The core idea here is that the toolchain language servers always call into `BuildSystemManager` and `BuildSystemManager` will always reply with build settings. If it hasn’t computed them yet, it will reply with fallback settings.
With that assumption, we can remove the `documentToPendingQueue` from `SourceKitServer` since there are no longer any documents that are pending – everything has a build settings immediately.
Similarly, `BuildSystemManager.mainFileStatuses` also isn’t needed anymore.
And lastly, since we know that `BuildSystemManager.buildSettings` will always return a value `registerForChangeNotifications` is changed not call `fileBuildSettingsChanged` immediately. Instead, it will only cause `fileBuildSettingsChanged` to be called when the file’s build settings change after the `registerForChangeNotifications` call.
Unfortuantely, we have a few potential out-of-order exeuction possibilities while we migrate everything else to also be asyncronous. But those should be low-probability issues that we can fix in follow-up commits, so I think it’s fine for now. All of these places are marked with `FIXME: (async)`
The asyncification changes caused some non-deterministic test failures. I believe that some of these are due to race conditions that are the result of the partial transition to actors.
Instead of merging the asyncification piece by piece, I will collect the changes asyncification changes in a branch and then qualify that branch througougly (running CI multiple times) before merging it into `main`.
Unfortuantely, we have a few potential out-of-order exeuction possibilities while we migrate everything else to also be asyncronous. But those should be low-probability issues that we can fix in follow-up commits, so I think it’s fine for now. All of these places are marked with `FIXME: (async)`
Replace the use of `sleep` which is a POSIX construct for the portable
`Thread.sleep(forTimeInterval:)` which has similar semantics but allows
the code to be built for other platforms. This allows us to finally
build the test suite for Windows.
Similar to how we reload the package if Package.swift is changed, we also watch `compilation_database.json` and `compile_flags.txt` and notify the build system delegate that build settings changed if these files are modified.
rdar://92388223 [#486]
