jerryscript/src/libecmaoperations/ecma-array-object.c

/* Copyright 2014 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "ecma-alloc.h"
#include "ecma-array-object.h"
#include "ecma-exceptions.h"
#include "ecma-globals.h"
#include "ecma-helpers.h"
#include "ecma-magic-strings.h"
#include "ecma-number-arithmetic.h"
#include "ecma-objects.h"
#include "ecma-objects-general.h"

/** \addtogroup ecma ---TODO---
 * @{
 *
 * \addtogroup ecmaarrayobject ECMA Array object related routines
 * @{
 */

/**
 * Reject sequence
 *
 * @return completion value
 *         Returned value must be freed with ecma_free_completion_value
 */
static ecma_completion_value_t
ecma_reject (bool is_throw) /**< Throw flag */
{
  if (is_throw)
  {
    return ecma_make_throw_value (ecma_new_standard_error (ECMA_ERROR_TYPE));
  }
  else
  {
    return ecma_make_simple_completion_value (ECMA_SIMPLE_VALUE_FALSE);
  }
} /* ecma_reject */

/**
 * [[DefineOwnProperty]] ecma array object's operation
 *
 * See also:
 *          ECMA-262 v5, 8.6.2; ECMA-262 v5, Table 8
 *          ECMA-262 v5, 15.4.5.1
 *
 * @return completion value
 *         Returned value must be freed with ecma_free_completion_value
 */
ecma_completion_value_t
ecma_op_array_object_define_own_property (ecma_object_t *obj_p, /**< the object */
                                          const ecma_char_t *property_name_p, /**< property name */
                                          ecma_property_descriptor_t property_desc, /**< property descriptor */
                                          bool is_throw) /**< flag that controls failure handling */
{
  JERRY_ASSERT (obj_p->u.object.type == ECMA_OBJECT_TYPE_ARRAY);

  const ecma_char_t* magic_string_length_p = ecma_get_magic_string (ECMA_MAGIC_STRING_LENGTH);

  // 1.
  ecma_property_t *len_prop_p = ecma_op_object_get_own_property (obj_p, magic_string_length_p);
  JERRY_ASSERT (len_prop_p != NULL && len_prop_p->type == ECMA_PROPERTY_NAMEDDATA);

  // 2.
  ecma_value_t old_len_value = len_prop_p->u.named_data_property.value;

  JERRY_ASSERT (old_len_value.value_type == ECMA_TYPE_NUMBER);

  ecma_number_t *num_p = ECMA_GET_POINTER (old_len_value.value);
  uint32_t old_len_uint32 = ecma_number_to_uint32 (*num_p);

  // 3.
  if (ecma_compare_zt_string_to_zt_string (property_name_p, magic_string_length_p) == 0)
  {
    // a.
    if (!property_desc.is_value_defined)
    {
      // i.
      return ecma_op_general_object_define_own_property (obj_p, property_name_p, property_desc, is_throw);
    }

    ecma_completion_value_t ret_value = ecma_make_empty_completion_value();

    // c.
    ecma_completion_value_t completion = ecma_op_to_number (property_desc.value);
    if (ecma_is_completion_value_throw (completion) )
    {
      ret_value = completion;
    }
    else
    {
      JERRY_ASSERT (ecma_is_completion_value_normal (completion)
                    && completion.value.value_type == ECMA_TYPE_NUMBER);

      ecma_number_t *new_len_num_p = ECMA_GET_POINTER (completion.value.value);

      uint32_t new_len_uint32 = ecma_number_to_uint32 (*new_len_num_p);

      // d.
      if (ecma_uint32_to_number (new_len_uint32) != *new_len_num_p)
      {
        ret_value = ecma_make_throw_value (ecma_new_standard_error (ECMA_ERROR_RANGE));
      }
      else
      {
        // b., e.
        ecma_property_descriptor_t new_len_property_desc = property_desc;
        new_len_property_desc.value = ecma_make_number_value (new_len_num_p);

        // f.
        if ( new_len_uint32 >= old_len_uint32 )
        {
          // i.
          ret_value = ecma_op_general_object_define_own_property (obj_p,
                                                                  magic_string_length_p,
                                                                  new_len_property_desc,
                                                                  is_throw);
        }
        else
        {
          // g.
          if (len_prop_p->u.named_data_property.writable == ECMA_PROPERTY_NOT_WRITABLE)
          {
            ret_value = ecma_reject (is_throw);
          }
          else
          {
            // h.
            bool new_writable;
            if (!new_len_property_desc.is_writable_defined
                || new_len_property_desc.writable == ECMA_PROPERTY_WRITABLE)
            {
              new_writable = true;
            }
            else
            {
              // ii.
              new_writable = false;

              // iii.
              new_len_property_desc.is_writable_defined = true;
              new_len_property_desc.writable = ECMA_PROPERTY_WRITABLE;
            }

            // j.
            ecma_completion_value_t succeeded = ecma_op_general_object_define_own_property (obj_p,
                                                                                            magic_string_length_p,
                                                                                            new_len_property_desc,
                                                                                            is_throw);

            /* Handling normal false and throw values */
            if (!ecma_is_completion_value_normal_true (succeeded))
            {
              // k.
              ret_value = completion;
            }

            // l.
            while (new_len_uint32 < old_len_uint32)
            {
              JERRY_UNIMPLEMENTED();
            }

            // m.
            if (!new_writable)
            {
              ecma_property_descriptor_t prop_desc_not_writable = ecma_make_empty_property_descriptor();

              prop_desc_not_writable.is_writable_defined = true;
              prop_desc_not_writable.writable = ECMA_PROPERTY_NOT_WRITABLE;

              ecma_completion_value_t completion_set_not_writable = ecma_op_general_object_define_own_property (obj_p,
                                                                                                                magic_string_length_p,
                                                                                                                prop_desc_not_writable,
                                                                                                                false);
              JERRY_ASSERT (ecma_is_completion_value_normal_true (completion_set_not_writable));
            }

            ret_value = ecma_make_simple_completion_value (ECMA_SIMPLE_VALUE_TRUE);
          }
        }
      }

      ecma_free_completion_value (completion);
    }

    return ret_value;
  }
  else
  {
    // 4.a.
    ecma_number_t number = ecma_zt_string_to_number (property_name_p);
    uint32_t index = ecma_number_to_uint32 (number);

    if (index >= ECMA_MAX_VALUE_OF_VALID_ARRAY_INDEX
        || ecma_uint32_to_number (index) != number)
    {
      // 5.
      return ecma_op_general_object_define_own_property (obj_p,
                                                         property_name_p,
                                                         property_desc,
                                                         false);
    }

    // 4.

    // b.
    if (index >= old_len_uint32
        && len_prop_p->u.named_data_property.writable == ECMA_PROPERTY_NOT_WRITABLE)
    {
      return ecma_reject(is_throw);
    }

    // c.
    ecma_completion_value_t succeeded = ecma_op_general_object_define_own_property (obj_p,
                                                                                    property_name_p,
                                                                                    property_desc,
                                                                                    false);
    // d.
    JERRY_ASSERT (ecma_is_completion_value_normal_true (succeeded)
                  || ecma_is_completion_value_normal_false (succeeded));

    if (ecma_is_completion_value_normal_false (succeeded))
    {
      return ecma_reject (is_throw);
    }

    // e.
    if (index >= old_len_uint32)
    {
      // i., ii.
      ecma_number_t *num_p = ecma_alloc_number();
      *num_p = ecma_op_number_add (ecma_uint32_to_number (index), ECMA_NUMBER_ONE);

      ecma_free_value (len_prop_p->u.named_data_property.value, false);
      len_prop_p->u.named_data_property.value = ecma_make_number_value (num_p);
    }

    // f.
    return ecma_make_simple_completion_value (ECMA_SIMPLE_VALUE_TRUE);
  }

  JERRY_UNREACHABLE();
} /* ecma_op_array_object_define_own_property */

/**
 * @}
 * @}
 */