A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
-[There are over 400 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
+[There are over 550 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
Lints are divided into categories, each with a default [lint level](https://doc.rust-lang.org/rustc/lints/levels.html).
You can choose how much Clippy is supposed to ~~annoy~~ help you by changing the lint level by category.
-Category | Description | Default level
--- | -- | --
-`clippy::all` | all lints that are on by default (correctness, style, complexity, perf) | **warn/deny**
-`clippy::correctness` | code that is outright wrong or very useless | **deny**
-`clippy::style` | code that should be written in a more idiomatic way | **warn**
-`clippy::complexity` | code that does something simple but in a complex way | **warn**
-`clippy::perf` | code that can be written to run faster | **warn**
-`clippy::pedantic` | lints which are rather strict or might have false positives | allow
-`clippy::nursery` | new lints that are still under development | allow
-`clippy::cargo` | lints for the cargo manifest | allow
+| Category | Description | Default level |
+| --------------------- | ----------------------------------------------------------------------------------- | ------------- |
+| `clippy::all` | all lints that are on by default (correctness, suspicious, style, complexity, perf) | **warn/deny** |
+| `clippy::correctness` | code that is outright wrong or useless | **deny** |
+| `clippy::suspicious` | code that is most likely wrong or useless | **warn** |
+| `clippy::style` | code that should be written in a more idiomatic way | **warn** |
+| `clippy::complexity` | code that does something simple but in a complex way | **warn** |
+| `clippy::perf` | code that can be written to run faster | **warn** |
+| `clippy::pedantic` | lints which are rather strict or have occasional false positives | allow |
+| `clippy::nursery` | new lints that are still under development | allow |
+| `clippy::cargo` | lints for the cargo manifest | allow |
More to come, please [file an issue](https://github.com/rust-lang/rust-clippy/issues) if you have ideas!
## Usage
-Below are instructions on how to use Clippy as a subcommand, compiled from source
-or in Travis CI.
+Below are instructions on how to use Clippy as a cargo subcommand,
+in projects that do not use cargo, or in Travis CI.
### As a cargo subcommand (`cargo clippy`)
One way to use Clippy is by installing Clippy through rustup as a cargo
subcommand.
-#### Step 1: Install rustup
+#### Step 1: Install Rustup
-You can install [rustup](https://rustup.rs/) on supported platforms. This will help
+You can install [Rustup](https://rustup.rs/) on supported platforms. This will help
us install Clippy and its dependencies.
-If you already have rustup installed, update to ensure you have the latest
-rustup and compiler:
+If you already have Rustup installed, update to ensure you have the latest
+Rustup and compiler:
```terminal
rustup update
#### Automatically applying Clippy suggestions
-Clippy can automatically apply some lint suggestions.
-Note that this is still experimental and only supported on the nightly channel:
+Clippy can automatically apply some lint suggestions, just like the compiler.
```terminal
-cargo clippy --fix -Z unstable-options
+cargo clippy --fix
```
-### Running Clippy from the command line without installing it
+#### Workspaces
-To have cargo compile your crate with Clippy without Clippy installation
-in your code, you can use:
+All the usual workspace options should work with Clippy. For example the following command
+will run Clippy on the `example` crate:
```terminal
-cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
+cargo clippy -p example
```
-*Note:* Be sure that Clippy was compiled with the same version of rustc that cargo invokes here!
+As with `cargo check`, this includes dependencies that are members of the workspace, like path dependencies.
+If you want to run Clippy **only** on the given crate, use the `--no-deps` option like this:
+
+```terminal
+cargo clippy -p example -- --no-deps
+```
+
+### Using `clippy-driver`
+
+Clippy can also be used in projects that do not use cargo. To do so, run `clippy-driver`
+with the same arguments you use for `rustc`. For example:
+
+```terminal
+clippy-driver --edition 2018 -Cpanic=abort foo.rs
+```
+
+Note that `clippy-driver` is designed for running Clippy only and should not be used as a general
+replacement for `rustc`. `clippy-driver` may produce artifacts that are not optimized as expected,
+for example.
### Travis CI
# etc.
```
-If you are on nightly, It might happen that Clippy is not available for a certain nightly release.
-In this case you can try to conditionally install Clippy from the Git repo.
-
-```yaml
-language: rust
-rust:
- - nightly
-before_script:
- - rustup component add clippy --toolchain=nightly || cargo install --git https://github.com/rust-lang/rust-clippy/ --force clippy
- # etc.
-```
-
Note that adding `-D warnings` will cause your build to fail if **any** warnings are found in your code.
That includes warnings found by rustc (e.g. `dead_code`, etc.). If you want to avoid this and only cause
an error for Clippy warnings, use `#![deny(clippy::all)]` in your code or `-D clippy::all` on the command
## Configuration
Some lints can be configured in a TOML file named `clippy.toml` or `.clippy.toml`. It contains a basic `variable =
-value` mapping eg.
+value` mapping e.g.
```toml
+avoid-breaking-exported-api = false
blacklisted-names = ["toto", "tata", "titi"]
cognitive-complexity-threshold = 30
```
See the [list of lints](https://rust-lang.github.io/rust-clippy/master/index.html) for more information about which
lints can be configured and the meaning of the variables.
+Note that configuration changes will not apply for code that has already been compiled and cached under `./target/`;
+for example, adding a new string to `doc-valid-idents` may still result in Clippy flagging that string. To be sure that
+any configuration changes are applied, you may want to run `cargo clean` and re-compile your crate from scratch.
+
To deactivate the “for further information visit *lint-link*” message you can
define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
You can add options to your code to `allow`/`warn`/`deny` Clippy lints:
-* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
+* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`).
+ Note that `rustc` has additional [lint groups](https://doc.rust-lang.org/rustc/lints/groups.html).
* all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`,
`#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive
cargo clippy -- -W clippy::lint_name
```
-This also works with lint groups. For example you
+This also works with lint groups. For example, you
can run Clippy with warnings for all lints enabled:
```terminal
cargo clippy -- -W clippy::pedantic
```terminal
cargo clippy -- -A clippy::all -W clippy::useless_format -W clippy::...
```
-Note that if you've run clippy before, this may only take effect after you've modified a file or ran `cargo clean`.
### Specifying the minimum supported Rust version
msrv = "1.30.0"
```
+Alternatively, the [`rust-version` field](https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field)
+in the `Cargo.toml` can be used.
+
+```toml
+# Cargo.toml
+rust-version = "1.30"
+```
+
The MSRV can also be specified as an inner attribute, like below.
```rust
You can also omit the patch version when specifying the MSRV, so `msrv = 1.30`
is equivalent to `msrv = 1.30.0`.
-Note: `custom_inner_attributes` is an unstable feature so it has to be enabled explicitly.
+Note: `custom_inner_attributes` is an unstable feature, so it has to be enabled explicitly.
Lints that recognize this configuration option can be found [here](https://rust-lang.github.io/rust-clippy/master/index.html#msrv)
## License
-Copyright 2014-2020 The Rust Project Developers
+Copyright 2014-2022 The Rust Project Developers
Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
[https://www.apache.org/licenses/LICENSE-2.0](https://www.apache.org/licenses/LICENSE-2.0)> or the MIT license
projects / rust.git / blobdiff