[](https://travis-ci.org/rust-lang-nursery/rust-clippy)
[](https://ci.appveyor.com/project/rust-lang-nursery/rust-clippy)
-[](https://crates.io/crates/clippy)
-[](#License)
+[](https://crates.io/crates/clippy)
+[](#license)
A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
-[There are 209 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
+[There are 259 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
+
+We have a bunch of lint categories to allow you to choose how much clippy is supposed to ~~annoy~~ help you:
+
+* `clippy` (everything that has no false positives)
+* `clippy_pedantic` (everything)
+* `clippy_nursery` (new lints that aren't quite ready yet)
+* `clippy_style` (code that should be written in a more idiomatic way)
+* `clippy_complexity` (code that does something simple but in a complex way)
+* `clippy_perf` (code that can be written in a faster way)
+* `clippy_cargo` (checks against the cargo manifest)
+* **`clippy_correctness`** (code that is just outright wrong or very very useless)
More to come, please [file an issue](https://github.com/rust-lang-nursery/rust-clippy/issues) if you have ideas!
As a general rule clippy will only work with the *latest* Rust nightly for now.
-### Optional dependency
-
-If you want to make clippy an optional dependency, you can do the following:
-
-In your `Cargo.toml`:
-
-```toml
-[dependencies]
-clippy = {version = "*", optional = true}
+To install Rust nightly, the recommended way is to use [rustup](https://rustup.rs/):
-[features]
-default = []
+```terminal
+rustup install nightly
```
-And, in your `main.rs` or `lib.rs`:
+### As a cargo subcommand (`cargo clippy`)
-```rust
-#![cfg_attr(feature="clippy", feature(plugin))]
+One way to use clippy is by installing clippy through cargo as a cargo
+subcommand.
-#![cfg_attr(feature="clippy", plugin(clippy))]
+```terminal
+cargo +nightly install clippy
```
-Then build by enabling the feature: `cargo build --features "clippy"`
+(The `+nightly` is not necessary if your default `rustup` install is nightly)
-Instead of adding the `cfg_attr` attributes you can also run clippy on demand:
-`cargo rustc --features clippy -- -Z no-trans -Z extra-plugins=clippy`
-(the `-Z no trans`, while not necessary, will stop the compilation process after
-typechecking (and lints) have completed, which can significantly reduce the runtime).
+Now you can run clippy by invoking `cargo +nightly clippy`.
-### As a cargo subcommand (`cargo clippy`)
-
-An alternate way to use clippy is by installing clippy through cargo as a cargo
-subcommand.
+To update the subcommand together with the latest nightly use the [rust-update](rust-update) script or run:
```terminal
-cargo install clippy
+rustup update nightly
+cargo +nightly install --force clippy
```
-Now you can run clippy by invoking `cargo clippy`, or
-`rustup run nightly cargo clippy` directly from a directory that is usually
-compiled with stable.
-
In case you are not using rustup, you need to set the environment flag
`SYSROOT` during installation so clippy knows where to find `librustc` and
similar crates.
SYSROOT=/path/to/rustc/sysroot cargo install clippy
```
-### Running clippy from the command line without installing
+### Running clippy from the command line without installing it
-To have cargo compile your crate with clippy without needing `#![plugin(clippy)]`
+To have cargo compile your crate with clippy without clippy installation
in your code, you can use:
```terminal
-cargo rustc -- -L /path/to/clippy_so/dir/ -Z extra-plugins=clippy
+cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
```
*[Note](https://github.com/rust-lang-nursery/rust-clippy/wiki#a-word-of-warning):*
Be sure that clippy was compiled with the same version of rustc that cargo invokes here!
-### As a Compiler Plugin
-
-*Note:* This is not a recommended installation method.
-
-Since stable Rust is backwards compatible, you should be able to
-compile your stable programs with nightly Rust with clippy plugged in to
-circumvent this.
-
-Add in your `Cargo.toml`:
-
-```toml
-[dependencies]
-clippy = "*"
-```
-
-You then need to add `#![feature(plugin)]` and `#![plugin(clippy)]` to the top
-of your crate entry point (`main.rs` or `lib.rs`).
-
-Sample `main.rs`:
-
-```rust
-#![feature(plugin)]
-
-#![plugin(clippy)]
-
-
-fn main(){
- let x = Some(1u8);
- match x {
- Some(y) => println!("{:?}", y),
- _ => ()
- }
-}
-```
-
-Produces this warning:
-
-```terminal
-src/main.rs:8:5: 11:6 warning: you seem to be trying to use match for destructuring a single type. Consider using `if let`, #[warn(single_match)] on by default
-src/main.rs:8 match x {
-src/main.rs:9 Some(y) => println!("{:?}", y),
-src/main.rs:10 _ => ()
-src/main.rs:11 }
-src/main.rs:8:5: 11:6 help: Try
-if let Some(y) = x { println!("{:?}", y) }
-```
-
## Configuration
-Some lints can be configured in a `clippy.toml` file. It contains basic `variable = value` mapping eg.
+Some lints can be configured in a TOML file named with `clippy.toml` or `.clippy.toml`. It contains basic `variable = value` mapping eg.
```toml
blacklisted-names = ["toto", "tata", "titi"]
cyclomatic-complexity-threshold = 30
```
-See the wiki for more information about which lints can be configured and the
+See the [list of lints](https://rust-lang-nursery.github.io/rust-clippy/master/index.html) for more information about which lints can be configured and the
meaning of the variables.
-You can also specify the path to the configuration file with:
-
-```rust
-#![plugin(clippy(conf_file="path/to/clippy's/configuration"))]
-```
-
-To deactivate the “for further information visit *wiki-link*” message you can
+To deactivate the “for further information visit *lint-link*” message you can
define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
### Allowing/denying lints
Note: `deny` produces errors instead of warnings.
For convenience, `cargo clippy` automatically defines a `cargo-clippy`
-features. This lets you set lints level and compile with or without clippy
+feature. This lets you set lint levels and compile with or without clippy
transparently:
```rust
#[cfg_attr(feature = "cargo-clippy", allow(needless_lifetimes))]
```
+## Updating rustc
+
+Sometimes, rustc moves forward without clippy catching up. Therefore updating
+rustc may leave clippy a non-functional state until we fix the resulting
+breakage.
+
+You can use the [rust-update](rust-update) script to update rustc only if
+clippy would also update correctly.
+
## License
Licensed under [MPL](https://www.mozilla.org/MPL/2.0/).
projects / rust.git / blobdiff