Bug: Renamed structure constructor does not behave as expected

[Balint_Aradi]

Dear Intel Fortran maintainers,

The following minimal working example demonstrates a possible bug in the current Intel Fortran compilers (ifort (IFORT) 2021.8.0 20221119 and ifx (IFORT) 2023.0.0 20221201).

When a structure constructor is renamed, its return type seems not be recognized correctly afterwards. Note, that using the original (non-renamed) name, the assignment (line 40) works fine, while the assignment with the renamed entities (line 48) triggers following compiler error:

> ifort -c intelbug.f90 
intelbug.f90(48): error #7497: The variable must be type compatible with the expression and of the same rank.   [INSTANCE]
    renamedcls%instance = renamed_type()
---------------^
compilation aborted for /home/aradi/sync/bccms/devel/fortuno/intelbug.f90 (code 1)

module testmod
  implicit none

  type :: orig_type
  end type orig_type

  interface orig_type
    module procedure new_orig_type
  end interface orig_type

  type :: orig_type_cls
    class(orig_type), allocatable :: instance
  end type orig_type_cls

contains

  function new_orig_type() result(this)
    type(orig_type) :: this
  end function new_orig_type

end module testmod


module testmod2
  use testmod, only : orig_type, orig_type_cls
  use testmod, only : renamed_type => orig_type, renamed_type_cls => orig_type_cls
end module testmod2


module testmod3
  implicit none

contains

  subroutine test1()
    use testmod2, only : orig_type, orig_type_cls
    type(orig_type_cls) :: origcls

    ! Works without problems
    origcls%instance = orig_type()
  end subroutine test1

  subroutine test2()
    use testmod2, only : renamed_type, renamed_type_cls
    type(renamed_type_cls) :: renamedcls

    ! Renamed type does not work as expected
    renamedcls%instance = renamed_type()
  end subroutine test2

end module testmod3

[FortranFan]

Intel compiler is wrong to issue the #7497 error here, clearly a bug that Intel Fortran team would want to fix also because it appears to be in the handling of the intermediate module with renamed entities, something that can have other, bigger implications.

[Barbara_P_Intel]

Thanks for reporting this. I filed a bug, CMPLRLLVM-45336. I'll let you know when it's fixed.

[andreasskeidsvoll]

@Barbara_P_Intel  Do you know if this bug will be fixed in the 2024.1 release? It affects a code that I work with quite a bit, which heavily depends on polymorphism and constructors. Also, I don't know if it's relevant, but I've found that the issue does not occur when "class" is replaced with "type" in line 12 in OP's example.

[Barbara_P_Intel]

The fix is not in the preview 2024.1.0 bits I have available. Code freeze is imminent. Doesn't look promising.

I'll pass along the change you identified to the compiler team.

[Barbara_P_Intel]

I'm not getting the error message with the nightly 2024.2.0 compilers. Look for this version's release in mid-2024.

Watch for the announcement!