Treat implicitly declared functions as an error

This is more safe.

diff --git a/build/Makefile.rules.arm b/build/Makefile.rules.arm
index 96ef96582f71cca36603ecdb77c2326f4b5422d8..1a9cc2f70a588862fc1a04c31da6050888fc5cd3 100644 (file)
--- a/build/Makefile.rules.arm
+++ b/build/Makefile.rules.arm
@@ -47,7 +47,7 @@ RPP_TARGET_CFLAGS += -DTARGET_$(call UPPERCASE,$(TARGET))
 TARGET_HAS_NAMES = $(filter TARGET_HAS_%,$(.VARIABLES))
 RPP_TARGET_CFLAGS += $(foreach name,$(TARGET_HAS_NAMES),$(if $(filter y,$($(name))),-D$(name)))
 
-ARM_COMPILER_CFLAGS = --gcc --diag_warning=225 --display_error_number  \
+ARM_COMPILER_CFLAGS = --gcc --diag_error=225 --display_error_number    \
                                          --diag_wrap=off --gen_func_subsections=on --enum_type=packed
 
 RPP_CFLAGS = $(RPP_TARGET_CFLAGS) -I$(ARM_COMPILER_DIR)/include        \