From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: [PATCH]: Re: Early backtrace. Date: Thu, 3 Feb 2022 21:35:26 +0000 Message-ID: References: <8335l05or3.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39245"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Stefan Monnier , emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Feb 03 22:38:43 2022 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 1nFjoR-000A3N-9A for ged-emacs-devel@m.gmane-mx.org; Thu, 03 Feb 2022 22:38:43 +0100 Original-Received: from localhost ([::1]:54552 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nFjoQ-0002aY-0o for ged-emacs-devel@m.gmane-mx.org; Thu, 03 Feb 2022 16:38:42 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:58872) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nFjla-0008Jv-NT for emacs-devel@gnu.org; Thu, 03 Feb 2022 16:35:48 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:45311 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1nFjlT-00030U-Ut for emacs-devel@gnu.org; Thu, 03 Feb 2022 16:35:44 -0500 Original-Received: (qmail 37740 invoked by uid 3782); 3 Feb 2022 21:35:27 -0000 Original-Received: from acm.muc.de (p4fe158a0.dip0.t-ipconnect.de [79.225.88.160]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Thu, 03 Feb 2022 22:35:27 +0100 Original-Received: (qmail 10620 invoked by uid 1000); 3 Feb 2022 21:35:26 -0000 Content-Disposition: inline In-Reply-To: <8335l05or3.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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:285849 Archived-At: Hello, Eli. On Thu, Feb 03, 2022 at 10:38:08 +0200, Eli Zaretskii wrote: > > From: Stefan Monnier > > Cc: emacs-devel@gnu.org > > Date: Wed, 02 Feb 2022 15:59:14 -0500 > > > OK. I've now committed this change. > > Yay! > How about adding to debug-early.el some minimal documentation, which > would explain how to use this facility for debugging bootstrap > problems and batch-mode problems in general? The doc strings you, > Alan, provided don't describe the context and the intended use in any > level of useful detail. I'm not sure entirely what's needed here, probably because I've been working a lot at this level for quite a long time. Still, I've tried to imporve the level of detail, and come up with this. Comments and criticism are welcome, as always: diff --git a/lisp/emacs-lisp/debug-early.el b/lisp/emacs-lisp/debug-early.el index 718000bfa4..aeb8e8f1b2 100644 --- a/lisp/emacs-lisp/debug-early.el +++ b/lisp/emacs-lisp/debug-early.el @@ -60,14 +60,20 @@ 'debug-early-backtrace (defalias 'debug-early #'(lambda (&rest args) - "Print a trace of Lisp function calls currently active. + "Print an error message with a backtrace of active Lisp function calls. The output stream used is the value of `standard-output'. -There should be two ARGS, the symbol `error' and a cons of -the error symbol and its data. +There should be two ARGS: the symbol `error' (which is ignored) +and a cons of the error symbol and the error data. + +This is a simplified version of `debug', intended to produce +diagnostics to help in debugging the early parts of the build +process. It is typically called by the Emacs core when an error +is signaled. -This is a simplified version of `debug', intended for use -in debugging the early parts of the build process." +`debug-early' is the default value of the symbol `debugger' +before enough Lisp has been loaded to support `debug' itself, and +in batch mode." (princ "\nError: ") (prin1 (car (car (cdr args)))) ; The error symbol. (princ " ") -- Alan Mackenzie (Nuremberg, Germany).