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-rw-r--r--src/cmd/cgo/out.go1988
1 files changed, 1988 insertions, 0 deletions
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
new file mode 100644
index 0000000..b2933e2
--- /dev/null
+++ b/src/cmd/cgo/out.go
@@ -0,0 +1,1988 @@
+// 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"
+ "cmd/internal/pkgpath"
+ "debug/elf"
+ "debug/macho"
+ "debug/pe"
+ "fmt"
+ "go/ast"
+ "go/printer"
+ "go/token"
+ "internal/xcoff"
+ "io"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "regexp"
+ "sort"
+ "strings"
+ "unicode"
+)
+
+var (
+ conf = printer.Config{Mode: printer.SourcePos, Tabwidth: 8}
+ noSourceConf = printer.Config{Tabwidth: 8}
+)
+
+// writeDefs creates output files to be compiled by gc and gcc.
+func (p *Package) writeDefs() {
+ var fgo2, fc io.Writer
+ f := creat(*objDir + "_cgo_gotypes.go")
+ defer f.Close()
+ fgo2 = f
+ if *gccgo {
+ f := creat(*objDir + "_cgo_defun.c")
+ defer f.Close()
+ fc = f
+ }
+ fm := creat(*objDir + "_cgo_main.c")
+
+ var gccgoInit strings.Builder
+
+ fflg := creat(*objDir + "_cgo_flags")
+ for k, v := range p.CgoFlags {
+ for _, arg := range v {
+ fmt.Fprintf(fflg, "_CGO_%s=%s\n", k, arg)
+ }
+ if k == "LDFLAGS" && !*gccgo {
+ for _, arg := range v {
+ fmt.Fprintf(fgo2, "//go:cgo_ldflag %q\n", arg)
+ }
+ }
+ }
+ fflg.Close()
+
+ // Write C main file for using gcc to resolve imports.
+ fmt.Fprintf(fm, "#include <stddef.h>\n") // For size_t below.
+ fmt.Fprintf(fm, "int main() { return 0; }\n")
+ if *importRuntimeCgo {
+ fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*) __attribute__((unused)), void *a __attribute__((unused)), int c __attribute__((unused)), size_t ctxt __attribute__((unused))) { }\n")
+ fmt.Fprintf(fm, "size_t _cgo_wait_runtime_init_done(void) { return 0; }\n")
+ fmt.Fprintf(fm, "void _cgo_release_context(size_t ctxt __attribute__((unused))) { }\n")
+ fmt.Fprintf(fm, "char* _cgo_topofstack(void) { return (char*)0; }\n")
+ } else {
+ // If we're not importing runtime/cgo, we *are* runtime/cgo,
+ // which provides these functions. We just need a prototype.
+ fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*), void *a, int c, size_t ctxt);\n")
+ fmt.Fprintf(fm, "size_t _cgo_wait_runtime_init_done(void);\n")
+ fmt.Fprintf(fm, "void _cgo_release_context(size_t);\n")
+ }
+ fmt.Fprintf(fm, "void _cgo_allocate(void *a __attribute__((unused)), int c __attribute__((unused))) { }\n")
+ fmt.Fprintf(fm, "void _cgo_panic(void *a __attribute__((unused)), int c __attribute__((unused))) { }\n")
+ fmt.Fprintf(fm, "void _cgo_reginit(void) { }\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, "// Code generated by cmd/cgo; DO NOT EDIT.\n\n")
+ fmt.Fprintf(fgo2, "package %s\n\n", p.PackageName)
+ fmt.Fprintf(fgo2, "import \"unsafe\"\n\n")
+ if *importSyscall {
+ fmt.Fprintf(fgo2, "import \"syscall\"\n\n")
+ }
+ if *importRuntimeCgo {
+ if !*gccgoDefineCgoIncomplete {
+ fmt.Fprintf(fgo2, "import _cgopackage \"runtime/cgo\"\n\n")
+ fmt.Fprintf(fgo2, "type _ _cgopackage.Incomplete\n") // prevent import-not-used error
+ } else {
+ fmt.Fprintf(fgo2, "//go:notinheap\n")
+ fmt.Fprintf(fgo2, "type _cgopackage_Incomplete struct{ _ struct{ _ struct{} } }\n")
+ }
+ }
+ if *importSyscall {
+ fmt.Fprintf(fgo2, "var _ syscall.Errno\n")
+ }
+ fmt.Fprintf(fgo2, "func _Cgo_ptr(ptr unsafe.Pointer) unsafe.Pointer { return ptr }\n\n")
+
+ if !*gccgo {
+ fmt.Fprintf(fgo2, "//go:linkname _Cgo_always_false runtime.cgoAlwaysFalse\n")
+ fmt.Fprintf(fgo2, "var _Cgo_always_false bool\n")
+ fmt.Fprintf(fgo2, "//go:linkname _Cgo_use runtime.cgoUse\n")
+ fmt.Fprintf(fgo2, "func _Cgo_use(interface{})\n")
+ }
+
+ typedefNames := make([]string, 0, len(typedef))
+ for name := range typedef {
+ if name == "_Ctype_void" {
+ // We provide an appropriate declaration for
+ // _Ctype_void below (#39877).
+ continue
+ }
+ typedefNames = append(typedefNames, name)
+ }
+ sort.Strings(typedefNames)
+ for _, name := range typedefNames {
+ def := typedef[name]
+ fmt.Fprintf(fgo2, "type %s ", name)
+ // We don't have source info for these types, so write them out without source info.
+ // Otherwise types would look like:
+ //
+ // type _Ctype_struct_cb struct {
+ // //line :1
+ // on_test *[0]byte
+ // //line :1
+ // }
+ //
+ // Which is not useful. Moreover we never override source info,
+ // so subsequent source code uses the same source info.
+ // Moreover, empty file name makes compile emit no source debug info at all.
+ var buf bytes.Buffer
+ noSourceConf.Fprint(&buf, fset, def.Go)
+ if bytes.HasPrefix(buf.Bytes(), []byte("_Ctype_")) ||
+ strings.HasPrefix(name, "_Ctype_enum_") ||
+ strings.HasPrefix(name, "_Ctype_union_") {
+ // This typedef is of the form `typedef a b` and should be an alias.
+ fmt.Fprintf(fgo2, "= ")
+ }
+ fmt.Fprintf(fgo2, "%s", buf.Bytes())
+ fmt.Fprintf(fgo2, "\n\n")
+ }
+ if *gccgo {
+ fmt.Fprintf(fgo2, "type _Ctype_void byte\n")
+ } else {
+ fmt.Fprintf(fgo2, "type _Ctype_void [0]byte\n")
+ }
+
+ if *gccgo {
+ fmt.Fprint(fgo2, gccgoGoProlog)
+ fmt.Fprint(fc, p.cPrologGccgo())
+ } else {
+ fmt.Fprint(fgo2, goProlog)
+ }
+
+ if fc != nil {
+ fmt.Fprintf(fc, "#line 1 \"cgo-generated-wrappers\"\n")
+ }
+ if fm != nil {
+ fmt.Fprintf(fm, "#line 1 \"cgo-generated-wrappers\"\n")
+ }
+
+ gccgoSymbolPrefix := p.gccgoSymbolPrefix()
+
+ cVars := make(map[string]bool)
+ for _, key := range nameKeys(p.Name) {
+ n := p.Name[key]
+ if !n.IsVar() {
+ continue
+ }
+
+ if !cVars[n.C] {
+ if *gccgo {
+ fmt.Fprintf(fc, "extern byte *%s;\n", n.C)
+ } else {
+ // Force a reference to all symbols so that
+ // the external linker will add DT_NEEDED
+ // entries as needed on ELF systems.
+ // Treat function variables differently
+ // to avoid type conflict errors from LTO
+ // (Link Time Optimization).
+ if n.Kind == "fpvar" {
+ fmt.Fprintf(fm, "extern void %s();\n", n.C)
+ } else {
+ fmt.Fprintf(fm, "extern char %s[];\n", n.C)
+ fmt.Fprintf(fm, "void *_cgohack_%s = %s;\n\n", n.C, n.C)
+ }
+ fmt.Fprintf(fgo2, "//go:linkname __cgo_%s %s\n", n.C, n.C)
+ fmt.Fprintf(fgo2, "//go:cgo_import_static %s\n", n.C)
+ fmt.Fprintf(fgo2, "var __cgo_%s byte\n", n.C)
+ }
+ cVars[n.C] = true
+ }
+
+ var node ast.Node
+ if n.Kind == "var" {
+ node = &ast.StarExpr{X: n.Type.Go}
+ } else if n.Kind == "fpvar" {
+ node = n.Type.Go
+ } else {
+ panic(fmt.Errorf("invalid var kind %q", n.Kind))
+ }
+ if *gccgo {
+ fmt.Fprintf(fc, `extern void *%s __asm__("%s.%s");`, n.Mangle, gccgoSymbolPrefix, gccgoToSymbol(n.Mangle))
+ fmt.Fprintf(&gccgoInit, "\t%s = &%s;\n", n.Mangle, n.C)
+ fmt.Fprintf(fc, "\n")
+ }
+
+ fmt.Fprintf(fgo2, "var %s ", n.Mangle)
+ conf.Fprint(fgo2, fset, node)
+ if !*gccgo {
+ fmt.Fprintf(fgo2, " = (")
+ conf.Fprint(fgo2, fset, node)
+ fmt.Fprintf(fgo2, ")(unsafe.Pointer(&__cgo_%s))", n.C)
+ }
+ fmt.Fprintf(fgo2, "\n")
+ }
+ if *gccgo {
+ fmt.Fprintf(fc, "\n")
+ }
+
+ for _, key := range nameKeys(p.Name) {
+ n := p.Name[key]
+ if n.Const != "" {
+ fmt.Fprintf(fgo2, "const %s = %s\n", n.Mangle, n.Const)
+ }
+ }
+ fmt.Fprintf(fgo2, "\n")
+
+ callsMalloc := false
+ for _, key := range nameKeys(p.Name) {
+ n := p.Name[key]
+ if n.FuncType != nil {
+ p.writeDefsFunc(fgo2, n, &callsMalloc)
+ }
+ }
+
+ fgcc := creat(*objDir + "_cgo_export.c")
+ fgcch := creat(*objDir + "_cgo_export.h")
+ if *gccgo {
+ p.writeGccgoExports(fgo2, fm, fgcc, fgcch)
+ } else {
+ p.writeExports(fgo2, fm, fgcc, fgcch)
+ }
+
+ if callsMalloc && !*gccgo {
+ fmt.Fprint(fgo2, strings.Replace(cMallocDefGo, "PREFIX", cPrefix, -1))
+ fmt.Fprint(fgcc, strings.Replace(strings.Replace(cMallocDefC, "PREFIX", cPrefix, -1), "PACKED", p.packedAttribute(), -1))
+ }
+
+ if err := fgcc.Close(); err != nil {
+ fatalf("%s", err)
+ }
+ if err := fgcch.Close(); err != nil {
+ fatalf("%s", err)
+ }
+
+ if *exportHeader != "" && len(p.ExpFunc) > 0 {
+ fexp := creat(*exportHeader)
+ fgcch, err := os.Open(*objDir + "_cgo_export.h")
+ if err != nil {
+ fatalf("%s", err)
+ }
+ defer fgcch.Close()
+ _, err = io.Copy(fexp, fgcch)
+ if err != nil {
+ fatalf("%s", err)
+ }
+ if err = fexp.Close(); err != nil {
+ fatalf("%s", err)
+ }
+ }
+
+ init := gccgoInit.String()
+ if init != "" {
+ // The init function does nothing but simple
+ // assignments, so it won't use much stack space, so
+ // it's OK to not split the stack. Splitting the stack
+ // can run into a bug in clang (as of 2018-11-09):
+ // this is a leaf function, and when clang sees a leaf
+ // function it won't emit the split stack prologue for
+ // the function. However, if this function refers to a
+ // non-split-stack function, which will happen if the
+ // cgo code refers to a C function not compiled with
+ // -fsplit-stack, then the linker will think that it
+ // needs to adjust the split stack prologue, but there
+ // won't be one. Marking the function explicitly
+ // no_split_stack works around this problem by telling
+ // the linker that it's OK if there is no split stack
+ // prologue.
+ fmt.Fprintln(fc, "static void init(void) __attribute__ ((constructor, no_split_stack));")
+ fmt.Fprintln(fc, "static void init(void) {")
+ fmt.Fprint(fc, init)
+ fmt.Fprintln(fc, "}")
+ }
+}
+
+// elfImportedSymbols is like elf.File.ImportedSymbols, but it
+// includes weak symbols.
+//
+// A bug in some versions of LLD (at least LLD 8) cause it to emit
+// several pthreads symbols as weak, but we need to import those. See
+// issue #31912 or https://bugs.llvm.org/show_bug.cgi?id=42442.
+//
+// When doing external linking, we hand everything off to the external
+// linker, which will create its own dynamic symbol tables. For
+// internal linking, this may turn weak imports into strong imports,
+// which could cause dynamic linking to fail if a symbol really isn't
+// defined. However, the standard library depends on everything it
+// imports, and this is the primary use of dynamic symbol tables with
+// internal linking.
+func elfImportedSymbols(f *elf.File) []elf.ImportedSymbol {
+ syms, _ := f.DynamicSymbols()
+ var imports []elf.ImportedSymbol
+ for _, s := range syms {
+ if (elf.ST_BIND(s.Info) == elf.STB_GLOBAL || elf.ST_BIND(s.Info) == elf.STB_WEAK) && s.Section == elf.SHN_UNDEF {
+ imports = append(imports, elf.ImportedSymbol{
+ Name: s.Name,
+ Library: s.Library,
+ Version: s.Version,
+ })
+ }
+ }
+ return imports
+}
+
+func dynimport(obj string) {
+ stdout := os.Stdout
+ if *dynout != "" {
+ f, err := os.Create(*dynout)
+ if err != nil {
+ fatalf("%s", err)
+ }
+ stdout = f
+ }
+
+ fmt.Fprintf(stdout, "package %s\n", *dynpackage)
+
+ if f, err := elf.Open(obj); err == nil {
+ if *dynlinker {
+ // Emit the cgo_dynamic_linker line.
+ if sec := f.Section(".interp"); sec != nil {
+ if data, err := sec.Data(); err == nil && len(data) > 1 {
+ // skip trailing \0 in data
+ fmt.Fprintf(stdout, "//go:cgo_dynamic_linker %q\n", string(data[:len(data)-1]))
+ }
+ }
+ }
+ sym := elfImportedSymbols(f)
+ for _, s := range sym {
+ targ := s.Name
+ if s.Version != "" {
+ targ += "#" + s.Version
+ }
+ checkImportSymName(s.Name)
+ checkImportSymName(targ)
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic %s %s %q\n", s.Name, targ, s.Library)
+ }
+ lib, _ := f.ImportedLibraries()
+ for _, l := range lib {
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic _ _ %q\n", l)
+ }
+ return
+ }
+
+ if f, err := macho.Open(obj); err == nil {
+ sym, _ := f.ImportedSymbols()
+ for _, s := range sym {
+ if len(s) > 0 && s[0] == '_' {
+ s = s[1:]
+ }
+ checkImportSymName(s)
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic %s %s %q\n", s, s, "")
+ }
+ lib, _ := f.ImportedLibraries()
+ for _, l := range lib {
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic _ _ %q\n", l)
+ }
+ return
+ }
+
+ if f, err := pe.Open(obj); err == nil {
+ sym, _ := f.ImportedSymbols()
+ for _, s := range sym {
+ ss := strings.Split(s, ":")
+ name := strings.Split(ss[0], "@")[0]
+ checkImportSymName(name)
+ checkImportSymName(ss[0])
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic %s %s %q\n", name, ss[0], strings.ToLower(ss[1]))
+ }
+ return
+ }
+
+ if f, err := xcoff.Open(obj); err == nil {
+ sym, err := f.ImportedSymbols()
+ if err != nil {
+ fatalf("cannot load imported symbols from XCOFF file %s: %v", obj, err)
+ }
+ for _, s := range sym {
+ if s.Name == "runtime_rt0_go" || s.Name == "_rt0_ppc64_aix_lib" {
+ // These symbols are imported by runtime/cgo but
+ // must not be added to _cgo_import.go as there are
+ // Go symbols.
+ continue
+ }
+ checkImportSymName(s.Name)
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic %s %s %q\n", s.Name, s.Name, s.Library)
+ }
+ lib, err := f.ImportedLibraries()
+ if err != nil {
+ fatalf("cannot load imported libraries from XCOFF file %s: %v", obj, err)
+ }
+ for _, l := range lib {
+ fmt.Fprintf(stdout, "//go:cgo_import_dynamic _ _ %q\n", l)
+ }
+ return
+ }
+
+ fatalf("cannot parse %s as ELF, Mach-O, PE or XCOFF", obj)
+}
+
+// checkImportSymName checks a symbol name we are going to emit as part
+// of a //go:cgo_import_dynamic pragma. These names come from object
+// files, so they may be corrupt. We are going to emit them unquoted,
+// so while they don't need to be valid symbol names (and in some cases,
+// involving symbol versions, they won't be) they must contain only
+// graphic characters and must not contain Go comments.
+func checkImportSymName(s string) {
+ for _, c := range s {
+ if !unicode.IsGraphic(c) || unicode.IsSpace(c) {
+ fatalf("dynamic symbol %q contains unsupported character", s)
+ }
+ }
+ if strings.Contains(s, "//") || strings.Contains(s, "/*") {
+ fatalf("dynamic symbol %q contains Go comment")
+ }
+}
+
+// Construct a gcc struct matching the gc 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 gc convention is to word-align the
+// input and output parameters.
+func (p *Package) structType(n *Name) (string, int64) {
+ var buf strings.Builder
+ 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
+ }
+ fmt.Fprintf(&buf, "\t\t%s r;\n", 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 off == 0 {
+ fmt.Fprintf(&buf, "\t\tchar unused;\n") // avoid empty struct
+ }
+ fmt.Fprintf(&buf, "\t}")
+ return buf.String(), off
+}
+
+func (p *Package) writeDefsFunc(fgo2 io.Writer, n *Name, callsMalloc *bool) {
+ name := n.Go
+ gtype := n.FuncType.Go
+ void := gtype.Results == nil || len(gtype.Results.List) == 0
+ 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,
+ }
+
+ // Builtins defined in the C prolog.
+ inProlog := builtinDefs[name] != ""
+ cname := fmt.Sprintf("_cgo%s%s", cPrefix, n.Mangle)
+ paramnames := []string(nil)
+ if d.Type.Params != 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)
+ }
+ }
+
+ if *gccgo {
+ // Gccgo style hooks.
+ fmt.Fprint(fgo2, "\n")
+ conf.Fprint(fgo2, fset, d)
+ fmt.Fprint(fgo2, " {\n")
+ if !inProlog {
+ fmt.Fprint(fgo2, "\tdefer syscall.CgocallDone()\n")
+ fmt.Fprint(fgo2, "\tsyscall.Cgocall()\n")
+ }
+ if n.AddError {
+ fmt.Fprint(fgo2, "\tsyscall.SetErrno(0)\n")
+ }
+ fmt.Fprint(fgo2, "\t")
+ if !void {
+ fmt.Fprint(fgo2, "r := ")
+ }
+ fmt.Fprintf(fgo2, "%s(%s)\n", cname, strings.Join(paramnames, ", "))
+
+ if n.AddError {
+ fmt.Fprint(fgo2, "\te := syscall.GetErrno()\n")
+ fmt.Fprint(fgo2, "\tif e != 0 {\n")
+ fmt.Fprint(fgo2, "\t\treturn ")
+ if !void {
+ fmt.Fprint(fgo2, "r, ")
+ }
+ fmt.Fprint(fgo2, "e\n")
+ fmt.Fprint(fgo2, "\t}\n")
+ fmt.Fprint(fgo2, "\treturn ")
+ if !void {
+ fmt.Fprint(fgo2, "r, ")
+ }
+ fmt.Fprint(fgo2, "nil\n")
+ } else if !void {
+ fmt.Fprint(fgo2, "\treturn r\n")
+ }
+
+ fmt.Fprint(fgo2, "}\n")
+
+ // declare the C function.
+ fmt.Fprintf(fgo2, "//extern %s\n", cname)
+ d.Name = ast.NewIdent(cname)
+ if n.AddError {
+ l := d.Type.Results.List
+ d.Type.Results.List = l[:len(l)-1]
+ }
+ conf.Fprint(fgo2, fset, d)
+ fmt.Fprint(fgo2, "\n")
+
+ return
+ }
+
+ if inProlog {
+ fmt.Fprint(fgo2, builtinDefs[name])
+ if strings.Contains(builtinDefs[name], "_cgo_cmalloc") {
+ *callsMalloc = true
+ }
+ return
+ }
+
+ // Wrapper calls into gcc, passing a pointer to the argument frame.
+ fmt.Fprintf(fgo2, "//go:cgo_import_static %s\n", cname)
+ fmt.Fprintf(fgo2, "//go:linkname __cgofn_%s %s\n", cname, cname)
+ fmt.Fprintf(fgo2, "var __cgofn_%s byte\n", cname)
+ fmt.Fprintf(fgo2, "var %s = unsafe.Pointer(&__cgofn_%s)\n", cname, cname)
+
+ nret := 0
+ if !void {
+ d.Type.Results.List[0].Names = []*ast.Ident{ast.NewIdent("r1")}
+ nret = 1
+ }
+ if n.AddError {
+ d.Type.Results.List[nret].Names = []*ast.Ident{ast.NewIdent("r2")}
+ }
+
+ fmt.Fprint(fgo2, "\n")
+ fmt.Fprint(fgo2, "//go:cgo_unsafe_args\n")
+ conf.Fprint(fgo2, fset, d)
+ fmt.Fprint(fgo2, " {\n")
+
+ // NOTE: Using uintptr to hide from escape analysis.
+ arg := "0"
+ if len(paramnames) > 0 {
+ arg = "uintptr(unsafe.Pointer(&p0))"
+ } else if !void {
+ arg = "uintptr(unsafe.Pointer(&r1))"
+ }
+
+ prefix := ""
+ if n.AddError {
+ prefix = "errno := "
+ }
+ fmt.Fprintf(fgo2, "\t%s_cgo_runtime_cgocall(%s, %s)\n", prefix, cname, arg)
+ if n.AddError {
+ fmt.Fprintf(fgo2, "\tif errno != 0 { r2 = syscall.Errno(errno) }\n")
+ }
+ fmt.Fprintf(fgo2, "\tif _Cgo_always_false {\n")
+ if d.Type.Params != nil {
+ for i := range d.Type.Params.List {
+ fmt.Fprintf(fgo2, "\t\t_Cgo_use(p%d)\n", i)
+ }
+ }
+ fmt.Fprintf(fgo2, "\t}\n")
+ fmt.Fprintf(fgo2, "\treturn\n")
+ fmt.Fprintf(fgo2, "}\n")
+}
+
+// writeOutput creates stubs for a specific source file to be compiled by gc
+func (p *Package) writeOutput(f *File, srcfile string) {
+ base := srcfile
+ base = strings.TrimSuffix(base, ".go")
+ base = filepath.Base(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, "// Code generated by cmd/cgo; DO NOT EDIT.\n\n")
+ if strings.ContainsAny(srcfile, "\r\n") {
+ // This should have been checked when the file path was first resolved,
+ // but we double check here just to be sure.
+ fatalf("internal error: writeOutput: srcfile contains unexpected newline character: %q", srcfile)
+ }
+ fmt.Fprintf(fgo1, "//line %s:1:1\n", srcfile)
+ fgo1.Write(f.Edit.Bytes())
+
+ // While we process the vars and funcs, also write gcc output.
+ // Gcc output starts with the preamble.
+ fmt.Fprintf(fgcc, "%s\n", builtinProlog)
+ fmt.Fprintf(fgcc, "%s\n", f.Preamble)
+ fmt.Fprintf(fgcc, "%s\n", gccProlog)
+ fmt.Fprintf(fgcc, "%s\n", tsanProlog)
+ fmt.Fprintf(fgcc, "%s\n", msanProlog)
+
+ for _, key := range nameKeys(f.Name) {
+ n := f.Name[key]
+ if n.FuncType != nil {
+ p.writeOutputFunc(fgcc, n)
+ }
+ }
+
+ fgo1.Close()
+ fgcc.Close()
+}
+
+// fixGo converts the internal Name.Go field into the name we should show
+// to users in error messages. There's only one for now: on input we rewrite
+// C.malloc into C._CMalloc, so change it back here.
+func fixGo(name string) string {
+ if name == "_CMalloc" {
+ return "malloc"
+ }
+ return name
+}
+
+var isBuiltin = map[string]bool{
+ "_Cfunc_CString": true,
+ "_Cfunc_CBytes": true,
+ "_Cfunc_GoString": true,
+ "_Cfunc_GoStringN": true,
+ "_Cfunc_GoBytes": true,
+ "_Cfunc__CMalloc": true,
+}
+
+func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) {
+ name := n.Mangle
+ if isBuiltin[name] || 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 {
+ p.writeGccgoOutputFunc(fgcc, n)
+ return
+ }
+
+ ctype, _ := p.structType(n)
+
+ // Gcc wrapper unpacks the C argument struct
+ // and calls the actual C function.
+ fmt.Fprintf(fgcc, "CGO_NO_SANITIZE_THREAD\n")
+ if n.AddError {
+ fmt.Fprintf(fgcc, "int\n")
+ } else {
+ 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 _cgo_errno;\n")
+ }
+ // We're trying to write a gcc struct that matches gc's layout.
+ // Use packed attribute to force no padding in this struct in case
+ // gcc has different packing requirements.
+ fmt.Fprintf(fgcc, "\t%s %v *_cgo_a = v;\n", ctype, p.packedAttribute())
+ if n.FuncType.Result != nil {
+ // Save the stack top for use below.
+ fmt.Fprintf(fgcc, "\tchar *_cgo_stktop = _cgo_topofstack();\n")
+ }
+ tr := n.FuncType.Result
+ if tr != nil {
+ fmt.Fprintf(fgcc, "\t__typeof__(_cgo_a->r) _cgo_r;\n")
+ }
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
+ if n.AddError {
+ fmt.Fprintf(fgcc, "\terrno = 0;\n")
+ }
+ fmt.Fprintf(fgcc, "\t")
+ if tr != nil {
+ fmt.Fprintf(fgcc, "_cgo_r = ")
+ if c := tr.C.String(); c[len(c)-1] == '*' {
+ fmt.Fprint(fgcc, "(__typeof__(_cgo_a->r)) ")
+ }
+ }
+ if n.Kind == "macro" {
+ fmt.Fprintf(fgcc, "%s;\n", n.C)
+ } else {
+ fmt.Fprintf(fgcc, "%s(", n.C)
+ for i := range n.FuncType.Params {
+ if i > 0 {
+ fmt.Fprintf(fgcc, ", ")
+ }
+ fmt.Fprintf(fgcc, "_cgo_a->p%d", i)
+ }
+ fmt.Fprintf(fgcc, ");\n")
+ }
+ if n.AddError {
+ fmt.Fprintf(fgcc, "\t_cgo_errno = errno;\n")
+ }
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
+ if n.FuncType.Result != nil {
+ // The cgo call may have caused a stack copy (via a callback).
+ // Adjust the return value pointer appropriately.
+ fmt.Fprintf(fgcc, "\t_cgo_a = (void*)((char*)_cgo_a + (_cgo_topofstack() - _cgo_stktop));\n")
+ // Save the return value.
+ fmt.Fprintf(fgcc, "\t_cgo_a->r = _cgo_r;\n")
+ // The return value is on the Go stack. If we are using msan,
+ // and if the C value is partially or completely uninitialized,
+ // the assignment will mark the Go stack as uninitialized.
+ // The Go compiler does not update msan for changes to the
+ // stack. It is possible that the stack will remain
+ // uninitialized, and then later be used in a way that is
+ // visible to msan, possibly leading to a false positive.
+ // Mark the stack space as written, to avoid this problem.
+ // See issue 26209.
+ fmt.Fprintf(fgcc, "\t_cgo_msan_write(&_cgo_a->r, sizeof(_cgo_a->r));\n")
+ }
+ if n.AddError {
+ fmt.Fprintf(fgcc, "\treturn _cgo_errno;\n")
+ }
+ fmt.Fprintf(fgcc, "}\n")
+ fmt.Fprintf(fgcc, "\n")
+}
+
+// Write out a wrapper for a function when using gccgo. This is a
+// simple wrapper that just calls the real function. We only need a
+// wrapper to support static functions in the prologue--without a
+// wrapper, we can't refer to the function, since the reference is in
+// a different file.
+func (p *Package) writeGccgoOutputFunc(fgcc *os.File, n *Name) {
+ fmt.Fprintf(fgcc, "CGO_NO_SANITIZE_THREAD\n")
+ if t := n.FuncType.Result; t != nil {
+ fmt.Fprintf(fgcc, "%s\n", t.C.String())
+ } else {
+ fmt.Fprintf(fgcc, "void\n")
+ }
+ fmt.Fprintf(fgcc, "_cgo%s%s(", cPrefix, n.Mangle)
+ for i, t := range n.FuncType.Params {
+ if i > 0 {
+ fmt.Fprintf(fgcc, ", ")
+ }
+ c := t.Typedef
+ if c == "" {
+ c = t.C.String()
+ }
+ fmt.Fprintf(fgcc, "%s p%d", c, i)
+ }
+ fmt.Fprintf(fgcc, ")\n")
+ fmt.Fprintf(fgcc, "{\n")
+ if t := n.FuncType.Result; t != nil {
+ fmt.Fprintf(fgcc, "\t%s _cgo_r;\n", t.C.String())
+ }
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
+ fmt.Fprintf(fgcc, "\t")
+ if t := n.FuncType.Result; t != nil {
+ fmt.Fprintf(fgcc, "_cgo_r = ")
+ // Cast to void* to avoid warnings due to omitted qualifiers.
+ if c := t.C.String(); c[len(c)-1] == '*' {
+ fmt.Fprintf(fgcc, "(void*)")
+ }
+ }
+ if n.Kind == "macro" {
+ fmt.Fprintf(fgcc, "%s;\n", n.C)
+ } else {
+ fmt.Fprintf(fgcc, "%s(", n.C)
+ for i := range n.FuncType.Params {
+ if i > 0 {
+ fmt.Fprintf(fgcc, ", ")
+ }
+ fmt.Fprintf(fgcc, "p%d", i)
+ }
+ fmt.Fprintf(fgcc, ");\n")
+ }
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
+ if t := n.FuncType.Result; t != nil {
+ fmt.Fprintf(fgcc, "\treturn ")
+ // Cast to void* to avoid warnings due to omitted qualifiers
+ // and explicit incompatible struct types.
+ if c := t.C.String(); c[len(c)-1] == '*' {
+ fmt.Fprintf(fgcc, "(void*)")
+ }
+ fmt.Fprintf(fgcc, "_cgo_r;\n")
+ }
+ fmt.Fprintf(fgcc, "}\n")
+ fmt.Fprintf(fgcc, "\n")
+}
+
+// packedAttribute returns host compiler struct attribute that will be
+// used to match gc's struct layout. For example, on 386 Windows,
+// gcc wants to 8-align int64s, but gc does not.
+// Use __gcc_struct__ to work around https://gcc.gnu.org/PR52991 on x86,
+// and https://golang.org/issue/5603.
+func (p *Package) packedAttribute() string {
+ s := "__attribute__((__packed__"
+ if !p.GccIsClang && (goarch == "amd64" || goarch == "386") {
+ s += ", __gcc_struct__"
+ }
+ return s + "))"
+}
+
+// exportParamName returns the value of param as it should be
+// displayed in a c header file. If param contains any non-ASCII
+// characters, this function will return the character p followed by
+// the value of position; otherwise, this function will return the
+// value of param.
+func exportParamName(param string, position int) string {
+ if param == "" {
+ return fmt.Sprintf("p%d", position)
+ }
+
+ pname := param
+
+ for i := 0; i < len(param); i++ {
+ if param[i] > unicode.MaxASCII {
+ pname = fmt.Sprintf("p%d", position)
+ break
+ }
+ }
+
+ return pname
+}
+
+// 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, fm, fgcc, fgcch io.Writer) {
+ p.writeExportHeader(fgcch)
+
+ fmt.Fprintf(fgcc, "/* Code generated by cmd/cgo; DO NOT EDIT. */\n\n")
+ fmt.Fprintf(fgcc, "#include <stdlib.h>\n")
+ fmt.Fprintf(fgcc, "#include \"_cgo_export.h\"\n\n")
+
+ // We use packed structs, but they are always aligned.
+ // The pragmas and address-of-packed-member are only recognized as
+ // warning groups in clang 4.0+, so ignore unknown pragmas first.
+ fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Wunknown-pragmas\"\n")
+ fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Wpragmas\"\n")
+ fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Waddress-of-packed-member\"\n")
+
+ fmt.Fprintf(fgcc, "extern void crosscall2(void (*fn)(void *), void *, int, size_t);\n")
+ fmt.Fprintf(fgcc, "extern size_t _cgo_wait_runtime_init_done(void);\n")
+ fmt.Fprintf(fgcc, "extern void _cgo_release_context(size_t);\n\n")
+ fmt.Fprintf(fgcc, "extern char* _cgo_topofstack(void);")
+ fmt.Fprintf(fgcc, "%s\n", tsanProlog)
+ fmt.Fprintf(fgcc, "%s\n", msanProlog)
+
+ for _, exp := range p.ExpFunc {
+ fn := exp.Func
+
+ // Construct a struct that will be used to communicate
+ // arguments from C to Go. The C and Go definitions
+ // just have to agree. The gcc struct will be compiled
+ // with __attribute__((packed)) so all padding must be
+ // accounted for explicitly.
+ ctype := "struct {\n"
+ gotype := new(bytes.Buffer)
+ fmt.Fprintf(gotype, "struct {\n")
+ off := int64(0)
+ npad := 0
+ argField := func(typ ast.Expr, namePat string, args ...interface{}) {
+ name := fmt.Sprintf(namePat, args...)
+ t := p.cgoType(typ)
+ 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 %s;\n", t.C, name)
+ fmt.Fprintf(gotype, "\t\t%s ", name)
+ noSourceConf.Fprint(gotype, fset, typ)
+ fmt.Fprintf(gotype, "\n")
+ off += t.Size
+ }
+ if fn.Recv != nil {
+ argField(fn.Recv.List[0].Type, "recv")
+ }
+ fntype := fn.Type
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ argField(atype, "p%d", i)
+ })
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ argField(atype, "r%d", i)
+ })
+ if ctype == "struct {\n" {
+ ctype += "\t\tchar unused;\n" // avoid empty struct
+ }
+ ctype += "\t}"
+ fmt.Fprintf(gotype, "\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, aname string, atype ast.Expr) {
+ fmt.Fprintf(fgcch, "\t%s r%d;", p.cgoType(atype).C, i)
+ if len(aname) > 0 {
+ fmt.Fprintf(fgcch, " /* %s */", aname)
+ }
+ fmt.Fprint(fgcch, "\n")
+ })
+ fmt.Fprintf(fgcch, "};\n")
+ gccResult = "struct " + exp.ExpName + "_return"
+ }
+
+ // Build the wrapper function compiled by gcc.
+ gccExport := ""
+ if goos == "windows" {
+ gccExport = "__declspec(dllexport) "
+ }
+ s := fmt.Sprintf("%s%s %s(", gccExport, 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, aname string, atype ast.Expr) {
+ if i > 0 || fn.Recv != nil {
+ s += ", "
+ }
+ s += fmt.Sprintf("%s %s", p.cgoType(atype).C, exportParamName(aname, i))
+ })
+ s += ")"
+
+ if len(exp.Doc) > 0 {
+ fmt.Fprintf(fgcch, "\n%s", exp.Doc)
+ if !strings.HasSuffix(exp.Doc, "\n") {
+ fmt.Fprint(fgcch, "\n")
+ }
+ }
+ fmt.Fprintf(fgcch, "extern %s;\n", s)
+
+ fmt.Fprintf(fgcc, "extern void _cgoexp%s_%s(void *);\n", cPrefix, exp.ExpName)
+ fmt.Fprintf(fgcc, "\nCGO_NO_SANITIZE_THREAD")
+ fmt.Fprintf(fgcc, "\n%s\n", s)
+ fmt.Fprintf(fgcc, "{\n")
+ fmt.Fprintf(fgcc, "\tsize_t _cgo_ctxt = _cgo_wait_runtime_init_done();\n")
+ // The results part of the argument structure must be
+ // initialized to 0 so the write barriers generated by
+ // the assignments to these fields in Go are safe.
+ //
+ // We use a local static variable to get the zeroed
+ // value of the argument type. This avoids including
+ // string.h for memset, and is also robust to C++
+ // types with constructors. Both GCC and LLVM optimize
+ // this into just zeroing _cgo_a.
+ fmt.Fprintf(fgcc, "\ttypedef %s %v _cgo_argtype;\n", ctype, p.packedAttribute())
+ fmt.Fprintf(fgcc, "\tstatic _cgo_argtype _cgo_zero;\n")
+ fmt.Fprintf(fgcc, "\t_cgo_argtype _cgo_a = _cgo_zero;\n")
+ 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, "\t_cgo_a.recv = recv;\n")
+ }
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ fmt.Fprintf(fgcc, "\t_cgo_a.p%d = %s;\n", i, exportParamName(aname, i))
+ })
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
+ fmt.Fprintf(fgcc, "\tcrosscall2(_cgoexp%s_%s, &_cgo_a, %d, _cgo_ctxt);\n", cPrefix, exp.ExpName, off)
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
+ fmt.Fprintf(fgcc, "\t_cgo_release_context(_cgo_ctxt);\n")
+ if gccResult != "void" {
+ if len(fntype.Results.List) == 1 && len(fntype.Results.List[0].Names) <= 1 {
+ fmt.Fprintf(fgcc, "\treturn _cgo_a.r0;\n")
+ } else {
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ fmt.Fprintf(fgcc, "\tr.r%d = _cgo_a.r%d;\n", i, i)
+ })
+ fmt.Fprintf(fgcc, "\treturn r;\n")
+ }
+ }
+ fmt.Fprintf(fgcc, "}\n")
+
+ // In internal linking mode, the Go linker sees both
+ // the C wrapper written above and the Go wrapper it
+ // references. Hence, export the C wrapper (e.g., for
+ // if we're building a shared object). The Go linker
+ // will resolve the C wrapper's reference to the Go
+ // wrapper without a separate export.
+ fmt.Fprintf(fgo2, "//go:cgo_export_dynamic %s\n", exp.ExpName)
+ // cgo_export_static refers to a symbol by its linker
+ // name, so set the linker name of the Go wrapper.
+ fmt.Fprintf(fgo2, "//go:linkname _cgoexp%s_%s _cgoexp%s_%s\n", cPrefix, exp.ExpName, cPrefix, exp.ExpName)
+ // In external linking mode, the Go linker sees the Go
+ // wrapper, but not the C wrapper. For this case,
+ // export the Go wrapper so the host linker can
+ // resolve the reference from the C wrapper to the Go
+ // wrapper.
+ fmt.Fprintf(fgo2, "//go:cgo_export_static _cgoexp%s_%s\n", cPrefix, exp.ExpName)
+
+ // Build the wrapper function compiled by cmd/compile.
+ // This unpacks the argument struct above and calls the Go function.
+ fmt.Fprintf(fgo2, "func _cgoexp%s_%s(a *%s) {\n", cPrefix, exp.ExpName, gotype)
+
+ fmt.Fprintf(fm, "void _cgoexp%s_%s(void* p){}\n", cPrefix, exp.ExpName)
+
+ fmt.Fprintf(fgo2, "\t")
+
+ if gccResult != "void" {
+ // Write results back to frame.
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 {
+ fmt.Fprintf(fgo2, ", ")
+ }
+ fmt.Fprintf(fgo2, "a.r%d", i)
+ })
+ fmt.Fprintf(fgo2, " = ")
+ }
+ if fn.Recv != nil {
+ fmt.Fprintf(fgo2, "a.recv.")
+ }
+ fmt.Fprintf(fgo2, "%s(", exp.Func.Name)
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 {
+ fmt.Fprint(fgo2, ", ")
+ }
+ fmt.Fprintf(fgo2, "a.p%d", i)
+ })
+ fmt.Fprint(fgo2, ")\n")
+ if gccResult != "void" {
+ // Verify that any results don't contain any
+ // Go pointers.
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ if !p.hasPointer(nil, atype, false) {
+ return
+ }
+ fmt.Fprintf(fgo2, "\t_cgoCheckResult(a.r%d)\n", i)
+ })
+ }
+ fmt.Fprint(fgo2, "}\n")
+ }
+
+ fmt.Fprintf(fgcch, "%s", gccExportHeaderEpilog)
+}
+
+// Write out the C header allowing C code to call exported gccgo functions.
+func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) {
+ gccgoSymbolPrefix := p.gccgoSymbolPrefix()
+
+ p.writeExportHeader(fgcch)
+
+ fmt.Fprintf(fgcc, "/* Code generated by cmd/cgo; DO NOT EDIT. */\n\n")
+ fmt.Fprintf(fgcc, "#include \"_cgo_export.h\"\n")
+
+ fmt.Fprintf(fgcc, "%s\n", gccgoExportFileProlog)
+ fmt.Fprintf(fgcc, "%s\n", tsanProlog)
+ fmt.Fprintf(fgcc, "%s\n", msanProlog)
+
+ for _, exp := range p.ExpFunc {
+ fn := exp.Func
+ fntype := fn.Type
+
+ cdeclBuf := new(strings.Builder)
+ resultCount := 0
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) { resultCount++ })
+ switch resultCount {
+ case 0:
+ fmt.Fprintf(cdeclBuf, "void")
+ case 1:
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ t := p.cgoType(atype)
+ fmt.Fprintf(cdeclBuf, "%s", t.C)
+ })
+ default:
+ // Declare a result struct.
+ 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, aname string, atype ast.Expr) {
+ t := p.cgoType(atype)
+ fmt.Fprintf(fgcch, "\t%s r%d;", t.C, i)
+ if len(aname) > 0 {
+ fmt.Fprintf(fgcch, " /* %s */", aname)
+ }
+ fmt.Fprint(fgcch, "\n")
+ })
+ fmt.Fprintf(fgcch, "};\n")
+ fmt.Fprintf(cdeclBuf, "struct %s_return", exp.ExpName)
+ }
+
+ cRet := cdeclBuf.String()
+
+ cdeclBuf = new(strings.Builder)
+ fmt.Fprintf(cdeclBuf, "(")
+ if fn.Recv != nil {
+ fmt.Fprintf(cdeclBuf, "%s recv", p.cgoType(fn.Recv.List[0].Type).C.String())
+ }
+ // Function parameters.
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 || fn.Recv != nil {
+ fmt.Fprintf(cdeclBuf, ", ")
+ }
+ t := p.cgoType(atype)
+ fmt.Fprintf(cdeclBuf, "%s p%d", t.C, i)
+ })
+ fmt.Fprintf(cdeclBuf, ")")
+ cParams := cdeclBuf.String()
+
+ if len(exp.Doc) > 0 {
+ fmt.Fprintf(fgcch, "\n%s", exp.Doc)
+ }
+
+ fmt.Fprintf(fgcch, "extern %s %s%s;\n", cRet, exp.ExpName, cParams)
+
+ // We need to use a name that will be exported by the
+ // Go code; otherwise gccgo will make it static and we
+ // will not be able to link against it from the C
+ // code.
+ goName := "Cgoexp_" + exp.ExpName
+ fmt.Fprintf(fgcc, `extern %s %s %s __asm__("%s.%s");`, cRet, goName, cParams, gccgoSymbolPrefix, gccgoToSymbol(goName))
+ fmt.Fprint(fgcc, "\n")
+
+ fmt.Fprint(fgcc, "\nCGO_NO_SANITIZE_THREAD\n")
+ fmt.Fprintf(fgcc, "%s %s %s {\n", cRet, exp.ExpName, cParams)
+ if resultCount > 0 {
+ fmt.Fprintf(fgcc, "\t%s r;\n", cRet)
+ }
+ fmt.Fprintf(fgcc, "\tif(_cgo_wait_runtime_init_done)\n")
+ fmt.Fprintf(fgcc, "\t\t_cgo_wait_runtime_init_done();\n")
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
+ fmt.Fprint(fgcc, "\t")
+ if resultCount > 0 {
+ fmt.Fprint(fgcc, "r = ")
+ }
+ fmt.Fprintf(fgcc, "%s(", goName)
+ if fn.Recv != nil {
+ fmt.Fprint(fgcc, "recv")
+ }
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 || fn.Recv != nil {
+ fmt.Fprintf(fgcc, ", ")
+ }
+ fmt.Fprintf(fgcc, "p%d", i)
+ })
+ fmt.Fprint(fgcc, ");\n")
+ fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
+ if resultCount > 0 {
+ fmt.Fprint(fgcc, "\treturn r;\n")
+ }
+ fmt.Fprint(fgcc, "}\n")
+
+ // Dummy declaration for _cgo_main.c
+ fmt.Fprintf(fm, `char %s[1] __asm__("%s.%s");`, goName, gccgoSymbolPrefix, gccgoToSymbol(goName))
+ fmt.Fprint(fm, "\n")
+
+ // For gccgo we use a wrapper function in Go, in order
+ // to call CgocallBack and CgocallBackDone.
+
+ // This code uses printer.Fprint, not conf.Fprint,
+ // because we don't want //line comments in the middle
+ // of the function types.
+ fmt.Fprint(fgo2, "\n")
+ fmt.Fprintf(fgo2, "func %s(", goName)
+ if fn.Recv != nil {
+ fmt.Fprint(fgo2, "recv ")
+ printer.Fprint(fgo2, fset, fn.Recv.List[0].Type)
+ }
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 || fn.Recv != nil {
+ fmt.Fprintf(fgo2, ", ")
+ }
+ fmt.Fprintf(fgo2, "p%d ", i)
+ printer.Fprint(fgo2, fset, atype)
+ })
+ fmt.Fprintf(fgo2, ")")
+ if resultCount > 0 {
+ fmt.Fprintf(fgo2, " (")
+ forFieldList(fntype.Results,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 {
+ fmt.Fprint(fgo2, ", ")
+ }
+ printer.Fprint(fgo2, fset, atype)
+ })
+ fmt.Fprint(fgo2, ")")
+ }
+ fmt.Fprint(fgo2, " {\n")
+ fmt.Fprint(fgo2, "\tsyscall.CgocallBack()\n")
+ fmt.Fprint(fgo2, "\tdefer syscall.CgocallBackDone()\n")
+ fmt.Fprint(fgo2, "\t")
+ if resultCount > 0 {
+ fmt.Fprint(fgo2, "return ")
+ }
+ if fn.Recv != nil {
+ fmt.Fprint(fgo2, "recv.")
+ }
+ fmt.Fprintf(fgo2, "%s(", exp.Func.Name)
+ forFieldList(fntype.Params,
+ func(i int, aname string, atype ast.Expr) {
+ if i > 0 {
+ fmt.Fprint(fgo2, ", ")
+ }
+ fmt.Fprintf(fgo2, "p%d", i)
+ })
+ fmt.Fprint(fgo2, ")\n")
+ fmt.Fprint(fgo2, "}\n")
+ }
+
+ fmt.Fprintf(fgcch, "%s", gccExportHeaderEpilog)
+}
+
+// writeExportHeader writes out the start of the _cgo_export.h file.
+func (p *Package) writeExportHeader(fgcch io.Writer) {
+ fmt.Fprintf(fgcch, "/* Code generated by cmd/cgo; DO NOT EDIT. */\n\n")
+ pkg := *importPath
+ if pkg == "" {
+ pkg = p.PackagePath
+ }
+ fmt.Fprintf(fgcch, "/* package %s */\n\n", pkg)
+ fmt.Fprintf(fgcch, "%s\n", builtinExportProlog)
+
+ // Remove absolute paths from #line comments in the preamble.
+ // They aren't useful for people using the header file,
+ // and they mean that the header files change based on the
+ // exact location of GOPATH.
+ re := regexp.MustCompile(`(?m)^(#line\s+\d+\s+")[^"]*[/\\]([^"]*")`)
+ preamble := re.ReplaceAllString(p.Preamble, "$1$2")
+
+ fmt.Fprintf(fgcch, "/* Start of preamble from import \"C\" comments. */\n\n")
+ fmt.Fprintf(fgcch, "%s\n", preamble)
+ fmt.Fprintf(fgcch, "\n/* End of preamble from import \"C\" comments. */\n\n")
+
+ fmt.Fprintf(fgcch, "%s\n", p.gccExportHeaderProlog())
+}
+
+// gccgoToSymbol converts a name to a mangled symbol for gccgo.
+func gccgoToSymbol(ppath string) string {
+ if gccgoMangler == nil {
+ var err error
+ cmd := os.Getenv("GCCGO")
+ if cmd == "" {
+ cmd, err = exec.LookPath("gccgo")
+ if err != nil {
+ fatalf("unable to locate gccgo: %v", err)
+ }
+ }
+ gccgoMangler, err = pkgpath.ToSymbolFunc(cmd, *objDir)
+ if err != nil {
+ fatalf("%v", err)
+ }
+ }
+ return gccgoMangler(ppath)
+}
+
+// Return the package prefix when using gccgo.
+func (p *Package) gccgoSymbolPrefix() string {
+ if !*gccgo {
+ return ""
+ }
+
+ if *gccgopkgpath != "" {
+ return gccgoToSymbol(*gccgopkgpath)
+ }
+ if *gccgoprefix == "" && p.PackageName == "main" {
+ return "main"
+ }
+ prefix := gccgoToSymbol(*gccgoprefix)
+ if prefix == "" {
+ prefix = "go"
+ }
+ return prefix + "." + p.PackageName
+}
+
+// Call a function for each entry in an ast.FieldList, passing the
+// index into the list, the name if any, and the type.
+func forFieldList(fl *ast.FieldList, fn func(int, string, ast.Expr)) {
+ if fl == nil {
+ return
+ }
+ i := 0
+ for _, r := range fl.List {
+ if r.Names == nil {
+ fn(i, "", r.Type)
+ i++
+ } else {
+ for _, n := range r.Names {
+ fn(i, n.Name, 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: 0, Align: 0, C: c("GoInt")},
+ "uint": {Size: 0, Align: 0, 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: 4, C: c("GoComplex64")},
+ "complex128": {Size: 16, Align: 8, 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 {
+ // Slice: pointer, len, cap.
+ return &Type{Size: p.PtrSize * 3, Align: p.PtrSize, C: c("GoSlice")}
+ }
+ // Non-slice array types are not supported.
+ case *ast.StructType:
+ // Not supported.
+ 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:
+ goTypesFixup := func(r *Type) *Type {
+ if r.Size == 0 { // int or uint
+ rr := new(Type)
+ *rr = *r
+ rr.Size = p.IntSize
+ rr.Align = p.IntSize
+ r = rr
+ }
+ if r.Align > p.PtrSize {
+ r.Align = p.PtrSize
+ }
+ return r
+ }
+ // 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 {
+ if defgo, ok := def.Go.(*ast.Ident); ok {
+ switch defgo.Name {
+ case "complex64", "complex128":
+ // MSVC does not support the _Complex keyword
+ // nor the complex macro.
+ // Use GoComplex64 and GoComplex128 instead,
+ // which are typedef-ed to a compatible type.
+ // See go.dev/issues/36233.
+ return goTypesFixup(goTypes[defgo.Name])
+ }
+ }
+ return def
+ }
+ if t.Name == "uintptr" {
+ return &Type{Size: p.PtrSize, Align: p.PtrSize, C: c("GoUintptr")}
+ }
+ if t.Name == "string" {
+ // The string data is 1 pointer + 1 (pointer-sized) int.
+ return &Type{Size: 2 * p.PtrSize, 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 {
+ return goTypesFixup(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 = `
+#line 1 "cgo-gcc-prolog"
+/*
+ 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)*-2UL+1UL];
+
+/* Check at compile time that the sizes we use match our expectations. */
+#define __cgo_size_assert(t, n) __cgo_compile_assert_eq(sizeof(t), (size_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)
+
+extern char* _cgo_topofstack(void);
+
+/*
+ We use packed structs, but they are always aligned.
+ The pragmas and address-of-packed-member are only recognized as warning
+ groups in clang 4.0+, so ignore unknown pragmas first.
+*/
+#pragma GCC diagnostic ignored "-Wunknown-pragmas"
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Waddress-of-packed-member"
+
+#include <errno.h>
+#include <string.h>
+`
+
+// Prologue defining TSAN functions in C.
+const noTsanProlog = `
+#define CGO_NO_SANITIZE_THREAD
+#define _cgo_tsan_acquire()
+#define _cgo_tsan_release()
+`
+
+// This must match the TSAN code in runtime/cgo/libcgo.h.
+// This is used when the code is built with the C/C++ Thread SANitizer,
+// which is not the same as the Go race detector.
+// __tsan_acquire tells TSAN that we are acquiring a lock on a variable,
+// in this case _cgo_sync. __tsan_release releases the lock.
+// (There is no actual lock, we are just telling TSAN that there is.)
+//
+// When we call from Go to C we call _cgo_tsan_acquire.
+// When the C function returns we call _cgo_tsan_release.
+// Similarly, when C calls back into Go we call _cgo_tsan_release
+// and then call _cgo_tsan_acquire when we return to C.
+// These calls tell TSAN that there is a serialization point at the C call.
+//
+// This is necessary because TSAN, which is a C/C++ tool, can not see
+// the synchronization in the Go code. Without these calls, when
+// multiple goroutines call into C code, TSAN does not understand
+// that the calls are properly synchronized on the Go side.
+//
+// To be clear, if the calls are not properly synchronized on the Go side,
+// we will be hiding races. But when using TSAN on mixed Go C/C++ code
+// it is more important to avoid false positives, which reduce confidence
+// in the tool, than to avoid false negatives.
+const yesTsanProlog = `
+#line 1 "cgo-tsan-prolog"
+#define CGO_NO_SANITIZE_THREAD __attribute__ ((no_sanitize_thread))
+
+long long _cgo_sync __attribute__ ((common));
+
+extern void __tsan_acquire(void*);
+extern void __tsan_release(void*);
+
+__attribute__ ((unused))
+static void _cgo_tsan_acquire() {
+ __tsan_acquire(&_cgo_sync);
+}
+
+__attribute__ ((unused))
+static void _cgo_tsan_release() {
+ __tsan_release(&_cgo_sync);
+}
+`
+
+// Set to yesTsanProlog if we see -fsanitize=thread in the flags for gcc.
+var tsanProlog = noTsanProlog
+
+// noMsanProlog is a prologue defining an MSAN function in C.
+// This is used when not compiling with -fsanitize=memory.
+const noMsanProlog = `
+#define _cgo_msan_write(addr, sz)
+`
+
+// yesMsanProlog is a prologue defining an MSAN function in C.
+// This is used when compiling with -fsanitize=memory.
+// See the comment above where _cgo_msan_write is called.
+const yesMsanProlog = `
+extern void __msan_unpoison(const volatile void *, size_t);
+
+#define _cgo_msan_write(addr, sz) __msan_unpoison((addr), (sz))
+`
+
+// msanProlog is set to yesMsanProlog if we see -fsanitize=memory in the flags
+// for the C compiler.
+var msanProlog = noMsanProlog
+
+const builtinProlog = `
+#line 1 "cgo-builtin-prolog"
+#include <stddef.h>
+
+/* Define intgo when compiling with GCC. */
+typedef ptrdiff_t intgo;
+
+#define GO_CGO_GOSTRING_TYPEDEF
+typedef struct { const char *p; intgo n; } _GoString_;
+typedef struct { char *p; intgo n; intgo c; } _GoBytes_;
+_GoString_ GoString(char *p);
+_GoString_ GoStringN(char *p, int l);
+_GoBytes_ GoBytes(void *p, int n);
+char *CString(_GoString_);
+void *CBytes(_GoBytes_);
+void *_CMalloc(size_t);
+
+__attribute__ ((unused))
+static size_t _GoStringLen(_GoString_ s) { return (size_t)s.n; }
+
+__attribute__ ((unused))
+static const char *_GoStringPtr(_GoString_ s) { return s.p; }
+`
+
+const goProlog = `
+//go:linkname _cgo_runtime_cgocall runtime.cgocall
+func _cgo_runtime_cgocall(unsafe.Pointer, uintptr) int32
+
+//go:linkname _cgoCheckPointer runtime.cgoCheckPointer
+func _cgoCheckPointer(interface{}, interface{})
+
+//go:linkname _cgoCheckResult runtime.cgoCheckResult
+func _cgoCheckResult(interface{})
+`
+
+const gccgoGoProlog = `
+func _cgoCheckPointer(interface{}, interface{})
+
+func _cgoCheckResult(interface{})
+`
+
+const goStringDef = `
+//go:linkname _cgo_runtime_gostring runtime.gostring
+func _cgo_runtime_gostring(*_Ctype_char) string
+
+// GoString converts the C string p into a Go string.
+func _Cfunc_GoString(p *_Ctype_char) string {
+ return _cgo_runtime_gostring(p)
+}
+`
+
+const goStringNDef = `
+//go:linkname _cgo_runtime_gostringn runtime.gostringn
+func _cgo_runtime_gostringn(*_Ctype_char, int) string
+
+// GoStringN converts the C data p with explicit length l to a Go string.
+func _Cfunc_GoStringN(p *_Ctype_char, l _Ctype_int) string {
+ return _cgo_runtime_gostringn(p, int(l))
+}
+`
+
+const goBytesDef = `
+//go:linkname _cgo_runtime_gobytes runtime.gobytes
+func _cgo_runtime_gobytes(unsafe.Pointer, int) []byte
+
+// GoBytes converts the C data p with explicit length l to a Go []byte.
+func _Cfunc_GoBytes(p unsafe.Pointer, l _Ctype_int) []byte {
+ return _cgo_runtime_gobytes(p, int(l))
+}
+`
+
+const cStringDef = `
+// CString converts the Go string s to a C string.
+//
+// The C string is allocated in the C heap using malloc.
+// It is the caller's responsibility to arrange for it to be
+// freed, such as by calling C.free (be sure to include stdlib.h
+// if C.free is needed).
+func _Cfunc_CString(s string) *_Ctype_char {
+ if len(s)+1 <= 0 {
+ panic("string too large")
+ }
+ p := _cgo_cmalloc(uint64(len(s)+1))
+ sliceHeader := struct {
+ p unsafe.Pointer
+ len int
+ cap int
+ }{p, len(s)+1, len(s)+1}
+ b := *(*[]byte)(unsafe.Pointer(&sliceHeader))
+ copy(b, s)
+ b[len(s)] = 0
+ return (*_Ctype_char)(p)
+}
+`
+
+const cBytesDef = `
+// CBytes converts the Go []byte slice b to a C array.
+//
+// The C array is allocated in the C heap using malloc.
+// It is the caller's responsibility to arrange for it to be
+// freed, such as by calling C.free (be sure to include stdlib.h
+// if C.free is needed).
+func _Cfunc_CBytes(b []byte) unsafe.Pointer {
+ p := _cgo_cmalloc(uint64(len(b)))
+ sliceHeader := struct {
+ p unsafe.Pointer
+ len int
+ cap int
+ }{p, len(b), len(b)}
+ s := *(*[]byte)(unsafe.Pointer(&sliceHeader))
+ copy(s, b)
+ return p
+}
+`
+
+const cMallocDef = `
+func _Cfunc__CMalloc(n _Ctype_size_t) unsafe.Pointer {
+ return _cgo_cmalloc(uint64(n))
+}
+`
+
+var builtinDefs = map[string]string{
+ "GoString": goStringDef,
+ "GoStringN": goStringNDef,
+ "GoBytes": goBytesDef,
+ "CString": cStringDef,
+ "CBytes": cBytesDef,
+ "_CMalloc": cMallocDef,
+}
+
+// Definitions for C.malloc in Go and in C. We define it ourselves
+// since we call it from functions we define, such as C.CString.
+// Also, we have historically ensured that C.malloc does not return
+// nil even for an allocation of 0.
+
+const cMallocDefGo = `
+//go:cgo_import_static _cgoPREFIX_Cfunc__Cmalloc
+//go:linkname __cgofn__cgoPREFIX_Cfunc__Cmalloc _cgoPREFIX_Cfunc__Cmalloc
+var __cgofn__cgoPREFIX_Cfunc__Cmalloc byte
+var _cgoPREFIX_Cfunc__Cmalloc = unsafe.Pointer(&__cgofn__cgoPREFIX_Cfunc__Cmalloc)
+
+//go:linkname runtime_throw runtime.throw
+func runtime_throw(string)
+
+//go:cgo_unsafe_args
+func _cgo_cmalloc(p0 uint64) (r1 unsafe.Pointer) {
+ _cgo_runtime_cgocall(_cgoPREFIX_Cfunc__Cmalloc, uintptr(unsafe.Pointer(&p0)))
+ if r1 == nil {
+ runtime_throw("runtime: C malloc failed")
+ }
+ return
+}
+`
+
+// cMallocDefC defines the C version of C.malloc for the gc compiler.
+// It is defined here because C.CString and friends need a definition.
+// We define it by hand, rather than simply inventing a reference to
+// C.malloc, because <stdlib.h> may not have been included.
+// This is approximately what writeOutputFunc would generate, but
+// skips the cgo_topofstack code (which is only needed if the C code
+// calls back into Go). This also avoids returning nil for an
+// allocation of 0 bytes.
+const cMallocDefC = `
+CGO_NO_SANITIZE_THREAD
+void _cgoPREFIX_Cfunc__Cmalloc(void *v) {
+ struct {
+ unsigned long long p0;
+ void *r1;
+ } PACKED *a = v;
+ void *ret;
+ _cgo_tsan_acquire();
+ ret = malloc(a->p0);
+ if (ret == 0 && a->p0 == 0) {
+ ret = malloc(1);
+ }
+ a->r1 = ret;
+ _cgo_tsan_release();
+}
+`
+
+func (p *Package) cPrologGccgo() string {
+ r := strings.NewReplacer(
+ "PREFIX", cPrefix,
+ "GCCGOSYMBOLPREF", p.gccgoSymbolPrefix(),
+ "_cgoCheckPointer", gccgoToSymbol("_cgoCheckPointer"),
+ "_cgoCheckResult", gccgoToSymbol("_cgoCheckResult"))
+ return r.Replace(cPrologGccgo)
+}
+
+const cPrologGccgo = `
+#line 1 "cgo-c-prolog-gccgo"
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef unsigned char byte;
+typedef intptr_t intgo;
+
+struct __go_string {
+ const unsigned char *__data;
+ intgo __length;
+};
+
+typedef struct __go_open_array {
+ void* __values;
+ intgo __count;
+ intgo __capacity;
+} Slice;
+
+struct __go_string __go_byte_array_to_string(const void* p, intgo len);
+struct __go_open_array __go_string_to_byte_array (struct __go_string str);
+
+extern void runtime_throw(const char *);
+
+const char *_cgoPREFIX_Cfunc_CString(struct __go_string s) {
+ char *p = malloc(s.__length+1);
+ if(p == NULL)
+ runtime_throw("runtime: C malloc failed");
+ memmove(p, s.__data, s.__length);
+ p[s.__length] = 0;
+ return p;
+}
+
+void *_cgoPREFIX_Cfunc_CBytes(struct __go_open_array b) {
+ char *p = malloc(b.__count);
+ if(p == NULL)
+ runtime_throw("runtime: C malloc failed");
+ memmove(p, b.__values, b.__count);
+ return p;
+}
+
+struct __go_string _cgoPREFIX_Cfunc_GoString(char *p) {
+ intgo len = (p != NULL) ? strlen(p) : 0;
+ return __go_byte_array_to_string(p, len);
+}
+
+struct __go_string _cgoPREFIX_Cfunc_GoStringN(char *p, int32_t n) {
+ return __go_byte_array_to_string(p, n);
+}
+
+Slice _cgoPREFIX_Cfunc_GoBytes(char *p, int32_t n) {
+ struct __go_string s = { (const unsigned char *)p, n };
+ return __go_string_to_byte_array(s);
+}
+
+void *_cgoPREFIX_Cfunc__CMalloc(size_t n) {
+ void *p = malloc(n);
+ if(p == NULL && n == 0)
+ p = malloc(1);
+ if(p == NULL)
+ runtime_throw("runtime: C malloc failed");
+ return p;
+}
+
+struct __go_type_descriptor;
+typedef struct __go_empty_interface {
+ const struct __go_type_descriptor *__type_descriptor;
+ void *__object;
+} Eface;
+
+extern void runtimeCgoCheckPointer(Eface, Eface)
+ __asm__("runtime.cgoCheckPointer")
+ __attribute__((weak));
+
+extern void localCgoCheckPointer(Eface, Eface)
+ __asm__("GCCGOSYMBOLPREF._cgoCheckPointer");
+
+void localCgoCheckPointer(Eface ptr, Eface arg) {
+ if(runtimeCgoCheckPointer) {
+ runtimeCgoCheckPointer(ptr, arg);
+ }
+}
+
+extern void runtimeCgoCheckResult(Eface)
+ __asm__("runtime.cgoCheckResult")
+ __attribute__((weak));
+
+extern void localCgoCheckResult(Eface)
+ __asm__("GCCGOSYMBOLPREF._cgoCheckResult");
+
+void localCgoCheckResult(Eface val) {
+ if(runtimeCgoCheckResult) {
+ runtimeCgoCheckResult(val);
+ }
+}
+`
+
+// builtinExportProlog is a shorter version of builtinProlog,
+// to be put into the _cgo_export.h file.
+// For historical reasons we can't use builtinProlog in _cgo_export.h,
+// because _cgo_export.h defines GoString as a struct while builtinProlog
+// defines it as a function. We don't change this to avoid unnecessarily
+// breaking existing code.
+// The test of GO_CGO_GOSTRING_TYPEDEF avoids a duplicate definition
+// error if a Go file with a cgo comment #include's the export header
+// generated by a different package.
+const builtinExportProlog = `
+#line 1 "cgo-builtin-export-prolog"
+
+#include <stddef.h>
+
+#ifndef GO_CGO_EXPORT_PROLOGUE_H
+#define GO_CGO_EXPORT_PROLOGUE_H
+
+#ifndef GO_CGO_GOSTRING_TYPEDEF
+typedef struct { const char *p; ptrdiff_t n; } _GoString_;
+#endif
+
+#endif
+`
+
+func (p *Package) gccExportHeaderProlog() string {
+ return strings.Replace(gccExportHeaderProlog, "GOINTBITS", fmt.Sprint(8*p.IntSize), -1)
+}
+
+// gccExportHeaderProlog is written to the exported header, after the
+// import "C" comment preamble but before the generated declarations
+// of exported functions. This permits the generated declarations to
+// use the type names that appear in goTypes, above.
+//
+// The test of GO_CGO_GOSTRING_TYPEDEF avoids a duplicate definition
+// error if a Go file with a cgo comment #include's the export header
+// generated by a different package. Unfortunately GoString means two
+// different things: in this prolog it means a C name for the Go type,
+// while in the prolog written into the start of the C code generated
+// from a cgo-using Go file it means the C.GoString function. There is
+// no way to resolve this conflict, but it also doesn't make much
+// difference, as Go code never wants to refer to the latter meaning.
+const gccExportHeaderProlog = `
+/* Start of boilerplate cgo prologue. */
+#line 1 "cgo-gcc-export-header-prolog"
+
+#ifndef GO_CGO_PROLOGUE_H
+#define GO_CGO_PROLOGUE_H
+
+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 GoIntGOINTBITS GoInt;
+typedef GoUintGOINTBITS GoUint;
+typedef size_t GoUintptr;
+typedef float GoFloat32;
+typedef double GoFloat64;
+#ifdef _MSC_VER
+#include <complex.h>
+typedef _Fcomplex GoComplex64;
+typedef _Dcomplex GoComplex128;
+#else
+typedef float _Complex GoComplex64;
+typedef double _Complex GoComplex128;
+#endif
+
+/*
+ static assertion to make sure the file is being used on architecture
+ at least with matching size of GoInt.
+*/
+typedef char _check_for_GOINTBITS_bit_pointer_matching_GoInt[sizeof(void*)==GOINTBITS/8 ? 1:-1];
+
+#ifndef GO_CGO_GOSTRING_TYPEDEF
+typedef _GoString_ GoString;
+#endif
+typedef void *GoMap;
+typedef void *GoChan;
+typedef struct { void *t; void *v; } GoInterface;
+typedef struct { void *data; GoInt len; GoInt cap; } GoSlice;
+
+#endif
+
+/* End of boilerplate cgo prologue. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+`
+
+// gccExportHeaderEpilog goes at the end of the generated header file.
+const gccExportHeaderEpilog = `
+#ifdef __cplusplus
+}
+#endif
+`
+
+// gccgoExportFileProlog is written to the _cgo_export.c file when
+// using gccgo.
+// We use weak declarations, and test the addresses, so that this code
+// works with older versions of gccgo.
+const gccgoExportFileProlog = `
+#line 1 "cgo-gccgo-export-file-prolog"
+extern _Bool runtime_iscgo __attribute__ ((weak));
+
+static void GoInit(void) __attribute__ ((constructor));
+static void GoInit(void) {
+ if(&runtime_iscgo)
+ runtime_iscgo = 1;
+}
+
+extern size_t _cgo_wait_runtime_init_done(void) __attribute__ ((weak));
+`
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 18:48:17 +0000