From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Sergei Organov Newsgroups: gmane.emacs.help Subject: Re: Problem advising nreverse. Date: Mon, 14 Dec 2009 14:07:56 +0300 Message-ID: References: <87skbg8jww.fsf@galatea.local> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1260788997 16752 80.91.229.12 (14 Dec 2009 11:09:57 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 14 Dec 2009 11:09:57 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Mon Dec 14 12:09:50 2009 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1NK8o7-00054d-JW for geh-help-gnu-emacs@m.gmane.org; Mon, 14 Dec 2009 12:09:39 +0100 Original-Received: from localhost ([127.0.0.1]:35635 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NK8o7-0004gs-FI for geh-help-gnu-emacs@m.gmane.org; Mon, 14 Dec 2009 06:09:39 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NK8nU-0004ey-PQ for help-gnu-emacs@gnu.org; Mon, 14 Dec 2009 06:09:00 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NK8nN-0004bH-7r for help-gnu-emacs@gnu.org; Mon, 14 Dec 2009 06:08:57 -0500 Original-Received: from [199.232.76.173] (port=39027 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NK8nM-0004b7-UU for help-gnu-emacs@gnu.org; Mon, 14 Dec 2009 06:08:53 -0500 Original-Received: from lo.gmane.org ([80.91.229.12]:57745) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NK8nM-0001N1-ES for help-gnu-emacs@gnu.org; Mon, 14 Dec 2009 06:08:52 -0500 Original-Received: from list by lo.gmane.org with local (Exim 4.50) id 1NK8my-0004Iu-Iu for help-gnu-emacs@gnu.org; Mon, 14 Dec 2009 12:08:28 +0100 Original-Received: from 89.175.180.246 ([89.175.180.246]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 14 Dec 2009 12:08:28 +0100 Original-Received: from osv by 89.175.180.246 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 14 Dec 2009 12:08:28 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 42 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 89.175.180.246 User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:70633 Archived-At: pjb@informatimago.com (Pascal J. Bourguignon) writes: > Sergei Organov writes: > >> Hello, >> >> It seems that an advice set for `nreverse' function fails to be called >> when `nreverse' is called from a byte compiled function: [...] >> Is it bug or feature? What's going on here? > > Indeed, it is a feature. > > Advices are not available from several call points: > > 1- when the advised function is called from C code. > > 2- when the advised function is a an opcode of the virtual machine. > You can observe the difference between the two primitives nreverse > and buffer-name for example, with: > > (disassemble (byte-compile (lambda (x) (nreverse x)))) > vs.: > (disassemble (byte-compile (lambda (x) (buffer-name x)))) > > In the former case, nreverse is a byte code, and therefore no > advice applies. In the later case, buffer-name is called with the > call byte code, which will go thru the advice. > > Notice that if you really want to advice such a low level primitive > function as nreverse, you can replace it with a lisp function (and > recompile all the code that uses it). Thanks a lot for the explanations and suggestion. Unfortunately this is not an option as intention was to advise `nreverse' during calls to a possibly buggy `ewoc-collect' function that for a long time errorneously called `nreverse' at the end (fixed since 2008). -- Sergei.