[PATCH] D46112: Allow _Atomic to be specified on incomplete types

[Eli Friedman via Phabricator via cfe-commits]

efriedma added a comment.

This generally makes sense.

Need some tests to make sure we emit an appropriate error if you try to actually use atomic operators (load/store) or intrinsics (__atomic_is_lock_free etc.) with an incomplete type.  And a test that code generation emits something appropriate.



================
Comment at: lib/Sema/SemaType.cpp:8022
+    else if (LangOpts.CPlusPlus && isCompleteType(Loc, T) &&
+             !T.isTriviallyCopyableType(Context))
       // Some other non-trivially-copyable type (probably a C++ class)
----------------
If you're going to allow incomplete types in C++, you'll need some code to handle the case where the type is initially incomplete, but completed later.


https://reviews.llvm.org/D46112