# - Adds a compiler flag if it is supported by the compiler # # This function checks that the supplied compiler flag is supported and then # adds it to the corresponding compiler flags # # add_cxx_compiler_flag(<FLAG> [<VARIANT>]) # # - Example # # include(AddCXXCompilerFlag) # add_cxx_compiler_flag(-Wall) # add_cxx_compiler_flag(-no-strict-aliasing RELEASE) # Requires CMake 2.6+ if(__add_cxx_compiler_flag) return() endif() set(__add_cxx_compiler_flag INCLUDED) include(CheckCXXCompilerFlag) function(mangle_compiler_flag FLAG OUTPUT) string(TOUPPER "HAVE_CXX_FLAG_${FLAG}" SANITIZED_FLAG) string(REPLACE "+" "X" SANITIZED_FLAG ${SANITIZED_FLAG}) string(REGEX REPLACE "[^A-Za-z_0-9]" "_" SANITIZED_FLAG ${SANITIZED_FLAG}) string(REGEX REPLACE "_+" "_" SANITIZED_FLAG ${SANITIZED_FLAG}) set(${OUTPUT} "${SANITIZED_FLAG}" PARENT_SCOPE) endfunction(mangle_compiler_flag) function(add_cxx_compiler_flag FLAG) mangle_compiler_flag("${FLAG}" MANGLED_FLAG) set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}") set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}") check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG}) set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}") if(${MANGLED_FLAG}) set(VARIANT ${ARGV1}) if(ARGV1) string(TOUPPER "_${VARIANT}" VARIANT) endif() set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${BENCHMARK_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE) endif() endfunction() function(add_required_cxx_compiler_flag FLAG) mangle_compiler_flag("${FLAG}" MANGLED_FLAG) set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}") set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}") check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG}) set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}") if(${MANGLED_FLAG}) set(VARIANT ${ARGV1}) if(ARGV1) string(TOUPPER "_${VARIANT}" VARIANT) endif() set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE) set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE) set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE) set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE) set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}" PARENT_SCOPE) else() message(FATAL_ERROR "Required flag '${FLAG}' is not supported by the compiler") endif() endfunction()