1 // Copyright 2009 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Cgo; see doc.go for an overview.
8 // Emit correct line number annotations.
9 // Make gc understand the annotations.
30 "cmd/internal/notsha256"
34 // A Package collects information about the package we're going to write.
36 PackageName string // name of package
42 CgoFlags map[string][]string // #cgo flags (CFLAGS, LDFLAGS)
43 Written map[string]bool
44 Name map[string]*Name // accumulated Name from Files
45 ExpFunc []*ExpFunc // accumulated ExpFunc from Files
47 GoFiles []string // list of Go files
48 GccFiles []string // list of gcc output files
49 Preamble string // collected preamble for _cgo_export.h
50 typedefs map[string]bool // type names that appear in the types of the objects we're interested in
51 typedefList []typedefInfo
54 // A typedefInfo is an element on Package.typedefList: a typedef name
55 // and the position where it was required.
56 type typedefInfo struct {
61 // A File collects information about a single Go input file.
63 AST *ast.File // parsed AST
64 Comments []*ast.CommentGroup // comments from file
65 Package string // Package name
66 Preamble string // C preamble (doc comment on import "C")
67 Ref []*Ref // all references to C.xxx in AST
68 Calls []*Call // all calls to C.xxx in AST
69 ExpFunc []*ExpFunc // exported functions for this file
70 Name map[string]*Name // map from Go name to Name
71 NamePos map[*Name]token.Pos // map from Name to position of the first reference
75 func (f *File) offset(p token.Pos) int {
76 return fset.Position(p).Offset
79 func nameKeys(m map[string]*Name) []string {
88 // A Call refers to a call of a C.xxx function in the AST.
95 // A Ref refers to an expression of the form C.xxx in the AST.
103 func (r *Ref) Pos() token.Pos {
104 return (*r.Expr).Pos()
107 var nameKinds = []string{"iconst", "fconst", "sconst", "type", "var", "fpvar", "func", "macro", "not-type"}
109 // A Name collects information about C.xxx.
111 Go string // name used in Go referring to package C
112 Mangle string // name used in generated Go
113 C string // name used in C
114 Define string // #define expansion
115 Kind string // one of the nameKinds
116 Type *Type // the type of xxx
119 Const string // constant definition
122 // IsVar reports whether Kind is either "var" or "fpvar"
123 func (n *Name) IsVar() bool {
124 return n.Kind == "var" || n.Kind == "fpvar"
127 // IsConst reports whether Kind is either "iconst", "fconst" or "sconst"
128 func (n *Name) IsConst() bool {
129 return strings.HasSuffix(n.Kind, "const")
132 // An ExpFunc is an exported function, callable from C.
133 // Such functions are identified in the Go input file
134 // by doc comments containing the line //export ExpName
135 type ExpFunc struct {
137 ExpName string // name to use from C
141 // A TypeRepr contains the string representation of a type.
142 type TypeRepr struct {
144 FormatArgs []interface{}
147 // A Type collects information about a type in both the C and Go worlds.
153 EnumValues map[string]int64
155 BadPointer bool // this pointer type should be represented as a uintptr (deprecated)
156 NotInHeap bool // this type should have a go:notinheap annotation
159 // A FuncType collects information about a function type in both the C and Go worlds.
160 type FuncType struct {
167 fmt.Fprint(os.Stderr, "usage: cgo -- [compiler options] file.go ...\n")
172 var ptrSizeMap = map[string]int64{
198 var intSizeMap = map[string]int64{
226 var fset = token.NewFileSet()
228 var dynobj = flag.String("dynimport", "", "if non-empty, print dynamic import data for that file")
229 var dynout = flag.String("dynout", "", "write -dynimport output to this file")
230 var dynpackage = flag.String("dynpackage", "main", "set Go package for -dynimport output")
231 var dynlinker = flag.Bool("dynlinker", false, "record dynamic linker information in -dynimport mode")
233 // This flag is for bootstrapping a new Go implementation,
234 // to generate Go types that match the data layout and
235 // constant values used in the host's C libraries and system calls.
236 var godefs = flag.Bool("godefs", false, "for bootstrap: write Go definitions for C file to standard output")
238 var srcDir = flag.String("srcdir", "", "source directory")
239 var objDir = flag.String("objdir", "", "object directory")
240 var importPath = flag.String("importpath", "", "import path of package being built (for comments in generated files)")
241 var exportHeader = flag.String("exportheader", "", "where to write export header if any exported functions")
243 var gccgo = flag.Bool("gccgo", false, "generate files for use with gccgo")
244 var gccgoprefix = flag.String("gccgoprefix", "", "-fgo-prefix option used with gccgo")
245 var gccgopkgpath = flag.String("gccgopkgpath", "", "-fgo-pkgpath option used with gccgo")
246 var gccgoMangler func(string) string
247 var importRuntimeCgo = flag.Bool("import_runtime_cgo", true, "import runtime/cgo in generated code")
248 var importSyscall = flag.Bool("import_syscall", true, "import syscall in generated code")
249 var trimpath = flag.String("trimpath", "", "applies supplied rewrites or trims prefixes to recorded source file paths")
251 var goarch, goos, gomips, gomips64 string
252 var gccBaseCmd []string
255 objabi.AddVersionFlag() // -V
260 // cgo -dynimport is essentially a separate helper command
261 // built into the cgo binary. It scans a gcc-produced executable
262 // and dumps information about the imported symbols and the
263 // imported libraries. The 'go build' rules for cgo prepare an
264 // appropriate executable and then use its import information
265 // instead of needing to make the linkers duplicate all the
266 // specialized knowledge gcc has about where to look for imported
267 // symbols and which ones to use.
273 // Generating definitions pulled from header files,
274 // to be checked into Go repositories.
275 // Line numbers are just noise.
276 conf.Mode &^= printer.SourcePos
284 // Find first arg that looks like a go file and assume everything before
285 // that are options to pass to gcc.
287 for i = len(args); i > 0; i-- {
288 if !strings.HasSuffix(args[i-1], ".go") {
296 // Save original command line arguments for the godefs generated comment. Relative file
297 // paths in os.Args will be rewritten to absolute file paths in the loop below.
298 osArgs := make([]string, len(os.Args))
299 copy(osArgs, os.Args[:])
302 for _, arg := range args[:i] {
303 if arg == "-fsanitize=thread" {
304 tsanProlog = yesTsanProlog
306 if arg == "-fsanitize=memory" {
307 msanProlog = yesMsanProlog
311 p := newPackage(args[:i])
313 // We need a C compiler to be available. Check this.
315 gccBaseCmd, err = checkGCCBaseCmd()
321 // Record CGO_LDFLAGS from the environment for external linking.
322 if ldflags := os.Getenv("CGO_LDFLAGS"); ldflags != "" {
323 args, err := splitQuoted(ldflags)
325 fatalf("bad CGO_LDFLAGS: %q (%s)", ldflags, err)
327 p.addToFlag("LDFLAGS", args)
330 // Need a unique prefix for the global C symbols that
331 // we use to coordinate between gcc and ourselves.
332 // We already put _cgo_ at the beginning, so the main
333 // concern is other cgo wrappers for the same functions.
334 // Use the beginning of the notsha256 of the input to disambiguate.
336 io.WriteString(h, *importPath)
337 fs := make([]*File, len(goFiles))
338 for i, input := range goFiles {
340 input = filepath.Join(*srcDir, input)
343 // Create absolute path for file, so that it will be used in error
344 // messages and recorded in debug line number information.
345 // This matches the rest of the toolchain. See golang.org/issue/5122.
346 if aname, err := filepath.Abs(input); err == nil {
350 b, err := ioutil.ReadFile(input)
354 if _, err = h.Write(b); err != nil {
358 // Apply trimpath to the file path. The path won't be read from after this point.
359 input, _ = objabi.ApplyRewrites(input, *trimpath)
363 f.Edit = edit.NewBuffer(b)
365 f.DiscardCgoDirectives()
369 cPrefix = fmt.Sprintf("_%x", h.Sum(nil)[0:6])
372 // make sure that _obj directory exists, so that we can write
373 // all the output files there.
374 os.Mkdir("_obj", 0777)
377 *objDir += string(filepath.Separator)
379 for i, input := range goFiles {
382 for _, cref := range f.Ref {
383 switch cref.Context {
384 case ctxCall, ctxCall2:
385 if cref.Name.Kind != "type" {
389 *cref.Expr = cref.Name.Type.Go
390 f.Edit.Replace(f.offset(old.Pos()), f.offset(old.End()), gofmt(cref.Name.Type.Go))
396 p.PackagePath = f.Package
399 os.Stdout.WriteString(p.godefs(f, osArgs))
401 p.writeOutput(f, input)
413 // newPackage returns a new Package that will invoke
414 // gcc with the additional arguments specified in args.
415 func newPackage(args []string) *Package {
416 goarch = runtime.GOARCH
417 if s := os.Getenv("GOARCH"); s != "" {
421 if s := os.Getenv("GOOS"); s != "" {
425 gomips = buildcfg.GOMIPS
426 gomips64 = buildcfg.GOMIPS64
427 ptrSize := ptrSizeMap[goarch]
429 fatalf("unknown ptrSize for $GOARCH %q", goarch)
431 intSize := intSizeMap[goarch]
433 fatalf("unknown intSize for $GOARCH %q", goarch)
436 // Reset locale variables so gcc emits English errors [sic].
437 os.Setenv("LANG", "en_US.UTF-8")
438 os.Setenv("LC_ALL", "C")
443 CgoFlags: make(map[string][]string),
444 Written: make(map[string]bool),
446 p.addToFlag("CFLAGS", args)
450 // Record what needs to be recorded about f.
451 func (p *Package) Record(f *File) {
452 if p.PackageName == "" {
453 p.PackageName = f.Package
454 } else if p.PackageName != f.Package {
455 error_(token.NoPos, "inconsistent package names: %s, %s", p.PackageName, f.Package)
461 for k, v := range f.Name {
462 if p.Name[k] == nil {
464 } else if p.incompleteTypedef(p.Name[k].Type) {
466 } else if p.incompleteTypedef(v.Type) {
468 } else if _, ok := nameToC[k]; ok {
469 // Names we predefine may appear inconsistent
470 // if some files typedef them and some don't.
472 } else if !reflect.DeepEqual(p.Name[k], v) {
473 error_(token.NoPos, "inconsistent definitions for C.%s", fixGo(k))
478 if f.ExpFunc != nil {
479 p.ExpFunc = append(p.ExpFunc, f.ExpFunc...)
480 p.Preamble += "\n" + f.Preamble
482 p.Decl = append(p.Decl, f.AST.Decls...)
485 // incompleteTypedef reports whether t appears to be an incomplete
486 // typedef definition.
487 func (p *Package) incompleteTypedef(t *Type) bool {
488 return t == nil || (t.Size == 0 && t.Align == -1)