1# - Adds a compiler flag if it is supported by the compiler
2#
3# This function checks that the supplied compiler flag is supported and then
4# adds it to the corresponding compiler flags
5#
6#  add_c_compiler_flag(<FLAG> [<VARIANT>])
7#
8# - Example
9#
10# include(AddCCompilerFlag)
11# add_c_compiler_flag(-Wall)
12# add_c_compiler_flag(-no-strict-aliasing RELEASE)
13# Requires CMake 2.6+
14
15if(__add_c_compiler_flag)
16  return()
17endif()
18set(__add_c_compiler_flag INCLUDED)
19
20include(CheckCCompilerFlag)
21
22function(add_c_compiler_flag FLAG)
23  string(TOUPPER "HAVE_C_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 ${SANITIZED_FLAG})
27  set(CMAKE_REQUIRED_FLAGS "${FLAG}")
28  check_c_compiler_flag("" ${SANITIZED_FLAG})
29  if(${SANITIZED_FLAG})
30    set(VARIANT ${ARGV1})
31    if(ARGV1)
32      string(REGEX REPLACE "[^A-Za-z_0-9]" "_" VARIANT "${VARIANT}")
33      string(TOUPPER "_${VARIANT}" VARIANT)
34    endif()
35    set(CMAKE_C_FLAGS${VARIANT} "${CMAKE_C_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)
36  endif()
37endfunction()
38
39