Re: clang static analyzer

From: Nicolas Pitre <nico@fluxnic.net>
Date: Dec 6, 2009, 15:39 UTC
Message-ID: <alpine.LFD.2.00.0912061032380.31174@xanadu.home>
In-Reply-To: <20091206145744.GA6725@coredump.intra.peff.net>

On Sun, 6 Dec 2009, Jeff King wrote:

Show 24 quoted lines

> On Sun, Dec 06, 2009 at 07:11:24AM +0100, Tomas Carnecky wrote:
> 
> > Clang again found many dead assignments/increments, but in the earlier
> > discussions you concluded that you want to keep those around. So I
> > focussed on another class of potential bugs: Argument with 'nonnull'
> > attribute passed null. There were a total of seven such issues. I then
> > tried to look through the code and see if they are valid or false
> > positives:
> 
> Thanks, I think you are moving in the right direction to manually
> investigate the output of clang, since it obviously does generate some
> false positives.
> 
> I think the next step for each site you found would be:
> 
>   1. If it really is a problem, then it should be easy to show a simple
>      case that can trigger the issue. Submit a patch fixing that site,
>      either describing the test case in the commit message, or adding a
>      case to the test suite.
> 
>   2. If it is a false positive, see what it would take to silence clang
>      and submit a patch.  I don't think we are opposed to annotations
>      that help analysis tools as long as those annotations aren't too
>      intrusive or make the code less readable.

I'm a bit skeptical here. Going down that route might mean that we'll eventually have to add all sort of crap to accommodate everyone's preferred static analysis tool of the day. Would be far nicer to try to make those tools more intelligent instead, or at least make them understand an out-of-line annotation format that does not clutter the code itself.

Nicolas