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Date:   Sat, 16 Feb 2019 09:34:08 +0100 (CET)
From:   Julia Lawall <julia.lawall@lip6.fr>
To:     Markus Elfring <Markus.Elfring@web.de>
cc:     Wen Yang <wen.yang99@zte.com.cn>,
        Gilles Muller <Gilles.Muller@lip6.fr>,
        Nicolas Palix <nicolas.palix@imag.fr>,
        Michal Marek <michal.lkml@markovi.net>,
        Yi Wang <wang.yi59@zte.com.cn>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Wen Yang <yellowriver2010@hotmail.com>,
        Cheng Shengyu <cheng.shengyu@zte.com.cn>,
        cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org
Subject: Re: [v5] coccinelle: semantic code search for missingput_device()
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Message-ID: <alpine.DEB.2.21.1902160933350.3212@hadrien>
References: <201902161504357846572@zte.com.cn> <10281c5d-8b32-0a02-17ae-20bf86f8dc65@web.de>
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On Sat, 16 Feb 2019, Markus Elfring wrote:

> > Thanks, We will change it to something like this:
> > In a function, for a local variable obtained by of_find_device_by_node()
>
> How do you think about another wording approach?
>
> 1. Precondition:
>    It will be checked where the return value is stored from
>    a call of the function “of_find_device_by_node”.
>
> 2. The source code search will be continued with …
>
>
> > Thank you, but a local variable is necessary.
>
> Would you like to take additional storage possibilities for a safer
> analysis approach into account?
>
> Is the restriction “local” really sufficient when such a pointer
> could be copied to other variables?

I've lost track of the original semantic patch, but perhaps it needs a

when != e1 = e

julia

>
>
> >> Can it happen that on other function will perform the desired reference release?
> >
> > Thanks.
> > Because the information of this local variable is not passed to the external function,
> > this situation does not exist.
>
> Will copied pointers matter here?
>
>
> > But it's over 80 characters.
>
> Long string literals can be accepted because of error message search concerns
> around a tool like “grep”.
>
>
> >> Will any more advanced error diagnostics be eventually developed?
> >
> > Hello, we are just doing the practical work in this field.
>
> Are you aware of additional software design options from computer science
> and existing analysis tools?
>
>
> > We also hope that it can support cross-function/cross-file/data stream analysis
> > and other functions.
>
> This functionality will need further clarification.
>
>
> > We are also analyzing the principle and code implementation of coccinelle,
> > hoping to contribute a little.
>
> I am curious on how this situation will evolve further.
>
> Regards,
> Markus
>
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