Re: Designs for better debug info in GCC

["Richard Guenther" <richard dot guenther at gmail dot com>]

On Dec 17, 2007 9:28 PM, Alexandre Oliva <aoliva@redhat.com> wrote:
> On Dec 17, 2007, Diego Novillo <dnovillo@google.com> wrote:
>
> > On 12/17/07 12:51, Alexandre Oliva wrote:
> >> I guess I'm to blame, for having naïvely put the code out without as
> >> much as a design and goals document
>
> > Yes, you are.
>
> Wow, thanks.  At least we agree on something! ;-)
>
> > You need to provide such a document now.
>
> Can't I instead provide it when it's ready?
>
> You know, it wasn't me who asked to have the thing developed in the
> open.  I didn't push it out just so that people who didn't want to
> understand it could beat on it before it was ready to defend itself.
> I put it out because there was an offer for contribution.

Yeah - that was me...

Fact is we had a discussion about debug information earlier this year from which
I took the conclusion that most people would appreciate an on-the-side
representation
to address the most limiting design issue of GCCs tree representation (only one
variable per SSA_NAME to track).

So I had the impression you worked in that direction and offered help.  Now, you
seemed to have come to the conclusion that this approach would not help your
goal and started on a different route.  Now the "mistake" maybe was to
before starting
this not to revive the former discussion based on your findings and
elaborate on your
goals.  (I realize this is the way development for GCC works most of
the time, but
this is not what I consider good practice for open source development)

Now - I think your goal is valid, and the choice of implementation might even be
the best one for it.  But we (the GCC community) have not yet decided if the
combination of "your goal" and "this best implementation" is what we want.
(I haven't decided myself either ;))

So my suggestion for you is to continue with your implementation and produce a
white paper about your design (which you ideally would present during the next
GCC summit, where we should do a discussion on this topic in some form).

We (myself and Matz) will continue to implement what is "our goal" (because we
internally committed to it, and to see limitations or problems with
the approach)
and possibly also will present about its outcome at the summit.

Thanks,
Richard.