Re: [RFC PATCH] rust: give Clippy the minimum supported Rust version

[Miguel Ojeda]

On Sat, Nov 23, 2024 at 11:24 PM Miguel Ojeda <ojeda@xxxxxxxxxx> wrote:
>
> Clippy's lints may avoid emitting a suggestion to use a language or
> library feature that is not supported by the minimum supported version,
> if given by the `msrv` field in the configuration file.
>
> For instance, Clippy should not suggest using `let ... else` in a lint
> if the MSRV did not implement that syntax.
>
> If the MSRV is not provided, Clippy will assume all features are available.
>
> Thus enable it with the minimum Rust version the kernel supports.
>
> Note that there is currently a small disadvantage in doing so: since
> we still use unstable features that nevertheless work in the range
> of versions we support (e.g. `#[expect(...)]`), we lose suggestions
> for those. However, over time we will stop using unstable features
> (especially language and library ones) as it is our goal, thus, in the
> end, we will want to have the `msrv` set.
>
> Rust is also considering adding a similar feature in `rustc` too, which
> we should probably enable if it becomes available [2].
>
> Link: https://github.com/rust-lang/rust-clippy/blob/8298da72e7b81fa30c515631b40fc4c0845948cb/clippy_utils/src/msrvs.rs#L20 [1]
> Link: https://github.com/rust-lang/compiler-team/issues/772 [2]
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>

Applied to `rust-next` -- thanks!

Cheers,
Miguel