content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * 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 com.taobao.android.dx.dex.code;
  
  import com.taobao.android.dx.io.Opcodes;
  import com.taobao.android.dx.rop.code.RegisterSpecList;
  import com.taobao.android.dx.rop.code.SourcePosition;
  import com.taobao.android.dx.util.AnnotatedOutput;
  
  /**
   * Pseudo-instruction which either turns into a {@code nop} or
   * nothingness, in order to make the subsequent instruction have an
   * even address. This is used to align (subsequent) instructions that
   * require it.
   */
  public final class OddSpacer extends VariableSizeInsn {
      /**
       * Constructs an instance. The output address of this instance is initially
       * unknown ({@code -1}).
       *
       * @param position {@code non-null;} source position
       */
      public OddSpacer(SourcePosition position) {
          super(position, RegisterSpecList.EMPTY);
      }
  
      /** {@inheritDoc} */
      @Override
      public int codeSize() {
          return (getAddress() & 1);
      }
  
      /** {@inheritDoc} */
      @Override
      public void writeTo(AnnotatedOutput out) {
          if (codeSize() != 0) {
              out.writeShort(InsnFormat.codeUnit(Opcodes.NOP, 0));
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public DalvInsn withRegisters(RegisterSpecList registers) {
          return new OddSpacer(getPosition());
      }
  
      /** {@inheritDoc} */
      @Override
      protected String argString() {
          return null;
      }
  
      /** {@inheritDoc} */
      @Override
      protected String listingString0(boolean noteIndices) {
          if (codeSize() == 0) {
              return null;
          }
  
          return "nop // spacer";
      }
  }
  