DefinedHelper.java

/*
** Module   : DefinedHelper.java
** Abstract : helper class to execute the defined() built-in preproc function
**
** Copyright (c) 2004-2019, Golden Code Development Corporation.
**
** -#- -I- --Date-- --------------------------------Description---------------------------------
** 001 GES 20190929 First version.
*/

/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
**   2. No Misrepresentation of Affiliation.
** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
**     You may not represent yourself for publicity purposes as associated with
**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
** 
**   3. No Misrepresentation of Source or Origin.
** 
**     You may not represent the covered work as solely your work.  All modified
**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.preproc;

import com.goldencode.p2j.util.*;

/**
 * Helper class to contain state for the {@code defined()} built-in function.
 */
public class DefinedHelper
{
   /** Current file environment details. */
   private Environment env = null;
   
   /**
    * Construct an instance.
    *
    * @param    env
    *           The current environment details.
    */
   public DefinedHelper(Environment env)
   {
      this.env = env;
   }
   
   /**  
    * Returns the symbol origin of a preprocessor variable specified as
    * the parameter.
    *
    * @param    symbol
    *           The text of the symbol to lookup.
    *
    * @return   1 for a global symbol, 2 for an include argument, 3 for a scoped symbol
    *           and 0 for an undefined symbol.
    */
   public integer defined(character symbol)
   {
      ScopedSymbolDictionary sym = env.getSym();
      String                 txt = symbol.toStringMessage();
      
      Symbol s = (Symbol) sym.lookupSymbol(txt);
      
      int type = Symbol.UNDEFINED;
      
      if (s != null)
      {
         switch (s.getOrigin())
         {
            case Symbol.GLOBAL:
               type = Symbol.GLOBAL;
               break;
            case Symbol.SCOPED:
               type = Symbol.SCOPED;
               break;
            case Symbol.ARGUMENT:
            
               // only consider this defined if it is part of the current scope, otherwise
               // ignore it
               if (sym.locateSymbol(txt) == 0)
               {
                  type = Symbol.ARGUMENT;
               }
               break;
            case Symbol.BUILTIN:
               throw new IllegalArgumentException("Built-in " + txt + " cannot be referenced" +
                                                  "inside of DEFINED()");
         }
      }
      
      return new integer(type);
   }
}