Revert "simple: The btf type must be a pointer"

This reverts commit 2f85ee2.

simple.go

@@ -6,7 +6,6 @@ package bice
 import (
 	"fmt"
 
-	"github.com/Asphaltt/mybtf"
 	"github.com/cilium/ebpf/asm"
 	"github.com/cilium/ebpf/btf"
 )
@@ -70,10 +69,6 @@ import (
 // The operator must be one of the following: =, ==, !=, <, <=, >, >=. '=' is
 // used for comparison too.
 func SimpleCompile(expr string, typ btf.Type) (asm.Instructions, error) {
-	if _, isPtr := mybtf.UnderlyingType(typ).(*btf.Pointer); !isPtr {
-		return nil, fmt.Errorf("type(%s) is not a pointer", typ)
-	}
-
 	ast, err := parse(expr)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse expression(%s): %w", expr, err)

simple_test.go

@@ -4,23 +4,15 @@
 package bice
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/cilium/ebpf"
-	"github.com/cilium/ebpf/btf"
 	"github.com/leonhwangprojects/bice/internal/test"
 )
 
 func TestSimpleCompile(t *testing.T) {
-	t.Run("non-pointer type", func(t *testing.T) {
-		_, err := SimpleCompile("skb->len > 1024", &btf.Int{})
-		test.AssertHaveErr(t, err)
-		test.AssertStrPrefix(t, err.Error(), fmt.Sprintf("type(%s) is not a pointer", &btf.Int{}))
-	})
-
 	t.Run("failed to parse", func(t *testing.T) {
-		_, err := SimpleCompile("a)(test)", getSkbBtf(t))
+		_, err := SimpleCompile("a)(test)", nil)
 		test.AssertHaveErr(t, err)
 		test.AssertStrPrefix(t, err.Error(), "failed to parse expression")
 	})