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To: Jeff Garzik <jgarzik@pobox.com>
Cc: Linus Torvalds <torvalds@transmeta.com>,
       "Richard B. Johnson" <root@chaos.analogic.com>,
       Martin Schwidefsky <schwidefsky@de.ibm.com>,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] s390 (7/13): gcc 3.3 adaptions.
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From: Andreas Schwab <schwab@suse.de>
Date: Mon, 24 Feb 2003 23:07:25 +0100
In-Reply-To: <20030224215335.GA24975@gtf.org> (Jeff Garzik's message of
 "Mon, 24 Feb 2003 16:53:35 -0500")
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Jeff Garzik <jgarzik@pobox.com> writes:

|> On Mon, Feb 24, 2003 at 10:35:24PM +0100, Andreas Schwab wrote:
|> > Linus Torvalds <torvalds@transmeta.com> writes:
|> > 
|> > |> Does gcc still warn about things like
|> > |> 
|> > |> 	#define COUNT (sizeof(array)/sizeof(element))
|> > |> 
|> > |> 	int i;
|> > |> 	for (i = 0; i < COUNT; i++)
|> > |> 		...
|> > |> 
|> > |> where COUNT is obviously unsigned (because sizeof is size_t and thus 
|> > |> unsigned)?
|> > |> 
|> > |> Gcc used to complain about things like that, which is a FUCKING DISASTER. 
|> > 
|> > How can you distinguish that from other occurrences of (int)<(size_t)?
|> 
|> The bounds are obviously constant and unsigned at compile time.

But that's not the point.  It's the runtime value of i that gets converted
(to unsigned), not the compile time value of COUNT.  Thus if i ever gets
negative you have a problem.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 N?rnberg
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