From: Nathan Chancellor <natechancellor@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com
Subject: Re: [PATCH] ASoC: wcd934x: Remove some unnecessary NULL checks
Date: Wed, 5 Feb 2020 08:50:06 -0700 [thread overview]
Message-ID: <20200205155006.GA21667@ubuntu-x2-xlarge-x86> (raw)
In-Reply-To: <20200205102238.GG3897@sirena.org.uk>
On Wed, Feb 05, 2020 at 10:22:38AM +0000, Mark Brown wrote:
> On Tue, Feb 04, 2020 at 12:32:15PM -0700, Nathan Chancellor wrote:
> > On Tue, Feb 04, 2020 at 10:00:39AM +0000, Mark Brown wrote:
>
> > > I'm not convincd this is a sensible warning, at the use site a
> > > pointer to an array in a struct looks identical to an array
> > > embedded in the struct so it's not such a bad idea to check and
> > > refactoring of the struct could easily introduce problems.
>
> > Other static checkers like smatch will warn about this as well (since I
> > am sure that is how Dan Carpenter found the same issue in the wcd9335
> > driver). Isn't an antipattern in the kernel to do things "just in
> > case we do something later"? There are plenty of NULL checks removed
> > from the kernel because they do not do anything now.
>
> I'm not convinced it is an antipattern - adding the checks would
> be a bit silly but with the way C works the warnings feel like
> false positives. If the compiler were able to warn about missing
> NULL checks in the case where the thing in the struct is a
> pointer I'd be a lot happier with this.
Yes, that would definitely be nice. I am not entirely sure that this is
possible with clang due to its architecture but I am far from a clang
internal expert.
> > I'd be fine with changing the check to something else that keeps the
> > same logic but doesn't create a warning; I am not exactly sure what that
> > would be because that is more of a specific driver logic thing, which I
> > am not familiar with.
>
> I've queued the change to be applied since it's shuts the
> compiler up but I'm really not convinced the compiler is helping
> here.
Thank you :)
Cheers,
Nathan
next prev parent reply other threads:[~2020-02-05 15:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 6:01 [PATCH] ASoC: wcd934x: Remove some unnecessary NULL checks Nathan Chancellor
2020-02-04 10:00 ` Mark Brown
2020-02-04 19:32 ` Nathan Chancellor
2020-02-05 10:22 ` Mark Brown
2020-02-05 15:50 ` Nathan Chancellor [this message]
2020-02-11 15:49 ` Applied "ASoC: wcd934x: Remove some unnecessary NULL checks" to the asoc tree Mark Brown
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