Cherry-pick 76fc35752d19ac605c1c1fd757af9c7c3bb4a906 to release/12.x #50102
Description
| Bugzilla Link | 50758 |
| Resolution | FIXED |
| Resolved on | Jun 22, 2021 17:36 |
| Version | 12.0 |
| OS | All |
| Blocks | #48661 |
| CC | @mclow,@tstellar |
| Fixed by commit(s) | 76fc357 fa21c5d |
Extended Description
That is:
[libc++] Make feature-test macros consistent with availability macros
Before this patch, feature-test macros didn't take special availability
markup into account, which means that feature-test macros can sometimes
appear to "lie". For example, if you compile in C++20 mode and target
macOS 10.13, the __cpp_lib_filesystem feature-test macro will be provided
even though the <filesystem> declarations are marked as unavailable.
This patch fixes that.
rdar://68142369
Differential Revision: https://reviews.llvm.org/D94983