diff options
Diffstat (limited to 'src/cmd/cgo/out.go')
| -rw-r--r-- | src/cmd/cgo/out.go | 745 |
1 files changed, 745 insertions, 0 deletions
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go new file mode 100644 index 000000000..498ab1566 --- /dev/null +++ b/src/cmd/cgo/out.go @@ -0,0 +1,745 @@ +// 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 main + +import ( + "bytes" + "debug/elf" + "debug/macho" + "debug/pe" + "fmt" + "go/ast" + "go/printer" + "go/token" + "os" + "path/filepath" + "strings" +) + +var objDir = "_obj" + string(filepath.Separator) + +// writeDefs creates output files to be compiled by 6g, 6c, and gcc. +// (The comments here say 6g and 6c but the code applies to the 8 and 5 tools too.) +func (p *Package) writeDefs() { + fgo2 := creat(objDir + "_cgo_gotypes.go") + fc := creat(objDir + "_cgo_defun.c") + fm := creat(objDir + "_cgo_main.c") + + fflg := creat(objDir + "_cgo_flags") + for k, v := range p.CgoFlags { + fmt.Fprintf(fflg, "_CGO_%s=%s\n", k, v) + } + fflg.Close() + + // Write C main file for using gcc to resolve imports. + fmt.Fprintf(fm, "int main() { return 0; }\n") + fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*, int), void *a, int c) { }\n") + fmt.Fprintf(fm, "void _cgo_allocate(void *a, int c) { }\n") + fmt.Fprintf(fm, "void _cgo_panic(void *a, int c) { }\n") + + // Write second Go output: definitions of _C_xxx. + // In a separate file so that the import of "unsafe" does not + // pollute the original file. + fmt.Fprintf(fgo2, "// Created by cgo - DO NOT EDIT\n\n") + fmt.Fprintf(fgo2, "package %s\n\n", p.PackageName) + fmt.Fprintf(fgo2, "import \"unsafe\"\n\n") + fmt.Fprintf(fgo2, "import \"os\"\n\n") + fmt.Fprintf(fgo2, "import _ \"runtime/cgo\"\n\n") + fmt.Fprintf(fgo2, "type _ unsafe.Pointer\n\n") + fmt.Fprintf(fgo2, "func _Cerrno(dst *os.Error, x int) { *dst = os.Errno(x) }\n") + + for name, def := range typedef { + fmt.Fprintf(fgo2, "type %s ", name) + printer.Fprint(fgo2, fset, def) + fmt.Fprintf(fgo2, "\n") + } + fmt.Fprintf(fgo2, "type _Ctype_void [0]byte\n") + + fmt.Fprintf(fc, cProlog) + + cVars := make(map[string]bool) + for _, n := range p.Name { + if n.Kind != "var" { + continue + } + + if !cVars[n.C] { + fmt.Fprintf(fm, "extern char %s[];\n", n.C) + fmt.Fprintf(fm, "void *_cgohack_%s = %s;\n\n", n.C, n.C) + + fmt.Fprintf(fc, "extern byte *%s;\n", n.C) + + cVars[n.C] = true + } + + fmt.Fprintf(fc, "void *·%s = &%s;\n", n.Mangle, n.C) + fmt.Fprintf(fc, "\n") + + fmt.Fprintf(fgo2, "var %s ", n.Mangle) + printer.Fprint(fgo2, fset, &ast.StarExpr{X: n.Type.Go}) + fmt.Fprintf(fgo2, "\n") + } + fmt.Fprintf(fc, "\n") + + for _, n := range p.Name { + if n.Const != "" { + fmt.Fprintf(fgo2, "const _Cconst_%s = %s\n", n.Go, n.Const) + } + } + fmt.Fprintf(fgo2, "\n") + + for _, n := range p.Name { + if n.FuncType != nil { + p.writeDefsFunc(fc, fgo2, n) + } + } + + p.writeExports(fgo2, fc, fm) + + fgo2.Close() + fc.Close() +} + +func dynimport(obj string) { + if f, err := elf.Open(obj); err == nil { + sym, err := f.ImportedSymbols() + if err != nil { + fatalf("cannot load imported symbols from ELF file %s: %v", obj, err) + } + for _, s := range sym { + targ := s.Name + if s.Version != "" { + targ += "@" + s.Version + } + fmt.Printf("#pragma dynimport %s %s %q\n", s.Name, targ, s.Library) + } + lib, err := f.ImportedLibraries() + if err != nil { + fatalf("cannot load imported libraries from ELF file %s: %v", obj, err) + } + for _, l := range lib { + fmt.Printf("#pragma dynimport _ _ %q\n", l) + } + return + } + + if f, err := macho.Open(obj); err == nil { + sym, err := f.ImportedSymbols() + if err != nil { + fatalf("cannot load imported symbols from Mach-O file %s: %v", obj, err) + } + for _, s := range sym { + if len(s) > 0 && s[0] == '_' { + s = s[1:] + } + fmt.Printf("#pragma dynimport %s %s %q\n", s, s, "") + } + lib, err := f.ImportedLibraries() + if err != nil { + fatalf("cannot load imported libraries from Mach-O file %s: %v", obj, err) + } + for _, l := range lib { + fmt.Printf("#pragma dynimport _ _ %q\n", l) + } + return + } + + if f, err := pe.Open(obj); err == nil { + sym, err := f.ImportedSymbols() + if err != nil { + fatalf("cannot load imported symbols from PE file %s: %v", obj, err) + } + for _, s := range sym { + ss := strings.Split(s, ":") + fmt.Printf("#pragma dynimport %s %s %q\n", ss[0], ss[0], strings.ToLower(ss[1])) + } + return + } + + fatalf("cannot parse %s as ELF, Mach-O or PE", obj) +} + +// Construct a gcc struct matching the 6c argument frame. +// Assumes that in gcc, char is 1 byte, short 2 bytes, int 4 bytes, long long 8 bytes. +// These assumptions are checked by the gccProlog. +// Also assumes that 6c convention is to word-align the +// input and output parameters. +func (p *Package) structType(n *Name) (string, int64) { + var buf bytes.Buffer + fmt.Fprint(&buf, "struct {\n") + off := int64(0) + for i, t := range n.FuncType.Params { + if off%t.Align != 0 { + pad := t.Align - off%t.Align + fmt.Fprintf(&buf, "\t\tchar __pad%d[%d];\n", off, pad) + off += pad + } + fmt.Fprintf(&buf, "\t\t%s p%d;\n", t.C, i) + off += t.Size + } + if off%p.PtrSize != 0 { + pad := p.PtrSize - off%p.PtrSize + fmt.Fprintf(&buf, "\t\tchar __pad%d[%d];\n", off, pad) + off += pad + } + if t := n.FuncType.Result; t != nil { + if off%t.Align != 0 { + pad := t.Align - off%t.Align + fmt.Fprintf(&buf, "\t\tchar __pad%d[%d];\n", off, pad) + off += pad + } + qual := "" + if c := t.C.String(); c[len(c)-1] == '*' { + qual = "const " + } + fmt.Fprintf(&buf, "\t\t%s%s r;\n", qual, t.C) + off += t.Size + } + if off%p.PtrSize != 0 { + pad := p.PtrSize - off%p.PtrSize + fmt.Fprintf(&buf, "\t\tchar __pad%d[%d];\n", off, pad) + off += pad + } + if n.AddError { + fmt.Fprint(&buf, "\t\tvoid *e[2]; /* os.Error */\n") + off += 2 * p.PtrSize + } + if off == 0 { + fmt.Fprintf(&buf, "\t\tchar unused;\n") // avoid empty struct + } + fmt.Fprintf(&buf, "\t}") + return buf.String(), off +} + +func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) { + name := n.Go + gtype := n.FuncType.Go + if n.AddError { + // Add "os.Error" to return type list. + // Type list is known to be 0 or 1 element - it's a C function. + err := &ast.Field{Type: ast.NewIdent("os.Error")} + l := gtype.Results.List + if len(l) == 0 { + l = []*ast.Field{err} + } else { + l = []*ast.Field{l[0], err} + } + t := new(ast.FuncType) + *t = *gtype + t.Results = &ast.FieldList{List: l} + gtype = t + } + + // Go func declaration. + d := &ast.FuncDecl{ + Name: ast.NewIdent(n.Mangle), + Type: gtype, + } + printer.Fprint(fgo2, fset, d) + fmt.Fprintf(fgo2, "\n") + + if name == "CString" || name == "GoString" || name == "GoStringN" || name == "GoBytes" { + // The builtins are already defined in the C prolog. + return + } + + var argSize int64 + _, argSize = p.structType(n) + + // C wrapper calls into gcc, passing a pointer to the argument frame. + fmt.Fprintf(fc, "void _cgo%s%s(void*);\n", cPrefix, n.Mangle) + fmt.Fprintf(fc, "\n") + fmt.Fprintf(fc, "void\n") + if argSize == 0 { + argSize++ + } + fmt.Fprintf(fc, "·%s(struct{uint8 x[%d];}p)\n", n.Mangle, argSize) + fmt.Fprintf(fc, "{\n") + fmt.Fprintf(fc, "\truntime·cgocall(_cgo%s%s, &p);\n", cPrefix, n.Mangle) + if n.AddError { + // gcc leaves errno in first word of interface at end of p. + // check whether it is zero; if so, turn interface into nil. + // if not, turn interface into errno. + // Go init function initializes ·_Cerrno with an os.Errno + // for us to copy. + fmt.Fprintln(fc, ` { + int32 e; + void **v; + v = (void**)(&p+1) - 2; /* v = final two void* of p */ + e = *(int32*)v; + v[0] = (void*)0xdeadbeef; + v[1] = (void*)0xdeadbeef; + if(e == 0) { + /* nil interface */ + v[0] = 0; + v[1] = 0; + } else { + ·_Cerrno(v, e); /* fill in v as os.Error for errno e */ + } + }`) + } + fmt.Fprintf(fc, "}\n") + fmt.Fprintf(fc, "\n") +} + +// writeOutput creates stubs for a specific source file to be compiled by 6g +// (The comments here say 6g and 6c but the code applies to the 8 and 5 tools too.) +func (p *Package) writeOutput(f *File, srcfile string) { + base := srcfile + if strings.HasSuffix(base, ".go") { + base = base[0 : len(base)-3] + } + base = strings.Map(slashToUnderscore, base) + fgo1 := creat(objDir + base + ".cgo1.go") + fgcc := creat(objDir + base + ".cgo2.c") + + p.GoFiles = append(p.GoFiles, base+".cgo1.go") + p.GccFiles = append(p.GccFiles, base+".cgo2.c") + + // Write Go output: Go input with rewrites of C.xxx to _C_xxx. + fmt.Fprintf(fgo1, "// Created by cgo - DO NOT EDIT\n\n") + fmt.Fprintf(fgo1, "//line %s:1\n", srcfile) + printer.Fprint(fgo1, fset, f.AST) + + // While we process the vars and funcs, also write 6c and gcc output. + // Gcc output starts with the preamble. + fmt.Fprintf(fgcc, "%s\n", f.Preamble) + fmt.Fprintf(fgcc, "%s\n", gccProlog) + + for _, n := range f.Name { + if n.FuncType != nil { + p.writeOutputFunc(fgcc, n) + } + } + + fgo1.Close() + fgcc.Close() +} + +func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) { + name := n.Mangle + if name == "_Cfunc_CString" || name == "_Cfunc_GoString" || name == "_Cfunc_GoStringN" || name == "_Cfunc_GoBytes" || p.Written[name] { + // The builtins are already defined in the C prolog, and we don't + // want to duplicate function definitions we've already done. + return + } + p.Written[name] = true + + ctype, _ := p.structType(n) + + // Gcc wrapper unpacks the C argument struct + // and calls the actual C function. + fmt.Fprintf(fgcc, "void\n") + fmt.Fprintf(fgcc, "_cgo%s%s(void *v)\n", cPrefix, n.Mangle) + fmt.Fprintf(fgcc, "{\n") + if n.AddError { + fmt.Fprintf(fgcc, "\tint e;\n") // assuming 32 bit (see comment above structType) + fmt.Fprintf(fgcc, "\terrno = 0;\n") + } + // We're trying to write a gcc struct that matches 6c/8c/5c's layout. + // Use packed attribute to force no padding in this struct in case + // gcc has different packing requirements. For example, + // on 386 Windows, gcc wants to 8-align int64s, but 8c does not. + fmt.Fprintf(fgcc, "\t%s __attribute__((__packed__)) *a = v;\n", ctype) + fmt.Fprintf(fgcc, "\t") + if t := n.FuncType.Result; t != nil { + fmt.Fprintf(fgcc, "a->r = ") + if c := t.C.String(); c[len(c)-1] == '*' { + fmt.Fprintf(fgcc, "(const %s) ", t.C) + } + } + fmt.Fprintf(fgcc, "%s(", n.C) + for i := range n.FuncType.Params { + if i > 0 { + fmt.Fprintf(fgcc, ", ") + } + fmt.Fprintf(fgcc, "a->p%d", i) + } + fmt.Fprintf(fgcc, ");\n") + if n.AddError { + fmt.Fprintf(fgcc, "\t*(int*)(a->e) = errno;\n") + } + fmt.Fprintf(fgcc, "}\n") + fmt.Fprintf(fgcc, "\n") +} + +// Write out the various stubs we need to support functions exported +// from Go so that they are callable from C. +func (p *Package) writeExports(fgo2, fc, fm *os.File) { + fgcc := creat(objDir + "_cgo_export.c") + fgcch := creat("_cgo_export.h") + + fmt.Fprintf(fgcch, "/* Created by cgo - DO NOT EDIT. */\n") + fmt.Fprintf(fgcch, "%s\n", gccExportHeaderProlog) + + fmt.Fprintf(fgcc, "/* Created by cgo - DO NOT EDIT. */\n") + fmt.Fprintf(fgcc, "#include \"_cgo_export.h\"\n") + + for _, exp := range p.ExpFunc { + fn := exp.Func + + // Construct a gcc struct matching the 6c argument and + // result frame. The gcc struct will be compiled with + // __attribute__((packed)) so all padding must be accounted + // for explicitly. + ctype := "struct {\n" + off := int64(0) + npad := 0 + if fn.Recv != nil { + t := p.cgoType(fn.Recv.List[0].Type) + ctype += fmt.Sprintf("\t\t%s recv;\n", t.C) + off += t.Size + } + fntype := fn.Type + forFieldList(fntype.Params, + func(i int, atype ast.Expr) { + t := p.cgoType(atype) + if off%t.Align != 0 { + pad := t.Align - off%t.Align + ctype += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) + off += pad + npad++ + } + ctype += fmt.Sprintf("\t\t%s p%d;\n", t.C, i) + off += t.Size + }) + if off%p.PtrSize != 0 { + pad := p.PtrSize - off%p.PtrSize + ctype += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) + off += pad + npad++ + } + forFieldList(fntype.Results, + func(i int, atype ast.Expr) { + t := p.cgoType(atype) + if off%t.Align != 0 { + pad := t.Align - off%t.Align + ctype += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) + off += pad + npad++ + } + ctype += fmt.Sprintf("\t\t%s r%d;\n", t.C, i) + off += t.Size + }) + if off%p.PtrSize != 0 { + pad := p.PtrSize - off%p.PtrSize + ctype += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) + off += pad + npad++ + } + if ctype == "struct {\n" { + ctype += "\t\tchar unused;\n" // avoid empty struct + } + ctype += "\t}" + + // Get the return type of the wrapper function + // compiled by gcc. + gccResult := "" + if fntype.Results == nil || len(fntype.Results.List) == 0 { + gccResult = "void" + } else if len(fntype.Results.List) == 1 && len(fntype.Results.List[0].Names) <= 1 { + gccResult = p.cgoType(fntype.Results.List[0].Type).C.String() + } else { + fmt.Fprintf(fgcch, "\n/* Return type for %s */\n", exp.ExpName) + fmt.Fprintf(fgcch, "struct %s_return {\n", exp.ExpName) + forFieldList(fntype.Results, + func(i int, atype ast.Expr) { + fmt.Fprintf(fgcch, "\t%s r%d;\n", p.cgoType(atype).C, i) + }) + fmt.Fprintf(fgcch, "};\n") + gccResult = "struct " + exp.ExpName + "_return" + } + + // Build the wrapper function compiled by gcc. + s := fmt.Sprintf("%s %s(", gccResult, exp.ExpName) + if fn.Recv != nil { + s += p.cgoType(fn.Recv.List[0].Type).C.String() + s += " recv" + } + forFieldList(fntype.Params, + func(i int, atype ast.Expr) { + if i > 0 || fn.Recv != nil { + s += ", " + } + s += fmt.Sprintf("%s p%d", p.cgoType(atype).C, i) + }) + s += ")" + fmt.Fprintf(fgcch, "\nextern %s;\n", s) + + fmt.Fprintf(fgcc, "extern _cgoexp%s_%s(void *, int);\n", cPrefix, exp.ExpName) + fmt.Fprintf(fgcc, "\n%s\n", s) + fmt.Fprintf(fgcc, "{\n") + fmt.Fprintf(fgcc, "\t%s __attribute__((packed)) a;\n", ctype) + if gccResult != "void" && (len(fntype.Results.List) > 1 || len(fntype.Results.List[0].Names) > 1) { + fmt.Fprintf(fgcc, "\t%s r;\n", gccResult) + } + if fn.Recv != nil { + fmt.Fprintf(fgcc, "\ta.recv = recv;\n") + } + forFieldList(fntype.Params, + func(i int, atype ast.Expr) { + fmt.Fprintf(fgcc, "\ta.p%d = p%d;\n", i, i) + }) + fmt.Fprintf(fgcc, "\tcrosscall2(_cgoexp%s_%s, &a, %d);\n", cPrefix, exp.ExpName, off) + if gccResult != "void" { + if len(fntype.Results.List) == 1 && len(fntype.Results.List[0].Names) <= 1 { + fmt.Fprintf(fgcc, "\treturn a.r0;\n") + } else { + forFieldList(fntype.Results, + func(i int, atype ast.Expr) { + fmt.Fprintf(fgcc, "\tr.r%d = a.r%d;\n", i, i) + }) + fmt.Fprintf(fgcc, "\treturn r;\n") + } + } + fmt.Fprintf(fgcc, "}\n") + + // Build the wrapper function compiled by 6c/8c + goname := exp.Func.Name.Name + if fn.Recv != nil { + goname = "_cgoexpwrap" + cPrefix + "_" + fn.Recv.List[0].Names[0].Name + "_" + goname + } + fmt.Fprintf(fc, "extern void ·%s();\n", goname) + fmt.Fprintf(fc, "\nvoid\n") + fmt.Fprintf(fc, "_cgoexp%s_%s(void *a, int32 n)\n", cPrefix, exp.ExpName) + fmt.Fprintf(fc, "{\n") + fmt.Fprintf(fc, "\truntime·cgocallback(·%s, a, n);\n", goname) + fmt.Fprintf(fc, "}\n") + + fmt.Fprintf(fm, "int _cgoexp%s_%s;\n", cPrefix, exp.ExpName) + + // Calling a function with a receiver from C requires + // a Go wrapper function. + if fn.Recv != nil { + fmt.Fprintf(fgo2, "func %s(recv ", goname) + printer.Fprint(fgo2, fset, fn.Recv.List[0].Type) + forFieldList(fntype.Params, + func(i int, atype ast.Expr) { + fmt.Fprintf(fgo2, ", p%d ", i) + printer.Fprint(fgo2, fset, atype) + }) + fmt.Fprintf(fgo2, ")") + if gccResult != "void" { + fmt.Fprint(fgo2, " (") + forFieldList(fntype.Results, + func(i int, atype ast.Expr) { + if i > 0 { + fmt.Fprint(fgo2, ", ") + } + printer.Fprint(fgo2, fset, atype) + }) + fmt.Fprint(fgo2, ")") + } + fmt.Fprint(fgo2, " {\n") + fmt.Fprint(fgo2, "\t") + if gccResult != "void" { + fmt.Fprint(fgo2, "return ") + } + fmt.Fprintf(fgo2, "recv.%s(", exp.Func.Name) + forFieldList(fntype.Params, + func(i int, atype ast.Expr) { + if i > 0 { + fmt.Fprint(fgo2, ", ") + } + fmt.Fprintf(fgo2, "p%d", i) + }) + fmt.Fprint(fgo2, ")\n") + fmt.Fprint(fgo2, "}\n") + } + } +} + +// Call a function for each entry in an ast.FieldList, passing the +// index into the list and the type. +func forFieldList(fl *ast.FieldList, fn func(int, ast.Expr)) { + if fl == nil { + return + } + i := 0 + for _, r := range fl.List { + if r.Names == nil { + fn(i, r.Type) + i++ + } else { + for _ = range r.Names { + fn(i, r.Type) + i++ + } + } + } +} + +func c(repr string, args ...interface{}) *TypeRepr { + return &TypeRepr{repr, args} +} + +// Map predeclared Go types to Type. +var goTypes = map[string]*Type{ + "int": &Type{Size: 4, Align: 4, C: c("int")}, + "uint": &Type{Size: 4, Align: 4, C: c("uint")}, + "int8": &Type{Size: 1, Align: 1, C: c("schar")}, + "uint8": &Type{Size: 1, Align: 1, C: c("uchar")}, + "int16": &Type{Size: 2, Align: 2, C: c("short")}, + "uint16": &Type{Size: 2, Align: 2, C: c("ushort")}, + "int32": &Type{Size: 4, Align: 4, C: c("int")}, + "uint32": &Type{Size: 4, Align: 4, C: c("uint")}, + "int64": &Type{Size: 8, Align: 8, C: c("int64")}, + "uint64": &Type{Size: 8, Align: 8, C: c("uint64")}, + "float": &Type{Size: 4, Align: 4, C: c("float")}, + "float32": &Type{Size: 4, Align: 4, C: c("float")}, + "float64": &Type{Size: 8, Align: 8, C: c("double")}, + "complex": &Type{Size: 8, Align: 8, C: c("__complex float")}, + "complex64": &Type{Size: 8, Align: 8, C: c("__complex float")}, + "complex128": &Type{Size: 16, Align: 16, C: c("__complex double")}, +} + +// Map an ast type to a Type. +func (p *Package) cgoType(e ast.Expr) *Type { + switch t := e.(type) { + case *ast.StarExpr: + x := p.cgoType(t.X) + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("%s*", x.C)} + case *ast.ArrayType: + if t.Len == nil { + return &Type{Size: p.PtrSize + 8, Align: p.PtrSize, C: c("GoSlice")} + } + case *ast.StructType: + // TODO + case *ast.FuncType: + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("void*")} + case *ast.InterfaceType: + return &Type{Size: 3 * p.PtrSize, Align: p.PtrSize, C: c("GoInterface")} + case *ast.MapType: + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("GoMap")} + case *ast.ChanType: + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("GoChan")} + case *ast.Ident: + // Look up the type in the top level declarations. + // TODO: Handle types defined within a function. + for _, d := range p.Decl { + gd, ok := d.(*ast.GenDecl) + if !ok || gd.Tok != token.TYPE { + continue + } + for _, spec := range gd.Specs { + ts, ok := spec.(*ast.TypeSpec) + if !ok { + continue + } + if ts.Name.Name == t.Name { + return p.cgoType(ts.Type) + } + } + } + for name, def := range typedef { + if name == t.Name { + return p.cgoType(def) + } + } + if t.Name == "uintptr" { + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("uintptr")} + } + if t.Name == "string" { + return &Type{Size: p.PtrSize + 4, Align: p.PtrSize, C: c("GoString")} + } + if r, ok := goTypes[t.Name]; ok { + if r.Align > p.PtrSize { + r.Align = p.PtrSize + } + return r + } + error(e.Pos(), "unrecognized Go type %s", t.Name) + return &Type{Size: 4, Align: 4, C: c("int")} + case *ast.SelectorExpr: + id, ok := t.X.(*ast.Ident) + if ok && id.Name == "unsafe" && t.Sel.Name == "Pointer" { + return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("void*")} + } + } + error(e.Pos(), "unrecognized Go type %T", e) + return &Type{Size: 4, Align: 4, C: c("int")} +} + +const gccProlog = ` +// Usual nonsense: if x and y are not equal, the type will be invalid +// (have a negative array count) and an inscrutable error will come +// out of the compiler and hopefully mention "name". +#define __cgo_compile_assert_eq(x, y, name) typedef char name[(x-y)*(x-y)*-2+1]; + +// Check at compile time that the sizes we use match our expectations. +#define __cgo_size_assert(t, n) __cgo_compile_assert_eq(sizeof(t), n, _cgo_sizeof_##t##_is_not_##n) + +__cgo_size_assert(char, 1) +__cgo_size_assert(short, 2) +__cgo_size_assert(int, 4) +typedef long long __cgo_long_long; +__cgo_size_assert(__cgo_long_long, 8) +__cgo_size_assert(float, 4) +__cgo_size_assert(double, 8) + +#include <errno.h> +#include <string.h> +` + +const builtinProlog = ` +typedef struct { char *p; int n; } _GoString_; +typedef struct { char *p; int n; int c; } _GoBytes_; +_GoString_ GoString(char *p); +_GoString_ GoStringN(char *p, int l); +_GoBytes_ GoBytes(void *p, int n); +char *CString(_GoString_); +` + +const cProlog = ` +#include "runtime.h" +#include "cgocall.h" + +void ·_Cerrno(void*, int32); + +void +·_Cfunc_GoString(int8 *p, String s) +{ + s = runtime·gostring((byte*)p); + FLUSH(&s); +} + +void +·_Cfunc_GoStringN(int8 *p, int32 l, String s) +{ + s = runtime·gostringn((byte*)p, l); + FLUSH(&s); +} + +void +·_Cfunc_GoBytes(int8 *p, int32 l, Slice s) +{ + s = runtime·gobytes((byte*)p, l); + FLUSH(&s); +} + +void +·_Cfunc_CString(String s, int8 *p) +{ + p = runtime·cmalloc(s.len+1); + runtime·memmove((byte*)p, s.str, s.len); + p[s.len] = 0; + FLUSH(&p); +} +` + +const gccExportHeaderProlog = ` +typedef unsigned int uint; +typedef signed char schar; +typedef unsigned char uchar; +typedef unsigned short ushort; +typedef long long int64; +typedef unsigned long long uint64; +typedef __SIZE_TYPE__ uintptr; + +typedef struct { char *p; int n; } GoString; +typedef void *GoMap; +typedef void *GoChan; +typedef struct { void *t; void *v; } GoInterface; +` |