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.annotation;
021
022import java.util.Arrays;
023import java.util.HashSet;
024import java.util.Set;
025
026import com.puppycrawl.tools.checkstyle.StatelessCheck;
027import com.puppycrawl.tools.checkstyle.api.DetailAST;
028import com.puppycrawl.tools.checkstyle.api.DetailNode;
029import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
030import com.puppycrawl.tools.checkstyle.api.TokenTypes;
031import com.puppycrawl.tools.checkstyle.checks.javadoc.AbstractJavadocCheck;
032import com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocTagInfo;
033import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
034
035/**
036 * <p>
037 * Verifies that the annotation {@code @Deprecated} and the Javadoc tag
038 * {@code @deprecated} are both present when either of them is present.
039 * </p>
040 * <p>
041 * Both ways of flagging deprecation serve their own purpose.
042 * The &#64;Deprecated annotation is used for compilers and development tools.
043 * The &#64;deprecated javadoc tag is used to document why something is deprecated
044 * and what, if any, alternatives exist.
045 * </p>
046 * <p>
047 * In order to properly mark something as deprecated both forms of
048 * deprecation should be present.
049 * </p>
050 * <p>
051 * Package deprecation is a exception to the rule of always using the
052 * javadoc tag and annotation to deprecate.  It is not clear if the javadoc
053 * tool will support it or not as newer versions keep flip flopping on if
054 * it is supported or will cause an error. See
055 * <a href="https://bugs.openjdk.java.net/browse/JDK-8160601">JDK-8160601</a>.
056 * The deprecated javadoc tag is currently the only way to say why the package
057 * is deprecated and what to use instead.  Until this is resolved, if you don't
058 * want to print violations on package-info, you can use a
059 * <a href="https://checkstyle.org/config_filters.html">filter</a> to ignore
060 * these files until the javadoc tool faithfully supports it. An example config
061 * using SuppressionSingleFilter is:
062 * </p>
063 * <pre>
064 * &lt;!-- required till https://bugs.openjdk.java.net/browse/JDK-8160601 --&gt;
065 * &lt;module name="SuppressionSingleFilter"&gt;
066 *     &lt;property name="checks" value="MissingDeprecatedCheck"/&gt;
067 *     &lt;property name="files" value="package-info\.java"/&gt;
068 * &lt;/module&gt;
069 * </pre>
070 * <ul>
071 * <li>
072 * Property {@code violateExecutionOnNonTightHtml} - Control when to
073 * print violations if the Javadoc being examined by this check violates the
074 * tight html rules defined at
075 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">
076 * Tight-HTML Rules</a>.
077 * Default value is {@code false}.
078 * </li>
079 * </ul>
080 * <p>
081 * To configure the check:
082 * </p>
083 * <pre>
084 * &lt;module name=&quot;MissingDeprecated&quot;/&gt;
085 * </pre>
086 * <p>
087 * Examples of validating source code:
088 * </p>
089 * <pre>
090 * &#64;Deprecated
091 * public static final int MY_CONST = 123456; // no violation
092 *
093 * &#47;** This javadoc is missing deprecated tag. *&#47;
094 * &#64;Deprecated
095 * public static final int COUNTER = 10; // violation
096 * </pre>
097 *
098 * @since 5.0
099 */
100@StatelessCheck
101public final class MissingDeprecatedCheck extends AbstractJavadocCheck {
102
103    /**
104     * A key is pointing to the warning message text in "messages.properties"
105     * file.
106     */
107    public static final String MSG_KEY_ANNOTATION_MISSING_DEPRECATED =
108            "annotation.missing.deprecated";
109
110    /**
111     * A key is pointing to the warning message text in "messages.properties"
112     * file.
113     */
114    public static final String MSG_KEY_JAVADOC_DUPLICATE_TAG =
115            "javadoc.duplicateTag";
116
117    /** {@link Deprecated Deprecated} annotation name. */
118    private static final String DEPRECATED = "Deprecated";
119
120    /** Fully-qualified {@link Deprecated Deprecated} annotation name. */
121    private static final String FQ_DEPRECATED = "java.lang." + DEPRECATED;
122
123    /** List of token types to find parent of. */
124    private static final Set<Integer> TYPES_HASH_SET = new HashSet<>(Arrays.asList(
125            TokenTypes.TYPE, TokenTypes.MODIFIERS, TokenTypes.ANNOTATION,
126            TokenTypes.ANNOTATIONS, TokenTypes.ARRAY_DECLARATOR,
127            TokenTypes.TYPE_PARAMETERS, TokenTypes.DOT));
128
129    @Override
130    public int[] getDefaultJavadocTokens() {
131        return getRequiredJavadocTokens();
132    }
133
134    @Override
135    public int[] getRequiredJavadocTokens() {
136        return new int[] {
137            JavadocTokenTypes.JAVADOC,
138        };
139    }
140
141    @Override
142    public void visitJavadocToken(DetailNode ast) {
143        final DetailAST parentAst = getParent(getBlockCommentAst());
144
145        final boolean containsAnnotation =
146            AnnotationUtil.containsAnnotation(parentAst, DEPRECATED)
147            || AnnotationUtil.containsAnnotation(parentAst, FQ_DEPRECATED);
148
149        final boolean containsJavadocTag = containsDeprecatedTag(ast);
150
151        if (containsAnnotation ^ containsJavadocTag) {
152            log(parentAst.getLineNo(), MSG_KEY_ANNOTATION_MISSING_DEPRECATED);
153        }
154    }
155
156    /**
157     * Checks to see if the javadoc contains a deprecated tag.
158     *
159     * @param javadoc the javadoc of the AST
160     * @return true if contains the tag
161     */
162    private boolean containsDeprecatedTag(DetailNode javadoc) {
163        boolean found = false;
164        for (DetailNode child : javadoc.getChildren()) {
165            if (child.getType() == JavadocTokenTypes.JAVADOC_TAG
166                    && child.getChildren()[0].getType() == JavadocTokenTypes.DEPRECATED_LITERAL) {
167                if (found) {
168                    log(child.getLineNumber(), MSG_KEY_JAVADOC_DUPLICATE_TAG,
169                            JavadocTagInfo.DEPRECATED.getText());
170                }
171                found = true;
172            }
173        }
174        return found;
175    }
176
177    /**
178     * Returns the parent node of the comment.
179     *
180     * @param commentBlock child node.
181     * @return parent node.
182     */
183    private static DetailAST getParent(DetailAST commentBlock) {
184        DetailAST result = commentBlock.getParent();
185
186        if (result == null) {
187            result = commentBlock.getNextSibling();
188        }
189
190        while (true) {
191            final int type = result.getType();
192            if (TYPES_HASH_SET.contains(type)) {
193                result = result.getParent();
194            }
195            else if (type == TokenTypes.SINGLE_LINE_COMMENT) {
196                result = result.getNextSibling();
197            }
198            else {
199                break;
200            }
201        }
202
203        return result;
204    }
205
206}