On Tue, Jul 1, 2008 at 2:44 PM, Eliot Miranda <eliot.miranda at gmail.com> wrote:
> Hi Igor,
>     this looks cool.  It is related to David Ungar's Klein which was an
> attempt at a self-hosted Self system, and to Exupery and Typed Smalltalk,
> and Ian's Cola.  Whenever I've thought about this style VM I've always been
> put off by a bug issue.  How are you going to deal with hard crashes?
> One needs some form of symbolic debugging at the machine code level.  If one
> is debugging the Squeak VM (or any other Smalltalk VM I've worked on) one
> can compile a version with debug symbols, use the platform's debugger (e.g.
> gdb) and write debugging functions in C to be called from that debugger.
> If one has a self-hosted Smalltalk system with no symbolic information that
> can be read by a platform's debugger because the system, being Smalltalk,
> has is own fully reflective self-description, then it seems to me one really
> is fishing about in a vast hex dump of the entire system, and that doesn't
> seem workable.

One way to fix this is to make debuggers work differently.  One image
should be able to inspect and control another, as in Spoon.  In
general, the debugger for image X runs in the controller of X, not in
X itself.  Of course, the compiler should probably be in the
controller, as well.  This would make a lot of things easier, such as
parallelism, security, and fault tolerance.

-Ralph