[flang] Missing diagnostic for non-definable actual to INTENT(INOUT) dummy

[DanielCChen]

Consider the following code:

module m
    type base
        integer id
        contains

        procedure, pass :: assgn => assgnBase
    end type

    type (base) :: b1_m(10)
    contains

    elemental subroutine assgnBase (b, i)
        class (base), intent(inout) :: b
        integer, intent(in):: i
        b%id = i
    end subroutine

end module

program ftpbnd502a
use m

    type(base) :: b1(10)
    integer(4) :: aSect(3) = (/1,2,3/)

    call b1(aSect)%assgn (1) !<-- this is illegal
end

Flang is silent even with -pedantic.

[llvmbot]

@llvm/issue-subscribers-flang-frontend

Author: Daniel Chen (DanielCChen)

Consider the following code: ``` module m type base integer id contains

    procedure, pass :: assgn => assgnBase
end type

type (base) :: b1_m(10)
contains

elemental subroutine assgnBase (b, i)
    class (base), intent(inout) :: b
    integer, intent(in):: i
    b%id = i
end subroutine

end module

program ftpbnd502a
use m

type(base) :: b1(10)
integer(4) :: aSect(3) = (/1,2,3/)

call b1(aSect)%assgn (1) !<-- this is illegal

end

Flang is silent even with `-pedantic`. 
</details>

[klausler]

Fortran 2023 15.5.2.5 paragraph 21: "If the procedure is nonelemental, the dummy argument does not have the VALUE attribute, and the actual argument is an array section having a vector subscript, the dummy argument is not definable and shall not have the ASYNCHRONOUS, INTENT (OUT), INTENT (INOUT), or VOLATILE attributes."

The restriction on vector subscripts with INTENT(IN OUT) dummy arguments only applies to non-ELEMENTAL procedures.

[DanielCChen]

Thanks. Right. I missed that.