1 ------------------------------------------------------------------------------
3 -- GNAT RUNTIME COMPONENTS --
5 -- S Y S T E M . W I D _ E N U M --
11 -- Copyright (C) 1992-2000 Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
34 ------------------------------------------------------------------------------
36 -- This package contains the routine used for Enumeration_Type'Width
38 package System.Wid_Enum is
39 pragma Pure (Wid_Enum);
41 function Width_Enumeration_8
43 Indexes : System.Address;
46 -- Used to compute Enum'Width where Enum is some enumeration subtype
47 -- other than those defined in package Standard. Names is a string with
48 -- a lower bound of 1 containing the characters of all the enumeration
49 -- literals concatenated together in sequence. Indexes is the address
50 -- of an array of type array (0 .. N) of Natural_8, where N is the
51 -- number of enumeration literals in the type. The Indexes values are
52 -- the starting subscript of each enumeration literal, indexed by Pos
53 -- values, with an extra entry at the end containing Names'Length + 1.
54 -- The reason that Indexes is passed by address is that the actual type
55 -- is created on the fly by the expander.
57 -- Lo and Hi are the Pos values of the lower and upper bounds of the
58 -- subtype. The result is the value of Width, i.e. the maximum value
59 -- of the length of any enumeration literal in the given range.
61 function Width_Enumeration_16
63 Indexes : System.Address;
66 -- Identical to Width_Enumeration_8 except that it handles types
67 -- using array (0 .. Num) of Natural_16 for the Indexes table.
69 function Width_Enumeration_32
71 Indexes : System.Address;
74 -- Identical to Width_Enumeration_8 except that it handles types
75 -- using array (0 .. Num) of Natural_32 for the Indexes table.