001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2018 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 EJB components.
039 * </p>
040 * <p>
041 * An example of how to configure the check is:
042 * </p>
043 * <pre>
044 * &lt;module name="IllegalToken"/&gt;
045 * </pre>
046 * <p> An example of how to configure the check to forbid
047 * a {@link TokenTypes#LITERAL_NATIVE LITERAL_NATIVE} token is:
048 * </p>
049 * <pre>
050 * &lt;module name="IllegalToken"&gt;
051 *     &lt;property name="tokens" value="LITERAL_NATIVE"/&gt;
052 * &lt;/module&gt;
053 * </pre>
054 */
055@StatelessCheck
056public class IllegalTokenCheck
057    extends AbstractCheck {
058
059    /**
060     * A key is pointing to the warning message text in "messages.properties"
061     * file.
062     */
063    public static final String MSG_KEY = "illegal.token";
064
065    @Override
066    public int[] getDefaultTokens() {
067        return new int[] {
068            TokenTypes.LABELED_STAT,
069        };
070    }
071
072    @Override
073    public int[] getAcceptableTokens() {
074        return TokenUtil.getAllTokenIds();
075    }
076
077    @Override
078    public int[] getRequiredTokens() {
079        return CommonUtil.EMPTY_INT_ARRAY;
080    }
081
082    @Override
083    public boolean isCommentNodesRequired() {
084        return true;
085    }
086
087    @Override
088    public void visitToken(DetailAST ast) {
089        log(
090            ast,
091            MSG_KEY,
092            convertToString(ast)
093        );
094    }
095
096    /**
097     * Converts given AST node to string representation.
098     * @param ast node to be represented as string
099     * @return string representation of AST node
100     */
101    private static String convertToString(DetailAST ast) {
102        final String tokenText;
103        switch (ast.getType()) {
104            case TokenTypes.LABELED_STAT:
105                tokenText = ast.getFirstChild().getText() + ast.getText();
106                break;
107            // multiline tokens need to become singlelined
108            case TokenTypes.COMMENT_CONTENT:
109                tokenText = JavadocUtil.escapeAllControlChars(ast.getText());
110                break;
111            default:
112                tokenText = ast.getText();
113                break;
114        }
115        return tokenText;
116    }
117
118}