Re: [PATCH v3 09/15] rust: pin-init: rewrite the initializer macros using `syn`

["Benno Lossin" <lossin@kernel.org>]

On Fri Jan 16, 2026 at 4:39 PM CET, Tamir Duberstein wrote:
> On Fri, Jan 16, 2026 at 4:28 AM Benno Lossin <lossin@kernel.org> wrote:
>>
>> On Fri Jan 16, 2026 at 1:19 AM CET, Tamir Duberstein wrote:
>> > On Thu, Jan 15, 2026 at 5:43 PM Benno Lossin <lossin@kernel.org> wrote:
>> >>
>> >> On Thu Jan 15, 2026 at 10:45 PM CET, Tamir Duberstein wrote:
>> >> > On Wed, Jan 14, 2026 at 1:20 PM Benno Lossin <lossin@kernel.org> wrote:
>> >> >>
>> >> >> Rewrite the initializer macros `[pin_]init!` using `syn`. No functional
>> >> >> changes intended aside from improved error messages on syntactic and
>> >> >> semantical errors. For example if one forgets to use `<-` with an
>> >> >> initializer (and instead uses `:`):
>> >> >>
>> >> >> <snip>
>> >> >>
>> >> >> Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
>> >> >> Signed-off-by: Benno Lossin <lossin@kernel.org>
>> >> >> ---
>> >> >>
>> >> >> <snip>
>> >> >>
>> >> >> -#[cfg(kernel)]
>> >> >> -pub use ::macros::paste;
>> >> >> -#[cfg(not(kernel))]
>> >> >> -pub use ::paste::paste;
>> >> >
>> >> > Now that `cfg(kernel)` is gone, can we also remove it from `rust/Makefile`
>> >> > and `scripts/generate_rust_analyzer.py`? That is already done for
>> >> > pin-init in patch 3 of this series:
>> >> > https://lore.kernel.org/all/20260114181934.1782470-4-lossin@kernel.org/.
>> >>
>> >> I'm still using `cfg(kernel)` in `src/lib.rs` for linking to the std
>> >> Box and Arc types.
>> >
>> > Are you sure? I'm not seeing it. It looks like the crate is no_std
>> > unless the std feature is activated and no features are activated in
>> > the kernel.
>>
>> Yes:
>>
>>     $ rg 'cfg.*kernel'
>>
>>     src/lib.rs
>>     260:#![cfg_attr(not(kernel), doc = "[`Arc<T>`]: alloc::alloc::sync::Arc")]
>>     261:#![cfg_attr(not(kernel), doc = "[`Box<T>`]: alloc::alloc::boxed::Box")]
>>     921:#[cfg_attr(not(kernel), doc = "[`Arc<T>`]: alloc::alloc::sync::Arc")]
>>     922:#[cfg_attr(not(kernel), doc = "[`Box<T>`]: alloc::alloc::boxed::Box")]
>>     1020:#[cfg_attr(not(kernel), doc = "[`Arc<T>`]: alloc::alloc::sync::Arc")]
>>     1021:#[cfg_attr(not(kernel), doc = "[`Box<T>`]: alloc::alloc::boxed::Box")]
>>
>> >> Also I don't want to have to reintroduce all that infrastructure when I
>> >> inevitably have to add new kernel workarounds.
>> >
>> > Then why remove it for pin-init?
>>
>> I don't understand, what is removed where? In patch 3 the `--cfg kernel`
>> is kept in all locations.
>
> You're right, I must've misread. It's fine to keep & sorry for the noise.

Don't worry, I appreciate you taking a look :)

Cheers,
Benno