X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fsystem.h;h=faae39055484875b237dd62dd0928e9903725da1;hp=4ae3ba0d34eeb50f3fc01c316286d51921714e58;hb=2af1c19e6a553878fcb2a5106f050d5ed7ac0f54;hpb=9d2614f07691a813a3c560a6c0bcd0a7be854ed5

diff --git a/urcu/system.h b/urcu/system.h
index 4ae3ba0..faae390 100644
--- a/urcu/system.h
+++ b/urcu/system.h
@@ -8,21 +8,23 @@
  *
  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
- * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
  *
- * Permission is hereby granted to use or copy this program
- * for any purpose,  provided the above notices are retained on all copies.
- * Permission to modify the code and to distribute modified code is granted,
- * provided the above notices are retained, and a notice that the code was
- * modified is included with the above copyright notice.
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
  */
 
 #include <urcu/compiler.h>
 #include <urcu/arch.h>
 
 /*
- * Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come before the load.
+ * Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come
+ * before the load.
  */
 #define _CMM_LOAD_SHARED(p)	       CMM_ACCESS_ONCE(p)
 
@@ -30,25 +32,28 @@
  * Load a data from shared memory, doing a cache flush if required.
  */
 #define CMM_LOAD_SHARED(p)			\
+	__extension__			\
 	({				\
 		cmm_smp_rmc();		\
 		_CMM_LOAD_SHARED(p);	\
 	})
 
 /*
- * Identify a shared store. A cmm_smp_wmc() or cmm_smp_mc() should follow the store.
+ * Identify a shared store. A cmm_smp_wmc() or cmm_smp_mc() should
+ * follow the store.
  */
-#define _CMM_STORE_SHARED(x, v)	({ CMM_ACCESS_ONCE(x) = (v); })
+#define _CMM_STORE_SHARED(x, v)	__extension__ ({ CMM_ACCESS_ONCE(x) = (v); })
 
 /*
- * Store v into x, where x is located in shared memory. Performs the required
- * cache flush after writing. Returns v.
+ * Store v into x, where x is located in shared memory. Performs the
+ * required cache flush after writing. Returns v.
  */
-#define CMM_STORE_SHARED(x, v)		\
-	({				\
-		typeof(x) _v = _CMM_STORE_SHARED(x, v);	\
-		cmm_smp_wmc();		\
-		_v;			\
+#define CMM_STORE_SHARED(x, v)						\
+	__extension__							\
+	({								\
+		__typeof__(x) _v = _CMM_STORE_SHARED(x, v);		\
+		cmm_smp_wmc();						\
+		_v = _v;	/* Work around clang "unused result" */	\
 	})
 
 #endif /* _URCU_SYSTEM_H */