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    1   /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
    2   package net.sourceforge.pmd.ast;
    3
    4   /***
    5    * This exception is thrown when parse errors are encountered.
    6    * You can explicitly create objects of this exception type by
    7    * calling the method generateParseException in the generated
    8    * parser.
    9    * <p/>
    10   * You can modify this class to customize your error reporting
    11   * mechanisms so long as you retain the public fields.
    12   */
    13  public class ParseException extends RuntimeException {
    14
    15      /***
    16       * This constructor is used by the method "generateParseException"
    17       * in the generated parser.  Calling this constructor generates
    18       * a new object of this type with the fields "currentToken",
    19       * "expectedTokenSequences", and "tokenImage" set.  The boolean
    20       * flag "specialConstructor" is also set to true to indicate that
    21       * this constructor was used to create this object.
    22       * This constructor calls its super class with the empty string
    23       * to force the "toString" method of parent class "Throwable" to
    24       * print the error message in the form:
    25       * ParseException: <result of getMessage>
    26       */
    27      public ParseException(Token currentTokenVal,
    28                            int[][] expectedTokenSequencesVal,
    29                            String[] tokenImageVal) {
    30          super("");
    31          specialConstructor = true;
    32          currentToken = currentTokenVal;
    33          expectedTokenSequences = expectedTokenSequencesVal;
    34          tokenImage = tokenImageVal;
    35      }
    36
    37      /***
    38       * The following constructors are for use by you for whatever
    39       * purpose you can think of.  Constructing the exception in this
    40       * manner makes the exception behave in the normal way - i.e., as
    41       * documented in the class "Throwable".  The fields "errorToken",
    42       * "expectedTokenSequences", and "tokenImage" do not contain
    43       * relevant information.  The JavaCC generated code does not use
    44       * these constructors.
    45       */
    46
    47      public ParseException() {
    48          super();
    49          specialConstructor = false;
    50      }
    51
    52      public ParseException(String message) {
    53          super(message);
    54          specialConstructor = false;
    55      }
    56
    57      /***
    58       * This variable determines which constructor was used to create
    59       * this object and thereby affects the semantics of the
    60       * "getMessage" method (see below).
    61       */
    62      protected boolean specialConstructor;
    63
    64      /***
    65       * This is the last token that has been consumed successfully.  If
    66       * this object has been created due to a parse error, the token
    67       * followng this token will (therefore) be the first error token.
    68       */
    69      public Token currentToken;
    70
    71      /***
    72       * Each entry in this array is an array of integers.  Each array
    73       * of integers represents a sequence of tokens (by their ordinal
    74       * values) that is expected at this point of the parse.
    75       */
    76      public int[][] expectedTokenSequences;
    77
    78      /***
    79       * This is a reference to the "tokenImage" array of the generated
    80       * parser within which the parse error occurred.  This array is
    81       * defined in the generated ...Constants interface.
    82       */
    83      public String[] tokenImage;
    84
    85      /***
    86       * This method has the standard behavior when this object has been
    87       * created using the standard constructors.  Otherwise, it uses
    88       * "currentToken" and "expectedTokenSequences" to generate a parse
    89       * error message and returns it.  If this object has been created
    90       * due to a parse error, and you do not catch it (it gets thrown
    91       * from the parser), then this method is called during the printing
    92       * of the final stack trace, and hence the correct error message
    93       * gets displayed.
    94       */
    95      public String getMessage() {
    96          if (!specialConstructor) {
    97              return super.getMessage();
    98          }
    99          StringBuffer expected = new StringBuffer();
    100         int maxSize = 0;
    101         for (int i = 0; i < expectedTokenSequences.length; i++) {
    102             if (maxSize < expectedTokenSequences[i].length) {
    103                 maxSize = expectedTokenSequences[i].length;
    104             }
    105             for (int j = 0; j < expectedTokenSequences[i].length; j++) {
    106                 expected.append(tokenImage[expectedTokenSequences[i][j]]).append(' ');
    107             }
    108             if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
    109                 expected.append("...");
    110             }
    111             expected.append(eol).append("    ");
    112         }
    113         String retval = "Encountered \"";
    114         Token tok = currentToken.next;
    115         for (int i = 0; i < maxSize; i++) {
    116             if (i != 0) retval += " ";
    117             if (tok.kind == 0) {
    118                 retval += tokenImage[0];
    119                 break;
    120             }
    121             retval += add_escapes(tok.image);
    122             tok = tok.next;
    123         }
    124         retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
    125         retval += "." + eol;
    126         if (expectedTokenSequences.length == 1) {
    127             retval += "Was expecting:" + eol + "    ";
    128         } else {
    129             retval += "Was expecting one of:" + eol + "    ";
    130         }
    131         retval += expected.toString();
    132         return retval;
    133     }
    134
    135     /***
    136      * The end of line string for this machine.
    137      */
    138     protected String eol = System.getProperty("line.separator", "\n");
    139
    140     /***
    141      * Used to convert raw characters to their escaped version
    142      * when these raw version cannot be used as part of an ASCII
    143      * string literal.
    144      */
    145     protected String add_escapes(String str) {
    146         StringBuffer retval = new StringBuffer();
    147         char ch;
    148         for (int i = 0; i < str.length(); i++) {
    149             switch (str.charAt(i)) {
    150                 case 0:
    151                     continue;
    152                 case '\b':
    153                     retval.append("//b");
    154                     continue;
    155                 case '\t':
    156                     retval.append("//t");
    157                     continue;
    158                 case '\n':
    159                     retval.append("//n");
    160                     continue;
    161                 case '\f':
    162                     retval.append("//f");
    163                     continue;
    164                 case '\r':
    165                     retval.append("//r");
    166                     continue;
    167                 case '\"':
    168                     retval.append("//\"");
    169                     continue;
    170                 case '\'':
    171                     retval.append("//\'");
    172                     continue;
    173                 case '//':
    174                     retval.append("////");
    175                     continue;
    176                 default:
    177                     if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
    178                         String s = "0000" + Integer.toString(ch, 16);
    179                         retval.append("//u" + s.substring(s.length() - 4, s.length()));
    180                     } else {
    181                         retval.append(ch);
    182                     }
    183                     continue;
    184             }
    185         }
    186         return retval.toString();
    187     }
    188
    189 }