RFC: Bump minimum GNU Make version to 3.81

[Richard Biener]

On Wed, Jun 24, 2026 at 6:53 PM Jonathan Wakely via Gcc <gcc@gcc.gnu.org> wrote:
>
> Currently we document that GNU Make 3.80 is required. That was
> released in 2002. GNU Make 3.81 was released in April 2006. I would
> like to suggest that 20 years is enough time for 3.81 to be
> widespread.
>
> Bumping the requirement to 3.81 would allow us to use the $(abspath
> ...) function, which we already started using in libstdc++, not
> realising that it relies on a newer version than our docs require.

OK, can you produce a patch to install.texi?  Can you check whether
branches are affected by the effective bump in requirement and backport
as well?

Thanks,
Richard.

> 3.81 also has $(lastword ...), $(realpath ...), $(or ...), and $(and ...).
>
> GNU Make 3.82 from 2010 adds the .ONESHELL feature but maybe 2010 is
> too modern for our tastes ;-)