[Bug fortran/82943] [F03] Error with type-bound procedure of parametrized derived type

[ctechnodev at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82943

Alexander Westbrooks <ctechnodev at gmail dot com> changed:

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                 CC|                            |ctechnodev at gmail dot com

--- Comment #11 from Alexander Westbrooks <ctechnodev at gmail dot com> ---
(In reply to vegard from comment #10)
> (In reply to kargl from comment #9)
> > (In reply to alig from comment #8)
> > > The problem still persists with GNU Fortran (GCC) 11.1.0.
> > 
> > The problem is likely to persist for the foreseeable future
> > as there is no one left to work on gfortran bugs.  Lacking 
> > a sudden influx of new volunteer contributors, it seems
> > the only way forward is to NOT use parameterized derived 
> > types with gfortran.
> 
> Any news here? I seem to be having this issue with gfortran (Homebrew GCC)
> 12.2.0
> 
> As a side note: I'm somewhat new to the fortran community, but could see
> myself contributing to gfortran in the future. Do you think you could point
> me to where I should read up on contributing?

Hello!

I'm new to the community as well. I have had the same issue with this bug and
first encountered it 5 years ago while working on my thesis. Two weeks ago I
decided to tackle this bug. I have found the issues in the code, and I was able
to successfully compiles the following example. I made sure that the LEN type
parameter condition was enforced as janus@gcc.gnu.org stated in Comment #6 and
I used inheritance in this example to test the added logic to ensure that a PDT
instance belonged to a PDT template. 

The only things I have left to do is write applicable test cases (which I
haven't done before. I am learning how to use the DejaGNU framework as I work
on this) and obtain some guidance on how to get this code verified by others
and ultimately accepted as fixed code into the compiler. I am reading the
documentation of the GNU Fortran rules and I hope to get the test cases
completed and have the fix under review within the next couple of weeks.

module testmod

    public :: foo

    type, public :: tough_lvl_0(a, b)
        integer, kind :: a = 1
        integer, len :: b
    contains
        procedure :: foo
    end type

    type, public, EXTENDS(tough_lvl_0) :: tough_lvl_1 (c)
        integer, len :: c
    contains
        procedure :: bar
    end type

    type, public, EXTENDS(tough_lvl_1) :: tough_lvl_2 (d)
        integer, len :: d
    contains
        procedure :: foobar
    end type

contains
    subroutine foo(this)
        class(tough_lvl_0(1,*)), intent(inout) :: this
    end subroutine

    subroutine bar(this)
        class(tough_lvl_1(1,*,*)), intent(inout) :: this
    end subroutine

    subroutine foobar(this)
        class(tough_lvl_2(1,*,*,*)), intent(inout) :: this
    end subroutine

end module

PROGRAM testprogram
    USE testmod

    TYPE(tough_lvl_0(1,5))     :: test_pdt_0
    TYPE(tough_lvl_1(1,5,6))   :: test_pdt_1
    TYPE(tough_lvl_2(1,5,6,7)) :: test_pdt_2

    CALL test_pdt_0%foo()

    CALL test_pdt_1%foo()
    CALL test_pdt_1%bar()

    CALL test_pdt_2%foo()
    CALL test_pdt_2%bar()
    CALL test_pdt_2%foobar()


END PROGRAM testprogram