Support serialization of ambiguous elements.

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 '../diagnostics/messages.dart';
 import '../elements/elements.dart';
 import '../elements/modelx.dart'
     show
+        AmbiguousImportX,
         DeferredLoaderGetterElementX,
         ErroneousElementX,
         WarnOnUseElementX,
         WrappedMessage;
 import 'constant_serialization.dart';
 import 'keys.dart';
 import 'modelz.dart';
 import 'serialization.dart';
 import 'serialization_util.dart';
 
@@ skipping 27 matching lines @@
   TYPEDEF,
   TYPEVARIABLE,
   PARAMETER,
   INITIALIZING_FORMAL,
   IMPORT,
   EXPORT,
   PREFIX,
   DEFERRED_LOAD_LIBRARY,
   LOCAL_VARIABLE,
   WARN_ON_USE,
+  AMBIGUOUS,
   EXTERNAL_LIBRARY,
   EXTERNAL_LIBRARY_MEMBER,
   EXTERNAL_CLASS_MEMBER,
   EXTERNAL_CONSTRUCTOR,
 }
 
 /// Set of serializers used to serialize different kinds of elements by
 /// encoding into them into [ObjectEncoder]s.
 ///
 /// This class is called from the [Serializer] when an [Element] needs
@@ skipping 10 matching lines @@
   const ConstructorSerializer(),
   const FieldSerializer(),
   const FunctionSerializer(),
   const TypedefSerializer(),
   const TypeVariableSerializer(),
   const ParameterSerializer(),
   const ImportSerializer(),
   const ExportSerializer(),
   const LocalVariableSerializer(),
   const WarnOnUseSerializer(),
+  const AmbiguousSerializer(),
 ];
 
 /// Interface for a function that can serialize a set of element kinds.
 abstract class ElementSerializer {
   /// Returns the [SerializedElementKind] for [element] if this serializer
   /// supports serialization of [element] or `null` otherwise.
   SerializedElementKind getSerializedKind(Element element);
 
   /// Serializes [element] into the [encoder] using the [kind] computed
   /// by [getSerializedKind].
@@ skipping 706 matching lines @@
 
   void serialize(WarnOnUseElementX element, ObjectEncoder encoder,
       SerializedElementKind kind) {
     encoder.setElement(Key.ENCLOSING, element.enclosingElement);
     encoder.setElement(Key.ELEMENT, element.wrappedElement);
     serializeWrappedMessage(encoder, Key.WARNING, element.warning);
     serializeWrappedMessage(encoder, Key.INFO, element.info);
   }
 }
 
+class AmbiguousSerializer implements ElementSerializer {
+  const AmbiguousSerializer();
+
+  SerializedElementKind getSerializedKind(Element element) {
+    if (element.isAmbiguous) {
+      return SerializedElementKind.AMBIGUOUS;
+    }
+    return null;
+  }
+
+  void serialize(AmbiguousImportX element, ObjectEncoder encoder,
+      SerializedElementKind kind) {
+    // TODO(johnniwinther): Also support [DuplicateElementX] if serialization
+    // of code with compile-time errors is supported.
+    encoder.setElement(Key.ENCLOSING, element.enclosingElement);
+    encoder.setElement(Key.EXISTING, element.existingElement);
+    encoder.setElement(Key.NEW, element.newElement);
+    encoder.setEnum(Key.MESSAGE_KIND, element.messageKind);
+    serializeMessageArguments(encoder, Key.ARGUMENTS, element.messageArguments);
+  }
+}
+
 /// Utility class for deserializing [Element]s.
 ///
 /// This is used by the [Deserializer].
 class ElementDeserializer {
   /// Deserializes an [Element] from an [ObjectDecoder].
   ///
   /// The class is called from the [Deserializer] when an [Element]
   /// needs deserialization. The [ObjectDecoder] ensures that any [Element],
   /// [DartType], and [ConstantExpression] that the deserialized [Element]
   /// depends upon are available.
@@ skipping 77 matching lines @@
         return new DeferredLoaderGetterElementX(decoder.getElement(Key.PREFIX));
       case SerializedElementKind.LOCAL_VARIABLE:
         return new LocalVariableElementZ(decoder);
       case SerializedElementKind.WARN_ON_USE:
         Element enclosing = decoder.getElement(Key.ENCLOSING);
         Element element = decoder.getElement(Key.ELEMENT);
         WrappedMessage warning =
             deserializeWrappedMessage(decoder, Key.WARNING);
         WrappedMessage info = deserializeWrappedMessage(decoder, Key.INFO);
         return new WarnOnUseElementX(warning, info, enclosing, element);
-      case SerializedElementKind.EXTERNAL_LIBRARY:
+      case SerializedElementKind.AMBIGUOUS:
+        Element enclosingElement = decoder.getElement(Key.ENCLOSING);
+        Element existingElement = decoder.getElement(Key.EXISTING);
+        Element newElement = decoder.getElement(Key.NEW);
+        MessageKind messageKind =
+            decoder.getEnum(Key.MESSAGE_KIND, MessageKind.values);
+        Map messageArguments =
+            deserializeMessageArguments(decoder, Key.ARGUMENTS);
+        return new AmbiguousImportX(
+            messageKind, messageArguments,
+            enclosingElement, existingElement, newElement);
+  case SerializedElementKind.EXTERNAL_LIBRARY:
       case SerializedElementKind.EXTERNAL_LIBRARY_MEMBER:
       case SerializedElementKind.EXTERNAL_CLASS_MEMBER:
       case SerializedElementKind.EXTERNAL_CONSTRUCTOR:
         break;
     }
     throw new UnsupportedError("Unexpected element kind '${elementKind}.");
   }
 }