001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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.JavadocUtil;
028import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
029
030/**
031 * <p>
032 * Checks for illegal tokens. By default labels are prohibited.
033 * </p>
034 * <p>
035 * Rationale: Certain language features can harm readability, lead to
036 * confusion or are not obvious to novice developers. Other features
037 * may be discouraged in certain frameworks, such as not having
038 * native methods in Enterprise JavaBeans components.
039 * </p>
040 * <ul>
041 * <li>
042 * Property {@code tokens} - tokens to check
043 * Default value is:
044 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LABELED_STAT">
045 * LABELED_STAT</a>.
046 * </li>
047 * </ul>
048 * <p>
049 * To configure the check:
050 * </p>
051 * <pre>
052 * &lt;module name=&quot;IllegalToken&quot;/&gt;
053 * </pre>
054 * <p>
055 * To configure the check to find token LITERAL_NATIVE:
056 * </p>
057 * <pre>
058 * &lt;module name=&quot;IllegalToken&quot;&gt;
059 *   &lt;property name=&quot;tokens&quot; value=&quot;LITERAL_NATIVE&quot;/&gt;
060 * &lt;/module&gt;
061 * </pre>
062 *
063 * @since 3.2
064 */
065@StatelessCheck
066public class IllegalTokenCheck
067    extends AbstractCheck {
068
069    /**
070     * A key is pointing to the warning message text in "messages.properties"
071     * file.
072     */
073    public static final String MSG_KEY = "illegal.token";
074
075    @Override
076    public int[] getDefaultTokens() {
077        return new int[] {
078            TokenTypes.LABELED_STAT,
079        };
080    }
081
082    @Override
083    public int[] getAcceptableTokens() {
084        return TokenUtil.getAllTokenIds();
085    }
086
087    @Override
088    public int[] getRequiredTokens() {
089        return CommonUtil.EMPTY_INT_ARRAY;
090    }
091
092    @Override
093    public boolean isCommentNodesRequired() {
094        return true;
095    }
096
097    @Override
098    public void visitToken(DetailAST ast) {
099        log(
100            ast,
101            MSG_KEY,
102            convertToString(ast)
103        );
104    }
105
106    /**
107     * Converts given AST node to string representation.
108     * @param ast node to be represented as string
109     * @return string representation of AST node
110     */
111    private static String convertToString(DetailAST ast) {
112        final String tokenText;
113        switch (ast.getType()) {
114            case TokenTypes.LABELED_STAT:
115                tokenText = ast.getFirstChild().getText() + ast.getText();
116                break;
117            // multiline tokens need to become singlelined
118            case TokenTypes.COMMENT_CONTENT:
119                tokenText = JavadocUtil.escapeAllControlChars(ast.getText());
120                break;
121            default:
122                tokenText = ast.getText();
123                break;
124        }
125        return tokenText;
126    }
127
128}