On Mon, Jul 27, 2026 at 08:21:45AM +0700, Ammar Faizi wrote: > On Mon, Jul 27, 2026 at 3:16 AM Thomas Weißschuh wrote: > > __auto_type is only supported from GCC 4.9. I think this is old enough, > > but it should be mentioned at least. > > We really should have a documented policy for that. > > I suggest using the Linux kernel's minimal requirements. It's GCC 8.1 > or Clang 17.0.1. Ref: https://docs.kernel.org/process/changes.html > > What do you think?
Since it's userland (i.e. not building with the kernel's compiler), and often used for ease of porting boot-time tools in headless or embedded environments, I'd really like that we keep compatibility for as long as possible with oldest compilers that continue to work. Last time I checked, it was still working fine with gcc-4.4. I still have my 4.7.4-based toolchains that I regularly use for troublehooting and compatibility checks (and faster builds), I can recheck. We should not require that to be verified by contributors (too painful), however, noting "still known to build fine with version X" is helpful. And the day we discover that this promise has been broken for a year or so, we know we can safely update it. I can recheck ASAP. > Should this be documented in nolibc.h as a comment? It can indeed be sufficient to add a line to the first comment block. However I'm thinking that we would benefit from adding a larger README in the sub-dir for contributors that explains some of the traps we often have to mention. thanks, Willy
