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

This reverts commit c47e8df.

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.

Author: petere

src/pl/plpython/plpy_cursorobject.c

@@ -20,7 +20,7 @@
 #include "utils/memutils.h"
 
 static PyObject *PLy_cursor_query(const char *query);
-static void PLy_cursor_dealloc(PLyCursorObject *self);
+static void PLy_cursor_dealloc(PyObject *arg);
 static PyObject *PLy_cursor_iternext(PyObject *self);
 static PyObject *PLy_cursor_fetch(PyObject *self, PyObject *args);
 static PyObject *PLy_cursor_close(PyObject *self, PyObject *unused);
@@ -33,43 +33,22 @@ static PyMethodDef PLy_cursor_methods[] = {
 	{NULL, NULL, 0, NULL}
 };
 
-static PyType_Slot PLyCursor_slots[] =
-{
-	{
-		Py_tp_dealloc, PLy_cursor_dealloc
-	},
-	{
-		Py_tp_doc, (char *) PLy_cursor_doc
-	},
-	{
-		Py_tp_iter, PyObject_SelfIter
-	},
-	{
-		Py_tp_iternext, PLy_cursor_iternext
-	},
-	{
-		Py_tp_methods, PLy_cursor_methods
-	},
-	{
-		0, NULL
-	}
+static PyTypeObject PLy_CursorType = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	.tp_name = "PLyCursor",
+	.tp_basicsize = sizeof(PLyCursorObject),
+	.tp_dealloc = PLy_cursor_dealloc,
+	.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+	.tp_doc = PLy_cursor_doc,
+	.tp_iter = PyObject_SelfIter,
+	.tp_iternext = PLy_cursor_iternext,
+	.tp_methods = PLy_cursor_methods,
 };
 
-static PyType_Spec PLyCursor_spec =
-{
-	.name = "PLyCursor",
-		.basicsize = sizeof(PLyCursorObject),
-		.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-		.slots = PLyCursor_slots,
-};
-
-static PyTypeObject *PLy_CursorType;
-
 void
 PLy_cursor_init_type(void)
 {
-	PLy_CursorType = (PyTypeObject *) PyType_FromSpec(&PLyCursor_spec);
-	if (!PLy_CursorType)
+	if (PyType_Ready(&PLy_CursorType) < 0)
 		elog(ERROR, "could not initialize PLy_CursorType");
 }
 
@@ -101,7 +80,7 @@ PLy_cursor_query(const char *query)
 	volatile MemoryContext oldcontext;
 	volatile ResourceOwner oldowner;
 
-	if ((cursor = PyObject_New(PLyCursorObject, PLy_CursorType)) == NULL)
+	if ((cursor = PyObject_New(PLyCursorObject, &PLy_CursorType)) == NULL)
 		return NULL;
 	cursor->portalname = NULL;
 	cursor->closed = false;
@@ -198,7 +177,7 @@ PLy_cursor_plan(PyObject *ob, PyObject *args)
 		return NULL;
 	}
 
-	if ((cursor = PyObject_New(PLyCursorObject, PLy_CursorType)) == NULL)
+	if ((cursor = PyObject_New(PLyCursorObject, &PLy_CursorType)) == NULL)
 		return NULL;
 	cursor->portalname = NULL;
 	cursor->closed = false;
@@ -293,30 +272,30 @@ PLy_cursor_plan(PyObject *ob, PyObject *args)
 }
 
 static void
-PLy_cursor_dealloc(PLyCursorObject *self)
+PLy_cursor_dealloc(PyObject *arg)
 {
-	PyTypeObject *tp = Py_TYPE(self);
+	PLyCursorObject *cursor;
 	Portal		portal;
 
-	if (!self->closed)
+	cursor = (PLyCursorObject *) arg;
+
+	if (!cursor->closed)
 	{
-		portal = GetPortalByName(self->portalname);
+		portal = GetPortalByName(cursor->portalname);
 
 		if (PortalIsValid(portal))
 		{
 			UnpinPortal(portal);
 			SPI_cursor_close(portal);
 		}
-		self->closed = true;
+		cursor->closed = true;
 	}
-	if (self->mcxt)
+	if (cursor->mcxt)
 	{
-		MemoryContextDelete(self->mcxt);
-		self->mcxt = NULL;
+		MemoryContextDelete(cursor->mcxt);
+		cursor->mcxt = NULL;
 	}
-
-	PyObject_Free(self);
-	Py_DECREF(tp);
+	arg->ob_type->tp_free(arg);
 }
 
 static PyObject *

src/pl/plpython/plpy_planobject.c

@@ -12,7 +12,7 @@
 #include "plpython.h"
 #include "utils/memutils.h"
 
-static void PLy_plan_dealloc(PLyPlanObject *self);
+static void PLy_plan_dealloc(PyObject *arg);
 static PyObject *PLy_plan_cursor(PyObject *self, PyObject *args);
 static PyObject *PLy_plan_execute(PyObject *self, PyObject *args);
 static PyObject *PLy_plan_status(PyObject *self, PyObject *args);
@@ -26,37 +26,20 @@ static PyMethodDef PLy_plan_methods[] = {
 	{NULL, NULL, 0, NULL}
 };
 
-static PyType_Slot PLyPlan_slots[] =
-{
-	{
-		Py_tp_dealloc, PLy_plan_dealloc
-	},
-	{
-		Py_tp_doc, (char *) PLy_plan_doc
-	},
-	{
-		Py_tp_methods, PLy_plan_methods
-	},
-	{
-		0, NULL
-	}
+static PyTypeObject PLy_PlanType = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	.tp_name = "PLyPlan",
+	.tp_basicsize = sizeof(PLyPlanObject),
+	.tp_dealloc = PLy_plan_dealloc,
+	.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+	.tp_doc = PLy_plan_doc,
+	.tp_methods = PLy_plan_methods,
 };
 
-static PyType_Spec PLyPlan_spec =
-{
-	.name = "PLyPlan",
-		.basicsize = sizeof(PLyPlanObject),
-		.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-		.slots = PLyPlan_slots,
-};
-
-static PyTypeObject *PLy_PlanType;
-
 void
 PLy_plan_init_type(void)
 {
-	PLy_PlanType = (PyTypeObject *) PyType_FromSpec(&PLyPlan_spec);
-	if (!PLy_PlanType)
+	if (PyType_Ready(&PLy_PlanType) < 0)
 		elog(ERROR, "could not initialize PLy_PlanType");
 }
 
@@ -65,7 +48,7 @@ PLy_plan_new(void)
 {
 	PLyPlanObject *ob;
 
-	if ((ob = PyObject_New(PLyPlanObject, PLy_PlanType)) == NULL)
+	if ((ob = PyObject_New(PLyPlanObject, &PLy_PlanType)) == NULL)
 		return NULL;
 
 	ob->plan = NULL;
@@ -80,27 +63,25 @@ PLy_plan_new(void)
 bool
 is_PLyPlanObject(PyObject *ob)
 {
-	return ob->ob_type == PLy_PlanType;
+	return ob->ob_type == &PLy_PlanType;
 }
 
 static void
-PLy_plan_dealloc(PLyPlanObject *self)
+PLy_plan_dealloc(PyObject *arg)
 {
-	PyTypeObject *tp = Py_TYPE(self);
+	PLyPlanObject *ob = (PLyPlanObject *) arg;
 
-	if (self->plan)
+	if (ob->plan)
 	{
-		SPI_freeplan(self->plan);
-		self->plan = NULL;
+		SPI_freeplan(ob->plan);
+		ob->plan = NULL;
 	}
-	if (self->mcxt)
+	if (ob->mcxt)
 	{
-		MemoryContextDelete(self->mcxt);
-		self->mcxt = NULL;
+		MemoryContextDelete(ob->mcxt);
+		ob->mcxt = NULL;
 	}
-
-	PyObject_Free(self);
-	Py_DECREF(tp);
+	arg->ob_type->tp_free(arg);
 }
 
 

src/pl/plpython/plpy_procedure.c

@@ -350,7 +350,6 @@ PLy_procedure_compile(PLyProcedure *proc, const char *src)
 {
 	PyObject   *crv = NULL;
 	char	   *msrc;
-	PyObject   *code0;
 
 	proc->globals = PyDict_Copy(PLy_interp_globals);
 
@@ -369,9 +368,7 @@ PLy_procedure_compile(PLyProcedure *proc, const char *src)
 	msrc = PLy_procedure_munge_source(proc->pyname, src);
 	/* Save the mangled source for later inclusion in tracebacks */
 	proc->src = MemoryContextStrdup(proc->mcxt, msrc);
-	code0 = Py_CompileString(msrc, "<string>", Py_file_input);
-	if (code0)
-		crv = PyEval_EvalCode(code0, proc->globals, NULL);
+	crv = PyRun_String(msrc, Py_file_input, proc->globals, NULL);
 	pfree(msrc);
 
 	if (crv != NULL)