[libobjc] Wrap CLASS_TABLE_HASH in do {} while (0)

2017-11-23  Tom de Vries  <tom@codesourcery.com>

	* class.c (CLASS_TABLE_HASH): Wrap in "do {} while (0)".

From-SVN: r255099

libobjc/ChangeLog

+2017-11-23  Tom de Vries  <tom@codesourcery.com>
+
+	* class.c (CLASS_TABLE_HASH): Wrap in "do {} while (0)".
+
 2017-11-17  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
 
 	* Makefile.in: Regenerate.

libobjc/class.c

@@ -154,13 +154,15 @@ static objc_mutex_t __class_table_lock = NULL;
    untouched.  */
 
 #define CLASS_TABLE_HASH(INDEX, HASH, CLASS_NAME)			\
+  do {									\
     HASH = 0;								\
     for (INDEX = 0; CLASS_NAME[INDEX] != '\0'; INDEX++)			\
       {									\
 	HASH = (HASH << 4) ^ (HASH >> 28) ^ CLASS_NAME[INDEX];		\
       }									\
 									\
-  HASH = (HASH ^ (HASH >> 10) ^ (HASH >> 20)) & CLASS_TABLE_MASK;
+    HASH = (HASH ^ (HASH >> 10) ^ (HASH >> 20)) & CLASS_TABLE_MASK;	\
+  } while (0)
 
 /* Setup the table.  */
 static void