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.whitespace;
021
022import java.util.Locale;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.CodePointUtil;
029import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
030
031/**
032 * <div>
033 * Checks the padding of an empty for initializer; that is whether a white
034 * space is required at an empty for initializer, or such white space is
035 * forbidden. No check occurs if there is a line wrap at the initializer, as in
036 * </div>
037 * <div class="wrapper"><pre class="prettyprint"><code class="language-java">
038 * for (
039 *     ; i &lt; j; i++, j--)
040 *  </code></pre></div>
041 *
042 * @since 3.4
043 */
044@StatelessCheck
045public class EmptyForInitializerPadCheck
046    extends AbstractCheck {
047
048    /**
049     * A key is pointing to the warning message text in "messages.properties"
050     * file.
051     */
052    public static final String MSG_PRECEDED = "ws.preceded";
053
054    /**
055     * A key is pointing to the warning message text in "messages.properties"
056     * file.
057     */
058    public static final String MSG_NOT_PRECEDED = "ws.notPreceded";
059
060    /** Semicolon literal. */
061    private static final String SEMICOLON = ";";
062
063    /** Specify policy on how to pad an empty for iterator. */
064    private PadOption option = PadOption.NOSPACE;
065
066    /**
067     * Creates a new {@code EmptyForInitializerPadCheck} instance.
068     */
069    public EmptyForInitializerPadCheck() {
070        // no code by default
071    }
072
073    /**
074     * Setter to specify policy on how to pad an empty for iterator.
075     *
076     * @param optionStr string to decode option from
077     * @throws IllegalArgumentException if unable to decode
078     * @since 3.4
079     */
080    public void setOption(String optionStr) {
081        option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
082    }
083
084    @Override
085    public int[] getDefaultTokens() {
086        return getRequiredTokens();
087    }
088
089    @Override
090    public int[] getAcceptableTokens() {
091        return getRequiredTokens();
092    }
093
094    @Override
095    public int[] getRequiredTokens() {
096        return new int[] {TokenTypes.FOR_INIT};
097    }
098
099    @Override
100    public void visitToken(DetailAST ast) {
101        if (!ast.hasChildren()) {
102            final int lineIdx = ast.getLineNo() - 1;
103            final int[] line = getLineCodePoints(lineIdx);
104            final int before = ast.getColumnNo() - 1;
105            // don't check if semi at beginning of line
106            if (ast.getColumnNo() > 0 && !CodePointUtil.hasWhitespaceBefore(before, line)) {
107                if (option == PadOption.NOSPACE
108                    && CommonUtil.isCodePointWhitespace(line, before)) {
109                    log(ast, MSG_PRECEDED, SEMICOLON);
110                }
111                else if (option == PadOption.SPACE
112                         && !CommonUtil.isCodePointWhitespace(line, before)) {
113                    log(ast, MSG_NOT_PRECEDED, SEMICOLON);
114                }
115            }
116        }
117    }
118
119}