Revert "Prepare for Python "Limited API" in PL/Python"

This reverts commit c47e8df815c1c45f4e4fc90d5817d67ab088279f.

That commit makes the plpython tests crash with Python 3.6.* and
3.7.*.  It will need further investigation and testing, so revert for
now.

1 files changed, 17 insertions, 24 deletions

diff --git a/src/pl/plpython/plpy_subxactobject.c b/src/pl/plpython/plpy_subxactobject.c
index cc7ff3f9df7..5c92a0e089a 100644
--- a/src/pl/plpython/plpy_subxactobject.c
+++ b/src/pl/plpython/plpy_subxactobject.c
@@ -15,6 +15,7 @@
 List	   *explicit_subtransactions = NIL;
 
 
+static void PLy_subtransaction_dealloc(PyObject *subxact);
 static PyObject *PLy_subtransaction_enter(PyObject *self, PyObject *unused);
 static PyObject *PLy_subtransaction_exit(PyObject *self, PyObject *args);
 
@@ -30,35 +31,21 @@ static PyMethodDef PLy_subtransaction_methods[] = {
 	{NULL, NULL, 0, NULL}
 };
 
-static PyType_Slot PLySubtransaction_slots[] =
-{
-	{
-		Py_tp_doc, (char *) PLy_subtransaction_doc
-	},
-	{
-		Py_tp_methods, PLy_subtransaction_methods
-	},
-	{
-		0, NULL
-	}
-};
-
-static PyType_Spec PLySubtransaction_spec =
-{
-	.name = "PLySubtransaction",
-		.basicsize = sizeof(PLySubtransactionObject),
-		.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-		.slots = PLySubtransaction_slots,
+static PyTypeObject PLy_SubtransactionType = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	.tp_name = "PLySubtransaction",
+	.tp_basicsize = sizeof(PLySubtransactionObject),
+	.tp_dealloc = PLy_subtransaction_dealloc,
+	.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+	.tp_doc = PLy_subtransaction_doc,
+	.tp_methods = PLy_subtransaction_methods,
 };
 
-static PyTypeObject *PLy_SubtransactionType;
-
 
 void
 PLy_subtransaction_init_type(void)
 {
-	PLy_SubtransactionType = (PyTypeObject *) PyType_FromSpec(&PLySubtransaction_spec);
-	if (!PLy_SubtransactionType)
+	if (PyType_Ready(&PLy_SubtransactionType) < 0)
 		elog(ERROR, "could not initialize PLy_SubtransactionType");
 }
 
@@ -68,7 +55,7 @@ PLy_subtransaction_new(PyObject *self, PyObject *unused)
 {
 	PLySubtransactionObject *ob;
 
-	ob = PyObject_New(PLySubtransactionObject, PLy_SubtransactionType);
+	ob = PyObject_New(PLySubtransactionObject, &PLy_SubtransactionType);
 
 	if (ob == NULL)
 		return NULL;
@@ -79,6 +66,12 @@ PLy_subtransaction_new(PyObject *self, PyObject *unused)
 	return (PyObject *) ob;
 }
 
+/* Python requires a dealloc function to be defined */
+static void
+PLy_subtransaction_dealloc(PyObject *subxact)
+{
+}
+
 /*
  * subxact.__enter__() or subxact.enter()
  *