// Copyright 2012 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_OBJECTS_VISITING_INL_H_ #define V8_OBJECTS_VISITING_INL_H_ namespace v8 { namespace internal { template<typename StaticVisitor> void StaticNewSpaceVisitor<StaticVisitor>::Initialize() { table_.Register(kVisitShortcutCandidate, &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor, int>::Visit); table_.Register(kVisitConsString, &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor, int>::Visit); table_.Register(kVisitSlicedString, &FixedBodyVisitor<StaticVisitor, SlicedString::BodyDescriptor, int>::Visit); table_.Register(kVisitSymbol, &FixedBodyVisitor<StaticVisitor, Symbol::BodyDescriptor, int>::Visit); table_.Register(kVisitFixedArray, &FlexibleBodyVisitor<StaticVisitor, FixedArray::BodyDescriptor, int>::Visit); table_.Register(kVisitFixedDoubleArray, &VisitFixedDoubleArray); table_.Register(kVisitFixedTypedArray, &VisitFixedTypedArray); table_.Register(kVisitFixedFloat64Array, &VisitFixedTypedArray); table_.Register(kVisitNativeContext, &FixedBodyVisitor<StaticVisitor, Context::ScavengeBodyDescriptor, int>::Visit); table_.Register(kVisitByteArray, &VisitByteArray); table_.Register(kVisitSharedFunctionInfo, &FixedBodyVisitor<StaticVisitor, SharedFunctionInfo::BodyDescriptor, int>::Visit); table_.Register(kVisitSeqOneByteString, &VisitSeqOneByteString); table_.Register(kVisitSeqTwoByteString, &VisitSeqTwoByteString); table_.Register(kVisitJSFunction, &VisitJSFunction); table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer); table_.Register(kVisitJSTypedArray, &VisitJSTypedArray); table_.Register(kVisitJSDataView, &VisitJSDataView); table_.Register(kVisitFreeSpace, &VisitFreeSpace); table_.Register(kVisitJSWeakCollection, &JSObjectVisitor::Visit); table_.Register(kVisitJSRegExp, &JSObjectVisitor::Visit); table_.template RegisterSpecializations<DataObjectVisitor, kVisitDataObject, kVisitDataObjectGeneric>(); table_.template RegisterSpecializations<JSObjectVisitor, kVisitJSObject, kVisitJSObjectGeneric>(); table_.template RegisterSpecializations<StructVisitor, kVisitStruct, kVisitStructGeneric>(); } template<typename StaticVisitor> int StaticNewSpaceVisitor<StaticVisitor>::VisitJSArrayBuffer( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); STATIC_ASSERT( JSArrayBuffer::kWeakFirstViewOffset == JSArrayBuffer::kWeakNextOffset + kPointerSize); VisitPointers( heap, HeapObject::RawField(object, JSArrayBuffer::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset)); VisitPointers( heap, HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset + 2 * kPointerSize), HeapObject::RawField(object, JSArrayBuffer::kSizeWithInternalFields)); return JSArrayBuffer::kSizeWithInternalFields; } template<typename StaticVisitor> int StaticNewSpaceVisitor<StaticVisitor>::VisitJSTypedArray( Map* map, HeapObject* object) { VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSTypedArray::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSTypedArray::kWeakNextOffset)); VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSTypedArray::kWeakNextOffset + kPointerSize), HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields)); return JSTypedArray::kSizeWithInternalFields; } template<typename StaticVisitor> int StaticNewSpaceVisitor<StaticVisitor>::VisitJSDataView( Map* map, HeapObject* object) { VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSDataView::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSDataView::kWeakNextOffset)); VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSDataView::kWeakNextOffset + kPointerSize), HeapObject::RawField(object, JSDataView::kSizeWithInternalFields)); return JSDataView::kSizeWithInternalFields; } 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(kVisitSymbol, &FixedBodyVisitor<StaticVisitor, Symbol::BodyDescriptor, void>::Visit); table_.Register(kVisitFixedArray, &FixedArrayVisitor::Visit); table_.Register(kVisitFixedDoubleArray, &DataObjectVisitor::Visit); table_.Register(kVisitFixedTypedArray, &DataObjectVisitor::Visit); table_.Register(kVisitFixedFloat64Array, &DataObjectVisitor::Visit); table_.Register(kVisitConstantPoolArray, &VisitConstantPoolArray); table_.Register(kVisitNativeContext, &VisitNativeContext); table_.Register(kVisitAllocationSite, &VisitAllocationSite); table_.Register(kVisitByteArray, &DataObjectVisitor::Visit); table_.Register(kVisitFreeSpace, &DataObjectVisitor::Visit); table_.Register(kVisitSeqOneByteString, &DataObjectVisitor::Visit); table_.Register(kVisitSeqTwoByteString, &DataObjectVisitor::Visit); table_.Register(kVisitJSWeakCollection, &VisitWeakCollection); 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); table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer); table_.Register(kVisitJSTypedArray, &VisitJSTypedArray); table_.Register(kVisitJSDataView, &VisitJSDataView); // Registration for kVisitJSRegExp is done by StaticVisitor. table_.Register(kVisitCell, &FixedBodyVisitor<StaticVisitor, Cell::BodyDescriptor, void>::Visit); table_.Register(kVisitPropertyCell, &VisitPropertyCell); 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); // TODO(ulan): It could be better to record slots only for strongly embedded // objects here and record slots for weakly embedded object during clearing // of non-live references in mark-compact. if (!rinfo->host()->IsWeakObject(object)) { StaticVisitor::MarkObject(heap, object); } } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitCell( Heap* heap, RelocInfo* rinfo) { ASSERT(rinfo->rmode() == RelocInfo::CELL); Cell* cell = rinfo->target_cell(); // No need to record slots because the cell space is not compacted during GC. if (!rinfo->host()->IsWeakObject(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 || target->ic_state() == GENERIC || target->ic_state() == POLYMORPHIC || heap->flush_monomorphic_ics() || heap->isolate()->serializer_enabled() || target->ic_age() != heap->global_ic_age() || target->is_invalidated_weak_stub())) { IC::Clear(heap->isolate(), rinfo->pc(), rinfo->host()->constant_pool()); 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 = Context::cast(object)->RawFieldOfElementAt(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. if (FLAG_collect_maps && map_object->CanTransition()) { MarkMapContents(heap, map_object); } else { StaticVisitor::VisitPointers(heap, HeapObject::RawField(object, Map::kPointerFieldsBeginOffset), HeapObject::RawField(object, Map::kPointerFieldsEndOffset)); } } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitPropertyCell( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); Object** slot = HeapObject::RawField(object, PropertyCell::kDependentCodeOffset); if (FLAG_collect_maps) { // Mark property cell dependent codes array but do not push it onto marking // stack, this will make references from it weak. We will clean dead // codes when we iterate over property cells in ClearNonLiveReferences. HeapObject* obj = HeapObject::cast(*slot); heap->mark_compact_collector()->RecordSlot(slot, slot, obj); StaticVisitor::MarkObjectWithoutPush(heap, obj); } else { StaticVisitor::VisitPointer(heap, slot); } StaticVisitor::VisitPointers(heap, HeapObject::RawField(object, PropertyCell::kPointerFieldsBeginOffset), HeapObject::RawField(object, PropertyCell::kPointerFieldsEndOffset)); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitAllocationSite( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); Object** slot = HeapObject::RawField(object, AllocationSite::kDependentCodeOffset); if (FLAG_collect_maps) { // Mark allocation site dependent codes array but do not push it onto // marking stack, this will make references from it weak. We will clean // dead codes when we iterate over allocation sites in // ClearNonLiveReferences. HeapObject* obj = HeapObject::cast(*slot); heap->mark_compact_collector()->RecordSlot(slot, slot, obj); StaticVisitor::MarkObjectWithoutPush(heap, obj); } else { StaticVisitor::VisitPointer(heap, slot); } StaticVisitor::VisitPointers(heap, HeapObject::RawField(object, AllocationSite::kPointerFieldsBeginOffset), HeapObject::RawField(object, AllocationSite::kPointerFieldsEndOffset)); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitWeakCollection( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); JSWeakCollection* weak_collection = reinterpret_cast<JSWeakCollection*>(object); // Enqueue weak collection in linked list of encountered weak collections. if (weak_collection->next() == heap->undefined_value()) { weak_collection->set_next(heap->encountered_weak_collections()); heap->set_encountered_weak_collections(weak_collection); } // Skip visiting the backing hash table containing the mappings and the // pointer to the other enqueued weak collections, both are post-processed. StaticVisitor::VisitPointers(heap, HeapObject::RawField(object, JSWeakCollection::kPropertiesOffset), HeapObject::RawField(object, JSWeakCollection::kTableOffset)); STATIC_ASSERT(JSWeakCollection::kTableOffset + kPointerSize == JSWeakCollection::kNextOffset); STATIC_ASSERT(JSWeakCollection::kNextOffset + kPointerSize == JSWeakCollection::kSize); // Partially initialized weak collection is enqueued, but table is ignored. if (!weak_collection->table()->IsHashTable()) return; // Mark the backing hash table without pushing it on the marking stack. Object** slot = HeapObject::RawField(object, JSWeakCollection::kTableOffset); HeapObject* obj = HeapObject::cast(*slot); heap->mark_compact_collector()->RecordSlot(slot, slot, obj); StaticVisitor::MarkObjectWithoutPush(heap, obj); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitCode( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); Code* code = Code::cast(object); if (FLAG_age_code && !heap->isolate()->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()); } if (FLAG_cleanup_code_caches_at_gc) { shared->ClearTypeFeedbackInfo(); } if (FLAG_cache_optimized_code && FLAG_flush_optimized_code_cache && !shared->optimized_code_map()->IsSmi()) { // Always flush the optimized code map if requested by flag. shared->ClearOptimizedCodeMap(); } MarkCompactCollector* collector = heap->mark_compact_collector(); if (collector->is_code_flushing_enabled()) { if (FLAG_cache_optimized_code && !shared->optimized_code_map()->IsSmi()) { // Add the shared function info holding an optimized code map to // the code flusher for processing of code maps after marking. collector->code_flusher()->AddOptimizedCodeMap(shared); // Treat all references within the code map weakly by marking the // code map itself but not pushing it onto the marking deque. FixedArray* code_map = FixedArray::cast(shared->optimized_code_map()); StaticVisitor::MarkObjectWithoutPush(heap, code_map); } 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; } } else { if (FLAG_cache_optimized_code && !shared->optimized_code_map()->IsSmi()) { // Flush optimized code map on major GCs without code flushing, // needed because cached code doesn't contain breakpoints. shared->ClearOptimizedCodeMap(); } } VisitSharedFunctionInfoStrongCode(heap, object); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitConstantPoolArray( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); ConstantPoolArray* array = ConstantPoolArray::cast(object); ConstantPoolArray::Iterator code_iter(array, ConstantPoolArray::CODE_PTR); while (!code_iter.is_finished()) { Address code_entry = reinterpret_cast<Address>( array->RawFieldOfElementAt(code_iter.next_index())); StaticVisitor::VisitCodeEntry(heap, code_entry); } ConstantPoolArray::Iterator heap_iter(array, ConstantPoolArray::HEAP_PTR); while (!heap_iter.is_finished()) { Object** slot = array->RawFieldOfElementAt(heap_iter.next_index()); HeapObject* object = HeapObject::cast(*slot); heap->mark_compact_collector()->RecordSlot(slot, slot, object); bool is_weak_object = (array->get_weak_object_state() == ConstantPoolArray::WEAK_OBJECTS_IN_OPTIMIZED_CODE && Code::IsWeakObjectInOptimizedCode(object)) || (array->get_weak_object_state() == ConstantPoolArray::WEAK_OBJECTS_IN_IC && Code::IsWeakObjectInIC(object)); if (!is_weak_object) { StaticVisitor::MarkObject(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->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>::VisitJSArrayBuffer( Map* map, HeapObject* object) { Heap* heap = map->GetHeap(); STATIC_ASSERT( JSArrayBuffer::kWeakFirstViewOffset == JSArrayBuffer::kWeakNextOffset + kPointerSize); StaticVisitor::VisitPointers( heap, HeapObject::RawField(object, JSArrayBuffer::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset)); StaticVisitor::VisitPointers( heap, HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset + 2 * kPointerSize), HeapObject::RawField(object, JSArrayBuffer::kSizeWithInternalFields)); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitJSTypedArray( Map* map, HeapObject* object) { StaticVisitor::VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSTypedArray::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSTypedArray::kWeakNextOffset)); StaticVisitor::VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSTypedArray::kWeakNextOffset + kPointerSize), HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields)); } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitJSDataView( Map* map, HeapObject* object) { StaticVisitor::VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSDataView::BodyDescriptor::kStartOffset), HeapObject::RawField(object, JSDataView::kWeakNextOffset)); StaticVisitor::VisitPointers( map->GetHeap(), HeapObject::RawField(object, JSDataView::kWeakNextOffset + kPointerSize), HeapObject::RawField(object, JSDataView::kSizeWithInternalFields)); } 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. if (map->HasTransitionArray()) { TransitionArray* transitions = map->transitions(); MarkTransitionArray(heap, transitions); } // Since descriptor arrays are potentially shared, ensure that only the // descriptors that belong to this map are marked. The first time a // non-empty descriptor array is marked, its header is also visited. The slot // holding the descriptor array will be implicitly recorded when the pointer // fields of this map are visited. DescriptorArray* descriptors = map->instance_descriptors(); if (StaticVisitor::MarkObjectWithoutPush(heap, descriptors) && descriptors->length() > 0) { StaticVisitor::VisitPointers(heap, descriptors->GetFirstElementAddress(), descriptors->GetDescriptorEndSlot(0)); } int start = 0; int end = map->NumberOfOwnDescriptors(); if (start < end) { StaticVisitor::VisitPointers(heap, descriptors->GetDescriptorStartSlot(start), descriptors->GetDescriptorEndSlot(end)); } // Mark prototype dependent codes array but do not push it onto marking // stack, this will make references from it weak. We will clean dead // codes when we iterate over maps in ClearNonLiveTransitions. Object** slot = HeapObject::RawField(map, Map::kDependentCodeOffset); HeapObject* obj = HeapObject::cast(*slot); heap->mark_compact_collector()->RecordSlot(slot, slot, obj); StaticVisitor::MarkObjectWithoutPush(heap, obj); // 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->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()) { return false; } // The function must have a valid context and not be a builtin. if (!IsValidNonBuiltinContext(function->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; } // We do not (yet?) flush code for generator functions, because we don't know // if there are still live activations (generator objects) on the heap. if (shared_info->is_generator()) { return false; } // If this is a full script wrapped in a function we do not flush the code. if (shared_info->is_toplevel()) { return false; } // If this is a function initialized with %SetCode then the one-to-one // relation between SharedFunctionInfo and Code is broken. if (shared_info->dont_flush()) { return false; } // Check age of code. If code aging is disabled we never flush. if (!FLAG_age_code || !shared_info->code()->IsOld()) { return false; } return true; } template<typename StaticVisitor> void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoStrongCode( Heap* heap, HeapObject* 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) { 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) | RelocInfo::ModeMask(RelocInfo::CELL) | RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) | RelocInfo::ModeMask(RelocInfo::JS_RETURN) | RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) | RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY); // There are two places where we iterate code bodies: here and the // templated CodeIterateBody (below). They should be kept in sync. IteratePointer(v, kRelocationInfoOffset); IteratePointer(v, kHandlerTableOffset); IteratePointer(v, kDeoptimizationDataOffset); IteratePointer(v, kTypeFeedbackInfoOffset); IterateNextCodeLink(v, kNextCodeLinkOffset); IteratePointer(v, kConstantPoolOffset); RelocIterator it(this, mode_mask); Isolate* isolate = this->GetIsolate(); for (; !it.done(); it.next()) { it.rinfo()->Visit(isolate, v); } } template<typename StaticVisitor> void Code::CodeIterateBody(Heap* heap) { int mode_mask = RelocInfo::kCodeTargetMask | RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) | RelocInfo::ModeMask(RelocInfo::CELL) | RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) | RelocInfo::ModeMask(RelocInfo::JS_RETURN) | RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) | RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY); // There are two places where we iterate code bodies: here and the non- // templated CodeIterateBody (above). They should be kept in sync. StaticVisitor::VisitPointer( heap, reinterpret_cast<Object**>(this->address() + kRelocationInfoOffset)); StaticVisitor::VisitPointer( heap, reinterpret_cast<Object**>(this->address() + kHandlerTableOffset)); StaticVisitor::VisitPointer( heap, reinterpret_cast<Object**>(this->address() + kDeoptimizationDataOffset)); StaticVisitor::VisitPointer( heap, reinterpret_cast<Object**>(this->address() + kTypeFeedbackInfoOffset)); StaticVisitor::VisitNextCodeLink( heap, reinterpret_cast<Object**>(this->address() + kNextCodeLinkOffset)); StaticVisitor::VisitPointer( heap, reinterpret_cast<Object**>(this->address() + kConstantPoolOffset)); RelocIterator it(this, mode_mask); for (; !it.done(); it.next()) { it.rinfo()->template Visit<StaticVisitor>(heap); } } } } // namespace v8::internal #endif // V8_OBJECTS_VISITING_INL_H_