/*

 * Copyright 1997-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// vframes are virtual stack frames representing source level activations.

// A single frame may hold several source level activations in the case of

// optimized code. The debugging stored with the optimized code enables

// us to unfold a frame as a stack of vframes.

// A cVFrame represents an activation of a non-java method.

// The vframe inheritance hierarchy:

// - vframe

//   - javaVFrame

//     - interpretedVFrame

//     - compiledVFrame     ; (used for both compiled Java methods and native stubs)

//   - externalVFrame

//     - entryVFrame        ; special frame created when calling Java from C

// - BasicLock

class vframe: public ResourceObj {

 protected:

  frame        _fr;      // Raw frame behind the virtual frame.

  RegisterMap  _reg_map; // Register map for the raw frame (used to handle callee-saved registers).

  JavaThread*  _thread;  // The thread owning the raw frame.

  vframe(const frame* fr, const RegisterMap* reg_map, JavaThread* thread);

  vframe(const frame* fr, JavaThread* thread);

 public:

  // Factory method for creating vframes

  static vframe* new_vframe(const frame* f, const RegisterMap *reg_map, JavaThread* thread);

  // Accessors

  frame              fr()           const { return _fr;       }

  CodeBlob*          cb()         const { return _fr.cb();  }

  nmethod*           nm()         const {

      assert( cb() != NULL && cb()->is_nmethod(), "usage");

      return (nmethod*) cb();

  }

// ???? Does this need to be a copy?

  frame*             frame_pointer() { return &_fr;       }

  const RegisterMap* register_map() const { return &_reg_map; }

  JavaThread*        thread()       const { return _thread;   }

  // Returns the sender vframe

  virtual vframe* sender() const;

  // Returns the next javaVFrame on the stack (skipping all other kinds of frame)

  javaVFrame *java_sender() const;

  // Answers if the this is the top vframe in the frame, i.e., if the sender vframe

  // is in the caller frame

  virtual bool is_top() const { return true; }

  // Returns top vframe within same frame (see is_top())

  virtual vframe* top() const;

  // Type testing operations

  virtual bool is_entry_frame()       const { return false; }

  virtual bool is_java_frame()        const { return false; }

  virtual bool is_interpreted_frame() const { return false; }

  virtual bool is_compiled_frame()    const { return false; }

#ifndef PRODUCT

  // printing operations

  virtual void print_value() const;

  virtual void print();

#endif

};

class javaVFrame: public vframe {

 public:

  // JVM state

  virtual methodOop                    method()         const = 0;

  virtual int                          bci()            const = 0;

  virtual StackValueCollection*        locals()         const = 0;

  virtual StackValueCollection*        expressions()    const = 0;

  // the order returned by monitors() is from oldest -> youngest#4418568

  virtual GrowableArray<MonitorInfo*>* monitors()       const = 0;

  // Debugging support via JVMTI.

  // NOTE that this is not guaranteed to give correct results for compiled vframes.

  // Deoptimize first if necessary.

  virtual void set_locals(StackValueCollection* values) const = 0;

  // Test operation

  bool is_java_frame() const { return true; }

 protected:

  javaVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {}

  javaVFrame(const frame* fr, JavaThread* thread) : vframe(fr, thread) {}

 public:

  // casting

  static javaVFrame* cast(vframe* vf) {

    assert(vf == NULL || vf->is_java_frame(), "must be java frame");

    return (javaVFrame*) vf;

  }

  // Return an array of monitors locked by this frame in the youngest to oldest order

  GrowableArray<MonitorInfo*>* locked_monitors();

  // printing used during stack dumps

  void print_lock_info_on(outputStream* st, int frame_count);

  void print_lock_info(int frame_count) { print_lock_info_on(tty, frame_count); }

#ifndef PRODUCT

 public:

  // printing operations

  void print();

  void print_value() const;

  void print_activation(int index) const;

  // verify operations

  virtual void verify() const;

  // Structural compare

  bool structural_compare(javaVFrame* other);

#endif

  friend class vframe;

};

class interpretedVFrame: public javaVFrame {

 public:

  // JVM state

  methodOop                    method()         const;

  int                          bci()            const;

  StackValueCollection*        locals()         const;

  StackValueCollection*        expressions()    const;

  GrowableArray<MonitorInfo*>* monitors()       const;

  void set_locals(StackValueCollection* values) const;

  // Test operation

  bool is_interpreted_frame() const { return true; }

 protected:

  interpretedVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : javaVFrame(fr, reg_map, thread) {};

 public:

  // Accessors for Byte Code Pointer

  u_char* bcp() const;

  void set_bcp(u_char* bcp);

  // casting

  static interpretedVFrame* cast(vframe* vf) {

    assert(vf == NULL || vf->is_interpreted_frame(), "must be interpreted frame");

    return (interpretedVFrame*) vf;

  }

 private:

  static const int bcp_offset;

  intptr_t* locals_addr_at(int offset) const;

  // returns where the parameters starts relative to the frame pointer

  int start_of_parameters() const;

#ifndef PRODUCT

 public:

  // verify operations

  void verify() const;

#endif

  friend class vframe;

};

class externalVFrame: public vframe {

 protected:

  externalVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {}

#ifndef PRODUCT

 public:

  // printing operations

  void print_value() const;

  void print();

#endif

  friend class vframe;

};

class entryVFrame: public externalVFrame {

 public:

  bool is_entry_frame() const { return true; }

 protected:

  entryVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread);

 public:

  // casting

  static entryVFrame* cast(vframe* vf) {

    assert(vf == NULL || vf->is_entry_frame(), "must be entry frame");

    return (entryVFrame*) vf;

  }

#ifndef PRODUCT

 public:

  // printing

  void print_value() const;

  void print();

#endif

  friend class vframe;

};

// A MonitorInfo is a ResourceObject that describes a the pair:

// 1) the owner of the monitor

// 2) the monitor lock

class MonitorInfo : public ResourceObj {

 private:

  oop        _owner; // the object owning the monitor

  BasicLock* _lock;

  oop        _owner_klass; // klass if owner was scalar replaced

  bool       _eliminated;

  bool       _owner_is_scalar_replaced;

 public:

  // Constructor

  MonitorInfo(oop owner, BasicLock* lock, bool eliminated, bool owner_is_scalar_replaced) {

    if (!owner_is_scalar_replaced) {

      _owner = owner;

      _owner_klass = NULL;

    } else {

      assert(eliminated, "monitor should be eliminated for scalar replaced object");

      _owner = NULL;

      _owner_klass = owner;

    }

    _lock  = lock;

    _eliminated = eliminated;

    _owner_is_scalar_replaced = owner_is_scalar_replaced;

  }

  // Accessors

  oop        owner() const {

    assert(!_owner_is_scalar_replaced, "should not be called for scalar replaced object");

    return _owner;

  }

  klassOop   owner_klass() const {

    assert(_owner_is_scalar_replaced, "should not be called for not scalar replaced object");

    return (klassOop)_owner_klass;

  }

  BasicLock* lock()  const { return _lock;  }

  bool eliminated()  const { return _eliminated; }

  bool owner_is_scalar_replaced()  const { return _owner_is_scalar_replaced; }

};

class vframeStreamCommon : StackObj {

 protected:

  // common

  frame        _frame;

  JavaThread*  _thread;

  RegisterMap  _reg_map;

  enum { interpreted_mode, compiled_mode, at_end_mode } _mode;

  int _sender_decode_offset;

  // Cached information

  methodOop _method;

  int       _bci;

  // Should VM activations be ignored or not

  bool _stop_at_java_call_stub;

  bool fill_in_compiled_inlined_sender();

  void fill_from_compiled_frame(int decode_offset);

  void fill_from_compiled_native_frame();

  void found_bad_method_frame();

  void fill_from_interpreter_frame();

  bool fill_from_frame();

  // Helper routine for security_get_caller_frame

  void skip_prefixed_method_and_wrappers();

 public:

  // Constructor

  vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) {

    _thread = thread;

  }

  // Accessors

  methodOop method() const { return _method; }

  int bci() const { return _bci; }

  intptr_t* frame_id() const { return _frame.id(); }

  address frame_pc() const { return _frame.pc(); }

  CodeBlob*          cb()         const { return _frame.cb();  }

  nmethod*           nm()         const {

      assert( cb() != NULL && cb()->is_nmethod(), "usage");

      return (nmethod*) cb();

  }

  // Frame type

  bool is_interpreted_frame() const { return _frame.is_interpreted_frame(); }

  bool is_entry_frame() const       { return _frame.is_entry_frame(); }

  // Iteration

  void next() {

    // handle frames with inlining

    if (_mode == compiled_mode    && fill_in_compiled_inlined_sender()) return;

    // handle general case

    do {

      _frame = _frame.sender(&_reg_map);

    } while (!fill_from_frame());

  }

  bool at_end() const { return _mode == at_end_mode; }

  // Implements security traversal. Skips depth no. of frame including

  // special security frames and prefixed native methods

  void security_get_caller_frame(int depth);

  // Helper routine for JVM_LatestUserDefinedLoader -- needed for 1.4

  // reflection implementation

  void skip_reflection_related_frames();

};

class vframeStream : public vframeStreamCommon {

 public:

  // Constructors

  vframeStream(JavaThread* thread, bool stop_at_java_call_stub = false)

    : vframeStreamCommon(thread) {

    _stop_at_java_call_stub = stop_at_java_call_stub;

    if (!thread->has_last_Java_frame()) {

      _mode = at_end_mode;

      return;

    }

    _frame = _thread->last_frame();

    while (!fill_from_frame()) {

      _frame = _frame.sender(&_reg_map);

    }

  }

  // top_frame may not be at safepoint, start with sender

  vframeStream(JavaThread* thread, frame top_frame, bool stop_at_java_call_stub = false);

};

inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() {

  if (_sender_decode_offset == DebugInformationRecorder::serialized_null) {

    return false;

  }

  fill_from_compiled_frame(_sender_decode_offset);

  return true;

}

inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {

  _mode = compiled_mode;

  // Range check to detect ridiculous offsets.

  if (decode_offset == DebugInformationRecorder::serialized_null ||

      decode_offset < 0 ||

      decode_offset >= nm()->scopes_data_size()) {

    // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.

    // If we attempt to read nmethod::scopes_data at serialized_null (== 0),

    // or if we read some at other crazy offset,

    // we will decode garbage and make wild references into the heap,

    // leading to crashes in product mode.

    // (This isn't airtight, of course, since there are internal

    // offsets which are also crazy.)

#ifdef ASSERT

    if (WizardMode) {

      tty->print_cr("Error in fill_from_frame: pc_desc for "

                    INTPTR_FORMAT " not found or invalid at %d",

                    _frame.pc(), decode_offset);

      nm()->print();

      nm()->method()->print_codes();

      nm()->print_code();

      nm()->print_pcs();

    }

#endif

    // Provide a cheap fallback in product mode.  (See comment above.)

    found_bad_method_frame();

    fill_from_compiled_native_frame();

    return;

  }

  // Decode first part of scopeDesc

  DebugInfoReadStream buffer(nm(), decode_offset);

  _sender_decode_offset = buffer.read_int();

  _method               = methodOop(buffer.read_oop());

  _bci                  = buffer.read_bci();

  assert(_method->is_method(), "checking type of decoded method");

}

// The native frames are handled specially. We do not rely on ScopeDesc info

// since the pc might not be exact due to the _last_native_pc trick.

inline void vframeStreamCommon::fill_from_compiled_native_frame() {

  _mode = compiled_mode;

  _sender_decode_offset = DebugInformationRecorder::serialized_null;

  _method = nm()->method();

  _bci = 0;

}

inline bool vframeStreamCommon::fill_from_frame() {

  // Interpreted frame

  if (_frame.is_interpreted_frame()) {

    fill_from_interpreter_frame();

    return true;

  }

  // Compiled frame

  if (cb() != NULL && cb()->is_nmethod()) {

    if (nm()->is_native_method()) {

      // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick.

      fill_from_compiled_native_frame();

    } else {

      PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc());

      int decode_offset;

      if (pc_desc == NULL) {

        // Should not happen, but let fill_from_compiled_frame handle it.

        // If we are trying to walk the stack of a thread that is not

        // at a safepoint (like AsyncGetCallTrace would do) then this is an

        // acceptable result. [ This is assuming that safe_for_sender

        // is so bullet proof that we can trust the frames it produced. ]

        //

        // So if we see that the thread is not safepoint safe

        // then simply produce the method and a bci of zero

        // and skip the possibility of decoding any inlining that

        // may be present. That is far better than simply stopping (or

        // asserting. If however the thread is safepoint safe this

        // is the sign of a compiler bug  and we'll let

        // fill_from_compiled_frame handle it.

        JavaThreadState state = _thread->thread_state();

        // in_Java should be good enough to test safepoint safety

        // if state were say in_Java_trans then we'd expect that

        // the pc would have already been slightly adjusted to

        // one that would produce a pcDesc since the trans state

        // would be one that might in fact anticipate a safepoint

        if (state == _thread_in_Java ) {

          // This will get a method a zero bci and no inlining.

          // Might be nice to have a unique bci to signify this

          // particular case but for now zero will do.

          fill_from_compiled_native_frame();

          // There is something to be said for setting the mode to

          // at_end_mode to prevent trying to walk further up the

          // stack. There is evidence that if we walk any further

          // that we could produce a bad stack chain. However until

          // we see evidence that allowing this causes us to find

          // frames bad enough to cause segv's or assertion failures

          // we don't do it as while we may get a bad call chain the

          // probability is much higher (several magnitudes) that we

          // get good data.

          return true;

        }

        decode_offset = DebugInformationRecorder::serialized_null;

      } else {

        decode_offset = pc_desc->scope_decode_offset();

      }

      fill_from_compiled_frame(decode_offset);

    }

    return true;

  }

  // End of stack?

  if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {

    _mode = at_end_mode;

    return true;

  }

  return false;

}

inline void vframeStreamCommon::fill_from_interpreter_frame() {

  methodOop method = _frame.interpreter_frame_method();

  intptr_t  bcx    = _frame.interpreter_frame_bcx();

  int       bci    = method->validate_bci_from_bcx(bcx);

  // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.

  if (bci < 0) {

    found_bad_method_frame();

    bci = 0;  // pretend it's on the point of entering

  }

  _mode   = interpreted_mode;

  _method = method;

  _bci    = bci;

}