Elements. Replace VariableElement.constantInitializer with Expression.

* Remove deprecated `VariableElement.constantInitializer2`.
* Remove deprecated `VariableFragment.initializer`.
* Remove deprecated `ConstantInitializer`.

Change-Id: I96a0692df5d13d59d4d9de1c38a5311e299e009e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/440542
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: scheglov

pkg/analyzer/CHANGELOG.md

@@ -11,6 +11,9 @@
 * Remove deprecated `LocalVariableFragment.nameOffset`.
 * Remove deprecated `JoinPatternVariableFragment.isConsistent`.
 * Remove deprecated `JoinPatternVariableFragment.variables2`.
+* Remove deprecated `VariableElement.constantInitializer2`.
+* Remove deprecated `VariableFragment.initializer`.
+* Remove deprecated `ConstantInitializer`.
 * `LibraryFragment` is not `Annotatable` anymore.
 * Stop implementing `ConstantEvaluationTarget` by `ElementAnnotation`.
   This is an internal interface that should not have been exposed.

pkg/analyzer/api.txt

@@ -3302,11 +3302,6 @@ package:analyzer/dart/element/element.dart:
     element (getter: ClassElement)
     nextFragment (getter: ClassFragment?)
     previousFragment (getter: ClassFragment?)
-  ConstantInitializer (class extends Object):
-    new (constructor: ConstantInitializer Function())
-    expression (getter: Expression)
-    fragment (getter: VariableFragment)
-    evaluate (method: DartObject? Function())
   ConstructorElement (class extends Object implements ExecutableElement, HasSinceSdkVersion):
     new (constructor: ConstructorElement Function())
     baseElement (getter: ConstructorElement)
@@ -4181,8 +4176,7 @@ package:analyzer/dart/element/element.dart:
     typeParameters2 (getter: List<TypeParameterFragment>, deprecated)
   VariableElement (class extends Object implements Element):
     new (constructor: VariableElement Function())
-    constantInitializer (getter: ConstantInitializer?)
-    constantInitializer2 (getter: ConstantInitializer?, deprecated)
+    constantInitializer (getter: Expression?)
     firstFragment (getter: VariableFragment)
     fragments (getter: List<VariableFragment>)
     hasImplicitType (getter: bool)
@@ -4195,7 +4189,6 @@ package:analyzer/dart/element/element.dart:
   VariableFragment (class extends Object implements Fragment):
     new (constructor: VariableFragment Function())
     element (getter: VariableElement)
-    initializer (getter: Expression?)
     nextFragment (getter: VariableFragment?)
     previousFragment (getter: VariableFragment?)
   BindPatternVariableElement2 (type alias for BindPatternVariableElement, deprecated)
@@ -4237,7 +4230,6 @@ package:analyzer/dart/element/element2.dart:
   BindPatternVariableFragment (see above)
   ClassElement (see above)
   ClassFragment (see above)
-  ConstantInitializer (see above)
   ConstructorElement (see above)
   ConstructorFragment (see above)
   DirectiveUri (see above)

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

@@ -358,27 +358,6 @@ abstract class ClassFragment implements InterfaceFragment {
   ClassFragment? get previousFragment;
 }
 
-/// The initializer of a constant variable, or the default value for a formal
-/// parameter.
-abstract class ConstantInitializer {
-  /// The expression of the initializer.
-  ///
-  /// For variables that have multiple fragments, this is the expression from
-  /// the last fragment. For formal parameters, only the first fragment can
-  /// have the default value.
-  Expression get expression;
-
-  /// The [VariableFragment] that has [expression].
-  ///
-  /// The offsets are inside the [LibraryFragment] that contains [fragment].
-  VariableFragment get fragment;
-
-  /// Returns the result of evaluating [expression], computes it if necessary.
-  ///
-  /// Returns `null` if the value could not be computed because of errors.
-  DartObject? evaluate();
-}
-
 /// An element representing a constructor defined by a class, enum, or extension
 /// type.
 ///
@@ -4052,15 +4031,7 @@ abstract class VariableElement implements Element {
   ///
   /// Is `null` if this variable is not a constant, or does not have the
   /// initializer or the default value specified.
-  ConstantInitializer? get constantInitializer;
-
-  /// The constant initializer for this constant variable, or the default
-  /// value for this formal parameter.
-  ///
-  /// Is `null` if this variable is not a constant, or does not have the
-  /// initializer or the default value specified.
-  @Deprecated('Use constantInitializer instead')
-  ConstantInitializer? get constantInitializer2;
+  Expression? get constantInitializer;
 
   @override
   VariableFragment get firstFragment;
@@ -4116,13 +4087,6 @@ abstract class VariableFragment implements Fragment {
   @override
   VariableElement get element;
 
-  /// The initializer for this constant variable fragment, or the default value
-  /// for this formal parameter fragment.
-  ///
-  /// Is `null` if this variable fragment is not a constant, or does not have
-  /// the initializer or the default value specified.
-  Expression? get initializer;
-
   @override
   VariableFragment? get nextFragment;
 

pkg/analyzer/lib/src/dart/constant/evaluation.dart

@@ -88,7 +88,7 @@ class ConstantEvaluationEngine {
     var libraryFragment = constant.libraryFragment!;
     var library = libraryFragment.element;
     if (constant is FormalParameterElementImpl) {
-      var defaultValue = constant.constantInitializer?.expression;
+      var defaultValue = constant.constantInitializer;
       if (defaultValue != null) {
         var diagnosticListener = RecordingDiagnosticListener();
         var diagnosticReporter = DiagnosticReporter(
@@ -106,7 +106,7 @@ class ConstantEvaluationEngine {
         constant.evaluationResult = _nullObject(library);
       }
     } else if (constant is VariableElementImpl) {
-      var constantInitializer = constant.constantInitializer?.expression;
+      var constantInitializer = constant.constantInitializer;
       if (constantInitializer != null) {
         var diagnosticReporter = DiagnosticReporter(
           RecordingDiagnosticListener(),
@@ -260,7 +260,7 @@ class ConstantEvaluationEngine {
 
     if (constant is VariableElementImpl) {
       var declaration = constant;
-      var initializer = declaration.constantInitializer?.expression;
+      var initializer = declaration.constantInitializer;
       if (initializer != null) {
         initializer.accept(referenceFinder);
       }
@@ -3063,7 +3063,7 @@ class _InstanceCreationEvaluator {
         var fieldType = substitution.substituteType(field.type);
         if (!typeSystem.runtimeTypeMatch(fieldValue, fieldType)) {
           var isRuntimeException = hasTypeParameterReference(field.type);
-          var errorNode = field.constantInitializer?.expression ?? _errorNode;
+          var errorNode = field.constantInitializer ?? _errorNode;
           return InvalidConstant.forEntity(
             entity: errorNode,
             diagnosticCode:

pkg/analyzer/lib/src/dart/constant/utilities.dart

@@ -182,7 +182,7 @@ class ConstantFinder extends RecursiveAstVisitor<void> {
     constantsToCompute.add(element);
 
     configuration.addErrorNode(
-      fromElement: element.constantInitializer?.expression,
+      fromElement: element.constantInitializer,
       fromAst: node,
     );
   }
@@ -202,7 +202,7 @@ class ConstantFinder extends RecursiveAstVisitor<void> {
       // Fill error nodes.
       if (element.constantInitializer case var constantInitializer?) {
         configuration.addErrorNode(
-          fromElement: constantInitializer.expression,
+          fromElement: constantInitializer,
           fromAst: node.initializer,
         );
       }

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

@@ -719,26 +719,12 @@ class ClassFragmentImpl extends InterfaceFragmentImpl implements ClassFragment {
   }
 }
 
-class ConstantInitializerImpl implements ConstantInitializer {
-  @override
+// TODO(scheglov): remove this
+class ConstantInitializerImpl {
   final VariableFragmentImpl fragment;
-
-  @override
   final ExpressionImpl expression;
 
-  /// The cached result of [evaluate].
-  Constant? _evaluationResult;
-
   ConstantInitializerImpl({required this.fragment, required this.expression});
-
-  @override
-  DartObject? evaluate() {
-    if (_evaluationResult case DartObjectImpl result) {
-      return result;
-    }
-    // TODO(scheglov): implement it
-    throw UnimplementedError();
-  }
 }
 
 class ConstructorElementImpl extends ExecutableElementImpl
@@ -3013,7 +2999,7 @@ class FormalParameterElementImpl extends PromotableElementImpl
   @override
   // TODO(augmentations): Implement the merge of formal parameters.
   String? get defaultValueCode {
-    return constantInitializer?.expression.toSource();
+    return constantInitializer2?.expression.toSource();
   }
 
   @override
@@ -6919,7 +6905,9 @@ class LocalFunctionElementImpl extends ExecutableElementImpl
 
   @override
   List<TypeParameterElementImpl> get typeParameters {
-    return firstFragment.typeParameters.map((fragment) => fragment.element).toList();
+    return firstFragment.typeParameters
+        .map((fragment) => fragment.element)
+        .toList();
   }
 
   @Deprecated('Use typeParameters instead')
@@ -9188,7 +9176,7 @@ class SuperFormalParameterElementImpl extends FormalParameterElementImpl
       return null;
     }
 
-    var constantInitializer = this.constantInitializer?.expression;
+    var constantInitializer = constantInitializer2?.expression;
     if (constantInitializer != null) {
       return constantInitializer.toSource();
     }
@@ -9202,7 +9190,7 @@ class SuperFormalParameterElementImpl extends FormalParameterElementImpl
 
   @override
   Constant? get evaluationResult {
-    if (constantInitializer != null) {
+    if (constantInitializer2 != null) {
       return super.evaluationResult;
     }
 
@@ -9285,7 +9273,7 @@ class SuperFormalParameterElementImpl extends FormalParameterElementImpl
 
   @override
   DartObject? computeConstantValue() {
-    if (constantInitializer != null) {
+    if (constantInitializer2 != null) {
       return super.computeConstantValue();
     }
 
@@ -10306,22 +10294,28 @@ abstract class VariableElementImpl extends ElementImpl
     implements VariableElement2OrMember, ConstantEvaluationTarget {
   ConstantInitializerImpl? _constantInitializer;
 
-  /// The result of evaluating [constantInitializer].
+  /// The result of evaluating [constantInitializer2].
   ///
-  /// Is `null` if [constantInitializer] is `null`, or if the value could not
+  /// Is `null` if [constantInitializer2] is `null`, or if the value could not
   /// be computed because of errors.
   Constant? evaluationResult;
 
   @override
-  ConstantInitializerImpl? get constantInitializer {
+  ExpressionImpl? get constantInitializer {
+    return constantInitializer2?.expression;
+  }
+
+  // TODO(scheglov): remove this
+  ConstantInitializerImpl? get constantInitializer2 {
     if (_constantInitializer case var result?) {
       return result;
     }
 
     for (var fragment in fragments.reversed) {
+      fragment as VariableFragmentImpl;
       if (fragment.initializer case ExpressionImpl expression) {
         return _constantInitializer = ConstantInitializerImpl(
-          fragment: fragment as VariableFragmentImpl,
+          fragment: fragment,
           expression: expression,
         );
       }
@@ -10330,12 +10324,6 @@ abstract class VariableElementImpl extends ElementImpl
     return null;
   }
 
-  @Deprecated('Use constantInitializer instead')
-  @override
-  ConstantInitializer? get constantInitializer2 {
-    return constantInitializer;
-  }
-
   @override
   bool get isConstantEvaluated => evaluationResult != null;
 
@@ -10425,7 +10413,7 @@ abstract class VariableFragmentImpl extends FragmentImpl
     setModifier(Modifier.IMPLICIT_TYPE, hasImplicitType);
   }
 
-  @override
+  // TODO(scheglov): remove this
   ExpressionImpl? get initializer {
     return constantInitializer;
   }

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

@@ -7,6 +7,7 @@ import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/element/display_string_builder.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/type.dart';
@@ -1255,16 +1256,10 @@ abstract class VariableMember extends Member
       super.baseElement as VariableElementImpl;
 
   @override
-  ConstantInitializer? get constantInitializer {
+  ExpressionImpl? get constantInitializer {
     return baseElement.constantInitializer;
   }
 
-  @Deprecated('Use constantInitializer instead')
-  @override
-  ConstantInitializer? get constantInitializer2 {
-    return constantInitializer;
-  }
-
   @override
   bool get hasImplicitType => baseElement.hasImplicitType;