diff --git a/_examples/llvm/build.sh b/_examples/llvm/build.sh
new file mode 100755
index 0000000000000000000000000000000000000000..7b37995e162d0f6675169c204faff4277e79bfd5
--- /dev/null
+++ b/_examples/llvm/build.sh
@@ -0,0 +1,35 @@
+#! /bin/bash
+
+wa native --target=avr arduino_blink.wa
+wa native array_0.wa
+wa native array_1.wa
+wa native array_2.wa
+wa native bitwise_logic.wa
+wa native compare.wa
+wa native convert_0.wa
+wa native convert_1.wa
+wa native convert_2.wa
+wa native convert_3.wa
+wa native float32.wa
+wa native global_constant.wa
+wa native global_variable_0.wa
+wa native global_variable_1.wa
+wa native heart.wa
+wa native internal_function.wa
+wa native loop_0.wa
+wa native loop_1.wa
+wa native multi_ret.wa
+wa native pointer.wa
+wa native prime.wa
+wa native print_0.wa
+wa native print_1.wa
+wa native print_2.wa
+wa native print_3.wa
+wa native shift.wa
+wa native struct_0.wa
+wa native struct_1.wa
+wa native struct_2.wa
+wa native struct_3.wa
+wa native unconditional_jump.wa
+
+rm -f *.ll *.s
diff --git a/_examples/llvm/internal_function.wa b/_examples/llvm/internal_function.wa
new file mode 100644
index 0000000000000000000000000000000000000000..d9e80e216c41d44848b0b4d6ad3793f8da19c01c
--- /dev/null
+++ b/_examples/llvm/internal_function.wa
@@ -0,0 +1,18 @@
+# Test the llvm backend.
+# Test anonymous functions and closure functions.
+
+fn main() {
+	print("Hello, ")
+	fn() {
+		println("World!")
+	}()
+
+	var i: int
+	show := fn() {
+		println("i = ", i)
+	}
+
+	for i = 0; i < 10; i++ {
+		show()
+	}
+}
diff --git a/internal/app/opt.go b/internal/app/opt.go
index e9806f9a84a5061cda491f2afcf3413afcdf47cb..5f856976cafd9de11b70b277622541db3bc8143a 100644
--- a/internal/app/opt.go
+++ b/internal/app/opt.go
@@ -44,6 +44,9 @@ func (opt *Option) Config() *config.Config {
 	case "arm64":
 		cfg.WaSizes.MaxAlign = 8
 		cfg.WaSizes.WordSize = 8
+	case "native":
+		cfg.WaSizes.MaxAlign = 8
+		cfg.WaSizes.WordSize = 8
 	default:
 		panic("todo")
 	}
diff --git a/internal/backends/compiler_llvm/compile.go b/internal/backends/compiler_llvm/compile.go
index 099aa1eba353a4225b585746070f495a35d9ba1b..3fb3c7744202ee1ca986c851ee0ff27e9bec113d 100644
--- a/internal/backends/compiler_llvm/compile.go
+++ b/internal/backends/compiler_llvm/compile.go
@@ -21,6 +21,7 @@ type Compiler struct {
 	output strings.Builder
 	debug  bool
 	fmts   []FmtStr
+	anofn  []*ssa.Function
 }
 
 func New(target string, debug bool) *Compiler {
@@ -142,6 +143,14 @@ func (p *Compiler) compilePackage(pkg *ssa.Package) error {
 		}
 	}
 
+	// Generate LLVM-IR for each internal function.
+	for _, v := range p.anofn {
+		if err := p.compileFunction(v); err != nil {
+			return err
+		}
+	}
+	p.anofn = []*ssa.Function{}
+
 	return nil
 }
 
diff --git a/internal/backends/compiler_llvm/compile_value.go b/internal/backends/compiler_llvm/compile_value.go
index 25c2479f08d49f4ca32152b1e360a0a7be832dd5..36f20ec857518d86a578e85046fcc3c75adbc170 100644
--- a/internal/backends/compiler_llvm/compile_value.go
+++ b/internal/backends/compiler_llvm/compile_value.go
@@ -387,6 +387,10 @@ func (p *Compiler) compileCall(val *ssa.Call) error {
 		// Emit the function name.
 		p.output.WriteString(" @")
 		callee := val.Call.StaticCallee()
+		// This callee is an internal function, whose body will be genereated later.
+		if callee.Parent() != nil {
+			p.anofn = append(p.anofn, callee)
+		}
 		if len(callee.LinkName()) > 0 {
 			p.output.WriteString(callee.LinkName())
 		} else {
diff --git a/main.go b/main.go
index bba24c43359e7d9b24e1c1e58a7cceb6ab99df69..dcde85e750469b31dcb1f43c1460353b6f4b0f13 100644
--- a/main.go
+++ b/main.go
@@ -304,7 +304,7 @@ func main() {
 				}
 				infile = c.Args().First()
 
-				ctx := app.NewApp(build_Options(c))
+				ctx := app.NewApp(build_Options(c, true))
 				if err := ctx.LLVM(infile, outfile, target, debug); err != nil {
 					fmt.Println(err)
 					os.Exit(1)
@@ -472,6 +472,7 @@ func build_Options(c *cli.Context, isLLVMBackend ...bool) *app.Option {
 	opt.TargetArch = "wasm"
 	if len(isLLVMBackend) > 0 && isLLVMBackend[0] {
 		opt.TargetArch = "native"
+		return opt
 	}
 	switch c.String("target") {
 	case "wa", config.WaOS_Walang: