Here's a minimum code of OpenMP with CMake. The code outputs "OpenMP: ON" if OpenMP is available and "OpenMP: OFF" otherwise.
CMakeLists.txt:
[code lang="cmake"] cmake_minimum_required(VERSION 2.8)
set(PROJ_NAME OpenMPtest) PROJECT(${PROJ_NAME})
Prevent compilation in-source
if( ${CMAKE_BINARY_DIR} STREQUAL ${PROJECT_SOURCE_DIR} ) Message( FATAL_ERROR "In-source build is not allowed. Create a build directory and run cmake in the directory.") endif()
enable C++11
include(CheckCXXCompilerFlag) CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11) CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X) if(COMPILER_SUPPORTS_CXX11) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11") elseif(COMPILER_SUPPORTS_CXX0X) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x") else() message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.") endif()
#
External libraries
#
OpenMP
find_package( OpenMP REQUIRED ) if (OPENMP_FOUND) message(STATUS "build with OpenMP") set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}" ) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}" ) set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_EXE_LINKER_FLAGS}") IF (UNIX) # pthreads is neaded for Linux to enable mutex to compile. FIND_PACKAGE(Threads REQUIRED) ENDIF (UNIX) endif()
#
Main
#
add_executable(${PROJ_NAME} main.cpp ) [/code]
main.cpp:
[code lang="cpp"]
ifdef _OPENMP
#include <omp.h>
endif
include <iostream>
int main() { std::cout << "OpenMP: " << std::flush; #ifdef _OPENMP std::cout << "ON" << std::endl; #else std::cout << "OFF" << std::endl; #endif return 0; }
[/code]
