2010-07-27 Paolo Carlini <paolo.carlini@oracle.com>
[official-gcc/alias-decl.git] / gcc / ada / s-atacco.ads
blob031240ed8a3e4804476ce56582a65aa297b1ce19
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . A D D R E S S _ T O _ A C C E S S _ C O N V E R S I O N S --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2009, 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 contents of the part following the private keyword. --
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 ------------------------------------------------------------------------------
36 generic
37 type Object (<>) is limited private;
39 package System.Address_To_Access_Conversions is
40 pragma Preelaborate;
41 pragma Elaborate_Body;
42 -- This pragma Elaborate_Body is there to ensure the requirement of what is
43 -- at the moment a dummy null body. The reason this null body is there is
44 -- that we used to have a real body, and it causes bootstrap problems with
45 -- old compilers if we try to remove the corresponding file.
47 pragma Compile_Time_Warning
48 (Object'Unconstrained_Array,
49 "Object is unconstrained array type" & ASCII.LF &
50 "To_Pointer results may not have bounds");
52 -- Capture constrained status, suppressing warnings, since this is
53 -- an obsolescent feature to use Constrained in this way (RM J.4).
55 pragma Warnings (Off);
56 Xyz : Boolean := Object'Constrained;
57 pragma Warnings (On);
59 type Object_Pointer is access all Object;
60 for Object_Pointer'Size use Standard'Address_Size;
62 pragma No_Strict_Aliasing (Object_Pointer);
63 -- Strictly speaking, this routine should not be used to generate pointers
64 -- to other than proper values of the proper type, but in practice, this
65 -- is done all the time. This pragma stops the compiler from doing some
66 -- optimizations that may cause unexpected results based on the assumption
67 -- of no strict aliasing.
69 function To_Pointer (Value : Address) return Object_Pointer;
70 function To_Address (Value : Object_Pointer) return Address;
72 pragma Import (Intrinsic, To_Pointer);
73 pragma Import (Intrinsic, To_Address);
75 end System.Address_To_Access_Conversions;