[PATCH] D130513: [Flang] Add -fconvert option to swap endianness for unformatted files

[Peixin Qiao via Phabricator via cfe-commits]

peixin added a comment.

  $ cat fconvert_option_main_2.f90 
  !
  ! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  ! See https://llvm.org/LICENSE.txt for license information.
  ! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  !
  ! checking for I/O: testing read with -fconvert=big-endian.
  ! The convert argument of open function has prior claim over fconvert option.
  ! Only main program intentionally compiled with -fconvert=big-endian.
  
  program fconvert_option_main_2
    use fconvert_option_openfile
    use fconvert_option_readfile
  
    integer, parameter :: n = 4
    integer :: del_flag = 0 ! 1 for deleting data file after read
    real :: arr(n) = [1.0, 2.0, 3.0, 4.0]
    character(:), allocatable :: filename
    integer :: arglen
  
    call get_command_argument(1, length = arglen)
    allocate(character(arglen) :: filename)
    call get_command_argument(1, value = filename)
  
    call open_for_read_LE(10, filename)
    call readfile(10, del_flag, arr, n, 0)
  
    call open_for_read_native(11, filename)
    call readfile(11, del_flag, arr, n, 4)
  
    print *, 'PASS'
  end
  $ cat fconvert_option_readfile.f90 
  !
  ! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  ! See https://llvm.org/LICENSE.txt for license information.
  ! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  !
  ! checking for I/O: readfile subroutine
  
  module fconvert_option_readfile
  
  contains
    subroutine readfile(fid, del_flag, expect, n, t)
      integer :: n, t
      integer :: fid, del_flag
      real :: expect(n)
      real :: buf(n)
  
      read (fid) buf
      if (del_flag .eq. 0) then
        close (fid)
      else
        close (fid, status='delete')
      end if
  
      do i = 1, n
        if (buf(i) .ne. expect(i)) stop (i+t)
      enddo
    end
  end
  $ cat fconvert_option_openfile.f90 
  !
  ! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  ! See https://llvm.org/LICENSE.txt for license information.
  ! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  !
  ! checking for I/O: openfile subroutines
  
  module fconvert_option_openfile
  
  contains
    subroutine open_for_read(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='old')
    end
    subroutine open_for_read_BE(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='old', convert="BIG_ENDIAN")
    end
    subroutine open_for_read_LE(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='old', convert="LITTLE_ENDIAN")
    end
    subroutine open_for_read_native(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='old', convert="NATIVE")
    end
  
    subroutine open_for_write(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='new')
    end
    subroutine open_for_write_BE(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='new', convert="BIG_ENDIAN")
    end
    subroutine open_for_write_LE(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='new', convert="LITTLE_ENDIAN")
    end
    subroutine open_for_write_native(fid, file_name)
      integer :: fid
      character(:), allocatable :: file_name
      open (fid, file=file_name, form='UNFORMATTED', status='new', convert="NATIVE")
    end
  end
  $ cat fconvert_option_writefile.f90 
  !
  ! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  ! See https://llvm.org/LICENSE.txt for license information.
  ! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  !
  ! checking for I/O: writefile subroutine
  
  module fconvert_option_writefile
  
  contains
    subroutine writefile(fid, buf, n)
      integer :: n
      real :: buf(n)
      integer :: fid
  
      write (fid) buf
      close (fid)
    end
  end
  $ cat run.sh 
  #!/bin/bash
  
  echo "---------- gfortran ----------"
  gfortran fconvert_option_readfile.f90 -c
  gfortran fconvert_option_openfile.f90 -c
  gfortran fconvert_option_writefile.f90 -c
  gfortran $1.f90 $2 -c
  gfortran $1.o fconvert_option_readfile.o fconvert_option_openfile.o fconvert_option_writefile.o
  ./a.out Inputs/fc_opt_data_$3 && rm *.o *.mod a.out
  
  echo && echo "---------- flang-new ----------"
  flang-new fconvert_option_readfile.f90 -c
  flang-new fconvert_option_openfile.f90 -c
  flang-new fconvert_option_writefile.f90 -c
  flang-new $1.f90 $2 -c
  flang-new -flang-experimental-exec $1.o fconvert_option_readfile.o fconvert_option_openfile.o fconvert_option_writefile.o 
  ./a.out Inputs/fc_opt_data_$3 && rm *.o *.mod a.out
  
  $ bash run.sh fconvert_option_main_2 -fconvert=big-endian little
  ---------- gfortran ----------
   PASS
  
  ---------- flang-new ----------
  
  fatal Fortran runtime error(./fconvert_option_readfile.f90:17): Unformatted variable-length sequential file input failed at record #1 (file offset 0): hit EOF reading record with length 268435456 bytes
  run.sh: line 17: 126614 Aborted                 (core dumped) ./a.out Inputs/fc_opt_data_$3

Not sure if this fail is caused by this patch or runtime IO functions. I will add our other internal tests to https://github.com/llvm/llvm-project/issues/55961 and you can also test those cases. The data is an array of "1.0 2.0 3.0 4.0" through little-endian or big-endian. You can create it by yourself.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130513/new/

https://reviews.llvm.org/D130513