Write decompiler filters for dropping illegal annotations and local variable tables

Author: rcx

src/main/java/club/bytecode/the/jda/JDA.java

@@ -4,6 +4,9 @@
 import club.bytecode.the.jda.api.JDANamespace;
 import club.bytecode.the.jda.api.JDAPlugin;
 import club.bytecode.the.jda.api.PluginLoader;
+import club.bytecode.the.jda.decompilers.filter.DecompileFilters;
+import club.bytecode.the.jda.decompilers.filter.DropLocalVariableTableFilter;
+import club.bytecode.the.jda.decompilers.filter.IllegalAnnotationFilter;
 import club.bytecode.the.jda.gui.MainViewerGUI;
 import club.bytecode.the.jda.gui.fileviewer.BytecodeFoldParser;
 import club.bytecode.the.jda.gui.fileviewer.BytecodeTokenizer;
@@ -73,6 +76,7 @@ public static void main(String[] args) {
             System.out.println("JDA v" + version);
             getJDADirectory();
 
+            registerModules();
             loadPlugins();
 
             Settings.loadGUI();
@@ -102,7 +106,12 @@ public static void unloadPlugin(JDAPlugin plugin) {
     public static List<JDAPlugin> getLoadedPlugins() {
         return Collections.unmodifiableList(plugins);
     }
-    
+
+    private static void registerModules() {
+        DecompileFilters.registerFilter(new IllegalAnnotationFilter());
+        DecompileFilters.registerFilter(new DropLocalVariableTableFilter());
+    }
+
     private static void loadPlugins() throws MalformedURLException {
         if (autoloadPlugin != null) {
             JDAPlugin plugin = autoloadPlugin.get();

src/main/java/club/bytecode/the/jda/decompilers/filter/DecompileFilters.java

@@ -10,6 +10,7 @@ public class DecompileFilters {
 
     public static void registerFilter(DecompileFilter filter) {
         BY_NAME.put(filter.getFullName(), filter);
+        System.out.println("Decompile filter registered: " + filter.getFullName());
     }
 
     public static Collection<DecompileFilter> getAllFilters() {

src/main/java/club/bytecode/the/jda/decompilers/filter/DropLocalVariableTableFilter.java

@@ -0,0 +1,22 @@
+package club.bytecode.the.jda.decompilers.filter;
+
+import club.bytecode.the.jda.JDA;
+import club.bytecode.the.jda.api.JDANamespace;
+import org.objectweb.asm.tree.ClassNode;
+
+public class DropLocalVariableTableFilter implements DecompileFilter {
+    @Override
+    public void process(ClassNode cn) {
+        cn.methods.forEach(methodNode -> methodNode.localVariables.clear());
+    }
+
+    @Override
+    public String getName() {
+        return "Drop local variable table";
+    }
+
+    @Override
+    public JDANamespace getNamespace() {
+        return JDA.namespace;
+    }
+}

src/main/java/club/bytecode/the/jda/decompilers/filter/IllegalAnnotationFilter.java

@@ -0,0 +1,28 @@
+package club.bytecode.the.jda.decompilers.filter;
+
+import club.bytecode.the.jda.JDA;
+import club.bytecode.the.jda.api.JDANamespace;
+import org.objectweb.asm.tree.ClassNode;
+
+public class IllegalAnnotationFilter implements DecompileFilter {
+    @Override
+    public void process(ClassNode cn) {
+        cn.methods.forEach(methodNode -> {
+            if (methodNode.invisibleAnnotations != null)
+                methodNode.invisibleAnnotations.removeIf(node -> node.desc.equals("@"));
+        });
+
+        if (cn.invisibleAnnotations != null)
+            cn.invisibleAnnotations.removeIf(node -> node.desc.equals("@"));
+    }
+
+    @Override
+    public String getName() {
+        return "Kill illegal annotations";
+    }
+
+    @Override
+    public JDANamespace getNamespace() {
+        return JDA.namespace;
+    }
+}