ID Number: Q74532
6.00 | 6.00
MS-DOS | OS/2
buglist6.00 fixlist6.00a
Summary:
SYMPTOMS
The Microsoft Macro Assembler (MASM) version 6.0 may generate
incorrect code when a near call is made to a procedure in another
segment. When a call is made from an offset greater that 0FDh in
the calling segment to a procedure declared in the same source
file, the call is made to an incorrect offset.
RESOLUTION
To work around this problem, code the procedure in another module
and declare it as external in the problem module.
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 program below illustrates this problem. It defines two
segments that are defined in the same group. Calls are being made from
different offsets in the file. All calls after offset 0FDh are made to
incorrect addresses rather than being set up as relocatable calls.
The following is incorrect code generated for the procedure called
Generic:
00F8 Generic proc near
00F8 E8 0000 R call Simple
00FB E8 0000 R call Simple
00FE E8 11B2 call Simple
0101 E8 5200 call Simple
0104 E8 11B2 call Simple
0107 E8 11B2 call Simple
010A E8 0854 call Simple
010D Generic endp
The correct code that should be generated would appear as follows:
00F8 Generic proc near
00F8 E8 0000 R call Simple
00FB E8 0000 R call Simple
00FE E8 0000 R call Simple
0101 E8 0000 R call Simple
0104 E8 0000 R call Simple
0107 E8 0000 R call Simple
010A E8 0000 R call Simple
010D Generic endp
Sample Code
-----------
; Assemble options needed: none
;
CGroup group Init, Code
ASSUME CS:CGroup
Code segment para public 'CODE'
Simple proc near
ret
Simple endp
Code ends
Init segment para public 'CODE'
ORG 0F8h
Generic proc near
call Simple
call Simple
call Simple
call Simple
call Simple
call Simple
call Simple
Generic endp
Init ends
end