Re: [PATCH] netfilter: conntrack: fix -Wformat

From: Tom Rix <trix@redhat.com>
To: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
	Joe Perches <joe@perches.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Dwaipayan Ray <dwaipayanray1@gmail.com>
Subject: Re: [PATCH] netfilter: conntrack: fix -Wformat
Date: Thu, 3 Dec 2020 06:39:03 -0800	[thread overview]
Message-ID: <844b0184-a74b-4d0a-8470-69d58323391a@redhat.com> (raw)
In-Reply-To: <CAKXUXMx0nSZqFfOF63J+awCpkPkgr-kuchUxd2-tuMbA2piD5A@mail.gmail.com>

On 12/2/20 11:26 PM, Lukas Bulwahn wrote:
> On Thu, Dec 3, 2020 at 1:46 AM Tom Rix <trix@redhat.com> wrote:
>>
>> On 12/2/20 2:34 PM, Nick Desaulniers wrote:
>>> On Tue, Nov 10, 2020 at 2:04 PM Joe Perches <joe@perches.com> wrote:
>>>> On Tue, 2020-11-10 at 14:00 -0800, Nick Desaulniers wrote:
>>>>
>>>>> Yeah, we could go through and remove %h and %hh to solve this, too, right?
>>>> Yup.
>>>>
>>>> I think one of the checkpatch improvement mentees is adding
>>>> some suggestion and I hope an automated fix mechanism for that.
>>>>
>>>> https://lore.kernel.org/lkml/5e3265c241602bb54286fbaae9222070daa4768e.camel@perches.com/
>>> + Tom, who's been looking at leveraging clang-tidy to automate such
>>> treewide mechanical changes.
>>> ex. https://reviews.llvm.org/D91789
>> This looks like a good one to automate.
>>
>> If you don't mind, I'll give it a try next.
>>
>> Need a break from semicolons ;)
>>
>> Tom
>>
>>> See also commit cbacb5ab0aa0 ("docs: printk-formats: Stop encouraging
>>> use of unnecessary %h[xudi] and %hh[xudi]") for a concise summary of
>>> related context.
> Nick, Tom,
>
> It is not a competition between checkpatch and clang-format, but if it would be:
>
> ...checkpatch was first...
>
> But jokes aside: Dwaipayan Ray, a mentee Joe and I are working with,
> has already submitted a patch to checkpatch that identifies those
> patterns and provides a fix:
>
> https://lore.kernel.org/lkml/20201128200046.78739-1-dwaipayanray1@gmail.com/
>
> Maybe that is helpful; and of course, clean-up patches to the various
> places still need to be sent out and having a second tool with
> clang-format that can check and provide automatic fixes as well is
> great.
>
> Tom, go for it: that clean-up is certainly helpful to get a "make
> CC=clang -W1" warning-free kernel build. For some smaller x86 kernel
> config (my playground config), there were not too many warnings
> outstanding, but the -Wformat was still among the larger class among
> them.

i see 17k for -Wformat-pedantic, beating out -Wextra-semi-stmt by a hefty 8k on my allyesconfig

Yes, enabling new warnings is one of the things i am chasing.

I agree if it can be done in checkpatch it should.

It is good to have multiple passes on cleaning.

checkpatch is best at fixing new problems, clang-tidy-fix is best at fixing old problems.

Tom

> Lukas
>