From cdefbd6aebc43c89aa1eafacd2edc10b605dfee7 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Fri, 14 Sep 2012 14:18:41 +0000 Subject: [PATCH] build-sys: Append -Werror when testing flags Clang don't treat unknown warnings flags as an error, but rather as a warning. The result is that the detection for whic CFLAGS are supported by this compiler will not work, since the compilation will succeed. With this patch we now successfully detect clang doesn't support -Wlogical-op, as opposed to previous behavior: checking if clang supports flag -Wlogical-op in envvar CFLAGS... no We use this macro only for LDFLAGS and CFLAGS, so it's safe to stash -Werror there. --- m4/attributes.m4 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/m4/attributes.m4 b/m4/attributes.m4 index e354375e3..f0bcf2421 100644 --- a/m4/attributes.m4 +++ b/m4/attributes.m4 @@ -41,7 +41,7 @@ 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])='$3'" + 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'"]) -- 2.30.2