diff --git a/chore/_xtool/llcppsigfetch/parse/cvt.go b/chore/_xtool/llcppsigfetch/parse/cvt.go
index 2588b760..de9965d0 100644
--- a/chore/_xtool/llcppsigfetch/parse/cvt.go
+++ b/chore/_xtool/llcppsigfetch/parse/cvt.go
@@ -7,6 +7,7 @@ import (
 	"unsafe"
 
 	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/cjson"
 	"github.com/goplus/llgo/c/clang"
 	"github.com/goplus/llgo/chore/llcppg/ast"
 )
@@ -79,19 +80,19 @@ func visit(cursor, parent clang.Cursor, clientData unsafe.Pointer) clang.ChildVi
 
 	switch cursor.Kind {
 	case clang.CursorInclusionDirective:
-		fmt.Println("todo: Process include")
+		// todo(zzy)
 		return clang.ChildVisit_Continue
 	case clang.CursorMacroDefinition:
-		fmt.Println("todo: Process macro")
+		// todo(zzy)
 		return clang.ChildVisit_Continue
 	case clang.CursorEnumDecl:
-		fmt.Println("todo: Process enum")
+		// todo(zzy)
 		return clang.ChildVisit_Continue
 	case clang.CursorClassDecl:
 		ct.ProcessClass(cursor)
 		return clang.ChildVisit_Continue
 	case clang.CursorStructDecl:
-		fmt.Println("todo: Process struct")
+		// todo(zzy)
 		return clang.ChildVisit_Continue
 	case clang.CursorFunctionDecl:
 		ct.ProcessFunc(cursor)
@@ -117,8 +118,7 @@ func (ct *Converter) UpdateCurFile(cursor clang.Cursor) {
 	defer filename.Dispose()
 
 	if filename.CStr() == nil {
-		// For some built-in macros, there is no file.
-		println("todo: filename is empty")
+		//todo(zzy): For some built-in macros, there is no file.
 		return
 	}
 
@@ -260,3 +260,65 @@ func IsExplicitUnsigned(t clang.Type) bool {
 		t.Kind == clang.TypeULong || t.Kind == clang.TypeULongLong ||
 		t.Kind == clang.TypeUInt128
 }
+
+func (ct *Converter) GetFilesJSON() *cjson.JSON {
+	root := cjson.Object()
+
+	Files := cjson.Object()
+	root.SetItem(c.Str("Files"), Files)
+
+	for _, file := range ct.files {
+		f := cjson.Object()
+		f.SetItem(c.Str("Path"), cjson.String(c.AllocaCStr(file.Path)))
+		ct.FileJSON(file, f)
+		Files.SetItem(c.AllocaCStr(file.Path), f)
+	}
+	return root
+}
+
+func (ct *Converter) FileJSON(file *ast.File, root *cjson.JSON) {
+	decls := cjson.Array()
+	includes := cjson.Array()
+	macros := cjson.Array()
+
+	for _, decl := range file.Decls {
+		ct.DeclJSON(decl, decls)
+	}
+
+	root.SetItem(c.Str("decls"), decls)
+	root.SetItem(c.Str("includes"), includes)
+	root.SetItem(c.Str("macros"), macros)
+}
+
+func (ct *Converter) DeclJSON(decl ast.Decl, root *cjson.JSON) {
+	switch d := decl.(type) {
+	case *ast.FuncDecl:
+		fn := cjson.Object()
+		fntype := cjson.Object()
+		fn.SetItem(c.Str("Name"), cjson.String(c.AllocaCStr(d.Name.Name)))
+		ct.TypeJSON(d.Type, fntype)
+		fn.SetItem(c.Str("Type"), fntype)
+		root.AddItem(fn)
+	}
+}
+func (ct *Converter) TypeJSON(t ast.Expr, root *cjson.JSON) {
+
+	switch d := t.(type) {
+	case *ast.FuncType:
+		params := cjson.Array()
+
+		for _, p := range d.Params.List {
+			param := cjson.Object()
+			ct.TypeJSON(p.Type, param)
+			params.AddItem(param)
+		}
+
+		root.SetItem(c.Str("Params"), params)
+		ret := cjson.Object()
+		ct.TypeJSON(d.Ret, ret)
+		root.SetItem(c.Str("Ret"), ret)
+	case *ast.BuiltinType:
+		root.SetItem(c.Str("Kind"), cjson.Number(float64(d.Kind)))
+		root.SetItem(c.Str("Flags"), cjson.Number(float64(d.Flags)))
+	}
+}
diff --git a/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/decl.go b/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/decl.go
new file mode 100644
index 00000000..3302084e
--- /dev/null
+++ b/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/decl.go
@@ -0,0 +1,26 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/chore/_xtool/llcppsigfetch/parse"
+)
+
+func main() {
+	TestFuncDecl()
+}
+
+func TestFuncDecl() {
+	content := `int foo(int a, int b);`
+	converter, err := parse.NewConverter(content, true)
+	if err != nil {
+		panic(err)
+	}
+
+	defer converter.Dispose()
+	converter.Convert()
+	if err != nil {
+		panic(err)
+	}
+	json := converter.GetFilesJSON()
+	c.Printf(c.Str("%s\n"), json.Print())
+}
diff --git a/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/llgo.expect b/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/llgo.expect
new file mode 100644
index 00000000..6300d577
--- /dev/null
+++ b/chore/_xtool/llcppsigfetch/parse/cvt_test/decl_test/llgo.expect
@@ -0,0 +1,30 @@
+#stdout
+{
+	"Files":	{
+		"temp.h":	{
+			"Path":	"temp.h",
+			"decls":	[{
+					"Name":	"foo",
+					"Type":	{
+						"Params":	[{
+								"Kind":	6,
+								"Flags":	0
+							}, {
+								"Kind":	6,
+								"Flags":	0
+							}],
+						"Ret":	{
+							"Kind":	6,
+							"Flags":	0
+						}
+					}
+				}],
+			"includes":	[],
+			"macros":	[]
+		}
+	}
+}
+
+#stderr
+
+#exit 0