Optional output argument error/bug

I’m getting the following run-time error in one of my Win32 programs.

*** Error 14, Attempt to alter an actual argument that is a constant, an expression, an INTENT(IN) argument, or a DO variable.

I’ve constructed a small program that demonstrates the error and consists of a Main and a Module as follows.

C ------------------------------------------------------------
C DEMO.FOR
      PROGRAM DEMO

      USE Calc

      CALL DibDob()                      !<<<<<< Line 13

      PRINT *, 'Demo program has run'

      END

! -----------------------------------------------------------
! CALC.F90
MODULE Calc

  PUBLIC :: DibDob

CONTAINS

! ----------------------------------------------------------
  SUBROUTINE DibDob (lVar)                !<<<<<< Line 17
    LOGICAL, OPTIONAL, INTENT(OUT) :: lVar

    IF (PRESENT(lVar)) lVar = .TRUE.

  END SUBROUTINE

END MODULE

I’m using a recently downloaded FTN95 Personal Edition with the options /ISO /IMPLICIT_NONE /NO_SCALAR_TO_ARRAY /RESTRICT_SYNTAX /CHECKMATE /BRIEF and linking with SLINK. The run-time error information is as follows (I’ve flagged the offending lines in the above code).

CALC!DIBDOB - in file calc.f90 at line 17 [+003c] main - in file demo.for at line 13 [+003b]

The problem seems to be with the OPTIONAL argument of INTENT(OUT). Can anyone see why this causes the error?

Keith

This bug has already been fixed. It is not a recent fix so the current release (5.10) should be OK. Make sure that you are also using the latest salflibc.dll (use saldiag.exe).

Ah – well, there must be something wrong with the download from the Polyhedron web site since I downloaded FTN95 only a few days ago. As I reported earlier, the compiler is declared as version 5.10 on the web site but prints version 4.9.0 on the console when I run it.

I located salflibc.dll with the search tool, saldiag.exe. The dll is Version 7.11.10.11. Is this the correct version? Also, I checked my system to make sure there is no old version that was being picked up.

The Polyhedron download appears to be out of date. You should download from the Silverfrost website.

Which seems to be down (http://silverfrost.com/ or http://www.silverfrost.com/ - both fail). I’m not having much luck lately.

You can grab the latest version from download.com too, the address is:

http://www.download.com/Silverfrost-FTN95/3000-2069_4-10698194.html

That did the trick. The problem has disappeared. Thanks Paul, thanks Andrew.