PyIter_Check() does not work when -Bsymbolic-functions is used.

test.c

// BUILD:
//   cc `python-config --cflags` -o a.out test.c `python-config --ldflags`
//   cc `python-config --cflags` -fPIE -o a-pie.out test.c `python-config --ldflags`
//
// PyIter_Check() does not work when -Bsymbolic-functions is used.
// On Ubuntu, -Bsymbolic-functions is included in compile flag.
// Workaround is -fPIE.
//
// https://bugs.launchpad.net/ubuntu/+source/python2.7/+bug/1196047
// https://groups.google.com/forum/?fromgroups=#!searchin/vim_dev/tests/vim_dev/CEaL812aLNI/aSuZ0Jin8BQJ

#include <Python.h>

static PyObject*
isiterator(PyObject *self, PyObject *args)
{
    PyObject *o;
    if(!PyArg_Parse(args, "O", &o))
        return NULL;
    return Py_BuildValue("i", PyIter_Check(o));
}

static PyMethodDef EmbMethods[] = {
    {"isiterator", isiterator, METH_O, ""},
    {NULL, NULL, 0, NULL}
};

int
main(int argc, char *argv[])
{
  Py_SetProgramName(argv[0]);
  Py_Initialize();
  Py_InitModule("emb", EmbMethods);
  PyRun_SimpleString("import emb\n"
                     "class C(object):\n"
                     "  pass\n"
                     "if emb.isiterator(C()) == 0:\n"
                     "  print('ok')\n"
                     "else:\n"
                     "  print('ng')\n");
  Py_Finalize();
  return 0;
}