Re: [pygccxml-development] Parameter passing, ownership semantics

[Gustavo C. <gjc...@gm...>]

On 2/18/07, Gustavo Carneiro <gjc...@gm...> wrote:
>
> On 2/18/07, Roman Yakovenko <rom...@gm...> wrote:
>
> > On 2/18/07, Gustavo Carneiro <gjc...@gm...> wrote:
> > > On 2/18/07, Roman Yakovenko <rom...@gm...> wrote:
> > > > I committed new function transformation: transfer ownership. The
> > > documentation
> > > > will come later. For usage example take a look on unittests:
> > > > ( look for "transfer_ownership" )
> > > >
> > > http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/unittests/function_transformations_tester.py?view=markup
> >
> > > >
> > > http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/unittests/data/function_transformations_to_be_exported.hpp?view=markup
> >
> > >
> > >   Thanks!
> > >
> > >   Unfortunately the generated code does not compile when I try to use
> > that
> > > feature:
> > >
> > > default/bindings/python/__call_policies.pypp.hpp:14:58:
> > > error: boost/python/suite/indexing/iterator_range.hpp: No
> > > such file or directory
> > > default/bindings/python/__call_policies.pypp.hpp:172:
> > > error: 'pyplusplus::call_policies::bpl::indexing' has not
> > > been declared
> > > default/bindings/python/__call_policies.pypp.hpp:172:
> > > error: ISO C++ forbids declaration of 'iterator_range' with no type
> > > default/bindings/python/__call_policies.pypp.hpp:172:
> > > error: typedef name may not be a nested-name-specifier
> > > default/bindings/python/__call_policies.pypp.hpp:172:
> > > error: expected ';' before '<' token
> > > [...etc...]
> > >
> > >   From "boost/python/suite/indexing/iterator_range.hpp: No
> > > such file or directory", does this sound like I need to get a newer
> > > boost::python library or something?
> >
> > Something like that. Boost.Python, out of the box, comes with little
> > support
> > to STL containers. To make the long story short you have to install new
> > indexing
> > suite that comes with Py++:
> > (
> > http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/indexing_suite_v2/
> > )
> >
> > Here you will find more information about new indexing suite
> > http://language-binding.net/pyplusplus/documentation/containers.html.
>
>
>
>   Thanks.
>
>   After much effort to rebuilt a patched boost library, it now compiles
> fine.  However, the methods that are affected by the transformation
> (Schedule*) are receiving some kind of name mangling:
>
> >>> dir(ns3.Simulator)
> ['Now', 'Run', 'ScheduleDestroy_126390ccfc1f22f22289536ea47d3ecb',
> 'ScheduleNow_3692da707df52052648f9d5435d958c4',
> 'Schedule_fbf096d706be19b392c1e3fbcd3bf544', 'Stop', '__class__',
> '__delattr__', '__dict__', '__doc__', '__getattribute__', '__hash__',
> '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__',
> '__repr__', '__setattr__', '__str__', '__weakref__']
>

  Even with the name mangling problem, something was not right:

gjc@nazgul:python$  python test-schedule.py
Traceback (most recent call last):
  File "test-schedule.py", line 11, in <module>
    Simulator.Schedule_fbf096d706be19b392c1e3fbcd3bf544(t1, ev)
Boost.Python.ArgumentError: Python argument types in
    Simulator.Schedule_fbf096d706be19b392c1e3fbcd3bf544(Time, MyEvent)
did not match C++ signature:
    Schedule_fbf096d706be19b392c1e3fbcd3bf544(ns3::Time time,
std::auto_ptr<ns3::EventImpl> event)

  Then I saw something I missed in the unit test, and added this code:

    EventImpl = mb.class_('EventImpl')
    EventImpl.held_type = 'std::auto_ptr< %s >' % EventImpl.decl_string

  (EventImpl is the type of the argument that is subject to the ownership
transfer)

  But with the above changes the code doesn't compile (errors below).  The
generated source contains:

    bp::class_< EventImpl_wrapper, std::auto_ptr< ::ns3::EventImpl >,
boost::noncopyable >( "EventImpl" )
        .def( bp::init< >() )

  The error comes from the ".def( bp::init< >() )" line.  Manually removing
the "std::auto_ptr< ::ns3::EventImpl >" part from the first line solves the
compilation error.

   Any hints?

/usr/include/boost/python/object/pointer_holder.hpp: In constructor
'boost::python::objects::pointer_holder<Pointer,
Value>::pointer_holder(PyObject*) [with Pointer =
std::auto_ptr<ns3::EventImpl>, Value = ns3::EventImpl]':
/usr/include/boost/python/object/make_holder.hpp:83:   instantiated from
'static void boost::python::objects::make_holder<0>::apply<Holder,
ArgList>::execute(PyObject*) [with Holder =
boost::python::objects::pointer_holder<std::auto_ptr<ns3::EventImpl>,
ns3::EventImpl>, ArgList = boost::mpl::vector0<mpl_::na>]'
/usr/include/boost/python/detail/make_keyword_range_fn.hpp:64:
instantiated from 'boost::python::api::object
boost::python::detail::make_keyword_range_constructor(const CallPolicies&,
const boost::python::detail::keyword_range&, Holder*, ArgList*, Arity*)
[with ArgList = boost::mpl::vector0<mpl_::na>, Arity =
boost::mpl::size<boost::mpl::vector0<mpl_::na> >, Holder =
boost::python::objects::pointer_holder<std::auto_ptr<ns3::EventImpl>,
ns3::EventImpl>, CallPolicies = boost::python::default_call_policies]'
/usr/include/boost/python/init.hpp:330:   instantiated from 'void
boost::python::detail::def_init_aux(ClassT&, const Signature&, NArgs, const
CallPoliciesT&, const char*, const boost::python::detail::keyword_range&)
[with ClassT = boost::python::class_<EventImpl_wrapper,
std::auto_ptr<ns3::EventImpl>, boost::noncopyable_::noncopyable,
boost::python::detail::not_specified>, CallPoliciesT =
boost::python::default_call_policies, Signature =
boost::mpl::vector0<mpl_::na>, NArgs =
boost::mpl::size<boost::mpl::vector0<mpl_::na> >]'
/usr/include/boost/python/init.hpp:399:   instantiated from 'static void
boost::python::detail::define_class_init_helper<0>::apply(ClassT&, const
CallPoliciesT&, const Signature&, NArgs, const char*, const
boost::python::detail::keyword_range&) [with ClassT =
boost::python::class_<EventImpl_wrapper, std::auto_ptr<ns3::EventImpl>,
boost::noncopyable_::noncopyable, boost::python::detail::not_specified>,
CallPoliciesT = boost::python::default_call_policies, Signature =
boost::mpl::vector0<mpl_::na>, NArgs =
boost::mpl::size<boost::mpl::vector0<mpl_::na> >]'
/usr/include/boost/python/init.hpp:171:   instantiated from 'void
boost::python::init_base<DerivedT>::visit(classT&) const [with classT =
boost::python::class_<EventImpl_wrapper, std::auto_ptr<ns3::EventImpl>,
boost::noncopyable_::noncopyable, boost::python::detail::not_specified>,
DerivedT = boost::python::init<mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_>]'
/usr/include/boost/python/def_visitor.hpp:31:   instantiated from 'static
void boost::python::def_visitor_access::visit(const V&, classT&) [with V =
boost::python::def_visitor<boost::python::init<mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_> >, classT =
boost::python::class_<EventImpl_wrapper, std::auto_ptr<ns3::EventImpl>,
boost::noncopyable_::noncopyable, boost::python::detail::not_specified>]'
/usr/include/boost/python/def_visitor.hpp:67:   instantiated from 'void
boost::python::def_visitor<DerivedVisitor>::visit(classT&) const [with
classT = boost::python::class_<EventImpl_wrapper,
std::auto_ptr<ns3::EventImpl>, boost::noncopyable_::noncopyable,
boost::python::detail::not_specified>, DerivedVisitor =
boost::python::init<mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_>]'
/usr/include/boost/python/class.hpp:225:   instantiated from
'boost::python::class_<T, X1, X2, X3>& boost::python::class_<T, X1, X2,
X3>::def(const boost::python::def_visitor<Derived>&) [with Derived =
boost::python::init<mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_>, W = EventImpl_wrapper, X1 = std::auto_ptr<ns3::EventImpl>, X2
= boost::noncopyable_::noncopyable, X3 =
boost::python::detail::not_specified]'
default/bindings/python/ns3.cpp:76:   instantiated from here
/usr/include/boost/python/object/pointer_holder.hpp:179: error: cannot
allocate an object of abstract type 'ns3::EventImpl'
./default/ns3/event-impl.h:28: note:   because the following virtual
functions are pure within 'ns3::EventImpl':
./default/ns3/event-impl.h:31: note:    virtual ns3::EventImpl::~EventImpl()
./default/ns3/event-impl.h:36: note:    virtual void
ns3::EventImpl::Notify()

-- 
Gustavo J. A. M. Carneiro
"The universe is always one step beyond logic."