Source code

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 * @author Oliver Burn
045 * @author Michael Tamm
046 */
047@StatelessCheck
048public class JavadocTypeCheck
049    extends AbstractCheck {
050
051    /**
052     * A key is pointing to the warning message text in "messages.properties"
053     * file.
054     */
055    public static final String MSG_JAVADOC_MISSING = "javadoc.missing";
056
057    /**
058     * A key is pointing to the warning message text in "messages.properties"
059     * file.
060     */
061    public static final String MSG_UNKNOWN_TAG = "javadoc.unknownTag";
062
063    /**
064     * A key is pointing to the warning message text in "messages.properties"
065     * file.
066     */
067    public static final String MSG_TAG_FORMAT = "type.tagFormat";
068
069    /**
070     * A key is pointing to the warning message text in "messages.properties"
071     * file.
072     */
073    public static final String MSG_MISSING_TAG = "type.missingTag";
074
075    /**
076     * A key is pointing to the warning message text in "messages.properties"
077     * file.
078     */
079    public static final String MSG_UNUSED_TAG = "javadoc.unusedTag";
080
081    /**
082     * A key is pointing to the warning message text in "messages.properties"
083     * file.
084     */
085    public static final String MSG_UNUSED_TAG_GENERAL = "javadoc.unusedTagGeneral";
086
087    /** Open angle bracket literal. */
088    private static final String OPEN_ANGLE_BRACKET = "<";
089
090    /** Close angle bracket literal. */
091    private static final String CLOSE_ANGLE_BRACKET = ">";
092
093    /** Pattern to match type name within angle brackets in javadoc param tag. */
094    private static final Pattern TYPE_NAME_IN_JAVADOC_TAG =
095            Pattern.compile("\\s*<([^>]+)>.*");
096
097    /** Pattern to split type name field in javadoc param tag. */
098    private static final Pattern TYPE_NAME_IN_JAVADOC_TAG_SPLITTER =
099            Pattern.compile("\\s+");
100
101    /** The scope to check for. */
102    private Scope scope = Scope.PRIVATE;
103    /** The visibility scope where Javadoc comments shouldn't be checked. **/
104    private Scope excludeScope;
105    /** Compiled regexp to match author tag content. **/
106    private Pattern authorFormat;
107    /** Compiled regexp to match version tag content. **/
108    private Pattern versionFormat;
109    /**
110     * Controls whether to ignore errors when a method has type parameters but
111     * does not have matching param tags in the javadoc. Defaults to false.
112     */
113    private boolean allowMissingParamTags;
114    /** Controls whether to flag errors for unknown tags. Defaults to false. */
115    private boolean allowUnknownTags;
116
117    /**
118     * Sets the scope to check.
119     * @param scope a scope.
120     */
121    public void setScope(Scope scope) {
122        this.scope = scope;
123    }
124
125    /**
126     * Set the excludeScope.
127     * @param excludeScope a scope.
128     */
129    public void setExcludeScope(Scope excludeScope) {
130        this.excludeScope = excludeScope;
131    }
132
133    /**
134     * Set the author tag pattern.
135     * @param pattern a pattern.
136     */
137    public void setAuthorFormat(Pattern pattern) {
138        authorFormat = pattern;
139    }
140
141    /**
142     * Set the version format pattern.
143     * @param pattern a pattern.
144     */
145    public void setVersionFormat(Pattern pattern) {
146        versionFormat = pattern;
147    }
148
149    /**
150     * Controls whether to allow a type which has type parameters to
151     * omit matching param tags in the javadoc. Defaults to false.
152     *
153     * @param flag a {@code Boolean} value
154     */
155    public void setAllowMissingParamTags(boolean flag) {
156        allowMissingParamTags = flag;
157    }
158
159    /**
160     * Controls whether to flag errors for unknown tags. Defaults to false.
161     * @param flag a {@code Boolean} value
162     */
163    public void setAllowUnknownTags(boolean flag) {
164        allowUnknownTags = flag;
165    }
166
167    @Override
168    public int[] getDefaultTokens() {
169        return getAcceptableTokens();
170    }
171
172    @Override
173    public int[] getAcceptableTokens() {
174        return new int[] {
175            TokenTypes.INTERFACE_DEF,
176            TokenTypes.CLASS_DEF,
177            TokenTypes.ENUM_DEF,
178            TokenTypes.ANNOTATION_DEF,
179        };
180    }
181
182    @Override
183    public int[] getRequiredTokens() {
184        return CommonUtils.EMPTY_INT_ARRAY;
185    }
186
187    @Override
188    public void visitToken(DetailAST ast) {
189        if (shouldCheck(ast)) {
190            final FileContents contents = getFileContents();
191            final int lineNo = ast.getLineNo();
192            final TextBlock textBlock = contents.getJavadocBefore(lineNo);
193            if (textBlock == null) {
194                log(lineNo, MSG_JAVADOC_MISSING);
195            }
196            else {
197                final List<JavadocTag> tags = getJavadocTags(textBlock);
198                if (ScopeUtils.isOuterMostType(ast)) {
199                    // don't check author/version for inner classes
200                    checkTag(lineNo, tags, JavadocTagInfo.AUTHOR.getName(),
201                            authorFormat);
202                    checkTag(lineNo, tags, JavadocTagInfo.VERSION.getName(),
203                            versionFormat);
204                }
205
206                final List<String> typeParamNames =
207                    CheckUtils.getTypeParameterNames(ast);
208
209                if (!allowMissingParamTags) {
210                    //Check type parameters that should exist, do
211                    for (final String typeParamName : typeParamNames) {
212                        checkTypeParamTag(
213                            lineNo, tags, typeParamName);
214                    }
215                }
216
217                checkUnusedTypeParamTags(tags, typeParamNames);
218            }
219        }
220    }
221
222    /**
223     * Whether we should check this node.
224     * @param ast a given node.
225     * @return whether we should check a given node.
226     */
227    private boolean shouldCheck(final DetailAST ast) {
228        final Scope customScope;
229
230        if (ScopeUtils.isInInterfaceOrAnnotationBlock(ast)) {
231            customScope = Scope.PUBLIC;
232        }
233        else {
234            final DetailAST mods = ast.findFirstToken(TokenTypes.MODIFIERS);
235            customScope = ScopeUtils.getScopeFromMods(mods);
236        }
237        final Scope surroundingScope = ScopeUtils.getSurroundingScope(ast);
238
239        return customScope.isIn(scope)
240            && (surroundingScope == null || surroundingScope.isIn(scope))
241            && (excludeScope == null
242                || !customScope.isIn(excludeScope)
243                || surroundingScope != null
244                && !surroundingScope.isIn(excludeScope));
245    }
246
247    /**
248     * Gets all standalone tags from a given javadoc.
249     * @param textBlock the Javadoc comment to process.
250     * @return all standalone tags from the given javadoc.
251     */
252    private List<JavadocTag> getJavadocTags(TextBlock textBlock) {
253        final JavadocTags tags = JavadocUtils.getJavadocTags(textBlock,
254            JavadocUtils.JavadocTagType.BLOCK);
255        if (!allowUnknownTags) {
256            for (final InvalidJavadocTag tag : tags.getInvalidTags()) {
257                log(tag.getLine(), tag.getCol(), MSG_UNKNOWN_TAG,
258                    tag.getName());
259            }
260        }
261        return tags.getValidTags();
262    }
263
264    /**
265     * Verifies that a type definition has a required tag.
266     * @param lineNo the line number for the type definition.
267     * @param tags tags from the Javadoc comment for the type definition.
268     * @param tagName the required tag name.
269     * @param formatPattern regexp for the tag value.
270     */
271    private void checkTag(int lineNo, List<JavadocTag> tags, String tagName,
272                          Pattern formatPattern) {
273        if (formatPattern != null) {
274            int tagCount = 0;
275            final String tagPrefix = "@";
276            for (int i = tags.size() - 1; i >= 0; i--) {
277                final JavadocTag tag = tags.get(i);
278                if (tag.getTagName().equals(tagName)) {
279                    tagCount++;
280                    if (!formatPattern.matcher(tag.getFirstArg()).find()) {
281                        log(lineNo, MSG_TAG_FORMAT, tagPrefix + tagName, formatPattern.pattern());
282                    }
283                }
284            }
285            if (tagCount == 0) {
286                log(lineNo, MSG_MISSING_TAG, tagPrefix + tagName);
287            }
288        }
289    }
290
291    /**
292     * Verifies that a type definition has the specified param tag for
293     * the specified type parameter name.
294     * @param lineNo the line number for the type definition.
295     * @param tags tags from the Javadoc comment for the type definition.
296     * @param typeParamName the name of the type parameter
297     */
298    private void checkTypeParamTag(final int lineNo,
299            final List<JavadocTag> tags, final String typeParamName) {
300        boolean found = false;
301        for (int i = tags.size() - 1; i >= 0; i--) {
302            final JavadocTag tag = tags.get(i);
303            if (tag.isParamTag()
304                && tag.getFirstArg().indexOf(OPEN_ANGLE_BRACKET
305                        + typeParamName + CLOSE_ANGLE_BRACKET) == 0) {
306                found = true;
307                break;
308            }
309        }
310        if (!found) {
311            log(lineNo, MSG_MISSING_TAG, JavadocTagInfo.PARAM.getText()
312                + " " + OPEN_ANGLE_BRACKET + typeParamName + CLOSE_ANGLE_BRACKET);
313        }
314    }
315
316    /**
317     * Checks for unused param tags for type parameters.
318     * @param tags tags from the Javadoc comment for the type definition.
319     * @param typeParamNames names of type parameters
320     */
321    private void checkUnusedTypeParamTags(
322        final List<JavadocTag> tags,
323        final List<String> typeParamNames) {
324        for (int i = tags.size() - 1; i >= 0; i--) {
325            final JavadocTag tag = tags.get(i);
326            if (tag.isParamTag()) {
327                final String typeParamName = extractTypeParamNameFromTag(tag);
328
329                if (!typeParamNames.contains(typeParamName)) {
330                    log(tag.getLineNo(), tag.getColumnNo(),
331                            MSG_UNUSED_TAG,
332                            JavadocTagInfo.PARAM.getText(),
333                            OPEN_ANGLE_BRACKET + typeParamName + CLOSE_ANGLE_BRACKET);
334                }
335            }
336        }
337    }
338
339    /**
340     * Extracts type parameter name from tag.
341     * @param tag javadoc tag to extract parameter name
342     * @return extracts type parameter name from tag
343     */
344    private static String extractTypeParamNameFromTag(JavadocTag tag) {
345        final String typeParamName;
346        final Matcher matchInAngleBrackets =
347                TYPE_NAME_IN_JAVADOC_TAG.matcher(tag.getFirstArg());
348        if (matchInAngleBrackets.find()) {
349            typeParamName = matchInAngleBrackets.group(1).trim();
350        }
351        else {
352            typeParamName = TYPE_NAME_IN_JAVADOC_TAG_SPLITTER.split(tag.getFirstArg())[0];
353        }
354        return typeParamName;
355    }
356
357}