diff --git a/docs/quick-start/example.md b/docs/quick-start/example.md
index 3e117c7f..078db4f4 100644
--- a/docs/quick-start/example.md
+++ b/docs/quick-start/example.md
@@ -56,14 +56,14 @@ struct PyVec2: Vec2 {
             return VAR(Vec2(x, y));
         });
 
-        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             PyVec2& self = _CAST(PyVec2&, obj);
             std::stringstream ss;
             ss << "vec2(" << self.x << ", " << self.y << ")";
             return VAR(ss.str());
         });
 
-        vm->bind__add__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* other){
+        vm->bind__add__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* other){
             PyVec2& self = _CAST(PyVec2&, obj);
             PyVec2& other_ = CAST(PyVec2&, other);
             return VAR_T(PyVec2, self + other_);
diff --git a/src/ceval.h b/src/ceval.h
index bcc5b3b4..521e3079 100644
--- a/src/ceval.h
+++ b/src/ceval.h
@@ -23,7 +23,7 @@ inline PyObject* VM::_run_top_frame(){
     StrName _name;
 
     while(true){
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         if(frame.index < base_id) FATAL_ERROR();
 #endif
         try{
@@ -34,9 +34,16 @@ inline PyObject* VM::_run_top_frame(){
  * DO NOT leave any strong reference of PyObject* in the C stack
  */
 {
+
+#if PK_ENABLE_CEVAL_CALLBACK
+#define CEVAL_STEP() byte = frame->next_bytecode(); if(_ceval_on_step) _ceval_on_step(this, frame, byte)
+#else
+#define CEVAL_STEP() byte = frame->next_bytecode()
+#endif
+
 #define DISPATCH_OP_CALL() { frame = top_frame(); goto __NEXT_FRAME; }
 __NEXT_FRAME:
-    Bytecode byte = frame->next_bytecode();
+    Bytecode CEVAL_STEP();
     // cache
     const CodeObject* co = frame->co;
     const auto& co_consts = co->consts;
@@ -49,16 +56,16 @@ static void* OP_LABELS[] = {
     #undef OPCODE
 };
 
-#define DISPATCH() { byte = frame->next_bytecode(); goto *OP_LABELS[byte.op];}
+#define DISPATCH() { CEVAL_STEP(); goto *OP_LABELS[byte.op];}
 #define TARGET(op) CASE_OP_##op:
 goto *OP_LABELS[byte.op];
 
 #else
 #define TARGET(op) case OP_##op:
-#define DISPATCH() { byte = frame->next_bytecode(); goto __NEXT_STEP;}
+#define DISPATCH() { CEVAL_STEP(); goto __NEXT_STEP;}
 
 __NEXT_STEP:;
-#if DEBUG_CEVAL_STEP
+#if PK_DEBUG_CEVAL_STEP
     _log_s_data();
 #endif
     switch (byte.op)
@@ -624,7 +631,7 @@ __NEXT_STEP:;
         _0 = POPX();   // super
         if(_0 == None) _0 = _t(tp_object);
         check_non_tagged_type(_0, tp_type);
-        _1 = new_type_object(frame->_module, _name, OBJ_GET(Type, _0));
+        _1 = new_type_object(frame->_module, _name, PK_OBJ_GET(Type, _0));
         PUSH(_1);
         DISPATCH();
     TARGET(END_CLASS)
@@ -703,7 +710,7 @@ __NEXT_STEP:;
     } DISPATCH();
 
 #if !PK_ENABLE_COMPUTED_GOTO
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
     default: throw std::runtime_error(fmt(OP_NAMES[byte.op], " is not implemented"));
 #else
     default: UNREACHABLE();
@@ -715,6 +722,7 @@ __NEXT_STEP:;
 #undef DISPATCH
 #undef TARGET
 #undef DISPATCH_OP_CALL
+#undef CEVAL_STEP
 /**********************************************************************/
             UNREACHABLE();
         }catch(HandledException& e){
@@ -725,7 +733,7 @@ __NEXT_STEP:;
             _e.st_push(frame->snapshot());
             _pop_frame();
             if(callstack.empty()){
-#if DEBUG_FULL_EXCEPTION
+#if PK_DEBUG_FULL_EXCEPTION
                 std::cerr << _e.summary() << std::endl;
 #endif
                 throw _e;
diff --git a/src/cffi.h b/src/cffi.h
index 87c3f362..fee224a3 100644
--- a/src/cffi.h
+++ b/src/cffi.h
@@ -9,7 +9,7 @@ namespace pkpy {
     static Type _type(VM* vm) {                 \
         static const StrName __x0(#mod);        \
         static const StrName __x1(#name);       \
-        return OBJ_GET(Type, vm->_modules[__x0]->attr(__x1));               \
+        return PK_OBJ_GET(Type, vm->_modules[__x0]->attr(__x1));               \
     }                                                                       \
     static void _check_type(VM* vm, PyObject* val){                         \
         if(!vm->isinstance(val, T::_type(vm))){                             \
@@ -72,7 +72,7 @@ struct VoidP{
             return VAR(self.hex());
         });
 
-        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             VoidP& self = _CAST(VoidP&, obj);
             std::stringstream ss;
             ss << "<void* at " << self.hex();
@@ -82,7 +82,7 @@ struct VoidP{
         });
 
 #define BIND_CMP(name, op)  \
-        vm->bind##name(OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){       \
+        vm->bind##name(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){       \
             if(!is_non_tagged_type(rhs, VoidP::_type(vm))) return vm->NotImplemented;       \
             return VAR(_CAST(VoidP&, lhs) op _CAST(VoidP&, rhs));                           \
         });
@@ -95,7 +95,7 @@ struct VoidP{
 
 #undef BIND_CMP
 
-        vm->bind__hash__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__hash__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             VoidP& self = _CAST(VoidP&, obj);
             return reinterpret_cast<i64>(self.ptr);
         });
@@ -122,13 +122,13 @@ struct VoidP{
             return VAR_T(VoidP, (char*)self.ptr + offset * self.base_offset);
         });
 
-        vm->bind__add__(OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
+        vm->bind__add__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
             VoidP& self = _CAST(VoidP&, lhs);
             i64 offset = CAST(i64, rhs);
             return VAR_T(VoidP, (char*)self.ptr + offset);
         });
 
-        vm->bind__sub__(OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
+        vm->bind__sub__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
             VoidP& self = _CAST(VoidP&, lhs);
             i64 offset = CAST(i64, rhs);
             return VAR_T(VoidP, (char*)self.ptr - offset);
@@ -243,7 +243,7 @@ struct C99Struct{
             return VAR_T(C99Struct, self);
         });
 
-        vm->bind__eq__(OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
+        vm->bind__eq__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* lhs, PyObject* rhs){
             C99Struct& self = _CAST(C99Struct&, lhs);
             if(!is_non_tagged_type(rhs, C99Struct::_type(vm))) return vm->NotImplemented;
             C99Struct& other = _CAST(C99Struct&, rhs);
@@ -328,7 +328,7 @@ struct C99ReflType final: ReflType{
             return VAR(self.size);
         });
 
-        vm->bind__getitem__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* key){
+        vm->bind__getitem__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* key){
             C99ReflType& self = _CAST(C99ReflType&, obj);
             const Str& name = CAST(Str&, key);
             auto it = std::lower_bound(self.fields.begin(), self.fields.end(), name.sv());
diff --git a/src/common.h b/src/common.h
index 781c8938..4cffbbb2 100644
--- a/src/common.h
+++ b/src/common.h
@@ -39,11 +39,11 @@ struct GIL {
     explicit GIL() { _mutex.lock(); }
     ~GIL() { _mutex.unlock(); }
 };
-#define GLOBAL_SCOPE_LOCK() auto _lock = GIL();
+#define PK_GLOBAL_SCOPE_LOCK() auto _lock = GIL();
 
 #else
 #define THREAD_LOCAL
-#define GLOBAL_SCOPE_LOCK()
+#define PK_GLOBAL_SCOPE_LOCK()
 #endif
 
 /*******************************************************************************/
@@ -119,11 +119,11 @@ struct Type {
 #define PK_ASSERT(x) if(!(x)) FATAL_ERROR();
 
 struct PyObject;
-#define BITS(p) (reinterpret_cast<i64>(p))
-inline bool is_tagged(PyObject* p) noexcept { return (BITS(p) & 0b11) != 0b00; }
-inline bool is_int(PyObject* p) noexcept { return (BITS(p) & 0b11) == 0b01; }
-inline bool is_float(PyObject* p) noexcept { return (BITS(p) & 0b11) == 0b10; }
-inline bool is_special(PyObject* p) noexcept { return (BITS(p) & 0b11) == 0b11; }
+#define PK_BITS(p) (reinterpret_cast<i64>(p))
+inline bool is_tagged(PyObject* p) noexcept { return (PK_BITS(p) & 0b11) != 0b00; }
+inline bool is_int(PyObject* p) noexcept { return (PK_BITS(p) & 0b11) == 0b01; }
+inline bool is_float(PyObject* p) noexcept { return (PK_BITS(p) & 0b11) == 0b10; }
+inline bool is_special(PyObject* p) noexcept { return (PK_BITS(p) & 0b11) == 0b11; }
 
 inline bool is_both_int_or_float(PyObject* a, PyObject* b) noexcept {
     return is_tagged(a) && is_tagged(b);
diff --git a/src/compiler.h b/src/compiler.h
index b78bf1c4..5a7b24e5 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -1101,4 +1101,7 @@ public:
     }
 };
 
+#undef BC_NOARG
+#undef BC_KEEPLINE
+
 } // namespace pkpy
\ No newline at end of file
diff --git a/src/config.h b/src/config.h
index 0546dfbc..cd8b6d96 100644
--- a/src/config.h
+++ b/src/config.h
@@ -14,6 +14,9 @@
 // This triggers necessary locks to make the VM thread-safe
 #define PK_ENABLE_THREAD            0
 
+// Enable this for `vm->_ceval_on_step`
+#define PK_ENABLE_CEVAL_CALLBACK    0
+
 // Whether to use `std::function` to do bindings or not
 // By default, functions to be binded must be a C function pointer without capture
 // However, someone thinks it's not convenient.
@@ -24,17 +27,17 @@
 /*************** debug settings ***************/
 
 // Enable this may help you find bugs
-#define DEBUG_EXTRA_CHECK           0
+#define PK_DEBUG_EXTRA_CHECK        0
 
 // Do not edit the following settings unless you know what you are doing
-#define DEBUG_NO_BUILTIN_MODULES    0
-#define DEBUG_DIS_EXEC              0
-#define DEBUG_CEVAL_STEP            0
-#define DEBUG_FULL_EXCEPTION        0
-#define DEBUG_MEMORY_POOL           0
-#define DEBUG_NO_MEMORY_POOL        0
-#define DEBUG_NO_AUTO_GC            0
-#define DEBUG_GC_STATS              0
+#define PK_DEBUG_NO_BUILTINS        0
+#define PK_DEBUG_DIS_EXEC           0
+#define PK_DEBUG_CEVAL_STEP         0
+#define PK_DEBUG_FULL_EXCEPTION     0
+#define PK_DEBUG_MEMORY_POOL        0
+#define PK_DEBUG_NO_MEMORY_POOL     0
+#define PK_DEBUG_NO_AUTO_GC         0
+#define PK_DEBUG_GC_STATS           0
 
 /*************** internal settings ***************/
 
@@ -75,7 +78,7 @@ inline const float kTypeAttrLoadFactor = 0.5f;
 #endif
 
 
-#if DEBUG_CEVAL_STEP && defined(PK_ENABLE_COMPUTED_GOTO)
+#if PK_DEBUG_CEVAL_STEP && defined(PK_ENABLE_COMPUTED_GOTO)
 #undef PK_ENABLE_COMPUTED_GOTO
 #endif
 
diff --git a/src/frame.h b/src/frame.h
index 3960dfc2..8afd6cdf 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -86,7 +86,7 @@ struct ValueStackImpl {
     PyObject** begin() { return _begin; }
     PyObject** end() { return _sp; }
     void reset(PyObject** sp) {
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         if(sp < _begin || sp > _begin + MAX_SIZE) FATAL_ERROR();
 #endif
         _sp = sp;
@@ -118,7 +118,7 @@ struct Frame {
     
     PyObject* f_closure_try_get(StrName name){
         if(_callable == nullptr) return nullptr;
-        Function& fn = OBJ_GET(Function, _callable);
+        Function& fn = PK_OBJ_GET(Function, _callable);
         if(fn._closure == nullptr) return nullptr;
         return fn._closure->try_get(name);
     }
@@ -134,7 +134,7 @@ struct Frame {
 
     Bytecode next_bytecode() {
         _ip = _next_ip++;
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         if(_ip >= co->codes.size()) FATAL_ERROR();
 #endif
         return co->codes[_ip];
diff --git a/src/gc.h b/src/gc.h
index d7db4d74..b247b295 100644
--- a/src/gc.h
+++ b/src/gc.h
@@ -65,7 +65,7 @@ struct ManagedHeap{
         return obj;
     }
 
-#if DEBUG_GC_STATS
+#if PK_DEBUG_GC_STATS
     inline static std::map<Type, int> deleted;
 #endif
 
@@ -76,7 +76,7 @@ struct ManagedHeap{
                 obj->gc.marked = false;
                 alive.push_back(obj);
             }else{
-#if DEBUG_GC_STATS
+#if PK_DEBUG_GC_STATS
                 deleted[obj->type] += 1;
 #endif
                 if(_gc_on_delete) _gc_on_delete(vm, obj);
@@ -96,7 +96,7 @@ struct ManagedHeap{
     }
 
     void _auto_collect(){
-#if !DEBUG_NO_AUTO_GC
+#if !PK_DEBUG_NO_AUTO_GC
         if(_gc_lock_counter > 0) return;
         if(gc_counter < gc_threshold) return;
         gc_counter = 0;
@@ -118,7 +118,7 @@ struct ManagedHeap{
     ~ManagedHeap(){
         for(PyObject* obj: _no_gc) { obj->~PyObject(); pool64.dealloc(obj); }
         for(PyObject* obj: gen) { obj->~PyObject(); pool64.dealloc(obj); }
-#if DEBUG_GC_STATS
+#if PK_DEBUG_GC_STATS
         for(auto& [type, count]: deleted){
             std::cout << "GC: " << obj_type_name(vm, type) << "=" << count << std::endl;
         }
diff --git a/src/iter.h b/src/iter.h
index 42ed993d..469e4316 100644
--- a/src/iter.h
+++ b/src/iter.h
@@ -13,10 +13,10 @@ struct RangeIter{
     RangeIter(Range r) : r(r), current(r.start) {}
 
     static void _register(VM* vm, PyObject* mod, PyObject* type){
-        vm->_all_types[OBJ_GET(Type, type)].subclass_enabled = false;
+        vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
         vm->bind_notimplemented_constructor<RangeIter>(type);
-        vm->bind__iter__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
-        vm->bind__next__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__iter__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
+        vm->bind__next__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             RangeIter& self = _CAST(RangeIter&, obj);
             bool has_next = self.r.step > 0 ? self.current < self.r.stop : self.current > self.r.stop;
             if(!has_next) return vm->StopIteration;
@@ -39,10 +39,10 @@ struct ArrayIter{
     void _gc_mark() const{ OBJ_MARK(ref); }
 
     static void _register(VM* vm, PyObject* mod, PyObject* type){
-        vm->_all_types[OBJ_GET(Type, type)].subclass_enabled = false;
+        vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
         vm->bind_notimplemented_constructor<ArrayIter>(type);
-        vm->bind__iter__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
-        vm->bind__next__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__iter__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
+        vm->bind__next__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             ArrayIter& self = _CAST(ArrayIter&, obj);
             if(self.current == self.end) return vm->StopIteration;
             return *self.current++;
@@ -56,15 +56,15 @@ struct StringIter{
     Str* str;
     int index;
 
-    StringIter(PyObject* ref) : ref(ref), str(&OBJ_GET(Str, ref)), index(0) {}
+    StringIter(PyObject* ref) : ref(ref), str(&PK_OBJ_GET(Str, ref)), index(0) {}
 
     void _gc_mark() const{ OBJ_MARK(ref); }
 
     static void _register(VM* vm, PyObject* mod, PyObject* type){
-        vm->_all_types[OBJ_GET(Type, type)].subclass_enabled = false;
+        vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
         vm->bind_notimplemented_constructor<StringIter>(type);
-        vm->bind__iter__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
-        vm->bind__next__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__iter__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
+        vm->bind__next__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             StringIter& self = _CAST(StringIter&, obj);
             // TODO: optimize this... operator[] is of O(n) complexity
             if(self.index == self.str->u8_length()) return vm->StopIteration;
@@ -114,10 +114,10 @@ struct Generator{
     }
 
     static void _register(VM* vm, PyObject* mod, PyObject* type){
-        vm->_all_types[OBJ_GET(Type, type)].subclass_enabled = false;
+        vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
         vm->bind_notimplemented_constructor<Generator>(type);
-        vm->bind__iter__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
-        vm->bind__next__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__iter__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
+        vm->bind__next__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             Generator& self = _CAST(Generator&, obj);
             return self.next(vm);
         });
diff --git a/src/linalg.h b/src/linalg.h
index 92b9a08f..31a22fb1 100644
--- a/src/linalg.h
+++ b/src/linalg.h
@@ -335,7 +335,7 @@ struct PyVec2: Vec2 {
             return VAR(Tuple({ VAR(self.x), VAR(self.y) }));
         });
 
-        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             PyVec2& self = _CAST(PyVec2&, obj);
             std::stringstream ss;
             ss << "vec2(" << self.x << ", " << self.y << ")";
@@ -395,7 +395,7 @@ struct PyVec3: Vec3 {
             return VAR(Tuple({ VAR(self.x), VAR(self.y), VAR(self.z) }));
         });
 
-        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             PyVec3& self = _CAST(PyVec3&, obj);
             std::stringstream ss;
             ss << "vec3(" << self.x << ", " << self.y << ", " << self.z << ")";
@@ -476,7 +476,7 @@ struct PyMat3x3: Mat3x3{
 
 #undef METHOD_PROXY_NONE
 
-        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+        vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
             PyMat3x3& self = _CAST(PyMat3x3&, obj);
             std::stringstream ss;
             ss << std::fixed << std::setprecision(4);
@@ -491,7 +491,7 @@ struct PyMat3x3: Mat3x3{
             return VAR_T(PyMat3x3, self);
         });
 
-        vm->bind__getitem__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* index){
+        vm->bind__getitem__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* index){
             PyMat3x3& self = _CAST(PyMat3x3&, obj);
             Tuple& t = CAST(Tuple&, index);
             if(t.size() != 2){
diff --git a/src/memory.h b/src/memory.h
index 996952ae..ec2d2893 100644
--- a/src/memory.h
+++ b/src/memory.h
@@ -40,7 +40,7 @@ struct DoubleLinkedList{
     }
 
     void pop_back(){
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(empty()) throw std::runtime_error("DoubleLinkedList::pop_back() called on empty list");
 #endif
         tail.prev->prev->next = &tail;
@@ -49,7 +49,7 @@ struct DoubleLinkedList{
     }
 
     void pop_front(){
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(empty()) throw std::runtime_error("DoubleLinkedList::pop_front() called on empty list");
 #endif
         head.next->next->prev = &head;
@@ -58,21 +58,21 @@ struct DoubleLinkedList{
     }
 
     T* back() const {
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(empty()) throw std::runtime_error("DoubleLinkedList::back() called on empty list");
 #endif
         return static_cast<T*>(tail.prev);
     }
 
     T* front() const {
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(empty()) throw std::runtime_error("DoubleLinkedList::front() called on empty list");
 #endif
         return static_cast<T*>(head.next);
     }
 
     void erase(T* node){
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(empty()) throw std::runtime_error("DoubleLinkedList::erase() called on empty list");
         LinkedListNode* n = head.next;
         while(n != &tail){
@@ -99,7 +99,7 @@ struct DoubleLinkedList{
     }
 
     bool empty() const {
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(size() == 0){
             if(head.next != &tail || tail.prev != &head){
                 throw std::runtime_error("DoubleLinkedList::size() returned 0 but the list is not empty");
@@ -152,7 +152,7 @@ struct MemoryPool{
         }
 
         Block* alloc(){
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
             if(empty()) throw std::runtime_error("Arena::alloc() called on empty arena");
 #endif
             _free_list_size--;
@@ -160,7 +160,7 @@ struct MemoryPool{
         }
 
         void dealloc(Block* block){
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
             if(full()) throw std::runtime_error("Arena::dealloc() called on full arena");
 #endif
             _free_list[_free_list_size] = block;
@@ -175,8 +175,8 @@ struct MemoryPool{
     void* alloc() { return alloc(sizeof(__T)); }
 
     void* alloc(size_t size){
-        GLOBAL_SCOPE_LOCK();
-#if DEBUG_NO_MEMORY_POOL
+        PK_GLOBAL_SCOPE_LOCK();
+#if PK_DEBUG_NO_MEMORY_POOL
         return malloc(size);
 #endif
         if(size > __BlockSize){
@@ -200,12 +200,12 @@ struct MemoryPool{
     }
 
     void dealloc(void* p){
-        GLOBAL_SCOPE_LOCK();
-#if DEBUG_NO_MEMORY_POOL
+        PK_GLOBAL_SCOPE_LOCK();
+#if PK_DEBUG_NO_MEMORY_POOL
         free(p);
         return;
 #endif
-#if DEBUG_MEMORY_POOL
+#if PK_DEBUG_MEMORY_POOL
         if(p == nullptr) throw std::runtime_error("MemoryPool::dealloc() called on nullptr");
 #endif
         Block* block = (Block*)((char*)p - sizeof(void*));
diff --git a/src/obj.h b/src/obj.h
index c089c4db..471dd71f 100644
--- a/src/obj.h
+++ b/src/obj.h
@@ -43,7 +43,7 @@ struct NativeFunc {
     T get_userdata() const {
         static_assert(std::is_trivially_copyable_v<T>);
         static_assert(sizeof(T) <= sizeof(UserData));
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         if(!_has_userdata) throw std::runtime_error("userdata not set");
 #endif
         return reinterpret_cast<const T&>(_userdata);
@@ -199,7 +199,7 @@ struct MappingProxy{
     NameDict& attr() noexcept { return obj->attr(); }
 };
 
-#define OBJ_GET(T, obj) (((Py_<T>*)(obj))->_value)
+#define PK_OBJ_GET(T, obj) (((Py_<T>*)(obj))->_value)
 
 #define OBJ_MARK(obj) \
     if(!is_tagged(obj) && !(obj)->gc.marked) {                      \
@@ -218,18 +218,18 @@ inline void gc_mark_namedict(NameDict& t){
 
 Str obj_type_name(VM* vm, Type type);
 
-#if DEBUG_NO_BUILTIN_MODULES
+#if PK_DEBUG_NO_BUILTINS
 #define OBJ_NAME(obj) Str("<?>")
 #else
 DEF_SNAME(__name__);
-#define OBJ_NAME(obj) OBJ_GET(Str, vm->getattr(obj, __name__))
+#define OBJ_NAME(obj) PK_OBJ_GET(Str, vm->getattr(obj, __name__))
 #endif
 
 const int kTpIntIndex = 2;
 const int kTpFloatIndex = 3;
 
 inline bool is_type(PyObject* obj, Type type) {
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
     if(obj == nullptr) throw std::runtime_error("is_type() called with nullptr");
     if(is_special(obj)) throw std::runtime_error("is_type() called with special object");
 #endif
@@ -241,7 +241,7 @@ inline bool is_type(PyObject* obj, Type type) {
 }
 
 inline bool is_non_tagged_type(PyObject* obj, Type type) {
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
     if(obj == nullptr) throw std::runtime_error("is_non_tagged_type() called with nullptr");
     if(is_special(obj)) throw std::runtime_error("is_non_tagged_type() called with special object");
 #endif
@@ -270,7 +270,7 @@ __T py_cast(VM* vm, PyObject* obj) {
         return to_void_p<T>(vm, obj);
     }else if constexpr(is_py_class<T>::value){
         T::_check_type(vm, obj);
-        return OBJ_GET(T, obj);
+        return PK_OBJ_GET(T, obj);
     }else if constexpr(std::is_pod_v<T>){
         return to_c99_struct<T>(vm, obj);
     }else {
@@ -286,7 +286,7 @@ __T _py_cast(VM* vm, PyObject* obj) {
     }else if constexpr(std::is_pointer_v<__T>){
         return to_void_p<__T>(vm, obj);
     }else if constexpr(is_py_class<T>::value){
-        return OBJ_GET(T, obj);
+        return PK_OBJ_GET(T, obj);
     }else if constexpr(std::is_pod_v<T>){
         return to_c99_struct<T>(vm, obj);
     }else {
@@ -430,8 +430,8 @@ struct Py_<DummyModule> final: PyObject {
 
 template<typename T>
 inline T lambda_get_userdata(PyObject** p){
-    if(p[-1] != PY_NULL) return OBJ_GET(NativeFunc, p[-1]).get_userdata<T>();
-    else return OBJ_GET(NativeFunc, p[-2]).get_userdata<T>();
+    if(p[-1] != PY_NULL) return PK_OBJ_GET(NativeFunc, p[-1]).get_userdata<T>();
+    else return PK_OBJ_GET(NativeFunc, p[-2]).get_userdata<T>();
 }
 
 
diff --git a/src/pocketpy.h b/src/pocketpy.h
index 6b60a2e9..6783ebd7 100644
--- a/src/pocketpy.h
+++ b/src/pocketpy.h
@@ -24,7 +24,7 @@ inline CodeObject_ VM::compile(Str source, Str filename, CompileMode mode, bool
     try{
         return compiler.compile();
     }catch(Exception& e){
-#if DEBUG_FULL_EXCEPTION
+#if PK_DEBUG_FULL_EXCEPTION
         std::cerr << e.summary() << std::endl;
 #endif
         _error(e);
@@ -75,9 +75,9 @@ inline void init_builtins(VM* _vm) {
 
     _vm->bind_builtin_func<2>("super", [](VM* vm, ArgsView args) {
         vm->check_non_tagged_type(args[0], vm->tp_type);
-        Type type = OBJ_GET(Type, args[0]);
+        Type type = PK_OBJ_GET(Type, args[0]);
         if(!vm->isinstance(args[1], type)){
-            Str _0 = obj_type_name(vm, OBJ_GET(Type, vm->_t(args[1])));
+            Str _0 = obj_type_name(vm, PK_OBJ_GET(Type, vm->_t(args[1])));
             Str _1 = obj_type_name(vm, type);
             vm->TypeError("super(): " + _0.escape() + " is not an instance of " + _1.escape());
         }
@@ -87,7 +87,7 @@ inline void init_builtins(VM* _vm) {
 
     _vm->bind_builtin_func<2>("isinstance", [](VM* vm, ArgsView args) {
         vm->check_non_tagged_type(args[1], vm->tp_type);
-        Type type = OBJ_GET(Type, args[1]);
+        Type type = PK_OBJ_GET(Type, args[1]);
         return VAR(vm->isinstance(args[0], type));
     });
 
@@ -260,11 +260,11 @@ inline void init_builtins(VM* _vm) {
     });
 
     _vm->bind__eq__(_vm->tp_object, [](VM* vm, PyObject* lhs, PyObject* rhs) { return VAR(lhs == rhs); });
-    _vm->bind__hash__(_vm->tp_object, [](VM* vm, PyObject* obj) { return BITS(obj); });
+    _vm->bind__hash__(_vm->tp_object, [](VM* vm, PyObject* obj) { return PK_BITS(obj); });
 
     _vm->cached_object__new__ = _vm->bind_constructor<1>("object", [](VM* vm, ArgsView args) {
         vm->check_non_tagged_type(args[0], vm->tp_type);
-        Type t = OBJ_GET(Type, args[0]);
+        Type t = PK_OBJ_GET(Type, args[0]);
         return vm->heap.gcnew<DummyInstance>(t, {});
     });
 
@@ -282,7 +282,7 @@ inline void init_builtins(VM* _vm) {
         return VAR(r);
     });
 
-    _vm->bind__iter__(_vm->tp_range, [](VM* vm, PyObject* obj) { return VAR_T(RangeIter, OBJ_GET(Range, obj)); });
+    _vm->bind__iter__(_vm->tp_range, [](VM* vm, PyObject* obj) { return VAR_T(RangeIter, PK_OBJ_GET(Range, obj)); });
     _vm->bind__repr__(_vm->_type("NoneType"), [](VM* vm, PyObject* obj) { return VAR("None"); });
     _vm->bind__json__(_vm->_type("NoneType"), [](VM* vm, PyObject* obj) { return VAR("null"); });
 
@@ -1362,11 +1362,11 @@ inline void VM::post_init(){
 
     _t(tp_object)->attr().set("__class__", property(CPP_LAMBDA(vm->_t(args[0]))));
     _t(tp_type)->attr().set("__base__", property([](VM* vm, ArgsView args){
-        const PyTypeInfo& info = vm->_all_types[OBJ_GET(Type, args[0])];
+        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, args[0])];
         return info.base.index == -1 ? vm->None : vm->_all_types[info.base].obj;
     }));
     _t(tp_type)->attr().set("__name__", property([](VM* vm, ArgsView args){
-        const PyTypeInfo& info = vm->_all_types[OBJ_GET(Type, args[0])];
+        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, args[0])];
         return VAR(info.name);
     }));
 
@@ -1396,7 +1396,7 @@ inline void VM::post_init(){
         return VAR(MappingProxy(args[0]));
     }));
 
-#if !DEBUG_NO_BUILTIN_MODULES
+#if !PK_DEBUG_NO_BUILTINS
     add_module_sys(this);
     add_module_traceback(this);
     add_module_time(this);
diff --git a/src/vm.h b/src/vm.h
index 38496941..70b5246f 100644
--- a/src/vm.h
+++ b/src/vm.h
@@ -28,17 +28,17 @@ namespace pkpy{
 #define DEF_NATIVE_2(ctype, ptype)                                      \
     template<> inline ctype py_cast<ctype>(VM* vm, PyObject* obj) {     \
         vm->check_non_tagged_type(obj, vm->ptype);                      \
-        return OBJ_GET(ctype, obj);                                     \
+        return PK_OBJ_GET(ctype, obj);                                     \
     }                                                                   \
     template<> inline ctype _py_cast<ctype>(VM* vm, PyObject* obj) {    \
-        return OBJ_GET(ctype, obj);                                     \
+        return PK_OBJ_GET(ctype, obj);                                     \
     }                                                                   \
     template<> inline ctype& py_cast<ctype&>(VM* vm, PyObject* obj) {   \
         vm->check_non_tagged_type(obj, vm->ptype);                      \
-        return OBJ_GET(ctype, obj);                                     \
+        return PK_OBJ_GET(ctype, obj);                                     \
     }                                                                   \
     template<> inline ctype& _py_cast<ctype&>(VM* vm, PyObject* obj) {  \
-        return OBJ_GET(ctype, obj);                                     \
+        return PK_OBJ_GET(ctype, obj);                                     \
     }                                                                   \
     inline PyObject* py_var(VM* vm, const ctype& value) { return vm->heap.gcnew(vm->ptype, value);}     \
     inline PyObject* py_var(VM* vm, ctype&& value) { return vm->heap.gcnew(vm->ptype, std::move(value));}
@@ -124,6 +124,10 @@ public:
 
     PyObject* _last_exception;
 
+#if PK_ENABLE_CEVAL_CALLBACK
+    void (*_ceval_on_step)(VM*, Frame*, Bytecode bc) = nullptr;
+#endif
+
     PrintFunc _stdout;
     PrintFunc _stderr;
     Bytes (*_import_handler)(const Str& name);
@@ -152,7 +156,7 @@ public:
     }
 
     FrameId top_frame() {
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         if(callstack.empty()) FATAL_ERROR();
 #endif
         return FrameId(&callstack.data(), callstack.size()-1);
@@ -194,7 +198,7 @@ public:
         do{
             val = cls->attr().try_get(name);
             if(val != nullptr) return val;
-            Type base = _all_types[OBJ_GET(Type, cls)].base;
+            Type base = _all_types[PK_OBJ_GET(Type, cls)].base;
             if(base.index == -1) break;
             cls = _all_types[base].obj;
         }while(true);
@@ -202,7 +206,7 @@ public:
     }
 
     bool isinstance(PyObject* obj, Type cls_t){
-        Type obj_t = OBJ_GET(Type, _t(obj));
+        Type obj_t = PK_OBJ_GET(Type, _t(obj));
         do{
             if(obj_t == cls_t) return true;
             Type base = _all_types[obj_t].base;
@@ -216,14 +220,14 @@ public:
         if(_module == nullptr) _module = _main;
         try {
             CodeObject_ code = compile(source, filename, mode);
-#if DEBUG_DIS_EXEC
+#if PK_DEBUG_DIS_EXEC
             if(_module == _main) std::cout << disassemble(code) << '\n';
 #endif
             return _exec(code, _module);
         }catch (const Exception& e){
             _stderr(this, e.summary() + "\n");
         }
-#if !DEBUG_FULL_EXCEPTION
+#if !PK_DEBUG_FULL_EXCEPTION
         catch (const std::exception& e) {
             Str msg = "An std::exception occurred! It could be a bug.\n";
             msg = msg + e.what();
@@ -301,7 +305,7 @@ public:
 
     Type _new_type_object(StrName name, Type base=0) {
         PyObject* obj = new_type_object(nullptr, name, base, false);
-        return OBJ_GET(Type, obj);
+        return PK_OBJ_GET(Type, obj);
     }
 
     PyObject* _find_type_object(const Str& type){
@@ -316,7 +320,7 @@ public:
 
     Type _type(const Str& type){
         PyObject* obj = _find_type_object(type);
-        return OBJ_GET(Type, obj);
+        return PK_OBJ_GET(Type, obj);
     }
 
     PyTypeInfo* _type_info(const Str& type){
@@ -325,7 +329,7 @@ public:
             for(auto& t: _all_types) if(t.name == type) return &t;
             FATAL_ERROR();
         }
-        return &_all_types[OBJ_GET(Type, obj)];
+        return &_all_types[PK_OBJ_GET(Type, obj)];
     }
 
     PyTypeInfo* _type_info(Type type){
@@ -344,7 +348,7 @@ public:
         PyObject* nf = bind_method<0>(_t(type), #name, [](VM* vm, ArgsView args){       \
             return lambda_get_userdata<PyObject*(*)(VM*, PyObject*)>(args.begin())(vm, args[0]);\
         });                                                                             \
-        OBJ_GET(NativeFunc, nf).set_userdata(f);                                        \
+        PK_OBJ_GET(NativeFunc, nf).set_userdata(f);                                        \
     }
 
     BIND_UNARY_SPECIAL(__repr__)
@@ -367,7 +371,7 @@ public:
         PyObject* nf = bind_method<1>(obj, #name, [](VM* vm, ArgsView args){            \
             return lambda_get_userdata<BinaryFuncC>(args.begin())(vm, args[0], args[1]); \
         });                                                                             \
-        OBJ_GET(NativeFunc, nf).set_userdata(f);                                        \
+        PK_OBJ_GET(NativeFunc, nf).set_userdata(f);                                        \
     }
 
     BIND_BINARY_SPECIAL(__eq__)
@@ -400,7 +404,7 @@ public:
         PyObject* nf = bind_method<1>(obj, "__getitem__", [](VM* vm, ArgsView args){
             return lambda_get_userdata<PyObject*(*)(VM*, PyObject*, PyObject*)>(args.begin())(vm, args[0], args[1]);
         });
-        OBJ_GET(NativeFunc, nf).set_userdata(f);
+        PK_OBJ_GET(NativeFunc, nf).set_userdata(f);
     }
 
     void bind__setitem__(Type type, void (*f)(VM*, PyObject*, PyObject*, PyObject*)){
@@ -410,7 +414,7 @@ public:
             lambda_get_userdata<void(*)(VM* vm, PyObject*, PyObject*, PyObject*)>(args.begin())(vm, args[0], args[1], args[2]);
             return vm->None;
         });
-        OBJ_GET(NativeFunc, nf).set_userdata(f);
+        PK_OBJ_GET(NativeFunc, nf).set_userdata(f);
     }
 
     void bind__delitem__(Type type, void (*f)(VM*, PyObject*, PyObject*)){
@@ -420,7 +424,7 @@ public:
             lambda_get_userdata<void(*)(VM*, PyObject*, PyObject*)>(args.begin())(vm, args[0], args[1]);
             return vm->None;
         });
-        OBJ_GET(NativeFunc, nf).set_userdata(f);
+        PK_OBJ_GET(NativeFunc, nf).set_userdata(f);
     }
 
     bool py_equals(PyObject* lhs, PyObject* rhs){
@@ -463,7 +467,7 @@ public:
     template<typename T, typename __T>
     PyObject* bind_default_constructor(__T&& type) {
         return bind_constructor<1>(std::forward<__T>(type), [](VM* vm, ArgsView args){
-            Type t = OBJ_GET(Type, args[0]);
+            Type t = PK_OBJ_GET(Type, args[0]);
             return vm->heap.gcnew<T>(t, T());
         });
     }
@@ -513,7 +517,7 @@ public:
     void IndexError(const Str& msg){ _error("IndexError", msg); }
     void ValueError(const Str& msg){ _error("ValueError", msg); }
     void NameError(StrName name){ _error("NameError", fmt("name ", name.escape() + " is not defined")); }
-    void KeyError(PyObject* obj){ _error("KeyError", OBJ_GET(Str, py_repr(obj))); }
+    void KeyError(PyObject* obj){ _error("KeyError", PK_OBJ_GET(Str, py_repr(obj))); }
     void BinaryOptError(const char* op) { TypeError(fmt("unsupported operand type(s) for ", op)); }
 
     void AttributeError(PyObject* obj, StrName name){
@@ -638,7 +642,7 @@ public:
         _modules.clear();
         _lazy_modules.clear();
     }
-#if DEBUG_CEVAL_STEP
+#if PK_DEBUG_CEVAL_STEP
     void _log_s_data(const char* title = nullptr);
 #endif
     void _unpack_as_list(ArgsView args, List& list);
@@ -672,7 +676,7 @@ inline PyObject* NativeFunc::operator()(VM* vm, ArgsView args) const{
     if(args.size() != argc && argc != -1) {
         vm->TypeError(fmt("expected ", argc, " arguments, got ", args.size()));
     }
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
     if(f == nullptr) FATAL_ERROR();
 #endif
     return f(vm, args);
@@ -698,10 +702,10 @@ DEF_NATIVE_2(StarWrapper, tp_star_wrapper)
 #define PY_CAST_INT(T)                                  \
 template<> inline T py_cast<T>(VM* vm, PyObject* obj){  \
     vm->check_int(obj);                                 \
-    return (T)(BITS(obj) >> 2);                         \
+    return (T)(PK_BITS(obj) >> 2);                         \
 }                                                       \
 template<> inline T _py_cast<T>(VM* vm, PyObject* obj){ \
-    return (T)(BITS(obj) >> 2);                         \
+    return (T)(PK_BITS(obj) >> 2);                         \
 }
 
 PY_CAST_INT(char)
@@ -718,20 +722,20 @@ PY_CAST_INT(unsigned long long)
 
 template<> inline float py_cast<float>(VM* vm, PyObject* obj){
     vm->check_float(obj);
-    i64 bits = BITS(obj) & Number::c1;
+    i64 bits = PK_BITS(obj) & Number::c1;
     return BitsCvt(bits)._float;
 }
 template<> inline float _py_cast<float>(VM* vm, PyObject* obj){
-    i64 bits = BITS(obj) & Number::c1;
+    i64 bits = PK_BITS(obj) & Number::c1;
     return BitsCvt(bits)._float;
 }
 template<> inline double py_cast<double>(VM* vm, PyObject* obj){
     vm->check_float(obj);
-    i64 bits = BITS(obj) & Number::c1;
+    i64 bits = PK_BITS(obj) & Number::c1;
     return BitsCvt(bits)._float;
 }
 template<> inline double _py_cast<double>(VM* vm, PyObject* obj){
-    i64 bits = BITS(obj) & Number::c1;
+    i64 bits = PK_BITS(obj) & Number::c1;
     return BitsCvt(bits)._float;
 }
 
@@ -1050,7 +1054,7 @@ inline Str VM::disassemble(CodeObject_ co){
     return Str(ss.str());
 }
 
-#if DEBUG_CEVAL_STEP
+#if PK_DEBUG_CEVAL_STEP
 inline void VM::_log_s_data(const char* title) {
     if(_main == nullptr) return;
     if(callstack.empty()) return;
@@ -1080,7 +1084,7 @@ inline void VM::_log_s_data(const char* title) {
             auto& f = CAST(Function&, obj);
             ss << f.decl->code->name << "(...)";
         } else if(is_type(obj, tp_type)){
-            Type t = OBJ_GET(Type, obj);
+            Type t = PK_OBJ_GET(Type, obj);
             ss << "<class " + _all_types[t].name.escape() + ">";
         } else if(is_type(obj, tp_list)){
             auto& t = CAST(List&, obj);
@@ -1220,7 +1224,7 @@ inline PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
     ArgsView args(p1 - ARGC - int(method_call), p1);
 
     if(is_non_tagged_type(callable, tp_native_func)){
-        const auto& f = OBJ_GET(NativeFunc, callable);
+        const auto& f = PK_OBJ_GET(NativeFunc, callable);
         if(KWARGC != 0) TypeError("native_func does not accept keyword arguments");
         PyObject* ret = f(this, args);
         s_data.reset(p0);
@@ -1327,12 +1331,12 @@ inline PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
         DEF_SNAME(__new__);
         PyObject* new_f = find_name_in_mro(callable, __new__);
         PyObject* obj;
-#if DEBUG_EXTRA_CHECK
+#if PK_DEBUG_EXTRA_CHECK
         PK_ASSERT(new_f != nullptr);
 #endif
         if(new_f == cached_object__new__) {
             // fast path for object.__new__
-            Type t = OBJ_GET(Type, callable);
+            Type t = PK_OBJ_GET(Type, callable);
             obj= vm->heap.gcnew<DummyInstance>(t, {});
         }else{
             PUSH(new_f);
@@ -1382,7 +1386,7 @@ inline PyObject* VM::getattr(PyObject* obj, StrName name, bool throw_err){
     PyObject* objtype;
     // handle super() proxy
     if(is_non_tagged_type(obj, tp_super)){
-        const Super& super = OBJ_GET(Super, obj);
+        const Super& super = PK_OBJ_GET(Super, obj);
         obj = super.first;
         objtype = _t(super.second);
     }else{
@@ -1419,7 +1423,7 @@ inline PyObject* VM::get_unbound_method(PyObject* obj, StrName name, PyObject**
     PyObject* objtype;
     // handle super() proxy
     if(is_non_tagged_type(obj, tp_super)){
-        const Super& super = OBJ_GET(Super, obj);
+        const Super& super = PK_OBJ_GET(Super, obj);
         obj = super.first;
         objtype = _t(super.second);
     }else{
@@ -1456,7 +1460,7 @@ inline void VM::setattr(PyObject* obj, StrName name, PyObject* value){
     PyObject* objtype;
     // handle super() proxy
     if(is_non_tagged_type(obj, tp_super)){
-        Super& super = OBJ_GET(Super, obj);
+        Super& super = PK_OBJ_GET(Super, obj);
         obj = super.first;
         objtype = _t(super.second);
     }else{
@@ -1547,7 +1551,7 @@ inline void VM::bind__hash__(Type type, i64 (*f)(VM*, PyObject*)){
         i64 ret = lambda_get_userdata<i64(*)(VM*, PyObject*)>(args.begin())(vm, args[0]);
         return VAR(ret);
     });
-    OBJ_GET(NativeFunc, nf).set_userdata(f);
+    PK_OBJ_GET(NativeFunc, nf).set_userdata(f);
 }
 
 inline void VM::bind__len__(Type type, i64 (*f)(VM*, PyObject*)){
@@ -1557,7 +1561,7 @@ inline void VM::bind__len__(Type type, i64 (*f)(VM*, PyObject*)){
         i64 ret = lambda_get_userdata<i64(*)(VM*, PyObject*)>(args.begin())(vm, args[0]);
         return VAR(ret);
     });
-    OBJ_GET(NativeFunc, nf).set_userdata(f);
+    PK_OBJ_GET(NativeFunc, nf).set_userdata(f);
 }