| // 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 ( |
| "fmt" |
| "go/ast" |
| "go/printer" |
| "go/token" |
| "os" |
| "strings" |
| ) |
| |
| func creat(name string) *os.File { |
| f, err := os.Open(name, os.O_WRONLY|os.O_CREAT|os.O_TRUNC, 0666) |
| if err != nil { |
| fatal("%s", err) |
| } |
| return f |
| } |
| |
| // 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 *Prog) writeDefs() { |
| pkgroot := os.Getenv("GOROOT") + "/pkg/" + os.Getenv("GOOS") + "_" + os.Getenv("GOARCH") |
| path := p.PackagePath |
| if !strings.HasPrefix(path, "/") { |
| path = pkgroot + "/" + path |
| } |
| |
| fgo2 := creat("_cgo_gotypes.go") |
| fc := creat("_cgo_defun.c") |
| |
| // 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") |
| fmt.Fprintf(fgo2, "package %s\n\n", p.Package) |
| fmt.Fprintf(fgo2, "import \"unsafe\"\n\n") |
| fmt.Fprintf(fgo2, "type _ unsafe.Pointer\n\n") |
| |
| for name, def := range p.Typedef { |
| fmt.Fprintf(fgo2, "type %s ", name) |
| printer.Fprint(fgo2, def) |
| fmt.Fprintf(fgo2, "\n") |
| } |
| fmt.Fprintf(fgo2, "type _C_void [0]byte\n") |
| |
| fmt.Fprintf(fc, cProlog, pkgroot, pkgroot, pkgroot, pkgroot, pkgroot) |
| |
| for name, def := range p.Vardef { |
| fmt.Fprintf(fc, "#pragma dynimport ·_C_%s %s \"%s.so\"\n", name, name, path) |
| fmt.Fprintf(fgo2, "var _C_%s ", name) |
| printer.Fprint(fgo2, &ast.StarExpr{X: def.Go}) |
| fmt.Fprintf(fgo2, "\n") |
| } |
| fmt.Fprintf(fc, "\n") |
| |
| for name, value := range p.Constdef { |
| fmt.Fprintf(fgo2, "const %s = %s\n", name, value) |
| } |
| |
| for name, value := range p.Enumdef { |
| fmt.Fprintf(fgo2, "const %s = %d\n", name, value) |
| } |
| fmt.Fprintf(fgo2, "\n") |
| |
| for name, def := range p.Funcdef { |
| // Go func declaration. |
| d := &ast.FuncDecl{ |
| Name: ast.NewIdent("_C_" + name), |
| Type: def.Go, |
| } |
| printer.Fprint(fgo2, d) |
| fmt.Fprintf(fgo2, "\n") |
| |
| if name == "CString" || name == "GoString" { |
| // The builtins are already defined in the C prolog. |
| continue |
| } |
| |
| // 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. |
| structType := "struct {\n" |
| off := int64(0) |
| npad := 0 |
| for i, t := range def.Params { |
| if off%t.Align != 0 { |
| pad := t.Align - off%t.Align |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += 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 |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| if t := def.Result; t != nil { |
| if off%t.Align != 0 { |
| pad := t.Align - off%t.Align |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += fmt.Sprintf("\t\t%s r;\n", t.C) |
| off += t.Size |
| } |
| if off%p.PtrSize != 0 { |
| pad := p.PtrSize - off%p.PtrSize |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| if len(def.Params) == 0 && def.Result == nil { |
| structType += "\t\tchar unused;\n" // avoid empty struct |
| off++ |
| } |
| structType += "\t}" |
| argSize := off |
| |
| // C wrapper calls into gcc, passing a pointer to the argument frame. |
| // Also emit #pragma to get a pointer to the gcc wrapper. |
| fmt.Fprintf(fc, "#pragma dynimport _cgo_%s _cgo_%s \"%s.so\"\n", name, name, path) |
| fmt.Fprintf(fc, "void (*_cgo_%s)(void*);\n", name) |
| fmt.Fprintf(fc, "\n") |
| fmt.Fprintf(fc, "void\n") |
| fmt.Fprintf(fc, "·_C_%s(struct{uint8 x[%d];}p)\n", name, argSize) |
| fmt.Fprintf(fc, "{\n") |
| fmt.Fprintf(fc, "\tcgocall(_cgo_%s, &p);\n", name) |
| fmt.Fprintf(fc, "}\n") |
| fmt.Fprintf(fc, "\n") |
| } |
| |
| p.writeExports(fgo2, fc) |
| |
| fgo2.Close() |
| fc.Close() |
| } |
| |
| // 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 *Prog) writeOutput(srcfile string) { |
| base := srcfile |
| if strings.HasSuffix(base, ".go") { |
| base = base[0 : len(base)-3] |
| } |
| fgo1 := creat(base + ".cgo1.go") |
| fgcc := creat(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") |
| fmt.Fprintf(fgo1, "//line %s:1\n", srcfile) |
| printer.Fprint(fgo1, p.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", p.Preamble) |
| fmt.Fprintf(fgcc, "%s\n", gccProlog) |
| |
| for name, def := range p.Funcdef { |
| _, ok := p.OutDefs[name] |
| if name == "CString" || name == "GoString" || ok { |
| // The builtins are already defined in the C prolog, and we don't |
| // want to duplicate function definitions we've already done. |
| continue |
| } |
| p.OutDefs[name] = true |
| |
| // 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. |
| structType := "struct {\n" |
| off := int64(0) |
| npad := 0 |
| for i, t := range def.Params { |
| if off%t.Align != 0 { |
| pad := t.Align - off%t.Align |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += 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 |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| if t := def.Result; t != nil { |
| if off%t.Align != 0 { |
| pad := t.Align - off%t.Align |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += fmt.Sprintf("\t\t%s r;\n", t.C) |
| off += t.Size |
| } |
| if off%p.PtrSize != 0 { |
| pad := p.PtrSize - off%p.PtrSize |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| if len(def.Params) == 0 && def.Result == nil { |
| structType += "\t\tchar unused;\n" // avoid empty struct |
| off++ |
| } |
| structType += "\t}" |
| |
| // Gcc wrapper unpacks the C argument struct |
| // and calls the actual C function. |
| fmt.Fprintf(fgcc, "void\n") |
| fmt.Fprintf(fgcc, "_cgo_%s(void *v)\n", name) |
| fmt.Fprintf(fgcc, "{\n") |
| fmt.Fprintf(fgcc, "\t%s *a = v;\n", structType) |
| fmt.Fprintf(fgcc, "\t") |
| if def.Result != nil { |
| fmt.Fprintf(fgcc, "a->r = ") |
| } |
| fmt.Fprintf(fgcc, "%s(", name) |
| for i := range def.Params { |
| if i > 0 { |
| fmt.Fprintf(fgcc, ", ") |
| } |
| fmt.Fprintf(fgcc, "a->p%d", i) |
| } |
| fmt.Fprintf(fgcc, ");\n") |
| fmt.Fprintf(fgcc, "}\n") |
| fmt.Fprintf(fgcc, "\n") |
| } |
| |
| fgo1.Close() |
| fgcc.Close() |
| } |
| |
| // Write out the various stubs we need to support functions exported |
| // from Go so that they are callable from C. |
| func (p *Prog) writeExports(fgo2, fc *os.File) { |
| if len(p.ExpFuncs) == 0 { |
| return |
| } |
| |
| fgcc := creat("_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.ExpFuncs { |
| fn := exp.Func |
| |
| // Construct a gcc struct matching the 6c argument and |
| // result frame. |
| structType := "struct {\n" |
| off := int64(0) |
| npad := 0 |
| if fn.Recv != nil { |
| t := p.cgoType(fn.Recv.List[0].Type) |
| structType += 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 |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += 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 |
| structType += 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 |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d]\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| structType += 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 |
| structType += fmt.Sprintf("\t\tchar __pad%d[%d];\n", npad, pad) |
| off += pad |
| npad++ |
| } |
| if structType == "struct {\n" { |
| structType += "\t\tchar unused;\n" // avoid empty struct |
| off++ |
| } |
| structType += "\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 |
| } 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 |
| 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(void *, int);\n", exp.ExpName) |
| fmt.Fprintf(fgcc, "\n%s\n", s) |
| fmt.Fprintf(fgcc, "{\n") |
| fmt.Fprintf(fgcc, "\t%s a;\n", structType) |
| 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, &a, (int) sizeof a);\n", exp.ExpName) |
| 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_" + fn.Recv.List[0].Names[0].Name() + "_" + goname |
| } |
| fmt.Fprintf(fc, "#pragma dynexport _cgoexp_%s _cgoexp_%s\n", exp.ExpName, exp.ExpName) |
| fmt.Fprintf(fc, "extern void ·%s();\n", goname) |
| fmt.Fprintf(fc, "\nvoid\n") |
| fmt.Fprintf(fc, "_cgoexp_%s(void *a, int32 n)\n", exp.ExpName) |
| fmt.Fprintf(fc, "{\n") |
| fmt.Fprintf(fc, "\tcgocallback(·%s, a, n);\n", goname) |
| fmt.Fprintf(fc, "}\n") |
| |
| // 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, fn.Recv.List[0].Type) |
| forFieldList(fntype.Params, |
| func(i int, atype ast.Expr) { |
| fmt.Fprintf(fgo2, ", p%d", i) |
| printer.Fprint(fgo2, 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, 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++ |
| } |
| } |
| } |
| } |
| |
| // Map predeclared Go types to Type. |
| var goTypes = map[string]*Type{ |
| "int": &Type{Size: 4, Align: 4, C: "int"}, |
| "uint": &Type{Size: 4, Align: 4, C: "uint"}, |
| "int8": &Type{Size: 1, Align: 1, C: "schar"}, |
| "uint8": &Type{Size: 1, Align: 1, C: "uchar"}, |
| "int16": &Type{Size: 2, Align: 2, C: "short"}, |
| "uint16": &Type{Size: 2, Align: 2, C: "ushort"}, |
| "int32": &Type{Size: 4, Align: 4, C: "int"}, |
| "uint32": &Type{Size: 4, Align: 4, C: "uint"}, |
| "int64": &Type{Size: 8, Align: 8, C: "int64"}, |
| "uint64": &Type{Size: 8, Align: 8, C: "uint64"}, |
| "float": &Type{Size: 4, Align: 4, C: "float"}, |
| "float32": &Type{Size: 4, Align: 4, C: "float"}, |
| "float64": &Type{Size: 8, Align: 8, C: "double"}, |
| "complex": &Type{Size: 8, Align: 8, C: "__complex float"}, |
| "complex64": &Type{Size: 8, Align: 8, C: "__complex float"}, |
| "complex128": &Type{Size: 16, Align: 16, C: "__complex double"}, |
| } |
| |
| // Map an ast type to a Type. |
| func (p *Prog) 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: x.C + "*"} |
| case *ast.ArrayType: |
| if t.Len == nil { |
| return &Type{Size: p.PtrSize + 8, Align: p.PtrSize, C: "GoSlice"} |
| } |
| case *ast.StructType: |
| // TODO |
| case *ast.FuncType: |
| return &Type{Size: p.PtrSize, Align: p.PtrSize, C: "void*"} |
| case *ast.InterfaceType: |
| return &Type{Size: 3 * p.PtrSize, Align: p.PtrSize, C: "GoInterface"} |
| case *ast.MapType: |
| return &Type{Size: p.PtrSize, Align: p.PtrSize, C: "GoMap"} |
| case *ast.ChanType: |
| return &Type{Size: p.PtrSize, Align: p.PtrSize, 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.AST.Decls { |
| 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 p.Typedef { |
| if name == t.Name() { |
| return p.cgoType(def) |
| } |
| } |
| if t.Name() == "uintptr" { |
| return &Type{Size: p.PtrSize, Align: p.PtrSize, C: "uintptr"} |
| } |
| if t.Name() == "string" { |
| return &Type{Size: p.PtrSize + 4, Align: p.PtrSize, 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 %v", e) |
| return &Type{Size: 4, Align: 4, 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) |
| ` |
| |
| const builtinProlog = ` |
| typedef struct { char *p; int n; } _GoString_; |
| _GoString_ GoString(char *p); |
| char *CString(_GoString_); |
| ` |
| |
| const cProlog = ` |
| #include "runtime.h" |
| #include "cgocall.h" |
| |
| #pragma dynimport initcgo initcgo "%s/libcgo.so" |
| #pragma dynimport libcgo_thread_start libcgo_thread_start "%s/libcgo.so" |
| #pragma dynimport libcgo_set_scheduler libcgo_set_scheduler "%s/libcgo.so" |
| #pragma dynimport _cgo_malloc _cgo_malloc "%s/libcgo.so" |
| #pragma dynimport _cgo_free free "%s/libcgo.so" |
| |
| void |
| ·_C_GoString(int8 *p, String s) |
| { |
| s = gostring((byte*)p); |
| FLUSH(&s); |
| } |
| |
| void |
| ·_C_CString(String s, int8 *p) |
| { |
| p = cmalloc(s.len+1); |
| mcpy((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 struct { char *p; int n; } GoString; |
| typedef void *GoMap; |
| typedef void *GoChan; |
| typedef struct { void *t; void *v; } GoInterface; |
| ` |