FIX: Public Labels Are Prefixed with Underscore Incorrectly

The information in this article applies to:

• Microsoft Macro Assembler for MS-DOS, versions 5.1
• Microsoft Macro Assembler for OS/2, versions 5.1

SYMPTOMS

If you assemble the following program with MASM version 5.1 and examine the public label, TheProc, you will find an underscore prefixed to it. Another symptom of the problem may occurs during link time. The linker will generate the error L2029 unresolved external on public labels.

CAUSE

The space before the comma in the structure initialization of Data1 causes the problem to occur.

RESOLUTION

Removing the space before the comma in the structure initialization of Data1 will allow you to work around the problem.

STATUS

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

Sample Code

; Assemble options needed: none

StrucType STRUC Label1 DB "LPT"

Label2  DB "   "

_DATA SEGMENT

Data1   StrucType < , "1">

_TEXT SEGMENT ASSUME CS:_TEXT, DS:_DATA PUBLIC TheProc

TheProc PROC NEAR

        mov ax, 4C00h
        int 21h

END