bug#30151: Debugger API

[Eli Zaretskii <eliz@gnu.org>]

> From: James Nguyen <james@jojojames.com>
> Cc: 30151@debbugs.gnu.org
> Date: Fri, 19 Jan 2018 01:25:47 -0800
> 
> Ideally, it'd be nice to have something simple that asks me:
> 1. Where to draw breakpoints in the buffer.
> 2. What locals exist and displaying them in some kind of 'locals' buffer.
> 3. Maybe an extra window that will display extraneous information (similar to jdibug's stacktrace buffer)
> 4. I'm missing some other common functionalities between debuggers.
> 
> I think some/all of ^ is very similar to gdb-many-windows but I've only ever seen that for *just* gdb.

I agree, but as I said, these capabilities need to be supported by the
underlying debuggers.  Currently, only gdb-mi.el provides them because
GDB includes a special interface for debugging front-ends, and that
interface provides the functionality required for the features shown
in gdb-many-windows.  If other debuggers can support similar
functionalities, gud.el could be extended to do that for them as well.

Perhaps the first step would be to look at what realgud does to
provide these features.  But please be aware that if you are going to
read realgud's source with the intent of doing something similar in
Emacs, you are advised to check with realgud's developers whether they
will be willing to sign legal paperwork, in case you end up copying
some of their code.

Thanks.