[libc++] Fix and document visibility attributes for Clang, GCC and Windows.
Summary:
This patch fixes a number of problems with the visibility macros across GCC (on Unix) and Windows (DLL import/export semantics). All of the visibility macros are now documented under `DesignDocs/VisibilityMacros.rst`. Now I'll no longer forget the subtleties of each!
This patch adds two new visibility macros:
* `_LIBCPP_ENUM_VIS` for controlling the typeinfo of enum types. Only Clang supports this.
* `_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS` for redefining visibility on explicit instantiation declarations. Clang and Windows require this.
After applying this patch GCC only emits one -Wattribute warning opposed to 30+.
Reviewers: mclow.lists, EricWF
Subscribers: beanz, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D24602
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281673 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__string b/include/__string
index 764ee56..fc6097a 100644
--- a/include/__string
+++ b/include/__string
@@ -701,7 +701,8 @@
}
template<class _Ptr>
-size_t _LIBCPP_INLINE_VISIBILITY __do_string_hash(_Ptr __p, _Ptr __e)
+inline _LIBCPP_INLINE_VISIBILITY
+size_t __do_string_hash(_Ptr __p, _Ptr __e)
{
typedef typename iterator_traits<_Ptr>::value_type value_type;
return __murmur2_or_cityhash<size_t>()(__p, (__e-__p)*sizeof(value_type));