From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Adam Porter Newsgroups: gmane.emacs.devel Subject: Re: pcase map binding form expansion failure on Emacs 27 only Date: Wed, 08 Sep 2021 09:28:25 -0500 Message-ID: <87wnnr3zw6.fsf@alphapapa.net> References: <87eea0610n.fsf@alphapapa.net> <87o8932p2x.fsf@laposte.net> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2442"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Sep 08 16:29:24 2021 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 1mNyZo-0000Od-0c for ged-emacs-devel@m.gmane-mx.org; Wed, 08 Sep 2021 16:29:24 +0200 Original-Received: from localhost ([::1]:50952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mNyZm-0003T7-I1 for ged-emacs-devel@m.gmane-mx.org; Wed, 08 Sep 2021 10:29:22 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:46716) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNyZ4-00026z-IQ for emacs-devel@gnu.org; Wed, 08 Sep 2021 10:28:38 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:60970) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNyZ2-0005tL-Qp for emacs-devel@gnu.org; Wed, 08 Sep 2021 10:28:38 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mNyZ0-0009lb-Bs for emacs-devel@gnu.org; Wed, 08 Sep 2021 16:28:34 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action 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:274347 Archived-At: Kevin Vigouroux via "Emacs development discussions." writes: > Your patch is not included in the latest Emacs release (27.2). So, the > macro expansion works as expected. I am not using the version of map.el included with Emacs 27.2. As I wrote in the original message: >> I confirmed that this happens even though map.el is installed at version >> 3.1, and even though that version is actually loaded, by using this form >> in the file: >> >> (eval-when-compile >> (save-excursion >> (message "MAP VERSION IS: %S" >> (package-desc-version (car (alist-get 'map package-alist)))) >> (message "MAP IS AT: %S" >> (locate-library "map")) >> (message "EXPANSION TEST: %S" >> (macroexpand-all '(pcase-let* (((map :max-width) plist)) >> max-width))))) >> >> Which produces output like (using my makem.sh script[0], which I use for >> linting and testing Emacs packages locally and on CI): >> >> LOG (2021-09-07 11:31:03): Compiling file: bufler-workspace.el... >> MAP VERSION IS: (3 1) >> MAP IS AT: "/tmp/tmp.cEPHlNUWYk/27.1/elpa/map-3.1/map.elc" >> EXPANSION TEST: (let* ((x6 (map-elt plist ':max-width))) (progn max-width)) >> Eager macro-expansion failure: (void-variable max-width) > > It seems to me that the `eval-when-compile' code is wrong. How is it wrong? The purpose of that code is to output a debug message when the file is being compiled, which it does. > What does the compiler really generate? It generates an incorrect macro expansion, which causes the eager macro expansion/void-variable errors which precipitated this thread. > #+begin_src emacs-lisp > (defvar plist (list :max-height 3 :max-width 2)) > > (eval-when-compile > (message "EXPANSION TEST: %S" > (macroexpand-all '(pcase-let* (((map :max-width) plist)) > max-width)))) > #+end_src > > #+begin_src emacs-lisp > ;; Load the latest version of the `map' library (v3.1) > ;; located in the Download directory. > (load-file "~/Downloads/map.el") > > ;; Byte-compile the sample test stored in the file > ;; /tmp/sample.el > (byte-compile-file "/tmp/sample.el") > > ;; Look at the compiled file > (find-file "/tmp/sample.elc") > #+end_src > > You can see in the compiled file that there is no instruction related to > the macro expansion. Obviously, there is no message displayed when the > byte-code interpreter runs the compiled code. It is not intended for a message to be displayed at runtime. That's why it's in `eval-when-compile'. > #+begin_quote > ;ELC > ;;; Compiled > ;;; in Emacs version 27.2 > ;;; with all optimizations. > > ;;; This file uses dynamic docstrings, first added in Emacs 19.29. > > ;;; This file does not contain utf-8 non-ASCII characters, > ;;; and so can be loaded in Emacs versions earlier than 23. > > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > > > (defvar plist (list :max-height 3 :max-width 2)) > #+end_quote > > So, I think that you have mixed things up when testing. I'm not sure you understand the problem I'm describing. Please see my original message. >> Even though I submitted the (very small) patch to map.el that added >> support for the (map :KEYWORD) binding form, I finally had to give in >> and apply a workaround in my package, using this binding form instead: >> >> ((map (:face face) (:max-width max-width)) plist) >> >> That form correctly expands on Emacs 26.3, 27, and 28.0.50. So at least >> I won't get any more bug reports about this problem on my package. >> >> But I would like to understand what's going on here, if possible. I'm >> pretty sure that there's no bug in my code: my the package depends on >> map 3.1, that version gets installed before my package does, that >> version is loaded before my package is compiled, and my package does >> (require 'map). I can't find any reason for it to only fail on Emacs >> 27. And since it's not only happening in my testing, but in the wild, >> something certainly seems fishy. > > Looking at things again, I'm not sure that imposing a given version for > a package is a good thing. I don't know what you mean by "imposing a given version for a package." The "Package-Requires" header instructs package.el to ensure that certain dependencies are installed at certain minimum versions. This is a standard practice in Emacs packages.