[libcxx] [llvm] [libc++] Diagnose when nullptrs are passed to string APIs (PR #122790)

[Mark de Wever via llvm-commits]

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@@ -1037,13 +1037,14 @@ public:
 #  endif // _LIBCPP_CXX03_LANG
 
   template <__enable_if_t<__is_allocator<_Allocator>::value, int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* __s) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* _LIBCPP_DIAGNOSE_NONNULL __s) {
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mordante wrote:

I feel the name `_LIBCPP_DIAGNOSE_NONNULL` is very confusion. I would expect a diagnostic when the value is not NULL. I think the name  `_LIBCPP_NONNULL` would be better and more in alignment with what we do for attributes. WDYT?

https://github.com/llvm/llvm-project/pull/122790