GCC selftest improvements

[Segher Boessenkool]

On Fri, Nov 22, 2019 at 11:36:18PM +0100, Jakub Jelinek wrote:
> On Fri, Nov 22, 2019 at 04:01:43PM -0600, Segher Boessenkool wrote:
> > On Fri, Nov 22, 2019 at 09:02:05PM +0000, Andrew Dean wrote:
> > > > > Many systems do not have a system compiler newer than this *four years
> > > > > old* one.  GCC 4.8 is the first GCC version that supports all of
> > > > > C++11, which is the only reason it would be even near acceptable to
> > > > > require something this *new*.
> > > > 
> > > > Agreed.  Note we're even shipping new service packs for SLE12 which has that
> > > > "ancient" compiler version (OTOH there _is_ a fully supported GCC 9 available
> > > > for SLE12 as well).
> > > > 
> > > > So, if we want C++11 then fine.  But requiring GCC 9+ isn't going to fly.  IIRC
> > > > GCC 6 is first having -std=c++14 by default, but unless there's a compelling
> > > > reason to use C++14 in GCC I'd rather not do it at this point.
> > > > 
> > > > Removing all the workarounds in the tree we have for GCC 4.[12].x would of
> > > > course be nice.
> > > > 
> > > > But I have to update the testers that still use GCC 4.1.x as host compiler :P
> > 
> > > Richard/Segher: Are we in agreement that we can move forward with updating to c++11 as the minimum version? I have made the simple change locally to modify the flag and verified that I got the exact same test results with/without the change. I can look into the work to add a configuration warning if the compiler doesn't support c++11, but wanted to make sure we are on the same page before doing so.
> > 
> > If GCC 4.8.5 works as bootstrap compiler, it is fine with me, and good
> > progress too.  (Which means 4.8.5 has to work for at least all primary
> > targets.)
> 
> What would be the advantage of bumping the requirement now as opposed to at
> the start of next stage 1 though?  We should be fixing bugs now, not
> introduce new features nor do code refactoring.

Oh, I meant for GCC 11, of course.  I thought we all agreed on that.


Segher