From: Nathan Chancellor <natechancellor@gmail.com>
To: Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
Arnd Bergmann <arnd@arndb.de>,
Nathan Chancellor <natechancellor@gmail.com>
Subject: [PATCH] kbuild: Enable -Wsometimes-uninitialized
Date: Mon, 29 Apr 2019 18:00:38 -0700 [thread overview]
Message-ID: <20190430010037.6216-1-natechancellor@gmail.com> (raw)
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?
| 1 +
1 file changed, 1 insertion(+)
--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
next reply other threads:[~2019-04-30 1:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-30 1:00 Nathan Chancellor [this message]
2019-04-30 7:16 ` [PATCH] kbuild: Enable -Wsometimes-uninitialized Arnd Bergmann
2019-04-30 9:33 ` Nathan Chancellor
2019-04-30 9:46 ` Arnd Bergmann
2019-04-30 20:54 ` Nathan Chancellor
2019-05-01 12:30 ` Masahiro Yamada
2019-05-23 1:50 ` Nathan Chancellor
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