I found another problem with the optimizer and the new undefined behavior. (letrec ([x (if #t 8 x)]) x) ;==>8
I also consider this correct in a strange sense :). Gustavo Welcome to Racket v6.0.1.4. > (letrec ([x x]) x) x: undefined; cannot use before initialization context...: C:\Program Files\Racket-6.0.1.4\collects\racket\private\misc.rkt:87:7 > (letrec ([x 5]) x) 5 > (letrec ([x (if #t 8 x)]) x) 8 > (letrec ([x (if #f 8 x)]) x) x: undefined; cannot use before initialization context...: C:\Program Files\Racket-6.0.1.4\collects\racket\private\misc.rkt:87:7 > On Wed, Apr 16, 2014 at 10:09 AM, Matthias Felleisen <matth...@ccs.neu.edu> wrote: > > Ah, too bad: > >> pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> --- OLD/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl >> +++ NEW/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl >> @@ -3416,5 +3416,16 @@ >> (read (open-input-bytes (get-output-bytes o)))))) >> >> ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; >> +;; Check that an unsufe opertion's argument is >> +;; not "optimized" away if it's a use of >> +;; a variable before definition: >> + >> +(err/rt-test (let () >> + (unsafe-fx+ x 1) >> + (define x 3) >> + x) >> + exn:fail:contract:variable?) >> + >> +;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > > > :-) > > On Apr 16, 2014, at 9:02 AM, Matthias Felleisen <matth...@ccs.neu.edu> wrote: > >> >> On Apr 15, 2014, at 9:29 PM, Asumu Takikawa <as...@ccs.neu.edu> wrote: >> >>> On 2014-04-15 18:13:31 -0400, claire alvis wrote: >>>> The push below includes changes to letrec expressions, internal >>>> definitions, units, classes, and certain ill-formed shared expressions so >>>> that they no longer leak the `undefined' value. >>> >>> This is great! (especially happy that TR, even with classes, doesn't >>> have to worry about #<undefined> anymore) >>> >>> BTW, I found this weird behavior: >>> >>> Welcome to Racket v6.0.1.3. >>> -> (require racket/unsafe/ops) >>> -> (let () (+ x 3) (define x 3) 5) >>> ; x: variable used before its definition [,bt for context] >>> -> (let () (unsafe-fx+ x 3) (define x 3) 5) >>> 5 >> >> >> I consider this correct in a strange sense. >> >> Interestingly enough, >> >>> (let () (displayln (unsafe-fx+ x 3)) (define x 3) 5) >> x: variable used before its definition >> context...: >> /Users/matthias/plt/racket/collects/racket/private/misc.rkt:87:7 >> >> which is good too. I don't know how Claire and Matthew did this, >> but it's good :-) >> _________________________ >> Racket Developers list: >> http://lists.racket-lang.org/dev > > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev _________________________ Racket Developers list: http://lists.racket-lang.org/dev
