--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-atacco.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,63 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+-- S Y S T E M . A D D R E S S _ T O _ A C C E S S _ C O N V E R S I O N S  --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 1992-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- This specification is derived from the Ada Reference Manual for use with --
+-- GNAT. The copyright notice above, and the license provisions that follow --
+-- apply solely to the  contents of the part following the private keyword. --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+generic
+   type Object (<>) is limited private;
+
+package System.Address_To_Access_Conversions is
+   pragma Preelaborate;
+
+   pragma Compile_Time_Warning
+     (Object'Unconstrained_Array,
+      "Object is unconstrained array type" & ASCII.LF &
+      "To_Pointer results may not have bounds");
+
+   type Object_Pointer is access all Object;
+   for Object_Pointer'Size use Standard'Address_Size;
+
+   pragma No_Strict_Aliasing (Object_Pointer);
+   --  Strictly speaking, this routine should not be used to generate pointers
+   --  to other than proper values of the proper type, but in practice, this
+   --  is done all the time. This pragma stops the compiler from doing some
+   --  optimizations that may cause unexpected results based on the assumption
+   --  of no strict aliasing.
+
+   function To_Pointer (Value : Address)        return Object_Pointer;
+   function To_Address (Value : Object_Pointer) return Address;
+
+   pragma Import (Intrinsic, To_Pointer);
+   pragma Import (Intrinsic, To_Address);
+
+end System.Address_To_Access_Conversions;