/*

 * 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.

 *

 */

// SimpleScopeDesc is used when all you need to extract from

// a given pc,nmethod pair is a methodOop and a bci. This is

// quite a bit faster than allocating a full ScopeDesc, but

// very limited in abilities.

class SimpleScopeDesc : public StackObj {

 private:

  methodOop _method;

  int _bci;

 public:

  SimpleScopeDesc(nmethod* code,address pc) {

    PcDesc* pc_desc = code->pc_desc_at(pc);

    assert(pc_desc != NULL, "Must be able to find matching PcDesc");

    DebugInfoReadStream buffer(code, pc_desc->scope_decode_offset());

    int ignore_sender = buffer.read_int();

    _method           = methodOop(buffer.read_oop());

    _bci              = buffer.read_bci();

  }

  methodOop method() { return _method; }

  int bci() { return _bci; }

};

// ScopeDescs contain the information that makes source-level debugging of

// nmethods possible; each scopeDesc describes a method activation

class ScopeDesc : public ResourceObj {

 public:

  // Constructor

  ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset, bool reexecute, bool return_oop);

  // Calls above, giving default value of "serialized_null" to the

  // "obj_decode_offset" argument.  (We don't use a default argument to

  // avoid a .hpp-.hpp dependency.)

  ScopeDesc(const nmethod* code, int decode_offset, bool reexecute, bool return_oop);

  // JVM state

  methodHandle method()   const { return _method; }

  int          bci()      const { return _bci;    }

  bool should_reexecute() const { return _reexecute; }

  bool return_oop()       const { return _return_oop; }

  GrowableArray<ScopeValue*>*   locals();

  GrowableArray<ScopeValue*>*   expressions();

  GrowableArray<MonitorValue*>* monitors();

  GrowableArray<ScopeValue*>*   objects();

  // Stack walking, returns NULL if this is the outer most scope.

  ScopeDesc* sender() const;

  // Returns where the scope was decoded

  int decode_offset() const { return _decode_offset; }

  // Tells whether sender() returns NULL

  bool is_top() const;

  // Tells whether sd is equal to this

  bool is_equal(ScopeDesc* sd) const;

 private:

  // Alternative constructor

  ScopeDesc(const ScopeDesc* parent);

  // JVM state

  methodHandle  _method;

  int           _bci;

  bool          _reexecute;

  bool          _return_oop;

  // Decoding offsets

  int _decode_offset;

  int _sender_decode_offset;

  int _locals_decode_offset;

  int _expressions_decode_offset;

  int _monitors_decode_offset;

  // Object pool

  GrowableArray<ScopeValue*>* _objects;

  // Nmethod information

  const nmethod* _code;

  // Decoding operations

  void decode_body();

  GrowableArray<ScopeValue*>* decode_scope_values(int decode_offset);

  GrowableArray<MonitorValue*>* decode_monitor_values(int decode_offset);

  GrowableArray<ScopeValue*>* decode_object_values(int decode_offset);

  DebugInfoReadStream* stream_at(int decode_offset) const;

 public:

  // Verification

  void verify();

#ifndef PRODUCT

 public:

  // Printing support

  void print_on(outputStream* st) const;

  void print_on(outputStream* st, PcDesc* pd) const;

  void print_value_on(outputStream* st) const;

#endif

};