From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Strange test in stdalign.m4 Date: Sat, 30 Mar 2013 08:58:09 +0300 Message-ID: <83ppyh4efi.fsf@gnu.org> References: <8338ve5k4u.fsf@gnu.org> <5155C712.2090409@cs.ucla.edu> <83txnu3yoo.fsf@gnu.org> <51565105.9010005@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: ger.gmane.org 1364623081 2496 80.91.229.3 (30 Mar 2013 05:58:01 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 30 Mar 2013 05:58:01 +0000 (UTC) Cc: emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Mar 30 06:58:28 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ULoo3-0007uR-Ak for ged-emacs-devel@m.gmane.org; Sat, 30 Mar 2013 06:58:23 +0100 Original-Received: from localhost ([::1]:53208 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULonf-0005lR-5x for ged-emacs-devel@m.gmane.org; Sat, 30 Mar 2013 01:57:59 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:45734) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULonb-0005l7-Gx for emacs-devel@gnu.org; Sat, 30 Mar 2013 01:57:56 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ULona-00072o-75 for emacs-devel@gnu.org; Sat, 30 Mar 2013 01:57:55 -0400 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:64234) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULonZ-0006za-Uw for emacs-devel@gnu.org; Sat, 30 Mar 2013 01:57:54 -0400 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MKG00300LQ03H00@a-mtaout20.012.net.il> for emacs-devel@gnu.org; Sat, 30 Mar 2013 08:57:47 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MKG002QNLWAMI90@a-mtaout20.012.net.il>; Sat, 30 Mar 2013 08:57:47 +0300 (IDT) In-reply-to: <51565105.9010005@cs.ucla.edu> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 X-Received-From: 80.179.55.166 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:158465 Archived-At: > Date: Fri, 29 Mar 2013 19:42:13 -0700 > From: Paul Eggert > CC: emacs-devel@gnu.org >=20 > On 03/29/2013 10:25 AM, Eli Zaretskii wrote: > >> The test works for me, with GCC 4.7.2 and 4.8.0. But you're rig= ht, it > >> > does rely on an extension to ISO C11. Which GCC versions > >> > were you using? > > The newest one was 4.4.3 (on fencepost). >=20 > But fencepost GCC 4.4.3 lacks stdalign.h, which means the test prog= ram > that you gave should fail to compile, and the stdalign.h test's fai= lure > to compile under GCC 4.4.3 is a feature not a bug. I.e., although > you've found a portability problem in that test, I don't see how > the problem is relevant to GCC 4.4.3. Yes, I know there's no stdalign.h on fencepost, but I injected the contents of gnulib's stdalign.h as a preamble to the test program, to see if it will work. The goal was to see whether the problem is specific to the (older) version of GCC I have on the particular Windows box where I first saw the failure. > You mentioned earlier that you saw the following diagnostics: >=20 > ta.c:36: error: expected specifier-qualifier-list before =E2=80= =98alignas_int=E2=80=99 > ta.c:36: error: =E2=80=98struct =E2=80=99 has no membe= r named =E2=80=98__b=E2=80=99 >=20 > Which compiler version emitted these diagnostics? The one on fencepost. The broader context of this is running the configure script on a Windows machine, where I arrange for the configure tests to use the header files in the nt/inc directory in order to pass some of the tests, which would have failed if only the system headers were used. In nt/inc, we have stdalign.h that is a copy of lib/stdalign.h, but the compiler might still be old. If you'd prefer not to modify the gnulib test (although I don't see downsides to that), I can force configure to accept nt/inc/stdalign.h by setting an autoconf variable, although I think fixing the test is cleaner. I just was stumped by the failure and didn't understand wha= t was going on.