--- Begin Message ---
|
Subject: |
[2.0.5+] Miscompilation with peval: local shadows module-ref |
|
Date: |
Wed, 08 Feb 2012 00:04:10 +0100 |
|
User-agent: |
Gnus/5.110018 (No Gnus v0.18) Emacs/24.0.93 (gnu/linux) |
Hi!
Consider this:
--8<---------------cut here---------------start------------->8---
scheme@(guile-user)> ,optimize (define (foo) (define bar (@ (chbouib) bar)) bar)
$11 = (define foo
(lambda ()
(let ((bar-1510 (if #f #f)))
(letrec*
()
(begin (set! bar-1510 bar-1510) bar-1510)))))
--8<---------------cut here---------------end--------------->8---
Here, the ‘bar’ local is always set to *undefined*, wrongfully.
Ludo’.
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#10756: [2.0.5+] Miscompilation with peval: local shadows module-ref |
|
Date: |
Fri, 06 Jul 2012 20:20:13 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) |
On Thu 08 Mar 2012 08:11, Mark H Weaver <address@hidden> writes:
>> scheme@(guile-user)> ,expand (define (foo) (define bar (@ (chbouib) bar))
>> bar)
>> $2 = (define foo
>> (lambda () (letrec* ((bar-92 bar-92)) bar-92)))
>>
>> Andy
>
> I've attached a patch that fixes this bug. Fixing '@' was literally a
> one word fix (w -> top-wrap), and the same would have been true of '@@'
> if not for the way it had been extended to support R6RS library forms.
> Unlike '@' which uses syntax->datum on the 'id' to strip the wrap, '@@'
> kept syntax objects fully intact and only changed their module.
>
> I think it was a mistake to overload '@@' to do these two different
> jobs, so I changed the R6RS-support syntax to (@@ @@ (mod ...) body) and
> left its behavior as-is, and then made (@@ (mod ...) id) act the same
> way as '@': use 'syntax->datum' on the 'id' and return top-wrap.
>
> I think it's okay to change the internal R6RS-support syntax in
> stable-2.0, because it's undocumented and only exists as a temporary
> intermediate form during macro expansion. What do you think?
>
> Also: since 'boot-9.go' was not automatically recompiled by changing
> 'r6rs-libraries.scm', I added explicit dependencies to
> module/Makefile.am. However, I'm almost wholly ignorant of automake, so
> please double-check what I did there.
Looks great to me, pushed. It's strictly incompatible, but hey. Sorry
for taking so long! The only thing I would note is that it seems to me
that this "R6RS-support" is useful in a general sense. Just an
impression though, I've never had occasion to use it outside the R6RS
libs.
Regards, and thanks very much,
Andy
--
http://wingolog.org/
--- End Message ---