Date: Mon, 31 Jan 2011 09:42:53 +0000 From: Alexander Best <arundel@freebsd.org> To: Julian Elischer <julian@freebsd.org> Cc: freebsd-hackers@freebsd.org, Roman Divacky <rdivacky@freebsd.org> Subject: Re: empty function macros Message-ID: <20110131094253.GA98011@freebsd.org> In-Reply-To: <4D46716E.6070500@freebsd.org> References: <20110130172941.GA10701@freebsd.org> <20110131075439.GA49765@freebsd.org> <4D46716E.6070500@freebsd.org>
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On Mon Jan 31 11, Julian Elischer wrote:
> On 1/30/11 11:54 PM, Roman Divacky wrote:
> >no problem with this with clang :)
> >
> >On Sun, Jan 30, 2011 at 05:29:41PM +0000, Alexander Best wrote:
> >>hi there,
> >>
> >>i noticed freebsd has a few of the following macros:
> >>
> >>#define FUNC(sb)
> >>
> >>when you do something like
> >>
> >>if (cond)
> >> FUNC(i)
>
> you missed an important part....
>
> it's probably
> if (cond)
> FUNC(i);
> (note the ';')
> THAT would be ok....
> without the ';' you just made whatever comes next conditional.
... still clang outputs a warning. sorry if i was unclear:
there's no issue with clang generating wrong code. i just thought we might be
able to stop clang from complaining.
basically
int
main(int argc, char **argv)
{
if (1 > 2)
;
}
produces a warning in clang, whereas with gcc (base) it doesn't.
cheers.
alex
>
> >>the compiler complains about an if statement with an empty body. any
> >>sensible
> >>way of dealing with this issue?
> >>
> >>i saw some reiserfs code which does the following to silence compilers:
> >>
> >>#define FUNC(sb) do { } while (0)
>
> yeah we do that too in some places.
> (certainly at work I have done so)
>
>
> >>cheers.
> >>alex
> >>
> >>--
> >>a13x
> >>_______________________________________________
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> >
--
a13x
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