6 :source-highlighter: rouge
10 IMPORTANT: the master copy of this document lives in the https://github.com/rust-analyzer/rust-analyzer repository
13 At its core, rust-analyzer is a *library* for semantic analysis of Rust code as it changes over time.
14 This manual focuses on a specific usage of the library -- running it as part of a server that implements the
15 https://microsoft.github.io/language-server-protocol/[Language Server Protocol] (LSP).
16 The LSP allows various code editors, like VS Code, Emacs or Vim, to implement semantic features like completion or goto definition by talking to an external language server process.
21 To improve this document, send a pull request: +
22 https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/manual.adoc[https://github.com/rust-analyzer/.../manual.adoc]
24 The manual is written in https://asciidoc.org[AsciiDoc] and includes some extra files which are generated from the source code. Run `cargo test` and `cargo test -p xtask` to create these and then `asciidoctor manual.adoc` to create an HTML copy.
27 If you have questions about using rust-analyzer, please ask them in the https://users.rust-lang.org/c/ide/14["`IDEs and Editors`"] topic of Rust users forum.
31 In theory, one should be able to just install the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>> and have it automatically work with any editor.
32 We are not there yet, so some editor specific setup is required.
34 Additionally, rust-analyzer needs the sources of the standard library.
35 If the source code is not present, rust-analyzer will attempt to install it automatically.
37 To add the sources manually, run the following command:
40 $ rustup component add rust-src
45 This is the best supported editor at the moment.
46 The rust-analyzer plugin for VS Code is maintained
47 https://github.com/rust-analyzer/rust-analyzer/tree/master/editors/code[in tree].
49 You can install the latest release of the plugin from
50 https://marketplace.visualstudio.com/items?itemName=matklad.rust-analyzer[the marketplace].
52 Note that the plugin may cause conflicts with the
53 https://marketplace.visualstudio.com/items?itemName=rust-lang.rust[official Rust plugin].
54 It is recommended to disable the Rust plugin when using the rust-analyzer extension.
56 By default, the plugin will prompt you to download the matching version of the server as well:
58 image::https://user-images.githubusercontent.com/9021944/75067008-17502500-54ba-11ea-835a-f92aac50e866.png[]
62 To disable this notification put the following to `settings.json`
66 { "rust-analyzer.updates.askBeforeDownload": false }
70 The server binary is stored in:
72 * Linux: `~/.config/Code/User/globalStorage/matklad.rust-analyzer`
73 * Linux (Remote, such as WSL): `~/.vscode-server/data/User/globalStorage/matklad.rust-analyzer`
74 * macOS: `~/Library/Application\ Support/Code/User/globalStorage/matklad.rust-analyzer`
75 * Windows: `%APPDATA%\Code\User\globalStorage\matklad.rust-analyzer`
77 Note that we only support two most recent versions of VS Code.
81 The extension will be updated automatically as new versions become available.
82 It will ask your permission to download the matching language server version binary if needed.
86 We ship nightly releases for VS Code.
87 To help us out with testing the newest code and follow the bleeding edge of our `master`, please use the following config:
91 { "rust-analyzer.updates.channel": "nightly" }
94 You will be prompted to install the `nightly` extension version.
95 Just click `Download now` and from that moment you will get automatic updates every 24 hours.
97 If you don't want to be asked for `Download now` every day when the new nightly version is released add the following to your `settings.json`:
100 { "rust-analyzer.updates.askBeforeDownload": false }
103 NOTE: Nightly extension should **only** be installed via the `Download now` action from VS Code.
105 ==== Manual installation
107 Alternatively, procure both `rust-analyzer.vsix` and your platform's matching `rust-analyzer-{platform}`, for example from the
108 https://github.com/rust-analyzer/rust-analyzer/releases[releases] page.
110 Install the extension with the `Extensions: Install from VSIX` command within VS Code, or from the command line via:
113 $ code --install-extension /path/to/rust-analyzer.vsix
116 Copy the `rust-analyzer-{platform}` binary anywhere, then add the path to your settings.json, for example:
119 { "rust-analyzer.server.path": "~/.local/bin/rust-analyzer-linux" }
122 ==== Building From Source
124 Alternatively, both the server and the Code plugin can be installed from source:
128 $ git clone https://github.com/rust-analyzer/rust-analyzer.git && cd rust-analyzer
129 $ cargo xtask install
132 You'll need Cargo, nodejs and npm for this.
134 Note that installing via `xtask install` does not work for VS Code Remote, instead you'll need to install the `.vsix` manually.
136 If you're not using Code, you can compile and install only the LSP server:
140 $ cargo xtask install --server
143 === rust-analyzer Language Server Binary
145 Other editors generally require the `rust-analyzer` binary to be in `$PATH`.
146 You can download pre-built binaries from the https://github.com/rust-analyzer/rust-analyzer/releases[releases] page.
147 You will need to uncompress and rename the binary for your platform, e.g. from `rust-analyzer-aarch64-apple-darwin.gz` on Mac OS to `rust-analyzer`, make it executable, then move it into a directory in your `$PATH`.
149 On Linux to install the `rust-analyzer` binary into `~/.local/bin`, these commands should work:
153 $ curl -L https://github.com/rust-analyzer/rust-analyzer/releases/latest/download/rust-analyzer-x86_64-unknown-linux-gnu.gz | gunzip -c - > ~/.local/bin/rust-analyzer
154 $ chmod +x ~/.local/bin/rust-analyzer
157 Make sure that `~/.local/bin` is listed in the `$PATH` variable and use the appropriate URL if you're not on a `x86-64` system.
159 Alternatively, you can install it from source using the command below.
160 You'll need the latest stable version of the Rust toolchain.
164 $ git clone https://github.com/rust-analyzer/rust-analyzer.git && cd rust-analyzer
165 $ cargo xtask install --server
168 If your editor can't find the binary even though the binary is on your `$PATH`, the likely explanation is that it doesn't see the same `$PATH` as the shell, see https://github.com/rust-analyzer/rust-analyzer/issues/1811[this issue].
169 On Unix, running the editor from a shell or changing the `.desktop` file to set the environment should help.
173 `rust-analyzer` is available in `rustup`, but only in the nightly toolchain:
177 $ rustup +nightly component add rust-analyzer-preview
180 However, in contrast to `component add clippy` or `component add rustfmt`, this does not actually place a `rust-analyzer` binary in `~/.cargo/bin`, see https://github.com/rust-lang/rustup/issues/2411[this issue].
184 The `rust-analyzer` binary can be installed from the repos or AUR (Arch User Repository):
186 - https://www.archlinux.org/packages/community/x86_64/rust-analyzer/[`rust-analyzer`] (built from latest tagged source)
187 - https://aur.archlinux.org/packages/rust-analyzer-git[`rust-analyzer-git`] (latest Git version)
189 Install it with pacman, for example:
193 $ pacman -S rust-analyzer
198 `rust-analyzer` is available in the GURU repository:
200 - https://gitweb.gentoo.org/repo/proj/guru.git/tree/dev-util/rust-analyzer-bin/rust-analyzer-bin-9999.ebuild[`dev-util/rust-analyzer-bin-9999`] (the https://github.com/rust-analyzer/rust-analyzer/releases/latest[latest release] as a live binary ebuild)
202 If not already, GURU must be enabled (e.g. using `app-eselect/eselect-repository`) and sync'd before running `emerge`:
206 $ eselect repository enable guru && emaint sync -r guru
207 $ emerge rust-analyzer-bin
212 The `rust-analyzer` binary can be installed via https://brew.sh/[Homebrew].
216 $ brew install rust-analyzer
221 Note this excellent https://robert.kra.hn/posts/2021-02-07_rust-with-emacs/[guide] from https://github.com/rksm[@rksm].
223 Prerequisites: You have installed the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>>.
225 Emacs support is maintained as part of the https://github.com/emacs-lsp/lsp-mode[Emacs-LSP] package in https://github.com/emacs-lsp/lsp-mode/blob/master/lsp-rust.el[lsp-rust.el].
227 1. Install the most recent version of `emacs-lsp` package by following the https://github.com/emacs-lsp/lsp-mode[Emacs-LSP instructions].
228 2. Set `lsp-rust-server` to `'rust-analyzer`.
229 3. Run `lsp` in a Rust buffer.
230 4. (Optionally) bind commands like `lsp-rust-analyzer-join-lines`, `lsp-extend-selection` and `lsp-rust-analyzer-expand-macro` to keys.
234 Prerequisites: You have installed the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>>.
235 Not needed if the extension can install/update it on its own, coc-rust-analyzer is one example.
237 The are several LSP client implementations for vim or neovim:
239 ==== coc-rust-analyzer
241 1. Install coc.nvim by following the instructions at
242 https://github.com/neoclide/coc.nvim[coc.nvim]
244 2. Run `:CocInstall coc-rust-analyzer` to install
245 https://github.com/fannheyward/coc-rust-analyzer[coc-rust-analyzer],
246 this extension implements _most_ of the features supported in the VSCode extension:
247 * automatically install and upgrade stable/nightly releases
248 * same configurations as VSCode extension, `rust-analyzer.server.path`, `rust-analyzer.cargo.features` etc.
249 * same commands too, `rust-analyzer.analyzerStatus`, `rust-analyzer.ssr` etc.
250 * inlay hints for variables and method chaining, _Neovim Only_
251 * semantic highlighting is not implemented yet
253 Note: for code actions, use `coc-codeaction-cursor` and `coc-codeaction-selected`; `coc-codeaction` and `coc-codeaction-line` are unlikely to be useful.
255 ==== LanguageClient-neovim
257 1. Install LanguageClient-neovim by following the instructions
258 https://github.com/autozimu/LanguageClient-neovim[here]
259 * The GitHub project wiki has extra tips on configuration
261 2. Configure by adding this to your vim/neovim config file (replacing the existing Rust-specific line if it exists):
265 let g:LanguageClient_serverCommands = {
266 \ 'rust': ['rust-analyzer'],
272 Install YouCompleteMe by following the instructions
273 https://github.com/ycm-core/YouCompleteMe#installation[here].
275 rust-analyzer is the default in ycm, it should work out of the box.
279 To use the LSP server in https://github.com/dense-analysis/ale[ale]:
283 let g:ale_linters = {'rust': ['analyzer']}
288 NeoVim 0.5 has built-in language server support.
289 For a quick start configuration of rust-analyzer, use https://github.com/neovim/nvim-lspconfig#rust_analyzer[neovim/nvim-lspconfig].
290 Once `neovim/nvim-lspconfig` is installed, use `+lua require'lspconfig'.rust_analyzer.setup({})+` in your `init.vim`.
292 You can also pass LSP settings to the server:
297 local nvim_lsp = require'lspconfig'
299 local on_attach = function(client)
300 require'completion'.on_attach(client)
303 nvim_lsp.rust_analyzer.setup({
306 ["rust-analyzer"] = {
308 importGranularity = "module",
309 importPrefix = "by_self",
312 loadOutDirsFromCheck = true
323 See https://sharksforarms.dev/posts/neovim-rust/ for more tips on getting started.
325 Check out https://github.com/simrat39/rust-tools.nvim for a batteries included rust-analyzer setup for neovim.
329 vim-lsp is installed by following https://github.com/prabirshrestha/vim-lsp[the plugin instructions].
330 It can be as simple as adding this line to your `.vimrc`:
334 Plug 'prabirshrestha/vim-lsp'
337 Next you need to register the `rust-analyzer` binary.
338 If it is available in `$PATH`, you may want to add this to your `.vimrc`:
342 if executable('rust-analyzer')
343 au User lsp_setup call lsp#register_server({
344 \ 'name': 'Rust Language Server',
345 \ 'cmd': {server_info->['rust-analyzer']},
346 \ 'whitelist': ['rust'],
351 There is no dedicated UI for the server configuration, so you would need to send any options as a value of the `initialization_options` field, as described in the <<_configuration,Configuration>> section.
352 Here is an example of how to enable the proc-macro support:
356 if executable('rust-analyzer')
357 au User lsp_setup call lsp#register_server({
358 \ 'name': 'Rust Language Server',
359 \ 'cmd': {server_info->['rust-analyzer']},
360 \ 'whitelist': ['rust'],
361 \ 'initialization_options': {
363 \ 'loadOutDirsFromCheck': v:true,
375 Prerequisites: You have installed the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>>.
377 You also need the `LSP` package.
380 1. If you've never installed a Sublime Text package, install Package Control:
381 * Open the command palette (Win/Linux: `ctrl+shift+p`, Mac: `cmd+shift+p`)
382 * Type `Install Package Control`, press enter
383 2. In the command palette, run `Package control: Install package`, and in the list that pops up, type `LSP` and press enter.
385 Finally, with your Rust project open, in the command palette, run `LSP: Enable Language Server In Project` or `LSP: Enable Language Server Globally`, then select `rust-analyzer` in the list that pops up to enable the rust-analyzer LSP.
386 The latter means that rust-analyzer is enabled by default in Rust projects.
388 If it worked, you should see "rust-analyzer, Line X, Column Y" on the left side of the bottom bar, and after waiting a bit, functionality like tooltips on hovering over variables should become available.
390 If you get an error saying `No such file or directory: 'rust-analyzer'`, see the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>> section on installing the language server binary.
394 GNOME Builder 3.37.1 and newer has native `rust-analyzer` support.
395 If the LSP binary is not available, GNOME Builder can install it when opening a Rust file.
400 Support for Rust development in the Eclipse IDE is provided by link:https://github.com/eclipse/corrosion[Eclipse Corrosion].
401 If available in PATH or in some standard location, `rust-analyzer` is detected and powers editing of Rust files without further configuration.
402 If `rust-analyzer` is not detected, Corrosion will prompt you for configuration of your Rust toolchain and language server with a link to the __Window > Preferences > Rust__ preference page; from here a button allows to download and configure `rust-analyzer`, but you can also reference another installation.
403 You'll need to close and reopen all .rs and Cargo files, or to restart the IDE, for this change to take effect.
407 Support for the language server protocol is built into Kate through the LSP plugin, which is included by default.
408 It is preconfigured to use Rls for rust sources, but allows you to use rust-analyzer through a simple settings change.
409 In the LSP Client settings of Kate, copy the content of the third tab "default parameters" to the second tab "server configuration".
410 Then in the configuration replace:
415 "rootIndicationFileNames": ["Cargo.lock", "Cargo.toml"],
416 "url": "https://github.com/rust-lang/rls",
417 "highlightingModeRegex": "^Rust$"
424 "command": ["rust-analyzer"],
425 "rootIndicationFileNames": ["Cargo.lock", "Cargo.toml"],
426 "url": "https://github.com/rust-analyzer/rust-analyzer",
427 "highlightingModeRegex": "^Rust$"
430 Then click on apply, and restart the LSP server for your rust project.
434 https://gitlab.com/cppit/jucipp[juCi++] has built-in support for the language server protocol, and since version 1.7.0 offers installation of both Rust and rust-analyzer when opening a Rust file.
438 Start with looking at the rust-analyzer version.
439 Try **Rust Analyzer: Show RA Version** in VS Code and `rust-analyzer --version` in the command line.
440 If the date is more than a week ago, it's better to update rust-analyzer version.
442 The next thing to check would be panic messages in rust-analyzer's log.
443 Log messages are printed to stderr, in VS Code you can see then in the `Output > Rust Analyzer Language Server` tab of the panel.
444 To see more logs, set `RA_LOG=info` environmental variable.
446 To fully capture LSP messages between the editor and the server, set `"rust-analyzer.trace.server": "verbose"` config and check
447 `Output > Rust Analyzer Language Server Trace`.
449 The root cause for many "`nothing works`" problems is that rust-analyzer fails to understand the project structure.
450 To debug that, first note the `rust-analyzer` section in the status bar.
451 If it has an error icon and red, that's the problem (hover will have somewhat helpful error message).
452 **Rust Analyzer: Status** prints dependency information for the current file.
453 Finally, `RA_LOG=project_model=debug` enables verbose logs during project loading.
455 If rust-analyzer outright crashes, try running `rust-analyzer analysis-stats /path/to/project/directory/` on the command line.
456 This command type checks the whole project in batch mode bypassing LSP machinery.
458 When filing issues, it is useful (but not necessary) to try to minimize examples.
459 An ideal bug reproduction looks like this:
462 $ git clone https://github.com/username/repo.git && cd repo && git switch --detach commit-hash
463 $ rust-analyzer --version
464 rust-analyzer dd12184e4 2021-05-08 dev
465 $ rust-analyzer analysis-stats .
469 It is especially useful when the `repo` doesn't use external crates or the standard library.
471 If you want to go as far as to modify the source code to debug the problem, be sure to take a look at the
472 https://github.com/rust-analyzer/rust-analyzer/tree/master/docs/dev[dev docs]!
476 **Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/rust-analyzer/src/config.rs[config.rs]
478 The <<_installation,Installation>> section contains details on configuration for some of the editors.
479 In general `rust-analyzer` is configured via LSP messages, which means that it's up to the editor to decide on the exact format and location of configuration files.
481 Some clients, such as <<vs-code,VS Code>> or <<coc-rust-analyzer,COC plugin in Vim>> provide `rust-analyzer` specific configuration UIs. Others may require you to know a bit more about the interaction with `rust-analyzer`.
483 For the later category, it might help to know that the initial configuration is specified as a value of the `initializationOptions` field of the https://microsoft.github.io/language-server-protocol/specifications/specification-current/#initialize[`InitializeParams` message, in the LSP protocol].
484 The spec says that the field type is `any?`, but `rust-analyzer` is looking for a JSON object that is constructed using settings from the list below.
485 Name of the setting, ignoring the `rust-analyzer.` prefix, is used as a path, and value of the setting becomes the JSON property value.
487 For example, a very common configuration is to enable proc-macro support, can be achieved by sending this JSON:
493 "loadOutDirsFromCheck": true,
501 Please consult your editor's documentation to learn more about how to configure https://microsoft.github.io/language-server-protocol/[LSP servers].
503 To verify which configuration is actually used by `rust-analyzer`, set `RA_LOG` environment variable to `rust_analyzer=info` and look for config-related messages.
504 Logs should show both the JSON that `rust-analyzer` sees as well as the updated config.
506 This is the list of config options `rust-analyzer` supports:
508 include::./generated_config.adoc[]
510 == Non-Cargo Based Projects
512 rust-analyzer does not require Cargo.
513 However, if you use some other build system, you'll have to describe the structure of your project for rust-analyzer in the `rust-project.json` format:
517 interface JsonProject {
518 /// Path to the directory with *source code* of
521 /// It should point to the directory where std,
522 /// core, and friends can be found:
524 /// https://github.com/rust-lang/rust/tree/master/library.
526 /// If provided, rust-analyzer automatically adds
527 /// dependencies on sysroot crates. Conversely,
528 /// if you omit this path, you can specify sysroot
529 /// dependencies yourself and, for example, have
530 /// several different "sysroots" in one graph of
532 sysroot_src?: string;
533 /// The set of crates comprising the current
534 /// project. Must include all transitive
535 /// dependencies as well as sysroot crate (libstd,
536 /// libcore and such).
541 /// Optional crate name used for display purposes,
542 /// without affecting semantics. See the `deps`
543 /// key for semantically-significant crate names.
544 display_name?: string;
545 /// Path to the root module of the crate.
547 /// Edition of the crate.
548 edition: "2015" | "2018" | "2021";
551 /// Should this crate be treated as a member of
552 /// current "workspace".
554 /// By default, inferred from the `root_module`
555 /// (members are the crates which reside inside
556 /// the directory opened in the editor).
558 /// Set this to `false` for things like standard
559 /// library and 3rd party crates to enable
560 /// performance optimizations (rust-analyzer
561 /// assumes that non-member crates don't change).
562 is_workspace_member?: boolean;
563 /// Optionally specify the (super)set of `.rs`
564 /// files comprising this crate.
566 /// By default, rust-analyzer assumes that only
567 /// files under `root_module.parent` can belong
568 /// to a crate. `include_dirs` are included
569 /// recursively, unless a subdirectory is in
572 /// Different crates can share the same `source`.
574 /// If two crates share an `.rs` file in common,
575 /// they *must* have the same `source`.
576 /// rust-analyzer assumes that files from one
577 /// source can't refer to files in another source.
579 include_dirs: string[],
580 exclude_dirs: string[],
582 /// The set of cfgs activated for a given crate, like
583 /// `["unix", "feature=\"foo\"", "feature=\"bar\""]`.
585 /// Target triple for this Crate.
587 /// Used when running `rustc --print cfg`
588 /// to get target-specific cfgs.
590 /// Environment variables, used for
592 env: { [key: string]: string; },
594 /// Whether the crate is a proc-macro crate.
595 is_proc_macro: boolean;
596 /// For proc-macro crates, path to compiled
597 /// proc-macro (.so file).
598 proc_macro_dylib_path?: string;
602 /// Index of a crate in the `crates` array.
604 /// Name as should appear in the (implicit)
605 /// `extern crate name` declaration.
610 This format is provisional and subject to change.
611 Specifically, the `roots` setup will be different eventually.
613 There are three ways to feed `rust-project.json` to rust-analyzer:
615 * Place `rust-project.json` file at the root of the project, and rust-analyzer will discover it.
616 * Specify `"rust-analyzer.linkedProjects": [ "path/to/rust-project.json" ]` in the settings (and make sure that your LSP client sends settings as a part of initialize request).
617 * Specify `"rust-analyzer.linkedProjects": [ { "roots": [...], "crates": [...] }]` inline.
619 Relative paths are interpreted relative to `rust-project.json` file location or (for inline JSON) relative to `rootUri`.
621 See https://github.com/rust-analyzer/rust-project.json-example for a small example.
623 You can set `RA_LOG` environmental variable to `rust_analyzer=info` to inspect how rust-analyzer handles config and project loading.
625 Note that calls to `cargo check` are disabled when using `rust-project.json` by default, so compilation errors and warnings will no longer be sent to your LSP client. To enable these compilation errors you will need to specify explicitly what command rust-analyzer should run to perform the checks using the `checkOnSave.overrideCommand` configuration. As an example, the following configuration explicitly sets `cargo check` as the `checkOnSave` command.
629 { "rust-analyzer.checkOnSave.overrideCommand": ["cargo", "check", "--message-format=json"] }
632 The `checkOnSave.overrideCommand` requires the command specified to output json error messages for rust-analyzer to consume. The `--message-format=json` flag does this for `cargo check` so whichever command you use must also output errors in this format. See the <<Configuration>> section for more information.
636 At the moment, rust-analyzer assumes that all code is trusted.
637 Here is a **non-exhaustive** list of ways to make rust-analyzer execute arbitrary code:
639 * proc macros and build scripts are executed by default
640 * `.cargo/config` can override `rustc` with an arbitrary executable
641 * `rust-toolchain.toml` can override `rustc` with an arbitrary executable
642 * VS Code plugin reads configuration from project directory, and that can be used to override paths to various executables, like `rustfmt` or `rust-analyzer` itself.
643 * rust-analyzer's syntax trees library uses a lot of `unsafe` and hasn't been properly audited for memory safety.
647 The LSP server performs no network access in itself, but runs `cargo metadata` which will update or download the crate registry and the source code of the project dependencies.
648 If enabled (the default), build scripts and procedural macros can do anything.
650 The Code extension automatically connects to GitHub to download updated LSP binaries and, if the nightly channel is selected, to perform update checks using the GitHub API. For `rust-analyzer` developers, using `cargo xtask release` uses the same API to put together the release notes.
652 Any other editor plugins are not under the control of the `rust-analyzer` developers. For any privacy concerns, you should check with their respective developers.
656 include::./generated_features.adoc[]
658 == Assists (Code Actions)
660 Assists, or code actions, are small local refactorings, available in a particular context.
661 They are usually triggered by a shortcut or by clicking a light bulb icon in the editor.
662 Cursor position or selection is signified by `┃` character.
664 include::./generated_assists.adoc[]
668 While most errors and warnings provided by rust-analyzer come from the `cargo check` integration, there's a growing number of diagnostics implemented using rust-analyzer's own analysis.
669 Some of these diagnostics don't respect `\#[allow]` or `\#[deny]` attributes yet, but can be turned off using the `rust-analyzer.diagnostics.enable`, `rust-analyzer.diagnostics.enableExperimental` or `rust-analyzer.diagnostics.disabled` settings.
671 include::./generated_diagnostic.adoc[]
676 ==== Color configurations
678 It is possible to change the foreground/background color of inlay hints.
679 Just add this to your `settings.json`:
684 "workbench.colorCustomizations": {
685 // Name of the theme you are currently using
687 "rust_analyzer.inlayHints.foreground": "#868686f0",
688 "rust_analyzer.inlayHints.background": "#3d3d3d48",
690 // Overrides for specific kinds of inlay hints
691 "rust_analyzer.inlayHints.foreground.typeHints": "#fdb6fdf0",
692 "rust_analyzer.inlayHints.foreground.paramHints": "#fdb6fdf0",
693 "rust_analyzer.inlayHints.background.chainingHints": "#6b0c0c81"
699 ==== Semantic style customizations
701 You can customize the look of different semantic elements in the source code.
702 For example, mutable bindings are underlined by default and you can override this behavior by adding the following section to your `settings.json`:
707 "editor.semanticTokenColorCustomizations": {
710 "fontStyle": "", // underline is the default
717 Most themes doesn't support styling unsafe operations differently yet. You can fix this by adding overrides for the rules `operator.unsafe`, `function.unsafe`, and `method.unsafe`:
722 "editor.semanticTokenColorCustomizations": {
724 "operator.unsafe": "#ff6600",
725 "function.unsafe": "#ff6600"
726 "method.unsafe": "#ff6600"
732 In addition to the top-level rules you can specify overrides for specific themes. For example, if you wanted to use a darker text color on a specific light theme, you might write:
737 "editor.semanticTokenColorCustomizations": {
739 "operator.unsafe": "#ff6600"
743 "operator.unsafe": "#572300"
750 Make sure you include the brackets around the theme name. For example, use `"[Ayu Light]"` to customize the theme Ayu Light.
752 ==== Special `when` clause context for keybindings.
753 You may use `inRustProject` context to configure keybindings for rust projects only.
760 "command": "rust-analyzer.toggleInlayHints",
761 "when": "inRustProject"
764 More about `when` clause contexts https://code.visualstudio.com/docs/getstarted/keybindings#_when-clause-contexts[here].
766 ==== Setting runnable environment variables
767 You can use "rust-analyzer.runnableEnv" setting to define runnable environment-specific substitution variables.
768 The simplest way for all runnables in a bunch:
770 "rust-analyzer.runnableEnv": {
771 "RUN_SLOW_TESTS": "1"
775 Or it is possible to specify vars more granularly:
777 "rust-analyzer.runnableEnv": [
779 // "mask": null, // null mask means that this rule will be applied for all runnables
788 "APP_ID": "2", // overwrites only APP_ID
794 You can use any valid regular expression as a mask.
795 Also note that a full runnable name is something like *run bin_or_example_name*, *test some::mod::test_name* or *test-mod some::mod*, so it is possible to distinguish binaries, single tests, and test modules with this masks: `"^run"`, `"^test "` (the trailing space matters!), and `"^test-mod"` respectively.
797 ==== Compiler feedback from external commands
799 Instead of relying on the built-in `cargo check`, you can configure Code to run a command in the background and use the `$rustc-watch` problem matcher to generate inline error markers from its output.
801 To do this you need to create a new https://code.visualstudio.com/docs/editor/tasks[VS Code Task] and set `rust-analyzer.checkOnSave.enable: false` in preferences.
803 For example, if you want to run https://crates.io/crates/cargo-watch[`cargo watch`] instead, you might add the following to `.vscode/tasks.json`:
810 "command": "cargo watch",
811 "problemMatcher": "$rustc-watch",