Re: [RFA] Reverse Debugging, 2/5

[Daniel Jacobowitz <drow at false dot org>]

On Mon, Oct 06, 2008 at 02:10:18PM -0700, Michael Snyder wrote:
> Pedro Alves wrote:
>> On Wednesday 01 October 2008 20:17:54, Michael Snyder wrote:
>>> +  /* TODO: check target for capability.  */
>>
>> Can we address this?  If you want to be able to query for support,
>> it would be a matter of defining a new qSupported feature.
>
> OK -- but what about existing targets that support reverse,
> but don't know about the qSupported query?
>
> When I put that comment in, I probably intended an implied
> question-mark -- that is, I wasn't asserting that a query
> would be useful, just wondering aloud...

All qSupported probes can be overridden by a manual setting.  I don't
feel particularly bad about forcing people to update, if there's a
workaround - that's part of getting protocol changes merged :-)

However, I'm not completely sure it's necessary in this case.  When do
we check for capability?  If it's only at the appropriate run/continue
command, then probing is OK - though this would make it hard to,
e.g., automatically enable IDE buttons.

> Yeah, I hear ya -- I'm not crazy about it either, and I
> don't think I knew about the idea of adding new tags onto
> the "T" packet two years ago.
>
> But... the discussion about the remote protocol for this
> happened back in '06.  There are now targets out in the field
> that implement it this way.  It would be bad form to break them...

I'm pretty sure nothing about this error was in that discussion.  At
least, I think I would have objected at the time.

-- 
Daniel Jacobowitz
CodeSourcery