diff options
Diffstat (limited to 'libcxx/docs')
| -rw-r--r-- | libcxx/docs/DesignDocs/VisibilityMacros.rst | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/libcxx/docs/DesignDocs/VisibilityMacros.rst b/libcxx/docs/DesignDocs/VisibilityMacros.rst index 861cc04ac45..2ee07142d85 100644 --- a/libcxx/docs/DesignDocs/VisibilityMacros.rst +++ b/libcxx/docs/DesignDocs/VisibilityMacros.rst @@ -22,6 +22,18 @@ Visibility Macros 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_OVERRIDABLE_FUNC_VIS** + Mark a symbol as being exported by the libc++ library, but allow it to be + overridden locally. On non-Windows, this is equivalent to `_LIBCPP_FUNC_VIS`. + This macro is applied to all `operator new` and `operator delete` overloads. + + **Windows Behavior**: Any symbol marked `dllimport` cannot be overridden + locally, since `dllimport` indicates the symbol should be bound to a separate + DLL. All `operator new` and `operator delete` overloads are required to be + locally overridable, and therefore must not be marked `dllimport`. On Windows, + this macro therefore expands to `__declspec(dllexport)` when building the + library and has an empty definition otherwise. + **_LIBCPP_INLINE_VISIBILITY** Mark a function as hidden and force inlining whenever possible. @@ -107,20 +119,6 @@ Visibility Macros versioning namespace. This allows throwing and catching some exception types between libc++ and libstdc++. -**_LIBCPP_NEW_DELETE_VIS** - Mark a symbol as being exported by the libc++ library. This macro must be - applied to all `operator new` and `operator delete` overloads. - - **Windows Behavior**: The `operator new` and `operator delete` overloads - should not be marked as `dllimport`; if they were, source files including the - `<new>` header (either directly or transitively) would lose the ability to use - local overloads of `operator new` and `operator delete`. On Windows, this - macro therefore expands to `__declspec(dllexport)` when building the library - and has an empty definition otherwise. A related caveat is that libc++ must be - included on the link line before `msvcrt.lib`, otherwise Microsoft's - definitions of `operator new` and `operator delete` inside `msvcrt.lib` will - end up being used instead of libc++'s. - Links ===== |
