-# 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)
-[](#License)
+[](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 279 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:
-A collection of lints to catch common mistakes and improve your Rust code.
+* `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!
Table of contents:
-* [Lint list](#lints)
* [Usage instructions](#usage)
* [Configuration](#configuration)
* [License](#license)
## 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.
-
-### 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}
-
-[features]
-default = []
-```
-
-And, in your `main.rs` or `lib.rs`:
-
-```rust
-#![cfg_attr(feature="clippy", feature(plugin))]
-
-#![cfg_attr(feature="clippy", plugin(clippy))]
-```
-
-Then build by enabling the feature: `cargo build --features "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).
+as an included feature during build. These options are detailed below.
### As a cargo subcommand (`cargo clippy`)
-An alternate 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 install clippy
-```
+#### Step 1: Install rustup
-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.
+You can install [rustup](http://rustup.rs/) on supported platforms. This will help
+us install Clippy and its dependencies.
-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.
+If you already have rustup installed, update to ensure you have the latest
+rustup and compiler:
```terminal
-SYSROOT=/path/to/rustc/sysroot cargo install clippy
+rustup update
```
-### Running clippy from the command line without installing
+#### Step 2: Install Clippy
-To have cargo compile your crate with clippy without needing `#![plugin(clippy)]`
-in your code, you can use:
+Once you have rustup and the latest stable release (at least Rust 1.29) installed, run the following command:
```terminal
-cargo rustc -- -L /path/to/clippy_so/dir/ -Z extra-plugins=clippy
-```
-
-*[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 = "*"
+rustup component add clippy-preview
```
-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`:
+Now you can run Clippy by invoking `cargo clippy`.
-```rust
-#![feature(plugin)]
+If it says that it can't find the `clippy` subcommand, please run `rustup self update`
-#![plugin(clippy)]
+### Running Clippy from the command line without installing it
+To have cargo compile your crate with Clippy without Clippy installation
+in your code, you can use:
-fn main(){
- let x = Some(1u8);
- match x {
- Some(y) => println!("{:?}", y),
- _ => ()
- }
-}
+```terminal
+cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
```
-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) }
+*[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!
+
+### Travis CI
+
+You can add Clippy to Travis CI in the same way you use it locally:
+
+```yml
+language: rust
+rust:
+ - stable
+ - beta
+before_script:
+ - rustup component add clippy-preview
+script:
+ - cargo clippy
+ # if you want the build job to fail when encountering warnings, use
+ - cargo clippy -- -D warnings
+ # in order to also check tests and none-default crate features, use
+ - cargo clippy --all-targets --all-features -- -D warnings
+ - cargo test
+ # etc.
```
## 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 `clippy.toml` or `.clippy.toml`. It contains a 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
-You can add options to `allow`/`warn`/`deny`:
+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)]`)
+* 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`
-features. This lets you set lints level and compile with or without clippy
-transparently:
-
+Note: To use the new `clippy::lint_name` syntax, `#![feature(tool_lints)]` has to be activated
+currently. If you want to compile your code with the stable toolchain you can use a `cfg_attr` to
+activate the `tool_lints` feature:
```rust
-#[cfg_attr(feature = "cargo-clippy", allow(needless_lifetimes))]
+#![cfg_attr(feature = "cargo-clippy", feature(tool_lints))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::lint_name))]
```
-## Lints
-
-[There are 209 lints included in this crate](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
+For this to work you have to use Clippy on the nightly toolchain: `cargo +nightly clippy`. If you
+want to use Clippy with the stable toolchain, you can stick to the old unscoped method to
+enable/disable Clippy lints until `tool_lints` are stable:
+```rust
+#![cfg_attr(feature = "cargo-clippy", allow(clippy_lint))]
+```
-More to come, please [file an issue](https://github.com/rust-lang-nursery/rust-clippy/issues) if you have ideas!
+If you do not want to include your lint levels in your code, you can globally enable/disable lints by passing extra flags to clippy during the run: `cargo clippy -- -A lint_name` will run clippy with `lint_name` disabled and `cargo clippy -- -W lint_name` will run it with that enabled. On newer compilers you may need to use `clippy::lint_name` instead.
## License
-Licensed under [MPL](https://www.mozilla.org/MPL/2.0/).
-If you're having issues with the license, let me know and I'll try to change it to something more permissive.
+Copyright 2014-2018 The Rust Project Developers
+
+Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+<LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+option. All files in the project carrying such notice may not be
+copied, modified, or distributed except according to those terms.
projects / rust.git / blobdiff