bpo-39960: Allow heap types in the "Carlo Verre" hack check that override "tp_setattro()" (GH-21092)

Automerge-Triggered-By: @gvanrossum

1 files changed, 80 insertions, 0 deletions

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index aafbc39..629102b 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -6528,6 +6528,80 @@ static PyType_Spec HeapCTypeWithWeakref_spec = {
     HeapCTypeWithWeakref_slots
 };
 
+PyDoc_STRVAR(heapctypesetattr__doc__,
+"A heap type without GC, but with overridden __setattr__.\n\n"
+"The 'value' attribute is set to 10 in __init__ and updated via attribute setting.");
+
+typedef struct {
+    PyObject_HEAD
+    long value;
+} HeapCTypeSetattrObject;
+
+static struct PyMemberDef heapctypesetattr_members[] = {
+    {"pvalue", T_LONG, offsetof(HeapCTypeSetattrObject, value)},
+    {NULL} /* Sentinel */
+};
+
+static int
+heapctypesetattr_init(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    ((HeapCTypeSetattrObject *)self)->value = 10;
+    return 0;
+}
+
+static void
+heapctypesetattr_dealloc(HeapCTypeSetattrObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    PyObject_Del(self);
+    Py_DECREF(tp);
+}
+
+static int
+heapctypesetattr_setattro(HeapCTypeSetattrObject *self, PyObject *attr, PyObject *value)
+{
+    PyObject *svalue = PyUnicode_FromString("value");
+    if (svalue == NULL)
+        return -1;
+    int eq = PyObject_RichCompareBool(svalue, attr, Py_EQ);
+    Py_DECREF(svalue);
+    if (eq < 0)
+        return -1;
+    if (!eq) {
+        return PyObject_GenericSetAttr((PyObject*) self, attr, value);
+    }
+    if (value == NULL) {
+        self->value = 0;
+        return 0;
+    }
+    PyObject *ivalue = PyNumber_Long(value);
+    if (ivalue == NULL)
+        return -1;
+    long v = PyLong_AsLong(ivalue);
+    Py_DECREF(ivalue);
+    if (v == -1 && PyErr_Occurred())
+        return -1;
+    self->value = v;
+    return 0;
+}
+
+static PyType_Slot HeapCTypeSetattr_slots[] = {
+    {Py_tp_init, heapctypesetattr_init},
+    {Py_tp_members, heapctypesetattr_members},
+    {Py_tp_setattro, heapctypesetattr_setattro},
+    {Py_tp_dealloc, heapctypesetattr_dealloc},
+    {Py_tp_doc, (char*)heapctypesetattr__doc__},
+    {0, 0},
+};
+
+static PyType_Spec HeapCTypeSetattr_spec = {
+    "_testcapi.HeapCTypeSetattr",
+    sizeof(HeapCTypeSetattrObject),
+    0,
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+    HeapCTypeSetattr_slots
+};
+
 static PyMethodDef meth_instance_methods[] = {
     {"meth_varargs", meth_varargs, METH_VARARGS},
     {"meth_varargs_keywords", (PyCFunction)(void(*)(void))meth_varargs_keywords, METH_VARARGS|METH_KEYWORDS},
@@ -6834,6 +6908,12 @@ PyInit__testcapi(void)
     }
     PyModule_AddObject(m, "HeapCTypeWithBuffer", HeapCTypeWithBuffer);
 
+    PyObject *HeapCTypeSetattr = PyType_FromSpec(&HeapCTypeSetattr_spec);
+    if (HeapCTypeSetattr == NULL) {
+        return NULL;
+    }
+    PyModule_AddObject(m, "HeapCTypeSetattr", HeapCTypeSetattr);
+
     PyObject *subclass_with_finalizer_bases = PyTuple_Pack(1, HeapCTypeSubclass);
     if (subclass_with_finalizer_bases == NULL) {
         return NULL;