From mboxrd@z Thu Jan  1 00:00:00 1970
From: Markus Elfring <Markus.Elfring@web.de>
Date: Fri, 15 Feb 2019 13:15:18 +0000
Subject: Re: [v5] Coccinelle: semantic code search for missing put_device()
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To: Julia Lawall <julia.lawall@lip6.fr>, Wen Yang <wen.yang99@zte.com.cn>
Cc: Yi Wang <wang.yi59@zte.com.cn>, kernel-janitors@vger.kernel.org, Michal Marek <michal.lkml@markovi.net>, Wen Yang <yellowriver2010@hotmail.com>, Nicolas Palix <nicolas.palix@imag.fr>, linux-kernel@vger.kernel.org, Cheng Shengyu <cheng.shengyu@zte.com.cn>, cocci@systeme.lip6.fr

>>> +id = of_find_device_by_node@p1(x)
…
>>> +if (id == NULL || ...) { ... return ...; }
>>> +... when != put_device(&id->dev)
>> …
>>> +    when != if (id) { ... put_device(&id->dev) ... }
>> …
>>
>> I would interpret this SmPL code in the way that the if statement
>> for the pointer check is “optional” in this line.
>> Is it an extra and redundant SmPL specification when the reference
>> release function could eventually be found just anywhere within
>> an implementation?
>
> The proposed when code is correct.

I agree that this SmPL code can work in the way it was designed.


> It is not redundant, because it checks for a particular control-flow pattern.

It took another moment until I dared to express a different software
development opinion also on this implementation detail.

Does the first SmPL when specification include the case that a call
of the function “put_device” can occur within a branch of an if statement?

Regards,
Markus