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Re: Prevent inlining


From: Linus Björnstam
Subject: Re: Prevent inlining
Date: Wed, 12 Feb 2020 22:49:58 +0100
User-agent: Cyrus-JMAP/3.1.7-802-g7a41c81-fmstable-20200203v1

If guile ever gets cross-module Inlining in even the simplest form, this will 
break. This kind of inlining is probably the most secure one to rely on ever 
(my for loops rely on it, for example). A more future proof option is maybe to 
(set! ...) A variable within the same module, which makes it implicitly boxed. 
Slow unless guile is able to do unboxing...

Ludo used the trick here: 
http://git.savannah.gnu.org/cgit/guile.git/commit/?id=bf1f5422bdb364667d6761dd73454558d6dbf895

-- 
  Linus Björnstam

On Wed, 12 Feb 2020, at 18:44, Stefan Israelsson Tampe wrote:
> Hi all,
> 
> Current guile inlines even variables exposed in the module interface, 
> and I understand that we must live with that and code around it. So 
> here is a few tips how to mitigate it.
> 
> The simplest way is to put this definition in a module:
> ------------------------
> (define-module (syntax not-inline)
>  #:export (not-inline))
> 
> (cond-expand
>  (guile-3.0
>  (define (not-inline x) x))
>  ((or (guile-2.0 guile-2.2)
>  (define-syntax-rule (not-inline x) x)))
> 
> -------------------------------------
> And then in another module do,
> 
> (use-modules (syntax not-inline))
> (define variable (not-inline 12))
> (define function (not-inline (lambda () ...)))
> etc
> 
> This is also an option (not perfect but you get the gist)
> 
> -----------------------------------------------------------------
> (define-module (syntax define-not-inlinable)
>  #:use-module (syntax not-inline)
>  #:export (inline define lambda define* lambda* define-values)
> (define inline (lambda (x) x))
> (define-syntax define
>  (syntax-rules (inline)
>  ((define (f . x) . code)
>  (define f (not-inline (lambda x . code)))
>  ((define f (inline x))
>  (define f x))
>  ((define f x)
>  (define f (not-inlinable x))))
> ----------------------------------------------------------------------------------
> using this module will make all usual define not inlineable and to 
> enable inlining you would
> explicitly ask for it like
> 
> (define f (inline (lambda (x) (+ x 10))))
> 
> If there is a need for this I can write the modules and expose it on 
> the intertubes.
> 
> WDYT
> 
> /Stefan
> 
> 
> 
>



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