|
1
20
21 package edu.umd.cs.findbugs.detect;
22
23
24 import edu.umd.cs.findbugs.*;
25 import org.apache.bcel.classfile.Method;
26
27 public class WrongMapIterator extends BytecodeScanningDetector implements StatelessDetector {
28 private BugReporter bugReporter;
29 private static final int SAW_NOTHING = 0;
30 private static final int SAW_MAP_LOAD1 = 1;
31 private static final int SAW_KEYSET = 2;
32 private static final int SAW_KEYSET_STORE = 3;
33 private static final int SAW_ITERATOR = 4;
34 private static final int SAW_ITERATOR_STORE = 5;
35 private static final int SAW_ITERATOR_LOAD = 6;
36 private static final int SAW_NEXT = 7;
37 private static final int SAW_CHECKCAST_ON_NEXT = 8;
38 private static final int SAW_KEY_STORE = 9;
39 private static final int NEED_KEYSET_LOAD = 10;
40 private static final int SAW_MAP_LOAD2 = 11;
41 private static final int SAW_KEY_LOAD = 12;
42
43 private int state;
44 private int loadedRegister;
45 private int mapRegister;
46 private int keySetRegister;
47 private int iteratorRegister;
48 private int keyRegister;
49
50
51 public WrongMapIterator(BugReporter bugReporter) {
52 this.bugReporter = bugReporter;
53 }
54
55
56
57 @Override 
58 public void visit(Method obj) {
59 state = SAW_NOTHING;
60 loadedRegister = -1;
61 mapRegister = -1;
62 keySetRegister = -1;
63 iteratorRegister = -1;
64 keyRegister = -1;
65 }
66
67 @Override
68 public void sawOpcode(int seen) {
69 switch (state)
70 {
71 case SAW_NOTHING:
72 loadedRegister = getLoadStoreRegister( seen, true );
73 if (loadedRegister >= 0)
74 state = SAW_MAP_LOAD1;
75 break;
76
77 case SAW_MAP_LOAD1:
78 if (((seen == INVOKEINTERFACE) || (seen == INVOKEVIRTUAL))
79 && ("keySet".equals(getNameConstantOperand()))
80 && ("()Ljava/util/Set;".equals(getSigConstantOperand()))) {
81 mapRegister = loadedRegister;
82 state = SAW_KEYSET;
83 }
84 else {
85 state = SAW_NOTHING;
86 }
87 break;
88
89 case SAW_KEYSET:
90 keySetRegister = getLoadStoreRegister( seen, false );
91 if (keySetRegister >= 0)
92 state = SAW_KEYSET_STORE;
93 else if ((seen == INVOKEINTERFACE)
94 && ("iterator".equals(getNameConstantOperand()))
95 && ("()Ljava/util/Iterator;".equals(getSigConstantOperand())))
96 state = SAW_ITERATOR;
97 else
98 state = SAW_NOTHING;
99 break;
100
101 case SAW_KEYSET_STORE:
102 if ((seen == INVOKEINTERFACE)
103 && ("iterator".equals(getNameConstantOperand()))
104 && ("()Ljava/util/Iterator;".equals(getSigConstantOperand())))
105 state = SAW_ITERATOR;
106 else
107 state = NEED_KEYSET_LOAD;
108 break;
109
110 case NEED_KEYSET_LOAD:
111 loadedRegister = getLoadStoreRegister( seen, true );
112 if (loadedRegister == iteratorRegister)
113 state = SAW_ITERATOR;
114 break;
115
116 case SAW_ITERATOR:
117 iteratorRegister = getLoadStoreRegister( seen, false );
118 if (iteratorRegister >= 0)
119 state = SAW_ITERATOR_STORE;
120 else
121 state = SAW_NOTHING;
122 break;
123
124 case SAW_ITERATOR_STORE:
125 loadedRegister = getLoadStoreRegister( seen, true );
126 if (loadedRegister == iteratorRegister)
127 state = SAW_ITERATOR_LOAD;
128 break;
129
130 case SAW_ITERATOR_LOAD:
131 if ((seen == INVOKEINTERFACE)
132 && ("next".equals(getNameConstantOperand()))
133 && ("()Ljava/lang/Object;".equals(getSigConstantOperand())))
134 state = SAW_NEXT;
135 else
136 state = SAW_ITERATOR_STORE;
137 break;
138
139 case SAW_NEXT:
140 if (seen == CHECKCAST)
141 state = SAW_CHECKCAST_ON_NEXT;
142 else {
143 keyRegister = getLoadStoreRegister( seen, false );
144 if (keyRegister >= 0)
145 state = SAW_KEY_STORE;
146 else
147 seen = SAW_NOTHING;
148 }
149 break;
150
151 case SAW_CHECKCAST_ON_NEXT:
152 keyRegister = getLoadStoreRegister( seen, false );
153 if (keyRegister >= 0)
154 state = SAW_KEY_STORE;
155 break;
156
157 case SAW_KEY_STORE:
158 loadedRegister = getLoadStoreRegister( seen, true );
159 if (loadedRegister == mapRegister)
160 state = SAW_MAP_LOAD2;
161 break;
162
163 case SAW_MAP_LOAD2:
164 loadedRegister = getLoadStoreRegister( seen, true );
165 if (loadedRegister == keyRegister)
166 state = SAW_KEY_LOAD;
167 else
168 state = SAW_KEY_STORE;
169 break;
170
171 case SAW_KEY_LOAD:
172 if (((seen == INVOKEINTERFACE) || (seen == INVOKEVIRTUAL))
173 && ("get".equals(getNameConstantOperand()))
174 && ("(Ljava/lang/Object;)Ljava/lang/Object;".equals(getSigConstantOperand()))) {
175 MethodAnnotation ma = MethodAnnotation.fromVisitedMethod(this);
176 bugReporter.reportBug(
177 new BugInstance("WMI_WRONG_MAP_ITERATOR", NORMAL_PRIORITY)
178 .addClass(this)
179 .addMethod(ma)
180 .addSourceLine(this, getPC()));
181 state = SAW_NOTHING;
182 }
183 break;
184 }
185 }
186
187 private int getLoadStoreRegister(int seen, boolean doLoad)
188 {
189 switch (seen)
190 {
191 case ALOAD_0:
192 case ALOAD_1:
193 case ALOAD_2:
194 case ALOAD_3:
195 if (doLoad)
196 return seen - ALOAD_0;
197 break;
198
199 case ALOAD:
200 if (doLoad)
201 return getRegisterOperand();
202 break;
203
204 case ASTORE_0:
205 case ASTORE_1:
206 case ASTORE_2:
207 case ASTORE_3:
208 if (!doLoad)
209 return seen - ASTORE_0;
210 break;
211
212 case ASTORE:
213 if (!doLoad)
214 return getRegisterOperand();
215 break;
216 }
217
218 return -1;
219 }
220 }
221 |
Popular Tags |
Java API By Example, From Geeks To Geeks.