content: // ASM: a very small and fast Java bytecode manipulation framework
  // Copyright (c) 2000-2011 INRIA, France Telecom
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  package com.alibaba.nacos.common.packagescan.classreading;
  
  /**
   * Copy from ASM, with less modifications
   * An entry of the constant pool, of the BootstrapMethods attribute, or of the (ASM specific) type
   * table of a class.
   *
   * @author Eric Bruneton
   * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.4">JVMS
   * 4.4</a>
   * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.23">JVMS
   * 4.7.23</a>
   */
  abstract class Symbol {
  
      /**
       * The tag value of CONSTANT_Class_info JVMS structures.
       */
      static final int CONSTANT_CLASS_TAG = 7;
  
      /**
       * The tag value of CONSTANT_Fieldref_info JVMS structures.
       */
      static final int CONSTANT_FIELDREF_TAG = 9;
  
      /**
       * The tag value of CONSTANT_Methodref_info JVMS structures.
       */
      static final int CONSTANT_METHODREF_TAG = 10;
  
      /**
       * The tag value of CONSTANT_InterfaceMethodref_info JVMS structures.
       */
      static final int CONSTANT_INTERFACE_METHODREF_TAG = 11;
  
      /**
       * The tag value of CONSTANT_String_info JVMS structures.
       */
      static final int CONSTANT_STRING_TAG = 8;
  
      /**
       * The tag value of CONSTANT_Integer_info JVMS structures.
       */
      static final int CONSTANT_INTEGER_TAG = 3;
  
      /**
       * The tag value of CONSTANT_Float_info JVMS structures.
       */
      static final int CONSTANT_FLOAT_TAG = 4;
  
      /**
       * The tag value of CONSTANT_Long_info JVMS structures.
       */
      static final int CONSTANT_LONG_TAG = 5;
  
      /**
       * The tag value of CONSTANT_Double_info JVMS structures.
       */
      static final int CONSTANT_DOUBLE_TAG = 6;
  
      /**
       * The tag value of CONSTANT_NameAndType_info JVMS structures.
       */
      static final int CONSTANT_NAME_AND_TYPE_TAG = 12;
  
      /**
       * The tag value of CONSTANT_Utf8_info JVMS structures.
       */
      static final int CONSTANT_UTF8_TAG = 1;
  
      /**
       * The tag value of CONSTANT_MethodHandle_info JVMS structures.
       */
      static final int CONSTANT_METHOD_HANDLE_TAG = 15;
  
      /**
       * The tag value of CONSTANT_MethodType_info JVMS structures.
       */
      static final int CONSTANT_METHOD_TYPE_TAG = 16;
  
      /**
       * The tag value of CONSTANT_Dynamic_info JVMS structures.
       */
      static final int CONSTANT_DYNAMIC_TAG = 17;
  
      /**
       * The tag value of CONSTANT_InvokeDynamic_info JVMS structures.
       */
      static final int CONSTANT_INVOKE_DYNAMIC_TAG = 18;
  
      /**
       * The tag value of CONSTANT_Module_info JVMS structures.
       */
      static final int CONSTANT_MODULE_TAG = 19;
  
      /**
       * The tag value of CONSTANT_Package_info JVMS structures.
       */
      static final int CONSTANT_PACKAGE_TAG = 20;
  
      // Tag values for the BootstrapMethods attribute entries (ASM specific tag).
  
      /**
       * The tag value of the BootstrapMethods attribute entries.
       */
      static final int BOOTSTRAP_METHOD_TAG = 64;
  
      // Tag values for the type table entries (ASM specific tags).
  
      /**
       * The tag value of a normal type entry in the (ASM specific) type table of a class.
       */
      static final int TYPE_TAG = 128;
  
      static final int UNINITIALIZED_TYPE_TAG = 129;
  
      /**
       * The tag value of a merged type entry in the (ASM specific) type table of a class.
       */
      static final int MERGED_TYPE_TAG = 130;
  
      // Instance fields.
  
      /**
       * The index of this symbol in the constant pool, in the BootstrapMethods attribute, or in the
       * (ASM specific) type table of a class (depending on the {@link #tag} value).
       */
      final int index;
  
      /**
       * A tag indicating the type of this symbol. Must be one of the static tag values defined in this
       * class.
       */
      final int tag;
  
      /**
       * The internal name of the owner class of this symbol. Only used for {@link
       * #CONSTANT_FIELDREF_TAG}, {@link #CONSTANT_METHODREF_TAG}, {@link
       * #CONSTANT_INTERFACE_METHODREF_TAG}, and {@link #CONSTANT_METHOD_HANDLE_TAG} symbols.
       */
      final String owner;
  
      /**
       * The name of the class field or method corresponding to this symbol. Only used for {@link
       * #CONSTANT_FIELDREF_TAG}, {@link #CONSTANT_METHODREF_TAG}, {@link
       * #CONSTANT_INTERFACE_METHODREF_TAG}, {@link #CONSTANT_NAME_AND_TYPE_TAG}, {@link
       * #CONSTANT_METHOD_HANDLE_TAG}, {@link #CONSTANT_DYNAMIC_TAG} and {@link
       * #CONSTANT_INVOKE_DYNAMIC_TAG} symbols.
       */
      final String name;
  
      /**
       * The string value of this symbol. This is:
       *
       * <ul>
       *   <li>a field or method descriptor for {@link #CONSTANT_FIELDREF_TAG}, {@link
       *       #CONSTANT_METHODREF_TAG}, {@link #CONSTANT_INTERFACE_METHODREF_TAG}, {@link
       *       #CONSTANT_NAME_AND_TYPE_TAG}, {@link #CONSTANT_METHOD_HANDLE_TAG}, {@link
       *       #CONSTANT_METHOD_TYPE_TAG}, {@link #CONSTANT_DYNAMIC_TAG} and {@link
       *       #CONSTANT_INVOKE_DYNAMIC_TAG} symbols,
       *   <li>an arbitrary string for {@link #CONSTANT_UTF8_TAG} and {@link #CONSTANT_STRING_TAG}
       *       symbols,
       *   <li>an internal class name for {@link #CONSTANT_CLASS_TAG}, {@link #TYPE_TAG} and {@link
       *       #UNINITIALIZED_TYPE_TAG} symbols,
       *   <li>{@literal null} for the other types of symbol.
       * </ul>
       */
      final String value;
  
      /**
       * The numeric value of this symbol. This is:
       *
       * <ul>
       *   <li>the symbol's value for {@link #CONSTANT_INTEGER_TAG},{@link #CONSTANT_FLOAT_TAG}, {@link
       *       #CONSTANT_LONG_TAG}, {@link #CONSTANT_DOUBLE_TAG},
       *   <li>the CONSTANT_MethodHandle_info reference_kind field value for {@link
       *       #CONSTANT_METHOD_HANDLE_TAG} symbols,
       *   <li>the CONSTANT_InvokeDynamic_info bootstrap_method_attr_index field value for {@link
       *       #CONSTANT_INVOKE_DYNAMIC_TAG} symbols,
       *   <li>the offset of a bootstrap method in the BootstrapMethods boostrap_methods array, for
       *       {@link #CONSTANT_DYNAMIC_TAG} or {@link #BOOTSTRAP_METHOD_TAG} symbols,
       *   <li>the bytecode offset of the NEW instruction that created an  type for {@link #UNINITIALIZED_TYPE_TAG} symbols,
       *   <li>the indices (in the class' type table) of two {@link #TYPE_TAG} source types for {@link
       *       #MERGED_TYPE_TAG} symbols,
       *   <li>0 for the other types of symbol.
       * </ul>
       */
      final long data;
  
      /**
       * Additional information about this symbol, generally computed lazily. <i>Warning: the value of
       * this field is ignored when comparing Symbol instances</i> (to avoid duplicate entries in a
       * SymbolTable). Therefore, this field should only contain data that can be computed from the
       * other fields of this class. It contains:
       *
       * <ul>
       *   <li>the {@link Type#getArgumentsAndReturnSizes} of the symbol's method descriptor for {@link
       *       #CONSTANT_METHODREF_TAG}, {@link #CONSTANT_INTERFACE_METHODREF_TAG} and {@link
       *       #CONSTANT_INVOKE_DYNAMIC_TAG} symbols,
       *   <li>the index in the InnerClasses_attribute 'classes' array (plus one) corresponding to this
       *       class, for {@link #CONSTANT_CLASS_TAG} symbols,
       *   <li>the index (in the class' type table) of the merged type of the two source types for
       *       {@link #MERGED_TYPE_TAG} symbols,
       *   <li>0 for the other types of symbol, or if this field has not been computed yet.
       * </ul>
       */
      int info;
  
      /**
       * Constructs a new Symbol. This constructor can't be used directly because the Symbol class is
       * abstract. Instead, use the factory methods of the  class.
       *
       * @param index the symbol index in the constant pool, in the BootstrapMethods attribute, or in
       *              the (ASM specific) type table of a class (depending on 'tag').
       * @param tag   the symbol type. Must be one of the static tag values defined in this class.
       * @param owner The internal name of the symbol's owner class. Maybe {@literal null}.
       * @param name  The name of the symbol's corresponding class field or method. Maybe {@literal
       *              null}.
       * @param value The string value of this symbol. Maybe {@literal null}.
       * @param data  The numeric value of this symbol.
       */
      Symbol(
              final int index,
              final int tag,
              final String owner,
              final String name,
              final String value,
              final long data) {
          this.index = index;
          this.tag = tag;
          this.owner = owner;
          this.name = name;
          this.value = value;
          this.data = data;
      }
  
  }
  