Elements. Move to ConstructorElementImpl flags 'isCycleFree' and 'isConstantEvaluated'.

Change-Id: Ie48daf0fddc758615b92e663911a70afd5e2db8f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/448882
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

Author: scheglov

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

@@ -68,8 +68,7 @@ class _ConstantWalker extends graph.DependencyWalker<_ConstantNode> {
     for (var node in scc) {
       var constant = node.constant;
       if (constant is ConstructorElementImpl) {
-        // TODO(scheglov): move the flag to the element
-        constant.firstFragment.isCycleFree = false;
+        constant.isCycleFree = false;
       }
       _getEvaluationEngine(node).generateCycleError(constantsInCycle, constant);
     }

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

@@ -170,10 +170,8 @@ class ConstantVerifier extends RecursiveAstVisitor<void> {
       // Check and report cycles.
       // Factory cycles are reported in elsewhere in
       // [ErrorVerifier._checkForRecursiveFactoryRedirect].
-      var element = node.declaredFragment;
-      if (element is ConstructorFragmentImpl &&
-          !element.isCycleFree &&
-          !element.isFactory) {
+      var element = node.declaredFragment!.element;
+      if (!element.isCycleFree && !element.isFactory) {
         _diagnosticReporter.atNode(
           node.returnType,
           CompileTimeErrorCode.recursiveConstantConstructor,

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

@@ -164,7 +164,7 @@ class ConstantEvaluationEngine {
         // the dependency graph to ensure that any constants referred to in
         // initializer lists and parameter defaults are evaluated before
         // invocations of the constructor.
-        constant.firstFragment.isConstantEvaluated = true;
+        constant.isConstantEvaluated = true;
       }
     } else if (constant is ElementAnnotationImpl) {
       var constNode = constant.annotationAst;
@@ -3560,7 +3560,7 @@ class _InstanceCreationEvaluator {
       );
     }
 
-    if (!constructor.baseElement.firstFragment.isCycleFree) {
+    if (!constructor.baseElement.isCycleFree) {
       // It's not safe to evaluate this constructor, so bail out.
       //
       // Instead of reporting an error at the call-sites, we will report an

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

@@ -628,6 +628,16 @@ class ConstructorElementImpl extends ExecutableElementImpl
   // So, ideally we should have some kind of "either" or "variant" here.
   InternalConstructorElement? _superConstructor;
 
+  /// For every constructor we initially set this flag to `true`, and then
+  /// set it to `false` during computing constant values if we detect that it
+  /// is a part of a cycle.
+  @trackedInternal
+  bool isCycleFree = true;
+
+  @override
+  @trackedInternal
+  bool isConstantEvaluated = false;
+
   ConstructorElementImpl({
     required this.name,
     required this.reference,
@@ -684,9 +694,6 @@ class ConstructorElementImpl extends ExecutableElementImpl
   @override
   bool get isConst => _firstFragment.isConst;
 
-  @override
-  bool get isConstantEvaluated => _firstFragment.isConstantEvaluated;
-
   @override
   bool get isDefaultConstructor => _firstFragment.isDefaultConstructor;
 
@@ -840,14 +847,6 @@ class ConstructorFragmentImpl extends ExecutableFragmentImpl
   @override
   ConstructorFragmentImpl? nextFragment;
 
-  /// For every constructor we initially set this flag to `true`, and then
-  /// set it to `false` during computing constant values if we detect that it
-  /// is a part of a cycle.
-  bool isCycleFree = true;
-
-  /// Return whether this constant is evaluated.
-  bool isConstantEvaluated = false;
-
   /// Initialize a newly created constructor element to have the given [name]
   /// and [offset].
   ConstructorFragmentImpl({required this.name});