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// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// THE POSSIBILITY OF SUCH DAMAGE.
package org.objectweb.asm;
/**
* An entry of the constant pool, of the BootstrapMethods attribute, or of the (ASM specific) type
* table of a class.
*
* @see JVMS
* 4.4
* @see JVMS
* 4.7.23
* @author Eric Bruneton
*/
abstract class Symbol {
// Tag values for the constant pool entries (using the same order as in the JVMS).
/** 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;
/**
* The tag value of an uninitialized type entry in the type table of a class. This type is used
* for the normal case where the NEW instruction is before the <init> constructor call (in
* bytecode offset order), i.e. when the label of the NEW instruction is resolved when the
* constructor call is visited. If the NEW instruction is after the constructor call, use the
* {@link #FORWARD_UNINITIALIZED_TYPE_TAG} tag value instead.
*/
static final int UNINITIALIZED_TYPE_TAG = 129;
/**
* The tag value of an uninitialized type entry in the type table of a class. This type is used
* for the unusual case where the NEW instruction is after the <init> constructor call (in
* bytecode offset order), i.e. when the label of the NEW instruction is not resolved when the
* constructor call is visited. If the NEW instruction is before the constructor call, use the
* {@link #UNINITIALIZED_TYPE_TAG} tag value instead.
*/
static final int FORWARD_UNINITIALIZED_TYPE_TAG = 130;
/** The tag value of a merged type entry in the (ASM specific) type table of a class. */
static final int MERGED_TYPE_TAG = 131;
// 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:
*
*
* - 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,
*
- an arbitrary string for {@link #CONSTANT_UTF8_TAG} and {@link #CONSTANT_STRING_TAG}
* symbols,
*
- an internal class name for {@link #CONSTANT_CLASS_TAG}, {@link #TYPE_TAG}, {@link
* #UNINITIALIZED_TYPE_TAG} and {@link #FORWARD_UNINITIALIZED_TYPE_TAG} symbols,
*
- {@literal null} for the other types of symbol.
*
*/
final String value;
/**
* The numeric value of this symbol. This is:
*
*
* - the symbol's value for {@link #CONSTANT_INTEGER_TAG},{@link #CONSTANT_FLOAT_TAG}, {@link
* #CONSTANT_LONG_TAG}, {@link #CONSTANT_DOUBLE_TAG},
*
- the CONSTANT_MethodHandle_info reference_kind field value for {@link
* #CONSTANT_METHOD_HANDLE_TAG} symbols (or this value left shifted by 8 bits for
* reference_kind values larger than or equal to H_INVOKEVIRTUAL and if the method owner is
* an interface),
*
- the CONSTANT_InvokeDynamic_info bootstrap_method_attr_index field value for {@link
* #CONSTANT_INVOKE_DYNAMIC_TAG} symbols,
*
- the offset of a bootstrap method in the BootstrapMethods boostrap_methods array, for
* {@link #CONSTANT_DYNAMIC_TAG} or {@link #BOOTSTRAP_METHOD_TAG} symbols,
*
- the bytecode offset of the NEW instruction that created an {@link
* Frame#ITEM_UNINITIALIZED} type for {@link #UNINITIALIZED_TYPE_TAG} symbols,
*
- the index of the {@link Label} (in the {@link SymbolTable#labelTable} table) of the NEW
* instruction that created an {@link Frame#ITEM_UNINITIALIZED} type for {@link
* #FORWARD_UNINITIALIZED_TYPE_TAG} symbols,
*
- the indices (in the class' type table) of two {@link #TYPE_TAG} source types for {@link
* #MERGED_TYPE_TAG} symbols,
*
- 0 for the other types of symbol.
*
*/
final long data;
/**
* Additional information about this symbol, generally computed lazily. Warning: the value of
* this field is ignored when comparing Symbol instances (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:
*
*
* - 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,
*
- the index in the InnerClasses_attribute 'classes' array (plus one) corresponding to this
* class, for {@link #CONSTANT_CLASS_TAG} symbols,
*
- the index (in the class' type table) of the merged type of the two source types for
* {@link #MERGED_TYPE_TAG} symbols,
*
- 0 for the other types of symbol, or if this field has not been computed yet.
*
*/
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 {@link SymbolTable} 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;
}
/**
* Returns the result {@link Type#getArgumentsAndReturnSizes} on {@link #value}.
*
* @return the result {@link Type#getArgumentsAndReturnSizes} on {@link #value} (memoized in
* {@link #info} for efficiency). This should only be used for {@link
* #CONSTANT_METHODREF_TAG}, {@link #CONSTANT_INTERFACE_METHODREF_TAG} and {@link
* #CONSTANT_INVOKE_DYNAMIC_TAG} symbols.
*/
int getArgumentsAndReturnSizes() {
if (info == 0) {
info = Type.getArgumentsAndReturnSizes(value);
}
return info;
}
}