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.javadoc;
021
022import java.util.List;
023import java.util.regex.Matcher;
024import java.util.regex.Pattern;
025
026import com.puppycrawl.tools.checkstyle.StatelessCheck;
027import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
028import com.puppycrawl.tools.checkstyle.api.DetailAST;
029import com.puppycrawl.tools.checkstyle.api.FileContents;
030import com.puppycrawl.tools.checkstyle.api.Scope;
031import com.puppycrawl.tools.checkstyle.api.TextBlock;
032import com.puppycrawl.tools.checkstyle.api.TokenTypes;
033import com.puppycrawl.tools.checkstyle.utils.CheckUtils;
034import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
035import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;
036import com.puppycrawl.tools.checkstyle.utils.ScopeUtils;
037
038/**
039 * Checks the Javadoc of a type.
040 *
041 * <p>Does not perform checks for author and version tags for inner classes, as
042 * they should be redundant because of outer class.
043 *
044 */
045@StatelessCheck
046public class JavadocTypeCheck
047    extends AbstractCheck {
048
049    /**
050     * A key is pointing to the warning message text in "messages.properties"
051     * file.
052     */
053    public static final String MSG_JAVADOC_MISSING = "javadoc.missing";
054
055    /**
056     * A key is pointing to the warning message text in "messages.properties"
057     * file.
058     */
059    public static final String MSG_UNKNOWN_TAG = "javadoc.unknownTag";
060
061    /**
062     * A key is pointing to the warning message text in "messages.properties"
063     * file.
064     */
065    public static final String MSG_TAG_FORMAT = "type.tagFormat";
066
067    /**
068     * A key is pointing to the warning message text in "messages.properties"
069     * file.
070     */
071    public static final String MSG_MISSING_TAG = "type.missingTag";
072
073    /**
074     * A key is pointing to the warning message text in "messages.properties"
075     * file.
076     */
077    public static final String MSG_UNUSED_TAG = "javadoc.unusedTag";
078
079    /**
080     * A key is pointing to the warning message text in "messages.properties"
081     * file.
082     */
083    public static final String MSG_UNUSED_TAG_GENERAL = "javadoc.unusedTagGeneral";
084
085    /** Open angle bracket literal. */
086    private static final String OPEN_ANGLE_BRACKET = "<";
087
088    /** Close angle bracket literal. */
089    private static final String CLOSE_ANGLE_BRACKET = ">";
090
091    /** Pattern to match type name within angle brackets in javadoc param tag. */
092    private static final Pattern TYPE_NAME_IN_JAVADOC_TAG =
093            Pattern.compile("\\s*<([^>]+)>.*");
094
095    /** Pattern to split type name field in javadoc param tag. */
096    private static final Pattern TYPE_NAME_IN_JAVADOC_TAG_SPLITTER =
097            Pattern.compile("\\s+");
098
099    /** The scope to check for. */
100    private Scope scope = Scope.PRIVATE;
101    /** The visibility scope where Javadoc comments shouldn't be checked. **/
102    private Scope excludeScope;
103    /** Compiled regexp to match author tag content. **/
104    private Pattern authorFormat;
105    /** Compiled regexp to match version tag content. **/
106    private Pattern versionFormat;
107    /**
108     * Controls whether to ignore errors when a method has type parameters but
109     * does not have matching param tags in the javadoc. Defaults to false.
110     */
111    private boolean allowMissingParamTags;
112    /** Controls whether to flag errors for unknown tags. Defaults to false. */
113    private boolean allowUnknownTags;
114
115    /**
116     * Sets the scope to check.
117     * @param scope a scope.
118     */
119    public void setScope(Scope scope) {
120        this.scope = scope;
121    }
122
123    /**
124     * Set the excludeScope.
125     * @param excludeScope a scope.
126     */
127    public void setExcludeScope(Scope excludeScope) {
128        this.excludeScope = excludeScope;
129    }
130
131    /**
132     * Set the author tag pattern.
133     * @param pattern a pattern.
134     */
135    public void setAuthorFormat(Pattern pattern) {
136        authorFormat = pattern;
137    }
138
139    /**
140     * Set the version format pattern.
141     * @param pattern a pattern.
142     */
143    public void setVersionFormat(Pattern pattern) {
144        versionFormat = pattern;
145    }
146
147    /**
148     * Controls whether to allow a type which has type parameters to
149     * omit matching param tags in the javadoc. Defaults to false.
150     *
151     * @param flag a {@code Boolean} value
152     */
153    public void setAllowMissingParamTags(boolean flag) {
154        allowMissingParamTags = flag;
155    }
156
157    /**
158     * Controls whether to flag errors for unknown tags. Defaults to false.
159     * @param flag a {@code Boolean} value
160     */
161    public void setAllowUnknownTags(boolean flag) {
162        allowUnknownTags = flag;
163    }
164
165    @Override
166    public int[] getDefaultTokens() {
167        return getAcceptableTokens();
168    }
169
170    @Override
171    public int[] getAcceptableTokens() {
172        return new int[] {
173            TokenTypes.INTERFACE_DEF,
174            TokenTypes.CLASS_DEF,
175            TokenTypes.ENUM_DEF,
176            TokenTypes.ANNOTATION_DEF,
177        };
178    }
179
180    @Override
181    public int[] getRequiredTokens() {
182        return CommonUtils.EMPTY_INT_ARRAY;
183    }
184
185    @Override
186    public void visitToken(DetailAST ast) {
187        if (shouldCheck(ast)) {
188            final FileContents contents = getFileContents();
189            final int lineNo = ast.getLineNo();
190            final TextBlock textBlock = contents.getJavadocBefore(lineNo);
191            if (textBlock == null) {
192                log(lineNo, MSG_JAVADOC_MISSING);
193            }
194            else {
195                final List<JavadocTag> tags = getJavadocTags(textBlock);
196                if (ScopeUtils.isOuterMostType(ast)) {
197                    // don't check author/version for inner classes
198                    checkTag(lineNo, tags, JavadocTagInfo.AUTHOR.getName(),
199                            authorFormat);
200                    checkTag(lineNo, tags, JavadocTagInfo.VERSION.getName(),
201                            versionFormat);
202                }
203
204                final List<String> typeParamNames =
205                    CheckUtils.getTypeParameterNames(ast);
206
207                if (!allowMissingParamTags) {
208                    //Check type parameters that should exist, do
209                    for (final String typeParamName : typeParamNames) {
210                        checkTypeParamTag(
211                            lineNo, tags, typeParamName);
212                    }
213                }
214
215                checkUnusedTypeParamTags(tags, typeParamNames);
216            }
217        }
218    }
219
220    /**
221     * Whether we should check this node.
222     * @param ast a given node.
223     * @return whether we should check a given node.
224     */
225    private boolean shouldCheck(final DetailAST ast) {
226        final Scope customScope;
227
228        if (ScopeUtils.isInInterfaceOrAnnotationBlock(ast)) {
229            customScope = Scope.PUBLIC;
230        }
231        else {
232            final DetailAST mods = ast.findFirstToken(TokenTypes.MODIFIERS);
233            customScope = ScopeUtils.getScopeFromMods(mods);
234        }
235        final Scope surroundingScope = ScopeUtils.getSurroundingScope(ast);
236
237        return customScope.isIn(scope)
238            && (surroundingScope == null || surroundingScope.isIn(scope))
239            && (excludeScope == null
240                || !customScope.isIn(excludeScope)
241                || surroundingScope != null
242                && !surroundingScope.isIn(excludeScope));
243    }
244
245    /**
246     * Gets all standalone tags from a given javadoc.
247     * @param textBlock the Javadoc comment to process.
248     * @return all standalone tags from the given javadoc.
249     */
250    private List<JavadocTag> getJavadocTags(TextBlock textBlock) {
251        final JavadocTags tags = JavadocUtils.getJavadocTags(textBlock,
252            JavadocUtils.JavadocTagType.BLOCK);
253        if (!allowUnknownTags) {
254            for (final InvalidJavadocTag tag : tags.getInvalidTags()) {
255                log(tag.getLine(), tag.getCol(), MSG_UNKNOWN_TAG,
256                    tag.getName());
257            }
258        }
259        return tags.getValidTags();
260    }
261
262    /**
263     * Verifies that a type definition has a required tag.
264     * @param lineNo the line number for the type definition.
265     * @param tags tags from the Javadoc comment for the type definition.
266     * @param tagName the required tag name.
267     * @param formatPattern regexp for the tag value.
268     */
269    private void checkTag(int lineNo, List<JavadocTag> tags, String tagName,
270                          Pattern formatPattern) {
271        if (formatPattern != null) {
272            int tagCount = 0;
273            final String tagPrefix = "@";
274            for (int i = tags.size() - 1; i >= 0; i--) {
275                final JavadocTag tag = tags.get(i);
276                if (tag.getTagName().equals(tagName)) {
277                    tagCount++;
278                    if (!formatPattern.matcher(tag.getFirstArg()).find()) {
279                        log(lineNo, MSG_TAG_FORMAT, tagPrefix + tagName, formatPattern.pattern());
280                    }
281                }
282            }
283            if (tagCount == 0) {
284                log(lineNo, MSG_MISSING_TAG, tagPrefix + tagName);
285            }
286        }
287    }
288
289    /**
290     * Verifies that a type definition has the specified param tag for
291     * the specified type parameter name.
292     * @param lineNo the line number for the type definition.
293     * @param tags tags from the Javadoc comment for the type definition.
294     * @param typeParamName the name of the type parameter
295     */
296    private void checkTypeParamTag(final int lineNo,
297            final List<JavadocTag> tags, final String typeParamName) {
298        boolean found = false;
299        for (int i = tags.size() - 1; i >= 0; i--) {
300            final JavadocTag tag = tags.get(i);
301            if (tag.isParamTag()
302                && tag.getFirstArg().indexOf(OPEN_ANGLE_BRACKET
303                        + typeParamName + CLOSE_ANGLE_BRACKET) == 0) {
304                found = true;
305                break;
306            }
307        }
308        if (!found) {
309            log(lineNo, MSG_MISSING_TAG, JavadocTagInfo.PARAM.getText()
310                + " " + OPEN_ANGLE_BRACKET + typeParamName + CLOSE_ANGLE_BRACKET);
311        }
312    }
313
314    /**
315     * Checks for unused param tags for type parameters.
316     * @param tags tags from the Javadoc comment for the type definition.
317     * @param typeParamNames names of type parameters
318     */
319    private void checkUnusedTypeParamTags(
320        final List<JavadocTag> tags,
321        final List<String> typeParamNames) {
322        for (int i = tags.size() - 1; i >= 0; i--) {
323            final JavadocTag tag = tags.get(i);
324            if (tag.isParamTag()) {
325                final String typeParamName = extractTypeParamNameFromTag(tag);
326
327                if (!typeParamNames.contains(typeParamName)) {
328                    log(tag.getLineNo(), tag.getColumnNo(),
329                            MSG_UNUSED_TAG,
330                            JavadocTagInfo.PARAM.getText(),
331                            OPEN_ANGLE_BRACKET + typeParamName + CLOSE_ANGLE_BRACKET);
332                }
333            }
334        }
335    }
336
337    /**
338     * Extracts type parameter name from tag.
339     * @param tag javadoc tag to extract parameter name
340     * @return extracts type parameter name from tag
341     */
342    private static String extractTypeParamNameFromTag(JavadocTag tag) {
343        final String typeParamName;
344        final Matcher matchInAngleBrackets =
345                TYPE_NAME_IN_JAVADOC_TAG.matcher(tag.getFirstArg());
346        if (matchInAngleBrackets.find()) {
347            typeParamName = matchInAngleBrackets.group(1).trim();
348        }
349        else {
350            typeParamName = TYPE_NAME_IN_JAVADOC_TAG_SPLITTER.split(tag.getFirstArg())[0];
351        }
352        return typeParamName;
353    }
354
355}