cmake/macros/MacroOpenMP.cmake

0001 # A macro wrapper to find OpenMP library
0002 #
0003 # Syntax:  DETECT_OPENMP()
0004 #
0005 # Once done this will be adjusted:
0006 #
0007 # OPENMP_FOUND     - OpenMP detection flag
0008 # OpenMP_CXX_FLAGS - flags to add to the CXX compiler for OpenMP support
0009 #
0010 # SPDX-FileCopyrightText: 2010-2024 by Gilles Caulier, <caulier dot gilles at gmail dot com>
0011 #
0012 # SPDX-License-Identifier: BSD-3-Clause
0013 #
0014
0015 macro(DETECT_OPENMP)
0016
0017     message(STATUS "Looking for OpenMP")
0018
0019     # NOTE: OpenMP under MacOSX do not support multithreading.
0020
0021     if(NOT APPLE)
0022
0023         find_package(OpenMP)
0024
0025         if(OPENMP_FOUND)
0026
0027             # Adjust some compiler flags depending of Operating system, that standard cmake find script do not set.
0028
0029             set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
0030
0031             if("${OpenMP_CXX_FLAGS}" STREQUAL "-fopenmp")
0032                 set(OPENMP_LDFLAGS "-lgomp")
0033             endif()
0034
0035             if("${OpenMP_CXX_FLAGS}" STREQUAL "-xopenmp")
0036                 set(OPENMP_LDFLAGS "-xopenmp")
0037             endif()
0038
0039             message(STATUS "OpenMP found with CXX flags: ${OpenMP_CXX_FLAGS}")
0040
0041         else()
0042
0043             message(STATUS "OpenMP not found")
0044
0045         endif()
0046
0047     else()
0048
0049         message(STATUS "OpenMP under OSX do not support multithreading.")
0050         message(STATUS "OpenMP detection is disabled.")
0051         set(OPENMP_FOUND FALSE)
0052
0053     endif()
0054
0055 endmacro()