[Ruby 3.0 support] Handle Kernel#clone with freeze: true argument

[andrykonchin]

This PR addresses issues:

[medium, java] Kernel#clone when called with the freeze: false keyword will call
#initialize_clone with the freeze: false keyword.
[Bug #14266]

and

[medium, java] Kernel#clone when called with the freeze: true keyword will call
#initialize_clone with the freeze: true keyword, and will
return a frozen copy even if the receiver is unfrozen.
[Feature #16175]

Related issue - #2453

Changes

• return a frozen copy when freeze: true
• handle freeze: nil
• pass freeze: to #initialize_clone

[andrykonchin]

I, probably, need help with passing a keyword argument to the #initialize_clone call here

initializeCloneNode.call(newObject, "initialize_clone", object);

I haven't found any similar example of calling a Ruby method from Java code with keyword arguments. Could you please point me to such an example?

[eregon]

I, probably, need help with passing a keyword argument to the #initialize_clone call here

Because we didn't do the keyword arguments changes yet for Ruby 3 it's just about passing a Hash with :freeze and true, but building that from Java is a little bit verbose, see org.truffleruby.core.hash.HashNodes.ConstructNode#construct (new RubyHash, PackedHashStoreLibrary.createStore(), PackedHashStoreLibrary.setHashedKeyValue).

(One easier way would be to create a (Ruby) method on Truffle::KernelOperations that calls it, and call that method, but that would then introduce an extra call which feels rather suboptimal.)

[eregon]

If you need any help don't hesitate to join our Slack as then it's easier to reply in real time.

[andrykonchin]

I would appreciate any advice regarding failed specs:

1)
Kernel#clone with freeze: true calls #initialize_clone with kwargs freeze: true FAILED
Expected [#<KernelSpecs::CloneFreeze:0x558>, {[:freeze, true]=>{}}] == [#<KernelSpecs::CloneFreeze:0x558>, {[:freeze, true]=>{}}]
to be truthy but was false
...spec/ruby/core/kernel/clone_spec.rb:97:in `block (4 levels) in <top (required)>'
...spec/ruby/core/kernel/clone_spec.rb:5:in `<top (required)>'

2)
Kernel#clone with freeze: false calls #initialize_clone with kwargs freeze: false FAILED
Expected [#<KernelSpecs::CloneFreeze:0x638>, {[:freeze, false]=>{}}] == [#<KernelSpecs::CloneFreeze:0x638>, {[:freeze, false]=>{}}]
to be truthy but was false
...spec/ruby/core/kernel/clone_spec.rb:129:in `block (4 levels) in <top (required)>'
...spec/ruby/core/kernel/clone_spec.rb:5:in `<top (required)>'

So actually {[:freeze, true]=>{}} doesn't equal {[:freeze, true]=>{}}.

I suppose there is an issue with a string representation of RubyHash. Actually, it's a correct Hash { freeze: true }.

And finally a key :freeze in recorded arguments doesn't equal a Symbol literal :freeze in the test case. I suppose it's related to how the key was created in the clone Java method.

[eregon]

The RubySymbol should be package-private so it's clear it shouldn't be used directly.
There is already coreSymbols().FREEZE which you can use :)

[andrykonchin]

Thank you. It fixed the failed specs as well 🎆

[eregon]

Primitive.object_equal or false == freeze is safer here to avoid calling == on some potentially random object.

[eregon]

We can just use freeze later instead of value, it can only be a boolean at this point.

[eregon]

This logic to create the Hash is a bit verbose, could you extract it to a method createFreezeBooleanHash() or so?

[andrykonchin]

Done. Please review.

[eregon]

Thank you for the great work on this PR!

[andrykonchin]

Thank you for your help 🙇.

I will squash commits and rebase on the master branch soon.

[eregon]

I pushed a couple commits on top, I'll do the rebase now.

[eregon]

I squashed the second commit in the first one to make it easier to rebase, should be all good now.