soot.coffi.Instruction_branch Maven / Gradle / Ivy
/* 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;
import soot.*;
/** Instruction subclasses are used to represent parsed bytecode; each
* bytecode operation has a corresponding subclass of Instruction.
*
* Each subclass is derived from one of
*
- Instruction
* - Instruction_noargs (an Instruction with no embedded arguments)
* - Instruction_byte (an Instruction with a single byte data argument)
* - Instruction_bytevar (a byte argument specifying a local variable)
* - Instruction_byteindex (a byte argument specifying a constant pool index)
* - Instruction_int (an Instruction with a single short data argument)
* - Instruction_intvar (a short argument specifying a local variable)
* - Instruction_intindex (a short argument specifying a constant pool index)
* - Instruction_intbranch (a short argument specifying a code offset)
* - Instruction_longbranch (an int argument specifying a code offset)
*
* @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
*/
abstract class Instruction_branch extends Instruction {
public int arg_i;
public Instruction target; // pointer to target instruction
public Instruction_branch(byte c) { super(c); branches = true; }
public String toString(cp_info constant_pool[]) {
return super.toString(constant_pool) + argsep
+ "[label_" + Integer.toString(target.label) + "]";
}
public void offsetToPointer(ByteCode bc) {
target = bc.locateInst(arg_i+label);
if (target==null) {
G.v().out.println("Warning: can't locate target of instruction");
G.v().out.println(" which should be at byte address " + (label+arg_i));
} else
target.labelled = true;
}
// returns the array of instructions which might be the target of a
// branch with this instruction, assuming the next instruction is next
public Instruction[] branchpoints(Instruction next) {
Instruction i[] = new Instruction[2];
i[0] = target; i[1] = next;
return i;
}
public String toString()
{
return super.toString()+ "\t"+target.label;
}
}