fix UBSan failures for mapobject

Author: picnixz

Python/bltinmodule.c

@@ -1325,6 +1325,8 @@ typedef struct {
     int strict;
 } mapobject;
 
+#define _mapobject_CAST(op)     ((mapobject *)(op))
+
 static PyObject *
 map_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
@@ -1428,25 +1430,28 @@ map_vectorcall(PyObject *type, PyObject * const*args,
 }
 
 static void
-map_dealloc(mapobject *lz)
+map_dealloc(PyObject *self)
 {
+    mapobject *lz = _mapobject_CAST(self);
     PyObject_GC_UnTrack(lz);
     Py_XDECREF(lz->iters);
     Py_XDECREF(lz->func);
     Py_TYPE(lz)->tp_free(lz);
 }
 
 static int
-map_traverse(mapobject *lz, visitproc visit, void *arg)
+map_traverse(PyObject *self, visitproc visit, void *arg)
 {
+    mapobject *lz = _mapobject_CAST(self);
     Py_VISIT(lz->iters);
     Py_VISIT(lz->func);
     return 0;
 }
 
 static PyObject *
-map_next(mapobject *lz)
+map_next(PyObject *self)
 {
+    mapobject *lz = _mapobject_CAST(self);
     Py_ssize_t i;
     PyObject *small_stack[_PY_FASTCALL_SMALL_STACK];
     PyObject **stack;
@@ -1529,8 +1534,9 @@ map_next(mapobject *lz)
 }
 
 static PyObject *
-map_reduce(mapobject *lz, PyObject *Py_UNUSED(ignored))
+map_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
+    mapobject *lz = _mapobject_CAST(self);
     Py_ssize_t numargs = PyTuple_GET_SIZE(lz->iters);
     PyObject *args = PyTuple_New(numargs+1);
     Py_ssize_t i;
@@ -1551,19 +1557,20 @@ map_reduce(mapobject *lz, PyObject *Py_UNUSED(ignored))
 PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");
 
 static PyObject *
-map_setstate(mapobject *lz, PyObject *state)
+map_setstate(PyObject *self, PyObject *state)
 {
     int strict = PyObject_IsTrue(state);
     if (strict < 0) {
         return NULL;
     }
+    mapobject *lz = _mapobject_CAST(self);
     lz->strict = strict;
     Py_RETURN_NONE;
 }
 
 static PyMethodDef map_methods[] = {
-    {"__reduce__", _PyCFunction_CAST(map_reduce), METH_NOARGS, reduce_doc},
-    {"__setstate__", _PyCFunction_CAST(map_setstate), METH_O, setstate_doc},
+    {"__reduce__", map_reduce, METH_NOARGS, reduce_doc},
+    {"__setstate__", map_setstate, METH_O, setstate_doc},
     {NULL,           NULL}           /* sentinel */
 };
 
@@ -1584,7 +1591,7 @@ PyTypeObject PyMap_Type = {
     sizeof(mapobject),                  /* tp_basicsize */
     0,                                  /* tp_itemsize */
     /* methods */
-    (destructor)map_dealloc,            /* tp_dealloc */
+    map_dealloc,                        /* tp_dealloc */
     0,                                  /* tp_vectorcall_offset */
     0,                                  /* tp_getattr */
     0,                                  /* tp_setattr */
@@ -1602,12 +1609,12 @@ PyTypeObject PyMap_Type = {
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
         Py_TPFLAGS_BASETYPE,            /* tp_flags */
     map_doc,                            /* tp_doc */
-    (traverseproc)map_traverse,         /* tp_traverse */
+    map_traverse,                       /* tp_traverse */
     0,                                  /* tp_clear */
     0,                                  /* tp_richcompare */
     0,                                  /* tp_weaklistoffset */
     PyObject_SelfIter,                  /* tp_iter */
-    (iternextfunc)map_next,     /* tp_iternext */
+    map_next,                           /* tp_iternext */
     map_methods,                        /* tp_methods */
     0,                                  /* tp_members */
     0,                                  /* tp_getset */
@@ -1620,7 +1627,7 @@ PyTypeObject PyMap_Type = {
     PyType_GenericAlloc,                /* tp_alloc */
     map_new,                            /* tp_new */
     PyObject_GC_Del,                    /* tp_free */
-    .tp_vectorcall = (vectorcallfunc)map_vectorcall
+    .tp_vectorcall = map_vectorcall
 };