/*

 * 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.

 *

 *

 */

// PcDescs map a physical PC (given as offset from start of nmethod) to

// the corresponding source scope and byte code index.

class nmethod;

class PcDesc VALUE_OBJ_CLASS_SPEC {

  friend class VMStructs;

 private:

  int _pc_offset;           // offset from start of nmethod

  int _scope_decode_offset; // offset for scope in nmethod

  int _obj_decode_offset;

  union PcDescFlags {

    int word;

    struct {

      unsigned int reexecute: 1;

      unsigned int is_method_handle_invoke: 1;

      unsigned int return_oop: 1;

    } bits;

    bool operator ==(const PcDescFlags& other) { return word == other.word; }

  } _flags;

 public:

  int pc_offset() const           { return _pc_offset;   }

  int scope_decode_offset() const { return _scope_decode_offset; }

  int obj_decode_offset() const   { return _obj_decode_offset; }

  void set_pc_offset(int x)           { _pc_offset           = x; }

  void set_scope_decode_offset(int x) { _scope_decode_offset = x; }

  void set_obj_decode_offset(int x)   { _obj_decode_offset   = x; }

  // Constructor (only used for static in nmethod.cpp)

  // Also used by ScopeDesc::sender()]

  PcDesc(int pc_offset, int scope_decode_offset, int obj_decode_offset);

  enum {

    // upper and lower exclusive limits real offsets:

    lower_offset_limit = -1,

    upper_offset_limit = (unsigned int)-1 >> 1

  };

  // Flags

  bool     should_reexecute()              const { return _flags.bits.reexecute; }

  void set_should_reexecute(bool z)              { _flags.bits.reexecute = z;    }

  // Does pd refer to the same information as pd?

  bool is_same_info(const PcDesc* pd) {

    return _scope_decode_offset == pd->_scope_decode_offset &&

      _obj_decode_offset == pd->_obj_decode_offset &&

      _flags == pd->_flags;

  }

  bool     is_method_handle_invoke()       const { return _flags.bits.is_method_handle_invoke;     }

  void set_is_method_handle_invoke(bool z)       {        _flags.bits.is_method_handle_invoke = z; }

  bool     return_oop()                    const { return _flags.bits.return_oop;     }

  void set_return_oop(bool z)                    {        _flags.bits.return_oop = z; }

  // Returns the real pc

  address real_pc(const nmethod* code) const;

  void print(nmethod* code);

  bool verify(nmethod* code);

};