Preserve original class and member names with @OriginalName

asm/src/main/java/dev/openrs2/asm/Transformer.java

@@ -2,6 +2,7 @@ package dev.openrs2.asm;
 
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.FieldNode;
 import org.objectweb.asm.tree.MethodNode;
 
 public abstract class Transformer {
@@ -11,9 +12,15 @@ public abstract class Transformer {
 		for (var clazz : library) {
 			transformClass(clazz);
 
+			for (var field : clazz.fields) {
+				transformField(clazz, field);
+			}
+
 			for (var method : clazz.methods) {
-				if ((method.access & (Opcodes.ACC_NATIVE | Opcodes.ACC_ABSTRACT)) == 0) {
 				transformMethod(clazz, method);
+
+				if ((method.access & (Opcodes.ACC_NATIVE | Opcodes.ACC_ABSTRACT)) == 0) {
+					transformCode(clazz, method);
 				}
 			}
 		}
@@ -29,10 +36,18 @@ public abstract class Transformer {
 		/* empty */
 	}
 
+	public void transformField(ClassNode clazz, FieldNode field) {
+		/* empty */
+	}
+
 	public void transformMethod(ClassNode clazz, MethodNode method) {
 		/* empty */
 	}
 
+	public void transformCode(ClassNode clazz, MethodNode method) {
+		/* empty */
+	}
+
 	public void postTransform(Library library) {
 		/* empty */
 	}

deob/pom.xml

@@ -19,6 +19,11 @@
       <artifactId>openrs2-asm</artifactId>
       <version>${project.version}</version>
     </dependency>
+    <dependency>
+      <groupId>dev.openrs2</groupId>
+      <artifactId>openrs2-deob-annotations</artifactId>
+      <version>${project.version}</version>
+    </dependency>
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>

deob/src/main/java/dev/openrs2/deob/Deobfuscator.java

@@ -15,6 +15,7 @@ import dev.openrs2.deob.path.ClassPath;
 import dev.openrs2.deob.path.TypedRemapper;
 import dev.openrs2.deob.transform.ClassForNameTransformer;
 import dev.openrs2.deob.transform.OpaquePredicateTransformer;
+import dev.openrs2.deob.transform.OriginalNameTransformer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -118,18 +119,33 @@ public final class Deobfuscator {
 
 		/* transform Class.forName() calls */
 		logger.info("Transforming Class.forName() calls");
-		var transformer = new ClassForNameTransformer(remapper);
+		Transformer transformer = new ClassForNameTransformer(remapper);
 		for (var library : libraries) {
 			transformer.transform(library);
 		}
 
-		var glTransformer = new ClassForNameTransformer(glRemapper);
+		transformer = new ClassForNameTransformer(glRemapper);
 		for (var library : glLibraries) {
-			glTransformer.transform(library);
+			transformer.transform(library);
+		}
+
+		transformer = new ClassForNameTransformer(unsignedRemapper);
+		transformer.transform(unsignedClient);
+
+		/* add @OriginalName annotations */
+		logger.info("Annotating classes and members with original names");
+		transformer = new OriginalNameTransformer(remapper);
+		for (var library : libraries) {
+			transformer.transform(library);
+		}
+
+		transformer = new OriginalNameTransformer(glRemapper);
+		for (var library : glLibraries) {
+			transformer.transform(library);
 		}
 
-		var unsignedTransformer = new ClassForNameTransformer(unsignedRemapper);
+		transformer = new OriginalNameTransformer(unsignedRemapper);
-		unsignedTransformer.transform(unsignedClient);
+		transformer.transform(unsignedClient);
 
 		/* write output jars */
 		logger.info("Writing output jars");

deob/src/main/java/dev/openrs2/deob/transform/ClassForNameTransformer.java

@@ -33,7 +33,7 @@ public final class ClassForNameTransformer extends Transformer {
 	}
 
 	@Override
-	public void transformMethod(ClassNode clazz, MethodNode method) {
+	public void transformCode(ClassNode clazz, MethodNode method) {
 		INVOKE_MATCHER.match(method).filter(ClassForNameTransformer::isClassForName).forEach(match -> {
 			var ldc = (LdcInsnNode) match.get(0);
 			ldc.cst = remapper.map((String) ldc.cst);

deob/src/main/java/dev/openrs2/deob/transform/OpaquePredicateTransformer.java

@@ -88,7 +88,7 @@ public final class OpaquePredicateTransformer extends Transformer {
 	}
 
 	@Override
-	public void transformMethod(ClassNode clazz, MethodNode method) {
+	public void transformCode(ClassNode clazz, MethodNode method) {
 		/* find and fix opaque predicates */
 		OPAQUE_PREDICATE_MATCHER.match(method).filter(match -> isOpaquePredicate(method, match)).forEach(match -> {
 			var branch = (JumpInsnNode) match.get(1);

deob/src/main/java/dev/openrs2/deob/transform/OriginalNameTransformer.java

@@ -0,0 +1,63 @@
+package dev.openrs2.deob.transform;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import dev.openrs2.asm.Transformer;
+import dev.openrs2.deob.annotations.OriginalName;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.commons.Remapper;
+import org.objectweb.asm.tree.AnnotationNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.FieldNode;
+import org.objectweb.asm.tree.MethodNode;
+
+public final class OriginalNameTransformer extends Transformer {
+	private static AnnotationNode createOriginalNameAnnotation(String name) {
+		var annotation = new AnnotationNode(Type.getDescriptor(OriginalName.class));
+		annotation.values = List.of("value", name);
+		return annotation;
+	}
+
+	private final Remapper remapper;
+
+	public OriginalNameTransformer(Remapper remapper) {
+		this.remapper = remapper;
+	}
+
+	@Override
+	public void transformClass(ClassNode clazz) {
+		if (clazz.name.equals(remapper.map(clazz.name))) {
+			return;
+		}
+
+		if (clazz.invisibleAnnotations == null) {
+			clazz.invisibleAnnotations = new ArrayList<>();
+		}
+		clazz.invisibleAnnotations.add(createOriginalNameAnnotation(clazz.name));
+	}
+
+	@Override
+	public void transformField(ClassNode clazz, FieldNode field) {
+		if (field.name.equals(remapper.mapFieldName(clazz.name, field.name, field.desc))) {
+			return;
+		}
+
+		if (field.invisibleAnnotations == null) {
+			field.invisibleAnnotations = new ArrayList<>();
+		}
+		field.invisibleAnnotations.add(createOriginalNameAnnotation(field.name));
+	}
+
+	@Override
+	public void transformMethod(ClassNode clazz, MethodNode method) {
+		if (method.name.equals(remapper.mapMethodName(clazz.name, method.name, method.desc))) {
+			return;
+		}
+
+		if (method.invisibleAnnotations == null) {
+			method.invisibleAnnotations = new ArrayList<>();
+		}
+		method.invisibleAnnotations.add(createOriginalNameAnnotation(method.name));
+	}
+}