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.coding;
021
022import com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
027import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
028
029/**
030 * <p>
031 * Checks if unnecessary semicolon is used after type member declaration.
032 * </p>
033 * <p>
034 * This check is not applicable to empty statements (unnecessary semicolons inside methods or
035 * init blocks),
036 * <a href="https://checkstyle.org/checks/coding/emptystatement.html">EmptyStatement</a>
037 * is responsible for it.
038 * </p>
039 * <ul>
040 * <li>
041 * Property {@code tokens} - tokens to check
042 * Type is {@code java.lang.String[]}.
043 * Validation type is {@code tokenSet}.
044 * Default value is:
045 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CLASS_DEF">
046 * CLASS_DEF</a>,
047 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INTERFACE_DEF">
048 * INTERFACE_DEF</a>,
049 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_DEF">
050 * ENUM_DEF</a>,
051 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ANNOTATION_DEF">
052 * ANNOTATION_DEF</a>,
053 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#VARIABLE_DEF">
054 * VARIABLE_DEF</a>,
055 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ANNOTATION_FIELD_DEF">
056 * ANNOTATION_FIELD_DEF</a>,
057 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#STATIC_INIT">
058 * STATIC_INIT</a>,
059 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INSTANCE_INIT">
060 * INSTANCE_INIT</a>,
061 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF">
062 * CTOR_DEF</a>,
063 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF">
064 * METHOD_DEF</a>,
065 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF">
066 * ENUM_CONSTANT_DEF</a>,
067 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#COMPACT_CTOR_DEF">
068 * COMPACT_CTOR_DEF</a>,
069 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RECORD_DEF">
070 * RECORD_DEF</a>.
071 * </li>
072 * </ul>
073 * <p>
074 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
075 * </p>
076 * <p>
077 * Violation Message Keys:
078 * </p>
079 * <ul>
080 * <li>
081 * {@code unnecessary.semicolon}
082 * </li>
083 * </ul>
084 *
085 * @since 8.24
086 */
087@StatelessCheck
088public final class UnnecessarySemicolonAfterTypeMemberDeclarationCheck extends AbstractCheck {
089
090    /**
091     * A key is pointing to the warning message text in "messages.properties"
092     * file.
093     */
094    public static final String MSG_SEMI = "unnecessary.semicolon";
095
096    @Override
097    public int[] getDefaultTokens() {
098        return getAcceptableTokens();
099    }
100
101    @Override
102    public int[] getAcceptableTokens() {
103        return new int[] {
104            TokenTypes.CLASS_DEF,
105            TokenTypes.INTERFACE_DEF,
106            TokenTypes.ENUM_DEF,
107            TokenTypes.ANNOTATION_DEF,
108            TokenTypes.VARIABLE_DEF,
109            TokenTypes.ANNOTATION_FIELD_DEF,
110            TokenTypes.STATIC_INIT,
111            TokenTypes.INSTANCE_INIT,
112            TokenTypes.CTOR_DEF,
113            TokenTypes.METHOD_DEF,
114            TokenTypes.ENUM_CONSTANT_DEF,
115            TokenTypes.COMPACT_CTOR_DEF,
116            TokenTypes.RECORD_DEF,
117        };
118    }
119
120    @Override
121    public int[] getRequiredTokens() {
122        return CommonUtil.EMPTY_INT_ARRAY;
123    }
124
125    @Override
126    public void visitToken(DetailAST ast) {
127        switch (ast.getType()) {
128            case TokenTypes.CLASS_DEF:
129            case TokenTypes.INTERFACE_DEF:
130            case TokenTypes.ENUM_DEF:
131            case TokenTypes.ANNOTATION_DEF:
132            case TokenTypes.RECORD_DEF:
133                checkTypeDefinition(ast);
134                break;
135            case TokenTypes.VARIABLE_DEF:
136                checkVariableDefinition(ast);
137                break;
138            case TokenTypes.ENUM_CONSTANT_DEF:
139                checkEnumConstant(ast);
140                break;
141            default:
142                checkTypeMember(ast);
143                break;
144        }
145    }
146
147    /**
148     * Checks if type member has unnecessary semicolon.
149     *
150     * @param ast type member
151     */
152    private void checkTypeMember(DetailAST ast) {
153        if (isSemicolon(ast.getNextSibling())) {
154            log(ast.getNextSibling(), MSG_SEMI);
155        }
156    }
157
158    /**
159     * Checks if type definition has unnecessary semicolon.
160     *
161     * @param ast type definition
162     */
163    private void checkTypeDefinition(DetailAST ast) {
164        if (!ScopeUtil.isOuterMostType(ast) && isSemicolon(ast.getNextSibling())) {
165            log(ast.getNextSibling(), MSG_SEMI);
166        }
167        final DetailAST firstMember =
168            ast.findFirstToken(TokenTypes.OBJBLOCK).getFirstChild().getNextSibling();
169        if (isSemicolon(firstMember) && !ScopeUtil.isInEnumBlock(firstMember)) {
170            log(firstMember, MSG_SEMI);
171        }
172    }
173
174    /**
175     * Checks if variable definition has unnecessary semicolon.
176     *
177     * @param variableDef variable definition
178     */
179    private void checkVariableDefinition(DetailAST variableDef) {
180        if (isSemicolon(variableDef.getLastChild()) && isSemicolon(variableDef.getNextSibling())) {
181            log(variableDef.getNextSibling(), MSG_SEMI);
182        }
183    }
184
185    /**
186     * Checks if enum constant has unnecessary semicolon.
187     *
188     * @param ast enum constant
189     */
190    private void checkEnumConstant(DetailAST ast) {
191        final DetailAST next = ast.getNextSibling();
192        if (isSemicolon(next) && isSemicolon(next.getNextSibling())) {
193            log(next.getNextSibling(), MSG_SEMI);
194        }
195    }
196
197    /**
198     * Checks that {@code ast} is a semicolon.
199     *
200     * @param ast token to check
201     * @return true if ast is semicolon, false otherwise
202     */
203    private static boolean isSemicolon(DetailAST ast) {
204        return ast != null && ast.getType() == TokenTypes.SEMI;
205    }
206}