Add Cargo-style project discovery for Buck and Bazel Users
This feature requires the user to add a command that generates a `rust-project.json` from a set of files. Project discovery can be invoked in two ways:
1. At extension activation time, which includes the generated `rust-project.json` as part of the linkedProjects argument in `InitializeParams`.
2. Through a new command titled "rust-analyzer: Add current file to workspace", which makes use of a new, rust-analyzer-specific LSP request that adds the workspace without erasing any existing workspaces. Note that there is no mechanism to _remove_ workspaces other than "quit the rust-analyzer server".
Few notes:
- I think that the command-running functionality _could_ merit being placed into its own extension (and expose it via extension contribution points) to provide build-system idiomatic progress reporting and status handling, but I haven't (yet) made an extension that does this nor does Buck expose this sort of functionality.
- This approach would _just work_ for Bazel. I'll try and get the tool that's responsible for Buck integration open-sourced soon.
- On the testing side of things, I've used this in around my employer's Buck-powered monorepo and it's a nice experience. That being said, I can't think of an open-source repository where this can be tested in public, so you might need to trust me on this one.
I'd love to get feedback on:
- Naming of LSP extensions/new commands. I'm not too pleased with how "rust-analyzer: Add current file to workspace" is named, in that it's creating a _new_ workspace. I think that this command being added should be gated on `rust-analyzer.discoverProjectCommand` on being set, so I can add this in sequent commits.
- My Typescript. It's not particularly good.
- Suggestions on handling folders with _both_ Cargo and non-Cargo build systems and if I make activation a bit better.
(I previously tried to add this functionality entirely within rust-analyzer-the-LSP server itself, but matklad was right—an extension side approach is much, much easier.)
This feature requires the user to add a command that generates a
`rust-project.json` from a set of files. Project discovery can be invoked
in two ways:
1. At extension activation time, which includes the generated
`rust-project.json` as part of the linkedProjects argument in
InitializeParams
2. Through a new command titled "Add current file to workspace", which
makes use of a new, rust-analyzer specific LSP request that adds
the workspace without erasing any existing workspaces.
I think that the command-running functionality _could_ merit being
placed into its own extension (and expose it via extension contribution
points), if only provide build-system idiomatic progress reporting and
status handling, but I haven't (yet) made an extension that does this.
VS Code problem matcher are restricted to be static "regexes". You can't
create a problem matcher dynamically, and you can't use custom code in
lieu of problem matcher.
This creates a problem for rust/cargo compiler errors. They use paths
relative to the root of the Cargo workspace, but VS Code doesn't
necessary know where that root is.
Luckily, there's a way out: our current problem matcher is defined like
this:
"fileLocation": [ "autoDetect", "${workspaceRoot}" ],
That means that relative pahts would be resoleved relative to workspace
root. VS Code allows to specify a command inside `${}`. So we can plug
custom logic there to fetch Cargo's workspace root!
And that's exactly what this PR is doing!
