[Bug fortran/103413] [10/11/12/13 Regression] ICE: Invalid expression in gfc_element_size since r10-2083-g8dc63166e0b85954

["sgk at troutmask dot apl.washington.edu" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103413

--- Comment #12 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Wed, Oct 26, 2022 at 06:24:04PM +0000, anlauf at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103413
> 
> --- Comment #11 from anlauf at gcc dot gnu.org ---
> (In reply to kargl from comment #10)
> > Well, a boz is typeless, so it cannot be compatible with any other type.
> > So, I would assume, you could do 
> > 
> > if (ts1->type == BT_BOZ || ts2->type == BT_BOZ)
> >    return false;
> 
> Yes, that's better.
> 
> > There is a caveat in that Fortran 2023 is going to allow
> > things like
> > 
> >     real :: x = z'1234'
> > 
> > if gfc_type_compatible is used in simple assignments, gfortran will
> > need to deal with that.
> 
> It is currently not used in those cases.

Hmmm, I wonder if there is duplicate code within gfortran
that re-implements gfc_type_compatible.  If time permits, 
I'll see what comes with a grep of "->type == *->type".


> The following is already rejected:
> 
> program p
>   real :: r
>   data r / z'1234' /
>   r = z'1234'
>   print *, r
> end
> 
> pr103413-boz.f90:3:18:
> 
>     3 |   data r / z'1234' /
>       |                  1
> Error: BOZ literal constant near (1) cannot be assigned to a REAL variable [see
> '-fno-allow-invalid-boz']

F2018

If a data-stmt-constant is a boz-literal-constant, the corresponding
variable shall be of type integer.

F2023 is unchanged.

> pr103413-boz.f90:4:6:
> 
>     4 |   r = z'1234'
>       |      1
> Error: BOZ literal constant at (1) is neither a DATA statement value nor an
> actual argument of INT/REAL/DBLE/CMPLX intrinsic subprogram [see
> '-fno-allow-invalid-boz']

This I need to look up in F2023.  The statement may be allowed
only in an initialization expression.

> Interestingly, -fno-allow-invalid-boz is not an allowed option...
> But even when using -fallow-invalid-boz, which degrades the above
> to a warning, I never get to gfc_type_compatible.

The lack of -fno-allow-invalid-boz was intentional.  A BOZ in
an invalid context is an error.  -fallow-invalid-boz allows
that invalid context, but issues a warning.  The only way to
disable the warning is with -w (ie., you disable all warnings).