[libc++] Add _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
It's useful to be able to disable visibility annotations entirely; for
example, if we're building libc++ static to include in another library,
and we don't want any libc++ functions getting exported out of that
library. This is a generalization of _LIBCPP_DISABLE_DLL_IMPORT_EXPORT.
Differential Revision: https://reviews.llvm.org/D26934
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@288690 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/UsingLibcxx.rst b/docs/UsingLibcxx.rst
index 8234994..1d2cc9e 100644
--- a/docs/UsingLibcxx.rst
+++ b/docs/UsingLibcxx.rst
@@ -149,3 +149,9 @@
This macro is used to enable -Wthread-safety annotations on libc++'s
``std::mutex`` and ``std::lock_guard``. By default these annotations are
disabled and must be manually enabled by the user.
+
+**_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS**:
+ This macro is used to disable all visibility annotations inside libc++.
+ Defining this macro and then building libc++ with hidden visibility gives a
+ build of libc++ which does not export any symbols, which can be useful when
+ building statically for inclusion into another library.