From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: New warnings on emacs-26 branch with gcc 8.2.0 Date: Sat, 11 Aug 2018 13:13:57 -0700 Organization: UCLA Computer Science Department Message-ID: <93d570e6-aa8f-8520-57e1-6007af162253@cs.ucla.edu> References: <86a7q0ai2z.fsf@gmail.com> <6d36dc4c-1e14-b6c8-e2f0-911d08f759e1@cs.ucla.edu> <8636vsxxjv.fsf@gmail.com> <880f6c74-daae-819d-c503-a52973b3f9d2@cs.ucla.edu> <861sbblwws.fsf@gmail.com> <1c65cdb5-f3a9-bfe1-c687-5cfce52c3945@cs.ucla.edu> <86pnyvjhxq.fsf@gmail.com> <7cfe570f-2c34-c55e-05b0-34ffdc6e4ee0@cs.ucla.edu> <86zhxtq6xa.fsf@gmail.com> <86zhxsiti7.fsf@gmail.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1534018363 29984 195.159.176.226 (11 Aug 2018 20:12:43 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 11 Aug 2018 20:12:43 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 To: Andy Moreton , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Aug 11 22:12:38 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1foaFa-0007hw-Kx for ged-emacs-devel@m.gmane.org; Sat, 11 Aug 2018 22:12:38 +0200 Original-Received: from localhost ([::1]:33086 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1foaHh-0007Aj-2M for ged-emacs-devel@m.gmane.org; Sat, 11 Aug 2018 16:14:49 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43757) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1foaH3-0007AT-Ep for emacs-devel@gnu.org; Sat, 11 Aug 2018 16:14:10 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1foaH0-00047B-9j for emacs-devel@gnu.org; Sat, 11 Aug 2018 16:14:09 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:36658) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1foaH0-00045r-2G for emacs-devel@gnu.org; Sat, 11 Aug 2018 16:14:06 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 1F10816072A; Sat, 11 Aug 2018 13:14:04 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 5Q6NqgjmEjCC; Sat, 11 Aug 2018 13:13:58 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 7992A160D70; Sat, 11 Aug 2018 13:13:58 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id cKF3RF4Vf2jX; Sat, 11 Aug 2018 13:13:58 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 2D59516072A; Sat, 11 Aug 2018 13:13:58 -0700 (PDT) In-Reply-To: <86zhxsiti7.fsf@gmail.com> Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:228433 Archived-At: Andy Moreton wrote: > Agreed, but the current solution minimises effort for gnulib imports, > rather than emacs developers, whose machines waste time and energy on > pointless configure checks for warnings. It helps Emacs developers too, not all of whom use the same GCC (or clang) version. I care about these warnings more than most, and I don't want to go down the rabbit hole of tracking multiple GCC and clang versions by hand in the Emacs source code. To improve 'configure' speed you can cache the results by using './configure --cache-file=FOO', as was mentioned elsewhere in this thread. On my platform (Ubuntu 18.04 x86-64, Xeon E3-1225 V2), this shrinks 'configure' time from 32.3 to 4.4 user+system CPU seconds, an 86% savings. If you can't use the cache for some reason, you can use a command like this: ./configure --disable-gcc-warnings This avoids the 'configure' warning tests you're worried about, and shrinks my 'configure' time from 32.3 to 25.8 user+system CPU seconds, a 20% savings. You can then build with "make WARN_CFLAGS='-Wall -Whatever'" with your own preferred hand-built warning list.