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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ I M G V --
-- --
-- S p e c --
-- --
-- Copyright (C) 2000-2023, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- Expand routines for Image, Value and Width attributes. These are the
-- attributes that make use of enumeration type image tables.
with Types; use Types;
package Exp_Imgv is
procedure Build_Enumeration_Image_Tables (E : Entity_Id; N : Node_Id);
-- Build the enumeration image tables for E, which is an enumeration
-- base type. The node N is the point in the tree where the resulting
-- declarations are to be inserted.
--
-- The form of the tables generated is as follows:
--
-- xxxS : constant string (1 .. M) := "chars";
-- xxxN : constant array (0 .. N) of Index_Type := (i1, i2, .., iN, j);
--
-- Here xxxS is a string obtained by concatenating all the names of the
-- enumeration literals in sequence, representing any wide characters
-- according to the current wide character encoding method, and with all
-- letters forced to upper case.
--
-- The array xxxN is an array of indexes into xxxS pointing to the start
-- of each name, with one extra entry at the end, which is the index to
-- the character just past the end of the last literal, i.e. it is the
-- length of xxxS + 1. The element type is the shortest of the possible
-- types that will hold all the values.
--
-- For example, for the type
--
-- type x is (hello,'!',goodbye);
--
-- the generated tables would consist of
--
-- xxxS : constant string (1 .. 15) := "hello'!'goodbye";
-- xxxN : constant array (0 .. 3) of Integer_8 := (1, 6, 9, 16);
--
-- Here Integer_8 is used since 16 < 2**(8-1).
--
-- If the entity E needs the tables, the necessary declarations are built
-- and the fields Lit_Strings and Lit_Indexes of E are set to point to the
-- corresponding entities. If no tables are needed (E is not a user defined
-- enumeration root type, or pragma Discard_Names is in effect), then the
-- declarations are not constructed and the fields remain Empty.
--
-- If the number of enumeration literals is large enough, a (perfect) hash
-- function mapping the literals to their position number is also built and
-- requires additional tables. See the System.Perfect_Hash_Generators unit
-- for a complete description of this processing.
procedure Expand_Image_Attribute (N : Node_Id);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attribute Image.
procedure Expand_Wide_Image_Attribute (N : Node_Id);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attribute Wide_Image.
procedure Expand_Wide_Wide_Image_Attribute (N : Node_Id);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attribute Wide_Wide_Image.
procedure Expand_Valid_Value_Attribute (N : Node_Id);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attribute Valid_Value.
procedure Expand_Value_Attribute (N : Node_Id);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attribute Value.
type Atype is (Normal, Wide, Wide_Wide);
-- Type of attribute in call to Expand_Width_Attribute
procedure Expand_Width_Attribute (N : Node_Id; Attr : Atype := Normal);
-- This procedure is called from Exp_Attr to expand an occurrence of the
-- attributes Width (Attr = Normal), or Wide_Width (Attr Wide), or
-- Wide_Wide_Width (Attr = Wide_Wide).
end Exp_Imgv;
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