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author | Gregory P. Smith <greg@krypto.org> | 2012-12-10 18:15:46 -0800 |
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committer | Gregory P. Smith <greg@krypto.org> | 2012-12-10 18:15:46 -0800 |
commit | 27cbcd6241d787b5e99c6ed05ec8377051f397aa (patch) | |
tree | 02fe4460f5a52993a36a9aa575397f9001700ae1 /Objects/unicodeobject.c | |
parent | 90555d0f0d0b8e4ffbbb37ba12a8e43020ad1e98 (diff) | |
download | cpython-git-27cbcd6241d787b5e99c6ed05ec8377051f397aa.tar.gz |
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.
Diffstat (limited to 'Objects/unicodeobject.c')
-rw-r--r-- | Objects/unicodeobject.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 565d298270..bb45b20b90 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -7686,7 +7686,7 @@ unicode_hash(PyUnicodeObject *self) { Py_ssize_t len; Py_UNICODE *p; - Py_hash_t x; + Py_uhash_t x; /* Unsigned for defined overflow behavior. */ #ifdef Py_DEBUG assert(_Py_HashSecret_Initialized); |