vala/valasymbol.vala

   1 /* valasymbol.vala
   2  *
   3  * Copyright (C) 2006-2007  Jürg Billeter
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  18  *
  19  * Author:
  20  *      Jürg Billeter <j@bitron.ch>
  21  */
  22
  23 using GLib;
  24
  25 /**
  26  * Represents a node in the symbol tree.
  27  */
  28 public class Vala.Symbol {
  29         /**
  30          * The code node that created this symbol, if applicable.
  31          */
  32         public weak CodeNode node { get; set; }
  33
  34         /**
  35          * The parent of this symbol.
  36          */
  37         public weak Symbol parent_symbol { get; set; }
  38
  39         /**
  40          * The symbol name.
  41          */
  42         public string name { get; set; }
  43
  44         /**
  45          * Specifies whether this symbol is active.
  46          *
  47          * Symbols may become inactive when they only apply to a part of a
  48          * scope. This is used for local variables not declared at the beginning
  49          * of the block to determine which variables need to be freed before
  50          * jump statements.
  51          */
  52         public bool active { get; set; }
  53
  54         private HashTable<string,Symbol> symbol_table = new HashTable.full (str_hash, str_equal, g_free, g_object_unref);
  55
  56         /**
  57          * Creates a new symbol.
  58          *
  59          * @param node the corresponding code node
  60          * @return     newly created symbol
  61          */
  62         public Symbol (CodeNode _node = null)  {
  63                 node = _node;
  64         }
  65
  66         construct {
  67                 active = true;
  68         }
  69
  70         /**
  71          * Returns the fully expanded name of this symbol for use in
  72          * human-readable messages.
  73          *
  74          * @return full name
  75          */
  76         public string get_full_name () {
  77                 if (parent_symbol == null) {
  78                         return name;
  79                 }
  80
  81                 if (name == null) {
  82                         return parent_symbol.get_full_name ();
  83                 }
  84
  85                 if (parent_symbol.get_full_name () == null) {
  86                         return name;
  87                 }
  88
  89                 return "%s.%s".printf (parent_symbol.get_full_name (), name);
  90         }
  91
  92         /**
  93          * Adds the specified symbol with the specified name to the symbol table
  94          * of this symbol.
  95          *
  96          * @param name name for the specified symbol
  97          * @param sym  a symbol
  98          */
  99         public void add (string! name, Symbol! sym) {
 100                 symbol_table.insert (name, sym);
 101                 sym.parent_symbol = this;
 102                 sym.name = name;
 103         }
 104
 105         /**
 106          * Returns the symbol stored in the symbol table with the specified
 107          * name.
 108          *
 109          * @param name name of the symbol to be returned
 110          * @return     found symbol or null
 111          */
 112         public Symbol lookup (string! name) {
 113                 Symbol sym = symbol_table.lookup (name);
 114                 if (sym != null && !sym.active) {
 115                         sym = null;
 116                 }
 117                 return sym;
 118         }
 119 }