Re: MI handshaking

[Bob Rossi <bob@brasko.net>]

On Wed, Nov 17, 2004 at 10:17:57AM -0500, Alain Magloire wrote:
> > 
> > On Sat, Nov 13, 2004 at 10:57:33AM +0200, Eli Zaretskii wrote:
> > > > Date: Fri, 12 Nov 2004 17:57:30 -0500
> > > > From: Andrew Cagney <cagney@gnu.org>
> > > > Cc: Bob Rossi <bob@brasko.net>, Nick Roberts <nick@nick.uklinux.net>,
> > > >         gdb-patches@sources.redhat.com
> > > > 
> > > > > =mi-handshake,versions=[mi1,mi2,mi3],stable=[mi2]
> > > > 
> > > > Yes, thanks for the correction with ``=''.   But not 
> > > > ``versions=[mi1,mi2,mi3]'' that's too much and misleading information.
> > > > 
> > > > I think the objective here needs to be to provide as much information as 
> > > > possible about what version of GDB and MI is running.  Hence the:
> > > > 
> > > > 	version="mi2"
> > > > 
> > > > (where hopefully VERSION version is a member of STABLE :-)
> > > 
> > > We've been through this discussion, and the only suggestion that
> > > brought a consensus was to print all the supported MI versions, not
> > > just one.  Let's not reopen that discussion again, even if the result
> > > looks ``too much and misleading''.  (Why ``misleading'', btw?)
> > 
> > Yeah, anyways it doesn't really matter for now. GDB only supports one
> > version, and I have a feeling it will stay that way for a long time.
> > 
> 
> sigh ... sorry for being dense (hopefully this will not be a long thread)
> but why are you keep on saying: "GDB only supports one version"
> for example, I have gdb-6.1.x and I can start
> # gdb -i mi1
> # gdb -i mi2
> # gdb -i mi3
> 
> that it is more then one version?

oops, sorry, I meant to say that GDB supports only 1 stable MI version.
This is only relavent when discussing what GDB should do when the user
starts with 'gdb -i=mi'.

I see 2 needs stemming from this patch.
   
   - I need the handshaking to happen before any other I/O.
     This allows my front end to determine the protocol that is going to
     be used by GDB.

   - Alain, it seems like you need this command to be available after
     the fact. Even though this seems unintuitive to me, I understand
     that it's not a perfect world, and this info could be useful later
     on, especially if you are not responsible for staring GDB.

It seems as if there is two parts to this patch. The first part does the
handshaking, and that takes care of the protocol that should be used.
Here, GDB will give all of the info necessary to help the front end determine
the protocol that it wants to use. For instance, the protocols possible,
the build date, the GDB version, ...

Also, as a second part, a new MI command could be added, that simply
repeats all of the info determined from the handshaking functionality.
This would allow front ends to query the information later on, if for
some reason it couldn't do it originally. Note however, this would not
repeat the handshaking, and the version of MI being used can not be
changed. 

Would this be OK for everyone?

Thanks,
Bob Rossi