How to avoid compilation errors like "error: no member named xxx in strut xxx"?

[Shuyi Cheng <chengshuyi@linux.alibaba.com>]

I am trying to write a bpf program that supports multiple linux kernel 
versions. However, there are some differences in the definition of 
struct net in these multiple kernel versions.

Therefore, when we include a certain kernel version of vmlinux.h, the 
compilation error "error: no member named'proc_inum' in strut net" will 
appear.

However, when we include another kernel version of vmlinux.h, the 
compilation will appear "error: no member named'ns.inum' in strut net".

Anakryiko mentioned in the issue of libbpf/libbpf-bootstrap: vmlinux.h 
is just a convenient way to have most of kernel types defined for you, 
so that you don't have to re-define them manually. Link here: https: 
//github.com/libbpf/libbpf-bootstrap/issues/31#issuecomment-861035643

But struct net is a very huge structure, and it may be very difficult to 
add it manually. So, how can we avoid compilation errors like "error: no 
member named'xxx' in xxx"