FIX: /Ge Fails to Detect Stack Overflow (106520)

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
				

NOTE: The /Ge compiler option is no longer used for stack-probe checks under FORTRAN PowerStation 32, version 4.0. Attempting to use this option will generate the message: