vmkit/include/mvm/Object.h

//===---------- Object.h - Common layout for all objects ------------------===//
//
//                     The Micro Virtual Machine
//
// This file is distributed under the University of Illinois Open Source 
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef MVM_OBJECT_H
#define MVM_OBJECT_H

#include <assert.h>

#include "types.h"
#include "MvmGC.h"

namespace mvm {


#define VT_DESTRUCTOR_OFFSET 0
#define VT_OPERATOR_DELETE_OFFSET 1
#define VT_TRACER_OFFSET 2
#define VT_PRINT_OFFSET 3
#define VT_HASHCODE_OFFSET 4
#define VT_NB_FUNCS 5
#define VT_SIZE 5 * sizeof(void*)


class PrintBuffer;

/// Object - Root of all objects. Define default implementations of virtual
/// methods and some commodity functions.
///
class Object : public gc {
public:
  
  /// getVirtualTable - Returns the virtual table of this object.
  ///
  VirtualTable* getVirtualTable() const {
    return ((VirtualTable**)(this))[0];
  }
  
  /// setVirtualTable - Sets the virtual table of this object.
  ///
  void setVirtualTable(VirtualTable* VT) {
    ((VirtualTable**)(this))[0] = VT;
  }

  /// printString - Returns a string representation of this object.
  ///
  char *printString(void) const;

  /// tracer - Default implementation of tracer. Does nothing.
  ///
  virtual void      TRACER {}

  /// print - Default implementation of print.
  ///
  virtual void      print(PrintBuffer *buf) const;

  /// hashCode - Default implementation of hashCode. Returns the address
  /// of this object.
  ///
  virtual intptr_t  hashCode(){ return (intptr_t)this;}
  
  /// initialise - All virtual machines must call Object::initialise to
  /// property initialise the PrintBuffer and NativeString classes. These
  /// classes are mainly used for debugging but also for object hashing.
  ///
  static void initialise();

};

} // end namespace mvm

#endif // MVM_OBJECT_H