Re: [PATCH v2] drm/i915: Disable -Wuninitialized

From: Nathan Chancellor
Date: Sat Jan 26 2019 - 02:58:01 EST


On Fri, Jan 25, 2019 at 11:34:19PM -0800, Nick Desaulniers wrote:
> On Fri, Jan 25, 2019 at 11:13 PM Nathan Chancellor
> <natechancellor@xxxxxxxxx> 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.
> >
> > Explicitly disable the warning like commit 46e2068081e9 ("drm/i915:
> > Disable some extra clang warnings").
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/220
> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
>
> Reviewed-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>
>
> probably could give Chris Wilson the suggested by tag.
> https://lore.kernel.org/lkml/154513398652.1108.7150969916024071452@skylake-alporthouse-com/
>

Ugh you're right, completely slipped my mind.

Suggested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

> > ---
> >
> > v1 -> v2:
> >
> > * Rather than disable the warning for the problematic folder, disable it
> > for the entire folder like Matthias's commit.
>
> Thanks for following up with a v2.

Thank you for the review!
Nathan

>
> --
> Thanks,
> ~Nick Desaulniers