Elements. Add DynamicElementImpl2, make DynamicElementImpl its fragment.

Change-Id: I1d88f84f59d2ebdf7e0a5bc3b54d2145b0cb42b9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/394241
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/element/element.dart

@@ -1913,28 +1913,89 @@ class DirectiveUriWithUnitImpl extends DirectiveUriWithRelativeUriImpl
 }
 
 /// The synthetic element representing the declaration of the type `dynamic`.
-class DynamicElementImpl extends ElementImpl implements TypeDefiningElement {
-  /// Return the unique instance of this class.
-  static DynamicElementImpl get instance => DynamicTypeImpl.instance.element;
+class DynamicElementImpl extends ElementImpl
+    implements TypeDefiningElement, TypeDefiningFragment {
+  /// The unique instance of this class.
+  static final DynamicElementImpl instance = DynamicElementImpl._();
 
   /// Initialize a newly created instance of this class. Instances of this class
   /// should <b>not</b> be created except as part of creating the type
   /// associated with this element. The single instance of this class should be
   /// accessed through the method [instance].
-  DynamicElementImpl() : super(Keyword.DYNAMIC.lexeme, -1) {
+  DynamicElementImpl._() : super(Keyword.DYNAMIC.lexeme, -1) {
     setModifier(Modifier.SYNTHETIC, true);
   }
 
   @override
   List<Element2> get children2 => const [];
 
+  @override
+  List<Fragment> get children3 => const [];
+
+  @override
+  DynamicElementImpl2 get element => DynamicElementImpl2.instance;
+
+  @override
+  Null get enclosingFragment => null;
+
   @override
   ElementKind get kind => ElementKind.DYNAMIC;
 
+  @override
+  Null get libraryFragment => null;
+
+  @override
+  String get name2 => 'dynamic';
+
+  @override
+  Null get nameOffset2 => null;
+
+  @override
+  Null get nextFragment => null;
+
+  @override
+  Null get previousFragment => null;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) => null;
 }
 
+/// The synthetic element representing the declaration of the type `dynamic`.
+class DynamicElementImpl2 extends TypeDefiningElementImpl2 {
+  /// The unique instance of this class.
+  static final DynamicElementImpl2 instance = DynamicElementImpl2._();
+
+  DynamicElementImpl2._();
+
+  @override
+  Null get documentationComment => null;
+
+  @override
+  DynamicElementImpl get firstFragment => DynamicElementImpl.instance;
+
+  @override
+  bool get isSynthetic => true;
+
+  @override
+  ElementKind get kind => ElementKind.DYNAMIC;
+
+  @override
+  Null get library2 => null;
+
+  @override
+  Metadata get metadata2 {
+    return MetadataImpl(0, const [], () => null);
+  }
+
+  @override
+  String get name3 => 'dynamic';
+
+  @override
+  T? accept2<T>(ElementVisitor2<T> visitor) {
+    return null;
+  }
+}
+
 /// A concrete implementation of an [ElementAnnotation].
 class ElementAnnotationImpl implements ElementAnnotation {
   /// The name of the top-level variable used to mark that a function always
@@ -8452,9 +8513,6 @@ class NeverElementImpl2 extends TypeDefiningElementImpl2 {
 
   NeverElementImpl2._();
 
-  @override
-  List<Element2> get children2 => const [];
-
   @override
   Null get documentationComment => null;
 

pkg/analyzer/lib/src/dart/element/type.dart

@@ -36,17 +36,14 @@ class DynamicTypeImpl extends TypeImpl
   /// The unique instance of this class.
   static final DynamicTypeImpl instance = DynamicTypeImpl._();
 
-  @override
-  final DynamicElementImpl element = DynamicElementImpl();
-
   /// Prevent the creation of instances of this class.
   DynamicTypeImpl._();
 
   @override
-  Element2? get element3 => switch (element) {
-        Fragment(:var element) => element,
-        _ => null,
-      };
+  DynamicElementImpl get element => DynamicElementImpl.instance;
+
+  @override
+  DynamicElementImpl2 get element3 => DynamicElementImpl2.instance;
 
   @override
   int get hashCode => 1;

pkg/analyzer/lib/src/utilities/extensions/element.dart

@@ -32,14 +32,14 @@ extension Element2OrNullExtension on Element2? {
   Element? get asElement {
     var self = this;
     switch (self) {
-      case DynamicElementImpl():
-        return self;
+      case DynamicElementImpl2():
+        return DynamicElementImpl.instance;
       case GetterElement():
         return self.firstFragment as Element;
       case MultiplyDefinedElementImpl2 element2:
         return element2.asElement;
-      case NeverElementImpl():
-        return self;
+      case NeverElementImpl2():
+        return NeverElementImpl.instance;
       case PrefixElementImpl():
         return self;
       case TopLevelFunctionElementImpl():
@@ -135,7 +135,7 @@ extension ElementOrNullExtension on Element? {
     if (self == null) {
       return null;
     } else if (self is DynamicElementImpl) {
-      return self;
+      return DynamicElementImpl2.instance;
     } else if (self is FunctionElementImpl) {
       return self.element;
     } else if (self is InterfaceElementImpl) {

pkg/analyzer/test/src/dart/resolution/extension_method_test.dart

@@ -454,7 +454,7 @@ extension E on dynamic {}
 NamedType
   name: dynamic
   element: dynamic@-1
-  element2: dynamic@-1
+  element2: dynamic
   type: dynamic
 ''');
   }
@@ -573,7 +573,7 @@ extension on dynamic {}
 NamedType
   name: dynamic
   element: dynamic@-1
-  element2: dynamic@-1
+  element2: dynamic
   type: dynamic
 ''');
   }

pkg/analyzer/test/src/dart/resolution/for_statement_test.dart

@@ -199,7 +199,7 @@ ForStatement
       type: NamedType
         name: dynamic
         element: dynamic@-1
-        element2: dynamic@-1
+        element2: dynamic
         type: dynamic
       name: v
       declaredElement: v@42

pkg/analyzer/test/src/dart/resolution/function_expression_invocation_test.dart

@@ -195,7 +195,7 @@ FunctionExpressionInvocation
       type: NamedType
         name: dynamic
         element: dynamic@-1
-        element2: dynamic@-1
+        element2: dynamic
         type: dynamic
       staticType: dynamic
     rightParenthesis: )
@@ -237,7 +237,7 @@ FunctionExpressionInvocation
       type: NamedType
         name: dynamic
         element: dynamic@-1
-        element2: dynamic@-1
+        element2: dynamic
         type: dynamic
       staticType: dynamic
     rightParenthesis: )

pkg/analyzer/test/src/dart/resolution/function_reference_test.dart

@@ -4220,7 +4220,7 @@ FunctionReference
         type: NamedType
           name: dynamic
           element: dynamic@-1
-          element2: dynamic@-1
+          element2: dynamic
           type: dynamic
         staticType: dynamic
       rightParenthesis: )

pkg/analyzer/test/src/dart/resolution/named_type_test.dart

@@ -109,7 +109,7 @@ dynamic a;
 NamedType
   name: dynamic
   element: dynamic@-1
-  element2: dynamic@-1
+  element2: dynamic
   type: dynamic
 ''');
   }
@@ -131,7 +131,7 @@ NamedType
     element2: <testLibraryFragment>::@prefix2::myCore
   name: dynamic
   element: dynamic@-1
-  element2: dynamic@-1
+  element2: dynamic
   type: dynamic
 ''');
   }
@@ -165,7 +165,7 @@ dynamic a;
 NamedType
   name: dynamic
   element: dynamic@-1
-  element2: dynamic@-1
+  element2: dynamic
   type: dynamic
 ''');
   }

pkg/analyzer/test/src/dart/resolution/prefixed_identifier_test.dart

@@ -254,10 +254,10 @@ PrefixedIdentifier
   identifier: SimpleIdentifier
     token: dynamic
     staticElement: dynamic@-1
-    element: dynamic@-1
+    element: dynamic
     staticType: Type
   staticElement: dynamic@-1
-  element: dynamic@-1
+  element: dynamic
   staticType: Type
 ''');
   }

pkg/analyzer/test/src/dart/resolution/simple_identifier_test.dart

@@ -179,7 +179,7 @@ main() {
 SimpleIdentifier
   token: dynamic
   staticElement: dynamic@-1
-  element: dynamic@-1
+  element: dynamic
   staticType: Type
 ''');
   }
@@ -217,7 +217,7 @@ main() {
 SimpleIdentifier
   token: dynamic
   staticElement: dynamic@-1
-  element: dynamic@-1
+  element: dynamic
   staticType: Type
 ''');
   }