gcc/ada/exp_imgv.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             E X P _ I M G V                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --            Copyright (C) 2000 Free Software Foundation, Inc.             --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- GNAT was originally developed  by the GNAT team at  New York University. --
  24 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  25 --                                                                          --
  26 ------------------------------------------------------------------------------
  27
  28 --  Expand routines for Image, Value and Width attributes. These are the
  29 --  attributes that make use of enumeration type image tables.
  30
  31 with Types; use Types;
  32
  33 package Exp_Imgv is
  34
  35    procedure Build_Enumeration_Image_Tables (E : Entity_Id; N : Node_Id);
  36    --  Build the enumeration image tables for E, which is an enumeration
  37    --  base type. The node N is the point in the tree where the resulting
  38    --  declarations are to be inserted.
  39    --
  40    --    The form of the tables generated is as follows:
  41    --
  42    --      xxxS : string := "chars";
  43    --      xxxI : array (0 .. N) of Natural_8/16/32 := (1, n, .., n);
  44    --
  45    --    Here xxxS is a string obtained by concatenating all the names
  46    --    of the enumeration literals in sequence, representing any wide
  47    --    characters according to the current wide character encoding
  48    --    method, and with all letters forced to upper case.
  49    --
  50    --    The array xxxI is an array of ones origin indexes to the start
  51    --    of each name, with one extra entry at the end, which is the index
  52    --    to the character just past the end of the last literal, i.e. it is
  53    --    the length of xxxS + 1. The element type is the shortest of the
  54    --    possible types that will hold all the values.
  55    --
  56    --      For example, for the type
  57    --
  58    --         type x is (hello,'!',goodbye);
  59    --
  60    --      the generated tables would consist of
  61    --
  62    --          xxxS : String := "hello'!'goodbye";
  63    --          xxxI : array (0 .. 3) of Natural_8 := (1, 6, 9, 16);
  64    --
  65    --      Here Natural_8 is used since 16 < 2**(8-1)
  66    --
  67    --    If the entity E needs the tables constructing, the necessary
  68    --    declarations are constructed, and the fields Lit_Strings and
  69    --    Lit_Indexes of E are set to point to the corresponding entities.
  70    --    If no tables are needed (E is not a user defined enumeration
  71    --    root type, or pragma Discard_Names is in effect, then the
  72    --    declarations are not constructed, and the fields remain Empty.
  73
  74    procedure Expand_Image_Attribute (N : Node_Id);
  75    --  This procedure is called from Exp_Attr to expand an occurrence
  76    --  of the attribute Image.
  77
  78    procedure Expand_Value_Attribute (N : Node_Id);
  79    --  This procedure is called from Exp_Attr to expand an occurrence
  80    --  of the attribute Value.
  81
  82    procedure Expand_Width_Attribute (N : Node_Id; Wide : Boolean);
  83    --  This procedure is called from Exp_Attr to expand an occurrence of
  84    --  the attributes Width (Wide = False) or Wide_Width (Wide = True).
  85
  86 end Exp_Imgv;