Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!mips!gumby!lilian
From: lilian@mips.COM (Lilian Leung)
Newsgroups: comp.sys.mips
Subject: Re: Fortran compiler bug?
Summary: Documented restriction on Mips FORTRAN
Message-ID: <39069@mips.mips.COM>
Date: 25 May 90 18:39:05 GMT
References: <149@snll-arpagw.UUCP>
Sender: news@mips.COM
Distribution: na
Lines: 50

In article <149@snll-arpagw.UUCP>, dandy@snll-arpagw.UUCP (David Dandy) writes:
> I ported a public domain Fortran code to my DECstation 3100, and received
> an f77 compiler error associated with a WRITE statement.  Eliminating all but
> the essential code, the offending subroutine looks like
> 
>       SUBROUTINE SKTEST ( LOUT, LINE, ILEN )
>       IMPLICIT DOUBLE PRECISION ( A-H, O-Z ), INTEGER ( I-N )
>       CHARACTER LINE*(*)
>       WRITE (LOUT, '(A)')
>      1    'Error in SKSNUM...'//LINE(:ILEN)//' not found...'
>       RETURN
>       END
...
> 
> Whether or not this is a bug with the MIPS 2.1 compiler, I have to admit
> that I don't know what the WRITE statement is supposed to be doing (even
> afters reading Wagener's explanation).  Does anyone know a work-around to
> this problem?  I need to get this working before MIPS releases their next
> compiler version.  Is this a bug, or is it not "standard F77"?  Please
> respond by e-mail if you know of a fix or a work-around.  It's frustrating
> to RTFM and still not be sure what's going on.


The above is a documented restriction on MIPS and ANSI FORTRAN.  
In Mips's Part II: FORTRAN Language Reference manaul, page 3-8, 
it states that "Except in a character assignment statement, 
concatenation of an operand with an asterisk(*) as its length specification 
is not allowed unless the operand is the symbolic name of a constant."
In ASNI X3.9-1978 FORTRAN, page 6-8, it says the same thing.

We will input this as a request for enhancement to our FORTRAN compiler.  

Meanwhile, the workaround is to assign  LINE(:ILEN) to a local character
variable with constant length specified and use that variable in your
write statement, like this:

        SUBROUTINE SKTEST ( LOUT, LINE, ILEN )
        IMPLICIT DOUBLE PRECISION ( A-H, O-Z ), INTEGER ( I-N )
        CHARACTER LINE*(*)
	CHARACTER*100 TEMP
	TEMP = LINE
        WRITE (LOUT, '(A)')
       1    'Error in SKSNUM...'//TEMP(:ILEN)//' not found...'
        RETURN
        END

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