PRB: Possible Cause of L2002 for Mixed C, MASM in Large Model (38216)
The information in this article applies to:
- Microsoft Macro Assembler (MASM) 5.0
- Microsoft Macro Assembler (MASM) 5.1
- Microsoft Macro Assembler (MASM) 5.1a
- Microsoft Macro Assembler (MASM) 6.0
- Microsoft Macro Assembler (MASM) 6.0a
- Microsoft Macro Assembler (MASM) 6.0b
This article was previously published under Q38216 SYMPTOMS
If a variable is referenced externally in an assembler routine
in the following manner:
.model large, c
.data
EXTRN Var:WORD
and declared globally in a large model C program as follows:
int Var;
the following error is generated:
error L2002: fixup overflow
CAUSE
This error occurs because the assembler would expect to find Var in
the segment _DATA in DGROUP. The C declaration, however, will put var
in the segment FAR_BSS, since it is an uninitialized global data
item in the large memory model.
Note that the same is true for the compact memory model.
RESOLUTION
One way to eliminate this error is to initialize Var in the C code:
int Var=0;
This will put it in the _DATA logical segment in DGROUP.
Another work-around is to delcare Var in the Assembly code so that
the assembler would expect to find Var in FAR_BSS, as follows:
.model large, c
.fardata?
EXTERN Var:WORD
In addition, be sure to use a segment override to access Var:
MOV ax, SEG Var
MOV es, ax
MOV bx, es:Var
Modification Type: | Major | Last Reviewed: | 10/17/2003 |
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Keywords: | KB38216 |
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