// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
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// modification, are permitted provided that the following conditions
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//    notice, this list of conditions and the following disclaimer.
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//    notice, this list of conditions and the following disclaimer in the
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//    this software without specific prior written permission.
//
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package scala.tools.asm.tree;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import scala.tools.asm.MethodVisitor;

/**
 * A node that represents a bytecode instruction. <i>An instruction can appear at most once in at
 * most one {@link InsnList} at a time</i>.
 *
 * @author Eric Bruneton
 */
public abstract class AbstractInsnNode {

  /** The type of {@link InsnNode} instructions. */
  public static final int INSN = 0;

  /** The type of {@link IntInsnNode} instructions. */
  public static final int INT_INSN = 1;

  /** The type of {@link VarInsnNode} instructions. */
  public static final int VAR_INSN = 2;

  /** The type of {@link TypeInsnNode} instructions. */
  public static final int TYPE_INSN = 3;

  /** The type of {@link FieldInsnNode} instructions. */
  public static final int FIELD_INSN = 4;

  /** The type of {@link MethodInsnNode} instructions. */
  public static final int METHOD_INSN = 5;

  /** The type of {@link InvokeDynamicInsnNode} instructions. */
  public static final int INVOKE_DYNAMIC_INSN = 6;

  /** The type of {@link JumpInsnNode} instructions. */
  public static final int JUMP_INSN = 7;

  /** The type of {@link LabelNode} "instructions". */
  public static final int LABEL = 8;

  /** The type of {@link LdcInsnNode} instructions. */
  public static final int LDC_INSN = 9;

  /** The type of {@link IincInsnNode} instructions. */
  public static final int IINC_INSN = 10;

  /** The type of {@link TableSwitchInsnNode} instructions. */
  public static final int TABLESWITCH_INSN = 11;

  /** The type of {@link LookupSwitchInsnNode} instructions. */
  public static final int LOOKUPSWITCH_INSN = 12;

  /** The type of {@link MultiANewArrayInsnNode} instructions. */
  public static final int MULTIANEWARRAY_INSN = 13;

  /** The type of {@link FrameNode} "instructions". */
  public static final int FRAME = 14;

  /** The type of {@link LineNumberNode} "instructions". */
  public static final int LINE = 15;

  /**
   * The opcode of this instruction, or -1 if this is not a JVM instruction (e.g. a label or a line
   * number).
   */
  protected int opcode;

  /**
   * The runtime visible type annotations of this instruction. This field is only used for real
   * instructions (i.e. not for labels, frames, or line number nodes). This list is a list of {@link
   * TypeAnnotationNode} objects. May be {@literal null}.
   */
  public List<TypeAnnotationNode> visibleTypeAnnotations;

  /**
   * The runtime invisible type annotations of this instruction. This field is only used for real
   * instructions (i.e. not for labels, frames, or line number nodes). This list is a list of {@link
   * TypeAnnotationNode} objects. May be {@literal null}.
   */
  public List<TypeAnnotationNode> invisibleTypeAnnotations;

  /** The previous instruction in the list to which this instruction belongs. */
  AbstractInsnNode previousInsn;

  /** The next instruction in the list to which this instruction belongs. */
  AbstractInsnNode nextInsn;

  /**
   * The index of this instruction in the list to which it belongs. The value of this field is
   * correct only when {@link InsnList#cache} is not null. A value of -1 indicates that this
   * instruction does not belong to any {@link InsnList}.
   */
  int index;

  /**
   * Constructs a new {@link AbstractInsnNode}.
   *
   * @param opcode the opcode of the instruction to be constructed.
   */
  protected AbstractInsnNode(final int opcode) {
    this.opcode = opcode;
    this.index = -1;
  }

  /**
   * Returns the opcode of this instruction.
   *
   * @return the opcode of this instruction, or -1 if this is not a JVM instruction (e.g. a label or
   *     a line number).
   */
  public int getOpcode() {
    return opcode;
  }

  /**
   * Returns the type of this instruction.
   *
   * @return the type of this instruction, i.e. one the constants defined in this class.
   */
  public abstract int getType();

  /**
   * Returns the previous instruction in the list to which this instruction belongs, if any.
   *
   * @return the previous instruction in the list to which this instruction belongs, if any. May be
   *     {@literal null}.
   */
  public AbstractInsnNode getPrevious() {
    return previousInsn;
  }

  /**
   * Returns the next instruction in the list to which this instruction belongs, if any.
   *
   * @return the next instruction in the list to which this instruction belongs, if any. May be
   *     {@literal null}.
   */
  public AbstractInsnNode getNext() {
    return nextInsn;
  }

  /**
   * Makes the given method visitor visit this instruction.
   *
   * @param methodVisitor a method visitor.
   */
  public abstract void accept(MethodVisitor methodVisitor);

  /**
   * Makes the given visitor visit the annotations of this instruction.
   *
   * @param methodVisitor a method visitor.
   */
  protected final void acceptAnnotations(final MethodVisitor methodVisitor) {
    if (visibleTypeAnnotations != null) {
      for (int i = 0, n = visibleTypeAnnotations.size(); i < n; ++i) {
        TypeAnnotationNode typeAnnotation = visibleTypeAnnotations.get(i);
        typeAnnotation.accept(
            methodVisitor.visitInsnAnnotation(
                typeAnnotation.typeRef, typeAnnotation.typePath, typeAnnotation.desc, true));
      }
    }
    if (invisibleTypeAnnotations != null) {
      for (int i = 0, n = invisibleTypeAnnotations.size(); i < n; ++i) {
        TypeAnnotationNode typeAnnotation = invisibleTypeAnnotations.get(i);
        typeAnnotation.accept(
            methodVisitor.visitInsnAnnotation(
                typeAnnotation.typeRef, typeAnnotation.typePath, typeAnnotation.desc, false));
      }
    }
  }

  /**
   * Returns a copy of this instruction.
   *
   * @param clonedLabels a map from LabelNodes to cloned LabelNodes.
   * @return a copy of this instruction. The returned instruction does not belong to any {@link
   *     InsnList}.
   */
  public abstract AbstractInsnNode clone(Map<LabelNode, LabelNode> clonedLabels);

  /**
   * Returns the clone of the given label.
   *
   * @param label a label.
   * @param clonedLabels a map from LabelNodes to cloned LabelNodes.
   * @return the clone of the given label.
   */
  static LabelNode clone(final LabelNode label, final Map<LabelNode, LabelNode> clonedLabels) {
    return clonedLabels.get(label);
  }

  /**
   * Returns the clones of the given labels.
   *
   * @param labels a list of labels.
   * @param clonedLabels a map from LabelNodes to cloned LabelNodes.
   * @return the clones of the given labels.
   */
  static LabelNode[] clone(
      final List<LabelNode> labels, final Map<LabelNode, LabelNode> clonedLabels) {
    LabelNode[] clones = new LabelNode[labels.size()];
    for (int i = 0, n = clones.length; i < n; ++i) {
      clones[i] = clonedLabels.get(labels.get(i));
    }
    return clones;
  }

  /**
   * Clones the annotations of the given instruction into this instruction.
   *
   * @param insnNode the source instruction.
   * @return this instruction.
   */
  protected final AbstractInsnNode cloneAnnotations(final AbstractInsnNode insnNode) {
    if (insnNode.visibleTypeAnnotations != null) {
      this.visibleTypeAnnotations = new ArrayList<>();
      for (int i = 0, n = insnNode.visibleTypeAnnotations.size(); i < n; ++i) {
        TypeAnnotationNode sourceAnnotation = insnNode.visibleTypeAnnotations.get(i);
        TypeAnnotationNode cloneAnnotation =
            new TypeAnnotationNode(
                sourceAnnotation.typeRef, sourceAnnotation.typePath, sourceAnnotation.desc);
        sourceAnnotation.accept(cloneAnnotation);
        this.visibleTypeAnnotations.add(cloneAnnotation);
      }
    }
    if (insnNode.invisibleTypeAnnotations != null) {
      this.invisibleTypeAnnotations = new ArrayList<>();
      for (int i = 0, n = insnNode.invisibleTypeAnnotations.size(); i < n; ++i) {
        TypeAnnotationNode sourceAnnotation = insnNode.invisibleTypeAnnotations.get(i);
        TypeAnnotationNode cloneAnnotation =
            new TypeAnnotationNode(
                sourceAnnotation.typeRef, sourceAnnotation.typePath, sourceAnnotation.desc);
        sourceAnnotation.accept(cloneAnnotation);
        this.invisibleTypeAnnotations.add(cloneAnnotation);
      }
    }
    return this;
  }
}
