Introduce ofpacts, an abstraction of OpenFlow actions.

[cascardo/ovs.git] / lib / compiler.h

diff --git a/lib/compiler.h b/lib/compiler.h
index 0075ca8..27612a7 100644 (file)
--- a/lib/compiler.h
+++ b/lib/compiler.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,14 +17,42 @@
 #ifndef COMPILER_H
 #define COMPILER_H 1
 
+#if __GNUC__ && !__CHECKER__
 #define NO_RETURN __attribute__((__noreturn__))
 #define OVS_UNUSED __attribute__((__unused__))
-#define PACKED __attribute__((__packed__))
 #define PRINTF_FORMAT(FMT, ARG1) __attribute__((__format__(printf, FMT, ARG1)))
 #define STRFTIME_FORMAT(FMT) __attribute__((__format__(__strftime__, FMT, 0)))
 #define MALLOC_LIKE __attribute__((__malloc__))
 #define ALWAYS_INLINE __attribute__((always_inline))
-#define likely(x) __builtin_expect((x),1)
-#define unlikely(x) __builtin_expect((x),0)
+#define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
+#define SENTINEL(N) __attribute__((sentinel(N)))
+#else
+#define NO_RETURN
+#define OVS_UNUSED
+#define PRINTF_FORMAT(FMT, ARG1)
+#define STRFTIME_FORMAT(FMT)
+#define MALLOC_LIKE
+#define ALWAYS_INLINE
+#define WARN_UNUSED_RESULT
+#define SENTINEL(N)
+#endif
+
+/* ISO C says that a C implementation may choose any integer type for an enum
+ * that is sufficient to hold all of its values.  Common ABIs (such as the
+ * System V ABI used on i386 GNU/Linux) always use a full-sized "int", even
+ * when a smaller type would suffice.
+ *
+ * In GNU C, "enum __attribute__((packed)) name { ... }" defines 'name' as an
+ * enum compatible with a type that is no bigger than necessary.  This is the
+ * intended use of OVS_PACKED_ENUM.
+ *
+ * OVS_PACKED_ENUM is intended for use only as a space optimization, since it
+ * only works with GCC.  That means that it must not be used in wire protocols
+ * or otherwise exposed outside of a single process. */
+#if __GNUC__ && !__CHECKER__
+#define OVS_PACKED_ENUM __attribute__((__packed__))
+#else
+#define OVS_PACKED_ENUM
+#endif
 
 #endif /* compiler.h */