f0aa2c1587
Don't lint accidental "prefixes" on enum variants |
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.github | ||
clippy_lints | ||
clippy_workspace_tests | ||
mini-macro | ||
src | ||
tests | ||
util | ||
.editorconfig | ||
.gitignore | ||
.remarkrc.json | ||
.travis.yml | ||
appveyor.yml | ||
build.rs | ||
Cargo.lock | ||
Cargo.toml | ||
CHANGELOG.md | ||
CONTRIBUTING.md | ||
LICENSE | ||
mut_range_bound | ||
pre_publish.sh | ||
publish.files | ||
PUBLISH.md | ||
README.md | ||
rls.toml | ||
rustfmt.toml |
rust-clippy
A collection of lints to catch common mistakes and improve your Rust code.
There are 209 lints included in this crate!
More to come, please file an issue if you have ideas!
Table of contents:
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. 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
:
[dependencies]
clippy = {version = "*", optional = true}
[features]
default = []
And, in your main.rs
or lib.rs
:
#![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 a cargo subcommand (cargo clippy
)
An alternate way to use clippy is by installing clippy through cargo as a cargo subcommand.
cargo install 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
To have cargo compile your crate with clippy without needing #![plugin(clippy)]
in your code, you can use:
cargo rustc -- -L /path/to/clippy_so/dir/ -Z extra-plugins=clippy
Note: 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
:
[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
:
#![feature(plugin)]
#![plugin(clippy)]
fn main(){
let x = Some(1u8);
match x {
Some(y) => println!("{:?}", y),
_ => ()
}
}
Produces this warning:
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.
blacklisted-names = ["toto", "tata", "titi"]
cyclomatic-complexity-threshold = 30
See the wiki 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:
#![plugin(clippy(conf_file="path/to/clippy's/configuration"))]
To deactivate the “for further information visit wiki-link” message you can
define the CLIPPY_DISABLE_DOCS_LINKS
environment variable.
Allowing/denying lints
You can add options to allow
/warn
/deny
:
-
the whole set of
Warn
lints using theclippy
lint group (#![deny(clippy)]
) -
all lints using both the
clippy
andclippy_pedantic
lint groups (#![deny(clippy)]
,#![deny(clippy_pedantic)]
). Note thatclippy_pedantic
contains some very aggressive lints prone to false positives. -
only some lints (
#![deny(single_match, 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:
#[cfg_attr(feature = "cargo-clippy", allow(needless_lifetimes))]
License
Licensed under MPL. If you're having issues with the license, let me know and I'll try to change it to something more permissive.