79 lines · plain
1# - Adds a compiler flag if it is supported by the compiler2#3# This function checks that the supplied compiler flag is supported and then4# adds it to the corresponding compiler flags5#6# add_cxx_compiler_flag(<FLAG> [<VARIANT>])7#8# - Example9#10# include(AddCXXCompilerFlag)11# add_cxx_compiler_flag(-Wall)12# add_cxx_compiler_flag(-no-strict-aliasing RELEASE)13# Requires CMake 2.6+14 15if(__add_cxx_compiler_flag)16 return()17endif()18set(__add_cxx_compiler_flag INCLUDED)19 20include(CheckCXXCompilerFlag)21 22function(mangle_compiler_flag FLAG OUTPUT)23 string(TOUPPER "HAVE_CXX_FLAG_${FLAG}" SANITIZED_FLAG)24 string(REPLACE "+" "X" SANITIZED_FLAG ${SANITIZED_FLAG})25 string(REGEX REPLACE "[^A-Za-z_0-9]" "_" SANITIZED_FLAG ${SANITIZED_FLAG})26 string(REGEX REPLACE "_+" "_" SANITIZED_FLAG ${SANITIZED_FLAG})27 set(${OUTPUT} "${SANITIZED_FLAG}" PARENT_SCOPE)28endfunction(mangle_compiler_flag)29 30function(add_cxx_compiler_flag FLAG)31 mangle_compiler_flag("${FLAG}" MANGLED_FLAG)32 set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")33 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")34 check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})35 set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")36 if(${MANGLED_FLAG})37 if(ARGC GREATER 1)38 set(VARIANT ${ARGV1})39 string(TOUPPER "_${VARIANT}" VARIANT)40 else()41 set(VARIANT "")42 endif()43 set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${BENCHMARK_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)44 endif()45endfunction()46 47function(add_required_cxx_compiler_flag FLAG)48 mangle_compiler_flag("${FLAG}" MANGLED_FLAG)49 set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")50 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")51 check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})52 set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")53 if(${MANGLED_FLAG})54 if(ARGC GREATER 1)55 set(VARIANT ${ARGV1})56 string(TOUPPER "_${VARIANT}" VARIANT)57 else()58 set(VARIANT "")59 endif()60 set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)61 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)62 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)63 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)64 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}" PARENT_SCOPE)65 else()66 message(FATAL_ERROR "Required flag '${FLAG}' is not supported by the compiler")67 endif()68endfunction()69 70function(check_cxx_warning_flag FLAG)71 mangle_compiler_flag("${FLAG}" MANGLED_FLAG)72 set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")73 # Add -Werror to ensure the compiler generates an error if the warning flag74 # doesn't exist.75 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror ${FLAG}")76 check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})77 set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")78endfunction()79