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1 package edu.umd.cs.findbugs.detect;
2
3 import static org.apache.bcel.Constants.*;
4
5 import java.util.BitSet  ;
6 import java.util.Iterator ;
7
8 import org.apache.bcel.classfile.Method;
9 import org.apache.bcel.generic.ConstantPoolGen;
10 import org.apache.bcel.generic.Instruction;
11 import org.apache.bcel.generic.InvokeInstruction;
12 import org.apache.bcel.generic.MethodGen;
13
14 import edu.umd.cs.findbugs.BugAnnotation;
15 import edu.umd.cs.findbugs.BugInstance;
16 import edu.umd.cs.findbugs.BugReporter;
17 import edu.umd.cs.findbugs.Detector;
18 import edu.umd.cs.findbugs.FieldAnnotation;
19 import edu.umd.cs.findbugs.LocalVariableAnnotation;
20 import edu.umd.cs.findbugs.SourceLineAnnotation;
21 import edu.umd.cs.findbugs.SystemProperties;
22 import edu.umd.cs.findbugs.ba.CFG;
23 import edu.umd.cs.findbugs.ba.CFGBuilderException;
24 import edu.umd.cs.findbugs.ba.ClassContext;
25 import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
26 import edu.umd.cs.findbugs.ba.Location;
27 import edu.umd.cs.findbugs.ba.MethodUnprofitableException;
28 import edu.umd.cs.findbugs.ba.SignatureParser;
29 import edu.umd.cs.findbugs.ba.XFactory;
30 import edu.umd.cs.findbugs.ba.XField;
31 import edu.umd.cs.findbugs.ba.vna.ValueNumber;
32 import edu.umd.cs.findbugs.ba.vna.ValueNumberDataflow;
33 import edu.umd.cs.findbugs.ba.vna.ValueNumberFrame;
34
35 public class FindSelfComparison2 implements Detector {
36
37 private BugReporter bugReporter;
38
39 public FindSelfComparison2(BugReporter bugReporter) {
40 this.bugReporter = bugReporter;
41 }
42
43 public void visitClassContext(ClassContext classContext) {
44 Method[] methodList = classContext.getJavaClass().getMethods();
45
46 for (Method method : methodList) {
47 if (method.getCode() == null)
48 continue;
49
50 try {
51 analyzeMethod(classContext, method);
52 } catch (MethodUnprofitableException mue) {
53 if (SystemProperties.getBoolean("unprofitable.debug")) bugReporter.logError("skipping unprofitable method in " + getClass().getName());
55 } catch (CFGBuilderException e) {
56 bugReporter.logError("Detector " + this.getClass().getName()
57 + " caught exception", e);
58 } catch (DataflowAnalysisException e) {
59 bugReporter.logError("Detector " + this.getClass().getName()
60 + " caught exception", e);
61 }
62 }
63 }
64
65 private void analyzeMethod(ClassContext classContext, Method method)
66 throws CFGBuilderException, DataflowAnalysisException {
67 CFG cfg = classContext.getCFG(method);
68 ValueNumberDataflow valueNumberDataflow = classContext
69 .getValueNumberDataflow(method);
70 ConstantPoolGen cpg = classContext.getConstantPoolGen();
71 MethodGen methodGen = classContext.getMethodGen(method);
72 String sourceFile = classContext.getJavaClass().getSourceFileName();
73
74 for (Iterator <Location> i = cfg.locationIterator(); i.hasNext();) {
75 Location location = i.next();
76
77 Instruction ins = location.getHandle().getInstruction();
78 switch(ins.getOpcode()) {
79 case INVOKEVIRTUAL:
80 case INVOKEINTERFACE:
81 InvokeInstruction iins = (InvokeInstruction) ins;
82 String invoking = iins.getName(cpg);
83 if (invoking.equals("equals") || invoking.equals("compareTo")) {
84 if (methodGen.getName().toLowerCase().indexOf("test") >= 0) break;
85 if (methodGen.getClassName().toLowerCase().indexOf("test") >= 0) break;
86 if (classContext.getJavaClass().getSuperclassName().toLowerCase().indexOf("test") >= 0) break;
87
88 String sig = iins.getSignature(cpg);
89
90 SignatureParser parser = new SignatureParser(sig);
91 if (parser.getNumParameters() == 1 &&
92 (invoking.equals("equals") && sig.endsWith(";)Z")
93 || invoking.equals("compareTo") && sig.endsWith(";)I")))
94 checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPARISON", methodGen, sourceFile);
95
96
97 }
98 break;
99
100 case LOR:
101 case LAND:
102 case LXOR:
103 case LSUB:
104 case IOR:
105 case IAND:
106 case IXOR:
107 case ISUB:
108 checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPUTATION", methodGen, sourceFile);
109 break;
110 case FCMPG:
111 case DCMPG:
112 case DCMPL:
113 case FCMPL:
114 break;
115 case LCMP:
116 case IF_ACMPEQ:
117 case IF_ACMPNE:
118 case IF_ICMPNE:
119 case IF_ICMPEQ:
120 case IF_ICMPGT:
121 case IF_ICMPLE:
122 case IF_ICMPLT:
123 case IF_ICMPGE:
124 checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPARISON", methodGen, sourceFile);
125
126 }
127
128
129 }
130 }
131
132
140 private void checkForSelfOperation(ClassContext classContext, Location location, ValueNumberDataflow valueNumberDataflow, String op, MethodGen methodGen, String sourceFile) throws DataflowAnalysisException {
141 ValueNumberFrame frame = valueNumberDataflow.getFactAtLocation(location);
142 if (!frame.isValid()) return;
143 Instruction ins = location.getHandle().getInstruction();
144 int opcode = ins.getOpcode();
145 int offset = 1;
146 if (opcode == LCMP || opcode == LXOR || opcode == LAND || opcode == LOR || opcode == LSUB)
147 offset = 2;
148 ValueNumber v0 = frame.getStackValue(0);
149 ValueNumber v1 = frame.getStackValue(offset);
150 if (!v1.equals(v0)) return;
151
152 int priority = HIGH_PRIORITY;
153 if (opcode == ISUB || opcode == LSUB || opcode == INVOKEINTERFACE || opcode == INVOKEVIRTUAL)
154 priority = NORMAL_PRIORITY;
155 XField field = FindNullDeref.findXFieldFromValueNumber(methodGen.getMethod(), location, v0, frame);
156 BugAnnotation annotation;
157 String prefix;
158 if (field != null) {
159 if (field.isVolatile()) return;
160 annotation = FieldAnnotation.fromXField(field);
161 prefix = "SA_FIELD_SELF_";
162 if (true) return; } else {
164 annotation = FindNullDeref.findLocalAnnotationFromValueNumber(methodGen.getMethod(), location, v0, frame);
165 prefix = "SA_LOCAL_SELF_" ;
166 if (opcode == ISUB) return; }
168 if (annotation == null) return;
169 SourceLineAnnotation sourceLine = SourceLineAnnotation.fromVisitedInstruction(classContext, methodGen, sourceFile, location.getHandle());
170 int line = sourceLine.getStartLine();
171 BitSet occursMultipleTimes = classContext.linesMentionedMultipleTimes(methodGen.getMethod());
172 if (line > 0 && occursMultipleTimes.get(line)) return;
173 BugInstance bug = new BugInstance(this, prefix + op, priority).addClassAndMethod(methodGen, sourceFile)
174 .add(annotation).addSourceLine(classContext, methodGen, sourceFile, location.getHandle());
175 bugReporter.reportBug(bug);
176 }
177
178 public void report() {
179 }
180
181 }
182 |
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