1 /*
2 * Copyright (c) 2011-2025 Yegor Bugayenko
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met: 1) Redistributions of source code must retain the above
9 * copyright notice, this list of conditions and the following
10 * disclaimer. 2) Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials provided
13 * with the distribution. 3) Neither the name of the Qulice.com nor
14 * the names of its contributors may be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
20 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29 * OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 package com.qulice.checkstyle;
32
33 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
34 import com.puppycrawl.tools.checkstyle.api.DetailAST;
35 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
36 import java.util.regex.Matcher;
37 import java.util.regex.Pattern;
38
39 /**
40 * C++ style inline comment is not allowed.
41 * Use //-style comment instead.
42 * @since 0.18
43 */
44 public final class SingleLineCommentCheck extends AbstractCheck {
45
46 /**
47 * Pattern for check.
48 * It is not final as it is initialized from the configuration.
49 */
50 private Pattern format = Pattern.compile("^$");
51
52 /**
53 * The message to report for a match.
54 * It is not final as it is initialized from the configuration.
55 */
56 private String message = "";
57
58 /**
59 * Comment line.
60 * It is not final because the visitToken method is called many times
61 * during the class under test and the field is reinitialized with a new object.
62 */
63 @SuppressWarnings("PMD.AvoidStringBufferField")
64 private StringBuilder line;
65
66 /**
67 * When inside a block comment, holds begin line number.
68 */
69 private int begin;
70
71 @Override
72 public boolean isCommentNodesRequired() {
73 return true;
74 }
75
76 @Override
77 public int[] getDefaultTokens() {
78 return new int[]{
79 TokenTypes.BLOCK_COMMENT_BEGIN,
80 TokenTypes.COMMENT_CONTENT,
81 TokenTypes.BLOCK_COMMENT_END,
82 };
83 }
84
85 @Override
86 public int[] getAcceptableTokens() {
87 return this.getDefaultTokens();
88 }
89
90 @Override
91 public int[] getRequiredTokens() {
92 return this.getDefaultTokens();
93 }
94
95 @Override
96 public void visitToken(final DetailAST ast) {
97 if (ast.getType() == TokenTypes.BLOCK_COMMENT_BEGIN) {
98 this.line = new StringBuilder(ast.getText());
99 this.begin = ast.getLineNo();
100 } else if (ast.getType() == TokenTypes.COMMENT_CONTENT) {
101 this.line.append(ast.getText());
102 } else {
103 this.line.append(ast.getText());
104 final Matcher matcher = this.format.matcher(this.line.toString());
105 if (matcher.matches() && this.singleLineCStyleComment(ast)) {
106 this.log(ast, this.message);
107 }
108 }
109 }
110
111 /**
112 * The method is called from checkstyle to configure this class.
113 * The parameter is set from the checks.xml file
114 * <module name="com.qulice.checkstyle.SingleLineCommentCheck"/> and
115 * <property name="format" value=" this regexp "/> property
116 *
117 * @param fmt Validatig regexp.
118 */
119 public void setFormat(final String fmt) {
120 this.format = Pattern.compile(fmt);
121 }
122
123 /**
124 * The method is called from checkstyle to configure this class.
125 * The parameter is set from the checks.xml file
126 * <module name="com.qulice.checkstyle.SingleLineCommentCheck"/> and
127 * <property name="message" value="This kind of comment is not allowed."/>
128 * property
129 *
130 * @param msg Error message.
131 */
132 public void setMessage(final String msg) {
133 this.message = msg;
134 }
135
136 /**
137 * Checks for the end of a comment line.
138 * @param ast Checkstyle's AST nodes.
139 * @return True if this is the end of the comment
140 * and the starting line number is equal to the ending line number.
141 */
142 private boolean singleLineCStyleComment(final DetailAST ast) {
143 return ast.getType() == TokenTypes.BLOCK_COMMENT_END && this.begin == ast.getLineNo();
144 }
145 }