Re: [PATCH] Fix some sparse warnings

From: Jeff King <peff@peff.net>
Date: Jul 16, 2013, 06:21 UTC
Message-ID: <20130716062122.GA4964@sigill.intra.peff.net>
In-Reply-To: <51E4E0C0.3060604@viscovery.net>

On Tue, Jul 16, 2013 at 07:57:20AM +0200, Johannes Sixt wrote:

Show 8 quoted lines

> Am 7/15/2013 19:31, schrieb Ramsay Jones:
> > Sparse issues three "Using plain integer as NULL pointer" warnings.
> > Each warning relates to the use of an '{0}' initialiser expression
> > in the declaration of an 'struct object_info'.
> 
> I question the value of this warning. Initialization with '= {0}' is a
> well-established idiom, and sparse should know about it. Also, plain 0
> *is* a null pointer constant.

I agree with you. It's not a bug, and I think sparse is being overly picky here; it is missing the forest for the trees in interpreting the idiom.

Still, it may be worth tweaking in the name of eliminating compiler noise, since it does not cost us very much to do so (and I believe we have done so in the past, too).

We could also ask people with sparse to turn off the "use NULL instead of 0" warning, but I think it _is_ a useful warning elsewhere (even though it is never a bug, it violates our style guidelines and may be an indication of a bug). It would be nice if sparse learned to ignore the warning in this particular idiom, but I am not going to hold my breath for that.

-Peff