Fix PyObject_CallNoArgs python version cfg

CHANGELOG.md

@@ -61,6 +61,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix `#[pyo3(from_py_with = "...")]` being ignored for 1-element tuple structs and transparent structs. [#2440](https://github.com/PyO3/pyo3/pull/2440)
 - Use `memoffset` for computing PyCell offsets [#2450](https://github.com/PyO3/pyo3/pull/2450)
 - Fix incorrect enum names being returned by `repr` for enums renamed by `#[pyclass(name)]` [#2457](https://github.com/PyO3/pyo3/pull/2457)
+- Fix incorrect Python version cfg definition on `PyObject_CallNoArgs`[#2476](https://github.com/PyO3/pyo3/pull/2476)
 
 ## [0.16.5] - 2022-05-15
 

pyo3-ffi/src/abstract_.rs

@@ -23,7 +23,7 @@ pub unsafe fn PyObject_DelAttr(o: *mut PyObject, attr_name: *mut PyObject) -> c_
 extern "C" {
     #[cfg(all(
         not(PyPy),
-        any(not(Py_LIMITED_API), Py_3_9) // Added to limited API in 3.9
+        any(Py_3_10, all(not(Py_LIMITED_API), Py_3_9)) // Added to python in 3.9 but to limited API in 3.10
     ))]
     pub fn PyObject_CallNoArgs(func: *mut PyObject) -> *mut PyObject;
     #[cfg_attr(PyPy, link_name = "PyPyObject_Call")]

src/instance.rs

@@ -647,7 +647,10 @@ impl<T> Py<T> {
     /// This is equivalent to the Python expression `self()`.
     pub fn call0(&self, py: Python<'_>) -> PyResult<PyObject> {
         cfg_if::cfg_if! {
-            if #[cfg(all(Py_3_9, not(PyPy)))] {
+            if #[cfg(all(
+                not(PyPy),
+                any(Py_3_10, all(not(Py_LIMITED_API), Py_3_9)) // PyObject_CallNoArgs was added to python in 3.9 but to limited API in 3.10
+            ))] {
                 // Optimized path on python 3.9+
                 unsafe {
                     PyObject::from_owned_ptr_or_err(py, ffi::PyObject_CallNoArgs(self.as_ptr()))

src/types/any.rs

@@ -484,7 +484,10 @@ impl PyAny {
     /// This is equivalent to the Python expression `help()`.
     pub fn call0(&self) -> PyResult<&PyAny> {
         cfg_if::cfg_if! {
-            if #[cfg(all(Py_3_9, not(PyPy)))] {
+            if #[cfg(all(
+                not(PyPy),
+                any(Py_3_10, all(not(Py_LIMITED_API), Py_3_9)) // PyObject_CallNoArgs was added to python in 3.9 but to limited API in 3.10
+            ))] {
                 // Optimized path on python 3.9+
                 unsafe {
                     self.py().from_owned_ptr_or_err(ffi::PyObject_CallNoArgs(self.as_ptr()))