Subject: bug#46843: closed (Re: bug#46843: 28.0.50; [native-comp] (lambda (x) (if (equal x b) (eq x b) (error ""))) miscompiled)

From: [email-masked] (GNU bug Tracking System)
Date: Mon, 01 Mar 2021 17:27:02 +0000

Your bug report

#46843: 28.0.50; [native-comp] (lambda (x) (if (equal x b) (eq x b) (error ""))) miscompiled

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
46843: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=46843
GNU Bug Tracking System
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Subject: Re: bug#46843: 28.0.50; [native-comp] (lambda (x) (if (equal x b) (eq x b) (error ""))) miscompiled
From: Andrea Corallo <[email-masked]>
To: Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <[email-masked]>
Cc: [email-masked], Pip Cet <[email-masked]>
Date: Mon, 01 Mar 2021 17:26:29 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <[email-masked]> writes:

> Pip Cet <[email-masked]> writes:
>
>> In *scratch*, evaluate
>>
>> (funcall
>>  (let* ((lexical-binding t)
>>         (a (list 'a))
>>         (b (cons a a)))
>>    (native-compile
>>     `(lambda (x) (if (equal x ',b) (eq x ',b) (error "")))))
>>  '((a) a))
>>
>> Expected result:
>>
>> nil
>>
>> Actual result:
>>
>> t
>
> Thanks for reporting this, will come-up with a fix.

Right 3d014e1bf4 is fixing the wrong assumtion that `equal' `eql' can be
treated as `eq' in propagation as every immediate in the compilation
unit is hash consed.  Indeed this assumtion is wrong for more than one
reason.

Now under `equal' `eql' we propagate only fixnums and symbols values,
all the other kind of values are promoted to their respective types and
propagated as such.

The patch adds some tests for that too.

As the two reproducer are working here I'm closing this.

Thanks for reporting.

  Andrea

Subject: 28.0.50; [native-comp] (lambda (x) (if (equal x b) (eq x b) (error ""))) miscompiled
From: Pip Cet <[email-masked]>
To: [email-masked]
Date: Mon, 1 Mar 2021 06:51:30 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

In *scratch*, evaluate

(funcall
 (let* ((lexical-binding t)
        (a (list 'a))
        (b (cons a a)))
   (native-compile
    `(lambda (x) (if (equal x ',b) (eq x ',b) (error "")))))
 '((a) a))

Expected result:

nil

Actual result:

t