Remove Unknown Syntax Nodes

These were used by libSyntax to indicate that it had encountered something
malformed or that it couldn't represent. This does not fit into the new parser's
resilience model, so we no longer need these nodes.

Author: CodaFi

CodeGeneration/Sources/SyntaxSupport/gyb_generated/CommonNodes.swift

@@ -38,26 +38,6 @@ public let COMMON_NODES: [Node] = [
        kind: "Syntax",
        parserFunction: "parsePattern"),
 
-  Node(name: "UnknownDecl",
-       nameForDiagnostics: "declaration",
-       kind: "Decl"),
-
-  Node(name: "UnknownExpr",
-       nameForDiagnostics: "expression",
-       kind: "Expr"),
-
-  Node(name: "UnknownStmt",
-       nameForDiagnostics: "statement",
-       kind: "Stmt"),
-
-  Node(name: "UnknownType",
-       nameForDiagnostics: "type",
-       kind: "Type"),
-
-  Node(name: "UnknownPattern",
-       nameForDiagnostics: "pattern",
-       kind: "Pattern"),
-
   Node(name: "Missing",
        nameForDiagnostics: nil,
        kind: "Syntax"),

Sources/SwiftSyntax/CMakeLists.txt

@@ -21,7 +21,6 @@ add_swift_host_library(SwiftSyntax
   SyntaxOtherNodes.swift
   SyntaxText.swift
   SyntaxTreeViewMode.swift
-  SyntaxVerifier.swift
   Utils.swift
 
   Raw/RawSyntax.swift

Sources/SwiftSyntax/Documentation.docc/SwiftSyntax.md.gyb

@@ -49,8 +49,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 - <doc:SwiftSyntax/SyntaxVisitor>
 - <doc:SwiftSyntax/SyntaxAnyVisitor>
 - <doc:SwiftSyntax/SyntaxRewriter>
-- <doc:SwiftSyntax/SyntaxVerifier>
-- <doc:SwiftSyntax/SyntaxVerifierError>
 - <doc:SwiftSyntax/SyntaxTreeViewMode>
 - <doc:SwiftSyntax/SyntaxVisitorContinueKind>
 - <doc:SwiftSyntax/ReversedTokenSequence>

Sources/SwiftSyntax/Documentation.docc/gyb_generated/SwiftSyntax.md

@@ -42,8 +42,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 - <doc:SwiftSyntax/SyntaxVisitor>
 - <doc:SwiftSyntax/SyntaxAnyVisitor>
 - <doc:SwiftSyntax/SyntaxRewriter>
-- <doc:SwiftSyntax/SyntaxVerifier>
-- <doc:SwiftSyntax/SyntaxVerifierError>
 - <doc:SwiftSyntax/SyntaxTreeViewMode>
 - <doc:SwiftSyntax/SyntaxVisitorContinueKind>
 - <doc:SwiftSyntax/ReversedTokenSequence>
@@ -52,7 +50,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 
 - <doc:SwiftSyntax/DeclSyntax>
 - <doc:SwiftSyntax/DeclSyntaxProtocol>
-- <doc:SwiftSyntax/UnknownDeclSyntax>
 - <doc:SwiftSyntax/TypealiasDeclSyntax>
 - <doc:SwiftSyntax/AssociatedtypeDeclSyntax>
 - <doc:SwiftSyntax/IfConfigDeclSyntax>
@@ -82,7 +79,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 
 - <doc:SwiftSyntax/StmtSyntax>
 - <doc:SwiftSyntax/StmtSyntaxProtocol>
-- <doc:SwiftSyntax/UnknownStmtSyntax>
 - <doc:SwiftSyntax/LabeledStmtSyntax>
 - <doc:SwiftSyntax/ContinueStmtSyntax>
 - <doc:SwiftSyntax/WhileStmtSyntax>
@@ -106,7 +102,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 
 - <doc:SwiftSyntax/ExprSyntax>
 - <doc:SwiftSyntax/ExprSyntaxProtocol>
-- <doc:SwiftSyntax/UnknownExprSyntax>
 - <doc:SwiftSyntax/InOutExprSyntax>
 - <doc:SwiftSyntax/PoundColumnExprSyntax>
 - <doc:SwiftSyntax/TryExprSyntax>
@@ -156,7 +151,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 
 - <doc:SwiftSyntax/TypeSyntax>
 - <doc:SwiftSyntax/TypeSyntaxProtocol>
-- <doc:SwiftSyntax/UnknownTypeSyntax>
 - <doc:SwiftSyntax/SimpleTypeIdentifierSyntax>
 - <doc:SwiftSyntax/MemberTypeIdentifierSyntax>
 - <doc:SwiftSyntax/ClassRestrictionTypeSyntax>
@@ -177,7 +171,6 @@ allows Swift tools to parse, inspect, generate, and transform Swift source code.
 
 - <doc:SwiftSyntax/PatternSyntax>
 - <doc:SwiftSyntax/PatternSyntaxProtocol>
-- <doc:SwiftSyntax/UnknownPatternSyntax>
 - <doc:SwiftSyntax/EnumCasePatternSyntax>
 - <doc:SwiftSyntax/IsTypePatternSyntax>
 - <doc:SwiftSyntax/OptionalPatternSyntax>

Sources/SwiftSyntax/Raw/gyb_generated/RawSyntaxNodes.swift

@@ -34,7 +34,7 @@ public struct RawDeclSyntax: RawDeclSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .unknownDecl, .missingDecl, .typealiasDecl, .associatedtypeDecl, .ifConfigDecl, .poundErrorDecl, .poundWarningDecl, .poundSourceLocation, .classDecl, .actorDecl, .structDecl, .protocolDecl, .extensionDecl, .functionDecl, .initializerDecl, .deinitializerDecl, .subscriptDecl, .importDecl, .accessorDecl, .variableDecl, .enumCaseDecl, .enumDecl, .operatorDecl, .precedenceGroupDecl, .macroDecl, .macroExpansionDecl: return true
+    case .missingDecl, .typealiasDecl, .associatedtypeDecl, .ifConfigDecl, .poundErrorDecl, .poundWarningDecl, .poundSourceLocation, .classDecl, .actorDecl, .structDecl, .protocolDecl, .extensionDecl, .functionDecl, .initializerDecl, .deinitializerDecl, .subscriptDecl, .importDecl, .accessorDecl, .variableDecl, .enumCaseDecl, .enumDecl, .operatorDecl, .precedenceGroupDecl, .macroDecl, .macroExpansionDecl: return true
     default: return false
     }
   }
@@ -65,7 +65,7 @@ public struct RawExprSyntax: RawExprSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .unknownExpr, .missingExpr, .inOutExpr, .poundColumnExpr, .tryExpr, .awaitExpr, .moveExpr, .identifierExpr, .superRefExpr, .nilLiteralExpr, .discardAssignmentExpr, .assignmentExpr, .sequenceExpr, .symbolicReferenceExpr, .prefixOperatorExpr, .binaryOperatorExpr, .arrowExpr, .infixOperatorExpr, .floatLiteralExpr, .tupleExpr, .arrayExpr, .dictionaryExpr, .integerLiteralExpr, .booleanLiteralExpr, .unresolvedTernaryExpr, .ternaryExpr, .memberAccessExpr, .unresolvedIsExpr, .isExpr, .unresolvedAsExpr, .asExpr, .typeExpr, .closureExpr, .unresolvedPatternExpr, .functionCallExpr, .subscriptExpr, .optionalChainingExpr, .forcedValueExpr, .postfixUnaryExpr, .specializeExpr, .stringLiteralExpr, .regexLiteralExpr, .keyPathExpr, .macroExpansionExpr, .postfixIfConfigExpr, .editorPlaceholderExpr: return true
+    case .missingExpr, .inOutExpr, .poundColumnExpr, .tryExpr, .awaitExpr, .moveExpr, .identifierExpr, .superRefExpr, .nilLiteralExpr, .discardAssignmentExpr, .assignmentExpr, .sequenceExpr, .symbolicReferenceExpr, .prefixOperatorExpr, .binaryOperatorExpr, .arrowExpr, .infixOperatorExpr, .floatLiteralExpr, .tupleExpr, .arrayExpr, .dictionaryExpr, .integerLiteralExpr, .booleanLiteralExpr, .unresolvedTernaryExpr, .ternaryExpr, .memberAccessExpr, .unresolvedIsExpr, .isExpr, .unresolvedAsExpr, .asExpr, .typeExpr, .closureExpr, .unresolvedPatternExpr, .functionCallExpr, .subscriptExpr, .optionalChainingExpr, .forcedValueExpr, .postfixUnaryExpr, .specializeExpr, .stringLiteralExpr, .regexLiteralExpr, .keyPathExpr, .macroExpansionExpr, .postfixIfConfigExpr, .editorPlaceholderExpr: return true
     default: return false
     }
   }
@@ -96,7 +96,7 @@ public struct RawStmtSyntax: RawStmtSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .unknownStmt, .missingStmt, .labeledStmt, .continueStmt, .whileStmt, .deferStmt, .expressionStmt, .repeatWhileStmt, .guardStmt, .forInStmt, .switchStmt, .doStmt, .returnStmt, .yieldStmt, .fallthroughStmt, .breakStmt, .declarationStmt, .throwStmt, .ifStmt, .poundAssertStmt: return true
+    case .missingStmt, .labeledStmt, .continueStmt, .whileStmt, .deferStmt, .expressionStmt, .repeatWhileStmt, .guardStmt, .forInStmt, .switchStmt, .doStmt, .returnStmt, .yieldStmt, .fallthroughStmt, .breakStmt, .declarationStmt, .throwStmt, .ifStmt, .poundAssertStmt: return true
     default: return false
     }
   }
@@ -127,7 +127,7 @@ public struct RawTypeSyntax: RawTypeSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .unknownType, .missingType, .simpleTypeIdentifier, .memberTypeIdentifier, .classRestrictionType, .arrayType, .dictionaryType, .metatypeType, .optionalType, .constrainedSugarType, .implicitlyUnwrappedOptionalType, .compositionType, .packExpansionType, .tupleType, .functionType, .attributedType, .namedOpaqueReturnType: return true
+    case .missingType, .simpleTypeIdentifier, .memberTypeIdentifier, .classRestrictionType, .arrayType, .dictionaryType, .metatypeType, .optionalType, .constrainedSugarType, .implicitlyUnwrappedOptionalType, .compositionType, .packExpansionType, .tupleType, .functionType, .attributedType, .namedOpaqueReturnType: return true
     default: return false
     }
   }
@@ -158,7 +158,7 @@ public struct RawPatternSyntax: RawPatternSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .unknownPattern, .missingPattern, .enumCasePattern, .isTypePattern, .optionalPattern, .identifierPattern, .asTypePattern, .tuplePattern, .wildcardPattern, .expressionPattern, .valueBindingPattern: return true
+    case .missingPattern, .enumCasePattern, .isTypePattern, .optionalPattern, .identifierPattern, .asTypePattern, .tuplePattern, .wildcardPattern, .expressionPattern, .valueBindingPattern: return true
     default: return false
     }
   }
@@ -179,131 +179,6 @@ public struct RawPatternSyntax: RawPatternSyntaxNodeProtocol {
   }
 }
 
-@_spi(RawSyntax)
-public struct RawUnknownDeclSyntax: RawDeclSyntaxNodeProtocol {
-
-  @_spi(RawSyntax)
-  public var layoutView: RawSyntaxLayoutView {
-    return raw.layoutView!
-  }
-
-  public static func isKindOf(_ raw: RawSyntax) -> Bool {
-    return raw.kind == .unknownDecl
-  }
-
-  public var raw: RawSyntax
-  init(raw: RawSyntax) {
-    assert(Self.isKindOf(raw))
-    self.raw = raw
-  }
-
-  public init?<Node: RawSyntaxNodeProtocol>(_ other: Node) {
-    guard Self.isKindOf(other.raw) else { return nil }
-    self.init(raw: other.raw)
-  }
-
-}
-
-@_spi(RawSyntax)
-public struct RawUnknownExprSyntax: RawExprSyntaxNodeProtocol {
-
-  @_spi(RawSyntax)
-  public var layoutView: RawSyntaxLayoutView {
-    return raw.layoutView!
-  }
-
-  public static func isKindOf(_ raw: RawSyntax) -> Bool {
-    return raw.kind == .unknownExpr
-  }
-
-  public var raw: RawSyntax
-  init(raw: RawSyntax) {
-    assert(Self.isKindOf(raw))
-    self.raw = raw
-  }
-
-  public init?<Node: RawSyntaxNodeProtocol>(_ other: Node) {
-    guard Self.isKindOf(other.raw) else { return nil }
-    self.init(raw: other.raw)
-  }
-
-}
-
-@_spi(RawSyntax)
-public struct RawUnknownStmtSyntax: RawStmtSyntaxNodeProtocol {
-
-  @_spi(RawSyntax)
-  public var layoutView: RawSyntaxLayoutView {
-    return raw.layoutView!
-  }
-
-  public static func isKindOf(_ raw: RawSyntax) -> Bool {
-    return raw.kind == .unknownStmt
-  }
-
-  public var raw: RawSyntax
-  init(raw: RawSyntax) {
-    assert(Self.isKindOf(raw))
-    self.raw = raw
-  }
-
-  public init?<Node: RawSyntaxNodeProtocol>(_ other: Node) {
-    guard Self.isKindOf(other.raw) else { return nil }
-    self.init(raw: other.raw)
-  }
-
-}
-
-@_spi(RawSyntax)
-public struct RawUnknownTypeSyntax: RawTypeSyntaxNodeProtocol {
-
-  @_spi(RawSyntax)
-  public var layoutView: RawSyntaxLayoutView {
-    return raw.layoutView!
-  }
-
-  public static func isKindOf(_ raw: RawSyntax) -> Bool {
-    return raw.kind == .unknownType
-  }
-
-  public var raw: RawSyntax
-  init(raw: RawSyntax) {
-    assert(Self.isKindOf(raw))
-    self.raw = raw
-  }
-
-  public init?<Node: RawSyntaxNodeProtocol>(_ other: Node) {
-    guard Self.isKindOf(other.raw) else { return nil }
-    self.init(raw: other.raw)
-  }
-
-}
-
-@_spi(RawSyntax)
-public struct RawUnknownPatternSyntax: RawPatternSyntaxNodeProtocol {
-
-  @_spi(RawSyntax)
-  public var layoutView: RawSyntaxLayoutView {
-    return raw.layoutView!
-  }
-
-  public static func isKindOf(_ raw: RawSyntax) -> Bool {
-    return raw.kind == .unknownPattern
-  }
-
-  public var raw: RawSyntax
-  init(raw: RawSyntax) {
-    assert(Self.isKindOf(raw))
-    self.raw = raw
-  }
-
-  public init?<Node: RawSyntaxNodeProtocol>(_ other: Node) {
-    guard Self.isKindOf(other.raw) else { return nil }
-    self.init(raw: other.raw)
-  }
-
-}
-
 @_spi(RawSyntax)
 public struct RawMissingSyntax: RawSyntaxNodeProtocol {
 

Sources/SwiftSyntax/Raw/gyb_generated/RawSyntaxValidation.swift

@@ -89,16 +89,6 @@ func validateLayout(layout: RawSyntaxBuffer, as kind: SyntaxKind) {
     break
   case .token:
     assertionFailure("validateLayout for .token kind is not supported")
-  case .unknownDecl:
-    break
-  case .unknownExpr:
-    break
-  case .unknownStmt:
-    break
-  case .unknownType:
-    break
-  case .unknownPattern:
-    break
   case .missing:
     assert(layout.count == 0)
     break

Sources/SwiftSyntax/Syntax.swift

@@ -272,11 +272,6 @@ public extension SyntaxProtocol {
     return raw.kind.isSyntaxCollection
   }
 
-  /// Whether or not this node represents an unknown node.
-  var isUnknown: Bool {
-    return raw.kind.isUnknown
-  }
-
   /// Whether this tree contains a missing token or unexpected node.
   var hasError: Bool {
     return raw.recursiveFlags.contains(.hasError)

Sources/SwiftSyntax/SyntaxKind.swift.gyb

@@ -39,18 +39,6 @@ public enum SyntaxKind {
     }
   }
 
-  public var isUnknown: Bool {
-    switch self {
-% for name in SYNTAX_BASE_KINDS:
-%   if name not in ["Syntax", "SyntaxCollection"]:
-    case .unknown${name}: return true
-%   end
-% end
-    case .unknown: return true
-    default: return false
-    }
-  }
-
   public var isMissing: Bool {
     switch self {
 % for name in SYNTAX_BASE_KINDS:

Sources/SwiftSyntax/SyntaxRewriter.swift.gyb

@@ -100,24 +100,15 @@ open class SyntaxRewriter {
 
 % end
 
-% for node in SYNTAX_NODES:
+% for node in NON_BASE_SYNTAX_NODES:
   /// Implementation detail of visit(_:). Do not call directly.
   private func visitImpl${node.name}(_ data: SyntaxData) -> Syntax {
-%   if node.is_base():
-      let node = Unknown${node.name}(data)
-      // Accessing _syntaxNode directly is faster than calling Syntax(node)
-      visitPre(node._syntaxNode)
-      defer { visitPost(node._syntaxNode) }
-      if let newNode = visitAny(node._syntaxNode) { return newNode }
-      return Syntax(visit(node))
-%   else:
-      let node = ${node.name}(data)
-      // Accessing _syntaxNode directly is faster than calling Syntax(node)
-      visitPre(node._syntaxNode)
-      defer { visitPost(node._syntaxNode) }
-      if let newNode = visitAny(node._syntaxNode) { return newNode }
-      return Syntax(visit(node))
-%   end
+    let node = ${node.name}(data)
+    // Accessing _syntaxNode directly is faster than calling Syntax(node)
+    visitPre(node._syntaxNode)
+    defer { visitPost(node._syntaxNode) }
+    if let newNode = visitAny(node._syntaxNode) { return newNode }
+    return Syntax(visit(node))
   }
 
 % end