1 files changed, 533 insertions, 2 deletions

diff --git a/src/3rdparty/v8/src/objects-visiting-inl.h b/src/3rdparty/v8/src/objects-visiting-inl.h
index 8ba92f7..71635ca 100644
--- a/src/3rdparty/v8/src/objects-visiting-inl.h
+++ b/src/3rdparty/v8/src/objects-visiting-inl.h
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 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:
@@ -56,7 +56,7 @@ void StaticNewSpaceVisitor<StaticVisitor>::Initialize() {
 
   table_.Register(kVisitFixedDoubleArray, &VisitFixedDoubleArray);
 
-  table_.Register(kVisitGlobalContext,
+  table_.Register(kVisitNativeContext,
                   &FixedBodyVisitor<StaticVisitor,
                   Context::ScavengeBodyDescriptor,
                   int>::Visit);
@@ -93,6 +93,537 @@ void StaticNewSpaceVisitor<StaticVisitor>::Initialize() {
 }
 
 
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::Initialize() {
+  table_.Register(kVisitShortcutCandidate,
+                  &FixedBodyVisitor<StaticVisitor,
+                  ConsString::BodyDescriptor,
+                  void>::Visit);
+
+  table_.Register(kVisitConsString,
+                  &FixedBodyVisitor<StaticVisitor,
+                  ConsString::BodyDescriptor,
+                  void>::Visit);
+
+  table_.Register(kVisitSlicedString,
+                  &FixedBodyVisitor<StaticVisitor,
+                  SlicedString::BodyDescriptor,
+                  void>::Visit);
+
+  table_.Register(kVisitFixedArray,
+                  &FlexibleBodyVisitor<StaticVisitor,
+                  FixedArray::BodyDescriptor,
+                  void>::Visit);
+
+  table_.Register(kVisitFixedDoubleArray, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitNativeContext, &VisitNativeContext);
+
+  table_.Register(kVisitByteArray, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitFreeSpace, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitSeqAsciiString, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitSeqTwoByteString, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitJSWeakMap, &StaticVisitor::VisitJSWeakMap);
+
+  table_.Register(kVisitOddball,
+                  &FixedBodyVisitor<StaticVisitor,
+                  Oddball::BodyDescriptor,
+                  void>::Visit);
+
+  table_.Register(kVisitMap, &VisitMap);
+
+  table_.Register(kVisitCode, &VisitCode);
+
+  table_.Register(kVisitSharedFunctionInfo, &VisitSharedFunctionInfo);
+
+  table_.Register(kVisitJSFunction, &VisitJSFunction);
+
+  // Registration for kVisitJSRegExp is done by StaticVisitor.
+
+  table_.Register(kVisitPropertyCell,
+                  &FixedBodyVisitor<StaticVisitor,
+                  JSGlobalPropertyCell::BodyDescriptor,
+                  void>::Visit);
+
+  table_.template RegisterSpecializations<DataObjectVisitor,
+                                          kVisitDataObject,
+                                          kVisitDataObjectGeneric>();
+
+  table_.template RegisterSpecializations<JSObjectVisitor,
+                                          kVisitJSObject,
+                                          kVisitJSObjectGeneric>();
+
+  table_.template RegisterSpecializations<StructObjectVisitor,
+                                          kVisitStruct,
+                                          kVisitStructGeneric>();
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeEntry(
+    Heap* heap, Address entry_address) {
+  Code* code = Code::cast(Code::GetObjectFromEntryAddress(entry_address));
+  heap->mark_compact_collector()->RecordCodeEntrySlot(entry_address, code);
+  StaticVisitor::MarkObject(heap, code);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitEmbeddedPointer(
+    Heap* heap, RelocInfo* rinfo) {
+  ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
+  ASSERT(!rinfo->target_object()->IsConsString());
+  HeapObject* object = HeapObject::cast(rinfo->target_object());
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, object);
+  StaticVisitor::MarkObject(heap, object);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitGlobalPropertyCell(
+    Heap* heap, RelocInfo* rinfo) {
+  ASSERT(rinfo->rmode() == RelocInfo::GLOBAL_PROPERTY_CELL);
+  JSGlobalPropertyCell* cell = rinfo->target_cell();
+  StaticVisitor::MarkObject(heap, cell);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitDebugTarget(
+    Heap* heap, RelocInfo* rinfo) {
+  ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
+          rinfo->IsPatchedReturnSequence()) ||
+         (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
+          rinfo->IsPatchedDebugBreakSlotSequence()));
+  Code* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget(
+    Heap* heap, RelocInfo* rinfo) {
+  ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
+  Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
+  // Monomorphic ICs are preserved when possible, but need to be flushed
+  // when they might be keeping a Context alive, or when the heap is about
+  // to be serialized.
+  if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub()
+      && (target->ic_state() == MEGAMORPHIC || heap->flush_monomorphic_ics() ||
+          Serializer::enabled() || target->ic_age() != heap->global_ic_age())) {
+    IC::Clear(rinfo->pc());
+    target = Code::GetCodeFromTargetAddress(rinfo->target_address());
+  }
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeAgeSequence(
+    Heap* heap, RelocInfo* rinfo) {
+  ASSERT(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
+  Code* target = rinfo->code_age_stub();
+  ASSERT(target != NULL);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitNativeContext(
+    Map* map, HeapObject* object) {
+  FixedBodyVisitor<StaticVisitor,
+                   Context::MarkCompactBodyDescriptor,
+                   void>::Visit(map, object);
+
+  MarkCompactCollector* collector = map->GetHeap()->mark_compact_collector();
+  for (int idx = Context::FIRST_WEAK_SLOT;
+       idx < Context::NATIVE_CONTEXT_SLOTS;
+       ++idx) {
+    Object** slot =
+        HeapObject::RawField(object, FixedArray::OffsetOfElementAt(idx));
+    collector->RecordSlot(slot, slot, *slot);
+  }
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitMap(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  Map* map_object = Map::cast(object);
+
+  // Clears the cache of ICs related to this map.
+  if (FLAG_cleanup_code_caches_at_gc) {
+    map_object->ClearCodeCache(heap);
+  }
+
+  // When map collection is enabled we have to mark through map's
+  // transitions and back pointers in a special way to make these links
+  // weak.  Only maps for subclasses of JSReceiver can have transitions.
+  STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+  if (FLAG_collect_maps &&
+      map_object->instance_type() >= FIRST_JS_RECEIVER_TYPE) {
+    MarkMapContents(heap, map_object);
+  } else {
+    StaticVisitor::VisitPointers(heap,
+        HeapObject::RawField(object, Map::kPointerFieldsBeginOffset),
+        HeapObject::RawField(object, Map::kPointerFieldsEndOffset));
+  }
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCode(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  Code* code = Code::cast(object);
+  if (FLAG_cleanup_code_caches_at_gc) {
+    code->ClearTypeFeedbackCells(heap);
+  }
+  if (FLAG_age_code && !Serializer::enabled()) {
+    code->MakeOlder(heap->mark_compact_collector()->marking_parity());
+  }
+  code->CodeIterateBody<StaticVisitor>(heap);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfo(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
+  if (shared->ic_age() != heap->global_ic_age()) {
+    shared->ResetForNewContext(heap->global_ic_age());
+  }
+  MarkCompactCollector* collector = heap->mark_compact_collector();
+  if (collector->is_code_flushing_enabled()) {
+    if (IsFlushable(heap, shared)) {
+      // This function's code looks flushable. But we have to postpone
+      // the decision until we see all functions that point to the same
+      // SharedFunctionInfo because some of them might be optimized.
+      // That would also make the non-optimized version of the code
+      // non-flushable, because it is required for bailing out from
+      // optimized code.
+      collector->code_flusher()->AddCandidate(shared);
+      // Treat the reference to the code object weakly.
+      VisitSharedFunctionInfoWeakCode(heap, object);
+      return;
+    }
+  }
+  VisitSharedFunctionInfoStrongCode(heap, object);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunction(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  JSFunction* function = JSFunction::cast(object);
+  MarkCompactCollector* collector = heap->mark_compact_collector();
+  if (collector->is_code_flushing_enabled()) {
+    if (IsFlushable(heap, function)) {
+      // This function's code looks flushable. But we have to postpone
+      // the decision until we see all functions that point to the same
+      // SharedFunctionInfo because some of them might be optimized.
+      // That would also make the non-optimized version of the code
+      // non-flushable, because it is required for bailing out from
+      // optimized code.
+      collector->code_flusher()->AddCandidate(function);
+      // Visit shared function info immediately to avoid double checking
+      // of its flushability later. This is just an optimization because
+      // the shared function info would eventually be visited.
+      SharedFunctionInfo* shared = function->unchecked_shared();
+      if (StaticVisitor::MarkObjectWithoutPush(heap, shared)) {
+        StaticVisitor::MarkObject(heap, shared->map());
+        VisitSharedFunctionInfoWeakCode(heap, shared);
+      }
+      // Treat the reference to the code object weakly.
+      VisitJSFunctionWeakCode(heap, object);
+      return;
+    } else {
+      // Visit all unoptimized code objects to prevent flushing them.
+      StaticVisitor::MarkObject(heap, function->shared()->code());
+      if (function->code()->kind() == Code::OPTIMIZED_FUNCTION) {
+        MarkInlinedFunctionsCode(heap, function->code());
+      }
+    }
+  }
+  VisitJSFunctionStrongCode(heap, object);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSRegExp(
+    Map* map, HeapObject* object) {
+  int last_property_offset =
+      JSRegExp::kSize + kPointerSize * map->inobject_properties();
+  StaticVisitor::VisitPointers(map->GetHeap(),
+      HeapObject::RawField(object, JSRegExp::kPropertiesOffset),
+      HeapObject::RawField(object, last_property_offset));
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::MarkMapContents(
+    Heap* heap, Map* map) {
+  // Make sure that the back pointer stored either in the map itself or
+  // inside its transitions array is marked. Skip recording the back
+  // pointer slot since map space is not compacted.
+  StaticVisitor::MarkObject(heap, HeapObject::cast(map->GetBackPointer()));
+
+  // Treat pointers in the transitions array as weak and also mark that
+  // array to prevent visiting it later. Skip recording the transition
+  // array slot, since it will be implicitly recorded when the pointer
+  // fields of this map are visited.
+  TransitionArray* transitions = map->unchecked_transition_array();
+  if (transitions->IsTransitionArray()) {
+    MarkTransitionArray(heap, transitions);
+  } else {
+    // Already marked by marking map->GetBackPointer() above.
+    ASSERT(transitions->IsMap() || transitions->IsUndefined());
+  }
+
+  // Mark the pointer fields of the Map. Since the transitions array has
+  // been marked already, it is fine that one of these fields contains a
+  // pointer to it.
+  StaticVisitor::VisitPointers(heap,
+      HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
+      HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::MarkTransitionArray(
+    Heap* heap, TransitionArray* transitions) {
+  if (!StaticVisitor::MarkObjectWithoutPush(heap, transitions)) return;
+
+  // Simple transitions do not have keys nor prototype transitions.
+  if (transitions->IsSimpleTransition()) return;
+
+  if (transitions->HasPrototypeTransitions()) {
+    // Mark prototype transitions array but do not push it onto marking
+    // stack, this will make references from it weak. We will clean dead
+    // prototype transitions in ClearNonLiveTransitions.
+    Object** slot = transitions->GetPrototypeTransitionsSlot();
+    HeapObject* obj = HeapObject::cast(*slot);
+    heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+    StaticVisitor::MarkObjectWithoutPush(heap, obj);
+  }
+
+  for (int i = 0; i < transitions->number_of_transitions(); ++i) {
+    StaticVisitor::VisitPointer(heap, transitions->GetKeySlot(i));
+  }
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::MarkInlinedFunctionsCode(
+    Heap* heap, Code* code) {
+  // For optimized functions we should retain both non-optimized version
+  // of its code and non-optimized version of all inlined functions.
+  // This is required to support bailing out from inlined code.
+  DeoptimizationInputData* data =
+      DeoptimizationInputData::cast(code->deoptimization_data());
+  FixedArray* literals = data->LiteralArray();
+  for (int i = 0, count = data->InlinedFunctionCount()->value();
+       i < count;
+       i++) {
+    JSFunction* inlined = JSFunction::cast(literals->get(i));
+    StaticVisitor::MarkObject(heap, inlined->shared()->code());
+  }
+}
+
+
+inline static bool IsValidNonBuiltinContext(Object* context) {
+  return context->IsContext() &&
+      !Context::cast(context)->global_object()->IsJSBuiltinsObject();
+}
+
+
+inline static bool HasSourceCode(Heap* heap, SharedFunctionInfo* info) {
+  Object* undefined = heap->undefined_value();
+  return (info->script() != undefined) &&
+      (reinterpret_cast<Script*>(info->script())->source() != undefined);
+}
+
+
+template<typename StaticVisitor>
+bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
+    Heap* heap, JSFunction* function) {
+  SharedFunctionInfo* shared_info = function->unchecked_shared();
+
+  // Code is either on stack, in compilation cache or referenced
+  // by optimized version of function.
+  MarkBit code_mark = Marking::MarkBitFrom(function->code());
+  if (code_mark.Get()) {
+    if (!FLAG_age_code) {
+      if (!Marking::MarkBitFrom(shared_info).Get()) {
+        shared_info->set_code_age(0);
+      }
+    }
+    return false;
+  }
+
+  // The function must have a valid context and not be a builtin.
+  if (!IsValidNonBuiltinContext(function->unchecked_context())) {
+    return false;
+  }
+
+  // We do not (yet) flush code for optimized functions.
+  if (function->code() != shared_info->code()) {
+    return false;
+  }
+
+  // Check age of optimized code.
+  if (FLAG_age_code && !function->code()->IsOld()) {
+    return false;
+  }
+
+  return IsFlushable(heap, shared_info);
+}
+
+
+template<typename StaticVisitor>
+bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
+    Heap* heap, SharedFunctionInfo* shared_info) {
+  // Code is either on stack, in compilation cache or referenced
+  // by optimized version of function.
+  MarkBit code_mark = Marking::MarkBitFrom(shared_info->code());
+  if (code_mark.Get()) {
+    return false;
+  }
+
+  // The function must be compiled and have the source code available,
+  // to be able to recompile it in case we need the function again.
+  if (!(shared_info->is_compiled() && HasSourceCode(heap, shared_info))) {
+    return false;
+  }
+
+  // We never flush code for API functions.
+  Object* function_data = shared_info->function_data();
+  if (function_data->IsFunctionTemplateInfo()) {
+    return false;
+  }
+
+  // Only flush code for functions.
+  if (shared_info->code()->kind() != Code::FUNCTION) {
+    return false;
+  }
+
+  // Function must be lazy compilable.
+  if (!shared_info->allows_lazy_compilation()) {
+    return false;
+  }
+
+  // If this is a full script wrapped in a function we do no flush the code.
+  if (shared_info->is_toplevel()) {
+    return false;
+  }
+
+  if (FLAG_age_code) {
+    return shared_info->code()->IsOld();
+  } else {
+    // How many collections newly compiled code object will survive before being
+    // flushed.
+    static const int kCodeAgeThreshold = 5;
+
+    // Age this shared function info.
+    if (shared_info->code_age() < kCodeAgeThreshold) {
+      shared_info->set_code_age(shared_info->code_age() + 1);
+      return false;
+    }
+    return true;
+  }
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoStrongCode(
+    Heap* heap, HeapObject* object) {
+  StaticVisitor::BeforeVisitingSharedFunctionInfo(object);
+  Object** start_slot =
+      HeapObject::RawField(object,
+                           SharedFunctionInfo::BodyDescriptor::kStartOffset);
+  Object** end_slot =
+      HeapObject::RawField(object,
+                           SharedFunctionInfo::BodyDescriptor::kEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoWeakCode(
+    Heap* heap, HeapObject* object) {
+  StaticVisitor::BeforeVisitingSharedFunctionInfo(object);
+  Object** name_slot =
+      HeapObject::RawField(object, SharedFunctionInfo::kNameOffset);
+  StaticVisitor::VisitPointer(heap, name_slot);
+
+  // Skip visiting kCodeOffset as it is treated weakly here.
+  STATIC_ASSERT(SharedFunctionInfo::kNameOffset + kPointerSize ==
+      SharedFunctionInfo::kCodeOffset);
+  STATIC_ASSERT(SharedFunctionInfo::kCodeOffset + kPointerSize ==
+      SharedFunctionInfo::kOptimizedCodeMapOffset);
+
+  Object** start_slot =
+      HeapObject::RawField(object,
+                           SharedFunctionInfo::kOptimizedCodeMapOffset);
+  Object** end_slot =
+      HeapObject::RawField(object,
+                           SharedFunctionInfo::BodyDescriptor::kEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionStrongCode(
+    Heap* heap, HeapObject* object) {
+  Object** start_slot =
+      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
+  Object** end_slot =
+      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+
+  VisitCodeEntry(heap, object->address() + JSFunction::kCodeEntryOffset);
+  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
+      JSFunction::kPrototypeOrInitialMapOffset);
+
+  start_slot =
+      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
+  end_slot =
+      HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionWeakCode(
+    Heap* heap, HeapObject* object) {
+  Object** start_slot =
+      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
+  Object** end_slot =
+      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+
+  // Skip visiting kCodeEntryOffset as it is treated weakly here.
+  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
+      JSFunction::kPrototypeOrInitialMapOffset);
+
+  start_slot =
+      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
+  end_slot =
+      HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
 void Code::CodeIterateBody(ObjectVisitor* v) {
   int mode_mask = RelocInfo::kCodeTargetMask |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |