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.FileStatefulCheck;
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 * Restricts nested {@code for} blocks to a specified depth.
030 * </div>
031 * <ul>
032 * <li>
033 * Property {@code max} - Specify maximum allowed nesting depth.
034 * Type is {@code int}.
035 * Default value is {@code 1}.
036 * </li>
037 * </ul>
038 *
039 * <p>
040 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
041 * </p>
042 *
043 * <p>
044 * Violation Message Keys:
045 * </p>
046 * <ul>
047 * <li>
048 * {@code nested.for.depth}
049 * </li>
050 * </ul>
051 *
052 * @since 5.3
053 */
054@FileStatefulCheck
055public final class NestedForDepthCheck extends AbstractCheck {
056
057    /**
058     * A key is pointing to the warning message text in "messages.properties"
059     * file.
060     */
061    public static final String MSG_KEY = "nested.for.depth";
062
063    /** Specify maximum allowed nesting depth. */
064    private int max = 1;
065    /** Current nesting depth. */
066    private int depth;
067
068    /**
069     * Setter to specify maximum allowed nesting depth.
070     *
071     * @param max maximum allowed nesting depth.
072     * @since 5.3
073     */
074    public void setMax(int max) {
075        this.max = max;
076    }
077
078    @Override
079    public int[] getDefaultTokens() {
080        return getRequiredTokens();
081    }
082
083    @Override
084    public int[] getAcceptableTokens() {
085        return getRequiredTokens();
086    }
087
088    @Override
089    public int[] getRequiredTokens() {
090        return new int[] {TokenTypes.LITERAL_FOR};
091    }
092
093    @Override
094    public void visitToken(DetailAST ast) {
095        if (depth > max) {
096            log(ast, MSG_KEY, depth, max);
097        }
098        ++depth;
099    }
100
101    @Override
102    public void leaveToken(DetailAST ast) {
103        --depth;
104    }
105
106}