Q67314: BC.EXE "Out of Memory" with Numeric Array Elements and SWAP

Article: Q67314
Product(s): See article
Version(s): 7.00 7.10 | 7.00 7.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | buglist7.00 buglist7.10 | mspl13_basic
Last Modified: 5-DEC-1990

Compiling the following code segment with the BC.EXE compiler gives a
"BC : Out of memory" error. The problem will occur for any simple
mathematical operation (addition, subtraction, multiplication, or
division) performed on the two static-array elements appearing in the
assignment statement below. The problem does not occur in the QBX.EXE
environment.

   DIM d#(1), e#(1), b!(1), c&(1)
   n = 1
   a% = b!(n) + c&(n)
   SWAP d#(n), e#(n)

Microsoft has confirmed this to be a problem in BC.EXE in Microsoft
BASIC Profession Development System (PDS) versions 7.00 and 7.10 for
MS-DOS and MS OS/2. We are researching this problem and will post new
information here as it becomes available.

You can work around the problem in any one of the following ways:

1. Compile the program with the BC /D option to produce debug code.

2. Use the CINT or CLNG function to convert the first array element in
   the mathematical expression to an integer type. The example above
   will compile without error if the assignment statement is changed
   as follows:

      a%= CINT(b!(n)) + c&(n)

3. Save one of the variables being swapped to a temporary variable and
   use the temporary variable as an argument to the SWAP statement.
   The example above will compile without error if the SWAP statement
   is changed as follows:

      f# = d#(n)
      SWAP f#,e#(n)

4. Use dynamic arrays (instead of static arrays) by adding
   REM $DYNAMIC to the top of the program.

The problem occurs when all of the following conditions occur
simultaneously (as shown in the first code example):

1. An integer variable (INTEGER or LONG type) is assigned to the
   addition, multiplication, division, or subtraction of two numeric
   static-array elements.

2. The first array element in the mathematical expression is of type
   SINGLE.

3. The second array element in the mathematical expression is of type
   LONG.

4. A SWAP of two array elements of any numeric type occurs after the
   assignment statement.

5. The code is compiled using BC.EXE

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.