Messages in this thread | | | Date | Mon, 14 Jul 2003 00:53:10 +0200 | From | Ingo Oeser <> | Subject | Re: Style question: Should one check for NULL pointers? |
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Hi,
On Thu, Jul 10, 2003 at 04:28:09PM -0400, Alan Stern wrote: > There are many places in the kernel where a function checks whether a > pointers it has been given is NULL. Now sometimes this makes perfect > sense because the function's description explicitly says that a NULL > pointer argument is valid. But in many, many cases (maybe even the > majority) it is nothing more than paranoia: the pointer can never be NULL > in a properly functioning system.
There are many meanings of NULL.
a) NULL -> I don't know Reaction: Ok, then do a generic/default variant.
b) NULL -> failure in caller passed down to us. Reaction: Pass it on, return -EINVAL or ignore the call
c) NULL -> failure in API (argument can't be NULL) Reaction: BUG_ON()
...
So the answer isn't only taste, it's a matter of simplicity and roboustness.
Regards
Ingo Oeser - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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