-dnl Check if the flag is supported by compiler
-dnl CC_CHECK_CFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
-
-AC_DEFUN([CC_CHECK_CFLAGS_SILENT], [
- AC_CACHE_VAL(AS_TR_SH([cc_cv_cflags_$1]),
- [ac_save_CFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS $1"
- AC_COMPILE_IFELSE([AC_LANG_SOURCE([int a;])],
- [eval "AS_TR_SH([cc_cv_cflags_$1])='yes'"],
- [eval "AS_TR_SH([cc_cv_cflags_$1])='no'"])
- CFLAGS="$ac_save_CFLAGS"
- ])
-
- AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
- [$2], [$3])
-])
-
-dnl Check if the flag is supported by compiler (cacheable)
-dnl CC_CHECK_CFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
-
-AC_DEFUN([CC_CHECK_CFLAGS], [
- AC_CACHE_CHECK([if $CC supports $1 flag],
- AS_TR_SH([cc_cv_cflags_$1]),
- CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
- )
-
- AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
- [$2], [$3])
-])
-
-dnl CC_CHECK_CFLAG_APPEND(FLAG, [action-if-found], [action-if-not-found])
-dnl Check for CFLAG and appends them to CFLAGS if supported
-AC_DEFUN([CC_CHECK_CFLAG_APPEND], [
- AC_CACHE_CHECK([if $CC supports $1 flag],
- AS_TR_SH([cc_cv_cflags_$1]),
- CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
- )
-
- AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
- [CFLAGS="$CFLAGS $1"; DEBUG_CFLAGS="$DEBUG_CFLAGS $1"; $2], [$3])
+dnl Check if FLAG in ENV-VAR is supported by compiler and append it
+dnl to WHERE-TO-APPEND variable
+dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG])
+
+AC_DEFUN([CC_CHECK_FLAG_APPEND], [
+ AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2],
+ AS_TR_SH([cc_cv_$2_$3]),
+ [eval "AS_TR_SH([cc_save_$2])='${$2}'"
+ eval "AS_TR_SH([$2])='-Werror $3'"
+ AC_COMPILE_IFELSE([AC_LANG_SOURCE([int a = 0; int main(void) { return a; } ])],
+ [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"],
+ [eval "AS_TR_SH([cc_cv_$2_$3])='no'"])
+ eval "AS_TR_SH([$2])='$cc_save_$2'"])
+
+ AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes],
+ [eval "$1='${$1} $3'"])