java/java-impl/src/com/intellij/codeInspection/dataFlow/instructions/DupInstruction.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   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.intellij.codeInspection.dataFlow.instructions;
  17
  18 import com.intellij.codeInspection.dataFlow.DataFlowRunner;
  19 import com.intellij.codeInspection.dataFlow.DfaInstructionState;
  20 import com.intellij.codeInspection.dataFlow.DfaMemoryState;
  21 import com.intellij.codeInspection.dataFlow.InstructionVisitor;
  22 import com.intellij.codeInspection.dataFlow.value.DfaValue;
  23
  24 /**
  25  * @author max
  26  */
  27 public class DupInstruction extends Instruction {
  28
  29   @Override
  30   public DfaInstructionState[] accept(DataFlowRunner runner, DfaMemoryState memState, InstructionVisitor visitor) {
  31     final DfaValue a = memState.pop();
  32     memState.push(a);
  33     memState.push(a);
  34     Instruction nextInstruction = runner.getInstruction(getIndex() + 1);
  35     return new DfaInstructionState[]{new DfaInstructionState(nextInstruction, memState)};
  36   }
  37
  38   public String toString() {
  39     return "DUP";
  40   }
  41 }