Re: [boost] [config] Single threaded builds with g++ >= 3.4: No longer possible?

From: Christoph Ludwig (cludwig_at_[hidden])
Date: 2005-01-18 11:32:47

Hi,

On Tue, Jan 18, 2005 at 03:49:17PM +0100, Andreas Huber wrote:
> >From boost/config/stdlib/libstdcpp3.hpp:
> 
> <quote>
> #ifdef __GLIBCXX__ // gcc 3.4 and greater:
> #  ifdef _GLIBCXX_HAVE_GTHR_DEFAULT
>      //
>      // If the std lib has thread support turned on, then turn it on in 
> Boost
>      // as well.  We do this because some gcc-3.4 std lib headers 
> define _REENTANT
>      // while others do not...
>      //
> #     define BOOST_HAS_THREADS
> #  else
> #     define BOOST_DISABLE_THREADS
> #  endif
> #endif
> </quote>
> 
> I suspect this means that ST builds are no longer possible on some GCC 
> platforms (I'm using MinGW). Could someone please confirm or deny this?

builds without MT support are still possible but you need to explicitly define
BOOST_DISABLE_THREADS (either via the compiler command line option or via your
own version of boost/config/user.hpp). 

Yes, it is annoying, but given that gcc 3.4 does not provide a way to detect
at compile time whether the option `-pthread' (or whatever it is on your
platform) is present on the compiler command line, there seems to be no better
solution. The corresponding PR in the gcc bug tracking system 
<URL:http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11953> did not see much
activity lately whence I entertain some doubt whether there will be a
resolution before gcc 4.0.

Christoph
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