🚀 go-pugleaf

      We are trying to use the output produced/generated from the flow analysis
    phase of the compile to develop a kind of static call tree of our code. 

To generate a call tree as a byproduct of compilation is a tempting
idea, but it has a fundamental flaw.  You can't generate a complete
call graph from any kind of output from cc1 (or cc1plus), because they
don't know about all the calls that are in the source.

For example, if a function contains this:

#ifdef vax
     foo ();
#endif

and you happen to be on a sun, by the time cc1 is running there is no
trace of the fact that a call to foo was present there.

If you rely on incomplete data for doing maintenance, bugs will
result.  When you change the way to call foo, you need to find *all*
the calls, not just those that happen to be enabled on the target you
are using today.

For this reason, I believe cross-referencing ought to be done by
parsing the source directly, *without* going through cpp.