Re: [Gcl-devel] Problem in WITH-PACKAGE-ITERATOR

[Peter Wood]

Hi
On Sat, Jan 18, 2003 at 05:54:07PM -0600, Paul F. Dietz wrote:
> >(compile nil '(lambda () (with-package-iterator (x "CL" (:external)) (x))))
                                                           ^^   ??  ^^
> Compiling gazonk0.lsp.
> ; (DEFUN COMPILER::CMP-ANON ...) is being compiled.
> ;; Warning: Type declaration was found for not bound variable #:G2648.
> ;; Warning: Type declaration was found for not bound variable #:G2647.
> ;; The variable #:G2646 is undefined.
> ;; The compiler will assume this variable is a global.
> ;; The variable #:G2649 is undefined.
> ;; The compiler will assume this variable is a global.
> End of Pass 1.
> End of Pass 2.
> OPTIMIZE levels: Safety=1 (No runtime error checking), Space=0, Speed=3
> Finished compiling gazonk0.lsp.
> Loading gazonk0.o
> start address -T 0x8d85fe0 Finished loading gazonk0.o
> #<compiled-function COMPILER::CMP-ANON>
> 
> >
> 
> 
> Those variables should not be global.

(BTW && OT: I have noticed that the compiler's 'messages' are not
always accurate.  Apart from that, I think :external in the test above
should not be in a list (?!))

The following changes fix the problem:

1) Move the form '(declare (fixnum ,x ,y))' to just after the
backquoted let form's variable list in the with-package-iterator macro.

2) Initialize ,access and ,dum to nil by also giving them default
bindings in the macro's backquoted let form.

Now it looks like this (/lsp/with-package-iterator.lsp):

(defmacro with-package-iterator ((name plist &rest symbol-types) . body)
  (let ((p (gensym)) (i (gensym)) (l (gensym)) (q (gensym)) (dum (gensym))
        (x (gensym))(y (gensym)) (access (gensym)) declaration)
    (multiple-value-setq (declaration body) (si::find-declarations body))
    (if (null symbol-types)
        (si::universal-error-handler :simple-program-error nil nil nil "Symbol 
type specifiers must be supplied."))
    `(let ((,p (cons t (if (atom ,plist) (list ,plist) ,plist))) (,q nil) (,l 
nil)
           (,i -1) (,x 0) (,y 0) (,dum nil) (,access nil)) ;;CHANGED
      (declare (fixnum ,x ,y)) ;;CHANGED
      (labels ((,name () 
                 (when (null (setq ,l (cdr ,l)))
                   (when (eql (incf ,i) (+ ,x ,y))
                     (when (null (setq ,q (cdr ,q))) 
                       (when (null (setq ,p (cdr ,p)))
                         (return-from ,name nil))
                       (rplaca ,p (coerce-to-package (car ,p)))
                       (setq ,q (list 
                                 (si::coerce-to-package (car ,p))))
                       (when (member :inherited (list ,@symbol-types))
                         (rplacd ,q (package-use-list (car ,q)))))
                     (multiple-value-setq (,y ,x) (si::package-size (car ,q)))
                     (when (or (not (member :internal (list ,@symbol-types)))
                               (not (eq (car ,p) (car ,q))))
                       (setq ,x 0))
                     (when (and (not (member :external (list ,@symbol-types)))
                                (eq (car ,p) (car ,q)))
                       (setq ,y 0))
                     (when (zerop (+ ,x ,y)) 
                       (setq ,i -1)
                       (return-from ,name (,name)))
                     (setq ,i 0))
                   (setq ,l (if (< ,i ,x)
                                (si::package-internal (car ,q) ,i)
                                (si::package-external (car ,q) (- ,i ,x)))))
                 (when (null ,l)
                   (return-from ,name (,name)))
                 (multiple-value-setq (,dum ,access) 
                   (find-symbol 
                    (symbol-name (car ,l)) (car ,p)))
                 (when (and (not (eq ,access :inherited)) 
                            (not (eq (car ,p) (car ,q))))
                   (return-from ,name (,name)))
                 (values 't (car ,l) ,access (car ,p))))
        ;;CHANGED
        ,@declaration
        ,@body))))

When I rerun your test with this fixed macro I get:

> (compile nil '(lambda () (with-package-iterator (x "CL" :external) (x))))

Compiling gazonk0.lsp.
End of Pass 1.  

;; Note: Tail-recursive call of X was replaced by iteration.
;; Note: Tail-recursive call of X was replaced by iteration.
;; Note: Tail-recursive call of X was replaced by iteration.
End of Pass 2.  
OPTIMIZE levels: Safety=2, Space=3, Speed=0
Finished compiling gazonk0.lsp.
Loading gazonk0.o
start address -T 0x8ccd000 Finished loading gazonk0.o
#<compiled-function 089f11cc>

>

Disclaimer: I haven't tried it compiled yet.

Regards,
Peter