AS3 deobfuscation - remove dead code

trunk/src/com/jpexs/asdec/abc/ABC.java

@@ -70,6 +70,14 @@ public class ABC {
       }
    }
 
+   public int removeDeadCode() {
+      int rem=0;
+      for(MethodBody body:bodies){
+         rem+=body.removeDeadCode();
+      }
+      return rem;
+   }
+   
    public int deobfuscateIdentifiers() {
       int ret = 0;
       for (int i = 1; i < instance_info.length; i++) {

trunk/src/com/jpexs/asdec/abc/avm2/AVM2Code.java

@@ -2463,4 +2463,70 @@ public class AVM2Code {
       }
       return stats;
    }
+
+   private void visitCode(int ip, boolean visited[]) {
+      while ((ip < visited.length) && (!visited[ip])) {
+         visited[ip] = true;
+         AVM2Instruction ins = code.get(ip);
+         if (ins.definition instanceof LookupSwitchIns) {
+            try {               
+               for(int i=2;i<ins.operands.length;i++){
+                  visitCode(adr2pos(pos2adr(ip) + ins.operands[i]), visited);
+               }
+               ip = adr2pos(pos2adr(ip) + ins.operands[0]);
+               continue;
+            } catch (ConvertException ex) {
+               
+            }
+         }
+         if (ins.definition instanceof JumpIns) {
+            try {
+               ip = adr2pos(pos2adr(ip) + ins.getBytes().length + ins.operands[0]);
+               continue;
+            } catch (ConvertException ex) {
+               Logger.getLogger(AVM2Code.class.getName()).log(Level.SEVERE, null, ex);
+            }
+         } else if (ins.definition instanceof IfTypeIns) {
+            try {
+               visitCode(adr2pos(pos2adr(ip) + ins.getBytes().length + ins.operands[0]), visited);
+            } catch (ConvertException ex) {
+               Logger.getLogger(AVM2Code.class.getName()).log(Level.SEVERE, null, ex);
+            }
+         }
+         ip++;
+      };
+   }
+
+   public int removeDeadCode(MethodBody body) {     
+      boolean visited[] = new boolean[code.size()];
+      for (int i = 0; i < visited.length; i++) {
+         visited[i] = false;
+      }
+      visitCode(0, visited);
+      for (ABCException e : body.exceptions) {
+         try {
+            visitCode(adr2pos(e.start), visited);
+            visitCode(adr2pos(e.target), visited);
+         } catch (ConvertException ex) {
+            Logger.getLogger(AVM2Code.class.getName()).log(Level.SEVERE, null, ex);
+         }
+      }
+      int cnt = 0;
+      for (int i = visited.length - 1; i >= 0; i--) {
+         if (!visited[i]) {
+            removeInstruction(i, body);
+            cnt++;
+         }
+      }
+      for (int i = code.size() - 1; i >= 0; i--) {
+         AVM2Instruction ins = code.get(i);
+         if (ins.definition instanceof JumpIns) {
+            if (ins.operands[0] == 0) {
+               removeInstruction(i, body);
+               cnt++;
+            }
+         }
+      }     
+      return cnt;
+   }
 }

trunk/src/com/jpexs/asdec/abc/gui/DetailPanel.java

@@ -117,6 +117,7 @@ public class DetailPanel extends JPanel implements ActionListener {
    public void actionPerformed(ActionEvent e) {
       if (e.getActionCommand().equals("EDITDETAIL")) {
          setEditMode(true);
+         methodTraitPanel.methodCodePanel.focusEditor();
       }
       if (e.getActionCommand().equals("CANCELDETAIL")) {
          setEditMode(false);

trunk/src/com/jpexs/asdec/abc/gui/MethodCodePanel.java

@@ -36,6 +36,10 @@ public class MethodCodePanel extends JPanel implements ActionListener {
    private ASMSourceEditorPane sourceTextArea;
    public JPanel buttonsPanel;
    
+   public void focusEditor(){
+      sourceTextArea.requestFocusInWindow();
+   }
+   
    public void setIgnoreCarret(boolean ignoreCarret) {
       sourceTextArea.setIgnoreCarret(ignoreCarret);
    }

trunk/src/com/jpexs/asdec/abc/types/MethodBody.java

@@ -47,6 +47,10 @@ public class MethodBody implements Cloneable {
       s += "\r\nCode:\r\n" + code.toString();
       return s;
    }
+   
+   public int removeDeadCode(){
+      return code.removeDeadCode(this);              
+   }
 
    public HashMap<Integer, String> getLocalRegNames(ABC abc) {
       HashMap<Integer, String> ret = new HashMap<Integer, String>();

trunk/src/com/jpexs/asdec/gui/MainFrame.java

@@ -228,9 +228,19 @@ public class MainFrame extends JFrame implements ActionListener {
       miRenameIdentifiers.setActionCommand("RENAMEIDENTIFIERS");
       miRenameIdentifiers.addActionListener(this);
 
+      JMenuItem miRemoveDeadCode = new JMenuItem("Remove dead code");
+      miRemoveDeadCode.setActionCommand("REMOVEDEADCODE");
+      miRemoveDeadCode.addActionListener(this);
+
+      JMenuItem miRemoveDeadCodeAll = new JMenuItem("Remove all dead code");
+      miRemoveDeadCodeAll.setActionCommand("REMOVEDEADCODEALL");
+      miRemoveDeadCodeAll.addActionListener(this);
+
 
       menuDeobfuscation.add(miSubLimiter);
       menuDeobfuscation.add(miRenameIdentifiers);
+      menuDeobfuscation.add(miRemoveDeadCode);
+      menuDeobfuscation.add(miRemoveDeadCodeAll);
 
 
       JMenu menuTools = new JMenu("Tools");
@@ -713,6 +723,33 @@ public class MainFrame extends JFrame implements ActionListener {
             JOptionPane.showMessageDialog(null, "No new version available.");
          }
       }
+
+      if (e.getActionCommand().startsWith("REMOVEDEADCODE")) {
+         Main.startWork("Removing dead code...");
+         final boolean all = e.getActionCommand().endsWith("ALL");
+         new SwingWorker() {
+            @Override
+            protected Object doInBackground() throws Exception {
+               int cnt = 0;
+               if (all) {
+                  for (DoABCTag tag : abcPanel.list) {
+                     cnt += tag.abc.removeDeadCode();
+                  }
+               }else{
+                  int bi=abcPanel.detailPanel.methodTraitPanel.methodCodePanel.getBodyIndex();
+                  if(bi!=-1){
+                     cnt += abcPanel.abc.bodies[bi].removeDeadCode();
+                  }
+                  abcPanel.detailPanel.methodTraitPanel.methodCodePanel.setBodyIndex(bi, abcPanel.abc);
+               }
+               Main.stopWork();
+               JOptionPane.showMessageDialog(null, "Instructions removed: " + cnt);
+               abcPanel.reload();
+               return true;
+            }
+         }.execute();
+      }
+
       if (e.getActionCommand().equals("RENAMEIDENTIFIERS")) {
          if (JOptionPane.showConfirmDialog(null, "Following procedure can damage SWF file which can be then unplayable.\r\nUSE IT ON YOUR OWN RISK. Do you want to continue?", "Warning", JOptionPane.OK_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE) == JOptionPane.OK_OPTION) {