Re: [RFC] Using values to handle unwinding

[Joel Brobecker <brobecker@adacore.com>]

>   - Uses GDB's value infrastructure.  Values carry around the
>     location information which previously took four extra arguments
>     to every unwinder.  And this lets us use our existing value
>     manipulation routines as necessary.

I really like this part. It looks very elegant to me.

>   - Simplifies getting other registers from the PREV frame.

This idea was under discussion on gdb-patches. I said it looked like
a good idea, but Mark expressed some concerns (to which I think you
tried to answer).

> This patch leaves the existing prev_register method.  If we want to
> adopt this new approach then I would recommend not doing that at all:
> just change the type of the prev_register field, break all targets
> until they are updated, and fix them.  We can do it on a branch and
> merge the whole branch at once, or do it quickly in HEAD.  Converting
> the DWARF-2 reader took me only an hour or two, which included writing
> the helper routines.

I don't mind breaking all the targets if this is the way we want
to do it. But either way, whether we use a branch or not, I'd like
us to break the target by breaking the build. This way, managing to
build again means we're done with the conversion.

If I understand the patch correctly, this is going to be the case,
right? You're removing some old routines, and replacing with a
new one that has a different name.

-- 
Joel