/*
 * Copyright (C) 2014, United States Government, as represented by the
 * Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 *
 * The Java Pathfinder core (jpf-core) platform is licensed under the
 * Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 *        http://www.apache.org/licenses/LICENSE-2.0. 
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and 
 * limitations under the License.
 */
package gov.nasa.jpf.jvm.bytecode;

import gov.nasa.jpf.vm.bytecode.NewInstruction;
import gov.nasa.jpf.vm.ClassInfo;
import gov.nasa.jpf.vm.ElementInfo;
import gov.nasa.jpf.vm.Heap;
import gov.nasa.jpf.vm.Instruction;
import gov.nasa.jpf.vm.LoadOnJPFRequired;
import gov.nasa.jpf.vm.MJIEnv;
import gov.nasa.jpf.vm.StackFrame;
import gov.nasa.jpf.vm.ThreadInfo;
import gov.nasa.jpf.vm.Types;


/**
 * Create new object
 * ... => ..., objectref
 */
public class NEW extends NewInstruction implements JVMInstruction  {
  protected String cname;
  protected int newObjRef = MJIEnv.NULL;

  public NEW (String clsDescriptor){
    cname = Types.getClassNameFromTypeName(clsDescriptor);
  }
  
  public String getClassName(){    // Needed for Java Race Finder
    return(cname);
  }

  @Override
  public Instruction execute (ThreadInfo ti) {
    Heap heap = ti.getHeap();
    ClassInfo ci;

    // resolve the referenced class
    try {
      ci = ti.resolveReferencedClass(cname);
    } catch(LoadOnJPFRequired lre) {
      return ti.getPC();
    }

    if (!ci.isRegistered()){
      ci.registerClass(ti);
    }

    // we might have to execute clinits
      if (ci.initializeClass(ti)) {
        // continue with the topframe and re-exec this insn once the clinits are done
        return ti.getPC();
      }

    if (heap.isOutOfMemory()) { // simulate OutOfMemoryError
      return ti.createAndThrowException("java.lang.OutOfMemoryError",
                                        "trying to allocate new " + cname);
    }

    ElementInfo ei = heap.newObject(ci, ti);
    int objRef = ei.getObjectRef();
    newObjRef = objRef;

    // pushes the return value onto the stack
    StackFrame frame = ti.getModifiableTopFrame();
    frame.pushRef( objRef);

    return getNext(ti);
  }

  @Override
  public int getLength() {
    return 3; // opcode, index1, index2
  }

  @Override
  public int getByteCode () {
    return 0xBB;
  }
  
  @Override
  public void accept(JVMInstructionVisitor insVisitor) {
	  insVisitor.visit(this);
  }

  public int getNewObjectRef() {
    return newObjRef;
  }

  @Override
  public String toString() {
    if (newObjRef != MJIEnv.NULL){
      return "new " + cname + '@' + Integer.toHexString(newObjRef);

    } else {
      return "new " + cname;
    }
  }
}