From: Daniel Berger <djberg96@...>
Date: 2006-08-02T09:55:07+09:00
Subject: Re: Static functions, extensions, linkage


Timothy Hunter wrote:
> Daniel Berger wrote:
> > Hi,
> >
> > How do you get at a static function from within a C extension?  I tried
> > this snippet where I attempt to use flo_plus from numeric.c:
> >
> > /* foo.c */
> > #include <ruby.h>
> >
> > extern VALUE flo_plus(VALUE, VALUE);
> >
> > static VALUE foo_test(VALUE x, VALUE y){
> >    return flo_plus(x, y);
> > }
> >
> > void Init_foo(){
> >    VALUE cFoo = rb_define_class("Foo", rb_cObject);
> >    rb_define_method(cFoo, "test", foo_test, 2);
> > }
> >
> > # test.rb
> > $:unshift Dir.pwd
> > require 'foo'
> > f = Foo.new
> > f.test
> >
> > This result is:
> >
> > ruby: symbol lookup error:
> > /home/djberge/programming/ruby/extensions/foo.so: undefined symbol:
> > flo_plus
> >
> > I tried linking explicitly against -lruby but that didn't help.
> >
> > Regards,
> >
> > Dan
> >
> >
> >
> Where is 'flo_plus' defined?

In numeric.c.  Note that it *builds* fine, it just doesn't *run*.

Regards,

Dan