From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Neil Jerram Newsgroups: gmane.lisp.guile.bugs Subject: Re: guile-2.0.0 fails to build without threads Date: Sat, 21 May 2011 15:29:01 +0100 Message-ID: <87vcx4yvo2.fsf@neil-laptop.ossau.uklinux.net> References: <4D9DCE98.5080808@gentoo.org> <87y63gj765.fsf@rapitore.luna> <87aafusesz.fsf@rapitore.luna> <874o62s7hu.fsf@rapitore.luna> <87y63eqmp3.fsf@rapitore.luna> <87hb9d4o8n.fsf@rapitore.luna> <87oc2xdxkv.fsf@rapitore.luna> <87ipt4f9fu.fsf@rapitore.luna> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1305988150 26919 80.91.229.12 (21 May 2011 14:29:10 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 21 May 2011 14:29:10 +0000 (UTC) Cc: bug-guile@gnu.org To: Marco Maggi Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Sat May 21 16:29:06 2011 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QNnAv-0001io-ER for guile-bugs@m.gmane.org; Sat, 21 May 2011 16:29:05 +0200 Original-Received: from localhost ([::1]:51524 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNnAt-0003aE-04 for guile-bugs@m.gmane.org; Sat, 21 May 2011 10:29:03 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:38669) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNnAm-0003Rh-Cf for bug-guile@gnu.org; Sat, 21 May 2011 10:28:57 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QNnAl-0007J6-2U for bug-guile@gnu.org; Sat, 21 May 2011 10:28:56 -0400 Original-Received: from mail3.uklinux.net ([80.84.72.33]:59578) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNnAk-0007Iv-TT for bug-guile@gnu.org; Sat, 21 May 2011 10:28:55 -0400 Original-Received: from arudy (unknown [78.149.193.7]) by mail3.uklinux.net (Postfix) with ESMTP id 2FD351F6645; Sat, 21 May 2011 15:28:48 +0100 (BST) Original-Received: from neil-laptop.ossau.uklinux.net (unknown [192.168.11.9]) by arudy (Postfix) with ESMTP id 2E5DD3801E; Sat, 21 May 2011 15:28:47 +0100 (BST) In-Reply-To: <87ipt4f9fu.fsf@rapitore.luna> (Marco Maggi's message of "Sat, 21 May 2011 15:51:49 +0200") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4-2.6 X-Received-From: 80.84.72.33 X-BeenThere: bug-guile@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:5603 Archived-At: Marco Maggi writes: > Someone left ACTION-IF-FALSE empty This is fine, isn't it? > and also left the test > without "checking" message in this chunk of "configure.ac": Agree that that is unhelpful. > maybe the problem is that GCC 4.6.0 with -O3 optimises the > program in such a way that the test is invalidated. Could it be that it is not strictly allowed to compare two pointers that don't point into the same object, and that GCC now enforces this? >From http://en.wikipedia.org/wiki/Pointer_%28computing%29, under "C and C++": "Pointer arithmetic, that is, the ability to modify a pointer's target address with arithmetic operations (as well as magnitude comparisons), is restricted by the language standard to remain within the bounds of a single array object (or just after it), though many non-segmented architectures will allow for more lenient arithmetic." Neil