diff options
author | Brad Fitzpatrick <bradfitz@golang.org> | 2018-06-12 16:16:38 +0000 |
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committer | Brad Fitzpatrick <bradfitz@golang.org> | 2018-06-12 19:10:34 +0000 |
commit | 39ad208c13368bbd1a129c5e2ed85d6ebc22401a (patch) | |
tree | ba5bfb6b598360693dc7e324632e41513da810e7 /test/strcopy.go | |
parent | 48987baa09856ea6f656abe8a90d264070db8fad (diff) | |
download | go-git-39ad208c13368bbd1a129c5e2ed85d6ebc22401a.tar.gz |
test: add test to verify that string copies don't get optimized away
Fixes #25834
Change-Id: I33e58dabfd04b84dfee1a9a3796796b5d19862e7
Reviewed-on: https://go-review.googlesource.com/118295
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'test/strcopy.go')
-rw-r--r-- | test/strcopy.go | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/test/strcopy.go b/test/strcopy.go new file mode 100644 index 0000000000..6d32baeec5 --- /dev/null +++ b/test/strcopy.go @@ -0,0 +1,29 @@ +// run + +// Copyright 2018 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 string([]byte(string)) makes a copy and doesn't reduce to +// nothing. (Issue 25834) + +package main + +import ( + "reflect" + "unsafe" +) + +func main() { + var ( + buf = make([]byte, 2<<10) + large = string(buf) + sub = large[10:12] + subcopy = string([]byte(sub)) + subh = *(*reflect.StringHeader)(unsafe.Pointer(&sub)) + subcopyh = *(*reflect.StringHeader)(unsafe.Pointer(&subcopy)) + ) + if subh.Data == subcopyh.Data { + panic("sub and subcopy have the same underlying array") + } +} |