[libcxx-commits] [libcxx] [z/OS][libc++] Guard to be used only when `align_val_t` is available (PR #114396)

[Louis Dionne via libcxx-commits]

================
@@ -66,16 +66,24 @@ class __small_buffer {
     if constexpr (__fits_in_buffer<_Stored>) {
       return std::launder(reinterpret_cast<_Stored*>(__buffer_));
     } else {
+#  ifdef _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
       byte* __allocation = static_cast<byte*>(::operator new[](sizeof(_Stored), align_val_t{alignof(_Stored)}));
       std::construct_at(reinterpret_cast<byte**>(__buffer_), __allocation);
       return std::launder(reinterpret_cast<_Stored*>(__allocation));
+#  else
+      return static_cast<_Stored*>(std::__libcpp_allocate(_BufferSize * sizeof(byte), _LIBCPP_ALIGNOF(byte)));
+#  endif // _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
     }
   }
 
   template <class _Stored>
   _LIBCPP_HIDE_FROM_ABI void __dealloc() noexcept {
     if constexpr (!__fits_in_buffer<_Stored>)
+#  ifdef _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
       ::operator delete[](*reinterpret_cast<void**>(__buffer_), sizeof(_Stored), align_val_t{alignof(_Stored)});
+#  else
+      std::__libcpp_deallocate((void*)__buffer_, _BufferSize * sizeof(byte), _LIBCPP_ALIGNOF(_Stored));
+#  endif // _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
----------------
ldionne wrote:

Similarly, here I would do this unconditionally (without `#if`):

```c++
std::__libcpp_deallocate((void*)__buffer_, _BufferSize * sizeof(byte), alignof(_Stored));
```

https://github.com/llvm/llvm-project/pull/114396