--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-stchop__limit.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,53 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
+--                                                                          --
+--     S Y S T E M . S T A C K _ C H E C K I N G . O P E R A T I O N S      --
+--                                                                          --
+--                                  S p e c                                 --
+--                                                                          --
+--          Copyright (C) 1999-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNARL 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/>.                                          --
+--                                                                          --
+-- GNARL was developed by the GNARL team at Florida State University.       --
+-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This version of this package is for implementations which use
+--  the stack limit approach (the limit of the stack is stored into a per
+--  thread variable).
+
+pragma Restrictions (No_Elaboration_Code);
+--  We want to guarantee the absence of elaboration code because the binder
+--  does not handle references to this package.
+
+pragma Polling (Off);
+--  Turn off polling, we do not want polling to take place during stack
+--  checking operations. It causes infinite loops and other problems.
+
+package System.Stack_Checking.Operations is
+   pragma Preelaborate;
+
+   procedure Initialize_Stack_Limit;
+   pragma Export (C, Initialize_Stack_Limit,
+                    "__gnat_initialize_stack_limit");
+   --  This procedure is called before elaboration to setup the stack limit
+   --  for the environment task and to register the hook to be called at
+   --  task creation.
+end System.Stack_Checking.Operations;