diff options
Diffstat (limited to 'src/cmd/cgo/out.go')
| -rw-r--r-- | src/cmd/cgo/out.go | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go index 6586531ada..d92bed9bf0 100644 --- a/src/cmd/cgo/out.go +++ b/src/cmd/cgo/out.go @@ -44,6 +44,7 @@ func (p *Package) writeDefs() { fmt.Fprintf(fm, "int main() { return 0; }\n") if *importRuntimeCgo { fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*, int), void *a, int c) { }\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 crosscall2. We just need a prototype. @@ -129,6 +130,7 @@ func (p *Package) writeDefs() { fmt.Fprintf(fc, `extern void *%s __asm__("%s.%s");`, n.Mangle, gccgoSymbolPrefix, n.Mangle) fmt.Fprintf(&gccgoInit, "\t%s = %s%s;\n", n.Mangle, amp, n.C) } else { + fmt.Fprintf(fc, "#pragma dataflag NOPTR /* C pointer, not heap pointer */ \n") fmt.Fprintf(fc, "void *·%s = %s%s;\n", n.Mangle, amp, n.C) } fmt.Fprintf(fc, "\n") @@ -397,6 +399,7 @@ func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) { // C wrapper calls into gcc, passing a pointer to the argument frame. fmt.Fprintf(fc, "#pragma cgo_import_static %s\n", cname) fmt.Fprintf(fc, "void %s(void*);\n", cname) + fmt.Fprintf(fc, "#pragma dataflag NOPTR\n") fmt.Fprintf(fc, "void *·%s = %s;\n", cname, cname) nret := 0 @@ -517,9 +520,13 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) { // Use packed attribute to force no padding in this struct in case // gcc has different packing requirements. fmt.Fprintf(fgcc, "\t%s %v *a = v;\n", ctype, p.packedAttribute()) + if n.FuncType.Result != nil { + // Save the stack top for use below. + fmt.Fprintf(fgcc, "\tchar *stktop = _cgo_topofstack();\n") + } fmt.Fprintf(fgcc, "\t") if t := n.FuncType.Result; t != nil { - fmt.Fprintf(fgcc, "a->r = ") + fmt.Fprintf(fgcc, "__typeof__(a->r) r = ") if c := t.C.String(); c[len(c)-1] == '*' { fmt.Fprint(fgcc, "(__typeof__(a->r)) ") } @@ -542,6 +549,13 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) { fmt.Fprintf(fgcc, "a->p%d", i) } fmt.Fprintf(fgcc, ");\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, "\ta = (void*)((char*)a + (_cgo_topofstack() - stktop));\n") + // Save the return value. + fmt.Fprintf(fgcc, "\ta->r = r;\n") + } if n.AddError { fmt.Fprintf(fgcc, "\treturn errno;\n") } @@ -1129,6 +1143,8 @@ __cgo_size_assert(__cgo_long_long, 8) __cgo_size_assert(float, 4) __cgo_size_assert(double, 8) +extern char* _cgo_topofstack(void); + #include <errno.h> #include <string.h> ` @@ -1151,20 +1167,31 @@ void *_CMalloc(size_t); const cProlog = ` #include "runtime.h" #include "cgocall.h" +#include "textflag.h" +#pragma dataflag NOPTR static void *cgocall_errno = runtime·cgocall_errno; +#pragma dataflag NOPTR void *·_cgo_runtime_cgocall_errno = &cgocall_errno; +#pragma dataflag NOPTR static void *runtime_gostring = runtime·gostring; +#pragma dataflag NOPTR void *·_cgo_runtime_gostring = &runtime_gostring; +#pragma dataflag NOPTR static void *runtime_gostringn = runtime·gostringn; +#pragma dataflag NOPTR void *·_cgo_runtime_gostringn = &runtime_gostringn; +#pragma dataflag NOPTR static void *runtime_gobytes = runtime·gobytes; +#pragma dataflag NOPTR void *·_cgo_runtime_gobytes = &runtime_gobytes; +#pragma dataflag NOPTR static void *runtime_cmalloc = runtime·cmalloc; +#pragma dataflag NOPTR void *·_cgo_runtime_cmalloc = &runtime_cmalloc; void ·_Cerrno(void*, int32); |