Re: [PATCH net-next v3 1/3] rust: core abstractions for network PHY drivers

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

On Sat, Oct 14, 2023 at 2:31 PM FUJITA Tomonori
<fujita.tomonori@gmail.com> wrote:
>
> I expect that you don't want a commit introducing UD so I squash your
> patch with the explanation to the commit log. If you want to merge
> your work to the patchset in a different way, please let me know.

No, that is all wrong.

Your commits are not introducing UB (at least regarding this topic /
that we know about), whether you use the workaround or not, and
whether you use `--rustified-enum` or not:

  - Using `--rustified-enum` does not introduce UB on its own. It does
introduce a *risk* of UB, which is why we do not want it.

  - The workaround is meant to avoid desync between the C enum and the
Rust `match`, i.e. forgetting to update the Rust side. It has nothing
to do with UB.

Furthermore, no, you should not squash the code into one of your
commits. It is not OK to do that, and even if it were, you would not
need to do so. Instead, you could put the feature into its own commit
(but the patch is still a WIP, I have not sent it formally yet), if
you want to showcase how it would work.

In any case, we have not even discussed/decided whether to use the
workaround. I sent it mainly for your benefit, so that you can show
the netdev maintainer(s) that it would be possible to keep C and Rust
enums in sync, so that hopefully their concern is gone.

Cheers,
Miguel