GCC 4.9 and newer have a new warning -Wdate-time, which warns on any use of __DATE__, __TIME__, or __TIMESTAMP__, which would make the build non-deterministic. Now that the kernel does not use any of those macros, turn on -Werror=date-time if available, to keep it that way.
The kernel already (optionally) records this information at build time in a single place; other kernel code should not duplicate that. Signed-off-by: Josh Triplett <j...@joshtriplett.org> --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index 14d592c..188eea7 100644 --- a/Makefile +++ b/Makefile @@ -668,6 +668,9 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int) # require functions to have arguments in prototypes, not empty 'int foo()' KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes) +# Prohibit date/time macros, which would make the build non-deterministic +KBUILD_CFLAGS += $(call cc-option,-Werror=date-time) + # use the deterministic mode of AR if available KBUILD_ARFLAGS := $(call ar-option,D) -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
