libstdc++/77686 use may_alias for std::function storage

	PR libstdc++/77686
	* include/std/functional (_Any_data): Add may_alias attribute.

From-SVN: r240574

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 4a20ad942f5f661913befe81441bf894a9d8f437..95f754522ec7859d1a3d2bc41f0e4b5a7455f38e 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2016-09-28  Jonathan Wakely  <jwakely@redhat.com>
+
+       PR libstdc++/77686
+       * include/std/functional (_Any_data): Add may_alias attribute.
+
 2016-09-27  Jonathan Wakely  <jwakely@redhat.com>
 
        * include/debug/safe_iterator.h (_Safe_iterator::operator++()): Fix

diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index 90dc36fa1fc63b51e7fd69a678ff27f9d3a3d046..9b0f801da1c9e4cdd49930543c954217ccbc27d3 100644 (file)
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1593,7 +1593,7 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
     void (_Undefined_class::*_M_member_pointer)();
   };
 
-  union _Any_data
+  union [[gnu::may_alias]] _Any_data
   {
     void*       _M_access()       { return &_M_pod_data[0]; }
     const void* _M_access() const { return &_M_pod_data[0]; }