Rewrite unused fields

src/main/java/net/runelite/deob/deobfuscators/UnusedFields.java

@@ -1,6 +1,8 @@
 package net.runelite.deob.deobfuscators;
 
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
 
 import net.runelite.asm.ClassFile;
 import net.runelite.asm.ClassGroup;
@@ -10,59 +12,46 @@ import net.runelite.asm.Method;
 import net.runelite.asm.attributes.Code;
 import net.runelite.asm.attributes.code.Instruction;
 import net.runelite.asm.attributes.code.instruction.types.FieldInstruction;
-import net.runelite.asm.attributes.code.instruction.types.GetFieldInstruction;
-import net.runelite.asm.attributes.code.instruction.types.SetFieldInstruction;
 
 public class UnusedFields implements Deobfuscator
 {
-	private static boolean isUnused(ClassGroup group, Field field)
+	private final Set<Field> used = new HashSet<>();
+
+	private void checkForFieldUsage(ClassGroup group)
 	{
-		int get = 0, set = 0;
 		for (ClassFile cf : group.getClasses())
 			for (Method m : cf.getMethods().getMethods())
 			{
 				Code code = m.getCode();
 				if (code == null)
 					continue;
-				
+
 				for (Instruction ins : code.getInstructions().getInstructions())
 				{
 					if (ins instanceof FieldInstruction)
 					{
 						FieldInstruction fi = (FieldInstruction) ins;
-						
-						if (fi.getMyField() != field)
-							continue;
 
-						if (ins instanceof GetFieldInstruction)
-							++get;
-						if (ins instanceof SetFieldInstruction)
-							++set;
+						used.add(fi.getMyField());
 					}
 				}
 			}
-
-		// for only checking 'get' wed need a way to remove field initialization in constructors/class initializers
-		return get + set == 0;
-//		if (get == 0)
-//			return true;
-//
-//		return false;
 	}
 	
 	@Override
 	public void run(ClassGroup group)
 	{
+		checkForFieldUsage(group);
+		
 		int count = 0;
 		for (ClassFile cf : group.getClasses())
 			for (Field f : new ArrayList<>(cf.getFields().getFields()))
-			{
-				if (isUnused(group, f))
+				if (!used.contains(f))
 				{
 					cf.getFields().getFields().remove(f);
 					++count;
 				}
-			}
+
 		System.out.println("Removed " + count + " unused fields");
 	}
 }