Clippy lint · Suspicious · checked with Clippy 0.1.99

clippy::unnecessary_clippy_cfg: no need to put clippy lints behind a `clippy` cfg

What it meansChecks for #[cfg_attr(clippy, allow(clippy::lint))] and suggests to replace it with #[allow(clippy::lint)]. It is in the suspicious group and warns by default.

What you see

warning: no need to put clippy lints behind a `clippy` cfg
 --> main.rs:1:1
  |
1 | #![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))]
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `#![allow(clippy::deprecated_cfg_attr)]`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#unnecessary_clippy_cfg
  = note: `#[warn(clippy::unnecessary_clippy_cfg)]` on by default

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

There is no reason to put clippy attributes behind a clippy cfg as they are not run by anything else than clippy.

Code that is most likely wrong or useless. Warns by default.

How to fix it

Clippy can fix this one for you: run cargo clippy --fix (add --allow-dirty if you have uncommitted changes). Review the diff before you commit.

Flagged

#![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))]

Write this instead

#![allow(clippy::deprecated_cfg_attr)]

Turn it off, or on

Allow it where it does not fit your code, as narrowly as you can:

On one item

#[allow(clippy::unnecessary_clippy_cfg)]
fn my_function() { /* ... */ }

Whole crate (Cargo.toml)

[lints.clippy]
unnecessary_clippy_cfg = "allow"

One run

cargo clippy -- -A clippy::unnecessary-clippy-cfg

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Suspiciousgroup

warndefault level

yesfixed by cargo clippy --fix

1.78.0added in Rust

Clippy's own documentation

What it does

Checks for #[cfg_attr(clippy, allow(clippy::lint))] and suggests to replace it with #[allow(clippy::lint)].

Why is this bad?

There is no reason to put clippy attributes behind a clippy cfg as they are not run by anything else than clippy.

Example

#![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))]

Use instead:

#![allow(clippy::deprecated_cfg_attr)]

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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