diff options
Diffstat (limited to 'src/cmd/cgo/out.go')
| -rw-r--r-- | src/cmd/cgo/out.go | 47 |
1 files changed, 35 insertions, 12 deletions
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go index 83ab95251..76c7247af 100644 --- a/src/cmd/cgo/out.go +++ b/src/cmd/cgo/out.go @@ -485,7 +485,7 @@ func (p *Package) writeOutput(f *File, srcfile string) { fgcc.Close() } -// fixGo convers the internal Name.Go field into the name we should show +// 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 { @@ -529,15 +529,8 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) { } // 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. - // Use __gcc_struct__ to work around http://gcc.gnu.org/PR52991 on x86, - // and http://golang.org/issue/5603. - extraAttr := "" - if !strings.Contains(p.gccBaseCmd()[0], "clang") && (goarch == "amd64" || goarch == "386") { - extraAttr = ", __gcc_struct__" - } - fmt.Fprintf(fgcc, "\t%s __attribute__((__packed__%v)) *a = v;\n", ctype, extraAttr) + // gcc has different packing requirements. + fmt.Fprintf(fgcc, "\t%s %v *a = v;\n", ctype, p.packedAttribute()) fmt.Fprintf(fgcc, "\t") if t := n.FuncType.Result; t != nil { fmt.Fprintf(fgcc, "a->r = ") @@ -618,6 +611,19 @@ func (p *Package) writeGccgoOutputFunc(fgcc *os.File, n *Name) { fmt.Fprintf(fgcc, "\n") } +// packedAttribute returns host compiler struct attribute that will be +// used to match 6c/8c/5c's struct layout. For example, on 386 Windows, +// gcc wants to 8-align int64s, but 8c does not. +// Use __gcc_struct__ to work around http://gcc.gnu.org/PR52991 on x86, +// and http://golang.org/issue/5603. +func (p *Package) packedAttribute() string { + s := "__attribute__((__packed__" + if !strings.Contains(p.gccBaseCmd()[0], "clang") && (goarch == "amd64" || goarch == "386") { + s += ", __gcc_struct__" + } + return s + "))" +} + // 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) { @@ -727,7 +733,7 @@ func (p *Package) writeExports(fgo2, fc, fm *os.File) { 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) + fmt.Fprintf(fgcc, "\t%s %v a;\n", ctype, p.packedAttribute()) if gccResult != "void" && (len(fntype.Results.List) > 1 || len(fntype.Results.List[0].Names) > 1) { fmt.Fprintf(fgcc, "\t%s r;\n", gccResult) } @@ -874,10 +880,24 @@ func (p *Package) writeGccgoExports(fgo2, fc, fm *os.File) { fmt.Fprintf(cdeclBuf, ")") cParams := cdeclBuf.String() + // 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(fgcch, `extern %s %s %s __asm__("%s.%s");`, cRet, goName, cParams, gccgoSymbolPrefix, goName) fmt.Fprint(fgcch, "\n") + // Use a #define so that the C code that includes + // cgo_export.h will be able to refer to the Go + // function using the expected name. + fmt.Fprintf(fgcch, "#define %s %s\n", exp.ExpName, goName) + + // Use a #undef in _cgo_export.c so that we ignore the + // #define from cgo_export.h, since here we are + // defining the real function. + fmt.Fprintf(fgcc, "#undef %s\n", exp.ExpName) + fmt.Fprint(fgcc, "\n") fmt.Fprintf(fgcc, "%s %s %s {\n", cRet, exp.ExpName, cParams) fmt.Fprint(fgcc, "\t") @@ -1219,7 +1239,10 @@ 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); const char *_cgoPREFIX_Cfunc_CString(struct __go_string s) { - return strndup((const char*)s.__data, s.__length); + char *p = malloc(s.__length+1); + memmove(p, s.__data, s.__length); + p[s.__length] = 0; + return p; } struct __go_string _cgoPREFIX_Cfunc_GoString(char *p) { |