1 package net.sourceforge.pmd.lang.java.rule;
2
3 import java.util.HashMap;
4 import java.util.Iterator;
5 import java.util.Map;
6
7 import net.sourceforge.pmd.RuleContext;
8 import net.sourceforge.pmd.lang.dfa.DataFlowNode;
9 import net.sourceforge.pmd.lang.dfa.VariableAccess;
10 import net.sourceforge.pmd.lang.dfa.pathfinder.CurrentPath;
11 import net.sourceforge.pmd.lang.dfa.pathfinder.DAAPathFinder;
12 import net.sourceforge.pmd.lang.dfa.pathfinder.Executable;
13 import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
14
15
16 public class UselessAssignment extends AbstractJavaRule implements Executable {
17
18 private RuleContext rc;
19
20 public Object visit(ASTMethodDeclaration node, Object data) {
21 this.rc = (RuleContext) data;
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37 DAAPathFinder a = new DAAPathFinder(node.getDataFlowNode().getFlow().get(0), this);
38 a.run();
39
40 return data;
41 }
42
43 private static class Usage {
44 public int accessType;
45 public DataFlowNode node;
46
47 public Usage(int accessType, DataFlowNode node) {
48 this.accessType = accessType;
49 this.node = node;
50 }
51
52 public String toString() {
53 return "accessType = " + accessType + ", line = " + node.getLine();
54 }
55 }
56
57 public void execute(CurrentPath path) {
58 Map<String, Usage> hash = new HashMap<String, Usage>();
59
60 for (Iterator<DataFlowNode> i = path.iterator(); i.hasNext();) {
61
62 DataFlowNode inode = i.next();
63 if (inode.getVariableAccess() == null) {
64 continue;
65 }
66 for (int j = 0; j < inode.getVariableAccess().size(); j++) {
67 VariableAccess va = inode.getVariableAccess().get(j);
68
69 Usage u = hash.get(va.getVariableName());
70 if (u != null) {
71
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74
75
76 if (va.isDefinition() && va.accessTypeMatches(u.accessType)) {
77
78 addViolation(rc, u.node.getNode(), va.getVariableName());
79 }
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92 }
93 u = new Usage(va.getAccessType(), inode);
94 hash.put(va.getVariableName(), u);
95 }
96 }
97 }
98 }