[SourceKit] Support building sourcekitd without building swift-syntax

[ahoppen]

This allows building sourcekitd and swift-refactor with SWIFT_BUILD_SWIFT_SYNTAX=NO. In these builds, the relatedidents and find-syntactic-rename-ranges requests will always return an error.

[bnbarham]

Do you run refactoring tests for Android? If so, I think we need to disable those as well.

They would all need a swift_swift_parser guard now. There's more than just this too, swiftRefactoring isn't built either and thus sourcekit will also fail to build.

What we probably need to do here is to have swiftRefactoring only depend on swiftIDEUtilsBridging if swift-syntax was built, then #if any sections of swiftRefactoring that depend on swiftIDEUtilsBridging. And maybe a warning in sourcekit to say that rename is unavailable without early swift-syntax.

[ahoppen]

@finagolfin Do you use sourcekitd and Swift tools on Android? If not, you could try setting SWIFT_BUILD_SOURCEKIT=NO and SWIFT_INCLUDE_TOOLS=NO to just not build sourcekitd and swift-refactor (+ the other tools in swift/tools)

[finagolfin]

Do you run refactoring tests for Android?

Yes, it appears they are normally run on the community Android CI, which I don't control but help monitor.

Do you use sourcekitd and Swift tools on Android?

Yes, I do. In fact, I even distribute sourcekit-lsp natively on Android, and have used it with an LSP-capable editor in the Termux terminal app for Android.

In any case, this issue has nothing to do with Android, but is about making the build and tests work with SWIFT_BUILD_SWIFT_SYNTAX turned off on any platform. I know the plan is to eventually make that flag a requirement, which is why every official CI now has a host Swift compiler and doesn't bother testing without it, but the community Android CI, which only runs on Ubuntu linux, doesn't install a prebuilt Swift compiler.

Would it be too much work to still support building without a host Swift compiler after this issue?

@drodriguez, maybe installing a host Swift compiler on the community Android CI would be best?

I don't know the best way forward here, just pointing out the problem of #70008 breaking the build on all platforms without a host Swift compiler.

[drodriguez]

@drodriguez, maybe installing a host Swift compiler on the community Android CI would be best?

I do not have time to work on those machines that much. I cannot also give anyone access to the machines because my company policies. Anyone is free to donate other machines that they control and can be added to the Community CI. Those machines are there as a favor, but I cannot invest that much time in them

[ahoppen]

OK, I’ll update the build so that swift-refactor and sourcekitd can build without SWIFT_BUILD_SWIFT_SYNTAX. Some functionality in sourcekitd (and thus sourcekit-lsp) won’t work without SWIFT_BUILD_SWIFT_SYNTAX though. For now, this will be rename and related identifiers (which is used by sourcekit-lsp’s textDocument/documentHighlight request).

[ahoppen]

Updated the PR so that sourcekitd and swift-refactor should build fine with SWIFT_BUILD_SWIFT_SYNTAX=NO. In these builds, the relatedidents and find-syntactic-rename-ranges requests will always return an error and the corresponding functionality in sourcekit-lsp will likewise not be available.

[ahoppen]

@swift-ci Please smoke test

[ahoppen]

@swift-ci Please smoke test

[ahoppen]

@swift-ci Please smoke test

[finagolfin]

Thanks, this fixed that issue, but now it is complaining about error: cannot find -lswiftIDEUtilsBridging: maybe one last tweak to make that gated on building swift-syntax too?

[ahoppen]

Let’s see if this fixes it: #70269