From: Laurent Julliard <Laurent.Julliard@...>
Date: 2001-06-27T00:59:03+09:00
Subject: [ruby-talk:16911] Re: rb_define_method when argc is -1

Thanks for the clarification Guy. 

So now comes a second question which is really why I asked about the
first one. I'm cuirrently working on a GNUstep (Objective C) binding for
Ruby with Avi Bryant (also on this ML). And I'm faced with a problem
that I cannot explain.

We have a piece of code that is already running and all the
rb_define_method seems to be accepted ok by Ruby. I can create new
objects ok, display the methods associated with the new Ruby class,
etc....

The problem I have is that after playing a couple of seconds with irb I
always have an error message and ruby aborts. Here is a sample session
(Foo is a dumb Objective C class with 3 little methods in it)

irb(main):001:0> require 'obj/cupertino' 
true
irb(main):003:0* Foo = ObjC.class("Foo")
Jun 26 17:34:33 irb[26026] Request to register ObjC Class Foo
(0x40278200)
Jun 26 17:34:33 irb[26026] Request to register ObjC Class NSObject
(0x40446d60)
Jun 26 17:34:33 irb[26026] 91 instance and 114 class methods defined for
class NSObject
Jun 26 17:34:33 irb[26026] VALUE for new Ruby Class NSObject =
0x4022e0d8
Jun 26 17:34:33 irb[26026] 3 instance and 0 class methods defined for
class Foo
Jun 26 17:34:33 irb[26026] VALUE for new Ruby Class Foo = 0x4022c030
ObjC::Foo
irb(main):004:0> p Foo
ObjC::Foo
nil
irb(main):006:0* Foo.ancestors
[ObjC::Foo, ObjC::NSObject, Object, Kernel]
irb(main):007:0> a = Foo.new
#<ObjC::Foo:0x4019d248>

then I repeat p Foo a couple times and the following error always shows
up

irb.rb:248: [BUG] rb_gc_mark(): unknown data type 0x20(0x40446d60) non
object
ruby 1.6.4 (2001-06-04) [i686-linux]
Aborted

What I don't understand here is that the value 0x40446d60 should be a
Ruby VALUE but it actually is the Objective C id value of the
corresponding class (see the Objective C log for the NSObject class)

I have been stuck on this problem for a long time now and I do not know
where to go from here....

-- 
Laurent JULLIARD - XR&T Technology and Alliances Office -  Open Source
team
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