[cfe-users] Errors when trying to use libcxx/libcxxabi with memory sanitizer

[Evgenii Stepanov via cfe-users]

Yes. Effectively you need two environments - one with
msan-instrumented libraries, and one without. Compilation should
happen in the latter (unless you want to instrument the compiler which
is not very productive), and resulting binaries should be run in the
former.

On Mon, Nov 23, 2015 at 10:50 AM, Schlottke-Lakemper, Michael
<m.schlottke-lakemper at aia.rwth-aachen.de> wrote:
>
>> On 23 Nov 2015, at 18:11 , Evgenii Stepanov <eugeni.stepanov at gmail.com> wrote:
>>
>> On Mon, Nov 23, 2015 at 12:59 AM, Schlottke-Lakemper, Michael via
>> cfe-users <cfe-users at lists.llvm.org> wrote:
>>> Hi folks,
>>>
>>> I'm trying to set up our cluster tool chain to support clang’s memory
>>> sanitizer for our multiphysics simulation program, but I can’t get it to
>>> work :-/
>>>
>>> I started with a regularly compiled clang installation (with libcxx,
>>> libcxxabi, and libomp built in-tree). With this, I compiled all necessary
>>> third-party libraries with “-O1 -fsanitize=memory” (OpenMPI, FFTW, Parallel
>>> netCDF). Then, I compiled the libcxx/libcxxabi libraries with msan-support
>>> by checking out the llvm source and the libcxx/libcxxabi repos into the
>>> llvm/projects/ directory. I configured them with LLVM_USE_SANITIZER=Memory
>>> and put the msan-instrumented libraries in the LD_LIBRARY_PATH.
>>>
>>> Finally, I tried to compile our tool, ZFS, with the memory sanitizer enabled
>>> and linked against the msan-compiled third-party libraries as well as the
>>> msan-instrumented libcxx/libcxxabi libraries (by putting them in the
>>> LD_LIBRARY_PATH). However, here I failed: either at configure time or at
>>> compile time (after doing some LD_LIBRARY_PATH trickery), clang exits with
>>> the following error:
>>>
>>> /pds/opt/llvm-20151121-r253770/bin/clang++: symbol lookup error:
>>> /pds/opt/libcxx-msan-20151121-r253770/lib/libc++abi.so.1: undefined symbol:
>>> __msan_va_arg_overflow_size_tls
>>>
>>> Any suggestions as to what I am doing wrong? Should I put the
>>> msan-instrumented libcxx in the LD_LIBRARY_PATH after compilation only?
>>
>> Yes, probably. In this case your compiler, which is not built with
>> MSan, picked up an instrumented libc++abi.
>> Sometimes it is convenient to set RPATH on all msan
>> libraries/executables and avoid LD_LIBRARY_PATH.
>
> Thanks for your answer. Unfortunately, I cannot avoid LD_LIBRARY_PATH as it includes our cluster-wide LLVM lib dir by default on all our hosts. Thus setting RPATH at compile/link time will have no effect as there is no way to make it overrule LD_LIBRARY_PATH afaik. Instrumenting all of Clang with MSan seems a bit overkill to me (and does not solve the RPATH/LD_LIBRARY_PATH issue at runtime anyways). I guess I’ll just have to live with manually changing the LD_LIBRARY_PATH after compilation then.
>
> Michael