diff options
| -rw-r--r-- | Objects/abstract.c | 105 |
1 files changed, 61 insertions, 44 deletions
diff --git a/Objects/abstract.c b/Objects/abstract.c index 33991a8..24b09f5 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -1740,45 +1740,46 @@ PyObject_CallMethod(PyObject *o, char *name, char *format, ...) /* isinstance(), issubclass() */ -static int -abstract_issubclass(PyObject *derived, PyObject *cls, int first) +static PyObject * +abstract_get_bases(PyObject *cls) { static PyObject *__bases__ = NULL; PyObject *bases; - int i, n; - int r = 0; if (__bases__ == NULL) { __bases__ = PyString_FromString("__bases__"); if (__bases__ == NULL) - return -1; + return NULL; } - if (first) { - bases = PyObject_GetAttr(cls, __bases__); - if (bases == NULL || !PyTuple_Check(bases)) { - Py_XDECREF(bases); - PyErr_SetString(PyExc_TypeError, - "issubclass() arg 2 must be a class"); - return -1; - } - Py_DECREF(bases); + bases = PyObject_GetAttr(cls, __bases__); + if (bases == NULL || !PyTuple_Check(bases)) { + Py_XDECREF(bases); + return NULL; } + return bases; +} + + +static int +abstract_issubclass(PyObject *derived, PyObject *cls) +{ + PyObject *bases; + int i, n; + int r = 0; + + if (derived == cls) return 1; - bases = PyObject_GetAttr(derived, __bases__); - if (bases == NULL || !PyTuple_Check(bases)) { - Py_XDECREF(bases); - PyErr_SetString(PyExc_TypeError, - "issubclass() arg 1 must be a class"); - return -1; - } + bases = abstract_get_bases(derived); + if (bases == NULL) + return 0; n = PyTuple_GET_SIZE(bases); for (i = 0; i < n; i++) { - r = abstract_issubclass(PyTuple_GET_ITEM(bases, i), cls, 0); + r = abstract_issubclass(PyTuple_GET_ITEM(bases, i), cls); if (r != 0) break; } @@ -1795,12 +1796,10 @@ PyObject_IsInstance(PyObject *inst, PyObject *cls) static PyObject *__class__ = NULL; int retval = 0; - if (PyClass_Check(cls)) { - if (PyInstance_Check(inst)) { - PyObject *inclass = - (PyObject*)((PyInstanceObject*)inst)->in_class; - retval = PyClass_IsSubclass(inclass, cls); - } + if (PyClass_Check(cls) && PyInstance_Check(inst)) { + PyObject *inclass = + (PyObject*)((PyInstanceObject*)inst)->in_class; + retval = PyClass_IsSubclass(inclass, cls); } else if (PyType_Check(cls)) { retval = PyObject_TypeCheck(inst, (PyTypeObject *)cls); @@ -1819,31 +1818,30 @@ PyObject_IsInstance(PyObject *inst, PyObject *cls) } return retval; } - else if (!PyInstance_Check(inst)) { + else { + PyObject *cls_bases = abstract_get_bases(cls); + if (cls_bases == NULL) { + PyErr_SetString(PyExc_TypeError, + "isinstance() arg 2 must be a class or type"); + return -1; + } + Py_DECREF(cls_bases); if (__class__ == NULL) { __class__ = PyString_FromString("__class__"); if (__class__ == NULL) return -1; } icls = PyObject_GetAttr(inst, __class__); - if (icls != NULL) { - retval = abstract_issubclass(icls, cls, 1); + if (icls == NULL) { + PyErr_Clear(); + retval = 0; + } + else { + retval = abstract_issubclass(icls, cls); Py_DECREF(icls); - if (retval < 0 && - !PyErr_ExceptionMatches(PyExc_TypeError)) - return -1; } - else - retval = -1; } - else - retval = -1; - if (retval < 0) { - PyErr_SetString(PyExc_TypeError, - "isinstance() arg 2 must be a class or type " - "or tuple of those"); - } return retval; } @@ -1853,7 +1851,26 @@ PyObject_IsSubclass(PyObject *derived, PyObject *cls) int retval; if (!PyClass_Check(derived) || !PyClass_Check(cls)) { - retval = abstract_issubclass(derived, cls, 1); + PyObject *derived_bases; + PyObject *cls_bases; + + derived_bases = abstract_get_bases(derived); + if (derived_bases == NULL) { + PyErr_SetString(PyExc_TypeError, + "issubclass() arg 1 must be a class"); + return -1; + } + Py_DECREF(derived_bases); + + cls_bases = abstract_get_bases(cls); + if (cls_bases == NULL) { + PyErr_SetString(PyExc_TypeError, + "issubclass() arg 2 must be a class"); + return -1; + } + Py_DECREF(cls_bases); + + retval = abstract_issubclass(derived, cls); } else { /* shortcut */ |