1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
// 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 ignore
// Generate builtin.go from builtin/runtime.go.
package main
import (
"bytes"
"flag"
"fmt"
"go/ast"
"go/format"
"go/parser"
"go/token"
"io"
"io/ioutil"
"log"
"os"
"path/filepath"
"strconv"
"strings"
)
var stdout = flag.Bool("stdout", false, "write to stdout instead of builtin.go")
func main() {
flag.Parse()
var b bytes.Buffer
fmt.Fprintln(&b, "// Code generated by mkbuiltin.go. DO NOT EDIT.")
fmt.Fprintln(&b)
fmt.Fprintln(&b, "package gc")
fmt.Fprintln(&b)
fmt.Fprintln(&b, `import "cmd/compile/internal/types"`)
mkbuiltin(&b, "runtime")
out, err := format.Source(b.Bytes())
if err != nil {
log.Fatal(err)
}
if *stdout {
_, err = os.Stdout.Write(out)
} else {
err = ioutil.WriteFile("builtin.go", out, 0666)
}
if err != nil {
log.Fatal(err)
}
}
func mkbuiltin(w io.Writer, name string) {
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, filepath.Join("builtin", name+".go"), nil, 0)
if err != nil {
log.Fatal(err)
}
var interner typeInterner
fmt.Fprintf(w, "var %sDecls = [...]struct { name string; tag int; typ int }{\n", name)
for _, decl := range f.Decls {
switch decl := decl.(type) {
case *ast.FuncDecl:
if decl.Recv != nil {
log.Fatal("methods unsupported")
}
if decl.Body != nil {
log.Fatal("unexpected function body")
}
fmt.Fprintf(w, "{%q, funcTag, %d},\n", decl.Name.Name, interner.intern(decl.Type))
case *ast.GenDecl:
if decl.Tok == token.IMPORT {
if len(decl.Specs) != 1 || decl.Specs[0].(*ast.ImportSpec).Path.Value != "\"unsafe\"" {
log.Fatal("runtime cannot import other package")
}
continue
}
if decl.Tok != token.VAR {
log.Fatal("unhandled declaration kind", decl.Tok)
}
for _, spec := range decl.Specs {
spec := spec.(*ast.ValueSpec)
if len(spec.Values) != 0 {
log.Fatal("unexpected values")
}
typ := interner.intern(spec.Type)
for _, name := range spec.Names {
fmt.Fprintf(w, "{%q, varTag, %d},\n", name.Name, typ)
}
}
default:
log.Fatal("unhandled decl type", decl)
}
}
fmt.Fprintln(w, "}")
fmt.Fprintln(w)
fmt.Fprintf(w, "func %sTypes() []*types.Type {\n", name)
fmt.Fprintf(w, "var typs [%d]*types.Type\n", len(interner.typs))
for i, typ := range interner.typs {
fmt.Fprintf(w, "typs[%d] = %s\n", i, typ)
}
fmt.Fprintln(w, "return typs[:]")
fmt.Fprintln(w, "}")
}
// typeInterner maps Go type expressions to compiler code that
// constructs the denoted type. It recognizes and reuses common
// subtype expressions.
type typeInterner struct {
typs []string
hash map[string]int
}
func (i *typeInterner) intern(t ast.Expr) int {
x := i.mktype(t)
v, ok := i.hash[x]
if !ok {
v = len(i.typs)
if i.hash == nil {
i.hash = make(map[string]int)
}
i.hash[x] = v
i.typs = append(i.typs, x)
}
return v
}
func (i *typeInterner) subtype(t ast.Expr) string {
return fmt.Sprintf("typs[%d]", i.intern(t))
}
func (i *typeInterner) mktype(t ast.Expr) string {
switch t := t.(type) {
case *ast.Ident:
switch t.Name {
case "byte":
return "types.Bytetype"
case "rune":
return "types.Runetype"
}
return fmt.Sprintf("types.Types[T%s]", strings.ToUpper(t.Name))
case *ast.SelectorExpr:
if t.X.(*ast.Ident).Name != "unsafe" || t.Sel.Name != "Pointer" {
log.Fatalf("unhandled type: %#v", t)
}
return "types.Types[TUNSAFEPTR]"
case *ast.ArrayType:
if t.Len == nil {
return fmt.Sprintf("types.NewSlice(%s)", i.subtype(t.Elt))
}
return fmt.Sprintf("types.NewArray(%s, %d)", i.subtype(t.Elt), intconst(t.Len))
case *ast.ChanType:
dir := "types.Cboth"
switch t.Dir {
case ast.SEND:
dir = "types.Csend"
case ast.RECV:
dir = "types.Crecv"
}
return fmt.Sprintf("types.NewChan(%s, %s)", i.subtype(t.Value), dir)
case *ast.FuncType:
return fmt.Sprintf("functype(nil, %s, %s)", i.fields(t.Params, false), i.fields(t.Results, false))
case *ast.InterfaceType:
if len(t.Methods.List) != 0 {
log.Fatal("non-empty interfaces unsupported")
}
return "types.Types[TINTER]"
case *ast.MapType:
return fmt.Sprintf("types.NewMap(%s, %s)", i.subtype(t.Key), i.subtype(t.Value))
case *ast.StarExpr:
return fmt.Sprintf("types.NewPtr(%s)", i.subtype(t.X))
case *ast.StructType:
return fmt.Sprintf("tostruct(%s)", i.fields(t.Fields, true))
default:
log.Fatalf("unhandled type: %#v", t)
panic("unreachable")
}
}
func (i *typeInterner) fields(fl *ast.FieldList, keepNames bool) string {
if fl == nil || len(fl.List) == 0 {
return "nil"
}
var res []string
for _, f := range fl.List {
typ := i.subtype(f.Type)
if len(f.Names) == 0 {
res = append(res, fmt.Sprintf("anonfield(%s)", typ))
} else {
for _, name := range f.Names {
if keepNames {
res = append(res, fmt.Sprintf("namedfield(%q, %s)", name.Name, typ))
} else {
res = append(res, fmt.Sprintf("anonfield(%s)", typ))
}
}
}
}
return fmt.Sprintf("[]*Node{%s}", strings.Join(res, ", "))
}
func intconst(e ast.Expr) int64 {
switch e := e.(type) {
case *ast.BasicLit:
if e.Kind != token.INT {
log.Fatalf("expected INT, got %v", e.Kind)
}
x, err := strconv.ParseInt(e.Value, 0, 64)
if err != nil {
log.Fatal(err)
}
return x
default:
log.Fatalf("unhandled expr: %#v", e)
panic("unreachable")
}
}
|
