FIX: Nested Structures May Hang Macro Assembler 6.0

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

SYMPTOMS

Nested structures may cause the Microsoft Macro Assembler (MASM) version 6.0 to hang when one structure contains a field of the type of another structure and it is initialized. The code below demonstrates the problem more clearly.

RESOLUTION

Pad the initializer to make it the size declared. In the sample code below, padding the initializer for the member called People to three characters corrects the problem.

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

In the sample code, notice that the structure member Nme has a length of three bytes. However, the structure called People initializes its Nme member to 'R', which is one character instead of three. This produces the problem.

Under MS-DOS, the assembler logo will appear, and the system will hang. Under OS/2, the following message appears:

The process has stopped.
The software diagnostic code (trap number) is 013.

Sample Code

; Assemble options needed: /c

.MODEL small

aStruct STRUCT
    Nme BYTE 3 DUP (?)
aStruct ENDS

bStruct STRUCT
    People aStruct <'R'>

; Replace above line with the following line to work around problem.
;
;   People aStruct <'R  '>    ; 'R' is followed by two spaces

bStruct  ENDS

.DATA
    Crash bStruct { }

END 

Additional query words: LOCK HANG STRUCT buglist6.00 fixlist6.00a

Keywords :
Version : MS-DOS:6.0
Platform : MS-DOS
Issue type :