remove stack of ifs in illegal state ex deob, get rid of using pcs in

frame to execute, need to remove more of this later, make jumps jump to
instructions, doesn't yet work

src/main/java/info/sigterm/deob/execution/Execution.java

@@ -21,6 +21,8 @@ public class Execution
 	
 	public void run()
 	{
+		// XXX update pc? some instructiosn rely on it still.
+		
 		int count = 0, fcount = 0;
 		for (ClassFile cf : group.getClasses())
 			for (Method method : cf.getMethods().getMethods())

src/main/java/info/sigterm/deob/execution/Frame.java

@@ -20,6 +20,7 @@ public class Frame
 	private Method method;
 	private boolean executing = true;
 	private int pc;
+	private Instruction cur; // current instruction
 	private Stack stack;
 	private Variables variables;
 	private List<InstructionContext> instructions = new ArrayList<>(); // instructions executed in this frame
@@ -48,6 +49,8 @@ public class Frame
 			variables.set(pos, new VariableContext(null, new Type(nat.getDescriptor().getTypeOfArg(i)).toStackType()));
 			pos += nat.getDescriptor().getTypeOfArg(i).getSlots();
 		}
+		
+		cur = code.getInstructions().getInstructions().get(0);
 	}
 	
 	protected Frame(Frame other)
@@ -56,6 +59,7 @@ public class Frame
 		this.method = other.method;
 		this.executing = other.executing;
 		this.pc = other.pc;
+		this.cur = other.cur;
 		this.stack = new Stack(other.stack);
 		this.variables = new Variables(other.variables);
 		this.visited = other.visited;
@@ -106,25 +110,19 @@ public class Frame
 	public void execute()
 	{
 		Instructions ins = method.getCode().getInstructions();
+		List<Instruction> instructions = ins.getInstructions();
+		
 		while (executing)
 		{
-			int oldPc = pc;
-			
-			Instruction i = ins.findInstruction(pc);
-			
-			if (i == null)
-			{
-				System.err.println("Cant find ins at pc " + pc + " in method " + method.getName() + " in " + method.getCode().getAttributes().getClassFile().getName());
-				System.exit(-1);
-			}
+			Instruction oldCur = cur;
 			
 			try
 			{
-				i.execute(this);
+				cur.execute(this);
 			}
 			catch (Throwable ex)
 			{
-				System.err.println("Error executing instruction " + i.getDesc(this));
+				System.err.println("Error executing instruction " + cur.getDesc(this));
 				System.err.println("Frame stack (grows downward):");
 				while (stack.getSize() > 0)
 				{
@@ -136,9 +134,14 @@ public class Frame
 				throw ex;
 			}
 			
-			if (oldPc == pc)
+			if (!executing)
+				break;
+			
+			if (oldCur == cur)
 			{
-				pc += i.getLength();
+				int idx = instructions.indexOf(cur);
+				assert idx != -1;
+				cur = instructions.get(idx + 1);
 			}
 			else
 			{
@@ -178,26 +181,17 @@ public class Frame
 		return false;
 	}
 	
-	public void jump(int offset)
+	public void jump(Instruction to)
 	{
-		jumpAbsolute(pc + offset);
-	}
-	
-	public void jumpAbsolute(int pc)
-	{
-		Instruction from = method.getCode().getInstructions().findInstruction(this.pc);
-		Instruction to = method.getCode().getInstructions().findInstruction(pc);
-		
-		assert from != null;
 		assert to != null;
 		
-		if (hasJumped(from, to))
+		if (hasJumped(cur, to))
 		{
 			executing = false;
 			return;
 		}
 		
-		doJump(from, to);
-		this.pc = pc;
+		doJump(cur, to);
+		cur = to;
 	}
 }