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.checks.coding;
21
22 import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
23 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
24 import com.puppycrawl.tools.checkstyle.api.DetailAST;
25 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26
27 /**
28 * <div>
29 * Restricts nested {@code for} blocks to a specified depth.
30 * </div>
31 *
32 * @since 5.3
33 */
34 @FileStatefulCheck
35 public final class NestedForDepthCheck extends AbstractCheck {
36
37 /**
38 * A key is pointing to the warning message text in "messages.properties"
39 * file.
40 */
41 public static final String MSG_KEY = "nested.for.depth";
42
43 /** Specify maximum allowed nesting depth. */
44 private int max = 1;
45 /** Current nesting depth. */
46 private int depth;
47
48 /**
49 * Creates a new {@code NestedForDepthCheck} instance.
50 */
51 public NestedForDepthCheck() {
52 // no code by default
53 }
54
55 /**
56 * Setter to specify maximum allowed nesting depth.
57 *
58 * @param max maximum allowed nesting depth.
59 * @since 5.3
60 */
61 public void setMax(int max) {
62 this.max = max;
63 }
64
65 @Override
66 public int[] getDefaultTokens() {
67 return getRequiredTokens();
68 }
69
70 @Override
71 public int[] getAcceptableTokens() {
72 return getRequiredTokens();
73 }
74
75 @Override
76 public int[] getRequiredTokens() {
77 return new int[] {TokenTypes.LITERAL_FOR};
78 }
79
80 @Override
81 public void visitToken(DetailAST ast) {
82 if (depth > max) {
83 log(ast, MSG_KEY, depth, max);
84 }
85 ++depth;
86 }
87
88 @Override
89 public void leaveToken(DetailAST ast) {
90 --depth;
91 }
92
93 }