lkml.org 
[lkml]   [2019]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: Clang warning in drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
On Wed, Mar 20, 2019 at 4:49 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Wed, Mar 20, 2019 at 2:37 AM Koenig, Christian
> <Christian.Koenig@amd.com> wrote:
> >
> > Am 20.03.19 um 05:34 schrieb Nathan Chancellor:
> > > On Wed, Mar 20, 2019 at 01:31:27AM +0000, Pan, Xinhui wrote:
> > >> these two enumerated types are same for now. both of them might change in the future.
>
> Please consider if the YAGNI principle applies here.
> https://martinfowler.com/bliki/Yagni.html
>
> > >>
> > >> I have not used clang, but would .block_id = (int)head->block fix your warning? If such change is acceptable, I can make one then.
>
> My preference on solutions, in order:
> 1. One enum (this is the simplest most type safe solution). Add
> another enum when you actually need it. Otherwise, YAGNI.

It make sense to have two enums. One is a firmware interface that is
only used by some asics and the other is for the general driver
interface (non-asic specific for the ras features.

> 2. Safe casting function (like the one Nathan supplied, maybe with
> WARN_ONCE rather than WARN). This ensures that at least if the types
> diverge you get a runtime warning. A compile-time warning would be
> preferred, but I haven't taken the time to think through how that
> might be implemented.

I'd prefer this one.

Alex

> 3. Cast to int (this has been used in other places throughout the
> kernel, but provides the weakest type safety and doesn't catch future
> divergence).
> 4. Disabling the warning. (I almost never advocate for this).
>
> > Another question is if it is such a good idea to just silence the warning?
>
> For the kernel, it seems that each maintainer can choose what to apply
> to their subsystem. I would recommend against disabling additional
> warnings that aren't disable kernel-wide for most cases.
> -Wenum-conversion has spotted many bugs. While the enums in question
> today are not different, they MIGHT eventually diverge and lead to
> bugs, like the others we've found and fixed throughout the kernel. So
> I would recommend fixing now, and be insulated in the future.
>
> --
> Thanks,
> ~Nick Desaulniers
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

\
 
 \ /
  Last update: 2019-03-21 05:45    [W:0.077 / U:6.496 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site