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To: Robert Millan <rmh@debian.org>
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Cc: freebsd-hackers@freebsd.org, Ed Maste <emaste@freebsd.org>,
	Dimitry Andric <dim@freebsd.org>
Subject: Re: [PATCH] __FreeBSD_cc_version in <sys/cdefs.h>
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On Tue, Jul 5, 2011 at 6:36 AM, Robert Millan <rmh@debian.org> wrote:
> 2011/7/5 Dimitry Andric <dim@freebsd.org>:
>> As far as I can see, this code only gives warnings when compiled with
>> gcc 4.5 or higher, and when using the -Wundef flag. =A0Isn't it easier t=
o
>> just remove the -Wundef flag here?
>
> Here's a patch to remove -Wundef. =A0I think it's a bad idea however,
> IMHO it's better to fix the cause of the warning instead.

The problem is that, IIRC, C guarantees that an undefined symbol when
checked in a #if context will evaluate to 0.  So -Wundef checks for
warnings on compliant code.

Personally I have no objection to the original patch.

Cheers,
matthew