move some stuffs related to Windows from ctypes/__init__.pyi to _ctypes.pyi, as at runtime.

stdlib/_ctypes.pyi

@@ -38,6 +38,10 @@ if sys.platform == "win32":
     FUNCFLAG_HRESULT: int
     FUNCFLAG_STDCALL: int
 
+    def FormatError(code: int = ...) -> str: ...
+    def get_last_error() -> int: ...
+    def set_last_error(value: int) -> int: ...
+
 class _CDataMeta(type):
     # By default mypy complains about the following two methods, because strictly speaking cls
     # might not be a Type[_CT]. However this can never actually happen, because the only class that

stdlib/ctypes/__init__.pyi

@@ -16,6 +16,9 @@ from collections.abc import Callable, Sequence
 from typing import Any, ClassVar, Generic, TypeVar, overload
 from typing_extensions import TypeAlias
 
+if sys.platform == "win32":
+    from _ctypes import FormatError as FormatError, get_last_error as get_last_error, set_last_error as set_last_error
+
 if sys.version_info >= (3, 9):
     from types import GenericAlias
 
@@ -138,14 +141,9 @@ def create_unicode_buffer(init: int | str, size: int | None = None) -> Array[c_w
 if sys.platform == "win32":
     def DllCanUnloadNow() -> int: ...
     def DllGetClassObject(rclsid: Any, riid: Any, ppv: Any) -> int: ...  # TODO not documented
-    def FormatError(code: int = ...) -> str: ...
     def GetLastError() -> int: ...
 
 def get_errno() -> int: ...
-
-if sys.platform == "win32":
-    def get_last_error() -> int: ...
-
 def memmove(dst: _CVoidPLike, src: _CVoidConstPLike, count: int) -> int: ...
 def memset(dst: _CVoidPLike, c: int, count: int) -> int: ...
 def POINTER(type: type[_CT]) -> type[_Pointer[_CT]]: ...
@@ -166,10 +164,6 @@ class _Pointer(Generic[_CT], _PointerLike, _CData):
 def pointer(__arg: _CT) -> _Pointer[_CT]: ...
 def resize(obj: _CData, size: int) -> None: ...
 def set_errno(value: int) -> int: ...
-
-if sys.platform == "win32":
-    def set_last_error(value: int) -> int: ...
-
 def sizeof(obj_or_type: _CData | type[_CData]) -> int: ...
 def string_at(address: _CVoidConstPLike, size: int = -1) -> bytes: ...
 

tests/stubtest_allowlists/win32.txt

@@ -23,11 +23,8 @@ ssl.SSLSocket.recvmsg
 ssl.SSLSocket.recvmsg_into
 ssl.SSLSocket.sendmsg
 winreg.HKEYType.handle
-_ctypes.FormatError
 _ctypes.FreeLibrary
 _ctypes.LoadLibrary
-_ctypes.get_last_error
-_ctypes.set_last_error
 
 
 # ==========