Elements. Change the return type of 'name3' implementations to nullable, update some bodies.

In particular, MethodElementImpl2, which can have a fragment without a
name, and can have a name without an actual fragment (when the fragment
is synthetic).

Change-Id: Ib3383867e4351e9a11ef39ce12bf5670a4db9ee2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/391701
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analysis_server/lib/src/protocol_server.dart

@@ -289,7 +289,7 @@ Location? newLocation_fromElement2(engine.Element2? element) {
     return _locationForArgs2(fragment, range);
   } else if (element is engine.LabelElement2) {
     var offset = element.nameOffset;
-    var length = element.name3.length;
+    var length = element.name3?.length ?? 0;
     var range = engine.SourceRange(offset, length);
     var fragment = element.enclosingFunction;
     return _locationForArgs2(fragment, range);

pkg/analysis_server/lib/src/services/correction/dart/change_to.dart

@@ -306,7 +306,7 @@ class ChangeTo extends ResolvedCorrectionProducer {
       if (superType == null) return;
 
       for (var constructor in superType.constructors2) {
-        if (constructor.name3.isEmpty) {
+        if (constructor.name3 == 'new') {
           var list = _formalParameterSuggestions(constructor, formalParameters);
           finder._updateList(list);
           break;

pkg/analyzer/lib/dart/element/element2.dart

@@ -253,7 +253,7 @@ abstract class ConstructorElement2
   ///
   /// The name of the unnamed constructor is `new`.
   @override
-  String get name3;
+  String? get name3;
 
   /// The constructor to which this constructor is redirecting.
   ///
@@ -977,9 +977,6 @@ abstract class GetterElement implements ExecutableElement2, FragmentedElement {
   @override
   GetterFragment? get firstFragment;
 
-  @override
-  String? get name3;
-
   /// The field or top-level variable associated with this getter.
   ///
   /// If this getter was explicitly defined (is not synthetic) then the variable
@@ -1196,9 +1193,6 @@ abstract class LabelElement2 implements Element2 {
   @override
   LibraryElement2 get library2;
 
-  @override
-  String get name3;
-
   /// The offset of the name in this element.
   int get nameOffset;
 }
@@ -1750,9 +1744,6 @@ abstract class PrefixElement2 implements Element2, FragmentedElement {
   @override
   LibraryElement2 get library2;
 
-  @override
-  String? get name3;
-
   /// The name lookup scope for this import prefix.
   ///
   /// It consists of elements imported into the enclosing library with this
@@ -1910,9 +1901,6 @@ abstract class SetterElement implements ExecutableElement2, FragmentedElement {
   @override
   SetterFragment? get firstFragment;
 
-  @override
-  String? get name3;
-
   /// The field or top-level variable associated with this setter.
   ///
   /// If this setter was explicitly defined (is not synthetic) then the variable

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

@@ -605,6 +605,11 @@ class ClassElementImpl extends ClassOrMixinElementImpl
       implicitConstructor.name = name;
       implicitConstructor.nameOffset = -1;
 
+      implicitConstructor.element = ConstructorElementImpl2(
+        superclassConstructor.element.name3,
+        implicitConstructor,
+      );
+
       var containerRef = reference!.getChild('@constructor');
       var referenceName = name.ifNotEmptyOrElse('new');
       var implicitReference = containerRef.getChild(referenceName);
@@ -1372,15 +1377,21 @@ class ConstructorElementImpl extends ExecutableElementImpl
     if (_element != null) {
       return _element!;
     }
+
     ConstructorFragment firstFragment = this;
     var previousFragment = firstFragment.previousFragment;
     while (previousFragment != null) {
       firstFragment = previousFragment;
       previousFragment = firstFragment.previousFragment;
     }
+    firstFragment as ConstructorElementImpl;
+
     // As a side-effect of creating the element, all of the fragments in the
     // chain will have their `_element` set to the newly created element.
-    return ConstructorElementImpl2(firstFragment as ConstructorElementImpl);
+    return ConstructorElementImpl2(
+      firstFragment.name2?.name ?? 'new',
+      firstFragment,
+    );
   }
 
   set element(ConstructorElement2 element) => _element = element;
@@ -1530,10 +1541,13 @@ class ConstructorElementImpl2 extends ExecutableElementImpl2
         FragmentedAnnotatableElementMixin<ConstructorFragment>,
         FragmentedElementMixin<ConstructorFragment>
     implements ConstructorElement2 {
+  @override
+  final String? name3;
+
   @override
   final ConstructorElementImpl firstFragment;
 
-  ConstructorElementImpl2(this.firstFragment) {
+  ConstructorElementImpl2(this.name3, this.firstFragment) {
     ConstructorElementImpl? fragment = firstFragment;
     while (fragment != null) {
       fragment.element = this;
@@ -1563,9 +1577,6 @@ class ConstructorElementImpl2 extends ExecutableElementImpl2
   @override
   ElementKind get kind => ElementKind.CONSTRUCTOR;
 
-  @override
-  String get name3 => firstFragment.name;
-
   @override
   ConstructorElement2? get redirectedConstructor2 =>
       (firstFragment.redirectedConstructor?.declaration
@@ -3997,7 +4008,7 @@ class FieldElementImpl2 extends PropertyInducingElementImpl2
   ElementKind get kind => ElementKind.FIELD;
 
   @override
-  String get name3 => firstFragment.name;
+  String? get name3 => firstFragment.name;
 
   @override
   SetterElement? get setter2 => firstFragment.setter?.element as SetterElement?;
@@ -4167,7 +4178,7 @@ class FormalParameterElementImpl extends PromotableElementImpl2
           as LibraryElement2;
 
   @override
-  String get name3 => firstFragment.name;
+  String? get name3 => firstFragment.name;
 
   @override
   // TODO(augmentations): Implement the merge of formal parameters.
@@ -7578,15 +7589,18 @@ class MethodElementImpl extends ExecutableElementImpl
     if (_element != null) {
       return _element!;
     }
+
     MethodFragment firstFragment = this;
     var previousFragment = firstFragment.previousFragment;
     while (previousFragment != null) {
       firstFragment = previousFragment;
       previousFragment = firstFragment.previousFragment;
     }
+    firstFragment as MethodElementImpl;
+
     // As a side-effect of creating the element, all of the fragments in the
     // chain will have their `_element` set to the newly created element.
-    return MethodElementImpl2(firstFragment as MethodElementImpl);
+    return MethodElementImpl2(firstFragment.name2?.name, firstFragment);
   }
 
   set element(MethodElement2 element) => _element = element;
@@ -7651,10 +7665,13 @@ class MethodElementImpl2 extends ExecutableElementImpl2
         FragmentedAnnotatableElementMixin<MethodFragment>,
         FragmentedElementMixin<MethodFragment>
     implements MethodElement2 {
+  @override
+  final String? name3;
+
   @override
   final MethodElementImpl firstFragment;
 
-  MethodElementImpl2(this.firstFragment) {
+  MethodElementImpl2(this.name3, this.firstFragment) {
     MethodElementImpl? fragment = firstFragment;
     while (fragment != null) {
       fragment.element = this;
@@ -7675,9 +7692,6 @@ class MethodElementImpl2 extends ExecutableElementImpl2
   @override
   ElementKind get kind => ElementKind.METHOD;
 
-  @override
-  String get name3 => firstFragment.name;
-
   @override
   T? accept2<T>(ElementVisitor2<T> visitor) {
     return visitor.visitMethodElement(this);
@@ -9483,10 +9497,7 @@ abstract class PropertyInducingElementImpl
 }
 
 abstract class PropertyInducingElementImpl2 extends VariableElementImpl2
-    implements PropertyInducingElement2 {
-  @override
-  String get name3;
-}
+    implements PropertyInducingElement2 {}
 
 /// Instances of this class are set for fields and top-level variables
 /// to perform top-level type inference during linking.
@@ -9810,7 +9821,7 @@ class TopLevelVariableElementImpl2 extends PropertyInducingElementImpl2
   ElementKind get kind => ElementKind.TOP_LEVEL_VARIABLE;
 
   @override
-  String get name3 => firstFragment.name;
+  String? get name3 => firstFragment.name;
 
   @override
   SetterElement? get setter2 =>
@@ -10129,7 +10140,7 @@ class TypeAliasElementImpl2 extends TypeDefiningElementImpl2
   ElementKind get kind => ElementKind.TYPE_ALIAS;
 
   @override
-  String get name3 => firstFragment.name;
+  String? get name3 => firstFragment.name2?.name;
 
   @override
   List<TypeParameterElement2> get typeParameters2 =>
@@ -10666,7 +10677,7 @@ mixin WrappedElementMixin implements ElementImpl2 {
   LibraryElement2? get library2 => _wrappedElement.library2;
 
   @override
-  String get name3 => _wrappedElement.name!;
+  String? get name3 => _wrappedElement.name3;
 
   ElementImpl get _wrappedElement;
 

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

@@ -1130,6 +1130,7 @@ class InheritanceManager3 {
       result.typeParameters = resultType.typeFormals;
       result.returnType = resultType.returnType;
       result.parameters = resultType.parameters;
+      result.element = MethodElementImpl2(firstMethod.name, result);
       return result;
     } else {
       var firstAccessor = first as PropertyAccessorElement;

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

@@ -72,7 +72,7 @@ class ConstructorMember extends ExecutableMember
   String get name => declaration.name;
 
   @override
-  String get name3 => declaration.name;
+  String? get name3 => _element2.name3;
 
   @override
   int? get nameEnd => declaration.nameEnd;
@@ -556,7 +556,7 @@ class FieldMember extends VariableMember
   String get name => declaration.name;
 
   @override
-  String get name3 => declaration.name;
+  String? get name3 => _element2.name3;
 
   @override
   Element2 get nonSynthetic2 => _element2.nonSynthetic2;
@@ -989,7 +989,7 @@ class MethodMember extends ExecutableMember
   String get name => declaration.name;
 
   @override
-  String get name3 => declaration.name;
+  String? get name3 => _element2.name3;
 
   @override
   Source get source => _declaration.source!;
@@ -1247,7 +1247,7 @@ abstract class PropertyAccessorMember extends ExecutableMember
   String get name => declaration.name;
 
   @override
-  String get name3 => declaration.name;
+  String? get name3 => _element2.name3;
 
   @override
   Source get source => _declaration.source!;

pkg/analyzer/lib/src/test_utilities/find_element2.dart

@@ -503,7 +503,7 @@ abstract class _FindElementBase {
     return _findInClassesLike(
       className: name,
       fromClass: (e) => e.constructors2.firstWhereOrNull((element) {
-        return element.name3.isEmpty;
+        return element.name3 == 'new';
       }),
       fromExtension: (_) => null,
     );

pkg/analyzer/test/src/summary/element_text.dart

@@ -253,13 +253,10 @@ class _Element2Writer extends _AbstractElementWriter {
   }
 
   String _elementName(Element2 e) {
-    var name = e.name3 ?? '<null>';
+    var name = e.name3 ?? '<null-name>';
     if (e is SetterElement) {
       expect(name, endsWith('='));
     }
-    if (name.isEmpty && e is ConstructorElement2) {
-      return 'new';
-    }
     return name;
   }
 

pkg/analyzer/test/src/summary/elements/class_test.dart

@@ -18252,7 +18252,7 @@ library
         synthetic new
           firstFragment: <testLibraryFragment>::@class::A::@constructor::new
       methods
-        
+        <null-name>
           firstFragment: <testLibraryFragment>::@class::A::@method::0
 ''');
   }

pkg/analyzer/test/src/summary/elements/extension_test.dart

@@ -670,7 +670,7 @@ library
           reference: <testLibraryFragment>::@extension::0
           element: <testLibraryFragment>::@extension::0#element
   extensions
-    extension <null>
+    extension <null-name>
       firstFragment: <testLibraryFragment>::@extension::0
 ''');
   }