diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/rangeobject.c | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c index 5c3230d..a848d67 100644 --- a/Objects/rangeobject.c +++ b/Objects/rangeobject.c @@ -915,22 +915,14 @@ get_len_of_range(long lo, long hi, long step) is not representable as a C long, OverflowError is raised. */ static PyObject * -fast_range_iter(long start, long stop, long step) +fast_range_iter(long start, long stop, long step, long len) { rangeiterobject *it = PyObject_New(rangeiterobject, &PyRangeIter_Type); - unsigned long ulen; if (it == NULL) return NULL; it->start = start; it->step = step; - ulen = get_len_of_range(start, stop, step); - if (ulen > (unsigned long)LONG_MAX) { - Py_DECREF(it); - PyErr_SetString(PyExc_OverflowError, - "range too large to represent as a range_iterator"); - return NULL; - } - it->len = (long)ulen; + it->len = len; it->index = 0; return (PyObject *)it; } @@ -1092,7 +1084,7 @@ range_iter(PyObject *seq) rangeobject *r = (rangeobject *)seq; longrangeiterobject *it; long lstart, lstop, lstep; - PyObject *int_it; + unsigned long ulen; assert(PyRange_Check(seq)); @@ -1113,12 +1105,22 @@ range_iter(PyObject *seq) PyErr_Clear(); goto long_range; } - int_it = fast_range_iter(lstart, lstop, lstep); - if (int_it == NULL && PyErr_ExceptionMatches(PyExc_OverflowError)) { - PyErr_Clear(); + ulen = get_len_of_range(lstart, lstop, lstep); + if (ulen > (unsigned long)LONG_MAX) { goto long_range; } - return (PyObject *)int_it; + /* check for potential overflow of lstart + ulen * lstep */ + if (ulen) { + if (lstep > 0) { + if (lstop > LONG_MAX - (lstep - 1)) + goto long_range; + } + else { + if (lstop < LONG_MIN + (-1 - lstep)) + goto long_range; + } + } + return fast_range_iter(lstart, lstop, lstep, (long)ulen); long_range: it = PyObject_New(longrangeiterobject, &PyLongRangeIter_Type); @@ -1204,7 +1206,7 @@ range_reverse(PyObject *seq, PyObject *Py_UNUSED(ignored)) new_stop = lstart - lstep; new_start = (long)(new_stop + ulen * lstep); - return fast_range_iter(new_start, new_stop, -lstep); + return fast_range_iter(new_start, new_stop, -lstep, (long)ulen); long_range: it = PyObject_New(longrangeiterobject, &PyLongRangeIter_Type); |