[libcxx-commits] [libcxx] [libc++] Fix possible out of range access in bitset (PR #121348)

[Louis Dionne via libcxx-commits]

================
@@ -283,21 +287,30 @@ inline _LIBCPP_HIDE_FROM_ABI void __bitset<_N_words, _Size>::__init(unsigned lon
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
 #  ifndef _LIBCPP_CXX03_LANG
-#    if __SIZEOF_SIZE_T__ == 8
-    : __first_{__v}
-#    elif __SIZEOF_SIZE_T__ == 4
+#    if (__SIZEOF_LONG_LONG__ + __SIZEOF_SIZE_T__ - 1) / __SIZEOF_SIZE_T__ == 1
+    : __first_{static_cast<__storage_type>(__v)}
+#    elif (__SIZEOF_LONG_LONG__ + __SIZEOF_SIZE_T__ - 1) / __SIZEOF_SIZE_T__ == 2
----------------
ldionne wrote:

```suggestion
#    elif __SIZEOF_LONG_LONG__ <= 2 * __SIZEOF_SIZE_T__
```

and so on for the other ones below

https://github.com/llvm/llvm-project/pull/121348