From: Jeremy Evans <merch-redmine@...>
Date: 2011-07-04T09:38:18+09:00
Subject: [ruby-core:37763] [Ruby 1.9 - Bug #3768] Constant Lookup doesn't work in a subclass of BasicObject


Issue #3768 has been updated by Jeremy Evans.


If BasicObject.const_missing calls Object.const_get and the constant does not exist in Object, you've at best got a SystemStackError (I got SIGILL when I tried).  I suppose this could work:

  class BasicObject
    def self.const_missing(name)
      ::Object.const_get(name) if ::Object.const_defined?(name)
    end
  end

While safer, I do not advocate such an approach.  For one, there's a TOCTOU race condition in threaded code if Object.remove_const is used.

Personally, I don't see this as a major issue.  There should be no need for this in BasicObject itself, and overriding const_missing in a BasicObject subclass is easy.
----------------------------------------
Bug #3768: Constant Lookup doesn't work in a subclass of BasicObject
http://redmine.ruby-lang.org/issues/3768

Author: Thomas Sawyer
Status: Rejected
Priority: Normal
Assignee: Yukihiro Matsumoto
Category: lib
Target version: 
ruby -v: 1.9.2-p0


=begin
 ruby-1.9.2-p0 > module M
 ruby-1.9.2-p0 ?>  end
  => nil
 ruby-1.9.2-p0 > class X < BasicObject
 ruby-1.9.2-p0 ?>    include M
 ruby-1.9.2-p0 ?>  end
 NameError: uninitialized constant X::M
         from (irb):4:in `<class:X>'
         from (irb):3
         from /home/trans/.rvm/rubies/ruby-1.9.2-p0/bin/irb:17:in `<main>'
=end



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