Re: [PUSHED/OBVIOUS] Remove gdb-gdb.gdb breakpoint on disappeared function info_command.

Philippe Waroquiers
2020-05-02T23:01:28Z

On Sat, 2020-05-02 at 22:19 +0100, Maciej W. Rozycki wrote:
> On Fri, 1 May 2020, Kevin Buettner via Gdb-patches wrote:
>
> > I couldn't find any clue from the ChangeLog entries about why that
> > break command was put into the .gdbinit file. It might be possible to
> > figure out more precisely when it was introduced, but I didn't attempt
> > this. I doubt that earlier imports would have any additional useful
> > info not already in the ChangeLog entries that I did examine.
>
> Hmm, I'm quite badly surprised to see this feature go, and I do hope it
> has been functionally (and hopefully transparently) replaced with whatever
> replaced `info_command'.
Neither Tom nor myself we understood the idea (and saw no description)
and as it was broken, it was deemed appropriate to just remove the
breakpoint command from gdb-gdb.gdb.
Sorry if this removal was a bad idea and inappropriate for PUSHED/OBVIOUS rule.

>
> Its use was quite obvious to anyone who actually debugged GDB from time
> to time: it was there so that you could break from the debuggee GDB into
> the debugger GDB with the use of the `info' command (with no arguments),
> as obviously using signals like SIGINT for that was quite problematic. I
> used to use this feature regularly, up until the last time a couple months
> back when I switched to non-GDB work.
I do limited GDB debugging, but was not aware of this feature.
I am not sure to understand the problem:
C-c works for me to interrupt GDB, and the top GDB gets
back the control (I typically launch top-gdb separately
and attach to the inferior GDB).
Can you explain more in details the problem this was solving ?

>
> So what's the current mechanism to do that? I do hope to have it the
> next time I poke at GDB.
If something done in the inferior GDB must trigger the top GDB to regain
control, we could add a specific dummy command
e.g. maintenance wake-up-top-gdb
and then have the breakpoint put on the wake_up_top_gdb_command function
implementing this dummy command.

Philippe