plugins/InspectionGadgets/src/com/siyeh/ig/psiutils/VariableAssignedVisitor.java

   1 /*
   2  * Copyright 2003-2008 Dave Griffith, Bas Leijdekkers
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.siyeh.ig.psiutils;
  17
  18 import com.intellij.psi.*;
  19 import com.intellij.psi.tree.IElementType;
  20 import org.jetbrains.annotations.NotNull;
  21
  22 public class VariableAssignedVisitor extends JavaRecursiveElementVisitor{
  23
  24     @NotNull private final PsiVariable variable;
  25     private final boolean recurseIntoClasses;
  26     private boolean assigned = false;
  27
  28     public VariableAssignedVisitor(@NotNull PsiVariable variable,
  29                                    boolean recurseIntoClasses){
  30         super();
  31         this.variable = variable;
  32         this.recurseIntoClasses = recurseIntoClasses;
  33     }
  34
  35     @Override public void visitElement(@NotNull PsiElement element){
  36         if(!assigned){
  37             super.visitElement(element);
  38         }
  39     }
  40
  41     @Override public void visitAssignmentExpression(
  42             @NotNull PsiAssignmentExpression assignment){
  43         if(assigned){
  44             return;
  45         }
  46         super.visitAssignmentExpression(assignment);
  47         final PsiExpression arg = assignment.getLExpression();
  48         if(VariableAccessUtils.mayEvaluateToVariable(arg, variable)){
  49             assigned = true;
  50         }
  51     }
  52
  53     @Override
  54     public void visitClass(PsiClass aClass) {
  55         if(!recurseIntoClasses){
  56             return;
  57         }
  58         if(assigned){
  59             return;
  60         }
  61         super.visitClass(aClass);
  62     }
  63
  64     @Override public void visitPrefixExpression(
  65             @NotNull PsiPrefixExpression prefixExpression){
  66         if(assigned){
  67             return;
  68         }
  69         super.visitPrefixExpression(prefixExpression);
  70         final PsiJavaToken operationSign = prefixExpression.getOperationSign();
  71         final IElementType tokenType = operationSign.getTokenType();
  72         if(!tokenType.equals(JavaTokenType.PLUSPLUS) &&
  73                    !tokenType.equals(JavaTokenType.MINUSMINUS)){
  74             return;
  75         }
  76         final PsiExpression operand = prefixExpression.getOperand();
  77         if(VariableAccessUtils.mayEvaluateToVariable(operand, variable)){
  78             assigned = true;
  79         }
  80     }
  81
  82     @Override public void visitPostfixExpression(
  83             @NotNull PsiPostfixExpression postfixExpression){
  84         if(assigned){
  85             return;
  86         }
  87         super.visitPostfixExpression(postfixExpression);
  88         final PsiJavaToken operationSign = postfixExpression.getOperationSign();
  89         final IElementType tokenType = operationSign.getTokenType();
  90         if(!tokenType.equals(JavaTokenType.PLUSPLUS) &&
  91                    !tokenType.equals(JavaTokenType.MINUSMINUS)){
  92             return;
  93         }
  94         final PsiExpression operand = postfixExpression.getOperand();
  95         if(VariableAccessUtils.mayEvaluateToVariable(operand, variable)){
  96             assigned = true;
  97         }
  98     }
  99
 100     public boolean isAssigned(){
 101         return assigned;
 102     }
 103 }