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Date:   Sun, 17 Feb 2019 12:48:02 +0100 (CET)
From:   Julia Lawall <julia.lawall@lip6.fr>
To:     Markus Elfring <Markus.Elfring@web.de>
cc:     Wen Yang <yellowriver2010@hotmail.com>,
        Gilles Muller <Gilles.Muller@lip6.fr>,
        Nicolas Palix <nicolas.palix@imag.fr>,
        Michal Marek <michal.lkml@markovi.net>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Wen Yang <wen.yang99@zte.com.cn>,
        Cheng Shengyu <cheng.shengyu@zte.com.cn>,
        kernel-janitors@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Coccinelle <cocci@systeme.lip6.fr>
Subject: Re: [PATCH v6] coccinelle: semantic code search for missing
 put_device()
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On Sun, 17 Feb 2019, Markus Elfring wrote:

> >>> +@search exists@
> >>> +local idexpression id;
> >>> +expression x,e,e1;
> >>> +position p1,p2;
> >>> +type T,T1,T2;
> >>> +@@
> >>> +
> >>> +id = of_find_device_by_node@p1(x)
> >>> +... when != e = id
> >>
> >> I suggest to increase your software development attention also for
> >> another implementation detail.
> >> Source code analysis triggers challenges for safe data flow handling.
> >> the semantic patch language supports search specifications for
> >> the exclusion of specific assignments.
> >>
> >> Does this SmPL code contain a questionable order for the source
> >> and target metavariables?
> >> Can the following variant be more appropriate?
> >>
> >> + ... when != id = e
> >
> > This is possible, but I think unlikely.
>
> Would you dare to interpret my update suggestion (reordering of two identifiers)
> as a required SmPL script correction?

I didn't suggest to reorder anything.  Both are needed.

And, no I don't consider it to be a required suggestion.  In practice,
reassigning such a variable is very unlikely.

julia