1 ////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code for adherence to a set of rules.
3 // Copyright (C) 2001-2019 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.api;
21
22 import java.util.Collections;
23 import java.util.HashSet;
24 import java.util.Set;
25 import java.util.SortedSet;
26 import java.util.TreeSet;
27
28 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
29
30 /**
31 * The base class for checks.
32 *
33 * @see <a href="{@docRoot}/../writingchecks.html" target="_top">Writing
34 * your own checks</a>
35 * @noinspection NoopMethodInAbstractClass
36 */
37 public abstract class AbstractCheck extends AbstractViolationReporter {
38
39 /**
40 * The check context.
41 * @noinspection ThreadLocalNotStaticFinal
42 */
43 private final ThreadLocal<FileContext> context = ThreadLocal.withInitial(FileContext::new);
44
45 /** The tokens the check is interested in. */
46 private final Set<String> tokens = new HashSet<>();
47
48 /** The tab width for column reporting. */
49 private int tabWidth = CommonUtil.DEFAULT_TAB_WIDTH;
50
51 /**
52 * The class loader to load external classes. Not initialized as this must
53 * be set by my creator.
54 */
55 private ClassLoader classLoader;
56
57 /**
58 * Returns the default token a check is interested in. Only used if the
59 * configuration for a check does not define the tokens.
60 * @return the default tokens
61 * @see TokenTypes
62 */
63 public abstract int[] getDefaultTokens();
64
65 /**
66 * The configurable token set.
67 * Used to protect Checks against malicious users who specify an
68 * unacceptable token set in the configuration file.
69 * The default implementation returns the check's default tokens.
70 * @return the token set this check is designed for.
71 * @see TokenTypes
72 */
73 public abstract int[] getAcceptableTokens();
74
75 /**
76 * The tokens that this check must be registered for.
77 * @return the token set this must be registered for.
78 * @see TokenTypes
79 */
80 public abstract int[] getRequiredTokens();
81
82 /**
83 * Whether comment nodes are required or not.
84 * @return false as a default value.
85 */
86 public boolean isCommentNodesRequired() {
87 return false;
88 }
89
90 /**
91 * Adds a set of tokens the check is interested in.
92 * @param strRep the string representation of the tokens interested in
93 * @noinspection WeakerAccess
94 */
95 public final void setTokens(String... strRep) {
96 Collections.addAll(tokens, strRep);
97 }
98
99 /**
100 * Returns the tokens registered for the check.
101 * @return the set of token names
102 */
103 public final Set<String> getTokenNames() {
104 return Collections.unmodifiableSet(tokens);
105 }
106
107 /**
108 * Returns the sorted set of {@link LocalizedMessage}.
109 * @return the sorted set of {@link LocalizedMessage}.
110 */
111 public SortedSet<LocalizedMessage> getMessages() {
112 return new TreeSet<>(context.get().messages);
113 }
114
115 /**
116 * Clears the sorted set of {@link LocalizedMessage} of the check.
117 */
118 public final void clearMessages() {
119 context.get().messages.clear();
120 }
121
122 /**
123 * Initialize the check. This is the time to verify that the check has
124 * everything required to perform it job.
125 */
126 public void init() {
127 // No code by default, should be overridden only by demand at subclasses
128 }
129
130 /**
131 * Destroy the check. It is being retired from service.
132 */
133 public void destroy() {
134 // No code by default, should be overridden only by demand at subclasses
135 }
136
137 /**
138 * Called before the starting to process a tree. Ideal place to initialize
139 * information that is to be collected whilst processing a tree.
140 * @param rootAST the root of the tree
141 */
142 public void beginTree(DetailAST rootAST) {
143 // No code by default, should be overridden only by demand at subclasses
144 }
145
146 /**
147 * Called after finished processing a tree. Ideal place to report on
148 * information collected whilst processing a tree.
149 * @param rootAST the root of the tree
150 */
151 public void finishTree(DetailAST rootAST) {
152 // No code by default, should be overridden only by demand at subclasses
153 }
154
155 /**
156 * Called to process a token.
157 * @param ast the token to process
158 */
159 public void visitToken(DetailAST ast) {
160 // No code by default, should be overridden only by demand at subclasses
161 }
162
163 /**
164 * Called after all the child nodes have been process.
165 * @param ast the token leaving
166 */
167 public void leaveToken(DetailAST ast) {
168 // No code by default, should be overridden only by demand at subclasses
169 }
170
171 /**
172 * Returns the lines associated with the tree.
173 * @return the file contents
174 */
175 public final String[] getLines() {
176 return context.get().fileContents.getLines();
177 }
178
179 /**
180 * Returns the line associated with the tree.
181 * @param index index of the line
182 * @return the line from the file contents
183 */
184 public final String getLine(int index) {
185 return context.get().fileContents.getLine(index);
186 }
187
188 /**
189 * Set the file contents associated with the tree.
190 * @param contents the manager
191 */
192 public final void setFileContents(FileContents contents) {
193 context.get().fileContents = contents;
194 }
195
196 /**
197 * Returns the file contents associated with the tree.
198 * @return the file contents
199 * @noinspection WeakerAccess
200 */
201 public final FileContents getFileContents() {
202 return context.get().fileContents;
203 }
204
205 /**
206 * Set the class loader associated with the tree.
207 * @param classLoader the class loader
208 */
209 public final void setClassLoader(ClassLoader classLoader) {
210 this.classLoader = classLoader;
211 }
212
213 /**
214 * Returns the class loader associated with the tree.
215 * @return the class loader
216 */
217 public final ClassLoader getClassLoader() {
218 return classLoader;
219 }
220
221 /**
222 * Get tab width to report errors with.
223 * @return the tab width to report errors with
224 */
225 protected final int getTabWidth() {
226 return tabWidth;
227 }
228
229 /**
230 * Set the tab width to report errors with.
231 * @param tabWidth an {@code int} value
232 */
233 public final void setTabWidth(int tabWidth) {
234 this.tabWidth = tabWidth;
235 }
236
237 /**
238 * Helper method to log a LocalizedMessage.
239 *
240 * @param ast a node to get line id column numbers associated
241 * with the message
242 * @param key key to locale message format
243 * @param args arguments to format
244 */
245 public final void log(DetailAST ast, String key, Object... args) {
246 // CommonUtil.lengthExpandedTabs returns column number considering tabulation
247 // characters, it takes line from the file by line number, ast column number and tab
248 // width as arguments. Returned value is 0-based, but user must see column number starting
249 // from 1, that is why result of the method CommonUtil.lengthExpandedTabs
250 // is increased by one.
251
252 final int col = 1 + CommonUtil.lengthExpandedTabs(
253 getLines()[ast.getLineNo() - 1], ast.getColumnNo(), tabWidth);
254 context.get().messages.add(
255 new LocalizedMessage(
256 ast.getLineNo(),
257 col,
258 ast.getColumnNo(),
259 ast.getType(),
260 getMessageBundle(),
261 key,
262 args,
263 getSeverityLevel(),
264 getId(),
265 getClass(),
266 getCustomMessages().get(key)));
267 }
268
269 @Override
270 public final void log(int line, String key, Object... args) {
271 context.get().messages.add(
272 new LocalizedMessage(
273 line,
274 getMessageBundle(),
275 key,
276 args,
277 getSeverityLevel(),
278 getId(),
279 getClass(),
280 getCustomMessages().get(key)));
281 }
282
283 @Override
284 public final void log(int lineNo, int colNo, String key,
285 Object... args) {
286 final int col = 1 + CommonUtil.lengthExpandedTabs(
287 getLines()[lineNo - 1], colNo, tabWidth);
288 context.get().messages.add(
289 new LocalizedMessage(
290 lineNo,
291 col,
292 getMessageBundle(),
293 key,
294 args,
295 getSeverityLevel(),
296 getId(),
297 getClass(),
298 getCustomMessages().get(key)));
299 }
300
301 /**
302 * The actual context holder.
303 */
304 private static class FileContext {
305
306 /** The sorted set for collecting messages. */
307 private final SortedSet<LocalizedMessage> messages = new TreeSet<>();
308
309 /** The current file contents. */
310 private FileContents fileContents;
311
312 }
313
314 }