001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 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;
026
027/**
028 * <div>
029 * Checks if call to superclass constructor without arguments is present.
030 * Such invocation is redundant because constructor body implicitly
031 * begins with a superclass constructor invocation {@code super();}
032 * See <a href="https://docs.oracle.com/javase/specs/jls/se13/html/jls-8.html#jls-8.8.7">
033 * specification</a> for detailed information.
034 * </div>
035 *
036 * @since 8.29
037 */
038@StatelessCheck
039public final class AvoidNoArgumentSuperConstructorCallCheck extends AbstractCheck {
040
041    /**
042     * A key is pointing to the warning message text in "messages.properties" file.
043     */
044    public static final String MSG_CTOR = "super.constructor.call";
045
046    /**
047     * Creates a new {@code AvoidNoArgumentSuperConstructorCallCheck} instance.
048     */
049    public AvoidNoArgumentSuperConstructorCallCheck() {
050        // no code by default
051    }
052
053    @Override
054    public int[] getDefaultTokens() {
055        return getRequiredTokens();
056    }
057
058    @Override
059    public int[] getAcceptableTokens() {
060        return getRequiredTokens();
061    }
062
063    @Override
064    public int[] getRequiredTokens() {
065        return new int[] {
066            TokenTypes.SUPER_CTOR_CALL,
067        };
068    }
069
070    @Override
071    public void visitToken(DetailAST ast) {
072        if (ast.getPreviousSibling() == null
073                && ast.getFirstChild().getType() == TokenTypes.LPAREN
074                && ast.findFirstToken(TokenTypes.ELIST).getChildCount() == 0) {
075            log(ast, MSG_CTOR);
076        }
077    }
078
079}