Populate PrototypeInfo with prototype_object value

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 5757 matching lines @@
   // any cleared weak cell.
   bool Compact();
   static int Grow(int number_of_entries) {
     if (number_of_entries < 5) return number_of_entries + 1;
     return number_of_entries * 5 / 4;
   }
   static const int kCodesStartIndex = kGroupCount;
 };
 
 
+class PrototypeInfo;
+
+
 // All heap objects have a Map that describes their structure.
 //  A Map contains information about:
 //  - Size information about the object
 //  - How to iterate over an object (for garbage collection)
 class Map: public HeapObject {
  public:
   // Instance size.
   // Size in bytes or kVariableSizeSentinel if instances do not have
   // a fixed size.
   inline int instance_size();
@@ skipping 187 matching lines @@
 
   inline FixedArrayBase* GetInitialElements();
 
   // [raw_transitions]: Provides access to the transitions storage field.
   // Don't call set_raw_transitions() directly to overwrite transitions, use
   // the TransitionArray::ReplaceTransitions() wrapper instead!
   DECL_ACCESSORS(raw_transitions, Object)
   // [prototype_info]: Per-prototype metadata. Aliased with transitions
   // (which prototype maps don't have).
   DECL_ACCESSORS(prototype_info, Object)
+  static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(Handle<Map> map,
+                                                        Isolate* isolate);
+  // [prototype object]: points from a prototype map (which is never shared)
+  // to the object using it. Can be a Smi if the map is no longer used by a
+  // prototype object. Always use the GetPrototypeObject() getter, which zaps
+  // invalid references on the fly; the raw value is in the prototype_info.
+  static void SetPrototypeObject(Handle<Map> map,
+                                 Handle<JSObject> prototype_obj,
+                                 Isolate* isolate);
+  Object* GetPrototypeObject();
 
   Map* FindRootMap();
   Map* FindFieldOwner(int descriptor);
 
   inline int GetInObjectPropertyOffset(int index);
 
   int NumberOfFields();
 
   // TODO(ishell): candidate with JSObject::MigrateToMap().
   bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
@@ skipping 551 matching lines @@
   static const int kSize = kValueOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
 };
 
 
 // Container for metadata stored on each prototype map.
 class PrototypeInfo : public Struct {
  public:
-  // [prototype_object]: The object using the map holding this PrototypeInfo.
-  DECL_ACCESSORS(prototype_object, JSObject)
+  // [prototype_object]: The object using the map holding this PrototypeInfo,
+  // or Smi(0) if uninitialized.
+  DECL_ACCESSORS(prototype_object, Object)
   // [prototype_users]: WeakFixedArray containing maps using this prototype,
   // or Smi(0) if uninitialized.
   DECL_ACCESSORS(prototype_users, Object)
   // [validity_cell]: Cell containing the validity bit for prototype chains
   // going through this object, or Smi(0) if uninitialized.
   DECL_ACCESSORS(validity_cell, Object)
 
   DECLARE_CAST(PrototypeInfo)
 
   // Dispatched behavior.
@@ skipping 4471 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_