/*

 * Copyright (c) 2015, 2019, 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_PRIMS_STACKWALK_HPP

#define SHARE_PRIMS_STACKWALK_HPP

#include "oops/oop.hpp"

#include "runtime/vframe.hpp"

// BaseFrameStream is an abstract base class for encapsulating the VM-side

// implementation of the StackWalker API.  There are two concrete subclasses:

// - JavaFrameStream:

//     -based on vframeStream; used in most instances

// - LiveFrameStream:

//     -based on javaVFrame; used for retrieving locals/monitors/operands for

//      LiveStackFrame

class BaseFrameStream : public StackObj {

private:

  enum {

    magic_pos = 0

  };

  JavaThread*           _thread;

  jlong                 _anchor;

protected:

  void fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS);

public:

  BaseFrameStream(JavaThread* thread) : _thread(thread), _anchor(0L) {}

  virtual void    next()=0;

  virtual bool    at_end()=0;

  virtual Method* method()=0;

  virtual int     bci()=0;

  virtual void    fill_frame(int index, objArrayHandle  frames_array,

                             const methodHandle& method, TRAPS)=0;

  void setup_magic_on_entry(objArrayHandle frames_array);

  bool check_magic(objArrayHandle frames_array);

  bool cleanup_magic_on_exit(objArrayHandle frames_array);

  bool is_valid_in(Thread* thread, objArrayHandle frames_array) {

    return (_thread == thread && check_magic(frames_array));

  }

  jlong address_value() {

    return (jlong) castable_address(this);

  }

  static BaseFrameStream* from_current(JavaThread* thread, jlong magic, objArrayHandle frames_array);

};

class JavaFrameStream : public BaseFrameStream {

private:

  vframeStream          _vfst;

  bool                  _need_method_info;

public:

  JavaFrameStream(JavaThread* thread, int mode);

  void next();

  bool at_end()    { return _vfst.at_end(); }

  Method* method() { return _vfst.method(); }

  int bci()        { return _vfst.bci(); }

  void fill_frame(int index, objArrayHandle  frames_array,

                  const methodHandle& method, TRAPS);

};

class LiveFrameStream : public BaseFrameStream {

private:

  enum {

    MODE_INTERPRETED = 0x01,

    MODE_COMPILED    = 0x02

  };

  javaVFrame*           _jvf;

  void fill_live_stackframe(Handle stackFrame, const methodHandle& method, TRAPS);

  static oop create_primitive_slot_instance(StackValueCollection* values,

                                            int i, BasicType type, TRAPS);

  static objArrayHandle monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors,

                                                 TRAPS);

  static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS);

public:

  LiveFrameStream(JavaThread* thread, RegisterMap* rm) : BaseFrameStream(thread) {

    _jvf = thread->last_java_vframe(rm);

  }

  void next()      { _jvf = _jvf->java_sender(); }

  bool at_end()    { return _jvf == NULL; }

  Method* method() { return _jvf->method(); }

  int bci()        { return _jvf->bci(); }

  void fill_frame(int index, objArrayHandle  frames_array,

                  const methodHandle& method, TRAPS);

};

class StackWalk : public AllStatic {

private:

  static int fill_in_frames(jlong mode, BaseFrameStream& stream,

                            int max_nframes, int start_index,

                            objArrayHandle frames_array,

                            int& end_index, TRAPS);

  static inline bool get_caller_class(int mode) {

    return (mode & JVM_STACKWALK_GET_CALLER_CLASS) != 0;

  }

  static inline bool skip_hidden_frames(int mode) {

    return (mode & JVM_STACKWALK_SHOW_HIDDEN_FRAMES) == 0;

  }

  static inline bool live_frame_info(int mode) {

    return (mode & JVM_STACKWALK_FILL_LIVE_STACK_FRAMES) != 0;

  }

public:

  static inline bool need_method_info(int mode) {

    return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0;

  }

  static inline bool use_frames_array(int mode) {

    return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0;

  }

  static oop walk(Handle stackStream, jlong mode,

                  int skip_frames, int frame_count, int start_index,

                  objArrayHandle frames_array,

                  TRAPS);

  static oop fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,

                             jlong mode, int skip_frames, int frame_count,

                             int start_index, objArrayHandle frames_array, TRAPS);

  static jint fetchNextBatch(Handle stackStream, jlong mode, jlong magic,

                             int frame_count, int start_index,

                             objArrayHandle frames_array, TRAPS);

};

#endif // SHARE_PRIMS_STACKWALK_HPP