/*

 * 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.

 *

 *

 */

// Classes used for serializing debugging information.

// These abstractions are introducted to provide symmetric

// read and write operations.

// ScopeValue        describes the value of a variable/expression in a scope

// - LocationValue   describes a value in a given location (in frame or register)

// - ConstantValue   describes a constant

class ScopeValue: public ResourceObj {

 public:

  // Testers

  virtual bool is_location() const { return false; }

  virtual bool is_object() const { return false; }

  virtual bool is_constant_int() const { return false; }

  virtual bool is_constant_double() const { return false; }

  virtual bool is_constant_long() const { return false; }

  virtual bool is_constant_oop() const { return false; }

  virtual bool equals(ScopeValue* other) const { return false; }

  // Serialization of debugging information

  virtual void write_on(DebugInfoWriteStream* stream) = 0;

  static ScopeValue* read_from(DebugInfoReadStream* stream);

};

// A Location value describes a value in a given location; i.e. the corresponding

// logical entity (e.g., a method temporary) lives in this location.

class LocationValue: public ScopeValue {

 private:

  Location  _location;

 public:

  LocationValue(Location location)           { _location = location; }

  bool      is_location() const              { return true; }

  Location  location() const                 { return _location; }

  // Serialization of debugging information

  LocationValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

// An ObjectValue describes an object eliminated by escape analysis.

class ObjectValue: public ScopeValue {

 private:

  int                        _id;

  ScopeValue*                _klass;

  GrowableArray<ScopeValue*> _field_values;

  Handle                     _value;

  bool                       _visited;

 public:

  ObjectValue(int id, ScopeValue* klass)

     : _id(id)

     , _klass(klass)

     , _field_values()

     , _value()

     , _visited(false) {

    assert(klass->is_constant_oop(), "should be constant klass oop");

  }

  ObjectValue(int id)

     : _id(id)

     , _klass(NULL)

     , _field_values()

     , _value()

     , _visited(false) {}

  // Accessors

  bool                        is_object() const         { return true; }

  int                         id() const                { return _id; }

  ScopeValue*                 klass() const             { return _klass; }

  GrowableArray<ScopeValue*>* field_values()            { return &_field_values; }

  ScopeValue*                 field_at(int i) const     { return _field_values.at(i); }

  int                         field_size()              { return _field_values.length(); }

  Handle                      value() const             { return _value; }

  bool                        is_visited() const        { return _visited; }

  void                        set_value(oop value)      { _value = Handle(value); }

  void                        set_visited(bool visited) { _visited = false; }

  // Serialization of debugging information

  void read_object(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

  void print_fields_on(outputStream* st) const;

};

// A ConstantIntValue describes a constant int; i.e., the corresponding logical entity

// is either a source constant or its computation has been constant-folded.

class ConstantIntValue: public ScopeValue {

 private:

  jint _value;

 public:

  ConstantIntValue(jint value)         { _value = value; }

  jint value() const                   { return _value;  }

  bool is_constant_int() const         { return true;    }

  bool equals(ScopeValue* other) const { return false;   }

  // Serialization of debugging information

  ConstantIntValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

class ConstantLongValue: public ScopeValue {

 private:

  jlong _value;

 public:

  ConstantLongValue(jlong value)       { _value = value; }

  jlong value() const                  { return _value;  }

  bool is_constant_long() const        { return true;    }

  bool equals(ScopeValue* other) const { return false;   }

  // Serialization of debugging information

  ConstantLongValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

class ConstantDoubleValue: public ScopeValue {

 private:

  jdouble _value;

 public:

  ConstantDoubleValue(jdouble value)   { _value = value; }

  jdouble value() const                { return _value;  }

  bool is_constant_double() const      { return true;    }

  bool equals(ScopeValue* other) const { return false;   }

  // Serialization of debugging information

  ConstantDoubleValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

// A ConstantOopWriteValue is created by the compiler to

// be written as debugging information.

class ConstantOopWriteValue: public ScopeValue {

 private:

  jobject _value;

 public:

  ConstantOopWriteValue(jobject value) { _value = value; }

  jobject value() const                { return _value;  }

  bool is_constant_oop() const         { return true;    }

  bool equals(ScopeValue* other) const { return false;   }

  // Serialization of debugging information

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

// A ConstantOopReadValue is created by the VM when reading

// debug information

class ConstantOopReadValue: public ScopeValue {

 private:

  Handle _value;

 public:

  Handle value() const                 { return _value;  }

  bool is_constant_oop() const         { return true;    }

  bool equals(ScopeValue* other) const { return false;   }

  // Serialization of debugging information

  ConstantOopReadValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

// MonitorValue describes the pair used for monitor_enter and monitor_exit.

class MonitorValue: public ResourceObj {

 private:

  ScopeValue* _owner;

  Location    _basic_lock;

  bool        _eliminated;

 public:

  // Constructor

  MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated = false);

  // Accessors

  ScopeValue*  owner()      const { return _owner; }

  Location     basic_lock() const { return _basic_lock;  }

  bool         eliminated() const { return _eliminated; }

  // Serialization of debugging information

  MonitorValue(DebugInfoReadStream* stream);

  void write_on(DebugInfoWriteStream* stream);

  // Printing

  void print_on(outputStream* st) const;

};

// DebugInfoReadStream specializes CompressedReadStream for reading

// debugging information. Used by ScopeDesc.

class DebugInfoReadStream : public CompressedReadStream {

 private:

  const nmethod* _code;

  const nmethod* code() const { return _code; }

  GrowableArray<ScopeValue*>* _obj_pool;

 public:

  DebugInfoReadStream(const nmethod* code, int offset, GrowableArray<ScopeValue*>* obj_pool = NULL) :

    CompressedReadStream(code->scopes_data_begin(), offset) {

    _code = code;

    _obj_pool = obj_pool;

  } ;

  oop read_oop() {

    return code()->oop_at(read_int());

  }

  ScopeValue* read_object_value();

  ScopeValue* get_cached_object();

  // BCI encoding is mostly unsigned, but -1 is a distinguished value

  int read_bci() { return read_int() + InvocationEntryBci; }

};

// DebugInfoWriteStream specializes CompressedWriteStream for

// writing debugging information. Used by ScopeDescRecorder.

class DebugInfoWriteStream : public CompressedWriteStream {

 private:

  DebugInformationRecorder* _recorder;

  DebugInformationRecorder* recorder() const { return _recorder; }

 public:

  DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size);

  void write_handle(jobject h);

  void write_bci(int bci) { write_int(bci - InvocationEntryBci); }

};