[Bug fortran/119136] Printing result of function that prints itself hangs

[kargl at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119136

--- Comment #25 from Steve Kargl <kargl at gcc dot gnu.org> ---
(In reply to Thomas Koenig from comment #24)
> (In reply to Jakub Jelinek from comment #23)
> 
> Jakub, if I understand you correctly, then this can be done as part
> of the lock if the support is there, but that is not guaranteed
> for all systems that gfortran runs on.  Hmm... how do we want to
> do this?

I had a short email exchange with Jerry off-line.  Another
possibility would be to disable the recursive IO check if
one uses -fopenmp or -fopenacc.  This would require adding
a component to libgfortran(compile_options_t) and passing
it to libgfortran.  In pseudocode, 

   /* Check if this is a parent I/O.  */
   if (p->child_dtio == 0 && !compile_options.fopenmp)
     {
       if (TRYLOCK(&p->lock))
         {
           generate_error (&dtp->common, ... );
           return;
         }
       UNLOCK(&p->lock);
    }