LegacyErrorException.java

/*
** Module   : LegacyErrorException.java
** Abstract : represents a thrown legacy OO error.
**
** Copyright (c) 2019-2025, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 CA  20190219 First version.
** 002 CA  20190628 Save the legacy error instance, as it may be needed when interpreting this 
**                  error from a different context.
** 003 CA  20200324 More fixes related to OO-like error processing via AppError.
** 004 CA  20220208 Added support for legacy OO errors thrown from a remote appserver call, via RETURN ERROR.
**     CA  20220531 Fixed propagation of explicit legacy exceptions - they must propagate if the block has 
**                  ON ERROR UNDO, THROW or if they are explicitly throw by the application.
** 005 VVT 20231215 Added a LegacyErrorException constructor, which does not modify call stack in its
**                  argument. See #8126.
** 006 GBB 20240318 "Legacy error"  is not an actual OE error msg, instead pass null and leave it to the 
**                  error handler.
** 007 CA  20240708 A block needs to be aware if a RETURN ERROR or UNDO, THROW was used for exit, as this will
**                  make a FINALLY block to act as if it executes in silent mode.
** 008 AP  20250121 populateCallStack() call removed: stack is now populated at the ProError object
**                  creation time. See discussion around #3827-527. Removed unused constructor.
*/

/*
** 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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**     clear that the modified work is not originating from Golden Code Development
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**     attribution required in this license.
*/

package com.goldencode.p2j.util;

import com.goldencode.p2j.oo.lang.*;

/**
 * An ERROR condition which acts like a throw OO error in 4GL.
 */
public class LegacyErrorException
extends ErrorConditionException
{
   /** 
    * The thrown {@link LegacyError}.  Used to hold a reference, so that the object will not be
    * deleted until this exception is caught.
    * <p>
    * Do not serialize this field.
    */
   private transient ObjectVar<? extends LegacyError> error;
   
   /** The explicit legacy object being thrown.  Will be non-null only for serializable instances. */
   private LegacyError errorRef;
   
   /** Flag indicating if this was from a RETURN ERROR statement. */
   private boolean fromReturn;
   
   /** Flag indicating this is an explicit thrown exception, by the application code. */
   private boolean explicit = false;
   
   /**
    * Create a new instance and populate error stack trace.
    * 
    * @param    error
    *           The referenced error.
    */
   public LegacyErrorException(object<? extends LegacyError> error)
   {
      this(error, false);
   }
   
   /**
    * Create a new instance and populate error stack trace.
    * 
    * @param    error
    *           The referenced error.
    * @param    fromReturn
    *           Flag indicating if this was from a RETURN ERROR statement.
    */
   public LegacyErrorException(final object<? extends LegacyError> error, final boolean fromReturn)
   {
      super((String) null);

      this.error = new ObjectVar<>(LegacyError.class);
      this.error.assign(error);
      
      this.errorRef = (error).ref();
      this.fromReturn = fromReturn;
   }

   /**
    * Duplicate this legacy OO error.  If the {@link #errorRef} is <code>null</code>, a new {@link AppError}
    * instance will be created. Otherwise, the {@link #errorRef} will be re-used and its 
    * {@link ProError#getCallStack() callstack} will be assumed as the server's stack trace.
    * 
    * @return   See above.
    */
   public LegacyErrorException duplicate()
   {
      ObjectVar<LegacyError> newError = new ObjectVar<>(LegacyError.class);
      
      if (errorRef == null)
      {
         newError.assign(ObjectOps.newInstance(AppError.class));
      }
      else
      {
         ObjectOps.registerObject(errorRef);
         newError.assign(errorRef); // re-use the instance as it was de-serialized
      }
      
      LegacyErrorException lex = new LegacyErrorException(newError, fromReturn);
      return lex;
   }
   
   /**
    * Clear the {@link #errorRef} and {@link #error}, as they can't be serialized to the remote side.
    * 
    * @param    clearRef
    *           When <code>true</code>, clear the {@link #errorRef}, too.
    */
   public void clearError(boolean clearRef)
   {
      error = null;
      if (clearRef)
      {
         errorRef = null;
      }
   }
   
   /**
    * Get the {@link #error}.
    * 
    * @return   See above.
    */
   public ObjectVar<? extends LegacyError> getError()
   {
      return error;
   }
   
   /**
    * Get the {@link #getErrorRef()}.
    * 
    * @return   See above.
    */
   public LegacyError getErrorRef()
   {
      return errorRef;
   }
   
   /**
    * Check the state of the {@link #fromReturn} flag.
    * 
    * @return   See above.
    */
   boolean isFromReturn()
   {
      return fromReturn;
   }

   /**
    * Set the {@link #fromReturn} flag state.
    *
    * @param   fromReturn
    *          Flag indicating if this exception is from a RETURN ERROR or UNDO, THROW top-level exit.
    */
   void setFromReturn(boolean fromReturn)
   {
      this.fromReturn = false;
   }
   
   /**
    * Set the {@link #explicit} flag.
    * 
    * @param    explicit
    *           <code>true</code> if this explicitly thrown by the application, and not FWD runtime.
    */
   void setExplicit(boolean explicit)
   {
      this.explicit = explicit;
   }
   
   /**
    * Check the {@link #explicit} flag.
    * 
    * @return    <code>true</code> if this explicitly thrown by the application, and not FWD runtime.
    */
   boolean isExplicit()
   {
      return explicit;
   }
}