From debbugs-submit-bounces@debbugs.gnu.org Sun Aug 02 07:14:23 2020 Received: (at submit) by debbugs.gnu.org; 2 Aug 2020 11:14:23 +0000 Received: from localhost ([127.0.0.1]:41831 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2Bwc-0006hO-Pw for submit@debbugs.gnu.org; Sun, 02 Aug 2020 07:14:23 -0400 Received: from lists.gnu.org ([209.51.188.17]:42402) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2Bwa-0006hG-Ej for submit@debbugs.gnu.org; Sun, 02 Aug 2020 07:14:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53856) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k2Bwa-0007Ma-82 for bug-gnu-emacs@gnu.org; Sun, 02 Aug 2020 07:14:20 -0400 Received: from mail-ej1-x62c.google.com ([2a00:1450:4864:20::62c]:43839) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k2BwY-000114-9u for bug-gnu-emacs@gnu.org; Sun, 02 Aug 2020 07:14:19 -0400 Received: by mail-ej1-x62c.google.com with SMTP id a21so35731793ejj.10 for ; Sun, 02 Aug 2020 04:14:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=srdP690UI3EacwvF+tX75CRg6laMED/S4lIgCqslA2I=; b=kZr1smKoW4Ta45Yoeid+KnQ7nKN1BjNGNnFMjV9xXRIYB0VqG6o7ZriOwDo6WBtz0S OnCnIEmqYHjot0JDdUlb7zTLqYGX0c4pyLpSwIR2XkdMmPq3CSKyLdNpLpMv0kl5Mqcn Widu+kh3l6l9Roe38wHUw/BpISNJyt/116GBAGP6iVwNDheRu0IxiiI44hn6nm3ijpOV ep43xse/7cdWoBWjIKifkNQiapRkVyapnb0OmzlH5iu0+qqkPq+if316jYm496o3h7D4 QbRDKTgGQSJM98KCqVJDboIDfb9GeBNFlHwg6ZVBLv8l53tv/Af+mKuxUHdpNOPCg5X/ BalA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=srdP690UI3EacwvF+tX75CRg6laMED/S4lIgCqslA2I=; b=sBet7gUJ6m9PKznvVUe2DYw7dphkiYtia834xkctBhHDW4K8H8XGnWwnvY0HwBNV1p Krmgkd+p7t94QLBtCkUHMKdnJA097UI5ayJ0nwpkhbWrWXkZITzC93zA9hy6G1u9V/Qk jV3HhoRySWbMr4vFGBauNrzz78AnYanrt9LIsaT3atQ3aB8S7zZoNPBZwBQtGrIFx/a2 wdtqaOTeHRT/2v9s+40J11OlCZsVlzBknDGFQYSI1yrNVDdo+8xSdhpcB0gazafOCXY4 8eBfTFzo3sqFXgu/Zhy1sjyq9/o2opOixZsX9G0cm3hHhFkKwRRxSMPsCucaaEEYD6Bw 3yHA== X-Gm-Message-State: AOAM530Y9z4L5Ua7IQ7BNaO4Yb3EEPhoUNIF8kXJzZrqdtjrgKtwgYJO bB4H5CojltxvirdyjIESEJwI8RjJ X-Google-Smtp-Source: ABdhPJzP64xo3dzqp8NpWswVJEQuA8NZN2CavszqTWbm82np9YdSsg0EHwwsaqLT652gJq3dDzQjvA== X-Received: by 2002:a17:906:a182:: with SMTP id s2mr5683492ejy.526.1596366855915; Sun, 02 Aug 2020 04:14:15 -0700 (PDT) Received: from phst1 (p57997836.dip0.t-ipconnect.de. [87.153.120.54]) by smtp.gmail.com with ESMTPSA id q21sm13052984ejr.75.2020.08.02.04.14.14 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 02 Aug 2020 04:14:15 -0700 (PDT) From: Philipp Stephani To: bug-gnu-emacs@gnu.org Subject: 28.0.50; cl-defgeneric with :method generates incorrect Edebug symbols Date: Sun, 02 Aug 2020 13:14:13 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::62c; envelope-from=p.stephani2@gmail.com; helo=mail-ej1-x62c.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Spam-Score: -0.1 (/) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -2.1 (--) Create a file /tmp/defmethod.el: $ cat /tmp/defmethod.el=20 (cl-defgeneric foo (_) (:method ((_ number)) 1)) Visit the file in Emacs: $ emacs -Q /tmp/defmethod.el Instrument the `cl-defgeneric' form using C-u C-M-x. The *Messages* buffer now contains Edebug: nil ((_ number)) Edebug: foo The second line is for the generic function itself. The first line, however, is for the method defined by the `:method' form. But its name should be `foo ((_ number))', not `nil ((_ number))'. This becomes a problem if there are multiple such generic functions with different names but identical signatures, because Edebug will then generate duplicate symbols. This breaks e.g. coverage instrumentation because the instrumented frequencies will be attached to the wrong symbol. Implementation-wise, I guess this is a problem with `edebug-match-cl-generic-method-args'. That function contains the snippet ;; Append the arguments to edebug-def-name. (setq edebug-def-name (intern (format "%s %s" edebug-def-name args))) However, `edebug-def-name' is only non-nil when using `cl-defmethod', not when using `cl-defgeneric' with `:method'. In GNU Emacs 28.0.50 (build 60, x86_64-pc-linux-gnu, GTK+ Version 3.24.18, = cairo version 1.16.0) of 2020-08-02 Repository revision: 929e7e141c5780e51173fda7d7fc5b73411e4465 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12008000 System Description: Debian GNU/Linux rodete Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Configured using: 'configure --enable-gcc-warnings=3Dwarn-only --enable-gtk-deprecation-warnings --without-pop --with-mailutils --enable-checking=3Dall --enable-check-lisp-object-type --with-modules 'CFLAGS=3D-O1 -ggdb3 -fno-omit-frame-pointer -fsanitize=3Daddress -fsanitize=3Dundefined -fsanitize=3Dpointer-compare -fsanitize=3Dpointer-subtract'' Configured features: XPM JPEG TIFF GIF PNG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY LIBSELINUX GNUTLS FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD JSON PDUMPER Important settings: value of $LANG: en_US.utf8 value of $XMODIFIERS: @im=3Dibus locale-coding-system: utf-8-unix Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc dired dired-loaddefs rfc822 mml easymenu mml-sec epa epg epg-config gnus-util rmail rmail-loaddefs text-property-search time-date mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils phst skeleton derived edmacro kmacro pcase ffap thingatpt url url-proxy url-privacy url-expand url-methods url-history url-cookie url-domsuf url-util url-parse auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs password-cache json map url-vars mailcap subr-x rx gnutls puny seq byte-opt gv bytecomp byte-compile cconv dbus xml compile comint ansi-color ring cl-loaddefs cl-lib tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads dbusbind inotify dynamic-setting system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 68799 8226) (symbols 48 8629 1) (strings 32 23745 2016) (string-bytes 1 764226) (vectors 16 13112) (vector-slots 8 166374 4864) (floats 8 25 30) (intervals 56 221 0) (buffers 992 11)) --=20 Google Germany GmbH Erika-Mann-Stra=C3=9Fe 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Diese E-Mail ist vertraulich. Falls Sie diese f=C3=A4lschlicherweise erhal= ten haben sollten, leiten Sie diese bitte nicht an jemand anderes weiter, l=C3=B6sche= n Sie alle Kopien und Anh=C3=A4nge davon und lassen Sie mich bitte wissen, dass d= ie E-Mail an die falsche Person gesendet wurde. This e-mail is confidential. If you received this communication by mistake, please don=E2=80=99t forward it to anyone else, please erase all copies and attachments, and please let me know that it has gone to the wrong person. From debbugs-submit-bounces@debbugs.gnu.org Sun Aug 02 07:41:11 2020 Received: (at 42672) by debbugs.gnu.org; 2 Aug 2020 11:41:11 +0000 Received: from localhost ([127.0.0.1]:41859 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2CMZ-00015p-5Z for submit@debbugs.gnu.org; Sun, 02 Aug 2020 07:41:11 -0400 Received: from mail-oo1-f52.google.com ([209.85.161.52]:39054) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2CMV-00015X-Nw for 42672@debbugs.gnu.org; Sun, 02 Aug 2020 07:41:10 -0400 Received: by mail-oo1-f52.google.com with SMTP id x1so4575021oox.6 for <42672@debbugs.gnu.org>; Sun, 02 Aug 2020 04:41:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=2CqYxnRgmV9OQOUR5KWZ3Biah34NNJi0yx36DdFm2oo=; b=qBovcoRZxCbhK3ip3DJ2Tqxan7j6ojgw4gRuSCb8fEWdwPjUb6IIXOEA+KHuD0qPgV X4X4OajUzpLcPIIwGS01XyI8bqY2FxR7fiqgdEdi0q3ZLt+VWCXZKpMACVTeWzksuxTm T8J+i/19k0XER0ywaS/mqB6ZFLQRigXdNIm8wzqsQNOjfesEPdmlbJbRNtYAzwd5AV5k fhlIqsUspETWQj/oauceADG9+D81DwhT5tpbugkoT8cJEXzwYwFzMjNB42ynrCtnY/R/ 0deXy4n1Ge0HltFjk34SvsDuDlwdxAdY53HGSeCBMwNfEehntAPgskA/UFdB//LjAZaN iNDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=2CqYxnRgmV9OQOUR5KWZ3Biah34NNJi0yx36DdFm2oo=; b=P+wzUULNDeF2Hdx2MZqUAN7uKmlTk5JmkW1eVIpS4ZDZ9Xg6yo6I6QazurfDIg6jY/ CKFGM9X8wN/RK8XWynaM68O6VBSSVMulQfFRwRr1UA5e1/FSIaWRUD0zSV+MraENKhvM Mq8djgzbpQasaib32oS/SCDGcqJfNVtpjPGt+Q8btIuI2u/DTN2u6MFVc/hwcAe175Z7 CrigCDiqvpl6HLm3cUuQk+L4CzI11jW9hJavLNeZx7Ggj1VW0cxy3Ti5jIs/BRrOZCmw xRRSAk5ZT9NoRlNavH4uPif4xtfXHoX739e4uPeH7OmqthjfvMHtLe14b/AYYiQ+woqD MdnA== X-Gm-Message-State: AOAM531Ng0e6K/WONXA9Qls+aWn8T24Tf7nZc5HeN/4O1ovFd/w0JPhc M8rMd3J0wQpIiXcyVIsn2RIcMklZkn3I8/V3D7OOulGv X-Google-Smtp-Source: ABdhPJxVSBLifTEqiVsBqgjZsM08jHu3/tUMVsMHnN41YvdPU13y/sRM5HwCt8g4cdgTyxDBnlXF4dfILE72EaiGgvQ= X-Received: by 2002:a4a:8257:: with SMTP id t23mr10315833oog.60.1596368461540; Sun, 02 Aug 2020 04:41:01 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Philipp Stephani Date: Sun, 2 Aug 2020 13:40:50 +0200 Message-ID: Subject: Re: bug#42672: 28.0.50; cl-defgeneric with :method generates incorrect Edebug symbols To: 42672@debbugs.gnu.org Content-Type: text/plain; charset="UTF-8" X-Spam-Score: 0.2 (/) X-Debbugs-Envelope-To: 42672 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.8 (/) Am So., 2. Aug. 2020 um 13:15 Uhr schrieb Philipp Stephani : > > > Create a file /tmp/defmethod.el: > > $ cat /tmp/defmethod.el > (cl-defgeneric foo (_) > (:method ((_ number)) 1)) > > Visit the file in Emacs: > > $ emacs -Q /tmp/defmethod.el > > Instrument the `cl-defgeneric' form using C-u C-M-x. The *Messages* > buffer now contains > > Edebug: nil ((_ number)) > Edebug: foo > > The second line is for the generic function itself. The first line, > however, is for the method defined by the `:method' form. But its name > should be `foo ((_ number))', not `nil ((_ number))'. This becomes a > problem if there are multiple such generic functions with different > names but identical signatures, because Edebug will then generate > duplicate symbols. This breaks e.g. coverage instrumentation because > the instrumented frequencies will be attached to the wrong symbol. > > Implementation-wise, I guess this is a problem with > `edebug-match-cl-generic-method-args'. That function contains the > snippet > > ;; Append the arguments to edebug-def-name. > (setq edebug-def-name > (intern (format "%s %s" edebug-def-name args))) > > However, `edebug-def-name' is only non-nil when using `cl-defmethod', > not when using `cl-defgeneric' with `:method'. > The code in edebug.el is somewhat obscure, but I think one piece of the problem is that `edebug-make-form-wrapper' unconditionally binds `edebug-def-name' to nil, so such Edebug specifications don't really work the way they are intended to work. There's some commented-out binding of `edebug-containing-def-name' in that function, indicating that the function is incomplete/buggy, and the corrected implementation was intended to cover this case (and similar cases with nested definitions such as `cl-flet'). From debbugs-submit-bounces@debbugs.gnu.org Sun Aug 02 16:01:27 2020 Received: (at 42672) by debbugs.gnu.org; 2 Aug 2020 20:01:27 +0000 Received: from localhost ([127.0.0.1]:43528 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2KAh-0001up-3M for submit@debbugs.gnu.org; Sun, 02 Aug 2020 16:01:27 -0400 Received: from mail-oi1-f172.google.com ([209.85.167.172]:37384) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1k2KAe-0001uc-Ma for 42672@debbugs.gnu.org; Sun, 02 Aug 2020 16:01:25 -0400 Received: by mail-oi1-f172.google.com with SMTP id e6so11354362oii.4 for <42672@debbugs.gnu.org>; Sun, 02 Aug 2020 13:01:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=72eehxz/EmF0iXyfqS/IU3oq6PROke905AdVSC6yobM=; b=O5NX5rRQNyFZHdMqcPOXx3ZkSF50PgYQ2GWvqsX52NVsjZFi7eW63QourYL9OAj1c2 Lf07YmI2RoCUual+D2xpRqXPG0N+8eIBEnhA0BxRGB+Drrzu7mv7vnLE148Iw593Cqjk Y2hDmScB6eWxbxL0VUTPTptfpQgf4C6NefRM+QumvVRXgOflRpEw8DMnsa9aR6g1PYkl yH8H+EgvPT8t7S92osDQrMeQYlLcdO6kGC3giHQ00Zu61rJyNCkaqbM2ByglbWC5+3gd Tyz0G5uBQbJMqw5DF9mhFzmyx+JMHH4BIcKVI5ZikoP+VrKvVvrAjNwwUFy8vu5zDzeE 8FJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=72eehxz/EmF0iXyfqS/IU3oq6PROke905AdVSC6yobM=; b=M6GIhDzgtRc39aTG4A6csdQf3af8uRf9WQBiA5t4vJVAgSvnyT5aAl9yAk8TYzbCMX VttSCyIV4SEnnNjbr2uPjKJbrwHvLXhEygwfwCBakV8PJnS1dn+wdSUWFXby+qEWNLaM zQ+UItuOtC8ZJOu5yFvl25mVP3PE/fGYreylsNtAUjhOmnEYucyhCEuwpa7mOUt+i3F/ wB0VE8B3rJXeSYSrIhuoMvZF4XzdukJbxxPL/AlsWWuvWfI1IkmT3+2XITx97wNOtIQG t3aijuXZc0c/+MnP/ELkD004mYbgaqEHjN/Q8hwyNiAtSwkb2rjPPsPQqY7BC36TPspI Gdlg== X-Gm-Message-State: AOAM533UFuLriSajCQ+5xmHXIYGCk0LF8ffg7x1MpesbIqNg2JMIxlRI QztmuRI79mP8Pcba0RBdanU3nbxzaSeqStRr9h/XjI5f X-Google-Smtp-Source: ABdhPJwiOyPQT4cKjha1P6g5Q+6wYFJANLoVvy1bztKp88nMRb9B3HtCXERw8JrCpZtnWYhxo69G9QY6x4ZXpOaoG8I= X-Received: by 2002:a05:6808:9bb:: with SMTP id e27mr3961524oig.9.1596398478517; Sun, 02 Aug 2020 13:01:18 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Philipp Stephani Date: Sun, 2 Aug 2020 22:01:07 +0200 Message-ID: Subject: Re: bug#42672: 28.0.50; cl-defgeneric with :method generates incorrect Edebug symbols To: 42672@debbugs.gnu.org Content-Type: text/plain; charset="UTF-8" X-Spam-Score: 0.2 (/) X-Debbugs-Envelope-To: 42672 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.8 (/) Am So., 2. Aug. 2020 um 13:15 Uhr schrieb Philipp Stephani : > > > Create a file /tmp/defmethod.el: > > $ cat /tmp/defmethod.el > (cl-defgeneric foo (_) > (:method ((_ number)) 1)) > > Visit the file in Emacs: > > $ emacs -Q /tmp/defmethod.el > > Instrument the `cl-defgeneric' form using C-u C-M-x. The *Messages* > buffer now contains > > Edebug: nil ((_ number)) > Edebug: foo > > The second line is for the generic function itself. The first line, > however, is for the method defined by the `:method' form. But its name > should be `foo ((_ number))', not `nil ((_ number))'. This becomes a > problem if there are multiple such generic functions with different > names but identical signatures, because Edebug will then generate > duplicate symbols. This breaks e.g. coverage instrumentation because > the instrumented frequencies will be attached to the wrong symbol. > > Implementation-wise, I guess this is a problem with > `edebug-match-cl-generic-method-args'. That function contains the > snippet > > ;; Append the arguments to edebug-def-name. > (setq edebug-def-name > (intern (format "%s %s" edebug-def-name args))) > > However, `edebug-def-name' is only non-nil when using `cl-defmethod', > not when using `cl-defgeneric' with `:method'. I've added a workaround (commit 3e0c3479b2). A more long-term solution should ensure that the name of the `cl-defgeneric' function is part of the method defined in this way.