[libcxx-commits] [PATCH] D120064: Fix EBO on std::optional and std::variant when targeting the MSVC ABI

Thu Mar 3 23:58:55 PST 2022

hans added a comment.

In D120064#3352471 <https://reviews.llvm.org/D120064#3352471>, @ldionne wrote:

> In D120064#3352402 <https://reviews.llvm.org/D120064#3352402>, @rnk wrote:
>
>> In D120064#3352256 <https://reviews.llvm.org/D120064#3352256>, @mstorsjo wrote:
>>
>>> @rnk @thakis @hans Is such an ABI break in libc++ for the clang-cl case tolerable for you guys?
>>
>> Yes, we can tolerate it, but that's not a great proxy for project policy.
>>
>> I think, in practice, libc++ is not the system-standard C++ library in MSVC environments. It would be reasonable for libc++ to proclaim that the MSVC libc++ ABI is unstable, for now. I expect we will discover more issues like this in the near future. We may wish to re-evaluate the placement of dllexport annotations, for example, since @smeenai informed me that they interact poorly with inlining.
>
> Yeah, I agree with that. We could update the Windows row in https://libcxx.llvm.org/#platform-and-compiler-support to say that the ABI is unstable -- would that be reasonable?

Sounds reasonable to me.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D120064/new/

https://reviews.llvm.org/D120064