bpo-36763: PyConfig_Read() handles PySys_AddXOption() (GH-15431) (GH-15435)

PyConfig_Read() is now responsible to handle early calls to
PySys_AddXOption() and PySys_AddWarnOption().

Options added by PySys_AddXOption() are now handled the same way than
PyConfig.xoptions and command line -X options.

For example, PySys_AddXOption(L"faulthandler") enables faulthandler
as expected.

(cherry picked from commit 120b707a6d43452e067daa55a8fdca69f9424abc)

2 files changed, 46 insertions, 31 deletions

diff --git a/Python/initconfig.c b/Python/initconfig.c
index 8a6ad7c..a87d8ae 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -2069,6 +2069,7 @@ config_init_warnoptions(PyConfig *config,
     /* The priority order for warnings configuration is (highest precedence
      * first):
      *
+     * - early PySys_AddWarnOption() calls
      * - the BytesWarning filter, if needed ('-b', '-bb')
      * - any '-W' command line options; then
      * - the 'PYTHONWARNINGS' environment variable; then
@@ -2124,6 +2125,13 @@ config_init_warnoptions(PyConfig *config,
             return status;
         }
     }
+
+    /* Handle early PySys_AddWarnOption() calls */
+    status = _PySys_ReadPreinitWarnOptions(config);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
     return _PyStatus_OK();
 }
 
@@ -2246,7 +2254,8 @@ config_read_cmdline(PyConfig *config)
     }
 
     status = config_init_warnoptions(config,
-                                  &cmdline_warnoptions, &env_warnoptions);
+                                     &cmdline_warnoptions,
+                                     &env_warnoptions);
     if (_PyStatus_EXCEPTION(status)) {
         goto done;
     }
@@ -2356,6 +2365,12 @@ PyConfig_Read(PyConfig *config)
         goto done;
     }
 
+    /* Handle early PySys_AddXOption() calls */
+    status = _PySys_ReadPreinitXOptions(config);
+    if (_PyStatus_EXCEPTION(status)) {
+        goto done;
+    }
+
     status = config_read(config);
     if (_PyStatus_EXCEPTION(status)) {
         goto done;
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 577b6fb..93ffce2 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2071,37 +2071,43 @@ _clear_preinit_entries(_Py_PreInitEntry *optionlist)
     PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
 }
 
-static void
-_clear_all_preinit_options(void)
+
+PyStatus
+_PySys_ReadPreinitWarnOptions(PyConfig *config)
 {
+    PyStatus status;
+    _Py_PreInitEntry entry;
+
+    for (entry = _preinit_warnoptions; entry != NULL; entry = entry->next) {
+        status = PyWideStringList_Append(&config->warnoptions, entry->value);
+        if (_PyStatus_EXCEPTION(status)) {
+            return status;
+        }
+    }
+
     _clear_preinit_entries(&_preinit_warnoptions);
-    _clear_preinit_entries(&_preinit_xoptions);
+    return _PyStatus_OK();
 }
 
-static int
-_PySys_ReadPreInitOptions(void)
+
+PyStatus
+_PySys_ReadPreinitXOptions(PyConfig *config)
 {
-    /* Rerun the add commands with the actual sys module available */
-    PyThreadState *tstate = _PyThreadState_GET();
-    if (tstate == NULL) {
-        /* Still don't have a thread state, so something is wrong! */
-        return -1;
-    }
-    _Py_PreInitEntry entry = _preinit_warnoptions;
-    while (entry != NULL) {
-        PySys_AddWarnOption(entry->value);
-        entry = entry->next;
-    }
-    entry = _preinit_xoptions;
-    while (entry != NULL) {
-        PySys_AddXOption(entry->value);
-        entry = entry->next;
+    PyStatus status;
+    _Py_PreInitEntry entry;
+
+    for (entry = _preinit_xoptions; entry != NULL; entry = entry->next) {
+        status = PyWideStringList_Append(&config->xoptions, entry->value);
+        if (_PyStatus_EXCEPTION(status)) {
+            return status;
+        }
     }
 
-    _clear_all_preinit_options();
-    return 0;
+    _clear_preinit_entries(&_preinit_xoptions);
+    return _PyStatus_OK();
 }
 
+
 static PyObject *
 get_warnoptions(void)
 {
@@ -2265,9 +2271,7 @@ PySys_AddXOption(const wchar_t *s)
     }
     if (_PySys_AddXOptionWithError(s) < 0) {
         /* No return value, therefore clear error state if possible */
-        if (_PyThreadState_UncheckedGet()) {
-            PyErr_Clear();
-        }
+        PyErr_Clear();
     }
 }
 
@@ -2926,13 +2930,9 @@ _PySys_InitMain(_PyRuntimeState *runtime, PyInterpreterState *interp)
     if (get_xoptions() == NULL)
         return -1;
 
-    /* Transfer any sys.warnoptions and sys._xoptions set directly
-     * by an embedding application from the linked list to the module. */
-    if (_PySys_ReadPreInitOptions() != 0)
-        return -1;
-
     if (PyErr_Occurred())
         return -1;
+
     return 0;
 
 err_occurred: