Add version-compat header

For polyfill macros, etc.

src/backend/distributed/commands/create_distributed_table.c

@@ -46,6 +46,7 @@
 #include "distributed/remote_commands.h"
 #include "distributed/worker_protocol.h"
 #include "distributed/worker_transaction.h"
+#include "distributed/version_compat.h"
 #include "executor/executor.h"
 #include "executor/spi.h"
 #include "nodes/execnodes.h"

src/backend/distributed/commands/multi_copy.c

@@ -69,6 +69,7 @@
 #include "distributed/remote_commands.h"
 #include "distributed/resource_lock.h"
 #include "distributed/shard_pruning.h"
+#include "distributed/version_compat.h"
 #include "executor/executor.h"
 #include "nodes/makefuncs.h"
 #include "tsearch/ts_locale.h"

src/backend/distributed/executor/multi_utility.c

@@ -56,6 +56,7 @@
 #include "distributed/transmit.h"
 #include "distributed/worker_protocol.h"
 #include "distributed/worker_transaction.h"
+#include "distributed/version_compat.h"
 #include "executor/executor.h"
 #include "foreign/foreign.h"
 #include "lib/stringinfo.h"

src/backend/distributed/master/master_citus_tools.c

@@ -23,6 +23,7 @@
 #include "distributed/multi_server_executor.h"
 #include "distributed/remote_commands.h"
 #include "distributed/worker_protocol.h"
+#include "distributed/version_compat.h"
 #include "lib/stringinfo.h"
 #include "utils/builtins.h"
 

src/backend/distributed/metadata/metadata_sync.c

@@ -38,6 +38,7 @@
 #include "distributed/pg_dist_node.h"
 #include "distributed/worker_manager.h"
 #include "distributed/worker_transaction.h"
+#include "distributed/version_compat.h"
 #include "foreign/foreign.h"
 #include "nodes/pg_list.h"
 #include "utils/builtins.h"

src/backend/distributed/planner/deparse_shard_query.c

@@ -20,6 +20,7 @@
 #include "distributed/metadata_cache.h"
 #include "distributed/multi_physical_planner.h"
 #include "distributed/multi_router_planner.h"
+#include "distributed/version_compat.h"
 #include "lib/stringinfo.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"

src/backend/distributed/utils/citus_ruleutils.c

@@ -37,6 +37,7 @@
 #include "distributed/multi_partitioning_utils.h"
 #include "distributed/relay_utility.h"
 #include "distributed/master_metadata_utility.h"
+#include "distributed/version_compat.h"
 #include "foreign/foreign.h"
 #include "lib/stringinfo.h"
 #include "nodes/nodes.h"

src/include/distributed/version_compat.h

@@ -0,0 +1,24 @@
+/*-------------------------------------------------------------------------
+ *
+ * version_compat.h
+ *	  Compatibility macros for writing code agnostic to PostgreSQL versions
+ *
+ * Copyright (c) 2017, Citus Data, Inc.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef VERSION_COMPAT_H
+#define VERSION_COMPAT_H
+
+#include "postgres.h"
+
+#if (PG_VERSION_NUM >= 90600 && PG_VERSION_NUM < 90700)
+
+/* Backports from PostgreSQL 10 */
+/* Accessor for the i'th attribute of tupdesc. */
+#define TupleDescAttr(tupdesc, i) ((tupdesc)->attrs[(i)])
+
+#endif
+
+#endif   /* VERSION_COMPAT_H */