001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.regexp;
021
022import java.util.regex.Matcher;
023
024import com.puppycrawl.tools.checkstyle.api.FileText;
025import com.puppycrawl.tools.checkstyle.api.LineColumn;
026
027/**
028 * A detector that matches across multiple lines.
029 */
030class MultilineDetector {
031
032    /**
033     * A key is pointing to the warning message text in "messages.properties"
034     * file.
035     */
036    public static final String MSG_REGEXP_EXCEEDED = "regexp.exceeded";
037
038    /**
039     * A key is pointing to the warning message text in "messages.properties"
040     * file.
041     */
042    public static final String MSG_REGEXP_MINIMUM = "regexp.minimum";
043
044    /**
045     * A key is pointing to the warning message text in "messages.properties"
046     * file.
047     */
048    public static final String MSG_EMPTY = "regexp.empty";
049    /**
050     * A key is pointing to the warning message text in "messages.properties"
051     * file.
052     */
053    public static final String MSG_STACKOVERFLOW = "regexp.StackOverflowError";
054
055    /** The detection options to use. */
056    private final DetectorOptions options;
057    /** Tracks the number of matches. */
058    private int currentMatches;
059    /** The matcher. */
060    private Matcher matcher;
061    /** The file text content. */
062    private FileText text;
063
064    /**
065     * Creates an instance.
066     *
067     * @param options the options to use.
068     */
069    /* package */ MultilineDetector(DetectorOptions options) {
070        this.options = options;
071    }
072
073    /**
074     * Processes an entire text file looking for matches.
075     *
076     * @param fileText the text to process
077     */
078    public void processLines(FileText fileText) {
079        text = new FileText(fileText);
080        resetState();
081
082        final String format = options.getFormat();
083        if (format == null || format.isEmpty()) {
084            options.getReporter().log(1, MSG_EMPTY);
085        }
086        else {
087            matcher = options.getPattern().matcher(fileText.getFullText());
088            findMatch();
089            finish();
090        }
091    }
092
093    /** Method that finds the matches. */
094    private void findMatch() {
095        try {
096            boolean foundMatch = matcher.find();
097
098            while (foundMatch) {
099                currentMatches++;
100                if (currentMatches > options.getMaximum()) {
101                    final LineColumn start = text.lineColumn(matcher.start());
102                    if (options.getMessage().isEmpty()) {
103                        options.getReporter().log(start.getLine(),
104                                MSG_REGEXP_EXCEEDED, matcher.pattern().toString());
105                    }
106                    else {
107                        options.getReporter()
108                                .log(start.getLine(), options.getMessage());
109                    }
110                }
111                foundMatch = matcher.find();
112            }
113        }
114        // see http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6337993 et al.
115        catch (StackOverflowError ignored) {
116            // OK http://blog.igorminar.com/2008/05/catching-stackoverflowerror-and-bug-in.html
117            // http://programmers.stackexchange.com/questions/
118            //        209099/is-it-ever-okay-to-catch-stackoverflowerror-in-java
119            options.getReporter().log(1, MSG_STACKOVERFLOW, matcher.pattern().toString());
120        }
121    }
122
123    /** Perform processing at the end of a set of lines. */
124    private void finish() {
125        if (currentMatches < options.getMinimum()) {
126            if (options.getMessage().isEmpty()) {
127                options.getReporter().log(1, MSG_REGEXP_MINIMUM,
128                        options.getMinimum(), options.getFormat());
129            }
130            else {
131                options.getReporter().log(1, options.getMessage());
132            }
133        }
134    }
135
136    /**
137     * Reset the state of the detector.
138     */
139    private void resetState() {
140        currentMatches = 0;
141    }
142
143}