gh-145055: Accept frozendict for globals in exec() and eval()

Author: vstinner

Doc/library/functions.rst

@@ -594,7 +594,7 @@ are always available.  They are listed here in alphabetical order.
 
    :param globals:
       The global namespace (default: ``None``).
-   :type globals: :class:`dict` | ``None``
+   :type globals: :class:`dict` | :class:`frozendict` | ``None``
 
    :param locals:
       The local namespace (default: ``None``).
@@ -643,6 +643,10 @@ are always available.  They are listed here in alphabetical order.
    If the given source is a string, then leading and trailing spaces and tabs
    are stripped.
 
+   It's possible to pass :class:`frozendict` to *globals* if the
+   :class:`!frozendict` has a ``__builtins__`` item. In this case, it's not
+   possible to assign or reassign global variables.
+
    See :func:`ast.literal_eval` for a function that can safely evaluate strings
    with expressions containing only literals.
 
@@ -660,6 +664,10 @@ are always available.  They are listed here in alphabetical order.
       The semantics of the default *locals* namespace have been adjusted as
       described for the :func:`locals` builtin.
 
+   .. versionchanged:: next
+
+      *globals* can now be a :class:`frozendict`.
+
 .. index:: pair: built-in function; exec
 
 .. function:: exec(source, /, globals=None, locals=None, *, closure=None)
@@ -688,6 +696,10 @@ are always available.  They are listed here in alphabetical order.
    respectively.  If provided, *locals* can be any mapping object.  Remember
    that at the module level, globals and locals are the same dictionary.
 
+   It's possible to pass :class:`frozendict` to *globals* if the
+   :class:`!frozendict` has a ``__builtins__`` item. In this case, it's not
+   possible to assign or reassign global variables.
+
    .. note::
 
       When ``exec`` gets two separate objects as *globals* and *locals*, the
@@ -737,6 +749,10 @@ are always available.  They are listed here in alphabetical order.
       The semantics of the default *locals* namespace have been adjusted as
       described for the :func:`locals` builtin.
 
+   .. versionchanged:: next
+
+      *globals* can now be a :class:`frozendict`.
+
 
 .. function:: filter(function, iterable, /)
 

Include/internal/pycore_dict.h

@@ -370,15 +370,15 @@ _PyDict_UniqueId(PyDictObject *mp)
 static inline void
 _Py_INCREF_DICT(PyObject *op)
 {
-    assert(PyDict_Check(op));
+    assert(PyAnyDict_Check(op));
     Py_ssize_t id = _PyDict_UniqueId((PyDictObject *)op);
     _Py_THREAD_INCREF_OBJECT(op, id);
 }
 
 static inline void
 _Py_DECREF_DICT(PyObject *op)
 {
-    assert(PyDict_Check(op));
+    assert(PyAnyDict_Check(op));
     Py_ssize_t id = _PyDict_UniqueId((PyDictObject *)op);
     _Py_THREAD_DECREF_OBJECT(op, id);
 }

Lib/test/test_builtin.py

@@ -784,6 +784,12 @@ def __getitem__(self, key):
                 raise ValueError
         self.assertRaises(ValueError, eval, "foo", {}, X())
 
+        # Pass frozenset to globals
+        ns = frozendict(x=1, data=[], __builtins__=__builtins__)
+        code = "data.append(x)"
+        eval(code, ns, ns)
+        self.assertEqual(ns['data'], [1])
+
     def test_eval_kwargs(self):
         data = {"A_GLOBAL_VALUE": 456}
         self.assertEqual(eval("globals()['A_GLOBAL_VALUE']", globals=data), 456)
@@ -882,6 +888,18 @@ def test_exec(self):
             del l['__builtins__']
         self.assertEqual((g, l), ({'a': 1}, {'b': 2}))
 
+        # Pass frozenset to globals
+        ns = frozendict(x=1, data=[], __builtins__=__builtins__)
+        code = "data.append(x)"
+        exec(code, ns, ns)
+        self.assertEqual(ns['data'], [1])
+
+        ns = frozendict(__builtins__=__builtins__)
+        code = "x = 1"
+        errmsg = "'frozendict' object does not support item assignment"
+        with self.assertRaisesRegex(TypeError, errmsg):
+            exec(code, ns, ns)
+
     def test_exec_kwargs(self):
         g = {}
         exec('global z\nz = 1', globals=g)

Misc/NEWS.d/next/Core_and_Builtins/2026-02-21-12-16-46.gh-issue-145055.VyT-zI.rst

@@ -0,0 +1,2 @@
+:func:`exec` and :func:`eval` now accept :class:`frozendict` for *globals*.
+Patch by Victor Stinner.

Objects/codeobject.c

@@ -1830,7 +1830,7 @@ identify_unbound_names(PyThreadState *tstate, PyCodeObject *co,
     assert(attrnames != NULL);
     assert(PySet_Check(attrnames));
     assert(PySet_GET_SIZE(attrnames) == 0 || counts != NULL);
-    assert(globalsns == NULL || PyDict_Check(globalsns));
+    assert(globalsns == NULL || PyAnyDict_Check(globalsns));
     assert(builtinsns == NULL || PyDict_Check(builtinsns));
     assert(counts == NULL || counts->total == 0);
     struct co_unbound_counts unbound = {0};

Objects/dictobject.c

@@ -2661,7 +2661,7 @@ _PyDict_LoadGlobalStackRef(PyDictObject *globals, PyDictObject *builtins, PyObje
 PyObject *
 _PyDict_LoadBuiltinsFromGlobals(PyObject *globals)
 {
-    if (!PyDict_Check(globals)) {
+    if (!PyAnyDict_Check(globals)) {
         PyErr_BadInternalCall();
         return NULL;
     }

Objects/funcobject.c

@@ -150,7 +150,7 @@ PyObject *
 PyFunction_NewWithQualName(PyObject *code, PyObject *globals, PyObject *qualname)
 {
     assert(globals != NULL);
-    assert(PyDict_Check(globals));
+    assert(PyAnyDict_Check(globals));
     _Py_INCREF_DICT(globals);
 
     PyCodeObject *code_obj = (PyCodeObject *)code;

Python/_warnings.c

@@ -1045,7 +1045,7 @@ setup_context(Py_ssize_t stack_level,
 
     /* Setup registry. */
     assert(globals != NULL);
-    assert(PyDict_Check(globals));
+    assert(PyAnyDict_Check(globals));
     int rc = PyDict_GetItemRef(globals, &_Py_ID(__warningregistry__),
                                registry);
     if (rc < 0) {
@@ -1269,7 +1269,7 @@ warnings_warn_explicit_impl(PyObject *module, PyObject *message,
     }
 
     if (module_globals && module_globals != Py_None) {
-        if (!PyDict_Check(module_globals)) {
+        if (!PyAnyDict_Check(module_globals)) {
             PyErr_Format(PyExc_TypeError,
                          "module_globals must be a dict, not '%.200s'",
                          Py_TYPE(module_globals)->tp_name);

Python/bltinmodule.c

@@ -1034,10 +1034,11 @@ builtin_eval_impl(PyObject *module, PyObject *source, PyObject *globals,
         PyErr_SetString(PyExc_TypeError, "locals must be a mapping");
         return NULL;
     }
-    if (globals != Py_None && !PyDict_Check(globals)) {
+    if (globals != Py_None && !PyAnyDict_Check(globals)) {
         PyErr_SetString(PyExc_TypeError, PyMapping_Check(globals) ?
-            "globals must be a real dict; try eval(expr, {}, mapping)"
-            : "globals must be a dict");
+            "globals must be a real dict or a frozendict; "
+            "try eval(expr, {}, mapping)"
+            : "globals must be a dict or a frozendict");
         return NULL;
     }
 
@@ -1191,9 +1192,10 @@ builtin_exec_impl(PyObject *module, PyObject *source, PyObject *globals,
         locals = Py_NewRef(globals);
     }
 
-    if (!PyDict_Check(globals)) {
-        PyErr_Format(PyExc_TypeError, "exec() globals must be a dict, not %.100s",
-                     Py_TYPE(globals)->tp_name);
+    if (!PyAnyDict_Check(globals)) {
+        PyErr_Format(PyExc_TypeError,
+                     "exec() globals must be a dict or a frozendict, not %T",
+                     globals);
         goto error;
     }
     if (!PyMapping_Check(locals)) {

Python/ceval.c

@@ -2717,7 +2717,7 @@ static PyObject *
 get_globals_builtins(PyObject *globals)
 {
     PyObject *builtins = NULL;
-    if (PyDict_Check(globals)) {
+    if (PyAnyDict_Check(globals)) {
         if (PyDict_GetItemRef(globals, &_Py_ID(__builtins__), &builtins) < 0) {
             return NULL;
         }
@@ -3572,7 +3572,7 @@ _PyEval_GetANext(PyObject *aiter)
 void
 _PyEval_LoadGlobalStackRef(PyObject *globals, PyObject *builtins, PyObject *name, _PyStackRef *writeto)
 {
-    if (PyDict_CheckExact(globals) && PyDict_CheckExact(builtins)) {
+    if (PyAnyDict_CheckExact(globals) && PyAnyDict_CheckExact(builtins)) {
         _PyDict_LoadGlobalStackRef((PyDictObject *)globals,
                                     (PyDictObject *)builtins,
                                     name, writeto);