gh-117987: Restore several functions removed in Python 3.13 alpha 1 (GH-117993)

Restore these functions removed in Python 3.13 alpha 1:

* Py_SetPythonHome()
* Py_SetProgramName()
* PySys_SetArgvEx()
* PySys_SetArgv()

Author: vstinner

Doc/c-api/init.rst

@@ -29,6 +29,8 @@ The following functions can be safely called before Python is initialized:
   * :c:func:`PyMem_SetAllocator`
   * :c:func:`PyMem_SetupDebugHooks`
   * :c:func:`PyObject_SetArenaAllocator`
+  * :c:func:`Py_SetProgramName`
+  * :c:func:`Py_SetPythonHome`
   * :c:func:`PySys_ResetWarnOptions`
 
 * Informative functions:
@@ -426,6 +428,34 @@ Process-wide parameters
 =======================
 
 
+.. c:function:: void Py_SetProgramName(const wchar_t *name)
+
+   .. index::
+      single: Py_Initialize()
+      single: main()
+      single: Py_GetPath()
+
+   This API is kept for backward compatibility: setting
+   :c:member:`PyConfig.program_name` should be used instead, see :ref:`Python
+   Initialization Configuration <init-config>`.
+
+   This function should be called before :c:func:`Py_Initialize` is called for
+   the first time, if it is called at all.  It tells the interpreter the value
+   of the ``argv[0]`` argument to the :c:func:`main` function of the program
+   (converted to wide characters).
+   This is used by :c:func:`Py_GetPath` and some other functions below to find
+   the Python run-time libraries relative to the interpreter executable.  The
+   default value is ``'python'``.  The argument should point to a
+   zero-terminated wide character string in static storage whose contents will not
+   change for the duration of the program's execution.  No code in the Python
+   interpreter will change the contents of this storage.
+
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:expr:`wchar_*` string.
+
+   .. deprecated:: 3.11
+
+
 .. c:function:: wchar_t* Py_GetProgramName()
 
    Return the program name set with :c:member:`PyConfig.program_name`, or the default.
@@ -627,6 +657,106 @@ Process-wide parameters
    ``sys.version``.
 
 
+.. c:function:: void PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath)
+
+   .. index::
+      single: main()
+      single: Py_FatalError()
+      single: argv (in module sys)
+
+   This API is kept for backward compatibility: setting
+   :c:member:`PyConfig.argv`, :c:member:`PyConfig.parse_argv` and
+   :c:member:`PyConfig.safe_path` should be used instead, see :ref:`Python
+   Initialization Configuration <init-config>`.
+
+   Set :data:`sys.argv` based on *argc* and *argv*.  These parameters are
+   similar to those passed to the program's :c:func:`main` function with the
+   difference that the first entry should refer to the script file to be
+   executed rather than the executable hosting the Python interpreter.  If there
+   isn't a script that will be run, the first entry in *argv* can be an empty
+   string.  If this function fails to initialize :data:`sys.argv`, a fatal
+   condition is signalled using :c:func:`Py_FatalError`.
+
+   If *updatepath* is zero, this is all the function does.  If *updatepath*
+   is non-zero, the function also modifies :data:`sys.path` according to the
+   following algorithm:
+
+   - If the name of an existing script is passed in ``argv[0]``, the absolute
+     path of the directory where the script is located is prepended to
+     :data:`sys.path`.
+   - Otherwise (that is, if *argc* is ``0`` or ``argv[0]`` doesn't point
+     to an existing file name), an empty string is prepended to
+     :data:`sys.path`, which is the same as prepending the current working
+     directory (``"."``).
+
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:expr:`wchar_*` string.
+
+   See also :c:member:`PyConfig.orig_argv` and :c:member:`PyConfig.argv`
+   members of the :ref:`Python Initialization Configuration <init-config>`.
+
+   .. note::
+      It is recommended that applications embedding the Python interpreter
+      for purposes other than executing a single script pass ``0`` as *updatepath*,
+      and update :data:`sys.path` themselves if desired.
+      See `CVE-2008-5983 <https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983>`_.
+
+      On versions before 3.1.3, you can achieve the same effect by manually
+      popping the first :data:`sys.path` element after having called
+      :c:func:`PySys_SetArgv`, for example using::
+
+         PyRun_SimpleString("import sys; sys.path.pop(0)\n");
+
+   .. versionadded:: 3.1.3
+
+   .. XXX impl. doesn't seem consistent in allowing ``0``/``NULL`` for the params;
+      check w/ Guido.
+
+   .. deprecated:: 3.11
+
+
+.. c:function:: void PySys_SetArgv(int argc, wchar_t **argv)
+
+   This API is kept for backward compatibility: setting
+   :c:member:`PyConfig.argv` and :c:member:`PyConfig.parse_argv` should be used
+   instead, see :ref:`Python Initialization Configuration <init-config>`.
+
+   This function works like :c:func:`PySys_SetArgvEx` with *updatepath* set
+   to ``1`` unless the :program:`python` interpreter was started with the
+   :option:`-I`.
+
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:expr:`wchar_*` string.
+
+   See also :c:member:`PyConfig.orig_argv` and :c:member:`PyConfig.argv`
+   members of the :ref:`Python Initialization Configuration <init-config>`.
+
+   .. versionchanged:: 3.4 The *updatepath* value depends on :option:`-I`.
+
+   .. deprecated:: 3.11
+
+
+.. c:function:: void Py_SetPythonHome(const wchar_t *home)
+
+   This API is kept for backward compatibility: setting
+   :c:member:`PyConfig.home` should be used instead, see :ref:`Python
+   Initialization Configuration <init-config>`.
+
+   Set the default "home" directory, that is, the location of the standard
+   Python libraries.  See :envvar:`PYTHONHOME` for the meaning of the
+   argument string.
+
+   The argument should point to a zero-terminated character string in static
+   storage whose contents will not change for the duration of the program's
+   execution.  No code in the Python interpreter will change the contents of
+   this storage.
+
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:expr:`wchar_*` string.
+
+   .. deprecated:: 3.11
+
+
 .. c:function:: wchar_t* Py_GetPythonHome()
 
    Return the default "home", that is, the value set by

Doc/data/stable_abi.dat

@@ -2011,12 +2011,8 @@ Removed
   * ``PySys_AddWarnOption()``: use :c:member:`PyConfig.warnoptions` instead.
   * ``PySys_AddXOption()``: use :c:member:`PyConfig.xoptions` instead.
   * ``PySys_HasWarnOptions()``: use :c:member:`PyConfig.xoptions` instead.
-  * ``PySys_SetArgvEx()``: set :c:member:`PyConfig.argv` instead.
-  * ``PySys_SetArgv()``: set :c:member:`PyConfig.argv` instead.
   * ``PySys_SetPath()``: set :c:member:`PyConfig.module_search_paths` instead.
   * ``Py_SetPath()``: set :c:member:`PyConfig.module_search_paths` instead.
-  * ``Py_SetProgramName()``: set :c:member:`PyConfig.program_name` instead.
-  * ``Py_SetPythonHome()``: set :c:member:`PyConfig.home` instead.
   * ``Py_SetStandardStreamEncoding()``: set :c:member:`PyConfig.stdio_encoding`
     instead, and set also maybe :c:member:`PyConfig.legacy_windows_stdio` (on
     Windows).
@@ -2073,6 +2069,16 @@ Pending Removal in Python 3.14
 
 * Creating immutable types (:c:macro:`Py_TPFLAGS_IMMUTABLETYPE`) with mutable
   bases using the C API.
+* Functions to configure the Python initialization, deprecated in Python 3.11:
+
+  * ``PySys_SetArgvEx()``: set :c:member:`PyConfig.argv` instead.
+  * ``PySys_SetArgv()``: set :c:member:`PyConfig.argv` instead.
+  * ``Py_SetProgramName()``: set :c:member:`PyConfig.program_name` instead.
+  * ``Py_SetPythonHome()``: set :c:member:`PyConfig.home` instead.
+
+  The :c:func:`Py_InitializeFromConfig` API should be used with
+  :c:type:`PyConfig` instead.
+
 * Global configuration variables:
 
   * :c:var:`Py_DebugFlag`: use :c:member:`PyConfig.parser_debug`

Doc/whatsnew/3.13.rst

@@ -34,8 +34,12 @@ PyAPI_FUNC(int) Py_Main(int argc, wchar_t **argv);
 PyAPI_FUNC(int) Py_BytesMain(int argc, char **argv);
 
 /* In pathconfig.c */
+Py_DEPRECATED(3.11) PyAPI_FUNC(void) Py_SetProgramName(const wchar_t *);
 Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetProgramName(void);
+
+Py_DEPRECATED(3.11) PyAPI_FUNC(void) Py_SetPythonHome(const wchar_t *);
 Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetPythonHome(void);
+
 Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetProgramFullPath(void);
 Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetPrefix(void);
 Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetExecPrefix(void);

Include/pylifecycle.h

@@ -7,6 +7,9 @@ extern "C" {
 PyAPI_FUNC(PyObject *) PySys_GetObject(const char *);
 PyAPI_FUNC(int) PySys_SetObject(const char *, PyObject *);
 
+Py_DEPRECATED(3.11) PyAPI_FUNC(void) PySys_SetArgv(int, wchar_t **);
+Py_DEPRECATED(3.11) PyAPI_FUNC(void) PySys_SetArgvEx(int, wchar_t **, int);
+
 PyAPI_FUNC(void) PySys_WriteStdout(const char *format, ...)
                  Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
 PyAPI_FUNC(void) PySys_WriteStderr(const char *format, ...)

Include/sysmodule.h

@@ -0,0 +1,8 @@
+Restore functions removed in Python 3.13 alpha 1:
+
+* :c:func:`Py_SetPythonHome`
+* :c:func:`Py_SetProgramName`
+* :c:func:`PySys_SetArgvEx`
+* :c:func:`PySys_SetArgv`
+
+Patch by Victor Stinner.

Misc/NEWS.d/next/C API/2024-04-17-16-48-17.gh-issue-117987.zsvNL1.rst

@@ -1336,10 +1336,8 @@
     added = '3.2'
 [function.PySys_SetArgv]
     added = '3.2'
-    abi_only = true
 [function.PySys_SetArgvEx]
     added = '3.2'
-    abi_only = true
 [function.PySys_SetObject]
     added = '3.2'
 [function.PySys_SetPath]
@@ -1672,10 +1670,8 @@
     added = '3.2'
 [function.Py_SetProgramName]
     added = '3.2'
-    abi_only = true
 [function.Py_SetPythonHome]
     added = '3.2'
-    abi_only = true
 [function.Py_SetRecursionLimit]
     added = '3.2'
 [function.Py_VaBuildValue]

Misc/stable_abi.toml

@@ -16,11 +16,9 @@
 
 // These functions were removed from Python 3.13 API but are still exported
 // for the stable ABI. We want to test them in this program.
-extern void Py_SetProgramName(const wchar_t *program_name);
 extern void PySys_AddWarnOption(const wchar_t *s);
 extern void PySys_AddXOption(const wchar_t *s);
 extern void Py_SetPath(const wchar_t *path);
-extern void Py_SetPythonHome(const wchar_t *home);
 
 
 int main_argc;

Programs/_testembed.c

@@ -251,8 +251,7 @@ Py_SetPath(const wchar_t *path)
 }
 
 
-// Removed in Python 3.13 API, but kept for the stable ABI
-PyAPI_FUNC(void)
+void
 Py_SetPythonHome(const wchar_t *home)
 {
     int has_value = home && home[0];
@@ -275,8 +274,7 @@ Py_SetPythonHome(const wchar_t *home)
 }
 
 
-// Removed in Python 3.13 API, but kept for the stable ABI
-PyAPI_FUNC(void)
+void
 Py_SetProgramName(const wchar_t *program_name)
 {
     int has_value = program_name && program_name[0];

Python/pathconfig.c

@@ -3872,8 +3872,7 @@ make_sys_argv(int argc, wchar_t * const * argv)
     return list;
 }
 
-// Removed in Python 3.13 API, but kept for the stable ABI
-PyAPI_FUNC(void)
+void
 PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath)
 {
     wchar_t* empty_argv[1] = {L""};
@@ -3917,8 +3916,7 @@ PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath)
     }
 }
 
-// Removed in Python 3.13 API, but kept for the stable ABI
-PyAPI_FUNC(void)
+void
 PySys_SetArgv(int argc, wchar_t **argv)
 {
 _Py_COMP_DIAG_PUSH