bootstrapper.cc.svn-base

Google浏览器V8内核代码

}


Genesis::~Genesis() {
  ASSERT(current_ == this);
  current_ = previous_;
}

static Handle<JSFunction> InstallFunction(Handle<JSObject> target,
                                          const char* name,
                                          InstanceType type,
                                          int instance_size,
                                          Handle<JSObject> prototype,
                                          Builtins::Name call,
                                          bool is_ecma_native) {
  Handle<String> symbol = Factory::LookupAsciiSymbol(name);
  Handle<Code> call_code = Handle<Code>(Builtins::builtin(call));
  Handle<JSFunction> function =
    Factory::NewFunctionWithPrototype(symbol,
                                      type,
                                      instance_size,
                                      prototype,
                                      call_code,
                                      is_ecma_native);
  SetProperty(target, symbol, function, DONT_ENUM);
  if (is_ecma_native) {
    function->shared()->set_instance_class_name(*symbol);
  }
  return function;
}


Handle<DescriptorArray> Genesis::ComputeFunctionInstanceDescriptor(
    bool make_prototype_read_only,
    bool make_prototype_enumerable) {
  Handle<DescriptorArray> result = Factory::empty_descriptor_array();

  // Add prototype.
  PropertyAttributes attributes = static_cast<PropertyAttributes>(
      (make_prototype_enumerable ? 0 : DONT_ENUM)
      | DONT_DELETE
      | (make_prototype_read_only ? READ_ONLY : 0));
  result =
      Factory::CopyAppendProxyDescriptor(
          result,
          Factory::prototype_symbol(),
          Factory::NewProxy(&Accessors::FunctionPrototype),
          attributes);

  attributes =
      static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
  // Add length.
  result =
      Factory::CopyAppendProxyDescriptor(
          result,
          Factory::length_symbol(),
          Factory::NewProxy(&Accessors::FunctionLength),
          attributes);

  // Add name.
  result =
      Factory::CopyAppendProxyDescriptor(
          result,
          Factory::name_symbol(),
          Factory::NewProxy(&Accessors::FunctionName),
          attributes);

  // Add arguments.
  result =
      Factory::CopyAppendProxyDescriptor(
          result,
          Factory::arguments_symbol(),
          Factory::NewProxy(&Accessors::FunctionArguments),
          attributes);

  // Add caller.
  result =
      Factory::CopyAppendProxyDescriptor(
          result,
          Factory::caller_symbol(),
          Factory::NewProxy(&Accessors::FunctionCaller),
          attributes);

  return result;
}


void Genesis::CreateRoots(v8::Handle<v8::ObjectTemplate> global_template,
                          Handle<Object> global_object) {
  HandleScope scope;
  // Allocate the global context FixedArray first and then patch the
  // closure and extension object later (we need the empty function
  // and the global object, but in order to create those, we need the
  // global context).
  global_context_ =
      Handle<Context>::cast(
          GlobalHandles::Create(*Factory::NewGlobalContext()));
  Top::set_security_context(*global_context());
  Top::set_context(*global_context());

  // Allocate the message listeners object.
  v8::NeanderArray listeners;
  global_context()->set_message_listeners(*listeners.value());

  // Allocate the debug event listeners object.
  v8::NeanderArray debug_event_listeners;
  global_context()->set_debug_event_listeners(*debug_event_listeners.value());

  // Allocate the map for function instances.
  Handle<Map> fm = Factory::NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
  global_context()->set_function_instance_map(*fm);
  // Please note that the prototype property for function instances must be
  // writable.
  Handle<DescriptorArray> function_map_descriptors =
      ComputeFunctionInstanceDescriptor(false, true);
  fm->set_instance_descriptors(*function_map_descriptors);

  // Allocate the function map first and then patch the prototype later
  fm = Factory::NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
  global_context()->set_function_map(*fm);
  function_map_descriptors = ComputeFunctionInstanceDescriptor(true);
  fm->set_instance_descriptors(*function_map_descriptors);

  Handle<String> object_name = Handle<String>(Heap::Object_symbol());

  {  // --- O b j e c t ---
    Handle<JSFunction> object_fun =
        Factory::NewFunction(object_name, Factory::null_value());
    Handle<Map> object_function_map =
        Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
    object_fun->set_initial_map(*object_function_map);
    object_function_map->set_constructor(*object_fun);

    global_context()->set_object_function(*object_fun);

    // Allocate a new prototype for the object function.
    Handle<JSObject> prototype = Factory::NewJSObject(Top::object_function(),
                                                      TENURED);

    global_context()->set_initial_object_prototype(*prototype);
    SetPrototype(object_fun, prototype);
    object_function_map->
      set_instance_descriptors(Heap::empty_descriptor_array());
  }

  // Allocate the empty function as the prototype for function ECMAScript
  // 262 15.3.4.
  Handle<String> symbol = Factory::LookupAsciiSymbol("Empty");
  Handle<JSFunction> empty_function =
      Factory::NewFunction(symbol, Factory::null_value());

  {  // --- E m p t y ---
    Handle<Code> code =
        Handle<Code>(Builtins::builtin(Builtins::EmptyFunction));
    Handle<String> source = Factory::NewStringFromAscii(CStrVector("() {}"));

    empty_function->set_code(*code);
    empty_function->shared()->set_script(*Factory::NewScript(source));
    empty_function->shared()->set_start_position(0);
    empty_function->shared()->set_end_position(source->length());
    empty_function->shared()->DontAdaptArguments();
    global_context()->function_map()->set_prototype(*empty_function);
    global_context()->function_instance_map()->set_prototype(*empty_function);

    // Allocate the function map first and then patch the prototype later
    Handle<Map> empty_fm = Factory::CopyMap(fm);
    empty_fm->set_instance_descriptors(*function_map_descriptors);
    empty_fm->set_prototype(global_context()->object_function()->prototype());
    empty_function->set_map(*empty_fm);
  }

  {  // --- G l o b a l ---
    Handle<String> global_name = Factory::LookupAsciiSymbol("global");
    Handle<JSFunction> global_function;

    if (global_template.IsEmpty()) {
      Handle<String> name = Handle<String>(Heap::empty_symbol());
      Handle<Code> code = Handle<Code>(Builtins::builtin(Builtins::Illegal));
      global_function = Factory::NewFunction(name, JS_GLOBAL_OBJECT_TYPE,
                                             JSGlobalObject::kSize, code, true);
      // Change the constructor property of the prototype of the
      // hidden global function to refer to the Object function.
      Handle<JSObject> prototype =
          Handle<JSObject>(
              JSObject::cast(global_function->instance_prototype()));
      SetProperty(prototype, Factory::constructor_symbol(),
                  Top::object_function(), NONE);
    } else {
      Handle<ObjectTemplateInfo> data = v8::Utils::OpenHandle(*global_template);
      Handle<FunctionTemplateInfo> global_constructor =
          Handle<FunctionTemplateInfo>(
              FunctionTemplateInfo::cast(data->constructor()));
      global_function = Factory::CreateApiFunction(global_constructor, true);
    }

    SetExpectedNofProperties(global_function, 100);
    global_function->shared()->set_instance_class_name(*global_name);
    global_function->initial_map()->set_needs_access_check();

    Handle<JSGlobalObject> object;
    if (global_object.location() != NULL) {
      ASSERT(global_object->IsJSGlobalObject());
      object =
          ReinitializeJSGlobalObject(
              global_function,
              Handle<JSGlobalObject>::cast(global_object));
    } else {
      object =
          Handle<JSGlobalObject>::cast(Factory::NewJSObject(global_function,
                                                            TENURED));
    }

    // Set the global context for the global object.
    object->set_global_context(*global_context());

    // Security setup: Set the security token of the global object to
    // its global context. This makes the security check between two
    // different contexts fail by default even in case of global
    // object reinitialization.
    object->set_security_token(*global_context());

    {  // --- G l o b a l   C o n t e x t ---
      // use the empty function as closure (no scope info)
      global_context()->set_closure(*empty_function);
      global_context()->set_fcontext(*global_context());
      global_context()->set_previous(NULL);

      // set extension and global object
      global_context()->set_extension(*object);
      global_context()->set_global(*object);
    }

    Handle<JSObject> global = Handle<JSObject>(global_context()->global());
    SetProperty(global, object_name, Top::object_function(), DONT_ENUM);
  }

  Handle<JSObject> global = Handle<JSObject>(global_context()->global());

  // Install global Function object
  InstallFunction(global, "Function", JS_FUNCTION_TYPE, JSFunction::kSize,
                  empty_function, Builtins::Illegal, true);  // ECMA native.

  {  // --- A r r a y ---
    Handle<JSFunction> array_function =
        InstallFunction(global, "Array", JS_ARRAY_TYPE, JSArray::kSize,
                        Top::initial_object_prototype(), Builtins::ArrayCode,
                        true);
    array_function->shared()->DontAdaptArguments();

    // This seems a bit hackish, but we need to make sure Array.length
    // is 1.
    array_function->shared()->set_length(1);
    Handle<DescriptorArray> array_descriptors =
        Factory::CopyAppendProxyDescriptor(
            Factory::empty_descriptor_array(),
            Factory::length_symbol(),
            Factory::NewProxy(&Accessors::ArrayLength),
            static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE));

    // Cache the fast JavaScript array map
    global_context()->set_js_array_map(array_function->initial_map());
    global_context()->js_array_map()->set_instance_descriptors(
        *array_descriptors);
    // array_function is used internally. JS code creating array object should
    // search for the 'Array' property on the global object and use that one
    // as the constructor. 'Array' property on a global object can be
    // overwritten by JS code.
    global_context()->set_array_function(*array_function);
  }

  {  // --- N u m b e r ---
    Handle<JSFunction> number_fun =
        InstallFunction(global, "Number", JS_VALUE_TYPE, JSValue::kSize,
                        Top::initial_object_prototype(), Builtins::Illegal,
                        true);
    global_context()->set_number_function(*number_fun);
  }

  {  // --- B o o l e a n ---
    Handle<JSFunction> boolean_fun =
        InstallFunction(global, "Boolean", JS_VALUE_TYPE, JSValue::kSize,
                        Top::initial_object_prototype(), Builtins::Illegal,
                        true);
    global_context()->set_boolean_function(*boolean_fun);
  }

  {  // --- S t r i n g ---
    Handle<JSFunction> string_fun =
        InstallFunction(global, "String", JS_VALUE_TYPE, JSValue::kSize,
                        Top::initial_object_prototype(), Builtins::Illegal,
                        true);
    global_context()->set_string_function(*string_fun);
    // Add 'length' property to strings.
    Handle<DescriptorArray> string_descriptors =
        Factory::CopyAppendProxyDescriptor(
            Factory::empty_descriptor_array(),
            Factory::length_symbol(),
            Factory::NewProxy(&Accessors::StringLength),
            static_cast<PropertyAttributes>(DONT_ENUM |
                                            DONT_DELETE |
                                            READ_ONLY));

    Handle<Map> string_map =
        Handle<Map>(global_context()->string_function()->initial_map());
    string_map->set_instance_descriptors(*string_descriptors);
  }

  {  // --- D a t e ---
    // Builtin functions for Date.prototype.
    Handle<JSFunction> date_fun =
        InstallFunction(global, "Date", JS_VALUE_TYPE, JSValue::kSize,
                        Top::initial_object_prototype(), Builtins::Illegal,
                        true);

    global_context()->set_date_function(*date_fun);
  }


  {  // -- R e g E x p
    // Builtin functions for RegExp.prototype.
    Handle<JSFunction> regexp_fun =
        InstallFunction(global, "RegExp", JS_REGEXP_TYPE, JSRegExp::kSize,
                        Top::initial_object_prototype(), Builtins::Illegal,
                        true);

    global_context()->set_regexp_function(*regexp_fun);
  }

  {  // --- arguments_boilerplate_
    // Make sure we can recognize argument objects at runtime.
    // This is done by introducing an anonymous function with
    // class_name equals 'Arguments'.
    Handle<String> symbol = Factory::LookupAsciiSymbol("Arguments");
    Handle<Code> code = Handle<Code>(Builtins::builtin(Builtins::Illegal));
    Handle<JSObject> prototype =
        Handle<JSObject>(