[Openmp-dev] Can OMPT component be statically linked to an application

[Jonas Hahnfeld via Openmp-dev]

On 2018-10-01 09:37, Itaru Kitayama via Openmp-dev wrote:
> Hi,
> 
> I'm trying to link my app statically with the upstream LLVM/Clang, but
> I get this at the last stage:
> 
> [100%] Linking CXX executable nest
> /usr/lib/gcc/aarch64-redhat-linux/4.8.5/../../../../lib64/libpthread.a(libpthread.o):
> In function `sem_open':
> (.text+0x7810): warning: the use of `mktemp' is dangerous, better use
> `mkstemp'
> /home/itaru/opt/llvm+clang-upstream/bin/../lib/libomp.a(ompt-general.cpp.o):
> In function `ompt_start_tool':
> /home/itaru/projects/llvm/projects/openmp/runtime/src/ompt-general.cpp:144:
> undefined reference to `dlsym'
> /home/itaru/opt/llvm+clang-upstream/bin/../lib/libomp.a(ompt-general.cpp.o):
> In function `ompt_try_start_tool(unsigned int, char const*)':
> ompt-general.cpp:(.text+0xf00): undefined reference to `dlopen'
> ompt-general.cpp:(.text+0xf20): undefined reference to `dlsym'

These symbols are in libdl.so which you probably need to add manually 
when linking statically.

> clang-8: error: linker command failed with exit code 1 (use -v to see
> invocation)
> make[3]: *** [nest/CMakeFiles/nest.dir/build.make:135: nest/nest]
> Error 1
> make[2]: *** [CMakeFiles/Makefile2:735: nest/CMakeFiles/nest.dir/all]
> Error 2
> make[1]: *** [CMakeFiles/Makefile2:747: nest/CMakeFiles/nest.dir/rule]
> Error 2
> make: *** [Makefile:364: nest] Error 2
> 
> I'm building a tool placing openmp and clang under projects and tools
> respectively under the top llvm directory. Any way to disable the OMPT
> completely as currently it is underdevelopment and have no interest in
> using it at the moment.

When building the OpenMP runtime you can add -DLIBOMP_OMPT_SUPPORT=OFF 
to CMake. This should disable support for OMPT and hence the references 
to dl* should go away.

Cheers,
Jonas