diff options
Diffstat (limited to 'libcxx/docs/DesignDocs')
| -rw-r--r-- | libcxx/docs/DesignDocs/VisibilityMacros.rst | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/libcxx/docs/DesignDocs/VisibilityMacros.rst b/libcxx/docs/DesignDocs/VisibilityMacros.rst index 878566ea0bc..493b445750e 100644 --- a/libcxx/docs/DesignDocs/VisibilityMacros.rst +++ b/libcxx/docs/DesignDocs/VisibilityMacros.rst @@ -46,6 +46,21 @@ Visibility Macros other words, the address of a function marked with this attribute is not guaranteed to be the same across translation units. +**_LIBCPP_HIDE_FROM_ABI_AFTER_V1** + Mark a function as being hidden from the ABI (per `_LIBCPP_HIDE_FROM_ABI`) + when libc++ is built with an ABI version after ABI v1. This macro is used to + maintain ABI compatibility for symbols that have been historically exported + by libc++ in v1 of the ABI, but that we don't want to export in the future. + + This macro works as follows. When we build libc++, we either hide the symbol + from the ABI (if the symbol is not part of the ABI in the version we're + building), or we leave it included. From user code (i.e. when we're not + building libc++), the macro always marks symbols as internal so that programs + built using new libc++ headers stop relying on symbols that are removed from + the ABI in a future version. Each time we release a new stable version of the + ABI, we should create a new _LIBCPP_HIDE_FROM_ABI_AFTER_XXX macro, and we can + use it to start removing symbols from the ABI after that stable version. + **_LIBCPP_TYPE_VIS** Mark a type's typeinfo, vtable and members as having default visibility. This attribute cannot be used on class templates. @@ -139,15 +154,6 @@ Visibility Macros against the libc++ headers after making `_LIBCPP_TYPE_VIS` and `_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS` expand to default visibility. -**_LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY** - Mark a member function of a class template as visible and always inline. This - macro should only be applied to member functions of class templates that are - externally instantiated. It is important that these symbols are not marked - as hidden as that will prevent the dylib definition from being found. - - This macro is used to maintain ABI compatibility for symbols that have been - historically exported by the libc++ library but are now marked inline. - **_LIBCPP_EXCEPTION_ABI** Mark the member functions, typeinfo, and vtable of the type as being exported by the libc++ library. This macro must be applied to all *exception types*. |
