From 0462104317bfc097a90707a13590248707324846 Mon Sep 17 00:00:00 2001 From: Thomas Haller Date: Tue, 24 Feb 2015 18:11:21 +0100 Subject: [PATCH] build: fix detecting support for -Wno-* compiler flags Since GCC 4.4, gcc does not warn about unknown -Wno-* flags. At least, it does not warning unless another warning is raised as well (https://gcc.gnu.org/wiki/FAQ#wnowarning). We didn't notice up to now, because we only tested flags that GCC actually supports. Hack around this, by checking for the -W* counterpart instead. --- m4/compiler_warnings.m4 | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/m4/compiler_warnings.m4 b/m4/compiler_warnings.m4 index c05a26d098..412acb9750 100644 --- a/m4/compiler_warnings.m4 +++ b/m4/compiler_warnings.m4 @@ -30,7 +30,8 @@ if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then -Wundef -Wimplicit-function-declaration \ -Wpointer-arith -Winit-self \ -Wmissing-include-dirs; do - CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS_EXTRA $option $CFLAGS_SAVED" + dnl GCC 4.4 does not warn when checking for -Wno-* flags (https://gcc.gnu.org/wiki/FAQ#wnowarning) + CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS_EXTRA $(printf '%s' "$option" | sed 's/^-Wno-/-W/') $CFLAGS_SAVED" AC_MSG_CHECKING([whether gcc understands $option]) AC_TRY_COMPILE([], [], has_option=yes,