From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-return-103864-listarch-gcc=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 17509 invoked by alias); 8 Oct 2004 17:08:56 -0000
Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc/>
List-Post: <mailto:gcc@gcc.gnu.org>
List-Help: <http://gcc.gnu.org/ml/>
Sender: gcc-owner@gcc.gnu.org
Received: (qmail 17498 invoked from network); 8 Oct 2004 17:08:55 -0000
Received: from unknown (HELO kiruna.synopsys.com) (198.182.44.80)
  by sourceware.org with SMTP; 8 Oct 2004 17:08:55 -0000
Received: from mother.synopsys.com (mother.synopsys.com [146.225.100.171])
	by kiruna.synopsys.com (Postfix) with ESMTP
	id 5A5C1F2AD; Fri,  8 Oct 2004 10:08:37 -0700 (PDT)
Received: from piper.synopsys.com (localhost [127.0.0.1])
	by mother.synopsys.com (8.9.1/8.9.1) with ESMTP id KAA05470;
	Fri, 8 Oct 2004 10:08:54 -0700 (PDT)
Received: (from jbuck@localhost)
	by piper.synopsys.com (8.11.6/8.11.6) id i98H8sT02225;
	Fri, 8 Oct 2004 10:08:54 -0700
X-Authentication-Warning: piper.synopsys.com: jbuck set sender to Joe.Buck@synopsys.com using -f
Date: Fri, 08 Oct 2004 17:59:00 -0000
From: Joe Buck <Joe.Buck@synopsys.COM>
To: Nick Ing-Simmons <nick@ing-simmons.net>, jamie@shareable.org,
	gcc@gcc.gnu.org, "'Morten Welinder'" <terra@gnome.org>,
	Dave Korn <dk@artimi.com>
Subject: Re: signed vs unsigned pointer warning
Message-ID: <20041008100853.A2207@synopsys.com>
References: <20040922161751.B4F6A1422D53@darter.rentec.com> <NUTMEGODkUqESudbgsy00000021@NUTMEG.CAM.ARTIMI.COM> <20040926192142.GA29842@mail.shareable.org> <20040926192142.GA29842@mail.shareable.org> <20041008130623.9516.4@llama.elixent.com> <20041008091714.A1695@synopsys.com> <m3d5zttbu6.fsf@multivac.cwru.edu>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5.1i
In-Reply-To: <m3d5zttbu6.fsf@multivac.cwru.edu>; from prj@po.cwru.edu on Fri, Oct 08, 2004 at 12:26:35PM -0400
X-SW-Source: 2004-10/txt/msg00362.txt.bz2

On Fri, Oct 08, 2004 at 12:26:35PM -0400, Paul Jarc wrote:
> Joe Buck <Joe.Buck@synopsys.COM> wrote:
> > Why can't an implementation define isxxx(c) to return something like
> >     table_lookup[(unsigned)(c)]
> > ?
> 
> Assuming EOF==-1, that fails to distinguish between EOF and character
> 255 (as does the 384-element table in the case where a signed char is
> passed).  The ctype macros are supposed to accept EOF as well as
> unsigned char values.

No, (unsigned)-1 does not turn into 255, it turns into a very large
number.  You cannot store EOF in a char.  Here's a bug fix:

	 table_lookup[1U+(unsigned)(c)]

Now EOF goes into slot 0.