purego: use a safe way to convert a pointer to a byte slice (#19)

Creating a `reflect.SliceHeader` is invalid. See https://pkg.go.dev/unsafe#Pointer

1 file · +6 -1

M dlfcn.go +6 -1


@@ -65,7 +65,12 @@ func Dlerror() string {
65	65		}
66	66		// use unsafe.Slice once we reach 1.17
67	67		s := make([]byte, length)
68		-	copy(s, ([]byte)(unsafe.Pointer(&reflect.SliceHeader{Data: msg, Len: length, Cap: length})))
	68	+	var src []byte
	69	+	h := (*reflect.SliceHeader)(unsafe.Pointer(&src))
	70	+	h.Data = msg
	71	+	h.Len = length
	72	+	h.Cap = length
	73	+	copy(s, src)
69	74		return string(s)
70	75		}
71	76

 	}
 	// use unsafe.Slice once we reach 1.17
 	s := make([]byte, length)
-	copy(s, *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{Data: msg, Len: length, Cap: length})))
+	var src []byte
+	h := (*reflect.SliceHeader)(unsafe.Pointer(&src))
+	h.Data = msg
+	h.Len = length
+	h.Cap = length
+	copy(s, src)
 	return string(s)
 }