move and rename from ctypes._FuncPointer to _ctypes.CFuncPtr

[junkmd]

• Please see ctypes._FuncPointer doesn't exist at runtime and _ctypes.CFuncPtr doesn't exist in typestub #10132

[junkmd]

Stubtests are failed.

Quoting from https://github.com/python/typeshed/actions/runs/4889040813/jobs/8727237786?pr=10140#step:5:19,

error: _ctypes.CFuncPtr cannot be subclassed at runtime, but isn't marked with @Final in the stub

However, the return value of CFUNCTYPE is a subclass of _ctypes.CFuncPtr at runtime.
https://github.com/python/cpython/blob/872cbc613245db7a1fc5e6656ed0135d2e115f50/Lib/ctypes/__init__.py#L73-L107

I wonder why it occurs.

Any opinions would be appreciated.

[JelleZijlstra]

Stubtest probably just tries to do something like:

>>> class X(ctypes._CFuncPtr): pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: class must define _flags_ which must be an integer

It can only be subclassed if the subclass sets fields like _flags_. I think we can simply add it to the allowlist (tests/stubtest_allowlists/py3_common.txt probably).

[junkmd]

Both adding _ctypes.CFuncPtr._flags_ to allowlists(6399ecd) and adding the _flags_ attribute to _ctypes.CFuncPtr(caedbda) doesn't resolve this problem 😭.

[AlexWaygood]

Both adding _ctypes.CFuncPtr._flags_ to allowlists(6399ecd) and adding the _flags_ attribute to _ctypes.CFuncPtr(caedbda) doesn't resolve this problem 😭.

You needed to add _ctypes.CFuncPtr to the allowlist rather than _ctypes.CFuncPtr._flags_ — I've corrected it for you :)

[junkmd]

@AlexWaygood
Thank you for the correction.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉