From 29283921b72fa9386322fc9eb301d00e88b634b6 Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Wed, 24 Oct 2018 18:53:11 +0100 Subject: m4: add Werror when checking for compiler flags Seemingly that at some point clang started accepting _any_ flags, whereas previously it would error out. These days, you can give it -Whamsandwich and it will succeed, while at the same time throwing an annoying warning. Add -Werror so that everything gets flagged and set accordingly. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108082 Cc: Vinson Lee Repored-by: Vinson Lee Signed-off-by: Emil Velikov Reviewed-by: Dylan Baker Reviewed-by: Eric Engestrom --- m4/ax_check_compile_flag.m4 | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'm4/ax_check_compile_flag.m4') diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4 index 51df0c09a7a..0fdca907e8b 100644 --- a/m4/ax_check_compile_flag.m4 +++ b/m4/ax_check_compile_flag.m4 @@ -55,6 +55,11 @@ # modified version of the Autoconf Macro, you may extend this special # exception to the GPL to apply to your modified version as well. +# Emil: +# Toggle Werror since at some point clang started treating unknown -W +# flags as warnings, succeeding with the build, yet issuing an annoying +# warning. + #serial 3 AC_DEFUN([AX_CHECK_COMPILE_FLAG], @@ -62,7 +67,7 @@ AC_DEFUN([AX_CHECK_COMPILE_FLAG], AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS - _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" + _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1 -Werror" AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], [AS_VAR_SET(CACHEVAR,[yes])], [AS_VAR_SET(CACHEVAR,[no])]) -- cgit v1.2.3