frames.cc 53.3 KB
Newer Older
1
// Copyright 2012 the V8 project authors. All rights reserved.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

30 31
#include "ast.h"
#include "deoptimizer.h"
32
#include "frames-inl.h"
33
#include "full-codegen.h"
34
#include "lazy-instance.h"
35
#include "mark-compact.h"
36
#include "safepoint-table.h"
37 38
#include "scopeinfo.h"
#include "string-stream.h"
39
#include "vm-state-inl.h"
40

41 42
#include "allocation-inl.h"

43 44
namespace v8 {
namespace internal {
45

46

47 48
ReturnAddressLocationResolver
    StackFrame::return_address_location_resolver_ = NULL;
49 50


51 52 53 54 55 56 57 58 59 60 61 62
// Iterator that supports traversing the stack handlers of a
// particular frame. Needs to know the top of the handler chain.
class StackHandlerIterator BASE_EMBEDDED {
 public:
  StackHandlerIterator(const StackFrame* frame, StackHandler* handler)
      : limit_(frame->fp()), handler_(handler) {
    // Make sure the handler has already been unwound to this frame.
    ASSERT(frame->sp() <= handler->address());
  }

  StackHandler* handler() const { return handler_; }

63 64 65
  bool done() {
    return handler_ == NULL || handler_->address() > limit_;
  }
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
  void Advance() {
    ASSERT(!done());
    handler_ = handler_->next();
  }

 private:
  const Address limit_;
  StackHandler* handler_;
};


// -------------------------------------------------------------------------


#define INITIALIZE_SINGLETON(type, field) field##_(this),
81 82
StackFrameIteratorBase::StackFrameIteratorBase(Isolate* isolate,
                                               bool can_access_heap_objects)
83 84 85
    : isolate_(isolate),
      STACK_FRAME_TYPE_LIST(INITIALIZE_SINGLETON)
      frame_(NULL), handler_(NULL),
86
      can_access_heap_objects_(can_access_heap_objects) {
87
}
88 89 90 91 92 93
#undef INITIALIZE_SINGLETON


StackFrameIterator::StackFrameIterator(Isolate* isolate)
    : StackFrameIteratorBase(isolate, true) {
  Reset(isolate->thread_local_top());
94
}
95

96 97 98 99 100

StackFrameIterator::StackFrameIterator(Isolate* isolate, ThreadLocalTop* t)
    : StackFrameIteratorBase(isolate, true) {
  Reset(t);
}
101 102


103
void StackFrameIterator::Advance() {
104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125
  ASSERT(!done());
  // Compute the state of the calling frame before restoring
  // callee-saved registers and unwinding handlers. This allows the
  // frame code that computes the caller state to access the top
  // handler and the value of any callee-saved register if needed.
  StackFrame::State state;
  StackFrame::Type type = frame_->GetCallerState(&state);

  // Unwind handlers corresponding to the current frame.
  StackHandlerIterator it(frame_, handler_);
  while (!it.done()) it.Advance();
  handler_ = it.handler();

  // Advance to the calling frame.
  frame_ = SingletonFor(type, &state);

  // When we're done iterating over the stack frames, the handler
  // chain must have been completely unwound.
  ASSERT(!done() || handler_ == NULL);
}


126
void StackFrameIterator::Reset(ThreadLocalTop* top) {
127
  StackFrame::State state;
128 129 130
  StackFrame::Type type = ExitFrame::GetStateForFramePointer(
      Isolate::c_entry_fp(top), &state);
  handler_ = StackHandler::FromAddress(Isolate::handler(top));
131
  if (SingletonFor(type) == NULL) return;
132 133 134 135
  frame_ = SingletonFor(type, &state);
}


136
StackFrame* StackFrameIteratorBase::SingletonFor(StackFrame::Type type,
137
                                             StackFrame::State* state) {
138 139 140 141 142 143 144 145
  if (type == StackFrame::NONE) return NULL;
  StackFrame* result = SingletonFor(type);
  ASSERT(result != NULL);
  result->state_ = *state;
  return result;
}


146
StackFrame* StackFrameIteratorBase::SingletonFor(StackFrame::Type type) {
147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164
#define FRAME_TYPE_CASE(type, field) \
  case StackFrame::type: result = &field##_; break;

  StackFrame* result = NULL;
  switch (type) {
    case StackFrame::NONE: return NULL;
    STACK_FRAME_TYPE_LIST(FRAME_TYPE_CASE)
    default: break;
  }
  return result;

#undef FRAME_TYPE_CASE
}


// -------------------------------------------------------------------------


165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
JavaScriptFrameIterator::JavaScriptFrameIterator(
    Isolate* isolate, StackFrame::Id id)
    : iterator_(isolate) {
  while (!done()) {
    Advance();
    if (frame()->id() == id) return;
  }
}


void JavaScriptFrameIterator::Advance() {
  do {
    iterator_.Advance();
  } while (!iterator_.done() && !iterator_.frame()->is_java_script());
}


void JavaScriptFrameIterator::AdvanceToArgumentsFrame() {
  if (!frame()->has_adapted_arguments()) return;
  iterator_.Advance();
  ASSERT(iterator_.frame()->is_arguments_adaptor());
}


// -------------------------------------------------------------------------


192 193 194 195 196 197
StackTraceFrameIterator::StackTraceFrameIterator(Isolate* isolate)
    : JavaScriptFrameIterator(isolate) {
  if (!done() && !IsValidFrame()) Advance();
}


198
void StackTraceFrameIterator::Advance() {
199
  while (true) {
200 201
    JavaScriptFrameIterator::Advance();
    if (done()) return;
202
    if (IsValidFrame()) return;
203 204 205
  }
}

206

207 208
bool StackTraceFrameIterator::IsValidFrame() {
    if (!frame()->function()->IsJSFunction()) return false;
209
    Object* script = frame()->function()->shared()->script();
210 211 212 213 214
    // Don't show functions from native scripts to user.
    return (script->IsScript() &&
            Script::TYPE_NATIVE != Script::cast(script)->type()->value());
}

215

216 217 218 219
// -------------------------------------------------------------------------


SafeStackFrameIterator::SafeStackFrameIterator(
220
    Isolate* isolate,
221 222 223 224
    Address fp, Address sp, Address js_entry_sp)
    : StackFrameIteratorBase(isolate, false),
      low_bound_(sp),
      high_bound_(js_entry_sp),
225 226
      top_frame_type_(StackFrame::NONE),
      external_callback_scope_(isolate->external_callback_scope()) {
227 228 229 230 231
  StackFrame::State state;
  StackFrame::Type type;
  ThreadLocalTop* top = isolate->thread_local_top();
  if (IsValidTop(top)) {
    type = ExitFrame::GetStateForFramePointer(Isolate::c_entry_fp(top), &state);
232
    top_frame_type_ = type;
233 234 235 236
  } else if (IsValidStackAddress(fp)) {
    ASSERT(fp != NULL);
    state.fp = fp;
    state.sp = sp;
237
    state.pc_address = StackFrame::ResolveReturnAddressLocation(
238
        reinterpret_cast<Address*>(StandardFrame::ComputePCAddress(fp)));
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
    // StackFrame::ComputeType will read both kContextOffset and kMarkerOffset,
    // we check only that kMarkerOffset is within the stack bounds and do
    // compile time check that kContextOffset slot is pushed on the stack before
    // kMarkerOffset.
    STATIC_ASSERT(StandardFrameConstants::kMarkerOffset <
                  StandardFrameConstants::kContextOffset);
    Address frame_marker = fp + StandardFrameConstants::kMarkerOffset;
    if (IsValidStackAddress(frame_marker)) {
      type = StackFrame::ComputeType(this, &state);
      top_frame_type_ = type;
    } else {
      // Mark the frame as JAVA_SCRIPT if we cannot determine its type.
      // The frame anyways will be skipped.
      type = StackFrame::JAVA_SCRIPT;
      // Top frame is incomplete so we cannot reliably determine its type.
      top_frame_type_ = StackFrame::NONE;
    }
256 257 258 259 260
  } else {
    return;
  }
  if (SingletonFor(type) == NULL) return;
  frame_ = SingletonFor(type, &state);
261 262 263
  if (frame_ == NULL) return;

  Advance();
264

265 266 267 268 269 270 271
  if (frame_ != NULL && !frame_->is_exit() &&
      external_callback_scope_ != NULL &&
      external_callback_scope_->scope_address() < frame_->fp()) {
    // Skip top ExternalCallbackScope if we already advanced to a JS frame
    // under it. Sampler will anyways take this top external callback.
    external_callback_scope_ = external_callback_scope_->previous();
  }
272 273 274
}


275
bool SafeStackFrameIterator::IsValidTop(ThreadLocalTop* top) const {
276 277
  Address c_entry_fp = Isolate::c_entry_fp(top);
  if (!IsValidExitFrame(c_entry_fp)) return false;
278
  // There should be at least one JS_ENTRY stack handler.
279 280 281 282
  Address handler = Isolate::handler(top);
  if (handler == NULL) return false;
  // Check that there are no js frames on top of the native frames.
  return c_entry_fp < handler;
283 284 285
}


286
void SafeStackFrameIterator::AdvanceOneFrame() {
287
  ASSERT(!done());
288
  StackFrame* last_frame = frame_;
289
  Address last_sp = last_frame->sp(), last_fp = last_frame->fp();
290 291 292 293 294
  // Before advancing to the next stack frame, perform pointer validity tests.
  if (!IsValidFrame(last_frame) || !IsValidCaller(last_frame)) {
    frame_ = NULL;
    return;
  }
295

296 297 298 299 300 301 302 303 304 305
  // Advance to the previous frame.
  StackFrame::State state;
  StackFrame::Type type = frame_->GetCallerState(&state);
  frame_ = SingletonFor(type, &state);
  if (frame_ == NULL) return;

  // Check that we have actually moved to the previous frame in the stack.
  if (frame_->sp() < last_sp || frame_->fp() < last_fp) {
    frame_ = NULL;
  }
306 307 308 309
}


bool SafeStackFrameIterator::IsValidFrame(StackFrame* frame) const {
310
  return IsValidStackAddress(frame->sp()) && IsValidStackAddress(frame->fp());
311 312 313 314 315
}


bool SafeStackFrameIterator::IsValidCaller(StackFrame* frame) {
  StackFrame::State state;
316 317 318 319 320 321
  if (frame->is_entry() || frame->is_entry_construct()) {
    // See EntryFrame::GetCallerState. It computes the caller FP address
    // and calls ExitFrame::GetStateForFramePointer on it. We need to be
    // sure that caller FP address is valid.
    Address caller_fp = Memory::Address_at(
        frame->fp() + EntryFrameConstants::kCallerFPOffset);
322
    if (!IsValidExitFrame(caller_fp)) return false;
323 324 325 326 327 328 329 330 331 332
  } else if (frame->is_arguments_adaptor()) {
    // See ArgumentsAdaptorFrame::GetCallerStackPointer. It assumes that
    // the number of arguments is stored on stack as Smi. We need to check
    // that it really an Smi.
    Object* number_of_args = reinterpret_cast<ArgumentsAdaptorFrame*>(frame)->
        GetExpression(0);
    if (!number_of_args->IsSmi()) {
      return false;
    }
  }
333 334
  frame->ComputeCallerState(&state);
  return IsValidStackAddress(state.sp) && IsValidStackAddress(state.fp) &&
335 336 337 338 339 340 341 342 343 344 345 346 347 348
      SingletonFor(frame->GetCallerState(&state)) != NULL;
}


bool SafeStackFrameIterator::IsValidExitFrame(Address fp) const {
  if (!IsValidStackAddress(fp)) return false;
  Address sp = ExitFrame::ComputeStackPointer(fp);
  if (!IsValidStackAddress(sp)) return false;
  StackFrame::State state;
  ExitFrame::FillState(fp, sp, &state);
  if (!IsValidStackAddress(reinterpret_cast<Address>(state.pc_address))) {
    return false;
  }
  return *state.pc_address != NULL;
349 350 351
}


352
void SafeStackFrameIterator::Advance() {
353
  while (true) {
354 355
    AdvanceOneFrame();
    if (done()) return;
356
    if (frame_->is_java_script()) return;
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374
    if (frame_->is_exit() && external_callback_scope_) {
      // Some of the EXIT frames may have ExternalCallbackScope allocated on
      // top of them. In that case the scope corresponds to the first EXIT
      // frame beneath it. There may be other EXIT frames on top of the
      // ExternalCallbackScope, just skip them as we cannot collect any useful
      // information about them.
      if (external_callback_scope_->scope_address() < frame_->fp()) {
        Address* callback_address =
            external_callback_scope_->callback_address();
        if (*callback_address != NULL) {
          frame_->state_.pc_address = callback_address;
        }
        external_callback_scope_ = external_callback_scope_->previous();
        ASSERT(external_callback_scope_ == NULL ||
               external_callback_scope_->scope_address() > frame_->fp());
        return;
      }
    }
375
  }
376 377 378
}


379 380 381
// -------------------------------------------------------------------------


382
Code* StackFrame::GetSafepointData(Isolate* isolate,
383
                                   Address inner_pointer,
384
                                   SafepointEntry* safepoint_entry,
385
                                   unsigned* stack_slots) {
386 387
  InnerPointerToCodeCache::InnerPointerToCodeCacheEntry* entry =
      isolate->inner_pointer_to_code_cache()->GetCacheEntry(inner_pointer);
388
  if (!entry->safepoint_entry.is_valid()) {
389
    entry->safepoint_entry = entry->code->GetSafepointEntry(inner_pointer);
390
    ASSERT(entry->safepoint_entry.is_valid());
391
  } else {
392 393
    ASSERT(entry->safepoint_entry.Equals(
        entry->code->GetSafepointEntry(inner_pointer)));
394 395 396 397
  }

  // Fill in the results and return the code.
  Code* code = entry->code;
398
  *safepoint_entry = entry->safepoint_entry;
399 400 401 402 403
  *stack_slots = code->stack_slots();
  return code;
}


404 405 406 407 408
bool StackFrame::HasHandler() const {
  StackHandlerIterator it(this, top_handler());
  return !it.done();
}

409

410 411 412 413 414
#ifdef DEBUG
static bool GcSafeCodeContains(HeapObject* object, Address addr);
#endif


415 416 417 418
void StackFrame::IteratePc(ObjectVisitor* v,
                           Address* pc_address,
                           Code* holder) {
  Address pc = *pc_address;
419
  ASSERT(GcSafeCodeContains(holder, pc));
420
  unsigned pc_offset = static_cast<unsigned>(pc - holder->instruction_start());
421 422 423 424 425 426
  Object* code = holder;
  v->VisitPointer(&code);
  if (code != holder) {
    holder = reinterpret_cast<Code*>(code);
    pc = holder->instruction_start() + pc_offset;
    *pc_address = pc;
427 428 429 430
  }
}


431 432
void StackFrame::SetReturnAddressLocationResolver(
    ReturnAddressLocationResolver resolver) {
433 434
  ASSERT(return_address_location_resolver_ == NULL);
  return_address_location_resolver_ = resolver;
435 436 437
}


438
StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
439
                                         State* state) {
440 441 442
  ASSERT(state->fp != NULL);
  if (StandardFrame::IsArgumentsAdaptorFrame(state->fp)) {
    return ARGUMENTS_ADAPTOR;
443
  }
444 445 446 447 448
  // The marker and function offsets overlap. If the marker isn't a
  // smi then the frame is a JavaScript frame -- and the marker is
  // really the function.
  const int offset = StandardFrameConstants::kMarkerOffset;
  Object* marker = Memory::Object_at(state->fp + offset);
449 450 451 452 453
  if (!marker->IsSmi()) {
    // If we're using a "safe" stack iterator, we treat optimized
    // frames as normal JavaScript frames to avoid having to look
    // into the heap to determine the state. This is safe as long
    // as nobody tries to GC...
454 455 456
    if (!iterator->can_access_heap_objects_) return JAVA_SCRIPT;
    Code::Kind kind = GetContainingCode(iterator->isolate(),
                                        *(state->pc_address))->kind();
457 458 459
    ASSERT(kind == Code::FUNCTION || kind == Code::OPTIMIZED_FUNCTION);
    return (kind == Code::OPTIMIZED_FUNCTION) ? OPTIMIZED : JAVA_SCRIPT;
  }
460
  return static_cast<StackFrame::Type>(Smi::cast(marker)->value());
461 462 463
}


464 465 466 467 468 469
#ifdef DEBUG
bool StackFrame::can_access_heap_objects() const {
  return iterator_->can_access_heap_objects_;
}
#endif

470

471 472
StackFrame::Type StackFrame::GetCallerState(State* state) const {
  ComputeCallerState(state);
473
  return ComputeType(iterator_, state);
474 475 476
}


477
Address StackFrame::UnpaddedFP() const {
478
#if V8_TARGET_ARCH_IA32
479 480 481 482 483 484 485 486 487 488 489 490
  if (!is_optimized()) return fp();
  int32_t alignment_state = Memory::int32_at(
    fp() + JavaScriptFrameConstants::kDynamicAlignmentStateOffset);

  return (alignment_state == kAlignmentPaddingPushed) ?
    (fp() + kPointerSize) : fp();
#else
  return fp();
#endif
}


491
Code* EntryFrame::unchecked_code() const {
492
  return isolate()->heap()->js_entry_code();
493 494 495
}


496 497 498 499 500
void EntryFrame::ComputeCallerState(State* state) const {
  GetCallerState(state);
}


501 502 503 504 505 506
void EntryFrame::SetCallerFp(Address caller_fp) {
  const int offset = EntryFrameConstants::kCallerFPOffset;
  Memory::Address_at(this->fp() + offset) = caller_fp;
}


507 508 509 510 511 512 513
StackFrame::Type EntryFrame::GetCallerState(State* state) const {
  const int offset = EntryFrameConstants::kCallerFPOffset;
  Address fp = Memory::Address_at(this->fp() + offset);
  return ExitFrame::GetStateForFramePointer(fp, state);
}


514
Code* EntryConstructFrame::unchecked_code() const {
515
  return isolate()->heap()->js_construct_entry_code();
516 517 518
}


519 520 521 522 523 524
Object*& ExitFrame::code_slot() const {
  const int offset = ExitFrameConstants::kCodeOffset;
  return Memory::Object_at(fp() + offset);
}


525 526
Code* ExitFrame::unchecked_code() const {
  return reinterpret_cast<Code*>(code_slot());
527 528 529
}


530
void ExitFrame::ComputeCallerState(State* state) const {
531
  // Set up the caller state.
532
  state->sp = caller_sp();
533
  state->fp = Memory::Address_at(fp() + ExitFrameConstants::kCallerFPOffset);
534 535
  state->pc_address = ResolveReturnAddressLocation(
      reinterpret_cast<Address*>(fp() + ExitFrameConstants::kCallerPCOffset));
536 537 538
}


539 540 541 542 543
void ExitFrame::SetCallerFp(Address caller_fp) {
  Memory::Address_at(fp() + ExitFrameConstants::kCallerFPOffset) = caller_fp;
}


544 545 546
void ExitFrame::Iterate(ObjectVisitor* v) const {
  // The arguments are traversed as part of the expression stack of
  // the calling frame.
547
  IteratePc(v, pc_address(), LookupCode());
548 549 550 551
  v->VisitPointer(&code_slot());
}


552
Address ExitFrame::GetCallerStackPointer() const {
553
  return fp() + ExitFrameConstants::kCallerSPDisplacement;
554 555 556
}


557 558 559 560 561 562 563 564 565
StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
  if (fp == 0) return NONE;
  Address sp = ComputeStackPointer(fp);
  FillState(fp, sp, state);
  ASSERT(*state->pc_address != NULL);
  return EXIT;
}


566 567 568 569 570
Address ExitFrame::ComputeStackPointer(Address fp) {
  return Memory::Address_at(fp + ExitFrameConstants::kSPOffset);
}


571 572 573
void ExitFrame::FillState(Address fp, Address sp, State* state) {
  state->sp = sp;
  state->fp = fp;
574
  state->pc_address = ResolveReturnAddressLocation(
575
      reinterpret_cast<Address*>(sp - 1 * kPCOnStackSize));
576 577 578
}


579
Address StandardFrame::GetExpressionAddress(int n) const {
580 581
  const int offset = StandardFrameConstants::kExpressionsOffset;
  return fp() + offset - n * kPointerSize;
582 583 584
}


585 586 587 588 589 590 591 592 593 594 595
Object* StandardFrame::GetExpression(Address fp, int index) {
  return Memory::Object_at(GetExpressionAddress(fp, index));
}


Address StandardFrame::GetExpressionAddress(Address fp, int n) {
  const int offset = StandardFrameConstants::kExpressionsOffset;
  return fp + offset - n * kPointerSize;
}


596 597 598 599 600 601 602
int StandardFrame::ComputeExpressionsCount() const {
  const int offset =
      StandardFrameConstants::kExpressionsOffset + kPointerSize;
  Address base = fp() + offset;
  Address limit = sp();
  ASSERT(base >= limit);  // stack grows downwards
  // Include register-allocated locals in number of expressions.
603
  return static_cast<int>((base - limit) / kPointerSize);
604 605 606
}


607
void StandardFrame::ComputeCallerState(State* state) const {
608 609
  state->sp = caller_sp();
  state->fp = caller_fp();
610 611
  state->pc_address = ResolveReturnAddressLocation(
      reinterpret_cast<Address*>(ComputePCAddress(fp())));
612 613 614
}


615 616 617 618 619 620
void StandardFrame::SetCallerFp(Address caller_fp) {
  Memory::Address_at(fp() + StandardFrameConstants::kCallerFPOffset) =
      caller_fp;
}


621 622 623 624 625 626 627 628 629
bool StandardFrame::IsExpressionInsideHandler(int n) const {
  Address address = GetExpressionAddress(n);
  for (StackHandlerIterator it(this, top_handler()); !it.done(); it.Advance()) {
    if (it.handler()->includes(address)) return true;
  }
  return false;
}


630
void StandardFrame::IterateCompiledFrame(ObjectVisitor* v) const {
631 632
  // Make sure that we're not doing "safe" stack frame iteration. We cannot
  // possibly find pointers in optimized frames in that state.
633
  ASSERT(can_access_heap_objects());
634 635 636

  // Compute the safepoint information.
  unsigned stack_slots = 0;
637
  SafepointEntry safepoint_entry;
638
  Code* code = StackFrame::GetSafepointData(
639
      isolate(), pc(), &safepoint_entry, &stack_slots);
640 641
  unsigned slot_space = stack_slots * kPointerSize;

642
  // Visit the outgoing parameters.
643 644 645 646
  Object** parameters_base = &Memory::Object_at(sp());
  Object** parameters_limit = &Memory::Object_at(
      fp() + JavaScriptFrameConstants::kFunctionOffset - slot_space);

647 648 649 650 651 652 653
  // Visit the parameters that may be on top of the saved registers.
  if (safepoint_entry.argument_count() > 0) {
    v->VisitPointers(parameters_base,
                     parameters_base + safepoint_entry.argument_count());
    parameters_base += safepoint_entry.argument_count();
  }

654
  // Skip saved double registers.
655
  if (safepoint_entry.has_doubles()) {
656 657
    // Number of doubles not known at snapshot time.
    ASSERT(!Serializer::enabled());
658
    parameters_base += DoubleRegister::NumAllocatableRegisters() *
659 660 661
        kDoubleSize / kPointerSize;
  }

662
  // Visit the registers that contain pointers if any.
663
  if (safepoint_entry.HasRegisters()) {
664
    for (int i = kNumSafepointRegisters - 1; i >=0; i--) {
665
      if (safepoint_entry.HasRegisterAt(i)) {
666 667 668 669 670 671 672 673 674
        int reg_stack_index = MacroAssembler::SafepointRegisterStackIndex(i);
        v->VisitPointer(parameters_base + reg_stack_index);
      }
    }
    // Skip the words containing the register values.
    parameters_base += kNumSafepointRegisters;
  }

  // We're done dealing with the register bits.
675 676
  uint8_t* safepoint_bits = safepoint_entry.bits();
  safepoint_bits += kNumSafepointRegisters >> kBitsPerByteLog2;
677 678 679 680 681 682 683 684

  // Visit the rest of the parameters.
  v->VisitPointers(parameters_base, parameters_limit);

  // Visit pointer spill slots and locals.
  for (unsigned index = 0; index < stack_slots; index++) {
    int byte_index = index >> kBitsPerByteLog2;
    int bit_index = index & (kBitsPerByte - 1);
685
    if ((safepoint_bits[byte_index] & (1U << bit_index)) != 0) {
686 687 688 689
      v->VisitPointer(parameters_limit + index);
    }
  }

690 691
  // Visit the return address in the callee and incoming arguments.
  IteratePc(v, pc_address(), code);
692 693 694 695 696 697 698

  // Visit the context in stub frame and JavaScript frame.
  // Visit the function in JavaScript frame.
  Object** fixed_base = &Memory::Object_at(
      fp() + StandardFrameConstants::kMarkerOffset);
  Object** fixed_limit = &Memory::Object_at(fp());
  v->VisitPointers(fixed_base, fixed_limit);
699 700 701 702 703 704 705 706 707
}


void StubFrame::Iterate(ObjectVisitor* v) const {
  IterateCompiledFrame(v);
}


Code* StubFrame::unchecked_code() const {
708
  return static_cast<Code*>(isolate()->FindCodeObject(pc()));
709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729
}


Address StubFrame::GetCallerStackPointer() const {
  return fp() + ExitFrameConstants::kCallerSPDisplacement;
}


int StubFrame::GetNumberOfIncomingArguments() const {
  return 0;
}


void OptimizedFrame::Iterate(ObjectVisitor* v) const {
#ifdef DEBUG
  // Make sure that optimized frames do not contain any stack handlers.
  StackHandlerIterator it(this, top_handler());
  ASSERT(it.done());
#endif

  IterateCompiledFrame(v);
730 731 732
}


733 734 735 736 737
void JavaScriptFrame::SetParameterValue(int index, Object* value) const {
  Memory::Object_at(GetParameterSlot(index)) = value;
}


738
bool JavaScriptFrame::IsConstructor() const {
739 740 741 742 743 744
  Address fp = caller_fp();
  if (has_adapted_arguments()) {
    // Skip the arguments adaptor frame and look at the real caller.
    fp = Memory::Address_at(fp + StandardFrameConstants::kCallerFPOffset);
  }
  return IsConstructFrame(fp);
745 746 747
}


748 749 750 751 752 753 754 755 756 757
int JavaScriptFrame::GetArgumentsLength() const {
  // If there is an arguments adaptor frame get the arguments length from it.
  if (has_adapted_arguments()) {
    return Smi::cast(GetExpression(caller_fp(), 0))->value();
  } else {
    return GetNumberOfIncomingArguments();
  }
}


758
Code* JavaScriptFrame::unchecked_code() const {
759
  return function()->code();
760 761 762
}


763
int JavaScriptFrame::GetNumberOfIncomingArguments() const {
764
  ASSERT(can_access_heap_objects() &&
765 766
         isolate()->heap()->gc_state() == Heap::NOT_IN_GC);

767
  return function()->shared()->formal_parameter_count();
768 769 770
}


771
Address JavaScriptFrame::GetCallerStackPointer() const {
772
  return fp() + StandardFrameConstants::kCallerSPOffset;
773 774 775
}


776 777
void JavaScriptFrame::GetFunctions(List<JSFunction*>* functions) {
  ASSERT(functions->length() == 0);
778
  functions->Add(function());
779 780 781 782 783
}


void JavaScriptFrame::Summarize(List<FrameSummary>* functions) {
  ASSERT(functions->length() == 0);
784
  Code* code_pointer = LookupCode();
785
  int offset = static_cast<int>(pc() - code_pointer->address());
786
  FrameSummary summary(receiver(),
787
                       function(),
788 789 790 791 792 793 794
                       code_pointer,
                       offset,
                       IsConstructor());
  functions->Add(summary);
}


795 796
void JavaScriptFrame::PrintTop(Isolate* isolate,
                               FILE* file,
797 798 799
                               bool print_args,
                               bool print_line_number) {
  // constructor calls
800
  HandleScope scope(isolate);
801
  DisallowHeapAllocation no_allocation;
802
  JavaScriptFrameIterator it(isolate);
803 804 805 806 807
  while (!it.done()) {
    if (it.frame()->is_java_script()) {
      JavaScriptFrame* frame = it.frame();
      if (frame->IsConstructor()) PrintF(file, "new ");
      // function name
808 809 810 811 812 813 814 815 816
      JSFunction* fun = frame->function();
      fun->PrintName();
      Code* js_code = frame->unchecked_code();
      Address pc = frame->pc();
      int code_offset =
          static_cast<int>(pc - js_code->instruction_start());
      PrintF("+%d", code_offset);
      SharedFunctionInfo* shared = fun->shared();
      if (print_line_number) {
817
        Code* code = Code::cast(isolate->FindCodeObject(pc));
818 819 820 821 822 823 824 825 826 827 828 829
        int source_pos = code->SourcePosition(pc);
        Object* maybe_script = shared->script();
        if (maybe_script->IsScript()) {
          Handle<Script> script(Script::cast(maybe_script));
          int line = GetScriptLineNumberSafe(script, source_pos) + 1;
          Object* script_name_raw = script->name();
          if (script_name_raw->IsString()) {
            String* script_name = String::cast(script->name());
            SmartArrayPointer<char> c_script_name =
                script_name->ToCString(DISALLOW_NULLS,
                                       ROBUST_STRING_TRAVERSAL);
            PrintF(file, " at %s:%d", *c_script_name, line);
830
          } else {
831
            PrintF(file, " at <unknown>:%d", line);
832
          }
833 834
        } else {
          PrintF(file, " at <unknown>:<unknown>");
835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857
        }
      }

      if (print_args) {
        // function arguments
        // (we are intentionally only printing the actually
        // supplied parameters, not all parameters required)
        PrintF(file, "(this=");
        frame->receiver()->ShortPrint(file);
        const int length = frame->ComputeParametersCount();
        for (int i = 0; i < length; i++) {
          PrintF(file, ", ");
          frame->GetParameter(i)->ShortPrint(file);
        }
        PrintF(file, ")");
      }
      break;
    }
    it.Advance();
  }
}


858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
void JavaScriptFrame::SaveOperandStack(FixedArray* store,
                                       int* stack_handler_index) const {
  int operands_count = store->length();
  ASSERT_LE(operands_count, ComputeOperandsCount());

  // Visit the stack in LIFO order, saving operands and stack handlers into the
  // array.  The saved stack handlers store a link to the next stack handler,
  // which will allow RestoreOperandStack to rewind the handlers.
  StackHandlerIterator it(this, top_handler());
  int i = operands_count - 1;
  *stack_handler_index = -1;
  for (; !it.done(); it.Advance()) {
    StackHandler* handler = it.handler();
    // Save operands pushed after the handler was pushed.
    for (; GetOperandSlot(i) < handler->address(); i--) {
      store->set(i, GetOperand(i));
    }
    ASSERT_GE(i + 1, StackHandlerConstants::kSlotCount);
    ASSERT_EQ(handler->address(), GetOperandSlot(i));
    int next_stack_handler_index = i + 1 - StackHandlerConstants::kSlotCount;
    handler->Unwind(isolate(), store, next_stack_handler_index,
                    *stack_handler_index);
    *stack_handler_index = next_stack_handler_index;
    i -= StackHandlerConstants::kSlotCount;
  }

  // Save any remaining operands.
  for (; i >= 0; i--) {
    store->set(i, GetOperand(i));
  }
}


void JavaScriptFrame::RestoreOperandStack(FixedArray* store,
                                          int stack_handler_index) {
  int operands_count = store->length();
  ASSERT_LE(operands_count, ComputeOperandsCount());
  int i = 0;
  while (i <= stack_handler_index) {
    if (i < stack_handler_index) {
      // An operand.
      ASSERT_EQ(GetOperand(i), isolate()->heap()->the_hole_value());
      Memory::Object_at(GetOperandSlot(i)) = store->get(i);
      i++;
    } else {
      // A stack handler.
      ASSERT_EQ(i, stack_handler_index);
      // The FixedArray store grows up.  The stack grows down.  So the operand
      // slot for i actually points to the bottom of the top word in the
      // handler.  The base of the StackHandler* is the address of the bottom
      // word, which will be the last slot that is in the handler.
      int handler_slot_index = i + StackHandlerConstants::kSlotCount - 1;
      StackHandler *handler =
          StackHandler::FromAddress(GetOperandSlot(handler_slot_index));
      stack_handler_index = handler->Rewind(isolate(), store, i, fp());
      i += StackHandlerConstants::kSlotCount;
    }
  }

  for (; i < operands_count; i++) {
    ASSERT_EQ(GetOperand(i), isolate()->heap()->the_hole_value());
    Memory::Object_at(GetOperandSlot(i)) = store->get(i);
  }
}


924 925 926 927 928 929 930 931 932 933 934 935 936
void FrameSummary::Print() {
  PrintF("receiver: ");
  receiver_->ShortPrint();
  PrintF("\nfunction: ");
  function_->shared()->DebugName()->ShortPrint();
  PrintF("\ncode: ");
  code_->ShortPrint();
  if (code_->kind() == Code::FUNCTION) PrintF(" NON-OPT");
  if (code_->kind() == Code::OPTIMIZED_FUNCTION) PrintF(" OPT");
  PrintF("\npc: %d\n", offset_);
}


937 938 939
JSFunction* OptimizedFrame::LiteralAt(FixedArray* literal_array,
                                      int literal_id) {
  if (literal_id == Translation::kSelfLiteralId) {
940
    return function();
941 942 943 944 945 946
  }

  return JSFunction::cast(literal_array->get(literal_id));
}


947 948 949 950
void OptimizedFrame::Summarize(List<FrameSummary>* frames) {
  ASSERT(frames->length() == 0);
  ASSERT(is_optimized());

951
  int deopt_index = Safepoint::kNoDeoptimizationIndex;
952
  DeoptimizationInputData* data = GetDeoptimizationData(&deopt_index);
953
  FixedArray* literal_array = data->LiteralArray();
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968

  // BUG(3243555): Since we don't have a lazy-deopt registered at
  // throw-statements, we can't use the translation at the call-site of
  // throw. An entry with no deoptimization index indicates a call-site
  // without a lazy-deopt. As a consequence we are not allowed to inline
  // functions containing throw.
  if (deopt_index == Safepoint::kNoDeoptimizationIndex) {
    JavaScriptFrame::Summarize(frames);
    return;
  }

  TranslationIterator it(data->TranslationByteArray(),
                         data->TranslationIndex(deopt_index)->value());
  Translation::Opcode opcode = static_cast<Translation::Opcode>(it.Next());
  ASSERT(opcode == Translation::BEGIN);
969 970
  it.Next();  // Drop frame count.
  int jsframe_count = it.Next();
971 972 973

  // We create the summary in reverse order because the frames
  // in the deoptimization translation are ordered bottom-to-top.
974
  bool is_constructor = IsConstructor();
975
  int i = jsframe_count;
976 977
  while (i > 0) {
    opcode = static_cast<Translation::Opcode>(it.Next());
978
    if (opcode == Translation::JS_FRAME) {
979
      i--;
980
      BailoutId ast_id = BailoutId(it.Next());
981
      JSFunction* function = LiteralAt(literal_array, it.Next());
982 983 984 985 986 987
      it.Next();  // Skip height.

      // The translation commands are ordered and the receiver is always
      // at the first position. Since we are always at a call when we need
      // to construct a stack trace, the receiver is always in a stack slot.
      opcode = static_cast<Translation::Opcode>(it.Next());
988 989 990
      ASSERT(opcode == Translation::STACK_SLOT ||
             opcode == Translation::LITERAL);
      int index = it.Next();
991 992 993

      // Get the correct receiver in the optimized frame.
      Object* receiver = NULL;
994 995
      if (opcode == Translation::LITERAL) {
        receiver = data->LiteralArray()->get(index);
996
      } else {
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011
        // Positive index means the value is spilled to the locals
        // area. Negative means it is stored in the incoming parameter
        // area.
        if (index >= 0) {
          receiver = GetExpression(index);
        } else {
          // Index -1 overlaps with last parameter, -n with the first parameter,
          // (-n - 1) with the receiver with n being the number of parameters
          // of the outermost, optimized frame.
          int parameter_count = ComputeParametersCount();
          int parameter_index = index + parameter_count;
          receiver = (parameter_index == -1)
              ? this->receiver()
              : this->GetParameter(parameter_index);
        }
1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
      }

      Code* code = function->shared()->code();
      DeoptimizationOutputData* output_data =
          DeoptimizationOutputData::cast(code->deoptimization_data());
      unsigned entry = Deoptimizer::GetOutputInfo(output_data,
                                                  ast_id,
                                                  function->shared());
      unsigned pc_offset =
          FullCodeGenerator::PcField::decode(entry) + Code::kHeaderSize;
      ASSERT(pc_offset > 0);

      FrameSummary summary(receiver, function, code, pc_offset, is_constructor);
      frames->Add(summary);
1026 1027 1028 1029 1030 1031
      is_constructor = false;
    } else if (opcode == Translation::CONSTRUCT_STUB_FRAME) {
      // The next encountered JS_FRAME will be marked as a constructor call.
      it.Skip(Translation::NumberOfOperandsFor(opcode));
      ASSERT(!is_constructor);
      is_constructor = true;
1032 1033 1034 1035 1036
    } else {
      // Skip over operands to advance to the next opcode.
      it.Skip(Translation::NumberOfOperandsFor(opcode));
    }
  }
1037
  ASSERT(!is_constructor);
1038 1039 1040 1041 1042 1043 1044
}


DeoptimizationInputData* OptimizedFrame::GetDeoptimizationData(
    int* deopt_index) {
  ASSERT(is_optimized());

1045
  JSFunction* opt_function = function();
1046 1047 1048 1049 1050 1051
  Code* code = opt_function->code();

  // The code object may have been replaced by lazy deoptimization. Fall
  // back to a slow search in this case to find the original optimized
  // code object.
  if (!code->contains(pc())) {
1052 1053
    code = isolate()->inner_pointer_to_code_cache()->
        GcSafeFindCodeForInnerPointer(pc());
1054 1055 1056 1057
  }
  ASSERT(code != NULL);
  ASSERT(code->kind() == Code::OPTIMIZED_FUNCTION);

1058 1059
  SafepointEntry safepoint_entry = code->GetSafepointEntry(pc());
  *deopt_index = safepoint_entry.deoptimization_index();
1060
  ASSERT(*deopt_index != Safepoint::kNoDeoptimizationIndex);
1061 1062 1063 1064 1065

  return DeoptimizationInputData::cast(code->deoptimization_data());
}


1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
int OptimizedFrame::GetInlineCount() {
  ASSERT(is_optimized());

  int deopt_index = Safepoint::kNoDeoptimizationIndex;
  DeoptimizationInputData* data = GetDeoptimizationData(&deopt_index);

  TranslationIterator it(data->TranslationByteArray(),
                         data->TranslationIndex(deopt_index)->value());
  Translation::Opcode opcode = static_cast<Translation::Opcode>(it.Next());
  ASSERT(opcode == Translation::BEGIN);
  USE(opcode);
1077 1078 1079
  it.Next();  // Drop frame count.
  int jsframe_count = it.Next();
  return jsframe_count;
1080 1081 1082
}


1083 1084 1085 1086
void OptimizedFrame::GetFunctions(List<JSFunction*>* functions) {
  ASSERT(functions->length() == 0);
  ASSERT(is_optimized());

1087
  int deopt_index = Safepoint::kNoDeoptimizationIndex;
1088
  DeoptimizationInputData* data = GetDeoptimizationData(&deopt_index);
1089
  FixedArray* literal_array = data->LiteralArray();
1090 1091 1092 1093 1094

  TranslationIterator it(data->TranslationByteArray(),
                         data->TranslationIndex(deopt_index)->value());
  Translation::Opcode opcode = static_cast<Translation::Opcode>(it.Next());
  ASSERT(opcode == Translation::BEGIN);
1095 1096
  it.Next();  // Drop frame count.
  int jsframe_count = it.Next();
1097 1098 1099

  // We insert the frames in reverse order because the frames
  // in the deoptimization translation are ordered bottom-to-top.
1100
  while (jsframe_count > 0) {
1101
    opcode = static_cast<Translation::Opcode>(it.Next());
1102 1103
    if (opcode == Translation::JS_FRAME) {
      jsframe_count--;
1104
      it.Next();  // Skip ast id.
1105
      JSFunction* function = LiteralAt(literal_array, it.Next());
1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
      it.Next();  // Skip height.
      functions->Add(function);
    } else {
      // Skip over operands to advance to the next opcode.
      it.Skip(Translation::NumberOfOperandsFor(opcode));
    }
  }
}


1116 1117 1118 1119 1120
int ArgumentsAdaptorFrame::GetNumberOfIncomingArguments() const {
  return Smi::cast(GetExpression(0))->value();
}


1121
Address ArgumentsAdaptorFrame::GetCallerStackPointer() const {
1122
  return fp() + StandardFrameConstants::kCallerSPOffset;
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132
}


Address InternalFrame::GetCallerStackPointer() const {
  // Internal frames have no arguments. The stack pointer of the
  // caller is at a fixed offset from the frame pointer.
  return fp() + StandardFrameConstants::kCallerSPOffset;
}


1133
Code* ArgumentsAdaptorFrame::unchecked_code() const {
1134
  return isolate()->builtins()->builtin(
1135
      Builtins::kArgumentsAdaptorTrampoline);
1136 1137 1138
}


1139
Code* InternalFrame::unchecked_code() const {
1140 1141 1142
  const int offset = InternalFrameConstants::kCodeOffset;
  Object* code = Memory::Object_at(fp() + offset);
  ASSERT(code != NULL);
1143
  return reinterpret_cast<Code*>(code);
1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
}


void StackFrame::PrintIndex(StringStream* accumulator,
                            PrintMode mode,
                            int index) {
  accumulator->Add((mode == OVERVIEW) ? "%5d: " : "[%d]: ", index);
}


void JavaScriptFrame::Print(StringStream* accumulator,
                            PrintMode mode,
                            int index) const {
1157
  HandleScope scope(isolate());
1158
  Object* receiver = this->receiver();
1159
  JSFunction* function = this->function();
1160 1161 1162 1163 1164 1165

  accumulator->PrintSecurityTokenIfChanged(function);
  PrintIndex(accumulator, mode, index);
  Code* code = NULL;
  if (IsConstructor()) accumulator->Add("new ");
  accumulator->PrintFunction(function, receiver, &code);
1166

1167 1168 1169 1170
  // Get scope information for nicer output, if possible. If code is NULL, or
  // doesn't contain scope info, scope_info will return 0 for the number of
  // parameters, stack local variables, context local variables, stack slots,
  // or context slots.
1171
  Handle<ScopeInfo> scope_info(ScopeInfo::Empty(isolate()));
1172

1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190
  Handle<SharedFunctionInfo> shared(function->shared());
  scope_info = Handle<ScopeInfo>(shared->scope_info());
  Object* script_obj = shared->script();
  if (script_obj->IsScript()) {
    Handle<Script> script(Script::cast(script_obj));
    accumulator->Add(" [");
    accumulator->PrintName(script->name());

    Address pc = this->pc();
    if (code != NULL && code->kind() == Code::FUNCTION &&
        pc >= code->instruction_start() && pc < code->instruction_end()) {
      int source_pos = code->SourcePosition(pc);
      int line = GetScriptLineNumberSafe(script, source_pos) + 1;
      accumulator->Add(":%d", line);
    } else {
      int function_start_pos = shared->start_position();
      int line = GetScriptLineNumberSafe(script, function_start_pos) + 1;
      accumulator->Add(":~%d", line);
1191
    }
1192 1193

    accumulator->Add("] ");
1194 1195
  }

1196 1197 1198 1199 1200 1201 1202 1203 1204
  accumulator->Add("(this=%o", receiver);

  // Print the parameters.
  int parameters_count = ComputeParametersCount();
  for (int i = 0; i < parameters_count; i++) {
    accumulator->Add(",");
    // If we have a name for the parameter we print it. Nameless
    // parameters are either because we have more actual parameters
    // than formal parameters or because we have no scope information.
1205 1206
    if (i < scope_info->ParameterCount()) {
      accumulator->PrintName(scope_info->ParameterName(i));
1207 1208 1209 1210 1211 1212 1213 1214 1215 1216
      accumulator->Add("=");
    }
    accumulator->Add("%o", GetParameter(i));
  }

  accumulator->Add(")");
  if (mode == OVERVIEW) {
    accumulator->Add("\n");
    return;
  }
1217 1218 1219 1220
  if (is_optimized()) {
    accumulator->Add(" {\n// optimized frame\n}\n");
    return;
  }
1221 1222 1223
  accumulator->Add(" {\n");

  // Compute the number of locals and expression stack elements.
1224 1225
  int stack_locals_count = scope_info->StackLocalCount();
  int heap_locals_count = scope_info->ContextLocalCount();
1226 1227 1228 1229 1230 1231 1232 1233
  int expressions_count = ComputeExpressionsCount();

  // Print stack-allocated local variables.
  if (stack_locals_count > 0) {
    accumulator->Add("  // stack-allocated locals\n");
  }
  for (int i = 0; i < stack_locals_count; i++) {
    accumulator->Add("  var ");
1234
    accumulator->PrintName(scope_info->StackLocalName(i));
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
    accumulator->Add(" = ");
    if (i < expressions_count) {
      accumulator->Add("%o", GetExpression(i));
    } else {
      accumulator->Add("// no expression found - inconsistent frame?");
    }
    accumulator->Add("\n");
  }

  // Try to get hold of the context of this frame.
  Context* context = NULL;
  if (this->context() != NULL && this->context()->IsContext()) {
    context = Context::cast(this->context());
  }

  // Print heap-allocated local variables.
1251
  if (heap_locals_count > 0) {
1252 1253
    accumulator->Add("  // heap-allocated locals\n");
  }
1254
  for (int i = 0; i < heap_locals_count; i++) {
1255
    accumulator->Add("  var ");
1256
    accumulator->PrintName(scope_info->ContextLocalName(i));
1257 1258 1259
    accumulator->Add(" = ");
    if (context != NULL) {
      if (i < context->length()) {
1260
        accumulator->Add("%o", context->get(Context::MIN_CONTEXT_SLOTS + i));
1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271
      } else {
        accumulator->Add(
            "// warning: missing context slot - inconsistent frame?");
      }
    } else {
      accumulator->Add("// warning: no context found - inconsistent frame?");
    }
    accumulator->Add("\n");
  }

  // Print the expression stack.
1272
  int expressions_start = stack_locals_count;
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
  if (expressions_start < expressions_count) {
    accumulator->Add("  // expression stack (top to bottom)\n");
  }
  for (int i = expressions_count - 1; i >= expressions_start; i--) {
    if (IsExpressionInsideHandler(i)) continue;
    accumulator->Add("  [%02d] : %o\n", i, GetExpression(i));
  }

  // Print details about the function.
  if (FLAG_max_stack_trace_source_length != 0 && code != NULL) {
1283
    SharedFunctionInfo* shared = function->shared();
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
    accumulator->Add("--------- s o u r c e   c o d e ---------\n");
    shared->SourceCodePrint(accumulator, FLAG_max_stack_trace_source_length);
    accumulator->Add("\n-----------------------------------------\n");
  }

  accumulator->Add("}\n\n");
}


void ArgumentsAdaptorFrame::Print(StringStream* accumulator,
                                  PrintMode mode,
                                  int index) const {
  int actual = ComputeParametersCount();
  int expected = -1;
1298 1299
  JSFunction* function = this->function();
  expected = function->shared()->formal_parameter_count();
1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326

  PrintIndex(accumulator, mode, index);
  accumulator->Add("arguments adaptor frame: %d->%d", actual, expected);
  if (mode == OVERVIEW) {
    accumulator->Add("\n");
    return;
  }
  accumulator->Add(" {\n");

  // Print actual arguments.
  if (actual > 0) accumulator->Add("  // actual arguments\n");
  for (int i = 0; i < actual; i++) {
    accumulator->Add("  [%02d] : %o", i, GetParameter(i));
    if (expected != -1 && i >= expected) {
      accumulator->Add("  // not passed to callee");
    }
    accumulator->Add("\n");
  }

  accumulator->Add("}\n\n");
}


void EntryFrame::Iterate(ObjectVisitor* v) const {
  StackHandlerIterator it(this, top_handler());
  ASSERT(!it.done());
  StackHandler* handler = it.handler();
1327
  ASSERT(handler->is_js_entry());
1328
  handler->Iterate(v, LookupCode());
1329
#ifdef DEBUG
1330 1331
  // Make sure that the entry frame does not contain more than one
  // stack handler.
1332 1333 1334
  it.Advance();
  ASSERT(it.done());
#endif
1335
  IteratePc(v, pc_address(), LookupCode());
1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
}


void StandardFrame::IterateExpressions(ObjectVisitor* v) const {
  const int offset = StandardFrameConstants::kContextOffset;
  Object** base = &Memory::Object_at(sp());
  Object** limit = &Memory::Object_at(fp() + offset) + 1;
  for (StackHandlerIterator it(this, top_handler()); !it.done(); it.Advance()) {
    StackHandler* handler = it.handler();
    // Traverse pointers down to - but not including - the next
    // handler in the handler chain. Update the base to skip the
    // handler and allow the handler to traverse its own pointers.
    const Address address = handler->address();
    v->VisitPointers(base, reinterpret_cast<Object**>(address));
    base = reinterpret_cast<Object**>(address + StackHandlerConstants::kSize);
    // Traverse the pointers in the handler itself.
1352
    handler->Iterate(v, LookupCode());
1353 1354 1355 1356 1357 1358 1359
  }
  v->VisitPointers(base, limit);
}


void JavaScriptFrame::Iterate(ObjectVisitor* v) const {
  IterateExpressions(v);
1360
  IteratePc(v, pc_address(), LookupCode());
1361 1362 1363 1364 1365 1366 1367
}


void InternalFrame::Iterate(ObjectVisitor* v) const {
  // Internal frames only have object pointers on the expression stack
  // as they never have any arguments.
  IterateExpressions(v);
1368
  IteratePc(v, pc_address(), LookupCode());
1369 1370 1371
}


1372 1373
void StubFailureTrampolineFrame::Iterate(ObjectVisitor* v) const {
  Object** base = &Memory::Object_at(sp());
1374 1375 1376 1377 1378 1379
  Object** limit = &Memory::Object_at(fp() +
                                      kFirstRegisterParameterFrameOffset);
  v->VisitPointers(base, limit);
  base = &Memory::Object_at(fp() + StandardFrameConstants::kMarkerOffset);
  const int offset = StandardFrameConstants::kContextOffset;
  limit = &Memory::Object_at(fp() + offset) + 1;
1380 1381 1382 1383 1384
  v->VisitPointers(base, limit);
  IteratePc(v, pc_address(), LookupCode());
}


1385 1386 1387 1388 1389 1390
Address StubFailureTrampolineFrame::GetCallerStackPointer() const {
  return fp() + StandardFrameConstants::kCallerSPOffset;
}


Code* StubFailureTrampolineFrame::unchecked_code() const {
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401
  Code* trampoline;
  StubFailureTrampolineStub(NOT_JS_FUNCTION_STUB_MODE).
      FindCodeInCache(&trampoline, isolate());
  if (trampoline->contains(pc())) {
    return trampoline;
  }

  StubFailureTrampolineStub(JS_FUNCTION_STUB_MODE).
      FindCodeInCache(&trampoline, isolate());
  if (trampoline->contains(pc())) {
    return trampoline;
1402
  }
1403

1404 1405 1406 1407 1408
  StubFailureTailCallTrampolineStub().FindCodeInCache(&trampoline, isolate());
  if (trampoline->contains(pc())) {
    return trampoline;
  }

1409 1410 1411 1412 1413
  UNREACHABLE();
  return NULL;
}


1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431
// -------------------------------------------------------------------------


JavaScriptFrame* StackFrameLocator::FindJavaScriptFrame(int n) {
  ASSERT(n >= 0);
  for (int i = 0; i <= n; i++) {
    while (!iterator_.frame()->is_java_script()) iterator_.Advance();
    if (i == n) return JavaScriptFrame::cast(iterator_.frame());
    iterator_.Advance();
  }
  UNREACHABLE();
  return NULL;
}


// -------------------------------------------------------------------------


1432 1433 1434 1435
static Map* GcSafeMapOfCodeSpaceObject(HeapObject* object) {
  MapWord map_word = object->map_word();
  return map_word.IsForwardingAddress() ?
      map_word.ToForwardingAddress()->map() : map_word.ToMap();
1436 1437 1438
}


1439
static int GcSafeSizeOfCodeSpaceObject(HeapObject* object) {
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
  return object->SizeFromMap(GcSafeMapOfCodeSpaceObject(object));
}


#ifdef DEBUG
static bool GcSafeCodeContains(HeapObject* code, Address addr) {
  Map* map = GcSafeMapOfCodeSpaceObject(code);
  ASSERT(map == code->GetHeap()->code_map());
  Address start = code->address();
  Address end = code->address() + code->SizeFromMap(map);
  return start <= addr && addr < end;
}
#endif


Code* InnerPointerToCodeCache::GcSafeCastToCode(HeapObject* object,
                                                Address inner_pointer) {
  Code* code = reinterpret_cast<Code*>(object);
  ASSERT(code != NULL && GcSafeCodeContains(code, inner_pointer));
  return code;
1460 1461 1462
}


1463 1464
Code* InnerPointerToCodeCache::GcSafeFindCodeForInnerPointer(
    Address inner_pointer) {
1465
  Heap* heap = isolate_->heap();
1466
  // Check if the inner pointer points into a large object chunk.
1467
  LargePage* large_page = heap->lo_space()->FindPage(inner_pointer);
1468 1469 1470
  if (large_page != NULL) {
    return GcSafeCastToCode(large_page->GetObject(), inner_pointer);
  }
1471

1472
  // Iterate through the page until we reach the end or find an object starting
1473 1474
  // after the inner pointer.
  Page* page = Page::FromAddress(inner_pointer);
1475

1476
  Address addr = page->skip_list()->StartFor(inner_pointer);
1477 1478 1479 1480

  Address top = heap->code_space()->top();
  Address limit = heap->code_space()->limit();

1481
  while (true) {
1482 1483 1484
    if (addr == top && addr != limit) {
      addr = limit;
      continue;
1485
    }
1486 1487 1488 1489

    HeapObject* obj = HeapObject::FromAddress(addr);
    int obj_size = GcSafeSizeOfCodeSpaceObject(obj);
    Address next_addr = addr + obj_size;
1490
    if (next_addr > inner_pointer) return GcSafeCastToCode(obj, inner_pointer);
1491
    addr = next_addr;
1492 1493 1494
  }
}

1495

1496 1497
InnerPointerToCodeCache::InnerPointerToCodeCacheEntry*
    InnerPointerToCodeCache::GetCacheEntry(Address inner_pointer) {
1498
  isolate_->counters()->pc_to_code()->Increment();
1499
  ASSERT(IsPowerOf2(kInnerPointerToCodeCacheSize));
1500
  uint32_t hash = ComputeIntegerHash(
1501 1502
      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(inner_pointer)),
      v8::internal::kZeroHashSeed);
1503 1504 1505
  uint32_t index = hash & (kInnerPointerToCodeCacheSize - 1);
  InnerPointerToCodeCacheEntry* entry = cache(index);
  if (entry->inner_pointer == inner_pointer) {
1506
    isolate_->counters()->pc_to_code_cached()->Increment();
1507
    ASSERT(entry->code == GcSafeFindCodeForInnerPointer(inner_pointer));
1508 1509
  } else {
    // Because this code may be interrupted by a profiling signal that
1510 1511
    // also queries the cache, we cannot update inner_pointer before the code
    // has been set. Otherwise, we risk trying to use a cache entry before
1512
    // the code has been computed.
1513
    entry->code = GcSafeFindCodeForInnerPointer(inner_pointer);
1514
    entry->safepoint_entry.Reset();
1515
    entry->inner_pointer = inner_pointer;
1516 1517 1518 1519 1520
  }
  return entry;
}


1521 1522 1523 1524 1525 1526 1527
// -------------------------------------------------------------------------


void StackHandler::Unwind(Isolate* isolate,
                          FixedArray* array,
                          int offset,
                          int previous_handler_offset) const {
1528
  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 5);
1529
  ASSERT_LE(0, offset);
1530
  ASSERT_GE(array->length(), offset + StackHandlerConstants::kSlotCount);
1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548
  // Unwinding a stack handler into an array chains it in the opposite
  // direction, re-using the "next" slot as a "previous" link, so that stack
  // handlers can be later re-wound in the correct order.  Decode the "state"
  // slot into "index" and "kind" and store them separately, using the fp slot.
  array->set(offset, Smi::FromInt(previous_handler_offset));        // next
  array->set(offset + 1, *code_address());                          // code
  array->set(offset + 2, Smi::FromInt(static_cast<int>(index())));  // state
  array->set(offset + 3, *context_address());                       // context
  array->set(offset + 4, Smi::FromInt(static_cast<int>(kind())));   // fp

  *isolate->handler_address() = next()->address();
}


int StackHandler::Rewind(Isolate* isolate,
                         FixedArray* array,
                         int offset,
                         Address fp) {
1549
  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 5);
1550
  ASSERT_LE(0, offset);
1551
  ASSERT_GE(array->length(), offset + StackHandlerConstants::kSlotCount);
1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
  Smi* prev_handler_offset = Smi::cast(array->get(offset));
  Code* code = Code::cast(array->get(offset + 1));
  Smi* smi_index = Smi::cast(array->get(offset + 2));
  Object* context = array->get(offset + 3);
  Smi* smi_kind = Smi::cast(array->get(offset + 4));

  unsigned state = KindField::encode(static_cast<Kind>(smi_kind->value())) |
      IndexField::encode(static_cast<unsigned>(smi_index->value()));

  Memory::Address_at(address() + StackHandlerConstants::kNextOffset) =
      *isolate->handler_address();
  Memory::Object_at(address() + StackHandlerConstants::kCodeOffset) = code;
  Memory::uintptr_at(address() + StackHandlerConstants::kStateOffset) = state;
  Memory::Object_at(address() + StackHandlerConstants::kContextOffset) =
      context;
1567
  SetFp(address() + StackHandlerConstants::kFPOffset, fp);
1568 1569 1570 1571 1572 1573 1574

  *isolate->handler_address() = address();

  return prev_handler_offset->value();
}


1575 1576
// -------------------------------------------------------------------------

1577
int NumRegs(RegList reglist) {
1578
  return CompilerIntrinsics::CountSetBits(reglist);
1579 1580 1581
}


1582 1583 1584 1585
struct JSCallerSavedCodeData {
  int reg_code[kNumJSCallerSaved];
};

1586
JSCallerSavedCodeData caller_saved_code_data;
1587

1588 1589 1590 1591 1592 1593 1594 1595
void SetUpJSCallerSavedCodeData() {
  int i = 0;
  for (int r = 0; r < kNumRegs; r++)
    if ((kJSCallerSaved & (1 << r)) != 0)
      caller_saved_code_data.reg_code[i++] = r;

  ASSERT(i == kNumJSCallerSaved);
}
1596

1597

1598
int JSCallerSavedCode(int n) {
1599
  ASSERT(0 <= n && n < kNumJSCallerSaved);
1600
  return caller_saved_code_data.reg_code[n];
1601 1602 1603
}


1604 1605 1606 1607 1608 1609 1610 1611 1612 1613
#define DEFINE_WRAPPER(type, field)                              \
class field##_Wrapper : public ZoneObject {                      \
 public:  /* NOLINT */                                           \
  field##_Wrapper(const field& original) : frame_(original) {    \
  }                                                              \
  field frame_;                                                  \
};
STACK_FRAME_TYPE_LIST(DEFINE_WRAPPER)
#undef DEFINE_WRAPPER

1614
static StackFrame* AllocateFrameCopy(StackFrame* frame, Zone* zone) {
1615 1616 1617
#define FRAME_TYPE_CASE(type, field) \
  case StackFrame::type: { \
    field##_Wrapper* wrapper = \
1618
        new(zone) field##_Wrapper(*(reinterpret_cast<field*>(frame))); \
1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629
    return &wrapper->frame_; \
  }

  switch (frame->type()) {
    STACK_FRAME_TYPE_LIST(FRAME_TYPE_CASE)
    default: UNREACHABLE();
  }
#undef FRAME_TYPE_CASE
  return NULL;
}

1630

1631
Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone) {
1632
  ZoneList<StackFrame*> list(10, zone);
1633
  for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
1634 1635
    StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
    list.Add(frame, zone);
1636 1637 1638 1639 1640
  }
  return list.ToVector();
}


1641
} }  // namespace v8::internal