Add flag CYTHON_USE_TP_FINALIZEto control whether tp_finalize is used.

Disable it on pypy3, since it doesn't support PEP 442 yet.

Cython/Compiler/ModuleNode.py

@@ -1408,7 +1408,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
 
         if not is_final_type:
             # in Py3.4+, call tp_finalize() as early as possible
-            code.putln("#if PY_VERSION_HEX >= 0x030400a1")
+            code.putln("#if CYTHON_USE_TP_FINALIZE")
             if needs_gc:
                 finalised_check = '!_PyGC_FINALIZED(o)'
             else:

Cython/Utility/AsyncGen.c

@@ -387,13 +387,13 @@ PyTypeObject __pyx_AsyncGenType_type = {
     0,                                          /* tp_cache */
     0,                                          /* tp_subclasses */
     0,                                          /* tp_weaklist */
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     0,                                  /*tp_del*/
 #else
     __Pyx_Coroutine_del,                /*tp_del*/
 #endif
     0,                                          /* tp_version_tag */
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     __Pyx_Coroutine_del,                        /* tp_finalize */
 #endif
 };

Cython/Utility/Coroutine.c

@@ -1553,13 +1553,13 @@ static PyTypeObject __pyx_CoroutineType_type = {
     0,                                  /*tp_cache*/
     0,                                  /*tp_subclasses*/
     0,                                  /*tp_weaklist*/
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     0,                                  /*tp_del*/
 #else
     __Pyx_Coroutine_del,                /*tp_del*/
 #endif
     0,                                  /*tp_version_tag*/
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     __Pyx_Coroutine_del,                /*tp_finalize*/
 #endif
 };
@@ -1653,13 +1653,13 @@ static PyTypeObject __pyx_GeneratorType_type = {
     0,                                  /*tp_cache*/
     0,                                  /*tp_subclasses*/
     0,                                  /*tp_weaklist*/
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     0,                                  /*tp_del*/
 #else
     __Pyx_Coroutine_del,                /*tp_del*/
 #endif
     0,                                  /*tp_version_tag*/
-#if PY_VERSION_HEX >= 0x030400a1
+#if CYTHON_USE_TP_FINALIZE
     __Pyx_Coroutine_del,                /*tp_finalize*/
 #endif
 };

Cython/Utility/ModuleSetupCode.c

@@ -77,6 +77,8 @@
   #define CYTHON_FAST_PYCALL 0
   #undef CYTHON_PEP489_MULTI_PHASE_INIT
   #define CYTHON_PEP489_MULTI_PHASE_INIT 0
+  #undef CYTHON_USE_TP_FINALIZE
+  #define CYTHON_USE_TP_FINALIZE 0
 
 #elif defined(PYSTON_VERSION)
   #define CYTHON_COMPILING_IN_PYPY 0
@@ -114,6 +116,8 @@
   #define CYTHON_FAST_PYCALL 0
   #undef CYTHON_PEP489_MULTI_PHASE_INIT
   #define CYTHON_PEP489_MULTI_PHASE_INIT 0
+  #undef CYTHON_USE_TP_FINALIZE
+  #define CYTHON_USE_TP_FINALIZE 0
 
 #else
   #define CYTHON_COMPILING_IN_PYPY 0
@@ -172,6 +176,9 @@
   #ifndef CYTHON_PEP489_MULTI_PHASE_INIT
     #define CYTHON_PEP489_MULTI_PHASE_INIT (PY_VERSION_HEX >= 0x03050000)
   #endif
+  #ifndef CYTHON_USE_TP_FINALIZE
+    #define CYTHON_USE_TP_FINALIZE (PY_VERSION_HEX >= 0x030400a1)
+  #endif
 #endif
 
 #if !defined(CYTHON_FAST_PYCCALL)