예제 #1
0
/**
 * [[Call]] implementation for Function objects,
 * created through 13.2 (ECMA_OBJECT_TYPE_FUNCTION)
 * or 15.3.4.5 (ECMA_OBJECT_TYPE_BOUND_FUNCTION),
 * and for built-in Function objects
 * from section 15 (ECMA_OBJECT_TYPE_FUNCTION).
 *
 * @return ecma value
 *         Returned value must be freed with ecma_free_value
 */
ecma_value_t
ecma_op_function_call (ecma_object_t *func_obj_p, /**< Function object */
                       ecma_value_t this_arg_value, /**< 'this' argument's value */
                       const ecma_value_t *arguments_list_p, /**< arguments list */
                       ecma_length_t arguments_list_len) /**< length of arguments list */
{
  JERRY_ASSERT (func_obj_p != NULL
                && !ecma_is_lexical_environment (func_obj_p));
  JERRY_ASSERT (ecma_op_is_callable (ecma_make_object_value (func_obj_p)));

  ecma_value_t ret_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_EMPTY);

  if (ecma_get_object_type (func_obj_p) == ECMA_OBJECT_TYPE_FUNCTION)
  {
    if (unlikely (ecma_get_object_is_builtin (func_obj_p)))
    {
      ret_value = ecma_builtin_dispatch_call (func_obj_p,
                                              this_arg_value,
                                              arguments_list_p,
                                              arguments_list_len);
    }
    else
    {
      /* Entering Function Code (ECMA-262 v5, 10.4.3) */
      ecma_extended_object_t *ext_func_p = (ecma_extended_object_t *) func_obj_p;

      ecma_object_t *scope_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_object_t,
                                                                ext_func_p->u.function.scope_cp);

      // 8.
      ecma_value_t this_binding;
      bool is_strict;
      bool is_no_lex_env;

      const ecma_compiled_code_t *bytecode_data_p;
      bytecode_data_p = ECMA_GET_INTERNAL_VALUE_POINTER (const ecma_compiled_code_t,
                                                         ext_func_p->u.function.bytecode_cp);

      is_strict = (bytecode_data_p->status_flags & CBC_CODE_FLAGS_STRICT_MODE) ? true : false;
      is_no_lex_env = (bytecode_data_p->status_flags & CBC_CODE_FLAGS_LEXICAL_ENV_NOT_NEEDED) ? true : false;

      // 1.
      if (is_strict)
      {
        this_binding = ecma_copy_value (this_arg_value);
      }
      else if (ecma_is_value_undefined (this_arg_value)
               || ecma_is_value_null (this_arg_value))
      {
        // 2.
        this_binding = ecma_make_object_value (ecma_builtin_get (ECMA_BUILTIN_ID_GLOBAL));
      }
      else
      {
        // 3., 4.
        this_binding = ecma_op_to_object (this_arg_value);

        JERRY_ASSERT (!ECMA_IS_VALUE_ERROR (this_binding));
      }

      // 5.
      ecma_object_t *local_env_p;
      if (is_no_lex_env)
      {
        local_env_p = scope_p;
      }
      else
      {
        local_env_p = ecma_create_decl_lex_env (scope_p);
        if (bytecode_data_p->status_flags & CBC_CODE_FLAGS_ARGUMENTS_NEEDED)
        {
          ecma_op_create_arguments_object (func_obj_p,
                                           local_env_p,
                                           arguments_list_p,
                                           arguments_list_len,
                                           bytecode_data_p);
        }
      }

      ret_value = vm_run (bytecode_data_p,
                          this_binding,
                          local_env_p,
                          false,
                          arguments_list_p,
                          arguments_list_len);

      if (!is_no_lex_env)
      {
        ecma_deref_object (local_env_p);
      }

      ecma_free_value (this_binding);
    }
  }
  else if (ecma_get_object_type (func_obj_p) == ECMA_OBJECT_TYPE_EXTERNAL_FUNCTION)
예제 #2
0
/**
 * Setup variables for arguments listed in formal parameter list,
 * and, if necessary, Arguments object with 'arguments' binding.
 *
 * See also:
 *          Declaration binding instantiation (ECMA-262 v5, 10.5), block 4 and 7
 *
 * @return completion value
 *         Returned value must be freed with ecma_free_completion_value
 */
static ecma_completion_value_t
ecma_function_call_setup_args_variables (ecma_object_t *func_obj_p, /**< Function object */
                                         ecma_object_t *env_p, /**< lexical environment */
                                         const ecma_value_t *arguments_list_p, /**< arguments list */
                                         ecma_length_t arguments_list_len, /**< length of argument list */
                                         bool is_strict, /**< flag indicating strict mode */
                                         bool do_instantiate_arguments_object) /**< flag indicating whether
                                                                                *   Arguments object should be
                                                                                *   instantiated */
{
  ecma_property_t *formal_parameters_prop_p = ecma_get_internal_property (func_obj_p,
                                                                          ECMA_INTERNAL_PROPERTY_FORMAL_PARAMETERS);
  ecma_collection_header_t *formal_parameters_p;
  formal_parameters_p = ECMA_GET_POINTER (ecma_collection_header_t,
                                          formal_parameters_prop_p->u.internal_property.value);

  if (formal_parameters_p != NULL)
  {
    ecma_length_t formal_parameters_count = formal_parameters_p->unit_number;

    ecma_collection_iterator_t formal_params_iterator;
    ecma_collection_iterator_init (&formal_params_iterator, formal_parameters_p);

    /*
     * Formal parameter list is stored in reversed order
     *
     * Although, specification defines ascending order of formal parameters list enumeration,
     * implementation enumerates the parameters in descending order.
     *
     * In the case, redundant SetMutableBinding invocation could be avoided.
     */
    for (ssize_t n = (ssize_t) formal_parameters_count - 1;
         n >= 0;
         n--)
    {
      ecma_value_t v;
      if (n >= (ssize_t) arguments_list_len)
      {
        v = ecma_make_simple_value (ECMA_SIMPLE_VALUE_UNDEFINED);
      }
      else
      {
        v = arguments_list_p[n];
      }

      bool is_moved = ecma_collection_iterator_next (&formal_params_iterator);
      JERRY_ASSERT (is_moved);

      ecma_value_t formal_parameter_name_value = *formal_params_iterator.current_value_p;
      ecma_string_t *formal_parameter_name_string_p = ecma_get_string_from_value (formal_parameter_name_value);

      bool arg_already_declared = ecma_op_has_binding (env_p, formal_parameter_name_string_p);
      if (!arg_already_declared)
      {
        ecma_completion_value_t completion = ecma_op_create_mutable_binding (env_p,
                                                                             formal_parameter_name_string_p,
                                                                             false);
        if (ecma_is_completion_value_throw (completion))
        {
          return completion;
        }

        JERRY_ASSERT (ecma_is_completion_value_empty (completion));

        completion = ecma_op_set_mutable_binding (env_p,
                                                  formal_parameter_name_string_p,
                                                  v,
                                                  is_strict);

        if (ecma_is_completion_value_throw (completion))
        {
          return completion;
        }

        JERRY_ASSERT (ecma_is_completion_value_empty (completion));
      }
    }
  }

  if (do_instantiate_arguments_object)
  {
    /*
     * According to ECMA-262 v5, 10.5, the Arguments object should be instantiated
     * after instantiating declared functions, and only if there is no binding named 'arguments'
     * by that time.
     *
     * However, we can setup Arguments object and 'arguments' binding here, because:
     *  - instantiation of Arguments object itself doesn't have any side effects;
     *  - if 'arguments' is name of a declared function in current scope,
     *    value of the binding would be overwritten, execution would proceed in correct state.
     *  - declaration of function, named 'arguments', is considered to be unrecommended (and so, rare) case,
     *    so instantiation of Arguments object here, in general, is supposed to not affect resource consumption
     *    significantly.
     */

    ecma_string_t *arguments_string_p = ecma_get_magic_string (LIT_MAGIC_STRING_ARGUMENTS);

    bool binding_already_declared = ecma_op_has_binding (env_p, arguments_string_p);

    if (!binding_already_declared)
    {
      ecma_object_t *args_obj_p = ecma_op_create_arguments_object (func_obj_p,
                                                                   env_p,
                                                                   formal_parameters_p,
                                                                   arguments_list_p,
                                                                   arguments_list_len,
                                                                   is_strict);

      if (is_strict)
      {
        ecma_op_create_immutable_binding (env_p, arguments_string_p);
        ecma_op_initialize_immutable_binding (env_p, arguments_string_p, ecma_make_object_value (args_obj_p));
      }
      else
      {
        ecma_completion_value_t completion = ecma_op_create_mutable_binding (env_p,
                                                                             arguments_string_p,
                                                                             false);
        JERRY_ASSERT (ecma_is_completion_value_empty (completion));

        completion = ecma_op_set_mutable_binding (env_p,
                                                  arguments_string_p,
                                                  ecma_make_object_value (args_obj_p),
                                                  false);
        JERRY_ASSERT (ecma_is_completion_value_empty (completion));
      }

      ecma_deref_object (args_obj_p);
    }

    ecma_deref_ecma_string (arguments_string_p);
  }

  return ecma_make_empty_completion_value ();
} /* ecma_function_call_setup_args_variables */