I suspect that we don’t wait for `TestSourceKitLSPClient` to finish deinitializing (and thus waiting for the shutdown response) when we destroy it in `tearDown` based on the logs in https://ci.swift.org/job/oss-swift-incremental-RA-macos-apple-silicon/9004 (rdar://160344405).
Since I generally dislike the `setUp` and `tearDown` methods and we have `CustomBuildServerTestProject` now to model a setup of a SourceKitLSP server with a custom build server, use that instead of manually hooking up the build server through a workspace.
The term *build system* predated our wide-spread adoption of BSP for communicating between SourceKit-LSP to the build system and was never really the correct term anyway – ie. a `JSONCompilationDatabaseBuildSystem` never really sounded right. We now have a correct term for the communication layer between SourceKit-LSP: A build server. Rename most occurrences of *build system* to *build server* to reflect this. There are unfortunately a couple lingering instances of *build system* that we can’t change, most notably: `fallbackBuildSystem` in the config file, the `workspace/waitForBuildSystemUpdates` BSP extension request and the `synchronize-for-build-system-updates` experimental feature.
When SourceKit-LSP is shut down, we should make sure that we don’t leave behind child processes, which will become orphans after SourceKit-LSP has terminated. What’s worse, when SourceKit-LSP has exited, these processes might not have any process to read their stdout/stderr, which can lead to them running indefinitely.
This change does not cover the termination of subprocess trees. For example, if we launch `swift build` and need to kill it because it doesn’t honor SIGINT, its child processes will still live on. Similarly, if we kill a BSP server, its child processes might live on. Fixing this is a drastically bigger endeavor, likely requiring changes to Foundation and/or TSC. I filed https://github.com/swiftlang/sourcekit-lsp/issues/2080 for it.
Otherwise, we would strip away the `-o`, leaving the command line without any output path option and thus not able to generate a unit file (which requires an output path).
If a source file is part of multiple targets, we should index it in the context of all of those targets because the different targets may produce different USRs since they might use different build settings to interpret the file.
Do not apply the standardized file normalization to the source file itself. Otherwise we would get the following behavior:
- We have a build system that uses standardized file paths and index a file as /tmp/test.c
- We are asking for the main files of /private/tmp/test.c
- Since indexstore-db uses realpath for everything, we find the unit for /tmp/test.c as a unit containing /private/tmp/test.c, which has /private/tmp/test.c as the main file.
- If we applied the path normalization, we would normalize /private/tmp/test.c to /tmp/test.c, thus reporting that /tmp/test.c is a main file containing /private/tmp/test.c,
But that doesn't make sense (it would, in fact cause us to treat /private/tmp/test.c as a header file that we should index using /tmp/test.c as a main file.
This allows us to more easily test behavior for build servers that have different behavior than SwiftPM and compile commands without having to implement the build server in Python.
