Re: [PATCH v3 00/11] cocci: make "incremental" possible + a ccache-like tool

From: Jeff King <peff@peff.net>
Date: Oct 17, 2022, 19:18 UTC
Message-ID: <Y02qgLP12p0c+XWB@coredump.intra.peff.net>
In-Reply-To: <221017.86czaqjnhy.gmgdl@evledraar.gmail.com>

On Mon, Oct 17, 2022 at 08:36:46PM +0200, Ævar Arnfjörð Bjarmason wrote:

Show 9 quoted lines

> > Maybe we don't do any of the things that could trigger problems in our
> > spatch rules. But it's not clear to me what we're risking. Do you have a
> > link for further discussion?
> 
> I think 10/11's commit message should answer your question:
> https://lore.kernel.org/git/patch-v3-10.11-52177ea2a68-20221014T152553Z-avarab@gmail.com/
> 
> The tl;dr is that it's not safe in the general case, as noted in the
> post you & the more recent one I linked to in 10/11.

Thanks. Holy cow, the coccinelle list is hard to use compared to lore/public-inbox. The direct link to the thread in question is:

  https://sympa.inria.fr/sympa/arc/cocci/2022-09/msg00001.html

(you'll need to click a javascript button to see it, though).

Show 9 quoted lines

> So, with this series doing:
> 
> 	perl -pi -e 's/swap/preincrement/g' contrib/coccinelle/swap.cocci
> 
> Will error it if you run it with "SPATCH_CONCAT_COCCI=Y", but not with
> "SPATCH_CONCAT_COCCI=", as the rule names conflict in the ALL.cocci.
> 
> But as 10/11 notes we can just avoid this by not picking conflicting
> names, which doesn't seem like an undue burden.

Yeah, that seems OK, then. In fact, I'd be fine with guidance in the README saying "don't bother with a name if you don't need it".

-Peff