Allow calls to init without leading self. or super.

ASTGen will need to diagnose the missing `self.` or `super.`

Author: ahoppen

Sources/SwiftParser/Declarations.swift

@@ -31,6 +31,7 @@ extension DeclarationModifier {
 extension TokenConsumer {
   func atStartOfDeclaration(
     isAtTopLevel: Bool = false,
+    allowInitDecl: Bool = true,
     allowRecovery: Bool = false
   ) -> Bool {
     if self.at(anyIn: PoundDeclarationStart.self) != nil {
@@ -93,20 +94,22 @@ extension TokenConsumer {
       var lookahead = subparser.lookahead()
       repeat {
         lookahead.consumeAnyToken()
-      } while lookahead.atStartOfDeclaration()
+      } while lookahead.atStartOfDeclaration(allowInitDecl: allowInitDecl)
       return lookahead.at(.identifier)
     case .caseKeyword:
       // When 'case' appears inside a function, it's probably a switch
       // case, not an enum case declaration.
       return false
+    case .initKeyword:
+      return allowInitDecl
     case .some(_):
       // All other decl start keywords unconditonally start a decl.
       return true
     case nil:
       if subparser.at(anyIn: ContextualDeclKeyword.self)?.0 != nil {
         subparser.consumeAnyToken()
         return subparser.atStartOfDeclaration(
-          isAtTopLevel: isAtTopLevel, allowRecovery: allowRecovery)
+          isAtTopLevel: isAtTopLevel, allowInitDecl: allowInitDecl, allowRecovery: allowRecovery)
       }
       return false
     }
@@ -1310,7 +1313,7 @@ extension Parser {
       whereClause = nil
     }
 
-    let items = self.parseOptionalCodeBlock()
+    let items = self.parseOptionalCodeBlock(allowInitDecl: false)
 
     return RawInitializerDeclSyntax(
       attributes: attrs.attributes,

Sources/SwiftParser/Diagnostics/MissingNodesError.swift

@@ -226,12 +226,15 @@ public struct MissingNodesError: ParserError {
   /// If applicable, returns a string that describes the node in which the missing nodes are expected.
   private func parentContextClause(anchor: Syntax?) -> String? {
     // anchorParent is the first parent that has a type name for diagnostics.
-    guard let anchorParent = anchor?.ancestorOrSelf(where: {
-      $0.nodeTypeNameForDiagnostics(allowBlockNames: false) != nil
+    guard let (anchorParent, anchorTypeName) = anchor?.ancestorOrSelf(mapping: { (node: Syntax) -> (Syntax, String)? in
+      if let name = node.nodeTypeNameForDiagnostics(allowBlockNames: false) {
+        return (node, name)
+      } else {
+        return nil
+      }
     }) else {
       return nil
     }
-    let anchorTypeName = anchorParent.nodeTypeNameForDiagnostics(allowBlockNames: false)!
     if anchorParent.is(SourceFileSyntax.self) {
       return nil
     }

Sources/SwiftParser/Diagnostics/ParserDiagnosticMessages.swift

@@ -224,10 +224,10 @@ public struct SpaceSeparatedIdentifiersError: ParserError {
   public let additionalTokens: [TokenSyntax]
 
   public var message: String {
-    if let anchorParent = firstToken.parent?.ancestorOrSelf(where: {
-      $0.nodeTypeNameForDiagnostics(allowBlockNames: false) != nil
+    if let name = firstToken.parent?.ancestorOrSelf(mapping: {
+      $0.nodeTypeNameForDiagnostics(allowBlockNames: false)
     }) {
-      return "found an unexpected second identifier in \(anchorParent.nodeTypeNameForDiagnostics(allowBlockNames: false)!)"
+      return "found an unexpected second identifier in \(name)"
     } else {
       return "found an unexpected second identifier"
     }
@@ -266,7 +266,7 @@ public struct UnexpectedNodesError: ParserError {
     if let parent = unexpectedNodes.parent {
       if let parentTypeName = parent.nodeTypeNameForDiagnostics(allowBlockNames: false), parent.children(viewMode: .sourceAccurate).first?.id == unexpectedNodes.id {
         message += " before \(parentTypeName)"
-      } else if let parentTypeName = parent.ancestorOrSelf(where: { $0.nodeTypeNameForDiagnostics(allowBlockNames: false) != nil })?.nodeTypeNameForDiagnostics(allowBlockNames: false) {
+      } else if let parentTypeName = parent.ancestorOrSelf(mapping: { $0.nodeTypeNameForDiagnostics(allowBlockNames: false) }) {
         message += " in \(parentTypeName)"
       }
     }

Sources/SwiftParser/Expressions.swift

@@ -1041,7 +1041,7 @@ extension Parser {
         poundDsohandle: tok,
         arena: self.arena
       ))
-    case (.identifier, let handle)?, (.selfKeyword, let handle)?:
+    case (.identifier, let handle)?, (.selfKeyword, let handle)?, (.initKeyword, let handle)?:
       // If we have "case let x." or "case let x(", we parse x as a normal
       // name, not a binding, because it is the start of an enum pattern or
       // call pattern.

Sources/SwiftParser/Names.swift

@@ -54,7 +54,7 @@ extension Parser {
   mutating func parseDeclNameRef(_ flags: DeclNameOptions = []) -> (RawTokenSyntax, RawDeclNameArgumentsSyntax?) {
     // Consume the base name.
     let ident: RawTokenSyntax
-    if self.at(.identifier) || self.at(any: [.selfKeyword, .capitalSelfKeyword]) {
+    if self.at(.identifier) || self.at(any: [.selfKeyword, .capitalSelfKeyword, .initKeyword]) {
       ident = self.expectIdentifierWithoutRecovery()
     } else if flags.contains(.operators), let (_, _) = self.at(anyIn: Operator.self) {
       ident = self.consumeAnyToken(remapping: .unspacedBinaryOperator)

Sources/SwiftParser/RawTokenKindSubset.swift

@@ -443,13 +443,15 @@ enum IdentifierTokens: RawTokenKindSubset {
   case anyKeyword
   case capitalSelfKeyword
   case identifier
+  case initKeyword
   case selfKeyword
 
   init?(lexeme: Lexer.Lexeme) {
     switch lexeme.tokenKind {
     case .anyKeyword: self = .anyKeyword
     case .capitalSelfKeyword: self = .capitalSelfKeyword
     case .identifier: self = .identifier
+    case .initKeyword: self = .initKeyword
     case .selfKeyword: self = .selfKeyword
     default: return nil
     }
@@ -460,6 +462,7 @@ enum IdentifierTokens: RawTokenKindSubset {
     case .anyKeyword: return .anyKeyword
     case .capitalSelfKeyword: return .capitalSelfKeyword
     case .identifier: return .identifier
+    case .initKeyword: return .initKeyword
     case .selfKeyword: return .selfKeyword
     }
   }
@@ -743,6 +746,7 @@ enum PrimaryExpressionStart: RawTokenKindSubset {
   case falseKeyword
   case floatingLiteral
   case identifier
+  case initKeyword
   case integerLiteral
   case leftBrace
   case leftParen
@@ -773,6 +777,7 @@ enum PrimaryExpressionStart: RawTokenKindSubset {
     case .falseKeyword: self = .falseKeyword
     case .floatingLiteral: self = .floatingLiteral
     case .identifier: self = .identifier
+    case .initKeyword: self = .initKeyword
     case .integerLiteral: self = .integerLiteral
     case .leftBrace: self = .leftBrace
     case .leftParen: self = .leftParen
@@ -806,6 +811,7 @@ enum PrimaryExpressionStart: RawTokenKindSubset {
     case .falseKeyword: return .falseKeyword
     case .floatingLiteral: return .floatingLiteral
     case .identifier: return .identifier
+    case .initKeyword: return .initKeyword
     case .integerLiteral: return .integerLiteral
     case .leftBrace: return .leftBrace
     case .leftParen: return .leftParen

Sources/SwiftParser/TopLevel.swift

@@ -37,12 +37,12 @@ extension Parser {
 }
 
 extension Parser {
-  mutating func parseCodeBlockItemList(isAtTopLevel: Bool, stopCondition: (inout Parser) -> Bool) -> RawCodeBlockItemListSyntax {
+  mutating func parseCodeBlockItemList(isAtTopLevel: Bool, allowInitDecl: Bool = true, stopCondition: (inout Parser) -> Bool) -> RawCodeBlockItemListSyntax {
     var elements = [RawCodeBlockItemSyntax]()
     var loopProgress = LoopProgressCondition()
     while !stopCondition(&self), loopProgress.evaluate(currentToken) {
       let newItemAtStartOfLine = self.currentToken.isAtStartOfLine
-      guard let newElement = self.parseCodeBlockItem(isAtTopLevel: isAtTopLevel) else {
+      guard let newElement = self.parseCodeBlockItem(isAtTopLevel: isAtTopLevel, allowInitDecl: allowInitDecl) else {
         break
       }
       if let lastItem = elements.last, lastItem.semicolon == nil && !newItemAtStartOfLine {
@@ -68,11 +68,11 @@ extension Parser {
   ///
   /// This function is used when parsing places where function bodies are
   /// optional - like the function requirements in protocol declarations.
-  mutating func parseOptionalCodeBlock() -> RawCodeBlockSyntax? {
+  mutating func parseOptionalCodeBlock(allowInitDecl: Bool = true) -> RawCodeBlockSyntax? {
     guard self.at(.leftBrace) else {
       return nil
     }
-    return self.parseCodeBlock()
+    return self.parseCodeBlock(allowInitDecl: allowInitDecl)
   }
 
   /// Parse a code block.
@@ -85,9 +85,9 @@ extension Parser {
   /// `introducer` is the `while`, `if`, ... keyword that is the cause that the code block is being parsed.
   /// If the left brace is missing, its indentation will be used to judge whether a following `}` was
   /// indented to close this code block or a surrounding context. See `expectRightBrace`.
-  mutating func parseCodeBlock(introducer: RawTokenSyntax? = nil) -> RawCodeBlockSyntax {
+  mutating func parseCodeBlock(introducer: RawTokenSyntax? = nil, allowInitDecl: Bool = true) -> RawCodeBlockSyntax {
     let (unexpectedBeforeLBrace, lbrace) = self.expect(.leftBrace)
-    let itemList = parseCodeBlockItemList(isAtTopLevel: false, stopCondition: { $0.at(.rightBrace) })
+    let itemList = parseCodeBlockItemList(isAtTopLevel: false, allowInitDecl: allowInitDecl, stopCondition: { $0.at(.rightBrace) })
     let (unexpectedBeforeRBrace, rbrace) = self.expectRightBrace(leftBrace: lbrace, introducer: introducer)
 
     return .init(
@@ -118,7 +118,7 @@ extension Parser {
   ///     statement → compiler-control-statement
   ///     statements → statement statements?
   @_spi(RawSyntax)
-  public mutating func parseCodeBlockItem(isAtTopLevel: Bool = false) -> RawCodeBlockItemSyntax? {
+  public mutating func parseCodeBlockItem(isAtTopLevel: Bool = false, allowInitDecl: Bool = true) -> RawCodeBlockItemSyntax? {
     if self.at(any: [.caseKeyword, .defaultKeyword]) {
       // 'case' and 'default' are invalid in code block items.
       // Parse them and put them in their own CodeBlockItem but as an unexpected node.
@@ -134,7 +134,7 @@ extension Parser {
 
     // FIXME: It is unfortunate that the Swift book refers to these as
     // "statements" and not "items".
-    let item = self.parseItem(isAtTopLevel: isAtTopLevel)
+    let item = self.parseItem(isAtTopLevel: isAtTopLevel, allowInitDecl: allowInitDecl)
     let semi = self.consume(if: .semicolon)
     var trailingSemis: [RawTokenSyntax] = []
     while let trailingSemi = self.consume(if: .semicolon) {
@@ -158,7 +158,7 @@ extension Parser {
   /// closing braces while trying to recover to the next item.
   /// If we are not at the top level, such a closing brace should close the
   /// wrapping declaration instead of being consumed by lookeahead.
-  private mutating func parseItem(isAtTopLevel: Bool = false) -> RawSyntax {
+  private mutating func parseItem(isAtTopLevel: Bool = false, allowInitDecl: Bool = true) -> RawSyntax {
     if self.at(.poundIfKeyword) {
       let directive = self.parsePoundIfDirective {
         $0.parseCodeBlockItem()
@@ -174,13 +174,13 @@ extension Parser {
       return RawSyntax(directive)
     } else if self.at(.poundSourceLocationKeyword) {
       return RawSyntax(self.parsePoundSourceLocationDirective())
-    } else if self.atStartOfDeclaration() {
+    } else if self.atStartOfDeclaration(allowInitDecl: allowInitDecl) {
       return RawSyntax(self.parseDeclaration())
     } else if self.atStartOfStatement() {
       return RawSyntax(self.parseStatement())
     } else if self.atStartOfExpression() {
       return RawSyntax(self.parseExpression())
-    } else if self.atStartOfDeclaration(isAtTopLevel: isAtTopLevel, allowRecovery: true) {
+    } else if self.atStartOfDeclaration(isAtTopLevel: isAtTopLevel, allowInitDecl: allowInitDecl, allowRecovery: true) {
       return RawSyntax(self.parseDeclaration())
     } else if self.atStartOfStatement(allowRecovery: true) {
       return RawSyntax(self.parseStatement())

Tests/SwiftParserTest/translated/InitDeinitTests.swift

@@ -333,15 +333,9 @@ final class InitDeinitTests: XCTestCase {
     AssertParse(
       """
       class Aaron {
-        init(x: Int) {}
-        convenience init() { init(x: 1️⃣1) } 
+        convenience init() { init(x: 1) }
       }
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 3: missing 'self.' at initializer invocation, Fix-It replacements: 24 - 24 = 'self.'
-        DiagnosticSpec(message: "expected type in parameter"),
-        DiagnosticSpec(message: "unexpected code '1' in parameter clause"),
-      ]
+      """
     )
   }
 
@@ -350,15 +344,10 @@ final class InitDeinitTests: XCTestCase {
       """
       class Theodosia: Aaron {
         init() {
-          init(x: 1️⃣2) 
+          init(x: 2)
         }
       }
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 3: missing 'super.' at initializer invocation, Fix-It replacements: 5 - 5 = 'super.'
-        DiagnosticSpec(message: "expected type in parameter"),
-        DiagnosticSpec(message: "unexpected code '2' in parameter clause"),
-      ]
+      """
     )
   }
 
@@ -367,14 +356,9 @@ final class InitDeinitTests: XCTestCase {
       """
       struct AaronStruct {
         init(x: Int) {}
-        init() { init(x: 1️⃣1) } 
+        init() { init(x: 1) }
       }
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 3: missing 'self.' at initializer invocation, Fix-It replacements: 12 - 12 = 'self.'
-        DiagnosticSpec(message: "expected type in parameter"),
-        DiagnosticSpec(message: "unexpected code '1' in parameter clause"),
-      ]
+      """
     )
   }
 
@@ -383,13 +367,9 @@ final class InitDeinitTests: XCTestCase {
       """
       enum AaronEnum: Int {
         case A = 1
-        init(x: Int) { init(rawValue: x)1️⃣! } 
+        init(x: Int) { init(rawValue: x)! }
       }
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 3: missing 'self.' at initializer invocation, Fix-It replacements: 18 - 18 = 'self.'
-        DiagnosticSpec(message: "unexpected code '!' in initializer"),
-      ]
+      """
     )
   }