| -----Original Message----- | From: Andrew Pinski <pins...@gmail.com> | Sent: Monday, October 28, 2019 2:52 PM | To: Jakub Jelinek <ja...@redhat.com> | Cc: Jeff Law <l...@redhat.com>; Segher Boessenkool | <seg...@kernel.crashing.org>; Gabriel Dos Reis <g...@microsoft.com>; | Andrew Dean <andrew.d...@microsoft.com>; David Malcolm | <dmalc...@redhat.com>; gcc@gcc.gnu.org; r...@cebitec.uni-bielefeld.de; | mikest...@comcast.net; ja...@redhat.com; Jonathan Wakely | <c...@kayari.org> | Subject: Re: GCC selftest improvements | | On Mon, Oct 28, 2019 at 2:47 PM Jakub Jelinek <ja...@redhat.com> 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? | > | > That is not a good idea, it will make it much harder to build gcc because | > not everybody has gcc-9 built as a system compiler. | > The previous minimum requirement of 4.1 is perhaps too old now that 4.8 | is | > something we could require and gain through that C++11 support, but we | > shouldn't follow Rust with "you can only build it with 6 weeks old previous | > release and nothing else". | > As discussed earlier, we gain most through C++11 support, there is no need | > to jump to C++17 or C++20 as requirement. | | Just a quick note. | RHEL/CentOS 7 uses GCC 4.8 as the system compiler. Requiring a new | compiler to compile GCC 10 will not work for me. | I normally bootstrap GCC 10 and then build a GCC 10 cross compiler. | Having to have an extra compiler inbetween is problematic for me. | | Thanks, | Andrew
I would think C++14 gives you a good compromise, as you have access to key C++11 functionalities with a less crippled constexpr support. -- Gaby
