From: "luke-gru (Luke Gruber) via ruby-core" <ruby-core@...>
Date: 2023-01-16T04:50:13+00:00
Subject: [ruby-core:111824] [Ruby master Bug#19345] Class variable access from top-level inappropriate error

Issue #19345 has been updated by luke-gru (Luke Gruber).


I just looked into this some more and if we want to allow the above code to work then we need to change the way the class variable cache works right now. Right now because the lookup of the class where we set the @@variables is static, it allows the class variable cache to cache the class. If we wanted it to be dynamic we would lose this cache.

----------------------------------------
Bug #19345: Class variable access from top-level inappropriate error
https://bugs.ruby-lang.org/issues/19345#change-101231

* Author: luke-gru (Luke Gruber)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN
----------------------------------------
I was looking at doing something like this:

```ruby
set_cvar = EnvUtil.labeled_class("SetCVar") do
  def self.set(val)
    @@a = val
  end
end
set_cvar.set(1) # fill write cache
set_cvar.freeze
set_cvar.set(2) # hit write cache, but should check frozen status
```

while working on a ruby issue (https://github.com/ruby/ruby/pull/7124) and I ran into an issue.
This code above gives the error "class variable access from toplevel (RuntimeError)"

Is this a bug or how it's supposed to work? The error is being raised in function `vm_get_cvar_base`.



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/