tools: m4: set -std=gnu17

Fedora 42 updated to GCC15 which now defaults to GNU23 as the default
instead of GNU17[1], and this breaks m4 compilation.

Its been reported upstream [2], so until its fixed lets simply set C
language version back to GNU17.

[1] https://gcc.gnu.org/gcc-15/porting_to.html#c23
[2] https://savannah.gnu.org/support/?111150

Link: https://github.com/openwrt/openwrt/pull/18505
(cherry picked from commit 8c141e53d720b14a1d8595e0f756f1619df6e763)
Link: https://github.com/openwrt/openwrt/pull/18581
Signed-off-by: Robert Marko <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19065
Signed-off-by: Hauke Mehrtens <[email protected]>

diff --git a/tools/m4/Makefile b/tools/m4/Makefile
index d621000daf56c1fe7c1453e3edca1c8762183106..82210c9e8446b1d2e4156fcf2547e22ee8f8e0da 100644 (file)
--- a/tools/m4/Makefile
+++ b/tools/m4/Makefile
@@ -19,6 +19,7 @@ HOST_BUILD_PARALLEL:=1
 
 include $(INCLUDE_DIR)/host-build.mk
 
+HOST_CFLAGS += -std=gnu17
 HOST_CONFIGURE_VARS += gl_cv_func_strstr_linear=no
 
 define Host/Uninstall