[llvm-dev] Building/Running LLVM Tests with Sanitizers

Fri Aug 31 11:30:47 PDT 2018

This would be nice.
So, to be clear, there would be libc++.so / libc++.a somewhere under
lib/clang/.../$triple/msan, and the driver would link that if libc++
is not specified explicitly on the command line? Would it also add
-rpath? This could be weird because toolchain may not be present when
the binary is run.

On Fri, Aug 31, 2018 at 11:14 AM, Vitaly Buka <vitalybuka at google.com> wrote:
> +Evgenii Stepanov
> sgtm
>
> On Fri, Aug 31, 2018 at 6:49 AM Brian Cain <brian.cain at gmail.com> wrote:
>>
>> Aside: would it be useful to execute a build of the libc++/libc++abi with
>> msan normally during release, and change the driver to look for these
>> msan-built C++ libs when "-fsanitize=memory"?  That would drastically cut
>> down on the complexity of using msan.
>>
>> On Fri, Aug 31, 2018 at 5:43 AM Dean Michael Berris via llvm-dev
>> <llvm-dev at lists.llvm.org> wrote:
>>>
>>> Thanks Vitaly and Peter,
>>>
>>> I went with a modified version of the instructions from
>>> https://github.com/google/sanitizers/wiki/MemorySanitizerBootstrappingClang
>>> — that’s a very helpful set of instructions!
>>>
>>> Cheers
>>>
>>> > On 31 Aug 2018, at 02:55, Vitaly Buka <vitalybuka at google.com> wrote:
>>> >
>>> > Another option is just to run corresponding script from
>>> > https://llvm.org/svn/llvm-project/zorg/trunk/zorg/buildbot/builders/sanitizers/
>>> > in empty directory.
>>> >
>>> > On Thu, Aug 30, 2018 at 5:00 AM Peter Smith via llvm-dev
>>> > <llvm-dev at lists.llvm.org> wrote:
>>> > Hello Dean,
>>> >
>>> > I've not done this myself for a while, I seem to remember it taking a
>>> > while to get right. When I did I found the page:
>>> >
>>> > https://github.com/google/sanitizers/wiki/MemorySanitizerBootstrappingClang
>>> > useful. The other thing that might work is following the individual
>>> > cmake steps from
>>> > http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-msan
>>> > . These aren't in the same structure as the monorepo but they may be
>>> > adaptable.
>>> >
>>> > My apologies if you've tried these already.
>>> >
>>> > Peter
>>> >
>>> > On 30 August 2018 at 12:42, Dean Michael Berris via llvm-dev
>>> > <llvm-dev at lists.llvm.org> wrote:
>>> > > Hi llvm-dev,
>>> > >
>>> > > I'm trying to reproduce an msan failure in one of the bots, but I
>>> > > can't seem to get the right incantation of building LLVM with msan.
>>> > > Here's what I've been doing:
>>> > >
>>> > > 1) Build the toolchain in one build directory, including
>>> > > `compiler-rt`.
>>> > >
>>> > > 2) Build the toolchain again with the just built toolchain in step 1,
>>> > > but this time with `-DLLVM_USE_SANITIZER=MemoryWithOrigins`.
>>> > >
>>> > > I get some msan errors, but of this kind instead of the one I'm
>>> > > expecting:
>>> > >
>>> > > ====
>>> > > $ ./unittests/XRay/XRayTests
>>> > > ==236769==WARNING: MemorySanitizer: use-of-uninitialized-value
>>> > >     #0 0x70eef8
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x70eef8)
>>> > >     #1 0x70d2dc
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x70d2dc)
>>> > >     #2 0x721044
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x721044)
>>> > >     #3 0x6e2a37
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x6e2a37)
>>> > >     #4 0x3722aa
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x3722aa)
>>> > >     #5 0x372868
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x372868)
>>> > >     #6 0x775a4c
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x775a4c)
>>> > >     #7 0x7f85b6c7e23f  (/lib/x86_64-linux-gnu/libc.so.6+0x2023f)
>>> > >     #8 0x2f4029
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x2f4029)
>>> > >
>>> > >   Uninitialized value was created by an allocation of 'ref.tmp' in
>>> > > the
>>> > > stack frame of function
>>> > >
>>> > > '_ZN7testing8internal12UnitTestImpl11AddTestInfoEPFvvES3_PNS_8TestInfoE'
>>> > >     #0 0x720f10
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x720f10)
>>> > >
>>> > > SUMMARY: MemorySanitizer: use-of-uninitialized-value
>>> > >
>>> > > (/usr/local/google/home/dberris/xray/llvm-project-build-msan/unittests/XRay/XRayTests+0x70eef8)
>>> > > Exiting
>>> > >
>>> > > ====
>>> > >
>>> > > Is there something else I'm missing here? I'm doing this on Linux. I
>>> > > tried building with libc++ from the first toolchain, but somehow the
>>> > > linker from the same toolchain in step 1 couldn't find the libc++
>>> > > with
>>> > > msan instrumentation.
>>> > >
>>> > > Here's the CMake command I'm using:
>>> > >
>>> > > ====
>>> > > cmake -GNinja
>>> > > -DCMAKE_C_COMPILER=$HOME/xray/llvm-project-build/bin/clang
>>> > > -DCMAKE_CXX_COMPILER=$HOME/xray/llvm-project-build/bin/clang++
>>> > > -DCMAKE_BUILD_TYPE=Debug -DLLVM_OPTIMIZED_TABLEGEN=On
>>> > > -DLLVM_ENABLE_ASSERTIONS=On -DLLVM_USE_SANITIZER=MemoryWithOrigins
>>> > > -DLLVM_ENABLE_LLD=On -DLLVM_INCLUDE_TESTS=On
>>> > > -DCMAKE_CXX_FLAGS=-stdlib=libc++ -DCMAKE_LINK_FLAGS=-stdlib=libc++
>>> > > ../llvm-project/llvm
>>> > > ====
>>> > >
>>> > > And I'm running the tests like so:
>>> > >
>>> > > ====
>>> > > ninja check-llvm
>>> > > ====
>>> > >
>>> > > I'm doing this with the monorepo, if that's relevant.
>>> > >
>>> > > Help?
>>> > >
>>> > > --
>>> > > Dean
>>> > > _______________________________________________
>>> > > LLVM Developers mailing list
>>> > > llvm-dev at lists.llvm.org
>>> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>> > _______________________________________________
>>> > LLVM Developers mailing list
>>> > llvm-dev at lists.llvm.org
>>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>> -- Dean
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>>
>> --
>> -Brian