/*

 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_CI_CIBASEOBJECT_HPP

#define SHARE_VM_CI_CIBASEOBJECT_HPP

#include "ci/ciClassList.hpp"

#include "memory/allocation.hpp"

#include "runtime/jniHandles.hpp"

// ciBaseObject

//

// This class represents an oop in the HotSpot virtual machine.

// Its subclasses are structured in a hierarchy which mirrors

// an aggregate of the VM's oop and klass hierarchies (see

// oopHierarchy.hpp).  Each instance of ciBaseObject holds a handle

// to a corresponding oop on the VM side and provides routines

// for accessing the information in its oop.  By using the ciBaseObject

// hierarchy for accessing oops in the VM, the compiler ensures

// that it is safe with respect to garbage collection; that is,

// GC and compilation can proceed independently without

// interference.

//

// Within the VM, the oop and klass hierarchies are separate.

// The compiler interface does not preserve this separation --

// the distinction between `Klass*' and `Klass' are not

// reflected in the interface and instead the Klass hierarchy

// is directly modeled as the subclasses of ciKlass.

class ciBaseObject : public ResourceObj {

  CI_PACKAGE_ACCESS

  friend class ciEnv;

protected:

  uint     _ident;

  enum { FLAG_BITS   = 1 };

  enum {

         SCAVENGABLE_FLAG = 1

       };

protected:

  ciBaseObject(): _ident(0) {}

  virtual const char* type_string() { return "ciBaseObject"; }

  void set_ident(uint id);

public:

  // A number unique to this object.

  uint ident();

  // What kind of ciBaseObject is this?

  virtual bool is_symbol() const       { return false; }

  virtual bool is_object() const       { return false; }

  virtual bool is_metadata() const     { return false; }

  ciSymbol* as_symbol() {

    assert(is_symbol(), "must be");

    return (ciSymbol*)this;

  }

  ciObject* as_object() {

    assert(is_object(), "must be");

    return (ciObject*)this;

  }

  ciMetadata* as_metadata() {

    assert(is_metadata(), "must be");

    return (ciMetadata*)this;

  }

};

#endif // SHARE_VM_CI_CIBASEOBJECT_HPP