Re: Re: [PATCH v2 0/3] Inline helpers into Rust without full LTO

[Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>]

On Mon, Mar 23, 2026 at 2:54 PM Mark Brown <broonie@kernel.org> wrote:
>
> Callers should never treat NULL any differently to any other non-error
> pointer, this is not a value intended for inspection by users.
>
> Having specific handling for NULLs is very much not a preferred
> interface, and most things shouldn't.  The caller should probably have
> it's own !CONFIG_REGULATOR checks rather than using the return value.

Yeah, that is the understanding I got from reading both the docs and
the comment, but I think the docs (i.e. not the comment in the stub)
could point that `NULL` is one possible pointer value (perhaps
including discouraging relying on particular values at the same time,
and perhaps mentioning `!CONFIG_REGULATOR`).

i.e. to me, "Pointer to a struct regulator corresponding to the
regulator producer," sounds in the docs a bit too much like it will be
a valid one... no?

Another perspective is that, when one reads the rendered docs:

  https://docs.kernel.org/driver-api/regulator.html#c.regulator_get

one sees the postconditions, but they happen to not apply in all cases
(in fact, perhaps not having the "Returns" there would increase the
chances one realizes that, but I understand that you want them to
treat it as fully opaque as much as possible).

It could also help things like AI review systems which may only notice
the docs and not the comment inside the stub.

Perhaps it could be at least a one-line comment in the real
definition, even if not in the rendered docs, to have a chance for
others to notice.

I don't know -- I hope that helps, in any case. Perhaps Daniel can
tell us what he thought when he was writing the code, as another
perspective, i.e. whether it was the docs or not the issue.

Thanks!

Cheers,
Miguel