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: How does one find out what file a library has been loaded from? Date: Thu, 21 Jul 2022 20:39:48 +0000 Message-ID: References: <83bktlnuog.fsf@gnu.org> <83sfmxm79z.fsf@gnu.org> <83fsiwncem.fsf@gnu.org> <83mtd3ngcw.fsf@gnu.org> <838rommjxj.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="7352"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Jul 21 22:41:22 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 1oEcz4-0001ga-Hd for ged-emacs-devel@m.gmane-mx.org; Thu, 21 Jul 2022 22:41:22 +0200 Original-Received: from localhost ([::1]:49192 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oEcz3-0000J5-0Q for ged-emacs-devel@m.gmane-mx.org; Thu, 21 Jul 2022 16:41:21 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47022) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oEcxf-0007NH-U3 for emacs-devel@gnu.org; Thu, 21 Jul 2022 16:39:55 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:13654 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1oEcxc-0004mA-El for emacs-devel@gnu.org; Thu, 21 Jul 2022 16:39:54 -0400 Original-Received: (qmail 67713 invoked by uid 3782); 21 Jul 2022 20:39:50 -0000 Original-Received: from acm.muc.de (p4fe15d83.dip0.t-ipconnect.de [79.225.93.131]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Thu, 21 Jul 2022 22:39:49 +0200 Original-Received: (qmail 7932 invoked by uid 1000); 21 Jul 2022 20:39:48 -0000 Content-Disposition: inline In-Reply-To: <838rommjxj.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:292392 Archived-At: Hello, Eli. On Thu, Jul 21, 2022 at 20:53:28 +0300, Eli Zaretskii wrote: > > Date: Thu, 21 Jul 2022 17:37:19 +0000 > > Cc: emacs-devel@gnu.org > > From: Alan Mackenzie > > > > +This function returns a file name associated with the file that > > > > +defined @var{symbol} (@pxref{eln files}). If @var{type} is > > > > +@code{nil}, then any kind of definition is acceptable. If @var{type} > > > > +is @code{defun}, @code{defvar}, or @code{defface}, that specifies > > > > +function definition, variable definition, or face definition only. > > > This change is for the worse: it introduces a vague and confusing > > > notion of "file name associated with the file that defines" a symbol. > > > This should be removed from the patch, as it doesn't add any useful > > > information, just muddies the waters. > > It's accurate, though. > No, it isn't accurate, because it doesn't say anything definitive. It says (or implies) there is nothing definitive to say. I think it says as much as you can say about the connection between the name of the loaded file and the file name recorded in load-history in a single sentence. > What exactly did you want to say here, and why? (See, I didn't even > understand you intention, from reading that text.) That there exists such a relationship between the file and the recorded file name, but avoiding the falsehood that the file name is (in general) the name of that file. As an example there is a relationship between (i) /home/acm/emacs/emacs.git/sub-master-5/lisp/progmodes/cc-engine.elc, the file name recorded in load-history; and (ii) "/home/acm/.emacs.d/eln-cache/29.0.50-850ec122/cc-engine-fae36ae5-5d7a60de.eln", the loaded file .. > > > > If you want to find the actual > > > > +file loaded from, and you suspect if may really be a native compiled > > > > +file, something like the following should help. You need to know the > > > > +name of a function which hasn't been advised, say @var{foo}, defined > > > > +in the suspected native compiled file. Then > > > > + > > > > +@lisp > > > > +(let ((foo-fun (symbol-function #'FOO))) > > > > + (and foo-fun (subr-native-elisp-p foo-fun) > > > > + (native-comp-unit-file (subr-native-comp-unit foo-fun)))) > > > > +@end lisp > > > > + > > > > +@noindent > > > > +will return either the name of the native compiled file defining > > > > +@var{foo}, or @code{nil} if there is no such file. > > > This is not a good way of documenting some technique in this manual. > > > The way we describe such stuff is by documenting the functions a > > > program needs to use, not by giving a random example which calls the > > > functions without any documentation of the functions themselves. > > OK. But I think here could be an exception. Describing the functions > > separately on their own page will not help users to get the loaded file > > name without a great deal of research. > You can describe them, and then show the example. Or fill in the > blanks as part of the functions' description. Why is giving the code snippet, as I proposed, not a good thing? Would it be better to write a new function incorporating the procedure, and document that? > > I've tried out this recipe and > > it works, but I don't yet know what these native-comp-unit functions are > > for, what they do in any detail, or even what a compilation-unit is. > > The functions are not already in the Elisp manual, and their doc strings > > are somewhat terse. > If you cannot figure it out from the code, feel free to ask questions. I can figure out just about anything from Emacs's code (apart from the philosophical things), but there are only so many hours in a day. > > I still think it would be a good thing to be able to get the name of an > > actual load file from the .elc name stored in load-history without > > having to go through the intermediate step of knowing a function name > > defined by it. > Did you try comp-el-to-eln-filename? No. How could I have known that such a function exists? It generates file names which might not name existing files. It doesn't seem ideal for the purpose. > > > Also, native-comp-unit-file doesn't exist in a build without native > > > compilation support, so some feature test is missing. > > Do you mean a test in the TexInfo sources which would test whether it's > > necessary to include that example in the finished manual? > No, I mean a test in the @example code. You want that snippet to be > complete, so that readers could copy it into their programs, right? Ah, I see. Yes, you're right. -- Alan Mackenzie (Nuremberg, Germany).