- [Finding something to fix/improve](#finding-something-to-fiximprove)
- [Writing code](#writing-code)
- [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)
- [Syncing changes between Clippy and `rust-lang/rust`](#syncing-changes-between-clippy-and-rust-langrust)
- [Patching git-subtree to work with big repos](#patching-git-subtree-to-work-with-big-repos)
[`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].
+`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 [if_chain] macro, [like this][nest-less].
+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 [`good-first-issue`]
first. Sometimes they are only somewhat involved code wise, but not difficult per-se.
[`E-medium`]: https://github.com/rust-lang/rust-clippy/labels/E-medium
[`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/
-[deep-nesting]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/mem_forget.rs#L29-L43
-[if_chain]: https://docs.rs/if_chain/*/if_chain
-[nest-less]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/bit_mask.rs#L124-L150
+[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
## Writing code
## Getting code-completion for rustc internals to work
-Unfortunately, [`rust-analyzer`][ra_homepage] does not (yet?) understand how Clippy uses compiler-internals
+### 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 rust-analyzer will be able to understand.
-Run `cargo dev ra_setup --repo-path <repo-path>` where `<repo-path>` is an absolute path to the rustc repo
+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
-Clippys `Cargo.toml`s and should allow rust-analyzer to understand most of the types that Clippy uses.
+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!
-[ra_homepage]: https://rust-analyzer.github.io/
[rustc_repo]: https://github.com/rust-lang/rust/
+[IntelliJ_rust_homepage]: https://intellij-rust.github.io/
+
+### Rust Analyzer
+As of [#6869][6869], [`rust-analyzer`][ra_homepage] can understand that Clippy uses compiler-internals
+using `extern crate` when `package.metadata.rust-analyzer.rustc_private` is set to `true` in Clippy's `Cargo.toml.`
+You will require a `nightly` toolchain with the `rustc-dev` component installed.
+Make sure that in the `rust-analyzer` configuration, you set
+```
+{ "rust-analyzer.rustcSource": "discover" }
+```
+and
+```
+{ "rust-analyzer.updates.channel": "nightly" }
+```
+You should be able to see information on things like `Expr` or `EarlyContext` now if you hover them, also
+a lot more type hints.
+This will work with `rust-analyzer 2021-03-15` shipped in nightly `1.52.0-nightly (107896c32 2021-03-15)` or later.
+
+[ra_homepage]: https://rust-analyzer.github.io/
+[6869]: https://github.com/rust-lang/rust-clippy/pull/6869
## How Clippy works
### Patching git-subtree to work with big repos
-Currently there's a bug in `git-subtree` that prevents it from working properly
+Currently, there's a bug in `git-subtree` that prevents it from working properly
with the [`rust-lang/rust`] repo. There's an open PR to fix that, but it's stale.
Before continuing with the following steps, we need to manually apply that fix to
our local copy of `git-subtree`.
2. Checkout the commit from the latest available nightly. You can get it using `rustup check`.
3. Sync the changes to the rust-copy of Clippy to your Clippy fork:
```bash
- # Make sure to change `your-github-name` to your github name in the following command
+ # Make sure to change `your-github-name` to your github name in the following command. Also be
+ # sure to either use a net-new branch, e.g. `sync-from-rust`, or delete the branch beforehand
+ # because changes cannot be fast forwarded
git subtree push -P src/tools/clippy git@github.com:your-github-name/rust-clippy sync-from-rust
```
- [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.
+- [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.
projects / rust.git / blobdiff