Elements. Return XyzImpl from 'declaration'.

Change-Id: I29ae5383aa583f18d31eabb827e6b1aedd43b430
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/411520
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

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

@@ -1468,7 +1468,7 @@ class ConstructorElementImpl extends ExecutableElementImpl
   }
 
   @override
-  ConstructorElement get declaration => this;
+  ConstructorElementImpl get declaration => this;
 
   @override
   String get displayName {
@@ -1769,6 +1769,9 @@ class ConstructorElementImpl2 extends ExecutableElementImpl2
 /// Common implementation for methods defined in [ConstructorElement].
 mixin ConstructorElementMixin
     implements ConstructorElement, ExecutableElementOrMember {
+  @override
+  ConstructorElementImpl get declaration;
+
   @override
   bool get isDefaultConstructor {
     // unnamed
@@ -2649,7 +2652,7 @@ abstract class ElementImpl implements Element, Element2 {
   }
 
   @override
-  Element get declaration => this;
+  ElementImpl get declaration => this;
 
   @override
   String get displayName => _name ?? '';
@@ -3790,6 +3793,9 @@ abstract class ExecutableElementImpl extends _ExistingElementImpl
         ...parameters,
       ];
 
+  @override
+  ExecutableElementImpl get declaration => this;
+
   @override
   ExecutableElementImpl2 get element;
 
@@ -4336,7 +4342,7 @@ class FieldElementImpl extends PropertyInducingElementImpl
   }
 
   @override
-  FieldElement get declaration => this;
+  FieldElementImpl get declaration => this;
 
   @override
   FieldElementImpl2 get element {
@@ -5304,7 +5310,7 @@ class FunctionElementImpl extends ExecutableElementImpl
   }
 
   @override
-  ExecutableElement get declaration => this;
+  ExecutableElementImpl get declaration => this;
 
   @override
   Fragment? get enclosingFragment {
@@ -8464,7 +8470,7 @@ class MethodElementImpl extends ExecutableElementImpl
   }
 
   @override
-  MethodElement get declaration => this;
+  MethodElementImpl get declaration => this;
 
   @override
   String get displayName {
@@ -8893,7 +8899,7 @@ class MultiplyDefinedElementImpl implements MultiplyDefinedElement {
   }
 
   @override
-  Element? get declaration => null;
+  ElementImpl? get declaration => null;
 
   @override
   String get displayName => name;
@@ -9511,7 +9517,7 @@ class ParameterElementImpl extends VariableElementImpl
   List<Fragment> get children3 => const [];
 
   @override
-  ParameterElement get declaration => this;
+  ParameterElementImpl get declaration => this;
 
   @override
   FormalParameterElementImpl get element {
@@ -9696,6 +9702,9 @@ class ParameterElementImpl_ofImplicitSetter extends ParameterElementImpl {
 /// [ParameterElement].
 mixin ParameterElementMixin
     implements ParameterElement, VariableElementOrMember {
+  @override
+  ParameterElementImpl get declaration;
+
   @override
   FormalParameterElementImpl get element;
 
@@ -10151,7 +10160,7 @@ class PropertyAccessorElementImpl extends ExecutableElementImpl
       correspondingSetter as SetterFragment?;
 
   @override
-  PropertyAccessorElement get declaration => this;
+  PropertyAccessorElementImpl get declaration => this;
 
   @override
   PropertyAccessorElementImpl2 get element {
@@ -10964,7 +10973,7 @@ class TopLevelVariableElementImpl extends PropertyInducingElementImpl
   }
 
   @override
-  TopLevelVariableElement get declaration => this;
+  TopLevelVariableElementImpl get declaration => this;
 
   @override
   bool get isExternal {
@@ -11484,7 +11493,7 @@ class TypeParameterElementImpl extends ElementImpl
   List<Fragment> get children3 => const [];
 
   @override
-  TypeParameterElement get declaration => this;
+  TypeParameterElementImpl get declaration => this;
 
   @override
   String get displayName => name;
@@ -11828,7 +11837,7 @@ abstract class VariableElementImpl extends ElementImpl
   ExpressionImpl? get constantInitializer => null;
 
   @override
-  VariableElement get declaration => this;
+  VariableElementImpl get declaration => this;
 
   @override
   String get displayName => name;

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

@@ -48,7 +48,8 @@ class ConstructorMember extends ExecutableMember
   ConstructorElement2 get baseElement => _element2;
 
   @override
-  ConstructorElement get declaration => super.declaration as ConstructorElement;
+  ConstructorElementImpl get declaration =>
+      _declaration as ConstructorElementImpl;
 
   @override
   String get displayName => declaration.displayName;
@@ -254,7 +255,8 @@ abstract class ExecutableMember extends Member
       children.map((fragment) => fragment.asElement2).nonNulls.toList();
 
   @override
-  ExecutableElement get declaration => super.declaration as ExecutableElement;
+  ExecutableElementImpl get declaration =>
+      _declaration as ExecutableElementImpl;
 
   @override
   String get displayName => declaration.displayName;
@@ -327,11 +329,11 @@ abstract class ExecutableMember extends Member
   @override
   List<ParameterElement> get parameters {
     return declaration.parameters.map<ParameterElement>((p) {
-      if (p is FieldFormalParameterElement) {
+      if (p is FieldFormalParameterElementImpl) {
         return FieldFormalParameterMember(
             p, augmentationSubstitution, _substitution);
       }
-      if (p is SuperFormalParameterElement) {
+      if (p is SuperFormalParameterElementImpl) {
         return SuperFormalParameterMember(
             p, augmentationSubstitution, _substitution);
       }
@@ -344,9 +346,7 @@ abstract class ExecutableMember extends Member
     var result = declaration.returnType;
     result = augmentationSubstitution.substituteType(result);
     result = _substitution.substituteType(result);
-    // TODO(paulberry): eliminate this cast by changing the type of
-    // `declaration`.
-    return result as TypeImpl;
+    return result;
   }
 
   @override
@@ -562,7 +562,7 @@ class FieldMember extends VariableMember
   }
 
   @override
-  FieldElement get declaration => super.declaration as FieldElement;
+  FieldElementImpl get declaration => _declaration as FieldElementImpl;
 
   @override
   String get displayName => declaration.displayName;
@@ -838,7 +838,7 @@ abstract class Member implements Element {
   AnalysisContext get context => _declaration.context;
 
   @override
-  Element get declaration => _declaration;
+  ElementImpl get declaration => _declaration as ElementImpl;
 
   @override
   String get displayName => _declaration.displayName;
@@ -1094,7 +1094,7 @@ class MethodMember extends ExecutableMember
   MethodElement2 get baseElement => _element2;
 
   @override
-  MethodElement get declaration => super.declaration as MethodElement;
+  MethodElementImpl get declaration => _declaration as MethodElementImpl;
 
   @override
   Element get enclosingElement3 => declaration.enclosingElement3;
@@ -1227,8 +1227,7 @@ class ParameterMember extends VariableMember
   }
 
   @override
-  ParameterElementImpl get declaration =>
-      super.declaration as ParameterElementImpl;
+  ParameterElementImpl get declaration => _declaration as ParameterElementImpl;
 
   @override
   String? get defaultValueCode => declaration.defaultValueCode;
@@ -1457,7 +1456,7 @@ abstract class PropertyAccessorMember extends ExecutableMember
 
   @override
   PropertyAccessorElementImpl get declaration =>
-      super.declaration as PropertyAccessorElementImpl;
+      _declaration as PropertyAccessorElementImpl;
 
   @override
   Element2 get enclosingElement2 {
@@ -1660,8 +1659,8 @@ class TopLevelVariableMember extends VariableMember
   }
 
   @override
-  TopLevelVariableElement get declaration =>
-      _declaration as TopLevelVariableElement;
+  TopLevelVariableElementImpl get declaration =>
+      _declaration as TopLevelVariableElementImpl;
 
   @override
   String get displayName => declaration.displayName;
@@ -1731,7 +1730,7 @@ abstract class VariableMember extends Member
   );
 
   @override
-  VariableElement get declaration => super.declaration as VariableElement;
+  VariableElementImpl get declaration => _declaration as VariableElementImpl;
 
   @override
   bool get hasImplicitType => declaration.hasImplicitType;
@@ -1758,9 +1757,7 @@ abstract class VariableMember extends Member
     var result = declaration.type;
     result = augmentationSubstitution.substituteType(result);
     result = _substitution.substituteType(result);
-    // TODO(paulberry): remove this cast by changing the type of `declaration`
-    // and the return type of `substituteType`
-    return _type = result as TypeImpl;
+    return _type = result;
   }
 
   @override

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

@@ -565,6 +565,12 @@ extension MethodElementExtension on MethodElement {
   }
 }
 
+extension MethodElementImplExtension on MethodElementImpl {
+  MethodElementImpl2 get asElement2 {
+    return element;
+  }
+}
+
 extension MethodElementOrMemberExtension on MethodElementOrMember {
   MethodElement2OrMember get asElement2 {
     return switch (this) {