Re: RFC: Enhancing ObjC message lookup in the presence of protocols

[Ziemowit Laski <zlaski at apple dot com>]

On 14 Oct 2004, at 7.34, David Ayers wrote:

> > My proposal to attack this problem goes as follows: Whenever we see
> > an interface or category declaration, we examine the protocols
> > adopted by said interface/category and insert their constituent
> > method signature into the global class or instance method hash tables
> > (as is already being done for methods declared by the
> > interface/category directly). Also, whenever we are dealing with a
> > root class (or a category of a root class), we add any instance
> > methods from the adopted protocols into the global class hash table
> > (just as instance methods directly declared by root classes and
> > categories already are).
>
> Isn't this exactly what my patch did?  The main reason I had to mark 
> the
> protocols adopted by root is for the case of forward declared protocols
> adopted by root classes in which case we haven't seen the methods yet.

Your patch did more than that, I think, but overall you do raise a good
point.  Either we should handle forward-declared protocols as you 
suggest,
or else I should drop the second part of my proposal.  At any rate,
let's defer this to the next patch, and separate it from adding
'Class <Proto>' to the compiler in the first place.

> PS: Will you also send a mail concerning the semantic changes to
> objc_comptypes that your implementation has introduced?  I do agree 
> with
> some of them, but I don't think that they should be part of this patch.

Which ones do you mean?  I did notice that objc_comptypes is buggy in
some cases (marked as FIXMEs in class-protocol-1.m), but I resisted
mission creep in that case, since these bugs can be fixed as part of
a future objc_comptypes rewrite.

Aside from this, do you see any other problems with my current patch?
I know it still doesn't do everything you want, and you do raise
a good point about forward-declared protocols, but we should separate
concerns here and attack remaining problems with a separate patch.

Thanks,

--Zem

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Ziemowit Laski                 1 Infinite Loop, MS 301-2K
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