From ea0276a0b318ea516ffffa0d142154433c2656cc Mon Sep 17 00:00:00 2001
From: rcx <rcx@users.noreply.github.com>
Date: Wed, 17 Jul 2019 03:42:38 -0400
Subject: [PATCH] Write decompiler filters for dropping illegal annotations and
 local variable tables

---
 src/main/java/club/bytecode/the/jda/JDA.java  | 11 +++++++-
 .../decompilers/filter/DecompileFilters.java  |  1 +
 .../filter/DropLocalVariableTableFilter.java  | 22 +++++++++++++++
 .../filter/IllegalAnnotationFilter.java       | 28 +++++++++++++++++++
 4 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/club/bytecode/the/jda/decompilers/filter/DropLocalVariableTableFilter.java
 create mode 100644 src/main/java/club/bytecode/the/jda/decompilers/filter/IllegalAnnotationFilter.java

diff --git a/src/main/java/club/bytecode/the/jda/JDA.java b/src/main/java/club/bytecode/the/jda/JDA.java
index d408120..3fa750d 100644
--- a/src/main/java/club/bytecode/the/jda/JDA.java
+++ b/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();
diff --git a/src/main/java/club/bytecode/the/jda/decompilers/filter/DecompileFilters.java b/src/main/java/club/bytecode/the/jda/decompilers/filter/DecompileFilters.java
index 15fcd21..1adbff4 100644
--- a/src/main/java/club/bytecode/the/jda/decompilers/filter/DecompileFilters.java
+++ b/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() {
diff --git a/src/main/java/club/bytecode/the/jda/decompilers/filter/DropLocalVariableTableFilter.java b/src/main/java/club/bytecode/the/jda/decompilers/filter/DropLocalVariableTableFilter.java
new file mode 100644
index 0000000..d5dee38
--- /dev/null
+++ b/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;
+    }
+}
diff --git a/src/main/java/club/bytecode/the/jda/decompilers/filter/IllegalAnnotationFilter.java b/src/main/java/club/bytecode/the/jda/decompilers/filter/IllegalAnnotationFilter.java
new file mode 100644
index 0000000..bc8233d
--- /dev/null
+++ b/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;
+    }
+}