rust: allow `clippy::needless_lifetimes`

commit 60fc1e6750133620e404d40b93df5afe32e3e6c6 upstream.

In beta Clippy (i.e. Rust 1.83.0), the `needless_lifetimes` lint has
been extended [1] to suggest eliding `impl` lifetimes, e.g.

    error: the following explicit lifetimes could be elided: 'a
    --> rust/kernel/list.rs:647:6
        |
    647 | impl<'a, T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'a, T, ID> {}
        |      ^^                                                                  ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
        = note: `-D clippy::needless-lifetimes` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::needless_lifetimes)]`
    help: elide the lifetimes
        |
    647 - impl<'a, T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'a, T, ID> {}
    647 + impl<T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'_, T, ID> {}

A possibility would have been to clean them -- the RFC patch [2] did
this, while asking if we wanted these cleanups. There is an open issue
[3] in Clippy about being able to differentiate some of the new cases,
e.g. those that do not involve introducing `'_`. Thus it seems others
feel similarly.

Thus, for the time being, we decided to `allow` the lint.

Link: https://github.com/rust-lang/rust-clippy/pull/13286
Link: https://lore.kernel.org/rust-for-linux/20241012231300.397010-1-ojeda@kernel.org/
Link: https://github.com/rust-lang/rust-clippy/issues/13514
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241116181538.369355-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Makefile b/Makefile
index 87dc2f810860214e84360daed266ead353550b5a..acc665843571e3f458e42f7025a1e6b7cb6eece9 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -456,6 +456,7 @@ export rust_common_flags := --edition=2021 \
                            -Wclippy::mut_mut \
                            -Wclippy::needless_bitwise_bool \
                            -Wclippy::needless_continue \
+                           -Aclippy::needless_lifetimes \
                            -Wclippy::no_mangle_with_rust_abi \
                            -Wclippy::dbg_macro