bug#70573: 30.0.50; Setting gud-gud-lldb-command-name does not take effect

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: 70573@debbugs.gnu.org
> Date: Thu, 25 Apr 2024 21:25:48 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > It looks like this part:
> >
> >   (interactive (list (gud-query-cmdline 'lldb)))
> >
> > is the culprit: the minor-mode, which is the argument to
> > gud-query-cmdline, should be 'gud-lldb, not 'lldb.  Here's my
> > evidence:
> >
> >   (when (and gud-comint-buffer
> >          (buffer-name gud-comint-buffer)
> >          (get-buffer-process gud-comint-buffer)
> >          (with-current-buffer gud-comint-buffer (eq gud-minor-mode 
> > 'gud-lldb)))
> >
> > Btw, this line seems also to be confused wrt the name of
> > gud-minor-mode:
> >
> >   (setq-local gud-minor-mode 'lldb)
> 
> I'm currently seriously confused by gud.el, I'm afraid. And I was
> already confused when I tried to mimic gud-gdb here, which does
> 
>   (interactive (list (gud-query-cmdline 'gud-gdb)))
> 
>   (when (and gud-comint-buffer
>          (buffer-name gud-comint-buffer)
>          (get-buffer-process gud-comint-buffer)
>          (with-current-buffer gud-comint-buffer (eq gud-minor-mode 'gdbmi)))
>     (gdb-restore-windows)
>     (error
>      "Multiple debugging requires restarting in text command mode"))
> 
>   (gud-common-init command-line nil 'gud-gdb-marker-filter)
>   (setq-local gud-minor-mode 'gdb)

I don't think the complications of GDB should concern you.  AFAIU, the
above tries to handle the tricky situation where we have 2 GDB minor
modes: gdbmi and gud-gdb.  There's no such problem with LLDB, AFAIU.

So I think you should copy-cat the other minor modes, like gud-pdb,
which don't have these complications.

> Would you agree that the interactive form should use gud-lldb, but that
> the setq-local is right? The setq-local is gud-gdb uses gdb, not
> gud-gdb. Or am I confusing myself here?

I think both should use gud-lldb, at least that's my understanding.
Look at gud-query-cmdline, gud-val, and gud-symbol, and you will see
that they encode the command name as gud-MINORMODE-SYMBOL, where
SYMBOL is "command-name" in this case.  So if the command name's
symbol is gud-gud-lldb-command-name, then MINORMODE must be gud-lldb,
for this stuff to work.