From: "matz (Yukihiro Matsumoto) via ruby-core" Date: 2026-10-07T08:20:43+00:00 Subject: [ruby-core:126964] [Ruby Feature#22379] Remove prism mismatch warning from `#syntax_tree` Issue #22379 has been updated by matz (Yukihiro Matsumoto). I don't want to simply remove the warning. Silently returning a node that does not correspond to the running code is dangerous, especially when the tree is used to generate something and not just to show a message. How about separating the two instead? The Prism that `#syntax_tree` uses would live under its own name, such as `Ruby::Prism` or `Ruby::Parser`, built into the interpreter and independent of the prism gem. Then `#syntax_tree` always returns nodes from the parser that compiled the code, and the gem can be any version. The warning would no longer be needed. It can be autoloaded, so programs that don't use `#syntax_tree` pay nothing. I know this means two sets of node classes. I'd like to hear from the prism maintainers and @mame whether this is feasible. Matz. ---------------------------------------- Feature #22379: Remove prism mismatch warning from `#syntax_tree` https://bugs.ruby-lang.org/issues/22379#change-119361 * Author: Earlopain (Earlopain _) * Status: Open ---------------------------------------- #21795 added `#syntax_tree` for a few objects. Currently it is implemented in a way that uses the prism gem, using node_id. Because it is theoretically possible that node_ids from the internal cruby version of prism don't match with the node_ids from the installed prism gem, a warning is emitted when the two versions don't match: ```rb def x = nil pp method(:x).syntax_tree # => syntax_tree: a prism gem other than the default gem is loaded; the result may not correspond exactly to the compiled code # => @ DefNode (location: (1,0)-(1,11)) # ... ``` That this version-mismatch happens is basically a given. As soon as the user has prism in their lockfile for any reason it will be triggered. When I encounter a warning I assume that I have to make some change in the code to avoid it but there is nothing realistic for me to do, except to stop using the method alltogether. The warning is verbose-only. However it's good practise to run test suites with warnings enabled to keep up on deprecations, so even there it does not fit. I would like this warning to become documentation only for the above reasons. @eregon also suggested to only warn when we can prove that the node_id doesn't match. That should be possible as well, since we have the code location from the iseq and can check if the node we found via prism lines up. However, that doesn't guarantee that the contents of the node are also the same. -- 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/