[Swig-user] python varargs using typemap not working well, a few issues

[sehmann <se...@gm...>]

Below I have included some code for reference.

With SWIG 2.0.9

Issue 1) performance concern about having an additional function layer here
+ doing tuple manipulation
Issue 2) the second PyTuple_GetSlice has a +1 for the last argument -- seems
wrong
Issue 3) $input is not mapped to the "varargs" variable, it is mapped to
"self"

Can someone concur with me so I can confidently file a bug against SWIG for
these?

This is the typemap and the static method I am wrapping:
%typemap(in) (...) (ArgList al)
{
    for (int j = 0; j < PyTuple_Size($input); ++j) {
        // TODO what if this fails to convert?
        boost::shared_ptr<Arg> a;
        if (ConvertPythonObjToValue(PyTuple_GetItem($input, j), a)) {
            al.push_back(a);
        }
    }

    $1 = &al;
}
class ConfigReader
{
public:
    static void writeYaml(...);
};

This is the generated code:

SWIGINTERN PyObject *_wrap_ConfigReader_writeYaml__varargs__(PyObject
*SWIGUNUSEDPARM(self), PyObject *args, PyObject *varargs) {
  PyObject *resultobj = 0;
  void *arg1 = 0 ;
  ArgList al1 ;

  if(!PyArg_UnpackTuple(args,(char *)"ConfigReader_writeYaml",0,1))
SWIG_fail;
  {
    for (int j = 0; j < PyTuple_Size(self); ++j) {
      // TODO what if this fails to convert?
      boost::shared_ptr<Arg> a;
      if (ConvertPythonObjToValue(PyTuple_GetItem(self, j), a)) {
        al1.push_back(a);
      }
    }

    arg1 = &al1;
  }
  {
    try {
      ConfigReader::writeYaml(arg1);
    } catch( std::runtime_error& e ) {
      PyErr_SetString(PyExc_RuntimeError, e.what());
      return NULL;
    }
  }
  resultobj = SWIG_Py_Void();
  return resultobj;
fail:
  return NULL;
}


SWIGINTERN PyObject *_wrap_ConfigReader_writeYaml(PyObject
*SWIGUNUSEDPARM(self), PyObject *args) {
  PyObject *resultobj;
  PyObject *varargs;
  PyObject *newargs;

  newargs = PyTuple_GetSlice(args,0,0);
  varargs = PyTuple_GetSlice(args,0,PyTuple_Size(args)+1);
  resultobj = _wrap_ConfigReader_writeYaml__varargs__(NULL,newargs,varargs);
  Py_XDECREF(newargs);
  Py_XDECREF(varargs);
  return resultobj;
}




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