1 files changed, 268 insertions, 0 deletions
diff --git a/src/cmd/cgo/main.go b/src/cmd/cgo/main.go
new file mode 100644
index 000000000..be9c2bc4f
--- /dev/null
+++ b/src/cmd/cgo/main.go
@@ -0,0 +1,268 @@
+// 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.
+
+// Cgo; see gmp.go for an overview.
+
+// TODO(rsc):
+//	Emit correct line number annotations.
+//	Make 6g understand the annotations.
+
+package main
+
+import (
+	"crypto/md5"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/token"
+	"io"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+)
+
+// A Package collects information about the package we're going to write.
+type Package struct {
+	PackageName string // name of package
+	PackagePath string
+	PtrSize     int64
+	GccOptions  []string
+	CgoFlags    map[string]string // #cgo flags (CFLAGS, LDFLAGS)
+	Written     map[string]bool
+	Name        map[string]*Name    // accumulated Name from Files
+	Typedef     map[string]ast.Expr // accumulated Typedef from Files
+	ExpFunc     []*ExpFunc          // accumulated ExpFunc from Files
+	Decl        []ast.Decl
+	GoFiles     []string // list of Go files
+	GccFiles    []string // list of gcc output files
+}
+
+// A File collects information about a single Go input file.
+type File struct {
+	AST      *ast.File           // parsed AST
+	Package  string              // Package name
+	Preamble string              // C preamble (doc comment on import "C")
+	Ref      []*Ref              // all references to C.xxx in AST
+	ExpFunc  []*ExpFunc          // exported functions for this file
+	Name     map[string]*Name    // map from Go name to Name
+	Typedef  map[string]ast.Expr // translations of all necessary types from C
+}
+
+// A Ref refers to an expression of the form C.xxx in the AST.
+type Ref struct {
+	Name    *Name
+	Expr    *ast.Expr
+	Context string // "type", "expr", "call", or "call2"
+}
+
+func (r *Ref) Pos() token.Pos {
+	return (*r.Expr).Pos()
+}
+
+// A Name collects information about C.xxx.
+type Name struct {
+	Go       string // name used in Go referring to package C
+	Mangle   string // name used in generated Go
+	C        string // name used in C
+	Define   string // #define expansion
+	Kind     string // "const", "type", "var", "func", "not-type"
+	Type     *Type  // the type of xxx
+	FuncType *FuncType
+	AddError bool
+	Const    string // constant definition
+}
+
+// A ExpFunc is an exported function, callable from C.
+// Such functions are identified in the Go input file
+// by doc comments containing the line //export ExpName
+type ExpFunc struct {
+	Func    *ast.FuncDecl
+	ExpName string // name to use from C
+}
+
+// A TypeRepr contains the string representation of a type.
+type TypeRepr struct {
+	Repr       string
+	FormatArgs []interface{}
+}
+
+// A Type collects information about a type in both the C and Go worlds.
+type Type struct {
+	Size       int64
+	Align      int64
+	C          *TypeRepr
+	Go         ast.Expr
+	EnumValues map[string]int64
+}
+
+// A FuncType collects information about a function type in both the C and Go worlds.
+type FuncType struct {
+	Params []*Type
+	Result *Type
+	Go     *ast.FuncType
+}
+
+func usage() {
+	fmt.Fprint(os.Stderr, "usage: cgo -- [compiler options] file.go ...\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+var ptrSizeMap = map[string]int64{
+	"386":   4,
+	"amd64": 8,
+	"arm":   4,
+}
+
+var cPrefix string
+
+var fset = token.NewFileSet()
+
+var dynobj = flag.String("dynimport", "", "if non-empty, print dynamic import data for that file")
+
+func main() {
+	flag.Usage = usage
+	flag.Parse()
+
+	if *dynobj != "" {
+		// cgo -dynimport is essentially a separate helper command
+		// built into the cgo binary.  It scans a gcc-produced executable
+		// and dumps information about the imported symbols and the
+		// imported libraries.  The Make.pkg rules for cgo prepare an
+		// appropriate executable and then use its import information
+		// instead of needing to make the linkers duplicate all the
+		// specialized knowledge gcc has about where to look for imported
+		// symbols and which ones to use.
+		dynimport(*dynobj)
+		return
+	}
+
+	args := flag.Args()
+	if len(args) < 1 {
+		usage()
+	}
+
+	// Find first arg that looks like a go file and assume everything before
+	// that are options to pass to gcc.
+	var i int
+	for i = len(args); i > 0; i-- {
+		if !strings.HasSuffix(args[i-1], ".go") {
+			break
+		}
+	}
+	if i == len(args) {
+		usage()
+	}
+
+	// Copy it to a new slice so it can grow.
+	gccOptions := make([]string, i)
+	copy(gccOptions, args[0:i])
+
+	goFiles := args[i:]
+
+	arch := os.Getenv("GOARCH")
+	if arch == "" {
+		fatalf("$GOARCH is not set")
+	}
+	ptrSize := ptrSizeMap[arch]
+	if ptrSize == 0 {
+		fatalf("unknown $GOARCH %q", arch)
+	}
+
+	// Clear locale variables so gcc emits English errors [sic].
+	os.Setenv("LANG", "en_US.UTF-8")
+	os.Setenv("LC_ALL", "C")
+	os.Setenv("LC_CTYPE", "C")
+
+	p := &Package{
+		PtrSize:    ptrSize,
+		GccOptions: gccOptions,
+		CgoFlags:   make(map[string]string),
+		Written:    make(map[string]bool),
+	}
+
+	// Need a unique prefix for the global C symbols that
+	// we use to coordinate between gcc and ourselves.
+	// We already put _cgo_ at the beginning, so the main
+	// concern is other cgo wrappers for the same functions.
+	// Use the beginning of the md5 of the input to disambiguate.
+	h := md5.New()
+	for _, input := range goFiles {
+		f, err := os.Open(input)
+		if err != nil {
+			fatalf("%s", err)
+		}
+		io.Copy(h, f)
+		f.Close()
+	}
+	cPrefix = fmt.Sprintf("_%x", h.Sum()[0:6])
+
+	fs := make([]*File, len(goFiles))
+	for i, input := range goFiles {
+		// Parse flags for all files before translating due to CFLAGS.
+		f := new(File)
+		f.ReadGo(input)
+		p.ParseFlags(f, input)
+		fs[i] = f
+	}
+
+	// make sure that _obj directory exists, so that we can write
+	// all the output files there.
+	os.Mkdir("_obj", 0777)
+
+	for i, input := range goFiles {
+		f := fs[i]
+		p.Translate(f)
+		for _, cref := range f.Ref {
+			switch cref.Context {
+			case "call", "call2":
+				if cref.Name.Kind != "type" {
+					break
+				}
+				*cref.Expr = cref.Name.Type.Go
+			}
+		}
+		if nerrors > 0 {
+			os.Exit(2)
+		}
+		pkg := f.Package
+		if dir := os.Getenv("CGOPKGPATH"); dir != "" {
+			pkg = filepath.Join(dir, pkg)
+		}
+		p.PackagePath = pkg
+		p.writeOutput(f, input)
+
+		p.Record(f)
+	}
+
+	p.writeDefs()
+	if nerrors > 0 {
+		os.Exit(2)
+	}
+}
+
+// Record what needs to be recorded about f.
+func (p *Package) Record(f *File) {
+	if p.PackageName == "" {
+		p.PackageName = f.Package
+	} else if p.PackageName != f.Package {
+		error(token.NoPos, "inconsistent package names: %s, %s", p.PackageName, f.Package)
+	}
+
+	if p.Name == nil {
+		p.Name = f.Name
+	} else {
+		for k, v := range f.Name {
+			if p.Name[k] == nil {
+				p.Name[k] = v
+			} else if !reflect.DeepEqual(p.Name[k], v) {
+				error(token.NoPos, "inconsistent definitions for C.%s", k)
+			}
+		}
+	}
+
+	p.ExpFunc = append(p.ExpFunc, f.ExpFunc...)
+	p.Decl = append(p.Decl, f.AST.Decls...)
+}