1 files changed, 225 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/mkbuiltin.go b/src/cmd/compile/internal/gc/mkbuiltin.go
new file mode 100644
index 0000000..63d2a12
--- /dev/null
+++ b/src/cmd/compile/internal/gc/mkbuiltin.go
@@ -0,0 +1,225 @@
+// 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")
+	}
+}