org.objectweb.asm.Item Maven / Gradle / Ivy
/***
* 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
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.objectweb.asm;
/**
* A constant pool item. Constant pool items can be created with the 'newXXX'
* methods in the {@link ClassWriter} class.
*
* @author Eric Bruneton
*/
final class Item {
/**
* Index of this item in the constant pool.
*/
int index;
/**
* Type of this constant pool item. A single class is used to represent all
* constant pool item types, in order to minimize the bytecode size of this
* package. The value of this field is one of {@link ClassWriter#INT},
* {@link ClassWriter#LONG}, {@link ClassWriter#FLOAT},
* {@link ClassWriter#DOUBLE}, {@link ClassWriter#UTF8},
* {@link ClassWriter#STR}, {@link ClassWriter#CLASS},
* {@link ClassWriter#NAME_TYPE}, {@link ClassWriter#FIELD},
* {@link ClassWriter#METH}, {@link ClassWriter#IMETH},
* {@link ClassWriter#MTYPE}, {@link ClassWriter#INDY}.
*
* MethodHandle constant 9 variations are stored using a range of 9 values
* from {@link ClassWriter#HANDLE_BASE} + 1 to
* {@link ClassWriter#HANDLE_BASE} + 9.
*
* Special Item types are used for Items that are stored in the ClassWriter
* {@link ClassWriter#typeTable}, instead of the constant pool, in order to
* avoid clashes with normal constant pool items in the ClassWriter constant
* pool's hash table. These special item types are
* {@link ClassWriter#TYPE_NORMAL}, {@link ClassWriter#TYPE_UNINIT} and
* {@link ClassWriter#TYPE_MERGED}.
*/
int type;
/**
* Value of this item, for an integer item.
*/
int intVal;
/**
* Value of this item, for a long item.
*/
long longVal;
/**
* First part of the value of this item, for items that do not hold a
* primitive value.
*/
String strVal1;
/**
* Second part of the value of this item, for items that do not hold a
* primitive value.
*/
String strVal2;
/**
* Third part of the value of this item, for items that do not hold a
* primitive value.
*/
String strVal3;
/**
* The hash code value of this constant pool item.
*/
int hashCode;
/**
* Link to another constant pool item, used for collision lists in the
* constant pool's hash table.
*/
Item next;
/**
* Constructs an uninitialized {@link Item}.
*/
Item() {
}
/**
* Constructs an uninitialized {@link Item} for constant pool element at
* given position.
*
* @param index
* index of the item to be constructed.
*/
Item(final int index) {
this.index = index;
}
/**
* Constructs a copy of the given item.
*
* @param index
* index of the item to be constructed.
* @param i
* the item that must be copied into the item to be constructed.
*/
Item(final int index, final Item i) {
this.index = index;
type = i.type;
intVal = i.intVal;
longVal = i.longVal;
strVal1 = i.strVal1;
strVal2 = i.strVal2;
strVal3 = i.strVal3;
hashCode = i.hashCode;
}
/**
* Sets this item to an integer item.
*
* @param intVal
* the value of this item.
*/
void set(final int intVal) {
this.type = ClassWriter.INT;
this.intVal = intVal;
this.hashCode = 0x7FFFFFFF & (type + intVal);
}
/**
* Sets this item to a long item.
*
* @param longVal
* the value of this item.
*/
void set(final long longVal) {
this.type = ClassWriter.LONG;
this.longVal = longVal;
this.hashCode = 0x7FFFFFFF & (type + (int) longVal);
}
/**
* Sets this item to a float item.
*
* @param floatVal
* the value of this item.
*/
void set(final float floatVal) {
this.type = ClassWriter.FLOAT;
this.intVal = Float.floatToRawIntBits(floatVal);
this.hashCode = 0x7FFFFFFF & (type + (int) floatVal);
}
/**
* Sets this item to a double item.
*
* @param doubleVal
* the value of this item.
*/
void set(final double doubleVal) {
this.type = ClassWriter.DOUBLE;
this.longVal = Double.doubleToRawLongBits(doubleVal);
this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal);
}
/**
* Sets this item to an item that do not hold a primitive value.
*
* @param type
* the type of this item.
* @param strVal1
* first part of the value of this item.
* @param strVal2
* second part of the value of this item.
* @param strVal3
* third part of the value of this item.
*/
@SuppressWarnings("fallthrough")
void set(final int type, final String strVal1, final String strVal2,
final String strVal3) {
this.type = type;
this.strVal1 = strVal1;
this.strVal2 = strVal2;
this.strVal3 = strVal3;
switch (type) {
case ClassWriter.CLASS:
this.intVal = 0; // intVal of a class must be zero, see visitInnerClass
case ClassWriter.UTF8:
case ClassWriter.STR:
case ClassWriter.MTYPE:
case ClassWriter.TYPE_NORMAL:
hashCode = 0x7FFFFFFF & (type + strVal1.hashCode());
return;
case ClassWriter.NAME_TYPE: {
hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
* strVal2.hashCode());
return;
}
// ClassWriter.FIELD:
// ClassWriter.METH:
// ClassWriter.IMETH:
// ClassWriter.HANDLE_BASE + 1..9
default:
hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
* strVal2.hashCode() * strVal3.hashCode());
}
}
/**
* Sets the item to an InvokeDynamic item.
*
* @param name
* invokedynamic's name.
* @param desc
* invokedynamic's desc.
* @param bsmIndex
* zero based index into the class attribute BootrapMethods.
*/
void set(String name, String desc, int bsmIndex) {
this.type = ClassWriter.INDY;
this.longVal = bsmIndex;
this.strVal1 = name;
this.strVal2 = desc;
this.hashCode = 0x7FFFFFFF & (ClassWriter.INDY + bsmIndex
* strVal1.hashCode() * strVal2.hashCode());
}
/**
* Sets the item to a BootstrapMethod item.
*
* @param position
* position in byte in the class attribute BootrapMethods.
* @param hashCode
* hashcode of the item. This hashcode is processed from the
* hashcode of the bootstrap method and the hashcode of all
* bootstrap arguments.
*/
void set(int position, int hashCode) {
this.type = ClassWriter.BSM;
this.intVal = position;
this.hashCode = hashCode;
}
/**
* Indicates if the given item is equal to this one. This method assumes
* that the two items have the same {@link #type}.
*
* @param i
* the item to be compared to this one. Both items must have the
* same {@link #type}.
* @return true if the given item if equal to this one,
* false otherwise.
*/
boolean isEqualTo(final Item i) {
switch (type) {
case ClassWriter.UTF8:
case ClassWriter.STR:
case ClassWriter.CLASS:
case ClassWriter.MTYPE:
case ClassWriter.TYPE_NORMAL:
return i.strVal1.equals(strVal1);
case ClassWriter.TYPE_MERGED:
case ClassWriter.LONG:
case ClassWriter.DOUBLE:
return i.longVal == longVal;
case ClassWriter.INT:
case ClassWriter.FLOAT:
return i.intVal == intVal;
case ClassWriter.TYPE_UNINIT:
return i.intVal == intVal && i.strVal1.equals(strVal1);
case ClassWriter.NAME_TYPE:
return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2);
case ClassWriter.INDY: {
return i.longVal == longVal && i.strVal1.equals(strVal1)
&& i.strVal2.equals(strVal2);
}
// case ClassWriter.FIELD:
// case ClassWriter.METH:
// case ClassWriter.IMETH:
// case ClassWriter.HANDLE_BASE + 1..9
default:
return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2)
&& i.strVal3.equals(strVal3);
}
}
}
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