From c4911f2db36d811896c73c008b4218d8fa9a4730 Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Thu, 25 Sep 2014 18:38:48 +0300 Subject: [PATCH] Build: Detect supported compiler warning flags better. Clang and nowadays also GCC accept any -Wfoobar option but then may give a warning that an unknown warning option was specified. To avoid adding unsupported warning options, the options are now tested with -Werror. Thanks to Charles Diza. --- configure.ac | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/configure.ac b/configure.ac index 2df67970..e41979bb 100644 --- a/configure.ac +++ b/configure.ac @@ -749,8 +749,9 @@ if test "$GCC" = yes ; then do AC_MSG_CHECKING([if $CC accepts $NEW_FLAG]) OLD_CFLAGS="$CFLAGS" - CFLAGS="$CFLAGS $NEW_FLAG" - AC_COMPILE_IFELSE([AC_LANG_SOURCE([void foo(void) { }])], [ + CFLAGS="$CFLAGS $NEW_FLAG -Werror" + AC_COMPILE_IFELSE([AC_LANG_SOURCE( + [void foo(void); void foo(void) { }])], [ AM_CFLAGS="$AM_CFLAGS $NEW_FLAG" AC_MSG_RESULT([yes]) ], [