[PATCH] D128927: [libc++] Always build c++experimental.a

[Mark de Wever via Phabricator via cfe-commits]

Mordante accepted this revision.
Mordante added a comment.
This revision is now accepted and ready to land.

Thanks for working on this! LGTM with some suggestions.



================
Comment at: libcxx/docs/ReleaseNotes.rst:226
+  experimental features provided by it. Note that vendors are encouraged to ship the
+  experimental library now that the compiler provides an ergonomic way to use it.
----------------
I agree this is a build system change, but I wonder how many users read this part and find the hidden gem.
Should we add a note at new features too? Maybe there we can mention format and ranges are available with this new switch.
(technically that actually belongs in the next patch, but I wouldn't mind to do it in this patch.)


================
Comment at: libcxx/docs/UsingLibcxx.rst:42
+default because they are neither API nor ABI stable. However, the Clang flag ``-funstable``
+can be used to turn those features on.
 
----------------
I think it would be good to explain what experimental features are. The current wording makes it sound the features may not be part of an IS, WP, or TS.

How about something like
```
Libc++ provides implementations of some experimental features. Experimental features
are either a TS or a feature in the Standard whose implementation is incomplete. Those
features are disabled by default because they are neither API nor ABI stable. However,
the Clang flag ``-funstable`` can be used to turn those features on.
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D128927/new/

https://reviews.llvm.org/D128927