From 2d67fb897d9266c7ea698a620a2c2a7d6ffb1eb0 Mon Sep 17 00:00:00 2001 From: "Gregory P. Smith" Date: Mon, 10 Dec 2012 18:15:46 -0800 Subject: Fix the internals of our hash functions to used unsigned values during hash computation as the overflow behavior of signed integers is undefined. In practice we require compiling everything with -fwrapv which forces overflow to be defined as twos compliment but this keeps the code cleaner for checkers or in the case where someone has compiled it without -fwrapv or their compiler's equivalent. Found by Clang trunk's Undefined Behavior Sanitizer (UBSan). Cleanup only - no functionality or hash values change. --- Objects/setobject.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'Objects/setobject.c') diff --git a/Objects/setobject.c b/Objects/setobject.c index 3abeefb97d..d8401f4ae7 100644 --- a/Objects/setobject.c +++ b/Objects/setobject.c @@ -77,7 +77,7 @@ NULL if the rich comparison returns an error. static setentry * set_lookkey(PySetObject *so, PyObject *key, register Py_hash_t hash) { - register Py_ssize_t i; + register size_t i; /* Unsigned for defined overflow behavior. */ register size_t perturb; register setentry *freeslot; register size_t mask = so->mask; @@ -159,7 +159,7 @@ set_lookkey(PySetObject *so, PyObject *key, register Py_hash_t hash) static setentry * set_lookkey_unicode(PySetObject *so, PyObject *key, register Py_hash_t hash) { - register Py_ssize_t i; + register size_t i; /* Unsigned for defined overflow behavior. */ register size_t perturb; register setentry *freeslot; register size_t mask = so->mask; @@ -768,7 +768,7 @@ static Py_hash_t frozenset_hash(PyObject *self) { PySetObject *so = (PySetObject *)self; - Py_hash_t h, hash = 1927868237L; + Py_uhash_t h, hash = 1927868237UL; setentry *entry; Py_ssize_t pos = 0; @@ -783,11 +783,11 @@ frozenset_hash(PyObject *self) hashes so that many distinct combinations collapse to only a handful of distinct hash values. */ h = entry->hash; - hash ^= (h ^ (h << 16) ^ 89869747L) * 3644798167u; + hash ^= (h ^ (h << 16) ^ 89869747UL) * 3644798167UL; } - hash = hash * 69069L + 907133923L; + hash = hash * 69069UL + 907133923UL; if (hash == -1) - hash = 590923713L; + hash = 590923713UL; so->hash = hash; return hash; } -- cgit v1.2.1