fix abi break change

Author: poor-circle

libcxx/docs/ABIGuarantees.rst

@@ -114,6 +114,10 @@ hand, backwards compatibility is generally guaranteed.
 
 There are multiple ABI flags that change the symbols exported from the built library:
 
+``_LIBCPP_ABI_DO_NOT_EXPORT_ALIGN``
+-------------------------------------------------
+This removes ``align()``. In the past ``align()`` is not an inline function, but now it changed to an inline function for performance.
+
 ``_LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON``
 -------------------------------------------------
 This removes ``__basic_string_common<true>::__throw_length_error()`` and

libcxx/docs/ReleaseNotes/22.rst

@@ -101,8 +101,6 @@ Potentially breaking changes
   ``_LIBCPP_ABI_NO_ITERATOR_BASES``. If you are using this flag and care about ABI stability, you should set
   ``_LIBCPP_ABI_NO_REVERSE_ITERATOR_SECOND_MEMBER`` as well.
 
-- ``align`` has been removed from libc++ dynamic library in ABI v2. You could use the ABI flag ``_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS`` to reserve it.
-
 Announcements About Future Releases
 -----------------------------------
 
@@ -118,7 +116,7 @@ ABI Affecting Changes
   potentially inheriting from the types they wrap. At this point in time we are not aware of any ABI changes caused by
   this.
 
-- ``align`` has been removed from libc++ dynamic library in ABI v2. You could use the ABI flag ``_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS`` to reserve it.
+- ``align`` has been removed from libc++ library in ABI v2. We also add a new ABI flag ``_LIBCPP_ABI_DO_NOT_EXPORT_ALIGN``.
 
 Build System Changes
 --------------------

libcxx/include/__configuration/abi.h

@@ -63,6 +63,7 @@
 
 // These flags are documented in ABIGuarantees.rst
 #  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
+#  define _LIBCPP_ABI_DO_NOT_EXPORT_ALIGN
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_TO_CHARS_BASE_10

libcxx/include/__memory/align.h

@@ -35,13 +35,13 @@ __align_impl(size_t __align, size_t __sz, void*& __ptr, size_t& __space) {
   return __r;
 }
 
-#ifndef _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
+#ifndef _LIBCPP_EXPORT_ALIGN_SYMBOL
 
 inline _LIBCPP_HIDE_FROM_ABI void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space) {
   return __align_impl(__align, __sz, __ptr, __space);
 }
 
-#endif // _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
+#endif // _LIBCPP_EXPORT_ALIGN_SYMBOL
 
 _LIBCPP_END_NAMESPACE_STD
 

libcxx/src/memory.cpp

@@ -8,9 +8,11 @@
 
 #include <__config>
 #ifdef _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
-#  define _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
 #  define _LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS
 #endif
+#ifndef _LIBCPP_ABI_DO_NOT_EXPORT_ALIGN
+#  define _LIBCPP_EXPORT_ALIGN_SYMBOL
+#endif
 
 #include <__functional/hash.h>
 #include <memory>
@@ -133,11 +135,11 @@ __sp_mut& __get_sp_mut(const void* p) {
 
 #endif // _LIBCPP_HAS_THREADS
 
-#if defined(_LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS)
+#if defined(_LIBCPP_EXPORT_ALIGN_SYMBOL)
 
 _LIBCPP_EXPORTED_FROM_ABI void* align(size_t alignment, size_t size, void*& ptr, size_t& space) {
   return __align_impl(alignment, size, ptr, space);
 }
-#endif // _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
+#endif // _LIBCPP_EXPORT_ALIGN_SYMBOL
 
 _LIBCPP_END_NAMESPACE_STD