GCC 9 linker error, missing GOMP_loop_nonmonotonic_dynamic_next

[Iain Sandoe]

> On 6 May 2019, at 09:02, Jakub Jelinek <jakub@redhat.com> wrote:
> 
> On Mon, May 06, 2019 at 02:41:41PM +0200, FX wrote:
>> Hi gcc and gfortran developers,
>> 
>> While testing GCC 9.1.0 before shipping it as part of Homebrew for macOS, we’re seeing the following OpenMP-based failure when recompiling several software packages with GCC 9. It includes both C++ and Fortran codes, which were working fine with the exact same setup and GCC 8.3.0.
>> 
>> The missing symbols we’re seeing are always in this list:
>> _GOMP_loop_nonmonotonic_dynamic_next
>> _GOMP_loop_nonmonotonic_dynamic_start
>> _GOMP_loop_ull_nonmonotonic_guided_next
>> _GOMP_loop_ull_nonmonotonic_guided_start
> 
> Those are certainly exported from my GCC 9 libgomp.so.1.0.0 (at least on
> Linux but I don't see how it could not be elsewhere).

I can’t, at present, see how it would be different Darwin.

> So, the most likely explanation would be you are compiling something with
> GCC 9, but linking against GCC 8 or earlier version of libgomp.

Could you file a PR with a reproducer - presumably even a trivial OpenMP program will fail?

thanks
Iain