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.bugs Subject: bug#66750: Unhelpful text in C-h v for variables with a lambda form as value Date: Sat, 28 Oct 2023 18:17:04 +0000 Message-ID: References: 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="33127"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 66750@debbugs.gnu.org, Andrea Corallo , Stefan Kangas , acm@muc.de To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Oct 28 20:17:51 2023 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 1qwnsd-0008TN-Cv for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 28 Oct 2023 20:17:51 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qwnsK-0004GK-Kv; Sat, 28 Oct 2023 14:17:32 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qwnsI-0004G7-Ll for bug-gnu-emacs@gnu.org; Sat, 28 Oct 2023 14:17:30 -0400 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qwnsI-0007D9-Dm for bug-gnu-emacs@gnu.org; Sat, 28 Oct 2023 14:17:30 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1qwnso-0004xL-5i for bug-gnu-emacs@gnu.org; Sat, 28 Oct 2023 14:18:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Alan Mackenzie Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 28 Oct 2023 18:18:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 66750 X-GNU-PR-Package: emacs Original-Received: via spool by 66750-submit@debbugs.gnu.org id=B66750.169851706719026 (code B ref 66750); Sat, 28 Oct 2023 18:18:02 +0000 Original-Received: (at 66750) by debbugs.gnu.org; 28 Oct 2023 18:17:47 +0000 Original-Received: from localhost ([127.0.0.1]:39523 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qwnsZ-0004wn-4C for submit@debbugs.gnu.org; Sat, 28 Oct 2023 14:17:47 -0400 Original-Received: from mail.muc.de ([193.149.48.3]:58995) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qwnsV-0004wU-As for 66750@debbugs.gnu.org; Sat, 28 Oct 2023 14:17:45 -0400 Original-Received: (qmail 1658 invoked by uid 3782); 28 Oct 2023 20:17:05 +0200 Original-Received: from acm.muc.de (p4fe15319.dip0.t-ipconnect.de [79.225.83.25]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sat, 28 Oct 2023 20:17:04 +0200 Original-Received: (qmail 20248 invoked by uid 1000); 28 Oct 2023 18:17:04 -0000 Content-Disposition: inline In-Reply-To: X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de 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-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:273460 Archived-At: Hello, Stefan. On Sat, Oct 28, 2023 at 13:17:13 -0400, Stefan Monnier wrote: > >> > Currently feature/named-lambdas is mostly working, not fully working. > Didn't know about this feature. It's been hanging around the savannah repository since July. > I like the idea of keeping better track of the origin of lambda > expressions (tho, admittedly, the same problem occurs with other kinds > of data: I have several times been faced with a keymap or a char-table, > wondering where the heel it came from). Maybe something similar might be possible for those type of objects. > I took a look at > git log -p main..origin/feature/named-lambdas > but that's 127kB, so ... could [you] briefly describe the overall design > (IOW, how it's seen by ELisp programmers, byte-compiler hackers, and > ELisp users)? Certainly. Each lambda expression has (usually) a defun within which it is defined. Sometimes it's in a defvar, or defcustom. That @dfn{defining symbol} is recorded in the lambda form in one of three ways: (i) For a cons form, it's (cadr form), a new field inserted between the symbol `lambda' and the argument list. (ii) For a byte-compiled form, it's (aref form 5), this new field going after the doc string and before any interactive form in the compiled form. (iii) For a native-compiled subr it's (subr-native-defining-symbol subr), a function defined in data.c. It accesses a new field in struct Lisp_Subr called defining_symbol. There are lots of detailed changes in eval.c and bytecomp.el (and friends). Also the macro `lambda' in subr.el has been amended to insert the current global defining-symbol if there isn't already a non-nil symbol in that position. cl-print-object/compiled-function has been amended to print the defining-symbol, and there is a new cl-print-object/subr which does the same. The intention is that compiled objects from earlier Emacsen can still be loaded and run by feature/named-lambdas, just without the defining symbols (which will appear to be nil). > Also, what other approaches have you considered/tried and what were the > problems you've encountered, if any? feature/named-lambdas was originally intended for use in backtraces. For the current bug, I've considered individually replacing each lambda with a named defun, so that C-h v will show that name rather than an unhelpful byte/native compiled anonymous function. That would be a lot of work - my scripting found 63 defcustoms set to lambdas, 29 uses in doc strings, and 215 suspicious occurrences with ordinary variables (quite a few of which will be harmless). Amending all these (I guess around 200 lambdas) would probably be too much work. > Stefan -- Alan Mackenzie (Nuremberg, Germany).