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.coding;
21
22 import com.puppycrawl.tools.checkstyle.StatelessCheck;
23 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
24 import com.puppycrawl.tools.checkstyle.api.DetailAST;
25 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
27 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
28 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
29
30 /**
31 * <div>
32 * Checks for illegal tokens. By default, labels are prohibited.
33 * </div>
34 *
35 * <p>
36 * Rationale: Certain language features can harm readability, lead to
37 * confusion or are not obvious to novice developers. Other features
38 * may be discouraged in certain frameworks, such as not having
39 * native methods in Enterprise JavaBeans components.
40 * </p>
41 * <ul>
42 * <li>
43 * Property {@code tokens} - tokens to check
44 * Type is {@code anyTokenTypesSet}.
45 * Default value is
46 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LABELED_STAT">
47 * LABELED_STAT</a>.
48 * </li>
49 * </ul>
50 *
51 * <p>
52 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
53 * </p>
54 *
55 * <p>
56 * Violation Message Keys:
57 * </p>
58 * <ul>
59 * <li>
60 * {@code illegal.token}
61 * </li>
62 * </ul>
63 *
64 * @since 3.2
65 */
66 @StatelessCheck
67 public class IllegalTokenCheck
68 extends AbstractCheck {
69
70 /**
71 * A key is pointing to the warning message text in "messages.properties"
72 * file.
73 */
74 public static final String MSG_KEY = "illegal.token";
75
76 @Override
77 public int[] getDefaultTokens() {
78 return new int[] {
79 TokenTypes.LABELED_STAT,
80 };
81 }
82
83 @Override
84 public int[] getAcceptableTokens() {
85 return TokenUtil.getAllTokenIds();
86 }
87
88 @Override
89 public int[] getRequiredTokens() {
90 return CommonUtil.EMPTY_INT_ARRAY;
91 }
92
93 @Override
94 public boolean isCommentNodesRequired() {
95 return true;
96 }
97
98 @Override
99 public void visitToken(DetailAST ast) {
100 log(
101 ast,
102 MSG_KEY,
103 convertToString(ast)
104 );
105 }
106
107 /**
108 * Converts given AST node to string representation.
109 *
110 * @param ast node to be represented as string
111 * @return string representation of AST node
112 */
113 private static String convertToString(DetailAST ast) {
114 final String tokenText;
115 switch (ast.getType()) {
116 case TokenTypes.LABELED_STAT:
117 tokenText = ast.getFirstChild().getText() + ast.getText();
118 break;
119 // multiline tokens need to become singlelined
120 case TokenTypes.COMMENT_CONTENT:
121 tokenText = JavadocUtil.escapeAllControlChars(ast.getText());
122 break;
123 default:
124 tokenText = ast.getText();
125 break;
126 }
127 return tokenText;
128 }
129
130 }