script that reports a fairly safe recursionlimit for a specific platform
diff --git a/Misc/find_recursionlimit.py b/Misc/find_recursionlimit.py
new file mode 100644
index 0000000..f16c29f
--- /dev/null
+++ b/Misc/find_recursionlimit.py
@@ -0,0 +1,88 @@
+#! /usr/bin/env python
+"""Find the maximum recursion limit that prevents core dumps
+
+This script finds the maximum safe recursion limit on a particular
+platform. If you need to change the recursion limit on your system,
+this script will tell you a safe upper bound. To use the new limit,
+call sys.setrecursionlimit.
+
+This module implements several ways to create infinite recursion in
+Python. Different implementations end up pushing different numbers of
+C stack frames, depending on how many calls through Python's abstract
+C API occur.
+
+After each round of tests, it prints a message
+Limit of NNNN is fine.
+
+It ends when Python causes a segmentation fault because the limit is
+too high. On platforms like Mac and Windows, it should exit with a
+MemoryError.
+
+NB: A program that does not use __methods__ can set a higher limit.
+"""
+
+import sys
+
+class RecursiveBlowup1:
+ def __init__(self):
+ self.__init__()
+
+def test_init():
+ return RecursiveBlowup1()
+
+class RecursiveBlowup2:
+ def __repr__(self):
+ return repr(self)
+
+def test_repr():
+ return repr(RecursiveBlowup2())
+
+class RecursiveBlowup4:
+ def __add__(self, x):
+ return x + self
+
+def test_add():
+ return RecursiveBlowup4() + RecursiveBlowup4()
+
+class RecursiveBlowup5:
+ def __getattr__(self, attr):
+ return getattr(self, attr)
+
+def test_getattr():
+ return RecursiveBlowup5().attr
+
+class RecursiveBlowup6:
+ def __getitem__(self, item):
+ return self[item - 2] + self[item - 1]
+
+def test_getitem():
+ return RecursiveBlowup6()[5]
+
+def test_recurse():
+ return test_recurse()
+
+def check_limit(n, test_func_name):
+ sys.setrecursionlimit(n)
+ if test_func_name.startswith("test_"):
+ print test_func_name[5:]
+ else:
+ print test_func_name
+ test_func = globals()[test_func_name]
+ try:
+ test_func()
+ except RuntimeError:
+ pass
+ else:
+ print "Yikes!"
+
+limit = 1000
+while 1:
+ check_limit(limit, "test_recurse")
+ check_limit(limit, "test_add")
+ check_limit(limit, "test_repr")
+ check_limit(limit, "test_init")
+ check_limit(limit, "test_getattr")
+ check_limit(limit, "test_getitem")
+ print "Limit of %d is fine" % limit
+ limit = limit + 100
+