Relocatable Object Module Format (OMF) Specification
Relocatable Object Module Format (OMF) Specification
Relocatable Object Module Format (OMF) Specification
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<strong>Relocatable</strong> <strong>Object</strong> <strong>Module</strong> <strong>Format</strong><br />
88H COMENT—Comment Record<br />
Description<br />
The COMENT record contains a character string that may represent a plain text comment, a symbol meaningful to<br />
a program accessing the object module, or even binary-encoded identification data. An object module can contain<br />
any number of COMENT records.<br />
History<br />
Before the VENDEXT record was added for TIS, the COMENT record was the primary way of extending the <strong>OMF</strong>.<br />
These extensions were added or changed for 32-bit linkers and continue to be supported in this standard. The<br />
comment classes that have been added or changed are 9D, A0, A1, A2, A4, AA, B0, and B1.<br />
Comment class A2 was added for Microsoft C version 5.0. Histories for comment classes A0, A3, A4, A6, A7, and<br />
A8 are given later in this section.<br />
68000 and big-endian comments were added for Microsoft C version 7.0.<br />
Record <strong>Format</strong><br />
The comment records are actually a group of items, classified by comment class.<br />
1 2 1 1 1<br />
88 Record<br />
Length<br />
Comment<br />
Type<br />
Comment<br />
Class<br />
Commentary Byte String (optional)<br />
Checksum<br />
Comment Type<br />
The Comment Type field is bit significant; its layout is<br />
<br />
NP NL 0 0 0 0 0 0<br />
where<br />
NP<br />
NL<br />
(no purge bit) is set if the comment is to be preserved by utility programs that manipulate object<br />
modules. This bit can protect an important comment, such as a copyright message, from deletion.<br />
(no list bit) is set if the comment is not to be displayed by utility programs that list the contents of<br />
object modules. This bit can hide a comment.<br />
The remaining bits are unused and should be set to 0.<br />
Comment Class and Commentary Byte String<br />
The Comment Class field is an 8-bit numeric field that conveys information by its value (accompanied by a null<br />
byte string) or indicates the information to be found in the accompanying byte string. The byte string's length is<br />
determined from the record length, not by an initial count byte.<br />
Tool Interface Standards (TIS) <strong>OMF</strong> <strong>Specification</strong>, Version 1.1 9