FIX: Nested Dups in Structure Cause Recursive Loop

MS-DOS          | OS/2

The information in this article applies to:

• Microsoft Macro Assembler for MS-DOS, versions 5.1 and 5.1a
• Microsoft Macro Assembler for OS/2, versions 5.0, 5.1, and 5.1a

SYMPTOMS

The following code uses nested DUP operators in the initialization of an array of structures. The Microsoft Macro Assembler (MASM) version 5.0, 5.1, and 5.1a will generate a stack overflow.

CAUSE

MASM goes into a recursive loop at the calculation of the size.

RESOLUTION

You can work around this problem by initializing each of the structures instead of using a nested DUP operator. The example below demonstrates this work around.

STATUS

Microsoft has confirmed this to be a problem in MASM versions 5.0, 5.1, and 5.1a. This problem was corrected in MASM version 6.0.

MORE INFORMATION

Sample Code

; Assemble options needed: none

a_struc STRUC

    a DW ?

_DATA SEGMENT 'DATA' a_var a_struc 4 DUP (<1>, 3 DUP (<0>)) b_var a_struc 4 DUP (<1>, <0>, <0>, <0>) _DATA ENDS

END