On 1/24/11 1:33 PM, Nicholas A. Bellinger wrote:
On Mon, 2011-01-24 at 14:56 -0600, James Bottomley wrote:
On Mon, 2011-01-24 at 12:37 -0800, Nicholas A. Bellinger wrote:
-#define TASK_CMD(task) ((struct se_cmd *)task->task_se_cmd)
-#define TASK_DEV(task) ((struct se_device *)task->se_dev)
+#define TASK_CMD(task) ((task)->task_se_cmd)
+#define TASK_DEV(task) ((task)->se_dev)
Part of the problem with the old code is that task was not parenthesized,
so if TASK_CMD() were used with an expression, you might not get what
you want. If you did TASK_CMD(p + 5), for example, you would get
((struct se_cmd *)p + 5->task_se_cmd)
Which wouldn't compile, but maybe other examples would compile and
would cause strange problems. So, it's a bad macro as it is.
Just my 2 cents.
Cheers,
Joe
If sparse is objecting to things like this then sparse needs fixing:
It's decreasing typesafety. the things being cast are void * ... they'd
be depositable into any pointer whatsoever without the cast. With the
cast in the #define, we pick up pointer mismatches (as we should).
Without it, we don't. As long as the define is always a specific type,
it *should* cast to it.
Hmmm, good point.. In that case I will go ahead and drop this part of
the patch.
Thanks!
--nab
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