On 29.10.21 12:53, Jakub Jelinek wrote:
> On Fri, Oct 29, 2021 at 12:09:55PM +0200, Tobias Burnus wrote:
>> [...] only routines calls to
>>    omp_get_num_teams() and omp_get_team_num()
>> are permitted in teams when closely nested.
> I'm afraid using DECL_ASSEMBLER_NAME opens a new can of worms. [...]
> At least for C++, [...]
> is meant to be checked by
>        || (DECL_CONTEXT (fndecl) != NULL_TREE
>            && TREE_CODE (DECL_CONTEXT (fndecl)) != TRANSLATION_UNIT_DECL)
> If that doesn't work for Fortran modules, we need to find out something
> different, e.g. setjmp_or_longjmp_p also relies on that...

It turned out that the current (pre-patch) code works correctly, except
that DECL_NAME for Fortran does not have the '_' suffix. I have now
updated the comments and just for omp_* and omp_*_8. That simplifies the
code and, fortunately, DECL_NAME does seem to work.

> On the other side, when we use DECL_NAME we don't currently differentiate
> between:
> extern "C" int omp_is_initial_device ();
> and say
> extern int omp_is_initial_device (double, float);
> where the latter is in C++ mangled differently.  Sure, one can't use
> the latter together with #include <omp.h>...

The question is whether anyone cares that we reject the latter?

> As mentioned in the PR, I really don't like this permit_num_teams argument,
> IMHO it is a caller that should check it, otherwise we end up in the
> function with myriads of future exceptions etc.
I concur – given that DECL_NAME seems to work fine (ignoring C++ w/o
extern "C").
> As for tests where you are adding parallel to avoid the new diagnostics,
> I'd suggest parallel if(0) instead, no need to create any extra threads...

Done.

Thanks for the comments!

Tobias
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