Avoid using the "tp_iternext" slot when CYTHON_USE_TYPE_SLOTS is disabled.

Cython/Compiler/ExprNodes.py

@@ -2808,7 +2808,7 @@ class IteratorNode(ExprNode):
             # PyObject_GetIter() fails if "tp_iternext" is not set, but the check below
             # makes it visible to the C compiler that the pointer really isn't NULL, so that
             # it can distinguish between the special cases and the generic case
-            code.putln("%s = Py_TYPE(%s)->tp_iternext; %s" % (
+            code.putln("%s = __Pyx_PyObject_GetIterNext(%s); %s" % (
                 self.iter_func_ptr, self.py_result(),
                 code.error_goto_if_null(self.iter_func_ptr, self.pos)))
         if self.may_be_a_sequence:
@@ -7775,7 +7775,7 @@ class SequenceNode(ExprNode):
         rhs.generate_disposal_code(code)
 
         iternext_func = code.funcstate.allocate_temp(self._func_iternext_type, manage_ref=False)
-        code.putln("%s = Py_TYPE(%s)->tp_iternext;" % (
+        code.putln("%s = __Pyx_PyObject_GetIterNext(%s);" % (
             iternext_func, iterator_temp))
 
         unpacking_error_label = code.new_label('unpacking_failed')

Cython/Utility/Coroutine.c

@@ -44,11 +44,7 @@ static CYTHON_INLINE PyObject* __Pyx_Generator_Yield_From(__pyx_CoroutineObject
                 return NULL;
         }
         // source_gen is now the iterator, make the first next() call
-#if CYTHON_USE_TYPE_SLOTS
-        retval = Py_TYPE(source_gen)->tp_iternext(source_gen);
-#else
-        retval = PyIter_Next(source_gen);
-#endif
+        retval = __Pyx_PyObject_GetIterNext(source_gen)(source_gen);
     }
     if (likely(retval)) {
         gen->yieldfrom = source_gen;
@@ -77,11 +73,7 @@ static PyObject* __Pyx__Coroutine_Yield_From_Generic(__pyx_CoroutineObject *gen,
     if (__Pyx_Coroutine_Check(source_gen)) {
         retval = __Pyx_Generator_Next(source_gen);
     } else {
-#if CYTHON_USE_TYPE_SLOTS
-        retval = Py_TYPE(source_gen)->tp_iternext(source_gen);
-#else
-        retval = PyIter_Next(source_gen);
-#endif
+        retval = __Pyx_PyObject_GetIterNext(source_gen)(source_gen);
     }
     if (retval) {
         gen->yieldfrom = source_gen;
@@ -857,7 +849,7 @@ static PyObject *__Pyx_Coroutine_Send(PyObject *self, PyObject *value) {
         #endif
         {
             if (value == Py_None)
-                ret = Py_TYPE(yf)->tp_iternext(yf);
+                ret = __Pyx_PyObject_GetIterNext(yf)(yf);
             else
                 ret = __Pyx_PyObject_CallMethod1(yf, PYIDENT("send"), value);
         }
@@ -955,7 +947,7 @@ static PyObject *__Pyx_Generator_Next(PyObject *self) {
             ret = __Pyx_Coroutine_Send(yf, Py_None);
         } else
         #endif
-            ret = Py_TYPE(yf)->tp_iternext(yf);
+            ret = __Pyx_PyObject_GetIterNext(yf)(yf);
         gen->is_running = 0;
         //Py_DECREF(yf);
         if (likely(ret)) {

Cython/Utility/ModuleSetupCode.c

@@ -711,8 +711,10 @@ static CYTHON_INLINE PyObject * __Pyx_PyDict_GetItemStrWithError(PyObject *dict,
 
 #if CYTHON_USE_TYPE_SLOTS
   #define __Pyx_PyType_HasFeature(type, feature)  ((__Pyx_PyType_GetFlags(type) & (feature)) != 0)
+  #define __Pyx_PyObject_GetIterNext(obj)  (Py_TYPE(obj)->tp_iternext)
 #else
   #define __Pyx_PyType_HasFeature(type, feature)  PyType_HasFeature(type, feature)
+  #define __Pyx_PyObject_GetIterNext(obj)  PyIter_Next
 #endif
 
 #if CYTHON_COMPILING_IN_LIMITED_API

Cython/Utility/ObjectHandling.c

@@ -133,7 +133,7 @@ static int __Pyx_unpack_tuple2_generic(PyObject* tuple, PyObject** pvalue1, PyOb
     if (unlikely(!iter)) goto bad;
     if (decref_tuple) { Py_DECREF(tuple); tuple = NULL; }
 
-    iternext = Py_TYPE(iter)->tp_iternext;
+    iternext = __Pyx_PyObject_GetIterNext(iter);
     value1 = iternext(iter); if (unlikely(!value1)) { index = 0; goto unpacking_failed; }
     value2 = iternext(iter); if (unlikely(!value2)) { index = 1; goto unpacking_failed; }
     if (!has_known_size && unlikely(__Pyx_IternextUnpackEndCheck(iternext(iter), 2))) goto bad;