[Python-checkins] bpo-43916: Add Py_TPFLAGS_DISALLOW_INSTANTIATION type flag (GH-25721)
vstinner
webhook-mailer at python.org
Fri Apr 30 06:46:19 EDT 2021
https://github.com/python/cpython/commit/3bb09947ec4837de75532e21dd4bd25db0a1f1b7
commit: 3bb09947ec4837de75532e21dd4bd25db0a1f1b7
branch: master
author: Victor Stinner <vstinner at python.org>
committer: vstinner <vstinner at python.org>
date: 2021年04月30日T12:46:15+02:00
summary:
bpo-43916: Add Py_TPFLAGS_DISALLOW_INSTANTIATION type flag (GH-25721)
Add a new Py_TPFLAGS_DISALLOW_INSTANTIATION type flag to disallow
creating type instances: set tp_new to NULL and don't create the
"__new__" key in the type dictionary.
The flag is set automatically on static types if tp_base is NULL or
&PyBaseObject_Type and tp_new is NULL.
Use the flag on the following types:
* _curses.ncurses_version type
* _curses_panel.panel
* _tkinter.Tcl_Obj
* _tkinter.tkapp
* _tkinter.tktimertoken
* _xxsubinterpretersmodule.ChannelID
* sys.flags type
* sys.getwindowsversion() type
* sys.version_info type
Update MyStr example in the C API documentation to use
Py_TPFLAGS_DISALLOW_INSTANTIATION.
Add _PyStructSequence_InitType() function to create a structseq type
with the Py_TPFLAGS_DISALLOW_INSTANTIATION flag set.
type_new() calls _PyType_CheckConsistency() at exit.
files:
A Misc/NEWS.d/next/C API/2021-04-29-17-35-48.bpo-43916.wvWt23.rst
M Doc/c-api/typeobj.rst
M Doc/whatsnew/3.10.rst
M Include/object.h
M Include/structseq.h
M Lib/test/test_sys.py
M Modules/_curses_panel.c
M Modules/_cursesmodule.c
M Modules/_tkinter.c
M Modules/_xxsubinterpretersmodule.c
M Objects/structseq.c
M Objects/typeobject.c
M Python/sysmodule.c
diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst
index 85f0262d10138..5e731bd5a6cbd 100644
--- a/Doc/c-api/typeobj.rst
+++ b/Doc/c-api/typeobj.rst
@@ -1199,6 +1199,25 @@ and :c:type:`PyType_Type` effectively act as defaults.)
.. versionadded:: 3.10
+ .. data:: Py_TPFLAGS_DISALLOW_INSTANTIATION
+
+ Disallow creating instances of the type: set
+ :c:member:`~PyTypeObject.tp_new` to NULL and don't create the ``__new__``
+ key in the type dictionary.
+
+ The flag must be set before creating the type, not after. For example, it
+ must be set before :c:func:`PyType_Ready` is called on the type.
+
+ The flag is set automatically on :ref:`static types <static-types>` if
+ :c:member:`~PyTypeObject.tp_base` is NULL or ``&PyBaseObject_Type`` and
+ :c:member:`~PyTypeObject.tp_new` is NULL.
+
+ **Inheritance:**
+
+ This flag is not inherited.
+
+ .. versionadded:: 3.10
+
.. c:member:: const char* PyTypeObject.tp_doc
@@ -1761,6 +1780,9 @@ and :c:type:`PyType_Type` effectively act as defaults.)
in :c:member:`~PyTypeObject.tp_new`, while for mutable types, most initialization should be
deferred to :c:member:`~PyTypeObject.tp_init`.
+ Set the :const:`Py_TPFLAGS_DISALLOW_INSTANTIATION` flag to disallow creating
+ instances of the type in Python.
+
**Inheritance:**
This field is inherited by subtypes, except it is not inherited by
@@ -2596,7 +2618,8 @@ A type that supports weakrefs, instance dicts, and hashing::
};
A str subclass that cannot be subclassed and cannot be called
-to create instances (e.g. uses a separate factory func)::
+to create instances (e.g. uses a separate factory func) using
+:c:data:`Py_TPFLAGS_DISALLOW_INSTANTIATION` flag::
typedef struct {
PyUnicodeObject raw;
@@ -2609,8 +2632,7 @@ to create instances (e.g. uses a separate factory func)::
.tp_basicsize = sizeof(MyStr),
.tp_base = NULL, // set to &PyUnicode_Type in module init
.tp_doc = "my custom str",
- .tp_flags = Py_TPFLAGS_DEFAULT,
- .tp_new = NULL,
+ .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
.tp_repr = (reprfunc)myobj_repr,
};
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst
index 2580a0368d0b3..1a390663c8a40 100644
--- a/Doc/whatsnew/3.10.rst
+++ b/Doc/whatsnew/3.10.rst
@@ -1708,6 +1708,10 @@ New Features
These functions allow to activate, deactivate and query the state of the garbage collector from C code without
having to import the :mod:`gc` module.
+* Add a new :c:data:`Py_TPFLAGS_DISALLOW_INSTANTIATION` type flag to disallow
+ creating type instances.
+ (Contributed by Victor Stinner in :issue:`43916`.)
+
Porting to Python 3.10
----------------------
diff --git a/Include/object.h b/Include/object.h
index cffe72cda869f..4c069998574b4 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -327,6 +327,10 @@ given type object has a specified feature.
#define Py_TPFLAGS_MAPPING (1 << 6)
#endif
+/* Disallow creating instances of the type: set tp_new to NULL and don't create
+ * the "__new__" key in the type dictionary. */
+#define Py_TPFLAGS_DISALLOW_INSTANTIATION (1UL << 7)
+
/* Set if the type object is immutable: type attributes cannot be set nor deleted */
#define Py_TPFLAGS_IMMUTABLETYPE (1UL << 8)
diff --git a/Include/structseq.h b/Include/structseq.h
index 8f51c89163a4e..af3af415b013a 100644
--- a/Include/structseq.h
+++ b/Include/structseq.h
@@ -27,6 +27,12 @@ PyAPI_FUNC(void) PyStructSequence_InitType(PyTypeObject *type,
PyAPI_FUNC(int) PyStructSequence_InitType2(PyTypeObject *type,
PyStructSequence_Desc *desc);
#endif
+#ifdef Py_BUILD_CORE
+extern int _PyStructSequence_InitType(
+ PyTypeObject *type,
+ PyStructSequence_Desc *desc,
+ unsigned long tp_flags);
+#endif
PyAPI_FUNC(PyTypeObject*) PyStructSequence_NewType(PyStructSequence_Desc *desc);
PyAPI_FUNC(PyObject *) PyStructSequence_New(PyTypeObject* type);
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index ee39375af3160..1fd5247a91bb5 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -605,11 +605,12 @@ def test_sys_flags(self):
def assert_raise_on_new_sys_type(self, sys_attr):
# Users are intentionally prevented from creating new instances of
# sys.flags, sys.version_info, and sys.getwindowsversion.
+ arg = sys_attr
attr_type = type(sys_attr)
with self.assertRaises(TypeError):
- attr_type()
+ attr_type(arg)
with self.assertRaises(TypeError):
- attr_type.__new__(attr_type)
+ attr_type.__new__(attr_type, arg)
def test_sys_flags_no_instantiation(self):
self.assert_raise_on_new_sys_type(sys.flags)
diff --git a/Misc/NEWS.d/next/C API/2021-04-29-17-35-48.bpo-43916.wvWt23.rst b/Misc/NEWS.d/next/C API/2021-04-29-17-35-48.bpo-43916.wvWt23.rst
new file mode 100644
index 0000000000000..0cec8103645e3
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2021-04-29-17-35-48.bpo-43916.wvWt23.rst
@@ -0,0 +1,2 @@
+Add a new :c:data:`Py_TPFLAGS_DISALLOW_INSTANTIATION` type flag to disallow
+creating type instances. Patch by Victor Stinner.
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
index 94caf8c93bc8c..0b328f9665a0a 100644
--- a/Modules/_curses_panel.c
+++ b/Modules/_curses_panel.c
@@ -520,7 +520,7 @@ static PyType_Slot PyCursesPanel_Type_slots[] = {
static PyType_Spec PyCursesPanel_Type_spec = {
.name = "_curses_panel.panel",
.basicsize = sizeof(PyCursesPanelObject),
- .flags = Py_TPFLAGS_DEFAULT,
+ .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
.slots = PyCursesPanel_Type_slots
};
@@ -656,7 +656,6 @@ _curses_panel_exec(PyObject *mod)
if (state->PyCursesPanel_Type == NULL) {
return -1;
}
- ((PyTypeObject *)state->PyCursesPanel_Type)->tp_new = NULL;
if (PyModule_AddType(mod, state->PyCursesPanel_Type) < 0) {
return -1;
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index d221cf1a92520..bcf9ad19386b2 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -4793,9 +4793,11 @@ PyInit__curses(void)
#ifdef NCURSES_VERSION
/* ncurses_version */
if (NcursesVersionType.tp_name == NULL) {
- if (PyStructSequence_InitType2(&NcursesVersionType,
- &ncurses_version_desc) < 0)
+ if (_PyStructSequence_InitType(&NcursesVersionType,
+ &ncurses_version_desc,
+ Py_TPFLAGS_DISALLOW_INSTANTIATION) < 0) {
return NULL;
+ }
}
v = make_ncurses_version();
if (v == NULL) {
@@ -4803,15 +4805,6 @@ PyInit__curses(void)
}
PyDict_SetItemString(d, "ncurses_version", v);
Py_DECREF(v);
-
- /* prevent user from creating new instances */
- NcursesVersionType.tp_init = NULL;
- NcursesVersionType.tp_new = NULL;
- if (PyDict_DelItemString(NcursesVersionType.tp_dict, "__new__") < 0 &&
- PyErr_ExceptionMatches(PyExc_KeyError))
- {
- PyErr_Clear();
- }
#endif /* NCURSES_VERSION */
SetDictInt("ERR", ERR);
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 46d6a6e0954f5..3a0e5def0cf3c 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -1002,7 +1002,7 @@ static PyType_Spec PyTclObject_Type_spec = {
"_tkinter.Tcl_Obj",
sizeof(PyTclObject),
0,
- Py_TPFLAGS_DEFAULT,
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
PyTclObject_Type_slots,
};
@@ -3294,7 +3294,7 @@ static PyType_Spec Tktt_Type_spec = {
"_tkinter.tktimertoken",
sizeof(TkttObject),
0,
- Py_TPFLAGS_DEFAULT,
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
Tktt_Type_slots,
};
@@ -3349,7 +3349,7 @@ static PyType_Spec Tkapp_Type_spec = {
"_tkinter.tkapp",
sizeof(TkappObject),
0,
- Py_TPFLAGS_DEFAULT,
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
Tkapp_Type_slots,
};
@@ -3537,7 +3537,6 @@ PyInit__tkinter(void)
Py_DECREF(m);
return NULL;
}
- ((PyTypeObject *)o)->tp_new = NULL;
if (PyModule_AddObject(m, "TkappType", o)) {
Py_DECREF(o);
Py_DECREF(m);
@@ -3550,7 +3549,6 @@ PyInit__tkinter(void)
Py_DECREF(m);
return NULL;
}
- ((PyTypeObject *)o)->tp_new = NULL;
if (PyModule_AddObject(m, "TkttType", o)) {
Py_DECREF(o);
Py_DECREF(m);
@@ -3563,7 +3561,6 @@ PyInit__tkinter(void)
Py_DECREF(m);
return NULL;
}
- ((PyTypeObject *)o)->tp_new = NULL;
if (PyModule_AddObject(m, "Tcl_Obj", o)) {
Py_DECREF(o);
Py_DECREF(m);
diff --git a/Modules/_xxsubinterpretersmodule.c b/Modules/_xxsubinterpretersmodule.c
index b94b130d70df7..9290255c66c3f 100644
--- a/Modules/_xxsubinterpretersmodule.c
+++ b/Modules/_xxsubinterpretersmodule.c
@@ -1780,7 +1780,12 @@ static PyTypeObject ChannelIDtype = {
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
+ // Use Py_TPFLAGS_DISALLOW_INSTANTIATION so the type cannot be instantiated
+ // from Python code. We do this because there is a strong relationship
+ // between channel IDs and the channel lifecycle, so this limitation avoids
+ // related complications. Use the _channel_id() function instead.
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE
+ | Py_TPFLAGS_DISALLOW_INSTANTIATION, /* tp_flags */
channelid_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
@@ -1791,19 +1796,6 @@ static PyTypeObject ChannelIDtype = {
0, /* tp_methods */
0, /* tp_members */
channelid_getsets, /* tp_getset */
- 0, /* tp_base */
- 0, /* tp_dict */
- 0, /* tp_descr_get */
- 0, /* tp_descr_set */
- 0, /* tp_dictoffset */
- 0, /* tp_init */
- 0, /* tp_alloc */
- // Note that we do not set tp_new to channelid_new. Instead we
- // set it to NULL, meaning it cannot be instantiated from Python
- // code. We do this because there is a strong relationship between
- // channel IDs and the channel lifecycle, so this limitation avoids
- // related complications.
- NULL, /* tp_new */
};
diff --git a/Objects/structseq.c b/Objects/structseq.c
index 88e63b658a420..bf59f47fcf073 100644
--- a/Objects/structseq.c
+++ b/Objects/structseq.c
@@ -459,8 +459,10 @@ initialize_members(PyStructSequence_Desc *desc, PyMemberDef* members,
members[k].name = NULL;
}
+
int
-PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
+_PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc,
+ unsigned long tp_flags)
{
PyMemberDef *members;
Py_ssize_t n_members, n_unnamed_members;
@@ -488,7 +490,7 @@ PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
type->tp_base = &PyTuple_Type;
type->tp_methods = structseq_methods;
type->tp_new = structseq_new;
- type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC;
+ type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | tp_flags;
type->tp_traverse = (traverseproc) structseq_traverse;
n_members = count_members(desc, &n_unnamed_members);
@@ -516,6 +518,12 @@ PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
return 0;
}
+int
+PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
+{
+ return _PyStructSequence_InitType(type, desc, 0);
+}
+
void
PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
{
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 1f8e2572a2daf..0f7f280bca0d6 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -158,6 +158,11 @@ _PyType_CheckConsistency(PyTypeObject *type)
CHECK(!(type->tp_flags & Py_TPFLAGS_READYING));
CHECK(type->tp_dict != NULL);
+ if (type->tp_flags & Py_TPFLAGS_DISALLOW_INSTANTIATION) {
+ CHECK(type->tp_new == NULL);
+ CHECK(_PyDict_ContainsId(type->tp_dict, &PyId___new__) == 0);
+ }
+
return 1;
#undef CHECK
}
@@ -1111,8 +1116,7 @@ type_call(PyTypeObject *type, PyObject *args, PyObject *kwds)
if (type->tp_new == NULL) {
_PyErr_Format(tstate, PyExc_TypeError,
- "cannot create '%.100s' instances",
- type->tp_name);
+ "cannot create '%s' instances", type->tp_name);
return NULL;
}
@@ -3185,6 +3189,8 @@ type_new_impl(type_new_ctx *ctx)
if (type_new_init_subclass(type, ctx->kwds) < 0) {
goto error;
}
+
+ assert(_PyType_CheckConsistency(type));
return (PyObject *)type;
error:
@@ -5651,7 +5657,6 @@ type_add_getset(PyTypeObject *type)
static void
inherit_special(PyTypeObject *type, PyTypeObject *base)
{
-
/* Copying tp_traverse and tp_clear is connected to the GC flags */
if (!(type->tp_flags & Py_TPFLAGS_HAVE_GC) &&
(base->tp_flags & Py_TPFLAGS_HAVE_GC) &&
@@ -5662,23 +5667,7 @@ inherit_special(PyTypeObject *type, PyTypeObject *base)
if (type->tp_clear == NULL)
type->tp_clear = base->tp_clear;
}
- {
- /* The condition below could use some explanation.
- It appears that tp_new is not inherited for static types
- whose base class is 'object'; this seems to be a precaution
- so that old extension types don't suddenly become
- callable (object.__new__ wouldn't insure the invariants
- that the extension type's own factory function ensures).
- Heap types, of course, are under our control, so they do
- inherit tp_new; static extension types that specify some
- other built-in type as the default also
- inherit object.__new__. */
- if (base != &PyBaseObject_Type ||
- (type->tp_flags & Py_TPFLAGS_HEAPTYPE)) {
- if (type->tp_new == NULL)
- type->tp_new = base->tp_new;
- }
- }
+
if (type->tp_basicsize == 0)
type->tp_basicsize = base->tp_basicsize;
@@ -5941,6 +5930,7 @@ inherit_slots(PyTypeObject *type, PyTypeObject *base)
}
static int add_operators(PyTypeObject *);
+static int add_tp_new_wrapper(PyTypeObject *type);
static int
@@ -5991,6 +5981,7 @@ type_ready_set_bases(PyTypeObject *type)
type->tp_base = base;
}
}
+ assert(type->tp_base != NULL || type == &PyBaseObject_Type);
/* Now the only way base can still be NULL is if type is
* &PyBaseObject_Type. */
@@ -6249,6 +6240,50 @@ type_ready_add_subclasses(PyTypeObject *type)
}
+// Set tp_new and the "__new__" key in the type dictionary.
+// Use the Py_TPFLAGS_DISALLOW_INSTANTIATION flag.
+static int
+type_ready_set_new(PyTypeObject *type)
+{
+ PyTypeObject *base = type->tp_base;
+ /* The condition below could use some explanation.
+
+ It appears that tp_new is not inherited for static types whose base
+ class is 'object'; this seems to be a precaution so that old extension
+ types don't suddenly become callable (object.__new__ wouldn't insure the
+ invariants that the extension type's own factory function ensures).
+
+ Heap types, of course, are under our control, so they do inherit tp_new;
+ static extension types that specify some other built-in type as the
+ default also inherit object.__new__. */
+ if (type->tp_new == NULL
+ && base == &PyBaseObject_Type
+ && !(type->tp_flags & Py_TPFLAGS_HEAPTYPE))
+ {
+ type->tp_flags |= Py_TPFLAGS_DISALLOW_INSTANTIATION;
+ }
+
+ if (!(type->tp_flags & Py_TPFLAGS_DISALLOW_INSTANTIATION)) {
+ if (type->tp_new != NULL) {
+ // If "__new__" key does not exists in the type dictionary,
+ // set it to tp_new_wrapper().
+ if (add_tp_new_wrapper(type) < 0) {
+ return -1;
+ }
+ }
+ else {
+ // tp_new is NULL: inherit tp_new from base
+ type->tp_new = base->tp_new;
+ }
+ }
+ else {
+ // Py_TPFLAGS_DISALLOW_INSTANTIATION sets tp_new to NULL
+ type->tp_new = NULL;
+ }
+ return 0;
+}
+
+
static int
type_ready(PyTypeObject *type)
{
@@ -6275,6 +6310,9 @@ type_ready(PyTypeObject *type)
if (type_ready_mro(type) < 0) {
return -1;
}
+ if (type_ready_set_new(type) < 0) {
+ return -1;
+ }
if (type_ready_fill_dict(type) < 0) {
return -1;
}
@@ -6898,8 +6936,8 @@ tp_new_wrapper(PyObject *self, PyObject *args, PyObject *kwds)
"__new__() called with non-type 'self'");
return NULL;
}
-
type = (PyTypeObject *)self;
+
if (!PyTuple_Check(args) || PyTuple_GET_SIZE(args) < 1) {
PyErr_Format(PyExc_TypeError,
"%s.__new__(): not enough arguments",
@@ -6961,16 +6999,18 @@ static struct PyMethodDef tp_new_methoddef[] = {
static int
add_tp_new_wrapper(PyTypeObject *type)
{
- PyObject *func;
-
int r = _PyDict_ContainsId(type->tp_dict, &PyId___new__);
- if (r > 0)
+ if (r > 0) {
return 0;
- if (r < 0)
+ }
+ if (r < 0) {
return -1;
- func = PyCFunction_NewEx(tp_new_methoddef, (PyObject *)type, NULL);
- if (func == NULL)
+ }
+
+ PyObject *func = PyCFunction_NewEx(tp_new_methoddef, (PyObject *)type, NULL);
+ if (func == NULL) {
return -1;
+ }
r = _PyDict_SetItemId(type->tp_dict, &PyId___new__, func);
Py_DECREF(func);
return r;
@@ -8558,11 +8598,6 @@ add_operators(PyTypeObject *type)
Py_DECREF(descr);
}
}
- if (type->tp_new != NULL) {
- if (add_tp_new_wrapper(type) < 0) {
- return -1;
- }
- }
return 0;
}
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 911c2d967b010..36297ff82e1c3 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2810,56 +2810,35 @@ _PySys_InitCore(PyThreadState *tstate, PyObject *sysdict)
/* version_info */
if (VersionInfoType.tp_name == NULL) {
- if (PyStructSequence_InitType2(&VersionInfoType,
- &version_info_desc) < 0) {
+ if (_PyStructSequence_InitType(&VersionInfoType,
+ &version_info_desc,
+ Py_TPFLAGS_DISALLOW_INSTANTIATION) < 0) {
goto type_init_failed;
}
}
version_info = make_version_info(tstate);
SET_SYS("version_info", version_info);
- /* prevent user from creating new instances */
- VersionInfoType.tp_init = NULL;
- VersionInfoType.tp_new = NULL;
- res = PyDict_DelItemString(VersionInfoType.tp_dict, "__new__");
- if (res < 0 && _PyErr_ExceptionMatches(tstate, PyExc_KeyError)) {
- _PyErr_Clear(tstate);
- }
/* implementation */
SET_SYS("implementation", make_impl_info(version_info));
// sys.flags: updated in-place later by _PySys_UpdateConfig()
if (FlagsType.tp_name == 0) {
- if (PyStructSequence_InitType2(&FlagsType, &flags_desc) < 0) {
+ if (_PyStructSequence_InitType(&FlagsType, &flags_desc,
+ Py_TPFLAGS_DISALLOW_INSTANTIATION) < 0) {
goto type_init_failed;
}
}
SET_SYS("flags", make_flags(tstate->interp));
- /* prevent user from creating new instances */
- FlagsType.tp_init = NULL;
- FlagsType.tp_new = NULL;
- res = PyDict_DelItemString(FlagsType.tp_dict, "__new__");
- if (res < 0) {
- if (!_PyErr_ExceptionMatches(tstate, PyExc_KeyError)) {
- goto err_occurred;
- }
- _PyErr_Clear(tstate);
- }
#if defined(MS_WINDOWS)
/* getwindowsversion */
- if (WindowsVersionType.tp_name == 0)
- if (PyStructSequence_InitType2(&WindowsVersionType,
- &windows_version_desc) < 0) {
+ if (WindowsVersionType.tp_name == 0) {
+ if (_PyStructSequence_InitType(&WindowsVersionType,
+ &windows_version_desc,
+ Py_TPFLAGS_DISALLOW_INSTANTIATION) < 0) {
goto type_init_failed;
}
- /* prevent user from creating new instances */
- WindowsVersionType.tp_init = NULL;
- WindowsVersionType.tp_new = NULL;
- assert(!_PyErr_Occurred(tstate));
- res = PyDict_DelItemString(WindowsVersionType.tp_dict, "__new__");
- if (res < 0 && _PyErr_ExceptionMatches(tstate, PyExc_KeyError)) {
- _PyErr_Clear(tstate);
}
#endif
More information about the Python-checkins
mailing list