From owner-freebsd-arch@FreeBSD.ORG  Mon Jan 31 12:36:18 2005
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id D5D0616A4CE
	for <arch@freebsd.org>; Mon, 31 Jan 2005 12:36:18 +0000 (GMT)
Received: from critter.freebsd.dk (f170.freebsd.dk [212.242.86.170])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 404A143D48
	for <arch@freebsd.org>; Mon, 31 Jan 2005 12:36:18 +0000 (GMT)
	(envelope-from phk@critter.freebsd.dk)
Received: from critter.freebsd.dk (localhost [127.0.0.1])
	by critter.freebsd.dk (8.13.1/8.13.1) with ESMTP id j0VCa9DH090393;
	Mon, 31 Jan 2005 13:36:09 +0100 (CET)
	(envelope-from phk@critter.freebsd.dk)
To: Andrew Reilly <andrew-freebsd@areilly.bpc-users.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Mon, 31 Jan 2005 23:26:09 +1100."
             <20050131122609.GA83556@gurney.reilly.home> 
Date: Mon, 31 Jan 2005 13:36:09 +0100
Message-ID: <90392.1107174969@critter.freebsd.dk>
Sender: phk@critter.freebsd.dk
cc: arch@freebsd.org
cc: Paul Richards <paul@originative.co.uk>
Subject: Re: c99/c++ localised variable definition 
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussion related to FreeBSD architecture
	<freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 31 Jan 2005 12:36:19 -0000

In message <20050131122609.GA83556@gurney.reilly.home>, Andrew Reilly writes:

>If you carelessly c++-ify a loop like:
>
>	for (int i = 0; i < N; i++)
>	{
>		if (some_condition(i)) break;
>	}
>	do_something_with(i);	/* use finishing index */
>
>you can miss the fact that the value of i is used outside of the
>loop.  The newly created scope for "i" shadows the presumably
>pre-existing definition of i at the top of the function, which
>is what do_something_with() gets to see.

I would _really_ hope we have the compiler warning about this
already ?

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.