[region-isolation] Add support for parsing arguments with transferring convention.

Author: gottesmm

CodeGeneration/Sources/SyntaxSupport/DeclNodes.swift

@@ -467,6 +467,7 @@ public let DECL_NODES: [Node] = [
           .keyword(._resultDependsOnSelf),
           .keyword(.required),
           .keyword(.static),
+          .keyword(.transferring),
           .keyword(.unowned),
           .keyword(.weak),
         ])

CodeGeneration/Sources/SyntaxSupport/KeywordSpec.swift

@@ -267,6 +267,7 @@ public enum Keyword: CaseIterable {
   case then
   case `throw`
   case `throws`
+  case transferring
   case transpose
   case `true`
   case `try`
@@ -670,6 +671,11 @@ public enum Keyword: CaseIterable {
       return KeywordSpec("throw", isLexerClassified: true)
     case .throws:
       return KeywordSpec("throws", isLexerClassified: true)
+    case .transferring:
+      return KeywordSpec(
+        "transferring",
+        experimentalFeature: .transferringArgsAndResults
+      )
     case .transpose:
       return KeywordSpec("transpose")
     case .true:

CodeGeneration/Sources/SyntaxSupport/TypeNodes.swift

@@ -52,6 +52,7 @@ public let TYPE_NODES: [Node] = [
           .keyword(._const),
           .keyword(.borrowing),
           .keyword(.consuming),
+          .keyword(.transferring),
           .keyword(._resultDependsOn),
         ]),
         isOptional: true

Sources/SwiftParser/Declarations.swift

@@ -19,7 +19,7 @@ extension DeclarationModifier {
       .borrowing, .class, .consuming, .convenience, .distributed, .dynamic,
       .final, .indirect, .infix, .isolated, .lazy, .mutating, .nonmutating,
       .optional, .override, .postfix, .prefix, .reasync, ._resultDependsOn, ._resultDependsOnSelf, .required,
-      .rethrows, .static, .weak:
+      .rethrows, .static, .weak, .transferring:
       return false
     case .fileprivate, .internal, .nonisolated, .package, .open, .private,
       .public, .unowned:

Sources/SwiftParser/Patterns.swift

@@ -353,6 +353,7 @@ extension Parser.Lookahead {
         && !self.at(.keyword(.__owned))
         && !self.at(.keyword(.borrowing))
         && !self.at(.keyword(.consuming))
+        && !(experimentalFeatures.contains(.transferringArgsAndResults) && self.at(.keyword(.transferring)))
         && !(experimentalFeatures.contains(.nonescapableTypes) && self.at(.keyword(._resultDependsOn)))
       {
         return true

Sources/SwiftParser/TokenPrecedence.swift

@@ -231,6 +231,7 @@ enum TokenPrecedence: Comparable {
       .__consuming, .final, .required, .optional, .lazy, .dynamic, .infix, .postfix, .prefix, .mutating, .nonmutating, .convenience, .override, .package, .open,
       .__setter_access, .indirect, .isolated, .nonisolated, .distributed, ._local,
       .inout, ._mutating, ._borrow, ._borrowing, .borrowing, ._consuming, .consuming, .consume, ._resultDependsOnSelf, ._resultDependsOn,
+      .transferring,
       // Accessors
       .get, .set, .didSet, .willSet, .unsafeAddress, .addressWithOwner, .addressWithNativeOwner, .unsafeMutableAddress,
       .mutableAddressWithOwner, .mutableAddressWithNativeOwner, ._read, ._modify,

Sources/SwiftParser/TokenSpecSet.swift

@@ -374,6 +374,7 @@ enum DeclarationModifier: TokenSpecSet {
   case required
   case `rethrows`
   case `static`
+  case transferring
   case unowned
   case weak
   case _resultDependsOn
@@ -414,6 +415,7 @@ enum DeclarationModifier: TokenSpecSet {
     case TokenSpec(.required): self = .required
     case TokenSpec(.rethrows): self = .rethrows
     case TokenSpec(.static): self = .static
+    case TokenSpec(.transferring): self = .transferring
     case TokenSpec(.unowned): self = .unowned
     case TokenSpec(.weak): self = .weak
     case TokenSpec(._resultDependsOn) where experimentalFeatures.contains(.nonescapableTypes): self = ._resultDependsOn
@@ -457,6 +459,7 @@ enum DeclarationModifier: TokenSpecSet {
     case .required: return .keyword(.required)
     case .rethrows: return TokenSpec(.rethrows, recoveryPrecedence: .declKeyword)
     case .static: return .keyword(.static)
+    case .transferring: return .keyword(.transferring)
     case .unowned: return TokenSpec(.unowned, recoveryPrecedence: .declKeyword)
     case .weak: return TokenSpec(.weak, recoveryPrecedence: .declKeyword)
     case ._resultDependsOn: return TokenSpec(._resultDependsOn, recoveryPrecedence: .declKeyword)
@@ -685,6 +688,7 @@ public enum TypeSpecifier: TokenSpecSet {
   case shared
   case borrowing
   case consuming
+  case transferring
 
   init?(lexeme: Lexer.Lexeme, experimentalFeatures: Parser.ExperimentalFeatures) {
     switch PrepareForKeywordMatch(lexeme) {
@@ -693,6 +697,7 @@ public enum TypeSpecifier: TokenSpecSet {
     case TokenSpec(.__shared): self = .shared
     case TokenSpec(.consuming): self = .consuming
     case TokenSpec(.borrowing): self = .borrowing
+    case TokenSpec(.transferring): self = .transferring
     default: return nil
     }
   }
@@ -705,6 +710,7 @@ public enum TypeSpecifier: TokenSpecSet {
     case TokenSpec(.__shared): self = .shared
     case TokenSpec(.consuming): self = .shared
     case TokenSpec(.borrowing): self = .shared
+    case TokenSpec(.transferring): self = .transferring
     default: return nil
     }
   }
@@ -716,6 +722,7 @@ public enum TypeSpecifier: TokenSpecSet {
     case .shared: return .keyword(.__shared)
     case .borrowing: return .keyword(.borrowing)
     case .consuming: return .keyword(.consuming)
+    case .transferring: return .keyword(.transferring)
     }
   }
 }

Tests/SwiftParserTest/TransferringTest.swift

@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+@_spi(ExperimentalLanguageFeatures) import SwiftParser
+import XCTest
+
+final class TransferringTests: ParserTestCase {
+  func testTransferingArg1() {
+    assertParse(
+      """
+      class Klass {}
+      func transferMain(_ x: transferring Klass) -> ()
+      """,
+      experimentalFeatures: .transferringArgsAndResults
+    )
+  }
+
+  func testTransferingArgMiddle() {
+    assertParse(
+      """
+      class Klass {}
+      func transferMain(_ y: Klass, _ x: transferring Klass, _ z: Klass) -> ()
+      """,
+      experimentalFeatures: .transferringArgsAndResults
+    )
+  }
+}