X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Futil.h;h=a899065a3af3ad9cc37a789dbd414a5baeeb8b8e;hb=e8f9a7bbf1b4dd4cfd4f16a3a9c28ccf406b7d26;hp=911ad3218a6855b75dd5a0a9df8f889d6f98cf88;hpb=33e191a01b2c5aad1e97c109e66dec4b4d280ef6;p=sliver-openvswitch.git

diff --git a/lib/util.h b/lib/util.h
index 911ad3218..a899065a3 100644
--- a/lib/util.h
+++ b/lib/util.h
@@ -87,8 +87,23 @@ void ovs_assert_failure(const char *, const char *, const char *) NO_RETURN;
 
 extern const char *program_name;
 
+#define __ARRAY_SIZE_NOCHECK(ARRAY) (sizeof(ARRAY) / sizeof((ARRAY)[0]))
+#ifdef __GNUC__
+/* return 0 for array types, 1 otherwise */
+#define __ARRAY_CHECK(ARRAY) 					\
+    !__builtin_types_compatible_p(typeof(ARRAY), typeof(&ARRAY[0]))
+
+/* compile-time fail if not array */
+#define __ARRAY_FAIL(ARRAY) (sizeof(char[-2*!__ARRAY_CHECK(ARRAY)]))
+#define __ARRAY_SIZE(ARRAY)					\
+    __builtin_choose_expr(__ARRAY_CHECK(ARRAY),			\
+        __ARRAY_SIZE_NOCHECK(ARRAY), __ARRAY_FAIL(ARRAY))
+#else
+#define __ARRAY_SIZE(ARRAY) __ARRAY_SIZE_NOCHECK(ARRAY)
+#endif
+
 /* Returns the number of elements in ARRAY. */
-#define ARRAY_SIZE(ARRAY) (sizeof ARRAY / sizeof *ARRAY)
+#define ARRAY_SIZE(ARRAY) __ARRAY_SIZE(ARRAY)
 
 /* Returns X / Y, rounding up.  X must be nonnegative to round correctly. */
 #define DIV_ROUND_UP(X, Y) (((X) + ((Y) - 1)) / (Y))
@@ -193,6 +208,10 @@ is_pow2(uintmax_t x)
 #define ASSIGN_CONTAINER(OBJECT, POINTER, MEMBER) \
     ((OBJECT) = OBJECT_CONTAINING(POINTER, OBJECT, MEMBER), (void) 0)
 
+/* Given ATTR, and TYPE, cast the ATTR to TYPE by first casting ATTR to
+ * (void *). This is to suppress the alignment warning issued by clang. */
+#define ALIGNED_CAST(TYPE, ATTR) ((TYPE) (void *) (ATTR))
+
 #ifdef  __cplusplus
 extern "C" {
 #endif