Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
CovariantEqualsCheck |
|
| 3.5;3.5 |
1 | //////////////////////////////////////////////////////////////////////////////// | |
2 | // checkstyle: Checks Java source code for adherence to a set of rules. | |
3 | // Copyright (C) 2001-2014 Oliver Burn | |
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 | package com.puppycrawl.tools.checkstyle.checks.coding; | |
20 | ||
21 | import com.google.common.collect.Sets; | |
22 | import com.puppycrawl.tools.checkstyle.api.Check; | |
23 | import com.puppycrawl.tools.checkstyle.api.DetailAST; | |
24 | import com.puppycrawl.tools.checkstyle.api.FullIdent; | |
25 | import com.puppycrawl.tools.checkstyle.api.TokenTypes; | |
26 | import com.puppycrawl.tools.checkstyle.checks.CheckUtils; | |
27 | import java.util.Set; | |
28 | ||
29 | /** | |
30 | * <p>Checks that if a class defines a covariant method equals, | |
31 | * then it defines method equals(java.lang.Object). | |
32 | * Inspired by findbugs, | |
33 | * http://www.cs.umd.edu/~pugh/java/bugs/docs/findbugsPaper.pdf | |
34 | * </p> | |
35 | * <p> | |
36 | * An example of how to configure the check is: | |
37 | * </p> | |
38 | * <pre> | |
39 | * <module name="CovariantEquals"/> | |
40 | * </pre> | |
41 | * @author Rick Giles | |
42 | * @version 1.0 | |
43 | */ | |
44 | 1 | public class CovariantEqualsCheck extends Check |
45 | { | |
46 | /** Set of equals method definitions */ | |
47 | 1 | private final Set<DetailAST> mEqualsMethods = Sets.newHashSet(); |
48 | ||
49 | @Override | |
50 | public int[] getDefaultTokens() | |
51 | { | |
52 | 1 | return new int[] {TokenTypes.CLASS_DEF, TokenTypes.LITERAL_NEW, }; |
53 | } | |
54 | ||
55 | @Override | |
56 | public int[] getRequiredTokens() | |
57 | { | |
58 | 0 | return getDefaultTokens(); |
59 | } | |
60 | ||
61 | @Override | |
62 | public void visitToken(DetailAST aAST) | |
63 | { | |
64 | 12 | mEqualsMethods.clear(); |
65 | 12 | boolean hasEqualsObject = false; |
66 | ||
67 | // examine method definitions for equals methods | |
68 | 12 | final DetailAST objBlock = aAST.findFirstToken(TokenTypes.OBJBLOCK); |
69 | 12 | if (objBlock != null) { |
70 | 11 | DetailAST child = objBlock.getFirstChild(); |
71 | 54 | while (child != null) { |
72 | 43 | if (child.getType() == TokenTypes.METHOD_DEF |
73 | && CheckUtils.isEqualsMethod(child)) | |
74 | { | |
75 | 15 | if (hasObjectParameter(child)) { |
76 | 6 | hasEqualsObject = true; |
77 | } | |
78 | else { | |
79 | 9 | mEqualsMethods.add(child); |
80 | } | |
81 | } | |
82 | 43 | child = child.getNextSibling(); |
83 | } | |
84 | ||
85 | // report equals method definitions | |
86 | 11 | if (!hasEqualsObject) { |
87 | 5 | for (DetailAST equalsAST : mEqualsMethods) { |
88 | 4 | final DetailAST nameNode = equalsAST |
89 | .findFirstToken(TokenTypes.IDENT); | |
90 | 4 | log(nameNode.getLineNo(), nameNode.getColumnNo(), |
91 | "covariant.equals"); | |
92 | 4 | } |
93 | } | |
94 | } | |
95 | 12 | } |
96 | ||
97 | /** | |
98 | * Tests whether a method definition AST has exactly one | |
99 | * parameter of type Object. | |
100 | * @param aAST the method definition AST to test. | |
101 | * Precondition: aAST is a TokenTypes.METHOD_DEF node. | |
102 | * @return true if aAST has exactly one parameter of type Object. | |
103 | */ | |
104 | private boolean hasObjectParameter(DetailAST aAST) | |
105 | { | |
106 | // one parameter? | |
107 | 15 | final DetailAST paramsNode = aAST.findFirstToken(TokenTypes.PARAMETERS); |
108 | 15 | if (paramsNode.getChildCount() != 1) { |
109 | 0 | return false; |
110 | } | |
111 | ||
112 | // parameter type "Object"? | |
113 | 15 | final DetailAST paramNode = |
114 | paramsNode.findFirstToken(TokenTypes.PARAMETER_DEF); | |
115 | 15 | final DetailAST typeNode = paramNode.findFirstToken(TokenTypes.TYPE); |
116 | 15 | final FullIdent fullIdent = FullIdent.createFullIdentBelow(typeNode); |
117 | 15 | final String name = fullIdent.getText(); |
118 | 15 | return ("Object".equals(name) || "java.lang.Object".equals(name)); |
119 | } | |
120 | } |