Existing tree functionality?

[Michael Tegtmeyer]

> struct foo {
>  	int i;
>  	void bar() {i=10;}
> };

> i is not a regular variable here, it's a member of a structure.

Agreed.

> No, but only because it's not really a variable, it's a structure
> member, and only ever accessed as such.  It thus doesn't appear as a
> VAR_DECL (in gcc terms), it appears in component accesses as a
> FIELD_DECL.

Sorry, I'm still pretty new to the tree layout. So what is the easiest way 
to access this? referenced_vars returns the 'this' variable which is 
obviously a structure. My understanding is that I can access it's fields
with the facilities available but 'i' is what was specifically 
referenced - not all of the fields. So the question is, what is the 
easiest way to obtain the specific field that was referenced in this case?