[analyzer] Switch more types to "Impl" types.

Field types, getter types, method return types, and method parameter
types are changed to `Impl` types in the following classes and
extensions:

- `CompoundAssignmentExpressionImpl`
- `ExecutableElementExtensionQuestion`
- `ExtensionElementImpl`
- `ExtensionResolutionError`
- `FunctionReferenceResolver`
- `InstanceElementImpl2`
- `InstantiatedExtensionWithMember`
- `InstantiatedExtensionWithMember2`
- `InterfaceElementImpl`
- `InvocationInferrer`
- `LexicalLookupResult`
- `LocalVariableTypeProvider`
- `PostfixExpressionResolver`
- `PropertyElementResolverResult`
- `RecordTypeExtension`
- `ResolutionResult`
- `ResolverVisitor`
- `SimpleResolutionResult`
- `TypePropertyResolver`

There is no change to the analyzer public API.

This is part of a larger arc of work to change the analyzer's use of
the shared code so that the type parameters it supplies are not part
of the analyzer public API. See
#59763.

Change-Id: I5d0d432301df38c7a5ccc7c65767cf73ce7b5d7d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405801
Commit-Queue: Paul Berry <[email protected]>
Auto-Submit: Paul Berry <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: stereotype441

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

@@ -3691,10 +3691,10 @@ base mixin CompoundAssignmentExpressionImpl
   Element? writeElement;
 
   @override
-  DartType? readType;
+  TypeImpl? readType;
 
   @override
-  DartType? writeType;
+  TypeImpl? writeType;
 
   @experimental
   @override

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

@@ -1717,7 +1717,7 @@ class ConstructorElementImpl2 extends ExecutableElementImpl2
           ?.element;
 
   @override
-  InterfaceType get returnType {
+  InterfaceTypeImpl get returnType {
     return firstFragment.returnType;
   }
 
@@ -3721,6 +3721,16 @@ class EnumElementImpl2 extends InterfaceElementImpl2
   }
 }
 
+/// Common base class for all analyzer-internal classes that implement
+/// `ExecutableElement2`.
+abstract class ExecutableElement2OrMember implements ExecutableElement2 {
+  @override
+  TypeImpl get returnType;
+
+  @override
+  FunctionTypeImpl get type;
+}
+
 /// A base class for concrete implementations of an [ExecutableElement].
 abstract class ExecutableElementImpl extends _ExistingElementImpl
     with TypeParameterizedElementMixin, MacroTargetElement
@@ -3917,7 +3927,7 @@ abstract class ExecutableElementImpl extends _ExistingElementImpl
 }
 
 abstract class ExecutableElementImpl2 extends FunctionTypedElementImpl2
-    implements ExecutableElement2 {
+    implements ExecutableElement2OrMember {
   @override
   ExecutableElement2 get baseElement => this;
 
@@ -4001,7 +4011,7 @@ class ExtensionElementImpl extends InstanceElementImpl
   }
 
   @override
-  DartType get extendedType {
+  TypeImpl get extendedType {
     return augmented.extendedType;
   }
 
@@ -4245,7 +4255,7 @@ class ExtensionTypeElementImpl2 extends InterfaceElementImpl2
 /// A concrete implementation of a [FieldElement].
 class FieldElementImpl extends PropertyInducingElementImpl
     with AugmentableElement<FieldElementImpl>
-    implements FieldElement, FieldFragment {
+    implements FieldElementOrMember, FieldFragment {
   /// True if this field inherits from a covariant parameter. This happens
   /// when it overrides a field in a supertype that is covariant.
   bool inheritsCovariant = false;
@@ -4448,6 +4458,13 @@ class FieldElementImpl2 extends PropertyInducingElementImpl2
   DartObject? computeConstantValue() => firstFragment.computeConstantValue();
 }
 
+/// Common base class for all analyzer-internal classes that implement
+/// `FieldElement`.
+abstract class FieldElementOrMember implements FieldElement {
+  @override
+  TypeImpl get type;
+}
+
 /// A [ParameterElementImpl] that has the additional information of the
 /// [FieldElement] associated with the parameter.
 class FieldFormalParameterElementImpl extends ParameterElementImpl
@@ -5136,7 +5153,7 @@ mixin FragmentedFunctionTypedElementMixin<E extends ExecutableFragment>
     };
   }
 
-  DartType get returnType => type.returnType;
+  TypeImpl get returnType => type.returnType;
 
   // TODO(augmentations): This is wrong. The function type needs to be a merge
   //  of the function types of all of the fragments, but I don't know how to
@@ -5718,7 +5735,7 @@ abstract class InstanceElementImpl2 extends ElementImpl2
         InstanceElement2,
         TypeParameterizedElement2 {
   @override
-  List<FieldElement> fields = [];
+  List<FieldElementOrMember> fields = [];
 
   @override
   List<PropertyAccessorElementOrMember> accessors = [];
@@ -5833,7 +5850,7 @@ abstract class InstanceElementImpl2 extends ElementImpl2
           multiline: multiline, preferTypeAlias: preferTypeAlias);
 
   @override
-  FieldElement? getField(String name) {
+  FieldElementOrMember? getField(String name) {
     var length = fields.length;
     for (var i = 0; i < length; i++) {
       var field = fields[i];
@@ -6279,13 +6296,13 @@ abstract class InterfaceElementImpl extends InstanceElementImpl
   }
 
   @override
-  PropertyAccessorElement? getGetter(String getterName) {
+  PropertyAccessorElementOrMember? getGetter(String getterName) {
     return accessors.firstWhereOrNull(
         (accessor) => accessor.isGetter && accessor.name == getterName);
   }
 
   @override
-  MethodElement? getMethod(String methodName) {
+  MethodElementOrMember? getMethod(String methodName) {
     return methods.firstWhereOrNull((method) => method.name == methodName);
   }
 
@@ -6398,7 +6415,7 @@ abstract class InterfaceElementImpl extends InstanceElementImpl
   /// This method should be used only for error recovery during analysis,
   /// when instance access to a static class member, defined in this class,
   /// or a superclass.
-  PropertyAccessorElement? lookupStaticGetter(
+  PropertyAccessorElementOrMember? lookupStaticGetter(
       String name, LibraryElement library) {
     return _implementationsOfGetter(name).firstWhereOrNull(
         (element) => element.isStatic && element.isAccessibleIn(library));
@@ -6409,7 +6426,8 @@ abstract class InterfaceElementImpl extends InstanceElementImpl
   /// This method should be used only for error recovery during analysis,
   /// when instance access to a static class member, defined in this class,
   /// or a superclass.
-  MethodElement? lookupStaticMethod(String name, LibraryElement library) {
+  MethodElementOrMember? lookupStaticMethod(
+      String name, LibraryElement library) {
     return _implementationsOfMethod(name).firstWhereOrNull(
         (element) => element.isStatic && element.isAccessibleIn(library));
   }
@@ -6443,16 +6461,16 @@ abstract class InterfaceElementImpl extends InstanceElementImpl
   /// The getters are returned based on the depth of their defining class; if
   /// this class contains a definition of the getter it will occur first, if
   /// Object contains a definition of the getter it will occur last.
-  Iterable<PropertyAccessorElement> _implementationsOfGetter(
+  Iterable<PropertyAccessorElementOrMember> _implementationsOfGetter(
       String getterName) sync* {
     var visitedClasses = <InterfaceElement>{};
-    InterfaceElement? classElement = this;
+    InterfaceElementImpl? classElement = this;
     while (classElement != null && visitedClasses.add(classElement)) {
       var getter = classElement.getGetter(getterName);
       if (getter != null) {
         yield getter;
       }
-      for (InterfaceType mixin in classElement.mixins.reversed) {
+      for (var mixin in classElement.mixins.reversed) {
         getter = mixin.element.getGetter(getterName);
         if (getter != null) {
           yield getter;
@@ -6473,15 +6491,16 @@ abstract class InterfaceElementImpl extends InstanceElementImpl
   /// The methods are returned based on the depth of their defining class; if
   /// this class contains a definition of the method it will occur first, if
   /// Object contains a definition of the method it will occur last.
-  Iterable<MethodElement> _implementationsOfMethod(String methodName) sync* {
+  Iterable<MethodElementOrMember> _implementationsOfMethod(
+      String methodName) sync* {
     var visitedClasses = <InterfaceElement>{};
-    InterfaceElement? classElement = this;
+    InterfaceElementImpl? classElement = this;
     while (classElement != null && visitedClasses.add(classElement)) {
       var method = classElement.getMethod(methodName);
       if (method != null) {
         yield method;
       }
-      for (InterfaceType mixin in classElement.mixins.reversed) {
+      for (var mixin in classElement.mixins.reversed) {
         method = mixin.element.getMethod(methodName);
         if (method != null) {
           yield method;
@@ -7734,10 +7753,10 @@ class LocalFunctionElementImpl extends ExecutableElementImpl2
   Metadata get metadata2 => _wrappedElement.metadata2;
 
   @override
-  DartType get returnType => _wrappedElement.returnType;
+  TypeImpl get returnType => _wrappedElement.returnType;
 
   @override
-  FunctionType get type => _wrappedElement.type;
+  FunctionTypeImpl get type => _wrappedElement.type;
 
   @override
   List<TypeParameterElement2> get typeParameters2 =>
@@ -8296,10 +8315,8 @@ final class MetadataImpl implements Metadata {
 
 /// Common base class for all analyzer-internal classes that implement
 /// `MethodElement2`.
-abstract class MethodElement2OrMember implements MethodElement2 {
-  @override
-  FunctionTypeImpl get type;
-}
+abstract class MethodElement2OrMember
+    implements MethodElement2, ExecutableElement2OrMember {}
 
 /// A concrete implementation of a [MethodElement].
 class MethodElementImpl extends ExecutableElementImpl
@@ -9924,6 +9941,11 @@ class PrefixFragmentImpl implements PrefixFragment {
 abstract class PromotableElementImpl2 extends VariableElementImpl2
     implements PromotableElement2 {}
 
+/// Common base class for all analyzer-internal classes that implement
+/// `PropertyAccessorElement2`.
+abstract class PropertyAccessorElement2OrMember
+    implements PropertyAccessorElement2, ExecutableElement2OrMember {}
+
 /// A concrete implementation of a [PropertyAccessorElement].
 class PropertyAccessorElementImpl extends ExecutableElementImpl
     with AugmentableElement<PropertyAccessorElementImpl>
@@ -10123,7 +10145,7 @@ class PropertyAccessorElementImpl extends ExecutableElementImpl
 }
 
 abstract class PropertyAccessorElementImpl2 extends ExecutableElementImpl2
-    implements PropertyAccessorElement2 {
+    implements PropertyAccessorElement2OrMember {
   @override
   PropertyAccessorElement2 get baseElement => this;
 

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

@@ -10,6 +10,7 @@ import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
+import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:meta/meta_meta.dart';
 
@@ -178,10 +179,12 @@ extension ExecutableElementExtension on ExecutableElement {
 }
 
 extension ExecutableElementExtensionQuestion on ExecutableElement? {
-  DartType? get firstParameterType {
+  TypeImpl? get firstParameterType {
     var self = this;
-    if (self is MethodElement) {
-      return self.parameters.firstOrNull?.type;
+    if (self is MethodElementOrMember) {
+      // TODO(paulberry): eliminate this cast by changing this extension to
+      // apply to `ExecutableElementOrMember?`.
+      return self.parameters.firstOrNull?.type as TypeImpl?;
     }
     return null;
   }
@@ -262,23 +265,27 @@ extension RecordTypeExtension on RecordType {
 
   /// The [name] is either an actual name like `foo` in `({int foo})`, or
   /// the name of a positional field like `$1` in `(int, String)`.
-  RecordTypeField? fieldByName(String name) {
+  RecordTypeFieldImpl? fieldByName(String name) {
     return namedField(name) ?? positionalField(name);
   }
 
-  RecordTypeNamedField? namedField(String name) {
+  RecordTypeNamedFieldImpl? namedField(String name) {
     for (var field in namedFields) {
       if (field.name == name) {
-        return field;
+        // TODO(paulberry): eliminate this cast by changing the extension to
+        // only apply to `RecordTypeImpl`.
+        return field as RecordTypeNamedFieldImpl;
       }
     }
     return null;
   }
 
-  RecordTypePositionalField? positionalField(String name) {
+  RecordTypePositionalFieldImpl? positionalField(String name) {
     var index = positionalFieldIndex(name);
     if (index != null && index < positionalFields.length) {
-      return positionalFields[index];
+      // TODO(paulberry): eliminate this cast by changing the extension to only
+      // apply to `RecordTypeImpl`.
+      return positionalFields[index] as RecordTypePositionalFieldImpl;
     }
     return null;
   }

pkg/analyzer/lib/src/dart/element/inheritance_manager3.dart

@@ -299,8 +299,6 @@ class InheritanceManager3 {
     }
 
     var substitution = Substitution.fromInterfaceType(type);
-    // TODO(paulberry): eliminate this cast by changing the return type of
-    // `ExecutalbeMember.from2`.
     return ExecutableMember.from2(rawElement, substitution);
   }
 

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

@@ -202,7 +202,7 @@ class ConstructorMember extends ExecutableMember
 /// An executable element defined in a parameterized type where the values of
 /// the type parameters are known.
 abstract class ExecutableMember extends Member
-    implements ExecutableElementOrMember, ExecutableElement2 {
+    implements ExecutableElementOrMember, ExecutableElement2OrMember {
   @override
   final List<TypeParameterElement> typeParameters;
 
@@ -379,7 +379,7 @@ abstract class ExecutableMember extends Member
     }
   }
 
-  static ExecutableElement2 from(
+  static ExecutableElement2OrMember from(
     ExecutableElement2 element,
     MapSubstitution substitution,
   ) {
@@ -507,7 +507,7 @@ class FieldFormalParameterMember extends ParameterMember
 /// parameters are known.
 class FieldMember extends VariableMember
     implements
-        FieldElement,
+        FieldElementOrMember,
         FieldElement2,
         VariableElement2OrMember,
         PropertyInducingElementOrMember {
@@ -1348,7 +1348,9 @@ class ParameterMember extends VariableMember
 /// A property accessor element defined in a parameterized type where the values
 /// of the type parameters are known.
 abstract class PropertyAccessorMember extends ExecutableMember
-    implements PropertyAccessorElementOrMember, PropertyAccessorElement2 {
+    implements
+        PropertyAccessorElementOrMember,
+        PropertyAccessorElement2OrMember {
   factory PropertyAccessorMember(
     PropertyAccessorElement declaration,
     MapSubstitution augmentationSubstitution,

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

@@ -35,7 +35,7 @@ class InstantiatedExtensionWithMember {
 
   ExtensionElement2 get extension => candidate.extension;
 
-  ExecutableElement2? get getter {
+  ExecutableElement2OrMember? get getter {
     var getter = candidate.getter;
     if (getter == null) {
       return null;

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

@@ -154,7 +154,7 @@ class CommentReferenceResolver {
     }
 
     if (element == null) {
-      InterfaceType enclosingType;
+      InterfaceTypeImpl enclosingType;
       var enclosingClass = _resolver.enclosingClass;
       if (enclosingClass != null) {
         enclosingType = enclosingClass.thisType;

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

@@ -483,10 +483,10 @@ enum ExtensionResolutionError implements ExtensionResolutionResult {
   ambiguous;
 
   @override
-  ExecutableElement? get getter => null;
+  ExecutableElementOrMember? get getter => null;
 
   @override
-  ExecutableElement2? get getter2 => null;
+  ExecutableElement2OrMember? get getter2 => null;
 
   @override
   ExecutableElement? get setter => null;