7af0c67855
Hey there clippy team! I've made some assumptions in this PR and I'm not at all certain they'll look like the right approach to you. I'm looking forward to any feedback or revision requests you have, thanks!
Prior to this commit the `indexing_slicing` lint was limited to indexing/slicing operations on arrays. This meant that the scope of a really useful lint didn't include vectors. In order to include vectors in the `indexing_slicing` lint a few steps were taken.
The `array_indexing.rs` source file in `clippy_lints` was renamed to `indexing_slicing.rs` to more accurately reflect the lint's new scope. The `OUT_OF_BOUNDS_INDEXING` lint persists through these changes so if we can know that a constant index or slice on an array is in bounds no lint is triggered.
The `array_indexing` tests in the `tests/ui` directory were also extended and moved to `indexing_slicing.rs` and `indexing_slicing.stderr`.
The `indexing_slicing` lint was moved to the `clippy_pedantic` lint group.
A specific "Consider using" string was added to each of the `indexing_slicing` lint reports.
At least one of the test scenarios might look peculiar and I'll leave it up to y'all to decide if it's palatable. It's the result of indexing the array `x` after `let x = [1, 2, 3, 4];`
```
error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)`instead
--> $DIR/indexing_slicing.rs:23:6
|
23 | &x[0..][..3];
| ^^^^^^^^^^^
```
The error string reports only on the second half's range-to, because the range-from is in bounds!
Again, thanks for taking a look.
Closes #2536
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| mini-macro | ||
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| util | ||
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| build.rs | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| min_version.txt | ||
| pre_publish.sh | ||
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| README.md | ||
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rust-clippy
A collection of lints to catch common mistakes and improve your Rust code.
There are 268 lints included in this crate!
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 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.
To install Rust nightly, the recommended way is to use rustup:
rustup install nightly
As a cargo subcommand (cargo clippy)
One way to use clippy is by installing clippy through cargo as a cargo subcommand.
cargo +nightly install clippy
(The +nightly is not necessary if your default rustup install is nightly)
Now you can run clippy by invoking cargo +nightly clippy.
To update the subcommand together with the latest nightly use the rust-update script or run:
rustup update nightly
cargo +nightly install --force clippy
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 it
To have cargo compile your crate with clippy without clippy installation in your code, you can use:
cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
Note: Be sure that clippy was compiled with the same version of rustc that cargo invokes here!
Configuration
Some lints can be configured in a TOML file named with clippy.toml or .clippy.toml. It contains basic variable = value mapping eg.
blacklisted-names = ["toto", "tata", "titi"]
cyclomatic-complexity-threshold = 30
See the list of lints for more information about which lints can be configured and the meaning of the variables.
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:
-
the whole set of
Warnlints using theclippylint group (#![deny(clippy)]) -
all lints using both the
clippyandclippy_pedanticlint groups (#![deny(clippy)],#![deny(clippy_pedantic)]). Note thatclippy_pedanticcontains some very aggressive lints prone to false positives. -
only some lints (
#![deny(single_match, box_vec)], etc) -
allow/warn/denycan 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:
#[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 script to update rustc only if clippy would also update correctly.
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.