gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Use empty do-while loop as macro…

gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Use empty do-while loop as macro body to avoid warnings.

2015-04-15  Chen Gang  <gang.chen.5i5j@gmail.com>

       * gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Use empty
       do-while loop as macro body to avoid warnings.

From-SVN: r222127

libgcc/ChangeLog

+2015-04-15  Chen Gang  <gang.chen.5i5j@gmail.com>
+
+	* gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Use empty
+	do-while loop as macro body to avoid warnings.
+
 2015-04-10  Jakub Jelinek  <jakub@redhat.com>
 	    Iain Sandoe  <iain@codesourcery.com>
 

libgcc/gthr-single.h

@@ -35,7 +35,7 @@ typedef int __gthread_recursive_mutex_t;
 
 #define __GTHREAD_ONCE_INIT 0
 #define __GTHREAD_MUTEX_INIT 0
-#define __GTHREAD_MUTEX_INIT_FUNCTION(mx)
+#define __GTHREAD_MUTEX_INIT_FUNCTION(mx) do {} while (0)
 #define __GTHREAD_RECURSIVE_MUTEX_INIT 0
 
 #define UNUSED __attribute__((__unused__))