[clang] [compiler-rt] [libcxx] [llvm] [clang] Warn about memset/memcpy to NonTriviallyCopyable types (PR #111434)

[Aaron Ballman via cfe-commits]

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@@ -102,7 +102,7 @@ struct __aliasing_iterator_wrapper {
 
     _LIBCPP_HIDE_FROM_ABI _Alias operator*() const _NOEXCEPT {
       _Alias __val;
-      __builtin_memcpy(&__val, std::__to_address(__base_), sizeof(value_type));
+      __builtin_memcpy(&__val, static_cast<const void*>(std::__to_address(__base_)), sizeof(value_type));
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AaronBallman wrote:

Yeah, this seems like it's plausibly UB. There's an assertion that `__val` is trivial, but I'm not seeing any such assertion for `__base_`; does something else ensure that `_BaseIter` is trivial?

https://github.com/llvm/llvm-project/pull/111434