在struct stat结构中，st_mode成员的数据类型错误？

struct stat
{
    struct rt_device *st_dev;
    uint16_t  st_ino;
    uint16_t  st_mode;
    uint16_t  st_nlink;
    uint16_t  st_uid;
    uint16_t  st_gid;
    struct rt_device *st_rdev;
    uint32_t  st_size;
    time_t    st_atime;
    long      st_spare1;
    time_t    st_mtime;
    long      st_spare2;
    time_t    st_ctime;
    long      st_spare3;
    uint32_t  st_blksize;
    uint32_t  st_blocks;
    long      st_spare4[2];
};

#define S_IFDIR 0x0040000