From ead63fe34690f0fc81031e50234e5801072e2bc7 Mon Sep 17 00:00:00 2001
From: chaotian <chaotian@vmware.com>
Date: Thu, 30 Nov 2023 10:15:48 +0800
Subject: [PATCH v3] Printing const-folder expression in ruleutils.c
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Previous coding in get_const_expr() has handled with negative number,
opexpr plus number is an exception. (ex. -1 could be a negative const
and also could be a opexpr ‘-’ plus number 1). So we needed to hacking
up in get_rule_sortgroupclause() for Opexpr cases and pre-calculate
opexpr plus number to real const by expression_planner().

There are two operators we need to worried about namely in4um and
numeric_uminus, and we also defined two macros Int4NegOperator
and NumericNegOperator in pg_operator.dat.
---
 src/backend/utils/adt/ruleutils.c   | 25 +++++++++++++++++++++++++
 src/include/catalog/pg_operator.dat |  4 ++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index ed7f40f053..6788e63192 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -6317,6 +6317,31 @@ get_rule_sortgroupclause(Index ref, List *tlist, bool force_colno,
 	}
 	else if (expr && IsA(expr, Const))
 		get_const_expr((Const *) expr, context, 1);
+	else if (expr && IsA(expr, OpExpr))
+	{
+		OpExpr		*opexpr = (OpExpr *)expr;
+		List		*args = opexpr->args;
+
+		/*
+		 * Const-folder the expression(opexpr plus const) to negative const,
+		 * mainly there are two operators we need to worried about, namely
+		 * in4um(Int4NegOperator) and numeric_uminus(NumericNegOperator),
+		 * and get_const_expr() is responsible for end up getting labeled
+		 * with a typecast.
+		 */
+		if (list_length(args) == 1)
+		{
+			Node	   *arg = (Node *) linitial(args);
+			Oid			opno = opexpr->opno;
+
+			if ((opno == Int4NegOperator ||
+				 opno == NumericNegOperator) &&
+				 IsA(arg, Const))
+				expr = (Node *)expression_planner((Expr *)expr);
+		}
+
+		get_rule_expr(expr, context, true);
+	}
 	else if (!expr || IsA(expr, Var))
 		get_rule_expr(expr, context, true);
 	else
diff --git a/src/include/catalog/pg_operator.dat b/src/include/catalog/pg_operator.dat
index b2cdea66c4..88e6825e58 100644
--- a/src/include/catalog/pg_operator.dat
+++ b/src/include/catalog/pg_operator.dat
@@ -575,7 +575,7 @@
 { oid => '557', descr => 'subtract',
   oprname => '-', oprleft => 'int4', oprright => 'int2', oprresult => 'int4',
   oprcode => 'int42mi' },
-{ oid => '558', descr => 'negate',
+{ oid => '558', oid_symbol => 'Int4NegOperator', descr => 'negate',
   oprname => '-', oprkind => 'l', oprleft => '0', oprright => 'int4',
   oprresult => 'int4', oprcode => 'int4um' },
 { oid => '559', descr => 'negate',
@@ -2064,7 +2064,7 @@
   oprjoin => 'icnlikejoinsel' },
 
 # NUMERIC type - OID's 1700-1799
-{ oid => '1751', descr => 'negate',
+{ oid => '1751', oid_symbol => 'NumericNegOperator', descr => 'negate',
   oprname => '-', oprkind => 'l', oprleft => '0', oprright => 'numeric',
   oprresult => 'numeric', oprcode => 'numeric_uminus' },
 { oid => '1752', descr => 'equal',
-- 
2.39.2 (Apple Git-143)