From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.devel Subject: Re: more compilation failures: -DSCM_DEBUG_TYPING_STRICTNESS=2 Date: Thu, 03 Sep 2009 13:48:02 +0200 Message-ID: <877hwg1c7h.fsf@gnu.org> References: <87bplu4fbr.fsf@gnu.org> <877hwheplm.fsf@gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1251978745 29113 80.91.229.12 (3 Sep 2009 11:52:25 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 3 Sep 2009 11:52:25 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Thu Sep 03 13:52:18 2009 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1MjArR-0002Fj-NZ for guile-devel@m.gmane.org; Thu, 03 Sep 2009 13:52:18 +0200 Original-Received: from localhost ([127.0.0.1]:56481 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MjArQ-0000ZT-P6 for guile-devel@m.gmane.org; Thu, 03 Sep 2009 07:52:16 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MjAo3-00070S-Oo for guile-devel@gnu.org; Thu, 03 Sep 2009 07:48:48 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MjAnt-0006vs-US for guile-devel@gnu.org; Thu, 03 Sep 2009 07:48:43 -0400 Original-Received: from [199.232.76.173] (port=38498 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MjAns-0006vN-J7 for guile-devel@gnu.org; Thu, 03 Sep 2009 07:48:36 -0400 Original-Received: from lo.gmane.org ([80.91.229.12]:38676) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MjAns-00025j-13 for guile-devel@gnu.org; Thu, 03 Sep 2009 07:48:36 -0400 Original-Received: from list by lo.gmane.org with local (Exim 4.50) id 1MjAnl-0000wy-H0 for guile-devel@gnu.org; Thu, 03 Sep 2009 13:48:29 +0200 Original-Received: from laptop-147-210-128-170.labri.fr ([147.210.128.170]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 03 Sep 2009 13:48:29 +0200 Original-Received: from ludo by laptop-147-210-128-170.labri.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 03 Sep 2009 13:48:29 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 28 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: laptop-147-210-128-170.labri.fr X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 17 Fructidor an 217 de la =?iso-8859-1?Q?R=E9volutio?= =?iso-8859-1?Q?n?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 821D 815D 902A 7EAB 5CEE D120 7FBA 3D4F EB1F 5364 X-OS: x86_64-unknown-linux-gnu User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) Cancel-Lock: sha1:0vlHiAyLrOHAM1HlZzCmV5ECQUE= X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:9255 Archived-At: Hi! Ken Raeburn writes: > On Sep 2, 2009, at 04:08, Ludovic Courtès wrote: >>> In the Guile case, I'm a tiny bit concerned about some of the >>> pointer/ >>> int games played (e.g., I'm pretty sure C99 does not guarantee that >>> you can convert an arbitrary uintptr_t value to pointer and back and >>> be guaranteed of getting the original value... but I don't know of a >>> platform that actually violates that assumption), but only a tiny >>> bit. >> >> Really? I think the whole purpose of `uintptr_t' is to allow that, >> isn't it? > > It's the other way around that's guaranteed to work: void* -> > (u)intptr_t -> void*. So any value originally derived from a valid > pointer will work, but arbitrary values may not. [...] Hmm, I see. Thanks for the interesting explanation! Now I understand that I've been lucky enough to live in a beautiful world with power-of-two pointer types, NULL == 0, etc. ;-) Thanks, Ludo'.