[PATCH] UBSan on Windows

[Timur Iskhodzhanov]

2014-10-24 10:26 GMT-07:00 Aaron Ballman <aaron at aaronballman.com>:
> On Fri, Oct 24, 2014 at 1:14 PM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
>> Hi Aaron,
>>
>> See also http://reviews.llvm.org/D5368 – Amine has made some progress
>> on UBSan lately as well, but didn't quite finish it.
>>
>> Can you please send the review via phab?
>
> I prefer to avoid phab; it's never worked as part of my workflow. Is
> it required for compiler-rt patches?

Not required, we just prefer it this way :)

>> Comments:
>> * Your implementation of atomic_exchange doesn't seem to be atomic?
>
> The same is true of all the atomic_exchange functions, no? This one is
> simply a copy of the other two, with the registers corrected for a
> 32-bit value.

Oh that's surprising the other implementations were done this way.
[I didn't see it 'cause there wasn't enough context in the patch]

> We should probably be using the InterlockedExchange functions on
> Windows instead of hand-rolling our own, but I felt that was a
> separate change for another patch.

Sounds reasonable, but please add a FIXME then.
Dmitry, can you please take a look?

>> * lib/ubsan/ubsan_value.h – please update the comment
>
> Can do.
>
>> * Does check-ubsan (?) work?
>
> I cannot get any of the check-*san tests to work within MSVC. There
> are significant CMake issues for this workflow, which I'm hoping to
> address as I have the time. For instance, I get a considerable number
> of link errors because the libraries are placed in:
>
> E:\llvm\2013\Release\lib\clang\3.6.0\lib\windows\Release\
>
> But the linker is given a path to find them at:
>
> E:\llvm\2013\Release\lib\clang\3.6.0\lib\windows\
>
> When I attempt to run check-ubsan, I get:
>
> 59>  Building Custom Rule
> E:/llvm/llvm/projects/compiler-rt/test/ubsan/CMakeLists.txt
> 59>  CMake does not need to re-run because
> E:\llvm\2013\projects\compiler-rt\test\ubsan\CMakeFiles\generate.stamp
> is up-to-date.
> 59>  Running UndefinedBehaviorSanitizer tests
> 59>  lit.py: LitConfig.py:79: warning: Unable to find 'bash'.
> 59>  lit.py: lit.common.cfg:20: fatal: Can't find compiler on path
> 'E:/llvm/2013/$(Configuration)/bin/clang.exe'
> 59>C:\Program Files
> (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.CppCommon.targets(170,5):
> error MSB6006: "cmd.exe" exited with code 2.
>
> I get this same error when attempting to run check-asan after manually
> fixing up the library paths.

Can you try to use ninja-based build for the time being?

>> * Have you tried Win64?
>
> I have not, just x86.

Please try and/or see Amine's patch – he has only enabled UBSan on 32-bit arch.

> Thanks!
>
> ~Aaron