ecma_ref_ecma_string -> ecma_copy_or_ref_ecma_string: copying ecma-string when the string's reference counter reaches maximum value.

src/libecmabuiltins/ecma-builtin-string-prototype-object.c

@@ -174,7 +174,7 @@ ecma_builtin_string_prototype_object_to_string (ecma_value_t this) /**< this arg
 
       ecma_string_t *prim_value_str_p = ECMA_GET_POINTER (prim_value_prop_p->u.internal_property.value);
 
-      ecma_ref_ecma_string (prim_value_str_p);
+      prim_value_str_p = ecma_copy_or_ref_ecma_string (prim_value_str_p);
 
       return ecma_make_normal_completion_value (ecma_make_string_value (prim_value_str_p));
     }

src/libecmaobjects/ecma-helpers-string.c

@@ -265,8 +265,8 @@ ecma_concat_ecma_strings (ecma_string_t *string1_p, /**< first ecma-string */
     string_desc_p->length = (ecma_length_t) length;
   }
 
-  ecma_ref_ecma_string (string1_p);
-  ecma_ref_ecma_string (string2_p);
+  string1_p = ecma_copy_or_ref_ecma_string (string1_p);
+  string2_p = ecma_copy_or_ref_ecma_string (string2_p);
 
   ECMA_SET_NON_NULL_POINTER (string_desc_p->u.concatenation.string1_cp, string1_p);
   ECMA_SET_NON_NULL_POINTER (string_desc_p->u.concatenation.string2_cp, string2_p);
@@ -278,18 +278,40 @@ ecma_concat_ecma_strings (ecma_string_t *string1_p, /**< first ecma-string */
  * Increase reference counter of ecma-string.
  *
  * @return pointer to same ecma-string descriptor with increased reference counter
+ *         or the ecma-string's copy with reference counter set to 1
  */
-void
-ecma_ref_ecma_string (ecma_string_t *string_desc_p) /**< string descriptor */
+ecma_string_t*
+ecma_copy_or_ref_ecma_string (ecma_string_t *string_desc_p) /**< string descriptor */
 {
   JERRY_ASSERT (string_desc_p != NULL);
   JERRY_ASSERT (string_desc_p->refs > 0);
 
   string_desc_p->refs++;
 
-  /* Check for overflow */
-  JERRY_ASSERT (string_desc_p->refs > 0);
-} /* ecma_ref_ecma_string */
+  if (unlikely (string_desc_p->refs == 0))
+  {
+    string_desc_p->refs--;
+
+    if (string_desc_p->container == ECMA_STRING_CONTAINER_CHARS_IN_DESC
+        || string_desc_p->container == ECMA_STRING_CONTAINER_LIT_TABLE
+        || string_desc_p->container == ECMA_STRING_CONTAINER_UINT32_IN_DESC)
+    {
+      ecma_string_t *new_str_p = ecma_alloc_string ();
+
+      *new_str_p = *string_desc_p;
+
+      new_str_p->refs = 1;
+
+      return new_str_p;
+    }
+    else
+    {
+      JERRY_UNIMPLEMENTED ();
+    }
+  }
+
+  return string_desc_p;
+} /* ecma_copy_or_ref_ecma_string */
 
 /**
  * Decrease reference counter and deallocate ecma-string if

src/libecmaobjects/ecma-helpers-value.c

@@ -212,9 +212,13 @@ ecma_copy_value (const ecma_value_t value, /**< ecma-value */
       ecma_string_t *string_p = ECMA_GET_POINTER(value.value);
       JERRY_ASSERT(string_p != NULL);
 
-      ecma_ref_ecma_string (string_p);
+      string_p = ecma_copy_or_ref_ecma_string (string_p);
 
-      value_copy = value;
+      value_copy = (ecma_value_t)
+      {
+        .value_type = ECMA_TYPE_STRING
+      };
+      ECMA_SET_NON_NULL_POINTER(value_copy.value, string_p);
 
       break;
     }

src/libecmaobjects/ecma-helpers.c

@@ -454,7 +454,7 @@ ecma_create_named_data_property (ecma_object_t *obj_p, /**< object */
 
   prop_p->type = ECMA_PROPERTY_NAMEDDATA;
 
-  ecma_ref_ecma_string (name_p);
+  name_p = ecma_copy_or_ref_ecma_string (name_p);
   ECMA_SET_NON_NULL_POINTER(prop_p->u.named_data_property.name_p, name_p);
 
   prop_p->u.named_data_property.writable = writable;
@@ -490,7 +490,7 @@ ecma_create_named_accessor_property (ecma_object_t *obj_p, /**< object */
 
   prop_p->type = ECMA_PROPERTY_NAMEDACCESSOR;
 
-  ecma_ref_ecma_string (name_p);
+  name_p = ecma_copy_or_ref_ecma_string (name_p);
   ECMA_SET_NON_NULL_POINTER(prop_p->u.named_accessor_property.name_p, name_p);
 
   ECMA_SET_POINTER(prop_p->u.named_accessor_property.get_p, get_p);

src/libecmaobjects/ecma-helpers.h

@@ -102,7 +102,7 @@ extern ecma_string_t* ecma_new_ecma_string_from_number (ecma_number_t number);
 extern ecma_string_t* ecma_new_ecma_string_from_lit_index (literal_index_t lit_index);
 extern ecma_string_t* ecma_new_ecma_string_from_magic_string_id (ecma_magic_string_id_t id);
 extern ecma_string_t* ecma_concat_ecma_strings (ecma_string_t *string1_p, ecma_string_t *string2_p);
-extern void ecma_ref_ecma_string (ecma_string_t *string_desc_p);
+extern ecma_string_t* ecma_copy_or_ref_ecma_string (ecma_string_t *string_desc_p);
 extern void ecma_deref_ecma_string (ecma_string_t *string_p);
 extern ecma_number_t ecma_string_to_number (const ecma_string_t *str_p);
 extern ssize_t ecma_string_to_zt_string (const ecma_string_t *string_desc_p,

src/libecmaoperations/ecma-conversion.c

@@ -421,7 +421,7 @@ ecma_op_to_string (ecma_value_t value) /**< ecma-value */
     case ECMA_TYPE_STRING:
     {
       res_p = ECMA_GET_POINTER (value.value);
-      ecma_ref_ecma_string (res_p);
+      res_p = ecma_copy_or_ref_ecma_string (res_p);
 
       break;
     }

src/libecmaoperations/ecma-reference.c

@@ -79,7 +79,7 @@ ecma_make_reference (ecma_value_t base, /**< base value */
                      ecma_string_t *name_p, /**< referenced name */
                      bool is_strict) /**< strict reference flag */
 {
-  ecma_ref_ecma_string (name_p);
+  name_p = ecma_copy_or_ref_ecma_string (name_p);
 
   ecma_reference_t ref = (ecma_reference_t)
   {

src/libecmaoperations/ecma-string-object.c

@@ -118,8 +118,7 @@ ecma_op_string_object_get_own_property (ecma_object_t *obj_p, /**< the array obj
   {
     uint32_index = property_name_p->u.uint32_number;
 
-    ecma_ref_ecma_string (property_name_p);
-    new_prop_name_p = property_name_p;
+    new_prop_name_p = ecma_copy_or_ref_ecma_string (property_name_p);
   }
   else
   {