From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Bug#38708: eq vs eql in byte-compiled code Date: Sat, 04 Jan 2020 14:49:06 -0500 Message-ID: References: <8cd1b5b2-b94e-ce64-0d70-c1b8b012d685@cs.ucla.edu> <1e0940ff-e418-bafc-66d3-72b562b2c65b@cs.ucla.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="40801"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: Mattias =?windows-1252?Q?Engdeg=E5rd?= , Pip Cet , emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jan 04 20:49:53 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1inpQl-000ASY-Ib for ged-emacs-devel@m.gmane.org; Sat, 04 Jan 2020 20:49:51 +0100 Original-Received: from localhost ([::1]:36394 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1inpQj-0005B3-P1 for ged-emacs-devel@m.gmane.org; Sat, 04 Jan 2020 14:49:49 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58561) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1inpQe-0005Ax-IH for emacs-devel@gnu.org; Sat, 04 Jan 2020 14:49:45 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1inpQc-0004LP-HM for emacs-devel@gnu.org; Sat, 04 Jan 2020 14:49:43 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:12463) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1inpQc-0004IU-Ac for emacs-devel@gnu.org; Sat, 04 Jan 2020 14:49:42 -0500 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 6182044D9DE; Sat, 4 Jan 2020 14:49:41 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 1F2D944D9CF; Sat, 4 Jan 2020 14:49:40 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1578167380; bh=tnCL3M6HRxPTwTZFgEBpACX3x1oHZk50TdbIfgSKVrM=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=GpCVqzU9jG5Lb6PqiMxGUAuDyEve9iFXScCSTa97sTy+LUXEjbN4aRp4ec8m/p3uM tIvfVZUfWApI19YqLXltL+MaBHLHVmdwRUrTxkyjMN4qfhc6jZE6ZZnx/dxYz+hc8i 6usnMb4+bDxrxWpc8XhSU/Fc5ZAm+fazG2m8gVPKjuVH/4TkQztaDZu3Tu3pg7bOPG fzUUhIGRxUmyOJukX34Vyqk7mPXHptoM4F0vLxtqkarI+KEDXX7JNB7hqO19h2WsoG 2KB7ap3SIy+5LMfQmRwkomtPZz4WRkTPoRZ9LbLtFtFIIhvBasbDrfYT+E7RUmFAtE s3nI2nGvWPOHQ== Original-Received: from alfajor (65-110-220-116.cpe.pppoe.ca [65.110.220.116]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id C6A30120C13; Sat, 4 Jan 2020 14:49:39 -0500 (EST) In-Reply-To: (Paul Eggert's message of "Sat, 4 Jan 2020 11:33:02 -0800") X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 132.204.25.50 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:243934 Archived-At: >>> * src/alloc.c (make_pure_bignum): Remove, as we can=E2=80=99t copy (much >>> less purecopy) bignums any more. >> Sounds dangerous: it means that pure objects which point to bignums >> could end up with dangling pointers because the GC won't see those >> pointers and will then GC the corresponding bignum. > > That dangerous thing can't happen, as the change causes purecopy to signa= l an > error when given a bignum. That is, bignums fall into the same category as > markers, overlays and other objects where purecopy signals an error. Sinc= e these > objects are not used in the early phase of building that calls purecopy, = this > should not be an issue. Ah, sorry, I missed that. It's OK then (and if/when we need to fix it, then we'll want to do the move I mentioned). Stefan