All the methods that this structure supported are now pulled
into the __vpiHandle class as virtual methods. This includes
the vpi_free_object_ method, which required some extra trickery.
Instead of C-like data structures where the __vpiHandle base is a
leading member, make the __vpiHandle a derived class. Give the base
class a virtual destructor so that dynamic_cast works reliably, and
now pretty much all of the junk for testing if an object really is
of the derived class goes away. Also, problems with casting up to
a vpiHandle become trivial non-issues.
This patch adds a trace command to the interactive prompt that can be
used to control statement tracing when the code is instrumented (has
%file_line opcodes).
Stephen Williams
Cary R