[libc++] Make sure we can build libc++ with -fvisibility=hidden
Summary:
When building with -fvisibility=hidden, some symbols do not get exported from
libc++.dylib. This means that some entities are not explicitly given default
visibility in the source code, and that we rely on the fact -fvisibility=default
is the default. This commit explicitly gives default visibility to those
symbols to avoid being dependent on the command line flags used.
The commit also remove symbols from the dylib -- those symbols do not
actually need to be exported from the dylib and this should not be an
ABI break.
Finally, in the future, we may want to mark the whole std:: namespace as
having hidden visibility (to switch from opt-out to opt-in), in which
case the changes done in this commit will be required.
Reviewers: EricWF
Subscribers: mgorny, christof, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D52662
llvm-svn: 345260
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 9b3222f6134f40b68e16faf694ed9e97bc9fd325
diff --git a/docs/DesignDocs/VisibilityMacros.rst b/docs/DesignDocs/VisibilityMacros.rst
index 08debbc..d0d4f0a 100644
--- a/docs/DesignDocs/VisibilityMacros.rst
+++ b/docs/DesignDocs/VisibilityMacros.rst
@@ -22,11 +22,11 @@
Mark a symbol as being exported by the libc++ library. This attribute must
be applied to the declaration of all functions exported by the libc++ dylib.
-**_LIBCPP_EXTERN_VIS**
+**_LIBCPP_EXPORTED_FROM_ABI**
Mark a symbol as being exported by the libc++ library. This attribute may
- only be applied to objects defined in the libc++ library. On Windows this
- macro applies `dllimport`/`dllexport` to the symbol. On all other platforms
- this macro has no effect.
+ only be applied to objects defined in the libc++ runtime library. On Windows,
+ this macro applies `dllimport`/`dllexport` to the symbol, and on other
+ platforms it gives the symbol default visibility.
**_LIBCPP_OVERRIDABLE_FUNC_VIS**
Mark a symbol as being exported by the libc++ library, but allow it to be