From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Using the GNU GMP Library for Bignums in Emacs Date: Mon, 9 Jul 2018 09:22:18 -0700 Organization: UCLA Computer Science Department Message-ID: References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <83bmecy6fx.fsf@gnu.org> <0d3175d8-d996-651e-b221-71978bde3a65@cs.ucla.edu> <87tvpdnzgy.fsf@tromey.com> <4c2a814f-c254-29e5-39cf-11b5f2e5c9c8@cs.ucla.edu> <87pnzzoeky.fsf@tromey.com> <1150776f-a8fe-86a1-680b-3d1a5d582c6a@cs.ucla.edu> <87lgano9c0.fsf@tromey.com> <87601pq8a7.fsf@tromey.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1531153228 29554 195.159.176.226 (9 Jul 2018 16:20:28 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 9 Jul 2018 16:20:28 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 Cc: Stefan Monnier , emacs-devel@gnu.org To: Tom Tromey Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Jul 09 18:20:24 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fcYtj-0007Ze-BO for ged-emacs-devel@m.gmane.org; Mon, 09 Jul 2018 18:20:23 +0200 Original-Received: from localhost ([::1]:43211 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcYvq-0005yR-IO for ged-emacs-devel@m.gmane.org; Mon, 09 Jul 2018 12:22:34 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53913) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcYvk-0005y7-8C for emacs-devel@gnu.org; Mon, 09 Jul 2018 12:22:29 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fcYvh-0004QQ-4W for emacs-devel@gnu.org; Mon, 09 Jul 2018 12:22:28 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:60104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fcYvg-0004Pz-QX for emacs-devel@gnu.org; Mon, 09 Jul 2018 12:22:25 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 82FF51607CC; Mon, 9 Jul 2018 09:22:23 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id a0CYXtDhVRq9; Mon, 9 Jul 2018 09:22:22 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id A04E31607BA; Mon, 9 Jul 2018 09:22:22 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id RFHqJnQJdI2e; Mon, 9 Jul 2018 09:22:22 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 50CC716060F; Mon, 9 Jul 2018 09:22:22 -0700 (PDT) Openpgp: preference=signencrypt Autocrypt: addr=eggert@cs.ucla.edu; prefer-encrypt=mutual; keydata= xsFNBEyAcmQBEADAAyH2xoTu7ppG5D3a8FMZEon74dCvc4+q1XA2J2tBy2pwaTqfhpxxdGA9 Jj50UJ3PD4bSUEgN8tLZ0san47l5XTAFLi2456ciSl5m8sKaHlGdt9XmAAtmXqeZVIYX/UFS 96fDzf4xhEmm/y7LbYEPQdUdxu47xA5KhTYp5bltF3WYDz1Ygd7gx07Auwp7iw7eNvnoDTAl KAl8KYDZzbDNCQGEbpY3efZIvPdeI+FWQN4W+kghy+P6au6PrIIhYraeua7XDdb2LS1en3Ss mE3QjqfRqI/A2ue8JMwsvXe/WK38Ezs6x74iTaqI3AFH6ilAhDqpMnd/msSESNFt76DiO1ZK QMr9amVPknjfPmJISqdhgB1DlEdw34sROf6V8mZw0xfqT6PKE46LcFefzs0kbg4GORf8vjG2 Sf1tk5eU8MBiyN/bZ03bKNjNYMpODDQQwuP84kYLkX2wBxxMAhBxwbDVZudzxDZJ1C2VXujC OJVxq2kljBM9ETYuUGqd75AW2LXrLw6+MuIsHFAYAgRr7+KcwDgBAfwhPBYX34nSSiHlmLC+ KaHLeCLF5ZI2vKm3HEeCTtlOg7xZEONgwzL+fdKo+D6SoC8RRxJKs8a3sVfI4t6CnrQzvJbB n6gxdgCu5i29J1QCYrCYvql2UyFPAK+do99/1jOXT4m2836j1wARAQABzSBQYXVsIEVnZ2Vy dCA8ZWdnZXJ0QGNzLnVjbGEuZWR1PsLBfgQTAQIAKAUCTIByZAIbAwUJEswDAAYLCQgHAwIG FQgCCQoLBBYCAwECH In-Reply-To: <87601pq8a7.fsf@tromey.com> Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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:227155 Archived-At: Tom Tromey wrote: > On the other hand, I see that Guile is using the mpz API. So, maybe in > practice it is safe enough to just set custom allocation functions and > let them throw. Guile treats memory allocation failure like stack overflow, in the sense that it relies on undefined behavior in both cases, I guess on the theory that it's typically better to try to keep running (with undefined behavior) than to give up and exit right away. GNU Emacs already takes a similar attitude toward stack overflow, so perhaps it could do the same for memory exhaustion within mpz routines. (Emacs could soften the blow by using a reserve, as I think it does already.) With all that in mind, I guess it's OK to use the mpz API after all. > one idea would be to put mini-gmp.c into the Emacs source tree, but > only compile it if the real GMP library is not found. That sounds like a good idea, given the above. We could also do this if the installed GMP library is too old for Emacs.