Messages in this thread Patch in this message | | | Date | Mon, 23 Dec 2013 13:56:06 -0800 | From | Josh Triplett <> | Subject | [PATCH 7/7] Makefile: Build with -Werror=date-time if the compiler supports it |
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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 <josh@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
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