FIX: /Ge Fails to Detect Stack Overflow

MS-DOS     | WINDOWS NT

The information in this article applies to:

• Microsoft FORTRAN PowerStation for MS-DOS versions 1.0 and 1.0a
• Microsoft FORTRAN PowerStation 32 version 1.0

SYMPTOMS

Programs compiled with the /Ge option produce the following run-time error

   DOSXMSF : fatal error DX1020: unhandled exception: General
   protection fault;

STATUS

Microsoft has confirmed this to be a problem in FORTRAN PowerStation version 1.0 for MS-DOS. This problem was corrected in Microsoft FORTRAN PowerStation 32, version 4.0.

MORE INFORMATION

The stack-checking routine enabled by the /Ge option does not detect stack overflow. Because the default stack size for the FORTRAN PowerStation is 32K, a general protection (GP) fault is unlikely to be caused by a stack overflow. The exception to this is when one of the following types of programs is written:

• Programs deliberately designed to use up the stack. This would involve extensive use of automatic variables, indirect recursion, or deeply nested subroutine and function calls totaling thousands of passed arguments.
• Programs that circumvent the link time check for stack use based on name decorations. These programs may cause stack overflow if they contain problems related to passing arguments. This check is circumvented by declaring the routine to use the C or VARYING calling conventions or by using the ALIAS attribute.
• Programs that call Assembly language routines that incorrectly use the stack.

Sample Code

The following code can be used to illustrate the problem:

C Compile options needed: /Ge

      subroutine recur(y)
      integer y
      y = y + 1
      call indrec(y)
      end

      subroutine indrec(i)
      integer i
      i = i + 1
      call recur(i)
      end

      integer x
      x = 0
      call recur(x)
      end

   Command line warning D2004: obsolete option /Ge ignored.