Implementing register variables.

src/libecmaobjects/ecma-globals.h

@@ -63,11 +63,11 @@ typedef enum {
  * Simple ecma-values
  */
 typedef enum {
+    ECMA_SIMPLE_VALUE_EMPTY, /**< empty value (see also: ECMA-262 v5, 8.9 Completion specification type) */
     ECMA_SIMPLE_VALUE_UNDEFINED, /**< undefined value */
     ECMA_SIMPLE_VALUE_NULL, /**< null value */
     ECMA_SIMPLE_VALUE_FALSE, /**< boolean false */
     ECMA_SIMPLE_VALUE_TRUE, /**< boolean true */
-    ECMA_SIMPLE_VALUE_EMPTY, /**< empty value (see also: ECMA-262 v5, 8.9 Completion specification type) */
     ECMA_SIMPLE_VALUE_ARRAY_REDIRECT, /**< special value for an array's elements that exists,
                                            but is stored directly in the array's property list
                                            (used for array elements with non-default attribute values) */

src/libecmaobjects/ecma-helpers-value.c

@@ -26,6 +26,18 @@
 #include "ecma-helpers.h"
 #include "globals.h"
 
+/**
+ * Check if the value is empty.
+ *
+ * @return true - if the value contains implementation-defined empty simple value,
+ *         false - otherwise.
+ */
+bool
+ecma_is_value_empty( ecma_value_t value) /**< ecma-value */
+{
+  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_EMPTY );
+} /* ecma_is_value_empty */
+
 /**
  * Check if the value is undefined.
  *

src/libecmaobjects/ecma-helpers.h

@@ -42,6 +42,7 @@ extern void* ecma_decompress_pointer(uintptr_t compressed_pointer);
     (field) = ecma_compress_pointer( non_compressed_pointer) & ( ( 1u << ECMA_POINTER_FIELD_WIDTH ) - 1)
 
 /* ecma-helpers-value.c */
+extern bool ecma_is_value_empty( ecma_value_t value);
 extern bool ecma_is_value_undefined( ecma_value_t value);
 extern bool ecma_is_value_null( ecma_value_t value);
 extern bool ecma_is_value_boolean( ecma_value_t value);