From mboxrd@z Thu Jan 1 00:00:00 1970 From: Segher Boessenkool Subject: Re: [PATCH 16/16] fix handling of integer constant expressions Date: Sun, 24 Jun 2007 20:18:52 +0200 Message-ID: References: <20070624174732.GZ21478@ftp.linux.org.uk> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-in-04.arcor-online.net ([151.189.21.44]:44224 "EHLO mail-in-04.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751269AbXFXST7 (ORCPT ); Sun, 24 Jun 2007 14:19:59 -0400 In-Reply-To: <20070624174732.GZ21478@ftp.linux.org.uk> Sender: linux-sparse-owner@vger.kernel.org List-Id: linux-sparse@vger.kernel.org To: Al Viro Cc: Linus Torvalds , linux-kernel@vger.kernel.org, linux-sparse@vger.kernel.org >> Hopefully correct handling of integer constant expressions. Please, >> review. > > Heh... The first catches are lovely: > struct fxsrAlignAssert { > int _:!(offsetof(struct task_struct, > thread.i387.fxsave) & 15); > }; That's... wow? > #define _IOC_TYPECHECK(t) \ > ((sizeof(t) == sizeof(t[1]) && \ > sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ > sizeof(t) : __invalid_size_argument_for_IOC) > poisoning _IOW() et.al., so those who do something like > > static const char *v4l1_ioctls[] = { > [_IOC_NR(VIDIOCGCAP)] = "VIDIOCGCAP", > > run into trouble. > The only reason that doesn't break gcc to hell and back is > that gcc has unfixed bugs in that area. If I understand correctly what bugs you are talking about, most (all?) of those were solved in the dark ages already (i.e., the 3.x series). > It certainly is not a valid C Why not? Nothing in the C standard says all your externs have to be defined in some other translation unit you link with AFAIK. > or even a remotely sane one. It's unusual at least :-) Segher