--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-dim.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,68 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--                           S Y S T E M . D I M                            --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2012-2017, 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  Defines the dimension terminology
+
+---------------------------
+-- Dimension Terminology --
+---------------------------
+
+--  * Dimensioned type
+
+--    A dimensioned type is a type (more accurately a first subtype) to which
+--    the aspect Dimension_System applies to.
+
+--      type Mks_Type is new Long_Long_Float
+--        with
+--         Dimension_System => (
+--          (Unit_Name => Meter,    Unit_Symbol => 'm',   Dim_Symbol => 'L'),
+--          (Unit_Name => Kilogram, Unit_Symbol => "kg",  Dim_Symbol => 'M'),
+--          (Unit_Name => Second,   Unit_Symbol => 's',   Dim_Symbol => 'T'),
+--          (Unit_Name => Ampere,   Unit_Symbol => 'A',   Dim_Symbol => 'I'),
+--          (Unit_Name => Kelvin,   Unit_Symbol => 'K',   Dim_Symbol => "Θ"),
+--          (Unit_Name => Mole,     Unit_Symbol => "mol", Dim_Symbol => 'N'),
+--          (Unit_Name => Candela,  Unit_Symbol => "cd",  Dim_Symbol => 'J'));
+
+--  * Dimensioned subtype
+
+--    A dimensioned subtype is a subtype directly defined from the dimensioned
+--    type and to which the aspect Dimension applies to.
+
+--      subtype Length is Mks_Type
+--        with
+--         Dimension => (Symbol => 'm',
+--           Meter =>  1,
+--           others => 0);
+
+package System.Dim is
+   pragma Pure;
+
+end System.Dim;