DOCUMENT:Q67760  06-MAY-2001  [masm]
TITLE   :FIX: Bad Object File Generated with MASM 5.1 and 5.1a
PRODUCT :Microsoft Macro Assembler
PROD/VER::5.1,5.1a
OPER/SYS:
KEYWORDS:

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

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

SYMPTOMS
========

The following mixed-language program does not assemble properly under the
Microsoft Macro Assembler (MASM) version 5.1 and 5.1a.

CAUSE
=====

The assembler does not generate the correct .OBJ record for the linker to
resolve the reference properly. When the .EXE is built, the _test variable is
located in the NULL segment instead of the _DATA segment; therefore, instead of
the residing 1 byte apart, they are actually 42h bytes apart.

RESOLUTION
==========

Removing the ASSUME statements from the assembly code eliminates the problem.
These ASSUME statements are not necessary.

STATUS
======

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

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

Sample Code #1
--------------

   ; Assemble options needed: none

           .model small, c

           .data
          ASSUME ds: nothing
   PUBLIC xxx
   xxx    DB 1
          ASSUME ds: @data
   PUBLIC yyy
   yyy    DB 2

          .code
   PUBLIC func
   func   PROC
          MOV ax, OFFSET yyy
          SUB ax, OFFSET xxx
          RET
   func   ENDP

          END

Sample Code #2
--------------

   /* Compile options needed: none
   */ 

   #include <stdio.h>
   extern char xxx;
   extern char yyy;

   void main ()
   {
      printf( "C distance of yyy - xxx = %X\n", &yyy - &xxx );
      printf( "MASM distance of yyy - xxx = %X\n", func () );
   }

Additional query words: 5.10 5.10a 6.00 buglist5.10 buglist5.10a fixlist6.00

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

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

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