Re: [PATCH] Fix some sparse warnings

From: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Date: Jul 18, 2013, 17:58 UTC
Message-ID: <51E82CD0.8060302@ramsay1.demon.co.uk>
In-Reply-To: <20130716062122.GA4964@sigill.intra.peff.net>

Jeff King wrote:

Show 14 quoted lines

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

Yes, last time this came up, I looked at writing a patch to sparse to allow this without complaint. It's still on my sparse TODO list, but even if I finished it tonight, it would take a while to get into a released version of sparse. ;-)

Show 8 quoted lines

> 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).

Indeed, if it wasn't for this, I would be happy to turn this warning off.

ATB, Ramsay Jones