[pygtk] virtual function without a return value

[Gustavo J. A. M. Carneiro]

On Dom, 2007-06-10 at 21:46 +0200, Sébastien Granjoux wrote:
> Hi All,
> 
> I'm writing a wrapper for a GInterface derived type, so I have written a 
> .defs file with something like
> 
> (define-virtual activate
>    (of-object "Plugin")
>    (c-name "plugin_activate")
>    (return-type "none")
> )
> 
> 
> Using codegen I get a function
> 
> static void _wrap_Plugin__proxy_do_activate(Plugin *self)
> {
> 	...
> 	py_retval = PyObject_CallObject(py_method, py_args);
> 	...
> 	py_retval = Py_BuildValue("(N)", py_retval);
> 	if (!PyArg_ParseTuple(py_retval, "")) {
> 	        if (PyErr_Occurred())
> 
> 
> I don't understand why codegen generates some code to extract the return 
> value from the python method as the C function doesn't need to return 
> anything. Moreover, I have an error (not fatal) "TypeError: function 
> takes exactly 0 arguments (1 given)" in PyArg_ParseTuple which I think 
> is due to the empty string "".
> 
> Is it something wrong in codegen or do I have made an error somewhere ?

  I think it's a bug in codegen.  A patch (codegen/reversewrapper.py)
would be most welcome; it just needs to special case where
PyArg_ParseTuple is called to parse return value if the template string
is "", then just check for Py_None instead of calling PyArg_ParseTuple.

-- 
Gustavo J. A. M. Carneiro
<gjc at inescporto.pt> <gustavo at users.sourceforge.net>
"The universe is always one step beyond logic" -- Frank Herbert