Preemptively disable unsigned integer sanitization in 32 and 64 bit versions of __murmur2_or_cityhash. This lets people use the unsigned integer overflow checker in UBSAN w/o getting hits from libc++'s hash code (where the unsigned integer overflow is legal and deliberate)> Patch by @danielaustin. Reviewed as: http://reviews.llvm.org/D15973 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@257368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config index c0b1ef2..b6f7bd3 100644 --- a/include/__config +++ b/include/__config
@@ -597,6 +597,11 @@ #define _LIBCPP_HAS_NO_ASAN +// Allow for build-time disabling of unsigned integer sanitization +#ifndef _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK +#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute((no_sanitize("unsigned integer"))) +#endif + #endif // __clang__ || __GNUC__ || _MSC_VER || __IBMCPP__ #ifndef _LIBCPP_HAS_NO_NOEXCEPT @@ -826,6 +831,10 @@ #define _LIBCPP_HAS_NO_ATOMIC_HEADER #endif +#ifndef _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK +#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK +#endif + #endif // __cplusplus #endif // _LIBCPP_CONFIG diff --git a/include/memory b/include/memory index 65369d2..3ef687c 100644 --- a/include/memory +++ b/include/memory
@@ -3194,7 +3194,7 @@ // murmur2 template <class _Size> _Size -__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len) +__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len) _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK { const _Size __m = 0x5bd1e995; const _Size __r = 24; @@ -3344,7 +3344,7 @@ // cityhash64 template <class _Size> _Size -__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len) +__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len) _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK { const char* __s = static_cast<const char*>(__key); if (__len <= 32) { 