Elements. Migrate VariableDeclarationResolver.

Change-Id: I4b28ec4a03bb6e0591c12d0c262fec9bedf0ecd9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/406688
Reviewed-by: Phil Quitslund <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -18389,11 +18389,8 @@ final class VariableDeclarationImpl extends DeclarationImpl
 
   @experimental
   @override
-  VariableFragment? get declaredFragment {
-    if (declaredElement case VariableFragment fragment) {
-      return fragment;
-    }
-    return null;
+  VariableElementImpl? get declaredFragment {
+    return declaredElement;
   }
 
   /// This overridden implementation of [documentationComment] looks in the

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

@@ -7831,7 +7831,7 @@ class LocalVariableElementImpl extends NonParameterVariableElementImpl
   List<Fragment> get children3 => const [];
 
   @override
-  LocalVariableElement2 get element => _element2;
+  LocalVariableElementImpl2 get element => _element2;
 
   @override
   Fragment get enclosingFragment => enclosingElement3 as Fragment;
@@ -9605,6 +9605,9 @@ class ParameterElementImpl_ofImplicitSetter extends ParameterElementImpl {
 /// [ParameterElement].
 mixin ParameterElementMixin
     implements ParameterElement, VariableElementOrMember {
+  @override
+  FormalParameterElementImpl get element;
+
   @override
   bool get isNamed => parameterKind.isNamed;
 
@@ -10556,6 +10559,11 @@ abstract class PropertyInducingElementImpl2 extends VariableElementImpl2
     }
   }
 
+  bool get shouldUseTypeForInitializerInference {
+    return (firstFragment as PropertyInducingElementImpl)
+        .shouldUseTypeForInitializerInference;
+  }
+
   List<PropertyInducingElementImpl> get _fragments;
 }
 
@@ -11706,7 +11714,7 @@ abstract class VariableElement2OrMember implements VariableElement2 {
 
 /// A concrete implementation of a [VariableElement].
 abstract class VariableElementImpl extends ElementImpl
-    implements VariableElementOrMember {
+    implements VariableElementOrMember, VariableFragment {
   /// The type of this variable.
   TypeImpl? _type;
 
@@ -11729,6 +11737,9 @@ abstract class VariableElementImpl extends ElementImpl
   @override
   String get displayName => name;
 
+  @override
+  VariableElementImpl2 get element;
+
   /// Return the result of evaluating this variable's initializer as a
   /// compile-time constant expression, or `null` if this variable is not a
   /// 'const' variable, if it does not have an initializer, or if the

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

@@ -1212,14 +1212,14 @@ class ParameterMember extends VariableMember
       children.map((fragment) => fragment.asElement2).nonNulls.toList();
 
   @override
-  ParameterElement get declaration => super.declaration as ParameterElement;
+  ParameterElementImpl get declaration =>
+      super.declaration as ParameterElementImpl;
 
   @override
   String? get defaultValueCode => declaration.defaultValueCode;
 
   @override
-  // TODO(scheglov): we lose types
-  FormalParameterElement get element => declaration.element;
+  FormalParameterElementImpl get element => declaration.element;
 
   @override
   Element2? get enclosingElement2 => _element2.enclosingElement2;

pkg/analyzer/lib/src/dart/resolver/variable_declaration_resolver.dart

@@ -2,10 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// ignore_for_file: analyzer_use_new_elements
-
 import 'package:_fe_analyzer_shared/src/types/shared_type.dart';
-import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/ast/extensions.dart';
 import 'package:analyzer/src/dart/element/element.dart';
@@ -40,17 +38,17 @@ class VariableDeclarationResolver {
       return;
     }
 
-    var element = node.declaredElement!;
+    var element = node.declaredFragment!.element;
     var isTopLevel =
-        element is FieldElement || element is TopLevelVariableElement;
+        element is FieldElement2 || element is TopLevelVariableElement2;
 
     if (isTopLevel) {
       _resolver.flowAnalysis.bodyOrInitializer_enter(node, null);
     } else if (element.isLate) {
       _resolver.flowAnalysis.flow?.lateInitializer_begin(node);
     }
 
-    var contextType = element is! PropertyInducingElementImpl ||
+    var contextType = element is! PropertyInducingElementImpl2 ||
             element.shouldUseTypeForInitializerInference
         ? element.type
         : UnknownInferredType.instance;
@@ -60,7 +58,7 @@ class VariableDeclarationResolver {
         _resolver.flowAnalysis.flow?.whyNotPromoted(initializer);
 
     var initializerType = initializer.typeOrThrow;
-    if (parent.type == null && element is LocalVariableElementImpl) {
+    if (parent.type == null && element is LocalVariableElementImpl2) {
       element.type = _resolver
           .variableTypeFromInitializerType(SharedTypeView(initializerType))
           .unwrapTypeView();
@@ -75,8 +73,9 @@ class VariableDeclarationResolver {
 
     // Initializers of top-level variables and fields are already included
     // into elements during linking.
-    if (element is ConstLocalVariableElementImpl) {
-      element.constantInitializer = initializer;
+    if (element is LocalVariableElementImpl2 && element.isConst) {
+      var fragment = element.firstFragment as ConstLocalVariableElementImpl;
+      fragment.constantInitializer = initializer;
     }
 
     _resolver.checkForAssignableExpressionAtType(