#[expect] does not work on arguments of trait methods and fn pointers

[theemathas]

I tried this code:

pub trait Trait {
    fn foo(#[expect(while_true)] x: i32);
}

pub fn bar() {
    let _: fn(#[expect(while_true)] y: i32);
}

I expected to get two unfulfilled_lint_expectations warnings due to the #[expect] attribute. Instead, the code compiles with no warnings.

See also #140087 and #140089

Meta

Issue reproduces on the playground with version 1.88.0-nightly (2025-04-07 e643f59f6da3a84f43e7)

[bjorn3]

I think lint level attributes are just not supported in that location at all.

[fmease]

Arguably duplicate of #33995