ASN1C compiling

我有一个小的asn1代码：

---------------------ASN1 文件

RectangleModule1 DEFINITIONS ::= 
BEGIN
Rectangle ::= SEQUENCE (SIZE(1..10)) OF SEQUENCE {
 item CHOICE    {
  height INTEGER,
  width  IA5String
 } --# UNTAGGED
}
END

当我用asn1c编译它时，它给了我Rectangle.c和Rectangle.h文件。矩形的输出如下所示：

-----------------------矩形.h------------------------------

/* Dependencies */
typedef enum item_PR {
  item_PR_NOTHING,    /* No components present */
item_PR_height,
item_PR_width
  } item_PR;
/* Rectangle */
typedef struct Rectangle {
  A_SEQUENCE_OF(struct Member {
    struct item {
        item_PR present;
        union item_u {
            long     height;
            IA5String_t  width;
        } choice;
        /* Context for parsing across buffer boundaries */
        asn_struct_ctx_t _asn_ctx;
    } item;
    /* Context for parsing across buffer boundaries */
    asn_struct_ctx_t _asn_ctx;
  } ) list;
  /* Context for parsing across buffer boundaries */
  asn_struct_ctx_t _asn_ctx;
 } Rectangle_t;

但我希望我的输出看起来像这样：

  /* Dependencies */
  typedef enum item_PR_sl {
  item_PR_NOTHING_sl,    /* No components present */
  item_PR_height_sl,
  item_PR_width_sl
  } item_PR_sl;
  /* Rectangle */
  typedef struct Rectangle {
  A_SEQUENCE_OF(struct Member {
        struct item_sl {
        item_PR_sl present;
        union item_u_sl {
            long     height;
            IA5String_t  width;
        } choice;
        /* Context for parsing across buffer boundaries */
        asn_struct_ctx_t _asn_ctx;
    } item;
    /* Context for parsing across buffer boundaries */
    asn_struct_ctx_t _asn_ctx;
} ) list;
/* Context for parsing across buffer boundaries */
asn_struct_ctx_t _asn_ctx;
  } Rectangle_t;

即，_sl连接到项目字段。我无法通过更改 asn 文件来执行此操作。我不知道constr_CHOICE和constr_SEQUENCE是如何工作的。任何帮助将不胜感激。