To make sure no non-compatible changes are introduced accidentally
validate the language standard when building the tests.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
 CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
-CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
+CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \
                $(call cc-option,-fno-stack-protector) \
                $(CFLAGS_STKP_$(ARCH)) $(CFLAGS_$(ARCH))
 LDFLAGS := -s