gcc/ada/s-stoele.ads

   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 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2002-2005 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- This specification is derived from the Ada Reference Manual for use with --
  12 -- GNAT. The copyright notice above, and the license provisions that follow --
  13 -- apply solely to the implementation dependent sections of this file.      --
  14 --                                                                          --
  15 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  16 -- terms of the  GNU General Public License as published  by the Free Soft- --
  17 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  18 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  19 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  20 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  21 -- for  more details.  You should have  received  a copy of the GNU General --
  22 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  23 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  24 -- Boston, MA 02110-1301, USA.                                              --
  25 --                                                                          --
  26 -- As a special exception,  if other files  instantiate  generics from this --
  27 -- unit, or you link  this unit with other files  to produce an executable, --
  28 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  29 -- covered  by the  GNU  General  Public  License.  This exception does not --
  30 -- however invalidate  any other reasons why  the executable file  might be --
  31 -- covered by the  GNU Public License.                                      --
  32 --                                                                          --
  33 -- GNAT was originally developed  by the GNAT team at  New York University. --
  34 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  35 --                                                                          --
  36 ------------------------------------------------------------------------------
  37
  38 --  Warning: declarations in this package are ambiguous with respect to the
  39 --  extra declarations that can be introduced into System using Extend_System.
  40 --  It is a good idea to avoid use clauses for this package!
  41
  42 package System.Storage_Elements is
  43 pragma Pure (Storage_Elements);
  44 --  Note that we take advantage of the implementation permission to make
  45 --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada 2005,
  46 --  this is Pure in any case (AI-362).
  47
  48 --  We also add the pragma Pure_Function to the operations in this package,
  49 --  because otherwise functions with parameters derived from Address are
  50 --  treated as non-pure by the back-end (see exp_ch6.adb). This is because
  51 --  in many cases such a parameter is used to hide read/out access to objects,
  52 --  and it would be unsafe to treat such functions as pure.
  53
  54    type Storage_Offset is range
  55      -(2 ** (Integer'(Standard'Address_Size) - 1)) ..
  56      +(2 ** (Integer'(Standard'Address_Size) - 1)) - Long_Long_Integer'(1);
  57
  58    subtype Storage_Count is Storage_Offset range 0 .. Storage_Offset'Last;
  59
  60    type Storage_Element is mod 2 ** Storage_Unit;
  61    for Storage_Element'Size use Storage_Unit;
  62
  63    type Storage_Array is
  64      array (Storage_Offset range <>) of aliased Storage_Element;
  65    for Storage_Array'Component_Size use Storage_Unit;
  66
  67    --  Address arithmetic
  68
  69    function "+" (Left : Address; Right : Storage_Offset) return Address;
  70    pragma Convention (Intrinsic, "+");
  71    pragma Inline_Always ("+");
  72    pragma Pure_Function ("+");
  73
  74    function "+" (Left : Storage_Offset; Right : Address) return Address;
  75    pragma Convention (Intrinsic, "+");
  76    pragma Inline_Always ("+");
  77    pragma Pure_Function ("+");
  78
  79    function "-" (Left : Address; Right : Storage_Offset) return Address;
  80    pragma Convention (Intrinsic, "-");
  81    pragma Inline_Always ("-");
  82    pragma Pure_Function ("-");
  83
  84    function "-" (Left, Right : Address) return Storage_Offset;
  85    pragma Convention (Intrinsic, "-");
  86    pragma Inline_Always ("-");
  87    pragma Pure_Function ("-");
  88
  89    function "mod"
  90      (Left  : Address;
  91       Right : Storage_Offset) return  Storage_Offset;
  92    pragma Convention (Intrinsic, "mod");
  93    pragma Inline_Always ("mod");
  94    pragma Pure_Function ("mod");
  95
  96    --  Conversion to/from integers
  97
  98    type Integer_Address is mod Memory_Size;
  99
 100    function To_Address (Value : Integer_Address) return Address;
 101    pragma Convention (Intrinsic, To_Address);
 102    pragma Inline_Always (To_Address);
 103    pragma Pure_Function (To_Address);
 104
 105    function To_Integer (Value : Address) return Integer_Address;
 106    pragma Convention (Intrinsic, To_Integer);
 107    pragma Inline_Always (To_Integer);
 108    pragma Pure_Function (To_Integer);
 109
 110 end System.Storage_Elements;