D is our last hope

[Iain Buclaw]

On Wednesday, 20 December 2023 at 15:12:37 UTC, Siarhei Siamashka 
wrote:
> On Wednesday, 20 December 2023 at 14:01:00 UTC, Richard (Rikki) 
> Andrew Cattermole wrote:
>> From what Iain has said that I remember, you can only use the 
>> last 3 major versions in binary form to compile the next 
>> version. They are pretty strict.
>
> Yes, if somebody is contributing a patch for GCC 14, then they 
> can't immediately rely on a newly added fancy GCC 13 feature, 
> but have to ensure that the code still can be successfully 
> compiled by GCC 11, GCC 12 and GCC 13. Even older versions may 
> or may not work, but this is not guaranteed.
>
> GDC 15 won't have an obligation to be compilable by GDC 11. But 
> this doesn't mean that GDC 15 (or DMD) suddenly needs to 
> intentionally break compatibility with GDC 11.
>

In reality people are still using gdc-9 to build gdc-14-trunk on 
certain old systems, so I'm still keeping compatibility with it 
for as long as gcc/g++ continue to have their baseline set at an 
earlier version (as of writing it's 4.8.x)

That incomplete C++11 compiler's days are numbered however.  Some 
good news is that soon gcc will switch to C++14, unfortunately 
though, that'll probably mean the baseline will become gcc-5.x 
instead - aligning with the Ada front-end.  At this rate, it'll 
be another 4 years before they catch up version 9.x and we'll all 
be at the same baseline. :-)