Re: git: 195b00ec45e5 - main - quot: Clean up

On Mon, Oct 20, 2025 at 9:42 AM Dag-Erling Smørgrav <des@freebsd.org> wrote:
>
> Ryan Libby <rlibby@gmail.com> writes:
> > Dag-Erling Smørgrav <des@freebsd.org> writes:
> >> In function 'usrrehash',
> >>     inlined from 'user' at /workspace/src/usr.sbin/quot/quot.c:244:3:
> >> /workspace/src/usr.sbin/quot/quot.c:210:22: error: argument 1 range [18446744071562067968, 18446744073709551615] exceeds maximum object size 9223372036854775807 [-Werror=alloc-size-larger-than=]
> >>   210 |         if ((users = calloc(nusers, sizeof(*users))) == NULL)
> >>       |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> In file included from /workspace/src/usr.sbin/quot/quot.c:51:
> >> /tmp/obj/workspace/src/amd64.amd64/tmp/usr/include/stdlib.h: In function 'user':
> >> /tmp/obj/workspace/src/amd64.amd64/tmp/usr/include/stdlib.h:92:10:
> >> note: in a call to allocation function 'calloc' declared here
> >>    92 | void    *calloc(size_t, size_t) __malloc_like __result_use_check
> >>       |          ^~~~~~
> >
> > Probably it is from
> > -WARNS?=        2
> >
> > I think gcc is saying that it thinks nusers may be negative.
>
> It's saying nusers may be large enough that the result of multiplying it
> by sizeof(*users) exceeds an arbitrary threshold, which is technically
> true but completely unhelpful.  This gcc option should not be used.
>
> DES
> --
> Dag-Erling Smørgrav - des@FreeBSD.org

The message is poor but the limit is not so arbitrary, it is
PTRDIFF_MAX.  It's saying that (size_t)nusers may be huge, because it
infers that nusers, being signed, may be negative -- though in reality
it will not be negative.  It says the range that will result in huge
values, (size_t)INT_MIN through (size_t)-1.

Sure, you could disable the warning, kern.mk does that and one other
user make file does too.  Or you could convince gcc with a type
constraint, or somehow else.  In any case, we should fix the gcc build.

Ryan