:source-highlighter: rouge
:experimental:
-// Master copy of this document lives in the https://github.com/rust-analyzer/rust-analyzer repository
-
At its core, rust-analyzer is a *library* for semantic analysis of Rust code as it changes over time.
This manual focuses on a specific usage of the library -- running it as part of a server that implements the
https://microsoft.github.io/language-server-protocol/[Language Server Protocol] (LSP).
https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/manual.adoc[https://github.com/rust-analyzer/.../manual.adoc]
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.
-
====
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.
$ cargo xtask install --server
----
-==== Troubleshooting
-
-Here are some useful self-diagnostic commands:
-
-* **Rust Analyzer: Show RA Version** shows the version of `rust-analyzer` binary.
-* **Rust Analyzer: Status** prints some statistics about the server, and dependency information for the current file.
-* To enable server-side logging, run with `env RA_LOG=info` and see `Output > Rust Analyzer Language Server` in VS Code's panel.
-* To log project loading (sysroot & `cargo metadata`), set `RA_LOG=project_model=debug`.
-* To log all LSP requests, add `"rust-analyzer.trace.server": "verbose"` to the settings and look for `Rust Analyzer Language Server Trace` in the panel.
-* To enable client-side logging, add `"rust-analyzer.trace.extension": true` to the settings and open `Output > Rust Analyzer Client` in the panel.
-
=== rust-analyzer Language Server Binary
Other editors generally require the `rust-analyzer` binary to be in `$PATH`.
settings = {
["rust-analyzer"] = {
assist = {
- importMergeBehavior = "last",
+ importGranularity = "module",
importPrefix = "by_self",
},
cargo = {
If `rust-analyzer` is not detected, Corrosion will prompt you for configuration of your Rust toolchain and language server with a link to the __Window > Preferences > Rust__ preference page; from here a button allows to download and configure `rust-analyzer`, but you can also reference another installation.
You'll need to close and reopen all .rs and Cargo files, or to restart the IDE, for this change to take effect.
+=== Kate Text Editor
+
+Support for the language server protocol is built into Kate through the LSP plugin, which is included by default.
+It is preconfigured to use Rls for rust sources, but allows you to use rust-analyzer through a simple settings change.
+In the LSP Client settings of Kate, copy the content of the third tab "default parameters" to the second tab "server configuration".
+Then in the configuration replace:
+[source,json]
+----
+ "rust": {
+ "command": ["rls"],
+ "rootIndicationFileNames": ["Cargo.lock", "Cargo.toml"],
+ "url": "https://github.com/rust-lang/rls",
+ "highlightingModeRegex": "^Rust$"
+ },
+----
+With
+[source,json]
+----
+ "rust": {
+ "command": ["rust-analyzer"],
+ "rootIndicationFileNames": ["Cargo.lock", "Cargo.toml"],
+ "url": "https://github.com/rust-analyzer/rust-analyzer",
+ "highlightingModeRegex": "^Rust$"
+ },
+----
+Then click on apply, and restart the LSP server for your rust project.
+
+== Troubleshooting
+
+Start with looking at the rust-analyzer version.
+Try **Rust Analyzer: Show RA Version** in VS Code and `rust-analyzer --version` in the command line.
+If the date is more than a week ago, it's better to update rust-analyzer version.
+
+The next thing to check would be panic messages in rust-analyzer's log.
+Log messages are printed to stderr, in VS Code you can see then in the `Output > Rust Analyzer Language Server` tab of the panel.
+To see more logs, set `RA_LOG=info` environmental variable.
+
+To fully capture LSP messages between the editor and the server, set `"rust-analyzer.trace.server": "verbose"` config and check
+`Output > Rust Analyzer Language Server Trace`.
+
+The root cause for many "`nothing works`" problems is that rust-analyzer fails to understand the project structure.
+To debug that, first note the `rust-analyzer` section in the status bar.
+If it has an error icon and red, that's the problem (hover will have somewhat helpful error message).
+**Rust Analyzer: Status** prints dependency information for the current file.
+Finally, `RA_LOG=project_model=debug` enables verbose logs during project loading.
+
+If rust-analyzer outright crashes, try running `rust-analyzer analysis-stats /path/to/project/directory/` on the command line.
+This command type checks the whole project in batch mode bypassing LSP machinery.
+
+When filing issues, it is useful (but not necessary) to try to minimize examples.
+An ideal bug reproduction looks like this:
+
+```bash
+$ git clone https://github.com/username/repo.git && cd repo && git switch --detach commit-hash
+$ rust-analyzer --version
+rust-analyzer dd12184e4 2021-05-08 dev
+$ rust-analyzer analysis-stats .
+💀 💀 💀
+```
+
+It is especially useful when the `repo` doesn't use external crates or the standard library.
+
== Configuration
**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/rust-analyzer/src/config.rs[config.rs]
* proc macros and build scripts are executed by default
* `.cargo/config` can override `rustc` with an arbitrary executable
+* `rust-toolchain.toml` can override `rustc` with an arbitrary executable
* 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.
* rust-analyzer's syntax trees library uses a lot of `unsafe` and hasn't been properly audited for memory safety.