How LINK Orders and Combines Segments

MS-DOS                                    | OS/2

The information in this article applies to:

• Microsoft LINK for MS-DOS, versions 3.x, 4.x, 5.0x, 5.1x, 5.3, 5.31.009, 5.5 and 5.6
• Microsoft LINK for OS/2, versions 5.0x, 5.1x, 5.3, and 5.31.009

Every application segment belongs to a named class such as "CODE," "DATA," or "BSS." LINK orders segments in the output file to place segments that have the same class into the file contiguously. LINK does not change the order of segment classes and, within each class, LINK does not change the order of segments.

In an assembly language application, if a segment does not have a class name, the linker assigns it to the null class, which is processed as any other segment class.

If the linker command line includes the /DOSSEG option switch or specifies a run-time library from a Microsoft language product, LINK imposes the following order on the segments in the output file:

   code     - class names that end in "CODE"

   far data - all segment classes except for "DGROUP" and code

   DGROUP   - (this segment is the default
               data segment for the application)
               - class "BEGDATA" (a special run-time segment)
               - near initialized data (all data except
                                        for "BSS" and "STACK")
               - near BSS uninitialized data (class "BSS")
               - stack (class "STACK")