Re: probing GDB for MI versions

['Bob Rossi' <bob at brasko dot net>]

Sorry if I was rude here, I am very frustrated.

No one has attempted to do what I am trying to do. Write a front end
that is capable of working with different GDB's.

If they do do this, I would like to know how they negotiate the MI
version to talk.

Again, you seem to be saying that if I generate a parser off of the MI
output syntax, that I am somehow wrong.

Is this the general feel of the community?

Bob Rossi


On Wed, Oct 06, 2004 at 05:55:28PM +0100, Dave Korn wrote:
> > -----Original Message-----
> > From: 'Bob Rossi'  
> > Sent: 06 October 2004 17:22
> 
> > On Wed, Oct 06, 2004 at 12:50:34PM +0100, Dave Korn wrote:
> > > > -----Original Message-----
> > > > From: gdb-owner On Behalf Of Bob Rossi
> > > > Sent: 06 October 2004 12:39
> 
> > > >    The front end has parsers for different versions of GDB's 
> > > > MI protocol. 
> > > >    The parser for MI2 may not work for the MI3 protocol.
> > > >    The parser for the MI3 protocol may not work for the 
> > MI2 protocol.
> > > >    The front end *can not* start up GDB just by using 
> > -interpreter=mi
> > > >    because it doesn't know what parser to use in this situation.
> > > >    Can we agree on this point for starters?
> > > 
> > >   No, we can't.  As long as the output from the -mi-version 
> > MI command stays
> > > in the same format, you can always parse that and determine 
> > which version to
> > > use.  
> 
> > Dave, you do not understand the problem at all. I do not 
> > appreciate your
> > defininative answer, especially since it is incorrect.
> 
> #1.  Well, I don't appreciate your rudeness, but hey, we don't always get
> what we want in life.  Guess you're just SOL.
> 
> #2.  My answer IS correct.  I DO understand the problem, and in fact I
> understand it better enough than you do that I can see the very very obvious
> solution (that you aren't capable of grasping) as well as the problem
> itself.
> 
> #3.  Why do you have to be the _only_ person in the entire software industry
> who isn't capable of dealing with elementary versioning and compatibility
> issues?  These techniques work fine for EVERYONE else but you.
> 
> > The actual MI output syntax is capable of changing between MI 
> > versions.
> 
>   Yes.  I hope we're all agreed that there is no hope of (nor point to)
> tracking a work-in-progress as it changes on a day-by-day basis.
> 
> > If the MI4 output syntax (grammar) has an incompatible change 
> > with MI3,
> > then 
> >    * the MI3 parser will not even be capable of parsing and 
> > building a 
> >      parse tree for the MI4 protocol.
> >    * the MI4 parser will not even be capable of parsing and building a
> >      parse tree for the MI3 protocol.
> 
>   Try and think outside the box.  Your over-reliance on tools is hobbling
> you.  You aren't obliged by statute to use an automatically generated parser
> based on a formal grammar.  You can use printf to send the -mi-version
> command to the gdb instance, and you can use sscanf to parse the version
> number out of the string "MI version is XXXX" that it returns.
> 
> > It is not possible to understand the output of the command no 
> > matter how simple it is. 
> 
>   Speak for yourself.  I can understand it, it's human readable.  I could
> write a very very very simple bit of code using sscanf that would understand
> it.  You might have a problem understanding it, but you're the only one who
> does, and there's no need for you to.
> 
> >If there is no parse tree, then there is no way to
> > understand the output from GDB.
> 
>   Don't be so facile.  You send one very simple command, get back one very
> simple output that you can parse with strcmp or sscanf, for crying out loud.
> Then you know what MI version you're dealing with.
> 
> > I don't understand the concept of an "utterly minimal 
> > unintelligent parser". 
> 
>   Well, you're clearly biting off more than you can chew with this entire
> project.  As I said above, something of the degree of complexity of a single
> sscanf statement is what I mean.
> 
> > That is rediculous. I am generating a parser from the grammar.
> >
> > There absolutly needs to be a way for the front end to ask GDB what
> > versions of the MI protocol it supports. 
> > 
> > There is no way the front end can ask GDB what protocols it 
> > supports if
> > it needs to talk to it with an MI protocol. Understood?
> 
>   I understand what you're claiming, but I gave you a perfectly clear and
> simple way of doing it.  You haven't demonstrated any problem with my
> proposal, because as you said above, you haven't even understood it yet.
> When you do understand it, you'll also understand that it works just fine.
> 
>     cheers, 
>       DaveK
> -- 
> Can't think of a witty .sigline today....