+dnl which flags does the compile support?
+if test "$GCC" = "yes"; then
+ for flag in -fno-strict-aliasing -Wall -std=gnu99 -pedantic -Wshadow -Wpointer-arith -Wcast-align -Wmissing-prototypes -Wmissing-declarations -Wnested-externs -Winline -W; do
+ oCFLAGS=$CFLAGS
+ CFLAGS="$CFLAGS $flag"
+ cachename=rd_cv_gcc_flag_`echo $flag|sed 's/[[^A-Za-z]]/_/g'`
+ AC_CACHE_CHECK([if gcc likes the $flag flag], $cachename,
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[return 0 ]])],[eval $cachename=yes],[eval $cachename=no])])
+ if eval test \$$cachename = no; then
+ CFLAGS=$oCFLAGS
+ fi
+ done
+fi
+
+