diff -r b40b0e18a918 -r dfce0539a77d jitcraft/Stack.h
--- a/jitcraft/Stack.h	Tue Jul 10 02:11:13 2012 -0700
+++ b/jitcraft/Stack.h	Wed Jul 11 01:12:54 2012 -0700
@@ -32,6 +32,7 @@
 class Reference;
 class Frame;
 class Stack;
+class Zone;
     
 union LocalSlot
 {
@@ -99,6 +100,10 @@
     bool isNative() const {
         return callee_ && callee_->is(MapKind_Native);
     }
+    Native *native() const {
+        assert(isNative());
+        return native_;
+    }
     Code *code() const {
         assert(code_);
         return code_;
@@ -175,7 +180,7 @@
     static const size_t STACK_SIZE = 1024 * 1024;
 
   public:
-    Stack();
+    Stack(Zone *zone);
     ~Stack();
 
     bool initialize();
@@ -198,11 +203,27 @@
     void popNativeFrame(NativeArgs &args);
 
   private:
+    Zone *zone_;
     char *buffer_;
     char *end_;
     Top top_;
 };
 
+class StackIter
+{
+    bytecode *pc_;
+    Frame *fp_;
+
+  public:
+    StackIter(Zone *zone);
+
+    bool done() const;
+    const char *function() const;
+    unsigned lineNumber() const;
+    const char *source() const;
+    void prev();
+};
+
 }
 
 #endif // _include_jc_stack_h_