/* Soot - a J*va Optimization Framework
* Copyright (C) 1997 Clark Verbrugge
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot.coffi;
/** Instruction subclasses are used to represent parsed bytecode; each
* bytecode operation has a corresponding subclass of Instruction.
* <p>
* Each subclass is derived from one of
* <ul><li>Instruction</li>
* <li>Instruction_noargs (an Instruction with no embedded arguments)</li>
* <li>Instruction_byte (an Instruction with a single byte data argument)</li>
* <li>Instruction_bytevar (a byte argument specifying a local variable)</li>
* <li>Instruction_byteindex (a byte argument specifying a constant pool index)</li>
* <li>Instruction_int (an Instruction with a single short data argument)</li>
* <li>Instruction_intvar (a short argument specifying a local variable)</li>
* <li>Instruction_intindex (a short argument specifying a constant pool index)</li>
* <li>Instruction_intbranch (a short argument specifying a code offset)</li>
* <li>Instruction_longbranch (an int argument specifying a code offset)</li>
* </ul>
* @author Clark Verbrugge
* @see Instruction
* @see Instruction_noargs
* @see Instruction_byte
* @see Instruction_bytevar
* @see Instruction_byteindex
* @see Instruction_int
* @see Instruction_intvar
* @see Instruction_intindex
* @see Instruction_intbranch
* @see Instruction_longbranch
* @see Instruction_Unknown
*/
class Instruction_bytevar extends Instruction implements Interface_OneIntArg
{
/**
* arg_b needs to be short in order to contain all the possible values for an unsigned byte
*/
public int arg_b;
public boolean isWide;
public Instruction_bytevar(byte c) { super(c); }
public String toString(cp_info constant_pool[]) {
return super.toString(constant_pool) + argsep + LOCALPREFIX + arg_b;
}
public int nextOffset(int curr) { return curr + 1 + ((isWide) ? 3 : 1); }
public int parse(byte bc[],int index)
{
int indexbyte1 = (bc[index]) & 0xff;
if(isWide)
{
int indexbyte2 = (bc[index+1]) & 0xff;
arg_b = (indexbyte1 << 8) | indexbyte2;
return index+2;
}
else
{
arg_b = indexbyte1;
return index+1;
}
}
public int compile(byte bc[],int index) { bc[index++] = code; bc[index++] = (byte) arg_b; return index; }
public int getIntArg()
{
return arg_b;
}
}