fix: allow new, subsequent `rust-project.json`-based workspaces to get proc macro expansion
As detailed in https://github.com/rust-lang/rust-analyzer/issues/14417#issuecomment-1485336174, `rust-project.json` workspaces added after the initial `rust-project.json`-based workspace was already indexed by rust-analyzer would not receive procedural macro expansion despite `config.expand_proc_macros` returning true. To fix this issue:
1. I changed `reload.rs` to check which workspaces are newly added.
2. Spawned new procedural macro expansion servers based on the _new_ workspaces.
1. This is to prevent spawning duplicate procedural macro expansion servers for already existing workspaces. While the overall memory usage of duplicate procedural macro servers is minimal, this is more about the _principle_ of not leaking processes 😅.
3. Launched procedural macro expansion if any workspaces are `rust-project.json`-based _or_ `same_workspaces` is true. `same_workspaces` being true (and reachable) indicates that that build scripts have finished building (in Cargo-based projects), while the build scripts in `rust-project.json`-based projects have _already been built_ by the build system that produced the `rust-project.json`.
I couldn't really think of structuring this code in a better way without engaging with https://github.com/rust-lang/rust-analyzer/issues/7444.
This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.
The change was automatically created with, so there are far less change
of an accidental typo.
```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```
Seems like these can be safely fixed. With one, I was particularly
surprised -- `Some(pats) => &**pats,` in body.rs?
```
cargo clippy --fix -- -A clippy::all -D clippy::explicit_auto_deref
```
Support multiple targets for checkOnSave (in conjunction with cargo 1.64.0+)
This PR adds support for the ability to pass multiple `--target` flags when using
`cargo` 1.64.0+.
## Questions
I needed to change the type of two configurations options, but I did not plurialize the names to
avoid too much churn, should I ?
## Zulip thread
https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Frust-analyzer/topic/Issue.2013282.20.28supporting.20multiple.20targets.20with.201.2E64.2B.29
## Example
To see it working, on a macOS machine:
```sh
$ cd /tmp
$ cargo new cargo-multiple-targets-support-ra-test
$ cd !$
$ mkdir .cargo
$ echo '
[build]
target = [
"aarch64-apple-darwin",
"x86_64-apple-darwin",
]
' > .cargo/config.toml
$ echo '
fn main() {
#[cfg(all(target_arch = "aarch64", target_os = "macos"))]
{
let a = std::fs::read_to_string("/tmp/test-read");
}
#[cfg(all(target_arch = "x86_64", target_os = "macos"))]
{
let a = std::fs::read_to_string("/tmp/test-read");
}
#[cfg(all(target_arch = "x86_64", target_os = "windows"))]
{
let a = std::fs::read_to_string("/tmp/test-read");
}
}
' > src/main.rs
# launch your favorite editor with the version of RA from this PR
#
# You should see warnings under the first two `let a = ...` but not the third
```
## Screen
![Two panes of a terminal emulator, on the left pane is the main.rs file described above, with warnings for the first two let a = declaration, on the right pane is a display of the .cargo/config.toml, an ls of the current files in the directory and a call to cargo build to show the same warnings as in the editor on the left pane](https://user-images.githubusercontent.com/7951708/192122707-7a00606a-e581-4534-b9d5-b81c92694e8e.png)
Helps with #13282