1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.parser;
  27 




  28 import java.util.HashSet;
  29 import java.util.regex.Pattern;
  30 import java.util.regex.PatternSyntaxException;
  31 import jdk.nashorn.internal.runtime.BitVector;
  32 import jdk.nashorn.internal.runtime.ECMAErrors;
  33 import jdk.nashorn.internal.runtime.ParserException;
  34 
  35 import jdk.nashorn.internal.joni.Option;
  36 import jdk.nashorn.internal.joni.Regex;
  37 import jdk.nashorn.internal.joni.Syntax;
  38 import jdk.nashorn.internal.joni.exception.JOniException;
  39 
  40 /**
  41  * This class is used to represent a parsed regular expression. Accepts input
  42  * pattern string and flagString. This is used by AbstractParser to validate
  43  * RegExp literals as well as by NativeRegExp to parse RegExp constructor arguments.
  44  */
  45 public final class RegExp {
  46     /** Pattern string. */
  47     private final String source;
  48 
  49     /** Global search flag for this regexp.*/
  50     private boolean global;
  51 
  52     /** Case insensitive flag for this regexp */
  53     private boolean ignoreCase;
  54 
  55     /** Multi-line flag for this regexp */
  56     private boolean multiline;
  57 
  58     /** Java regexp pattern to use for match. We compile to one of these */
  59     private Regex regex;
  60 
  61     /** BitVector that keeps track of groups in negative lookahead */
  62     private BitVector groupsInNegativeLookahead;
  63 
  64     /**
  65      * Creates RegExpLiteral object from given input and flagString.
  66      *
  67      * @param source RegExp pattern string
  68      * @param flagString RegExp flags
  69      * @throws ParserException if flagString is invalid or input string has syntax error.
  70      */
  71     public RegExp(final String source, final String flagString) throws ParserException {
  72         this.source = source;
  73         final HashSet<Character> usedFlags = new HashSet<>();
  74         int option = Option.SINGLELINE;
  75 
  76         for (final char ch : flagString.toCharArray()) {
  77             if (usedFlags.contains(ch)) {
  78                 throwParserException("repeated.flag", Character.toString(ch));
  79             }
  80 
  81             switch (ch) {
  82             case 'g':
  83                 this.global = true;
  84                 usedFlags.add(ch);
  85                 break;
  86             case 'i':
  87                 this.ignoreCase = true;
  88                 option |= Option.IGNORECASE;
  89                 usedFlags.add(ch);
  90                 break;
  91             case 'm':
  92                 this.multiline = true;
  93                 option &= ~Option.SINGLELINE;
  94                 option |= Option.NEGATE_SINGLELINE;
  95                 usedFlags.add(ch);
  96                 break;
  97             default:
  98                 throwParserException("unsupported.flag", Character.toString(ch));
  99             }
 100         }
 101 
 102         try {
 103             RegExpScanner parsed;
 104 
 105             try {
 106                 parsed = RegExpScanner.scan(source);
 107             } catch (final PatternSyntaxException e) {
 108                 // refine the exception with a better syntax error, if this
 109                 // passes, just rethrow what we have
 110                 Pattern.compile(source, 0);
 111                 throw e;
 112             }
 113 
 114             if (parsed != null) {
 115                 char[] javaPattern = parsed.getJavaPattern().toCharArray();
 116                 this.regex = new Regex(javaPattern, 0, javaPattern.length, option, Syntax.JAVASCRIPT);
 117                 this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead();
 118             }
 119         } catch (final PatternSyntaxException e2) {
 120             throwParserException("syntax", e2.getMessage());
 121         } catch (JOniException e2) {
 122             throwParserException("syntax", e2.getMessage());
 123         }
 124 
 125     }
 126 
 127     /**
 128      * @return the source string
 129      */
 130     public String getSource() {
 131         return source;
 132     }
 133 
 134     /**
 135      * @return the global
 136      */
 137     public boolean isGlobal() {
 138         return global;
 139     }
 140 
 141     /**
 142      * @return the ignoreCase
 143      */
 144     public boolean isIgnoreCase() {
 145         return ignoreCase;
 146     }
 147 
 148     /**
 149      * @return the multiline
 150      */
 151     public boolean isMultiline() {
 152         return multiline;
 153     }
 154 
 155     /**
 156      * @return the pattern
 157      */
 158     public Regex getRegex() {
 159         return regex;
 160     }
 161 
 162     /**
 163      * @return the groupsInNegativeLookahead
 164      */
 165     public BitVector getGroupsInNegativeLookahead() {
 166         return groupsInNegativeLookahead;
 167     }
 168 
 169     /**
 170      * Validation method for RegExp input and flagString - we don't care about the RegExp object
 171      *
 172      * @param input        regexp input
 173      * @param flagString   flag string
 174      *
 175      * @throws ParserException if invalid regexp and flags
 176      */
 177     @SuppressWarnings({"unused", "ResultOfObjectAllocationIgnored"})
 178     public static void validate(final String input, final String flagString) throws ParserException {
 179         new RegExp(input, flagString);
 180     }
 181 
 182     private static void throwParserException(final String key, final String str) throws ParserException {
 183         throw new ParserException(ECMAErrors.getMessage("parser.error.regex." + key, str));
 184     }
 185 }
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