copied PyCFunction_Call() from CPython to be used when compiling for PyPy

Cython/Utility/CythonFunction.c

@@ -392,6 +392,59 @@ __Pyx_CyFunction_repr(__pyx_CyFunctionObject *op)
 #endif
 }
 
+#if CYTHON_COMPILING_IN_PYPY
+/* originally copied from PyCFunction_Call() in CPython's Objects/methodobject.c */
+/* PyPy does not have this function */
+static PyObject * __Pyx_CyFunction_Call(PyObject *func, PyObject *arg, PyObject *kw) {
+    PyCFunctionObject* f = (PyCFunctionObject*)func;
+    PyCFunction meth = PyCFunction_GET_FUNCTION(func);
+    PyObject *self = PyCFunction_GET_SELF(func);
+    Py_ssize_t size;
+
+    switch (PyCFunction_GET_FLAGS(func) & ~(METH_CLASS | METH_STATIC | METH_COEXIST)) {
+    case METH_VARARGS:
+        if (likely(kw == NULL) || PyDict_Size(kw) == 0)
+            return (*meth)(self, arg);
+        break;
+    case METH_VARARGS | METH_KEYWORDS:
+        return (*(PyCFunctionWithKeywords)meth)(self, arg, kw);
+    case METH_NOARGS:
+        if (likely(kw == NULL) || PyDict_Size(kw) == 0) {
+            size = PyTuple_GET_SIZE(arg);
+            if (size == 0)
+                return (*meth)(self, NULL);
+            PyErr_Format(PyExc_TypeError,
+                "%.200s() takes no arguments (%zd given)",
+                f->m_ml->ml_name, size);
+            return NULL;
+        }
+        break;
+    case METH_O:
+        if (likely(kw == NULL) || PyDict_Size(kw) == 0) {
+            size = PyTuple_GET_SIZE(arg);
+            if (size == 1)
+                return (*meth)(self, PyTuple_GET_ITEM(arg, 0));
+            PyErr_Format(PyExc_TypeError,
+                "%.200s() takes exactly one argument (%zd given)",
+                f->m_ml->ml_name, size);
+            return NULL;
+        }
+        break;
+    default:
+        PyErr_SetString(PyExc_SystemError, "Bad call flags in "
+                        "__Pyx_CyFunction_Call. METH_OLDARGS is no "
+                        "longer supported!");
+
+        return NULL;
+    }
+    PyErr_Format(PyExc_TypeError, "%.200s() takes no keyword arguments",
+                 f->m_ml->ml_name);
+    return NULL;
+}
+#else
+#define __Pyx_CyFunction_Call PyCFunction_Call
+#endif
+
 static PyTypeObject __pyx_CyFunctionType_type = {
     PyVarObject_HEAD_INIT(0, 0)
     __Pyx_NAMESTR("cython_function_or_method"), /*tp_name*/
@@ -411,7 +464,7 @@ static PyTypeObject __pyx_CyFunctionType_type = {
     0,                                  /*tp_as_sequence*/
     0,                                  /*tp_as_mapping*/
     0,                                  /*tp_hash*/
-    __Pyx_PyCFunction_Call,             /*tp_call*/
+    __Pyx_CyFunction_Call,              /*tp_call*/
     0,                                  /*tp_str*/
     0,                                  /*tp_getattro*/
     0,                                  /*tp_setattro*/