Serialize default constructors separately.

pkg/compiler/lib/src/serialization/element_serialization.dart

 // Copyright (c) 2015, 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 dart2js.serialization.elements;
 
 import '../common.dart';
 import '../constants/constructors.dart';
 import '../constants/expressions.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
 import 'constant_serialization.dart';
 import 'keys.dart';
 import 'modelz.dart';
 import 'serialization.dart';
 import 'serialization_util.dart';
 
 /// Enum kinds used for encoding [Element]s.
 enum SerializedElementKind {
   LIBRARY,
   COMPILATION_UNIT,
   CLASS,
   ENUM,
   NAMED_MIXIN_APPLICATION,
   GENERATIVE_CONSTRUCTOR,
+  DEFAULT_CONSTRUCTOR,
   FACTORY_CONSTRUCTOR,
   REDIRECTING_FACTORY_CONSTRUCTOR,
   FORWARDING_CONSTRUCTOR,
   TOPLEVEL_FIELD,
   STATIC_FIELD,
   INSTANCE_FIELD,
   ENUM_CONSTANT,
   TOPLEVEL_FUNCTION,
   TOPLEVEL_GETTER,
   TOPLEVEL_SETTER,
@@ skipping 299 matching lines @@
       encoder.setType(Key.MIXIN, mixinElement.mixinType);
     }
   }
 }
 
 class ConstructorSerializer implements ElementSerializer {
   const ConstructorSerializer();
 
   SerializedElementKind getSerializedKind(Element element) {
     if (element.isGenerativeConstructor) {
-      if (element.enclosingClass.isNamedMixinApplication) {
+      ConstructorElement constructor = element;
+      if (constructor.enclosingClass.isNamedMixinApplication) {
         return SerializedElementKind.FORWARDING_CONSTRUCTOR;
+      } else if (constructor.definingConstructor != null) {
+        return SerializedElementKind.DEFAULT_CONSTRUCTOR;
       } else {
         return SerializedElementKind.GENERATIVE_CONSTRUCTOR;
       }
     } else if (element.isFactoryConstructor) {
       ConstructorElement constructor = element;
       if (constructor.isRedirectingFactory) {
         return SerializedElementKind.REDIRECTING_FACTORY_CONSTRUCTOR;
       } else {
         return SerializedElementKind.FACTORY_CONSTRUCTOR;
       }
@@ skipping 12 matching lines @@
       SerializerUtil.serializePosition(element, encoder);
       SerializerUtil.serializeParameters(element, encoder);
       encoder.setBool(Key.IS_CONST, element.isConst);
       encoder.setBool(Key.IS_EXTERNAL, element.isExternal);
       if (element.isConst && !element.isFromEnvironmentConstructor) {
         ConstantConstructor constantConstructor = element.constantConstructor;
         ObjectEncoder constantEncoder = encoder.createObject(Key.CONSTRUCTOR);
         const ConstantConstructorSerializer()
             .visit(constantConstructor, constantEncoder);
       }
-      if (element.definingConstructor != null) {
-        assert(invariant(
-            element,
-            element.definingConstructor.enclosingClass ==
-                element.enclosingClass.superclass,
-            message: "Unexpected defining constructor: "
-                "${element.definingConstructor}"));
-        encoder.setString(
-            Key.DEFINING_CONSTRUCTOR, element.definingConstructor.name);
-      }
       if (kind == SerializedElementKind.GENERATIVE_CONSTRUCTOR) {
         encoder.setBool(Key.IS_REDIRECTING, element.isRedirectingGenerative);
       }
       encoder.setElement(Key.EFFECTIVE_TARGET, element.effectiveTarget);
       if (kind == SerializedElementKind.REDIRECTING_FACTORY_CONSTRUCTOR) {
         encoder.setType(
             Key.EFFECTIVE_TARGET_TYPE,
             element
                 .computeEffectiveTargetType(element.enclosingClass.thisType));
         encoder.setElement(Key.IMMEDIATE_REDIRECTION_TARGET,
@@ skipping 283 matching lines @@
       case SerializedElementKind.TOPLEVEL_FIELD:
         return new TopLevelFieldElementZ(decoder);
       case SerializedElementKind.STATIC_FIELD:
         return new StaticFieldElementZ(decoder);
       case SerializedElementKind.ENUM_CONSTANT:
         return new EnumConstantElementZ(decoder);
       case SerializedElementKind.INSTANCE_FIELD:
         return new InstanceFieldElementZ(decoder);
       case SerializedElementKind.GENERATIVE_CONSTRUCTOR:
         return new GenerativeConstructorElementZ(decoder);
+      case SerializedElementKind.DEFAULT_CONSTRUCTOR:
+        return new DefaultConstructorElementZ(decoder);
       case SerializedElementKind.FACTORY_CONSTRUCTOR:
         return new FactoryConstructorElementZ(decoder);
       case SerializedElementKind.REDIRECTING_FACTORY_CONSTRUCTOR:
         return new RedirectingFactoryConstructorElementZ(decoder);
       case SerializedElementKind.FORWARDING_CONSTRUCTOR:
         return new ForwardingConstructorElementZ(
             decoder.getElement(Key.CLASS), decoder.getElement(Key.ELEMENT));
       case SerializedElementKind.TOPLEVEL_FUNCTION:
         return new TopLevelFunctionElementZ(decoder);
       case SerializedElementKind.STATIC_FUNCTION:
@@ skipping 32 matching lines @@
         return new LocalVariableElementZ(decoder);
       case SerializedElementKind.EXTERNAL_LIBRARY:
       case SerializedElementKind.EXTERNAL_LIBRARY_MEMBER:
       case SerializedElementKind.EXTERNAL_STATIC_MEMBER:
       case SerializedElementKind.EXTERNAL_CONSTRUCTOR:
         break;
     }
     throw new UnsupportedError("Unexpected element kind '${elementKind}.");
   }
 }