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)
+						used.add(fi.getMyField());
-							++get;
-						if (ins instanceof SetFieldInstruction)
-							++set;
 					}
 				}
 			}
-
-		// 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 (!used.contains(f))
-				if (isUnused(group, f))
 				{
 					cf.getFields().getFields().remove(f);
 					++count;
 				}
-			}
+
 		System.out.println("Removed " + count + " unused fields");
 	}
 }

src/test/java/net/runelite/deob/deobfuscators/UnusedFieldsTest.java

@@ -0,0 +1,40 @@
+package net.runelite.deob.deobfuscators;
+
+import java.io.File;
+import java.io.IOException;
+import net.runelite.asm.ClassGroup;
+import net.runelite.deob.util.JarUtil;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+public class UnusedFieldsTest
+{
+	private static final File GAMEPACK = new File(RenameUniqueTest.class.getResource("/gamepack_v16.jar").getFile());
+
+	@Rule
+	public TemporaryFolder folder = new TemporaryFolder();
+
+	private ClassGroup group;
+
+	@Before
+	public void before() throws IOException
+	{
+		group = JarUtil.loadJar(GAMEPACK);
+	}
+
+	@After
+	public void after() throws IOException
+	{
+		JarUtil.saveJar(group, folder.newFile());
+	}
+
+	@Test
+	public void testRun()
+	{
+		UnusedFields uf = new UnusedFields();
+		uf.run(group);
+	}
+}