linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chris Wilson <chris@chris-wilson.co.uk>
To: Nathan Chancellor <natechancellor@gmail.com>,
	Nick Desaulniers <ndesaulniers@google.com>
Cc: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
	rodrigo.vivi@intel.com, intel-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org,
	LKML <linux-kernel@vger.kernel.org>,
	Matthias Kaehlcke <mka@chromium.org>
Subject: Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o
Date: Tue, 18 Dec 2018 11:53:06 +0000	[thread overview]
Message-ID: <154513398652.1108.7150969916024071452@skylake-alporthouse-com> (raw)
In-Reply-To: <CAKwvOdm2r8bfXQCBiUjnQNnCs8ETxzYQHK4ZjMrfLyRvw77zAQ@mail.gmail.com>

Quoting Nick Desaulniers (2018-10-25 23:20:58)
> On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > This warning is disabled by default in scripts/Makefile.extrawarn when
> > W= is not provided but this Makefile adds -Wall after this warning is
> > disabled so it shows up in the build when it shouldn't:
> >
> > In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> > drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> > variable 'wq' is uninitialized when used within its own initialization
> > [-Werror,-Wuninitialized]
> >         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
> >                                         ^~
> > ./include/linux/wait.h:74:63: note: expanded from macro
> > 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
> >         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
> >                                ~~~~                                  ^~~~
> > ./include/linux/wait.h:72:33: note: expanded from macro
> > '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
> >         ({ init_waitqueue_head(&name); name; })
> >                                        ^~~~
> > 1 error generated.
> >
> > This warning looks to be a false positive given that init_waitqueue_head
> > initializes name before it is used. Rather than disable the warning for
> > the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> 
> cc author/reviewer of 46e2068081e9.
> 
> I'm fine with the patch as is, unless others prefer to disable it for
> the whole subdir?  We could be playing whack-a-mole in the future
> disabling this warning for other translation units.

Yes, exactly this since the warning is generated by a core header and a
fairly common pattern its use is not restricted to any single file.
(Will not all selftests similarly explode?)

The other false-positive clang-6 gave was for local_clock_us().
Presumably that one is fixed?
-Chris

  reply	other threads:[~2018-12-18 11:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-25 19:36 Nathan Chancellor
2018-10-25 22:20 ` Nick Desaulniers
2018-12-18 11:53   ` Chris Wilson [this message]
2018-12-18 19:01     ` Nathan Chancellor
2018-12-18 19:43       ` Nick Desaulniers
2018-12-17 17:41 ` Nathan Chancellor

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=154513398652.1108.7150969916024071452@skylake-alporthouse-com \
    --to=chris@chris-wilson.co.uk \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=jani.nikula@linux.intel.com \
    --cc=joonas.lahtinen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mka@chromium.org \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --cc=rodrigo.vivi@intel.com \
    --subject='Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).