dnl From stackoverflow, with some changes dnl @synopsis CXX_FLAGS_CHECK [compiler flags] dnl @summary check whether compiler supports given C++ flags or not AC_DEFUN([CXX_FLAG_CHECK], [dnl AC_MSG_CHECKING([if $CXX supports $1]) AC_LANG_PUSH([C++]) ac_saved_cxxflags="$CXXFLAGS" CXXFLAGS="-Werror $1" AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], [cxx_flag_check=yes], [cxx_flag_check=no] ) AC_MSG_RESULT([$cxx_flag_check]) CXXFLAGS="$ac_saved_cxxflags" if test "$cxx_flag_check" = yes then CXX_COMPILER_FLAGS="$1 $CXX_COMPILER_FLAGS " fi AC_LANG_POP([C++]) ]) AC_DEFUN([C_FLAG_CHECK], [dnl AC_MSG_CHECKING([if $CC supports $1]) AC_LANG_PUSH([C]) ac_saved_ccflags="$CFLAGS" CFLAGS="-Werror $1" AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], [cc_flag_check=yes], [cc_flag_check=no] ) AC_MSG_RESULT([$cc_flag_check]) CFLAGS="$ac_saved_ccflags" if test "$cc_flag_check" = yes then C_COMPILER_FLAGS="$1 $C_COMPILER_FLAGS " fi AC_LANG_POP([C]) ])