From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Should Emacs 26 be portable to Glibc 2.28? Date: Thu, 08 Mar 2018 15:39:13 +0200 Message-ID: <83bmfyptz2.fsf@gnu.org> References: <96913ef6-44d4-cd63-8a37-5080be2d22dc@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1520516258 29189 195.159.176.226 (8 Mar 2018 13:37:38 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 8 Mar 2018 13:37:38 +0000 (UTC) Cc: emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Mar 08 14:37:33 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 1etvjd-0007Q4-79 for ged-emacs-devel@m.gmane.org; Thu, 08 Mar 2018 14:37:29 +0100 Original-Received: from localhost ([::1]:39094 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etvlg-0004we-3W for ged-emacs-devel@m.gmane.org; Thu, 08 Mar 2018 08:39:36 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46674) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etvlQ-0004rH-MF for emacs-devel@gnu.org; Thu, 08 Mar 2018 08:39:22 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1etvlP-0001Di-K6 for emacs-devel@gnu.org; Thu, 08 Mar 2018 08:39:20 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:59363) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etvlP-0001Dd-FK; Thu, 08 Mar 2018 08:39:19 -0500 Original-Received: from [176.228.60.248] (port=3688 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1etvlO-0004CT-K0; Thu, 08 Mar 2018 08:39:19 -0500 In-reply-to: <96913ef6-44d4-cd63-8a37-5080be2d22dc@cs.ucla.edu> (message from Paul Eggert on Wed, 7 Mar 2018 18:09:49 -0800) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e 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:223494 Archived-At: > From: Paul Eggert > Date: Wed, 7 Mar 2018 18:09:49 -0800 > > The attached patch, which I've installed into Emacs master, fixes a > incompatibility between Emacs and the planned 2.28 release of glibc. > Should I install it into the emacs-26 branch? glibc 2.28 is currently > scheduled for August, so this shouldn't be much of an issue until then; > however, as the patch is reasonably conservative and it's likely there > won't be another Emacs release before August, it might make sense to > install this patch into the emacs-26 branch now. > > The underlying problem is that Emacs (via gnulib) mucks with glibc > internals that are planned to change in glibc 2.28. For more see the > thread here: > > https://lists.gnu.org/r/bug-gnulib/2018-03/msg00000.html Thanks. In the name of paranoia, would it be possible to make the first of these two changes backward-compatible, by doing this instead: > diff --git a/lib/fpending.c b/lib/fpending.c > index c84e3a5b4e..789f50e4e4 100644 > --- a/lib/fpending.c > +++ b/lib/fpending.c > @@ -32,7 +32,7 @@ __fpending (FILE *fp) > /* Most systems provide FILE as a struct and the necessary bitmask in > , because they need it for implementing getc() and putc() as > fast macros. */ > -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ > +#if defined _IO_ftrylockfile || defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ > return fp->_IO_write_ptr - fp->_IO_write_base; > #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__ > /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */ With that, I think we can safely install this on the release branch.