rust-analyzer/docs/user

The main interface to rust-analyzer is the LSP implementation. To install lsp server, clone the repository and then run cargo xtask install --server (which is shorthand for cargo install --path ./crates/ra_lsp_server). This will produce a binary named ra_lsp_server which you should be able to use it with any LSP-compatible editor. We use custom extensions to LSP, so special client-side support is required to take full advantage of rust-analyzer. This repository contains support code for VS Code and Emacs.

$ git clone git@github.com:rust-analyzer/rust-analyzer && cd rust-analyzer
$ cargo xtask install --server

Rust Analyzer needs sources of rust standard library to work, so you might also need to execute

$ rustup component add rust-src

See ./features.md document for a list of features that are available.

VS Code

Prerequisites:

In order to build the VS Code plugin, you need to have node.js and npm with a minimum version of 10 installed. Please refer to node.js and npm documentation for installation instructions.

You will also need the most recent version of VS Code: we don't try to maintain compatibility with older versions yet.

The experimental VS Code plugin can then be built and installed by executing the following commands:

$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
$ cd rust-analyzer
$ cargo xtask install

The automatic installation is expected to just work for common cases, if it doesn't, report bugs!

Note #1831: If you are using the popular Vim emulation plugin, you will likely need to turn off the rust-analyzer.enableEnhancedTyping setting.

If you have an unusual setup (for example, code is not in the PATH), you should adapt these manual installation instructions:

$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
$ cd rust-analyzer
$ cargo install --path ./crates/ra_lsp_server/ --force --locked
$ cd ./editors/code
$ npm install
$ npm run package
$ code --install-extension ./rust-analyzer-0.1.0.vsix

It's better to remove existing Rust plugins to avoid interference.

Beyond basic LSP features, there are some extension commands which you can invoke via Ctrl+Shift+P or bind to a shortcut. See ./features.md for details.

For updates, pull the latest changes from the master branch, run cargo xtask install again, and restart VS Code instance. See microsoft/vscode#72308 for why a full restart is needed.

VS Code Remote

You can also use rust-analyzer with the Visual Studio Code Remote extensions (Remote SSH, Remote WSL, Remote Containers). In this case, however, you have to manually install the .vsix package:

1. Build the extension on the remote host using the instructions above (ignore the error if code cannot be found in your PATH: VSCode doesn't need to be installed on the remote host).
2. In Visual Studio Code open a connection to the remote host.
3. Open the Extensions View (View > Extensions, keyboard shortcut: Ctrl+Shift+X).
4. From the top-right kebab menu (···) select Install from VSIX...
5. Inside the rust-analyzer directory find the editors/code subdirectory and choose the rust-analyzer-0.1.0.vsix file.
6. Restart Visual Studio Code and re-establish the connection to the remote host.

In case of errors please make sure that ~/.cargo/bin is in your PATH on the remote host.

Settings

• rust-analyzer.highlightingOn: enables experimental syntax highlighting. Colors can be configured via editor.tokenColorCustomizations. As an example, Pale Fire color scheme tweaks rust colors.
• rust-analyzer.enableEnhancedTyping: by default, rust-analyzer intercepts. Enter key to make it easier to continue comments. Note that it may conflict with VIM emulation plugin.
• rust-analyzer.raLspServerPath: path to ra_lsp_server executable
• rust-analyzer.enableCargoWatchOnStartup: prompt to install & enable cargo watch for live error highlighting (note, this does not use rust-analyzer)
• rust-analyzer.excludeGlobs: a list of glob-patterns for exclusion (see globset docs for syntax). Note: glob patterns are applied to all Cargo packages and a rooted at a package root. This is not very intuitive and a limitation of a current implementation.
• rust-analyzer.useClientWatching: use client provided file watching instead of notify watching.
• rust-analyzer.cargo-watch.command: cargo-watch command. (e.g: clippy will run as cargo watch -x clippy )
• rust-analyzer.cargo-watch.arguments: cargo-watch check arguments. (e.g: --features="shumway,pdf" will run as cargo watch -x "check --features="shumway,pdf"" )
• rust-analyzer.cargo-watch.ignore: list of patterns for cargo-watch to ignore (will be passed as --ignore)
• rust-analyzer.trace.server: enables internal logging
• rust-analyzer.trace.cargo-watch: enables cargo-watch logging
• RUST_SRC_PATH: environment variable that overwrites the sysroot
• rust-analyzer.featureFlags -- a JSON object to tweak fine-grained behavior:

  {
      // Show diagnostics produced by rust-analyzer itself.
      "lsp.diagnostics": true,
      // Automatically insert `()` and `<>` when completing functions and types.
      "completion.insertion.add-call-parenthesis": true,
      // Enable completions like `.if`, `.match`, etc.
      "completion.enable-postfix": true,
      // Show notification when workspace is fully loaded
      "notifications.workspace-loaded": true,
      // Show error when no Cargo.toml was found
      "notifications.cargo-toml-not-found": true,
  }
  

Emacs

Prerequisites:

emacs-lsp, dash and ht packages.

Installation:

• add rust-analyzer.el to load path and require it in init.el
• run lsp in a rust buffer
• (Optionally) bind commands like rust-analyzer-join-lines, rust-analyzer-extend-selection and rust-analyzer-expand-macro to keys, and enable rust-analyzer-inlay-hints-mode to get inline type hints

Vim and NeoVim (coc-rust-analyzer)

• Install coc.nvim by following the instructions at coc.nvim (nodejs required)
• Run :CocInstall coc-rust-analyzer to install coc-rust-analyzer, this extension implements most of the features supported in the VSCode extension:
  • same configurations as VSCode extension, rust-analyzer.raLspServerPath, rust-analyzer.enableCargoWatchOnStartup etc.
  • same commands too, rust-analyzer.analyzerStatus, rust-analyzer.startCargoWatch etc.
  • highlighting and inlay_hints are not implemented yet

Vim and NeoVim (LanguageClient-neovim)

• Install LanguageClient-neovim by following the instructions here

  • The github project wiki has extra tips on configuration

• Configure by adding this to your vim/neovim config file (replacing the existing rust specific line if it exists):

let g:LanguageClient_serverCommands = {
\ 'rust': ['ra_lsp_server'],
\ }

NeoVim (nvim-lsp)

NeoVim 0.5 (not yet released) has built in language server support. For a quick start configuration of rust-analyzer, use neovim/nvim-lsp. Once neovim/nvim-lsp is installed, use lua require'nvim_lsp'.rust_analyzer.setup({}) in your init.vim.

Sublime Text 3

Prequisites:

LSP package.

Installation:

• Invoke the command palette with Ctrl+Shift+P
• Type LSP Settings to open the LSP preferences editor
• Add the following LSP client definition to your settings:

"rust-analyzer": {
    "command": ["ra_lsp_server"],
    "languageId": "rust",
    "scopes": ["source.rust"],
    "syntaxes": [
        "Packages/Rust/Rust.sublime-syntax",
        "Packages/Rust Enhanced/RustEnhanced.sublime-syntax"
    ],
    "initializationOptions": {
      "featureFlags": {
      }
    },
}

• You can now invoke the command palette and type LSP enable to locally/globally enable the rust-analyzer LSP (type LSP enable, then choose either locally or globally, then select rust-analyzer)

Setting up the PATH variable

On Unix systems, rustup adds ~/.cargo/bin to PATH by modifying the shell's startup file. Depending on your configuration, your Desktop Environment might not actually load it. If you find that rust-analyzer only runs when starting the editor from the terminal, you will have to set up your PATH variable manually.

There are a couple of ways to do that:

• for Code, set rust-analyzer.raLspServerPath to ~/.cargo/bin (the ~ is automatically resolved by the extension)
• copy the binary to a location that is already in PATH, e.g. /usr/local/bin
• on Linux, use PAM to configure the PATH variable, by e.g. putting PATH DEFAULT=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:@{HOME}/.cargo/bin:@{HOME}/.local/bin in your ~/.pam_environment file; note that this might interfere with other defaults set by the system administrator via /etc/environment.