Make function CreateTemplateTupleDesc compatable with PG12

Move CreateTemplateTupleDesc to compat module to support compatibility
with PG12.

Author: maksm90

compat.c

@@ -1,4 +1,5 @@
 #include "postgres.h"
+#include "access/tupdesc.h"
 
 #include "pg_wait_sampling.h"
 
@@ -11,3 +12,13 @@ shm_mq_detach_compat(shm_mq_handle *mqh, shm_mq *mq)
 	shm_mq_detach(mq);
 #endif
 }
+
+inline TupleDesc
+CreateTemplateTupleDescCompat(int nattrs, bool hasoid)
+{
+#if PG_VERSION_NUM >= 120000
+	return CreateTemplateTupleDesc(nattrs);
+#else
+	return CreateTemplateTupleDesc(nattrs, hasoid);
+#endif
+}

pg_wait_sampling.c

@@ -380,11 +380,7 @@ pg_wait_sampling_get_current(PG_FUNCTION_ARGS)
 		params->ts = GetCurrentTimestamp();
 
 		funcctx->user_fctx = params;
-#if PG_VERSION_NUM >= 120000
-		tupdesc = CreateTemplateTupleDesc(4);
-#else
-		tupdesc = CreateTemplateTupleDesc(4, false);
-#endif
+		tupdesc = CreateTemplateTupleDescCompat(4, false);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "pid",
 						   INT4OID, -1, 0);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "type",
@@ -589,11 +585,7 @@ pg_wait_sampling_get_profile(PG_FUNCTION_ARGS)
 		funcctx->max_calls = profile->count;
 
 		/* Make tuple descriptor */
-#if PG_VERSION_NUM >= 120000
-		tupdesc = CreateTemplateTupleDesc(5);
-#else
-		tupdesc = CreateTemplateTupleDesc(5, false);
-#endif
+		tupdesc = CreateTemplateTupleDescCompat(5, false);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "pid",
 						   INT4OID, -1, 0);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "type",
@@ -711,11 +703,7 @@ pg_wait_sampling_get_history(PG_FUNCTION_ARGS)
 		funcctx->max_calls = history->count;
 
 		/* Make tuple descriptor */
-#if PG_VERSION_NUM >= 120000
-		tupdesc = CreateTemplateTupleDesc(5);
-#else
-		tupdesc = CreateTemplateTupleDesc(5, false);
-#endif
+		tupdesc = CreateTemplateTupleDescCompat(5, false);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "pid",
 						   INT4OID, -1, 0);
 		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "sample_ts",

pg_wait_sampling.h

@@ -84,5 +84,6 @@ extern void alloc_history(History *, int);
 extern void collector_main(Datum main_arg);
 
 extern void shm_mq_detach_compat(shm_mq_handle *mqh, shm_mq *mq);
+extern TupleDesc CreateTemplateTupleDescCompat(int nattrs, bool hasoid);
 
 #endif