SourceKit – source.request.cursorinfo

Valid Sept 2017 with swift:master

Flow

• Requests.cpp:handleSemanticRequest()
  • SwiftSourceDocInfo.cpp:SwiftLangSupport::getCursorInfo()
    • SwiftSourceDocInfo.cpp:resolveCursor()
    • Create CursorInfoConsumer
    • ASTManager::processASTAsync()
      • CursorInfo::handlePrimaryAST()
        • SwiftSourceDocInfo.cpp:passCursorInfoForDecl()
  • Callback Requests.cpp::reportCursorInfo()

ASTManager

This is a cache layer to avoid compiling the same file repeatedly.

Key difference here over request.structure – the file is properly compiled up to Sema and type-checked, not just parsed. Presence of USRs is giveaway.

CursorInfoConsumer

Pulls attributes from the ValueDecl for propagation. Note this means we cannot be talking about an extension per se because that is further up the hierarchy.

Doc comment handling: uses ide::getDocumentationCommentAsXML() which does the parent lookup for class inheritance and protcol extensions, then does some custom code to look up protocol conformance. This routine creates all the XML for the full_as_xml field including the declaration: CommentToXMLConverter::visitCommentParts uses a very customized declaration printer based on PrintOptions::printInterface(). In particular it shows most decl attributes except @discardableResult. Probably because that is on by default on interfaces generated from ObjC. Which makes no sense here.

Uses PrintOptions::printQuickHelpDeclaration() style for the annotated declaration field, and also the fully-annotated declaration field. In particular this means ‘include decl attributes except @available’.

Uses ide::walkOverriddenDecls() to find USRs of swift + objC things that have been overridden (functions and properties not nominals).

Related declarations code is incomplete but should return declarations with the same name in the same (or lower?) scope.

Group names. This looks to be something to do with module definitions and serialization. Ignore for now.

CursorInfo and reportCursorInfo

So then these fields are are returned in the cursorinfo:

• Kind
• Name

And optionally:

• USR
• Type name
• Doc comment as XML
• Annotated declaration
• Fully-annotated declaration
• Module name [only if symbol from a separate module]
• Group name [only if symbol from a separate module]
• Localization key (from doc comment)
• Offset and Length
• Filename
• Overridden USRs list
• Available actions [can’t find any code that sets this though…]
• Parent name offset (only for ParamDecls)
• Related declarations list
• IsSystem - either ‘true’ or not here at all
• Type USR
• Container Type USR

And never:

• TypeInterface (always empty in CursorInfo)