wine's kernel32/time test fails with clang, passes with gcc

[llvmbot]

Bugzilla Link	8083
Resolution	INVALID
Resolved on	Sep 06, 2010 13:55
Version	2.7
OS	Linux
Attachments	source example
Reporter	LLVM Bugzilla Contributor
CC	@asl

Extended Description

From http://bugs.winehq.org/show_bug.cgi?id=24270.

I've narrowed the case down a bit, but it's still in the form of a wine test. Hopefully it'll give you a starting point though. If I can provide any more information, please let me know.

Clang used:
austin@midna:~/wine-clang/dlls/kernel32/tests$ clang --version
clang version 1.1 (branches/release_27)
Target: x86_64-pc-linux-gnu
Thread model: posix

Same test passes with:
austin@midna:~/wine-clang/dlls/kernel32/tests$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ./configure --enable-languages=c,c++
Thread model: posix
gcc version 4.6.0 20100821 (experimental) (GCC)

stripped down testcase attached.

On clang, make time.ok gives:
../../../tools/runtest -q -P wine -M kernel32.dll -T ../../.. -p kernel32_test.exe.so time.c && touch time.ok
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​3. Got 2004-03-02 02:00. Expect hour = 03
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​3. Got 2004-03-02 02:00. Expect hour = 03
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​1. Got 2004-03-02 02:00. Expect hour = 01
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​2. Got 2004-03-02 02:00. Expect hour = 01
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​3. Got 2004-03-02 02:00. Expect hour = 03
time.c:96: Test failed: Test SystemTimeToTzSpecificLocalTime #​3. Got 2004-03-17 02:00. Expect hour = 03
make: *** [time.ok] Error 6

on gcc, passes without error.

[asl]

In the current form the testcase is pretty useless:

1. Please provide a preprocessed source of the test. If possible, try to reduce it.
2. Please provide a way how the test can be executed standalone or with minimal set of tool involved.

Thanks!

[llvmbot]

clang -m32 -E output
Here's the preprocessed file (from -E). I'll work on reducing it down further.

[llvmbot]

Turns out wine was trying to access a member of an array beyond the defined end. Gcc was allowing it, clang wasn't, but it's undefined behavior.

Invalid, sorry for the spam.