1 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.
5 [![Build Status](https://travis-ci.org/rust-lang-nursery/rust-clippy.svg?branch=master)](https://travis-ci.org/rust-lang-nursery/rust-clippy)
6 [![Windows Build status](https://ci.appveyor.com/api/projects/status/id677xpw1dguo7iw?svg=true)](https://ci.appveyor.com/project/rust-lang-libs/rust-clippy)
7 [![Current Version](https://meritbadge.herokuapp.com/clippy)](https://crates.io/crates/clippy)
8 [![License: MPL-2.0](https://img.shields.io/crates/l/clippy.svg)](#license)
10 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
12 [There are 276 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
14 We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
16 * `clippy::all` (everything that has no false positives)
17 * `clippy::pedantic` (everything)
18 * `clippy::nursery` (new lints that aren't quite ready yet)
19 * `clippy::style` (code that should be written in a more idiomatic way)
20 * `clippy::complexity` (code that does something simple but in a complex way)
21 * `clippy::perf` (code that can be written in a faster way)
22 * `clippy::cargo` (checks against the cargo manifest)
23 * **`clippy::correctness`** (code that is just outright wrong or very very useless)
25 More to come, please [file an issue](https://github.com/rust-lang-nursery/rust-clippy/issues) if you have ideas!
29 * [Usage instructions](#usage)
30 * [Configuration](#configuration)
35 Since this is a tool for helping the developer of a library or application
36 write better code, it is recommended not to include Clippy as a hard dependency.
37 Options include using it as an optional dependency, as a cargo subcommand, or
38 as an included feature during build. These options are detailed below.
40 ### As a cargo subcommand (`cargo clippy`)
42 One way to use Clippy is by installing Clippy through rustup as a cargo
45 #### Step 1: Install rustup
47 You can install [rustup](http://rustup.rs/) on supported platforms. This will help
48 us install Clippy and its dependencies.
50 If you already have rustup installed, update to ensure you have the latest
57 #### Step 2: Install Clippy
59 Once you have rustup and the latest stable release (at least Rust 1.29) installed, run the following command:
62 rustup component add clippy-preview
65 Now you can run Clippy by invoking `cargo clippy`.
67 ### Running Clippy from the command line without installing it
69 To have cargo compile your crate with Clippy without Clippy installation
70 in your code, you can use:
73 cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
76 *[Note](https://github.com/rust-lang-nursery/rust-clippy/wiki#a-word-of-warning):*
77 Be sure that Clippy was compiled with the same version of rustc that cargo invokes here!
81 You can add Clippy to Travis CI in the same way you use it locally:
87 - rustup component add clippy-preview
90 # if you want the build job to fail when encountering warnings, use
91 - cargo clippy -- -D warnings
92 # in order to also check tests and none-default crate features, use
93 - cargo clippy --all-targets --all-features -- -D warnings
100 Some lints can be configured in a TOML file named `clippy.toml` or `.clippy.toml`. It contains a basic `variable = value` mapping eg.
103 blacklisted-names = ["toto", "tata", "titi"]
104 cyclomatic-complexity-threshold = 30
107 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
108 meaning of the variables.
110 To deactivate the “for further information visit *lint-link*” message you can
111 define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
113 ### Allowing/denying lints
115 You can add options to your code to `allow`/`warn`/`deny` Clippy lints:
117 * the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
119 * all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`,
120 `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive
121 lints prone to false positives.
123 * only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc)
125 * `allow`/`warn`/`deny` can be limited to a single function or module using `#[allow(...)]`, etc
127 Note: `deny` produces errors instead of warnings.
129 Note: To use the new `clippy::lint_name` syntax, `#![feature(tool_lints)]` has to be activated
130 currently. If you want to compile your code with the stable toolchain you can use a `cfg_attr` to
131 activate the `tool_lints` feature:
133 #![cfg_attr(feature = "cargo-clippy", feature(tool_lints))]
134 #![cfg_attr(feature = "cargo-clippy", allow(clippy::lint_name))]
137 For this to work you have to use Clippy on the nightly toolchain: `cargo +nightly clippy`. If you
138 want to use Clippy with the stable toolchain, you can stick to the old unscoped method to
139 enable/disable Clippy lints until `tool_lints` are stable:
141 #![cfg_attr(feature = "cargo-clippy", allow(clippy_lint))]
146 Licensed under [MPL](https://www.mozilla.org/MPL/2.0/).
147 If you're having issues with the license, let me know and I'll try to change it to something more permissive.