On Mon, Oct 28, 2019 at 11:12 PM Segher Boessenkool <seg...@kernel.crashing.org> wrote: > > On Mon, Oct 28, 2019 at 03:41:13PM -0600, Jeff Law wrote: > > On 10/28/19 2:27 PM, Segher Boessenkool wrote: > > > On Mon, Oct 28, 2019 at 01:40:03PM -0600, Jeff Law wrote: > > >> On 10/25/19 6:01 PM, Gabriel Dos Reis wrote: > > >>> Jason, Jonathan - is the situation on the terrain really that dire that > > >>> C++11 (or C++14) isn't at all available for platforms that GCC is > > >>> bootstrapped from? > > >> The argument that I'd make is that's relatively uncommon (I know, I know > > >> AIX) that bootstrapping in those environments may well require first > > >> building something like gcc-9. > > >> > > >> I'd really like to see us move to C++11 or beyond. Sadly, I don't think > > >> we have any good mechanism for making this kind of technical decision > > >> when there isn't consensus. > > > > > > Which GCC version will be required to work as bootstrap compiler? Will > > > 4.8.5 be enough? > > I'd say gcc-9. What would we gain by making it 4.8 or anything else > > that old? > > 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