From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Why do emacs backtraces lack line numbers? Date: Tue, 20 Dec 2022 21:34:25 +0200 Message-ID: <83k02lc1j2.fsf@gnu.org> References: Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40554"; mail-complaints-to="usenet@ciao.gmane.io" To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Dec 20 20:35:16 2022 Return-path: Envelope-to: geh-help-gnu-emacs@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 1p7iOR-000AIx-8f for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 20 Dec 2022 20:35:15 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p7iNS-00011y-K2; Tue, 20 Dec 2022 14:34:14 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p7iNP-0000xQ-Sw for help-gnu-emacs@gnu.org; Tue, 20 Dec 2022 14:34:11 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p7iNP-0003hU-Jo for help-gnu-emacs@gnu.org; Tue, 20 Dec 2022 14:34:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=5qOUc/rdnRfHkF1au8B4kG/DrEf7ivqti6E53tJvGfY=; b=kMG7xQR/lm89 FO6VCcF/1Tzd84BLbsDh6u22r7zG8EwQeL+Phgvcs5+Et08KZBV2ZMmHYsmDzqHiRGS8LKWZqs+W5 cJBV4ghdg40tQ189zUZY3oNBhpZcACLB0OQhJVreiPT+978atS28c6XPCyhhvrSgCpYM9emIr8TRt K5bvC1CIJEZa81i9NW9OHMS8J8wJHcBN2h8XSTzEkTdfLs+utMBEqXclH4HWzYIiC2iPkabAAHV1i ZdffPVCLlng+2N3dKUwDQQs6yFCqpFXAbOto8ijmpo7+0ORPfTUrc4+fSuC39HuM5vhaEfZkD/iiB z0Mi+V43O7/8xEkrmQDr1Q==; Original-Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p7iNO-0004yq-TO for help-gnu-emacs@gnu.org; Tue, 20 Dec 2022 14:34:11 -0500 In-Reply-To: (message from John Yates on Tue, 20 Dec 2022 11:50:46 -0500) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:141878 Archived-At: > From: John Yates > Date: Tue, 20 Dec 2022 11:50:46 -0500 > > I am doing my first significant bit of coding in elisp. > > Relative to other environments that I have used, something > that I miss sorely is line numbers in backtraces. > > What explains their absence? The line information needs to be recorded somewhere, before it can be presented. In compiled programs, for example, the compiler records the line-number information in the debug info it generates. None of this is present in Lisp, and moreover, until Emacs 29 the byte compiler didn't even have a good idea of which line number it is processing at any given time. So I guess the simple answer is: because Emacs doesn't know.