8000 [3.12] gh-105227: Add PyType_GetDict() (GH-105747) (#106600) · python/cpython@41057b2 · GitHub
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[3.12] gh-105227: Add PyType_GetDict() (GH-105747) (#106600)
gh-105227: Add PyType_GetDict() (GH-105747) This compensates for static builtin types having `tp_dict` set to `NULL`. (cherry picked from commit a840806) Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com> Co-authored-by: Petr Viktorin <encukou@gmail.com>
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‎Doc/c-api/type.rst

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@@ -50,6 +50,23 @@ Type Objects
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The return type is now ``unsigned long`` rather than ``long``.
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.. c:function:: PyObject* PyType_GetDict(PyTypeObject* type)
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Return the type object's internal namespace, which is otherwise only
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exposed via a read-only proxy (``cls.__dict__``). This is a
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replacement for accessing :c:member:`~PyTypeObject.tp_dict` directly.
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The returned dictionary must be treated as read-only.
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This function is meant for specific embedding and language-binding cases,
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where direct access to the dict is necessary and indirect access
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(e.g. via the proxy or :c:func:`PyObject_GetAttr`) isn't adequate.
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Extension modules should continue to use ``tp_dict``,
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directly or indirectly, when setting up their own types.
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.. versionadded:: 3.12
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.. c:function:: void PyType_Modified(PyTypeObject *type)
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Invalidate the internal lookup cache for the type and all of its

‎Doc/c-api/typeobj.rst

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@@ -1717,7 +1717,19 @@ and :c:type:`PyType_Type` effectively act as defaults.)
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called; it may also be initialized to a dictionary containing initial attributes
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for the type. Once :c:func:`PyType_Ready` has initialized the type, extra
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attributes for the type may be added to this dictionary only if they don't
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correspond to overloaded operations (like :meth:`__add__`).
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correspond to overloaded operations (like :meth:`__add__`). Once
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initialization for the type has finished, this field should be
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treated as read-only.
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Some types may not store their dictionary in this slot.
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Use :c:func:`PyType_GetDict` to retreive the dictionary for an arbitrary
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type.
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.. versionchanged:: 3.12
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Internals detail: For static builtin types, this is always ``NULL``.
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Instead, the dict for such types is stored on ``PyInterpreterState``.
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Use :c:func:`PyType_GetDict` to get the dict for an arbitrary type.
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**Inheritance:**
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‎Include/cpython/object.h

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@@ -283,6 +283,7 @@ PyAPI_FUNC(PyTypeObject *) _PyType_CalculateMetaclass(PyTypeObject *, PyObject *
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PyAPI_FUNC(PyObject *) _PyType_GetDocFromInternalDoc(const char *, const char *);
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PyAPI_FUNC(PyObject *) _PyType_GetTextSignatureFromInternalDoc(const char *, const char *);
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PyAPI_FUNC(PyObject *) PyType_GetModuleByDef(PyTypeObject *, PyModuleDef *);
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PyAPI_FUNC(PyObject *) PyType_GetDict(PyTypeObject *);
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PyAPI_FUNC(int) PyObject_Print(PyObject *, FILE *, int);
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PyAPI_FUNC(void) _Py_BreakPoint(void);

‎Misc/NEWS.d/next/C API/2023-06-13-14-24-55.gh-issue-105227.HDL9aF.rst

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The new :c:func:`PyType_GetDict` provides the dictionary for the given type
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object that is normally exposed by ``cls.__dict__``. Normally it's
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sufficient to use :c:member:`~PyTypeObject.tp_dict`, but for the static
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builtin types :c:member:`!tp_dict` is now always ``NULL``. :c:func:`!PyType_GetDict()`
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provides the correct dict object instead.

‎Modules/_testcapimodule.c

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@@ -640,6 +640,30 @@ test_get_type_qualname(PyObject *self, PyObject *Py_UNUSED(ignored))
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Py_RETURN_NONE;
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}
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static PyObject *
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test_get_type_dict(PyObject *self, PyObject *Py_UNUSED(ignored))
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{
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/* Test for PyType_GetDict */
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// Assert ints have a `to_bytes` method
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PyObject *long_dict = PyType_GetDict(&PyLong_Type);
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assert(long_dict);
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assert(PyDict_GetItemString(long_dict, "to_bytes")); // borrowed ref
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Py_DECREF(long_dict);
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// Make a new type, add an attribute to it and assert it's there
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PyObject *HeapTypeNameType = PyType_FromSpec(&HeapTypeNameType_Spec);
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assert(HeapTypeNameType);
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assert(PyObject_SetAttrString(
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HeapTypeNameType, "new_attr", Py_NewRef(Py_None)) >= 0);
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PyObject *type_dict = PyType_GetDict((PyTypeObject*)HeapTypeNameType);
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assert(type_dict);
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assert(PyDict_GetItemString(type_dict, "new_attr")); // borrowed ref
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Py_DECREF(HeapTypeNameType);
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Py_DECREF(type_dict);
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Py_RETURN_NONE;
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}
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static PyObject *
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pyobject_repr_from_null(PyObject *self, PyObject *Py_UNUSED(ignored))
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{
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{"test_get_statictype_slots", test_get_statictype_slots, METH_NOARGS},
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{"test_get_type_name", test_get_type_name, METH_NOARGS},
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{"test_get_type_qualname", test_get_type_qualname, METH_NOARGS},
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{"test_get_type_dict", test_get_type_dict, METH_NOARGS},
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{"_test_thread_state", test_thread_state, METH_VARARGS},
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#ifndef MS_WINDOWS
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{"_spawn_pthread_waiter", spawn_pthread_waiter, METH_NOARGS},

‎Objects/typeobject.c

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return lookup_tp_dict(self);
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}
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PyObject *
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PyType_GetDict(PyTypeObject *self)
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{
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PyObject *dict = lookup_tp_dict(self);
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return _Py_XNewRef(dict);
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}
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static inline void
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set_tp_dict(PyTypeObject *self, PyObject *dict)
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{

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