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) 2002-2009, 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 pragma Compiler_Unit;
  41
  42 package System.Storage_Elements is
  43    pragma Pure;
  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
  52    --  objects, 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    --  Note: the reason for the Long_Long_Integer qualification here is to
  58    --  avoid a bogus ambiguity when this unit is analyzed in an rtsfind
  59    --  context. It may be possible to remove this in the future, but it is
  60    --  certainly harmless in any case ???
  61
  62    subtype Storage_Count is Storage_Offset range 0 .. Storage_Offset'Last;
  63
  64    type Storage_Element is mod 2 ** Storage_Unit;
  65    for Storage_Element'Size use Storage_Unit;
  66
  67    pragma Universal_Aliasing (Storage_Element);
  68    --  This type is used by the expander to implement aggregate copy
  69
  70    type Storage_Array is
  71      array (Storage_Offset range <>) of aliased Storage_Element;
  72    for Storage_Array'Component_Size use Storage_Unit;
  73
  74    --  Address arithmetic
  75
  76    function "+" (Left : Address; Right : Storage_Offset) return Address;
  77    pragma Convention (Intrinsic, "+");
  78    pragma Inline_Always ("+");
  79    pragma Pure_Function ("+");
  80
  81    function "+" (Left : Storage_Offset; Right : Address) return Address;
  82    pragma Convention (Intrinsic, "+");
  83    pragma Inline_Always ("+");
  84    pragma Pure_Function ("+");
  85
  86    function "-" (Left : Address; Right : Storage_Offset) return Address;
  87    pragma Convention (Intrinsic, "-");
  88    pragma Inline_Always ("-");
  89    pragma Pure_Function ("-");
  90
  91    function "-" (Left, Right : Address) return Storage_Offset;
  92    pragma Convention (Intrinsic, "-");
  93    pragma Inline_Always ("-");
  94    pragma Pure_Function ("-");
  95
  96    function "mod"
  97      (Left  : Address;
  98       Right : Storage_Offset) return  Storage_Offset;
  99    pragma Convention (Intrinsic, "mod");
 100    pragma Inline_Always ("mod");
 101    pragma Pure_Function ("mod");
 102
 103    --  Conversion to/from integers
 104
 105    type Integer_Address is mod Memory_Size;
 106
 107    function To_Address (Value : Integer_Address) return Address;
 108    pragma Convention (Intrinsic, To_Address);
 109    pragma Inline_Always (To_Address);
 110    pragma Pure_Function (To_Address);
 111
 112    function To_Integer (Value : Address) return Integer_Address;
 113    pragma Convention (Intrinsic, To_Integer);
 114    pragma Inline_Always (To_Integer);
 115    pragma Pure_Function (To_Integer);
 116
 117 end System.Storage_Elements;