Re: [PATCH 06/12] rust: pin-init: rewrite `#[pin_data]` using `syn`

[Benno Lossin]

On Fri Jan 9, 2026 at 5:46 PM CET, Gary Guo wrote:
> On Fri Jan 9, 2026 at 4:39 PM GMT, Benno Lossin wrote:
>> On Fri Jan 9, 2026 at 1:47 PM CET, Gary Guo wrote:
>>> On Thu Jan 8, 2026 at 1:50 PM GMT, Benno Lossin wrote:
>>>> +fn strip_pin_annotations(struct_: &mut syn::ItemStruct) {
>>>> +    for field in &mut struct_.fields {
>>>> +        field.attrs.retain(|a| !a.path().is_ident("pin"));
>>>> +    }
>>>> +}
>>>
>>> Multiple places have similar things for stripping annotations and checking if
>>> structurally pinned. Would it make sense to do this at the very beginning, and
>>> build a `HashSet` of structurally pinned fields, and use that as canonical
>>> source for all generate_ functions?
>>
>> There is https://github.com/Rust-for-Linux/pin-init/pull/94, and I don't
>> want to take away their work. I'll contact them and see if we can fold
>> it into this commit/series.
>
> I don't think that's the same? I am proposing remove `#[pin]` and build a set at
> the very beginning of `fn pin_data` and just use that set. Which is not what the
> reference PR does.

Oh yeah you're right. But `Field` doesn't implement `Hash`, so we sadly
can't create a set of pinned fields. I'll just create a Vec with a bool
and pass that around.

Cheers,
Benno