Files
runelite/src/main/java/info/sigterm/deob/deobfuscators/MethodInliner.java
2015-08-08 21:51:15 -04:00

301 lines
8.0 KiB
Java

package info.sigterm.deob.deobfuscators;
import info.sigterm.deob.ClassFile;
import info.sigterm.deob.ClassGroup;
import info.sigterm.deob.Deobfuscator;
import info.sigterm.deob.Method;
import info.sigterm.deob.attributes.Code;
import info.sigterm.deob.attributes.code.Instruction;
import info.sigterm.deob.attributes.code.Instructions;
import info.sigterm.deob.attributes.code.instruction.types.InvokeInstruction;
import info.sigterm.deob.attributes.code.instruction.types.LVTInstruction;
import info.sigterm.deob.attributes.code.instruction.types.ReturnInstruction;
import info.sigterm.deob.attributes.code.instructions.AStore;
import info.sigterm.deob.attributes.code.instructions.DStore;
import info.sigterm.deob.attributes.code.instructions.FStore;
import info.sigterm.deob.attributes.code.instructions.Goto;
import info.sigterm.deob.attributes.code.instructions.IStore;
import info.sigterm.deob.attributes.code.instructions.InvokeStatic;
import info.sigterm.deob.attributes.code.instructions.LStore;
import info.sigterm.deob.attributes.code.instructions.NOP;
import info.sigterm.deob.signature.Signature;
import info.sigterm.deob.signature.Type;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class MethodInliner implements Deobfuscator
{
private Map<Method, Integer> calls = new HashMap<>();
private Set<Method> removeMethods = new HashSet<>();
private void countCalls(Method m)
{
Code code = m.getCode();
if (code == null)
return;
Instructions ins = code.getInstructions();
for (Instruction i : ins.getInstructions())
{
// can only inline static method calls
if (!(i instanceof InvokeStatic))
continue;
List<Method> invokedMethods = ((InvokeInstruction) i).getMethods();
if (invokedMethods.isEmpty())
continue; // not our method
assert invokedMethods.size() == 1;
Method invokedMethod = invokedMethods.get(0);
Integer count = calls.get(invokedMethod);
if (count == null)
calls.put(invokedMethod, 1);
else
calls.put(invokedMethod, count + 1);
}
}
private int processMethod(Method m)
{
int inlineCount = 0;
Code code = m.getCode();
if (code == null)
return inlineCount;
Instructions ins = code.getInstructions();
for (Instruction i : ins.getInstructions())
{
// can only inline static method calls
if (!(i instanceof InvokeStatic))
continue;
List<Method> invokedMethods = ((InvokeInstruction) i).getMethods();
if (invokedMethods.isEmpty())
continue; // not our method
Method invokedMethod = invokedMethods.get(0);
Integer count = calls.get(invokedMethod);
if (count == null || count != 1)
continue; // only inline methods called once
assert m != invokedMethod;
int invokeIdx = ins.getInstructions().indexOf(i);
assert invokeIdx != -1;
int lvtIndex = code.getMaxLocals(),
//startLvtIndex = lvtIndex,
theirLocals = invokedMethod.getCode().getMaxLocals();
if (lvtIndex + theirLocals > 127)
continue;
if (invokedMethod.isSynchronized())
continue;
if (!invokedMethod.getCode().getExceptions().getExceptions().isEmpty())
continue;
// assign variables on stack to lvt
Signature descriptor = invokedMethod.getDescriptor();
Map<Integer, Integer> lvtIndexes = new HashMap<>();
for (int j = 0, idx = 0; j < descriptor.size(); ++j)
{
lvtIndexes.put(j, idx);
idx += descriptor.getTypeOfArg(j).getSlots();
}
for (int j = descriptor.size() - 1; j >= 0; --j)
{
Type type = descriptor.getTypeOfArg(j);
int paramLvtIndex = lvtIndexes.get(j);
// insert instruction to store top of stack in lvt
Instruction storeIns = null;
if (type.getArrayDims() == 0)
{
switch (type.getType())
{
case "B":
case "Z":
case "C":
case "S":
case "I":
storeIns = new IStore(ins, lvtIndex + paramLvtIndex);
//lvtIndex += type.getSlots();
break;
case "J":
storeIns = new LStore(ins, lvtIndex + paramLvtIndex);
//lvtIndex += type.getSlots();
break;
case "F":
storeIns = new FStore(ins, lvtIndex + paramLvtIndex);
//lvtIndex += type.getSlots();
break;
case "D":
storeIns = new DStore(ins, lvtIndex + paramLvtIndex);
//lvtIndex += type.getSlots();
break;
}
}
if (type.getArrayDims() != 0 || type.getType().startsWith("L"))
{
assert storeIns == null;
storeIns = new AStore(ins, lvtIndex + paramLvtIndex);
//lvtIndex += type.getSlots();
}
assert storeIns != null;
// insert storeIns before invoke instruction
ins.getInstructions().add(invokeIdx++, storeIns);
}
inline(m, i, invokedMethod, /*start*/lvtIndex);
++inlineCount;
break;
}
return inlineCount;
}
private void inline(Method method, Instruction invokeIns, Method invokeMethod, int lvtBase)
{
Code methodCode = method.getCode(),
invokeMethodCode = invokeMethod.getCode();
Instructions methodInstructions = methodCode.getInstructions(),
invokeMethodInstructions = invokeMethodCode.getInstructions();
int idx = methodInstructions.getInstructions().indexOf(invokeIns); // index of invoke ins, before removal
assert idx != -1;
Instruction nextInstruction = methodInstructions.getInstructions().get(idx + 1);
// move stuff which jumps to invokeIns to nop
Instruction nop = new NOP(methodInstructions);
methodInstructions.getInstructions().add(idx + 1, nop);
++idx;
for (Instruction fromI : invokeIns.from)
{
assert fromI.jump.contains(invokeIns);
fromI.jump.remove(invokeIns);
fromI.replace(invokeIns, nop);
fromI.jump.add(nop);
nop.from.add(fromI);
}
invokeIns.from.clear();
methodInstructions.remove(invokeIns);
methodInstructions.buildJumpGraph();
invokeMethodInstructions.buildJumpGraph();
for (Instruction i : invokeMethodInstructions.getInstructions())
{
// move instructions over.
if (i instanceof ReturnInstruction)
{
// XXX I am assuming that this function leaves the stack in a clean state?
// instead of return, jump to next instruction after the invoke
Instruction oldI = i;
i = new Goto(methodInstructions, nextInstruction);
i.jump.addAll(oldI.jump);
i.from.addAll(oldI.from);
for (Instruction i2 : oldI.from)
i2.replace(oldI, i);
oldI.from.clear();
}
if (i instanceof LVTInstruction)
{
LVTInstruction lvt = (LVTInstruction) i;
// offset lvt index
int newIndex = lvtBase + lvt.getVariableIndex();
Instruction oldI = i;
i = lvt.setVariableIndex(newIndex);
i.jump.addAll(oldI.jump);
i.from.addAll(oldI.from);
for (Instruction i2 : oldI.from)
i2.replace(oldI, i);
oldI.from.clear();
}
methodInstructions.getInstructions().add(idx++, i);
i.setInstructions(methodInstructions);
}
// old method goes away
invokeMethodInstructions.getInstructions().clear();
removeMethods.add(invokeMethod);
}
@Override
public void run(ClassGroup group)
{
int total = 0;
int i;
do
{
i = pass(group);
total += i;
}
while (i > 0);
System.out.println("[TOTAL] Inlined " + total + " methods");
}
private int pass(ClassGroup group)
{
group.buildClassGraph();
int count = 0;
calls.clear();
removeMethods.clear();
for (ClassFile cf : group.getClasses())
{
for (Method m : cf.getMethods().getMethods())
{
countCalls(m);
}
}
for (ClassFile cf : group.getClasses())
{
for (Method m : cf.getMethods().getMethods())
{
count += processMethod(m);
}
}
for (Method m : removeMethods)
m.getMethods().removeMethod(m);
System.out.println("Inlined " + count + " methods");
return count;
}
}