Disguise accessor properties as data properties

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg [email protected]

Author: zherczeg

jerry-core/api/jerry.c

@@ -3373,6 +3373,57 @@ jerry_free_property_descriptor_fields (const jerry_property_descriptor_t *prop_d
   }
 } /* jerry_free_property_descriptor_fields */
 
+/**
+ * Hide the getter/setter functions of an accessor property, so the property is
+ * returned as a data property when the property descriptor is requested.
+ *
+ * Note:
+ *     - only ordinary objects are supported
+ *
+ * @return true - if the operation is successful
+ *         thrown error - otherwise
+ */
+jerry_value_t
+jerry_hide_own_accessor_property (const jerry_value_t obj_val, /**< object value */
+                                  const jerry_value_t prop_name_val) /**< property name */
+{
+  if (!ecma_is_value_object (obj_val)
+      || !ecma_is_value_prop_name (prop_name_val))
+  {
+    return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (wrong_args_msg_p)));
+  }
+
+  ecma_object_t *object_p = ecma_get_object_from_value (obj_val);
+
+#if ENABLED (JERRY_BUILTIN_PROXY)
+  if (ECMA_OBJECT_IS_PROXY (object_p))
+  {
+    return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (wrong_args_msg_p)));
+  }
+#endif /* ENABLED (JERRY_BUILTIN_PROXY) */
+
+  ecma_extended_property_ref_t ext_property_ref = { .property_ref.value_p = NULL, .property_p = NULL };
+  ecma_property_t property;
+
+  property = ecma_op_object_get_own_property (object_p,
+                                              ecma_get_prop_name_from_value (prop_name_val),
+                                              &ext_property_ref.property_ref,
+                                              ECMA_PROPERTY_GET_EXT_REFERENCE);
+
+  if (property == ECMA_PROPERTY_TYPE_NOT_FOUND || property == ECMA_PROPERTY_TYPE_NOT_FOUND_AND_STOP)
+  {
+    return jerry_throw (ecma_raise_reference_error (ECMA_ERR_MSG ("Property not found")));
+  }
+
+  if (ECMA_PROPERTY_GET_TYPE (property) != ECMA_PROPERTY_TYPE_NAMEDACCESSOR)
+  {
+    return jerry_throw (ecma_raise_reference_error (ECMA_ERR_MSG ("Property is not accessor property")));
+  }
+
+  *ext_property_ref.property_p |= ECMA_PROPERTY_FLAG_HIDDEN_ACCESSOR;
+  return ECMA_VALUE_TRUE;
+} /* jerry_hide_own_accessor_property */
+
 /**
  * Invoke function specified by a function value
  *

jerry-core/ecma/base/ecma-globals.h

@@ -443,6 +443,11 @@ typedef enum
 #define ECMA_PROPERTY_ENUMERABLE_WRITABLE \
   (ECMA_PROPERTY_FLAG_ENUMERABLE | ECMA_PROPERTY_FLAG_WRITABLE)
 
+/**
+ * Property flag named accessor which is returned as data property.
+ */
+#define ECMA_PROPERTY_FLAG_HIDDEN_ACCESSOR ECMA_PROPERTY_FLAG_WRITABLE
+
 /**
  * No attributes can be changed for this property.
  */
@@ -1182,6 +1187,7 @@ typedef enum
   ECMA_PROP_IS_CONFIGURABLE_DEFINED = (1 << 7), /** Is [[Configurable]] defined? */
   ECMA_PROP_IS_ENUMERABLE_DEFINED = (1 << 8), /** Is [[Enumerable]] defined? */
   ECMA_PROP_IS_WRITABLE_DEFINED = (1 << 9), /** Is [[Writable]] defined? */
+  ECMA_PROP_IS_HIDDEN_ACCESSOR = (1 << 10), /** Is hidden accessor */
 } ecma_property_descriptor_status_flags_t;
 
 /**
@@ -1196,7 +1202,6 @@ typedef enum
  */
 typedef struct
 {
-
   /** any combination of ecma_property_descriptor_status_flags_t bits */
   uint16_t flags;
 

jerry-core/ecma/builtin-objects/ecma-builtin-object.c

@@ -725,6 +725,17 @@ ecma_builtin_object_object_get_own_property_descriptor (ecma_object_t *obj_p, /*
 
   if (ecma_is_value_true (status))
   {
+    if (JERRY_UNLIKELY (prop_desc.flags & ECMA_PROP_IS_HIDDEN_ACCESSOR))
+    {
+      status = ecma_op_to_data_property (obj_p, &prop_desc);
+
+      if (ECMA_IS_VALUE_ERROR (status))
+      {
+        ecma_free_property_descriptor (&prop_desc);
+        return status;
+      }
+    }
+
     /* 4. */
     ecma_object_t *desc_obj_p = ecma_op_from_property_descriptor (&prop_desc);
 
@@ -786,6 +797,20 @@ ecma_builtin_object_object_get_own_property_descriptors (ecma_object_t *obj_p) /
 
     if (ecma_is_value_true (status))
     {
+      if (JERRY_UNLIKELY (prop_desc.flags & ECMA_PROP_IS_HIDDEN_ACCESSOR))
+      {
+        status = ecma_op_to_data_property (obj_p, &prop_desc);
+
+        if (ECMA_IS_VALUE_ERROR (status))
+        {
+          ecma_free_property_descriptor (&prop_desc);
+          ecma_deref_object (descriptors_p);
+          ecma_collection_free (prop_names_p);
+
+          return status;
+        }
+      }
+
       /* 4.b */
       ecma_object_t *desc_obj_p = ecma_op_from_property_descriptor (&prop_desc);
       /* 4.c */

jerry-core/ecma/operations/ecma-conversion.c

@@ -908,6 +908,50 @@ ecma_op_to_property_descriptor (ecma_value_t obj_value, /**< object value */
   return ret_value;
 } /* ecma_op_to_property_descriptor */
 
+/**
+ * Convert accessor to data property.
+ *
+ * @return ECMA_VALUE_EMPTY - if the opertation is successful
+ *         error - otherwise
+ */
+ecma_value_t
+ecma_op_to_data_property (ecma_object_t *object_p, /**< base object */
+                          ecma_property_descriptor_t *prop_desc_p) /**< [in/out] property descriptor */
+{
+  JERRY_ASSERT (prop_desc_p->flags & ECMA_PROP_IS_HIDDEN_ACCESSOR);
+
+  ecma_value_t result = ECMA_VALUE_UNDEFINED;
+  uint16_t flags = prop_desc_p->flags;
+
+  if ((flags & ECMA_PROP_IS_GET_DEFINED) && prop_desc_p->get_p != NULL)
+  {
+    result = ecma_op_function_call (prop_desc_p->get_p, ecma_make_object_value (object_p), NULL, 0);
+
+    if (ECMA_IS_VALUE_ERROR (result))
+    {
+      return result;
+    }
+
+    ecma_deref_object (prop_desc_p->get_p);
+    prop_desc_p->get_p = NULL;
+  }
+
+  if ((flags & ECMA_PROP_IS_SET_DEFINED) && prop_desc_p->set_p != NULL)
+  {
+    ecma_deref_object (prop_desc_p->set_p);
+    prop_desc_p->set_p = NULL;
+
+    flags |= ECMA_PROP_IS_WRITABLE;
+  }
+
+  flags |= ECMA_PROP_IS_WRITABLE_DEFINED | ECMA_PROP_IS_VALUE_DEFINED;
+  flags &= (uint16_t) ~(ECMA_PROP_IS_GET_DEFINED | ECMA_PROP_IS_SET_DEFINED | ECMA_PROP_IS_HIDDEN_ACCESSOR);
+
+  prop_desc_p->value = result;
+  prop_desc_p->flags = flags;
+  return ECMA_VALUE_EMPTY;
+} /* ecma_op_to_data_property */
+
 /**
  * IsInteger operation.
  *

jerry-core/ecma/operations/ecma-conversion.h

@@ -72,6 +72,7 @@ ecma_collection_t *ecma_op_create_list_from_array_like (ecma_value_t arr, bool p
 
 ecma_object_t *ecma_op_from_property_descriptor (const ecma_property_descriptor_t *src_prop_desc_p);
 ecma_value_t ecma_op_to_property_descriptor (ecma_value_t obj_value, ecma_property_descriptor_t *out_prop_desc_p);
+ecma_value_t ecma_op_to_data_property (ecma_object_t *object_p, ecma_property_descriptor_t *prop_desc_p);
 
 /**
  * @}

jerry-core/ecma/operations/ecma-objects-general.c

@@ -504,15 +504,9 @@ ecma_op_general_object_define_own_property (ecma_object_t *object_p, /**< the ob
       }
     }
   }
-  else
+  else if (is_current_configurable)
   {
     /* 9. */
-    if (!is_current_configurable)
-    {
-      /* a. */
-      return ecma_reject (property_desc_p->flags & ECMA_PROP_IS_THROW);
-    }
-
     ecma_property_value_t *value_p = ext_property_ref.property_ref.value_p;
 
     if (property_desc_type == ECMA_PROPERTY_TYPE_NAMEDACCESSOR)
@@ -549,6 +543,81 @@ ecma_op_general_object_define_own_property (ecma_object_t *object_p, /**< the ob
     prop_flags = (ecma_property_t) (prop_flags | property_desc_type);
     *(ext_property_ref.property_p) = prop_flags;
   }
+  else
+  {
+    /* Property is non-configurable. */
+    if (current_property_type != ECMA_PROPERTY_TYPE_NAMEDACCESSOR
+        || !(current_prop & ECMA_PROPERTY_FLAG_HIDDEN_ACCESSOR))
+    {
+      /* a. */
+      return ecma_reject (property_desc_p->flags & ECMA_PROP_IS_THROW);
+    }
+
+    /* Non-standard extension. */
+    ecma_getter_setter_pointers_t *getter_setter_pair_p;
+    getter_setter_pair_p = ecma_get_named_accessor_property (ext_property_ref.property_ref.value_p);
+
+    if (getter_setter_pair_p->setter_cp == JMEM_CP_NULL)
+    {
+      const uint16_t mask = ECMA_PROP_IS_WRITABLE_DEFINED | ECMA_PROP_IS_WRITABLE;
+
+      if ((property_desc_p->flags & mask) == mask)
+      {
+        return ecma_reject (property_desc_p->flags & ECMA_PROP_IS_THROW);
+      }
+
+      if (!(property_desc_p->flags & ECMA_PROP_IS_VALUE_DEFINED))
+      {
+        return ECMA_VALUE_TRUE;
+      }
+
+      ecma_value_t result = ECMA_VALUE_UNDEFINED;
+
+      if (getter_setter_pair_p->getter_cp != JMEM_CP_NULL)
+      {
+        ecma_object_t *getter_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, getter_setter_pair_p->getter_cp);
+        result = ecma_op_function_call (getter_p, ecma_make_object_value (object_p), NULL, 0);
+
+        if (ECMA_IS_VALUE_ERROR (result))
+        {
+          return result;
+        }
+      }
+
+      bool same_value = ecma_op_same_value (property_desc_p->value, result);
+      ecma_free_value (result);
+
+      if (!same_value)
+      {
+        return ecma_reject (property_desc_p->flags & ECMA_PROP_IS_THROW);
+      }
+      return ECMA_VALUE_TRUE;
+    }
+
+    if (property_desc_p->flags & ECMA_PROP_IS_VALUE_DEFINED)
+    {
+      ecma_object_t *setter_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, getter_setter_pair_p->setter_cp);
+
+      ecma_value_t result;
+      result = ecma_op_function_call (setter_p, ecma_make_object_value (object_p), &property_desc_p->value, 1);
+
+      if (ECMA_IS_VALUE_ERROR (result))
+      {
+        return result;
+      }
+
+      ecma_free_value (result);
+    }
+
+    /* Because the property is non-configurable, it cannot be modified. */
+    if ((property_desc_p->flags & ECMA_PROP_IS_WRITABLE_DEFINED)
+        && !(property_desc_p->flags & ECMA_PROP_IS_WRITABLE))
+    {
+      getter_setter_pair_p->setter_cp = JMEM_CP_NULL;
+    }
+
+    return ECMA_VALUE_TRUE;
+  }
 
   /* 12. */
   if (property_desc_type == ECMA_PROPERTY_TYPE_NAMEDDATA)

jerry-core/ecma/operations/ecma-objects.c

@@ -65,8 +65,8 @@
  * See also:
  *          ECMA-262 v5, 8.6.2; ECMA-262 v5, Table 8
  *
- * @return pointer to a property - if it exists,
- *         NULL (i.e. ecma-undefined) - otherwise.
+ * @return property descriptor - if it exists,
+ *         ECMA_PROPERTY_TYPE_NOT_FOUND / ECMA_PROPERTY_TYPE_NOT_FOUND_AND_STOP - otherwise.
  */
 ecma_property_t
 ecma_op_object_get_own_property (ecma_object_t *object_p, /**< the object */
@@ -1892,7 +1892,6 @@ ecma_op_object_get_own_property_descriptor (ecma_object_t *object_p, /**< the ob
   }
   else
   {
-
     ecma_getter_setter_pointers_t *get_set_pair_p = ecma_get_named_accessor_property (property_ref.value_p);
     prop_desc_p->flags |= (ECMA_PROP_IS_GET_DEFINED | ECMA_PROP_IS_SET_DEFINED);
 
@@ -1915,6 +1914,11 @@ ecma_op_object_get_own_property_descriptor (ecma_object_t *object_p, /**< the ob
       prop_desc_p->set_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, get_set_pair_p->setter_cp);
       ecma_ref_object (prop_desc_p->set_p);
     }
+
+    if (property & ECMA_PROPERTY_FLAG_HIDDEN_ACCESSOR)
+    {
+      prop_desc_p->flags |= ECMA_PROP_IS_HIDDEN_ACCESSOR;
+    }
   }
 
   return ECMA_VALUE_TRUE;

jerry-core/include/jerryscript-core.h

@@ -633,6 +633,7 @@ bool jerry_get_own_property_descriptor (const jerry_value_t obj_val,
                                         const jerry_value_t prop_name_val,
                                         jerry_property_descriptor_t *prop_desc_p);
 void jerry_free_property_descriptor_fields (const jerry_property_descriptor_t *prop_desc_p);
+jerry_value_t jerry_hide_own_accessor_property (const jerry_value_t obj_val, const jerry_value_t prop_name_val);
 
 jerry_value_t jerry_call_function (const jerry_value_t func_obj_val, const jerry_value_t this_val,
                                    const jerry_value_t args_p[], jerry_size_t args_count);