Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH] kbuild: Enable -Wsometimes-uninitialized | Date | Mon, 29 Apr 2019 18:00:38 -0700 |
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This is Clang's version of GCC's -Wmaybe-uninitialized. Up to this point, it has not been used because -Wuninitialized has been disabled, which also turns off -Wsometimes-uninitialized, meaning that we miss out on finding some bugs [1]. In my experience, it appears to be more accurate than GCC and catch some things that GCC can't.
All of these warnings have now been fixed in -next across arm, arm64, and x86_64 defconfig/allyesconfig so this should be enabled for everyone to prevent more from easily creeping in.
As of next-20190429:
$ git log --oneline --grep="sometimes-uninitialized" | wc -l 45
[1]: https://lore.kernel.org/lkml/86649ee4-9794-77a3-502c-f4cd10019c36@lca.pw/
Link: https://github.com/ClangBuiltLinux/linux/issues/381 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> ---
Masahiro, I am not sure how you want to handle merging this with regards to all of the patches floating around in -next but I wanted to send this out to let everyone know this is ready to be turned on.
Arnd, are there many remaning -Wsometimes-uninitialized warnings in randconfigs?
scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+)
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 768306add591..f4332981ea85 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -72,5 +72,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format) KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) +KBUILD_CFLAGS += $(call cc-option, -Wsometimes-uninitialized) endif endif -- 2.21.0
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