# PreprocessorHintsWorker.java

    /*
    ** Module   : PreprocesorHintsWorker.java
    ** Abstract : provides a pattern engine service to lookup preprocessor hints
    **
    ** Copyright (c) 2005-2023, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- ----------------Description-----------------
    ** 001 NVS 20050525   @21280 Created initial version based on UastHints-
    **                           Worker code.
    ** 002 GES 20090518   @42393 Import change.
    ** 003 CA  20170825          If hints can't be loaded, log the exception.
    ** 004 CA  20170829          Made loadHints() public.
    ** 005 CA  20211214          The AST manager plugin must be context-local, for runtime conversion, as the
    **                           InMemoryRegistryPlugin is not thread-safe.
    ** 006 GBB 20230512          Logging methods replaced by CentralLogger/ConversionStatus.
    */
    /*
    ** 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
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    **
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    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
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    **
    **     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
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    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.preproc;

    import java.io.*;
    import java.util.*;
    import java.util.logging.*;

    import com.goldencode.ast.*;
    import com.goldencode.p2j.cfg.*;
    import com.goldencode.p2j.convert.*;
    import com.goldencode.p2j.pattern.*;

    /**
     * Provides a pattern engine service to query the preprocessor hints linked to
     * an AST.
     */
    public class PreprocessorHintsWorker
    extends AbstractPatternWorker
    {
       /** Logger. */
       private static final ConversionStatus LOG = ConversionStatus.get(PreprocessorHintsWorker.class);

       /** Stores the current AST's hints object. */
       private PreprocessorHints hints = null;

       /**
        * Default constructor which calls the super-class constructor, registers
        * its libraries and initializes its instance members.
        */
       public PreprocessorHintsWorker()
       throws ConfigurationException
       {
          super();
          setLibrary(new HintsReader());
       }

       /**
        * Resets the current hints instance to <code>null</code> each time a new
        * AST is visited.  This enables the lazy loading of hints files only when
        * needed.
        *
        * @param   ast
        *          The root node of the source AST about to be processed by the
        *          pattern engine.
        */
       public void visitAst(Aast ast)
       {
          hints = null;
       }

       /**
        * Provides a service for reading preprocessor hints associated with the
        * current AST.  This class is a <code>PatternEngine</code> worker.
        */
       public class HintsReader
       {
          /**
           * Gets the PreprocessorHints instance for this file.
           *
           * @return <code>preprocessorHints</code> instance.
           */
          public PreprocessorHints getHints()
          {
             if (!loadHints())
                return null;

             return hints;
          }

          /**
           * Loads the hints file for an AST if it exists and hasn't already been
           * loaded.
           *
           * @return   <code>true</code> if there are hints for this file and the
           *           hints are loaded, <code>false</code> if no hints are
           *           available.
           */
          public boolean loadHints()
          {
             if (hints == null)
             {
                try
                {
                   Aast src  = getResolver().getSourceAst();
                   File file = Configuration.toFile(src.getFilename());

                   hints = new PreprocessorHints(file.getAbsolutePath());
                }

                catch (Exception exc)
                {
                   LOG.log(Level.SEVERE, "", exc);
                   // any failure drops us out
                   return false;
                }
             }

             return true;
          }
       }
    }