let res_call_visible ff call_stmt = match ff with
| Isrc -> true
| Iproto -> false
| Iff (slice, _) ->
let key = PdgIndex.Key.call_outret_key call_stmt in
let _, ff_marks = slice.T.ff_marks in
try
let m = PdgIndex.FctIndex.find_info ff_marks key in
visible_mark m
with Not_found -> false