1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.regexp;
21
22 import java.util.regex.Matcher;
23
24 import com.puppycrawl.tools.checkstyle.api.FileText;
25 import com.puppycrawl.tools.checkstyle.api.LineColumn;
26
27 /**
28 * A detector that matches across multiple lines.
29 */
30 class MultilineDetector {
31
32 /**
33 * A key is pointing to the warning message text in "messages.properties"
34 * file.
35 */
36 public static final String MSG_REGEXP_EXCEEDED = "regexp.exceeded";
37
38 /**
39 * A key is pointing to the warning message text in "messages.properties"
40 * file.
41 */
42 public static final String MSG_REGEXP_MINIMUM = "regexp.minimum";
43
44 /**
45 * A key is pointing to the warning message text in "messages.properties"
46 * file.
47 */
48 public static final String MSG_EMPTY = "regexp.empty";
49 /**
50 * A key is pointing to the warning message text in "messages.properties"
51 * file.
52 */
53 public static final String MSG_STACKOVERFLOW = "regexp.StackOverflowError";
54
55 /** The detection options to use. */
56 private final DetectorOptions options;
57 /** Tracks the number of matches. */
58 private int currentMatches;
59 /** The matcher. */
60 private Matcher matcher;
61 /** The file text content. */
62 private FileText text;
63
64 /**
65 * Creates an instance.
66 *
67 * @param options the options to use.
68 */
69 /* package */ MultilineDetector(DetectorOptions options) {
70 this.options = options;
71 }
72
73 /**
74 * Processes an entire text file looking for matches.
75 *
76 * @param fileText the text to process
77 */
78 public void processLines(FileText fileText) {
79 text = new FileText(fileText);
80 resetState();
81
82 final String format = options.getFormat();
83 if (format == null || format.isEmpty()) {
84 options.getReporter().log(1, MSG_EMPTY);
85 }
86 else {
87 matcher = options.getPattern().matcher(fileText.getFullText());
88 findMatch();
89 finish();
90 }
91 }
92
93 /** Method that finds the matches. */
94 private void findMatch() {
95 try {
96 boolean foundMatch = matcher.find();
97
98 while (foundMatch) {
99 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 }