+1  (in particular none that break compatibility.)

Ron

> -----Original Message-----
> From: squeak-dev-bounces at lists.squeakfoundation.org [mailto:squeak-dev-
> bounces at lists.squeakfoundation.org] On Behalf Of Andreas Raab
> Sent: Monday, August 14, 2006 8:04 PM
> To: The general-purpose Squeak developers list
> Subject: Re: Proposal for Extensible Primitives (was: FFI)
> 
> Hi Lukas -
> 
> What problem exactly are you trying to solve? The way I understand it
> the problem we have is a dependency problem - how can the FFI cleanly
> interact with the parser. To do this, I would simply add a class
> variable that points to some FFI support class handling the parsing
> requests. If the FFI is loaded it registers the appropriate entry point
> and it unregisters it when unloading. As far as I can see, no further
> changes are needed, in particular none that break compatibility.
> 
> Cheers,
>    - Andreas
> 
> Lukas Renggli wrote:
> > I propose the following changes:
> >
> > Problem: FFI is hardcoded into the Squeak parser and uses a special
> > parsing method. While parsing pragmas the implementation has to check
> > for special conditions (Parser>>pragmaStatement) to trigger special
> > handling of FFI functions (Parser>>externalFunctionDeclaration). This
> > adds unnecessary code requirements to the base image and violates the
> > extensibility of the system.
> >
> > Current State: Squeak primitives in 3.9 are already parsed using the
> > pragma parser, they fully comply the new syntax. As a post operation
> > the parser checks for these primitive pragmas and modifies the
> > compiled method to call the primitive instead of the fallback code.
> > FFI primitives have a slightly different syntax than the pragmas
> > therefor are handled differently.
> >
> > Solution: Unify parsing of pragmas and FFI primitives. Make the
> > primitive parsing extensible using pragmas.
> >
> > Proceeding: As a first step I would remove all the hardcoded code to
> > parse Squeak and FFI primitives. Then I would tag the already
> > implemented methods #primitive: and #primitive:module: using the newly
> > introduced pragma #primitive, so that the parser is able to
> > automatically detect these methods and postprocess the compiled method
> > after the parsing.
> >
> > Proceeding FFI: The FFI package would add two extension methods to the
> > parser, in the example below these would be #cdecel:module: and
> > #apicall:module:. The implementation would look similar as the current
> > implementation in #externalFunctionDeclaration, the parsing however
> > (except for the C declaration) would have been done by the pragma
> > parser already. The syntax of FFI primitives would need to be changed
> > from
> >
> >     XSetBackground: xDisplay with: xGC with: bg
> >         <cdecl: void 'XSetBackground' (X11Display* X11GC long) module:
> > 'X11'>
> >         ^self externalCallFailed
> >
> > to something like
> >
> >     XSetBackground: xDisplay with: xGC with: bg
> >         <cdecl: 'void XSetBackground(X11Display* X11GC long)' module:
> > 'X11'>
> >         ^self externalCallFailed
> >
> > As a free goodie, we could now look for all FFI calls by simply
> > looking at the senders of #cdecel:module: and #apicall:module:.
> >
> > I can do the proposed changes. We can also discuss about the
> > implementation, though I won't go into any discussion if pragmas are
> > good or evil ;-)
> >
> > Cheers,
> > Lukas
> >
>