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1
19
20 package edu.umd.cs.findbugs.detect;
21
22 import edu.umd.cs.findbugs.*;
23 import org.apache.bcel.Repository;
24 import org.apache.bcel.classfile.Method;
25
26 public class ReadReturnShouldBeChecked extends BytecodeScanningDetector
27 implements StatelessDetector {
28
29 boolean sawRead = false;
30
31 boolean sawSkip = false;
32
33 boolean recentCallToAvailable = false;
34
35 int sawAvailable = 0;
36
37 boolean wasBufferedInputStream = false;
38
39 private BugReporter bugReporter;
40
41 private int readPC, skipPC;
42
43 private String  lastCallClass = null, lastCallMethod = null,
44 lastCallSig = null;
45
46 public ReadReturnShouldBeChecked(BugReporter bugReporter) {
47 this.bugReporter = bugReporter;
48 }
49
50 @Override
51 public void visit(Method obj) {
52 sawAvailable = 0;
53 sawRead = false;
54 sawSkip = false;
55 }
57
58 private boolean isInputStream() {
59 try {
60 if (lastCallClass.startsWith("[")) return false;
61 return (Repository.instanceOf(lastCallClass,
62 "java.io.InputStream")
63 || Repository.implementationOf(lastCallClass,
64 "java.io.DataInput") || Repository
65 .instanceOf(lastCallClass, "java.io.Reader"))
66 && !Repository.instanceOf(lastCallClass,
67 "java.io.ByteArrayInputStream");
68 } catch (ClassNotFoundException e) {
69 return false;
70 }
71 }
72
73 private boolean isBufferedInputStream() {
74 try {
75 if (lastCallClass.startsWith("[")) return false;
76 return Repository.instanceOf(
77 lastCallClass,"java.io.BufferedInputStream");
78 } catch (ClassNotFoundException e) {
79 return false;
80 }
81 }
82 @Override
83 public void sawOpcode(int seen) {
84
85 if (seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE) {
86 lastCallClass = getDottedClassConstantOperand();
87 lastCallMethod = getNameConstantOperand();
88 lastCallSig = getSigConstantOperand();
89 }
90
91 if (seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE)
92 if (getNameConstantOperand().equals("available")
93 && getSigConstantOperand().equals("()I")
94 || getNameConstantOperand().startsWith("get")
95 && getNameConstantOperand().endsWith("Length")
96 && getSigConstantOperand().equals("()I")
97 || getClassConstantOperand().equals("java/io/File")
98 && getNameConstantOperand().equals("length")
99 && getSigConstantOperand().equals("()J")) {
100 sawAvailable = 70;
101 return;
102 }
103 sawAvailable--;
104 if ((seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE)
105 && getNameConstantOperand().equals("read")
106
107 && (getSigConstantOperand().equals("([B)I")
108 || getSigConstantOperand().equals("([BII)I")
109 || getSigConstantOperand().equals("([C)I") || getSigConstantOperand()
110 .equals("([CII)I")) && isInputStream()) {
111 sawRead = true;
112 recentCallToAvailable = sawAvailable > 0;
113 readPC = getPC();
114 return;
115 }
116 if ((seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE)
117 && getNameConstantOperand().equals("skip")
118 && getSigConstantOperand().equals("(J)J")
119 && isInputStream() ) {
120
124 wasBufferedInputStream = isBufferedInputStream();
125 sawSkip = true;
126 recentCallToAvailable = sawAvailable > 0 && !wasBufferedInputStream;
127 skipPC = getPC();
128 return;
129
130 }
131
132 if ((seen == POP) || (seen == POP2)) {
133
134 if (sawRead) {
135 bugReporter.reportBug(new BugInstance(this, "RR_NOT_CHECKED",
136 recentCallToAvailable ? LOW_PRIORITY : NORMAL_PRIORITY)
137 .addClassAndMethod(this).addCalledMethod(lastCallClass,
138 lastCallMethod, lastCallSig, false)
139 .addSourceLine(this, readPC));
140 } else if (sawSkip) {
141
142 bugReporter.reportBug(new BugInstance(this, "SR_NOT_CHECKED",
143 (wasBufferedInputStream ? HIGH_PRIORITY
144 : recentCallToAvailable ? LOW_PRIORITY
145 : NORMAL_PRIORITY)).addClassAndMethod(
146 this).addCalledMethod(lastCallClass, lastCallMethod,
147 lastCallSig, false).addSourceLine(this, skipPC));
148 }
149 }
150 sawRead = false;
151 sawSkip = false;
152 }
153 }
154 |
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