On Mon, Mar 17, 2025 at 04:35:42PM -0400, Tamir Duberstein wrote: > On Mon, Mar 17, 2025 at 4:28 PM Boqun Feng <boqun.feng@xxxxxxxxx> wrote: > > > > On Mon, Mar 17, 2025 at 03:05:45PM -0400, Tamir Duberstein wrote: > > > On Mon, Mar 17, 2025 at 2:50 PM Tamir Duberstein <tamird@xxxxxxxxx> wrote: > > > > > > > > On Mon, Mar 17, 2025 at 2:17 PM Boqun Feng <boqun.feng@xxxxxxxxx> wrote: > > > > > > > > > > Then we should fix clippy or how we set msrv rather adding the stub. > > > > > @Miguel? > > > > > > > > I filed https://github.com/rust-lang/rust-clippy/issues/14425. > > > > > > I don't think we can wait for that to be fixed, though. Usually clippy > > > is distributed with rustc via rustup, so even if this is eventually > > > fixed, all versions between 1.84.0 and the fix will need this > > > workaround until MSRV is >= 1.84.0. > > > > We need to take one step back to evalute this "workaround". > > > > First, expose_provenance() and with_exposed_provenance{,_mut}() API are > > clearly defined as equavilent to `as` operation [1]. Therefore, the > > changes in this patch doing the conversion with expose_provenance() and > > with_exposed_provenance{,_mut}() don't change anything related to > > provenance in practice. > > > > I do agree we want to use the explicit provenance API, but I don't think > > we want to introduce some API that we know we will change them latter > > when we bump the rustc minimal version. So the question is: are these > > stubs what we want even though in the future our minimal rustc version > > stablizes provenance API? If not, then the cost of this patch cannot > > justify its benefits IMO. > > > > Now let's also look into why we choose a msrv for clippy, I would guess > > it's because we need to support all the versions of rustc starting at > > 1.78 and we want clippy to report a problem based on 1.78 even though > > we're using a higher version of rustc. But for this particular case, we > > use a feature that has already been stablized in a higher version of > > rustc, which means the problem reported by clippy doesn't help us, nor > > does it provide better code. Frankly speaking, I think we have other > > ways to ensure the support of all rustc versions without a msrv for > > clippy. If I was to choose, I would simply drop the msrv. But maybe I'm > > missing something. > > > > The point is tools should help us to write good and maintainable code, > > we shouldn't introduce complicated structure of code just because some > > tools fail to do its job. > > > > [1]: https://doc.rust-lang.org/std/ptr/fn.with_exposed_provenance_mut.html > > Even if we globally disable this clippy lint, we still need stubs > because exposed_provenance was added in 1.79.0. Did your suggestion > address this? Perhaps I missed it. No, I didn't. That's a separate topic though, because I can see the argument that: because with_exposed_provenance() is a function rather than a method, it won't be very benefical to use ptr::with_exposed_provenance() instead of kernel::with_exposed_provenance(), therefor these stubs of exposed_provenance make sense to exist. But I don't think the same argument works for ptr::{with_,map_,}addr(). Regards, Boqun
