[Bug fortran/84506] New: INQUIRE(pos=) always sets pos=0 with -fdefault-integer-8

[albandil at atlas dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84506

            Bug ID: 84506
           Summary: INQUIRE(pos=) always sets pos=0 with
                    -fdefault-integer-8
           Product: gcc
           Version: 7.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: albandil at atlas dot cz
  Target Milestone: ---

INQUIRE(pos=...) seems to set 'pos' to zero when the unit number is 64bit
integer. This can be illustrated on the following example, which writes four
characters to a stream file and then INQUIRES position:

  program TestInquire

      implicit none

      integer :: iUnit, iPos

      open(newunit=iunit, file='output.txt', access='stream',
position='append', form='unformatted')
      write(iUnit) 'TEXT'
      inquire(iUnit, pos=iPos)

      print *, iPos

  end program TestInquire

The expected output is '5', which can be obtained by compilation using the
command

  gfortran -ffree-form -std=f2008 inquire.f -o inquire

However, when the following command is used to compile the program, the output
is '0':

  gfortran -ffree-form -std=f2008 inquire.f -o inquire -fdefault-integer-8

Both 4-byte and 8-byte mode produce '5' when Intel Fortran Compiler 17.0.1 is
used,

  ifort -free -stand=f08 inquire.f -o inquire
  ifort -free -stand=f08 inquire.f -o inquire -i8