[Flang] Compilation error when source-expr of source specifier in allocate statement is the sum of two internal functions

[ohno-fj]

Version of flang-new : 19.0.0(f2f9cdd22171f0c54cad7c6b183857f3d856c344)/AArch64

When source-expr of source specifier in allocate statement is the sum of two internal functions (SOURCE=(pptr() + pptr1())), a compilation-time error occurs.
When there is only one internal function (SOURCE=(pptr())), the compilation succeeds.

The following are the test program, Flang-new, Gfortran and ifort compilation/execution result.

fe2_polymorphic_ut230_2.f90:

module mod1
  type ty
     integer(kind=4) :: num=1
  end type ty
  type, extends(ty):: ty1
     integer(kind=8) :: num2=3
  end type ty1
end module mod1

program main
  use mod1
  TYPE con
     class(ty),POINTER::ptr
  END TYPE con
  INTERFACE OPERATOR(+)
     function pls(a,b)
       import ty1
       import ty
       class(ty), allocatable, intent(in) :: a
       class(ty), allocatable, intent(in) :: b
       type(ty1) :: pls
     END function pls
  END INTERFACE operator(+)
  TYPE(con)::obj(10)
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
  if(obj(1)%ptr%num == 70) print*,'pass'
contains
  function pptr()
    class(ty),allocatable::pptr
    allocate(pptr)
    pptr%num = 30
  end function pptr
  function pptr1()
    class(ty),allocatable::pptr1
    allocate(pptr1)
    pptr1%num = 40
  end function pptr1
END program main

function pls(a,b)
  use mod1
  class(ty), allocatable, intent(in) :: a
  class(ty), allocatable, intent(in) :: b
  type(ty1) :: pls
  pls%num = a%num + b%num
END function pls

$ flang-new fe2_polymorphic_ut230_2.f90
error: Semantic errors in fe2_polymorphic_ut230_2.f90
./fe2_polymorphic_ut230_2.f90:25:31: error: No intrinsic or user-defined OPERATOR(+) matches operand types CLASS(ty) and CLASS(ty)
    allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
                                ^^^^^^^^^^^^^^^^
$

$ gfortran fe2_polymorphic_ut230_2.f90 ; ./a.out
 pass
$

$ ifort -diag-disable=10448 fe2_polymorphic_ut230_2.f90
fe2_polymorphic_ut230_2.f90(25): error #9140: The allocatable result of a function reference may not be argument associated with an allocatable dummy argument.   [PPTR]
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
------------------------------^
fe2_polymorphic_ut230_2.f90(25): error #9140: The allocatable result of a function reference may not be argument associated with an allocatable dummy argument.   [PPTR1]
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
---------------------------------------^
compilation aborted for fe2_polymorphic_ut230_2.f90 (code 1)
$

[llvmbot]

@llvm/issue-subscribers-flang-frontend

Author: None (ohno-fj)

``` Version of flang-new : 19.0.0(f2f9cdd)/AArch64 ```

When source-expr of source specifier in allocate statement is the sum of two internal functions (SOURCE=(pptr() + pptr1())), a compilation-time error occurs.
When there is only one internal function (SOURCE=(pptr())), the compilation succeeds.

The following are the test program, Flang-new, Gfortran and ifort compilation/execution result.

fe2_polymorphic_ut230_2.f90:

module mod1
  type ty
     integer(kind=4) :: num=1
  end type ty
  type, extends(ty):: ty1
     integer(kind=8) :: num2=3
  end type ty1
end module mod1

program main
  use mod1
  TYPE con
     class(ty),POINTER::ptr
  END TYPE con
  INTERFACE OPERATOR(+)
     function pls(a,b)
       import ty1
       import ty
       class(ty), allocatable, intent(in) :: a
       class(ty), allocatable, intent(in) :: b
       type(ty1) :: pls
     END function pls
  END INTERFACE operator(+)
  TYPE(con)::obj(10)
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
  if(obj(1)%ptr%num == 70) print*,'pass'
contains
  function pptr()
    class(ty),allocatable::pptr
    allocate(pptr)
    pptr%num = 30
  end function pptr
  function pptr1()
    class(ty),allocatable::pptr1
    allocate(pptr1)
    pptr1%num = 40
  end function pptr1
END program main

function pls(a,b)
  use mod1
  class(ty), allocatable, intent(in) :: a
  class(ty), allocatable, intent(in) :: b
  type(ty1) :: pls
  pls%num = a%num + b%num
END function pls

$ flang-new fe2_polymorphic_ut230_2.f90
error: Semantic errors in fe2_polymorphic_ut230_2.f90
./fe2_polymorphic_ut230_2.f90:25:31: error: No intrinsic or user-defined OPERATOR(+) matches operand types CLASS(ty) and CLASS(ty)
    allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
                                ^^^^^^^^^^^^^^^^
$

$ gfortran fe2_polymorphic_ut230_2.f90 ; ./a.out
 pass
$

$ ifort -diag-disable=10448 fe2_polymorphic_ut230_2.f90
fe2_polymorphic_ut230_2.f90(25): error #<!-- -->9140: The allocatable result of a function reference may not be argument associated with an allocatable dummy argument.   [PPTR]
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
------------------------------^
fe2_polymorphic_ut230_2.f90(25): error #<!-- -->9140: The allocatable result of a function reference may not be argument associated with an allocatable dummy argument.   [PPTR1]
  allocate(obj(1)%ptr,SOURCE=(pptr() + pptr1()))
---------------------------------------^
compilation aborted for fe2_polymorphic_ut230_2.f90 (code 1)
$

[klausler]

The error is correct. The specific procedure pls defined to extend the generic OPERATOR(+) must be passed actual arguments that are allocatables. While it is possible to declare the result variable of a function like pptr to be an allocatable, the value of a function reference in the context of an expression is not an allocatable. See F'2023 8.5.3; only variables and components can be allocatables.