DOCUMENT:Q118341  24-MAR-2000  [fortran]
TITLE   :FIX: MATHERRQQ: Access Violation on C8ARG1 and C16ARG1
PRODUCT :Microsoft Fortran Compiler
PROD/VER::1.0,1.0a
OPER/SYS:
KEYWORDS:kberrmsg kbFortranPS kbLangFortran

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0, 1.0a 
 - Microsoft Fortran Powerstation 32 for Windows NT, version 1.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

In Windows NT, Dr. Watson reports an access violation when parts of MATHERRQQ's
INFO record are passed to other routines. The problem occurs when passing
MTH$E_INFO members: C8ARG1, C8ARG2, C16ARG1, or C16ARG2.

In MS-DOS (Windows, version 3.1), the error message is:

   DOSXMSF : fatal error DX1020: unhandled exception:
   General Protection Fault.

RESOLUTION
==========

Do not pass C8ARG1, C8ARG2, C16ARG1, or C16ARG2 directly to another routine.
Assign the value to a temporary variable and pass the variable instead.

STATUS
======

Microsoft has confirmed this to be a bug in the products listed at the beginning
of this article. This problem was corrected in Microsoft FORTRAN PowerStation
32, version 4.0.

MORE INFORMATION
================

To reproduce the problem, compile and run the sample code below.

To use the program without error, comment out the four lines that print C8ARG1,
C8ARG2, C16ARG1, and C16ARG2.

Sample Code
-----------

   c compile options needed: none

         include 'flib.fi'
         implicit none
         include 'flib.fd'
         complex a,b,c
         call LCWRQQ(#133F)
         a=(233.75875785857,145.8498498998989)
         b=(345.84984984900,298.849849849989)
         c=a**b
         write(*,*)'****** successful completion ******'
         end

         SUBROUTINE MATHERRQQ(name, length, info, retcode)
         INCLUDE 'FLIB.FD'
         INTEGER*2 length
         CHARACTER name(length)
         RECORD / MTH$E_INFO / info
         INTEGER*2 retcode
         PRINT *, 'Entered MATHERRQQ'
         PRINT *, 'Failing function: ', name, '      Length: ', length
         PRINT *, 'Error Type: ', info.errcode

         SELECT CASE (info.errcode)
         CASE (MTH$E_OVERFLOW)
            PRINT *, 'OVERFLOW'
         CASE DEFAULT
            PRINT *, 'UNKNOWN'
         END SELECT

         SELECT CASE (info.ftype)
         CASE (TY$CMPLX8)
            PRINT *, 'Type: COMPLEX*8'
            PRINT *, 'Argument1: ', info.c8arg1
            PRINT *, 'Argument2: ', info.c8arg2
            info.c8res = 0.0
            retcode = 1
         CASE (TY$CMPLX16)
            PRINT *, 'Type: COMPLEX*16'

            PRINT *, 'Argument1: ', info.c16arg1
            PRINT *, 'Argument2: ', info.c16arg2
            info.c16res = 0.0
            retcode = 1
         END SELECT
         END

Additional query words: 1.00 1.00a

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Keywords          : kberrmsg kbFortranPS kbLangFortran 
Technology        : kbAudDeveloper kbFortranSearch kbZNotKeyword2 kbZNotKeyword3 kbFORTRANPower32100NT kbFORTRANPower100DOS kbFORTRANPower100aDOS
Version           : :1.0,1.0a
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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