Clippy welcomes contributions from everyone. There are many ways to contribute to Clippy and the following document
explains how you can contribute and how to get started. If you have any questions about contributing or need help with
-anything, feel free to ask questions on issues or visit the `#clippy` on [Discord].
+anything, feel free to ask questions on issues or visit the `#clippy` on [Zulip].
All contributors are expected to follow the [Rust Code of Conduct].
-* [Getting started](#getting-started)
- * [Finding something to fix/improve](#finding-something-to-fiximprove)
-* [Writing code](#writing-code)
-* [How Clippy works](#how-clippy-works)
-* [Fixing nightly build failures](#fixing-build-failures-caused-by-rust)
-* [Issue and PR Triage](#issue-and-pr-triage)
-* [Bors and Homu](#bors-and-homu)
-* [Contributions](#contributions)
-
-[Discord]: https://discord.gg/rust-lang
+- [Contributing to Clippy](#contributing-to-clippy)
+ - [The Clippy book](#the-clippy-book)
+ - [High level approach](#high-level-approach)
+ - [Finding something to fix/improve](#finding-something-to-fiximprove)
+ - [Getting code-completion for rustc internals to work](#getting-code-completion-for-rustc-internals-to-work)
+ - [IntelliJ Rust](#intellij-rust)
+ - [Rust Analyzer](#rust-analyzer)
+ - [How Clippy works](#how-clippy-works)
+ - [Issue and PR triage](#issue-and-pr-triage)
+ - [Bors and Homu](#bors-and-homu)
+ - [Contributions](#contributions)
+
+[Zulip]: https://rust-lang.zulipchat.com/#narrow/stream/clippy
[Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct
-## Getting started
+## The Clippy book
+
+If you're new to Clippy and don't know where to start, the [Clippy book] includes
+a [developer guide] and is a good place to start your journey.
+
+[Clippy book]: https://doc.rust-lang.org/nightly/clippy/index.html
+[developer guide]: https://doc.rust-lang.org/nightly/clippy/development/index.html
-High level approach:
+## High level approach
1. Find something to fix/improve
2. Change code (likely some file in `clippy_lints/src/`)
-3. Follow the instructions in the [docs for writing lints](doc/adding_lints.md) such as running the `setup-toolchain.sh` script
+3. Follow the instructions in the [Basics docs](book/src/development/basics.md)
+ to get set up
4. Run `cargo test` in the root directory and wiggle code until it passes
5. Open a PR (also can be done after 2. if you run into problems)
-### Finding something to fix/improve
+## Finding something to fix/improve
-All issues on Clippy are mentored, if you want help with a bug just ask @Manishearth, @llogiq, @mcarton or @oli-obk.
+All issues on Clippy are mentored, if you want help simply ask someone from the
+Clippy team directly by mentioning them in the issue or over on [Zulip]. All
+currently active team members can be found
+[here](https://github.com/rust-lang/highfive/blob/master/highfive/configs/rust-lang/rust-clippy.json#L3)
-Some issues are easier than others. The [`good first issue`] label can be used to find the easy issues.
-If you want to work on an issue, please leave a comment so that we can assign it to you!
+Some issues are easier than others. The [`good-first-issue`] label can be used to find the easy
+issues. You can use `@rustbot claim` to assign the issue to yourself.
There are also some abandoned PRs, marked with [`S-inactive-closed`].
Pretty often these PRs are nearly completed and just need some extra steps
[`T-AST`] issues will generally need you to match against a predefined syntax structure.
To figure out how this syntax structure is encoded in the AST, it is recommended to run
-`rustc -Z ast-json` on an example of the structure and compare with the [nodes in the AST docs].
-Usually the lint will end up to be a nested series of matches and ifs, [like so].
+`rustc -Z unpretty=ast-tree` on an example of the structure and compare with the [nodes in the AST docs].
+Usually the lint will end up to be a nested series of matches and ifs, [like so][deep-nesting].
+But we can make it nest-less by using [let chains], [like this][nest-less].
-[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an E-easy issue first.
-They are mostly classified as [`E-medium`], since they might be somewhat involved code wise,
-but not difficult per-se.
+[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an [`good-first-issue`]
+first. Sometimes they are only somewhat involved code wise, but not difficult per-se.
+Note that [`E-medium`] issues may require some knowledge of Clippy internals or some
+debugging to find the actual problem behind the issue.
[`T-middle`] issues can be more involved and require verifying types. The [`ty`] module contains a
lot of methods that are useful, though one of the most useful would be `expr_ty` (gives the type of
an AST expression). `match_def_path()` in Clippy's `utils` module can also be useful.
-[`good first issue`]: https://github.com/rust-lang/rust-clippy/labels/good%20first%20issue
+[`good-first-issue`]: https://github.com/rust-lang/rust-clippy/labels/good-first-issue
[`S-inactive-closed`]: https://github.com/rust-lang/rust-clippy/pulls?q=is%3Aclosed+label%3AS-inactive-closed
[`T-AST`]: https://github.com/rust-lang/rust-clippy/labels/T-AST
[`T-middle`]: https://github.com/rust-lang/rust-clippy/labels/T-middle
[`E-medium`]: https://github.com/rust-lang/rust-clippy/labels/E-medium
-[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc/ty
+[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty
[nodes in the AST docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/
-[like so]: https://github.com/rust-lang/rust-clippy/blob/de5ccdfab68a5e37689f3c950ed1532ba9d652a0/src/misc.rs#L34
+[deep-nesting]: https://github.com/rust-lang/rust-clippy/blob/5e4f0922911536f80d9591180fa604229ac13939/clippy_lints/src/mem_forget.rs#L31-L45
+[let chains]: https://github.com/rust-lang/rust/pull/94927
+[nest-less]: https://github.com/rust-lang/rust-clippy/blob/5e4f0922911536f80d9591180fa604229ac13939/clippy_lints/src/bit_mask.rs#L133-L159
+
+## Getting code-completion for rustc internals to work
+
+### IntelliJ Rust
+Unfortunately, [`IntelliJ Rust`][IntelliJ_rust_homepage] does not (yet?) understand how Clippy uses compiler-internals
+using `extern crate` and it also needs to be able to read the source files of the rustc-compiler which are not
+available via a `rustup` component at the time of writing.
+To work around this, you need to have a copy of the [rustc-repo][rustc_repo] available which can be obtained via
+`git clone https://github.com/rust-lang/rust/`.
+Then you can run a `cargo dev` command to automatically make Clippy use the rustc-repo via path-dependencies
+which `IntelliJ Rust` will be able to understand.
+Run `cargo dev setup intellij --repo-path <repo-path>` where `<repo-path>` is a path to the rustc repo
+you just cloned.
+The command will add path-dependencies pointing towards rustc-crates inside the rustc repo to
+Clippy's `Cargo.toml`s and should allow `IntelliJ Rust` to understand most of the types that Clippy uses.
+Just make sure to remove the dependencies again before finally making a pull request!
+
+[rustc_repo]: https://github.com/rust-lang/rust/
+[IntelliJ_rust_homepage]: https://intellij-rust.github.io/
+
+### Rust Analyzer
+For [`rust-analyzer`][ra_homepage] to work correctly make sure that in the `rust-analyzer` configuration you set
+
+```json
+{ "rust-analyzer.rustc.source": "discover" }
+```
-## Writing code
+You should be able to see information on things like `Expr` or `EarlyContext` now if you hover them, also
+a lot more type hints.
-Have a look at the [docs for writing lints][adding_lints] for more details. [Llogiq's blog post on lints]
-is also a nice primer to lint-writing, though it does get into advanced stuff and may be a bit outdated.
+To have `rust-analyzer` also work in the `clippy_dev` and `lintcheck` crates, add the following configuration
-If you want to add a new lint or change existing ones apart from bugfixing, it's
-also a good idea to give the [stability guarantees][rfc_stability] and
-[lint categories][rfc_lint_cats] sections of the [Clippy 1.0 RFC][clippy_rfc] a
-quick read.
+```json
+{
+ "rust-analyzer.linkedProjects": [
+ "./Cargo.toml",
+ "clippy_dev/Cargo.toml",
+ "lintcheck/Cargo.toml",
+ ]
+}
+```
-[adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
-[Llogiq's blog post on lints]: https://llogiq.github.io/2015/06/04/workflows.html
-[clippy_rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md
-[rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees
-[rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
+[ra_homepage]: https://rust-analyzer.github.io/
## How Clippy works
[early_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html
[late_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.LateLintPass.html
-## Fixing build failures caused by Rust
-
-Clippy will sometimes fail to build from source because building it depends on unstable internal Rust features. Most of
-the times we have to adapt to the changes and only very rarely there's an actual bug in Rust. Fixing build failures
-caused by Rust updates, can be a good way to learn about Rust internals.
-
-In order to find out why Clippy does not work properly with a new Rust commit, you can use the [rust-toolstate commit
-history][toolstate_commit_history]. You will then have to look for the last commit that contains
-`test-pass -> build-fail` or `test-pass -> test-fail` for the `clippy-driver` component.
-[Here][toolstate_commit] is an example.
-
-The commit message contains a link to the PR. The PRs are usually small enough to discover the breaking API change and
-if they are bigger, they likely include some discussion that may help you to fix Clippy.
-
-To check if Clippy is available for a specific target platform, you can check
-the [rustup component history][rustup_component_history].
-
-If you decide to make Clippy work again with a Rust commit that breaks it,
-you probably want to install the latest Rust from master locally and run Clippy
-using that version of Rust.
-
-You can set up the master toolchain by running `./setup-toolchain.sh`. That script will install
-[rustup-toolchain-install-master][rtim] and master toolchain, then run `rustup override set master`.
-
-After fixing the build failure on this repository, we can submit a pull request
-to [`rust-lang/rust`] to fix the toolstate.
-
-To submit a pull request, you should follow these steps:
-
-```bash
-# Assuming you already cloned the rust-lang/rust repo and you're in the correct directory
-git submodule update --remote src/tools/clippy
-cargo update -p clippy
-git add -u
-git commit -m "Update Clippy"
-./x.py test -i --stage 1 src/tools/clippy # This is optional and should succeed anyway
-# Open a PR in rust-lang/rust
-```
-
-[rustup_component_history]: https://rust-lang.github.io/rustup-components-history
-[toolstate_commit_history]: https://github.com/rust-lang-nursery/rust-toolstate/commits/master
-[toolstate_commit]: https://github.com/rust-lang-nursery/rust-toolstate/commit/aad74d8294e198a7cf8ac81a91aebb7f3bbcf727
-[rtim]: https://github.com/kennytm/rustup-toolchain-install-master
-[`rust-lang/rust`]: https://github.com/rust-lang/rust
-
## Issue and PR triage
Clippy is following the [Rust triage procedure][triage] for issues and pull
responding to issues there may not always be enough time to stay on top of it
all.
-Our highest priority is fixing [crashes][l-crash] and [bugs][l-bug]. We don't
+Our highest priority is fixing [crashes][l-crash] and [bugs][l-bug], for example
+an ICE in a popular crate that many other crates depend on. We don't
want Clippy to crash on your code and we want it to be as reliable as the
suggestions from Rust compiler errors.
+We have prioritization labels and a sync-blocker label, which are described below.
+- [P-low][p-low]: Requires attention (fix/response/evaluation) by a team member but isn't urgent.
+- [P-medium][p-medium]: Should be addressed by a team member until the next sync.
+- [P-high][p-high]: Should be immediately addressed and will require an out-of-cycle sync or a backport.
+- [L-sync-blocker][l-sync-blocker]: An issue that "blocks" a sync.
+Or rather: before the sync this should be addressed,
+e.g. by removing a lint again, so it doesn't hit beta/stable.
+
## Bors and Homu
We use a bot powered by [Homu][homu] to help automate testing and landing of pull
If you have @bors permissions, you can find an overview of the available
commands [here][homu_instructions].
-[triage]: https://forge.rust-lang.org/triage-procedure.html
-[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash%20%3Aboom%3A
-[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug%20%3Abeetle%3A
+[triage]: https://forge.rust-lang.org/release/triage-procedure.html
+[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash
+[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug
+[p-low]: https://github.com/rust-lang/rust-clippy/labels/P-low
+[p-medium]: https://github.com/rust-lang/rust-clippy/labels/P-medium
+[p-high]: https://github.com/rust-lang/rust-clippy/labels/P-high
+[l-sync-blocker]: https://github.com/rust-lang/rust-clippy/labels/L-sync-blocker
[homu]: https://github.com/rust-lang/homu
-[homu_instructions]: https://buildbot2.rust-lang.org/homu/
-[homu_queue]: https://buildbot2.rust-lang.org/homu/queue/clippy
+[homu_instructions]: https://bors.rust-lang.org/
+[homu_queue]: https://bors.rust-lang.org/queue/clippy
## Contributions
projects / rust.git / blobdiff