Add frame_new function to _testcapimodule.c.

Move frame test from test_python_api.py to test_frame.py.
python · kumaraditya303 · Dec 23, 2022 · Dec 12, 2022 · Dec 12, 2022 · Dec 12, 2022
commit 4e70dc50580212e74aac4c12dd3255933fe85224
diff --git a/Lib/test/test_ctypes/test_python_api.py b/Lib/test/test_ctypes/test_python_api.py
@@ -81,36 +81,6 @@ def test_pyobject_repr(self):
         self.assertEqual(repr(py_object(42)), "py_object(42)")
         self.assertEqual(repr(py_object(object)), "py_object(%r)" % object)
 
-    def test_PyFrame_New_f_back(self):
-        """Test that accessing `f_back` does not cause a segmentation fault on
-        a frame created with ctypes (GH-99110)."""
-        # Adapted from:
-        # https://naleraphael.github.io/blog/posts/devlog_create_a_builtin_frame_object/
-
-        p_memtype = POINTER(c_ulong if sizeof(c_void_p) == 8 else c_uint)
-        pythonapi.PyFrame_New.argtypes = (
-            p_memtype,   # PyThreadState *tstate
-            p_memtype,   # PyCodeObject *code
-            py_object,   # PyObject *globals
-            py_object    # PyObject *locals
-        )
-        pythonapi.PyFrame_New.restype = py_object   # PyFrameObject*
-        pythonapi.PyThreadState_Get.argtypes = None
-        pythonapi.PyThreadState_Get.restype = p_memtype
-
-        def dummy():
-            pass
-
-        frame = pythonapi.PyFrame_New(
-            pythonapi.PyThreadState_Get(),          # thread state
-            cast(id(dummy.__code__), p_memtype),    # a code object
-            globals(),
-            locals(),
-        )
-
-        # The following line should not cause a segmentation fault.
-        self.assertEqual(frame.f_back, None)
-
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_frame.py b/Lib/test/test_frame.py
@@ -408,6 +408,15 @@ def test_frame_get_generator(self):
         frame = next(gen)
         self.assertIs(gen, _testcapi.frame_getgenerator(frame))
 
+    def test_frame_fback_api(self):
+        """Test that accessing `f_back` does not cause a segmentation fault on
+        a frame created with `PyFrame_New` (GH-99110)."""
+        def dummy():
+            pass
+
+        frame = _testcapi.frame_new(dummy.__code__, globals(), locals())
+        # The following line should not cause a segmentation fault.
+        self.assertEqual(frame.f_back, None)
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
@@ -20,6 +20,7 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
+#include "frameobject.h"          // PyFrame_New
 #include "marshal.h"              // PyMarshal_WriteLongToFile
 #include "structmember.h"         // for offsetof(), T_OBJECT
 #include <float.h>                // FLT_MAX
@@ -2911,6 +2912,22 @@ frame_getlasti(PyObject *self, PyObject *frame)
     return PyLong_FromLong(lasti);
 }
 
+static PyObject *
+frame_new(PyObject *self, PyObject *args)
+{
+    PyObject *code, *globals, *locals;
+    if (!PyArg_ParseTuple(args, "OOO", &code, &globals, &locals)) {
+        return NULL;
+    }
+    if (!PyCode_Check(code)) {
+        PyErr_SetString(PyExc_TypeError, "argument must be a code object");
+        return NULL;
+    }
+    PyThreadState *tstate = PyThreadState_Get();
+
+    return (PyObject *)PyFrame_New(tstate, (PyCodeObject *)code, globals, locals);
+}
+
 static PyObject *
 test_frame_getvar(PyObject *self, PyObject *args)
 {
@@ -3352,6 +3369,7 @@ static PyMethodDef TestMethods[] = {
     {"frame_getgenerator", frame_getgenerator, METH_O, NULL},
     {"frame_getbuiltins", frame_getbuiltins, METH_O, NULL},
     {"frame_getlasti", frame_getlasti, METH_O, NULL},
+    {"frame_new", frame_new, METH_VARARGS, NULL},
     {"frame_getvar", test_frame_getvar, METH_VARARGS, NULL},
     {"frame_getvarstring", test_frame_getvarstring, METH_VARARGS, NULL},
     {"eval_get_func_name", eval_get_func_name, METH_O, NULL},