delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2006/05/01/13:35:56

X-Spam-Check-By: sourceware.org
Message-ID: <445646ED.8090004@variadic.org>
Date: Mon, 01 May 2006 10:35:41 -0700
From: Steven Brown <swbrown AT variadic DOT org>
User-Agent: Thunderbird 1.5.0.2 (X11/20060421)
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: Fixing the state of C++ in Cygwin
References: <Pine DOT OSF DOT 4 DOT 21 DOT 0604301216110 DOT 9489-100000 AT ax0rm1 DOT roma1 DOT infn DOT it>
In-Reply-To: <Pine.OSF.4.21.0604301216110.9489-100000@ax0rm1.roma1.infn.it>
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

(resending as the list seems to have eaten it, apologies if it gets
duplicated)

Angelo Graziosi wrote:

> It seems that applying the patch only, without rebuilding GCC works (the
> ROOt, a CERN application, problems seem solved).

The template is explicitly instantiated in libstdc++, so that shouldn't
work afaik.  The compiler won't be compiling the modified code, as it
trusts it will find it already compiled during link.  Does rOOt disable
explicit instantiation via tweaking _GLIBCXX_EXTERN_TEMPLATE?

At first, I tried writing m4 to apply the patch and disable the explicit
instantiation as a transparent fix[1], but it only worked in some cases.
 From my understanding of that part of the toolchain, it gets in a
non-deterministic linking state.  There will be an implementation of the
template compiled in libstdc++ and your code (if explicit instantiation
is disabled).  When it goes to link (remember, libstdc++ is linked
statically in Cygwin), the linker is going to remove the duplicate,
which might be the new one or the old one.


[1]
https://svn.variadic.org/public/trunk/ax_dll_string_fix/ax_dll_string_fix.m4


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019