address comments

pkg/meta/model/job_args.go

@@ -1328,10 +1328,10 @@ type IndexArg struct {
 
 // IndexArgSplitOpt is a field of IndexArg used by index presplit.
 type IndexArgSplitOpt struct {
-	Lower      []string   `json:"lower"`
-	Upper      []string   `json:"upper"`
-	Num        int64      `json:"num"`
-	ValueLists [][]string `json:"value_lists"`
+	Lower      []string   `json:"lower,omitempty"`
+	Upper      []string   `json:"upper,omitempty"`
+	Num        int64      `json:"num,omitempty"`
+	ValueLists [][]string `json:"value_lists,omitempty"`
 }
 
 // ModifyIndexArgs is the argument for add/drop/rename index jobs,

pkg/parser/ast/ddl.go

@@ -735,7 +735,7 @@ type IndexOption struct {
 	Visibility   IndexVisibility
 	PrimaryKeyTp model.PrimaryKeyType
 	Global       bool
-	SplitOpt     *SplitOption `json:"-"`
+	SplitOpt     *SplitOption `json:"-"` // SplitOption contains expr nodes, which cannot marshal for DDL job arguments.
 }
 
 // IsEmpty is true if only default options are given
@@ -851,30 +851,11 @@ func (n *IndexOption) Accept(v Visitor) (Node, bool) {
 	}
 	n = newNode.(*IndexOption)
 	if n.SplitOpt != nil {
-		for i, val := range n.SplitOpt.Lower {
-			node, ok := val.Accept(v)
-			if !ok {
-				return n, false
-			}
-			n.SplitOpt.Lower[i] = node.(ExprNode)
-		}
-		for i, val := range n.SplitOpt.Upper {
-			node, ok := val.Accept(v)
-			if !ok {
-				return n, false
-			}
-			n.SplitOpt.Upper[i] = node.(ExprNode)
-		}
-
-		for i, list := range n.SplitOpt.ValueLists {
-			for j, val := range list {
-				node, ok := val.Accept(v)
-				if !ok {
-					return n, false
-				}
-				n.SplitOpt.ValueLists[i][j] = node.(ExprNode)
-			}
+		node, ok := n.SplitOpt.Accept(v)
+		if !ok {
+			return n, false
 		}
+		n.SplitOpt = node.(*SplitOption)
 	}
 	return v.Leave(n)
 }

pkg/parser/ast/dml.go

@@ -3840,6 +3840,8 @@ type SplitRegionStmt struct {
 }
 
 type SplitOption struct {
+	stmtNode
+
 	Lower      []ExprNode
 	Upper      []ExprNode
 	Num        int64
@@ -3899,29 +3901,13 @@ func (n *SplitRegionStmt) Accept(v Visitor) (Node, bool) {
 		return n, false
 	}
 	n.Table = node.(*TableName)
-	for i, val := range n.SplitOpt.Lower {
-		node, ok := val.Accept(v)
-		if !ok {
-			return n, false
-		}
-		n.SplitOpt.Lower[i] = node.(ExprNode)
-	}
-	for i, val := range n.SplitOpt.Upper {
-		node, ok := val.Accept(v)
+
+	if n.SplitOpt != nil {
+		node, ok := n.SplitOpt.Accept(v)
 		if !ok {
 			return n, false
 		}
-		n.SplitOpt.Upper[i] = node.(ExprNode)
-	}
-
-	for i, list := range n.SplitOpt.ValueLists {
-		for j, val := range list {
-			node, ok := val.Accept(v)
-			if !ok {
-				return n, false
-			}
-			n.SplitOpt.ValueLists[i][j] = node.(ExprNode)
-		}
+		n.SplitOpt = node.(*SplitOption)
 	}
 	return v.Leave(n)
 }
@@ -3974,6 +3960,41 @@ func (n *SplitOption) Restore(ctx *format.RestoreCtx) error {
 	return nil
 }
 
+// Accept implements Node Accept interface.
+func (n *SplitOption) Accept(v Visitor) (Node, bool) {
+	newNode, skipChildren := v.Enter(n)
+	if skipChildren {
+		return v.Leave(newNode)
+	}
+	n = newNode.(*SplitOption)
+
+	for i, val := range n.Lower {
+		node, ok := val.Accept(v)
+		if !ok {
+			return n, false
+		}
+		n.Lower[i] = node.(ExprNode)
+	}
+	for i, val := range n.Upper {
+		node, ok := val.Accept(v)
+		if !ok {
+			return n, false
+		}
+		n.Upper[i] = node.(ExprNode)
+	}
+
+	for i, list := range n.ValueLists {
+		for j, val := range list {
+			node, ok := val.Accept(v)
+			if !ok {
+				return n, false
+			}
+			n.ValueLists[i][j] = node.(ExprNode)
+		}
+	}
+	return v.Leave(n)
+}
+
 type FulltextSearchModifier int
 
 const (

pkg/parser/parser.go

@@ -1482,7 +1482,7 @@ var (
 		58097: 547,  // voter (1599x)
 		57971: 548,  // weightString (1599x)
 		57505: 549,  // on (1514x)
-		40:    550,  // '(' (1511x)
+		40:    550,  // '(' (1512x)
 		57590: 551,  // with (1381x)
 		57353: 552,  // stringLit (1351x)
 		58185: 553,  // not2 (1315x)
@@ -1507,7 +1507,7 @@ var (
 		57381: 572,  // charType (1034x)
 		58174: 573,  // eq (1030x)
 		57426: 574,  // fetch (1028x)
-		58169: 575,  // intLit (1023x)
+		58169: 575,  // intLit (1024x)
 		57541: 576,  // set (1021x)
 		57477: 577,  // limit (1019x)
 		57431: 578,  // forKwd (1015x)
@@ -1754,7 +1754,7 @@ var (
 		58535: 819,  // NUM (124x)
 		58897: 820,  // logAnd (107x)
 		58898: 821,  // logOr (107x)
-		58389: 822,  // EqOpt (101x)
+		58389: 822,  // EqOpt (102x)
 		57407: 823,  // deleteKwd (87x)
 		58802: 824,  // TableName (82x)
 		58780: 825,  // StringName (56x)
@@ -10090,7 +10090,7 @@ var (
 		{2156, 2156, 2156, 2156, 2156, 2156, 2156, 8: 2156, 19: 2156, 2156, 52: 2156, 58: 2156, 61: 2156, 100: 2156, 2156, 2156, 2156, 105: 2156, 107: 2156, 551: 2156, 561: 2156, 565: 2156, 581: 2156},
 		{2155, 2155, 2155, 2155, 2155, 2155, 2155, 8: 2155, 19: 2155, 2155, 52: 2155, 58: 2155, 61: 2155, 100: 2155, 2155, 2155, 2155, 105: 2155, 107: 2155, 551: 2155, 561: 2155, 565: 2155, 581: 2155},
 		{2154, 2154, 2154, 2154, 2154, 2154, 2154, 8: 2154, 19: 2154, 2154, 52: 2154, 58: 2154, 61: 2154, 100: 2154, 2154, 2154, 2154, 105: 2154, 107: 2154, 551: 2154, 561: 2154, 565: 2154, 581: 2154},
-		{573: 5491},
+		{550: 2374, 573: 4695, 575: 2374, 822: 5491},
 		{200: 5486, 224: 5488, 241: 5485, 247: 5489, 256: 5487, 1027: 5490},
 		// 2550
 		{200: 5486, 224: 5488, 241: 5485, 247: 5489, 256: 5487, 1027: 5484},

pkg/parser/parser.y

@@ -6645,13 +6645,13 @@ IndexOption:
 			Global: false,
 		}
 	}
-|   "PRE_SPLIT_REGIONS" "=" '(' SplitOption ')'
+|   "PRE_SPLIT_REGIONS" EqOpt '(' SplitOption ')'
     {
 		$$ = &ast.IndexOption{
 			SplitOpt: $4.(*ast.SplitOption),
 		}
 	}
-|   "PRE_SPLIT_REGIONS" "=" Int64Num
+|   "PRE_SPLIT_REGIONS" EqOpt Int64Num
 	{
 		$$ = &ast.IndexOption{
 			SplitOpt:  &ast.SplitOption{

pkg/util/split.go

@@ -27,7 +27,7 @@ func GetValuesList(lower, upper []byte, num int, valuesList [][]byte) [][]byte {
 	startV := getUint64FromBytes(lower[commonPrefixIdx:], 0)
 	// To get `num` regions, only need to split `num-1` idx keys.
 	buf := make([]byte, 8)
-	for i := 0; i < num-1; i++ {
+	for range num - 1 {
 		value := make([]byte, 0, commonPrefixIdx+8)
 		value = append(value, lower[:commonPrefixIdx]...)
 		startV += step