-ifneq ($(filter 4.%,$(GCCVERSION)),)
+ifneq ($(filter 4.%,$(shell gcc -dumpversion)),)
GCC4=1
endif
CFLAGS += -Wredundant-decls
# warn if the format string is not a string literal
CFLAGS += -Wformat-nonliteral
+# missing prototypes
+CFLAGS += -Wmissing-prototypes