From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: Wsometimes-uninitialized warning
Date: Mon, 17 Sep 2018 10:35:09 +0100 [thread overview]
Message-ID: <20180917093508.GA19927@arm.com> (raw)
In-Reply-To: <137d09a45fb990ecf6f5a4af4cb04eaf@codeaurora.org>
On Sat, Sep 15, 2018 at 08:48:36AM -0700, Sodagudi Prasad wrote:
> Hi All,
>
> I have observed compile time issues with modules incremental compilation
> using clang.
> I referred to following clang documentation about this warning.
> http://releases.llvm.org/3.2/tools/clang/docs/ReleaseNotes.html
>
> But in kernel code, PERCPU_OP macro default case is not reachable to throw
> this -Wsometimes-uninitialized warning.
> BUILD_BUG() is getting used for the default cases of the PERCPU_OP macro.
> Have you observed -Wsometimes-uninitialized warnings with clang when
> compiling 4.14.6?
>
>
> /arch/arm64/include/asm/percpu.h:102:1: note: variable 'ret' is declared
> here
> /arch/arm64/include/asm/percpu.h:52:2: note: expanded from macro 'PERCPU_OP'
> unsigned long loop, ret; \
> ^
> /arch/arm64/include/asm/percpu.h:103:1: error: variable 'ret' is used
> uninitialized whenever switch default is taken
> [-Werror,-Wsometimes-uninitialized]
> PERCPU_OP(and, and)
> ^~~~~~~~~~~~~~~~~~~
> /arch/arm64/include/asm/percpu.h:95:2: note: expanded from macro 'PERCPU_OP'
> default: \
>
>
> Do you have any suggestions/comments?
FWIW, I had a go at rewriting that file last week:
https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?h=pcpu&id=126c36f538d494d0342ba8e95013936b85d7c5e2
With that, the switch statement disappears altogether.
Will
parent reply other threads:[~2018-09-17 9:35 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <137d09a45fb990ecf6f5a4af4cb04eaf@codeaurora.org>]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180917093508.GA19927@arm.com \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.