DOCUMENT:Q70360  30-OCT-1999  [utilities]
TITLE   :PRB: LINK Does Not Generate L2041 Error with /NOD and /DOSSEG
PRODUCT :Microsoft Programming Utilities
PROD/VER:MS-DOS:3.x,4.x,5.0x,5.1x,5.2x,5.3x,5.5,5.6; OS/2:5.0x,5.1,5.11,5.13,5.15
OPER/SYS:
KEYWORDS:kb16bitonly

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

 - Microsoft LINK for MS-DOS, versions 3.x, 4.x, 5.0x, 5.1x, 5.2x, 5.3x, 5.5, 5.6 
 - Microsoft LINK for OS/2, versions 5.0x, 5.1, 5.11, 5.13, 5.15 
-------------------------------------------------------------------------------

SYMPTOMS
========

An attempt to link an application using /NOD and /DOSSEG succeeds without an
error message, even though the combined size of the stack and data for the
DGROUP segment exceeds 64K. This occurs even though the compiler is designed to
cause /DOSSEG segment ordering and thus enable the linker to generate a L2041
error.

CAUSE
=====

The LINK command line being used does not enable segment ordering, so DGROUP is
not even being created.

RESOLUTION
==========

Specify a run-time library on the LINK command line that defines the segments
needed to create DGROUP. All Microsoft C Run-Time libraries do this.

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

If the LINK command line includes the /NOD option but not /DOSSEG and no
run-time libraries are specified, then segment ordering is not enabled. Adding
the /DOSSEG option to the LINK command line but still omitting run-time
libraries will still not give the L2041 error message, even though segment
ordering will be enabled.

This is because the /DOSSEG switch only forces a certain segment class ordering
convention; it doesn't actually define the segments that compose DGROUP. As a
result, the "L2041: stack plus data exceed 64K" message can't be generated
because there is no DGROUP to which the stack and data segments belong.

Linking with C run-time libraries introduces both the grouping and implementation
of data segments to form DGROUP, so in cases where the code contributes more
then 64k of data to DGROUP, error L2041 is given.

Note that Microsoft high-level language run-time libraries automatically enable
the /DOSSEG option by means of a special object-module record included in
libraries. To enable the /DOSSEG option in code developed with the Microsoft
Macro Assembler (MASM), specify the .DOSSEG directive in a MASM source code
file.

The following C source code example demonstrates this problem. Each of the
following LINK command lines demonstrate the possible scenarios and the error
messages that result.

Command line 1: link test;

Result set 1:

   LINK : fatal error L2041: stack plus data exceed 64k

Command line 2: link /NOD test;

Result set 2:

   LINK : warning L4021: no stack segment
   (unresolved externals)
   LINK : warning L4038: program has no starting address

NOTE: This result set does not include the L2041 error -- an error that you might
expect.

Command line 3: link /NOD /DOSSEG test;

Result set 3:

   LINK : warning L4021: no stack segment (unresolved externals) LINK : warning
   L4038: program has no starting address

NOTE: This result set contains the same errors as those generated when the /NOD
switch is specified by itself.

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

   /*
    * Compile options needed: /c
    */ 

   unsigned char a[30*1024] = {0};  /* 30k         */ 
   unsigned char b[30*1024] = {0};  /* 30k         */ 
   unsigned char c[10*1024];        /* 10k         */ 
                                    /* Total = 70k */ 
   void main(void)
   { }

Additional query words: 4.06 4.07 4.10 5.01.20 5.01.21 5.02 5.03 5.05 5.10 5.11 5.13 5.15 5.20 5.30 5.31.009 5.50 5.60

======================================================================
Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbZNotKeyword3 kbLINKSearch kbLINK3xDOSSearch kbLINK4xDOSSearch kbLINK50xDOSSearch kbLINK510xDOSSearch kbLINK520xDOSSearch kbLINK530xDOSSearch kbLINK50xOS2Search kbLINK550DOS kbLINK560DOS kbLINK510OS2 kbLINK511OS2 kbLINK513OS2 kbLINK515OS2
Version           : MS-DOS:3.x,4.x,5.0x,5.1x,5.2x,5.3x,5.5,5.6; OS/2:5.0x,5.1,5.11,5.13,5.15

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

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 1999.