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author | Ian Lance Taylor <iant@golang.org> | 2012-03-22 09:44:31 -0700 |
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committer | Ian Lance Taylor <iant@golang.org> | 2012-03-22 09:44:31 -0700 |
commit | 47b6197a011f201b6975407c36978dac0b1f87d7 (patch) | |
tree | c82070a6c466eb6c223e050e43672c6eda8102ba | |
parent | 08959defa89f3a37775f744a52bfbbff93e742d6 (diff) | |
download | go-47b6197a011f201b6975407c36978dac0b1f87d7.tar.gz go-47b6197a011f201b6975407c36978dac0b1f87d7.zip |
cmd/gc: when expanding append inline, preserve arguments
Fixes #3369.
R=golang-dev, gri, lvd, r
CC=golang-dev
https://golang.org/cl/5876044
-rw-r--r-- | src/cmd/gc/walk.c | 6 | ||||
-rw-r--r-- | test/fixedbugs/bug428.go | 19 |
2 files changed, 25 insertions, 0 deletions
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c index 5c8282b52e..ff6f1d28bd 100644 --- a/src/cmd/gc/walk.c +++ b/src/cmd/gc/walk.c @@ -2358,6 +2358,12 @@ append(Node *n, NodeList **init) walkexprlistsafe(n->list, init); + // walkexprlistsafe will leave OINDEX (s[n]) along if both s + // and n are name or literal, but those may index the slice we're + // modifying here. Fix explicitly. + for(l = n->list; l; l=l->next) + l->n = cheapexpr(l->n, init); + nsrc = n->list->n; argc = count(n->list) - 1; if (argc < 1) { diff --git a/test/fixedbugs/bug428.go b/test/fixedbugs/bug428.go new file mode 100644 index 0000000000..298c455183 --- /dev/null +++ b/test/fixedbugs/bug428.go @@ -0,0 +1,19 @@ +// run + +// Copyright 2012 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. + +// Test that when the compiler expands append inline it does not +// overwrite a value before it needs it (issue 3369). + +package main + +func main() { + s := make([]byte, 5, 6) + copy(s, "12346") + s = append(s[:len(s)-1], '5', s[len(s)-1]) + if string(s) != "123456" { + panic(s) + } +} |