Function dispatcher_vectorcall

numpy/core/src/multiarray/arrayfunction_override.c:500–645

static PyObject *
dispatcher_vectorcall(PyArray_ArrayFunctionDispatcherObject *self,
        PyObject *const *args, Py_ssize_t len_args, PyObject *kwnames)
{
    PyObject *result = NULL;
    PyObject *types = NULL;
    PyObject *relevant_args = NULL;

    PyObject *public_api;

    /* __array_function__ passes args, kwargs.  These may be filled: */
    PyObject *packed_args = NULL;
    PyObject *packed_kwargs = NULL;

    PyObject *implementing_args[NPY_MAXARGS];
    PyObject *array_function_methods[NPY_MAXARGS];

    int num_implementing_args;

    if (self->relevant_arg_func != NULL) {
        public_api = (PyObject *)self;

        /* Typical path, need to call the relevant_arg_func and unpack them */
        relevant_args = PyObject_Vectorcall(
                self->relevant_arg_func, args, len_args, kwnames);
        if (relevant_args == NULL) {
            fix_name_if_typeerror(self);
            return NULL;
        }
        Py_SETREF(relevant_args, PySequence_Fast(relevant_args,
                "dispatcher for __array_function__ did not return an iterable"));
        if (relevant_args == NULL) {
            return NULL;
        }

        num_implementing_args = get_implementing_args_and_methods(
                relevant_args, implementing_args, array_function_methods);
        if (num_implementing_args < 0) {
            Py_DECREF(relevant_args);
            return NULL;
        }
    }
    else {
        /* For like= dispatching from Python, the public_symbol is the impl */
        public_api = self->default_impl;

        /*
         * We are dealing with `like=` from Python.  For simplicity, the
         * Python code passes it on as the first argument.
         */
        if (PyVectorcall_NARGS(len_args) == 0) {
            PyErr_Format(PyExc_TypeError,
                    "`like` argument dispatching, but first argument is not "
                    "positional in call to %S.", self->default_impl);
            return NULL;
        }

        array_function_methods[0] = get_array_function(args[0]);