Add Blurb and fix a refleak before anybody notices

ambv · ambv · commit 1ef282b75e78 · 2023-10-12T17:15:28.000+02:00
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
@@ -552,6 +552,10 @@ Miscellaneous options
      This option may be useful for users who need to limit CPU resources of a
      container system. See also :envvar:`PYTHON_CPU_COUNT`.
      If *n* is ``default``, nothing is overridden.
+   * :samp:`-X presite={package.module}` specifies a module that should be
+     imported before ``site.py`` is executed.  Python needs to be
+     :ref:`built in debug mode <debug-build>` for this option to exist.
+     See also :envvar:`PYTHON_PRESITE <PYTHON_PRESITE=package.module>`.
 
    It also allows passing arbitrary values and retrieving them through the
    :data:`sys._xoptions` dictionary.
@@ -602,6 +606,8 @@ Miscellaneous options
    .. versionadded:: 3.13
       The ``-X cpu_count`` option.
 
+      The ``-X presite`` option.
+
 
 Options you shouldn't use
 ~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -1100,3 +1106,13 @@ Debug-mode variables
    Need Python configured with the :option:`--with-trace-refs` build option.
 
    .. versionadded:: 3.11
+
+.. envvar:: PYTHON_PRESITE=package.module
+
+   If this variable is set to a module, that module will be imported
+   early in the interpreter lifecycle, before ``site.py`` is executed.
+
+   See also the :option:`-X presite <-X>` command-line option,
+   which takes precedence over this variable.
+
+   .. versionadded:: 3.13
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-10-12-17-15-23.gh-issue-110722.sjMwQe.rst b/Misc/NEWS.d/next/Core and Builtins/2023-10-12-17-15-23.gh-issue-110722.sjMwQe.rst
@@ -0,0 +1,3 @@
+Add :envvar:`PYTHON_PRESITE=package.module` to import a module early in the
+interpreter lifecycle before ``site.py`` is executed.  Python needs to be
+:ref:`built in debug mode <debug-build>` for this option to exist.
diff --git a/Python/initconfig.c b/Python/initconfig.c
@@ -305,6 +305,9 @@ static const char usage_envvars[] =
 #ifdef Py_STATS
 "PYTHONSTATS             : turns on statistics gathering\n"
 #endif
+#ifdef Py_DEBUG
+"PYTHON_PRESITE=pkg.mod  : import this module before site.py is run\n"
+#endif
 ;
 
 #if defined(MS_WINDOWS)
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
@@ -1170,10 +1170,11 @@ init_interp_main(PyThreadState *tstate)
         else {
             PyObject *presite = PyImport_Import(presite_modname);
             if (presite == NULL) {
-                fprintf(stderr, "pre-site import failed; traceback:\n");
+                fprintf(stderr, "pre-site import failed:\n");
                 _PyErr_Print(tstate);
             }
             Py_XDECREF(presite);
+            Py_DECREF(presite_modname);
         }
     }
 #endif

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+Add :envvar:`PYTHON_PRESITE=package.module` to import a module early in the
	`2`	+interpreter lifecycle before ``site.py`` is executed. Python needs to be
	`3`	+:ref:`built in debug mode <debug-build>` for this option to exist.
Original file line number	Diff line number	Diff line change
`@@ -305,6 +305,9 @@ static const char usage_envvars[] =`
`305`	`305`	`#ifdef Py_STATS`
`306`	`306`	`"PYTHONSTATS : turns on statistics gathering\n"`
`307`	`307`	`#endif`
	`308`	`+#ifdef Py_DEBUG`
	`309`	`+"PYTHON_PRESITE=pkg.mod : import this module before site.py is run\n"`
	`310`	`+#endif`
`308`	`311`	`;`
`309`	`312`
`310`	`313`	`#if defined(MS_WINDOWS)`
Original file line number	Diff line number	Diff line change
`@@ -1170,10 +1170,11 @@ init_interp_main(PyThreadState *tstate)`
`1170`	`1170`	`else {`
`1171`	`1171`	`PyObject *presite = PyImport_Import(presite_modname);`
`1172`	`1172`	`if (presite == NULL) {`
`1173`		`- fprintf(stderr, "pre-site import failed; traceback:\n");`
	`1173`	`+ fprintf(stderr, "pre-site import failed:\n");`
`1174`	`1174`	`_PyErr_Print(tstate);`
`1175`	`1175`	`}`
`1176`	`1176`	`Py_XDECREF(presite);`
	`1177`	`+ Py_DECREF(presite_modname);`
`1177`	`1178`	`}`
`1178`	`1179`	`}`
`1179`	`1180`	`#endif`