erichkeane wrote: > > > > > The MSVC FE team hasn't expressed enthusiasm for adding ugly > > > > > spellings. If I learn more I'll relay that info. > > > > > > > > > > > > Thank you for checking! Unfortunately, I think that's a reason for > > > > Clang to not support it for the `msvc` vendor prefix either. > > > > > > > > > What is the alternative? > > > > > > Can you get away with not using `[[msvc::no_unique_address]]`? If so, I'd > > go that route. > > No. We need it to have a reasonable ABI. > > If not, I'd say use the attribute with the non-ugly spelling and woe unto > > anyone defining `msvc` as a macro despite that being a perfectly valid > > thing for them to do. You could be "kind" and do > > ``` > > #ifdef msvc > > #error "Microsoft's vendor specific attribute prefix steals this identifier > > from the user's namespace, please file an issue with Microsoft if you see > > this diagnostic" > > #endif > > ``` > > > > > > > > > > > > > > > > > > > > > > > > or something along those lines. > > This steals both `msvc` and `no_unique_address` and does that on all > platforms, not just MSVC, so that's not exactly a thrilling solution. Would > defining a namespace like `__clang_msvc__` be an option? libc++ only cares > about Clang on MSVC targets, so it's pretty much irrelevant what MSVC does > for us. Adding an alias like `[[_Clang::__no_unique_address__]]` would also > work if that's more palatable. That'd have to be added to any msvc attributes > libc++ cares about of course (though currently that's only > `[[msvc::no_unique_address]]`).
I'm personally sympathetic, and would be ok with something that we know MSVC won't step on (`__clang_msvc__` would be fine to me). As far as the `no_unique_address`, I THINK we already get the double-underscore spelling of that, don't we? I don't think we exclude the MSVC spellings from that. https://github.com/llvm/llvm-project/pull/113765 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
