dnl @synopsis AC_CHECK_CC_OPT(flag, cachevarname) dnl dnl @obsoleted Use CFLAGS/CXXFLAGS related macros as soon as possible. dnl dnl AC_CHECK_CC_OPT(-fvomit-frame,vomitframe) would show a message as dnl like "checking wether gcc accepts -fvomit-frame ... no" and sets dnl the shell-variable $vomitframe to either "-fvomit-frame" or (in dnl this case) just a simple "". In many cases you would then call dnl AC_SUBST(_fvomit_frame_,$vomitframe) to create a substitution that dnl could be fed as "CFLAGS = @_funsigned_char_@ @_fvomit_frame_@. dnl dnl In consequence this function is much more general than their dnl specific counterparts like ac_cxx_rtti.m4 that will test for dnl -fno-rtti -fno-exceptions. dnl dnl This macro will be obsolete in the very near future - there should dnl be two macros AX_CFLAGS_OPTION and AX_CXXFLAGS_OPTION that will add dnl directly to the CFLAGS/CXXFLAGS unless a ac_subst-variable was dnl given. Remind me of doing so if I forget about writing it all up - dnl to use $CC-cc directly in here instead of ac_compile macro is bad dnl anyway. dnl dnl @category Obsolete dnl @author Guido U. Draheim dnl @version 2006-10-13 dnl @license GPLWithACException AC_DEFUN([AC_CHECK_CC_OPT], [AC_CACHE_CHECK(whether ${CC-cc} accepts [$1], [$2], [AC_SUBST($2) echo 'void f(){}' > conftest.c if test -z "`${CC-cc} -c $1 conftest.c 2>&1`"; then $2="$1" else $2="" fi rm -f conftest* ])])