) = x.ptr + } +} + +// SetBool sets v's underlying value. +// It panics if v's Kind is not Bool or if CanSet() is false. +func (v Value) SetBool(x bool) { + v.mustBeAssignable() + v.mustBe(Bool) + *(*bool)(v.ptr) = x +} + +// SetBytes sets v's underlying value. +// It panics if v's underlying value is not a slice of bytes. +func (v Value) SetBytes(x []byte) { + v.mustBeAssignable() + v.mustBe(Slice) + if v.typ.Elem().Kind() != Uint8 { + panic("reflect.Value.SetBytes of non-byte slice") + } + *(*[]byte)(v.ptr) = x +} + +// setRunes sets v's underlying value. +// It panics if v's underlying value is not a slice of runes (int32s). +func (v Value) setRunes(x []rune) { + v.mustBeAssignable() + v.mustBe(Slice) + if v.typ.Elem().Kind() != Int32 { + panic("reflect.Value.setRunes of non-rune slice") + } + *(*[]rune)(v.ptr) = x +} + +// SetComplex sets v's underlying value to x. +// It panics if v's Kind is not Complex64 or Complex128, or if CanSet() is false. +func (v Value) SetComplex(x complex128) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetComplex", v.kind()}) + case Complex64: + *(*complex64)(v.ptr) = complex64(x) + case Complex128: + *(*complex128)(v.ptr) = x + } +} + +// SetFloat sets v's underlying value to x. +// It panics if v's Kind is not Float32 or Float64, or if CanSet() is false. +func (v Value) SetFloat(x float64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetFloat", v.kind()}) + case Float32: + *(*float32)(v.ptr) = float32(x) + case Float64: + *(*float64)(v.ptr) = x + } +} + +// SetInt sets v's underlying value to x. +// It panics if v's Kind is not Int, Int8, Int16, Int32, or Int64, or if CanSet() is false. +func (v Value) SetInt(x int64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetInt", v.kind()}) + case Int: + *(*int)(v.ptr) = int(x) + case Int8: + *(*int8)(v.ptr) = int8(x) + case Int16: + *(*int16)(v.ptr) = int16(x) + case Int32: + *(*int32)(v.ptr) = int32(x) + case Int64: + *(*int64)(v.ptr) = x + } +} + +// SetLen sets v's length to n. +// It panics if v's Kind is not Slice or if n is negative or +// greater than the capacity of the slice. +func (v Value) SetLen(n int) { + v.mustBeAssignable() + v.mustBe(Slice) + s := (*unsafeheader.Slice)(v.ptr) + if uint(n) > uint(s.Cap) { + panic("reflect: slice length out of range in SetLen") + } + s.Len = n +} + +// SetCap sets v's capacity to n. +// It panics if v's Kind is not Slice or if n is smaller than the length or +// greater than the capacity of the slice. +func (v Value) SetCap(n int) { + v.mustBeAssignable() + v.mustBe(Slice) + s := (*unsafeheader.Slice)(v.ptr) + if n < s.Len || n > s.Cap { + panic("reflect: slice capacity out of range in SetCap") + } + s.Cap = n +} + +// SetMapIndex sets the element associated with key in the map v to elem. +// It panics if v's Kind is not Map. +// If elem is the zero Value, SetMapIndex deletes the key from the map. +// Otherwise if v holds a nil map, SetMapIndex will panic. +// As in Go, key's elem must be assignable to the map's key type, +// and elem's value must be assignable to the map's elem type. +func (v Value) SetMapIndex(key, elem Value) { + v.mustBe(Map) + v.mustBeExported() + key.mustBeExported() + tt := (*mapType)(unsafe.Pointer(v.typ)) + key = key.assignTo("reflect.Value.SetMapIndex", tt.key, nil) + var k unsafe.Pointer + if key.flag&flagIndir != 0 { + k = key.ptr + } else { + k = unsafe.Pointer(&key.ptr) + } + if elem.typ == nil { + mapdelete(v.typ, v.pointer(), k) + return + } + elem.mustBeExported() + elem = elem.assignTo("reflect.Value.SetMapIndex", tt.elem, nil) + var e unsafe.Pointer + if elem.flag&flagIndir != 0 { + e = elem.ptr + } else { + e = unsafe.Pointer(&elem.ptr) + } + mapassign(v.typ, v.pointer(), k, e) +} + +// SetUint sets v's underlying value to x. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64, or if CanSet() is false. +func (v Value) SetUint(x uint64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetUint", v.kind()}) + case Uint: + *(*uint)(v.ptr) = uint(x) + case Uint8: + *(*uint8)(v.ptr) = uint8(x) + case Uint16: + *(*uint16)(v.ptr) = uint16(x) + case Uint32: + *(*uint32)(v.ptr) = uint32(x) + case Uint64: + *(*uint64)(v.ptr) = x + case Uintptr: + *(*uintptr)(v.ptr) = uintptr(x) + } +} + +// SetPointer sets the unsafe.Pointer value v to x. +// It panics if v's Kind is not UnsafePointer. +func (v Value) SetPointer(x unsafe.Pointer) { + v.mustBeAssignable() + v.mustBe(UnsafePointer) + *(*unsafe.Pointer)(v.ptr) = x +} + +// SetString sets v's underlying value to x. +// It panics if v's Kind is not String or if CanSet() is false. +func (v Value) SetString(x string) { + v.mustBeAssignable() + v.mustBe(String) + *(*string)(v.ptr) = x +} + +// Slice returns v[i:j]. +// It panics if v's Kind is not Array, Slice or String, or if v is an unaddressable array, +// or if the indexes are out of bounds. +func (v Value) Slice(i, j int) Value { + var ( + cap int + typ *sliceType + base unsafe.Pointer + ) + switch kind := v.kind(); kind { + default: + panic(&ValueError{"reflect.Value.Slice", v.kind()}) + + case Array: + if v.flag&flagAddr == 0 { + panic("reflect.Value.Slice: slice of unaddressable array") + } + tt := (*arrayType)(unsafe.Pointer(v.typ)) + cap = int(tt.len) + typ = (*sliceType)(unsafe.Pointer(tt.slice)) + base = v.ptr + + case Slice: + typ = (*sliceType)(unsafe.Pointer(v.typ)) + s := (*unsafeheader.Slice)(v.ptr) + base = s.Data + cap = s.Cap + + case String: + s := (*unsafeheader.String)(v.ptr) + if i < 0 || j < i || j > s.Len { + panic("reflect.Value.Slice: string slice index out of bounds") + } + var t unsafeheader.String + if i < s.Len { + t = unsafeheader.String{Data: arrayAt(s.Data, i, 1, "i < s.Len"), Len: j - i} + } + return Value{v.typ, unsafe.Pointer(&t), v.flag} + } + + if i < 0 || j < i || j > cap { + panic("reflect.Value.Slice: slice index out of bounds") + } + + // Declare slice so that gc can see the base pointer in it. + var x []unsafe.Pointer + + // Reinterpret as *unsafeheader.Slice to edit. + s := (*unsafeheader.Slice)(unsafe.Pointer(&x)) + s.Len = j - i + s.Cap = cap - i + if cap-i > 0 { + s.Data = arrayAt(base, i, typ.elem.Size(), "i < cap") + } else { + // do not advance pointer, to avoid pointing beyond end of slice + s.Data = base + } + + fl := v.flag.ro() | flagIndir | flag(Slice) + return Value{typ.common(), unsafe.Pointer(&x), fl} +} + +// Slice3 is the 3-index form of the slice operation: it returns v[i:j:k]. +// It panics if v's Kind is not Array or Slice, or if v is an unaddressable array, +// or if the indexes are out of bounds. +func (v Value) Slice3(i, j, k int) Value { + var ( + cap int + typ *sliceType + base unsafe.Pointer + ) + switch kind := v.kind(); kind { + default: + panic(&ValueError{"reflect.Value.Slice3", v.kind()}) + + case Array: + if v.flag&flagAddr == 0 { + panic("reflect.Value.Slice3: slice of unaddressable array") + } + tt := (*arrayType)(unsafe.Pointer(v.typ)) + cap = int(tt.len) + typ = (*sliceType)(unsafe.Pointer(tt.slice)) + base = v.ptr + + case Slice: + typ = (*sliceType)(unsafe.Pointer(v.typ)) + s := (*unsafeheader.Slice)(v.ptr) + base = s.Data + cap = s.Cap + } + + if i < 0 || j < i || k < j || k > cap { + panic("reflect.Value.Slice3: slice index out of bounds") + } + + // Declare slice so that the garbage collector + // can see the base pointer in it. + var x []unsafe.Pointer + + // Reinterpret as *unsafeheader.Slice to edit. + s := (*unsafeheader.Slice)(unsafe.Pointer(&x)) + s.Len = j - i + s.Cap = k - i + if k-i > 0 { + s.Data = arrayAt(base, i, typ.elem.Size(), "i < k <= cap") + } else { + // do not advance pointer, to avoid pointing beyond end of slice + s.Data = base + } + + fl := v.flag.ro() | flagIndir | flag(Slice) + return Value{typ.common(), unsafe.Pointer(&x), fl} +} + +// String returns the string v's underlying value, as a string. +// String is a special case because of Go's String method convention. +// Unlike the other getters, it does not panic if v's Kind is not String. +// Instead, it returns a string of the form "<T value>" where T is v's type. +// The fmt package treats Values specially. It does not call their String +// method implicitly but instead prints the concrete values they hold. +func (v Value) String() string { + switch k := v.kind(); k { + case Invalid: + return "<invalid Value>" + case String: + return *(*string)(v.ptr) + } + // If you call String on a reflect.Value of other type, it's better to + // print something than to panic. Useful in debugging. + return "<" + v.Type().String() + " Value>" +} + +// TryRecv attempts to receive a value from the channel v but will not block. +// It panics if v's Kind is not Chan. +// If the receive delivers a value, x is the transferred value and ok is true. +// If the receive cannot finish without blocking, x is the zero Value and ok is false. +// If the channel is closed, x is the zero value for the channel's element type and ok is false. +func (v Value) TryRecv() (x Value, ok bool) { + v.mustBe(Chan) + v.mustBeExported() + return v.recv(true) +} + +// TrySend attempts to send x on the channel v but will not block. +// It panics if v's Kind is not Chan. +// It reports whether the value was sent. +// As in Go, x's value must be assignable to the channel's element type. +func (v Value) TrySend(x Value) bool { + v.mustBe(Chan) + v.mustBeExported() + return v.send(x, true) +} + +// Type returns v's type. +func (v Value) Type() Type { + f := v.flag + if f == 0 { + panic(&ValueError{"reflect.Value.Type", Invalid}) + } + if f&flagMethod == 0 { + // Easy case + return v.typ + } + + // Method value. + // v.typ describes the receiver, not the method type. + i := int(v.flag) >> flagMethodShift + if v.typ.Kind() == Interface { + // Method on interface. + tt := (*interfaceType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &tt.methods[i] + return v.typ.typeOff(m.typ) + } + // Method on concrete type. + ms := v.typ.exportedMethods() + if uint(i) >= uint(len(ms)) { + panic("reflect: internal error: invalid method index") + } + m := ms[i] + return v.typ.typeOff(m.mtyp) +} + +// Uint returns v's underlying value, as a uint64. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64. +func (v Value) Uint() uint64 { + k := v.kind() + p := v.ptr + switch k { + case Uint: + return uint64(*(*uint)(p)) + case Uint8: + return uint64(*(*uint8)(p)) + case Uint16: + return uint64(*(*uint16)(p)) + case Uint32: + return uint64(*(*uint32)(p)) + case Uint64: + return *(*uint64)(p) + case Uintptr: + return uint64(*(*uintptr)(p)) + } + panic(&ValueError{"reflect.Value.Uint", v.kind()}) +} + +//go:nocheckptr +// This prevents inlining Value.UnsafeAddr when -d=checkptr is enabled, +// which ensures cmd/compile can recognize unsafe.Pointer(v.UnsafeAddr()) +// and make an exception. + +// UnsafeAddr returns a pointer to v's data. +// It is for advanced clients that also import the "unsafe" package. +// It panics if v is not addressable. +func (v Value) UnsafeAddr() uintptr { + // TODO: deprecate + if v.typ == nil { + panic(&ValueError{"reflect.Value.UnsafeAddr", Invalid}) + } + if v.flag&flagAddr == 0 { + panic("reflect.Value.UnsafeAddr of unaddressable value") + } + return uintptr(v.ptr) +} + +// StringHeader is the runtime representation of a string. +// It cannot be used safely or portably and its representation may +// change in a later release. +// Moreover, the Data field is not sufficient to guarantee the data +// it references will not be garbage collected, so programs must keep +// a separate, correctly typed pointer to the underlying data. +type StringHeader struct { + Data uintptr + Len int +} + +// SliceHeader is the runtime representation of a slice. +// It cannot be used safely or portably and its representation may +// change in a later release. +// Moreover, the Data field is not sufficient to guarantee the data +// it references will not be garbage collected, so programs must keep +// a separate, correctly typed pointer to the underlying data. +type SliceHeader struct { + Data uintptr + Len int + Cap int +} + +func typesMustMatch(what string, t1, t2 Type) { + if t1 != t2 { + panic(what + ": " + t1.String() + " != " + t2.String()) + } +} + +// arrayAt returns the i-th element of p, +// an array whose elements are eltSize bytes wide. +// The array pointed at by p must have at least i+1 elements: +// it is invalid (but impossible to check here) to pass i >= len, +// because then the result will point outside the array. +// whySafe must explain why i < len. (Passing "i < len" is fine; +// the benefit is to surface this assumption at the call site.) +func arrayAt(p unsafe.Pointer, i int, eltSize uintptr, whySafe string) unsafe.Pointer { + return add(p, uintptr(i)*eltSize, "i < len") +} + +// grow grows the slice s so that it can hold extra more values, allocating +// more capacity if needed. It also returns the old and new slice lengths. +func grow(s Value, extra int) (Value, int, int) { + i0 := s.Len() + i1 := i0 + extra + if i1 < i0 { + panic("reflect.Append: slice overflow") + } + m := s.Cap() + if i1 <= m { + return s.Slice(0, i1), i0, i1 + } + if m == 0 { + m = extra + } else { + for m < i1 { + if i0 < 1024 { + m += m + } else { + m += m / 4 + } + } + } + t := MakeSlice(s.Type(), i1, m) + Copy(t, s) + return t, i0, i1 +} + +// Append appends the values x to a slice s and returns the resulting slice. +// As in Go, each x's value must be assignable to the slice's element type. +func Append(s Value, x ...Value) Value { + s.mustBe(Slice) + s, i0, i1 := grow(s, len(x)) + for i, j := i0, 0; i < i1; i, j = i+1, j+1 { + s.Index(i).Set(x[j]) + } + return s +} + +// AppendSlice appends a slice t to a slice s and returns the resulting slice. +// The slices s and t must have the same element type. +func AppendSlice(s, t Value) Value { + s.mustBe(Slice) + t.mustBe(Slice) + typesMustMatch("reflect.AppendSlice", s.Type().Elem(), t.Type().Elem()) + s, i0, i1 := grow(s, t.Len()) + Copy(s.Slice(i0, i1), t) + return s +} + +// Copy copies the contents of src into dst until either +// dst has been filled or src has been exhausted. +// It returns the number of elements copied. +// Dst and src each must have kind Slice or Array, and +// dst and src must have the same element type. +// +// As a special case, src can have kind String if the element type of dst is kind Uint8. +func Copy(dst, src Value) int { + dk := dst.kind() + if dk != Array && dk != Slice { + panic(&ValueError{"reflect.Copy", dk}) + } + if dk == Array { + dst.mustBeAssignable() + } + dst.mustBeExported() + + sk := src.kind() + var stringCopy bool + if sk != Array && sk != Slice { + stringCopy = sk == String && dst.typ.Elem().Kind() == Uint8 + if !stringCopy { + panic(&ValueError{"reflect.Copy", sk}) + } + } + src.mustBeExported() + + de := dst.typ.Elem() + if !stringCopy { + se := src.typ.Elem() + typesMustMatch("reflect.Copy", de, se) + } + + var ds, ss unsafeheader.Slice + if dk == Array { + ds.Data = dst.ptr + ds.Len = dst.Len() + ds.Cap = ds.Len + } else { + ds = *(*unsafeheader.Slice)(dst.ptr) + } + if sk == Array { + ss.Data = src.ptr + ss.Len = src.Len() + ss.Cap = ss.Len + } else if sk == Slice { + ss = *(*unsafeheader.Slice)(src.ptr) + } else { + sh := *(*unsafeheader.String)(src.ptr) + ss.Data = sh.Data + ss.Len = sh.Len + ss.Cap = sh.Len + } + + return typedslicecopy(de.common(), ds, ss) +} + +// A runtimeSelect is a single case passed to rselect. +// This must match ../runtime/select.go:/runtimeSelect +type runtimeSelect struct { + dir SelectDir // SelectSend, SelectRecv or SelectDefault + typ *rtype // channel type + ch unsafe.Pointer // channel + val unsafe.Pointer // ptr to data (SendDir) or ptr to receive buffer (RecvDir) +} + +// rselect runs a select. It returns the index of the chosen case. +// If the case was a receive, val is filled in with the received value. +// The conventional OK bool indicates whether the receive corresponds +// to a sent value. +//go:noescape +func rselect([]runtimeSelect) (chosen int, recvOK bool) + +// A SelectDir describes the communication direction of a select case. +type SelectDir int + +// NOTE: These values must match ../runtime/select.go:/selectDir. + +const ( + _ SelectDir = iota + SelectSend // case Chan <- Send + SelectRecv // case <-Chan: + SelectDefault // default +) + +// A SelectCase describes a single case in a select operation. +// The kind of case depends on Dir, the communication direction. +// +// If Dir is SelectDefault, the case represents a default case. +// Chan and Send must be zero Values. +// +// If Dir is SelectSend, the case represents a send operation. +// Normally Chan's underlying value must be a channel, and Send's underlying value must be +// assignable to the channel's element type. As a special case, if Chan is a zero Value, +// then the case is ignored, and the field Send will also be ignored and may be either zero +// or non-zero. +// +// If Dir is SelectRecv, the case represents a receive operation. +// Normally Chan's underlying value must be a channel and Send must be a zero Value. +// If Chan is a zero Value, then the case is ignored, but Send must still be a zero Value. +// When a receive operation is selected, the received Value is returned by Select. +// +type SelectCase struct { + Dir SelectDir // direction of case + Chan Value // channel to use (for send or receive) + Send Value // value to send (for send) +} + +// Select executes a select operation described by the list of cases. +// Like the Go select statement, it blocks until at least one of the cases +// can proceed, makes a uniform pseudo-random choice, +// and then executes that case. It returns the index of the chosen case +// and, if that case was a receive operation, the value received and a +// boolean indicating whether the value corresponds to a send on the channel +// (as opposed to a zero value received because the channel is closed). +// Select supports a maximum of 65536 cases. +func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool) { + if len(cases) > 65536 { + panic("reflect.Select: too many cases (max 65536)") + } + // NOTE: Do not trust that caller is not modifying cases data underfoot. + // The range is safe because the caller cannot modify our copy of the len + // and each iteration makes its own copy of the value c. + var runcases []runtimeSelect + if len(cases) > 4 { + // Slice is heap allocated due to runtime dependent capacity. + runcases = make([]runtimeSelect, len(cases)) + } else { + // Slice can be stack allocated due to constant capacity. + runcases = make([]runtimeSelect, len(cases), 4) + } + + haveDefault := false + for i, c := range cases { + rc := &runcases[i] + rc.dir = c.Dir + switch c.Dir { + default: + panic("reflect.Select: invalid Dir") + + case SelectDefault: // default + if haveDefault { + panic("reflect.Select: multiple default cases") + } + haveDefault = true + if c.Chan.IsValid() { + panic("reflect.Select: default case has Chan value") + } + if c.Send.IsValid() { + panic("reflect.Select: default case has Send value") + } + + case SelectSend: + ch := c.Chan + if !ch.IsValid() { + break + } + ch.mustBe(Chan) + ch.mustBeExported() + tt := (*chanType)(unsafe.Pointer(ch.typ)) + if ChanDir(tt.dir)&SendDir == 0 { + panic("reflect.Select: SendDir case using recv-only channel") + } + rc.ch = ch.pointer() + rc.typ = &tt.rtype + v := c.Send + if !v.IsValid() { + panic("reflect.Select: SendDir case missing Send value") + } + v.mustBeExported() + v = v.assignTo("reflect.Select", tt.elem, nil) + if v.flag&flagIndir != 0 { + rc.val = v.ptr + } else { + rc.val = unsafe.Pointer(&v.ptr) + } + + case SelectRecv: + if c.Send.IsValid() { + panic("reflect.Select: RecvDir case has Send value") + } + ch := c.Chan + if !ch.IsValid() { + break + } + ch.mustBe(Chan) + ch.mustBeExported() + tt := (*chanType)(unsafe.Pointer(ch.typ)) + if ChanDir(tt.dir)&RecvDir == 0 { + panic("reflect.Select: RecvDir case using send-only channel") + } + rc.ch = ch.pointer() + rc.typ = &tt.rtype + rc.val = unsafe_New(tt.elem) + } + } + + chosen, recvOK = rselect(runcases) + if runcases[chosen].dir == SelectRecv { + tt := (*chanType)(unsafe.Pointer(runcases[chosen].typ)) + t := tt.elem + p := runcases[chosen].val + fl := flag(t.Kind()) + if ifaceIndir(t) { + recv = Value{t, p, fl | flagIndir} + } else { + recv = Value{t, *(*unsafe.Pointer)(p), fl} + } + } + return chosen, recv, recvOK +} + +/* + * constructors + */ + +// implemented in package runtime +func unsafe_New(*rtype) unsafe.Pointer +func unsafe_NewArray(*rtype, int) unsafe.Pointer + +// MakeSlice creates a new zero-initialized slice value +// for the specified slice type, length, and capacity. +func MakeSlice(typ Type, len, cap int) Value { + if typ.Kind() != Slice { + panic("reflect.MakeSlice of non-slice type") + } + if len < 0 { + panic("reflect.MakeSlice: negative len") + } + if cap < 0 { + panic("reflect.MakeSlice: negative cap") + } + if len > cap { + panic("reflect.MakeSlice: len > cap") + } + + s := unsafeheader.Slice{Data: unsafe_NewArray(typ.Elem().(*rtype), cap), Len: len, Cap: cap} + return Value{typ.(*rtype), unsafe.Pointer(&s), flagIndir | flag(Slice)} +} + +// MakeChan creates a new channel with the specified type and buffer size. +func MakeChan(typ Type, buffer int) Value { + if typ.Kind() != Chan { + panic("reflect.MakeChan of non-chan type") + } + if buffer < 0 { + panic("reflect.MakeChan: negative buffer size") + } + if typ.ChanDir() != BothDir { + panic("reflect.MakeChan: unidirectional channel type") + } + t := typ.(*rtype) + ch := makechan(t, buffer) + return Value{t, ch, flag(Chan)} +} + +// MakeMap creates a new map with the specified type. +func MakeMap(typ Type) Value { + return MakeMapWithSize(typ, 0) +} + +// MakeMapWithSize creates a new map with the specified type +// and initial space for approximately n elements. +func MakeMapWithSize(typ Type, n int) Value { + if typ.Kind() != Map { + panic("reflect.MakeMapWithSize of non-map type") + } + t := typ.(*rtype) + m := makemap(t, n) + return Value{t, m, flag(Map)} +} + +// Indirect returns the value that v points to. +// If v is a nil pointer, Indirect returns a zero Value. +// If v is not a pointer, Indirect returns v. +func Indirect(v Value) Value { + if v.Kind() != Ptr { + return v + } + return v.Elem() +} + +// ValueOf returns a new Value initialized to the concrete value +// stored in the interface i. ValueOf(nil) returns the zero Value. +func ValueOf(i interface{}) Value { + if i == nil { + return Value{} + } + + // TODO: Maybe allow contents of a Value to live on the stack. + // For now we make the contents always escape to the heap. It + // makes life easier in a few places (see chanrecv/mapassign + // comment below). + escapes(i) + + return unpackEface(i) +} + +// Zero returns a Value representing the zero value for the specified type. +// The result is different from the zero value of the Value struct, +// which represents no value at all. +// For example, Zero(TypeOf(42)) returns a Value with Kind Int and value 0. +// The returned value is neither addressable nor settable. +func Zero(typ Type) Value { + if typ == nil { + panic("reflect: Zero(nil)") + } + t := typ.(*rtype) + fl := flag(t.Kind()) + if ifaceIndir(t) { + var p unsafe.Pointer + if t.size <= maxZero { + p = unsafe.Pointer(&zeroVal[0]) + } else { + p = unsafe_New(t) + } + return Value{t, p, fl | flagIndir} + } + return Value{t, nil, fl} +} + +// must match declarations in runtime/map.go. +const maxZero = 1024 + +//go:linkname zeroVal runtime.zeroVal +var zeroVal [maxZero]byte + +// New returns a Value representing a pointer to a new zero value +// for the specified type. That is, the returned Value's Type is PtrTo(typ). +func New(typ Type) Value { + if typ == nil { + panic("reflect: New(nil)") + } + t := typ.(*rtype) + ptr := unsafe_New(t) + fl := flag(Ptr) + return Value{t.ptrTo(), ptr, fl} +} + +// NewAt returns a Value representing a pointer to a value of the +// specified type, using p as that pointer. +func NewAt(typ Type, p unsafe.Pointer) Value { + fl := flag(Ptr) + t := typ.(*rtype) + return Value{t.ptrTo(), p, fl} +} + +// assignTo returns a value v that can be assigned directly to typ. +// It panics if v is not assignable to typ. +// For a conversion to an interface type, target is a suggested scratch space to use. +// target must be initialized memory (or nil). +func (v Value) assignTo(context string, dst *rtype, target unsafe.Pointer) Value { + if v.flag&flagMethod != 0 { + v = makeMethodValue(context, v) + } + + switch { + case directlyAssignable(dst, v.typ): + // Overwrite type so that they match. + // Same memory layout, so no harm done. + fl := v.flag&(flagAddr|flagIndir) | v.flag.ro() + fl |= flag(dst.Kind()) + return Value{dst, v.ptr, fl} + + case implements(dst, v.typ): + if target == nil { + target = unsafe_New(dst) + } + if v.Kind() == Interface && v.IsNil() { + // A nil ReadWriter passed to nil Reader is OK, + // but using ifaceE2I below will panic. + // Avoid the panic by returning a nil dst (e.g., Reader) explicitly. + return Value{dst, nil, flag(Interface)} + } + x := valueInterface(v, false) + if dst.NumMethod() == 0 { + *(*interface{})(target) = x + } else { + ifaceE2I(dst, x, target) + } + return Value{dst, target, flagIndir | flag(Interface)} + } + + // Failed. + panic(context + ": value of type " + v.typ.String() + " is not assignable to type " + dst.String()) +} + +// Convert returns the value v converted to type t. +// If the usual Go conversion rules do not allow conversion +// of the value v to type t, Convert panics. +func (v Value) Convert(t Type) Value { + if v.flag&flagMethod != 0 { + v = makeMethodValue("Convert", v) + } + op := convertOp(t.common(), v.typ) + if op == nil { + panic("reflect.Value.Convert: value of type " + v.typ.String() + " cannot be converted to type " + t.String()) + } + return op(v, t) +} + +// convertOp returns the function to convert a value of type src +// to a value of type dst. If the conversion is illegal, convertOp returns nil. +func convertOp(dst, src *rtype) func(Value, Type) Value { + switch src.Kind() { + case Int, Int8, Int16, Int32, Int64: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtInt + case Float32, Float64: + return cvtIntFloat + case String: + return cvtIntString + } + + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtUint + case Float32, Float64: + return cvtUintFloat + case String: + return cvtUintString + } + + case Float32, Float64: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64: + return cvtFloatInt + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtFloatUint + case Float32, Float64: + return cvtFloat + } + + case Complex64, Complex128: + switch dst.Kind() { + case Complex64, Complex128: + return cvtComplex + } + + case String: + if dst.Kind() == Slice && dst.Elem().PkgPath() == "" { + switch dst.Elem().Kind() { + case Uint8: + return cvtStringBytes + case Int32: + return cvtStringRunes + } + } + + case Slice: + if dst.Kind() == String && src.Elem().PkgPath() == "" { + switch src.Elem().Kind() { + case Uint8: + return cvtBytesString + case Int32: + return cvtRunesString + } + } + + case Chan: + if dst.Kind() == Chan && specialChannelAssignability(dst, src) { + return cvtDirect + } + } + + // dst and src have same underlying type. + if haveIdenticalUnderlyingType(dst, src, false) { + return cvtDirect + } + + // dst and src are non-defined pointer types with same underlying base type. + if dst.Kind() == Ptr && dst.Name() == "" && + src.Kind() == Ptr && src.Name() == "" && + haveIdenticalUnderlyingType(dst.Elem().common(), src.Elem().common(), false) { + return cvtDirect + } + + if implements(dst, src) { + if src.Kind() == Interface { + return cvtI2I + } + return cvtT2I + } + + return nil +} + +// makeInt returns a Value of type t equal to bits (possibly truncated), +// where t is a signed or unsigned int type. +func makeInt(f flag, bits uint64, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 1: + *(*uint8)(ptr) = uint8(bits) + case 2: + *(*uint16)(ptr) = uint16(bits) + case 4: + *(*uint32)(ptr) = uint32(bits) + case 8: + *(*uint64)(ptr) = bits + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +// makeFloat returns a Value of type t equal to v (possibly truncated to float32), +// where t is a float32 or float64 type. +func makeFloat(f flag, v float64, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 4: + *(*float32)(ptr) = float32(v) + case 8: + *(*float64)(ptr) = v + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +// makeFloat returns a Value of type t equal to v, where t is a float32 type. +func makeFloat32(f flag, v float32, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + *(*float32)(ptr) = v + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +// makeComplex returns a Value of type t equal to v (possibly truncated to complex64), +// where t is a complex64 or complex128 type. +func makeComplex(f flag, v complex128, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 8: + *(*complex64)(ptr) = complex64(v) + case 16: + *(*complex128)(ptr) = v + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +func makeString(f flag, v string, t Type) Value { + ret := New(t).Elem() + ret.SetString(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +func makeBytes(f flag, v []byte, t Type) Value { + ret := New(t).Elem() + ret.SetBytes(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +func makeRunes(f flag, v []rune, t Type) Value { + ret := New(t).Elem() + ret.setRunes(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +// These conversion functions are returned by convertOp +// for classes of conversions. For example, the first function, cvtInt, +// takes any value v of signed int type and returns the value converted +// to type t, where t is any signed or unsigned int type. + +// convertOp: intXX -> [u]intXX +func cvtInt(v Value, t Type) Value { + return makeInt(v.flag.ro(), uint64(v.Int()), t) +} + +// convertOp: uintXX -> [u]intXX +func cvtUint(v Value, t Type) Value { + return makeInt(v.flag.ro(), v.Uint(), t) +} + +// convertOp: floatXX -> intXX +func cvtFloatInt(v Value, t Type) Value { + return makeInt(v.flag.ro(), uint64(int64(v.Float())), t) +} + +// convertOp: floatXX -> uintXX +func cvtFloatUint(v Value, t Type) Value { + return makeInt(v.flag.ro(), uint64(v.Float()), t) +} + +// convertOp: intXX -> floatXX +func cvtIntFloat(v Value, t Type) Value { + return makeFloat(v.flag.ro(), float64(v.Int()), t) +} + +// convertOp: uintXX -> floatXX +func cvtUintFloat(v Value, t Type) Value { + return makeFloat(v.flag.ro(), float64(v.Uint()), t) +} + +// convertOp: floatXX -> floatXX +func cvtFloat(v Value, t Type) Value { + if v.Type().Kind() == Float32 && t.Kind() == Float32 { + // Don't do any conversion if both types have underlying type float32. + // This avoids converting to float64 and back, which will + // convert a signaling NaN to a quiet NaN. See issue 36400. + return makeFloat32(v.flag.ro(), *(*float32)(v.ptr), t) + } + return makeFloat(v.flag.ro(), v.Float(), t) +} + +// convertOp: complexXX -> complexXX +func cvtComplex(v Value, t Type) Value { + return makeComplex(v.flag.ro(), v.Complex(), t) +} + +// convertOp: intXX -> string +func cvtIntString(v Value, t Type) Value { + s := "\uFFFD" + if x := v.Int(); int64(rune(x)) == x { + s = string(rune(x)) + } + return makeString(v.flag.ro(), s, t) +} + +// convertOp: uintXX -> string +func cvtUintString(v Value, t Type) Value { + s := "\uFFFD" + if x := v.Uint(); uint64(rune(x)) == x { + s = string(rune(x)) + } + return makeString(v.flag.ro(), s, t) +} + +// convertOp: []byte -> string +func cvtBytesString(v Value, t Type) Value { + return makeString(v.flag.ro(), string(v.Bytes()), t) +} + +// convertOp: string -> []byte +func cvtStringBytes(v Value, t Type) Value { + return makeBytes(v.flag.ro(), []byte(v.String()), t) +} + +// convertOp: []rune -> string +func cvtRunesString(v Value, t Type) Value { + return makeString(v.flag.ro(), string(v.runes()), t) +} + +// convertOp: string -> []rune +func cvtStringRunes(v Value, t Type) Value { + return makeRunes(v.flag.ro(), []rune(v.String()), t) +} + +// convertOp: direct copy +func cvtDirect(v Value, typ Type) Value { + f := v.flag + t := typ.common() + ptr := v.ptr + if f&flagAddr != 0 { + // indirect, mutable word - make a copy + c := unsafe_New(t) + typedmemmove(t, c, ptr) + ptr = c + f &^= flagAddr + } + return Value{t, ptr, v.flag.ro() | f} // v.flag.ro()|f == f? +} + +// convertOp: concrete -> interface +func cvtT2I(v Value, typ Type) Value { + target := unsafe_New(typ.common()) + x := valueInterface(v, false) + if typ.NumMethod() == 0 { + *(*interface{})(target) = x + } else { + ifaceE2I(typ.(*rtype), x, target) + } + return Value{typ.common(), target, v.flag.ro() | flagIndir | flag(Interface)} +} + +// convertOp: interface -> interface +func cvtI2I(v Value, typ Type) Value { + if v.IsNil() { + ret := Zero(typ) + ret.flag |= v.flag.ro() + return ret + } + return cvtT2I(v.Elem(), typ) +} + +// implemented in ../runtime +func chancap(ch unsafe.Pointer) int +func chanclose(ch unsafe.Pointer) +func chanlen(ch unsafe.Pointer) int + +// Note: some of the noescape annotations below are technically a lie, +// but safe in the context of this package. Functions like chansend +// and mapassign don't escape the referent, but may escape anything +// the referent points to (they do shallow copies of the referent). +// It is safe in this package because the referent may only point +// to something a Value may point to, and that is always in the heap +// (due to the escapes() call in ValueOf). + +//go:noescape +func chanrecv(ch unsafe.Pointer, nb bool, val unsafe.Pointer) (selected, received bool) + +//go:noescape +func chansend(ch unsafe.Pointer, val unsafe.Pointer, nb bool) bool + +func makechan(typ *rtype, size int) (ch unsafe.Pointer) +func makemap(t *rtype, cap int) (m unsafe.Pointer) + +//go:noescape +func mapaccess(t *rtype, m unsafe.Pointer, key unsafe.Pointer) (val unsafe.Pointer) + +//go:noescape +func mapassign(t *rtype, m unsafe.Pointer, key, val unsafe.Pointer) + +//go:noescape +func mapdelete(t *rtype, m unsafe.Pointer, key unsafe.Pointer) + +// m escapes into the return value, but the caller of mapiterinit +// doesn't let the return value escape. +//go:noescape +func mapiterinit(t *rtype, m unsafe.Pointer) unsafe.Pointer + +//go:noescape +func mapiterkey(it unsafe.Pointer) (key unsafe.Pointer) + +//go:noescape +func mapiterelem(it unsafe.Pointer) (elem unsafe.Pointer) + +//go:noescape +func mapiternext(it unsafe.Pointer) + +//go:noescape +func maplen(m unsafe.Pointer) int + +// call calls fn with a copy of the n argument bytes pointed at by arg. +// After fn returns, reflectcall copies n-retoffset result bytes +// back into arg+retoffset before returning. If copying result bytes back, +// the caller must pass the argument frame type as argtype, so that +// call can execute appropriate write barriers during the copy. +// +//go:linkname call runtime.reflectcall +func call(argtype *rtype, fn, arg unsafe.Pointer, n uint32, retoffset uint32) + +func ifaceE2I(t *rtype, src interface{}, dst unsafe.Pointer) + +// memmove copies size bytes to dst from src. No write barriers are used. +//go:noescape +func memmove(dst, src unsafe.Pointer, size uintptr) + +// typedmemmove copies a value of type t to dst from src. +//go:noescape +func typedmemmove(t *rtype, dst, src unsafe.Pointer) + +// typedmemmovepartial is like typedmemmove but assumes that +// dst and src point off bytes into the value and only copies size bytes. +//go:noescape +func typedmemmovepartial(t *rtype, dst, src unsafe.Pointer, off, size uintptr) + +// typedmemclr zeros the value at ptr of type t. +//go:noescape +func typedmemclr(t *rtype, ptr unsafe.Pointer) + +// typedmemclrpartial is like typedmemclr but assumes that +// dst points off bytes into the value and only clears size bytes. +//go:noescape +func typedmemclrpartial(t *rtype, ptr unsafe.Pointer, off, size uintptr) + +// typedslicecopy copies a slice of elemType values from src to dst, +// returning the number of elements copied. +//go:noescape +func typedslicecopy(elemType *rtype, dst, src unsafeheader.Slice) int + +//go:noescape +func typehash(t *rtype, p unsafe.Pointer, h uintptr) uintptr + +// Dummy annotation marking that the value x escapes, +// for use in cases where the reflect code is so clever that +// the compiler cannot follow. +func escapes(x interface{}) { + if dummy.b { + dummy.x = x + } +} + +var dummy struct { + b bool + x interface{} +} |