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Date: Thu, 31 Mar 2022 11:14:10 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [PATCH v2 2/2] Documentation: dev-tools: Enhance static analysis
 section with discussion
Message-ID: <20220331081409.GY12805@kadam>
References: <cover.1648593132.git.marcelo.schmitt1@gmail.com>
 <11f4750c6d4c175994dfd36d1ff385f68f61bd02.1648593132.git.marcelo.schmitt1@gmail.com>
 <CABVgOSkb5CpnXDF_m7iy=A7RmN+KmY0T38TeZ4hKbmkdQgt6Yw@mail.gmail.com>
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To: David Gow <davidgow@google.com>
Cc: Marcelo Schmitt <marcelo.schmitt1@gmail.com>, Jonathan Corbet <corbet@lwn.net>, Mauro Carvalho Chehab <mchehab+huawei@kernel.org>, Daniel Latypov <dlatypov@google.com>, "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>, linux-sparse@vger.kernel.org, cocci@inria.fr, smatch@vger.kernel.org, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Shuah Khan <skhan@linuxfoundation.org>, julia.lawall@inria.fr
List-ID: <smatch.vger.kernel.org>

On Wed, Mar 30, 2022 at 10:48:13AM +0800, David Gow wrote:
> > +
> > +Smatch does flow analysis and, if allowed to build the function database, it
> > +also does cross function analysis. Smatch tries to answer questions like where
> > +is this buffer allocated? How big is it? Can this index be controlled by the
> > +user? Is this variable larger than that variable?
> > +
> > +It's generally easier to write checks in Smatch than it is to write checks in
> > +Sparse. Nevertheless, there are some overlaps between Sparse and Smatch checks
> > +because there is no reason for re-implementing Sparse's check in Smatch.
> 
> This last sentence isn't totally clear to me. Should this "because" be "so"?
> 

I stopped reading your email when you wrote "Cheers, David" but I should
have scrolled down.

There is not very much overlap between Sparse and Smatch.  Both have a
warning for if (!x & y).  That is a tiny thing.  The big overlap is when
it comes to the locking checks.  The Smatch check for locking is
honestly way better and more capable.

I always run both Sparse and Smatch on my patches.  I should run
Coccinelle as well, but I'm more familiar with Sparse and Smatch.

regards,
dan carpenter