| // 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" |
| "strings" |
| ) |
| |
| var conf = printer.Config{Mode: printer.SourcePos, Tabwidth: 8} |
| |
| // 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") |
| if *importRuntimeCgo { |
| fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*, int), void *a, int c) { }\n") |
| } else { |
| // If we're not importing runtime/cgo, we *are* runtime/cgo, |
| // which provides crosscall2. We just need a prototype. |
| fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*, int), void *a, int c);") |
| } |
| 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 \"syscall\"\n\n") |
| if !*gccgo && *importRuntimeCgo { |
| fmt.Fprintf(fgo2, "import _ \"runtime/cgo\"\n\n") |
| } |
| fmt.Fprintf(fgo2, "type _ unsafe.Pointer\n\n") |
| fmt.Fprintf(fgo2, "func _Cerrno(dst *error, x int) { *dst = syscall.Errno(x) }\n") |
| |
| for name, def := range typedef { |
| fmt.Fprintf(fgo2, "type %s ", name) |
| conf.Fprint(fgo2, fset, def.Go) |
| fmt.Fprintf(fgo2, "\n\n") |
| } |
| fmt.Fprintf(fgo2, "type _Ctype_void [0]byte\n") |
| |
| if *gccgo { |
| fmt.Fprintf(fc, cPrologGccgo) |
| } else { |
| fmt.Fprintf(fc, cProlog) |
| } |
| |
| cVars := make(map[string]bool) |
| for _, key := range nameKeys(p.Name) { |
| n := p.Name[key] |
| 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) |
| conf.Fprint(fgo2, fset, &ast.StarExpr{X: n.Type.Go}) |
| fmt.Fprintf(fgo2, "\n") |
| } |
| fmt.Fprintf(fc, "\n") |
| |
| for _, key := range nameKeys(p.Name) { |
| n := p.Name[key] |
| if n.Const != "" { |
| fmt.Fprintf(fgo2, "const _Cconst_%s = %s\n", n.Go, n.Const) |
| } |
| } |
| fmt.Fprintf(fgo2, "\n") |
| |
| for _, key := range nameKeys(p.Name) { |
| n := p.Name[key] |
| if n.FuncType != nil { |
| p.writeDefsFunc(fc, fgo2, n) |
| } |
| } |
| |
| if *gccgo { |
| p.writeGccgoExports(fgo2, fc, fm) |
| } else { |
| p.writeExports(fgo2, fc, fm) |
| } |
| |
| fgo2.Close() |
| fc.Close() |
| } |
| |
| func dynimport(obj string) { |
| stdout := os.Stdout |
| if *dynout != "" { |
| f, err := os.Create(*dynout) |
| if err != nil { |
| fatalf("%s", err) |
| } |
| stdout = f |
| } |
| |
| 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.Fprintf(stdout, "#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.Fprintf(stdout, "#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.Fprintf(stdout, "#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.Fprintf(stdout, "#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.Fprintf(stdout, "#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 |
| } |
| c := t.Typedef |
| if c == "" { |
| c = t.C.String() |
| } |
| fmt.Fprintf(&buf, "\t\t%s p%d;\n", 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]; /* 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 "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("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, |
| } |
| |
| if *gccgo { |
| // Gccgo style hooks. |
| // we hook directly into C. gccgo goes not support cgocall yet. |
| if !n.AddError { |
| fmt.Fprintf(fgo2, "//extern %s\n", n.C) |
| conf.Fprint(fgo2, fset, d) |
| fmt.Fprint(fgo2, "\n") |
| } else { |
| // write a small wrapper to retrieve errno. |
| cname := fmt.Sprintf("_cgo%s%s", cPrefix, n.Mangle) |
| paramnames := []string(nil) |
| for i, param := range d.Type.Params.List { |
| paramName := fmt.Sprintf("p%d", i) |
| param.Names = []*ast.Ident{ast.NewIdent(paramName)} |
| paramnames = append(paramnames, paramName) |
| } |
| conf.Fprint(fgo2, fset, d) |
| fmt.Fprintf(fgo2, "{\n") |
| fmt.Fprintf(fgo2, "\tsyscall.SetErrno(0)\n") |
| fmt.Fprintf(fgo2, "\tr := %s(%s)\n", cname, strings.Join(paramnames, ", ")) |
| fmt.Fprintf(fgo2, "\te := syscall.GetErrno()\n") |
| fmt.Fprintf(fgo2, "\tif e != 0 {\n") |
| fmt.Fprintf(fgo2, "\t\treturn r, e\n") |
| fmt.Fprintf(fgo2, "\t}\n") |
| fmt.Fprintf(fgo2, "\treturn r, nil\n") |
| fmt.Fprintf(fgo2, "}\n") |
| // declare the C function. |
| fmt.Fprintf(fgo2, "//extern %s\n", n.C) |
| d.Name = ast.NewIdent(cname) |
| l := d.Type.Results.List |
| d.Type.Results.List = l[:len(l)-1] |
| conf.Fprint(fgo2, fset, d) |
| fmt.Fprint(fgo2, "\n") |
| } |
| return |
| } |
| conf.Fprint(fgo2, fset, d) |
| fmt.Fprint(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 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") |
| conf.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 _, key := range nameKeys(f.Name) { |
| n := f.Name[key] |
| 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 |
| |
| if *gccgo { |
| // we don't use wrappers with gccgo. |
| return |
| } |
| |
| 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, t := range n.FuncType.Params { |
| if i > 0 { |
| fmt.Fprintf(fgcc, ", ") |
| } |
| // We know the type params are correct, because |
| // the Go equivalents had good type params. |
| // However, our version of the type omits the magic |
| // words const and volatile, which can provoke |
| // C compiler warnings. Silence them by casting |
| // all pointers to void*. (Eventually that will produce |
| // other warnings.) |
| if c := t.C.String(); c[len(c)-1] == '*' { |
| fmt.Fprintf(fgcc, "(void*)") |
| } |
| 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(*objDir + "_cgo_export.h") |
| |
| fmt.Fprintf(fgcch, "/* Created by cgo - DO NOT EDIT. */\n") |
| fmt.Fprintf(fgcch, "%s\n", p.Preamble) |
| fmt.Fprintf(fgcch, "%s\n", gccExportHeaderProlog) |
| |
| fmt.Fprintf(fgcc, "/* Created by cgo - DO NOT EDIT. */\n") |
| fmt.Fprintf(fgcc, "#include \"_cgo_export.h\"\n") |
| |
| fmt.Fprintf(fgcc, "\nextern void crosscall2(void (*fn)(void *, int), void *, int);\n\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 void _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, "#pragma dynexport %s %s\n", goname, goname) |
| fmt.Fprintf(fc, "extern void ·%s();\n\n", goname) |
| fmt.Fprintf(fc, "#pragma textflag 7\n") // no split stack, so no use of m or g |
| fmt.Fprintf(fc, "void\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) |
| conf.Fprint(fgo2, fset, fn.Recv.List[0].Type) |
| forFieldList(fntype.Params, |
| func(i int, atype ast.Expr) { |
| fmt.Fprintf(fgo2, ", p%d ", i) |
| conf.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, ", ") |
| } |
| conf.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") |
| } |
| } |
| } |
| |
| // Write out the C header allowing C code to call exported gccgo functions. |
| func (p *Package) writeGccgoExports(fgo2, fc, fm *os.File) { |
| fgcc := creat(*objDir + "_cgo_export.c") |
| fgcch := creat(*objDir + "_cgo_export.h") |
| _ = fgcc |
| |
| fmt.Fprintf(fgcch, "/* Created by cgo - DO NOT EDIT. */\n") |
| fmt.Fprintf(fgcch, "%s\n", p.Preamble) |
| fmt.Fprintf(fgcch, "%s\n", gccExportHeaderProlog) |
| fmt.Fprintf(fm, "#include \"_cgo_export.h\"\n") |
| |
| clean := func(r rune) rune { |
| switch { |
| case 'A' <= r && r <= 'Z', 'a' <= r && r <= 'z', |
| '0' <= r && r <= '9': |
| return r |
| } |
| return '_' |
| } |
| |
| var gccgoSymbolPrefix string |
| if *gccgopkgpath != "" { |
| gccgoSymbolPrefix = strings.Map(clean, *gccgopkgpath) |
| } else { |
| if *gccgoprefix == "" && p.PackageName == "main" { |
| gccgoSymbolPrefix = "main" |
| } else { |
| prefix := strings.Map(clean, *gccgoprefix) |
| if prefix == "" { |
| prefix = "go" |
| } |
| gccgoSymbolPrefix = prefix + "." + p.PackageName |
| } |
| } |
| |
| for _, exp := range p.ExpFunc { |
| // TODO: support functions with receivers. |
| fn := exp.Func |
| fntype := fn.Type |
| |
| if !ast.IsExported(fn.Name.Name) { |
| fatalf("cannot export unexported function %s with gccgo", fn.Name) |
| } |
| |
| cdeclBuf := new(bytes.Buffer) |
| resultCount := 0 |
| forFieldList(fntype.Results, |
| func(i int, atype ast.Expr) { resultCount++ }) |
| switch resultCount { |
| case 0: |
| fmt.Fprintf(cdeclBuf, "void") |
| case 1: |
| forFieldList(fntype.Results, |
| func(i int, atype ast.Expr) { |
| t := p.cgoType(atype) |
| fmt.Fprintf(cdeclBuf, "%s", t.C) |
| }) |
| default: |
| // Declare a result struct. |
| fmt.Fprintf(fgcch, "struct %s_result {\n", exp.ExpName) |
| forFieldList(fntype.Results, |
| func(i int, atype ast.Expr) { |
| t := p.cgoType(atype) |
| fmt.Fprintf(fgcch, "\t%s r%d;\n", t.C, i) |
| }) |
| fmt.Fprintf(fgcch, "};\n") |
| fmt.Fprintf(cdeclBuf, "struct %s_result", exp.ExpName) |
| } |
| |
| // The function name. |
| fmt.Fprintf(cdeclBuf, " "+exp.ExpName) |
| gccgoSymbol := fmt.Sprintf("%s.%s", gccgoSymbolPrefix, exp.Func.Name) |
| fmt.Fprintf(cdeclBuf, " (") |
| // Function parameters. |
| forFieldList(fntype.Params, |
| func(i int, atype ast.Expr) { |
| if i > 0 { |
| fmt.Fprintf(cdeclBuf, ", ") |
| } |
| t := p.cgoType(atype) |
| fmt.Fprintf(cdeclBuf, "%s p%d", t.C, i) |
| }) |
| fmt.Fprintf(cdeclBuf, ")") |
| cdecl := cdeclBuf.String() |
| |
| fmt.Fprintf(fgcch, "extern %s __asm__(\"%s\");\n", cdecl, gccgoSymbol) |
| // Dummy declaration for _cgo_main.c |
| fmt.Fprintf(fm, "%s {}\n", cdecl) |
| } |
| } |
| |
| // 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{ |
| "bool": {Size: 1, Align: 1, C: c("GoUint8")}, |
| "byte": {Size: 1, Align: 1, C: c("GoUint8")}, |
| "int": {Size: 4, Align: 4, C: c("GoInt")}, |
| "uint": {Size: 4, Align: 4, C: c("GoUint")}, |
| "rune": {Size: 4, Align: 4, C: c("GoInt32")}, |
| "int8": {Size: 1, Align: 1, C: c("GoInt8")}, |
| "uint8": {Size: 1, Align: 1, C: c("GoUint8")}, |
| "int16": {Size: 2, Align: 2, C: c("GoInt16")}, |
| "uint16": {Size: 2, Align: 2, C: c("GoUint16")}, |
| "int32": {Size: 4, Align: 4, C: c("GoInt32")}, |
| "uint32": {Size: 4, Align: 4, C: c("GoUint32")}, |
| "int64": {Size: 8, Align: 8, C: c("GoInt64")}, |
| "uint64": {Size: 8, Align: 8, C: c("GoUint64")}, |
| "float32": {Size: 4, Align: 4, C: c("GoFloat32")}, |
| "float64": {Size: 8, Align: 8, C: c("GoFloat64")}, |
| "complex64": {Size: 8, Align: 8, C: c("GoComplex64")}, |
| "complex128": {Size: 16, Align: 16, C: c("GoComplex128")}, |
| } |
| |
| // 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: 2 * 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) |
| } |
| } |
| } |
| if def := typedef[t.Name]; def != nil { |
| return def |
| } |
| if t.Name == "uintptr" { |
| return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("GoUintptr")} |
| } |
| if t.Name == "string" { |
| return &Type{Size: p.PtrSize + 4, Align: p.PtrSize, C: c("GoString")} |
| } |
| if t.Name == "error" { |
| return &Type{Size: 2 * p.PtrSize, Align: p.PtrSize, C: c("GoInterface")} |
| } |
| 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(), "Go type not supported in export: %s", gofmt(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 cPrologGccgo = ` |
| #include <stdint.h> |
| #include <string.h> |
| |
| struct __go_string { |
| const unsigned char *__data; |
| int __length; |
| }; |
| |
| typedef struct __go_open_array { |
| void* __values; |
| int __count; |
| int __capacity; |
| } Slice; |
| |
| struct __go_string __go_byte_array_to_string(const void* p, int len); |
| struct __go_open_array __go_string_to_byte_array (struct __go_string str); |
| |
| const char *CString(struct __go_string s) { |
| return strndup((const char*)s.__data, s.__length); |
| } |
| |
| struct __go_string GoString(char *p) { |
| int len = (p != NULL) ? strlen(p) : 0; |
| return __go_byte_array_to_string(p, len); |
| } |
| |
| struct __go_string GoStringN(char *p, int n) { |
| return __go_byte_array_to_string(p, n); |
| } |
| |
| Slice GoBytes(char *p, int n) { |
| struct __go_string s = { (const unsigned char *)p, n }; |
| return __go_string_to_byte_array(s); |
| } |
| ` |
| |
| const gccExportHeaderProlog = ` |
| typedef int GoInt; |
| typedef unsigned int GoUint; |
| typedef signed char GoInt8; |
| typedef unsigned char GoUint8; |
| typedef short GoInt16; |
| typedef unsigned short GoUint16; |
| typedef int GoInt32; |
| typedef unsigned int GoUint32; |
| typedef long long GoInt64; |
| typedef unsigned long long GoUint64; |
| typedef __SIZE_TYPE__ GoUintptr; |
| typedef float GoFloat32; |
| typedef double GoFloat64; |
| typedef __complex float GoComplex64; |
| typedef __complex double GoComplex128; |
| |
| typedef struct { char *p; int n; } GoString; |
| typedef void *GoMap; |
| typedef void *GoChan; |
| typedef struct { void *t; void *v; } GoInterface; |
| ` |
