[Ns-developers] fixing src/contrib/wscript for xml-gtkconfig store

[Raj Bhattacharjea]

On systems without GTK+, but on which libxml is found by waf, the xml
config store (which has been merged to ns-3-dev) wscript code screws
things up:

    if bld.env['ENABLE_GTK_CONFIG_STORE']:
        headers.source.append ('gtk-config-store.h')
        module.source.append ('gtk-config-store.cc')
        module.uselib = 'GTK_CONFIG_STORE'

    if bld.env['ENABLE_LIBXML2']:
        module.source.append ('xml-config.cc')
        module.uselib = module.uselib + ' LIBXML2'

The issue is that module.uselib won't not exist as an rvalue in the
second "if" block if the first one didn't execute.  The first thing I
think of is:

     if bld.env['ENABLE_LIBXML2']:
         module.source.append ('xml-config.cc')
-        module.uselib = module.uselib + ' LIBXML2'
+        if bld.env['ENABLE_GTK_CONFIG_STORE']:
+            module.uselib = module.uselib + ' LIBXML2'
+        else:
+            module.uselib =' LIBXML2'

But I'm not sure this is right.  Mathieu, what is the desired behavior
if GTK is not present but libxml is?  How can we fix this?

-- 
Raj Bhattacharjea
Georgia Institute of Technology
School of Electrical and Computer Engineering
Ph.D. Candidate
Systems Analyst
404.894.2955