[XML-SIG] Availability of libxml2 and libxslt Python bindings

Fred L. Drake, Jr. fdrake@acm.org
Thu, 21 Feb 2002 14:28:38 -0500

Daniel Veillard writes:
 >   Come'on zlib is shared and used for example by libpng. And if your
 > graphic library need it you would have to have a special version
 > of libpng statically compiled against zlib, nahhh you cannot impose
 > this, on any platform !

For modules which are loaded into the global symbol space, this isn't
a problem.  "Normal" linking of an application to it's libraries works
fine because of this, as does a dynamic object's use of libraries
loaded by the main application.  When different dynamic objects need
to share a library and RTLD_GLOBAL is not set, we have a very
different situation.  Hannu showed that sharing the symbol space makes
this problem go away.

I remember playing with this once, and I ended up linking the
dependent dynamic object to the other.  It worked, but it can be
fragile (due to the search for the first if the dependent object is
loaded first).  Basically, you'd need to add A.so to the link command
for B.so; I forget if there were any other magical parameters to
give.  This might be worth playing with.

 >   No I'm not gonna ship with library statically linked inside my
 > shared library. The linker should be fixed instead.

That's another option, even if you don't like it.  It helps avoid API
version dependence of the compiled module.


Fred L. Drake, Jr.  <fdrake at acm.org>
PythonLabs at Zope Corporation