/*
* Copyright (C) 2010-2016 JPEXS, All rights reserved.
*
* 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 3.0 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.
*/
package com.jpexs.decompiler.flash.abc.avm2.deobfuscation;
import com.jpexs.decompiler.flash.abc.ABC;
import com.jpexs.decompiler.flash.abc.avm2.AVM2Code;
import com.jpexs.decompiler.flash.abc.avm2.instructions.AVM2Instruction;
import com.jpexs.decompiler.flash.abc.avm2.instructions.IfTypeIns;
import com.jpexs.decompiler.flash.abc.avm2.instructions.jumps.JumpIns;
import com.jpexs.decompiler.flash.abc.types.MethodBody;
import com.jpexs.decompiler.flash.abc.types.traits.Trait;
import com.jpexs.decompiler.flash.helpers.SWFDecompilerAdapter;
import java.util.List;
import java.util.Map;
/**
*
* AVM2 Deobfuscator removing single assigned local registers.
*
* Example: var a = true; var b = false; ... if(a){ ...ok }else{ not executed }
*
* @author JPEXS
*/
public class AVM2DeobfuscatorJumps extends SWFDecompilerAdapter {
@Override
public void avm2CodeRemoveTraps(String path, int classIndex, boolean isStatic, int scriptIndex, ABC abc, Trait trait, int methodInfo, MethodBody body) throws InterruptedException {
AVM2Code code = body.getCode();
boolean found;
do {
found = false;
Map<Integer, List<Integer>> refs = body.getCode().visitCode(body);
loopi:
for (int i = 0; i < code.code.size(); i++) {
AVM2Instruction ins = code.code.get(i);
if (ins.definition instanceof JumpIns) {
long targetAddr = ins.getTargetAddress();
{
for (int r : refs.get(i)) {
if (r >= 0) { //Not Exception start/end
AVM2Instruction srcIns = code.code.get(r);
if ((srcIns.definition instanceof JumpIns) || ((srcIns.definition instanceof IfTypeIns) && (r != i - 1))) {
int oldop = srcIns.operands[0];
srcIns.operands[0] = (int) (targetAddr - (srcIns.getAddress() + srcIns.getBytesLength()));
if (srcIns.operands[0] != oldop) {
found = true;
}
}
}
}
}
}
}
code.removeDeadCode(body);
} while (found);
}
}