[SourceKit] Add syntaxtype for #error/#warning syntax coloring

[johnfairh]

This PR allows Xcode etc. to syntax-highlight #error/#warning like #if, & like #error in C, instead of like regular language keywords.

Before (now):

After (with Xcode change...):

From SR-6964. Per discussion there this introduces a new syntax type for these types of compiler control statement that includes #sourceLocation.

If this still sounds like a good idea at all then it's probably only worth taking if the Xcode change will happen - otherwise #error etc. will get no coloring at all which looks worse.

[harlanhaskins]

Thank you for this!

[harlanhaskins]

@swift-ci please smoke test

[harlanhaskins]

swift/tools/SourceKit/lib/SwiftLang/SwiftLangSupport.cpp:343:12: error: use of undeclared identifier 'KindPoundStmtKeyword'
    return KindPoundStmtKeyword;

Not sure why that symbol isn't showing up on Linux.

[johnfairh]

Repushed to change terminology per Jordan.

@harlanhaskins yw; the gyb stuff is new to SourceKit since I last looked so I might have missed something, or there could be a missing dependency somewhere that is not regenerating the .def file?

[harlanhaskins]

I think @nkcsgexi knows more about this?

[nkcsgexi]

hmm, the .def file should be generated by the gyb file before we build anything related to sourcekit. Does this build error happen in CI too? @swift-ci please smoke test

[nkcsgexi]

it seems CI has the issue in the first place. Let's try a clean build. @swift-ci Please clean smoke test

[nkcsgexi]

I think I didn't set the gyb dependency properly so that the added UID won't trigger another generation of the .def file. I tried to fix it by #14770. 🙃

[nkcsgexi]

LGTM! Thanks for simplifying the syntax model walk-around.

[johnfairh]

Thanks! @nkcsgexi can you take care of opening an internal ticket/whatever so Xcode picks this up?

[nkcsgexi]

@johnfairh , I'm sure this will be eventually integrated into Xcode; and whether we have an internal ticket or not doesn't change the timeline 😄