diff --git a/cmd/llcppcfg/gen/cfg.go b/cmd/llcppcfg/gen/cfg.go
index f0993bab3..dbe80e0d6 100644
--- a/cmd/llcppcfg/gen/cfg.go
+++ b/cmd/llcppcfg/gen/cfg.go
@@ -1,7 +1,6 @@
 package gen
 
 import (
-	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -16,15 +15,11 @@ import (
 )
 
 type Config struct {
-	name           string
-	flag           FlagMode
-	exts           []string
-	deps           []string
-	excludeSubdirs []string
-}
-
-func NewConfig(name string, flag FlagMode, exts, deps, excludeSubdirs []string) *Config {
-	return &Config{name: name, flag: flag, exts: exts, deps: deps, excludeSubdirs: excludeSubdirs}
+	Name           string
+	IsCpp          bool
+	Exts           []string
+	Deps           []string
+	ExcludeSubdirs []string
 }
 
 type llcppCfgKey string
@@ -34,13 +29,6 @@ const (
 	cfgCflagsKey llcppCfgKey = "cflags"
 )
 
-type FlagMode int
-
-const (
-	WithTab FlagMode = 1 << iota
-	WithCpp
-)
-
 type emptyStringError struct {
 	name string
 }
@@ -189,25 +177,6 @@ func parseCFlagsEntry(cflags, cflag string, exts []string, excludeSubdirs []stri
 	return &cflagEntry
 }
 
-func sortIncludes(expandCflags string, cfg *llcppg.Config, exts []string, excludeSubdirs []string) {
-	list := strings.Fields(expandCflags)
-	includeList := NewIncludeList()
-	for i, cflag := range list {
-		pCflagEntry := parseCFlagsEntry(expandCflags, cflag, exts, excludeSubdirs)
-		includeList.AddCflagEntry(i, pCflagEntry)
-	}
-	cfg.Include = includeList.include
-}
-
-func newLLCppgConfig(name string, flag FlagMode) *llcppg.Config {
-	cfg := llcppg.NewDefault()
-	cfg.Name = name
-	cfg.CFlags = fmt.Sprintf("$(pkg-config --cflags %s)", name)
-	cfg.Libs = fmt.Sprintf("$(pkg-config --libs %s)", name)
-	cfg.Cplusplus = (flag&WithCpp != 0)
-	return cfg
-}
-
 func NormalizePackageName(name string) string {
 	fields := strings.FieldsFunc(name, func(r rune) bool {
 		return !unicode.IsLetter(r) && r != '_' && !unicode.IsDigit(r)
@@ -220,24 +189,35 @@ func NormalizePackageName(name string) string {
 	return strings.Join(fields, "_")
 }
 
+func (c *Config) toLLCppg() *llcppg.Config {
+	cfg := llcppg.NewDefault()
+	cfg.Name = NormalizePackageName(c.Name)
+	cfg.CFlags = fmt.Sprintf("$(pkg-config --cflags %s)", c.Name)
+	cfg.Libs = fmt.Sprintf("$(pkg-config --libs %s)", c.Name)
+	cfg.Cplusplus = c.IsCpp
+	cfg.Deps = c.Deps
+
+	expandCFlags := ExpandName(c.Name, "", cfgCflagsKey)
+	cfg.Include = c.sortIncludes(expandCFlags, c.Exts, c.ExcludeSubdirs)
+
+	return cfg
+}
+
+func (c *Config) sortIncludes(expandCflags string, exts []string, excludeSubdirs []string) []string {
+	list := strings.Fields(expandCflags)
+	includeList := NewIncludeList()
+	for i, cflag := range list {
+		pCflagEntry := parseCFlagsEntry(expandCflags, cflag, exts, excludeSubdirs)
+		includeList.AddCflagEntry(i, pCflagEntry)
+	}
+	return includeList.include
+}
+
 func Do(genCfg *Config) ([]byte, error) {
-	if len(genCfg.name) == 0 {
+	if len(genCfg.Name) == 0 {
 		return nil, newEmptyStringError("name")
 	}
-	cfg := newLLCppgConfig(genCfg.name, genCfg.flag)
-	expandCFlags := ExpandName(genCfg.name, "", cfgCflagsKey)
-	sortIncludes(expandCFlags, cfg, genCfg.exts, genCfg.excludeSubdirs)
-	cfg.Name = NormalizePackageName(cfg.Name)
-	cfg.Deps = genCfg.deps
+	cfg := genCfg.toLLCppg()
 
-	buf := bytes.NewBuffer([]byte{})
-	jsonEncoder := json.NewEncoder(buf)
-	if genCfg.flag&WithTab != 0 {
-		jsonEncoder.SetIndent("", "\t")
-	}
-	err := jsonEncoder.Encode(cfg)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
+	return json.MarshalIndent(cfg, "", "  ")
 }
diff --git a/cmd/llcppcfg/gen/cfg_test.go b/cmd/llcppcfg/gen/cfg_test.go
index 7a5d5ed77..922317eb2 100644
--- a/cmd/llcppcfg/gen/cfg_test.go
+++ b/cmd/llcppcfg/gen/cfg_test.go
@@ -442,7 +442,7 @@ func Test_sortIncludes(t *testing.T) {
 				[]string{".h"},
 				[]string{},
 			},
-			[]string{},
+			nil,
 		},
 		{
 			"deps/case4_recircle",
@@ -464,7 +464,8 @@ func Test_sortIncludes(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			sortIncludes(tt.args.expandCflags, tt.args.cfg, tt.args.exts, tt.args.excludeSubdirs)
+			c := &Config{Exts: tt.args.exts, ExcludeSubdirs: tt.args.excludeSubdirs}
+			tt.args.cfg.Include = c.sortIncludes(tt.args.expandCflags, tt.args.exts, tt.args.excludeSubdirs)
 			if !reflect.DeepEqual(tt.args.cfg.Include, tt.wantInclude) {
 				t.Errorf("sortIncludes() = %v, want %v", tt.args.cfg.Include, tt.wantInclude)
 			}
@@ -474,8 +475,8 @@ func Test_sortIncludes(t *testing.T) {
 
 func TestNewLLCppConfig(t *testing.T) {
 	type args struct {
-		name string
-		flag FlagMode
+		name  string
+		isCpp bool
 	}
 	tests := []struct {
 		name string
@@ -486,7 +487,7 @@ func TestNewLLCppConfig(t *testing.T) {
 			"libcjson",
 			args{
 				"libcjson",
-				WithTab,
+				false,
 			},
 			&llcppg.Config{
 				Name:           "libcjson",
@@ -499,8 +500,9 @@ func TestNewLLCppConfig(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := newLLCppgConfig(tt.args.name, tt.args.flag); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("NewLLCppgConfig() = %v, want %v", got, tt.want)
+			c := &Config{Name: tt.args.name, IsCpp: tt.args.isCpp}
+			if got := c.toLLCppg(); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("NewLLCppgConfig() = %#v, want %#v", got, tt.want)
 			}
 		})
 	}
diff --git a/cmd/llcppcfg/gen/types.go b/cmd/llcppcfg/gen/types.go
index e1820022c..844b3701b 100644
--- a/cmd/llcppcfg/gen/types.go
+++ b/cmd/llcppcfg/gen/types.go
@@ -57,7 +57,7 @@ type IncludeList struct {
 }
 
 func NewIncludeList() *IncludeList {
-	return &IncludeList{include: make([]string, 0), absPathMap: make(map[string]struct{}), relPathMap: make(map[string]struct{})}
+	return &IncludeList{absPathMap: make(map[string]struct{}), relPathMap: make(map[string]struct{})}
 }
 
 func (p *IncludeList) AddCflagEntry(index int, entry *CflagEntry) {
diff --git a/cmd/llcppcfg/llcppcfg.go b/cmd/llcppcfg/llcppcfg.go
index ba892cc8d..812d13d4c 100644
--- a/cmd/llcppcfg/llcppcfg.go
+++ b/cmd/llcppcfg/llcppcfg.go
@@ -17,10 +17,9 @@ usage: llcppcfg [-cpp|-tab|-excludes|-exts|-help] libname`)
 
 func main() {
 	var dependencies string
-	var cpp, help, tab bool
+	var cpp, help bool
 	flag.BoolVar(&cpp, "cpp", false, "if it is c++ lib")
 	flag.BoolVar(&help, "help", false, "print help message")
-	flag.BoolVar(&tab, "tab", true, "generate .cfg config file with tab indent")
 	extsString := ""
 	flag.StringVar(&extsString, "exts", ".h", "extra include file extensions for example -exts=\".h .hpp .hh\"")
 	excludes := ""
@@ -44,14 +43,14 @@ func main() {
 	if len(excludes) > 0 {
 		excludeSubdirs = strings.Fields(excludes)
 	}
-	var flag gen.FlagMode
-	if cpp {
-		flag |= gen.WithCpp
-	}
-	if tab {
-		flag |= gen.WithTab
-	}
-	buf, err := gen.Do(gen.NewConfig(name, flag, exts, deps, excludeSubdirs))
+
+	buf, err := gen.Do(&gen.Config{
+		Name:           name,
+		Exts:           exts,
+		Deps:           deps,
+		IsCpp:          cpp,
+		ExcludeSubdirs: excludeSubdirs,
+	})
 	if err != nil {
 		panic(err)
 	}