[libcxx-commits] [libcxx] libcxx: fix bogus integer sanitizer warnings in hash helpers (PR #146715)

[via libcxx-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Jean-Michaël Celerier (jcelerier)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/146715.diff


2 Files Affected:

- (modified) libcxx/include/__config (+2) 
- (modified) libcxx/include/__functional/hash.h (+3-2) 


``````````diff
diff --git a/libcxx/include/__config b/libcxx/include/__config
index af8a297fdf3fd..5bbb54f94ae23 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1156,8 +1156,10 @@ typedef __char32_t char32_t;
 // Allow for build-time disabling of unsigned integer sanitization
 #  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
 #    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
+#    define _LIBCPP_DISABLE_UBSAN_INTEGER_CHECK __attribute__((__no_sanitize__("integer")))
 #  else
 #    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
+#    define _LIBCPP_DISABLE_UBSAN_INTEGER_CHECK
 #  endif
 
 #  if __has_feature(nullability)
diff --git a/libcxx/include/__functional/hash.h b/libcxx/include/__functional/hash.h
index 489a6f00b8a3d..5c4fa39c772f5 100644
--- a/libcxx/include/__functional/hash.h
+++ b/libcxx/include/__functional/hash.h
@@ -132,11 +132,12 @@ struct __murmur2_or_cityhash<_Size, 64> {
   static const _Size __k2 = 0x9ae16a3b2f90404fULL;
   static const _Size __k3 = 0xc949d7c7509e6557ULL;
 
-  _LIBCPP_HIDE_FROM_ABI static _Size __rotate(_Size __val, int __shift) {
+  _LIBCPP_HIDE_FROM_ABI static _Size _LIBCPP_DISABLE_UBSAN_INTEGER_CHECK __rotate(_Size __val, int __shift) {
     return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
   }
 
-  _LIBCPP_HIDE_FROM_ABI static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
+  _LIBCPP_HIDE_FROM_ABI static _Size _LIBCPP_DISABLE_UBSAN_INTEGER_CHECK
+  __rotate_by_at_least_1(_Size __val, int __shift) {
     return (__val >> __shift) | (__val << (64 - __shift));
   }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/146715