Refactor resolution code in the vm to properly handle ambiguity errors.

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2268 matching lines @@
 
   // Library scope name dictionary.
   //
   // TODO(turnidge): The Lookup functions are not consistent in how
   // they deal with private names.  Go through and make them a bit
   // more regular.
   void AddClass(const Class& cls) const;
   void AddObject(const Object& obj, const String& name) const;
   void ReplaceObject(const Object& obj, const String& name) const;
   RawObject* LookupExport(const String& name) const;
-  RawObject* LookupObject(const String& name) const;
-  RawClass* LookupClass(const String& name) const;
-  RawClass* LookupClassAllowPrivate(const String& name) const;
+  RawObject* LookupObject(const String& name,
+                          String* ambiguity_error_msg) const;
+  RawObject* LookupObjectAllowPrivate(const String& name,
+                                      String* ambiguity_error_msg) const;
+  RawObject* LookupLocalObjectAllowPrivate(const String& name) const;
   RawObject* LookupLocalObject(const String& name) const;
+  RawObject* LookupImportedObject(const String& name,
+                                  String* ambiguity_error_msg) const;
+  RawClass* LookupClass(const String& name, String* ambiguity_error_msg) const;
+  RawClass* LookupClassAllowPrivate(const String& name,
+                                    String* ambiguity_error_msg) const;
   RawClass* LookupLocalClass(const String& name) const;
-  RawField* LookupFieldAllowPrivate(const String& name) const;
+  RawField* LookupFieldAllowPrivate(const String& name,
+                                    String* ambiguity_error_msg) const;
   RawField* LookupLocalField(const String& name) const;
-  RawFunction* LookupFunctionAllowPrivate(const String& name) const;
+  RawFunction* LookupFunctionAllowPrivate(const String& name,
+                                          String* ambiguity_error_msg) const;
   RawFunction* LookupLocalFunction(const String& name) const;
   RawLibraryPrefix* LookupLocalLibraryPrefix(const String& name) const;
   RawScript* LookupScript(const String& url) const;
   RawArray* LoadedScripts() const;
 
   void AddAnonymousClass(const Class& cls) const;
 
   void AddExport(const Namespace& ns) const;
 
   void AddClassMetadata(const Class& cls, intptr_t token_pos) const;
@@ skipping 3700 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_