1 /***
2 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
3 */
4 package net.sourceforge.pmd.rules.design;
5
6 import net.sourceforge.pmd.AbstractRule;
7 import net.sourceforge.pmd.RuleContext;
8 import net.sourceforge.pmd.ast.ASTAssignmentOperator;
9 import net.sourceforge.pmd.ast.ASTNullLiteral;
10 import net.sourceforge.pmd.ast.ASTStatementExpression;
11 import net.sourceforge.pmd.ast.SimpleNode;
12
13 public class NullAssignmentRule extends AbstractRule {
14
15 public Object visit(ASTStatementExpression expr, Object data) {
16 if (expr.jjtGetNumChildren() <= 2) {
17 return expr.childrenAccept(this, data);
18 }
19
20 if (expr.jjtGetChild(1) instanceof ASTAssignmentOperator) {
21 SimpleNode curr = (SimpleNode) expr.jjtGetChild(2);
22 for (int i = 0; i < 8; i++) {
23 if (curr.jjtGetNumChildren() != 0) {
24 curr = (SimpleNode) curr.jjtGetChild(0);
25 }
26 }
27
28 if (curr instanceof ASTNullLiteral) {
29 RuleContext ctx = (RuleContext) data;
30 ctx.getReport().addRuleViolation(createRuleViolation(ctx, expr));
31 }
32
33 return data;
34 } else {
35 return expr.childrenAccept(this, data);
36 }
37 }
38 }