Re: linux-next: manual merge of the rust tree with the char-misc tree

[Miguel Ojeda]

Hi Greg,

On Mon, May 16, 2022 at 9:49 AM Greg KH <greg@xxxxxxxxx> wrote:
>
> Odd, why does the Rust binder implementation require the IOCTL
> definitions to be in an enum instead of a #define?

It is because bindgen (the tool which generates the "raw" C bindings)
only works with simple C `#define`s. Thus there are two options when
one hits something like this: either copy-paste them manually into the
Rust side (which adds maintenance), or change them into real
objects/identifiers in the C side.

There may be support in the future for expanding macros that end up in
a numeric one: https://github.com/rust-lang/rust-bindgen/issues/753.

Stephen: the resolution looks fine, thanks!

> If that's required, I can take that type of change now to prevent merge
> issues in the future.

We have two so far: this one (for the RFC Android patch) and another
small one in include/linux/spinlock.h (for the `sync` module).

So far I have put those changes in their respective patches, but if
you prefer I can send them independently too (like the prerequisite
patches).

Cheers,
Miguel