Re: New feature "source-id"

Gerhard Gappmeier
2014-03-16T09:43:21Z

On Saturday, March 15, 2014 07:34:08 PM Doug Evans wrote:
> On Sat, Mar 15, 2014 at 1:06 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> >> Date: Sat, 15 Mar 2014 10:32:12 -0700
> >> From: Doug Evans <dje@google.com>
> >> Cc: gdb-patches <gdb-patches@sourceware.org>
> >>
> >> But IMO the fetching of source must go through the Extension Language
> >> API.
> >> See gdb/extension*.[ch].
> >> I.e., don't do the popen in gdb. Just call out to the extension
> >> language via the API (e.g, Python), passing it the necessary
> >> parameters.
> >
> > That would mean the feature will be unavailable in a GDB compiled
> > without Python and Guile.
Actually I agree with Eli. I would prefer if this would work without pyhton.
Using th popen approach it is very flexible. You can write fetch scripts with
whatever language you like. My example scripts are simple BASH scripts that
call wget.
But maybe I just don't understand what you mean with that extension language
api. Does this require to implement fetch scripts with python? Do you have
security concerns with popen or what is the reason for this?
>
> Actually, that could be an orthogonal question: the Extension Language
> API also provides an interface to gdb's own scripting language (e.g.,
> to support auto-loading .gdb scripts).
> I'm not sure I would go that route though. I have no problem with
> requiring Python or Guile in order to support this.
>
> Note that one concern I have is that it may be that some sites will
> want to have some of gdb's state updated when source files are
> automagically fetched. E.g., maybe one would want to update the
> source search path.
Actually a search path is not required. The script outputs the filename to
stdout which is then read by GDB and use to open the file. There is no need
for any search path to make this working.

> Maybe not, but at any rate I don't want this
> feature to preclude doing things like that, and one can't do that if
> the feature works by running an external program via popen.
>
> btw, Gerhard, this would require a copyright assignment.
> Do you have one? [If/when (and at this point I'd say it's still a big
> "if") there is general consensus on adding the feature you'll need to
> complete an assignment before the patch can be added to the FSF
> sources. Let me know if you need the necessary paperwork. There's no
> rush on that, but it's something to keep in mind.
I've no problem with signing a copyright assigment. Just let me know what I
need to do for it. It's me first contribution to FSF.