[es6] Better support for built-ins subclassing.

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 2198 matching lines @@
   // Support functions for v8 api (needed for correct interceptor behavior).
   MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
       Handle<JSObject> object, Handle<Name> name);
   MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
       Handle<JSObject> object, uint32_t index);
   MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
       Handle<JSObject> object, Handle<Name> name);
 
   // Get the header size for a JSObject.  Used to compute the index of
   // internal fields as well as the number of internal fields.
+  static inline int GetHeaderSize(InstanceType instance_type);
   inline int GetHeaderSize();
 
+  // Get the size of the header with internal fields of a JSObject.
+  // Used to calculate the instance size.
+  static inline int GetHeaderWithInternalFieldsSize(InstanceType instance_type);
+
   inline int GetInternalFieldCount();
   inline int GetInternalFieldOffset(int index);
   inline Object* GetInternalField(int index);
   inline void SetInternalField(int index, Object* value);
   inline void SetInternalField(int index, Smi* value);
 
   // Returns the number of properties on this object filtering out properties
   // with the specified attributes (ignoring interceptors).
   int NumberOfOwnProperties(PropertyAttributes filter = NONE);
   // Fill in details for properties into storage starting at the specified
@@ skipping 4548 matching lines @@
   // Whether this function is defined in native code or extensions.
   inline bool IsBuiltin();
 
   // Check whether or not this function is inlineable.
   bool IsInlineable();
 
   // Source size of this function.
   int SourceSize();
 
   // Calculate the instance size.
-  int CalculateInstanceSize();
+  int CalculateInstanceSize(InstanceType instance_type);
 
   // Calculate the number of in-object properties.
-  int CalculateInObjectProperties();
+  int CalculateInObjectProperties(InstanceType instance_type);
 
   inline bool has_simple_parameters();
 
   // Initialize a SharedFunctionInfo from a parsed function literal.
   static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
                                       FunctionLiteral* lit);
 
   // Dispatched behavior.
   DECLARE_PRINTER(SharedFunctionInfo)
   DECLARE_VERIFIER(SharedFunctionInfo)
@@ skipping 476 matching lines @@
 
   inline BindingsArray* function_bindings();
   inline void set_function_bindings(BindingsArray* bindings);
 
   // The initial map for an object created by this constructor.
   inline Map* initial_map();
   static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
                             Handle<Object> prototype);
   inline bool has_initial_map();
   static void EnsureHasInitialMap(Handle<JSFunction> function);
+  static Handle<Map> EnsureDerivedHasInitialMap(
+      Handle<JSFunction> original_constructor, Handle<JSFunction> constructor);
 
   // Get and set the prototype property on a JSFunction. If the
   // function has an initial map the prototype is set on the initial
   // map. Otherwise, the prototype is put in the initial map field
   // until an initial map is needed.
   inline bool has_prototype();
   inline bool has_instance_prototype();
   inline Object* prototype();
   inline Object* instance_prototype();
   static void SetPrototype(Handle<JSFunction> function,
@@ skipping 3481 matching lines @@
   // (elements + properties) in the current level.
   int levelLength_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyAccumulator);
 };
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_