Fix issue 4361 by checking in the resolver if the getter/setter exists.

lib/compiler/implementation/resolver.dart

 // Copyright (c) 2012, 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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(TypeAnnotation annotation);
 }
 
@@ skipping 1311 matching lines @@
       }
     }
   }
 
   visitSend(Send node) {
     Element target = resolveSend(node);
     if (!Element.isInvalid(target)
         && target.kind == ElementKind.ABSTRACT_FIELD) {
       AbstractFieldElement field = target;
       target = field.getter;
+      if (Element.isInvalid(target) && !inInstanceContext) {
+        // TODO(karlklose): make this a runtime error.
+        error(node.selector, MessageKind.CANNOT_RESOLVE_GETTER);
+      }
     }
 
     bool resolvedArguments = false;
     if (node.isOperator) {
       String operatorString = node.selector.asOperator().source.stringValue;
       if (operatorString === 'is' || operatorString === 'as') {
         assert(node.arguments.tail.isEmpty());
         resolveTypeTest(node.arguments.head);
         resolvedArguments = true;
       } else if (operatorString === '?') {
@@ skipping 41 matching lines @@
     // unqualified.
     useElement(node, target);
     registerSend(selector, target);
     return node.isPropertyAccess ? target : null;
   }
 
   visitSendSet(SendSet node) {
     Element target = resolveSend(node);
     Element setter = target;
     Element getter = target;
+    String source = node.assignmentOperator.source.stringValue;
+    bool isComplex = source !== '=';
     if (target != null && target.kind == ElementKind.ABSTRACT_FIELD) {
       AbstractFieldElement field = target;
       setter = field.setter;
       getter = field.getter;
+      if (Element.isInvalid(setter) && !inInstanceContext) {
+        // TODO(karlklose): make this a runtime error.
+        error(node.selector, MessageKind.CANNOT_RESOLVE_SETTER);
+      }
+      if (isComplex && Element.isInvalid(getter) && !inInstanceContext) {
+        // TODO(karlklose): make this a runtime error.
+        error(node.selector, MessageKind.CANNOT_RESOLVE_GETTER);
+      }
     }
 
     visit(node.argumentsNode);
 
     // TODO(ngeoffray): Check if the target can be assigned.
     // TODO(ngeoffray): Warn if target is null and the send is
     // unqualified.
 
     Selector selector = mapping.getSelector(node);
-    String source = node.assignmentOperator.source.stringValue;
-    bool isComplex = source !== '=';
     if (isComplex) {
       if (selector.isSetter()) {
         // TODO(kasperl): We're registering the getter selector for
         // compound assignments on the AST selector node. In the code
         // generator, we then fetch it from there when generating the
         // getter for a SendSet node.
         Selector getterSelector = new Selector.getterFrom(selector);
         registerSend(getterSelector, getter);
         mapping.setSelector(node.selector, getterSelector);
         useElement(node.selector, getter);
@@ skipping 1219 matching lines @@
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) {
     return library.find(name);
   }
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
   String toString() => '$element';
 }