Unexpected macro parsing

[TiagoMaiaL]

Issue Kind

Parse of Valid Source Produced Invalid Syntax Tree

Source Code

struct S {
#if swift(>=2.2)
  let x: Int
#else
  // There should be no error here.
  let x: @#$()%&*)@#$(%&*
#endif
}

Description

The above code is from the swift project, and can be found here.

Instead of parsing x as a constant declaration, with @#$()%&*)@#$(%&* as its type, the above code only parses let x: @ as a variableDecl. The rest of the type is parsed in a wrong way, and the following #$() sequence is parsed as a macroExpansionDecl.

The following test fails:

  func testIfConfigExpr36() {
    AssertParse(
      """
      struct S {
      #if swift(>=2.2)
        let x: Int
      #else
        // There should be no error here.
        let x: @#$()%&*)@#$(%&*
      #endif
      }
      """
    )
  }

[ahoppen]

rdar://106732638

[ahoppen]

This behaves as expected because the parser doesn’t evaluate #if directives. The warnings in if directives will be emitted when invoking swift-parser-cli but will be hidden when SwiftParser is invoked from the compiler here: https://github.com/apple/swift/blob/8fa394f441e24e82e3da7d33a404ebe3ac7ea30a/lib/ASTGen/Sources/ASTGen/SourceFile.swift#L91-L96