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 static java.util.regex.Pattern.CASE_INSENSITIVE;
  29 import static java.util.regex.Pattern.MULTILINE;
  30 import static java.util.regex.Pattern.UNICODE_CASE;
  31 
  32 import java.util.HashSet;
  33 import java.util.regex.Pattern;
  34 import java.util.regex.PatternSyntaxException;
  35 import jdk.nashorn.internal.runtime.BitVector;
  36 import jdk.nashorn.internal.runtime.ECMAErrors;
  37 import jdk.nashorn.internal.runtime.ParserException;
  38 





  39 /**
  40  * This class is used to represent a parsed regular expression. Accepts input
  41  * pattern string and flagString. This is used by AbstractParser to validate
  42  * RegExp literals as well as by NativeRegExp to parse RegExp constructor arguments.
  43  */
  44 public final class RegExp {
  45     /** Pattern string. */
  46     private final String input;
  47 
  48     /** Global search flag for this regexp.*/
  49     private boolean global;
  50 
  51     /** Case insensitive flag for this regexp */
  52     private boolean ignoreCase;
  53 
  54     /** Multi-line flag for this regexp */
  55     private boolean multiline;
  56 
  57     /** Java regexp pattern to use for match. We compile to one of these */
  58     private Pattern pattern;
  59 
  60     /** BitVector that keeps track of groups in negative lookahead */
  61     private BitVector groupsInNegativeLookahead;
  62 
  63     /**
  64      * Creates RegExpLiteral object from given input and flagString.
  65      *
  66      * @param input RegExp pattern string
  67      * @param flagString RegExp flags
  68      * @throws ParserException if flagString is invalid or input string has syntax error.
  69      */
  70     public RegExp(final String input, final String flagString) throws ParserException {
  71         this.input = input;
  72         final HashSet<Character> usedFlags = new HashSet<>();
  73         int flags = 0;
  74 
  75         for (final char ch : flagString.toCharArray()) {
  76             if (usedFlags.contains(ch)) {
  77                 throwParserException("repeated.flag", Character.toString(ch));
  78             }
  79 
  80             switch (ch) {
  81             case 'g':
  82                 this.global = true;
  83                 usedFlags.add(ch);
  84                 break;
  85             case 'i':
  86                 this.ignoreCase = true;
  87                 flags |= CASE_INSENSITIVE | UNICODE_CASE;
  88                 usedFlags.add(ch);
  89                 break;
  90             case 'm':
  91                 this.multiline = true;
  92                 flags |= MULTILINE;

  93                 usedFlags.add(ch);
  94                 break;
  95             default:
  96                 throwParserException("unsupported.flag", Character.toString(ch));
  97             }
  98         }
  99 
 100         try {
 101             RegExpScanner parsed;
 102 
 103             try {
 104                 parsed = RegExpScanner.scan(input);
 105             } catch (final PatternSyntaxException e) {
 106                 // refine the exception with a better syntax error, if this
 107                 // passes, just rethrow what we have
 108                 Pattern.compile(input, flags);
 109                 throw e;
 110             }
 111 
 112             if (parsed != null) {
 113                 this.pattern = Pattern.compile(parsed.getJavaPattern(), flags);

 114                 this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead();
 115             }
 116         } catch (final PatternSyntaxException e2) {
 117             throwParserException("syntax", e2.getMessage());


 118         }
 119 
 120     }
 121 
 122     /**
 123      * @return the input
 124      */
 125     public String getInput() {
 126         return input;
 127     }
 128 
 129     /**
 130      * @return the global
 131      */
 132     public boolean isGlobal() {
 133         return global;
 134     }
 135 
 136     /**
 137      * @return the ignoreCase
 138      */
 139     public boolean isIgnoreCase() {
 140         return ignoreCase;
 141     }
 142 
 143     /**
 144      * @return the multiline
 145      */
 146     public boolean isMultiline() {
 147         return multiline;
 148     }
 149 
 150     /**
 151      * @return the pattern
 152      */
 153     public Pattern getPattern() {
 154         return pattern;
 155     }
 156 
 157     /**
 158      * @return the groupsInNegativeLookahead
 159      */
 160     public BitVector getGroupsInNegativeLookahead() {
 161         return groupsInNegativeLookahead;
 162     }
 163 
 164     /**
 165      * Validation method for RegExp input and flagString - we don't care about the RegExp object
 166      *
 167      * @param input        regexp input
 168      * @param flagString   flag string
 169      *
 170      * @throws ParserException if invalid regexp and flags
 171      */
 172     @SuppressWarnings({"unused", "ResultOfObjectAllocationIgnored"})
 173     public static void validate(final String input, final String flagString) throws ParserException {
 174         new RegExp(input, flagString);
 175     }
 176 
 177     private static void throwParserException(final String key, final String str) throws ParserException {
 178         throw new ParserException(ECMAErrors.getMessage("parser.error.regex." + key, str));
 179     }
 180 }
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