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1 package olhotak.liveness;
2
3 import soot.*;
4 import soot.util.*;
5 import java.util.*;
6 import soot.jimple.*;
7 import soot.toolkits.graph.*;
8 import soot.toolkits.scalar.*;
9
10 class LiveVariablesAnalysis extends BackwardFlowAnalysis
11 {
12 protected void copy(Object  src, Object dest)
13 {
14 FlowSet srcSet = (FlowSet) src;
15 FlowSet destSet = (FlowSet) dest;
16
17 srcSet.copy(destSet);
18 }
19
20 protected void merge(Object src1, Object src2, Object dest)
21 {
22 FlowSet srcSet1 = (FlowSet) src1;
23 FlowSet srcSet2 = (FlowSet) src2;
24 FlowSet destSet = (FlowSet) dest;
25
26 srcSet1.union(srcSet2, destSet);
27 }
28
29 protected void flowThrough(Object srcValue, Object unit,
30 Object destValue)
31 {
32 FlowSet dest = (FlowSet) destValue;
33 FlowSet src = (FlowSet) srcValue;
34 Unit s = (Unit) unit;
35 src.copy (dest);
36
37 Iterator boxIt = s.getDefBoxes().iterator();
39 while (boxIt.hasNext()) {
40 ValueBox box = (ValueBox) boxIt.next();
41 Value value = box.getValue();
42 if (value instanceof Local)
43 dest.remove(value);
44 }
45
46 boxIt = s.getUseBoxes().iterator();
48 while (boxIt.hasNext()) {
49 ValueBox box = (ValueBox) boxIt.next();
50 Value value = box.getValue();
51 if (value instanceof Local)
52 dest.add(value);
53 }
54 }
55
56 protected Object entryInitialFlow()
57 {
58 return new ArraySparseSet();
59 }
60
61 protected Object newInitialFlow()
62 {
63 return new ArraySparseSet();
64 }
65
66 LiveVariablesAnalysis(DirectedGraph g)
67 {
68 super(g);
69
70 doAnalysis();
71 }
72 }
73 |
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