On Mon, Sep 14, 2009 at 11:35 AM, Andrea Fazzi <andrea.fazzi@alcacoop.it> wrote:

>
> Excerpts from Aman Gupta's message of lun set 14 11:28:58 +0200 2009:

>>
>> I'm using ffi-swig-generator on:
>>
>> typedef void (*MyCallback) (void *data);
>> typedef struct {
>>   void (*member) (MyCallback cb);
>> } MyStruct;
>>
>> which generates:
>>
>>   callback(:MyCallback, [ :pointer ], :void)
>>   class MyStruct < FFI::Struct
>>     layout(
>>       :member, callback([ :MyCallback ], :void)
>>     )
>>   end
>>
>> This works fine on with ruby-ffi, but on jruby I get:
>>
>> /custom/jruby/lib/ruby/1.8/ffi/types.rb:17:in `find_type': Unable to
>> resolve type 'MyCallback' (FFI::TypeError)
>>     from /custom/jruby/lib/ruby/1.8/ffi/library.rb:213:in `find_type'
>>     from /custom/jruby/lib/ruby/1.8/ffi/struct.rb:149:in `find_type'
>>     from /custom/jruby/lib/ruby/1.8/ffi/library.rb:148:in `callback'
>>     from /custom/jruby/lib/ruby/1.8/ffi/library.rb:148:in `each'
>>     from /custom/jruby/lib/ruby/1.8/ffi/library.rb:148:in `map'
>>     from /custom/jruby/lib/ruby/1.8/ffi/library.rb:148:in `callback'

>
> Ruby-FFI support for callback parameters in callbacks was added in rev
>
> 8d6045c2305f32929f4da5a28d28397523df0170
>
> Maybe that JRuby still doesn't implement it?

JRuby supports it, just doesn't recognize the callback if its defined
before the struct the way ffi-swig-generator does it. The issue is in
FFI::Struct#find_type, but I got very confused trying to fix it.

If I nest the callback definition inline, it works as expected:

  class MyStruct < FFI::Struct
    layout(
      :member, callback([ callback([ :pointer ], :void) ], :void)
    )
  end

>
> --
> Andrea Fazzi @ alca.le.it
> Follow me on http://twitter.com/remogatto
>