Re: do { } while (0) question

From: Jiri Slaby
Date: Tue Aug 01 2006 - 04:49:51 EST


Heiko Carstens wrote:
Hi Andrew,

your commit e2c2770096b686b4d2456173f53cb50e01aa635c does this:

---
Always use do {} while (0). Failing to do so can cause subtle compile
failures or bugs.

-#define hotcpu_notifier(fn, pri)
-#define register_hotcpu_notifier(nb)
-#define unregister_hotcpu_notifier(nb)
+#define hotcpu_notifier(fn, pri) do { } while (0)
+#define register_hotcpu_notifier(nb) do { } while (0)
+#define unregister_hotcpu_notifier(nb) do { } while (0)

#if KILLER == 1
#define MACRO
#else
#define MACRO do { } while (0)
#endif

{
if (some_condition)
MACRO

if_this_is_not_called_you_loose_your_data();
}

How do you want to define KILLER, 0 or 1? I personally choose 0.

regards,
--
<a href="http://www.fi.muni.cz/~xslaby/";>Jiri Slaby</a>
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8 22A0 32CC 55C3 39D4 7A7E
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/