[Bug fortran/109500] SIGABRT when calling a function that returns an unallocated value

["anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109500

--- Comment #11 from anlauf at gcc dot gnu.org ---
(In reply to Leandro Lupori from comment #10)
> Wouldn't it be better to turn this into a warning?
> 
> Although using the result of a function as an allocatable argument doesn't
> conform with Fortran standards, it has been supported by gfortran for quite
> some time. This change may break existing code.

Well, then the existing code seems to violate the Fortran standard,
and it seems it was a bug that gfortran accepted it silently.

The code in comment#0 seems to be silently accepted by the Intel classic
Fortran compiler (ifort), but crashes the new one (ifx).  I've asked
Intel on their opinion.

I've also learned that the same happens for the case of passing f() to
a subroutine, as in:

  call s(f())
[...]
contains
  subroutine s(p)
    integer, allocatable :: p
  end subroutine s
[...]

This is rejected by NAG and also Nvidia and AMD flang, and crashes ifx.

Do you have anybody else supporting the view that the code in question
should work as an extension?

As I said before, there are legal ways to return from a procedure with
the result variable either allocated or not, but this cannot be a function.