Any way to know context of expression evaluation?

If I have a call to bar being executed:
def bar (x, y)
    foo x, y
end

And the evaluation of x throws a (resumable, in my case) exception, is there
is any way to figure out that the x was being evaluated in preparation for
the "foo" call? I have some information about foo that I would like to
exploit in handling the exception.

Thanks!

Totally inadequate context for my question, which is a bit more complex than
it appears. I'll re-phrase and re-post. Sorry for the noise.

"itsme213" <itsme213@hotmail.com> wrote in message
news:dlatd.268$RC4.229@fe1.texas.rr.com...

If I have a call to bar being executed:
def bar (x, y)
    foo x, y
end

And the evaluation of x throws a (resumable, in my case) exception, is

there

···

is any way to figure out that the x was being evaluated in preparation for
the "foo" call? I have some information about foo that I would like to
exploit in handling the exception.

Thanks!