From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: "Eli Zaretskii" Newsgroups: gmane.emacs.devel Subject: Re: USE_LSB_TAG and MS-DOS Date: Tue, 18 May 2004 17:09:14 +0200 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: <2719-Tue18May2004170914+0300-eliz@gnu.org> References: <2719-Sat15May2004150718+0300-eliz@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: deer.gmane.org X-Trace: sea.gmane.org 1084891981 14004 80.91.224.253 (18 May 2004 14:53:01 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 18 May 2004 14:53:01 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Tue May 18 16:52:44 2004 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1BQ5xU-0002Ce-00 for ; Tue, 18 May 2004 16:52:44 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.35 #1 (Debian)) id 1BQ5xU-0004ks-00 for ; Tue, 18 May 2004 16:52:44 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1BQ5Jf-00070g-Dz for emacs-devel@quimby.gnus.org; Tue, 18 May 2004 10:11:35 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.34) id 1BQ5JJ-00070O-Tr for emacs-devel@gnu.org; Tue, 18 May 2004 10:11:14 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.34) id 1BQ5In-0006vl-Jj for emacs-devel@gnu.org; Tue, 18 May 2004 10:11:12 -0400 Original-Received: from [192.114.186.23] (helo=aragorn.inter.net.il) by monty-python.gnu.org with esmtp (Exim 4.34) id 1BQ5Im-0006um-OH for emacs-devel@gnu.org; Tue, 18 May 2004 10:10:41 -0400 Original-Received: from zaretski ([80.230.149.238]) by aragorn.inter.net.il (MOS 3.4.6-GR) with ESMTP id CXC00024; Tue, 18 May 2004 17:10:28 +0300 (IDT) Original-To: Stefan Monnier X-Mailer: emacs 21.3.50 (via feedmail 8 I) and Blat ver 1.8.9 In-reply-to: (message from Stefan Monnier on 16 May 2004 19:40:23 -0400) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.4 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:23627 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:23627 > From: Stefan Monnier > Date: 16 May 2004 19:40:23 -0400 > > > Btw, the way DECL_ALIGN and USE_LSB_TAG are defined on lisp.h doesn't > > leave any elegant way for specific platforms to turn that off without > > cluttering lisp.h with ugly OS-specific #ifdef's. Perhaps we should > > devise a cleaner way. > > It was devised in the hope that it will only be turned on where it's safe. > Obviously, that's not the way it works, but at least it *should* work that > way, so I think we're just hitting a bug. > After all, all we need is to make sure pointers are multiples of 8. > GNU malloc guarantees that AFAIK for malloced objects and DECL_ALIGN allows > to get the same guarantee for static objects, so if we have both the only > reasonf ro USE_LSB_TAG to fail is a bug, right? I still think we should have an easy way to force or disable use of LSB tags. lisp.h already checks MAC_OSX for that, which is not nice IMHO. How about if USE_LSB_TAG's value will tell this, viz - if USE_LSB_TAG is defined to a non-zero value, always use LSB tags - if it is zero, don't use them - if it's undefined, lisp.h will use the current method to define it to either zero or 1 With this setup, Mac OSX could #define USE_LSB_TAG 1 in its config file, and be done with that.