[ruby-core:121106] [Ruby master Feature#21140] Add a method to get the address of certain JIT related functions
From:
"maximecb (Maxime Chevalier-Boisvert) via ruby-core" <ruby-core@...>
Date:
2025-02-18 18:30:39 UTC
List:
ruby-core #121106
Issue #21140 has been updated by maximecb (Maxime Chevalier-Boisvert). > I think it can be both a side project as well as a piece of software that millions of people rely on. I apologize for the tone of my post which was rather hostile. I woke up with a pretty bad headache this morning and was in a grumpy mood. My main point is that I am afraid that things get merged into Ruby without fully weighing the implications eg Ractors. This was merged because of the enthusiasm of one specific core dev, but it's been in non-working state until recently. I am sure that your API will work but as we were discussing in the YJIT meeting, we have a problem where C extensions already have access to lots of things which they really shouldn't have direct access to. We should make sure to tell Ruby extension developers "this is a JIT API and there are no stability guarantees between Ruby versions". This should be made 1000% clear in the documentation with **ALL CAPS AND BOLD FONTS** but there is still a risk that people will abuse it and some gems could break. We can say "oh well, their fault, they were stupid", but imagine if 5 years from now we make some CRuby change and 3 gems that Shopify depends on blow up. What do we do then? We'd have no choice but to roll back those CRuby changes and it could stall CRuby development in some areas. My recommendation: guard this API behind a special configure flag that is separate from YJIT's. Something like `--enable-jit-gem-api`. That way you get to have your cake and eat it too. Ruby devs can build a custom Ruby and do anything they want with it. You get to write your own Ruby JIT gem and embed it into your IoT toaster. You can even build your own Ruby and deploy it into production at your startup if you want to, but you also effectively shield the rest of Ruby users from security and avoid Ruby gems that have no JIT needs becoming dependent on this API. ---------------------------------------- Feature #21140: Add a method to get the address of certain JIT related functions https://bugs.ruby-lang.org/issues/21140#change-112026 * Author: tenderlovemaking (Aaron Patterson) * Status: Open ---------------------------------------- Feature #21116 extracted RJIT as a gem. But RJIT accesses certain internal functions which it cannot access as a gem. For example it used the `rb_str_bytesize` function, but this symbol is not exported, so we cannot access it (even from a C extension). Instead of exporting these symbols, I would like to propose an API for getting access to their addresses in Ruby. For example ```ruby RubyVM::RJIT.address_of(:rb_str_bytesize) # => 123456 ``` I would like to limit the addresses to [this list](https://github.com/ruby/ruby/blob/f32d5071b7b01f258eb45cf533496d82d5c0f6a1/tool/rjit/bindgen.rb#L510-L578) which are the ones required by RJIT. -- 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/lists/ruby-core.ml.ruby-lang.org/