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 21:09:28 +0200 Message-ID: References: <20070624174732.GZ21478@ftp.linux.org.uk> <20070624184449.GB21478@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-13.arcor-online.net ([151.189.21.53]:55297 "EHLO mail-in-13.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649AbXFXTJq (ORCPT ); Sun, 24 Jun 2007 15:09:46 -0400 In-Reply-To: <20070624184449.GB21478@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 >> 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). > > Alas, no. gcc is amazingly (and inconsistently) sloppy about the > things it accepts as integer constant expressions. Ah yes, now I see what you were talking about. Most of this is well-known, but feel free to file more PRs :-) >>> 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. > > It's not about externs. It's about things like > > unsigned n; > int a[] = {[n - n + n - n] = 1}; > > And yes, gcc does eat that. Yeah. > With -pedantic -std=c99, at that. > However, > > unsigned n; > int a[] = {[n + n - n - n] = 1}; > > gets you error: nonconstant array index in initializer > > And that's 4.1, not 3.x... Why are you using such an ancient compiler? :-) (Not that it is fixed in the current release though). Segher