From: timsuth@... (Tim Sutherland)
Date: 2005-01-28T10:55:56+09:00
Subject: Re: [ANN] ruby-dl2-0.0

In article <41F93283.9060409@ttsky.net>, Takaaki Tateishi wrote:
>Hello,
>
>It's my pleasure to inform you that Ruby/DL2 has come out.
>
>  http://rubyforge.org/projects/ruby-dl2/
>
>I made it work with both of ruby-1.8 and ruby-1.9. Please try
>it and let me know what you think except for incompatibility
>between Ruby/DL and Ruby/DL2. I have a plan to replace Ruby/DL
>of ruby-1.9 with Ruby/DL2 after hearing serveral opinions.
>
>Best regards,
>
>P.S.
>I'd like you to read test/test_import.rb instead of a tutorial,
>since there is no documentation about Ruby/DL2.

Installing with ruby 1.9.0 (2005-01-27) [i686-linux],

tim@alien:~/d/ruby-dl2-0.0$ ruby extconf.rb 
checking for dlfcn.h... yes
checking for main() in -ldl... yes
checking for dlopen()... yes
checking for dlclose()... yes
checking for dlsym()... yes
checking for dlerror()... yes
creating Makefile
/usr/local/stow/ruby-cvs//lib/ruby/1.9/mkmf.rb:875: warning: global variable `$preload' not initialized

tim@alien:~/d/ruby-dl2-0.0$ make
gcc -fPIC -g -O2 -fno-defer-pop -fno-omit-frame-pointer  -I. -I/usr/local/stow/ruby-cvs//lib/ruby/1.9/i686-linux -I/usr/local/stow/ruby-cvs//lib/ruby/1.9/i686-linux -I. -DHAVE_DLFCN_H -DHAVE_DLOPEN -DHAVE_DLCLOSE -DHAVE_DLSYM -DHAVE_DLERROR  -c cfunc.c
gcc -fPIC -g -O2 -fno-defer-pop -fno-omit-frame-pointer  -I. -I/usr/local/stow/ruby-cvs//lib/ruby/1.9/i686-linux -I/usr/local/stow/ruby-cvs//lib/ruby/1.9/i686-linux -I. -DHAVE_DLFCN_H -DHAVE_DLOPEN -DHAVE_DLCLOSE -DHAVE_DLSYM -DHAVE_DLERROR  -c cptr.c
generating callback.h
../mkcallback.rb:126:in `%': too many arguments for format string (ArgumentError)
	from ./mkcallback.rb:126
	from ./mkcallback.rb:111:in `each'
	from ./mkcallback.rb:111
	from ./mkcallback.rb:110:in `each'
	from ./mkcallback.rb:110
	from ./mkcallback.rb:109:in `each'
	from ./mkcallback.rb:109
	from ./mkcallback.rb:100:in `each'
	from ./mkcallback.rb:100
make: *** [callback.h] Error 1

(NB: At this point callback.h exists.)

If we run make again, the build succeeds but trying to require 'dl' produces
irb: relocation error:
/usr/local/stow/ruby-cvs//lib/ruby/site_ruby/1.9/i686-linux/dl.so: undefined
symbol: rb_dl_init_callbacks

Apart from fixing the bug is causing the error, I guess mkcallback.rb
should delete callback.h if an exception reaches the top-level.

The actual bug in question is caused by the line
      return #{DLTYPE[ty][:conv] % "ret"};

Most of the time we have things like
  INT => {
    :name => 'int',
    :type => 'int',
    :conv => 'NUM2INT(%s)',
  }

but there is also

  VOID => {
    :name => 'void',
    :type => 'void',
    :conv => "",
  }


Thanks for all your work. Ruby/DL has long been my favourite Ruby extension
:-)