org.eclipse.tracecompass.ctf.core/src/org/eclipse/tracecompass/internal/ctf/core/event/metadata/exceptions/CtfAntlrException.java

   1 /*******************************************************************************
   2  * Copyright (c) 2013, 2014 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Alexandre Montplaisir - Initial API and implementation
  11  *   Matthew Khouzam - Addition to have more descriptive errors
  12  *******************************************************************************/
  13
  14 package org.eclipse.tracecompass.internal.ctf.core.event.metadata.exceptions;
  15
  16 import java.lang.reflect.Field;
  17
  18 import org.antlr.runtime.MismatchedTokenException;
  19 import org.antlr.runtime.RecognitionException;
  20 import org.eclipse.tracecompass.ctf.core.CTFException;
  21 import org.eclipse.tracecompass.ctf.parser.CTFLexer;
  22
  23 /**
  24  * CTF Reader exception but dealing with Antlr-specific parsing problems.
  25  *
  26  * It is separated from the main {@link CTFException} - and is not part of the
  27  * API - to isolate the Antlr-specific classes and avoid pushing that dependency
  28  * to the users of this plugin.
  29  *
  30  * @author Matthew Khouzam
  31  */
  32 public class CtfAntlrException extends CTFException {
  33
  34     private static final long serialVersionUID = -7078624493350073777L;
  35
  36     private final int fErrorLine;
  37     private final String fFile;
  38     private String fExpectingName = ""; //$NON-NLS-1$
  39     private int fExpectedValue = -1;
  40     private String fActualName = ""; //$NON-NLS-1$
  41     private int fActualValue = -1;
  42
  43     private final int fCharPositionInLine;
  44
  45     /**
  46      * Re-throw the exception but read its data
  47      *
  48      * @param e
  49      *            the previous recognition exception (Antlr specific)
  50      */
  51     public CtfAntlrException(MismatchedTokenException e) {
  52         super(e);
  53         fErrorLine = e.line;
  54         fCharPositionInLine = e.charPositionInLine;
  55         fFile = "metadata"; //$NON-NLS-1$ // we're in CTF, the only thing using antlr is metadata
  56         parseMismatchedException(e);
  57     }
  58
  59     /**
  60      * Re-throw the exception but read its data
  61      *
  62      * @param e
  63      *            the previous recognition exception (Antlr specific)
  64      */
  65     public CtfAntlrException(RecognitionException e) {
  66         super(e);
  67         fErrorLine = e.line;
  68         fCharPositionInLine = e.charPositionInLine;
  69         fFile = "metadata"; //$NON-NLS-1$ // we're in CTF, the only thing using antlr is metadata
  70     }
  71
  72     /**
  73      * Re-throw the exception but read its data
  74      *
  75      * @param e
  76      *            the previous rewrite exception (Antlr specific)
  77      */
  78     public CtfAntlrException(Exception e) {
  79         super(e);
  80         fErrorLine = -1;
  81         fCharPositionInLine = -1;
  82         fFile = "metadata"; //$NON-NLS-1$ // we're in CTF, the only thing using antlr is metadata
  83     }
  84
  85     private void parseMismatchedException(MismatchedTokenException m) {
  86         // Iterate through the tokens that are hidden in the CTFLexer
  87         // They are private static final int fields.
  88         for (Field f : CTFLexer.class.getDeclaredFields()) {
  89             f.setAccessible(true);
  90             String name;
  91             int value;
  92             try {
  93                 name = f.getName();
  94                 final boolean isInt = (f.getType().isPrimitive());
  95                 if (isInt) {
  96                     value = ((Integer) f.get(null)).intValue();
  97                     if (value == m.expecting) {
  98                         this.fExpectingName = name;
  99                         this.fExpectedValue = value;
 100                     }
 101                     if (value == m.c) {
 102                         this.fActualName = name;
 103                         this.fActualValue = value;
 104                     }
 105                 }
 106             } catch (NullPointerException e1) {
 107                 // Pokemon, gotta catch em all!
 108                 // actually useful since f may not have a
 109                 // value
 110             } catch (IllegalArgumentException e1) {
 111                 // Catch these exceptions (reflexion)
 112             } catch (IllegalAccessException e1) {
 113                 // Catch these exceptions (reflexion)
 114             }
 115             if (!this.fExpectingName.isEmpty() && !this.fActualName.isEmpty()) {
 116                 return;
 117             }
 118         }
 119     }
 120
 121     @Override
 122     public String getMessage() {
 123         final String message = super.getMessage();
 124         if (fErrorLine == -1) {
 125             return message;
 126         }
 127         String expected = "" + this.fExpectedValue; //$NON-NLS-1$
 128         String actual = "" + this.fActualValue; //$NON-NLS-1$
 129         String newMessage = message.replaceAll(expected, this.fExpectingName);
 130         newMessage = newMessage.replaceAll(actual, this.fActualName);
 131         return newMessage + " at " + fFile + ":" + fErrorLine + ":" + fCharPositionInLine; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 132     }
 133
 134 }