Path: utzoo!attcan!uunet!decwrl!ucbvax!IBM.COM!RAH
From: RAH@IBM.COM ("Russell A. Heise")
Newsgroups: comp.sys.ibm.pc.rt
Subject: Fortran runtime error handling
Message-ID: <101090.091535.heise1@ibm.com>
Date: 10 Oct 90 14:17:39 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 42


 maine@elxsi.dfrf.nasa.gov (Richard Maine) writes:

 > I've run into some annoying "features" of the error handling in the
 > Fortran runtimes in AIX 3.1 for the IBM RS 6000 series.  Has anybody
 > else run into these?
 >
 > ... sample program ...
 >
 > My reading of IBM's Fortran manual is that much of this behavior is
 > intentional; the runtimes are "supposed" to "fix up" errors for you
 > instead of reporting them with err= or iostat=, which are reserved for
 > "data transfer errors" instead of data content errors.  Perhaps it is
 > accidental that some cases don't print warning messages about the
 > fixup, but it appears intentional that neither err= or iostat= is used
 > to report the error.  Does anybody really think of these as "features"
 > instead of serious bugs, or do people like getting wrong answers?

 No, this behavior is not good.  Development is working on fixing it and
 the changes will be included in a future update.  Contact your local IBM
 rep and have him/her report this as a problem.  That will insure that
 you get the changes.
 >
 > ...
 >
 >   Hitting an end of file causes an error message to be splatted all
 >   over the screen even if the program handles the condition with an
 >   iostat= specifier.  (An end= specifier seems to work as expected).
 >   Likewise, errors in opening a file cause error messages that cannot
 >   be disabled.  The program works correctly, except for the ugly
 >   error messages.

 Actually, you can control these messages.  Try the following command line:
   xrf_messages=no; export xrf_messages
 >
 > ...
 >
 >   Until the last problem above is fixed, I would be very reluctant
 >   to trust computations on this system.  There is too much chance
 >   of simple typographical errors causing undiagnosed garbage results.

Russ Heise, AIX Technical Support, IBM