1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 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.ScopeUtil;
28
29 /**
30 * <div>
31 * Checks if unnecessary semicolon is used after type member declaration.
32 * </div>
33 *
34 * <p>
35 * Notes:
36 * This check is not applicable to empty statements (unnecessary semicolons inside methods or
37 * init blocks),
38 * <a href="https://checkstyle.org/checks/coding/emptystatement.html">EmptyStatement</a>
39 * is responsible for it.
40 * </p>
41 * <ul>
42 * <li>
43 * Property {@code tokens} - tokens to check
44 * Type is {@code java.lang.String[]}.
45 * Validation type is {@code tokenSet}.
46 * Default value is:
47 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CLASS_DEF">
48 * CLASS_DEF</a>,
49 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INTERFACE_DEF">
50 * INTERFACE_DEF</a>,
51 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_DEF">
52 * ENUM_DEF</a>,
53 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ANNOTATION_DEF">
54 * ANNOTATION_DEF</a>,
55 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#VARIABLE_DEF">
56 * VARIABLE_DEF</a>,
57 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ANNOTATION_FIELD_DEF">
58 * ANNOTATION_FIELD_DEF</a>,
59 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#STATIC_INIT">
60 * STATIC_INIT</a>,
61 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INSTANCE_INIT">
62 * INSTANCE_INIT</a>,
63 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF">
64 * CTOR_DEF</a>,
65 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF">
66 * METHOD_DEF</a>,
67 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF">
68 * ENUM_CONSTANT_DEF</a>,
69 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#COMPACT_CTOR_DEF">
70 * COMPACT_CTOR_DEF</a>,
71 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RECORD_DEF">
72 * RECORD_DEF</a>.
73 * </li>
74 * </ul>
75 *
76 * <p>
77 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
78 * </p>
79 *
80 * <p>
81 * Violation Message Keys:
82 * </p>
83 * <ul>
84 * <li>
85 * {@code unnecessary.semicolon}
86 * </li>
87 * </ul>
88 *
89 * @since 8.24
90 */
91 @StatelessCheck
92 public final class UnnecessarySemicolonAfterTypeMemberDeclarationCheck extends AbstractCheck {
93
94 /**
95 * A key is pointing to the warning message text in "messages.properties"
96 * file.
97 */
98 public static final String MSG_SEMI = "unnecessary.semicolon";
99
100 @Override
101 public int[] getDefaultTokens() {
102 return getAcceptableTokens();
103 }
104
105 @Override
106 public int[] getAcceptableTokens() {
107 return new int[] {
108 TokenTypes.CLASS_DEF,
109 TokenTypes.INTERFACE_DEF,
110 TokenTypes.ENUM_DEF,
111 TokenTypes.ANNOTATION_DEF,
112 TokenTypes.VARIABLE_DEF,
113 TokenTypes.ANNOTATION_FIELD_DEF,
114 TokenTypes.STATIC_INIT,
115 TokenTypes.INSTANCE_INIT,
116 TokenTypes.CTOR_DEF,
117 TokenTypes.METHOD_DEF,
118 TokenTypes.ENUM_CONSTANT_DEF,
119 TokenTypes.COMPACT_CTOR_DEF,
120 TokenTypes.RECORD_DEF,
121 };
122 }
123
124 @Override
125 public int[] getRequiredTokens() {
126 return CommonUtil.EMPTY_INT_ARRAY;
127 }
128
129 @Override
130 public void visitToken(DetailAST ast) {
131 switch (ast.getType()) {
132 case TokenTypes.CLASS_DEF:
133 case TokenTypes.INTERFACE_DEF:
134 case TokenTypes.ENUM_DEF:
135 case TokenTypes.ANNOTATION_DEF:
136 case TokenTypes.RECORD_DEF:
137 checkTypeDefinition(ast);
138 break;
139 case TokenTypes.VARIABLE_DEF:
140 checkVariableDefinition(ast);
141 break;
142 case TokenTypes.ENUM_CONSTANT_DEF:
143 checkEnumConstant(ast);
144 break;
145 default:
146 checkTypeMember(ast);
147 break;
148 }
149 }
150
151 /**
152 * Checks if type member has unnecessary semicolon.
153 *
154 * @param ast type member
155 */
156 private void checkTypeMember(DetailAST ast) {
157 if (isSemicolon(ast.getNextSibling())) {
158 log(ast.getNextSibling(), MSG_SEMI);
159 }
160 }
161
162 /**
163 * Checks if type definition has unnecessary semicolon.
164 *
165 * @param ast type definition
166 */
167 private void checkTypeDefinition(DetailAST ast) {
168 if (!ScopeUtil.isOuterMostType(ast) && isSemicolon(ast.getNextSibling())) {
169 log(ast.getNextSibling(), MSG_SEMI);
170 }
171 final DetailAST firstMember =
172 ast.findFirstToken(TokenTypes.OBJBLOCK).getFirstChild().getNextSibling();
173 if (isSemicolon(firstMember) && !ScopeUtil.isInEnumBlock(firstMember)) {
174 log(firstMember, MSG_SEMI);
175 }
176 }
177
178 /**
179 * Checks if variable definition has unnecessary semicolon.
180 *
181 * @param variableDef variable definition
182 */
183 private void checkVariableDefinition(DetailAST variableDef) {
184 if (isSemicolon(variableDef.getLastChild()) && isSemicolon(variableDef.getNextSibling())) {
185 log(variableDef.getNextSibling(), MSG_SEMI);
186 }
187 }
188
189 /**
190 * Checks if enum constant has unnecessary semicolon.
191 *
192 * @param ast enum constant
193 */
194 private void checkEnumConstant(DetailAST ast) {
195 final DetailAST next = ast.getNextSibling();
196 if (isSemicolon(next) && isSemicolon(next.getNextSibling())) {
197 log(next.getNextSibling(), MSG_SEMI);
198 }
199 }
200
201 /**
202 * Checks that {@code ast} is a semicolon.
203 *
204 * @param ast token to check
205 * @return true if ast is semicolon, false otherwise
206 */
207 private static boolean isSemicolon(DetailAST ast) {
208 return ast != null && ast.getType() == TokenTypes.SEMI;
209 }
210 }