RE: [PATCH v2] Replace the symbol needs evaluator with a parser

["Zaric, Zoran (Zare)" <Zoran.Zaric@amd.com>]

[AMD Official Use Only - Internal Distribution Only]

> > For gimli (again) we have a maximum operation count to avoid this kind
> > of problem.  gdb could do this as well.
> >
> > Meanwhile, about the linear scan -- it seems to me that nothing in
> > DWARF requires (1) that the expression not contain embedded garbage,
> > and (2) that it not be possible to branch to the middle of some other
> > instruction.  (If there is text along these lines, I'd like to hear
> > about it; I looked in the past and couldn't find it.)
> 
> I am not sure about your point about  expressions not contain embedded
> garbage. The DWARF expression is a byte stream with clearly defined
> content for every operation.
> 
> Regarding jumping in the middle of another operation, this is true, DWARF
> doesn't prevent that or define what is supposed to be done.
> 
> And I agree it would be really useful to have a checking mechanism that
> converts that byte stream into an internal representation, where during that
> conversion we could check and report all kind of things that can be wrong
> with the expression.
> 

Sorry Tom, I didn't get what you were aiming at by the 1 and 2. To late for me I guess.

And yes, my scanner would have a problem if somebody used DWARF like that, and it would behave differently then the evaluator, but the previous evaluation (without accessing the target) would hit many the same issues as well. The only issue that it wouldn't probably hit is if the absolute jump would jump over the garbage.

Zoran