# Repository: rust-lang/rust-analyzer
# Stars: 16271

## CLAUDE.md

**Reminder: All AI usage must be disclosed in commit messages, see
CONTRIBUTING.md for more details.**

## Build Commands

```bash
cargo build                    # Build all crates
cargo test                     # Run all tests
cargo test -p <crate>          # Run tests for a specific crate (e.g., cargo test -p hir-ty)
cargo lint                     # Run clippy on all targets
cargo xtask codegen            # Run code generation
cargo xtask tidy               # Run tidy checks
UPDATE_EXPECT=1 cargo test     # Update test expectations (snapshot tests)
RUN_SLOW_TESTS=1 cargo test    # Run heavy/slow tests
```

## Key Architectural Invariants

- Typing in a function body never invalidates global derived data
- Parser/syntax tree is built per-file to enable parallel parsing
- The server is stateless (HTTP-like); context must be re-created from request parameters
- Cancellation uses salsa's cancellation mechanism; computations panic with a `Cancelled` payload

### Code Generation

Generated code is committed to the repo. Grammar and AST are generated from `ungrammar`. Run `cargo test -p xtask` after adding inline parser tests (`// test test_name` comments).

## Testing

Tests are snapshot-based using `expect-test`. Test fixtures use a mini-language:
- `$0` marks cursor position
- `// ^^^^` labels attach to the line above
- `//- minicore: sized, fn` includes parts of minicore (minimal core library)
- `//- /path/to/file.rs crate:name deps:dep1,dep2` declares files/crates

## Style Notes

- Use `stdx::never!` and `stdx::always!` instead of `assert!` for recoverable invariants
- Use `T![fn]` macro instead of `SyntaxKind::FN_KW`
- Use keyword name mangling over underscore prefixing for identifiers: `crate` → `krate`, `fn` → `func`, `struct` → `strukt`, `type` → `ty`


## README.md

<p align="center">
  <img
    src="https://raw.githubusercontent.com/rust-lang/rust-analyzer/master/assets/logo-wide.svg"
    alt="rust-analyzer logo">
</p>

rust-analyzer is a language server that provides IDE functionality for
writing Rust programs. You can use it with any editor that supports
the [Language Server
Protocol](https://microsoft.github.io/language-server-protocol/) (VS
Code, Vim, Emacs, Zed, etc).

rust-analyzer features include go-to-definition, find-all-references,
refactorings and code completion. rust-analyzer also supports
integrated formatting (with rustfmt) and integrated diagnostics (with
rustc and clippy).

Internally, rust-analyzer is structured as a set of libraries for
analyzing Rust code. See
[Architecture](https://rust-analyzer.github.io/book/contributing/architecture.html)
in the manual.

[![codecov](https://codecov.io/github/rust-lang/rust-analyzer/graph/badge.svg)](https://app.codecov.io/github/rust-lang/rust-analyzer/tree/master)

## Quick Start

https://rust-analyzer.github.io/book/installation.html

## Documentation

If you want to **contribute** to rust-analyzer check out the [CONTRIBUTING.md](./CONTRIBUTING.md) or
if you are just curious about how things work under the hood, see the
[Contributing](https://rust-analyzer.github.io/book/contributing) section of the manual.

If you want to **use** rust-analyzer's language server with your editor of
choice, check [the manual](https://rust-analyzer.github.io/book/).
It also contains some tips & tricks to help you be more productive when using rust-analyzer.

## Security and Privacy

See the [security](https://rust-analyzer.github.io/book/security.html) and
[privacy](https://rust-analyzer.github.io/book/privacy.html) sections of the manual.

## Communication

For usage and troubleshooting requests, please use "IDEs and Editors" category of the Rust forum:

https://users.rust-lang.org/c/ide/14

For questions about development and implementation, join rust-analyzer working group on Zulip:

https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Frust-analyzer

## Quick Links

* Website: https://rust-analyzer.github.io/
* Metrics: https://rust-analyzer.github.io/metrics/
* API docs: https://rust-lang.github.io/rust-analyzer/ide/
* Changelog: https://rust-analyzer.github.io/thisweek

## License

rust-analyzer is primarily distributed under the terms of both the MIT
license and the Apache License (Version 2.0).

See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.