1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.filters;
21
22 import java.io.IOException;
23 import java.nio.charset.StandardCharsets;
24 import java.nio.file.Files;
25 import java.nio.file.Path;
26 import java.util.ArrayList;
27 import java.util.Collection;
28 import java.util.Objects;
29 import java.util.Optional;
30 import java.util.regex.Matcher;
31 import java.util.regex.Pattern;
32 import java.util.regex.PatternSyntaxException;
33
34 import com.puppycrawl.tools.checkstyle.AbstractAutomaticBean;
35 import com.puppycrawl.tools.checkstyle.PropertyType;
36 import com.puppycrawl.tools.checkstyle.XdocsPropertyType;
37 import com.puppycrawl.tools.checkstyle.api.AuditEvent;
38 import com.puppycrawl.tools.checkstyle.api.FileText;
39 import com.puppycrawl.tools.checkstyle.api.Filter;
40 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
41
42 /**
43 * <div>
44 * Filter {@code SuppressWithPlainTextCommentFilter} uses plain text to suppress
45 * audit events. The filter knows nothing about AST, it treats only plain text
46 * comments and extracts the information required for suppression from the plain
47 * text comments. Currently, the filter supports only single-line comments.
48 * </div>
49 *
50 * <p>
51 * Please, be aware of the fact that, it is not recommended to use the filter
52 * for Java code anymore.
53 * </p>
54 *
55 * <p>
56 * Rationale: Sometimes there are legitimate reasons for violating a check.
57 * When this is a matter of the code in question and not personal preference,
58 * the best place to override the policy is in the code itself. Semi-structured
59 * comments can be associated with the check. This is sometimes superior to
60 * a separate suppressions file, which must be kept up-to-date as the source
61 * file is edited.
62 * </p>
63 *
64 * <p>
65 * Note that the suppression comment should be put before the violation.
66 * You can use more than one suppression comment each on separate line.
67 * </p>
68 *
69 * <p>
70 * Notes:
71 * Properties {@code offCommentFormat} and {@code onCommentFormat} must have equal
72 * <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/regex/Matcher.html#groupCount()">
73 * paren counts</a>.
74 * </p>
75 *
76 * <p>
77 * SuppressWithPlainTextCommentFilter can suppress Checks that have Treewalker or
78 * Checker as parent module.
79 * </p>
80 *
81 * @since 8.6
82 */
83 public class SuppressWithPlainTextCommentFilter extends AbstractAutomaticBean implements Filter {
84
85 /** Comment format which turns checkstyle reporting off. */
86 private static final String DEFAULT_OFF_FORMAT = "// CHECKSTYLE:OFF";
87
88 /** Comment format which turns checkstyle reporting on. */
89 private static final String DEFAULT_ON_FORMAT = "// CHECKSTYLE:ON";
90
91 /** Default check format to suppress. By default, the filter suppress all checks. */
92 private static final String DEFAULT_CHECK_FORMAT = ".*";
93
94 /** List of suppressions from the file. By default, Its null. */
95 private final Collection<Suppression> currentFileSuppressionCache = new ArrayList<>();
96
97 /** File name that was suppressed. By default, Its empty. */
98 private String currentFileName = "";
99
100 /** Specify comment pattern to trigger filter to begin suppression. */
101 private Pattern offCommentFormat = CommonUtil.createPattern(DEFAULT_OFF_FORMAT);
102
103 /** Specify comment pattern to trigger filter to end suppression. */
104 private Pattern onCommentFormat = CommonUtil.createPattern(DEFAULT_ON_FORMAT);
105
106 /** Specify check pattern to suppress. */
107 @XdocsPropertyType(PropertyType.PATTERN)
108 private String checkFormat = DEFAULT_CHECK_FORMAT;
109
110 /** Specify message pattern to suppress. */
111 @XdocsPropertyType(PropertyType.PATTERN)
112 private String messageFormat;
113
114 /** Specify check ID pattern to suppress. */
115 @XdocsPropertyType(PropertyType.PATTERN)
116 private String idFormat;
117
118 /**
119 * Setter to specify comment pattern to trigger filter to begin suppression.
120 *
121 * @param pattern off comment format pattern.
122 * @since 8.6
123 */
124 public final void setOffCommentFormat(Pattern pattern) {
125 offCommentFormat = pattern;
126 }
127
128 /**
129 * Setter to specify comment pattern to trigger filter to end suppression.
130 *
131 * @param pattern on comment format pattern.
132 * @since 8.6
133 */
134 public final void setOnCommentFormat(Pattern pattern) {
135 onCommentFormat = pattern;
136 }
137
138 /**
139 * Setter to specify check pattern to suppress.
140 *
141 * @param format pattern for check format.
142 * @since 8.6
143 */
144 public final void setCheckFormat(String format) {
145 checkFormat = format;
146 }
147
148 /**
149 * Setter to specify message pattern to suppress.
150 *
151 * @param format pattern for message format.
152 * @since 8.6
153 */
154 public final void setMessageFormat(String format) {
155 messageFormat = format;
156 }
157
158 /**
159 * Setter to specify check ID pattern to suppress.
160 *
161 * @param format pattern for check ID format
162 * @since 8.24
163 */
164 public final void setIdFormat(String format) {
165 idFormat = format;
166 }
167
168 @Override
169 public boolean accept(AuditEvent event) {
170 boolean accepted = true;
171 if (event.getViolation() != null) {
172 final String eventFileName = event.getFileName();
173
174 if (!currentFileName.equals(eventFileName)) {
175 currentFileName = eventFileName;
176 final FileText fileText = getFileText(eventFileName);
177 currentFileSuppressionCache.clear();
178 if (fileText != null) {
179 cacheSuppressions(fileText);
180 }
181 }
182
183 accepted = getNearestSuppression(currentFileSuppressionCache, event) == null;
184 }
185 return accepted;
186 }
187
188 @Override
189 protected void finishLocalSetup() {
190 // No code by default
191 }
192
193 /**
194 * Caches {@link FileText} instance created based on the given file name.
195 *
196 * @param fileName the name of the file.
197 * @return {@link FileText} instance.
198 * @throws IllegalStateException if the file could not be read.
199 */
200 private static FileText getFileText(String fileName) {
201 final Path path = Path.of(fileName);
202 FileText result = null;
203
204 // some violations can be on a directory, instead of a file
205 if (!Files.isDirectory(path)) {
206 try {
207 result = new FileText(path.toFile(), StandardCharsets.UTF_8.name());
208 }
209 catch (IOException exc) {
210 throw new IllegalStateException("Cannot read source file: " + fileName, exc);
211 }
212 }
213
214 return result;
215 }
216
217 /**
218 * Collects the list of {@link Suppression} instances retrieved from the given {@link FileText}.
219 *
220 * @param fileText {@link FileText} instance.
221 */
222 private void cacheSuppressions(FileText fileText) {
223 for (int lineNo = 0; lineNo < fileText.size(); lineNo++) {
224 final Optional<Suppression> suppression = getSuppression(fileText, lineNo);
225 suppression.ifPresent(currentFileSuppressionCache::add);
226 }
227 }
228
229 /**
230 * Tries to extract the suppression from the given line.
231 *
232 * @param fileText {@link FileText} instance.
233 * @param lineNo line number.
234 * @return {@link Optional} of {@link Suppression}.
235 */
236 private Optional<Suppression> getSuppression(FileText fileText, int lineNo) {
237 final String line = fileText.get(lineNo);
238 final Matcher onCommentMatcher = onCommentFormat.matcher(line);
239 final Matcher offCommentMatcher = offCommentFormat.matcher(line);
240
241 Suppression suppression = null;
242 if (onCommentMatcher.find()) {
243 suppression = new Suppression(onCommentMatcher.group(0),
244 lineNo + 1, SuppressionType.ON, this);
245 }
246 if (offCommentMatcher.find()) {
247 suppression = new Suppression(offCommentMatcher.group(0),
248 lineNo + 1, SuppressionType.OFF, this);
249 }
250
251 return Optional.ofNullable(suppression);
252 }
253
254 /**
255 * Finds the nearest {@link Suppression} instance which can suppress
256 * the given {@link AuditEvent}. The nearest suppression is the suppression which scope
257 * is before the line and column of the event.
258 *
259 * @param suppressions collection of {@link Suppression} instances.
260 * @param event {@link AuditEvent} instance.
261 * @return {@link Suppression} instance.
262 */
263 private static Suppression getNearestSuppression(Collection<Suppression> suppressions,
264 AuditEvent event) {
265 return suppressions
266 .stream()
267 .filter(suppression -> suppression.isMatch(event))
268 .reduce((first, second) -> second)
269 .filter(suppression -> suppression.suppressionType != SuppressionType.ON)
270 .orElse(null);
271 }
272
273 /** Enum which represents the type of the suppression. */
274 private enum SuppressionType {
275
276 /** On suppression type. */
277 ON,
278 /** Off suppression type. */
279 OFF,
280
281 }
282
283 /** The class which represents the suppression. */
284 private static final class Suppression {
285
286 /** The regexp which is used to match the event source.*/
287 private final Pattern eventSourceRegexp;
288 /** The regexp which is used to match the event message.*/
289 private final Pattern eventMessageRegexp;
290 /** The regexp which is used to match the event ID.*/
291 private final Pattern eventIdRegexp;
292
293 /** Suppression line.*/
294 private final int lineNo;
295
296 /** Suppression type. */
297 private final SuppressionType suppressionType;
298
299 /**
300 * Creates new suppression instance.
301 *
302 * @param text suppression text.
303 * @param lineNo suppression line number.
304 * @param suppressionType suppression type.
305 * @param filter the {@link SuppressWithPlainTextCommentFilter} with the context.
306 * @throws IllegalArgumentException if there is an error in the filter regex syntax.
307 */
308 private Suppression(
309 String text,
310 int lineNo,
311 SuppressionType suppressionType,
312 SuppressWithPlainTextCommentFilter filter
313 ) {
314 this.lineNo = lineNo;
315 this.suppressionType = suppressionType;
316
317 final Pattern commentFormat;
318 if (this.suppressionType == SuppressionType.ON) {
319 commentFormat = filter.onCommentFormat;
320 }
321 else {
322 commentFormat = filter.offCommentFormat;
323 }
324
325 // Expand regexp for check and message
326 // Does not intern Patterns with Utils.getPattern()
327 String format = "";
328 try {
329 format = CommonUtil.fillTemplateWithStringsByRegexp(
330 filter.checkFormat, text, commentFormat);
331 eventSourceRegexp = Pattern.compile(format);
332 if (filter.messageFormat == null) {
333 eventMessageRegexp = null;
334 }
335 else {
336 format = CommonUtil.fillTemplateWithStringsByRegexp(
337 filter.messageFormat, text, commentFormat);
338 eventMessageRegexp = Pattern.compile(format);
339 }
340 if (filter.idFormat == null) {
341 eventIdRegexp = null;
342 }
343 else {
344 format = CommonUtil.fillTemplateWithStringsByRegexp(
345 filter.idFormat, text, commentFormat);
346 eventIdRegexp = Pattern.compile(format);
347 }
348 }
349 catch (final PatternSyntaxException exc) {
350 throw new IllegalArgumentException(
351 "unable to parse expanded comment " + format, exc);
352 }
353 }
354
355 /**
356 * Indicates whether some other object is "equal to" this one.
357 *
358 * @noinspection EqualsCalledOnEnumConstant
359 * @noinspectionreason EqualsCalledOnEnumConstant - enumeration is needed to keep
360 * code consistent
361 */
362 @Override
363 public boolean equals(Object other) {
364 if (this == other) {
365 return true;
366 }
367 if (other == null || getClass() != other.getClass()) {
368 return false;
369 }
370 final Suppression suppression = (Suppression) other;
371 return lineNo == suppression.lineNo
372 && Objects.equals(suppressionType, suppression.suppressionType)
373 && Objects.equals(eventSourceRegexp, suppression.eventSourceRegexp)
374 && Objects.equals(eventMessageRegexp, suppression.eventMessageRegexp)
375 && Objects.equals(eventIdRegexp, suppression.eventIdRegexp);
376 }
377
378 @Override
379 public int hashCode() {
380 return Objects.hash(
381 lineNo, suppressionType, eventSourceRegexp, eventMessageRegexp,
382 eventIdRegexp);
383 }
384
385 /**
386 * Checks whether the suppression matches the given {@link AuditEvent}.
387 *
388 * @param event {@link AuditEvent} instance.
389 * @return true if the suppression matches {@link AuditEvent}.
390 */
391 private boolean isMatch(AuditEvent event) {
392 return isInScopeOfSuppression(event)
393 && isCheckMatch(event)
394 && isIdMatch(event)
395 && isMessageMatch(event);
396 }
397
398 /**
399 * Checks whether {@link AuditEvent} is in the scope of the suppression.
400 *
401 * @param event {@link AuditEvent} instance.
402 * @return true if {@link AuditEvent} is in the scope of the suppression.
403 */
404 private boolean isInScopeOfSuppression(AuditEvent event) {
405 return lineNo <= event.getLine();
406 }
407
408 /**
409 * Checks whether {@link AuditEvent} source name matches the check format.
410 *
411 * @param event {@link AuditEvent} instance.
412 * @return true if the {@link AuditEvent} source name matches the check format.
413 */
414 private boolean isCheckMatch(AuditEvent event) {
415 final Matcher checkMatcher = eventSourceRegexp.matcher(event.getSourceName());
416 return checkMatcher.find();
417 }
418
419 /**
420 * Checks whether the {@link AuditEvent} module ID matches the ID format.
421 *
422 * @param event {@link AuditEvent} instance.
423 * @return true if the {@link AuditEvent} module ID matches the ID format.
424 */
425 private boolean isIdMatch(AuditEvent event) {
426 boolean match = true;
427 if (eventIdRegexp != null) {
428 if (event.getModuleId() == null) {
429 match = false;
430 }
431 else {
432 final Matcher idMatcher = eventIdRegexp.matcher(event.getModuleId());
433 match = idMatcher.find();
434 }
435 }
436 return match;
437 }
438
439 /**
440 * Checks whether the {@link AuditEvent} message matches the message format.
441 *
442 * @param event {@link AuditEvent} instance.
443 * @return true if the {@link AuditEvent} message matches the message format.
444 */
445 private boolean isMessageMatch(AuditEvent event) {
446 boolean match = true;
447 if (eventMessageRegexp != null) {
448 final Matcher messageMatcher = eventMessageRegexp.matcher(event.getMessage());
449 match = messageMatcher.find();
450 }
451 return match;
452 }
453 }
454
455 }