Re: Starting multiple GUD session; doc problem

[Stephen Leake <stephen_leake@member.fsf.org>]

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

>  > Since the info manual never mentions "--annotate=3", I thought it was
>  > always necessary. So yes, I found it ambiguous.
>
> I guess it presupposes a knowledge of "--fullname" and
> "--annotate=3". 

Yes.

> Ideally it would mention neither but give the user the option of
> switching between the two in terms of their functionality.

Yes. Maybe after the release.

>  >                         and that is the behavior I was expecting. In
>  > particular, I don't have to do anything special to get two debugging
>  > sessions.
>  >
>  > At the same time, if you don't customize 'gdb-many-windows', "gdb
>  > --annotate=3" in Emacs 22 also works the same as "gdb" in Emacs 21,
>  > except that it doesn't allow multiple debugging sessions. So that's
>  > why I was surprised by this.
>
> I've arranged so that it starts up the same way. However it has much
> more functionality. If you create a breakpoint a red bullet is
> placed in the fringe/margin so you don't have to remember where your
> breakpoints are. 

That is nice.

> You can view the stack, examine watch expressions, manipulate
> breakpoints...

You can do all that with text command mode as well. But with GUI mode,
you can do it with only the mouse, and all of the results are always
visible. It's a trade of screen usage between showing program state
and program source, and of mouse vs keyboard. It is nice to have the
choice.

>  > (aside; I don't understand why the tooltips are not available in "text
>  > command mode". Is "--annotate" required to get tooltip variable values?)
>
> The section Debugger Operation says
>
>       GUD tooltips are disabled when you use GDB in text command mode
>    (*note GDB Graphical Interface::), because displaying an expression's
>    value in GDB can sometimes expand a macro and result in a side effect
>    that interferes with the program's operation.  The GDB graphical
>    interface supports GUD tooltips and assures they will not cause side
>    effects.

Ok. I'm mostly using Ada, which doesn't have macros. So perhaps after
the release we could explore relaxing that restriction for Ada (and
other languages where it would be safe).

I _often_ run two debugging sessions, to find the difference between
two programs (one that works and one that doesn't). Running them in
separate Emacs sessions is dangerous, because they usually share lots
of code, and I don't want to risk editing the same file in two
different Emacs sessions. (This is one area where Emacs is better than
other IDEs.) So I'd like to have as many debugger features as possible
while running two debugging sessions.

I'll go read the manual more thoroughly now :).

-- 
-- Stephe