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/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2014 Eric Lafortune (eric@graphics.cornell.edu)
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package proguard.classfile.instruction;
import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.instruction.visitor.InstructionVisitor;
/**
* This Instruction represents a simple instruction without variable arguments
* or constant pool references.
*
* @author Eric Lafortune
*/
public class TableSwitchInstruction extends SwitchInstruction
{
public int lowCase;
public int highCase;
/**
* Creates an uninitialized TableSwitchInstruction.
*/
public TableSwitchInstruction() {}
/**
* Creates a new TableSwitchInstruction with the given arguments.
*/
public TableSwitchInstruction(byte opcode,
int defaultOffset,
int lowCase,
int highCase,
int[] jumpOffsets)
{
this.opcode = opcode;
this.defaultOffset = defaultOffset;
this.lowCase = lowCase;
this.highCase = highCase;
this.jumpOffsets = jumpOffsets;
}
/**
* Copies the given instruction into this instruction.
* @param tableSwitchInstruction the instruction to be copied.
* @return this instruction.
*/
public TableSwitchInstruction copy(TableSwitchInstruction tableSwitchInstruction)
{
this.opcode = tableSwitchInstruction.opcode;
this.defaultOffset = tableSwitchInstruction.defaultOffset;
this.lowCase = tableSwitchInstruction.lowCase;
this.highCase = tableSwitchInstruction.highCase;
this.jumpOffsets = tableSwitchInstruction.jumpOffsets;
return this;
}
// Implementations for Instruction.
public Instruction shrink()
{
// There aren't any ways to shrink this instruction.
return this;
}
protected void readInfo(byte[] code, int offset)
{
// Skip up to three padding bytes.
offset += -offset & 3;
// Read the three 32-bit arguments.
defaultOffset = readInt(code, offset); offset += 4;
lowCase = readInt(code, offset); offset += 4;
highCase = readInt(code, offset); offset += 4;
// Read the jump offsets.
jumpOffsets = new int[highCase - lowCase + 1];
for (int index = 0; index < jumpOffsets.length; index++)
{
jumpOffsets[index] = readInt(code, offset); offset += 4;
}
}
protected void writeInfo(byte[] code, int offset)
{
// Write up to three padding bytes.
while ((offset & 3) != 0)
{
writeByte(code, offset++, 0);
}
// Write the three 32-bit arguments.
writeInt(code, offset, defaultOffset); offset += 4;
writeInt(code, offset, lowCase); offset += 4;
writeInt(code, offset, highCase); offset += 4;
// Write the jump offsets.
int length = highCase - lowCase + 1;
for (int index = 0; index < length; index++)
{
writeInt(code, offset, jumpOffsets[index]); offset += 4;
}
}
public int length(int offset)
{
return 1 + (-(offset+1) & 3) + 12 + (highCase - lowCase + 1) * 4;
}
public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, InstructionVisitor instructionVisitor)
{
instructionVisitor.visitTableSwitchInstruction(clazz, method, codeAttribute, offset, this);
}
}
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