Re: [GIT PULL] gpio: updates for v6.6

[Bartosz Golaszewski]

On Tue, Aug 29, 2023 at 10:29 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 29 Aug 2023 at 04:43, Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> >
> > Driver improvements:
> > - use autopointers and guards from cleanup.h in gpio-sim
>
> So I've pulled this, but I'm not entirely convinced some of this was a cleanup.
>
> That gpio_sim_config_make_device_group() change is "interesting". Doing
>
>         return &no_free_ptr(dev)->group;
>
> looks a bit crazy. My first reaction to it was 'that can't be right".
> It _is_ right, but I'm not convinced that getting rid of one kfree()
> call in the error path above it is worth that kind of semantic
> complexity.
>
> I guess we'll get more used to this - and it will look a bit less
> crazy in the process - but I did want to just note that I'm not
> entirely convinced we should encourage things like this.
>
>               Linus

I on the other hand absolutely love SBRM in C. I have been using
autopointers a lot in user-space when coding in GLib/GObject and it
quickly becomes second nature with no_free_ptr() not being much
different from g_steal_pointer(). It's an even better pattern when
used with reference counted objects where the cleanup function just
drops the reference so you can do a less "crazy" return
object_ref(obj);

Maybe this particular example doesn't save a lot of code but I think
it's worth using SBRM consistently across a given file, otherwise
mixing both styles will lead to an unreadable mess.

Bartosz