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: JSON/YAML/TOML/etc. parsing performance Date: Wed, 4 Oct 2017 10:51:33 -0700 Organization: UCLA Computer Science Department Message-ID: <73477c99-1600-a53d-d84f-737837d0f91f@cs.ucla.edu> References: <87poaqhc63.fsf@lifelogs.com> <8360ceh5f1.fsf@gnu.org> <83h8vl5lf9.fsf@gnu.org> <83r2um3fqi.fsf@gnu.org> <43520b71-9e25-926c-d744-78098dad6441@cs.ucla.edu> <83o9pnzddc.fsf@gnu.org> <472176ce-846b-1f24-716b-98eb95ceaa47@cs.ucla.edu> <83d163z6dy.fsf@gnu.org> 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 1507139509 17804 195.159.176.226 (4 Oct 2017 17:51:49 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 4 Oct 2017 17:51:49 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 Cc: p.stephani2@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Oct 04 19:51:45 2017 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 1dznpg-00042S-9p for ged-emacs-devel@m.gmane.org; Wed, 04 Oct 2017 19:51:44 +0200 Original-Received: from localhost ([::1]:36302 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dznpn-00068s-Ot for ged-emacs-devel@m.gmane.org; Wed, 04 Oct 2017 13:51:51 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:51241) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dznpf-00068j-Qv for emacs-devel@gnu.org; Wed, 04 Oct 2017 13:51:44 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dznpf-00024W-5W for emacs-devel@gnu.org; Wed, 04 Oct 2017 13:51:43 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:38278) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dznpa-0001wJ-LF; Wed, 04 Oct 2017 13:51:38 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id A8E8B160D12; Wed, 4 Oct 2017 10:51:34 -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 2VxU8a6vNw3G; Wed, 4 Oct 2017 10:51:33 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id D163C160E10; Wed, 4 Oct 2017 10:51:33 -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 f2sYA63HPg3M; Wed, 4 Oct 2017 10:51:33 -0700 (PDT) Original-Received: from Penguin.CS.UCLA.EDU (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id B8939160D12; Wed, 4 Oct 2017 10:51:33 -0700 (PDT) In-Reply-To: <83d163z6dy.fsf@gnu.org> 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:219082 Archived-At: On 10/04/2017 01:03 AM, Eli Zaretskii wrote: > Why didn't we add similar checks there? If Emacs allocates the objects there is no problem, since it never allocates objects larger than PTRDIFF_MAX. Generally this is what gnutls.c and image.c do. There are places where they do need overflow checks (notably, image size calculation); in some cases the checks are there, in some they're old code that nobody has ever cleaned up and which undoubtedly has problems, and in either case the PTRDIFF_MAX versus SIZE_MAX issue is a bit of a sideshow as each image library has its own idea about what integer type to use. We should not encourage more use of size_t within Emacs, as it's an unsigned type and unsigned types have the problems I mentioned.