Distributing program with OpenMP

Runtimes OpenMP
1

I'd like to distribute my program that uses OpenMP built with CLang
5.0. I use CLang/LLVM as provided by MacPorts.

I need to distribute my program to users who won't have MacPorts or a
compiler installed.

Unsurprisingly, output of otool shows that my program needs libomp.dylib:

otool -L myprogram
myprogram:
/opt/local/lib/libomp/libomp.dylib (compatibility version 5.0.0,
current version 5.0.0)
/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.1.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
version 1226.10.1)

Previously, I had compiled my program using gcc and was able to link
OpenMP statically

otool -L myprogram
myprogram:
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
version 159.1.0)

By doing something like this:

if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
  set(CMAKE_EXE_LINKER_FLAGS "-static-libgcc -static-libstdc++")
endif()

Is there a way to do this with CLang?

If not, what is the preferred way to bundle the required OpenMP library?

I build from a CMake environment, so on Windows, I already do this:
INCLUDE( InstallRequiredSystemLibraries )
to grab all the required OpenMP libraries and whatnot.

My program is distributed as a dumb *.zip file -- nothing that gets
installed to the system. Will this still work in this paradigm, or
will I need to get permission and install this library?

Rob

2

Hi Bob,

static linking of the OpenMP runtime is in general discouraged because it produces all sort of nasty problems if there is still any shared library that also uses OpenMP. I think this is also why no static library is built by default but you can build only the OpenMP runtime yourself and enable an option for that (-DLIBOMP_ENABLE_SHARED=OFF). Then you might try passing -static to clang or some similar options.
Another possibility would be to bundle the shared library and set an rpath for the current (relative) directory. I think this might be possible but I can't verify at the moment.

Let us know if any of this worked,
Jonas