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 17:37:19 +0000 Message-ID: References: <83bktlnuog.fsf@gnu.org> <83sfmxm79z.fsf@gnu.org> <83fsiwncem.fsf@gnu.org> <83mtd3ngcw.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="22036"; 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 19:40:01 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 1oEa9Y-0005SE-Vu for ged-emacs-devel@m.gmane-mx.org; Thu, 21 Jul 2022 19:40:00 +0200 Original-Received: from localhost ([::1]:44838 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oEa9X-0002SZ-GW for ged-emacs-devel@m.gmane-mx.org; Thu, 21 Jul 2022 13:39:59 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36274) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oEa7E-0000MZ-8N for emacs-devel@gnu.org; Thu, 21 Jul 2022 13:37:36 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:64364 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1oEa7B-0001Qq-Ur for emacs-devel@gnu.org; Thu, 21 Jul 2022 13:37:35 -0400 Original-Received: (qmail 48930 invoked by uid 3782); 21 Jul 2022 17:37:20 -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 19:37:19 +0200 Original-Received: (qmail 7134 invoked by uid 1000); 21 Jul 2022 17:37:19 -0000 Content-Disposition: inline In-Reply-To: <83mtd3ngcw.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=ham 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:292385 Archived-At: Hello, Eli. On Thu, Jul 21, 2022 at 09:13:03 +0300, Eli Zaretskii wrote: > > Date: Wed, 20 Jul 2022 20:34:05 +0000 > > Cc: emacs-devel@gnu.org > > From: Alan Mackenzie > > Here's a first preliminary effort at amending loading.texi: > Thanks, but it "needs work"(TM). > > @defun symbol-file symbol &optional type > > -This function returns the name of the file that defined @var{symbol}. > > -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 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. The current text is not accurate. The situation it is describing is vague and confusing. Would this strategy be an improvement: "This function returns a file name. When the file from which the function was loaded was a source file or byte compiled file ....... When that file was a native compiled file ......."? [ .... ] > > - The command @code{eval-region} updates @code{load-history}, but does so > > -by adding the symbols defined to the element for the file being visited, > > -rather than replacing that element. @xref{Eval}. > > +@anchor{eln files} For backwards compatibility, @code{load-history} > > +stores and @code{symbol-file} returns the name of a notional byte > > +compiled @file{.elc} file in the same directory as its source file > > +when the real file loaded from is a natively compiled file elsewhere. > > +This @file{.elc} file may or may not actually exist. For other files, > > +their absolute file names are used. > This last sentence is "out of the blue": what "other files"? Files other than "a natively compiled file elsewhere". But I'll admit it doesn't read well, yet. > The text should also have a cross-reference to where native > compilation is described in the manual. OK. > > 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. 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. 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. > 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? > Finally, "FOO" is not how we refer to a meta-syntactic variable in the > manual: we use @var{foo} instead. Sorry. I thought that @var{FOO} would not work in @lisp, but I tried it out and it does work. I've already corrected it. > > +The command @code{eval-region} updates @code{load-history}, but does > > +so by adding the symbols defined to the element for the file being > > +visited, rather than replacing that element. @xref{Eval}. > This part should be before the text which explains the issues with > loading *.eln files. OK, that's easily fixed. -- Alan Mackenzie (Nuremberg, Germany).