Issue with MOVE_ALLOC

[OP1]

The following code prints out a non-zero value for ERROR (the value is -858993460). I don't understand how MOVE_ALLOC fails here.

This is with Intel Fortran Compiler Classic 2021.5.0, on Windows 10, x64, non-coarray code.

It also looks like there is a non-printable character in MESSAGE - but that's probably a different problem.

MODULE M
    IMPLICIT NONE
    TYPE :: W
    END TYPE W
    TYPE :: T
        TYPE(W), ALLOCATABLE :: A(:)
        CONTAINS
            PROCEDURE :: P
    END TYPE T
    CONTAINS
    SUBROUTINE P(SELF, A)
        IMPLICIT NONE
        CLASS(T), INTENT(INOUT) :: SELF
        TYPE(W), ALLOCATABLE, INTENT(INOUT) :: A(:)
        CHARACTER(LEN = 132) :: MESSAGE
        INTEGER :: ERROR
        CALL MOVE_ALLOC(A, SELF%A, STAT = ERROR, ERRMSG = MESSAGE)
        IF (ERROR /= 0 ) THEN
            WRITE(*, *) ERROR, (MESSAGE == ' '), TRIM(MESSAGE)
            STOP
        END IF
    END SUBROUTINE P
END MODULE M

PROGRAM MAIN
    USE M
    IMPLICIT NONE
    TYPE(T) :: VAR
    TYPE(W), ALLOCATABLE :: A(:)
    ALLOCATE(A(1))
    CALL VAR%P(A)
END PROGRAM MAIN

[Barbara_P_Intel]

I just tried this using ifort 2021.5.0 on both Linux and Windows. 

No error message printed on either OS.

[jimdempseyatthecove]

Barbra,

The issue was, on no error condition, the STAT= variable would be left untouched.

Therefore, should you have run your test from a Debug build, it would have pre-initialized the STAT variable ERROR with 0, and thus would not be a conclusive test. A proper test would be to pre-set the STAT variable ERROR to non-zero before the call to MOVE_ALLOC. 

Now, you may have done this with your test program, but the sample program, and your reply, give no assurance that you had done so.

Jim Dempsey

[FortranFan · Accepted solution]

@Barbara_P_Intel ,

Please see this other thread by OP and comments in there re: debug compile (/Od) and the treatment of the optional STAT= dummy argument as possibly INTENT(INOUT) versus INTENT(OUT) per the standard, and Ron Green's investigation, etc.  Some or all of it may be relevant to this thread also:

https://community.intel.com/t5/Intel-Fortran-Compiler/Issue-with-MOVE-ALLOC/m-p/1368121#M160577

[Barbara_P_Intel]

Thanks for the clarification. My experience is mostly on Linux. I have limited experience with Windows and VS. I learned something new!