From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#47067: 28.0.50; [feature/native-comp] Crash while scrolling through dispnew.c Date: Fri, 12 Mar 2021 15:27:30 +0000 Message-ID: References: <83sg52lykn.fsf@gnu.org> <83mtv8lrmf.fsf@gnu.org> <83czw4lelg.fsf@gnu.org> Reply-To: Andrea Corallo Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7669"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 47067@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Mar 12 16:51:01 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lKk44-0001s6-TH for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 12 Mar 2021 16:51:00 +0100 Original-Received: from localhost ([::1]:47506 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lKk43-0000U1-Ty for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 12 Mar 2021 10:50:59 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:43288) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKjhr-0006iB-1k for bug-gnu-emacs@gnu.org; Fri, 12 Mar 2021 10:28:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:46565) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lKjhq-0008K9-9Z for bug-gnu-emacs@gnu.org; Fri, 12 Mar 2021 10:28:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1lKjhq-0004d6-5l for bug-gnu-emacs@gnu.org; Fri, 12 Mar 2021 10:28:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Andrea Corallo Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 12 Mar 2021 15:28:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 47067 X-GNU-PR-Package: emacs Original-Received: via spool by 47067-submit@debbugs.gnu.org id=B47067.161556286617775 (code B ref 47067); Fri, 12 Mar 2021 15:28:02 +0000 Original-Received: (at 47067) by debbugs.gnu.org; 12 Mar 2021 15:27:46 +0000 Original-Received: from localhost ([127.0.0.1]:58111 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lKjha-0004cd-1J for submit@debbugs.gnu.org; Fri, 12 Mar 2021 10:27:46 -0500 Original-Received: from mx.sdf.org ([205.166.94.24]:58711) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lKjhU-0004cP-M1 for 47067@debbugs.gnu.org; Fri, 12 Mar 2021 10:27:44 -0500 Original-Received: from mab (ma.sdf.org [205.166.94.33]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 12CFRUIw002809 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Fri, 12 Mar 2021 15:27:33 GMT In-Reply-To: <83czw4lelg.fsf@gnu.org> (Eli Zaretskii's message of "Fri, 12 Mar 2021 14:51:39 +0200") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:202168 Archived-At: Eli Zaretskii writes: >> From: Andrea Corallo >> Cc: 47067@debbugs.gnu.org >> Date: Fri, 12 Mar 2021 12:04:34 +0000 >> >> >> > emacs -Q >> >> > C-h sit-for RET >> >> > Click on the link to subr.el >> >> > In subr.el go to where sit-for calls sleep-for and type C-h f RET >> >> > Click on "C source code" to display dispnew.c >> >> > Scroll down with C-n or C-v >> >> >> >> I can't reproduce here :/ >> > >> > Did you try the 32-bit build --with-wide-int? It could be specific to >> > that configuration. >> >> Good point, it tried on 32-bit before and now 32-bit --with-wide-int but >> still could not reproduce. > > Is there any data I can collect to help diagnose the issue? Anything > at all? Like maybe disassembly of this F632d626567696e6e696e672d6f662d73746174656d656e742d31_c_beginning_of_statement_1_0() > function or some part of it? > > IOW, if the problem is miscompilation to native code, what facilities > do we have to report the details if the simple recipe doesn't > reproduce the problem? We will have this kind of problems in the near > future, so having a good way of reporting the details might help > eliminate bugs faster. Generally speaking the first step is to identify the function that is responsible for the bug, this is often on the top of the back-trace but not necessarily. In the unfortunate case I typically proceed by bisection. When the function is identified I typically construct a single function reproducer, for this I typically need the input parameters and I try to substitute all other values coming from the environment with something I can control. This step involve understanding which part of the environment are captured by the function (say: point, current buffer content etc etc...). At that point I reduce the function searching for the minimal piece of code that behaves differently when native compiled. At this point will typically start the "smart" part of the investigation. Here the problem is that being not reproducible we are stuck in the first steps, reproducibility is tipically a pre for this kind of analysis. But again if it's a miscompilation it *must* be reproducible because code is not morphing so probably we are not reproducing it precisely? BTW cc-engine.el is dynamic scope, this means we do not perform any optimization in comp.el and we perform a bare 1:1 translation, so at this stage I'd be rather skeptical this is miscompiled. Thanks Andrea