Re: +USE_CC_FEATURES+= c17

[Greg Troxel <gdt%lexort.com@localhost>]

Martin Husemann <martin%duskware.de@localhost> writes:

> On Wed, May 21, 2025 at 11:20:34PM +0900, Makoto Fujiwara wrote:
>> Following are on NetBSD/amd64 9.
>> 
>> 1. c11/C++17
>>   does not make things (the same situation as 9.4 pbulk build)
>> 
>> 2. c17/c++17
>>   packages fine

If upstream documents c11, that seems odd.

> This is a bit puzzling as C17 did not introduce any new features over C11.

gcc.mk, which I intend to follow upstream docs, says that one needs 4.9
for c11 and 8 for c17, which is rounded to 10 following our
netbsd-centric limited-versions policy.

I can't find the docs right now but a quick web search supports "c17
needs gcc8".


It could be that there is something about gcc7 that is broken, or
something about rust that is out of spec, leading to failure with gcc7.


I would want to look into the build and see if --std=c17 is really being
set.

But, it may be that GCC_REQD+=10 with a comment is the answer here.  I
think it's very important to explain any setting that is other than a
translation of an upstream README, or for those upstreams that don't
believe in documentation (e.g. GNU Radio), a translation of upstream's
maze of twisty cmake files.