Re: RFA: Remove gdb-events

[Vladimir Prus <vladimir@codesourcery.com>]

Tom Tromey wrote:

> My understanding is that the gdb "events" mechanism is deprecated in
> favor of using observers.
> 
> This patch removes events and adds observers where needed.
> 
> Most of this patch is straightforward.  There are a few odd pieces:
> 
> * Removing the call to clear_gdb_event_hooks.  In theory I think this
>   could confuse some caller.  However, in practice I think it is
>   probably nothing to worry about.
> 
> * The architecture_changed observer is needed for gdbtk, but the only
>   place where this is notified is deprecated.  Since my goal here is
>   to remove events, I think this is probably fine.  It certainly
>   doesn't seem any worse.
> 
> * MI installs a new set of event handlers, does some work, then
>   uninstalls them.  Instead of trying to replicate this behavior --
>   say by deinstalling other observers -- I just made the MI observer
>   conditional on a global flag, which is set and reset at the
>   appropriate points.

I think it would have been nicer to install observers in mi_interpreter_init,
but it's not critical matter. The mi_can_breakpoint_notify will probably
remain forever, so that we report breakpoints differently when they are created
during -break-insert and when they are created by other commands -- the 
former needs to report new breakpoint as part of ^done reply, and the latter
has to use notification.

I don't have any objections to the MI part of this change -- thanks for asking
for an opinion!

- Volodya