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1
19
20 package edu.umd.cs.findbugs.detect;
21
22
23 import edu.umd.cs.findbugs.*;
24 import java.util.*;
25 import org.apache.bcel.Repository;
26 import org.apache.bcel.classfile.*;
27
28 public @java.lang.Deprecated  class FindBadCast extends BytecodeScanningDetector implements StatelessDetector {
29
30
31 private HashSet<String > castTo = new HashSet<String >();
32
33 BugReporter bugReporter;
34
35 final static boolean DEBUG = false;
36
37 public FindBadCast(BugReporter bugReporter) {
38 this.bugReporter = bugReporter;
39 abstractCollectionClasses.add("java/util/Collection");
40 abstractCollectionClasses.add("java/util/List");
41 abstractCollectionClasses.add("java/util/Set");
42 abstractCollectionClasses.add("java/util/Map");
43 concreteCollectionClasses.add("java/util/LinkedHashMap");
44 concreteCollectionClasses.add("java/util/LinkedHashSet");
45 concreteCollectionClasses.add("java/util/HashMap");
46 concreteCollectionClasses.add("java/util/HashSet");
47 concreteCollectionClasses.add("java/util/TreeMap");
48 concreteCollectionClasses.add("java/util/TreeSet");
49 concreteCollectionClasses.add("java/util/ArrayList");
50 concreteCollectionClasses.add("java/util/LinkedList");
51 concreteCollectionClasses.add("java/util/Hashtable");
52 concreteCollectionClasses.add("java/util/Vector");
53 }
54
55 private Set<String > concreteCollectionClasses = new HashSet<String >();
56 private Set<String > abstractCollectionClasses = new HashSet<String >();
57
58
59
60 @Override
61 public void visit(JavaClass obj) {
62 }
63
64 @Override
65 public void visit(Method obj) {
66 }
67
68
74 private int parameters;
75 OpcodeStack stack = new OpcodeStack();
76 @Override
77 public void visit(Code obj) {
78 if (DEBUG) {
79 System.out.println(getFullyQualifiedMethodName());
80 }
81 parameters = stack.resetForMethodEntry(this);
82 castTo.clear();
83 super.visit(obj);
84 }
85
86
87 @Override
88 public void sawOpcode(int seen) {
89 stack.mergeJumps(this);
90 if (DEBUG) {
91 System.out.println(stack);
92 printOpCode(seen);
93 }
94
95 if (stack.getStackDepth() > 0) {
96 if (seen == CHECKCAST || seen == INSTANCEOF) {
97 if (DEBUG)
98 System.out.println(" ... checking ... ");
99 OpcodeStack.Item it = stack.getStackItem(0);
100 String signature = it.getSignature();
101 if (signature.length() > 0 && signature.charAt(0) == 'L')
102 signature = signature.substring(1, signature.length() - 1);
103 String signatureDot = signature.replace('/', '.');
104 String to = getClassConstantOperand();
105 if (to.length() > 0 && to.charAt(0) == 'L')
106 to = to.substring(1, to.length() - 1);
107 String toDot = to.replace('/', '.');
108 if (signature.length() > 0
109 && !signature.equals("java/lang/Object")
110 && !signature.equals(to)) {
111
112 try {
113 JavaClass toClass = Repository.lookupClass(toDot);
114 JavaClass signatureClass = Repository
115 .lookupClass(signatureDot);
116 if (DEBUG)
117 System.out.println(" ... checking ...... ");
118 if (!castTo.contains(to)
119 && !Repository.instanceOf(signatureClass,
120 toClass)) {
121 if (!Repository.instanceOf(toClass, signatureClass)
122 && ((!toClass.isInterface() && !signatureClass
123 .isInterface())
124 || signatureClass.isFinal() || toClass
125 .isFinal()))
126 bugReporter
127 .reportBug(new BugInstance(
128 this,
129 seen == CHECKCAST ? "BC_IMPOSSIBLE_CAST"
130 : "BC_IMPOSSIBLE_INSTANCEOF",
131 seen == CHECKCAST ? HIGH_PRIORITY
132 : NORMAL_PRIORITY)
133 .addClassAndMethod(this)
134 .addSourceLine(this).addClass(
135 signatureDot).addClass(
136 toDot));
137 else if (seen == CHECKCAST) {
138 int priority = NORMAL_PRIORITY;
139 if (DEBUG) {
140 System.out.println("Checking BC in "
141 + getFullyQualifiedMethodName());
142 System.out.println("to class: " + toClass);
143 System.out.println("from class: "
144 + signatureClass);
145 System.out.println("instanceof : "
146 + Repository.instanceOf(toClass,
147 signatureClass));
148 }
149 if (Repository.instanceOf(toClass,
150 signatureClass))
151 priority += 2;
152 if (getThisClass().equals(toClass)
153 || getThisClass()
154 .equals(signatureClass))
155 priority += 1;
156 if (DEBUG)
157 System.out
158 .println(" priority: " + priority);
159 if (toClass.isInterface())
160 priority++;
161 if (DEBUG)
162 System.out
163 .println(" priority: " + priority);
164 if (priority <= LOW_PRIORITY
165 && (signatureClass.isInterface() || signatureClass
166 .isAbstract()))
167 priority++;
168 if (DEBUG)
169 System.out
170 .println(" priority: " + priority);
171 if (concreteCollectionClasses
172 .contains(signature)
173 || abstractCollectionClasses
174 .contains(signature))
175 priority--;
176 if (concreteCollectionClasses.contains(to)
177 || abstractCollectionClasses
178 .contains(to))
179 priority--;
180 if (DEBUG)
181 System.out
182 .println(" priority: " + priority);
183 int reg = it.getRegisterNumber();
184 if (reg >= 0 && reg < parameters
185 && it.isInitialParameter()
186 && getMethod().isPublic()) {
187 priority--;
188 if (getPC() < 4 && priority > LOW_PRIORITY)
189 priority--;
190 }
191 if (DEBUG)
192 System.out
193 .println(" priority: " + priority);
194 if (getMethodName().equals("compareTo"))
195 priority++;
196 if (DEBUG)
197 System.out
198 .println(" priority: " + priority);
199 if (priority < HIGH_PRIORITY)
200 priority = HIGH_PRIORITY;
201 if (priority <= LOW_PRIORITY) {
202 String bug = "BC_UNCONFIRMED_CAST";
203 if (concreteCollectionClasses.contains(to))
204 bug = "BC_BAD_CAST_TO_CONCRETE_COLLECTION";
205 else if (abstractCollectionClasses
206 .contains(to)
207 && (signature
208 .equals("java/util/Collection") || signature
209 .equals("java/lang/Iterable")))
210 bug = "BC_BAD_CAST_TO_ABSTRACT_COLLECTION";
211 bugReporter.reportBug(new BugInstance(this,
212 bug, priority).addClassAndMethod(
213 this).addSourceLine(this).addClass(
214 signatureDot).addClass(toDot));
215 }
216 }
217
218 }
219
220 } catch (RuntimeException e) {
221 } catch (ClassNotFoundException e) {
223 }
225 }
226 }
227 if (seen == INSTANCEOF) {
228 String to = getClassConstantOperand();
229 castTo.add(to);
230 }
231 }
232 stack.sawOpcode(this,seen);
233
234 }
235
236
237
238
239 }
240 |
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