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.rop.code.RegisterSpecList;
  import com.taobao.android.dx.rop.code.SourcePosition;
  import com.taobao.android.dx.rop.cst.Constant;
  
  /**
   * Instruction which has a single constant argument in addition
   * to all the normal instruction information.
   */
  public final class CstInsn extends FixedSizeInsn {
      /** {@code non-null;} the constant argument for this instruction */
      private final Constant constant;
  
      /**
       * {@code >= -1;} the constant pool index for {@link #constant}, or
       * {@code -1} if not yet set
       */
      private int index;
  
      /**
       * {@code >= -1;} the constant pool index for the class reference in
       * {@link #constant} if any, or {@code -1} if not yet set
       */
      private int classIndex;
  
      /**
       * Constructs an instance. The output address of this instance is
       * initially unknown ({@code -1}) as is the constant pool index.
       *
       * @param opcode the opcode; one of the constants from {@link Dops}
       * @param position {@code non-null;} source position
       * @param registers {@code non-null;} register list, including a
       * result register if appropriate (that is, registers may be either
       * ins or outs)
       * @param constant {@code non-null;} constant argument
       */
      public CstInsn(Dop opcode, SourcePosition position,
                     RegisterSpecList registers, Constant constant) {
          super(opcode, position, registers);
  
          if (constant == null) {
              throw new NullPointerException("constant == null");
          }
  
          this.constant = constant;
          this.index = -1;
          this.classIndex = -1;
      }
  
      /** {@inheritDoc} */
      @Override
      public DalvInsn withOpcode(Dop opcode) {
          CstInsn result =
              new CstInsn(opcode, getPosition(), getRegisters(), constant);
  
          if (index >= 0) {
              result.setIndex(index);
          }
  
          if (classIndex >= 0) {
              result.setClassIndex(classIndex);
          }
  
          return result;
      }
  
      /** {@inheritDoc} */
      @Override
      public DalvInsn withRegisters(RegisterSpecList registers) {
          CstInsn result =
              new CstInsn(getOpcode(), getPosition(), registers, constant);
  
          if (index >= 0) {
              result.setIndex(index);
          }
  
          if (classIndex >= 0) {
              result.setClassIndex(classIndex);
          }
  
          return result;
      }
  
      /**
       * Gets the constant argument.
       *
       * @return {@code non-null;} the constant argument
       */
      public Constant getConstant() {
          return constant;
      }
  
      /**
       * Gets the constant's index. It is only valid to call this after
       * {@link #setIndex} has been called.
       *
       * @return {@code >= 0;} the constant pool index
       */
      public int getIndex() {
          if (index < 0) {
              throw new RuntimeException("index not yet set for " + constant);
          }
  
          return index;
      }
  
      /**
       * Returns whether the constant's index has been set for this instance.
       *
       * @see #setIndex
       *
       * @return {@code true} iff the index has been set
       */
      public boolean hasIndex() {
          return (index >= 0);
      }
  
      /**
       * Sets the constant's index. It is only valid to call this method once
       * per instance.
       *
       * @param index {@code >= 0;} the constant pool index
       */
      public void setIndex(int index) {
          if (index < 0) {
              throw new IllegalArgumentException("index < 0");
          }
  
          if (this.index >= 0) {
              throw new RuntimeException("index already set");
          }
  
          this.index = index;
      }
  
      /**
       * Gets the constant's class index. It is only valid to call this after
       * {@link #setClassIndex} has been called.
       *
       * @return {@code >= 0;} the constant's class's constant pool index
       */
      public int getClassIndex() {
          if (classIndex < 0) {
              throw new RuntimeException("class index not yet set");
          }
  
          return classIndex;
      }
  
      /**
       * Returns whether the constant's class index has been set for this
       * instance.
       *
       * @see #setClassIndex
       *
       * @return {@code true} iff the index has been set
       */
      public boolean hasClassIndex() {
          return (classIndex >= 0);
      }
  
      /**
       * Sets the constant's class index. This is the constant pool index
       * for the class referred to by this instance's constant. Only
       * reference constants have a class, so it is only on instances
       * with reference constants that this method should ever be
       * called. It is only valid to call this method once per instance.
       *
       * @param index {@code >= 0;} the constant's class's constant pool index
       */
      public void setClassIndex(int index) {
          if (index < 0) {
              throw new IllegalArgumentException("index < 0");
          }
  
          if (this.classIndex >= 0) {
              throw new RuntimeException("class index already set");
          }
  
          this.classIndex = index;
      }
  
      /** {@inheritDoc} */
      @Override
      protected String argString() {
          return constant.toHuman();
      }
  }
  