Questions about specification and possible implementations

["Scott E. Fahlman" <Fahlman@CMU-CS-C.ARPA>]

One of the reasons that TRACE is only semi-documented (you ought to have
it and you should call it TRACE if you do) is that it doesn't come up in
portable code.  It's clear that you want TRACE to be as powerful as
possible -- if there are things the user might want to see that he can't
see, that makes debugging a bit harder.  It's also clear that
implementations are going to vary in the degree to which they allow you
to trace calls from compiled code.  Some implementations are going to
use all sorts of tricks to get full efficiency, and some of these may
interfere with tracing.  I think that the right attitude is that
interpreted code definitely should be traceable and anything else you
get is gravy.

So it seems to me that each implementation should do the best it can on
this, and should document which things you can trace and which you
can't.  Do we need to say anything more about this?

-- Scott