[Bug libstdc++/77686] [6/7 Regression] wrong code on arm-linux-gnueabi and arm-linux-gnueabihf

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77686

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
;; Function void std::function<_Res(_ArgTypes
...)>::swap(std::function<_Res(_ArgTypes ...)>&) [with _Res = void; _ArgTypes =
{}] (null)
;; enabled by -tree-original


<<< Unknown tree: must_not_throw_expr
  <<cleanup_point <<< Unknown tree: expr_stmt
  std::swap<std::_Any_data> ((union _Any_data &) &((struct function *)
this)->D.45189._M_functor, (union _Any_data &) &((struct function *)
__x)->D.45189._M_functor) >>>>>;
^^^^


doing std::swap on _Any_data.  That's of course bogus.

      /**
       *  @brief Swap the targets of two %function objects.
       *  @param __x A %function with identical call signature.
       *
       *  Swap the targets of @c this function object and @a __f. This
       *  function will not throw an %exception.
       */
      void swap(function& __x) noexcept
      {
        std::swap(_M_functor, __x._M_functor);
        std::swap(_M_manager, __x._M_manager);
        std::swap(_M_invoker, __x._M_invoker);
      }

and swap() seems to be used in multiple places throughout functional.