diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c index 34ac32436b7..5768285b84b 100644 --- a/src/cmd/gc/walk.c +++ b/src/cmd/gc/walk.c @@ -2312,7 +2312,7 @@ reorder4(NodeList *ll) * copies of escaped parameters to the heap. */ NodeList* -paramstoheap(Type **argin) +paramstoheap(Type **argin, int out) { Type *t; Iter savet; @@ -2322,6 +2322,12 @@ paramstoheap(Type **argin) nn = nil; for(t = structfirst(&savet, argin); t != T; t = structnext(&savet)) { v = t->nname; + if(v == N && out && hasdefer) { + // Defer might stop a panic and show the + // return values as they exist at the time of panic. + // Make sure to zero them on entry to the function. + nn = list(nn, nod(OAS, nodarg(t, 1), N)); + } if(v == N || !(v->class & PHEAP)) continue; @@ -2366,9 +2372,9 @@ heapmoves(void) { NodeList *nn; - nn = paramstoheap(getthis(curfn->type)); - nn = concat(nn, paramstoheap(getinarg(curfn->type))); - nn = concat(nn, paramstoheap(getoutarg(curfn->type))); + nn = paramstoheap(getthis(curfn->type), 0); + nn = concat(nn, paramstoheap(getinarg(curfn->type), 0)); + nn = concat(nn, paramstoheap(getoutarg(curfn->type), 1)); curfn->enter = concat(curfn->enter, nn); curfn->exit = returnsfromheap(getoutarg(curfn->type)); } diff --git a/test/fixedbugs/bug266.go b/test/fixedbugs/bug266.go new file mode 100644 index 00000000000..25c246f7df8 --- /dev/null +++ b/test/fixedbugs/bug266.go @@ -0,0 +1,26 @@ +// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG: bug266 + +// Copyright 2010 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 + +func f() int { + defer func() { + recover() + }() + panic("oops") +} + +func g() int { + return 12345 +} + +func main() { + g() // leave 12345 on stack + x := f() + if x != 0 { + panic(x) + } +}