inspections/impl/com/intellij/codeInspection/dataFlow/instructions/FieldReferenceInstruction.java

   1 package com.intellij.codeInspection.dataFlow.instructions;
   2
   3 import com.intellij.codeInspection.dataFlow.DataFlowRunner;
   4 import com.intellij.codeInspection.dataFlow.DfaInstructionState;
   5 import com.intellij.codeInspection.dataFlow.DfaMemoryState;
   6 import com.intellij.codeInspection.dataFlow.InstructionVisitor;
   7 import com.intellij.codeInspection.dataFlow.value.DfaValue;
   8 import com.intellij.psi.PsiArrayAccessExpression;
   9 import com.intellij.psi.PsiExpression;
  10 import com.intellij.psi.PsiReferenceExpression;
  11 import org.jetbrains.annotations.NonNls;
  12 import org.jetbrains.annotations.Nullable;
  13
  14 /**
  15  * @author max
  16  */
  17 public class FieldReferenceInstruction extends Instruction {
  18   private final PsiExpression myExpression;
  19   private final boolean myIsPhysical;
  20   @Nullable private final String mySyntheticFieldName;
  21
  22   public FieldReferenceInstruction(PsiExpression expression, @Nullable @NonNls String syntheticFieldName) {
  23     myExpression = expression;
  24     myIsPhysical = expression.isPhysical();
  25     mySyntheticFieldName = syntheticFieldName;
  26   }
  27
  28   @Override
  29   public DfaInstructionState[] accept(DataFlowRunner runner, DfaMemoryState stateBefore, InstructionVisitor visitor) {
  30     return visitor.visitFieldReference(this, runner, stateBefore);
  31   }
  32
  33   public DfaInstructionState[] apply(DataFlowRunner runner, DfaMemoryState memState) {
  34     final DfaValue qualifier = memState.pop();
  35     if (myIsPhysical && !memState.applyNotNull(qualifier)) {
  36       onInstructionProducesNPE(runner);
  37       return DfaInstructionState.EMPTY_ARRAY;
  38     }
  39
  40     return new DfaInstructionState[]{new DfaInstructionState(runner.getInstruction(getIndex() + 1), memState)};
  41   }
  42
  43   protected void onInstructionProducesNPE(final DataFlowRunner runner) {
  44
  45   }
  46
  47   public String toString() {
  48     return "FIELD_REFERENCE: " + myExpression.getText();
  49   }
  50
  51   public PsiExpression getExpression() { return myExpression; }
  52
  53   public PsiExpression getElementToAssert() {
  54     if (mySyntheticFieldName != null) return myExpression;
  55     return myExpression instanceof PsiArrayAccessExpression
  56            ? ((PsiArrayAccessExpression)myExpression).getArrayExpression()
  57            : ((PsiReferenceExpression)myExpression).getQualifierExpression();
  58   }
  59 }