Re: [Patch, fortran] PR110987 and PR113885 - gimplifier ICEs and wrong results in finalization

[Harald Anlauf <anlauf@gmx.de>]

Hi Paul,

Am 28.03.24 um 16:39 schrieb Paul Richard Thomas:
> Hi All,
>
> The attached patch has two elements:
>
> (i) A fix for gimplifier ICEs with derived type having no components. The
> reporter himself suggested (thanks Kirill!):
>
> -  if (derived && derived->attr.zero_comp)
> +  if (derived && (derived->components == NULL))
>
> As far as I can tell, this is the correct fix. I tried setting
> attr.zero_comp in resolve.cc for all the OK types without components but
> this caused all sorts of fallout.
>
> (ii) Final calls were occurring in the wrong place for finalizable
> elemental function calls within scalarizer loops. This caused incorrect
> results even for derived types with components. This is also fixed.

yes, this looks good here.

> It should be noted that finalizer calls from the rhs of an assignment are
> occurring at the wrong time, since F2018/24-7.5.6.3 requires:
> "If an executable construct references a nonpointer function, the result is
> finalized after execution of the innermost executable construct containing
> the reference.", while in the present implementation, this happening just
> before assignment to the lhs temporary. Fixing this is going to be really
> tough and invasive, so I decided that getting the right results and the
> correct number of finalization should be sufficient for the 14-branch
> release. As it happens, I had been mulling over how to do this for
> finalizations hidden in constructors and other contexts than assignment
> (eg. write statements or allocation with source). It's a few months away
> and will be appropriate for stage 1.
>
> Regtests on x86_64 - OK for mainline and then, after a bit, for backporting
> to 13-branch?

The patch looks rather "conservative" (read: safe) and appears to
fix the regressions very well, so go ahead as planned.

Thanks for the patch!

Harald

> Regards to all
>
> Paul
>
> Fortran: Fix a gimplifier ICE/wrong result with finalization [PR104555]
>
> 2024-03-28  Paul Thomas  <pault@gcc.gnu.org>
>
> gcc/fortran
> PR fortran/36337
> PR fortran/110987
> PR fortran/113885
> * trans-expr.cc (gfc_trans_assignment_1): Place finalization
> block before rhs post block for elemental rhs.
> * trans.cc (gfc_finalize_tree_expr): Check directly if a type
> has no components, rather than the zero components attribute.
> Treat elemental zero component expressions in the same way as
> scalars.
>
>
> gcc/testsuite/
> PR fortran/113885
> * gfortran.dg/finalize_54.f90: New test.
> * gfortran.dg/finalize_55.f90: New test.
>
> gcc/testsuite/
> PR fortran/110987
> * gfortran.dg/finalize_56.f90: New test.
>