FIX: Entire DLLEXPORTed Arrays Cannot Be Written Implicitly

The information in this article applies to:

• Microsoft FORTRAN PowerStation 32 for Windows NT, version 1.0

SYMPTOMS

An attempt to print out an array that is exported from a common block in a dynamic-link library (DLL) may produce incorrect values when the entire array is printed at once (by giving only the array name in the I/O statement or by using an implied do loop).

This problem occurs when writing to all types of files and to the display.

RESOLUTION

Use an implied do loop and add 0 (zero) to the array index, or write the array elements individually.

STATUS

Microsoft has confirmed this to be a problem in Microsoft FORTRAN PowerStation 32 for Windows NT, version 1.0. This problem was fixed in FORTRAN PowerStation, version 4.0.

MORE INFORMATION

The following sample code illustrates this problem:

Sample Code #1

C Compile options needed: none

C FORTRAN Main Source:

      interface to subroutine bar[dllimport]()
      end
      common /bridge[dllimport]/ i
      integer*4 i(4)
      i(2) = 2

      write(*,*) 'In Main: i = ', i
      do loop=1,4
        write(*,*) 'In main: i = ', i(loop)
      end do

      write(*,*) 'Calling DLL routine...'
      call bar

      write(*,*) 'In Main: i = ', (i(loop), loop=1,4)
      do loop=1,4
        write(*,*) 'In main: i = ', i(loop)
      end do
      end

Sample Code #2

C FORTRAN DLL Source:

      subroutine bar[dllexport]()
      common /bridge[dllexport]/ i
      integer*4 i(4)
      i(3) = 33
      write(*,*) 'In DLL:  i = ', i
      return
      end

Program Output (corrected for CR/LF anomalies)

In Main: i =   550774271   637468674      139472 -1869574000
In main: i =           0
In main: i =           2
In main: i =           0
In main: i =           0

In DLL:  i =           0           2          33           0
In Main: i =   550774271   637468674      139472 -1869574000
In main: i =           0
In main: i =           2
In main: i =          33
In main: i =           0