gh-101101: Unstable C API tier (PEP 689) (GH-101102)

1 files changed, 92 insertions, 6 deletions

diff --git a/Doc/c-api/code.rst b/Doc/c-api/code.rst
index ae75d68..062ef3a 100644
--- a/Doc/c-api/code.rst
+++ b/Doc/c-api/code.rst
@@ -33,28 +33,47 @@ bound into a function.
 
    Return the number of free variables in *co*.
 
-.. c:function:: PyCodeObject* PyCode_New(int argcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *linetable, PyObject *exceptiontable)
+.. c:function:: PyCodeObject* PyUnstable_Code_New(int argcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *linetable, PyObject *exceptiontable)
 
    Return a new code object.  If you need a dummy code object to create a frame,
-   use :c:func:`PyCode_NewEmpty` instead.  Calling :c:func:`PyCode_New` directly
-   will bind you to a precise Python version since the definition of the bytecode
-   changes often. The many arguments of this function are inter-dependent in complex
+   use :c:func:`PyCode_NewEmpty` instead.
+
+   Since the definition of the bytecode changes often, calling
+   :c:func:`PyCode_New` directly can bind you to a precise Python version.
+
+   The many arguments of this function are inter-dependent in complex
    ways, meaning that subtle changes to values are likely to result in incorrect
    execution or VM crashes. Use this function only with extreme care.
 
    .. versionchanged:: 3.11
       Added ``exceptiontable`` parameter.
 
-.. c:function:: PyCodeObject* PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *linetable, PyObject *exceptiontable)
+   .. index:: single: PyCode_New
+
+   .. versionchanged:: 3.12
+
+      Renamed from ``PyCode_New`` as part of :ref:`unstable-c-api`.
+      The old name is deprecated, but will remain available until the
+      signature changes again.
+
+.. c:function:: PyCodeObject* PyUnstable_Code_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *linetable, PyObject *exceptiontable)
 
    Similar to :c:func:`PyCode_New`, but with an extra "posonlyargcount" for positional-only arguments.
    The same caveats that apply to ``PyCode_New`` also apply to this function.
 
-   .. versionadded:: 3.8
+   .. index:: single: PyCode_NewWithPosOnlyArgs
+
+   .. versionadded:: 3.8 as ``PyCode_NewWithPosOnlyArgs``
 
    .. versionchanged:: 3.11
       Added ``exceptiontable`` parameter.
 
+   .. versionchanged:: 3.12
+
+      Renamed to ``PyUnstable_Code_NewWithPosOnlyArgs``.
+      The old name is deprecated, but will remain available until the
+      signature changes again.
+
 .. c:function:: PyCodeObject* PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
 
    Return a new empty code object with the specified filename,
@@ -165,3 +184,70 @@ bound into a function.
    :c:func:`PyErr_WriteUnraisable`. Otherwise it should return ``0``.
 
    .. versionadded:: 3.12
+
+
+Extra information
+-----------------
+
+To support low-level extensions to frame evaluation, such as external
+just-in-time compilers, it is possible to attach arbitrary extra data to
+code objects.
+
+These functions are part of the unstable C API tier:
+this functionality is a CPython implementation detail, and the API
+may change without deprecation warnings.
+
+.. c:function:: Py_ssize_t PyUnstable_Eval_RequestCodeExtraIndex(freefunc free)
+
+   Return a new an opaque index value used to adding data to code objects.
+
+   You generally call this function once (per interpreter) and use the result
+   with ``PyCode_GetExtra`` and ``PyCode_SetExtra`` to manipulate
+   data on individual code objects.
+
+   If *free* is not ``NULL``: when a code object is deallocated,
+   *free* will be called on non-``NULL`` data stored under the new index.
+   Use :c:func:`Py_DecRef` when storing :c:type:`PyObject`.
+
+   .. index:: single: _PyEval_RequestCodeExtraIndex
+
+   .. versionadded:: 3.6 as ``_PyEval_RequestCodeExtraIndex``
+
+   .. versionchanged:: 3.12
+
+     Renamed to ``PyUnstable_Eval_RequestCodeExtraIndex``.
+     The old private name is deprecated, but will be available until the API
+     changes.
+
+.. c:function:: int PyUnstable_Code_GetExtra(PyObject *code, Py_ssize_t index, void **extra)
+
+   Set *extra* to the extra data stored under the given index.
+   Return 0 on success. Set an exception and return -1 on failure.
+
+   If no data was set under the index, set *extra* to ``NULL`` and return
+   0 without setting an exception.
+
+   .. index:: single: _PyCode_GetExtra
+
+   .. versionadded:: 3.6 as ``_PyCode_GetExtra``
+
+   .. versionchanged:: 3.12
+
+     Renamed to ``PyUnstable_Code_GetExtra``.
+     The old private name is deprecated, but will be available until the API
+     changes.
+
+.. c:function:: int PyUnstable_Code_SetExtra(PyObject *code, Py_ssize_t index, void *extra)
+
+   Set the extra data stored under the given index to *extra*.
+   Return 0 on success. Set an exception and return -1 on failure.
+
+   .. index:: single: _PyCode_SetExtra
+
+   .. versionadded:: 3.6 as ``_PyCode_SetExtra``
+
+   .. versionchanged:: 3.12
+
+     Renamed to ``PyUnstable_Code_SetExtra``.
+     The old private name is deprecated, but will be available until the API
+     changes.