Re: incorrect compiler warning about unused var

[Sam S. <sd...@gn...>]

Don Cohen wrote:
> In cvs head I notice the following warning which I think is wrong.
> (COMPILE 'AP-COMPILED::F1301 
>  '(LAMBDA (|GenFn| X2 X3 X4 &AUX |GenFun | |Exhausted | X5 X6) X2 X3 X4 
>    (SETQ |GenFun | (FUNCALL |GenFn| X4 X2 X3)) 
>    (LOOP UNTIL (MULTIPLE-VALUE-SETQ (|Exhausted | X5 X6) (FUNCALL |GenFun |)) 
>     COLLECT (LIST X3 X2 X4 X5 X6)))) 
> WARNING: in AP-COMPILED::F1301 : variable |Exhausted | is assigned but
> not read 

indeed, |Exhausted | is assigned a value by MULTIPLE-VALUE-SETQ but that value 
is never accessed.
you need to declare it IGNORABLE to avoid this warning.
note that the value stored in |Exhausted | is indeed used by the LOOP UNTIL 
clause, but that values comes from evaluating (FUNCALL ..), not from the 
variable, so there is not reason to store a value in |Exhausted |.