FIX: COMM Directive Produces Error If Count Field Not Specified

The information in this article applies to:

• Microsoft Macro Assembler for MS-DOS, version 6.0
• Microsoft Macro Assembler for OS/2, version 6.0

SYMPTOMS

The Microsoft Macro Assembler (MASM) version 6.0 will produce a syntax error when multiple variables (separated by commas) are listed following a COMM directive if any variable, except the last one in the list, does not have a count field specified. For example, assembling sample code #1 with MASM 6.0 produces the following error:

   error A2008: syntax error: dec

   error A2008: syntax error: inc

RESOLUTION

The following methods may be used to work around these problems:

1. Place the count field with each variable specified. For example:

         COMM NEAR var1:word:1,var2:word:1,var3:word:3
   

   -or-

2. Make multiple COMM statements. For example:

         COMM NEAR var1:word
         COMM NEAR var2:word
   

STATUS

Microsoft has confirmed this to be a problem in MASM version 6.0. This problem was corrected in MASM version 6.0a.

MORE INFORMATION

The sample code below illustrates this problem. MASM version 5.1 and 5.1a assemble the code without any errors. According to the BNF Grammar in Appendix B of the "Microsoft Macro Assembler Programmer's Guide," this should also assemble correctly with MASM version 6.0.

Sample Code #1

; Assemble options needed: none

.MODEL small .DATA

  COMM NEAR var1:WORD,   var2:WORD    ; This doesn't work
; COMM NEAR var1:WORD:1, var2:WORD    ; This works
END

Sample Code #2

; Assemble options needed: none

.MODEL small .DATA

  COMM NEAR var1:WORD,
            var2:WORD, var3:WORD      ; This doesn't work

;           var2:WORD:1, var3:WORD:1  ; This works
END