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1   /**
2    * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
3    */
4   package net.sourceforge.pmd.symboltable;
5   
6   import net.sourceforge.pmd.ast.ASTAssignmentOperator;
7   import net.sourceforge.pmd.ast.ASTExpression;
8   import net.sourceforge.pmd.ast.ASTName;
9   import net.sourceforge.pmd.ast.ASTPostfixExpression;
10  import net.sourceforge.pmd.ast.ASTPreDecrementExpression;
11  import net.sourceforge.pmd.ast.ASTPreIncrementExpression;
12  import net.sourceforge.pmd.ast.ASTPrimaryExpression;
13  import net.sourceforge.pmd.ast.ASTPrimaryPrefix;
14  import net.sourceforge.pmd.ast.ASTStatementExpression;
15  import net.sourceforge.pmd.ast.Node;
16  import net.sourceforge.pmd.ast.SimpleNode;
17  
18  public class NameOccurrence {
19  
20      private SimpleNode location;
21      private String image;
22      private NameOccurrence qualifiedName;
23  
24      private boolean isMethodOrConstructorInvocation;
25      private int argumentCount;
26  
27      private final static String THIS = "this";
28      private final static String SUPER = "super";
29  
30      private final static String THIS_DOT = "this.";
31      private final static String SUPER_DOT = "super.";
32  
33      public NameOccurrence(SimpleNode location, String image) {
34          this.location = location;
35          this.image = image;
36      }
37  
38      public void setIsMethodOrConstructorInvocation() {
39          isMethodOrConstructorInvocation = true;
40      }
41  
42      public void setArgumentCount(int count) {
43          argumentCount = count;
44      }
45  
46      public int getArgumentCount() {
47          return argumentCount;
48      }
49  
50      public boolean isMethodOrConstructorInvocation() {
51          return isMethodOrConstructorInvocation;
52      }
53  
54      public void setNameWhichThisQualifies(NameOccurrence qualifiedName) {
55          this.qualifiedName = qualifiedName;
56      }
57  
58      public NameOccurrence getNameForWhichThisIsAQualifier() {
59          return qualifiedName;
60      }
61  
62      public boolean isPartOfQualifiedName() {
63          return qualifiedName != null;
64      }
65  
66      public SimpleNode getLocation() {
67          return location;
68      }
69  
70      public boolean isOnRightHandSide() {
71          SimpleNode node = (SimpleNode) location.jjtGetParent().jjtGetParent().jjtGetParent();
72          return node instanceof ASTExpression && node.jjtGetNumChildren() == 3;
73      }
74  
75  
76      public boolean isOnLeftHandSide() {
77          // I detest this method with every atom of my being
78          SimpleNode primaryExpression;
79          if (location.jjtGetParent() instanceof ASTPrimaryExpression) {
80              primaryExpression = (SimpleNode) location.jjtGetParent().jjtGetParent();
81          } else if (location.jjtGetParent().jjtGetParent() instanceof ASTPrimaryExpression) {
82              primaryExpression = (SimpleNode) location.jjtGetParent().jjtGetParent().jjtGetParent();
83          } else {
84              throw new RuntimeException("Found a NameOccurrence that didn't have an ASTPrimary Expression as parent or grandparent.  Parent = " + location.jjtGetParent() + " and grandparent = " + location.jjtGetParent().jjtGetParent());
85          }
86  
87          if (isStandAlonePostfix(primaryExpression)) {
88              return true;
89          }
90  
91          if (primaryExpression.jjtGetNumChildren() <= 1) {
92              return false;
93          }
94  
95          if (!(primaryExpression.jjtGetChild(1) instanceof ASTAssignmentOperator)) {
96              return false;
97          }
98  
99          if (isPartOfQualifiedName() /* or is an array type */) {
100             return false;
101         }
102 
103         if (isCompoundAssignment(primaryExpression)) {
104             return false;
105         }
106 
107         return true;
108     }
109 
110     private boolean isCompoundAssignment(SimpleNode primaryExpression) {
111         return ((ASTAssignmentOperator) (primaryExpression.jjtGetChild(1))).isCompound();
112     }
113 
114     private boolean isStandAlonePostfix(SimpleNode primaryExpression) {
115         if (!(primaryExpression instanceof ASTPostfixExpression) || !(primaryExpression.jjtGetParent() instanceof ASTStatementExpression)) {
116             return false;
117         }
118 
119         ASTPrimaryPrefix pf = (ASTPrimaryPrefix) ((ASTPrimaryExpression) primaryExpression.jjtGetChild(0)).jjtGetChild(0);
120         if (pf.usesThisModifier()) {
121             return true;
122         }
123 
124         return thirdChildHasDottedName(primaryExpression);
125     }
126 
127     private boolean thirdChildHasDottedName(SimpleNode primaryExpression) {
128         Node thirdChild = primaryExpression.jjtGetChild(0).jjtGetChild(0).jjtGetChild(0);
129         return thirdChild instanceof ASTName && ((ASTName) thirdChild).getImage().indexOf('.') == -1;
130     }
131 
132     /**
133      * Assert it the occurrence is a self assignment such as:
134      * <code>
135      * 		i += 3;
136      * </code>
137      *
138      * @return true, if the occurrence is self-assignment, false, otherwise.
139      */
140     public boolean isSelfAssignment() {
141         Node l = location;
142         while (true) {
143             Node p = l.jjtGetParent();
144             Node gp = p.jjtGetParent();
145             Node node = gp.jjtGetParent();
146             if (node instanceof ASTPreDecrementExpression || node instanceof ASTPreIncrementExpression || node instanceof ASTPostfixExpression) {
147                 return true;
148             }
149 
150             if (node instanceof ASTStatementExpression) {
151                 ASTStatementExpression exp = (ASTStatementExpression) node;
152                 if (exp.jjtGetNumChildren() >= 2 && exp.jjtGetChild(1) instanceof ASTAssignmentOperator) {
153                     ASTAssignmentOperator op = (ASTAssignmentOperator) exp.jjtGetChild(1);
154                     if (op.isCompound()) {
155                         return true;
156                     }
157                 }
158             }
159 
160             // deal with extra parenthesis: "(i)++"
161             if (p instanceof ASTPrimaryPrefix && p.jjtGetNumChildren() == 1 &&
162                     gp instanceof ASTPrimaryExpression && gp.jjtGetNumChildren() == 1&&
163                     node instanceof ASTExpression && node.jjtGetNumChildren() == 1 &&
164                     node.jjtGetParent() instanceof ASTPrimaryPrefix && node.jjtGetParent().jjtGetNumChildren() == 1) {
165                 l = node;
166                 continue;
167             }
168 
169             // catch this.i++ or ++this.i
170             if (gp instanceof ASTPreDecrementExpression || gp instanceof ASTPreIncrementExpression || gp instanceof ASTPostfixExpression) {
171                 return true;
172             }
173 
174             return false;
175         }
176     }
177 
178     /**
179      * Simply return true is the image is equal to keyword 'this' or 'super'.
180      *
181      * @return return true if image equal to 'this' or 'super'.
182      */
183     public boolean isThisOrSuper() {
184         return image.equals(THIS) || image.equals(SUPER);
185     }
186 
187     /**
188      * Simply return if the image start with keyword 'this' or 'super'.
189      *
190      * @return true, if keyword is used, false otherwise.
191      */
192     public boolean useThisOrSuper() {
193 		Node node = location.jjtGetParent();
194 		if ( node instanceof ASTPrimaryExpression ) {
195 			ASTPrimaryExpression primaryExpression = (ASTPrimaryExpression)node;
196 			ASTPrimaryPrefix prefix = primaryExpression.getFirstChildOfType(ASTPrimaryPrefix.class);
197 			if ( prefix != null )
198 				return (prefix.usesSuperModifier() || prefix.usesThisModifier());
199 		}
200     	return image.startsWith(THIS_DOT) || image.startsWith(SUPER_DOT);
201     }
202 
203     @Override
204     public boolean equals(Object o) {
205         NameOccurrence n = (NameOccurrence) o;
206         return n.getImage().equals(getImage());
207     }
208 
209     @Override
210     public int hashCode() {
211         return getImage().hashCode();
212     }
213 
214     public String getImage() {
215         return image;
216     }
217 
218     @Override
219     public String toString() {
220         return getImage() + ":" + location.getBeginLine() + ":" + location.getClass() + (this.isMethodOrConstructorInvocation() ? "(method call)" : "");
221     }
222 }