From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Andrea Corallo Newsgroups: gmane.emacs.devel Subject: Re: Correct line/column numbers in byte compiler messages [Was: GNU is looking for Google Summer of Code Projects] Date: Thu, 19 Mar 2020 20:43:15 +0000 Message-ID: References: <20200319203449.GA4180@ACM> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="1575"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) Cc: Rocky Bernstein , Stefan Monnier , emacs-devel To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Mar 19 21:44:08 2020 Return-path: Envelope-to: ged-emacs-devel@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 1jF21P-0000HW-G4 for ged-emacs-devel@m.gmane-mx.org; Thu, 19 Mar 2020 21:44:07 +0100 Original-Received: from localhost ([::1]:42804 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jF21O-0003xU-Iz for ged-emacs-devel@m.gmane-mx.org; Thu, 19 Mar 2020 16:44:06 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:40853) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jF20c-00032b-4z for emacs-devel@gnu.org; Thu, 19 Mar 2020 16:43:19 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jF20b-0000xc-0J for emacs-devel@gnu.org; Thu, 19 Mar 2020 16:43:18 -0400 Original-Received: from mx.sdf.org ([205.166.94.20]:65281) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jF20a-0000tz-PE; Thu, 19 Mar 2020 16:43:16 -0400 Original-Received: from sdf.org (ma.sdf.org [205.166.94.33]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02JKhFCZ023165 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Thu, 19 Mar 2020 20:43:15 GMT Original-Received: (from akrl@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02JKhFKs028382; Thu, 19 Mar 2020 20:43:15 GMT In-Reply-To: <20200319203449.GA4180@ACM> (Alan Mackenzie's message of "Thu, 19 Mar 2020 20:34:49 +0000") X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 205.166.94.20 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:245588 Archived-At: Alan Mackenzie writes: > "More precise line numbers" is a misconstruction, even though I've used > such language myself in the past. Line numbers don't come from a > physical instrument which measures with, say +-1% accuracy. CORRECT > line (and column) numbers are what we need. > > You will recall that the output of correct line/column numbers for byte > compiler messages is a solved problem. I solved it and presented the > fix in December 2018. This fix was rejected because it made Emacs > slightly slower. > > In the 3=C2=BD years I've been grappling with this problem, I've tried all > sorts of things like "fat cons cells". They don't work, and can't work. > They can't work because large chunks of our software chew up and spit > out cons cells with gay abandon (I'm talking about the byte compiler and > things like cconv.el here). More to the point, users' macros chew up and > spit out cons cells, and we have no control over them. So whilst we > could, with a lot of tedious effort, clean up our own software to > preserve cons cells (believe me, I've tried), this would fail in users' > macros. > > Since then I've worked a fair bit on creating a "double" Emacs core, one > core being for normal use, the other for byte compiling. There's a fair > amount of work still to do on this, but I know how to do it. The problem > is that I have been discouraged by the prospect of having this solution > vetoed too, since it will make Emacs quite a bit bigger. > > I don't think it is fair to give this problem to a group of summer > coders. It is too hard a problem, both technically and politically. > Hi Alan, Sorry I'm new to Emacs development, where can be found the code of your attempt? Is it in a feature branch? Thanks Andrea --=20 akrl@sdf.org