Revert Python-space ctypes tests

This reverts commit 9d454de.
This reverts commit 1fea8e5.

Author: jakelishman

Lib/test/support/__init__.py

@@ -69,7 +69,7 @@
     "BrokenIter",
     "in_systemd_nspawn_sync_suppressed",
     "run_no_yield_async_fn", "run_yielding_async_fn", "async_yield",
-    "reset_code", "on_github_actions", "ctypes_py_buffer",
+    "reset_code", "on_github_actions"
     ]
 
 
@@ -3272,47 +3272,3 @@ def linked_to_musl():
         return _linked_to_musl
     _linked_to_musl = tuple(map(int, version.split('.')))
     return _linked_to_musl
-
-
-try:
-    import ctypes
-
-    class _py_buffer(ctypes.Structure):
-        _fields_ = [
-            ("buf", ctypes.c_void_p),
-            ("obj", ctypes.py_object),
-            ("len", ctypes.c_ssize_t),
-            ("itemsize", ctypes.c_ssize_t),
-            ("readonly", ctypes.c_int),
-            ("ndim", ctypes.c_int),
-            ("format", ctypes.c_char_p),
-            ("shape", ctypes.POINTER(ctypes.c_ssize_t)),
-            ("strides", ctypes.POINTER(ctypes.c_ssize_t)),
-            ("suboffsets", ctypes.POINTER(ctypes.c_ssize_t)),
-            ("internal", ctypes.c_void_p),
-        ]
-except ImportError:
-    _py_buffer = None
-
-
-@contextlib.contextmanager
-def ctypes_py_buffer(ob, flags=inspect.BufferFlags.SIMPLE):
-    """
-    Safely acquire a `Py_buffer` as a ctypes struct.
-
-    `ob` must implement the buffer protocol, and the retrieved buffer is
-    released on exit of the context manager.
-
-    Skips any test using it if `ctypes` is unavailable.
-    """
-    from .import_helper import import_module
-
-    ctypes = import_module("ctypes")
-    buf = _py_buffer()
-    ctypes.pythonapi.PyObject_GetBuffer(ctypes.py_object(ob),
-                                        ctypes.byref(buf),
-                                        ctypes.c_int(flags))
-    try:
-        yield buf
-    finally:
-        ctypes.pythonapi.PyBuffer_Release(ctypes.byref(buf))

Lib/test/test_array.py

@@ -8,7 +8,6 @@
 from test.support import import_helper
 from test.support import os_helper
 from test.support import _2G
-from test.support import ctypes_py_buffer
 import weakref
 import pickle
 import operator
@@ -68,21 +67,6 @@ def test_empty(self):
         a += a
         self.assertEqual(len(a), 0)
 
-    def test_empty_alignment(self):
-        # gh-140557: pointer alignment of empty allocation
-        ctypes = import_helper.import_module("ctypes")
-        self.enterContext(warnings.catch_warnings())
-        warnings.filterwarnings(
-            "ignore",
-            message="The 'u' type code is deprecated and "
-                    "will be removed in Python 3.16",
-            category=DeprecationWarning)
-        max_align = ctypes.alignment(ctypes.c_longdouble)
-        for typecode in typecodes:
-            a = array.array(typecode)
-            with ctypes_py_buffer(a) as buf:
-                self.assertEqual(buf.buf % max_align, 0)
-
 
 # Machine format codes.
 #

Lib/test/test_builtin.py

@@ -38,7 +38,6 @@
 from test.support.testcase import ComplexesAreIdenticalMixin
 from test.support.warnings_helper import check_warnings
 from test.support import requires_IEEE_754
-from test.support import ctypes_py_buffer
 from unittest.mock import MagicMock, patch
 try:
     import pty, signal
@@ -2428,14 +2427,6 @@ def iterator():
             yield b'B'
         self.assertEqual(bytearray(b'A,B'), array.join(iterator()))
 
-    def test_bytearray_empty_alignment(self):
-        # gh-140557: alignment of pointer in empty allocation
-        ctypes = import_module("ctypes")
-        max_align = ctypes.alignment(ctypes.c_longdouble)
-        array = bytearray()
-        with ctypes_py_buffer(array) as buf:
-            self.assertEqual(buf.buf % max_align, 0)
-
     def test_construct_singletons(self):
         for const in None, Ellipsis, NotImplemented:
             tp = type(const)