From owner-freebsd-hackers@FreeBSD.ORG  Fri May  1 12:31:36 2009
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id EA28D1065675
	for <freebsd-hackers@freebsd.org>; Fri,  1 May 2009 12:31:36 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from kabab.cs.huji.ac.il (kabab.cs.huji.ac.il [132.65.16.84])
	by mx1.freebsd.org (Postfix) with ESMTP id 99FC58FC1C
	for <freebsd-hackers@freebsd.org>; Fri,  1 May 2009 12:31:36 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from pampa.cs.huji.ac.il ([132.65.80.32])
	by kabab.cs.huji.ac.il with esmtp
	id 1Lzrtu-0006cn-Pp; Fri, 01 May 2009 15:31:34 +0300
X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2
To: Marius Strobl <marius@alchemy.franken.de>
In-reply-to: <20090501112239.GA23199@alchemy.franken.de> 
References: <49F4070C.2000108@gmx.de>
	<20090501112239.GA23199@alchemy.franken.de>
Comments: In-reply-to Marius Strobl <marius@alchemy.franken.de>
	message dated "Fri, 01 May 2009 13:22:39 +0200."
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Fri, 01 May 2009 15:31:33 +0300
From: Danny Braniss <danny@cs.huji.ac.il>
Message-ID: <E1Lzrtu-0006cn-Pp@kabab.cs.huji.ac.il>
Cc: Maxim Sobolev <sobomax@freebsd.org>,
	FreeBSD Hackers <freebsd-hackers@freebsd.org>,
	Roman Divacky <rdivacky@freebsd.org>, Ed Schouten <ed@freebsd.org>,
	Christoph Mallon <christoph.mallon@gmx.de>, Warner Losh <imp@freebsd.org>
Subject: Re: C99: Suggestions for style(9) 
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 01 May 2009 12:31:37 -0000

> On Sun, Apr 26, 2009 at 09:02:36AM +0200, Christoph Mallon wrote:
> > 
> > return with parentheses:
> > Removed, because it does not improve maintainability in any way. There 
> > is no source for confusion here, so the rule even contradicts the rule, 
> > which states not to use redundant parentheses. Maybe, decades ago it was 
> > just a workaround for a broken compiler, which does not exist anymore.
> 
> FYI, the idea behind this rule is said to be to able to use
> a macro return(), f.e. for debugging you then can do:
> #define	return(x) do {							\
> 	printf("returning from %s with %d\n", __func__, (x));		\
> 	return (x);							\
> } while (0)
> 
> Given the this is a nifty feature and parentheses around the
> return value don't hurt maintainability in any way IMO this
> rule should stay.

short version:
	not nifty, dirty yes!
long version:

it's already quiet difficult to read the sources with so many MaCrOs roaming
around, but if you change if, return, then, else, switch etc, etc
to a macro invocation, there will be a slight discrepancy between
the undertsanding of the code and its running effect.
btw, what if x is a pointer?, or a quad? or a complex ...

my .02$

danny