Specifying reason in expect(clippy::needless_return) triggers false positive "this lint expectation is unfulfilled"

[schuetzm]

Summary

It seems the reason option has an effect on whether the lint warns about an unfulfilled expectation.

Lint Name

clippy::needless_return

Reproducer

I tried this code:

fn a(x: Option<u8>) -> Option<u8> {
    match x {
        Some(_) => None,
        None => {
            #[expect(clippy::needless_return, reason = "Use early return for errors.")]
            return None;
        }
    }
}

fn b(x: Option<u8>) -> Option<u8> {
    match x {
        Some(_) => None,
        None => {
            #[expect(clippy::needless_return)]
            return None;
        }
    }
}

I saw this happen:
The warning about unfulfilled expectations is printed for function a, but not for b:

  |
5 |             #[expect(clippy::needless_return, reason = "Use early return for errors.")]
  |                      ^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: Use early return for errors.
  = note: `#[warn(unfulfilled_lint_expectations)]` on by default

I expected to see this happen:
No warning should be printed for either function.

Version

rustc 1.81.0 (eeb90cda1 2024-09-04)
binary: rustc
commit-hash: eeb90cda1969383f56a2637cbd3037bdf598841c
commit-date: 2024-09-04
host: x86_64-unknown-linux-gnu
release: 1.81.0
LLVM version: 18.1.7

Additional Labels

No response

[vHugoObject]

@rustbot claim

[Jarcho]

This lint has a hack to make#[expect(..)] work since normally it doesn't trigger when an attribute is present on the statement. It needs to be extended to ignore the reason field.