Re: [boost] 1.32 release preparation

From: Reece Dunn (msclrhd_at_[hidden])
Date: 2004-06-25 05:41:32

Mathew Robertson wrote:
> > > To allow the autoconf tools (ie configure) to detect the presence of 
>the various Boost libs and header file versions, would it be possible to 
>add a C-linkage function to each libraries' source file(s).  This would 
>allow users to add a configure check which detects if a particular library 
>instance is installed.  For example, we add the following code to each 
>library instance:
> > >
> > >    extern "C" boost_autoconf() {}
> > >
> > > This allows autoconf users to add a test to their configure.in script:
> > >
> > >   AC_CHECK_LIB(boost_regex,boost_autoconf,...,[Boost::Regex library 
>not found])
> >
> > I don't see why you need a function with C linkage for this to work.
> > The behavior of autoconf depends on the current language specified
> > in configure.ac at the point where you call AC_CHECK_LIB. If that 
>language
> > is C++, you should well be able to test for functions with C++ linkage.
> > See 
>http://www.gnu.org/software/autoconf/manual/autoconf-2.57/html_chapter/autoconf_5.html#SEC43
>
>Yeah - thats what I'm trying to do.  Specifically, I'm trying to detect if 
>"libboost_regex..." is installed, so I have the following:
>
>AC_CHECK_LIB(boost_regex-gcc,<somefunc>,,AC_ERROR([Must have the 
>Boost::Regex library installed])
>
>Now the problem is, 'What do I put in for <somefunc>?'   All other C++ 
>libraries I have used, specifically contain a C-linkage function to allow 
>configure to detect it.

I am not familiar with the autoconf tool, but is it possible to have 
something like this:

// include_test.cpp
#include <boost/regex.hpp>

int main()
{
   // simple regex use here
   return( 0 );
}
//--end

That way, you'd get a compile error if regex.hpp is not found (Boost is not 
on the system) or a link error if the library is not available (library 
hasn't been built or configured).

I am not sure how this translates to autoconf: have you had a look to see 
how GCC checks for stdio.h, etc.?

Regards,
Reece

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