[analyzer] use PromotableElement2 to interface to shared analysis code.

Change the analyzer's use of the following shared classes and mixins
to supply `PromotableElement2` instead of `PromotableElement` as the
type parameter that represents promotable variables:
- `AssignedVariables`
- `AssignedVariablesForTesting`
- `CaseHeadOrDefaultInfo`
- `DemoteViaExplicitWrite`
- `FlowAnalysis`
- `GeneratedTypeConstraint`
- `MatchContext`
- `MergedTypeConstraint`
- `NonPromotionReasonVisitor`
- `SwitchExpressionMemberInfo`
- `SwitchStatementMemberInfo`
- `TypeAnalyzer`
- `TypeAnalyzerErrors`
- `TypeAnalyzerOperations`
- `TypeAnalyzerOperationsMixin`
- `TypeConstraintFromArgument`
- `TypeConstraintFromExtendsClause`
- `TypeConstraintFromFunctionContext`
- `TypeConstraintFromReturnType`
- `TypeConstraintGenerator`
- `TypeConstraintGeneratorMixin`
- `TypeConstraintOrigin`
- `UnknownTypeConstraintOrigin`
- `VariableBinder`
- `VariableBinderErrors`

This ensures that all references to variables within the shared code
are using the new analyzer element model.

As a result of this type change, a lot of analyzer code that
interfaces with shared logic needs to change to use the new element
model.

Also, a few additional members need to be added to
`BindPatternVariableElementImpl2`, `JoinPatternVariableElementImpl2`,
`LocalVariableElementImpl2`, and `PatternVariableElementImpl2` to
allow members of the underlying `_wrappedElement` to be accessed.

Change-Id: Ie925eeb82523c769c4d869a37551718f75d334ca
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/400660
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Paul Berry <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: stereotype441

pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart

@@ -4429,7 +4429,10 @@ class _FlowAnalysisImpl<Node extends Object, Statement extends Node,
 
   /// For debugging only: the set of [Variable]s that have been passed to
   /// [declare] so far.  This is used to detect unnecessary calls to [declare].
-  final Set<Variable> _debugDeclaredVariables = {};
+  final Set<Variable> _debugDeclaredVariables =
+      // TODO(paulberry): consider changing back to `{}` once
+      // https://github.com/dart-lang/sdk/issues/59753 is fixed.
+      new Set.identity();
 
   @override
   late final SsaNode<Type> _superSsaNode = new SsaNode<Type>(null);

pkg/analyzer/analyzer_use_new_elements.txt

@@ -85,7 +85,6 @@ lib/src/dart/resolver/property_element_resolver.dart
 lib/src/dart/resolver/resolution_result.dart
 lib/src/dart/resolver/resolution_visitor.dart
 lib/src/dart/resolver/scope.dart
-lib/src/dart/resolver/shared_type_analyzer.dart
 lib/src/dart/resolver/simple_identifier_resolver.dart
 lib/src/dart/resolver/this_lookup.dart
 lib/src/dart/resolver/type_property_resolver.dart

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

@@ -820,8 +820,8 @@ final class AssignedVariablePatternImpl extends VariablePatternImpl
 
   @override
   DartType computePatternSchema(ResolverVisitor resolverVisitor) {
-    var element = this.element;
-    if (element is PromotableElement) {
+    var element = element2;
+    if (element is PromotableElement2) {
       return resolverVisitor
           .analyzeAssignedVariablePatternSchema(element)
           .unwrapTypeSchemaView();
@@ -5029,7 +5029,7 @@ final class DeclaredVariablePatternImpl extends VariablePatternImpl
     var result = resolverVisitor.analyzeDeclaredVariablePattern(
         context,
         this,
-        declaredElement!,
+        declaredElement2!,
         declaredElement!.name,
         type?.typeOrThrow.wrapSharedTypeView());
     declaredElement!.type = result.staticType.unwrapTypeView();
@@ -9210,7 +9210,7 @@ final class GuardedPatternImpl extends AstNodeImpl implements GuardedPattern {
 
   /// Variables declared in [pattern], available in [whenClause] guard, and
   /// to the `ifTrue` node.
-  late Map<String, PatternVariableElementImpl> variables;
+  late Map<String, PatternVariableElementImpl2> variables;
 
   @override
   final WhenClauseImpl? whenClause;
@@ -17274,7 +17274,7 @@ class SwitchStatementCaseGroup {
   final bool hasLabels;
 
   /// Joined variables declared in [members], available in [statements].
-  late Map<String, PromotableElement> variables;
+  late Map<String, PromotableElement2> variables;
 
   SwitchStatementCaseGroup(this.members, this.hasLabels);
 

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

@@ -140,6 +140,12 @@ class BindPatternVariableElementImpl2 extends PatternVariableElementImpl2
   BindPatternVariableFragment get firstFragment =>
       super.firstFragment as BindPatternVariableFragment;
 
+  /// This flag is set to `true` if this variable clashes with another
+  /// pattern variable with the same name within the same pattern.
+  set isDuplicate(bool value) => _wrappedElement.isDuplicate = value;
+
+  DeclaredVariablePatternImpl get node => _wrappedElement.node;
+
   @override
   BindPatternVariableElementImpl get _wrappedElement =>
       super._wrappedElement as BindPatternVariableElementImpl;
@@ -6596,9 +6602,23 @@ class JoinPatternVariableElementImpl2 extends PatternVariableElementImpl2
   JoinPatternVariableFragment get firstFragment =>
       super.firstFragment as JoinPatternVariableFragment;
 
+  shared.JoinedPatternVariableInconsistency get inconsistency =>
+      _wrappedElement.inconsistency;
+
+  set inconsistency(shared.JoinedPatternVariableInconsistency value) =>
+      _wrappedElement.inconsistency = value;
+
   @override
   bool get isConsistent => _wrappedElement.isConsistent;
 
+  set isFinal(bool value) => _wrappedElement.isFinal = value;
+
+  /// The identifiers that reference this element.
+  List<SimpleIdentifier> get references => _wrappedElement.references;
+
+  /// The variables that join into this variable.
+  List<PatternVariableElementImpl> get variables => _wrappedElement.variables;
+
   @override
   List<PatternVariableElement2> get variables2 =>
       _wrappedElement.variables.map((fragment) => fragment.element).toList();
@@ -7598,6 +7618,8 @@ class LocalVariableElementImpl2 extends PromotableElementImpl2
   @override
   DartType get type => _wrappedElement.type;
 
+  set type(DartType type) => _wrappedElement.type = type;
+
   LocalVariableElementImpl get wrappedElement {
     return _wrappedElement;
   }
@@ -8964,7 +8986,11 @@ abstract class NonParameterVariableElementImpl extends VariableElementImpl
   NonParameterVariableElementImpl(String super.name, super.offset);
 
   @override
-  Element get enclosingElement3 => super.enclosingElement3!;
+  Element get enclosingElement3 =>
+      // TODO(paulberry): `!` is not appropriate here because variable elements
+      // aren't guaranteed to have enclosing elements. See
+      // https://github.com/dart-lang/sdk/issues/59750.
+      super.enclosingElement3!;
 
   bool get hasInitializer {
     return hasModifier(Modifier.HAS_INITIALIZER);
@@ -9345,6 +9371,11 @@ class PatternVariableElementImpl2 extends LocalVariableElementImpl2
   PatternVariableFragment get firstFragment =>
       super.firstFragment as PatternVariableFragment;
 
+  /// This flag is set to `true` while we are visiting the [WhenClause] of
+  /// the [GuardedPattern] that declares this variable.
+  set isVisitingWhenClause(bool value) =>
+      _wrappedElement.isVisitingWhenClause = value;
+
   @override
   JoinPatternVariableElement2? get join2 =>
       JoinPatternVariableElementImpl2(_wrappedElement.join!);

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

@@ -21,6 +21,7 @@ import 'package:_fe_analyzer_shared/src/type_inference/type_constraint.dart'
         UnknownTypeConstraintOrigin;
 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/dart/element/type.dart';
 import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/element/element.dart';
@@ -29,20 +30,20 @@ import 'package:analyzer/src/dart/element/type_schema.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
 
 /// Instance of [shared.GeneratedTypeConstraint] specific to the Analyzer.
-typedef GeneratedTypeConstraint = shared
-    .GeneratedTypeConstraint<DartType, TypeParameterElement, PromotableElement>;
+typedef GeneratedTypeConstraint = shared.GeneratedTypeConstraint<DartType,
+    TypeParameterElement, PromotableElement2>;
 
 /// Instance of [shared.MergedTypeConstraint] specific to the Analyzer.
 typedef MergedTypeConstraint = shared.MergedTypeConstraint<DartType,
-    TypeParameterElement, PromotableElement, InterfaceType, InterfaceElement>;
+    TypeParameterElement, PromotableElement2, InterfaceType, InterfaceElement>;
 
 /// Instance of [shared.TypeConstraintFromArgument] specific to the Analyzer.
 typedef TypeConstraintFromArgument = shared.TypeConstraintFromArgument<DartType,
-    PromotableElement, TypeParameterElement, InterfaceType, InterfaceElement>;
+    PromotableElement2, TypeParameterElement, InterfaceType, InterfaceElement>;
 
 /// Instance of [shared.TypeConstraintFromExtendsClause] specific to the Analyzer.
 typedef TypeConstraintFromExtendsClause
-    = shared.TypeConstraintFromExtendsClause<DartType, PromotableElement,
+    = shared.TypeConstraintFromExtendsClause<DartType, PromotableElement2,
         TypeParameterElement, InterfaceType, InterfaceElement>;
 
 /// Instance of [shared.TypeConstraintFromFunctionContext] specific to the Analyzer.
@@ -51,7 +52,7 @@ typedef TypeConstraintFromFunctionContext
         DartType,
         DartType,
         DartType,
-        PromotableElement,
+        PromotableElement2,
         TypeParameterElement,
         InterfaceType,
         InterfaceElement>;
@@ -61,19 +62,19 @@ typedef TypeConstraintFromReturnType = shared.TypeConstraintFromReturnType<
     DartType,
     DartType,
     DartType,
-    PromotableElement,
+    PromotableElement2,
     TypeParameterElement,
     InterfaceType,
     InterfaceElement>;
 
 /// Instance of [shared.TypeConstraintOrigin] specific to the Analyzer.
 typedef TypeConstraintOrigin = shared.TypeConstraintOrigin<DartType,
-    PromotableElement, TypeParameterElement, InterfaceType, InterfaceElement>;
+    PromotableElement2, TypeParameterElement, InterfaceType, InterfaceElement>;
 
 /// Instance of [shared.UnknownTypeConstraintOrigin] specific to the Analyzer.
 typedef UnknownTypeConstraintOrigin = shared.UnknownTypeConstraintOrigin<
     DartType,
-    PromotableElement,
+    PromotableElement2,
     TypeParameterElement,
     InterfaceType,
     InterfaceElement>;
@@ -83,7 +84,7 @@ typedef UnknownTypeConstraintOrigin = shared.UnknownTypeConstraintOrigin<
 class TypeConstraintGatherer extends shared.TypeConstraintGenerator<
         DartType,
         ParameterElement,
-        PromotableElement,
+        PromotableElement2,
         TypeParameterElement,
         InterfaceType,
         InterfaceElement,
@@ -92,7 +93,7 @@ class TypeConstraintGatherer extends shared.TypeConstraintGenerator<
         shared.TypeConstraintGeneratorMixin<
             DartType,
             ParameterElement,
-            PromotableElement,
+            PromotableElement2,
             TypeParameterElement,
             InterfaceType,
             InterfaceElement,

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

@@ -7,6 +7,7 @@ import 'package:_fe_analyzer_shared/src/types/shared_type.dart';
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_provider.dart';
 import 'package:analyzer/error/listener.dart';
@@ -54,6 +55,7 @@ class AssignmentExpressionResolver {
 
     var readElement = leftResolution.readElement;
     var writeElement = leftResolution.writeElement;
+    var writeElement2 = leftResolution.writeElement2;
 
     if (hasRead) {
       _resolver.setReadElement(
@@ -101,8 +103,8 @@ class AssignmentExpressionResolver {
         whyNotPromoted: whyNotPromoted, contextType: contextType);
 
     if (flow != null) {
-      if (writeElement is PromotableElement) {
-        flow.write(node, writeElement, SharedTypeView(node.typeOrThrow),
+      if (writeElement2 is PromotableElement2) {
+        flow.write(node, writeElement2, SharedTypeView(node.typeOrThrow),
             hasRead ? null : right);
       }
       if (isIfNull) {
@@ -359,8 +361,8 @@ class AssignmentExpressionShared {
     if (flow == null) return;
 
     if (left is SimpleIdentifier) {
-      var element = left.staticElement;
-      if (element is PromotableElement) {
+      var element = left.element;
+      if (element is PromotableElement2) {
         var assigned = flowAnalysis.isDefinitelyAssigned(left, element);
         var unassigned = flowAnalysis.isDefinitelyUnassigned(left, element);
 
@@ -377,7 +379,7 @@ class AssignmentExpressionShared {
               _errorReporter.atNode(
                 left,
                 CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_LOCAL,
-                arguments: [element.name],
+                arguments: [element.name3!],
               );
             }
           }

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

@@ -8,6 +8,7 @@ import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/syntactic_entity.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_provider.dart';
 import 'package:analyzer/error/listener.dart';
@@ -139,14 +140,14 @@ class BinaryExpressionResolver {
     }
 
     if (left is SimpleIdentifierImpl && right is NullLiteralImpl) {
-      var element = left.staticElement;
-      if (element is PromotableElement &&
+      var element = left.element;
+      if (element is PromotableElement2 &&
           flowAnalysis.isDefinitelyUnassigned(left, element)) {
         reportNullComparison(left, node.operator);
       }
     } else if (right is SimpleIdentifierImpl && left is NullLiteralImpl) {
-      var element = right.staticElement;
-      if (element is PromotableElement &&
+      var element = right.element;
+      if (element is PromotableElement2 &&
           flowAnalysis.isDefinitelyUnassigned(right, element)) {
         reportNullComparison(node.operator, right);
       }