Improve empty checks of ecma strings

JerryScript-DCO-1.0-Signed-off-by: László Langó llango.u-szeged@partner.samsung.com

Author: LaszloLango

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

@@ -893,6 +893,19 @@ ecma_string_raw_chars (const ecma_string_t *string_p, /**< ecma-string */
   return result_p;
 } /* ecma_string_raw_chars */
 
+/**
+ * Checks whether ecma string is empty or not
+ *
+ * @return true  - if empty
+ *         false - otherwise
+ */
+bool
+ecma_string_is_empty (const ecma_string_t *str_p) /**< ecma-string */
+{
+  return (ECMA_STRING_GET_CONTAINER (str_p) == ECMA_STRING_CONTAINER_MAGIC_STRING
+          && str_p->u.magic_string_id == LIT_MAGIC_STRING__EMPTY);
+} /* ecma_string_is_empty */
+
 /**
  * Long path part of ecma-string to ecma-string comparison routine
  *

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

@@ -179,6 +179,7 @@ extern bool ecma_string_get_array_index (const ecma_string_t *, uint32_t *);
 extern lit_utf8_size_t __attr_return_value_should_be_checked___
 ecma_string_to_utf8_string (const ecma_string_t *, lit_utf8_byte_t *, lit_utf8_size_t);
 extern const lit_utf8_byte_t *ecma_string_raw_chars (const ecma_string_t *, lit_utf8_size_t *, bool *);
+extern bool ecma_string_is_empty (const ecma_string_t *);
 
 extern bool ecma_compare_ecma_strings_equal_hashes (const ecma_string_t *, const ecma_string_t *);
 extern bool ecma_compare_ecma_strings (const ecma_string_t *, const ecma_string_t *);

jerry-core/ecma/builtin-objects/ecma-builtin-error-prototype.c

@@ -123,11 +123,11 @@ ecma_builtin_error_prototype_object_to_string (ecma_value_t this_arg) /**< this
 
         ecma_string_t *ret_str_p;
 
-        if (ecma_string_get_length (name_string_p) == 0)
+        if (ecma_string_is_empty (name_string_p))
         {
           ret_str_p = ecma_copy_or_ref_ecma_string (msg_string_p);
         }
-        else if (ecma_string_get_length (msg_string_p) == 0)
+        else if (ecma_string_is_empty (msg_string_p))
         {
           ret_str_p = ecma_copy_or_ref_ecma_string (name_string_p);
         }

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

@@ -1491,9 +1491,7 @@ ecma_builtin_json_object (ecma_object_t *obj_p, /**< the object*/
       member_str_p = tmp_str_p;
 
       /* 8.b.iii */
-      bool is_gap_empty = (ecma_string_get_length (context_p->gap_str_p) == 0);
-
-      if (!is_gap_empty)
+      if (!ecma_string_is_empty (context_p->gap_str_p))
       {
         ecma_string_t *space_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_SPACE_CHAR);
 
@@ -1544,10 +1542,8 @@ ecma_builtin_json_object (ecma_object_t *obj_p, /**< the object*/
   /* 10. */
   else
   {
-    bool is_gap_empty = (ecma_string_get_length (context_p->gap_str_p) == 0);
-
     /* 10.a */
-    if (is_gap_empty)
+    if (ecma_string_is_empty (context_p->gap_str_p))
     {
       ecma_string_t *left_brace_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_LEFT_BRACE_CHAR);
       ecma_string_t *right_brace_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_RIGHT_BRACE_CHAR);
@@ -1684,9 +1680,8 @@ ecma_builtin_json_array (ecma_object_t *obj_p, /**< the array object*/
     /* 10. */
     else
     {
-      bool is_gap_empty = (ecma_string_get_length (context_p->gap_str_p) == 0);
       /* 10.a */
-      if (is_gap_empty)
+      if (ecma_string_is_empty (context_p->gap_str_p))
       {
         ecma_string_t *left_square_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_LEFT_SQUARE_CHAR);
         ecma_string_t *right_square_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_RIGHT_SQUARE_CHAR);

jerry-core/ecma/builtin-objects/ecma-builtin-regexp-prototype.c

@@ -162,7 +162,7 @@ ecma_builtin_regexp_prototype_compile (ecma_value_t this_arg, /**< this argument
                         ecma_op_to_string (pattern_arg),
                         ret_value);
 
-        if (ecma_string_get_length (ecma_get_string_from_value (regexp_str_value)) == 0)
+        if (ecma_string_is_empty (ecma_get_string_from_value (regexp_str_value)))
         {
           pattern_string_p = ecma_get_magic_string (LIT_MAGIC_STRING_EMPTY_NON_CAPTURE_GROUP);
         }

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

@@ -103,7 +103,7 @@ ecma_builtin_regexp_dispatch_construct (const ecma_value_t *arguments_list_p, /*
                       ecma_op_to_string (pattern_value),
                       ret_value);
 
-      if (ecma_string_get_length (ecma_get_string_from_value (regexp_str_value)) == 0)
+      if (ecma_string_is_empty (ecma_get_string_from_value (regexp_str_value)))
       {
         pattern_string_p = ecma_get_magic_string (LIT_MAGIC_STRING_EMPTY_NON_CAPTURE_GROUP);
       }

jerry-core/ecma/builtin-objects/ecma-builtin-string-prototype.c

@@ -138,10 +138,11 @@ ecma_builtin_string_prototype_object_char_at (ecma_value_t this_arg, /**< this a
 
   /* 4 */
   ecma_string_t *original_string_p = ecma_get_string_from_value (to_string_val);
-  const ecma_length_t len = ecma_string_get_length (original_string_p);
 
   /* 5 */
-  if (index_num < 0 || index_num >= len || !len)
+  if (ecma_string_is_empty (original_string_p)
+      || index_num >= ecma_string_get_length (original_string_p)
+      || index_num < 0)
   {
     ret_value = ecma_make_string_value (ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY));
   }
@@ -1673,9 +1674,6 @@ ecma_builtin_string_prototype_object_split (ecma_value_t this_arg, /**< this arg
       }
       else /* if (!ecma_is_value_undefined (arg1)) */
       {
-        /* 6. */
-        const ecma_length_t string_length = ecma_string_get_length (ecma_get_string_from_value (this_to_string_val));
-
         /* 8. */
         ecma_value_t separator = ecma_make_simple_value (ECMA_SIMPLE_VALUE_EMPTY);
 
@@ -1695,8 +1693,11 @@ ecma_builtin_string_prototype_object_split (ecma_value_t this_arg, /**< this arg
           ECMA_FINALIZE (separator_to_string_val);
         }
 
+        const ecma_string_t *this_to_string_p = ecma_get_string_from_value (this_to_string_val);
+
         /* 11. */
-        if (string_length == 0 && ecma_is_value_empty (ret_value))
+        if (ecma_string_is_empty (this_to_string_p)
+            && ecma_is_value_empty (ret_value))
         {
           /* 11.a */
           ecma_value_t match_result = ecma_builtin_helper_split_match (this_to_string_val,
@@ -1744,6 +1745,9 @@ ecma_builtin_string_prototype_object_split (ecma_value_t this_arg, /**< this arg
 
           bool separator_is_empty = false;
 
+          /* 6. */
+          const ecma_length_t string_length = ecma_string_get_length (this_to_string_p);
+
           /* 13. */
           while (curr_pos < string_length && !should_return && ecma_is_value_empty (ret_value))
           {

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

@@ -222,7 +222,7 @@ ecma_op_to_boolean (ecma_value_t value) /**< ecma value */
   {
     ecma_string_t *str_p = ecma_get_string_from_value (value);
 
-    return ecma_string_get_length (str_p) != 0;
+    return !ecma_string_is_empty (str_p);
   }
 
   JERRY_ASSERT (ecma_is_value_object (value));