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: Passing C pointers through guile Date: Fri, 11 Jul 2008 16:42:03 +0200 Message-ID: <87d4lkwkhw.fsf@gnu.org> References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1215787368 12848 80.91.229.12 (11 Jul 2008 14:42:48 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 11 Jul 2008 14:42:48 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Fri Jul 11 16:43:35 2008 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 1KHJqE-0000ha-Jf for guile-devel@m.gmane.org; Fri, 11 Jul 2008 16:43:22 +0200 Original-Received: from localhost ([127.0.0.1]:49488 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KHJpM-00064f-Sj for guile-devel@m.gmane.org; Fri, 11 Jul 2008 10:42:28 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KHJpG-000627-AT for guile-devel@gnu.org; Fri, 11 Jul 2008 10:42:22 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KHJpD-0005z3-WB for guile-devel@gnu.org; Fri, 11 Jul 2008 10:42:21 -0400 Original-Received: from [199.232.76.173] (port=57880 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KHJpD-0005ys-SO for guile-devel@gnu.org; Fri, 11 Jul 2008 10:42:19 -0400 Original-Received: from main.gmane.org ([80.91.229.2]:37867 helo=ciao.gmane.org) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1KHJpD-0005Hi-Lh for guile-devel@gnu.org; Fri, 11 Jul 2008 10:42:19 -0400 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1KHJp5-0008Jg-7O for guile-devel@gnu.org; Fri, 11 Jul 2008 14:42:11 +0000 Original-Received: from 193.50.110.151 ([193.50.110.151]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 11 Jul 2008 14:42:11 +0000 Original-Received: from ludo by 193.50.110.151 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 11 Jul 2008 14:42:11 +0000 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 26 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 193.50.110.151 X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 24 Messidor an 216 de la =?iso-8859-1?Q?R=E9volution?= 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: i686-pc-linux-gnu User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) Cancel-Lock: sha1:G+3+JrXfVABs/gnkwGlHJSyrsqg= X-detected-kernel: by monty-python.gnu.org: Linux 2.6, seldom 2.4 (older, 4) 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:7368 Archived-At: Hi, "Kjetil S. Matheussen" writes: > The code in question doesn't run on those platforms anyway, > since there's a lot of strict linux stuff. You are certainly aware that GNU/Linux *is* available on sparc64, alpha, etc. > However, I don't the storage of pointers in unsigned longs (which is a > perfectly legal thing to do if done correctly), would pose any problem > for running it on other hardware. Again, it's not "perfectly legal", no matter whether you do it "correctly" (whatever that means) or not: the C standard makes no provision regarding the size of `long' versus the size of pointer types. It happens to work on the mainstream platforms you're using, but it's definitely not portable. And I suppose that's the reason why you want `scm_{to,from}_uintptr ()' in the first place, otherwise you'd just live (dangerously) with `scm_{to,from}_unsigned_long ()'. Thanks, Ludovic.