factory.cc.svn-base

Google浏览器V8内核代码

                                            *shared,
                                            Heap::the_hole_value()),
                     JSFunction);
}


Handle<JSFunction> Factory::NewFunctionWithPrototype(Handle<String> name,
                                                     InstanceType type,
                                                     int instance_size,
                                                     Handle<JSObject> prototype,
                                                     Handle<Code> code,
                                                     bool force_initial_map) {
  // Allocate the function
  Handle<JSFunction> function = NewFunction(name, prototype);

  function->set_code(*code);

  if (force_initial_map ||
      type != JS_OBJECT_TYPE ||
      instance_size != JSObject::kHeaderSize) {
    Handle<Map> initial_map = NewMap(type, instance_size);
    function->set_initial_map(*initial_map);
    initial_map->set_constructor(*function);
  }

  // Set function.prototype and give the prototype a constructor
  // property that refers to the function.
  SetPrototypeProperty(function, prototype);
  SetProperty(prototype, Factory::constructor_symbol(), function, DONT_ENUM);
  return function;
}

Handle<Code> Factory::NewCode(const CodeDesc& desc, ScopeInfo<>* sinfo,
                              Code::Flags flags) {
  CALL_HEAP_FUNCTION(Heap::CreateCode(desc, sinfo, flags), Code);
}


Handle<Code> Factory::CopyCode(Handle<Code> code) {
  CALL_HEAP_FUNCTION(Heap::CopyCode(*code), Code);
}


#define CALL_GC(RETRY)                                                     \
  do {                                                                     \
    if (!Heap::CollectGarbage(Failure::cast(RETRY)->requested(),           \
                              Failure::cast(RETRY)->allocation_space())) { \
      /* TODO(1181417): Fix this. */                                       \
      V8::FatalProcessOutOfMemory("Factory CALL_GC");                      \
    }                                                                      \
  } while (false)


// Allocate the new array. We cannot use the CALL_HEAP_FUNCTION macro here,
// because the stack-allocated CallbacksDescriptor instance is not GC safe.
Handle<DescriptorArray> Factory::CopyAppendProxyDescriptor(
    Handle<DescriptorArray> array,
    Handle<String> key,
    Handle<Object> value,
    PropertyAttributes attributes) {
  GC_GREEDY_CHECK();
  CallbacksDescriptor desc(*key, *value, attributes);
  Object* obj = array->CopyInsert(&desc, REMOVE_TRANSITIONS);
  if (obj->IsRetryAfterGC()) {
    CALL_GC(obj);
    CallbacksDescriptor desc(*key, *value, attributes);
    obj = array->CopyInsert(&desc, REMOVE_TRANSITIONS);
    if (obj->IsFailure()) {
      // TODO(1181417): Fix this.
      V8::FatalProcessOutOfMemory("CopyAppendProxyDescriptor");
    }
  }
  return Handle<DescriptorArray>(DescriptorArray::cast(obj));
}

#undef CALL_GC


Handle<String> Factory::SymbolFromString(Handle<String> value) {
  CALL_HEAP_FUNCTION(Heap::LookupSymbol(*value), String);
}


Handle<DescriptorArray> Factory::CopyAppendCallbackDescriptors(
    Handle<DescriptorArray> array,
    Handle<Object> descriptors) {
  v8::NeanderArray callbacks(descriptors);
  int nof_callbacks = callbacks.length();
  Handle<DescriptorArray> result =
      NewDescriptorArray(array->number_of_descriptors() + nof_callbacks);

  // Number of descriptors added to the result so far.
  int descriptor_count = 0;

  // Copy the descriptors from the array.
  DescriptorWriter w(*result);
  for (DescriptorReader r(*array); !r.eos(); r.advance()) {
    w.WriteFrom(&r);
    descriptor_count++;
  }

  // Number of duplicates detected.
  int duplicates = 0;

  // Fill in new callback descriptors.  Process the callbacks from
  // back to front so that the last callback with a given name takes
  // precedence over previously added callbacks with that name.
  for (int i = nof_callbacks - 1; i >= 0; i--) {
    Handle<AccessorInfo> entry =
        Handle<AccessorInfo>(AccessorInfo::cast(callbacks.get(i)));
    // Ensure the key is a symbol before writing into the instance descriptor.
    Handle<String> key =
        SymbolFromString(Handle<String>(String::cast(entry->name())));
    // Check if a descriptor with this name already exists before writing.
    if (result->BinarySearch(*key, 0, descriptor_count - 1) ==
        DescriptorArray::kNotFound) {
      CallbacksDescriptor desc(*key, *entry, entry->property_attributes());
      w.Write(&desc);
      descriptor_count++;
    } else {
      duplicates++;
    }
  }

  // If duplicates were detected, allocate a result of the right size
  // and transfer the elements.
  if (duplicates > 0) {
    Handle<DescriptorArray> new_result =
        NewDescriptorArray(result->number_of_descriptors() - duplicates);
    DescriptorWriter w(*new_result);
    DescriptorReader r(*result);
    while (!w.eos()) {
      w.WriteFrom(&r);
      r.advance();
    }
    result = new_result;
  }

  // Sort the result before returning.
  result->Sort();
  return result;
}


Handle<JSObject> Factory::NewJSObject(Handle<JSFunction> constructor,
                                      PretenureFlag pretenure) {
  CALL_HEAP_FUNCTION(Heap::AllocateJSObject(*constructor, pretenure), JSObject);
}


Handle<JSObject> Factory::NewJSObjectFromMap(Handle<Map> map) {
  CALL_HEAP_FUNCTION(Heap::AllocateJSObjectFromMap(*map, NOT_TENURED),
                     JSObject);
}


Handle<JSObject> Factory::NewObjectLiteral(int expected_number_of_properties) {
  Handle<Map> map = Handle<Map>(Top::object_function()->initial_map());
  map = Factory::CopyMap(map);
  map->set_instance_descriptors(Heap::empty_descriptor_array());
  map->set_unused_property_fields(expected_number_of_properties);
  CALL_HEAP_FUNCTION(Heap::AllocateJSObjectFromMap(*map, TENURED),
                     JSObject);
}


Handle<JSArray> Factory::NewArrayLiteral(int length) {
  return NewJSArrayWithElements(NewFixedArray(length), TENURED);
}


Handle<JSArray> Factory::NewJSArray(int length,
                                    PretenureFlag pretenure) {
  Handle<JSObject> obj = NewJSObject(Top::array_function(), pretenure);
  CALL_HEAP_FUNCTION(Handle<JSArray>::cast(obj)->Initialize(length), JSArray);
}


Handle<JSArray> Factory::NewJSArrayWithElements(Handle<FixedArray> elements,
                                                PretenureFlag pretenure) {
  Handle<JSArray> result =
      Handle<JSArray>::cast(NewJSObject(Top::array_function(), pretenure));
  result->SetContent(*elements);
  return result;
}


Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(Handle<String> name) {
  CALL_HEAP_FUNCTION(Heap::AllocateSharedFunctionInfo(*name),
                     SharedFunctionInfo);
}


Handle<Dictionary> Factory::DictionaryAtNumberPut(Handle<Dictionary> dictionary,
                                                  uint32_t key,
                                                  Handle<Object> value) {
  CALL_HEAP_FUNCTION(dictionary->AtNumberPut(key, *value), Dictionary);
}


Handle<JSFunction> Factory::NewFunctionHelper(Handle<String> name,
                                              Handle<Object> prototype) {
  Handle<SharedFunctionInfo> function_share = NewSharedFunctionInfo(name);
  CALL_HEAP_FUNCTION(Heap::AllocateFunction(*Top::function_map(),
                                            *function_share,
                                            *prototype),
                     JSFunction);
}


Handle<JSFunction> Factory::NewFunction(Handle<String> name,
                                        Handle<Object> prototype) {
  Handle<JSFunction> fun = NewFunctionHelper(name, prototype);
  fun->set_context(Top::context()->global_context());
  return fun;
}


Handle<Object> Factory::ToObject(Handle<Object> object,
                                 Handle<Context> global_context) {
  CALL_HEAP_FUNCTION(object->ToObject(*global_context), Object);
}


Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
  // Get the original code of the function.
  Handle<Code> code(shared->code());

  // Create a copy of the code before allocating the debug info object to avoid
  // allocation while setting up the debug info object.
  Handle<Code> original_code(*Factory::CopyCode(code));

  // Allocate initial fixed array for active break points before allocating the
  // debug info object to avoid allocation while setting up the debug info
  // object.
  Handle<FixedArray> break_points(
      Factory::NewFixedArray(Debug::kEstimatedNofBreakPointsInFunction));

  // Create and set up the debug info object. Debug info contains function, a
  // copy of the original code, the executing code and initial fixed array for
  // active break points.
  Handle<DebugInfo> debug_info =
      Handle<DebugInfo>::cast(Factory::NewStruct(DEBUG_INFO_TYPE));
  debug_info->set_shared(*shared);
  debug_info->set_original_code(*original_code);
  debug_info->set_code(*code);
  debug_info->set_break_points(*break_points);

  // Link debug info to function.
  shared->set_debug_info(*debug_info);

  return debug_info;
}


Handle<JSObject> Factory::NewArgumentsObject(Handle<Object> callee,
                                             int length) {
  CALL_HEAP_FUNCTION(Heap::AllocateArgumentsObject(*callee, length), JSObject);
}


Handle<JSFunction> Factory::CreateApiFunction(
    Handle<FunctionTemplateInfo> obj,
    bool is_global) {
  Handle<Code> code = Handle<Code>(Builtins::builtin(Builtins::HandleApiCall));

  int internal_field_count = 0;
  if (!obj->instance_template()->IsUndefined()) {
    Handle<ObjectTemplateInfo> instance_template =
        Handle<ObjectTemplateInfo>(
            ObjectTemplateInfo::cast(obj->instance_template()));
    internal_field_count =
        Smi::cast(instance_template->internal_field_count())->value();
  }

  int instance_size = kPointerSize * internal_field_count;
  if (is_global) {
    instance_size += JSGlobalObject::kSize;
  } else {
    instance_size += JSObject::kHeaderSize;
  }

  InstanceType type = is_global ? JS_GLOBAL_OBJECT_TYPE : JS_OBJECT_TYPE;

  Handle<JSFunction> result =
      Factory::NewFunction(Factory::empty_symbol(), type, instance_size,
                           code, true);
  // Set class name.
  Handle<Object> class_name = Handle<Object>(obj->class_name());
  if (class_name->IsString()) {
    result->shared()->set_instance_class_name(*class_name);
    result->shared()->set_name(*class_name);
  }

  Handle<Map> map = Handle<Map>(result->initial_map());

  // Mark as undetectable if needed.
  if (obj->undetectable()) {
    map->set_is_undetectable();
  }

  // Mark as hidden for the __proto__ accessor if needed.
  if (obj->hidden_prototype()) {
    map->set_is_hidden_prototype();
  }

  // Mark as needs_access_check if needed.
  if (obj->needs_access_check()) {
    map->set_needs_access_check();
  }

  // Set interceptor information in the map.
  if (!obj->named_property_handler()->IsUndefined()) {
    map->set_has_named_interceptor();
  }
  if (!obj->indexed_property_handler()->IsUndefined()) {
    map->set_has_indexed_interceptor();
  }

  // Set instance call-as-function information in the map.
  if (!obj->instance_call_handler()->IsUndefined()) {
    map->set_has_instance_call_handler();
  }

  result->shared()->set_function_data(*obj);
  result->shared()->DontAdaptArguments();

  // Recursively copy parent templates' accessors, 'data' may be modified.
  Handle<DescriptorArray> array =
      Handle<DescriptorArray>(map->instance_descriptors());
  while (true) {
    Handle<Object> props = Handle<Object>(obj->property_accessors());
    if (!props->IsUndefined()) {
      array = Factory::CopyAppendCallbackDescriptors(array, props);
    }
    Handle<Object> parent = Handle<Object>(obj->parent_template());
    if (parent->IsUndefined()) break;
    obj = Handle<FunctionTemplateInfo>::cast(parent);
  }
  if (!array->IsEmpty()) {
    map->set_instance_descriptors(*array);
  }

  return result;
}


Handle<MapCache> Factory::NewMapCache(int at_least_space_for) {
  CALL_HEAP_FUNCTION(MapCache::Allocate(at_least_space_for), MapCache);
}


static Object* UpdateMapCacheWith(Context* context,
                                  FixedArray* keys,
                                  Map* map) {
  Object* result = MapCache::cast(context->map_cache())->Put(keys, map);
  if (!result->IsFailure()) context->set_map_cache(MapCache::cast(result));
  return result;
}


Handle<MapCache> Factory::AddToMapCache(Handle<Context> context,
                                        Handle<FixedArray> keys,
                                        Handle<Map> map) {
  CALL_HEAP_FUNCTION(UpdateMapCacheWith(*context, *keys, *map), MapCache);
}


Handle<Map> Factory::ObjectLiteralMapFromCache(Handle<Context> context,
                                               Handle<FixedArray> keys) {
  if (context->map_cache()->IsUndefined()) {
    // Allocate the new map cache for the global context.
    Handle<MapCache> new_cache = NewMapCache(24);
    context->set_map_cache(*new_cache);
  }
  // Check to see whether there is a maching element in the cache.
  Handle<MapCache> cache =
      Handle<MapCache>(MapCache::cast(context->map_cache()));
  Handle<Object> result = Handle<Object>(cache->Lookup(*keys));
  if (result->IsMap()) return Handle<Map>::cast(result);
  // Create a new map and add it to the cache.
  Handle<Map> map =
      CopyMap(Handle<Map>(context->object_function()->initial_map()));
  AddToMapCache(context, keys, map);
  return Handle<Map>(map);
}


void Factory::ConfigureInstance(Handle<FunctionTemplateInfo> desc,
                                Handle<JSObject> instance,
                                bool* pending_exception) {
  // Configure the instance by adding the properties specified by the
  // instance template.
  Handle<Object> instance_template = Handle<Object>(desc->instance_template());
  if (!instance_template->IsUndefined()) {
    Execution::ConfigureInstance(instance,
                                 instance_template,
                                 pending_exception);
  } else {
    *pending_exception = false;
  }
}


} }  // namespace v8::internal