--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/g-except.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,82 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--                      G N A T . E X C E P T I O N S                       --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--                     Copyright (C) 2000-2017, AdaCore                     --
+--                                                                          --
+-- 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 package provides an interface for raising predefined exceptions
+--  with an exception message. It can be used from Pure units.
+
+--  There is no prohibition in Ada that prevents exceptions being raised
+--  from within pure units. The raise statement is perfectly acceptable.
+
+--  However, it is not normally possible to raise an exception with a
+--  message because the routine Ada.Exceptions.Raise_Exception is not in
+--  a Pure unit. This is an annoying and unnecessary restriction and this
+--  package allows for raising the standard predefined exceptions at least.
+
+package GNAT.Exceptions is
+   pragma Pure;
+
+   type Exception_Type is limited null record;
+   --  Type used to specify which exception to raise
+
+   --  Really Exception_Type is Exception_Id, but Exception_Id can't be
+   --  used directly since it is declared in the non-pure unit Ada.Exceptions,
+
+   --  Exception_Id is in fact simply a pointer to the type Exception_Data
+   --  declared in System.Standard_Library (which is also non-pure). So what
+   --  we do is to define it here as a by reference type (any by reference
+   --  type would do), and then Import the definitions from Standard_Library.
+   --  Since this is a by reference type, these will be passed by reference,
+   --  which has the same effect as passing a pointer.
+
+   --  This type is not private because keeping it by reference would require
+   --  defining it in a way (e.g. using a tagged type) that would drag in other
+   --  run-time files, which is unwanted in the case of e.g. Ravenscar where we
+   --  want to minimize the number of run-time files needed by default.
+
+   CE : constant Exception_Type;  -- Constraint_Error
+   PE : constant Exception_Type;  -- Program_Error
+   SE : constant Exception_Type;  -- Storage_Error
+   TE : constant Exception_Type;  -- Tasking_Error
+   --  One of these constants is used in the call to specify the exception
+
+   procedure Raise_Exception (E : Exception_Type; Message : String);
+   pragma Import (Ada, Raise_Exception, "__gnat_raise_exception");
+   pragma No_Return (Raise_Exception);
+   --  Raise specified exception with specified message
+
+private
+   pragma Import (C, CE, "constraint_error");
+   pragma Import (C, PE, "program_error");
+   pragma Import (C, SE, "storage_error");
+   pragma Import (C, TE, "tasking_error");
+   --  References to the exception structures in the standard library
+
+end GNAT.Exceptions;