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Q76217: FIX: Nested Structures May Hang Macro Assembler 6.0

Article: Q76217
Product(s): Microsoft Macro Assembler
Version(s): MS-DOS:6.0
Operating System(s): 
Keyword(s): 
Last Modified: 04-MAY-2001

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

- Microsoft Macro Assembler (MASM), version 6.0 
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SYMPTOMS
========

Nested structures may cause the Microsoft Macro Assembler (MASM) version 6.0 to
hang when one structure contains a field of the type of another structure and it
is initialized. The code below demonstrates the problem more clearly.

RESOLUTION
==========

Pad the initializer to make it the size declared. In the sample code below,
padding the initializer for the member called People to three characters
corrects the problem.

STATUS
======

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

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

In the sample code, notice that the structure member Nme has a length of three
bytes. However, the structure called People initializes its Nme member to 'R',
which is one character instead of three. This produces the problem.

Under MS-DOS, the assembler logo will appear, and the system will hang. Under
OS/2, the following message appears:

  The process has stopped.
  The software diagnostic code (trap number) is 013.

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

  ; Assemble options needed: /c

  .MODEL small

  aStruct STRUCT
      Nme BYTE 3 DUP (?)
  aStruct ENDS

  bStruct STRUCT
      People aStruct <'R'>

  ; Replace above line with the following line to work around problem.
  ;
  ;   People aStruct <'R  '>    ; 'R' is followed by two spaces

  bStruct  ENDS

  .DATA
      Crash bStruct { }

  END

Additional query words: LOCK HANG STRUCT buglist6.00 fixlist6.00a

======================================================================
Keywords          :  
Technology        : kbMASMsearch kbAudDeveloper kbMASM600
Version           : MS-DOS:6.0
Solution Type     : kbfix

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

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