1 files changed, 54 insertions, 0 deletions
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 56df5730db0..27214a129c2 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -1,12 +1,14 @@
 /* Function object implementation */
 
 #include "Python.h"
+#include "pycore_code.h"          // _PyCode_VerifyStateless()
 #include "pycore_dict.h"          // _Py_INCREF_DICT()
 #include "pycore_function.h"      // _PyFunction_Vectorcall
 #include "pycore_long.h"          // _PyLong_GetOne()
 #include "pycore_modsupport.h"    // _PyArg_NoKeywords()
 #include "pycore_object.h"        // _PyObject_GC_UNTRACK()
 #include "pycore_pyerrors.h"      // _PyErr_Occurred()
+#include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "pycore_stats.h"
 
 
@@ -1240,6 +1242,58 @@ PyTypeObject PyFunction_Type = {
 };
 
 
+int
+_PyFunction_VerifyStateless(PyThreadState *tstate, PyObject *func)
+{
+    assert(!PyErr_Occurred());
+    assert(PyFunction_Check(func));
+
+    // Check the globals.
+    PyObject *globalsns = PyFunction_GET_GLOBALS(func);
+    if (globalsns != NULL && !PyDict_Check(globalsns)) {
+        _PyErr_Format(tstate, PyExc_TypeError,
+                      "unsupported globals %R", globalsns);
+        return -1;
+    }
+    // Check the builtins.
+    PyObject *builtinsns = PyFunction_GET_BUILTINS(func);
+    if (builtinsns != NULL && !PyDict_Check(builtinsns)) {
+        _PyErr_Format(tstate, PyExc_TypeError,
+                      "unsupported builtins %R", builtinsns);
+        return -1;
+    }
+    // Disallow __defaults__.
+    PyObject *defaults = PyFunction_GET_DEFAULTS(func);
+    if (defaults != NULL && defaults != Py_None && PyDict_Size(defaults) > 0)
+    {
+        _PyErr_SetString(tstate, PyExc_ValueError, "defaults not supported");
+        return -1;
+    }
+    // Disallow __kwdefaults__.
+    PyObject *kwdefaults = PyFunction_GET_KW_DEFAULTS(func);
+    if (kwdefaults != NULL && kwdefaults != Py_None
+            && PyDict_Size(kwdefaults) > 0)
+    {
+        _PyErr_SetString(tstate, PyExc_ValueError,
+                         "keyword defaults not supported");
+        return -1;
+    }
+    // Disallow __closure__.
+    PyObject *closure = PyFunction_GET_CLOSURE(func);
+    if (closure != NULL && closure != Py_None && PyTuple_GET_SIZE(closure) > 0)
+    {
+        _PyErr_SetString(tstate, PyExc_ValueError, "closures not supported");
+        return -1;
+    }
+    // Check the code.
+    PyCodeObject *co = (PyCodeObject *)PyFunction_GET_CODE(func);
+    if (_PyCode_VerifyStateless(tstate, co, NULL, globalsns, builtinsns) < 0) {
+        return -1;
+    }
+    return 0;
+}
+
+
 static int
 functools_copy_attr(PyObject *wrapper, PyObject *wrapped, PyObject *name)
 {