Parsing a struct typedef in emacs semantics when typedef and struct in different files

Question

Supposing I have as typedef struct definition like this:

typedef struct IP_ROUTE_ IP_ROUTE;

struct IP_ROUTE_ {
    unsigned    prefix;
    unsigned    mask;
    unsigned    next_hop;
};

All is fine. Semantic parses it nicely and if I do..

IP_ROUTE   r;

r->

I get struct specific completion popup menu. No problem with that.

However if typedef is in one file and the struct declaration is in another file then I have problems. There is no completion popup menu.

ip_route.h

typedef struct IP_ROUTE_ IP_ROUTE;

ip_route_internal.h

struct IP_ROUTE_ {
    unsigned    prefix;
    unsigned    mask;
    unsigned    next_hop;
};

Then the completion does not work.