Re: Simultaneous gdb session badness

[Michael Welsh Duggan <md5i@cs.cmu.edu>]

Nick Roberts <nickrob@snap.net.nz> writes:

> Michael Welsh Duggan writes:
>  > I wish I could say just when this problem cropped up, but...
>  > 
>  > In the current CVS, I cannot run gdb though the gud on two seperate
>  > programs simultanously.  For example, if I start a gud session for
>  > program A, then one for program B, if I then type "b main" in program
>  > A's gud buffer, the breakpoint gets set in program B.
>  >
>  > This definitely worked in 21.3, and I can remember doing it in earlier
>  > versions of 22.0.  It is a frequent occurence for me to want to run
>  > seperate gdb session in the same emacs, especially when they are
>  > intercommunicating processes.
>
> The default behaviour for gdb in Emacs has changed considerably since 21.3.
> You could read the manual to understand these differences.  It says
> (GDB Graphical Interface):
>
> Manual>   You can also run GDB in text command mode, which creates a buffer
> Manual> for input and output to GDB.  To do this, set `gud-gdb-command-name'
> Manual> to `"gdb --fullname"' or edit the startup command in the minibuffer to
> Manual> say that.  You need to do use text command mode to run multiple
> Manual> debugging sessions within one Emacs session.

Yes, I see that now.  It was not obvious from NEWS, so I didn't
realize I needed to reread the gdb manual.  (I remember reading the
messages covering bits of this on emacs-devel now that you brought
this up, but I obviously didn't read them closely enough.)

More importantly though, if one cannot run multiple sessions without
using --fullname, M-x gdb should not allow you to attempt to so.  It
would be much better for it to give an understandable error message
letting the user know what is going on.

> Text command mode refers to the mode used in 21.3.  The default mode for
> 22.1 is referred to as graphical mode and uses "gdb --annotate=3".
>
> When your gdb sessions are independent, you can always uses separate Emacs
> sessions, of course.

Of course, but I have this thing about running more than one emacs on
a machine at a time.  Call it silly, but I prefer not to do it.

-- 
Michael Welsh Duggan
(md5i@cs.cmu.edu)