1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 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.utils;
21
22 import java.util.Optional;
23
24 import com.puppycrawl.tools.checkstyle.api.DetailAST;
25 import com.puppycrawl.tools.checkstyle.api.Scope;
26 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
27
28 /**
29 * Contains utility methods for working on scope.
30 *
31 */
32 public final class ScopeUtil {
33
34 /** Prevent instantiation. */
35 private ScopeUtil() {
36 }
37
38 /**
39 * Returns the {@code Scope} explicitly specified by the modifier set.
40 * Returns {@code null} if there are no modifiers.
41 *
42 * @param aMods root node of a modifier set
43 * @return a {@code Scope} value or {@code null}
44 */
45 public static Scope getDeclaredScopeFromMods(DetailAST aMods) {
46 Scope result = null;
47 for (DetailAST token = aMods.getFirstChild(); token != null;
48 token = token.getNextSibling()) {
49 switch (token.getType()) {
50 case TokenTypes.LITERAL_PUBLIC:
51 result = Scope.PUBLIC;
52 break;
53 case TokenTypes.LITERAL_PROTECTED:
54 result = Scope.PROTECTED;
55 break;
56 case TokenTypes.LITERAL_PRIVATE:
57 result = Scope.PRIVATE;
58 break;
59 default:
60 break;
61 }
62 }
63 return result;
64 }
65
66 /**
67 * Returns the {@code Scope} for a given {@code DetailAST}.
68 *
69 * @param ast the DetailAST to examine
70 * @return a {@code Scope} value
71 */
72 public static Scope getScope(DetailAST ast) {
73 return Optional.ofNullable(ast.findFirstToken(TokenTypes.MODIFIERS))
74 .map(ScopeUtil::getDeclaredScopeFromMods)
75 .orElseGet(() -> getDefaultScope(ast));
76 }
77
78 /**
79 * Returns the {@code Scope} specified by the modifier set. If no modifiers are present,
80 * the default scope is used.
81 *
82 * @param aMods root node of a modifier set
83 * @return a {@code Scope} value
84 * @see #getDefaultScope(DetailAST)
85 */
86 public static Scope getScopeFromMods(DetailAST aMods) {
87 return Optional.ofNullable(getDeclaredScopeFromMods(aMods))
88 .orElseGet(() -> getDefaultScope(aMods));
89 }
90
91 /**
92 * Returns the default {@code Scope} for a {@code DetailAST}.
93 * <p>The following rules are taken into account:</p>
94 * <ul>
95 * <li>enum constants are public</li>
96 * <li>enum constructors are private</li>
97 * <li>interface members are public</li>
98 * <li>everything else is package private</li>
99 * </ul>
100 *
101 * @param ast DetailAST to process
102 * @return a {@code Scope} value
103 */
104 private static Scope getDefaultScope(DetailAST ast) {
105 final Scope result;
106 if (isInEnumBlock(ast)) {
107 if (ast.getType() == TokenTypes.ENUM_CONSTANT_DEF) {
108 result = Scope.PUBLIC;
109 }
110 else if (ast.getType() == TokenTypes.CTOR_DEF) {
111 result = Scope.PRIVATE;
112 }
113 else {
114 result = Scope.PACKAGE;
115 }
116 }
117 else if (isInInterfaceOrAnnotationBlock(ast)) {
118 result = Scope.PUBLIC;
119 }
120 else {
121 result = Scope.PACKAGE;
122 }
123 return result;
124 }
125
126 /**
127 * Returns the scope of the surrounding "block".
128 *
129 * @param node the node to return the scope for
130 * @return the Scope of the surrounding block
131 */
132 public static Scope getSurroundingScope(DetailAST node) {
133 Scope returnValue = null;
134 for (DetailAST token = node;
135 token != null;
136 token = token.getParent()) {
137 final int type = token.getType();
138 if (TokenUtil.isTypeDeclaration(type)) {
139 final Scope tokenScope = getScope(token);
140 if (returnValue == null || returnValue.isIn(tokenScope)) {
141 returnValue = tokenScope;
142 }
143 }
144 else if (type == TokenTypes.LITERAL_NEW) {
145 returnValue = Scope.ANONINNER;
146 // because Scope.ANONINNER is not in any other Scope
147 break;
148 }
149 }
150
151 return returnValue;
152 }
153
154 /**
155 * Returns whether a node is directly contained within a class block.
156 *
157 * @param node the node to check if directly contained within a class block.
158 * @return a {@code boolean} value
159 */
160 public static boolean isInClassBlock(DetailAST node) {
161 return isInBlockOf(node, TokenTypes.CLASS_DEF);
162 }
163
164 /**
165 * Returns whether a node is directly contained within a record block.
166 *
167 * @param node the node to check if directly contained within a record block.
168 * @return a {@code boolean} value
169 */
170 public static boolean isInRecordBlock(DetailAST node) {
171 return isInBlockOf(node, TokenTypes.RECORD_DEF);
172 }
173
174 /**
175 * Returns whether a node is directly contained within an interface block.
176 *
177 * @param node the node to check if directly contained within an interface block.
178 * @return a {@code boolean} value
179 */
180 public static boolean isInInterfaceBlock(DetailAST node) {
181 return isInBlockOf(node, TokenTypes.INTERFACE_DEF);
182 }
183
184 /**
185 * Returns whether a node is directly contained within an annotation block.
186 *
187 * @param node the node to check if directly contained within an annotation block.
188 * @return a {@code boolean} value
189 */
190 public static boolean isInAnnotationBlock(DetailAST node) {
191 return isInBlockOf(node, TokenTypes.ANNOTATION_DEF);
192 }
193
194 /**
195 * Returns whether a node is directly contained within a specified block.
196 *
197 * @param node the node to check if directly contained within a specified block.
198 * @param tokenType type of token.
199 * @return a {@code boolean} value
200 */
201 private static boolean isInBlockOf(DetailAST node, int tokenType) {
202 boolean returnValue = false;
203
204 // Loop up looking for a containing interface block
205 for (DetailAST token = node.getParent();
206 token != null && !returnValue;
207 token = token.getParent()) {
208 if (token.getType() == tokenType) {
209 returnValue = true;
210 }
211 else if (token.getType() == TokenTypes.LITERAL_NEW
212 || TokenUtil.isTypeDeclaration(token.getType())) {
213 break;
214 }
215 }
216
217 return returnValue;
218 }
219
220 /**
221 * Returns whether a node is directly contained within an interface or
222 * annotation block.
223 *
224 * @param node the node to check if directly contained within an interface
225 * or annotation block.
226 * @return a {@code boolean} value
227 */
228 public static boolean isInInterfaceOrAnnotationBlock(DetailAST node) {
229 return isInInterfaceBlock(node) || isInAnnotationBlock(node);
230 }
231
232 /**
233 * Returns whether a node is directly contained within an enum block.
234 *
235 * @param node the node to check if directly contained within an enum block.
236 * @return a {@code boolean} value
237 */
238 public static boolean isInEnumBlock(DetailAST node) {
239 boolean returnValue = false;
240
241 // Loop up looking for a containing interface block
242 for (DetailAST token = node.getParent();
243 token != null; token = token.getParent()) {
244 if (TokenUtil.isOfType(token, TokenTypes.INTERFACE_DEF,
245 TokenTypes.ANNOTATION_DEF, TokenTypes.CLASS_DEF,
246 TokenTypes.LITERAL_NEW, TokenTypes.ENUM_DEF)) {
247 returnValue = token.getType() == TokenTypes.ENUM_DEF;
248 break;
249 }
250 }
251
252 return returnValue;
253 }
254
255 /**
256 * Returns whether the scope of a node is restricted to a code block.
257 * A code block is a method or constructor body, an initializer block, or lambda body.
258 *
259 * @param node the node to check
260 * @return a {@code boolean} value
261 */
262 public static boolean isInCodeBlock(DetailAST node) {
263 boolean returnValue = false;
264 final int[] tokenTypes = {
265 TokenTypes.METHOD_DEF,
266 TokenTypes.CTOR_DEF,
267 TokenTypes.INSTANCE_INIT,
268 TokenTypes.STATIC_INIT,
269 TokenTypes.LAMBDA,
270 TokenTypes.COMPACT_CTOR_DEF,
271 };
272
273 // Loop up looking for a containing code block
274 for (DetailAST token = node.getParent();
275 token != null;
276 token = token.getParent()) {
277 if (TokenUtil.isOfType(token, tokenTypes)) {
278 returnValue = true;
279 break;
280 }
281 }
282
283 return returnValue;
284 }
285
286 /**
287 * Returns whether a node is contained in the outermost type block.
288 *
289 * @param node the node to check
290 * @return a {@code boolean} value
291 */
292 public static boolean isOuterMostType(DetailAST node) {
293 boolean returnValue = true;
294 for (DetailAST parent = node.getParent();
295 parent != null;
296 parent = parent.getParent()) {
297 if (TokenUtil.isTypeDeclaration(parent.getType())) {
298 returnValue = false;
299 break;
300 }
301 }
302
303 return returnValue;
304 }
305
306 /**
307 * Determines whether a node is a local variable definition.
308 * I.e. if it is declared in a code block, a for initializer,
309 * or a catch parameter.
310 *
311 * @param node the node to check.
312 * @return whether aAST is a local variable definition.
313 */
314 public static boolean isLocalVariableDef(DetailAST node) {
315 final boolean localVariableDef;
316 // variable declaration?
317 if (node.getType() == TokenTypes.VARIABLE_DEF) {
318 final DetailAST parent = node.getParent();
319 localVariableDef = TokenUtil.isOfType(parent, TokenTypes.SLIST,
320 TokenTypes.FOR_INIT, TokenTypes.FOR_EACH_CLAUSE);
321 }
322
323 else if (node.getType() == TokenTypes.RESOURCE) {
324 localVariableDef = node.getChildCount() > 1;
325 }
326
327 // catch parameter?
328 else if (node.getType() == TokenTypes.PARAMETER_DEF) {
329 final DetailAST parent = node.getParent();
330 localVariableDef = parent.getType() == TokenTypes.LITERAL_CATCH;
331 }
332
333 else {
334 localVariableDef = false;
335 }
336
337 return localVariableDef;
338 }
339
340 /**
341 * Determines whether a node is a class field definition.
342 * I.e. if a variable is not declared in a code block, a for initializer,
343 * or a catch parameter.
344 *
345 * @param node the node to check.
346 * @return whether a node is a class field definition.
347 */
348 public static boolean isClassFieldDef(DetailAST node) {
349 return node.getType() == TokenTypes.VARIABLE_DEF
350 && !isLocalVariableDef(node);
351 }
352
353 /**
354 * Checks whether ast node is in a specific scope.
355 *
356 * @param ast the node to check.
357 * @param scope a {@code Scope} value.
358 * @return true if the ast node is in the scope.
359 */
360 public static boolean isInScope(DetailAST ast, Scope scope) {
361 final Scope surroundingScopeOfAstToken = getSurroundingScope(ast);
362 return surroundingScopeOfAstToken == scope;
363 }
364
365 }