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| author | Gregory P. Smith <greg@krypto.org> | 2012-12-10 18:15:46 -0800 |
|---|---|---|
| committer | Gregory P. Smith <greg@krypto.org> | 2012-12-10 18:15:46 -0800 |
| commit | 27cbcd6241d787b5e99c6ed05ec8377051f397aa (patch) | |
| tree | 02fe4460f5a52993a36a9aa575397f9001700ae1 /Include | |
| 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 'Include')
| -rw-r--r-- | Include/pyport.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Include/pyport.h b/Include/pyport.h index 9666cf28f9..c74ff9c7a4 100644 --- a/Include/pyport.h +++ b/Include/pyport.h @@ -145,7 +145,7 @@ Used in: PY_LONG_LONG #endif /* Prime multiplier used in string and various other hashes. */ -#define _PyHASH_MULTIPLIER 1000003 /* 0xf4243 */ +#define _PyHASH_MULTIPLIER 1000003UL /* 0xf4243 */ /* Parameters used for the numeric hash implementation. See notes for _PyHash_Double in Objects/object.c. Numeric hashes are based on |