|
1
19
20
25
26
27
29
30 package soot.jimple.toolkits.annotation.nullcheck;
31 import soot.options.*;
32
33 import soot.*;
34 import soot.jimple.*;
35 import soot.util.*;
36 import java.io.*;
37 import java.util.*;
38 import soot.tagkit.*;
39 import soot.jimple.toolkits.annotation.tags.*;
40 import soot.toolkits.graph.*;
41 import soot.toolkits.scalar.*;
42
43
55
56 public class NullPointerChecker extends BodyTransformer
57 {
58 public NullPointerChecker( Singletons.Global g ) {}
59 public static NullPointerChecker v() { return G.v().soot_jimple_toolkits_annotation_nullcheck_NullPointerChecker(); }
60
61 private boolean isProfiling = false;
62
63 private boolean enableOther = true;
64
65 protected void internalTransform(Body body, String  phaseName, Map options)
66 {
67 isProfiling = PhaseOptions.getBoolean(options, "profiling");
68 enableOther = !PhaseOptions.getBoolean(options, "onlyarrayref");
69
70 {
71 Date start = new Date();
72
73 if (Options.v().verbose())
74 G.v().out.println("[npc] Null pointer check for "+body.getMethod().getName()
75 +" started on "+start);
76
77 BranchedRefVarsAnalysis analysis = new BranchedRefVarsAnalysis(
78 new ExceptionalUnitGraph(body));
79
80 SootClass counterClass = null;
81 SootMethod increase = null;
82
83 if (isProfiling)
84 {
85 counterClass = Scene.v().loadClassAndSupport("MultiCounter");
86 increase = counterClass.getMethod("void increase(int)") ;
87 }
88
89 Chain units = body.getUnits();
90
91 Iterator stmtIt = units.snapshotIterator() ;
92
93 while (stmtIt.hasNext())
94 {
95 Stmt s = (Stmt)stmtIt.next() ;
96
97 Value obj = null;
98
99 if (s.containsArrayRef())
100 {
101 ArrayRef aref = (ArrayRef)s.getArrayRef();
102 obj = aref.getBase();
103 }
104 else
105 {
106 if (enableOther)
107 {
108 if (s instanceof ThrowStmt)
110 {
111 obj = ((ThrowStmt)s).getOp();
112 }
113 else
114 if (s instanceof MonitorStmt)
116 {
117 obj = ((MonitorStmt)s).getOp();
118 }
119 else
120 {
121 Iterator boxIt;
122 boxIt = s.getDefBoxes().iterator();
123 while (boxIt.hasNext())
124 {
125 ValueBox vBox = (ValueBox)boxIt.next();
126 Value v = vBox.getValue();
127
128 if (v instanceof InstanceFieldRef)
130 {
131 obj = ((InstanceFieldRef)v).getBase();
132 break;
133 }
134 else
135 if (v instanceof InstanceInvokeExpr)
137 {
138 obj = ((InstanceInvokeExpr)v).getBase();
139 break;
140 }
141 else
142 if (v instanceof LengthExpr)
144 {
145 obj = ((LengthExpr)v).getOp();
146 break;
147 }
148 }
149 boxIt = s.getUseBoxes().iterator();
150 while (boxIt.hasNext())
151 {
152 ValueBox vBox = (ValueBox)boxIt.next();
153 Value v = vBox.getValue();
154
155 if (v instanceof InstanceFieldRef)
157 {
158 obj = ((InstanceFieldRef)v).getBase();
159 break;
160 }
161 else
162 if (v instanceof InstanceInvokeExpr)
164 {
165 obj = ((InstanceInvokeExpr)v).getBase();
166 break;
167 }
168 else
169 if (v instanceof LengthExpr)
171 {
172 obj = ((LengthExpr)v).getOp();
173 break;
174 }
175 }
176 }
177 }
178 }
179
180 if (obj != null)
182 {
183 FlowSet beforeSet = (FlowSet)analysis.getFlowBefore(s);
184
185 int vInfo = analysis.anyRefInfo(obj, beforeSet);
186
187 boolean needCheck =
188 (vInfo != analysis.kNonNull);
189
190 if (isProfiling)
191 {
192 int whichCounter = 5;
193 if (!needCheck)
194 whichCounter = 6;
195
196 units.insertBefore(Jimple.v().newInvokeStmt(
197 Jimple.v().newStaticInvokeExpr(increase.makeRef(),
198 IntConstant.v(whichCounter))), s);
199 }
200
201 {
202 Tag nullTag = new NullCheckTag(needCheck);
203 s.addTag(nullTag);
204 }
205 }
206 }
207
208 Date finish = new Date();
209 if (Options.v().verbose())
210 {
211 long runtime = finish.getTime()-start.getTime();
212 long mins = runtime/60000;
213 long secs = (runtime%60000)/1000;
214 G.v().out.println("[npc] Null pointer checker finished. It took "
215 +mins+" mins and "+secs+" secs.");
216 }
217 }
218 }
219 }
220 |
Popular Tags |
Java API By Example, From Geeks To Geeks.