Reduce the memory consumption of function objects. (#1954)

Several properties of strict and bound functions are moved to
lazy property instantiation. The memory consumption of bound
functions are also reduced when only a this is present.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/ecma/base/ecma-gc.c

@@ -336,12 +336,23 @@ ecma_gc_mark (ecma_object_t *object_p) /**< object to mark from */
 
         ecma_gc_set_object_visited (target_func_obj_p, true);
 
-        ecma_length_t args_length = ext_function_p->u.bound_function.args_length;
+        ecma_value_t args_len_or_this = ext_function_p->u.bound_function.args_len_or_this;
+
+        if (!ecma_is_value_integer_number (args_len_or_this))
+        {
+          if (ecma_is_value_object (args_len_or_this))
+          {
+            ecma_gc_set_object_visited (ecma_get_object_from_value (args_len_or_this), true);
+          }
+          break;
+        }
+
+        ecma_integer_value_t args_length = ecma_get_integer_from_value (args_len_or_this);
         ecma_value_t *args_p = (ecma_value_t *) (ext_function_p + 1);
 
         JERRY_ASSERT (args_length > 0);
 
-        for (ecma_length_t i = 0; i < args_length; i++)
+        for (ecma_integer_value_t i = 0; i < args_length; i++)
         {
           if (ecma_is_value_object (args_p[i]))
           {
@@ -659,15 +670,25 @@ ecma_gc_sweep (ecma_object_t *object_p) /**< object to free */
     if (object_type == ECMA_OBJECT_TYPE_BOUND_FUNCTION)
     {
       ecma_extended_object_t *ext_function_p = (ecma_extended_object_t *) object_p;
-      ecma_length_t args_length = ext_function_p->u.bound_function.args_length;
+
+      ecma_value_t args_len_or_this = ext_function_p->u.bound_function.args_len_or_this;
+
+      if (!ecma_is_value_integer_number (args_len_or_this))
+      {
+        ecma_free_value_if_not_object (args_len_or_this);
+        ecma_dealloc_extended_object (ext_function_p, sizeof (ecma_extended_object_t));
+        return;
+      }
+
+      ecma_integer_value_t args_length = ecma_get_integer_from_value (args_len_or_this);
       ecma_value_t *args_p = (ecma_value_t *) (ext_function_p + 1);
 
-      for (ecma_length_t i = 0; i < args_length; i++)
+      for (ecma_integer_value_t i = 0; i < args_length; i++)
       {
         ecma_free_value_if_not_object (args_p[i]);
       }
 
-      size_t args_size = args_length * sizeof (ecma_value_t);
+      size_t args_size = ((size_t) args_length) * sizeof (ecma_value_t);
       ecma_dealloc_extended_object (ext_function_p, sizeof (ecma_extended_object_t) + args_size);
       return;
     }

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

@@ -768,7 +768,7 @@ typedef struct
     struct
     {
       ecma_value_t target_function; /**< target function */
-      ecma_length_t args_length; /**< length of arguments */
+      ecma_value_t args_len_or_this; /**< length of arguments or this value */
     } bound_function;
 
     ecma_external_handler_t external_handler_cb; /**< external function */

jerry-core/ecma/base/ecma-helpers-string.c

@@ -1337,29 +1337,41 @@ ecma_string_raw_chars (const ecma_string_t *string_p, /**< ecma-string */
 } /* ecma_string_raw_chars */
 
 /**
- * Checks whether ecma string is empty or not
+ * Checks whether the string equals to the magic string id.
  *
- * @return true  - if empty
+ * @return true - if the string equals to the magic string id
  *         false - otherwise
  */
-bool
-ecma_string_is_empty (const ecma_string_t *str_p) /**< ecma-string */
+inline bool __attr_always_inline___
+ecma_compare_ecma_string_to_magic_id (const ecma_string_t *string_p, /**< property name */
+                                      lit_magic_string_id_t id) /**< magic string id */
 {
-  return (ECMA_STRING_GET_CONTAINER (str_p) == ECMA_STRING_CONTAINER_MAGIC_STRING
-          && str_p->u.magic_string_id == LIT_MAGIC_STRING__EMPTY);
+  return (ECMA_STRING_GET_CONTAINER (string_p) == ECMA_STRING_CONTAINER_MAGIC_STRING
+          && string_p->u.magic_string_id == id);
+} /* ecma_compare_ecma_string_to_magic_id */
+
+/**
+ * Checks whether ecma string is empty or not
+ *
+ * @return true - if the string is an empty string
+ *         false - otherwise
+ */
+inline bool __attr_always_inline___
+ecma_string_is_empty (const ecma_string_t *string_p) /**< ecma-string */
+{
+  return ecma_compare_ecma_string_to_magic_id (string_p, LIT_MAGIC_STRING__EMPTY);
 } /* ecma_string_is_empty */
 
 /**
  * Checks whether the string equals to "length".
  *
- * @return true if the string equals to "length"
- *         false otherwise
+ * @return true - if the string equals to "length"
+ *         false - otherwise
  */
 inline bool __attr_always_inline___
 ecma_string_is_length (const ecma_string_t *string_p) /**< property name */
 {
-  return (ECMA_STRING_GET_CONTAINER (string_p) == ECMA_STRING_CONTAINER_MAGIC_STRING
-          && string_p->u.magic_string_id == LIT_MAGIC_STRING_LENGTH);
+  return ecma_compare_ecma_string_to_magic_id (string_p, LIT_MAGIC_STRING_LENGTH);
 } /* ecma_string_is_length */
 
 /**

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

@@ -201,7 +201,8 @@ const lit_utf8_byte_t *ecma_string_raw_chars (const ecma_string_t *string_p, lit
 void ecma_init_ecma_string_from_uint32 (ecma_string_t *string_desc_p, uint32_t uint32_number);
 void ecma_init_ecma_length_string (ecma_string_t *string_desc_p);
 void ecma_init_ecma_magic_string (ecma_string_t *string_desc_p, lit_magic_string_id_t id);
-bool ecma_string_is_empty (const ecma_string_t *str_p);
+bool ecma_compare_ecma_string_to_magic_id (const ecma_string_t *string_p, lit_magic_string_id_t id);
+bool ecma_string_is_empty (const ecma_string_t *string_p);
 bool ecma_string_is_length (const ecma_string_t *string_p);
 
 jmem_cpointer_t ecma_string_to_property_name (ecma_string_t *prop_name_p, ecma_property_t *name_type_p);