Re: [RFC] Add expat to the GDB sources

[Daniel Jacobowitz <drow at false dot org>]

On Tue, Jul 25, 2006 at 12:48:51AM +0200, Mark Kettenis wrote:
> Where do you think my frstration about external dependencies comes
> from ;-).  However, GCC will build fine without most of those
> packages: without GMP/MPFR you won't get gfortran, and without zip you
> won't get gjc/libjava.  But at least you can still build the C
> compiler, which you can then use to build the other dependencies.
> 
> I think the GNU Make requirements are a serious mistake by the GCC
> developers.

I don't.  I was there for the discussion that led to the current
requirements, and the reasoning was compelling.  Much of it was in
person (at the Summit) and so there's limited transcripts.  But
it may not have been my best choice of example; I don't know if you
ever had to work with the internals of the GCC build system before they
adopted the GNU make requirement.  And they're still improving to take
advantage of even more useful GNU make features to simplify their build
system to the point where developers in other areas can often grok
what's going on.  Well, not there yet.

> Translated to GDB this would mean that without expat you'd still get a
> usable gdb, but loose goodies like the new flash support (which isn't
> terribly useful for a native gdb anyway).

I dislike this idea, as I've said before:

  - for the same reason I dislike #if.  The code is far more likely to
    rot if you can build GDB with it preprocessed or Makefile'd out.

  - for the bug reports we'll get where GDB mysteriously fails to have
    some feature.

But that's not the end of the world; if the outcome of this discussion
is that conditionalizing features is preferable to bundling expat, I'm
willing to adjust it to do so.  I'd spit out a big warning at the end
of configure if expat was not found.  And probably warnings during
debug sessions if the expat code paths would have triggered.

... And maybe rethink using the minimal expat versus the more
feature-complete libxml2, but I'd need to talk to Vladimir about that;
he's written XML parsers more recently than I have now.

-- 
Daniel Jacobowitz
CodeSourcery