dnl Check if the compiler supports -Wall
dnl
dnl
AC_DEFUN([VIM_GCC_WALL],
[EXTRA_CFLAGS=""
if test -n "$GCC"
then
	changequote(,)dnl
	cat > conftest.$ac_ext <<EOF
#line __oline__ "configure"
int main(int argc, char *argv[]) { return argv[argc-1] == 0; }
EOF
	changequote([,])dnl
	AC_MSG_CHECKING(for gcc -Wall option)
	cf_save_CFLAGS="$CFLAGS"
	CFLAGS="$cf_save_CFLAGS -Wall"
	if AC_TRY_EVAL(ac_compile); then
		AC_MSG_RESULT(-Wall)
		EXTRA_CFLAGS="-Wall"
	else
		AC_MSG_RESULT(NO)
	fi
	rm -f conftest*
	CFLAGS="$cf_save_CFLAGS"
fi
CFLAGS="$CFLAGS $EXTRA_CFLAGS"
])dnl