--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-atocou.adb	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,93 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--               S Y S T E M . A T O M I C _ C O U N T E R S                --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--          Copyright (C) 2011-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This is version of the package, for use on platforms where this capability
+--  is not supported. All Atomic_Counter operations raises Program_Error,
+--  Atomic_Unsigned operations processed in non-atomic manner.
+
+package body System.Atomic_Counters is
+
+   ---------------
+   -- Decrement --
+   ---------------
+
+   function Decrement (Item : in out Atomic_Counter) return Boolean is
+   begin
+      raise Program_Error;
+      return False;
+   end Decrement;
+
+   function Decrement (Item : aliased in out Atomic_Unsigned) return Boolean is
+   begin
+      --  Could not use Item := Item - 1; because it is disabled in spec.
+      Item := Atomic_Unsigned'Pred (Item);
+      return Item = 0;
+   end Decrement;
+
+   procedure Decrement (Item : aliased in out Atomic_Unsigned) is
+   begin
+      Item := Atomic_Unsigned'Pred (Item);
+   end Decrement;
+
+   ---------------
+   -- Increment --
+   ---------------
+
+   procedure Increment (Item : in out Atomic_Counter) is
+   begin
+      raise Program_Error;
+   end Increment;
+
+   procedure Increment (Item : aliased in out Atomic_Unsigned) is
+   begin
+      Item := Atomic_Unsigned'Succ (Item);
+   end Increment;
+
+   ----------------
+   -- Initialize --
+   ----------------
+
+   procedure Initialize (Item : out Atomic_Counter) is
+   begin
+      raise Program_Error;
+   end Initialize;
+
+   ------------
+   -- Is_One --
+   ------------
+
+   function Is_One (Item : Atomic_Counter) return Boolean is
+   begin
+      raise Program_Error;
+      return False;
+   end Is_One;
+
+end System.Atomic_Counters;