/*

 * Copyright (c) 1997, 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.

 *

 */

#include "precompiled.hpp"

#include "classfile/javaClasses.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "code/codeCache.hpp"

#include "code/debugInfoRec.hpp"

#include "code/nmethod.hpp"

#include "code/pcDesc.hpp"

#include "code/scopeDesc.hpp"

#include "interpreter/interpreter.hpp"

#include "interpreter/oopMapCache.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/frame.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/objectMonitor.hpp"

#include "runtime/objectMonitor.inline.hpp"

#include "runtime/signature.hpp"

#include "runtime/stubRoutines.hpp"

#include "runtime/synchronizer.hpp"

#include "runtime/thread.inline.hpp"

#include "runtime/vframe.inline.hpp"

#include "runtime/vframeArray.hpp"

#include "runtime/vframe_hp.hpp"

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

: _reg_map(reg_map), _thread(thread) {

  assert(fr != NULL, "must have frame");

  _fr = *fr;

}

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

: _reg_map(thread), _thread(thread) {

  assert(fr != NULL, "must have frame");

  _fr = *fr;

}

vframe* vframe::new_vframe(const frame* f, const RegisterMap* reg_map, JavaThread* thread) {

  // Interpreter frame

  if (f->is_interpreted_frame()) {

    return new interpretedVFrame(f, reg_map, thread);

  }

  // Compiled frame

  CodeBlob* cb = f->cb();

  if (cb != NULL) {

    if (cb->is_compiled()) {

      CompiledMethod* nm = (CompiledMethod*)cb;

      return new compiledVFrame(f, reg_map, thread, nm);

    }

    if (f->is_runtime_frame()) {

      // Skip this frame and try again.

      RegisterMap temp_map = *reg_map;

      frame s = f->sender(&temp_map);

      return new_vframe(&s, &temp_map, thread);

    }

  }

  // External frame

  return new externalVFrame(f, reg_map, thread);

}

vframe* vframe::sender() const {

  RegisterMap temp_map = *register_map();

  assert(is_top(), "just checking");

  if (_fr.is_entry_frame() && _fr.is_first_frame()) return NULL;

  frame s = _fr.real_sender(&temp_map);

  if (s.is_first_frame()) return NULL;

  return vframe::new_vframe(&s, &temp_map, thread());

}

vframe* vframe::top() const {

  vframe* vf = (vframe*) this;

  while (!vf->is_top()) vf = vf->sender();

  return vf;

}

javaVFrame* vframe::java_sender() const {

  vframe* f = sender();

  while (f != NULL) {

    if (f->is_java_frame()) return javaVFrame::cast(f);

    f = f->sender();

  }

  return NULL;

}

// ------------- javaVFrame --------------

GrowableArray<MonitorInfo*>* javaVFrame::locked_monitors() {

  assert(SafepointSynchronize::is_at_safepoint() || JavaThread::current() == thread(),

         "must be at safepoint or it's a java frame of the current thread");

  GrowableArray<MonitorInfo*>* mons = monitors();

  GrowableArray<MonitorInfo*>* result = new GrowableArray<MonitorInfo*>(mons->length());

  if (mons->is_empty()) return result;

  bool found_first_monitor = false;

  ObjectMonitor *pending_monitor = thread()->current_pending_monitor();

  ObjectMonitor *waiting_monitor = thread()->current_waiting_monitor();

  oop pending_obj = (pending_monitor != NULL ? (oop) pending_monitor->object() : (oop) NULL);

  oop waiting_obj = (waiting_monitor != NULL ? (oop) waiting_monitor->object() : (oop) NULL);

  for (int index = (mons->length()-1); index >= 0; index--) {

    MonitorInfo* monitor = mons->at(index);

    if (monitor->eliminated() && is_compiled_frame()) continue; // skip eliminated monitor

    oop obj = monitor->owner();

    if (obj == NULL) continue; // skip unowned monitor

    //

    // Skip the monitor that the thread is blocked to enter or waiting on

    //

    if (!found_first_monitor && (obj == pending_obj || obj == waiting_obj)) {

      continue;

    }

    found_first_monitor = true;

    result->append(monitor);

  }

  return result;

}

void javaVFrame::print_locked_object_class_name(outputStream* st, Handle obj, const char* lock_state) {

  if (obj.not_null()) {

    st->print("\t- %s <" INTPTR_FORMAT "> ", lock_state, p2i(obj()));

    if (obj->klass() == SystemDictionary::Class_klass()) {

      st->print_cr("(a java.lang.Class for %s)", java_lang_Class::as_external_name(obj()));

    } else {

      Klass* k = obj->klass();

      st->print_cr("(a %s)", k->external_name());

    }

  }

}

void javaVFrame::print_lock_info_on(outputStream* st, int frame_count) {

  Thread* THREAD = Thread::current();

  ResourceMark rm(THREAD);

  // If this is the first frame and it is java.lang.Object.wait(...)

  // then print out the receiver. Locals are not always available,

  // e.g., compiled native frames have no scope so there are no locals.

  if (frame_count == 0) {

    if (method()->name() == vmSymbols::wait_name() &&

        method()->method_holder()->name() == vmSymbols::java_lang_Object()) {

      const char *wait_state = "waiting on"; // assume we are waiting

      // If earlier in the output we reported java.lang.Thread.State ==

      // "WAITING (on object monitor)" and now we report "waiting on", then

      // we are still waiting for notification or timeout. Otherwise if

      // we earlier reported java.lang.Thread.State == "BLOCKED (on object

      // monitor)", then we are actually waiting to re-lock the monitor.

      StackValueCollection* locs = locals();

      if (!locs->is_empty()) {

        StackValue* sv = locs->at(0);

        if (sv->type() == T_OBJECT) {

          Handle o = locs->at(0)->get_obj();

          if (java_lang_Thread::get_thread_status(thread()->threadObj()) ==

                                java_lang_Thread::BLOCKED_ON_MONITOR_ENTER) {

            wait_state = "waiting to re-lock in wait()";

          }

          print_locked_object_class_name(st, o, wait_state);

        }

      } else {

        st->print_cr("\t- %s <no object reference available>", wait_state);

      }

    } else if (thread()->current_park_blocker() != NULL) {

      oop obj = thread()->current_park_blocker();

      Klass* k = obj->klass();

      st->print_cr("\t- %s <" INTPTR_FORMAT "> (a %s)", "parking to wait for ", p2i(obj), k->external_name());

    }

    else if (thread()->osthread()->get_state() == OBJECT_WAIT) {

      // We are waiting on an Object monitor but Object.wait() isn't the

      // top-frame, so we should be waiting on a Class initialization monitor.

      InstanceKlass* k = thread()->class_to_be_initialized();

      if (k != NULL) {

        st->print_cr("\t- waiting on the Class initialization monitor for %s", k->external_name());

      }

    }

  }

  // Print out all monitors that we have locked, or are trying to lock,

  // including re-locking after being notified or timing out in a wait().

  GrowableArray<MonitorInfo*>* mons = monitors();

  if (!mons->is_empty()) {

    bool found_first_monitor = false;

    for (int index = (mons->length()-1); index >= 0; index--) {

      MonitorInfo* monitor = mons->at(index);

      if (monitor->eliminated() && is_compiled_frame()) { // Eliminated in compiled code

        if (monitor->owner_is_scalar_replaced()) {

          Klass* k = java_lang_Class::as_Klass(monitor->owner_klass());

          st->print("\t- eliminated <owner is scalar replaced> (a %s)", k->external_name());

        } else {

          Handle obj(THREAD, monitor->owner());

          if (obj() != NULL) {

            print_locked_object_class_name(st, obj, "eliminated");

          }

        }

        continue;

      }

      if (monitor->owner() != NULL) {

        // the monitor is associated with an object, i.e., it is locked

        const char *lock_state = "locked"; // assume we have the monitor locked

        if (!found_first_monitor && frame_count == 0) {

          // If this is the first frame and we haven't found an owned

          // monitor before, then we need to see if we have completed

          // the lock or if we are blocked trying to acquire it. Only

          // an inflated monitor that is first on the monitor list in

          // the first frame can block us on a monitor enter.

          markWord mark = monitor->owner()->mark();

          if (mark.has_monitor() &&

              ( // we have marked ourself as pending on this monitor

                mark.monitor() == thread()->current_pending_monitor() ||

                // we are not the owner of this monitor

                !mark.monitor()->is_entered(thread())

              )) {

            lock_state = "waiting to lock";

          }

        }

        print_locked_object_class_name(st, Handle(THREAD, monitor->owner()), lock_state);

        found_first_monitor = true;

      }

    }

  }

}

// ------------- interpretedVFrame --------------

u_char* interpretedVFrame::bcp() const {

  return fr().interpreter_frame_bcp();

}

void interpretedVFrame::set_bcp(u_char* bcp) {

  fr().interpreter_frame_set_bcp(bcp);

}

intptr_t* interpretedVFrame::locals_addr_at(int offset) const {

  assert(fr().is_interpreted_frame(), "frame should be an interpreted frame");

  return fr().interpreter_frame_local_at(offset);

}

GrowableArray<MonitorInfo*>* interpretedVFrame::monitors() const {

  GrowableArray<MonitorInfo*>* result = new GrowableArray<MonitorInfo*>(5);

  for (BasicObjectLock* current = (fr().previous_monitor_in_interpreter_frame(fr().interpreter_frame_monitor_begin()));

       current >= fr().interpreter_frame_monitor_end();

       current = fr().previous_monitor_in_interpreter_frame(current)) {

    result->push(new MonitorInfo(current->obj(), current->lock(), false, false));

  }

  return result;

}

int interpretedVFrame::bci() const {

  return method()->bci_from(bcp());

}

Method* interpretedVFrame::method() const {

  return fr().interpreter_frame_method();

}

static StackValue* create_stack_value_from_oop_map(const InterpreterOopMap& oop_mask,

                                                   int index,

                                                   const intptr_t* const addr) {

  assert(index >= 0 &&

         index < oop_mask.number_of_entries(), "invariant");

  // categorize using oop_mask

  if (oop_mask.is_oop(index)) {

    // reference (oop) "r"

    Handle h(Thread::current(), addr != NULL ? (*(oop*)addr) : (oop)NULL);

    return new StackValue(h);

  }

  // value (integer) "v"

  return new StackValue(addr != NULL ? *addr : 0);

}

static bool is_in_expression_stack(const frame& fr, const intptr_t* const addr) {

  assert(addr != NULL, "invariant");

  // Ensure to be 'inside' the expresion stack (i.e., addr >= sp for Intel).

  // In case of exceptions, the expression stack is invalid and the sp

  // will be reset to express this condition.

  if (frame::interpreter_frame_expression_stack_direction() > 0) {

    return addr <= fr.interpreter_frame_tos_address();

  }

  return addr >= fr.interpreter_frame_tos_address();

}

static void stack_locals(StackValueCollection* result,

                         int length,

                         const InterpreterOopMap& oop_mask,

                         const frame& fr) {

  assert(result != NULL, "invariant");

  for (int i = 0; i < length; ++i) {

    const intptr_t* const addr = fr.interpreter_frame_local_at(i);

    assert(addr != NULL, "invariant");

    assert(addr >= fr.sp(), "must be inside the frame");

    StackValue* const sv = create_stack_value_from_oop_map(oop_mask, i, addr);

    assert(sv != NULL, "sanity check");

    result->add(sv);

  }

}

static void stack_expressions(StackValueCollection* result,

                              int length,

                              int max_locals,

                              const InterpreterOopMap& oop_mask,

                              const frame& fr) {

  assert(result != NULL, "invariant");

  for (int i = 0; i < length; ++i) {

    const intptr_t* addr = fr.interpreter_frame_expression_stack_at(i);

    assert(addr != NULL, "invariant");

    if (!is_in_expression_stack(fr, addr)) {

      // Need to ensure no bogus escapes.

      addr = NULL;

    }

    StackValue* const sv = create_stack_value_from_oop_map(oop_mask,

                                                           i + max_locals,

                                                           addr);

    assert(sv != NULL, "sanity check");

    result->add(sv);

  }

}

StackValueCollection* interpretedVFrame::locals() const {

  return stack_data(false);

}

StackValueCollection* interpretedVFrame::expressions() const {

  return stack_data(true);

}

/*

 * Worker routine for fetching references and/or values

 * for a particular bci in the interpretedVFrame.

 *

 * Returns data for either "locals" or "expressions",

 * using bci relative oop_map (oop_mask) information.

 *

 * @param expressions  bool switch controlling what data to return

                       (false == locals / true == expression)

 *

 */

StackValueCollection* interpretedVFrame::stack_data(bool expressions) const {

  InterpreterOopMap oop_mask;

  method()->mask_for(bci(), &oop_mask);

  const int mask_len = oop_mask.number_of_entries();

  // If the method is native, method()->max_locals() is not telling the truth.

  // For our purposes, max locals instead equals the size of parameters.

  const int max_locals = method()->is_native() ?

    method()->size_of_parameters() : method()->max_locals();

  assert(mask_len >= max_locals, "invariant");

  const int length = expressions ? mask_len - max_locals : max_locals;

  assert(length >= 0, "invariant");

  StackValueCollection* const result = new StackValueCollection(length);

  if (0 == length) {

    return result;

  }

  if (expressions) {

    stack_expressions(result, length, max_locals, oop_mask, fr());

  } else {

    stack_locals(result, length, oop_mask, fr());

  }

  assert(length == result->size(), "invariant");

  return result;

}

void interpretedVFrame::set_locals(StackValueCollection* values) const {

  if (values == NULL || values->size() == 0) return;

  // If the method is native, max_locals is not telling the truth.

  // maxlocals then equals the size of parameters

  const int max_locals = method()->is_native() ?

    method()->size_of_parameters() : method()->max_locals();

  assert(max_locals == values->size(), "Mismatch between actual stack format and supplied data");

  // handle locals

  for (int i = 0; i < max_locals; i++) {

    // Find stack location

    intptr_t *addr = locals_addr_at(i);

    // Depending on oop/int put it in the right package

    const StackValue* const sv = values->at(i);

    assert(sv != NULL, "sanity check");

    if (sv->type() == T_OBJECT) {

      *(oop *) addr = (sv->get_obj())();

    } else {                   // integer

      *addr = sv->get_int();

    }

  }

}

// ------------- cChunk --------------

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

: externalVFrame(fr, reg_map, thread) {}

#ifdef ASSERT

void vframeStreamCommon::found_bad_method_frame() const {

  // 6379830 Cut point for an assertion that occasionally fires when

  // we are using the performance analyzer.

  // Disable this assert when testing the analyzer with fastdebug.

  // -XX:SuppressErrorAt=vframe.cpp:XXX (XXX=following line number)

  fatal("invalid bci or invalid scope desc");

}

#endif

// top-frame will be skipped

vframeStream::vframeStream(JavaThread* thread, frame top_frame,

  bool stop_at_java_call_stub) : vframeStreamCommon(thread) {

  _stop_at_java_call_stub = stop_at_java_call_stub;

  // skip top frame, as it may not be at safepoint

  _prev_frame = top_frame;

  _frame  = top_frame.sender(&_reg_map);

  while (!fill_from_frame()) {

    _prev_frame = _frame;

    _frame = _frame.sender(&_reg_map);

  }

}

// Step back n frames, skip any pseudo frames in between.

// This function is used in Class.forName, Class.newInstance, Method.Invoke,

// AccessController.doPrivileged.

void vframeStreamCommon::security_get_caller_frame(int depth) {

  assert(depth >= 0, "invalid depth: %d", depth);

  for (int n = 0; !at_end(); security_next()) {

    if (!method()->is_ignored_by_security_stack_walk()) {

      if (n == depth) {

        // We have reached the desired depth; return.

        return;

      }

      n++;  // this is a non-skipped frame; count it against the depth

    }

  }

  // NOTE: At this point there were not enough frames on the stack

  // to walk to depth.  Callers of this method have to check for at_end.

}

void vframeStreamCommon::security_next() {

  if (method()->is_prefixed_native()) {

    skip_prefixed_method_and_wrappers();  // calls next()

  } else {

    next();

  }

}

void vframeStreamCommon::skip_prefixed_method_and_wrappers() {

  ResourceMark rm;

  HandleMark hm;

  int    method_prefix_count = 0;

  char** method_prefixes = JvmtiExport::get_all_native_method_prefixes(&method_prefix_count);

  Klass* prefixed_klass = method()->method_holder();

  const char* prefixed_name = method()->name()->as_C_string();

  size_t prefixed_name_len = strlen(prefixed_name);

  int prefix_index = method_prefix_count-1;