Merge branch 'main' into json_ft

Author: eendebakpt

Doc/using/cmdline.rst

@@ -669,6 +669,13 @@ Miscellaneous options
 
      .. versionadded:: 3.14
 
+   * :samp:`-X tlbc={0,1}` enables (1, the default) or disables (0) thread-local
+     bytecode in builds configured with :option:`--disable-gil`.  When disabled,
+     this also disables the specializing interpreter.  See also
+     :envvar:`PYTHON_TLBC`.
+
+     .. versionadded:: 3.14
+
    It also allows passing arbitrary values and retrieving them through the
    :data:`sys._xoptions` dictionary.
 
@@ -1302,6 +1309,16 @@ conflict.
 
    .. versionadded:: 3.13
 
+.. envvar:: PYTHON_TLBC
+
+   If set to ``1`` enables thread-local bytecode. If set to ``0`` thread-local
+   bytecode and the specializing interpreter are disabled.  Only applies to
+   builds configured with :option:`--disable-gil`.
+
+   See also the :option:`-X tlbc <-X>` command-line option.
+
+   .. versionadded:: 3.14
+
 Debug-mode variables
 ~~~~~~~~~~~~~~~~~~~~
 

Lib/test/test__interpreters.py

@@ -485,6 +485,21 @@ def test_signatures(self):
         msg = r'_interpreters.run_func\(\) argument 3 must be dict, not int'
         with self.assertRaisesRegex(TypeError, msg):
             _interpreters.run_func(self.id, lambda: None, shared=1)
+        # See https://github.com/python/cpython/issues/135855
+        msg = r'_interpreters.set___main___attrs\(\) argument 2 must be dict, not int'
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.set___main___attrs(self.id, 1)
+
+    def test_invalid_shared_none(self):
+        msg = r'must be dict, not None'
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.exec(self.id, 'a', shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.run_string(self.id, 'a', shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.run_func(self.id, lambda: None, shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.set___main___attrs(self.id, None)
 
     def test_invalid_shared_encoding(self):
         # See https://github.com/python/cpython/issues/127196

Misc/NEWS.d/next/Library/2025-06-23-10-19-11.gh-issue-135855.-J0AGF.rst

@@ -0,0 +1,3 @@
+Raise :exc:`TypeError` instead of :exc:`SystemError` when
+:func:`!_interpreters.set___main___attrs` is passed a non-dict object.
+Patch by Brian Schubert.

Misc/NEWS.d/next/Library/2025-06-24-14-43-24.gh-issue-135878.Db4roX.rst

@@ -0,0 +1,3 @@
+Fixes a crash of :class:`types.SimpleNamespace` on :term:`free threading` builds,
+when several threads were calling its :meth:`~object.__repr__` method at the
+same time.

Modules/_interpretersmodule.c

@@ -1039,8 +1039,8 @@ interp_set___main___attrs(PyObject *self, PyObject *args, PyObject *kwargs)
     PyObject *id, *updates;
     int restricted = 0;
     if (!PyArg_ParseTupleAndKeywords(args, kwargs,
-                                     "OO|$p:" MODULE_NAME_STR ".set___main___attrs",
-                                     kwlist, &id, &updates, &restricted))
+                                     "OO!|$p:" MODULE_NAME_STR ".set___main___attrs",
+                                     kwlist, &id, &PyDict_Type, &updates, &restricted))
     {
         return NULL;
     }
@@ -1054,16 +1054,14 @@ interp_set___main___attrs(PyObject *self, PyObject *args, PyObject *kwargs)
     }
 
     // Check the updates.
-    if (updates != Py_None) {
-        Py_ssize_t size = PyObject_Size(updates);
-        if (size < 0) {
-            return NULL;
-        }
-        if (size == 0) {
-            PyErr_SetString(PyExc_ValueError,
-                            "arg 2 must be a non-empty mapping");
-            return NULL;
-        }
+    Py_ssize_t size = PyDict_Size(updates);
+    if (size < 0) {
+        return NULL;
+    }
+    if (size == 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "arg 2 must be a non-empty dict");
+        return NULL;
     }
 
     _PyXI_session *session = _PyXI_NewSession();

Objects/namespaceobject.c

@@ -124,9 +124,10 @@ namespace_repr(PyObject *ns)
         if (PyUnicode_Check(key) && PyUnicode_GET_LENGTH(key) > 0) {
             PyObject *value, *item;
 
-            value = PyDict_GetItemWithError(d, key);
-            if (value != NULL) {
+            int has_key = PyDict_GetItemRef(d, key, &value);
+            if (has_key == 1) {
                 item = PyUnicode_FromFormat("%U=%R", key, value);
+                Py_DECREF(value);
                 if (item == NULL) {
                     loop_error = 1;
                 }
@@ -135,7 +136,7 @@ namespace_repr(PyObject *ns)
                     Py_DECREF(item);
                 }
             }
-            else if (PyErr_Occurred()) {
+            else if (has_key < 0) {
                 loop_error = 1;
             }
         }

Python/crossinterp.c

@@ -2617,6 +2617,7 @@ _PyXI_Enter(_PyXI_session *session,
     // Convert the attrs for cross-interpreter use.
     _PyXI_namespace *sharedns = NULL;
     if (nsupdates != NULL) {
+        assert(PyDict_Check(nsupdates));
         Py_ssize_t len = PyDict_Size(nsupdates);
         if (len < 0) {
             if (result != NULL) {