Mercurial > cpython-lru_cache-weakref
diff Objects/tupleobject.c @ 43451:381ed41003e7 legacy-trunk
tuple.__repr__ did not consider a reference loop as it is not possible from
Python code; but it is possible from C. object.__str__ had the issue of not
expecting a type to doing something within it's tp_str implementation that
could trigger an infinite recursion, but it could in C code.. Both found
thanks to BaseException and how it handles its repr.
Closes issue #1686386. Thanks to Thomas Herve for taking an initial stab at
coming up with a solution.
| author | Brett Cannon <bcannon@gmail.com> |
|---|---|
| date | Sun, 30 Sep 2007 19:45:10 +0000 |
| parents | 7630248b593c |
| children | 106a71c51477 |
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--- a/Objects/tupleobject.c Thu Sep 27 07:35:10 2007 +0000 +++ b/Objects/tupleobject.c Sun Sep 30 19:45:10 2007 +0000 @@ -216,6 +216,15 @@ PyObject *s, *temp; PyObject *pieces, *result = NULL; + /* While not mutable, it is still possible to end up with a cycle in a + tuple through an object that stores itself within a tuple (and thus + infinitely asks for the repr of itself). This should only be + possible within a type. */ + i = Py_ReprEnter((PyObject *)v); + if (i != 0) { + return i > 0 ? PyString_FromString("(...)") : NULL; + } + n = Py_Size(v); if (n == 0) return PyString_FromString("()"); @@ -226,7 +235,10 @@ /* Do repr() on each element. */ for (i = 0; i < n; ++i) { + if (Py_EnterRecursiveCall(" while getting the repr of a tuple")) + goto Done; s = PyObject_Repr(v->ob_item[i]); + Py_LeaveRecursiveCall(); if (s == NULL) goto Done; PyTuple_SET_ITEM(pieces, i, s); @@ -261,6 +273,7 @@ Done: Py_DECREF(pieces); + Py_ReprLeave((PyObject *)v); return result; }