Re: [PATCH] primitive resolution for public refs

[BT Templeton <bpt@hcoop.net>]

Noah Lavine <noah.b.lavine@gmail.com> writes:

> Hello,
>
> Are you sure this is correct? What if someone calls the module-set!
> function on that module between the definition and use of whatever
> function you're compiling?
>
> I agree very strongly that we need to be able to do this sort of
> optimization, but I think we might need some sort of caching mechanism
> to do it right, where the cache of compiled function bodies is
> invalidated by module-set!.

I don't think I've changed the correctness wrt `module-set!' and the
like -- the current, private-refs-only optimization already exhibits the
problem you describe:

| scheme@(guile-user)> (define old-car car)
| scheme@(guile-user)> (module-set! (current-module)
|                                   'car
|                                   (lambda (x) (format #t "car ~A~%" x) (old-car x)))
| scheme@(guile-user)> ,x (lambda (x) ((@@ (guile) car) x))
| [...]
| Disassembly of #<procedure 1d23ae0 at <current input>:4:0 (x)>:
|   
|   0    (assert-nargs-ee/locals 1)      ;; 1 arg, 0 locals
|   2    (local-ref 0)                   ;; `x'
|   4    (car)
|   5    (return)

I'm not certain it's otherwise correct; I just added a workaround for
the specific issue mentioned in the comment.

> On Mon, Mar 12, 2012 at 12:42 PM, BT Templeton <bpt@hcoop.net> wrote:
>> * module/language/tree-il/primitives.scm (resolve-primitives!): Resolve
>>  public module-refs to primitives.
>> ---
>>  module/language/tree-il/primitives.scm |   16 +++++++++-------
>>  1 files changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/module/language/tree-il/primitives.scm b/module/language/tree-il/primitives.scm
>> index 3c6769d..1dcab20 100644
>> --- a/module/language/tree-il/primitives.scm
>> +++ b/module/language/tree-il/primitives.scm
>> @@ -265,13 +265,15 @@
>>                                (module-variable mod name)))
>>                (lambda (name) (make-primitive-ref src name))))
>>        ((<module-ref> src mod name public?)
>> -        ;; for the moment, we're disabling primitive resolution for
>> -        ;; public refs because resolve-interface can raise errors.
>> -        (let ((m (and (not public?) (resolve-module mod))))
>> -          (and m
>> -               (and=> (hashq-ref *interesting-primitive-vars*
>> -                                 (module-variable m name))
>> -                      (lambda (name) (make-primitive-ref src name))))))
>> +        (and=> (and=> (resolve-module mod)
>> +                      (if public?
>> +                          module-public-interface
>> +                          identity))
>> +               (lambda (m)
>> +                 (and=> (hashq-ref *interesting-primitive-vars*
>> +                                   (module-variable m name))
>> +                        (lambda (name)
>> +                          (make-primitive-ref src name))))))
>>        ((<call> src proc args)
>>         (and (primitive-ref? proc)
>>              (make-primcall src (primitive-ref-name proc) args)))
>> --
>> 1.7.9.1

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