mirror of
https://github.com/rust-lang/rust-analyzer
synced 2024-12-28 05:53:45 +00:00
94 lines
3.5 KiB
Markdown
94 lines
3.5 KiB
Markdown
# Debugging VSCode plugin and the language server
|
|
|
|
## Prerequisites
|
|
|
|
- Install [LLDB](https://lldb.llvm.org/) and the [LLDB Extension](https://marketplace.visualstudio.com/items?itemName=vadimcn.vscode-lldb).
|
|
- Open the root folder in VSCode. Here you can access the preconfigured debug setups.
|
|
|
|
<img height=150px src="https://user-images.githubusercontent.com/36276403/74611090-92ec5380-5101-11ea-8a41-598f51f3f3e3.png" alt="Debug options view">
|
|
|
|
- Install all TypeScript dependencies
|
|
```bash
|
|
cd editors/code
|
|
npm install
|
|
```
|
|
|
|
## Common knowledge
|
|
|
|
* All debug configurations open a new `[Extension Development Host]` VSCode instance
|
|
where **only** the `rust-analyzer` extension being debugged is enabled.
|
|
* To activate the extension you need to open any Rust project folder in `[Extension Development Host]`.
|
|
|
|
|
|
## Debug TypeScript VSCode extension
|
|
|
|
- `Run Installed Extension` - runs the extension with the globally installed `rust-analyzer` binary.
|
|
- `Run Extension (Debug Build)` - runs extension with the locally built LSP server (`target/debug/rust-analyzer`).
|
|
|
|
TypeScript debugging is configured to watch your source edits and recompile.
|
|
To apply changes to an already running debug process, press <kbd>Ctrl+Shift+P</kbd> and run the following command in your `[Extension Development Host]`
|
|
|
|
```
|
|
> Developer: Reload Window
|
|
```
|
|
|
|
## Debug Rust LSP server
|
|
|
|
- When attaching a debugger to an already running `rust-analyzer` server on Linux you might need to enable `ptrace` for unrelated processes by running:
|
|
|
|
```
|
|
echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
|
|
```
|
|
|
|
|
|
- By default, the LSP server is built without debug information. To enable it, you'll need to change `Cargo.toml`:
|
|
```toml
|
|
[profile.dev]
|
|
debug = 2
|
|
```
|
|
|
|
- Select `Run Extension (Debug Build)` to run your locally built `target/debug/rust-analyzer`.
|
|
|
|
- In the original VSCode window once again select the `Attach To Server` debug configuration.
|
|
|
|
- A list of running processes should appear. Select the `rust-analyzer` from this repo.
|
|
|
|
- Navigate to `crates/rust-analyzer/src/main_loop.rs` and add a breakpoint to the `on_request` function.
|
|
|
|
- Go back to the `[Extension Development Host]` instance and hover over a Rust variable and your breakpoint should hit.
|
|
|
|
If you need to debug the server from the very beginning, including its initialization code, you can use the `--wait-dbg` command line argument or `RA_WAIT_DBG` environment variable. The server will spin at the beginning of the `try_main` function (see `crates\rust-analyzer\src\bin\main.rs`)
|
|
```rust
|
|
let mut d = 4;
|
|
while d == 4 { // set a breakpoint here and change the value
|
|
d = 4;
|
|
}
|
|
```
|
|
|
|
## Demo
|
|
|
|
- [Debugging TypeScript VScode extension](https://www.youtube.com/watch?v=T-hvpK6s4wM).
|
|
- [Debugging Rust LSP server](https://www.youtube.com/watch?v=EaNb5rg4E0M).
|
|
|
|
## Troubleshooting
|
|
|
|
### Can't find the `rust-analyzer` process
|
|
|
|
It could be a case of just jumping the gun.
|
|
|
|
The `rust-analyzer` is only started once the `onLanguage:rust` activation.
|
|
|
|
Make sure you open a rust file in the `[Extension Development Host]` and try again.
|
|
|
|
### Can't connect to `rust-analyzer`
|
|
|
|
Make sure you have run `echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope`.
|
|
|
|
By default this should reset back to 1 every time you log in.
|
|
|
|
### Breakpoints are never being hit
|
|
|
|
Check your version of `lldb`. If it's version 6 and lower, use the `classic` adapter type.
|
|
It's `lldb.adapterType` in settings file.
|
|
|
|
If you're running `lldb` version 7, change the lldb adapter type to `bundled` or `native`.
|