exceptions and integrating intrp/jit

[Senthil Kumar]

Alexandre Oliva wrote:

>
> > I merged the two structs into one, and I thought that
> > the simplest way would be to make the JIT also register
> > its exceptionFrame with the current thread and have similar
> > semantics as we have with the intrp, i.e. have a prev pointer
> > which points to the previous frame.
> 
> This would be too inefficient; the current implementation does not
> introduce any overhead when no exception is thrown; it would be a pity
> to lose this.  How about the following strategy?  You go unwinding the
> stack, collecting exception information with the JIT mechanism if the
> method is JIT compiled, or from the jmpbuf linked list if the PC
> corresponds to code from the interpreter's virtualMachine.  I believe
> this would work.
> 

I am sorry, but I just do not understand what you are trying to say.

The problem is that some methods might be JIT and some
method might be interpreted in the call chain and thus one
cannot use either the JIT or the interpreted mechanism exclusively.

Could you elaborate a little more on your scheme?

Also thanks for mentioning the exception prolouge. I assume
that somehow a pointer to the previous exception frame
is set in the prolouge. Is this correct?