diff options
| -rw-r--r-- | Misc/NEWS | 11 | ||||
| -rw-r--r-- | Modules/cPickle.c | 9 | ||||
| -rw-r--r-- | Objects/typeobject.c | 32 |
3 files changed, 49 insertions, 3 deletions
@@ -75,6 +75,17 @@ Build C API ----- +- PyType_Ready(): If a type declares that it participates in gc + (Py_TPFLAGS_HAVE_GC), and its base class does not, and its base class's + tp_free slot is the default _PyObject_Del, and type does not define + a tp_free slot itself, _PyObject_GC_Del is assigned to type->tp_free. + Previously _PyObject_Del was inherited, which could at best lead to a + segfault. In addition, if even after this magic the type's tp_free + slot is _PyObject_Del or NULL, and the type is a base type + (Py_TPFLAGS_BASETYPE), TypeError is raised: since the type is a base + type, its dealloc function must call type->tp_free, and since the type + is gc'able, tp_free must not be NULL or _PyObject_Del. + New platforms ------------- diff --git a/Modules/cPickle.c b/Modules/cPickle.c index 733587e..b928e47 100644 --- a/Modules/cPickle.c +++ b/Modules/cPickle.c @@ -2853,7 +2853,7 @@ Pickler_dealloc(Picklerobject *self) Py_XDECREF(self->inst_pers_func); Py_XDECREF(self->dispatch_table); PyMem_Free(self->write_buf); - PyObject_GC_Del(self); + self->ob_type->tp_free((PyObject *)self); } static int @@ -5212,7 +5212,7 @@ Unpickler_dealloc(Unpicklerobject *self) free(self->buf); } - PyObject_GC_Del(self); + self->ob_type->tp_free((PyObject *)self); } static int @@ -5534,6 +5534,11 @@ init_stuff(PyObject *module_dict) #define INIT_STR(S) if (!( S ## _str=PyString_InternFromString(#S))) return -1; + if (PyType_Ready(&Unpicklertype) < 0) + return -1; + if (PyType_Ready(&Picklertype) < 0) + return -1; + INIT_STR(__class__); INIT_STR(__getinitargs__); INIT_STR(__dict__); diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 9a23227..18b50fc 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -3044,8 +3044,25 @@ inherit_slots(PyTypeObject *type, PyTypeObject *base) COPYSLOT(tp_dictoffset); COPYSLOT(tp_init); COPYSLOT(tp_alloc); - COPYSLOT(tp_free); COPYSLOT(tp_is_gc); + if ((type->tp_flags & Py_TPFLAGS_HAVE_GC) == + (base->tp_flags & Py_TPFLAGS_HAVE_GC)) { + /* They agree about gc. */ + COPYSLOT(tp_free); + } + else if ((type->tp_flags & Py_TPFLAGS_HAVE_GC) && + type->tp_free == NULL && + base->tp_free == _PyObject_Del) { + /* A bit of magic to plug in the correct default + * tp_free function when a derived class adds gc, + * didn't define tp_free, and the base uses the + * default non-gc tp_free. + */ + type->tp_free = PyObject_GC_Del; + } + /* else they didn't agree about gc, and there isn't something + * obvious to be done -- the type is on its own. + */ } } @@ -3149,6 +3166,19 @@ PyType_Ready(PyTypeObject *type) inherit_slots(type, (PyTypeObject *)b); } + /* Sanity check for tp_free. */ + if (PyType_IS_GC(type) && (type->tp_flags & Py_TPFLAGS_BASETYPE) && + (type->tp_free == NULL || type->tp_free == PyObject_Del)) { + /* This base class needs to call tp_free, but doesn't have + * one, or its tp_free is for non-gc'ed objects. + */ + PyErr_Format(PyExc_TypeError, "type '%.100s' participates in " + "gc and is a base type but has inappropriate " + "tp_free slot", + type->tp_name); + goto error; + } + /* if the type dictionary doesn't contain a __doc__, set it from the tp_doc slot. */ |