Issue #20539: Improve math.factorial error messages and types for large inputs.
- Better message for the OverflowError in large positive inputs.
- Changed exception type from OverflowError to ValueError for large negative inputs.
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 48f84ba..c9f3f16 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -422,9 +422,17 @@
self.assertEqual(math.factorial(i), py_factorial(i))
self.assertRaises(ValueError, math.factorial, -1)
self.assertRaises(ValueError, math.factorial, -1.0)
+ self.assertRaises(ValueError, math.factorial, -10**100)
+ self.assertRaises(ValueError, math.factorial, -1e100)
self.assertRaises(ValueError, math.factorial, math.pi)
- self.assertRaises(OverflowError, math.factorial, sys.maxsize+1)
- self.assertRaises(OverflowError, math.factorial, 10e100)
+
+ # Other implementations may place different upper bounds.
+ @support.cpython_only
+ def testFactorialHugeInputs(self):
+ # Currently raises ValueError for inputs that are too large
+ # to fit into a C long.
+ self.assertRaises(OverflowError, math.factorial, 10**100)
+ self.assertRaises(OverflowError, math.factorial, 1e100)
def testFloor(self):
self.assertRaises(TypeError, math.floor)
diff --git a/Misc/NEWS b/Misc/NEWS
index f7490e9..dc61927 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -31,6 +31,10 @@
Library
-------
+- Issue #20539: Improved math.factorial error message for large positive inputs
+ and changed exception type (OverflowError -> ValueError) for large negative
+ inputs.
+
- Issue #21172: isinstance check relaxed from dict to collections.Mapping.
- Issue #21155: asyncio.EventLoop.create_unix_server() now raises a ValueError
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 7f094ff..7f525ea 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1408,6 +1408,7 @@
math_factorial(PyObject *self, PyObject *arg)
{
long x;
+ int overflow;
PyObject *result, *odd_part, *two_valuation;
if (PyFloat_Check(arg)) {
@@ -1421,15 +1422,22 @@
lx = PyLong_FromDouble(dx);
if (lx == NULL)
return NULL;
- x = PyLong_AsLong(lx);
+ x = PyLong_AsLongAndOverflow(lx, &overflow);
Py_DECREF(lx);
}
else
- x = PyLong_AsLong(arg);
+ x = PyLong_AsLongAndOverflow(arg, &overflow);
- if (x == -1 && PyErr_Occurred())
+ if (x == -1 && PyErr_Occurred()) {
return NULL;
- if (x < 0) {
+ }
+ else if (overflow == 1) {
+ PyErr_Format(PyExc_OverflowError,
+ "factorial() argument should not exceed %ld",
+ LONG_MAX);
+ return NULL;
+ }
+ else if (overflow == -1 || x < 0) {
PyErr_SetString(PyExc_ValueError,
"factorial() not defined for negative values");
return NULL;