Q30379: FIX: Structure References Using ‘.’ Cause Confusion

Article: Q30379
Product(s): Microsoft Macro Assembler
Version(s): 5.1,5.1a
Operating System(s): 
Keyword(s): 
Last Modified: 06-MAY-2001

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

- Microsoft Macro Assembler (MASM), versions 5.1, 5.1a 
-------------------------------------------------------------------------------

SYMPTOMS
========

Variable names in the assembler can begin with the following character:

     '.'

Structure references use the character '.' as an add operator. This means the
label '.cat' is different than the element 'cat' in a structure. The assembler
can become confused distinguishing the two uses in a program, and can generate
the following error message:

  Error A2028: Operator expected' occurs on 'mov ax,duck.cat'

STATUS
======

Microsoft has confirmed this to be a problem with MASM versions 5.1 and 5.1a.
This problem was corrected in MASM version 6.0.

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

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

         .MODEL SMALL
     mouse  struc
     cat     dw   1
     dog     dw   2
     mouse  ends
         .DATA
     duck    mouse  <>
         .CODE
     start:  mov  ax,@data
             mov  ds,ax
     .cat    dw   4
             mov  ax,duck.cat
      END start

Additional query words: 5.10 5.10a buglist5.10 buglist5.10a fixlist6.00

======================================================================
Keywords          :  
Technology        : kbMASMsearch kbAudDeveloper kbMASM510 kbMASM510a
Version           : :5.1,5.1a
Solution Type     : kbfix

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

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.