CMake/Modules/CheckCCompilerFlag.cmake
Brad King ed6be501de Fix CHECK_(C|CXX)_COMPILER_FLAG for Clang (#12394)
This compiler warns and returns 0 for unrecognized flags.  We fix the
compiler flag check macros by looking for a warning in the output.
2011-08-08 12:53:17 -04:00

42 lines
2.0 KiB
CMake

# - Check whether the C compiler supports a given flag.
# CHECK_C_COMPILER_FLAG(<flag> <var>)
# <flag> - the compiler flag
# <var> - variable to store the result
# This internally calls the check_c_source_compiles macro.
# See help for CheckCSourceCompiles for a listing of variables
# that can modify the build.
#=============================================================================
# Copyright 2006-2010 Kitware, Inc.
# Copyright 2006 Alexander Neundorf <neundorf@kde.org>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
INCLUDE(CheckCSourceCompiles)
MACRO (CHECK_C_COMPILER_FLAG _FLAG _RESULT)
SET(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
SET(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
CHECK_C_SOURCE_COMPILES("int main(void) { return 0; }" ${_RESULT}
# Some compilers do not fail with a bad flag
FAIL_REGEX "warning: command line option .* is valid for .* but not for C"
# Apple gcc
FAIL_REGEX "unrecognized .*option" # GNU
FAIL_REGEX "unknown .*option" # Clang
FAIL_REGEX "ignoring unknown option" # MSVC
FAIL_REGEX "warning D9002" # MSVC, any lang
FAIL_REGEX "[Uu]nknown option" # HP
FAIL_REGEX "[Ww]arning: [Oo]ption" # SunPro
FAIL_REGEX "command option .* is not recognized" # XL
)
SET (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
ENDMACRO (CHECK_C_COMPILER_FLAG)