ctypes: pointer is a function, not a class (#8446)

Author: AlexWaygood

stdlib/ctypes/__init__.pyi

@@ -100,7 +100,7 @@ class _FuncPointer(_PointerLike, _CData):
     @overload
     def __init__(self, func_spec: tuple[str | int, CDLL], paramflags: tuple[_PF, ...] = ...) -> None: ...
     @overload
-    def __init__(self, vtlb_index: int, name: str, paramflags: tuple[_PF, ...] = ..., iid: pointer[c_int] = ...) -> None: ...
+    def __init__(self, vtlb_index: int, name: str, paramflags: tuple[_PF, ...] = ..., iid: _Pointer[c_int] = ...) -> None: ...
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
 
 class _NamedFuncPointer(_FuncPointer):
@@ -156,14 +156,14 @@ if sys.platform == "win32":
 
 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]]: ...
+def POINTER(type: type[_CT]) -> type[_Pointer[_CT]]: ...
 
-# The real ctypes.pointer is a function, not a class. The stub version of pointer behaves like
-# ctypes._Pointer in that it is the base class for all pointer types. Unlike the real _Pointer,
-# it can be instantiated directly (to mimic the behavior of the real pointer function).
-class pointer(Generic[_CT], _PointerLike, _CData):
+class _Pointer(Generic[_CT], _PointerLike, _CData):
     _type_: type[_CT]
     contents: _CT
+    @overload
+    def __init__(self) -> None: ...
+    @overload
     def __init__(self, arg: _CT) -> None: ...
     @overload
     def __getitem__(self, __i: int) -> _CT: ...
@@ -174,6 +174,7 @@ class pointer(Generic[_CT], _PointerLike, _CData):
     @overload
     def __setitem__(self, __s: slice, __o: Iterable[_CT]) -> None: ...
 
+def pointer(__arg: _CT) -> _Pointer[_CT]: ...
 def resize(obj: _CData, size: int) -> None: ...
 def set_errno(value: int) -> int: ...
 

stdlib/ctypes/wintypes.pyi

@@ -1,6 +1,7 @@
 from ctypes import (
     Array,
     Structure,
+    _Pointer,
     _SimpleCData,
     c_byte,
     c_char,
@@ -18,7 +19,6 @@ from ctypes import (
     c_void_p,
     c_wchar,
     c_wchar_p,
-    pointer,
 )
 from typing_extensions import TypeAlias
 
@@ -181,55 +181,55 @@ class WIN32_FIND_DATAW(Structure):
     cFileName: Array[WCHAR]
     cAlternateFileName: Array[WCHAR]
 
-# These pointer type definitions use pointer[...] instead of POINTER(...), to allow them
+# These pointer type definitions use _Pointer[...] instead of POINTER(...), to allow them
 # to be used in type annotations.
-PBOOL: TypeAlias = pointer[BOOL]
-LPBOOL: TypeAlias = pointer[BOOL]
-PBOOLEAN: TypeAlias = pointer[BOOLEAN]
-PBYTE: TypeAlias = pointer[BYTE]
-LPBYTE: TypeAlias = pointer[BYTE]
-PCHAR: TypeAlias = pointer[CHAR]
-LPCOLORREF: TypeAlias = pointer[COLORREF]
-PDWORD: TypeAlias = pointer[DWORD]
-LPDWORD: TypeAlias = pointer[DWORD]
-PFILETIME: TypeAlias = pointer[FILETIME]
-LPFILETIME: TypeAlias = pointer[FILETIME]
-PFLOAT: TypeAlias = pointer[FLOAT]
-PHANDLE: TypeAlias = pointer[HANDLE]
-LPHANDLE: TypeAlias = pointer[HANDLE]
-PHKEY: TypeAlias = pointer[HKEY]
-LPHKL: TypeAlias = pointer[HKL]
-PINT: TypeAlias = pointer[INT]
-LPINT: TypeAlias = pointer[INT]
-PLARGE_INTEGER: TypeAlias = pointer[LARGE_INTEGER]
-PLCID: TypeAlias = pointer[LCID]
-PLONG: TypeAlias = pointer[LONG]
-LPLONG: TypeAlias = pointer[LONG]
-PMSG: TypeAlias = pointer[MSG]
-LPMSG: TypeAlias = pointer[MSG]
-PPOINT: TypeAlias = pointer[POINT]
-LPPOINT: TypeAlias = pointer[POINT]
-PPOINTL: TypeAlias = pointer[POINTL]
-PRECT: TypeAlias = pointer[RECT]
-LPRECT: TypeAlias = pointer[RECT]
-PRECTL: TypeAlias = pointer[RECTL]
-LPRECTL: TypeAlias = pointer[RECTL]
-LPSC_HANDLE: TypeAlias = pointer[SC_HANDLE]
-PSHORT: TypeAlias = pointer[SHORT]
-PSIZE: TypeAlias = pointer[SIZE]
-LPSIZE: TypeAlias = pointer[SIZE]
-PSIZEL: TypeAlias = pointer[SIZEL]
-LPSIZEL: TypeAlias = pointer[SIZEL]
-PSMALL_RECT: TypeAlias = pointer[SMALL_RECT]
-PUINT: TypeAlias = pointer[UINT]
-LPUINT: TypeAlias = pointer[UINT]
-PULARGE_INTEGER: TypeAlias = pointer[ULARGE_INTEGER]
-PULONG: TypeAlias = pointer[ULONG]
-PUSHORT: TypeAlias = pointer[USHORT]
-PWCHAR: TypeAlias = pointer[WCHAR]
-PWIN32_FIND_DATAA: TypeAlias = pointer[WIN32_FIND_DATAA]
-LPWIN32_FIND_DATAA: TypeAlias = pointer[WIN32_FIND_DATAA]
-PWIN32_FIND_DATAW: TypeAlias = pointer[WIN32_FIND_DATAW]
-LPWIN32_FIND_DATAW: TypeAlias = pointer[WIN32_FIND_DATAW]
-PWORD: TypeAlias = pointer[WORD]
-LPWORD: TypeAlias = pointer[WORD]
+PBOOL: TypeAlias = _Pointer[BOOL]
+LPBOOL: TypeAlias = _Pointer[BOOL]
+PBOOLEAN: TypeAlias = _Pointer[BOOLEAN]
+PBYTE: TypeAlias = _Pointer[BYTE]
+LPBYTE: TypeAlias = _Pointer[BYTE]
+PCHAR: TypeAlias = _Pointer[CHAR]
+LPCOLORREF: TypeAlias = _Pointer[COLORREF]
+PDWORD: TypeAlias = _Pointer[DWORD]
+LPDWORD: TypeAlias = _Pointer[DWORD]
+PFILETIME: TypeAlias = _Pointer[FILETIME]
+LPFILETIME: TypeAlias = _Pointer[FILETIME]
+PFLOAT: TypeAlias = _Pointer[FLOAT]
+PHANDLE: TypeAlias = _Pointer[HANDLE]
+LPHANDLE: TypeAlias = _Pointer[HANDLE]
+PHKEY: TypeAlias = _Pointer[HKEY]
+LPHKL: TypeAlias = _Pointer[HKL]
+PINT: TypeAlias = _Pointer[INT]
+LPINT: TypeAlias = _Pointer[INT]
+PLARGE_INTEGER: TypeAlias = _Pointer[LARGE_INTEGER]
+PLCID: TypeAlias = _Pointer[LCID]
+PLONG: TypeAlias = _Pointer[LONG]
+LPLONG: TypeAlias = _Pointer[LONG]
+PMSG: TypeAlias = _Pointer[MSG]
+LPMSG: TypeAlias = _Pointer[MSG]
+PPOINT: TypeAlias = _Pointer[POINT]
+LPPOINT: TypeAlias = _Pointer[POINT]
+PPOINTL: TypeAlias = _Pointer[POINTL]
+PRECT: TypeAlias = _Pointer[RECT]
+LPRECT: TypeAlias = _Pointer[RECT]
+PRECTL: TypeAlias = _Pointer[RECTL]
+LPRECTL: TypeAlias = _Pointer[RECTL]
+LPSC_HANDLE: TypeAlias = _Pointer[SC_HANDLE]
+PSHORT: TypeAlias = _Pointer[SHORT]
+PSIZE: TypeAlias = _Pointer[SIZE]
+LPSIZE: TypeAlias = _Pointer[SIZE]
+PSIZEL: TypeAlias = _Pointer[SIZEL]
+LPSIZEL: TypeAlias = _Pointer[SIZEL]
+PSMALL_RECT: TypeAlias = _Pointer[SMALL_RECT]
+PUINT: TypeAlias = _Pointer[UINT]
+LPUINT: TypeAlias = _Pointer[UINT]
+PULARGE_INTEGER: TypeAlias = _Pointer[ULARGE_INTEGER]
+PULONG: TypeAlias = _Pointer[ULONG]
+PUSHORT: TypeAlias = _Pointer[USHORT]
+PWCHAR: TypeAlias = _Pointer[WCHAR]
+PWIN32_FIND_DATAA: TypeAlias = _Pointer[WIN32_FIND_DATAA]
+LPWIN32_FIND_DATAA: TypeAlias = _Pointer[WIN32_FIND_DATAA]
+PWIN32_FIND_DATAW: TypeAlias = _Pointer[WIN32_FIND_DATAW]
+LPWIN32_FIND_DATAW: TypeAlias = _Pointer[WIN32_FIND_DATAW]
+PWORD: TypeAlias = _Pointer[WORD]
+LPWORD: TypeAlias = _Pointer[WORD]

tests/stubtest_allowlists/py3_common.txt

@@ -84,7 +84,6 @@ ctypes.Array._length_
 ctypes.CDLL._FuncPtr  # None at class level but initialized in __init__ to this value
 ctypes.memmove  # CFunctionType
 ctypes.memset  # CFunctionType
-ctypes.pointer  # imported C function
 ctypes.string_at  # docstring argument name is wrong
 ctypes.wstring_at  # docstring argument name is wrong
 distutils.command.bdist_packager  # It exists in docs as package name but not in code except as a mention in a comment.