public inbox for gcc-help@gcc.gnu.org
 help / color / mirror / Atom feed
From: Nick Stokes <randomaccessiterator@gmail.com>
To: Jonathan Wakely <jwakely.gcc@gmail.com>
Cc: gcc-help@gcc.gnu.org
Subject: Re: g++ cross distro compilation problem
Date: Fri, 21 Jan 2011 14:35:00 -0000	[thread overview]
Message-ID: <AANLkTikn8iLCf7Z-F-jhE0dceDSRnFuy5BBRZwvk9_Js@mail.gmail.com> (raw)
In-Reply-To: <AANLkTi=sKLjadQWWg7XxkVsCdD=arEmvoiSVS4P-0Uaa@mail.gmail.com>

On Fri, Jan 21, 2011 at 4:16 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 21 January 2011 02:03, Nick Stokes wrote:
>>>
>>> But unfortunately this didn't work either. The reason is subtle (and
>>> elusive!): On CentOS (where gcc is built) the GCC features.h header is
>>> defining __USE_XOPEN2K, and not __USE_XOPEN2K8  conditioned on
>>> _XOPEN_SOURCE (or _POSIX_C_SOURCE) being defined.   But on the
>>> front-end SUSE, the /usr/include/locale.h is expecting __USE_XOPEN2K8,
>>> hence fails.
>
> By "GCC features.h header" do you mean one under the GCC installation
> tree in /opt, or /usr/include/features.h?  If the former, that
> explains the problem - you have a fixinclude'd features.h created on
> the old system, which has a glibc that predates POSIX 2008, so
> _GNU_SOURCE doesn't define __USE_XOPEN2K8 (as I think it would on a
> newer glibc)
>


Yes, exactly. CentOS isn't really "cutting edge" in updates..


>> I guess I can sweep under the rug for now by defining __USE_XOPEN2K8.
>> Incidentally, I need to make this transparent for users. Is it
>> possible to add such "custom" definitions to gcc at configure time (or
>> is there some other way to accomplish this)?
>
> http://gcc.gnu.org/onlinedocs/gcc/Spec-Files.html
>
> Or you can provide a wrapper script which invokes the actual gcc
> driver with the additional flags you need.
>
> Rather than defining __USE_XOPEN2K8 (which is definitely not meant to
> be defined/undefined by users) I would consider modifying the
> features.h file so that _GNU_SOURCE sets __XOPEN28K.  You could try
> building the same GCC on a login machine, and compare the features.h
> from that build (if it has one, otherwise just use
> /usr/include/features.h)
>

This sounds best.

Thanks a lot Jonathan!

      reply	other threads:[~2011-01-21 14:35 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-19  0:39 Nick Stokes
2011-01-19  0:57 ` Ian Lance Taylor
2011-01-19  1:14 ` Jonathan Wakely
2011-01-19  1:17   ` Jonathan Wakely
2011-01-19 23:27     ` Nick Stokes
2011-01-20  0:47       ` Jonathan Wakely
2011-01-20 15:53         ` Nick Stokes
2011-01-20 16:40           ` Jonathan Wakely
2011-01-20 19:29             ` Nick Stokes
2011-01-20 19:58               ` Jonathan Wakely
2011-01-20 20:01                 ` Jonathan Wakely
2011-01-21  0:57                   ` Nick Stokes
2011-01-21  2:03                     ` Nick Stokes
2011-01-21  9:16                       ` Jonathan Wakely
2011-01-21 14:35                         ` Nick Stokes [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=AANLkTikn8iLCf7Z-F-jhE0dceDSRnFuy5BBRZwvk9_Js@mail.gmail.com \
    --to=randomaccessiterator@gmail.com \
    --cc=gcc-help@gcc.gnu.org \
    --cc=jwakely.gcc@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).