Sync `rust-analyzer`, add `rust-analyzer-proc-macro-srv` binary to Rustc component
As discussed earlier with `@jyn514` and `@pietroalbini,` I'm also going to use this PR to have `dist::Rustc` build the `rust-analyzer-proc-macro-srv` binary introduced in:
* https://github.com/rust-lang/rust-analyzer/pull/12871
fix: Insert spaces when inlining a function defined in a macro.
(partially) fixes#12860.
This PR (only) addresses the whitespace issue when inlining functions defined in macros.
Additionally, the indentation/spacing is not ideal, but works, e.g.
```rs
macro_rules! define_function {
() => { fn test_function_macro() {
if let Some(3) = 3i32.checked_add(0) {
println!("3 + 0 == 3");
}
} };
}
define_function!();
fn main() {
test_function_macro();
}
// previously became
// ...
fn main() {
ifletSome(3)=3i32.checked_add(0){println!("3 + 0 == 3");};
}
// now becomes
// ...
fn main() {
if let Some(3) = 3i32.checked_add(0){
println!("3 + 0 == 3");
};
}
```
The `self` -> `this` problem[^this] is (probably?) a separate problem that I am also looking into.
[^this]: As mentioned in [my comment on the above issue](https://github.com/rust-lang/rust-analyzer/issues/12860#issuecomment-1193231766), inlining a method defined in a macro does not properly replace `self` with the new local `this`.
Add `rust-analyzer-proc-macro-srv` binary, use it if found in sysroot
This adds a `bin` crate which simply runs `proc_macro_srv::cli::run()` (it does no CLI argument parsing, nothing).
The intent is to build that crate in Rust CI as part of the `dist::Rustc` component, then ship it in the sysroot: it would probably land in something like `~/.rustup/toolchains/nightly-2022-07-23-x86_64-unknown-linux-gnu/libexec/proc-macro-srv-cli`.
This makes https://github.com/rust-lang/rustup/pull/3022 less pressing. (Instead of teaching RA about rustup components, we simply teach it to look in the sysroot via `rustc --print sysroot`. If it can't find `proc-macro-srv-cli`, it falls back to its own `proc-macro` subcommand).
This is closely related to https://github.com/rust-lang/rust-analyzer/issues/12803 (but doesn't close it yet).
Things to address now:
* [ ] What should the binary be named? What should the crate be named? We can pick different names with `[bin]` in the `Cargo.toml`
Things to address later:
* Disable the "multi ABI compatibility scheme" when building that binary in Rust CI (that'll probably happen in `rust-lang/rust`)
* Teaching RA to look in the sysroot
Things to address much, much later:
* Is JSON a good fit here
* Do we want to add versioning to future-proof it?
* Other bikesheds
When built with `--features sysroot` on `nightly-2022-07-23-x86_64-unknown-linux-gnu`, the binary is 7.4MB. After stripping debuginfo, it's 2.6MB. When compressed to `.tar.xz`, it's 619KB.
In a Zulip discussion, `@jyn514` and `@Mark-Simulacrum` seemed to think that those sizes weren't a stopper for including the binary in the rustc component, even before we shrink it down further.
feat: Spawn a proc-macro-srv instance per workspace
cc https://github.com/rust-lang/rust-analyzer/issues/12855
The idea is to have each server be spawned with the appropriate toolchain, that way workspaces with differing toolchains shouldn't suffer from proc-macro abi mismatches.
