`allow(clippy::duplicated_attributes)` does not take effect across out-of-line modules

[dtolnay]

Summary

For this particular lint, module-level #![allow(clippy::duplicated_attributes)] suppresses occurrences of the lint within that module, and within in-line modules in the same file, but not in modules from other files.

This behavior is unlike what happens with allow for all other clippy lints, in which it applies to the whole module hierarchy across files.

Reproducer

// src/lib.rs

#![allow(clippy::duplicated_attributes)]

pub mod here {
    #[allow(dead_code)]
    #[allow(dead_code)]
    pub fn foo() {}
}

pub mod there;

// src/there.rs

#[allow(dead_code)]
#[allow(dead_code)]
pub fn foo() {}

$ cargo clippy
warning: duplicated attribute
 --> src/there.rs:4:9
  |
4 | #[allow(dead_code)]
  |         ^^^^^^^^^
  |
note: first defined here
 --> src/there.rs:3:9
  |
3 | #[allow(dead_code)]
  |         ^^^^^^^^^
help: remove this attribute
 --> src/there.rs:4:9
  |
4 | #[allow(dead_code)]
  |         ^^^^^^^^^
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#duplicated_attributes
  = note: `#[warn(clippy::duplicated_attributes)]` on by default

The occurrence within mod here is suppressed by the allow but the one within mod there is not.

Version

rustc 1.79.0-nightly (85e449a32 2024-03-22)
binary: rustc
commit-hash: 85e449a3237e82c9ade8936a82bd4fc64cfe1057
commit-date: 2024-03-22
host: x86_64-unknown-linux-gnu
release: 1.79.0-nightly
LLVM version: 18.1.2

Additional Labels

No response

[dtolnay]

@GuillaumeGomez @blyxyas (the lint is new from #12378)

[J-ZhengLi]

It appears to be another victim of early pass, just like the one lint from #12436

@rustbot label -I-false-positive

edit: I wonder what else can be done except moving those to late pass tho 🤔

[y21]

we should also probably add a comment here saying that you should prefer adding the lint to Attributes (instead of EarlyAttributes) if at all possible since this is what's causing these issues

rust-clippy/clippy_lints/src/attrs/mod.rs

Line 588 in 4a8c949

impl_lint_pass!(EarlyAttributes => [

[jdonszelmann]

fixed, this is no longer a pre-expansion lint after some recent changes of mine for the attribute rework (@y21)

[dtolnay]

Using cargo bisect-rustc --component=clippy --regress=success -- clippy, the fix bisects to nightly-2024-04-20. Within the PRs that day, probably rust-lang/rust#124123, and within that, probably #12646.