ID Number: Q77078
6.00 6.00a | 6.00 6.00a
MS-DOS | OS/2
buglist6.00 buglist6.00a
Summary:
PROBLEM ID: MSM9110001
SYMPTOMS
When using the DUP operator in the Microsoft Macro Assembler (MASM)
versions 6.0 and 6.0a, you must place a whitespace character before
the DUP operator if using the "?" operator. If no whitespace is
present, no error message is produced by the assembler, and incorrect
code will be generated. The assembler will generate one data item for
the specified type, initialized to the value of the repeat size for the
DUP operator.
RESOLUTION
To work around the problem, place a space between the repeat size
and the DUP operator. Initializing the variable will cause a syntax
error to be generated.
STATUS
Microsoft has confirmed this to be a problem in MASM versions 6.0
and 6.0a. We are researching this problem and will post new information
here as it has become available.
More Information:
The code example below generates a listing file that shows the size
generated for the respective DUP statements. It can be seen that the
first DUP operation generates 4 data bytes; however, the second
generates 1 data byte initialized to 4.
The assembler has problems parsing this statement because the DUP
operator begins with a letter (d), which is a valid radix suffix.
Sample Code
-----------
; Assemble options needed: /Fl
.MODEL SMALL
.STACK
.DATA
a db 4 dup(0)
size_a db SIZEOF a
b db 4dup(?)
size_b db SIZEOF b
.CODE
start:
mov ax,4C00H
int 21H ;Terminate Process
END start
END
Additional reference words: 6.00