src/lib/gnat/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) 2002-2013, 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 3,  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.                                     --
  21 --                                                                          --
  22 -- As a special exception under Section 7 of GPL version 3, you are granted --
  23 -- additional permissions described in the GCC Runtime Library Exception,   --
  24 -- version 3.1, as published by the Free Software Foundation.               --
  25 --                                                                          --
  26 -- You should have received a copy of the GNU General Public License and    --
  27 -- a copy of the GCC Runtime Library Exception along with this program;     --
  28 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  29 -- <http://www.gnu.org/licenses/>.                                          --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 --  Warning: declarations in this package are ambiguous with respect to the
  37 --  extra declarations that can be introduced into System using Extend_System.
  38 --  It is a good idea to avoid use clauses for this package.
  39
  40 package System.Storage_Elements is
  41    pragma Pure;
  42    --  Note that we take advantage of the implementation permission to make
  43    --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada 2005,
  44    --  this is Pure in any case (AI-362).
  45
  46    --  We also add the pragma Pure_Function to the operations in this package,
  47    --  because otherwise functions with parameters derived from Address are
  48    --  treated as non-pure by the back-end (see exp_ch6.adb). This is because
  49    --  in many cases such a parameter is used to hide read/out access to
  50    --  objects, and it would be unsafe to treat such functions as pure.
  51
  52    type Storage_Offset is range
  53      -(2 ** (Integer'(Standard'Address_Size) - 1)) ..
  54      +(2 ** (Integer'(Standard'Address_Size) - 1)) - Long_Long_Integer'(1);
  55    --  Note: the reason for the Long_Long_Integer qualification here is to
  56    --  avoid a bogus ambiguity when this unit is analyzed in an rtsfind
  57    --  context. It may be possible to remove this in the future, but it is
  58    --  certainly harmless in any case ???
  59
  60    subtype Storage_Count is Storage_Offset range 0 .. Storage_Offset'Last;
  61
  62    type Storage_Element is mod 2 ** Storage_Unit;
  63    for Storage_Element'Size use Storage_Unit;
  64
  65    pragma Universal_Aliasing (Storage_Element);
  66    --  This type is used by the expander to implement aggregate copy
  67
  68    type Storage_Array is
  69      array (Storage_Offset range <>) of aliased Storage_Element;
  70    for Storage_Array'Component_Size use Storage_Unit;
  71
  72    --  Address arithmetic
  73
  74    function "+" (Left : Address; Right : Storage_Offset) return Address;
  75    pragma Convention (Intrinsic, "+");
  76    pragma Inline_Always ("+");
  77    pragma Pure_Function ("+");
  78
  79    function "+" (Left : Storage_Offset; Right : Address) return Address;
  80    pragma Convention (Intrinsic, "+");
  81    pragma Inline_Always ("+");
  82    pragma Pure_Function ("+");
  83
  84    function "-" (Left : Address; Right : Storage_Offset) return Address;
  85    pragma Convention (Intrinsic, "-");
  86    pragma Inline_Always ("-");
  87    pragma Pure_Function ("-");
  88
  89    function "-" (Left, Right : Address) return Storage_Offset;
  90    pragma Convention (Intrinsic, "-");
  91    pragma Inline_Always ("-");
  92    pragma Pure_Function ("-");
  93
  94    function "mod"
  95      (Left  : Address;
  96       Right : Storage_Offset) return  Storage_Offset;
  97    pragma Convention (Intrinsic, "mod");
  98    pragma Inline_Always ("mod");
  99    pragma Pure_Function ("mod");
 100
 101    --  Conversion to/from integers
 102
 103    type Integer_Address is mod Memory_Size;
 104
 105    function To_Address (Value : Integer_Address) return Address;
 106    pragma Convention (Intrinsic, To_Address);
 107    pragma Inline_Always (To_Address);
 108    pragma Pure_Function (To_Address);
 109
 110    function To_Integer (Value : Address) return Integer_Address;
 111    pragma Convention (Intrinsic, To_Integer);
 112    pragma Inline_Always (To_Integer);
 113    pragma Pure_Function (To_Integer);
 114
 115 end System.Storage_Elements;