.ERRE/.ERRNZ (Error if Expression False/True)

The .ERRE and .ERRNZ directives test the value of an Expression.

Syntax

.ERRE Expression
   or
.ERRNZ Expression

Remarks

If the Expression evaluates to be false (zero), the .ERRE directive produces an error. If the Expression evaluates to be true (not zero), the .ERRNZ directive produces an error. The Expression must evaluate to an absolute value and cannot contain forward references.

Example

In this example, .ERRE checks the boundaries of a parameter that the program passes to the macro BUFFER. If count is less than or equal to 128, the expression that the directive tests is true (not zero) and the directive produces no error. If COUNT is greater than 128, the expression is false (zero) and the directive produces an error.

BUFFER MACRO  COUNT,BNAME
       .ERRE   COUNT LE 128
       BNAME DB COUNT DUP (0) ;; Reserve memory, but no more than 128 bytes
       ENDM

BUFFER 128,BUF1  ; Data reserved - no error
BUFFER 129,BUF2  ; Error produced

---

[Back: .ERRDIF/.ERRDIFI (Error if Arguments are Different)]
[Next: .ERRIDN/.ERRIDNI (Error if Arguments are Identical)]