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.devel Subject: Re: Correct byte compiler error/warning positions. The solution! Date: Sat, 27 Nov 2021 12:51:13 +0200 Message-ID: <83wnktzxb2.fsf@gnu.org> References: <83pmqm16vz.fsf@gnu.org> <8335nh29pt.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="29342"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Nov 27 11:51:57 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 1mqvJC-0007OT-Vz for ged-emacs-devel@m.gmane-mx.org; Sat, 27 Nov 2021 11:51:55 +0100 Original-Received: from localhost ([::1]:37488 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mqvJB-0003MM-Op for ged-emacs-devel@m.gmane-mx.org; Sat, 27 Nov 2021 05:51:53 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:52204) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mqvIQ-0002NY-Qg for emacs-devel@gnu.org; Sat, 27 Nov 2021 05:51:06 -0500 Original-Received: from [2001:470:142:3::e] (port=54450 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mqvIQ-00011O-FL; Sat, 27 Nov 2021 05:51:06 -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=Pb66vpK7FTGDpqdQ0mAWftqZpif8S6ucS0yLerTDiog=; b=F5Nch9TK+a9C dzoafuLIXkamdE+3YezWmrAeH+Uw1waCfnE3/dT7RxvxeCrxAtgramP8WL6r4tW+Gf5B5+A/XWxxb zeDbFgKfoBFFBy5MiOvx/mAleg9UO7INPiS3FApIZ0wyS39Eq/LbaXwJ0cXEmDYS5cVDx/Cv6Zn87 t6kZ6YUEpcJtY+RDxlye7vCVnf7Y5poWsg8gjTsBDYL178WDP9znBZDCTXdhXxqC1vyIylGtz/1h5 S8kSuiyGfnBmSF6BC808UDjZRM2ydPJ7yH7P3rqPtmKiAHkkR2SpA1WU8iY5c8aXPFUO+m3b0m/un /F0wMK9uH2FWNGJ7QYeGvg==; Original-Received: from [87.69.77.57] (port=4923 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 1mqvIQ-0001C2-0L; Sat, 27 Nov 2021 05:51:06 -0500 In-Reply-To: (message from Alan Mackenzie on Sat, 27 Nov 2021 10:33:07 +0000) 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:280320 Archived-At: > Date: Sat, 27 Nov 2021 10:33:07 +0000 > Cc: emacs-devel@gnu.org > From: Alan Mackenzie > > > > I meant that NILP will be implemented as a binary comparison against > > > zero, omitting the awkward test for symbols_with_position_enabled. > > > Please don't write code that assumes Qnil is zero. (Or maybe I still > > misunderstand what exactly you mean by the above.) > > Don't worry! The new code merely assumes Qnil is a symbol, and leaves it > to the compiler to optimise for Qnil being binary zero. Once again, you cannot compare structures with == in portable C. And the Lisp_Object type can be struct. As long as what you say above doesn't mean that you compare with ==, I'm okay with what you propose.