Refine compat version of ExecEvalExpr routine

Author: Maksim Milyutin

src/include/compat/pg_compat.h

@@ -165,13 +165,20 @@ extern void create_plain_partial_paths(PlannerInfo *root,
 
 /*
  * ExecEvalExpr
+ *
+ * 'errmsg' specifies error string when result of ExecEvalExpr doesn't return
+ * 		a single value
  */
 #if PG_VERSION_NUM >= 100000
-#define ExecEvalExprCompat(expr, econtext, isNull, isDone) \
+#define ExecEvalExprCompat(expr, econtext, isNull, errmsg) \
 	ExecEvalExpr((expr), (econtext), (isNull))
-#else
-#define ExecEvalExprCompat(expr, econtext, isNull, isDone) \
-	ExecEvalExpr((expr), (econtext), (isNull), (isDone))
+#elif PG_VERSION_NUM >= 90500
+#define ExecEvalExprCompat(expr, econtext, isNull, errmsg) \
+	do { \
+		ExecEvalExpr((expr), (econtext), (isNull), (isDone)); \
+		if (isDone != ExprSingleResult) \
+			elog(ERROR, (errmsg)); \
+	} while (0)
 #endif
 
 

src/partition_filter.c

@@ -600,9 +600,6 @@ partition_filter_exec(CustomScanState *node)
 		ResultRelInfoHolder		   *rri_holder;
 		bool						isnull;
 		Datum						value;
-#if PG_VERSION_NUM < 100000
-		ExprDoneCond				itemIsDone;
-#endif
 		TupleTableSlot			   *tmp_slot;
 
 		/* Fetch PartRelationInfo for this partitioned relation */
@@ -624,17 +621,12 @@ partition_filter_exec(CustomScanState *node)
 		tmp_slot = econtext->ecxt_scantuple;
 		econtext->ecxt_scantuple = slot;
 		value = ExecEvalExprCompat(state->expr_state, econtext, &isnull,
-								   &itemIsDone);
+					ERR_PART_ATTR_MULTIPLE_RESULTS);
 		econtext->ecxt_scantuple = tmp_slot;
 
 		if (isnull)
 			elog(ERROR, ERR_PART_ATTR_NULL);
 
-#if PG_VERSION_NUM < 100000
-		if (itemIsDone != ExprSingleResult)
-			elog(ERROR, ERR_PART_ATTR_MULTIPLE_RESULTS);
-#endif
-
 		/* Search for a matching partition */
 		rri_holder = select_partition_for_insert(value, prel->ev_type, prel,
 												 &state->result_parts, estate);

src/pl_funcs.c

@@ -1153,9 +1153,6 @@ pathman_update_trigger_func(PG_FUNCTION_ARGS)
 	Datum					value;
 	Oid						value_type;
 	bool					isnull;
-#if PG_VERSION_NUM < 100000
-	ExprDoneCond			itemIsDone;
-#endif
 
 	Oid					   *parts;
 	int						nparts;
@@ -1204,17 +1201,13 @@ pathman_update_trigger_func(PG_FUNCTION_ARGS)
 														 source_rel,
 														 new_tuple,
 														 &value_type);
-	value = ExecEvalExprCompat(expr_state, econtext, &isnull, &itemIsDone);
+	value = ExecEvalExprCompat(expr_state, econtext, &isnull,
+				ERR_PART_ATTR_MULTIPLE_RESULTS);
 	MemoryContextSwitchTo(old_mcxt);
 
 	if (isnull)
 		elog(ERROR, ERR_PART_ATTR_NULL);
 
-#if PG_VERSION_NUM < 100000
-	if (itemIsDone != ExprSingleResult)
-		elog(ERROR, ERR_PART_ATTR_MULTIPLE_RESULTS);
-#endif
-
 	/* Search for matching partitions */
 	parts = find_partitions_for_value(value, value_type, prel, &nparts);
 

src/utility_stmt_hooking.c

@@ -607,9 +607,6 @@ PathmanCopyFrom(CopyState cstate, Relation parent_rel,
 	{
 		TupleTableSlot		   *slot,
 							   *tmp_slot;
-#if PG_VERSION_NUM < 100000
-		ExprDoneCond			itemIsDone;
-#endif
 		bool					skip_tuple,
 								isnull;
 		Oid						tuple_oid = InvalidOid;
@@ -653,17 +650,13 @@ PathmanCopyFrom(CopyState cstate, Relation parent_rel,
 		/* Execute expression */
 		tmp_slot = econtext->ecxt_scantuple;
 		econtext->ecxt_scantuple = slot;
-		value = ExecEvalExprCompat(expr_state, econtext, &isnull, &itemIsDone);
+		value = ExecEvalExprCompat(expr_state, econtext, &isnull,
+					ERR_PART_ATTR_MULTIPLE_RESULTS);
 		econtext->ecxt_scantuple = tmp_slot;
 
 		if (isnull)
 			elog(ERROR, ERR_PART_ATTR_NULL);
 
-#if PG_VERSION_NUM < 100000
-		if (itemIsDone != ExprSingleResult)
-			elog(ERROR, ERR_PART_ATTR_MULTIPLE_RESULTS);
-#endif
-
 		/* Search for a matching partition */
 		rri_holder = select_partition_for_insert(value,
 												 prel->ev_type, prel,