From owner-freebsd-current  Tue Nov 30  7:15:25 1999
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Date: Tue, 30 Nov 1999 07:15:22 -0800 (PST)
From: David Wolfskill <dhw@whistle.com>
Message-Id: <199911301515.HAA18242@pau-amma.whistle.com>
To: itojun@iijlab.net, julian@whistle.com
Subject: Re: trigraph in IPV6?
Cc: current@FreeBSD.ORG
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>From: itojun@iijlab.net
>Date: Tue, 30 Nov 1999 23:02:21 +0900

>>../../netinet6/in6.c: warning: 1 trigraph(s) encountered
>>haven't seen one of  THOSE for a while....

>	Could you tell me which line was that?  I don't see any...

Indeed.  The only line I see (as of the 1.1 version of the file, dated
1999/11/22 02:44:59) that has 2 consecutive '?' characters at all (which
sequence introduces all trigraphs) is line 892, which reads

 *	SIOCGLIFADDR: get first address. (???)

And my copy of the May 13, 1988 DpANS C states (section 2.2.1.1):

	2.2.1.1 Trigraph sequences

	All occurrences in a source file of the following sequences of
	three characters (called trigraph sequences(5)) are replaced
	with the corresponding single charcacter.

		??=	#
		??(	[
		??/	\
		??)	]
		??'	^
		??<	{
		??!	|
		??>	}
		??-	~

	No other trigraph sequences exist.  Each ? that does not begin
	one of the trigraphs listed above is not changed.  [Example
	& footnote elided -- dhw]


K&R, 2nd ed., p. 229 appears to agree with the above.

I suspect a bogus warning from gcc's lexical analyzer.

Cheers,
david
-- 
David Wolfskill		dhw@whistle.com		UNIX System Administrator
voice: (650) 577-7158	pager: (888) 347-0197	FAX: (650) 372-5915


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