-# rust-clippy
+We are currently in the process of discussing Clippy 1.0 via the RFC process in https://github.com/rust-lang/rfcs/pull/2476 . The RFC's goal is to clarify policies around lint categorizations and the policy around which lints should be in the compiler and which lints should be in Clippy. Please leave your thoughts on the RFC PR.
+
+# Clippy
[](https://travis-ci.org/rust-lang-nursery/rust-clippy)
-[](https://ci.appveyor.com/project/rust-lang-nursery/rust-clippy)
-[](https://crates.io/crates/clippy)
+[](https://ci.appveyor.com/project/rust-lang-libs/rust-clippy)
+[](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 257 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
+[There are 273 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:
+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)
+* `clippy::all` (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!
## Usage
Since this is a tool for helping the developer of a library or application
-write better code, it is recommended not to include clippy as a hard dependency.
+write better code, it is recommended not to include Clippy as a hard dependency.
Options include using it as an optional dependency, as a cargo subcommand, or
-as an included feature during build. All of these options are detailed below.
-
-As a general rule clippy will only work with the *latest* Rust nightly for now.
-
-To install Rust nightly, the recommended way is to use [rustup](https://rustup.rs/):
-
-```terminal
-rustup install nightly
-```
+as an included feature during build. These options are detailed below.
### As a cargo subcommand (`cargo clippy`)
-One way to use clippy is by installing clippy through cargo as a cargo
+One way to use Clippy is by installing Clippy through rustup as a cargo
subcommand.
-```terminal
-cargo +nightly install clippy
-```
-
-(The `+nightly` is not necessary if your default `rustup` install is nightly)
+#### Step 1: Install rustup
-Now you can run clippy by invoking `cargo +nightly clippy`.
+You can install [rustup](http://rustup.rs/) on supported platforms. This will help
+us install clippy and its dependencies.
-To update the subcommand together with the latest nightly use the [rust-update](rust-update) script or run:
+If you already have rustup installed, update to ensure you have the latest
+rustup and compiler:
```terminal
-rustup update nightly
-cargo +nightly install --force clippy
+rustup update
```
-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.
-
-```terminal
-SYSROOT=/path/to/rustc/sysroot cargo install clippy
-```
+#### Step 2: Install nightly toolchain
-### Optional dependency
+Rustup integration is still new, you will need a relatively new nightly (2018-07-15 or later).
-In some cases you might want to include clippy in your project directly, as an
-optional dependency. To do this, just modify `Cargo.toml`:
+To install Rust nightly with [rustup](https://rustup.rs/):
-```toml
-[dependencies]
-clippy = { version = "*", optional = true }
-```
-
-And, in your `main.rs` or `lib.rs`, add these lines:
-
-```rust
-#![cfg_attr(feature="clippy", feature(plugin))]
-#![cfg_attr(feature="clippy", plugin(clippy))]
+```terminal
+rustup install nightly
```
-Then build by enabling the feature: `cargo +nightly build --features "clippy"`.
+#### Step 3: Install clippy
-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).
+Once you have rustup and the nightly toolchain installed, run the following command:
-Alternatively, to only run clippy when testing:
-
-```toml
-[dev-dependencies]
-clippy = { version = "*" }
+```terminal
+rustup component add clippy-preview --toolchain=nightly
```
-and add to `main.rs` or `lib.rs`:
-
-```
-#![cfg_attr(test, feature(plugin))]
-#![cfg_attr(test, plugin(clippy))]
-```
+Now you can run Clippy by invoking `cargo +nightly clippy`. If nightly is your
+default toolchain in rustup, `cargo clippy` will work fine.
-### Running clippy from the command line without installing it
+### Running Clippy from the command line without installing it
-To have cargo compile your crate with clippy without clippy installation and without needing `#![plugin(clippy)]`
+To have cargo compile your crate with Clippy without Clippy installation
in your code, you can use:
```terminal
```
*[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) }
-```
+Be sure that Clippy was compiled with the same version of rustc that cargo invokes here!
## Configuration
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 *lint-link*” message you can
define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
You can add options to `allow`/`warn`/`deny`:
-* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy)]`)
+* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
-* all lints using both the `clippy` and `clippy_pedantic` lint groups (`#![deny(clippy)]`,
- `#![deny(clippy_pedantic)]`). Note that `clippy_pedantic` contains some very aggressive
+* 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
lints prone to false positives.
-* only some lints (`#![deny(single_match, box_vec)]`, etc)
+* only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc)
* `allow`/`warn`/`deny` can be limited to a single function or module using `#[allow(...)]`, etc
Note: `deny` produces errors instead of warnings.
-For convenience, `cargo clippy` automatically defines a `cargo-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
+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.
+Clippy would also update correctly.
## License
projects / rust.git / blobdiff