Make swift-syntax build in Swift 6 language mode

Author: ahoppen

Package.swift

@@ -294,7 +294,8 @@ let package = Package(
       dependencies: ["_InstructionCounter", "_SwiftSyntaxTestSupport", "SwiftIDEUtils", "SwiftParser", "SwiftSyntax"],
       exclude: ["Inputs"]
     ),
-  ]
+  ],
+  swiftLanguageVersions: [.v5, .version("6")]
 )
 
 // This is a fake target that depends on all targets in the package.

Sources/SwiftCompilerPlugin/CompilerPlugin.swift

@@ -14,7 +14,8 @@
 
 #if swift(>=6.0)
 public import SwiftSyntaxMacros
-private import Foundation
+// preconcurrency because stdin, stdout and stderr are not marked Sendable on Linux
+@preconcurrency private import Foundation
 private import SwiftCompilerPluginMessageHandling
 #else
 import SwiftSyntaxMacros

Sources/SwiftParser/ExpressionInterpretedAsVersionTuple.swift

@@ -10,7 +10,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if swift(>=6)
+@_spi(RawSyntax) public import SwiftSyntax
+#else
 @_spi(RawSyntax) import SwiftSyntax
+#endif
 
 extension ExprSyntax {
   /// Parse the source code of this node as a `VersionTupleSyntax`.

Sources/SwiftParser/TokenSpec.swift

@@ -49,7 +49,7 @@ struct PrepareForKeywordMatch {
 /// matching against and is thus able to rule out one of the branches in
 /// `matches(rawTokenKind:text:)` based on the matched kind.
 @_spi(AlternateTokenIntrospection)
-public struct TokenSpec {
+public struct TokenSpec: Sendable {
   /// The kind we expect the token that we want to consume to have.
   /// This can be a keyword, in which case the ``TokenSpec`` will also match an
   /// identifier with the same text as the keyword and remap it to that keyword

Sources/SwiftParser/TokenSpecSet.swift

@@ -10,11 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6)
-@_spi(RawSyntax) @_spi(ExperimentalLanguageFeatures) public import SwiftSyntax
-#else
 @_spi(RawSyntax) @_spi(ExperimentalLanguageFeatures) import SwiftSyntax
-#endif
 
 /// A set of `TokenSpecs`. We expect to consume one of the sets specs in the
 /// parser.

Sources/SwiftSyntaxMacrosTestSupport/Assertions.swift

@@ -63,7 +63,7 @@ public struct NoteSpec {
     message: String,
     line: Int,
     column: Int,
-    originatorFile: StaticString = #file,
+    originatorFile: StaticString = #filePath,
     originatorLine: UInt = #line
   ) {
     self.message = message

SwiftSyntaxDevUtils/Sources/swift-syntax-dev-utils/common/Paths.swift

@@ -14,7 +14,7 @@ import Foundation
 
 enum Paths {
   static var packageDir: URL {
-    URL(fileURLWithPath: #file)
+    URL(fileURLWithPath: #filePath)
       .deletingLastPathComponent()
       .deletingLastPathComponent()
       .deletingLastPathComponent()

Tests/PerformanceTest/InstructionsCountAssertion.swift

@@ -17,7 +17,7 @@ fileprivate var baselineURL: URL {
   if let baselineFile = ProcessInfo.processInfo.environment["BASELINE_FILE"] {
     return URL(fileURLWithPath: baselineFile)
   } else {
-    return URL(fileURLWithPath: #file)
+    return URL(fileURLWithPath: #filePath)
       .deletingLastPathComponent()
       .appendingPathComponent("baselines.json")
   }

Tests/PerformanceTest/ParsingPerformanceTests.swift

@@ -18,7 +18,7 @@ import _SwiftSyntaxTestSupport
 class ParsingPerformanceTests: XCTestCase {
 
   var inputFile: URL {
-    return URL(fileURLWithPath: #file)
+    return URL(fileURLWithPath: #filePath)
       .deletingLastPathComponent()
       .appendingPathComponent("Inputs")
       .appendingPathComponent("MinimalCollections.swift.input")

Tests/PerformanceTest/SyntaxClassifierPerformanceTests.swift

@@ -19,7 +19,7 @@ import _SwiftSyntaxTestSupport
 class SyntaxClassifierPerformanceTests: XCTestCase {
 
   var inputFile: URL {
-    return URL(fileURLWithPath: #file)
+    return URL(fileURLWithPath: #filePath)
       .deletingLastPathComponent()
       .appendingPathComponent("Inputs")
       .appendingPathComponent("MinimalCollections.swift.input")

Tests/PerformanceTest/VisitorPerformanceTests.swift

@@ -18,7 +18,7 @@ import _SwiftSyntaxTestSupport
 class VisitorPerformanceTests: XCTestCase {
 
   var inputFile: URL {
-    return URL(fileURLWithPath: #file)
+    return URL(fileURLWithPath: #filePath)
       .deletingLastPathComponent()
       .appendingPathComponent("Inputs")
       .appendingPathComponent("MinimalCollections.swift.input")

Tests/SwiftParserTest/ParserTests.swift

@@ -61,14 +61,20 @@ class ParserTests: ParserTestCase {
     checkDiagnostics: Bool,
     shouldExclude: @Sendable (URL) -> Bool = { _ in false }
   ) {
-    let fileURLs = FileManager.default
+    // nonisolated(unsafe) because [URL] is not marked Sendable on Linux.
+    let _fileURLs = FileManager.default
       .enumerator(at: path, includingPropertiesForKeys: nil)!
       .compactMap({ $0 as? URL })
       .filter {
         $0.pathExtension == "swift"
           || $0.pathExtension == "sil"
           || $0.pathExtension == "swiftinterface"
       }
+    #if swift(>=6.0)
+    nonisolated(unsafe) let fileURLs = _fileURLs
+    #else
+    let fileURLs = _fileURLs
+    #endif
 
     print("\(name) - processing \(fileURLs.count) source files")
     DispatchQueue.concurrentPerform(iterations: fileURLs.count) { fileURLIndex in
@@ -85,7 +91,7 @@ class ParserTests: ParserTestCase {
     }
   }
 
-  let packageDir = URL(fileURLWithPath: #file)
+  let packageDir = URL(fileURLWithPath: #filePath)
     .deletingLastPathComponent()
     .deletingLastPathComponent()
     .deletingLastPathComponent()

Tests/SwiftParserTest/SequentialToConcurrentEditTranslationTests.swift

@@ -37,7 +37,7 @@ func verifySequentialToConcurrentTranslation(
   _ sequential: [IncrementalEdit],
   _ expectedConcurrent: [IncrementalEdit],
   testString: String = longString,
-  file: StaticString = #file,
+  file: StaticString = #filePath,
   line: UInt = #line
 ) {
   let concurrent = ConcurrentEdits(fromSequential: sequential)

Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift

@@ -200,8 +200,8 @@ struct AllLexicalContextsMacro: DeclarationMacro {
   }
 }
 
-public struct LexicalContextDescriptionMacro: ExpressionMacro {
-  public static func expansion(
+struct LexicalContextDescriptionMacro: ExpressionMacro {
+  static func expansion(
     of node: some FreestandingMacroExpansionSyntax,
     in context: some MacroExpansionContext
   ) throws -> ExprSyntax {