Function PyUFunc_CheckOverride

numpy/core/src/umath/override.c:213–434

* Check a set of args for the `__array_ufunc__` method. If more than one of * the input arguments implements `__array_ufunc__`, they are tried in the * order: subclasses before superclasses, otherwise left to right. The first * (non-None) routine returning something other than `NotImplemented` * determines the result. If all of the `__array_ufunc__` operations return * `NotImplemented` (or a

 * result of the operation, if any. If *result is NULL, there is no override.
 */
NPY_NO_EXPORT int
PyUFunc_CheckOverride(PyUFuncObject *ufunc, char *method,
        PyObject *in_args, PyObject *out_args, PyObject *wheremask_obj,
        PyObject *const *args, Py_ssize_t len_args, PyObject *kwnames,
        PyObject **result)
{
    int status;

    int num_override_args;
    PyObject *with_override[NPY_MAXARGS];
    PyObject *array_ufunc_methods[NPY_MAXARGS];

    PyObject *method_name = NULL;
    PyObject *normal_kwds = NULL;

    PyObject *override_args = NULL;

    /*
     * Check inputs for overrides
     */
    num_override_args = get_array_ufunc_overrides(
           in_args, out_args, wheremask_obj, with_override, array_ufunc_methods);
    if (num_override_args == -1) {
        goto fail;
    }
    /* No overrides, bail out.*/
    if (num_override_args == 0) {
        *result = NULL;
        return 0;
    }

    /*
     * Normalize ufunc arguments, note that any input and output arguments
     * have already been stored in `in_args` and `out_args`.
     */
    normal_kwds = PyDict_New();
    if (normal_kwds == NULL) {
        goto fail;
    }
    if (initialize_normal_kwds(out_args,
            args, len_args, kwnames, normal_kwds) < 0) {
        goto fail;
    }

    /*
     * Reduce-like methods can pass keyword arguments also by position,
     * in which case the additional positional arguments have to be copied
     * into the keyword argument dictionary. The `__call__` and `__outer__`
     * method have to normalize sig and signature.
     */

    /* ufunc.__call__ */
    if (strcmp(method, "__call__") == 0) {
        status = normalize_signature_keyword(normal_kwds);
    }
    /* ufunc.reduce */
    else if (strcmp(method, "reduce") == 0) {
        static const char *keywords[] = {