Put metadata fields in their owner class.

runtime/vm/class_finalizer.cc

 // 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.
 
 #include "vm/class_finalizer.h"
 
 #include "vm/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
@@ skipping 2128 matching lines @@
       func = func.Clone(cls);
       cloned_funcs.Add(func);
     }
   }
   functions = Array::MakeArray(cloned_funcs);
   cls.SetFunctions(functions);
 
   // Now clone the fields from the mixin class. There should be no
   // existing fields in the mixin application class.
   ASSERT(Array::Handle(cls.fields()).Length() == 0);
-  Array& fields = Array::Handle(isolate, mixin_cls.fields());
+  const Array& fields = Array::Handle(isolate, mixin_cls.fields());
   Field& field = Field::Handle(isolate);
   const GrowableObjectArray& cloned_fields =
       GrowableObjectArray::Handle(isolate, GrowableObjectArray::New());
   const intptr_t num_fields = fields.Length();
   for (intptr_t i = 0; i < num_fields; i++) {
     field ^= fields.At(i);
     if (!field.is_static()) {
       field = field.Clone(cls);
       cloned_fields.Add(field);
     }
   }
-  fields = Array::MakeArray(cloned_fields);
-  cls.SetFields(fields);
+  cls.AddFields(cloned_fields);
 
   if (FLAG_trace_class_finalization) {
     OS::Print("Done applying mixin members of %s to %s\n",
               mixin_cls.ToCString(),
               cls.ToCString());
   }
 }
 
 
 void ClassFinalizer::FinalizeTypesInClass(const Class& cls) {
@@ skipping 106 matching lines @@
   // Add this class to the direct subclasses of the superclass, unless the
   // superclass is Object.
   if (!super_type.IsNull() && !super_type.IsObjectType()) {
     ASSERT(!super_class.IsNull());
     super_class.AddDirectSubclass(cls);
   }
   // A top level class is parsed eagerly so just finalize it.
   if (cls.IsTopLevel()) {
     FinalizeClass(cls);
   } else {
     // This class should not contain any fields or functions yet, because it has

[Ivan Posva, 2014/05/08 05:18:50]

Please update the comment. Especially since it appears that this class now can
already contain fields when we get here.

[rmacnak, 2014/05/08 18:14:54]

Noted the class might contain metadata fields for type parameters.

     // not been compiled yet. Since 'ResolveAndFinalizeMemberTypes(cls)' has not
     // been called yet, unfinalized member types could choke the snapshotter.
-    ASSERT(Array::Handle(cls.fields()).Length() == 0);
     ASSERT(Array::Handle(cls.functions()).Length() == 0);
   }
 }
 
 
 void ClassFinalizer::FinalizeClass(const Class& cls) {
   HANDLESCOPE(Isolate::Current());
   if (cls.is_finalized()) {
     return;
   }
@@ skipping 769 matching lines @@
   expected_name ^= String::New("_offset");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
   field ^= fields_array.At(2);
   ASSERT(field.Offset() == TypedDataView::length_offset());
   name ^= field.name();
   ASSERT(name.Equals("length"));
 #endif
 }
 
 }  // namespace dart