From owner-svn-src-all@freebsd.org Fri Apr 28 01:02:27 2017 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 79918D531B4; Fri, 28 Apr 2017 01:02:27 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 333856B8; Fri, 28 Apr 2017 01:02:26 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (localhost [127.0.0.1]) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3) with ESMTP id v3S12KVi073905; Thu, 27 Apr 2017 18:02:20 -0700 (PDT) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: (from freebsd@localhost) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3/Submit) id v3S12KFL073904; Thu, 27 Apr 2017 18:02:20 -0700 (PDT) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <201704280102.v3S12KFL073904@pdx.rh.CN85.dnsmgr.net> Subject: Re: svn commit: r314937 - in stable/10/sys: fs/ext2fs modules/ext2fs In-Reply-To: <20170428081746.H4303@besplex.bde.org> To: Bruce Evans Date: Thu, 27 Apr 2017 18:02:20 -0700 (PDT) CC: Gleb Smirnoff , Ngie Cooper , Ed Maste , "Pedro F. Giffuni" , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-stable@freebsd.org" , "svn-src-stable-10@freebsd.org" Reply-To: rgrimes@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Apr 2017 01:02:27 -0000 > On Thu, 27 Apr 2017, Gleb Smirnoff wrote: > > > On Thu, Apr 27, 2017 at 03:00:56PM -0700, Ngie Cooper wrote: > > N> On Thu, Apr 27, 2017 at 1:52 PM, Ed Maste wrote: > > N> > On 8 March 2017 at 21:47, Pedro F. Giffuni wrote: > > N> >> Author: pfg > > N> >> Date: Thu Mar 9 02:47:01 2017 > > N> >> New Revision: 314937 > > N> >> URL: https://svnweb.freebsd.org/changeset/base/314937 > > N> >> > > N> >> Log: > > N> >> Revert 294545: > > N> >> Bringing back ext4: add support for reading sparse files > > N> > > > N> > Tinderbox is broken on GCC architectures, e.g. from powerpc.LINT64: > > N> > > > N> > In file included from /scratch/tmp/emaste/freebsd/sys/fs/ext2fs/inode.h:46, > > N> > from /scratch/tmp/emaste/freebsd/sys/fs/ext2fs/ext2_alloc.c:50: > > N> > /scratch/tmp/emaste/freebsd/sys/fs/ext2fs/ext2_extents.h:91: warning: > > N> > declaration does not declare anything > > N> > > N> ... because of anonymous unions not being supported in gcc 4.2.1. > > Anonymous unions have been a standard gcc feature since nearly gcc-1. > > > The whole kernel is built with option that enables them on 4.2.1. > > > > CFLAGS.gcc+= -fms-extensions > > This is a bad way to enable standard gcc anonymous unions. It also > enables ms extensions which also gives unused extensions of standard > gcc anonymous, and other even more unwanted ms features. > > The correct way to enable gcc features is to compile with -std=gnu99. > This has been done for a long time in userland, but the has been ^+kernel? > misconfigured to use -std=c99 for a long time. This is sort of > backwards -- the kernel is inherently more unportable and can't > possible be compiled by a C99 compiler, while parts of userland > can. However, userland is larger, so people setting excessive > -std flags soon found that -std=c99 doesn't work. > > With no -std flag, gcc defaults to something like -std=gnu89, so > it supports its old anonymous unions feature but not the many > C99 features needed to compile almost anything now. > > Bruce > > -- Rod Grimes rgrimes@freebsd.org