Handle use of constant constructors with default values.

pkg/compiler/lib/src/elements/modelx.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library elements.modelx;
 
 import '../common.dart';
 import '../common/resolution.dart' show Resolution, ParsingContext;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_constructors.dart';
@@ skipping 238 matching lines @@
   get isExternal => unsupported();
   get constantConstructor => null;
 
   bool get isRedirectingGenerative => unsupported();
   bool get isRedirectingFactory => unsupported();
 
   computeType(Resolution resolution) => unsupported();
 
   bool get hasFunctionSignature => false;
 
+  bool get hasEffectiveTarget => true;
+
   get effectiveTarget => this;
 
   computeEffectiveTargetType(InterfaceType newType) => unsupported();
 
   get definingConstructor => null;
 
   FunctionElement asFunctionElement() => this;
 
   String get message {
     return MessageTemplate.TEMPLATES[messageKind]
@@ skipping 1115 matching lines @@
   VariableDefinitions parseNode(Element element, ParsingContext parsing) {
     return definitions;
   }
 
   DartType computeType(Element element, Resolution resolution) => type;
 }
 
 abstract class ConstantVariableMixin implements VariableElement {
   ConstantExpression constantCache;
 
+  // TODO(johnniwinther): Update the on `constant = ...` when evaluation of
+  // constant expression can handle references to unanalyzed constant variables.
+  @override
+  bool get hasConstant => false;
+
   ConstantExpression get constant {
     if (isPatch) {
       ConstantVariableMixin originVariable = origin;
       return originVariable.constant;
     }
     assert(invariant(this, !isConst || constantCache != null,
         message: "Constant has not been computed for $this."));
     return constantCache;
   }
 
@@ skipping 788 matching lines @@
 
   // TODO(johnniwinther): This should also return true for cyclic redirecting
   // generative constructors.
   bool get isCyclicRedirection => effectiveTarget.isRedirectingFactory;
 
   /// These fields are set by the post process queue when checking for cycles.
   ConstructorElement effectiveTargetInternal;
   DartType _effectiveTargetType;
   bool _isEffectiveTargetMalformed;
 
+  bool get hasEffectiveTarget => effectiveTargetInternal != null;
+
   void setEffectiveTarget(ConstructorElement target, DartType type,
       {bool isMalformed: false}) {
     assert(invariant(this, target != null,
         message: 'No effective target provided for $this.'));
     assert(invariant(this, effectiveTargetInternal == null,
         message: 'Effective target has already been computed for $this.'));
     effectiveTargetInternal = target;
     _effectiveTargetType = type;
     _isEffectiveTargetMalformed = isMalformed;
   }
@@ skipping 1072 matching lines @@
       body = node.asFunctionExpression().body;
     }
     return new ParsedResolvedAst(
         declaration,
         node,
         body,
         definingElement.treeElements,
         definingElement.compilationUnit.script.resourceUri);
   }
 }