1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                             E X P _ I M G V                              --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 2000-2007, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26--  Expand routines for Image, Value and Width attributes. These are the
27--  attributes that make use of enumeration type image tables.
28
29with Types; use Types;
30
31package Exp_Imgv is
32
33   procedure Build_Enumeration_Image_Tables (E : Entity_Id; N : Node_Id);
34   --  Build the enumeration image tables for E, which is an enumeration
35   --  base type. The node N is the point in the tree where the resulting
36   --  declarations are to be inserted.
37   --
38   --    The form of the tables generated is as follows:
39   --
40   --      xxxS : string := "chars";
41   --      xxxI : array (0 .. N) of Natural_8/16/32 := (1, n, .., n);
42   --
43   --    Here xxxS is a string obtained by concatenating all the names
44   --    of the enumeration literals in sequence, representing any wide
45   --    characters according to the current wide character encoding
46   --    method, and with all letters forced to upper case.
47   --
48   --    The array xxxI is an array of ones origin indexes to the start
49   --    of each name, with one extra entry at the end, which is the index
50   --    to the character just past the end of the last literal, i.e. it is
51   --    the length of xxxS + 1. The element type is the shortest of the
52   --    possible types that will hold all the values.
53   --
54   --      For example, for the type
55   --
56   --         type x is (hello,'!',goodbye);
57   --
58   --      the generated tables would consist of
59   --
60   --          xxxS : String := "hello'!'goodbye";
61   --          xxxI : array (0 .. 3) of Natural_8 := (1, 6, 9, 16);
62   --
63   --      Here Natural_8 is used since 16 < 2**(8-1)
64   --
65   --    If the entity E needs the tables constructing, the necessary
66   --    declarations are constructed, and the fields Lit_Strings and
67   --    Lit_Indexes of E are set to point to the corresponding entities.
68   --    If no tables are needed (E is not a user defined enumeration
69   --    root type, or pragma Discard_Names is in effect, then the
70   --    declarations are not constructed, and the fields remain Empty.
71
72   procedure Expand_Image_Attribute (N : Node_Id);
73   --  This procedure is called from Exp_Attr to expand an occurrence
74   --  of the attribute Image.
75
76   procedure Expand_Wide_Image_Attribute (N : Node_Id);
77   --  This procedure is called from Exp_Attr to expand an occurrence
78   --  of the attribute Wide_Image.
79
80   procedure Expand_Wide_Wide_Image_Attribute (N : Node_Id);
81   --  This procedure is called from Exp_Attr to expand an occurrence
82   --  of the attribute Wide_Wide_Image.
83
84   procedure Expand_Value_Attribute (N : Node_Id);
85   --  This procedure is called from Exp_Attr to expand an occurrence
86   --  of the attribute Value.
87
88   type Atype is (Normal, Wide, Wide_Wide);
89   --  Type of attribute in call to Expand_Width_Attribute
90
91   procedure Expand_Width_Attribute (N : Node_Id; Attr : Atype := Normal);
92   --  This procedure is called from Exp_Attr to expand an occurrence of the
93   --  attributes Width (Attr = Normal), or Wide_Width (Attr Wide), or
94   --  Wide_Wide_Width (Attr = Wide_Wide).
95
96end Exp_Imgv;
97