From ed0a5fd8cacb1964111d03ff37627f6bea5e6026 Mon Sep 17 00:00:00 2001 From: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com> Date: Mon, 10 Nov 2025 17:46:41 +0000 Subject: [PATCH 1/2] gh-141004: Document `PyType_FastSubclass` (GH-141313) Co-authored-by: Peter Bierma --- Doc/c-api/type.rst | 12 ++++++++++++ Doc/c-api/typeobj.rst | 4 ++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/Doc/c-api/type.rst b/Doc/c-api/type.rst index 5bdbff4e0ad990..479ede70b01f5d 100644 --- a/Doc/c-api/type.rst +++ b/Doc/c-api/type.rst @@ -133,6 +133,18 @@ Type Objects Type features are denoted by single bit flags. +.. c:function:: int PyType_FastSubclass(PyTypeObject *type, int flag) + + Return non-zero if the type object *type* sets the subclass flag *flag*. + Subclass flags are denoted by + :c:macro:`Py_TPFLAGS_*_SUBCLASS `. + This function is used by many ``_Check`` functions for common types. + + .. seealso:: + :c:func:`PyObject_TypeCheck`, which is used as a slower alternative in + ``_Check`` functions for types that don't come with subclass flags. + + .. c:function:: int PyType_IS_GC(PyTypeObject *o) Return true if the type object includes support for the cycle detector; this diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst index 9d23aea5734ea3..34d19acdf17868 100644 --- a/Doc/c-api/typeobj.rst +++ b/Doc/c-api/typeobj.rst @@ -1351,8 +1351,8 @@ and :c:data:`PyType_Type` effectively act as defaults.) .. c:macro:: Py_TPFLAGS_BASE_EXC_SUBCLASS .. c:macro:: Py_TPFLAGS_TYPE_SUBCLASS - These flags are used by functions such as - :c:func:`PyLong_Check` to quickly determine if a type is a subclass + Functions such as :c:func:`PyLong_Check` will call :c:func:`PyType_FastSubclass` + with one of these flags to quickly determine if a type is a subclass of a built-in type; such specific checks are faster than a generic check, like :c:func:`PyObject_IsInstance`. Custom types that inherit from built-ins should have their :c:member:`~PyTypeObject.tp_flags` From 86513f6c2ebdd1fb692c39b84786ea41d88c84fd Mon Sep 17 00:00:00 2001 From: Peter Bierma Date: Mon, 10 Nov 2025 16:35:47 -0500 Subject: [PATCH 2/2] gh-141004: Document missing frame APIs (GH-141189) Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com> --- Doc/c-api/frame.rst | 57 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/Doc/c-api/frame.rst b/Doc/c-api/frame.rst index 1a52e146a69751..fb17cf7f1da6b2 100644 --- a/Doc/c-api/frame.rst +++ b/Doc/c-api/frame.rst @@ -29,6 +29,12 @@ See also :ref:`Reflection `. Previously, this type was only available after including ````. +.. c:function:: PyFrameObject *PyFrame_New(PyThreadState *tstate, PyCodeObject *code, PyObject *globals, PyObject *locals) + + Create a new frame object. This function returns a :term:`strong reference` + to the new frame object on success, and returns ``NULL`` with an exception + set on failure. + .. c:function:: int PyFrame_Check(PyObject *obj) Return non-zero if *obj* is a frame object. @@ -161,6 +167,57 @@ See :pep:`667` for more information. Return non-zero if *obj* is a frame :func:`locals` proxy. + +Legacy Local Variable APIs +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +These APIs are :term:`soft deprecated`. As of Python 3.13, they do nothing. +They exist solely for backwards compatibility. + + +.. c:function:: void PyFrame_LocalsToFast(PyFrameObject *f, int clear) + + This function is :term:`soft deprecated` and does nothing. + + Prior to Python 3.13, this function would copy the :attr:`~frame.f_locals` + attribute of *f* to the internal "fast" array of local variables, allowing + changes in frame objects to be visible to the interpreter. If *clear* was + true, this function would process variables that were unset in the locals + dictionary. + + .. versionchanged:: 3.13 + This function now does nothing. + + +.. c:function:: void PyFrame_FastToLocals(PyFrameObject *f) + + This function is :term:`soft deprecated` and does nothing. + + Prior to Python 3.13, this function would copy the internal "fast" array + of local variables (which is used by the interpreter) to the + :attr:`~frame.f_locals` attribute of *f*, allowing changes in local + variables to be visible to frame objects. + + .. versionchanged:: 3.13 + This function now does nothing. + + +.. c:function:: int PyFrame_FastToLocalsWithError(PyFrameObject *f) + + This function is :term:`soft deprecated` and does nothing. + + Prior to Python 3.13, this function was similar to + :c:func:`PyFrame_FastToLocals`, but would return ``0`` on success, and + ``-1`` with an exception set on failure. + + .. versionchanged:: 3.13 + This function now does nothing. + + +.. seealso:: + :pep:`667` + + Internal Frames ^^^^^^^^^^^^^^^