cmakeopenmp

CMake cannot find OpenMP

I am trying to compile with OpenMP. My CMakeLists.txt contains the line

find_package(OpenMP REQUIRED)

and CMake errors out with

CMake Error at /opt/ros/groovy/share/catkin/cmake/catkinConfig.cmake:72 (find_package):
  Could not find a configuration file for package openmp.

  Set openmp_DIR to the directory containing a CMake configuration file for
  openmp.  The file will have one of the following names:

    openmpConfig.cmake
    openmp-config.cmake

Checking my filesystem, I see that I have /usr/share/cmake-2.8/Modules/FindOpenMP.cmake but no openmpConfig.cmake or openmp-config.cmake. What do I need to do to fix this?

Solution

  • OpenMp is not a package, if it's supported, it comes as a part of the your compiler. Try setting CMAKE_C_FLAGS or CMAKE_CXX_FLAGS accordingly. e.g:

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fopenmp") activates OpenMP for compiling C sources when gcc is used. For other compilers, you should first detect the compiler and then add appropriate flags