Allow functions to have custom construct stubs that are called...

src/objects.h

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2725 matching lines @@
 // SharedFunctionInfo describes the JSFunction information that can be
 // shared by multiple instances of the function.
 class SharedFunctionInfo: public HeapObject {
  public:
   // [name]: Function name.
   DECL_ACCESSORS(name, Object)
 
   // [code]: Function code.
   DECL_ACCESSORS(code, Code)
 
+  // [construct stub]: Code stub for constructing instances of this function.
+  DECL_ACCESSORS(construct_stub, Code)
+
   // Returns if this function has been compiled to native code yet.
   inline bool is_compiled();
 
   // [length]: The function length - usually the number of declared parameters.
   // Use up to 2^30 parameters.
   inline int length();
   inline void set_length(int value);
 
   // [formal parameter count]: The declared number of parameters.
   inline int formal_parameter_count();
@@ skipping 75 matching lines @@
   // Casting.
   static inline SharedFunctionInfo* cast(Object* obj);
 
   // Constants.
   static const int kDontAdaptArgumentsSentinel = -1;
 
   // Layout description.
   // (An even number of integers has a size that is a multiple of a pointer.)
   static const int kNameOffset = HeapObject::kHeaderSize;
   static const int kCodeOffset = kNameOffset + kPointerSize;
-  static const int kLengthOffset = kCodeOffset + kPointerSize;
+  static const int kConstructStubOffset = kCodeOffset + kPointerSize;
+  static const int kLengthOffset = kConstructStubOffset + kPointerSize;
   static const int kFormalParameterCountOffset = kLengthOffset + kIntSize;
   static const int kExpectedNofPropertiesOffset =
       kFormalParameterCountOffset + kIntSize;
   static const int kStartPositionAndTypeOffset =
       kExpectedNofPropertiesOffset + kIntSize;
   static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
   static const int kFunctionTokenPositionOffset = kEndPositionOffset + kIntSize;
   static const int kInstanceClassNameOffset =
       kFunctionTokenPositionOffset + kIntSize;
   static const int kExternalReferenceDataOffset =
@@ skipping 1596 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_