From: ZyX <kp-pav@yandex.ru>
To: Mikael Magnusson <mikachu@gmail.com>
Cc: Peter Stephenson <p.stephenson@samsung.com>,
zsh workers <zsh-workers@zsh.org>
Subject: Re: Fishier code in handlefeatures
Date: Tue, 06 Jan 2015 03:36:09 +0300 [thread overview]
Message-ID: <2001361420504569@web17g.yandex.ru> (raw)
In-Reply-To: <CAHYJk3QP+mPCGpjia6aB+UxwGa9ePVceK7v4RBu-aMC5epYLRw@mail.gmail.com>
06.01.2015, 03:32, "Mikael Magnusson" <mikachu@gmail.com>:
> On Tue, Jan 6, 2015 at 1:24 AM, ZyX <kp-pav@yandex.ru> wrote:
>> 06.01.2015, 03:21, "Mikael Magnusson" <mikachu@gmail.com>:
>>> mod_export int
>>> handlefeatures(Module m, Features f, int **enables)
>>> {
>>> if (!enables || *enables)
>>> return setfeatureenables(m, f, *enables);
>>> *enables = getfeatureenables(m, f);
>>> return 0;
>>> }
>>>
>>> so if enables is NULL, we immediately do *enables? I'm not sure what's
>>> intended here but obviously it somehow works.
>> NULL is false, so if enables is NULL !enables is true and *enables is not evaluated due to short-circuiting. Nothing wrong here.
>
> Read the next line too.
Ah. You mean dereference in function arguments, good catch.
Guess this code means that `enables` is never NULL and first part of the condition should be dropped in order not to confuse people.
>
> --
> Mikael Magnusson
next prev parent reply other threads:[~2015-01-06 0:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-06 0:20 Mikael Magnusson
2015-01-06 0:24 ` ZyX
2015-01-06 0:32 ` Mikael Magnusson
2015-01-06 0:36 ` ZyX [this message]
2015-01-06 7:45 ` Bart Schaefer
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