Article: Q35114
Product(s): Microsoft Macro Assembler
Version(s): 5.1,5.1a,6.0,6.0a,6.0b
Operating System(s):
Keyword(s):
Last Modified: 06-MAY-2001
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The information in this article applies to:
- Microsoft Macro Assembler (MASM), versions 5.1, 5.1a, 6.0, 6.0a, 6.0b
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SYMPTOMS
========
The comparison of a constant and a relocatable is not allowed. The following
example demonstrates three approaches to comparing a constant and a relocatable.
In the Microsoft Macro Assembler (MASM) 5.1 and 5.1a you will get the warning:
warning A4031: Operand types must match
on the first of these approaches. In MASM 6.0, 6.0a, and 6.0b you will get the
error:
error A2026: constant expected
on the first of these approaches, and you will get the error:
error A2094: operand must be relocatable
on the second. The third approach, which turns the relocatable into a constant by
subtracting the beginning of the segment, will work.
CAUSE
=====
You can not compare a constant to a relocatable at assembly time because the
linker may change the value of the relocatable at link time.
RESOLUTION
==========
This is the expected behavior of MASM. The third approach in the example below
demonstrates the prefered way to compare a constant and a relocatable.
MORE INFORMATION
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Sample Code
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; Assemble options needed: none
_DATA SEGMENT 'DATA'
a_var DW ?
.ERRNZ 08000h LT a_var ; constant LT relocatable
.ERRNZ _DATA:08000h LT a_var ; cast constant to relocatable
.ERRNZ 08000h LT a_var- @CurSeg ; difference of relocatables
_DATA ENDS
END
Additional query words: 5.10 5.10a 6.00 6.00a 6.00b
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Keywords :
Technology : kbMASMsearch kbAudDeveloper kbMASM510 kbMASM600 kbMASM600a kbMASM510a kbMASM600b
Version : :5.1,5.1a,6.0,6.0a,6.0b
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