Re: [PATCH] Fix PR82396: qsort comparator non-negative on sorted output

[Jakub Jelinek <jakub at redhat dot com>]

On Wed, Oct 04, 2017 at 02:12:11PM +0100, Ramana Radhakrishnan wrote:
> On Wed, Oct 4, 2017 at 12:01 PM, Richard Sandiford
> <richard.sandiford@linaro.org> wrote:
> > Wilco Dijkstra <Wilco.Dijkstra@arm.com> writes:
> >> Christophe Lyon wrote:
> >>
> >>> FWIW, I confirm that this patch fixes the build failure I reported at:
> >>> https://gcc.gnu.org/ml/gcc-patches/2017-09/msg01980.html
> >>
> >> Thanks, now committed as r253399.
> >
> > I don't think it's reasonable to commit this as obvious.  You said
> > yourself in the covering message that "it doesn't at all restore
> > the original behaviour since we no longer compare the base address".
> > So even with the bootstrap failure, I think the patch needed review
> > before going in.
> 
> I agree that this patch shouldn't have gone in without review from a
> maintainer of the appropriate area regardless of whether this fixes a
> bootstrap failure or not.
> 
> However we need a scheduler maintainer or global reviewer to please
> help review this patch or help come up with an alternative patch. A
> primary platform broken for 5 days with a commit and no public
> response from the original poster is really not appropriate behaviour
> in this community. If not, the original patch should have been
> considered for reverting under the 48 hour rule .

A workaround that could be committed as obvious would be wrapping
some qsort call affected by this into (), i.e. instead of doing
qsort (...); do (qsort) (...);
That way you revert to previous behavior for the problematic qsort and not
change anything else.
The committed patch isn't in any way obvious and really needs to be reviewed
by a scheduler maintainer.

	Jakub