Re: [PATCH 00/36] treewide: remove conditional returns with no effect

Jani Nikula <[email protected]> Mon, 27 Jul 2026 14:36:57 +0300
Newsgroups org.freedesktop.lists.nouveau,dev.linux.lists.dm-devel,dev.linux.lists.iommu,org.kernel.vger.dmaengine,org.kernel.vger.linux-cifs,org.kernel.vger.linux-clk,org.kernel.vger.linux-crypto,org.kernel.vger.linux-edac,org.kernel.vger.linux-gpio,org.kernel.vger.linux-iio,org.kernel.vger.linux-input,org.kernel.vger.linux-kernel,org.kernel.vger.linux-media,org.kernel.vger.linux-pm,org.kernel.vger.linux-rdma,org.kernel.vger.linux-rtc,org.kernel.vger.linux-s390,org.kernel.vger.linux-scsi,org.kernel.vger.linux-sound,org.kernel.vger.linux-usb,org.kernel.vger.linux-wireless,org.kernel.vger.lvs-devel,org.kernel.vger.netdev,org.kernel.vger.netfilter-devel,org.kernel.vger.platform-driver-x86,org.kvack.linux-mm,org.osuosl.intel-wired-lan
Organization Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland
Message-ID <[email protected]>
On Mon, 27 Jul 2026, Sang-Heon Jeon <[email protected]> wrote:
> Hello,
>
> On Mon, Jul 27, 2026 at 5:30=E2=80=AFPM Jani Nikula <[email protected]=
tel.com> wrote:
>>
>> On Fri, 24 Jul 2026, Jakub Kicinski <[email protected]> wrote:
>> > On Fri, 24 Jul 2026 03:45:02 +0900 Sang-Heon Jeon wrote:
>> >> Patch 1 adds a Coccinelle script that matches the pattern, including
>> >> negation and constant-comparison variants. Where a local variable is
>> >> assigned right before the check, the assignment and the two returns
>> >> turn into a single return of the assigned expression.
>> >
>> > Huh, I thought we already had such script. Various script children have
>> > been sending such "cleanups" in the past.
>>
>> We did, and it was removed, I believe in 1a617a8475e8 ("coccinelle:
>> misc: remove "complex return code" warnings"), because people just don't
>> want this constant churn.
>>
>> It's perfectly fine to have the error case and happy day scenario
>> separated.
>
> Thanks for sharing the history.
>
> I checked the mailing list. The removed script looks similar to the
> new one, but it is different. The removed script reported a
> conditional return followed by an explicit return 0, where the error
> case and happy day scenario are separated as you mentioned, and Johan
> also complained about this 10 years ago.
>
> But the new script only reports when both branches return the same
> variable, not the explicit 0. So, I think the new script is close to
> the restricted version that Julia mentioned 10 years ago, and it
> should be acceptable.

ret =3D=3D=3D 0 after an if (ret) return.

BR,
Jani.


>
>>
>> BR,
>> Jani.
>>
>>
>> --
>> Jani Nikula, Intel
>
> Best Regards,
> Sang-Heon Jeon

--=20
Jani Nikula, Intel