Relocatable Object Module Format (OMF) Specification

Relocatable Object Module Format
C6H ALIAS—Alias Definition Record
Description
This record has been introduced to support link-time aliasing, a method by which compilers or assemblers may
direct the linker to substitute all references to one symbol for another.
History
The record is an extension to the original set of 8086 object record types for FORTRAN version 5.1 (Microsoft
LINK version 5.13).
Record Format
1 2 1
C6 Record Length Alias Name Substitute Name Checksum
Alias Name Field
A regular length-preceded name of the alias symbol.
Substitute Name Field
A regular length-preceded name of the substitute symbol.
Notes
This record consists of two symbolic names: the alias symbol and the substitute symbol. The alias
symbol behaves very much like a PUBDEF in that it must be unique. If a PUBDEF of an alias symbol
is encountered later, the PUBDEF overrides the alias. If another ALIAS record with a different
substitute symbol is encountered, a warning is emitted by most linkers, and the second substitute
symbol is used.
When attempting to satisfy an external reference, if an ALIAS record whose alias symbol matches is
found, the linker will halt the search for alias symbol definitions and will attempt to satisfy the reference
with the substitute symbol.
All ALIAS records must appear before the Link Pass 2 record.
66 OMF Specification, Version 1.1 Tool Interface Standards (TIS)