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

[Tamir Duberstein]

On Fri, Jan 16, 2026 at 4:28 AM Benno Lossin <lossin@xxxxxxxxxx> 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@xxxxxxxxxx> 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@xxxxxxxxxx> 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@xxxxxxxxxx>
> >> >> Signed-off-by: Benno Lossin <lossin@xxxxxxxxxx>
> >> >> ---
> >> >>
> >> >> <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@xxxxxxxxxx/.
> >>
> >> 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.