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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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#ifndef SHARE_VM_OOPS_OOPSHIERARCHY_HPP
#define SHARE_VM_OOPS_OOPSHIERARCHY_HPP

#include "metaprogramming/integralConstant.hpp"
#include "metaprogramming/primitiveConversions.hpp"
#include "runtime/globals.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/macros.hpp"

// OBJECT hierarchy
// This hierarchy is a representation hierarchy, i.e. if A is a superclass
// of B, A's representation is a prefix of B's representation.

// Compressed oop class
class narrowOop {
public:
  typedef uint32_t PrimitiveType;

private:
  PrimitiveType _value;

public:
  narrowOop() : _value(0) {}
  narrowOop(const narrowOop& o) : _value(o._value) {}
  narrowOop(const volatile narrowOop& o) : _value(o._value) {}
  narrowOop(const PrimitiveType value) : _value(value) {}

  PrimitiveType value() { return _value; }

  bool operator==(const narrowOop o) const { return _value == o._value; }
  bool operator!=(const narrowOop o) const { return _value != o._value; }

  narrowOop& operator=(const narrowOop o) { _value = o._value; return *this; }

  operator PrimitiveType () const { return _value; }
};

template<>
struct PrimitiveConversions::Translate<narrowOop> : public TrueType {
  typedef narrowOop Value;
  typedef narrowOop::PrimitiveType Decayed;

  static Decayed decay(Value x) { return x.value(); }
  static Value recover(Decayed x) { return narrowOop(x); }
};

// If compressed klass pointers then use narrowKlass.
typedef juint  narrowKlass;

typedef void* OopOrNarrowOopStar;
typedef class   markOopDesc*                markOop;

// Because oop and its subclasses <type>Oop are class types, arbitrary
// conversions are not accepted by the compiler.  Applying a cast to
// an oop will cause the best matched conversion operator to be
// invoked returning the underlying oopDesc* type if appropriate.
// No copy constructors, explicit user conversions or operators of
// numerical type should be defined within the oop class. Most C++
// compilers will issue a compile time error concerning the overloading
// ambiguity between operators of numerical and pointer types. If
// a conversion to or from an oop to a numerical type is needed,
// use the inline template methods, cast_*_oop, defined below.
//
// Converting NULL to oop to Handle implicit is no longer accepted by the
// compiler because there are too many steps in the conversion.  Use Handle()
// instead, which generates less code anyway.

class Thread;
class PromotedObject;


class oop {
  oopDesc* _o;

#ifdef CHECK_UNHANDLED_OOPS
  void register_oop();
  void unregister_oop();
#endif

  // friend class markOop;
public:
  oop() : _o(NULL)                      { CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) register_oop();) }
  oop(const oop& o) : _o(o._o)          { CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) register_oop();) }
  oop(const volatile oop& o) : _o(o._o) { CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) register_oop();) }
  oop(const void* p) : _o((oopDesc*)p)  { CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) register_oop();) }
  ~oop()                                {
    CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) unregister_oop();)
  }

  oopDesc* obj() const                { return _o; }

  // General access
  oopDesc*  operator->() const        { return _o; }
  bool operator==(const oop o) const  { return _o == o._o; }
  bool operator==(void *p) const      { return _o == p; }
  bool operator!=(const oop o) const  { return _o != o._o; }
  bool operator!=(void *p) const      { return _o != p; }

  // Assignment
  oop& operator=(const oop& o)                            { _o = o._o; return *this; }
  volatile oop& operator=(const oop& o) volatile          { _o = o._o; return *this; }
  volatile oop& operator=(const volatile oop& o) volatile { _o = o._o; return *this; }

  // Explict user conversions
  operator void* () const             { return (void *)_o; }
  operator HeapWord* () const         { return (HeapWord*)_o; }
  operator oopDesc* () const          { return _o; }
  operator intptr_t* () const         { return (intptr_t*)_o; }
  operator PromotedObject* () const   { return (PromotedObject*)_o; }
  operator markOop () const           { return markOop(_o); }
  operator address () const           { return (address)_o; }

  // from javaCalls.cpp
  operator jobject () const           { return (jobject)_o; }

  // from parNewGeneration and other things that want to get to the end of
  // an oop for stuff (like ObjArrayKlass.cpp)
  operator oop* () const              { return (oop *)_o; }
};

template<>
struct PrimitiveConversions::Translate<oop> : public TrueType {
  typedef oop Value;
  typedef oopDesc* Decayed;

  static Decayed decay(Value x) { return x.obj(); }
  static Value recover(Decayed x) { return oop(x); }
};

#define DEF_OOP(type)                                                      \
   class type##OopDesc;                                                    \
   class type##Oop : public oop {                                          \
     public:                                                               \
       type##Oop() : oop() {}                                              \
       type##Oop(const oop& o) : oop(o) {}                                 \
       type##Oop(const volatile oop& o) : oop(o) {}                        \
       type##Oop(const void* p) : oop(p) {}                                \
       operator type##OopDesc* () const { return (type##OopDesc*)obj(); }  \
       type##OopDesc* operator->() const {                                 \
            return (type##OopDesc*)obj();                                  \
       }                                                                   \
       type##Oop& operator=(const type##Oop& o) {                          \
            oop::operator=(o);                                             \
            return *this;                                                  \
       }                                                                   \
       volatile type##Oop& operator=(const type##Oop& o) volatile {        \
            (void)const_cast<oop&>(oop::operator=(o));                     \
            return *this;                                                  \
       }                                                                   \
       volatile type##Oop& operator=(const volatile type##Oop& o) volatile {\
            (void)const_cast<oop&>(oop::operator=(o));                     \
            return *this;                                                  \
       }                                                                   \
   };                                                                      \
                                                                           \
   template<>                                                              \
   struct PrimitiveConversions::Translate<type##Oop> : public TrueType {   \
     typedef type##Oop Value;                                              \
     typedef type##OopDesc* Decayed;                                       \
                                                                           \
     static Decayed decay(Value x) { return (type##OopDesc*)x.obj(); }     \
     static Value recover(Decayed x) { return type##Oop(x); }              \
   };

DEF_OOP(instance);
DEF_OOP(array);
DEF_OOP(objArray);
DEF_OOP(typeArray);

// It is ambiguous C++ behavior to have the oop structure contain explicit
// user defined conversions of both numerical and pointer type.
// Define inline methods to provide the numerical conversions.
template <class T> inline oop cast_to_oop(T value) {
  return (oop)((void *)(value));
}
template <class T> inline T cast_from_oop(oop o) {
  return (T)((void*)o);
}

// The metadata hierarchy is separate from the oop hierarchy

//      class MetaspaceObj
class   ConstMethod;
class   ConstantPoolCache;
class   MethodData;
//      class Metadata
class   Method;
class   ConstantPool;
//      class CHeapObj
class   CompiledICHolder;


// The klass hierarchy is separate from the oop hierarchy.

class Klass;
class   InstanceKlass;
class     InstanceMirrorKlass;
class     InstanceClassLoaderKlass;
class     InstanceRefKlass;
class   ArrayKlass;
class     ObjArrayKlass;
class     TypeArrayKlass;

#endif // SHARE_VM_OOPS_OOPSHIERARCHY_HPP