OpenMP is not correctly included in the CMake file and causes compile errors

[schulz0r]

Dear developer team,
I am using Apple Clang to compile ColPack. The compiler throws errors because of missing omp headers. This is because the CMakeLists.txt does not include OpenMP in a correct way. Here is an instruction manual on how to include OpenMP to your projects:

target_link_libraries(ColPack_static PUBLIC OpenMP::OpenMP_CXX)
...
target_link_libraries(ColPack_shared PUBLIC OpenMP::OpenMP_CXX)

It is not enough to add a compiler flag indicating that OMP is being used. It consists of headers, binaries etc., so you have to link ColPack against the whole target OpenMP::OpenMP_CXX. CMake does the rest for you, including adding the needed compiler flags. I think you can savely delete the lines where you set with the set_target_properties() call.

Regards
Schulz0r