Allow frame/attribute removing transformer to operate on ClassNode

Some obfuscated samples have issues with keeping frames as-is, so these transformers when put first allow frames to be recomputed.

Author: Col-E

recaf-core/src/main/java/software/coley/recaf/services/deobfuscation/transform/generic/FrameRemovingTransformer.java

@@ -4,6 +4,11 @@
 import jakarta.enterprise.context.Dependent;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.FrameNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.MethodNode;
 import software.coley.recaf.info.JvmClassInfo;
 import software.coley.recaf.services.transform.JvmClassTransformer;
 import software.coley.recaf.services.transform.JvmTransformerContext;
@@ -23,10 +28,25 @@ public class FrameRemovingTransformer implements JvmClassTransformer {
 	public void transform(@Nonnull JvmTransformerContext context, @Nonnull Workspace workspace,
 	                      @Nonnull WorkspaceResource resource, @Nonnull JvmClassBundle bundle,
 	                      @Nonnull JvmClassInfo initialClassState) throws TransformationException {
-		ClassReader reader = new ClassReader(context.getBytecode(bundle, initialClassState));
-		ClassWriter writer = new ClassWriter(reader, 0);
-		reader.accept(writer, ClassReader.SKIP_FRAMES);
-		context.setBytecode(bundle, initialClassState, writer.toByteArray());
+		if (context.isNode(bundle, initialClassState)) {
+			ClassNode node = context.getNode(bundle, initialClassState);
+			for (MethodNode method : node.methods) {
+				InsnList instructions = method.instructions;
+				if (instructions != null) {
+					for (int i = instructions.size() - 1; i > 0; i--) {
+						AbstractInsnNode insn = instructions.get(i);
+						if (insn instanceof FrameNode)
+							instructions.remove(insn);
+					}
+				}
+			}
+		} else {
+			ClassReader reader = new ClassReader(context.getBytecode(bundle, initialClassState));
+			ClassWriter writer = new ClassWriter(reader, 0);
+			reader.accept(writer, ClassReader.SKIP_FRAMES);
+			context.setBytecode(bundle, initialClassState, writer.toByteArray());
+		}
+		context.setRecomputeFrames(initialClassState.getName());
 	}
 
 	@Nonnull

recaf-core/src/main/java/software/coley/recaf/services/deobfuscation/transform/generic/UnknownAttributeRemovingTransformer.java

@@ -2,15 +2,12 @@
 
 import jakarta.annotation.Nonnull;
 import jakarta.enterprise.context.Dependent;
-import org.objectweb.asm.AnnotationVisitor;
-import org.objectweb.asm.Attribute;
 import org.objectweb.asm.ClassReader;
-import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.FieldVisitor;
-import org.objectweb.asm.MethodVisitor;
-import org.objectweb.asm.RecordComponentVisitor;
-import software.coley.recaf.RecafConstants;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.FieldNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.RecordComponentNode;
 import software.coley.recaf.info.JvmClassInfo;
 import software.coley.recaf.services.transform.JvmClassTransformer;
 import software.coley.recaf.services.transform.JvmTransformerContext;
@@ -31,10 +28,26 @@ public class UnknownAttributeRemovingTransformer implements JvmClassTransformer
 	public void transform(@Nonnull JvmTransformerContext context, @Nonnull Workspace workspace,
 	                      @Nonnull WorkspaceResource resource, @Nonnull JvmClassBundle bundle,
 	                      @Nonnull JvmClassInfo initialClassState) throws TransformationException {
-		ClassReader reader = new ClassReader(context.getBytecode(bundle, initialClassState));
-		ClassWriter writer = new ClassWriter(reader, 0);
-		reader.accept(new UnknownAttributeRemovingVisitor(writer), 0);
-		context.setBytecode(bundle, initialClassState, writer.toByteArray());
+		if (context.isNode(bundle, initialClassState)) {
+			ClassNode node = context.getNode(bundle, initialClassState);
+			if (node.attrs != null)
+				node.attrs.clear();
+			for (FieldNode field : node.fields)
+				if (field.attrs != null)
+					field.attrs.clear();
+			for (MethodNode method : node.methods)
+				if (method.attrs != null)
+					method.attrs.clear();
+			if (node.recordComponents != null)
+				for (RecordComponentNode recordComponent : node.recordComponents)
+					if (recordComponent.attrs != null)
+						recordComponent.attrs.clear();
+		} else {
+			ClassReader reader = new ClassReader(context.getBytecode(bundle, initialClassState));
+			ClassWriter writer = new ClassWriter(reader, 0);
+			reader.accept(new UnknownAttributeRemovingVisitor(writer), 0);
+			context.setBytecode(bundle, initialClassState, writer.toByteArray());
+		}
 	}
 
 	@Nonnull

recaf-core/src/main/java/software/coley/recaf/services/transform/JvmTransformerContext.java

@@ -221,6 +221,19 @@ public boolean pruneDeadCode(@Nonnull ClassNode declaringClass, @Nonnull MethodN
 		return getJvmTransformer(DeadCodeRemovingTransformer.class).prune(declaringClass, method);
 	}
 
+	/**
+	 * @param bundle
+	 * 		Bundle containing the class.
+	 * @param info
+	 * 		The class's model in the workspace.
+	 *
+	 * @return {@code true} when the context currently has the class represented as a node <i>(vs raw {@code byte[]})</i.>
+	 */
+	public boolean isNode(@Nonnull JvmClassBundle bundle, @Nonnull JvmClassInfo info) {
+		JvmClassData data = getJvmClassData(bundle, info);
+		return data.node != null;
+	}
+
 	/**
 	 * Gets the current ASM node representation of the given class.
 	 * <p/>