gcc/ada/s-stoele.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --               S Y S T E M . S T O R A G E _ E L E M E N T S              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --        Copyright (C) 1992,1993,1994 Free Software Foundation, Inc.       --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 with Unchecked_Conversion;
  36 package body System.Storage_Elements is
  37
  38    pragma Suppress (All_Checks);
  39
  40    function To_Address is new Unchecked_Conversion (Storage_Offset, Address);
  41    function To_Offset  is new Unchecked_Conversion (Address, Storage_Offset);
  42
  43    --  Address arithmetic
  44
  45    function "+" (Left : Address; Right : Storage_Offset) return Address is
  46    begin
  47       return Left + To_Address (Right);
  48    end "+";
  49
  50    function "+" (Left : Storage_Offset; Right : Address) return Address is
  51    begin
  52       return To_Address (Left) + Right;
  53    end "+";
  54
  55    function "-" (Left : Address; Right : Storage_Offset) return Address is
  56    begin
  57       return Left - To_Address (Right);
  58    end "-";
  59
  60    function "-" (Left, Right : Address) return Storage_Offset is
  61    begin
  62       return To_Offset (Left - Right);
  63    end "-";
  64
  65    function "mod" (Left : Address; Right : Storage_Offset)
  66      return Storage_Offset is
  67    begin
  68       if Right >= 0 then
  69          return Storage_Offset (Address'(Left mod Address (Right)));
  70       else
  71          return -Storage_Offset (Address'(Left mod Address (-Right)));
  72       end if;
  73    end "mod";
  74
  75    --  Conversion to/from integers
  76
  77    function To_Address (Value : Integer_Address) return Address is
  78    begin
  79       return Address (Value);
  80    end To_Address;
  81
  82    function To_Integer (Value : Address) return Integer_Address is
  83    begin
  84       return Integer_Address (Value);
  85    end To_Integer;
  86
  87 end System.Storage_Elements;