Re: [PATCH 2/2] rust: enable `too-long-first-doc-paragraph` clippy lint

[Charalampos Mitrodimas <charmitro@posteo.net>]

Benno Lossin <benno.lossin@proton.me> writes:

> Introduced in Rust 1.82.0 [1], this lint ensures that the first line of
> documentation is short. That is because those lines get rendered in the
> html version of the docs directly next to the items and should therefore
> be short.
> Additionally, a short first sentence might help developers remember the
> rest of the documentation if they have read it already before.
>
> Reviewers have pointed this out manually on several occasions, thus
> enable the lint.
>
> Here is an example error fixed in the previous commit:
>
>     error: first doc comment paragraph is too long
>       --> rust/kernel/driver.rs:13:1
>        |
>     13 | / /// The [`RegistrationOps`] trait serves as generic interface for subsystems (e.g., PCI, Platform,
>     14 | | /// Amba, etc.) to provide the corresponding subsystem specific implementation to register /
>     15 | | /// unregister a driver of the particular type (`RegType`).
>     16 | | ///
>     17 | | /// For instance, the PCI subsystem would set `RegType` to `bindings::pci_driver` and call
>        | |_^
>        |
>        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph
>        = note: `-D clippy::too-long-first-doc-paragraph` implied by `-D warnings`
>        = help: to override `-D warnings` add `#[allow(clippy::too_long_first_doc_paragraph)]`
>
>     error: aborting due to 1 previous error
>
> The exact length can be configured in the .clippy.toml if we need to do
> so.
>
> Link: https://github.com/rust-lang/rust-clippy/issues/12989 [1]
> Signed-off-by: Benno Lossin <benno.lossin@proton.me>
> ---
>  Makefile | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/Makefile b/Makefile
> index 9e0d63d9d94b..d00cbeb63714 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -486,6 +486,7 @@ export rust_common_flags := --edition=2021 \
>  			    -Wclippy::undocumented_unsafe_blocks \
>  			    -Wclippy::unnecessary_safety_comment \
>  			    -Wclippy::unnecessary_safety_doc \
> +			    -Wclippy::too-long-first-doc-paragraph \
>  			    -Wrustdoc::missing_crate_level_docs \
>  			    -Wrustdoc::unescaped_backticks

Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>