1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . S T O R A G E _ E L E M E N T S --
9 -- Copyright (C) 2002-2004 Free Software Foundation, Inc. --
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. --
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, 59 Temple Place - Suite 330, Boston, --
24 -- MA 02111-1307, USA. --
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. --
33 -- GNAT was originally developed by the GNAT team at New York University. --
34 -- Extensive contributions were provided by Ada Core Technologies Inc. --
36 ------------------------------------------------------------------------------
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!
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).
47 -- We also add the pragma Pure_Function to the operations in this package,
48 -- because otherwise functions with parameters derived from Address are
49 -- treated as non-pure by the back-end (see exp_ch6.adb). This is because
50 -- in many cases such a parameter is used to hide read/out access to objects,
51 -- and it would be unsafe to treat such functions as pure.
53 type Storage_Offset
is range
54 -(2 ** (Standard
."-" (Standard
'Address_Size, 1))) ..
55 +(2 ** (Standard
."-" (Standard
'Address_Size, 1))) - 1;
57 -- Note: the reason for the qualification of "-" here by Standard is
58 -- that we have a current bug in GNAT that otherwise causes a bogus
59 -- ambiguity when this unit is analyzed in an Rtsfind context.
61 subtype Storage_Count
is Storage_Offset
range 0 .. Storage_Offset
'Last;
63 type Storage_Element
is mod 2 ** Storage_Unit
;
64 for Storage_Element
'Size use Storage_Unit
;
67 array (Storage_Offset
range <>) of aliased Storage_Element
;
68 for Storage_Array
'Component_Size use Storage_Unit
;
72 function "+" (Left
: Address
; Right
: Storage_Offset
) return Address
;
73 pragma Convention
(Intrinsic
, "+");
74 pragma Inline_Always
("+");
75 pragma Pure_Function
("+");
77 function "+" (Left
: Storage_Offset
; Right
: Address
) return Address
;
78 pragma Convention
(Intrinsic
, "+");
79 pragma Inline_Always
("+");
80 pragma Pure_Function
("+");
82 function "-" (Left
: Address
; Right
: Storage_Offset
) return Address
;
83 pragma Convention
(Intrinsic
, "-");
84 pragma Inline_Always
("-");
85 pragma Pure_Function
("-");
87 function "-" (Left
, Right
: Address
) return Storage_Offset
;
88 pragma Convention
(Intrinsic
, "-");
89 pragma Inline_Always
("-");
90 pragma Pure_Function
("-");
94 Right
: Storage_Offset
) return Storage_Offset
;
95 pragma Convention
(Intrinsic
, "mod");
96 pragma Inline_Always
("mod");
97 pragma Pure_Function
("mod");
99 -- Conversion to/from integers
101 type Integer_Address
is mod Memory_Size
;
103 function To_Address
(Value
: Integer_Address
) return Address
;
104 pragma Convention
(Intrinsic
, To_Address
);
105 pragma Inline_Always
(To_Address
);
106 pragma Pure_Function
(To_Address
);
108 function To_Integer
(Value
: Address
) return Integer_Address
;
109 pragma Convention
(Intrinsic
, To_Integer
);
110 pragma Inline_Always
(To_Integer
);
111 pragma Pure_Function
(To_Integer
);
113 end System
.Storage_Elements
;