Re: 329-gary-allow-RTLD_GLOBAL

[Bob Friesenhahn]

On Tue, 22 May 2007, Ralf Wildenhues wrote:
> > Except for annoyance to the end-user, I was originally thinking that
> > we don't need to distinguish.  When the developer's libltdl client
> > code calls lt_dladvise_global, we could have it emit a warning to
> > stderr that says: If what you are trying to do won't work without
> > calling lt_dladvise_global(), then you're code will not be fully
> > portable.
>
> Hmm.  That will be informative the first time, and annoying the next
> million times, if the user chose to accept this limitation.  So yes,
> a documentation patch is better.  That way not only the fact about
> some unportability but also its intensity may be conveyed.  ;-)

It is a pity that many Linux application developers develop for Linux 
only and openly claim to have no interest at all in portability to 
other systems.  The same folks are also unlikely to read the 
documentation.

Given the current world order (odor?), I am inclined that RTLD_GLOBAL 
should not be supported in libltdl unless an additional configure.ac 
macro/option is supplied.  This would require a concious decision on 
the part of application developers (at least those bundling libltdl) 
to depend on this non-portable support.  Unfortunately, it does not 
cover the case of an already installed libltdl which may or may not be 
configured to support RTLD_GLOBAL.  The macro can test if the already 
installed libltdl has the support, but if it does, applications could 
still depend on the API feature without a special configure test.

Bob
======================================
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/