Unhandled Java exception: org.jruby.RubyContinuation$Continuation #6507
Description
When running the following script
require 'parser/current'
code = "def main; CONSTANT = nil; end"
parser = Parser::CurrentRuby.new
buffer = Parser::Source::Buffer.new('code', source: code)
parser.parse(buffer)
as bin/jruby repro.rb, the script fails with:
Unhandled Java exception: org.jruby.RubyContinuation$Continuation
org.jruby.RubyContinuation$Continuation: null
The expected behavior for this way of using the parser gem is that the script silently ends. There are ways to get it to report parse failures (parser.diagnostics.consumer = ->(diag) {puts diag.render}), but those don't otherwise change the behavior.
This is using the whitequark/parser gem, 3.0.0.0. The issue was originally found using parser 2.7.2.0 on JRuby 9.2.13.0.
Further context
This issue is related to a combination of parser, racc and JRuby. Similar code is otherwise handled as expected:
$ bin/jruby -e 'def main; CONSTANT = nil; end'
SyntaxError: -e:1: dynamic constant assignment
With Parser::CurrentRuby.parse(code) instead of the Parser invocation in the reproduction:
$ bin/jruby repro.rb
(string):2:3: error: dynamic constant assignment
(string):2: CONSTANT = nil
(string):2: ^~~~~~~~
Parser::SyntaxError: dynamic constant assignment
process at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/diagnostic/engine.rb:72
diagnostic at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/builders/default.rb:2189
assignable at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/builders/default.rb:668
_reduce_102 at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/ruby25.rb:3958
_racc_do_parse_c at com/headius/racc/Cparse.java:709
do_parse at jruby/lib/ruby/stdlib/racc/parser.rb:264
parse at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/base.rb:190
parse at jruby/lib/ruby/gems/shared/gems/parser-3.0.0.0/lib/parser/base.rb:33
<main> at repro.rb:14
This bug is probably related to whitequark/parser#305, #4071, ruby/racc@68bafd3 and ruby/racc#91, via #6194.
However my takeaway from those issues and that commit is that this should not be able to happen, as current JRuby should be using racc-1.5+ since at least JRuby 9.1.12.0, which doesn't use RubyContinuation any more. Since it does happen, I wonder whether an old version of the racc cparse.java, possibly in compiled form, lingers in the JRuby codebase and is actually being used.
Further observations
-
Although RubyContinuation isn't being used any more, it's still imported into https://github.com/ruby/racc/blob/092af4e2829b9e21e55be321aaa6ce29edf2615c/ext/racc/com/headius/racc/Cparse.java.
-
Some racc tests are being skipped on JRuby: ruby/racc@cf37713, ruby/racc@3107211
Environment Information
$ bin/jruby -v
jruby 9.2.15.0-SNAPSHOT (2.5.7) 2020-12-25 69334b7b49 OpenJDK 64-Bit Server VM 11.0.9.1+1-Ubuntu-0ubuntu1.20.04 on 11.0.9.1+1-Ubuntu-0ubuntu1.20.04 +jit [linux-x86_64]
$ uname -a
Linux photon 5.4.0-59-generic #65-Ubuntu SMP Thu Dec 10 12:01:51 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux