debugger status

debugger status

[Andy Wingo]

Hey all,

It's been a few days, but I finished what I was aiming to do with the
debugger, which is just the basic break-at-procedure, break-at-source,
step, next, and finish thing. See the manual in Git for docs.

The stepping is all based on source locations, which is cool but
somewhat hampered by Guile's inability to give source location
information for non-pairs. (See "Source Properties" in the manual.)

I don't know what the real solution is, but it's not something I'm going
to poke right now.

Also, it would be nice to do expression stepping instead of source and
procedure stepping, but we would have to record the expressions and map
instruction pointers to subexpressions somehow. Possible to do, but not
implemented currently.

Also also, it would be nice if Guile's source properties had a range --
not just the start line and column, but the end line and column too.

Also also also, the debugger should have two modes, one where it's
coming from an error and one where it's coming from a breakpoint. In the
error case -- the only one we have had so far -- we show source
information for the instruction that was just executed. But in the
breakpoint case, the top frame needs to show source information for the
instruction that's going to be executed next.

Anyway, those are all the bugs and enhancements that I know about. Do
file bugs if the debugger isn't working for you.

Cheers,

Andy
-- 
http://wingolog.org/

Re: debugger status

[Ludovic Courtès]

Howdy!

Andy Wingo <wingo@pobox.com> writes:

> It's been a few days, but I finished what I was aiming to do with the
> debugger, which is just the basic break-at-procedure, break-at-source,
> step, next, and finish thing. See the manual in Git for docs.

Yaaay!  You are an awesome person, sir!

> The stepping is all based on source locations, which is cool but
> somewhat hampered by Guile's inability to give source location
> information for non-pairs. (See "Source Properties" in the manual.)
>
> I don't know what the real solution is, but it's not something I'm going
> to poke right now.
>
> Also, it would be nice to do expression stepping instead of source and
> procedure stepping, but we would have to record the expressions and map
> instruction pointers to subexpressions somehow. Possible to do, but not
> implemented currently.
>
> Also also, it would be nice if Guile's source properties had a range --
> not just the start line and column, but the end line and column too.
>
> Also also also, the debugger should have two modes, one where it's
> coming from an error and one where it's coming from a breakpoint. In the
> error case -- the only one we have had so far -- we show source
> information for the instruction that was just executed. But in the
> breakpoint case, the top frame needs to show source information for the
> instruction that's going to be executed next.

All good points, which I agree all qualify as “future work”.  :-)

Thanks for the great work!

Ludo’.