GCC 9 linker error, missing GOMP_loop_nonmonotonic_dynamic_next

[Jakub Jelinek]

On Tue, May 07, 2019 at 10:47:40AM +0200, FX wrote:
> >> 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 confirm they are present.
> 
> The issue I am having is indeed due to GCC 9 trying to link against the wrong library: it turns out that LLVM’s libomp also ships a libgomp.dylib, as a symlink to libomp.dylib (and same thing with static libraries). This is what is interfering here.
> 
> So, quick questions:
> 
>  - are LLVM’s libomp and GCC’s libgomp supposed to be 100% compatible?

libomp is Intel library and they try to be ABI compatible, but are usually
behind and often even the symbols they provide are just stubs that do
nothing, e.g. for GOMP_target and various other offloading related APIs.
So that one is silent wrong code.

>  - if not, why is LLVM symlinking its library under another name?

You need to ask them.

	Jakub