IFNONNULL.java example

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VarexJ-master
//
// Copyright (C) 2006 United States Government as represented by the
// Administrator of the National Aeronautics and Space Administration
// (NASA).  All Rights Reserved.
// 
// This software is distributed under the NASA Open Source Agreement
// (NOSA), version 1.3.  The NOSA has been approved by the Open Source
// Initiative.  See the file NOSA-1.3-JPF at the top of the distribution
// directory tree for the complete NOSA document.
// 
// THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
// KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
// LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
// SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
// A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
// THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
// DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
//
package gov.nasa.jpf.jvm.bytecode;

import cmu.conditional.Conditional;
import java.util.function.Function;
import cmu.conditional.One;
import de.fosd.typechef.featureexpr.FeatureExpr;
import gov.nasa.jpf.vm.MJIEnv;
import gov.nasa.jpf.vm.StackFrame;


/**
 * Branch if reference not null
 * ..., value => ..., result
 */
public class IFNONNULL extends IfInstruction {

  public IFNONNULL(int targetPc) {
    super(targetPc);
  }

  private final static Function<Integer, Conditional<Boolean>> IFNONNULL_ = new Function<Integer, Conditional<Boolean>>() {
	  public Conditional<Boolean> apply(Integer x) {
		  return One.valueOf(x.intValue() != MJIEnv.NULL);
	  }
  };

  public Conditional<Boolean> popConditionValue (FeatureExpr ctx, StackFrame frame) {
		return frame.pop(ctx).mapr(IFNONNULL_).simplifyValues();
  }

  public int getByteCode () {
    return 0xC7;
  }
  
  public void accept(InstructionVisitor insVisitor) {
	  insVisitor.visit(this);
  }
}