PRB: Run-time Subroutines Do Not Appear to Function

The information in this article applies to:

• Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0 and 1.0a
• Microsoft FORTRAN PowerStation 32 for Windows NT, version 1.0 and 4.0

SYMPTOMS

The code compiles, links, and runs with no errors, but some of the run-time subroutines do not appear to function correctly. Unexpected results are returned.

CAUSE

The subroutine may not have an interface statement or a parameter used in the subroutine may not be defined.

RESOLUTION

Include FLIB.FI prior to the PROGRAM statement or as the first line in any file that uses these subroutines or functions. Also, include FLIB.FD inside the main program or any subroutine or function that uses the run- time subroutines.

MORE INFORMATION

The following code sample compiles, links, and runs without generating an error, but the array is not sorted and the random seed is initialized with a zero. In the case of the SORTQQ routine, the last argument is a parameter defined in FLIB.FD. Because that file is not included, the variable is typed as a REAL and initialized to zero. SORTQQ fails to sort because the size of the data items to be sorted is zero.

If the file FLIB.FI is included by changing the first INCLUDE from a comment into an executed line, you will receive these errors:

   F4016 : SEED : formal argument ARG: type mismatch
   F4016 : SORTQQ : formal argument SIZE: type mismatch

To solve the problem in the sample below, change both include lines from comments into executable lines.

Additionally, there may be several run-time subroutines that use parameters defined in the FLIB.FD file, but the documentation fails to indicate that you must include FLIB.FD. The following is a partial list of those subroutines:

   ELLIPSE, ELLIPSE_W
   GETWRITEMODE
   PIE, PIE_W
   REMAPALLPALETTE, REMAPPALETE
   SEED
   SETWRITEMODE

Sample Code

C Compile options needed: none

C INCLUDE 'flib.fi'

      PROGRAM Test

      INTEGER maxsize
      INTEGER*4 buf(100)
      INTEGER*4 i
      REAL*4 rdm

      PRINT*, "Enter the number of values (max = 100): "
      READ(*, "(I4)") maxsize
      IF(maxsize .GT. 100 ) maxsize = 100

      CALL SEED(RND$TIMESEED)
      DO i = 1, maxsize
          CALL RANDOM(rdm)

C         Random value from 1 to maxsize
          buf(i) = INT4(rdm * maxsize + 1.0)
      END DO

      WRITE(*, "(5I6)") (buf(i), i = 1, maxsize)
      PRINT*

      CALL SORTQQ(LOC(buf), maxsize, SRT$INTEGER4)

      WRITE(*, "(5I6)") (buf(i), i = 1, maxsize)
      PRINT*

      END