[Parser] Handle deinit and subscript as declaration name references

Treat `deinit` and `subscript` the same way we treat `init` when parsing
an expression, treating it as a declaration reference expression.

Fixes rdar://121687968.

Author: DougGregor

Sources/SwiftParser/Expressions.swift

@@ -1120,7 +1120,7 @@ extension Parser {
           arena: self.arena
         )
       )
-    case (.identifier, let handle)?, (.self, let handle)?, (.`init`, let handle)?:
+    case (.identifier, let handle)?, (.self, let handle)?, (.`init`, let handle)?, (.`deinit`, let handle)?, (.`subscript`, let handle)?:
       // If we have "case let x" followed by ".", "(", "[", or a generic
       // argument list, we parse x as a normal name, not a binding, because it
       // is the start of an enum or expr pattern.

Sources/SwiftParser/Names.swift

@@ -66,7 +66,7 @@ extension Parser {
   mutating func parseDeclReferenceExpr(_ flags: DeclNameOptions = []) -> RawDeclReferenceExprSyntax {
     // Consume the base name.
     let base: RawTokenSyntax
-    if let identOrSelf = self.consume(if: .identifier, .keyword(.self), .keyword(.Self)) ?? self.consume(if: .keyword(.`init`)) {
+    if let identOrSelf = self.consume(if: .identifier, .keyword(.self), .keyword(.Self)) ?? self.consume(if: .keyword(.`init`)) ?? self.consume(if: .keyword(.`deinit`)) ?? self.consume(if: .keyword(.`subscript`)) {
       base = identOrSelf
     } else if flags.contains(.operators), let (_, _) = self.at(anyIn: Operator.self) {
       base = self.consumeAnyToken(remapping: .binaryOperator)

Sources/SwiftParser/TokenSpecSet.swift

@@ -869,6 +869,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
   case `Any`
   case atSign  // For recovery
   case `Self`
+  case `deinit`
   case dollarIdentifier
   case `false`
   case floatLiteral
@@ -886,6 +887,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
   case regexSlash
   case extendedRegexDelimiter
   case `self`
+  case `subscript`
   case `super`
   case `true`
   case wildcard
@@ -899,6 +901,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
     case TokenSpec(.Any): self = .Any
     case TokenSpec(.atSign): self = .atSign
     case TokenSpec(.Self): self = .Self
+    case TokenSpec(.deinit): self = .`deinit`
     case TokenSpec(.dollarIdentifier): self = .dollarIdentifier
     case TokenSpec(.false): self = .false
     case TokenSpec(.floatLiteral): self = .floatLiteral
@@ -916,6 +919,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
     case TokenSpec(.regexSlash): self = .regexSlash
     case TokenSpec(.regexPoundDelimiter): self = .extendedRegexDelimiter
     case TokenSpec(.self): self = .self
+    case TokenSpec(.subscript): self = .`subscript`
     case TokenSpec(.super): self = .super
     case TokenSpec(.true): self = .true
     case TokenSpec(.wildcard): self = .wildcard
@@ -932,6 +936,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
     case .Any: return .keyword(.Any)
     case .atSign: return .atSign
     case .Self: return .keyword(.Self)
+    case .`deinit`: return .keyword(.`deinit`)
     case .dollarIdentifier: return .dollarIdentifier
     case .false: return .keyword(.false)
     case .floatLiteral: return .floatLiteral
@@ -949,6 +954,7 @@ enum PrimaryExpressionStart: TokenSpecSet {
     case .regexSlash: return .regexSlash
     case .extendedRegexDelimiter: return .regexPoundDelimiter
     case .self: return .keyword(.self)
+    case .`subscript`: return .keyword(.subscript)
     case .super: return .keyword(.super)
     case .true: return .keyword(.true)
     case .wildcard: return .wildcard

Tests/SwiftParserTest/AttributeTests.swift

@@ -689,6 +689,43 @@ final class AttributeTests: ParserTestCase {
     )
   }
 
+  func testAttachedNames() {
+    assertParse(
+      """
+      @attached(member, names: named(deinit))
+      macro m()
+      """
+    )
+
+    assertParse(
+      """
+      @attached(member, names: named(init))
+      macro m()
+      """
+    )
+
+    assertParse(
+      """
+      @attached(member, names: named(init(a:b:)))
+      macro m()
+      """
+    )
+
+    assertParse(
+      """
+      @attached(member, names: named(subscript))
+      macro m()
+      """
+    )
+
+    assertParse(
+      """
+      @attached(member, names: named(subscript(a:b:)))
+      macro m()
+      """
+    )
+  }
+
   func testAttachedExtensionAttribute() {
     assertParse(
       """