From owner-freebsd-current@FreeBSD.ORG Mon Feb 9 14:48:29 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1F9191065678 for ; Mon, 9 Feb 2009 14:48:29 +0000 (UTC) (envelope-from christoph.mallon@gmx.de) Received: from mail.gmx.net (mail.gmx.net [213.165.64.20]) by mx1.freebsd.org (Postfix) with SMTP id 7B9308FC16 for ; Mon, 9 Feb 2009 14:48:28 +0000 (UTC) (envelope-from christoph.mallon@gmx.de) Received: (qmail invoked by alias); 09 Feb 2009 14:48:26 -0000 Received: from p54A3E6F0.dip.t-dialin.net (EHLO tron.homeunix.org) [84.163.230.240] by mail.gmx.net (mp001) with SMTP; 09 Feb 2009 15:48:26 +0100 X-Authenticated: #1673122 X-Provags-ID: V01U2FsdGVkX1/3SGIX4ZL38ICiuzMJ32NOnrIo+IsEszbdf9020r sv39Y6hfqr6B+4 Message-ID: <49904238.50505@gmx.de> Date: Mon, 09 Feb 2009 15:48:24 +0100 From: Christoph Mallon User-Agent: Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Hans Petter Selasky References: <20090206045349.GQ78804@elvis.mu.org> <200902091450.07014.hselasky@c2i.net> <499038DE.3050501@gmx.de> <200902091534.12506.hselasky@c2i.net> In-Reply-To: <200902091534.12506.hselasky@c2i.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.53 Cc: usb@freebsd.org, freebsd-current@freebsd.org, Alfred Perlstein Subject: Re: HEADSUP usb2/usb4bsd to become default in GENERIC X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Feb 2009 14:48:30 -0000 Hans Petter Selasky schrieb: > On Monday 09 February 2009, Christoph Mallon wrote: >> Hans Petter Selasky schrieb: >>> On Monday 09 February 2009, Christoph Mallon wrote: >>>> Christoph Mallon schrieb: >>>>> are named "err" or "error". This should be investigated, so here's the >>>>> complete list: >>>> Sorry, my MUA seems to have damaged the list. You can get the list here: >>>> http://tron.homeunix.org/usb2.unread.log >>> I think some of these errors depend if you have USB debugging compiled or >>> not. At least GCC does not warn? >> No, it does not depend on USB debugging. >> GCC has no warning at all for variables which are only assigned to. >> It only can warn about variables, which are only initialised. >> >> { >> int x = 23; // GCC warns here ... >> int y; // ... but not here - cparser does >> y = 42; >> y++; >> } >> >> cparser has an analysis, which can warn about "y", too. >> >> I manually verified all 40 warnings and I cannot find any users (i.e. >> readers) for these variables. > > What is the correct way to discard the return argument of a function? That's > basically what most of the warnings are about. > > 1) (void)my_fn() cast > 2) if (my_fn()) { } > 3) err = my_fn(); > 4) my_fn(); Just to understand this correctly: You want to discard error codes? Basically I see four categories: 1) Getting the softc and not using it. This can be removed completely. Example: sc = ATMEGA_BUS2SC(xfer->xroot->bus); 2) calling mtx_owned() and discarding the return value. Can be removed, too, after checking that the value is really unnecessary. Example: use_polling = mtx_owned(xfer->xroot->xfer_mtx) ? 1 : 0; 3) Getting some value and not using it. Can be removed, too, after checking that the value is really unnecessary. Example: ep_no = (xfer->endpoint & UE_ADDR); 4) The rest are return values of functions, which contain error codes. Discarding them is questionable at best. Example: (err is not read) if (udev->flags.suspended) { err = DEVICE_SUSPEND(iface->subdev); device_printf(iface->subdev, "Suspend failed\n"); } return (0); /* success */