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pythonc++compilationwarningscython

What is this 'bad:' label generated by Cython?

While cythonizing my Cython source code files, I can see a dozen of warnings about a label named 'bad:' generated by Cython, for example:

read_input.cpp:30037:3: warning: label ‘bad’ defined but not used [-Wunused-label]

The C++ generated function is like this:

static PyObject* __pyx_convert__to_py_struct__VehicleCaps(struct VehicleCaps s) {
  PyObject* res;
  PyObject* member;
  res = __Pyx_PyDict_NewPresized(0); if (unlikely(!res)) return NULL;
  return res;
  bad:
  Py_XDECREF(member);
  Py_DECREF(res);
  return NULL;
}

The 'bad:' label is in there, I don't get it why Cython is generating this unused label and it shows warnings.

Do I have really fix these warnings? or it's safe to leave them untouched?

Solution

  • It's for goto bad if something fails in the function, but it doesn't look like anything can fail, so it's unused.

    It isn't a problem so you can ignore it. But Cython generally tries not to generate unused labels, so feel free to report it as a (small) bug