Remove support for Live Object List and inspector module.

src/liveobjectlist.cc

-// Copyright 2011 the V8 project authors. All rights reserved.
-// 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.
-
-#ifdef LIVE_OBJECT_LIST
-
-#include <ctype.h>
-#include <stdlib.h>
-
-#include "v8.h"
-
-#include "checks.h"
-#include "global-handles.h"
-#include "heap.h"
-#include "inspector.h"
-#include "isolate.h"
-#include "list-inl.h"
-#include "liveobjectlist-inl.h"
-#include "string-stream.h"
-#include "v8utils.h"
-#include "v8conversions.h"
-
-namespace v8 {
-namespace internal {
-
-
-typedef int (*RawComparer)(const void*, const void*);
-
-
-#ifdef CHECK_ALL_OBJECT_TYPES
-
-#define DEBUG_LIVE_OBJECT_TYPES(v) \
-  v(Smi, "unexpected: Smi") \
-  \
-  v(CodeCache, "unexpected: CodeCache") \
-  v(BreakPointInfo, "unexpected: BreakPointInfo") \
-  v(DebugInfo, "unexpected: DebugInfo") \
-  v(TypeSwitchInfo, "unexpected: TypeSwitchInfo") \
-  v(SignatureInfo, "unexpected: SignatureInfo") \
-  v(Script, "unexpected: Script") \
-  v(ObjectTemplateInfo, "unexpected: ObjectTemplateInfo") \
-  v(FunctionTemplateInfo, "unexpected: FunctionTemplateInfo") \
-  v(CallHandlerInfo, "unexpected: CallHandlerInfo") \
-  v(InterceptorInfo, "unexpected: InterceptorInfo") \
-  v(AccessCheckInfo, "unexpected: AccessCheckInfo") \
-  v(AccessorInfo, "unexpected: AccessorInfo") \
-  v(ExternalTwoByteString, "unexpected: ExternalTwoByteString") \
-  v(ExternalAsciiString, "unexpected: ExternalAsciiString") \
-  v(ExternalString, "unexpected: ExternalString") \
-  v(SeqTwoByteString, "unexpected: SeqTwoByteString") \
-  v(SeqOneByteString, "unexpected: SeqOneByteString") \
-  v(SeqString, "unexpected: SeqString") \
-  v(JSFunctionResultCache, "unexpected: JSFunctionResultCache") \
-  v(NativeContext, "unexpected: NativeContext") \
-  v(MapCache, "unexpected: MapCache") \
-  v(CodeCacheHashTable, "unexpected: CodeCacheHashTable") \
-  v(CompilationCacheTable, "unexpected: CompilationCacheTable") \
-  v(SymbolTable, "unexpected: SymbolTable") \
-  v(Dictionary, "unexpected: Dictionary") \
-  v(HashTable, "unexpected: HashTable") \
-  v(DescriptorArray, "unexpected: DescriptorArray") \
-  v(ExternalFloatArray, "unexpected: ExternalFloatArray") \
-  v(ExternalUnsignedIntArray, "unexpected: ExternalUnsignedIntArray") \
-  v(ExternalIntArray, "unexpected: ExternalIntArray") \
-  v(ExternalUnsignedShortArray, "unexpected: ExternalUnsignedShortArray") \
-  v(ExternalShortArray, "unexpected: ExternalShortArray") \
-  v(ExternalUnsignedByteArray, "unexpected: ExternalUnsignedByteArray") \
-  v(ExternalByteArray, "unexpected: ExternalByteArray") \
-  v(JSValue, "unexpected: JSValue")
-
-#else
-#define DEBUG_LIVE_OBJECT_TYPES(v)
-#endif
-
-
-#define FOR_EACH_LIVE_OBJECT_TYPE(v) \
-  DEBUG_LIVE_OBJECT_TYPES(v) \
-  \
-  v(JSArray, "JSArray") \
-  v(JSRegExp, "JSRegExp") \
-  v(JSFunction, "JSFunction") \
-  v(JSGlobalObject, "JSGlobal") \
-  v(JSBuiltinsObject, "JSBuiltins") \
-  v(GlobalObject, "Global") \
-  v(JSGlobalProxy, "JSGlobalProxy") \
-  v(JSObject, "JSObject") \
-  \
-  v(Context, "meta: Context") \
-  v(ByteArray, "meta: ByteArray") \
-  v(ExternalPixelArray, "meta: PixelArray") \
-  v(ExternalArray, "meta: ExternalArray") \
-  v(FixedArray, "meta: FixedArray") \
-  v(String, "String") \
-  v(HeapNumber, "HeapNumber") \
-  \
-  v(Code, "meta: Code") \
-  v(Map, "meta: Map") \
-  v(Oddball, "Oddball") \
-  v(Foreign, "meta: Foreign") \
-  v(SharedFunctionInfo, "meta: SharedFunctionInfo") \
-  v(Struct, "meta: Struct") \
-  \
-  v(HeapObject, "HeapObject")
-
-
-enum /* LiveObjectType */ {
-#define DECLARE_OBJECT_TYPE_ENUM(type, name) kType##type,
-  FOR_EACH_LIVE_OBJECT_TYPE(DECLARE_OBJECT_TYPE_ENUM)
-  kInvalidLiveObjType,
-  kNumberOfTypes
-#undef DECLARE_OBJECT_TYPE_ENUM
-};
-
-
-LiveObjectType GetObjectType(HeapObject* heap_obj) {
-  // TODO(mlam): investigate usint Map::instance_type() instead.
-#define CHECK_FOR_OBJECT_TYPE(type, name) \
-  if (heap_obj->Is##type()) return kType##type;
-  FOR_EACH_LIVE_OBJECT_TYPE(CHECK_FOR_OBJECT_TYPE)
-#undef CHECK_FOR_OBJECT_TYPE
-
-  UNREACHABLE();
-  return kInvalidLiveObjType;
-}
-
-
-inline const char* GetObjectTypeDesc(LiveObjectType type) {
-  static const char* const name[kNumberOfTypes] = {
-  #define DEFINE_OBJECT_TYPE_NAME(type, name) name,
-    FOR_EACH_LIVE_OBJECT_TYPE(DEFINE_OBJECT_TYPE_NAME)
-    "invalid"
-  #undef DEFINE_OBJECT_TYPE_NAME
-  };
-  ASSERT(type < kNumberOfTypes);
-  return name[type];
-}
-
-
-const char* GetObjectTypeDesc(HeapObject* heap_obj) {
-  LiveObjectType type = GetObjectType(heap_obj);
-  return GetObjectTypeDesc(type);
-}
-
-
-bool IsOfType(LiveObjectType type, HeapObject* obj) {
-  // Note: there are types that are more general (e.g. JSObject) that would
-  // have passed the Is##type_() test for more specialized types (e.g.
-  // JSFunction).  If we find a more specialized match but we're looking for
-  // the general type, then we should reject the ones that matches the
-  // specialized type.
-#define CHECK_OBJECT_TYPE(type_, name) \
-  if (obj->Is##type_()) return (type == kType##type_);
-
-  FOR_EACH_LIVE_OBJECT_TYPE(CHECK_OBJECT_TYPE)
-#undef CHECK_OBJECT_TYPE
-
-  return false;
-}
-
-
-const AllocationSpace kInvalidSpace = static_cast<AllocationSpace>(-1);
-
-static AllocationSpace FindSpaceFor(String* space_str) {
-  SmartArrayPointer<char> s =
-      space_str->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
-
-  const char* key_str = *s;
-  switch (key_str[0]) {
-    case 'c':
-      if (strcmp(key_str, "cell") == 0) return CELL_SPACE;
-      if (strcmp(key_str, "code") == 0) return CODE_SPACE;
-      break;
-    case 'l':
-      if (strcmp(key_str, "lo") == 0) return LO_SPACE;
-      break;
-    case 'm':
-      if (strcmp(key_str, "map") == 0) return MAP_SPACE;
-      break;
-    case 'n':
-      if (strcmp(key_str, "new") == 0) return NEW_SPACE;
-      break;
-    case 'o':
-      if (strcmp(key_str, "old-pointer") == 0) return OLD_POINTER_SPACE;
-      if (strcmp(key_str, "old-data") == 0) return OLD_DATA_SPACE;
-      break;
-  }
-  return kInvalidSpace;
-}
-
-
-static bool InSpace(AllocationSpace space, HeapObject* heap_obj) {
-  Heap* heap = ISOLATE->heap();
-  if (space != LO_SPACE) {
-    return heap->InSpace(heap_obj, space);
-  }
-
-  // This is an optimization to speed up the check for an object in the LO
-  // space by exclusion because we know that all object pointers passed in
-  // here are guaranteed to be in the heap.  Hence, it is safe to infer
-  // using an exclusion test.
-  // Note: calling Heap::InSpace(heap_obj, LO_SPACE) is too slow for our
-  // filters.
-  int first_space = static_cast<int>(FIRST_SPACE);
-  int last_space = static_cast<int>(LO_SPACE);
-  for (int sp = first_space; sp < last_space; sp++) {
-    if (heap->InSpace(heap_obj, static_cast<AllocationSpace>(sp))) {
-      return false;
-    }
-  }
-  SLOW_ASSERT(heap->InSpace(heap_obj, LO_SPACE));
-  return true;
-}
-
-
-static LiveObjectType FindTypeFor(String* type_str) {
-  SmartArrayPointer<char> s =
-      type_str->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
-
-#define CHECK_OBJECT_TYPE(type_, name) { \
-    const char* type_desc = GetObjectTypeDesc(kType##type_); \
-    const char* key_str = *s; \
-    if (strstr(type_desc, key_str) != NULL) return kType##type_; \
-  }
-  FOR_EACH_LIVE_OBJECT_TYPE(CHECK_OBJECT_TYPE)
-#undef CHECK_OBJECT_TYPE
-
-  return kInvalidLiveObjType;
-}
-
-
-class LolFilter {
- public:
-  explicit LolFilter(Handle<JSObject> filter_obj);
-
-  inline bool is_active() const { return is_active_; }
-  inline bool Matches(HeapObject* obj) {
-    return !is_active() || MatchesSlow(obj);
-  }
-
- private:
-  void InitTypeFilter(Handle<JSObject> filter_obj);
-  void InitSpaceFilter(Handle<JSObject> filter_obj);
-  void InitPropertyFilter(Handle<JSObject> filter_obj);
-  bool MatchesSlow(HeapObject* obj);
-
-  bool is_active_;
-  LiveObjectType type_;
-  AllocationSpace space_;
-  Handle<String> prop_;
-};
-
-
-LolFilter::LolFilter(Handle<JSObject> filter_obj)
-    : is_active_(false),
-      type_(kInvalidLiveObjType),
-      space_(kInvalidSpace),
-      prop_() {
-  if (filter_obj.is_null()) return;
-
-  InitTypeFilter(filter_obj);
-  InitSpaceFilter(filter_obj);
-  InitPropertyFilter(filter_obj);
-}
-
-
-void LolFilter::InitTypeFilter(Handle<JSObject> filter_obj) {
-  Handle<String> type_sym = FACTORY->LookupAsciiSymbol("type");
-  MaybeObject* maybe_result = filter_obj->GetProperty(*type_sym);
-  Object* type_obj;
-  if (maybe_result->ToObject(&type_obj)) {
-    if (type_obj->IsString()) {
-      String* type_str = String::cast(type_obj);
-      type_ = FindTypeFor(type_str);
-      if (type_ != kInvalidLiveObjType) {
-        is_active_ = true;
-      }
-    }
-  }
-}
-
-
-void LolFilter::InitSpaceFilter(Handle<JSObject> filter_obj) {
-  Handle<String> space_sym = FACTORY->LookupAsciiSymbol("space");
-  MaybeObject* maybe_result = filter_obj->GetProperty(*space_sym);
-  Object* space_obj;
-  if (maybe_result->ToObject(&space_obj)) {
-    if (space_obj->IsString()) {
-      String* space_str = String::cast(space_obj);
-      space_ = FindSpaceFor(space_str);
-      if (space_ != kInvalidSpace) {
-        is_active_ = true;
-      }
-    }
-  }
-}
-
-
-void LolFilter::InitPropertyFilter(Handle<JSObject> filter_obj) {
-  Handle<String> prop_sym = FACTORY->LookupAsciiSymbol("prop");
-  MaybeObject* maybe_result = filter_obj->GetProperty(*prop_sym);
-  Object* prop_obj;
-  if (maybe_result->ToObject(&prop_obj)) {
-    if (prop_obj->IsString()) {
-      prop_ = Handle<String>(String::cast(prop_obj));
-      is_active_ = true;
-    }
-  }
-}
-
-
-bool LolFilter::MatchesSlow(HeapObject* obj) {
-  if ((type_ != kInvalidLiveObjType) && !IsOfType(type_, obj)) {
-    return false;  // Fail because obj is not of the type of interest.
-  }
-  if ((space_ != kInvalidSpace) && !InSpace(space_, obj)) {
-    return false;  // Fail because obj is not in the space of interest.
-  }
-  if (!prop_.is_null() && obj->IsJSObject()) {
-    LookupResult result;
-    obj->Lookup(*prop_, &result);
-    if (!result.IsProperty()) {
-      return false;  // Fail because obj does not have the property of interest.
-    }
-  }
-  return true;
-}
-
-
-class LolIterator {
- public:
-  LolIterator(LiveObjectList* older, LiveObjectList* newer)
-      : older_(older),
-        newer_(newer),
-        curr_(0),
-        elements_(0),
-        count_(0),
-        index_(0) { }
-
-  inline void Init() {
-    SetCurrent(newer_);
-    // If the elements_ list is empty, then move on to the next list as long
-    // as we're not at the last list (indicated by done()).
-    while ((elements_ == NULL) && !Done()) {
-      SetCurrent(curr_->prev_);
-    }
-  }
-
-  inline bool Done() const {
-    return (curr_ == older_);
-  }
-
-  // Object level iteration.
-  inline void Next() {
-    index_++;
-    if (index_ >= count_) {
-      // Iterate backwards until we get to the oldest list.
-      while (!Done()) {
-        SetCurrent(curr_->prev_);
-        // If we have elements to process, we're good to go.
-        if (elements_ != NULL) break;
-
-        // Else, we should advance to the next older list.
-      }
-    }
-  }
-
-  inline int Id() const {
-    return elements_[index_].id_;
-  }
-  inline HeapObject* Obj() const {
-    return elements_[index_].obj_;
-  }
-
-  inline int LolObjCount() const {
-    if (curr_ != NULL) return curr_->obj_count_;
-    return 0;
-  }
-
- protected:
-  inline void SetCurrent(LiveObjectList* new_curr) {
-    curr_ = new_curr;
-    if (curr_ != NULL) {
-      elements_ = curr_->elements_;
-      count_ = curr_->obj_count_;
-      index_ = 0;
-    }
-  }
-
-  LiveObjectList* older_;
-  LiveObjectList* newer_;
-  LiveObjectList* curr_;
-  LiveObjectList::Element* elements_;
-  int count_;
-  int index_;
-};
-
-
-class LolForwardIterator : public LolIterator {
- public:
-  LolForwardIterator(LiveObjectList* first, LiveObjectList* last)
-      : LolIterator(first, last) {
-  }
-
-  inline void Init() {
-    SetCurrent(older_);
-    // If the elements_ list is empty, then move on to the next list as long
-    // as we're not at the last list (indicated by Done()).
-    while ((elements_ == NULL) && !Done()) {
-      SetCurrent(curr_->next_);
-    }
-  }
-
-  inline bool Done() const {
-    return (curr_ == newer_);
-  }
-
-  // Object level iteration.
-  inline void Next() {
-    index_++;
-    if (index_ >= count_) {
-      // Done with current list.  Move on to the next.
-      while (!Done()) {  // If not at the last list already, ...
-        SetCurrent(curr_->next_);
-        // If we have elements to process, we're good to go.
-        if (elements_ != NULL) break;
-
-        // Else, we should advance to the next list.
-      }
-    }
-  }
-};
-
-
-// Minimizes the white space in a string.  Tabs and newlines are replaced
-// with a space where appropriate.
-static int CompactString(char* str) {
-  char* src = str;
-  char* dst = str;
-  char prev_ch = 0;
-  while (*dst != '\0') {
-    char ch = *src++;
-    // We will treat non-ASCII chars as '?'.
-    if ((ch & 0x80) != 0) {
-      ch = '?';
-    }
-    // Compact contiguous whitespace chars into a single ' '.
-    if (isspace(ch)) {
-      if (prev_ch != ' ') *dst++ = ' ';
-      prev_ch = ' ';
-      continue;
-    }
-    *dst++ = ch;
-    prev_ch = ch;
-  }
-  return (dst - str);
-}
-
-
-// Generates a custom description based on the specific type of
-// object we're looking at.  We only generate specialized
-// descriptions where we can.  In all other cases, we emit the
-// generic info.
-static void GenerateObjectDesc(HeapObject* obj,
-                               char* buffer,
-                               int buffer_size) {
-  Vector<char> buffer_v(buffer, buffer_size);
-  ASSERT(obj != NULL);
-  if (obj->IsJSArray()) {
-    JSArray* jsarray = JSArray::cast(obj);
-    double length = jsarray->length()->Number();
-    OS::SNPrintF(buffer_v,
-                 "%p <%s> len %g",
-                 reinterpret_cast<void*>(obj),
-                 GetObjectTypeDesc(obj),
-                 length);
-
-  } else if (obj->IsString()) {
-    String* str = String::cast(obj);
-    // Only grab up to 160 chars in case they are double byte.
-    // We'll only dump 80 of them after we compact them.
-    const int kMaxCharToDump = 80;
-    const int kMaxBufferSize = kMaxCharToDump * 2;
-    SmartArrayPointer<char> str_sp = str->ToCString(DISALLOW_NULLS,
-                                                    ROBUST_STRING_TRAVERSAL,
-                                                    0,
-                                                    kMaxBufferSize);
-    char* str_cstr = *str_sp;
-    int length = CompactString(str_cstr);
-    OS::SNPrintF(buffer_v,
-                 "%p <%s> '%.80s%s'",
-                 reinterpret_cast<void*>(obj),
-                 GetObjectTypeDesc(obj),
-                 str_cstr,
-                 (length > kMaxCharToDump) ? "..." : "");
-
-  } else if (obj->IsJSFunction() || obj->IsSharedFunctionInfo()) {
-    SharedFunctionInfo* sinfo;
-    if (obj->IsJSFunction()) {
-      JSFunction* func = JSFunction::cast(obj);
-      sinfo = func->shared();
-    } else {
-      sinfo = SharedFunctionInfo::cast(obj);
-    }
-
-    String* name = sinfo->DebugName();
-    SmartArrayPointer<char> name_sp =
-        name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
-    char* name_cstr = *name_sp;
-
-    HeapStringAllocator string_allocator;
-    StringStream stream(&string_allocator);
-    sinfo->SourceCodePrint(&stream, 50);
-    SmartArrayPointer<const char> source_sp = stream.ToCString();
-    const char* source_cstr = *source_sp;
-
-    OS::SNPrintF(buffer_v,
-                 "%p <%s> '%s' %s",
-                 reinterpret_cast<void*>(obj),
-                 GetObjectTypeDesc(obj),
-                 name_cstr,
-                 source_cstr);
-
-  } else if (obj->IsFixedArray()) {
-    FixedArray* fixed = FixedArray::cast(obj);
-
-    OS::SNPrintF(buffer_v,
-                 "%p <%s> len %d",
-                 reinterpret_cast<void*>(obj),
-                 GetObjectTypeDesc(obj),
-                 fixed->length());
-
-  } else {
-    OS::SNPrintF(buffer_v,
-                 "%p <%s>",
-                 reinterpret_cast<void*>(obj),
-                 GetObjectTypeDesc(obj));
-  }
-}
-
-
-// Utility function for filling in a line of detail in a verbose dump.
-static bool AddObjDetail(Handle<FixedArray> arr,
-                         int index,
-                         int obj_id,
-                         Handle<HeapObject> target,
-                         const char* desc_str,
-                         Handle<String> id_sym,
-                         Handle<String> desc_sym,
-                         Handle<String> size_sym,
-                         Handle<JSObject> detail,
-                         Handle<String> desc,
-                         Handle<Object> error) {
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-  detail = factory->NewJSObject(isolate->object_function());
-  if (detail->IsFailure()) {
-    error = detail;
-    return false;
-  }
-
-  int size = 0;
-  char buffer[512];
-  if (desc_str == NULL) {
-    ASSERT(!target.is_null());
-    HeapObject* obj = *target;
-    GenerateObjectDesc(obj, buffer, sizeof(buffer));
-    desc_str = buffer;
-    size = obj->Size();
-  }
-  desc = factory->NewStringFromAscii(CStrVector(desc_str));
-  if (desc->IsFailure()) {
-    error = desc;
-    return false;
-  }
-
-  { MaybeObject* maybe_result = detail->SetProperty(*id_sym,
-                                                    Smi::FromInt(obj_id),
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return false;
-  }
-  { MaybeObject* maybe_result = detail->SetProperty(*desc_sym,
-                                                    *desc,
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return false;
-  }
-  { MaybeObject* maybe_result = detail->SetProperty(*size_sym,
-                                                    Smi::FromInt(size),
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return false;
-  }
-
-  arr->set(index, *detail);
-  return true;
-}
-
-
-class DumpWriter {
- public:
-  virtual ~DumpWriter() {}
-
-  virtual void ComputeTotalCountAndSize(LolFilter* filter,
-                                        int* count,
-                                        int* size) = 0;
-  virtual bool Write(Handle<FixedArray> elements_arr,
-                     int start,
-                     int dump_limit,
-                     LolFilter* filter,
-                     Handle<Object> error) = 0;
-};
-
-
-class LolDumpWriter: public DumpWriter {
- public:
-  LolDumpWriter(LiveObjectList* older, LiveObjectList* newer)
-      : older_(older), newer_(newer) {
-  }
-
-  void ComputeTotalCountAndSize(LolFilter* filter, int* count, int* size) {
-    *count = 0;
-    *size = 0;
-
-    LolIterator it(older_, newer_);
-    for (it.Init(); !it.Done(); it.Next()) {
-      HeapObject* heap_obj = it.Obj();
-      if (!filter->Matches(heap_obj)) {
-        continue;
-      }
-
-      *size += heap_obj->Size();
-      (*count)++;
-    }
-  }
-
-  bool Write(Handle<FixedArray> elements_arr,
-             int start,
-             int dump_limit,
-             LolFilter* filter,
-             Handle<Object> error) {
-    // The lols are listed in latest to earliest.  We want to dump from
-    // earliest to latest.  So, compute the last element to start with.
-    int index = 0;
-    int count = 0;
-
-    Isolate* isolate = Isolate::Current();
-    Factory* factory = isolate->factory();
-
-    // Prefetch some needed symbols.
-    Handle<String> id_sym = factory->LookupAsciiSymbol("id");
-    Handle<String> desc_sym = factory->LookupAsciiSymbol("desc");
-    Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-
-    // Fill the array with the lol object details.
-    Handle<JSObject> detail;
-    Handle<String> desc;
-    Handle<HeapObject> target;
-
-    LiveObjectList* first_lol = (older_ != NULL) ?
-                                older_->next_ : LiveObjectList::first_;
-    LiveObjectList* last_lol = (newer_ != NULL) ? newer_->next_ : NULL;
-
-    LolForwardIterator it(first_lol, last_lol);
-    for (it.Init(); !it.Done() && (index < dump_limit); it.Next()) {
-      HeapObject* heap_obj = it.Obj();
-
-      // Skip objects that have been filtered out.
-      if (!filter->Matches(heap_obj)) {
-        continue;
-      }
-
-      // Only report objects that are in the section of interest.
-      if (count >= start) {
-        target = Handle<HeapObject>(heap_obj);
-        bool success = AddObjDetail(elements_arr,
-                                    index++,
-                                    it.Id(),
-                                    target,
-                                    NULL,
-                                    id_sym,
-                                    desc_sym,
-                                    size_sym,
-                                    detail,
-                                    desc,
-                                    error);
-        if (!success) return false;
-      }
-      count++;
-    }
-    return true;
-  }
-
- private:
-  LiveObjectList* older_;
-  LiveObjectList* newer_;
-};
-
-
-class RetainersDumpWriter: public DumpWriter {
- public:
-  RetainersDumpWriter(Handle<HeapObject> target,
-                      Handle<JSObject> instance_filter,
-                      Handle<JSFunction> args_function)
-      : target_(target),
-        instance_filter_(instance_filter),
-        args_function_(args_function) {
-  }
-
-  void ComputeTotalCountAndSize(LolFilter* filter, int* count, int* size) {
-    Handle<FixedArray> retainers_arr;
-    Handle<Object> error;
-
-    *size = -1;
-    LiveObjectList::GetRetainers(target_,
-                                 instance_filter_,
-                                 retainers_arr,
-                                 0,
-                                 Smi::kMaxValue,
-                                 count,
-                                 filter,
-                                 NULL,
-                                 *args_function_,
-                                 error);
-  }
-
-  bool Write(Handle<FixedArray> elements_arr,
-             int start,
-             int dump_limit,
-             LolFilter* filter,
-             Handle<Object> error) {
-    int dummy;
-    int count;
-
-    // Fill the retainer objects.
-    count = LiveObjectList::GetRetainers(target_,
-                                         instance_filter_,
-                                         elements_arr,
-                                         start,
-                                         dump_limit,
-                                         &dummy,
-                                         filter,
-                                         NULL,
-                                         *args_function_,
-                                         error);
-    if (count < 0) {
-        return false;
-    }
-    return true;
-  }
-
- private:
-  Handle<HeapObject> target_;
-  Handle<JSObject> instance_filter_;
-  Handle<JSFunction> args_function_;
-};
-
-
-class LiveObjectSummary {
- public:
-  explicit LiveObjectSummary(LolFilter* filter)
-      : total_count_(0),
-        total_size_(0),
-        found_root_(false),
-        found_weak_root_(false),
-        filter_(filter) {
-    memset(counts_, 0, sizeof(counts_[0]) * kNumberOfEntries);
-    memset(sizes_, 0, sizeof(sizes_[0]) * kNumberOfEntries);
-  }
-
-  void Add(HeapObject* heap_obj) {
-    int size = heap_obj->Size();
-    LiveObjectType type = GetObjectType(heap_obj);
-    ASSERT(type != kInvalidLiveObjType);
-    counts_[type]++;
-    sizes_[type] += size;
-    total_count_++;
-    total_size_ += size;
-  }
-
-  void set_found_root() { found_root_ = true; }
-  void set_found_weak_root() { found_weak_root_ = true; }
-
-  inline int Count(LiveObjectType type) {
-    return counts_[type];
-  }
-  inline int Size(LiveObjectType type) {
-    return sizes_[type];
-  }
-  inline int total_count() {
-    return total_count_;
-  }
-  inline int total_size() {
-    return total_size_;
-  }
-  inline bool found_root() {
-    return found_root_;
-  }
-  inline bool found_weak_root() {
-    return found_weak_root_;
-  }
-  int GetNumberOfEntries() {
-    int entries = 0;
-    for (int i = 0; i < kNumberOfEntries; i++) {
-      if (counts_[i]) entries++;
-    }
-    return entries;
-  }
-
-  inline LolFilter* filter() { return filter_; }
-
-  static const int kNumberOfEntries = kNumberOfTypes;
-
- private:
-  int counts_[kNumberOfEntries];
-  int sizes_[kNumberOfEntries];
-  int total_count_;
-  int total_size_;
-  bool found_root_;
-  bool found_weak_root_;
-
-  LolFilter* filter_;
-};
-
-
-// Abstraction for a summary writer.
-class SummaryWriter {
- public:
-  virtual ~SummaryWriter() {}
-  virtual void Write(LiveObjectSummary* summary) = 0;
-};
-
-
-// A summary writer for filling in a summary of lol lists and diffs.
-class LolSummaryWriter: public SummaryWriter {
- public:
-  LolSummaryWriter(LiveObjectList* older_lol,
-                   LiveObjectList* newer_lol)
-      : older_(older_lol), newer_(newer_lol) {
-  }
-
-  void Write(LiveObjectSummary* summary) {
-    LolFilter* filter = summary->filter();
-
-    // Fill the summary with the lol object details.
-    LolIterator it(older_, newer_);
-    for (it.Init(); !it.Done(); it.Next()) {
-      HeapObject* heap_obj = it.Obj();
-      if (!filter->Matches(heap_obj)) {
-        continue;
-      }
-      summary->Add(heap_obj);
-    }
-  }
-
- private:
-  LiveObjectList* older_;
-  LiveObjectList* newer_;
-};
-
-
-// A summary writer for filling in a retainers list.
-class RetainersSummaryWriter: public SummaryWriter {
- public:
-  RetainersSummaryWriter(Handle<HeapObject> target,
-                         Handle<JSObject> instance_filter,
-                         Handle<JSFunction> args_function)
-      : target_(target),
-        instance_filter_(instance_filter),
-        args_function_(args_function) {
-  }
-
-  void Write(LiveObjectSummary* summary) {
-    Handle<FixedArray> retainers_arr;
-    Handle<Object> error;
-    int dummy_total_count;
-    LiveObjectList::GetRetainers(target_,
-                                 instance_filter_,
-                                 retainers_arr,
-                                 0,
-                                 Smi::kMaxValue,
-                                 &dummy_total_count,
-                                 summary->filter(),
-                                 summary,
-                                 *args_function_,
-                                 error);
-  }
-
- private:
-  Handle<HeapObject> target_;
-  Handle<JSObject> instance_filter_;
-  Handle<JSFunction> args_function_;
-};
-
-
-uint32_t LiveObjectList::next_element_id_ = 1;
-int LiveObjectList::list_count_ = 0;
-int LiveObjectList::last_id_ = 0;
-LiveObjectList* LiveObjectList::first_ = NULL;
-LiveObjectList* LiveObjectList::last_ = NULL;
-
-
-LiveObjectList::LiveObjectList(LiveObjectList* prev, int capacity)
-    : prev_(prev),
-      next_(NULL),
-      capacity_(capacity),
-      obj_count_(0) {
-  elements_ = NewArray<Element>(capacity);
-  id_ = ++last_id_;
-
-  list_count_++;
-}
-
-
-LiveObjectList::~LiveObjectList() {
-  DeleteArray<Element>(elements_);
-  delete prev_;
-}
-
-
-int LiveObjectList::GetTotalObjCountAndSize(int* size_p) {
-  int size = 0;
-  int count = 0;
-  LiveObjectList* lol = this;
-  do {
-    // Only compute total size if requested i.e. when size_p is not null.
-    if (size_p != NULL) {
-      Element* elements = lol->elements_;
-      for (int i = 0; i < lol->obj_count_; i++) {
-        HeapObject* heap_obj = elements[i].obj_;
-        size += heap_obj->Size();
-      }
-    }
-    count += lol->obj_count_;
-    lol = lol->prev_;
-  } while (lol != NULL);
-
-  if (size_p != NULL) {
-    *size_p = size;
-  }
-  return count;
-}
-
-
-// Adds an object to the lol.
-// Returns true if successful, else returns false.
-bool LiveObjectList::Add(HeapObject* obj) {
-  // If the object is already accounted for in the prev list which we inherit
-  // from, then no need to add it to this list.
-  if ((prev() != NULL) && (prev()->Find(obj) != NULL)) {
-    return true;
-  }
-  ASSERT(obj_count_ <= capacity_);
-  if (obj_count_ == capacity_) {
-    // The heap must have grown and we have more objects than capacity to store
-    // them.
-    return false;  // Fail this addition.
-  }
-  Element& element = elements_[obj_count_++];
-  element.id_ = next_element_id_++;
-  element.obj_ = obj;
-  return true;
-}
-
-
-// Comparator used for sorting and searching the lol.
-int LiveObjectList::CompareElement(const Element* a, const Element* b) {
-  const HeapObject* obj1 = a->obj_;
-  const HeapObject* obj2 = b->obj_;
-  // For lol elements, it doesn't matter which comes first if 2 elements point
-  // to the same object (which gets culled later).  Hence, we only care about
-  // the the greater than / less than relationships.
-  return (obj1 > obj2) ? 1 : (obj1 == obj2) ? 0 : -1;
-}
-
-
-// Looks for the specified object in the lol, and returns its element if found.
-LiveObjectList::Element* LiveObjectList::Find(HeapObject* obj) {
-  LiveObjectList* lol = this;
-  Element key;
-  Element* result = NULL;
-
-  key.obj_ = obj;
-  // Iterate through the chain of lol's to look for the object.
-  while ((result == NULL) && (lol != NULL)) {
-    result = reinterpret_cast<Element*>(
-        bsearch(&key, lol->elements_, lol->obj_count_,
-                sizeof(Element),
-                reinterpret_cast<RawComparer>(CompareElement)));
-    lol = lol->prev_;
-  }
-  return result;
-}
-
-
-// "Nullifies" (convert the HeapObject* into an SMI) so that it will get cleaned
-// up in the GCEpilogue, while preserving the sort order of the lol.
-// NOTE: the lols need to be already sorted before NullifyMostRecent() is
-// called.
-void LiveObjectList::NullifyMostRecent(HeapObject* obj) {
-  LiveObjectList* lol = last();
-  Element key;
-  Element* result = NULL;
-
-  key.obj_ = obj;
-  // Iterate through the chain of lol's to look for the object.
-  while (lol != NULL) {
-    result = reinterpret_cast<Element*>(
-        bsearch(&key, lol->elements_, lol->obj_count_,
-                sizeof(Element),
-                reinterpret_cast<RawComparer>(CompareElement)));
-    if (result != NULL) {
-      // Since there may be more than one (we are nullifying dup's after all),
-      // find the first in the current lol, and nullify that.  The lol should
-      // be sorted already to make this easy (see the use of SortAll()).
-      int i = result - lol->elements_;
-
-      // NOTE: we sort the lol in increasing order.  So, if an object has been
-      // "nullified" (its lowest bit will be cleared to make it look like an
-      // SMI), it would/should show up before the equivalent dups that have not
-      // yet been "nullified".  Hence, we should be searching backwards for the
-      // first occurence of a matching object and nullify that instance.  This
-      // will ensure that we preserve the expected sorting order.
-      for (i--; i > 0; i--) {
-        Element* element = &lol->elements_[i];
-        HeapObject* curr_obj = element->obj_;
-        if (curr_obj != obj) {
-            break;  // No more matches.  Let's move on.
-        }
-        result = element;  // Let this earlier match be the result.
-      }
-
-      // Nullify the object.
-      NullifyNonLivePointer(&result->obj_);
-      return;
-    }
-    lol = lol->prev_;
-  }
-}
-
-
-// Sorts the lol.
-void LiveObjectList::Sort() {
-  if (obj_count_ > 0) {
-    Vector<Element> elements_v(elements_, obj_count_);
-    elements_v.Sort(CompareElement);
-  }
-}
-
-
-// Sorts all captured lols starting from the latest.
-void LiveObjectList::SortAll() {
-  LiveObjectList* lol = last();
-  while (lol != NULL) {
-    lol->Sort();
-    lol = lol->prev_;
-  }
-}
-
-
-// Counts the number of objects in the heap.
-static int CountHeapObjects() {
-  int count = 0;
-  // Iterate over all the heap spaces and count the number of objects.
-  HeapIterator iterator;
-  HeapObject* heap_obj = NULL;
-  while ((heap_obj = iterator.next()) != NULL) {
-    count++;
-  }
-  return count;
-}
-
-
-// Captures a current snapshot of all objects in the heap.
-MaybeObject* LiveObjectList::Capture() {
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-  HandleScope scope(isolate);
-
-  // Count the number of objects in the heap.
-  int total_count = CountHeapObjects();
-  int count = total_count;
-  int size = 0;
-
-  LiveObjectList* last_lol = last();
-  if (last_lol != NULL) {
-    count -= last_lol->TotalObjCount();
-  }
-
-  LiveObjectList* lol;
-
-  // Create a lol large enough to track all the objects.
-  lol = new LiveObjectList(last_lol, count);
-  if (lol == NULL) {
-    return NULL;  // No memory to proceed.
-  }
-
-  // The HeapIterator needs to be in its own scope because it disables
-  // allocation, and we need allocate below.
-  {
-    // Iterate over all the heap spaces and add the objects.
-    HeapIterator iterator;
-    HeapObject* heap_obj = NULL;
-    bool failed = false;
-    while (!failed && (heap_obj = iterator.next()) != NULL) {
-      failed = !lol->Add(heap_obj);
-      size += heap_obj->Size();
-    }
-    ASSERT(!failed);
-
-    lol->Sort();
-
-    // Add the current lol to the list of lols.
-    if (last_ != NULL) {
-      last_->next_ = lol;
-    } else {
-      first_ = lol;
-    }
-    last_ = lol;
-
-#ifdef VERIFY_LOL
-    if (FLAG_verify_lol) {
-      Verify(true);
-    }
-#endif
-  }
-
-  Handle<String> id_sym = factory->LookupAsciiSymbol("id");
-  Handle<String> count_sym = factory->LookupAsciiSymbol("count");
-  Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-
-  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
-  if (result->IsFailure()) return Object::cast(*result);
-
-  { MaybeObject* maybe_result = result->SetProperty(*id_sym,
-                                                    Smi::FromInt(lol->id()),
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-  }
-  { MaybeObject* maybe_result = result->SetProperty(*count_sym,
-                                                    Smi::FromInt(total_count),
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-  }
-  { MaybeObject* maybe_result = result->SetProperty(*size_sym,
-                                                    Smi::FromInt(size),
-                                                    NONE,
-                                                    kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-  }
-
-  return *result;
-}
-
-
-// Delete doesn't actually deletes an lol.  It just marks it as invisible since
-// its contents are considered to be part of subsequent lists as well.  The
-// only time we'll actually delete the lol is when we Reset() or if the lol is
-// invisible, and its element count reaches 0.
-bool LiveObjectList::Delete(int id) {
-  LiveObjectList* lol = last();
-  while (lol != NULL) {
-    if (lol->id() == id) {
-      break;
-    }
-    lol = lol->prev_;
-  }
-
-  // If no lol is found for this id, then we fail to delete.
-  if (lol == NULL) return false;
-
-  // Else, mark the lol as invisible i.e. id == 0.
-  lol->id_ = 0;
-  list_count_--;
-  ASSERT(list_count_ >= 0);
-  if (lol->obj_count_ == 0) {
-    // Point the next lol's prev to this lol's prev.
-    LiveObjectList* next = lol->next_;
-    LiveObjectList* prev = lol->prev_;
-    // Point next's prev to prev.
-    if (next != NULL) {
-      next->prev_ = lol->prev_;
-    } else {
-      last_ = lol->prev_;
-    }
-    // Point prev's next to next.
-    if (prev != NULL) {
-      prev->next_ = lol->next_;
-    } else {
-      first_ = lol->next_;
-    }
-
-    lol->prev_ = NULL;
-    lol->next_ = NULL;
-
-    // Delete this now empty and invisible lol.
-    delete lol;
-  }
-
-  // Just in case we've marked everything invisible, then clean up completely.
-  if (list_count_ == 0) {
-    Reset();
-  }
-
-  return true;
-}
-
-
-MaybeObject* LiveObjectList::Dump(int older_id,
-                                  int newer_id,
-                                  int start_idx,
-                                  int dump_limit,
-                                  Handle<JSObject> filter_obj) {
-  if ((older_id < 0) || (newer_id < 0) || (last() == NULL)) {
-    return Failure::Exception();  // Fail: 0 is not a valid lol id.
-  }
-  if (newer_id < older_id) {
-    // They are not in the expected order.  Swap them.
-    int temp = older_id;
-    older_id = newer_id;
-    newer_id = temp;
-  }
-
-  LiveObjectList* newer_lol = FindLolForId(newer_id, last());
-  LiveObjectList* older_lol = FindLolForId(older_id, newer_lol);
-
-  // If the id is defined, and we can't find a LOL for it, then we have an
-  // invalid id.
-  if ((newer_id != 0) && (newer_lol == NULL)) {
-    return Failure::Exception();  // Fail: the newer lol id is invalid.
-  }
-  if ((older_id != 0) && (older_lol == NULL)) {
-    return Failure::Exception();  // Fail: the older lol id is invalid.
-  }
-
-  LolFilter filter(filter_obj);
-  LolDumpWriter writer(older_lol, newer_lol);
-  return DumpPrivate(&writer, start_idx, dump_limit, &filter);
-}
-
-
-MaybeObject* LiveObjectList::DumpPrivate(DumpWriter* writer,
-                                         int start,
-                                         int dump_limit,
-                                         LolFilter* filter) {
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-
-  HandleScope scope(isolate);
-
-  // Calculate the number of entries of the dump.
-  int count = -1;
-  int size = -1;
-  writer->ComputeTotalCountAndSize(filter, &count, &size);
-
-  // Adjust for where to start the dump.
-  if ((start < 0) || (start >= count)) {
-    return Failure::Exception();  // invalid start.
-  }
-
-  int remaining_count = count - start;
-  if (dump_limit > remaining_count) {
-    dump_limit = remaining_count;
-  }
-
-  // Allocate an array to hold the result.
-  Handle<FixedArray> elements_arr = factory->NewFixedArray(dump_limit);
-  if (elements_arr->IsFailure()) return Object::cast(*elements_arr);
-
-  // Fill in the dump.
-  Handle<Object> error;
-  bool success = writer->Write(elements_arr,
-                               start,
-                               dump_limit,
-                               filter,
-                               error);
-  if (!success) return Object::cast(*error);
-
-  MaybeObject* maybe_result;
-
-  // Allocate the result body.
-  Handle<JSObject> body = factory->NewJSObject(isolate->object_function());
-  if (body->IsFailure()) return Object::cast(*body);
-
-  // Set the updated body.count.
-  Handle<String> count_sym = factory->LookupAsciiSymbol("count");
-  maybe_result = body->SetProperty(*count_sym,
-                                   Smi::FromInt(count),
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  // Set the updated body.size if appropriate.
-  if (size >= 0) {
-    Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-    maybe_result = body->SetProperty(*size_sym,
-                                     Smi::FromInt(size),
-                                     NONE,
-                                     kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-  }
-
-  // Set body.first_index.
-  Handle<String> first_sym = factory->LookupAsciiSymbol("first_index");
-  maybe_result = body->SetProperty(*first_sym,
-                                   Smi::FromInt(start),
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  // Allocate the JSArray of the elements.
-  Handle<JSObject> elements = factory->NewJSObject(isolate->array_function());
-  if (elements->IsFailure()) return Object::cast(*elements);
-
-  maybe_result = Handle<JSArray>::cast(elements)->SetContent(*elements_arr);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  // Set body.elements.
-  Handle<String> elements_sym = factory->LookupAsciiSymbol("elements");
-  maybe_result = body->SetProperty(*elements_sym,
-                                   *elements,
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  return *body;
-}
-
-
-MaybeObject* LiveObjectList::Summarize(int older_id,
-                                       int newer_id,
-                                       Handle<JSObject> filter_obj) {
-  if ((older_id < 0) || (newer_id < 0) || (last() == NULL)) {
-    return Failure::Exception();  // Fail: 0 is not a valid lol id.
-  }
-  if (newer_id < older_id) {
-    // They are not in the expected order.  Swap them.
-    int temp = older_id;
-    older_id = newer_id;
-    newer_id = temp;
-  }
-
-  LiveObjectList* newer_lol = FindLolForId(newer_id, last());
-  LiveObjectList* older_lol = FindLolForId(older_id, newer_lol);
-
-  // If the id is defined, and we can't find a LOL for it, then we have an
-  // invalid id.
-  if ((newer_id != 0) && (newer_lol == NULL)) {
-    return Failure::Exception();  // Fail: the newer lol id is invalid.
-  }
-  if ((older_id != 0) && (older_lol == NULL)) {
-    return Failure::Exception();  // Fail: the older lol id is invalid.
-  }
-
-  LolFilter filter(filter_obj);
-  LolSummaryWriter writer(older_lol, newer_lol);
-  return SummarizePrivate(&writer, &filter, false);
-}
-
-
-// Creates a summary report for the debugger.
-// Note: the SummaryWriter takes care of iterating over objects and filling in
-// the summary.
-MaybeObject* LiveObjectList::SummarizePrivate(SummaryWriter* writer,
-                                              LolFilter* filter,
-                                              bool is_tracking_roots) {
-  HandleScope scope;
-  MaybeObject* maybe_result;
-
-  LiveObjectSummary summary(filter);
-  writer->Write(&summary);
-
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-
-  // The result body will look like this:
-  // body: {
-  //   count: <total_count>,
-  //   size: <total_size>,
-  //   found_root: <boolean>,       // optional.
-  //   found_weak_root: <boolean>,  // optional.
-  //   summary: [
-  //     {
-  //       desc: "<object type name>",
-  //       count: <count>,
-  //       size: size
-  //     },
-  //     ...
-  //   ]
-  // }
-
-  // Prefetch some needed symbols.
-  Handle<String> desc_sym = factory->LookupAsciiSymbol("desc");
-  Handle<String> count_sym = factory->LookupAsciiSymbol("count");
-  Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-  Handle<String> summary_sym = factory->LookupAsciiSymbol("summary");
-
-  // Allocate the summary array.
-  int entries_count = summary.GetNumberOfEntries();
-  Handle<FixedArray> summary_arr =
-      factory->NewFixedArray(entries_count);
-  if (summary_arr->IsFailure()) return Object::cast(*summary_arr);
-
-  int idx = 0;
-  for (int i = 0; i < LiveObjectSummary::kNumberOfEntries; i++) {
-    // Allocate the summary record.
-    Handle<JSObject> detail = factory->NewJSObject(isolate->object_function());
-    if (detail->IsFailure()) return Object::cast(*detail);
-
-    // Fill in the summary record.
-    LiveObjectType type = static_cast<LiveObjectType>(i);
-    int count = summary.Count(type);
-    if (count) {
-      const char* desc_cstr = GetObjectTypeDesc(type);
-      Handle<String> desc = factory->LookupAsciiSymbol(desc_cstr);
-      int size = summary.Size(type);
-
-      maybe_result = detail->SetProperty(*desc_sym,
-                                         *desc,
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-      maybe_result = detail->SetProperty(*count_sym,
-                                         Smi::FromInt(count),
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-      maybe_result = detail->SetProperty(*size_sym,
-                                         Smi::FromInt(size),
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-
-      summary_arr->set(idx++, *detail);
-    }
-  }
-
-  // Wrap the summary fixed array in a JS array.
-  Handle<JSObject> summary_obj =
-    factory->NewJSObject(isolate->array_function());
-  if (summary_obj->IsFailure()) return Object::cast(*summary_obj);
-
-  maybe_result = Handle<JSArray>::cast(summary_obj)->SetContent(*summary_arr);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  // Create the body object.
-  Handle<JSObject> body = factory->NewJSObject(isolate->object_function());
-  if (body->IsFailure()) return Object::cast(*body);
-
-  // Fill out the body object.
-  int total_count = summary.total_count();
-  int total_size = summary.total_size();
-  maybe_result = body->SetProperty(*count_sym,
-                                   Smi::FromInt(total_count),
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  maybe_result = body->SetProperty(*size_sym,
-                                   Smi::FromInt(total_size),
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  if (is_tracking_roots) {
-    int found_root = summary.found_root();
-    int found_weak_root = summary.found_weak_root();
-    Handle<String> root_sym = factory->LookupAsciiSymbol("found_root");
-    Handle<String> weak_root_sym =
-        factory->LookupAsciiSymbol("found_weak_root");
-    maybe_result = body->SetProperty(*root_sym,
-                                     Smi::FromInt(found_root),
-                                     NONE,
-                                     kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-    maybe_result = body->SetProperty(*weak_root_sym,
-                                     Smi::FromInt(found_weak_root),
-                                     NONE,
-                                     kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-  }
-
-  maybe_result = body->SetProperty(*summary_sym,
-                                   *summary_obj,
-                                   NONE,
-                                   kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  return *body;
-}
-
-
-// Returns an array listing the captured lols.
-// Note: only dumps the section starting at start_idx and only up to
-// dump_limit entries.
-MaybeObject* LiveObjectList::Info(int start_idx, int dump_limit) {
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-
-  HandleScope scope(isolate);
-  MaybeObject* maybe_result;
-
-  int total_count = LiveObjectList::list_count();
-  int dump_count = total_count;
-
-  // Adjust for where to start the dump.
-  if (total_count == 0) {
-      start_idx = 0;  // Ensure this to get an empty list.
-  } else if ((start_idx < 0) || (start_idx >= total_count)) {
-    return Failure::Exception();  // invalid start.
-  }
-  dump_count -= start_idx;
-
-  // Adjust for the dump limit.
-  if (dump_count > dump_limit) {
-    dump_count = dump_limit;
-  }
-
-  // Allocate an array to hold the result.
-  Handle<FixedArray> list = factory->NewFixedArray(dump_count);
-  if (list->IsFailure()) return Object::cast(*list);
-
-  // Prefetch some needed symbols.
-  Handle<String> id_sym = factory->LookupAsciiSymbol("id");
-  Handle<String> count_sym = factory->LookupAsciiSymbol("count");
-  Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-
-  // Fill the array with the lol details.
-  int idx = 0;
-  LiveObjectList* lol = first_;
-  while ((lol != NULL) && (idx < start_idx)) {  // Skip tail entries.
-    if (lol->id() != 0) {
-      idx++;
-    }
-    lol = lol->next();
-  }
-  idx = 0;
-  while ((lol != NULL) && (dump_limit != 0)) {
-    if (lol->id() != 0) {
-      int count;
-      int size;
-      count = lol->GetTotalObjCountAndSize(&size);
-
-      Handle<JSObject> detail =
-          factory->NewJSObject(isolate->object_function());
-      if (detail->IsFailure()) return Object::cast(*detail);
-
-      maybe_result = detail->SetProperty(*id_sym,
-                                         Smi::FromInt(lol->id()),
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-      maybe_result = detail->SetProperty(*count_sym,
-                                         Smi::FromInt(count),
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-      maybe_result = detail->SetProperty(*size_sym,
-                                         Smi::FromInt(size),
-                                         NONE,
-                                         kNonStrictMode);
-      if (maybe_result->IsFailure()) return maybe_result;
-      list->set(idx++, *detail);
-      dump_limit--;
-    }
-    lol = lol->next();
-  }
-
-  // Return the result as a JS array.
-  Handle<JSObject> lols = factory->NewJSObject(isolate->array_function());
-
-  maybe_result = Handle<JSArray>::cast(lols)->SetContent(*list);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
-  if (result->IsFailure()) return Object::cast(*result);
-
-  maybe_result = result->SetProperty(*count_sym,
-                                     Smi::FromInt(total_count),
-                                     NONE,
-                                     kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  Handle<String> first_sym = factory->LookupAsciiSymbol("first_index");
-  maybe_result = result->SetProperty(*first_sym,
-                                     Smi::FromInt(start_idx),
-                                     NONE,
-                                     kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  Handle<String> lists_sym = factory->LookupAsciiSymbol("lists");
-  maybe_result = result->SetProperty(*lists_sym,
-                                     *lols,
-                                     NONE,
-                                     kNonStrictMode);
-  if (maybe_result->IsFailure()) return maybe_result;
-
-  return *result;
-}
-
-
-// Deletes all captured lols.
-void LiveObjectList::Reset() {
-  LiveObjectList* lol = last();
-  // Just delete the last.  Each lol will delete it's prev automatically.
-  delete lol;
-
-  next_element_id_ = 1;
-  list_count_ = 0;
-  last_id_ = 0;
-  first_ = NULL;
-  last_ = NULL;
-}
-
-
-// Gets the object for the specified obj id.
-Object* LiveObjectList::GetObj(int obj_id) {
-  Element* element = FindElementFor<int>(GetElementId, obj_id);
-  if (element != NULL) {
-    return Object::cast(element->obj_);
-  }
-  return HEAP->undefined_value();
-}
-
-
-// Gets the obj id for the specified address if valid.
-int LiveObjectList::GetObjId(Object* obj) {
-  // Make a heap object pointer from the address.
-  HeapObject* hobj = HeapObject::cast(obj);
-  Element* element = FindElementFor<HeapObject*>(GetElementObj, hobj);
-  if (element != NULL) {
-    return element->id_;
-  }
-  return 0;  // Invalid address.
-}
-
-
-// Gets the obj id for the specified address if valid.
-Object* LiveObjectList::GetObjId(Handle<String> address) {
-  SmartArrayPointer<char> addr_str =
-      address->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
-
-  Isolate* isolate = Isolate::Current();
-
-  // Extract the address value from the string.
-  int value =
-      static_cast<int>(StringToInt(isolate->unicode_cache(), *address, 16));
-  Object* obj = reinterpret_cast<Object*>(value);
-  return Smi::FromInt(GetObjId(obj));
-}
-
-
-// Helper class for copying HeapObjects.
-class LolVisitor: public ObjectVisitor {
- public:
-  LolVisitor(HeapObject* target, Handle<HeapObject> handle_to_skip)
-      : target_(target), handle_to_skip_(handle_to_skip), found_(false) {}
-
-  void VisitPointer(Object** p) { CheckPointer(p); }
-
-  void VisitPointers(Object** start, Object** end) {
-    // Check all HeapObject pointers in [start, end).
-    for (Object** p = start; !found() && p < end; p++) CheckPointer(p);
-  }
-
-  inline bool found() const { return found_; }
-  inline bool reset() { return found_ = false; }
-
- private:
-  inline void CheckPointer(Object** p) {
-    Object* object = *p;
-    if (HeapObject::cast(object) == target_) {
-      // We may want to skip this handle because the handle may be a local
-      // handle in a handle scope in one of our callers.  Once we return,
-      // that handle will be popped.  Hence, we don't want to count it as
-      // a root that would have kept the target object alive.
-      if (!handle_to_skip_.is_null() &&
-          handle_to_skip_.location() == reinterpret_cast<HeapObject**>(p)) {
-        return;  // Skip this handle.
-      }
-      found_ = true;
-    }
-  }
-
-  HeapObject* target_;
-  Handle<HeapObject> handle_to_skip_;
-  bool found_;
-};
-
-
-inline bool AddRootRetainerIfFound(const LolVisitor& visitor,
-                                   LolFilter* filter,
-                                   LiveObjectSummary* summary,
-                                   void (*SetRootFound)(LiveObjectSummary* s),
-                                   int start,
-                                   int dump_limit,
-                                   int* total_count,
-                                   Handle<FixedArray> retainers_arr,
-                                   int* count,
-                                   int* index,
-                                   const char* root_name,
-                                   Handle<String> id_sym,
-                                   Handle<String> desc_sym,
-                                   Handle<String> size_sym,
-                                   Handle<Object> error) {
-  HandleScope scope;
-
-  // Scratch handles.
-  Handle<JSObject> detail;
-  Handle<String> desc;
-  Handle<HeapObject> retainer;
-
-  if (visitor.found()) {
-    if (!filter->is_active()) {
-      (*total_count)++;
-      if (summary) {
-        SetRootFound(summary);
-      } else if ((*total_count > start) && ((*index) < dump_limit)) {
-        (*count)++;
-        if (!retainers_arr.is_null()) {
-          return AddObjDetail(retainers_arr,
-                              (*index)++,
-                              0,
-                              retainer,
-                              root_name,
-                              id_sym,
-                              desc_sym,
-                              size_sym,
-                              detail,
-                              desc,
-                              error);
-        }
-      }
-    }
-  }
-  return true;
-}
-
-
-inline void SetFoundRoot(LiveObjectSummary* summary) {
-  summary->set_found_root();
-}
-
-
-inline void SetFoundWeakRoot(LiveObjectSummary* summary) {
-  summary->set_found_weak_root();
-}
-
-
-int LiveObjectList::GetRetainers(Handle<HeapObject> target,
-                                 Handle<JSObject> instance_filter,
-                                 Handle<FixedArray> retainers_arr,
-                                 int start,
-                                 int dump_limit,
-                                 int* total_count,
-                                 LolFilter* filter,
-                                 LiveObjectSummary* summary,
-                                 JSFunction* arguments_function,
-                                 Handle<Object> error) {
-  HandleScope scope;
-
-  // Scratch handles.
-  Handle<JSObject> detail;
-  Handle<String> desc;
-  Handle<HeapObject> retainer;
-
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-
-  // Prefetch some needed symbols.
-  Handle<String> id_sym = factory->LookupAsciiSymbol("id");
-  Handle<String> desc_sym = factory->LookupAsciiSymbol("desc");
-  Handle<String> size_sym = factory->LookupAsciiSymbol("size");
-
-  NoHandleAllocation ha;
-  int count = 0;
-  int index = 0;
-  Handle<JSObject> last_obj;
-
-  *total_count = 0;
-
-  // Iterate roots.
-  LolVisitor lol_visitor(*target, target);
-  isolate->heap()->IterateStrongRoots(&lol_visitor, VISIT_ALL);
-  if (!AddRootRetainerIfFound(lol_visitor,
-                              filter,
-                              summary,
-                              SetFoundRoot,
-                              start,
-                              dump_limit,
-                              total_count,
-                              retainers_arr,
-                              &count,
-                              &index,
-                              "<root>",
-                              id_sym,
-                              desc_sym,
-                              size_sym,
-                              error)) {
-    return -1;
-  }
-
-  lol_visitor.reset();
-  isolate->heap()->IterateWeakRoots(&lol_visitor, VISIT_ALL);
-  if (!AddRootRetainerIfFound(lol_visitor,
-                              filter,
-                              summary,
-                              SetFoundWeakRoot,
-                              start,
-                              dump_limit,
-                              total_count,
-                              retainers_arr,
-                              &count,
-                              &index,
-                              "<weak root>",
-                              id_sym,
-                              desc_sym,
-                              size_sym,
-                              error)) {
-    return -1;
-  }
-
-  // Iterate the live object lists.
-  LolIterator it(NULL, last());
-  for (it.Init(); !it.Done() && (index < dump_limit); it.Next()) {
-    HeapObject* heap_obj = it.Obj();
-
-    // Only look at all JSObjects.
-    if (heap_obj->IsJSObject()) {
-      // Skip context extension objects and argument arrays as these are
-      // checked in the context of functions using them.
-      JSObject* obj = JSObject::cast(heap_obj);
-      if (obj->IsJSContextExtensionObject() ||
-          obj->map()->constructor() == arguments_function) {
-        continue;
-      }
-
-      // Check if the JS object has a reference to the object looked for.
-      if (obj->ReferencesObject(*target)) {
-        // Check instance filter if supplied. This is normally used to avoid
-        // references from mirror objects (see Runtime_IsInPrototypeChain).
-        if (!instance_filter->IsUndefined()) {
-          Object* V = obj;
-          while (true) {
-            Object* prototype = V->GetPrototype();
-            if (prototype->IsNull()) {
-              break;
-            }
-            if (*instance_filter == prototype) {
-              obj = NULL;  // Don't add this object.
-              break;
-            }
-            V = prototype;
-          }
-        }
-
-        if (obj != NULL) {
-          // Skip objects that have been filtered out.
-          if (filter->Matches(heap_obj)) {
-            continue;
-          }
-
-          // Valid reference found add to instance array if supplied an update
-          // count.
-          last_obj = Handle<JSObject>(obj);
-          (*total_count)++;
-
-          if (summary != NULL) {
-            summary->Add(heap_obj);
-          } else if ((*total_count > start) && (index < dump_limit)) {
-            count++;
-            if (!retainers_arr.is_null()) {
-              retainer = Handle<HeapObject>(heap_obj);
-              bool success = AddObjDetail(retainers_arr,
-                                          index++,
-                                          it.Id(),
-                                          retainer,
-                                          NULL,
-                                          id_sym,
-                                          desc_sym,
-                                          size_sym,
-                                          detail,
-                                          desc,
-                                          error);
-              if (!success) return -1;
-            }
-          }
-        }
-      }
-    }
-  }
-
-  // Check for circular reference only. This can happen when the object is only
-  // referenced from mirrors and has a circular reference in which case the
-  // object is not really alive and would have been garbage collected if not
-  // referenced from the mirror.
-
-  if (*total_count == 1 && !last_obj.is_null() && *last_obj == *target) {
-    count = 0;
-    *total_count = 0;
-  }
-
-  return count;
-}
-
-
-MaybeObject* LiveObjectList::GetObjRetainers(int obj_id,
-                                             Handle<JSObject> instance_filter,
-                                             bool verbose,
-                                             int start,
-                                             int dump_limit,
-                                             Handle<JSObject> filter_obj) {
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-  Heap* heap = isolate->heap();
-
-  HandleScope scope(isolate);
-
-  // Get the target object.
-  HeapObject* heap_obj = HeapObject::cast(GetObj(obj_id));
-  if (heap_obj == heap->undefined_value()) {
-    return heap_obj;
-  }
-
-  Handle<HeapObject> target = Handle<HeapObject>(heap_obj);
-
-  // Get the constructor function for context extension and arguments array.
-  JSObject* arguments_boilerplate =
-      isolate->context()->native_context()->arguments_boilerplate();
-  JSFunction* arguments_function =
-      JSFunction::cast(arguments_boilerplate->map()->constructor());
-
-  Handle<JSFunction> args_function = Handle<JSFunction>(arguments_function);
-  LolFilter filter(filter_obj);
-
-  if (!verbose) {
-    RetainersSummaryWriter writer(target, instance_filter, args_function);
-    return SummarizePrivate(&writer, &filter, true);
-
-  } else {
-    RetainersDumpWriter writer(target, instance_filter, args_function);
-    Object* body_obj;
-    MaybeObject* maybe_result =
-        DumpPrivate(&writer, start, dump_limit, &filter);
-    if (!maybe_result->ToObject(&body_obj)) {
-      return maybe_result;
-    }
-
-    // Set body.id.
-    Handle<JSObject> body = Handle<JSObject>(JSObject::cast(body_obj));
-    Handle<String> id_sym = factory->LookupAsciiSymbol("id");
-    maybe_result = body->SetProperty(*id_sym,
-                                     Smi::FromInt(obj_id),
-                                     NONE,
-                                     kNonStrictMode);
-    if (maybe_result->IsFailure()) return maybe_result;
-
-    return *body;
-  }
-}
-
-
-Object* LiveObjectList::PrintObj(int obj_id) {
-  Object* obj = GetObj(obj_id);
-  if (!obj) {
-    return HEAP->undefined_value();
-  }
-
-  EmbeddedVector<char, 128> temp_filename;
-  static int temp_count = 0;
-  const char* path_prefix = ".";
-
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-  Heap* heap = isolate->heap();
-
-  if (FLAG_lol_workdir) {
-    path_prefix = FLAG_lol_workdir;
-  }
-  OS::SNPrintF(temp_filename, "%s/lol-print-%d", path_prefix, ++temp_count);
-
-  FILE* f = OS::FOpen(temp_filename.start(), "w+");
-
-  PrintF(f, "@%d ", LiveObjectList::GetObjId(obj));
-#ifdef OBJECT_PRINT
-#ifdef INSPECTOR
-  Inspector::DumpObjectType(f, obj);
-#endif  // INSPECTOR
-  PrintF(f, "\n");
-  obj->Print(f);
-#else  // !OBJECT_PRINT
-  obj->ShortPrint(f);
-#endif  // !OBJECT_PRINT
-  PrintF(f, "\n");
-  Flush(f);
-  fclose(f);
-
-  // Create a string from the temp_file.
-  // Note: the mmapped resource will take care of closing the file.
-  MemoryMappedExternalResource* resource =
-      new MemoryMappedExternalResource(temp_filename.start(), true);
-  if (resource->exists() && !resource->is_empty()) {
-    Handle<String> dump_string =
-        factory->NewExternalStringFromAscii(resource);
-    heap->external_string_table()->AddString(*dump_string);
-    return *dump_string;
-  } else {
-    delete resource;
-  }
-  return HEAP->undefined_value();
-}
-
-
-class LolPathTracer: public PathTracer {
- public:
-  LolPathTracer(FILE* out,
-                Object* search_target,
-                WhatToFind what_to_find)
-      : PathTracer(search_target, what_to_find, VISIT_ONLY_STRONG), out_(out) {}
-
- private:
-  void ProcessResults();
-
-  FILE* out_;
-};
-
-
-void LolPathTracer::ProcessResults() {
-  if (found_target_) {
-    PrintF(out_, "=====================================\n");
-    PrintF(out_, "====        Path to object       ====\n");
-    PrintF(out_, "=====================================\n\n");
-
-    ASSERT(!object_stack_.is_empty());
-    Object* prev = NULL;
-    for (int i = 0, index = 0; i < object_stack_.length(); i++) {
-      Object* obj = object_stack_[i];
-
-      // Skip this object if it is basically the internals of the
-      // previous object (which would have dumped its details already).
-      if (prev && prev->IsJSObject() &&
-          (obj != search_target_)) {
-        JSObject* jsobj = JSObject::cast(prev);
-        if (obj->IsFixedArray() &&
-            jsobj->properties() == FixedArray::cast(obj)) {
-          // Skip this one because it would have been printed as the
-          // properties of the last object already.
-          continue;
-        } else if (obj->IsHeapObject() &&
-                   jsobj->elements() == HeapObject::cast(obj)) {
-          // Skip this one because it would have been printed as the
-          // elements of the last object already.
-          continue;
-        }
-      }
-
-      // Print a connecting arrow.
-      if (i > 0) PrintF(out_, "\n     |\n     |\n     V\n\n");
-
-      // Print the object index.
-      PrintF(out_, "[%d] ", ++index);
-
-      // Print the LOL object ID:
-      int id = LiveObjectList::GetObjId(obj);
-      if (id > 0) PrintF(out_, "@%d ", id);
-
-#ifdef OBJECT_PRINT
-#ifdef INSPECTOR
-      Inspector::DumpObjectType(out_, obj);
-#endif  // INSPECTOR
-      PrintF(out_, "\n");
-      obj->Print(out_);
-#else  // !OBJECT_PRINT
-      obj->ShortPrint(out_);
-      PrintF(out_, "\n");
-#endif  // !OBJECT_PRINT
-      Flush(out_);
-    }
-    PrintF(out_, "\n");
-    PrintF(out_, "=====================================\n\n");
-    Flush(out_);
-  }
-}
-
-
-Object* LiveObjectList::GetPathPrivate(HeapObject* obj1, HeapObject* obj2) {
-  EmbeddedVector<char, 128> temp_filename;
-  static int temp_count = 0;
-  const char* path_prefix = ".";
-
-  if (FLAG_lol_workdir) {
-    path_prefix = FLAG_lol_workdir;
-  }
-  OS::SNPrintF(temp_filename, "%s/lol-getpath-%d", path_prefix, ++temp_count);
-
-  FILE* f = OS::FOpen(temp_filename.start(), "w+");
-
-  Isolate* isolate = Isolate::Current();
-  Factory* factory = isolate->factory();
-  Heap* heap = isolate->heap();
-
-  // Save the previous verbosity.
-  bool prev_verbosity = FLAG_use_verbose_printer;
-  FLAG_use_verbose_printer = false;
-
-  // Dump the paths.
-  {
-    // The tracer needs to be scoped because its usage asserts no allocation,
-    // and we need to allocate the result string below.
-    LolPathTracer tracer(f, obj2, LolPathTracer::FIND_FIRST);
-
-    bool found = false;
-    if (obj1 == NULL) {
-      // Check for ObjectGroups that references this object.
-      // TODO(mlam): refactor this to be more modular.
-      {
-        List<ObjectGroup*>* groups = isolate->global_handles()->object_groups();
-        for (int i = 0; i < groups->length(); i++) {
-          ObjectGroup* group = groups->at(i);
-          if (group == NULL) continue;
-
-          bool found_group = false;
-          for (size_t j = 0; j < group->length_; j++) {
-            Object* object = *(group->objects_[j]);
-            HeapObject* hobj = HeapObject::cast(object);
-            if (obj2 == hobj) {
-              found_group = true;
-              break;
-            }
-          }
-
-          if (found_group) {
-            PrintF(f,
-                   "obj %p is a member of object group %p {\n",
-                   reinterpret_cast<void*>(obj2),
-                   reinterpret_cast<void*>(group));
-            for (size_t j = 0; j < group->length_; j++) {
-              Object* object = *(group->objects_[j]);
-              if (!object->IsHeapObject()) continue;
-
-              HeapObject* hobj = HeapObject::cast(object);
-              int id = GetObjId(hobj);
-              if (id != 0) {
-                PrintF(f, "  @%d:", id);
-              } else {
-                PrintF(f, "  <no id>:");
-              }
-
-              char buffer[512];
-              GenerateObjectDesc(hobj, buffer, sizeof(buffer));
-              PrintF(f, " %s", buffer);
-              if (hobj == obj2) {
-                PrintF(f, " <===");
-              }
-              PrintF(f, "\n");
-            }
-            PrintF(f, "}\n");
-          }
-        }
-      }
-
-      PrintF(f, "path from roots to obj %p\n", reinterpret_cast<void*>(obj2));
-      heap->IterateRoots(&tracer, VISIT_ONLY_STRONG);
-      found = tracer.found();
-
-      if (!found) {
-        PrintF(f, "  No paths found. Checking symbol tables ...\n");
-        SymbolTable* symbol_table = HEAP->raw_unchecked_symbol_table();
-        tracer.VisitPointers(reinterpret_cast<Object**>(&symbol_table),
-                             reinterpret_cast<Object**>(&symbol_table)+1);
-        found = tracer.found();
-        if (!found) {
-          symbol_table->IteratePrefix(&tracer);
-          found = tracer.found();
-        }
-      }
-
-      if (!found) {
-        PrintF(f, "  No paths found. Checking weak roots ...\n");
-        // Check weak refs next.
-        isolate->global_handles()->IterateWeakRoots(&tracer);
-        found = tracer.found();
-      }
-
-    } else {
-      PrintF(f, "path from obj %p to obj %p:\n",
-             reinterpret_cast<void*>(obj1), reinterpret_cast<void*>(obj2));
-      tracer.TracePathFrom(reinterpret_cast<Object**>(&obj1));
-      found = tracer.found();
-    }
-
-    if (!found) {
-      PrintF(f, "  No paths found\n\n");
-    }
-  }
-
-  // Flush and clean up the dumped file.
-  Flush(f);
-  fclose(f);
-
-  // Restore the previous verbosity.
-  FLAG_use_verbose_printer = prev_verbosity;
-
-  // Create a string from the temp_file.
-  // Note: the mmapped resource will take care of closing the file.
-  MemoryMappedExternalResource* resource =
-      new MemoryMappedExternalResource(temp_filename.start(), true);
-  if (resource->exists() && !resource->is_empty()) {
-    Handle<String> path_string =
-        factory->NewExternalStringFromAscii(resource);
-    heap->external_string_table()->AddString(*path_string);
-    return *path_string;
-  } else {
-    delete resource;
-  }
-  return heap->undefined_value();
-}
-
-
-Object* LiveObjectList::GetPath(int obj_id1,
-                                int obj_id2,
-                                Handle<JSObject> instance_filter) {
-  HandleScope scope;
-
-  // Get the target object.
-  HeapObject* obj1 = NULL;
-  if (obj_id1 != 0) {
-    obj1 = HeapObject::cast(GetObj(obj_id1));
-    if (obj1 == HEAP->undefined_value()) {
-      return obj1;
-    }
-  }
-
-  HeapObject* obj2 = HeapObject::cast(GetObj(obj_id2));
-  if (obj2 == HEAP->undefined_value()) {
-    return obj2;
-  }
-
-  return GetPathPrivate(obj1, obj2);
-}
-
-
-void LiveObjectList::DoProcessNonLive(HeapObject* obj) {
-  // We should only be called if we have at least one lol to search.
-  ASSERT(last() != NULL);
-  Element* element = last()->Find(obj);
-  if (element != NULL) {
-    NullifyNonLivePointer(&element->obj_);
-  }
-}
-
-
-void LiveObjectList::IterateElementsPrivate(ObjectVisitor* v) {
-  LiveObjectList* lol = last();
-  while (lol != NULL) {
-    Element* elements = lol->elements_;
-    int count = lol->obj_count_;
-    for (int i = 0; i < count; i++) {
-      HeapObject** p = &elements[i].obj_;
-      v->VisitPointer(reinterpret_cast<Object** >(p));
-    }
-    lol = lol->prev_;
-  }
-}
-
-
-// Purpose: Called by GCEpilogue to purge duplicates.  Not to be called by
-// anyone else.
-void LiveObjectList::PurgeDuplicates() {
-  bool is_sorted = false;
-  LiveObjectList* lol = last();
-  if (!lol) {
-    return;  // Nothing to purge.
-  }
-
-  int total_count = lol->TotalObjCount();
-  if (!total_count) {
-    return;  // Nothing to purge.
-  }
-
-  Element* elements = NewArray<Element>(total_count);
-  int count = 0;
-
-  // Copy all the object elements into a consecutive array.
-  while (lol) {
-    memcpy(&elements[count], lol->elements_, lol->obj_count_ * sizeof(Element));
-    count += lol->obj_count_;
-    lol = lol->prev_;
-  }
-  qsort(elements, total_count, sizeof(Element),
-        reinterpret_cast<RawComparer>(CompareElement));
-
-  ASSERT(count == total_count);
-
-  // Iterate over all objects in the consolidated list and check for dups.
-  total_count--;
-  for (int i = 0; i < total_count; ) {
-    Element* curr = &elements[i];
-    HeapObject* curr_obj = curr->obj_;
-    int j = i+1;
-    bool done = false;
-
-    while (!done && (j < total_count)) {
-      // Process if the element's object is still live after the current GC.
-      // Non-live objects will be converted to SMIs i.e. not HeapObjects.
-      if (curr_obj->IsHeapObject()) {
-        Element* next = &elements[j];
-        HeapObject* next_obj = next->obj_;
-        if (next_obj->IsHeapObject()) {
-          if (curr_obj != next_obj) {
-            done = true;
-            continue;  // Live object but no match.  Move on.
-          }
-
-          // NOTE: we've just GCed the LOLs.  Hence, they are no longer sorted.
-          // Since we detected at least one need to search for entries, we'll
-          // sort it to enable the use of NullifyMostRecent() below.  We only
-          // need to sort it once (except for one exception ... see below).
-          if (!is_sorted) {
-            SortAll();
-            is_sorted = true;
-          }
-
-          // We have a match.  Need to nullify the most recent ref to this
-          // object.  We'll keep the oldest ref:
-          // Note: we will nullify the element record in the LOL
-          // database, not in the local sorted copy of the elements.
-          NullifyMostRecent(curr_obj);
-        }
-      }
-      // Either the object was already marked for purging, or we just marked
-      // it.  Either way, if there's more than one dup, then we need to check
-      // the next element for another possible dup against the current as well
-      // before we move on.  So, here we go.
-      j++;
-    }
-
-    // We can move on to checking the match on the next element.
-    i = j;
-  }
-
-  DeleteArray<Element>(elements);
-}
-
-
-// Purpose: Purges dead objects and resorts the LOLs.
-void LiveObjectList::GCEpiloguePrivate() {
-  // Note: During the GC, ConsStrings may be collected and pointers may be
-  // forwarded to its constituent string.  As a result, we may find dupes of
-  // objects references in the LOL list.
-  // Another common way we get dups is that free chunks that have been swept
-  // in the oldGen heap may be kept as ByteArray objects in a free list.
-  //
-  // When we promote live objects from the youngGen, the object may be moved
-  // to the start of these free chunks.  Since there is no free or move event
-  // for the free chunks, their addresses will show up 2 times: once for their
-  // original free ByteArray selves, and once for the newly promoted youngGen
-  // object.  Hence, we can get a duplicate address in the LOL again.
-  //
-  // We need to eliminate these dups because the LOL implementation expects to
-  // only have at most one unique LOL reference to any object at any time.
-  PurgeDuplicates();
-
-  // After the GC, sweep away all free'd Elements and compact.
-  LiveObjectList* prev = NULL;
-  LiveObjectList* next = NULL;
-
-  // Iterating from the youngest lol to the oldest lol.
-  for (LiveObjectList* lol = last(); lol; lol = prev) {
-    Element* elements = lol->elements_;
-    prev = lol->prev();  // Save the prev.
-
-    // Remove any references to collected objects.
-    int i = 0;
-    while (i < lol->obj_count_) {
-      Element& element = elements[i];
-      if (!element.obj_->IsHeapObject()) {
-        // If the HeapObject address was converted into a SMI, then this
-        // is a dead object.  Copy the last element over this one.
-        element = elements[lol->obj_count_ - 1];
-        lol->obj_count_--;
-        // We've just moved the last element into this index.  We'll revisit
-        // this index again.  Hence, no need to increment the iterator.
-      } else {
-        i++;  // Look at the next element next.
-      }
-    }
-
-    int new_count = lol->obj_count_;
-
-    // Check if there are any more elements to keep after purging the dead ones.
-    if (new_count == 0) {
-      DeleteArray<Element>(elements);
-      lol->elements_ = NULL;
-      lol->capacity_ = 0;
-      ASSERT(lol->obj_count_ == 0);
-
-      // If the list is also invisible, the clean up the list as well.
-      if (lol->id_ == 0) {
-        // Point the next lol's prev to this lol's prev.
-        if (next) {
-          next->prev_ = lol->prev_;
-        } else {
-          last_ = lol->prev_;
-        }
-
-        // Delete this now empty and invisible lol.
-        delete lol;
-
-        // Don't point the next to this lol since it is now deleted.
-        // Leave the next pointer pointing to the current lol.
-        continue;
-      }
-
-    } else {
-      // If the obj_count_ is less than the capacity and the difference is
-      // greater than a specified threshold, then we should shrink the list.
-      int diff = lol->capacity_ - new_count;
-      const int kMaxUnusedSpace = 64;
-      if (diff > kMaxUnusedSpace) {  // Threshold for shrinking.
-        // Shrink the list.
-        Element* new_elements = NewArray<Element>(new_count);
-        memcpy(new_elements, elements, new_count * sizeof(Element));
-
-        DeleteArray<Element>(elements);
-        lol->elements_ = new_elements;
-        lol->capacity_ = new_count;
-      }
-      ASSERT(lol->obj_count_ == new_count);
-
-      lol->Sort();  // We've moved objects.  Re-sort in case.
-    }
-
-    // Save the next (for the previous link) in case we need it later.
-    next = lol;
-  }
-
-#ifdef VERIFY_LOL
-  if (FLAG_verify_lol) {
-    Verify();
-  }
-#endif
-}
-
-
-#ifdef VERIFY_LOL
-void LiveObjectList::Verify(bool match_heap_exactly) {
-  OS::Print("Verifying the LiveObjectList database:\n");
-
-  LiveObjectList* lol = last();
-  if (lol == NULL) {
-    OS::Print("  No lol database to verify\n");
-    return;
-  }
-
-  OS::Print("  Preparing the lol database ...\n");
-  int total_count = lol->TotalObjCount();
-
-  Element* elements = NewArray<Element>(total_count);
-  int count = 0;
-
-  // Copy all the object elements into a consecutive array.
-  OS::Print("  Copying the lol database ...\n");
-  while (lol != NULL) {
-    memcpy(&elements[count], lol->elements_, lol->obj_count_ * sizeof(Element));
-    count += lol->obj_count_;
-    lol = lol->prev_;
-  }
-  qsort(elements, total_count, sizeof(Element),
-        reinterpret_cast<RawComparer>(CompareElement));
-
-  ASSERT(count == total_count);
-
-  // Iterate over all objects in the heap and check for:
-  // 1. object in LOL but not in heap i.e. error.
-  // 2. object in heap but not in LOL (possibly not an error).  Usually
-  //    just means that we don't have the a capture of the latest heap.
-  //    That is unless we did this verify immediately after a capture,
-  //    and specified match_heap_exactly = true.
-
-  int number_of_heap_objects = 0;
-  int number_of_matches = 0;
-  int number_not_in_heap = total_count;
-  int number_not_in_lol = 0;
-
-  OS::Print("  Start verify ...\n");
-  OS::Print("  Verifying ...");
-  Flush();
-  HeapIterator iterator;
-  HeapObject* heap_obj = NULL;
-  while ((heap_obj = iterator.next()) != NULL) {
-    number_of_heap_objects++;
-
-    // Check if the heap_obj is in the lol.
-    Element key;
-    key.obj_ = heap_obj;
-
-    Element* result = reinterpret_cast<Element*>(
-        bsearch(&key, elements, total_count, sizeof(Element),
-                reinterpret_cast<RawComparer>(CompareElement)));
-
-    if (result != NULL) {
-      number_of_matches++;
-      number_not_in_heap--;
-      // Mark it as found by changing it into a SMI (mask off low bit).
-      // Note: we cannot use HeapObject::cast() here because it asserts that
-      // the HeapObject bit is set on the address, but we're unsetting it on
-      // purpose here for our marking.
-      result->obj_ = reinterpret_cast<HeapObject*>(heap_obj->address());
-
-    } else {
-      number_not_in_lol++;
-      if (match_heap_exactly) {
-        OS::Print("heap object %p NOT in lol database\n", heap_obj);
-      }
-    }
-    // Show some sign of life.
-    if (number_of_heap_objects % 1000 == 0) {
-      OS::Print(".");
-      fflush(stdout);
-    }
-  }
-  OS::Print("\n");
-
-  // Reporting lol objects not found in the heap.
-  if (number_not_in_heap) {
-    int found = 0;
-    for (int i = 0; (i < total_count) && (found < number_not_in_heap); i++) {
-      Element& element = elements[i];
-      if (element.obj_->IsHeapObject()) {
-        OS::Print("lol database object [%d of %d] %p NOT in heap\n",
-                  i, total_count, element.obj_);
-        found++;
-      }
-    }
-  }
-
-  DeleteArray<Element>(elements);
-
-  OS::Print("number of objects in lol database %d\n", total_count);
-  OS::Print("number of heap objects .......... %d\n", number_of_heap_objects);
-  OS::Print("number of matches ............... %d\n", number_of_matches);
-  OS::Print("number NOT in heap .............. %d\n", number_not_in_heap);
-  OS::Print("number NOT in lol database ...... %d\n", number_not_in_lol);
-
-  if (number_of_matches != total_count) {
-    OS::Print("  *** ERROR: "
-              "NOT all lol database objects match heap objects.\n");
-  }
-  if (number_not_in_heap != 0) {
-    OS::Print("  *** ERROR: %d lol database objects not found in heap.\n",
-              number_not_in_heap);
-  }
-  if (match_heap_exactly) {
-    if (!(number_not_in_lol == 0)) {
-      OS::Print("  *** ERROR: %d heap objects NOT found in lol database.\n",
-                number_not_in_lol);
-    }
-  }
-
-  ASSERT(number_of_matches == total_count);
-  ASSERT(number_not_in_heap == 0);
-  ASSERT(number_not_in_lol == (number_of_heap_objects - total_count));
-  if (match_heap_exactly) {
-    ASSERT(total_count == number_of_heap_objects);
-    ASSERT(number_not_in_lol == 0);
-  }
-
-  OS::Print("  Verify the lol database is sorted ...\n");
-  lol = last();
-  while (lol != NULL) {
-    Element* elements = lol->elements_;
-    for (int i = 0; i < lol->obj_count_ - 1; i++) {
-      if (elements[i].obj_ >= elements[i+1].obj_) {
-        OS::Print("  *** ERROR: lol %p obj[%d] %p > obj[%d] %p\n",
-                  lol, i, elements[i].obj_, i+1, elements[i+1].obj_);
-      }
-    }
-    lol = lol->prev_;
-  }
-
-  OS::Print("  DONE verifying.\n\n\n");
-}
-
-
-void LiveObjectList::VerifyNotInFromSpace() {
-  OS::Print("VerifyNotInFromSpace() ...\n");
-  LolIterator it(NULL, last());
-  Heap* heap = ISOLATE->heap();
-  int i = 0;
-  for (it.Init(); !it.Done(); it.Next()) {
-    HeapObject* heap_obj = it.Obj();
-    if (heap->InFromSpace(heap_obj)) {
-      OS::Print(" ERROR: VerifyNotInFromSpace: [%d] obj %p in From space %p\n",
-                i++, heap_obj, Heap::new_space()->FromSpaceStart());
-    }
-  }
-}
-#endif  // VERIFY_LOL
-
-
-} }  // namespace v8::internal
-
-#endif  // LIVE_OBJECT_LIST