Re: [PATCH] doc: Add table of MI versions

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 15 Jan 2019 15:37:45 -0500
> From: Simon Marchi <simon.marchi@polymtl.ca>
> Cc: simon.marchi@ericsson.com, gdb-patches@sourceware.org
> 
> Since @sc{gdb/mi} is used by a variety of front ends to
> @value{GDBN}, changes to the MI interface may break existing usage.
> This section describes how the protocol changes and how to request
> previous version of the protocol when it does.

OK, thanks.

> >   new versions of the MI protocol are not compatible with the old
> >   versions
> 
> I thought this was quite obvious by the fact that we say that we 
> introduce a new version when we make breaking changes.  But I can add 
> this sentence, which would result in this:
> 
> If the changes are likely to break front ends, the MI version level
> will be increased by one.  The new versions of the MI protocol are not 
> compatible
> with the old versions.  Old versions of MI remain available, allowing 
> front ends
> to keep using them until they are modified to use the latest MI version.

Fine by me.

> >> About the idea itself, I don't think we need to implement this.
> > 
> > We don't need to agree with it, we just need to preserve the
> > suggestion.
> 
> I have opened [1], is it fine to remove the comment from gdb.texinfo?

No objections from me.

> >> If front ends request a specific version of MI (which is good
> >> practice, in my experience), they won't need to query it.
> > 
> > What if a front end can support several versions, provided that it
> > knows the latest version which is provided?  Why require such a front
> > end to request the lowest common denominator, instead of adapting to
> > the latest version it can support?
> 
> I don't think we require front ends to use the lowest common 
> denominator.  Instead, it should request 
> max(version_known_by_the_front_end, version_known_by_gdb).

And I think version_known_by_gdb needs this command, doesn't it?

Thanks.