JRuby

ClassCastException with DummyDynamicScope in String#rpartition? with -X+C

Details

  • Type: Bug Bug
  • Status: Resolved Resolved
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: JRuby 1.6.7, JRuby 1.7.0.pre1
  • Fix Version/s: JRuby 1.7.0.RC1
  • Component/s: None
  • Labels:
    None
  • Number of attachments :
    0

Description

Trying my code with -X+C I got this weird error.
It does not seems to be due to String#rpartition, but rather because of a bad scope.

Steps to reproduce:
$ git clone git://github.com/jruby/perfer.git
$ bundle
$ JRUBY_OPTS="-X+C -Xbacktrace.style=raw" bin/perfer run examples/file_stat.rb

The output I got is in this gist: https://gist.github.com/f821b76e79c7d34e84bd

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Thomas E Enebo added a comment -

Just to add some notes:

            pos = regex.search19(context, this, value.getRealSize(), true);
            if (pos < 0) return rpartitionMismatch(runtime);
            sep = (RubyString)RubyRegexp.nth_match(0, context.getCurrentScope().getBackRef(runtime));

The ClassCast is this last line, but it should not class cast since pos >= 0. Benoit is correct that this must be some bad scope setup. Plus it works in mixed + interp modes.

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Thomas E Enebo added a comment - Just to add some notes: pos = regex.search19(context, this, value.getRealSize(), true); if (pos < 0) return rpartitionMismatch(runtime); sep = (RubyString)RubyRegexp.nth_match(0, context.getCurrentScope().getBackRef(runtime)); The ClassCast is this last line, but it should not class cast since pos >= 0. Benoit is correct that this must be some bad scope setup. Plus it works in mixed + interp modes.
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Charles Oliver Nutter added a comment -

The issue was that rpartition and partition were not specified as needing access to the caller's backref (reads = BACKREF, writes = BACKREF in @JRubyMethod), and as a result no scope was being set up for the caller. In this particular case, a dummy scope was being set up for the caller (for one of the other calls or constructs in the method) and DummyDynamicScope always returns nil for backref.

Trivial reproduction:

def foo
  Object
  "/Users/headius/projects/jruby/tmp/perfer/examples/file_stat.rb:4:in `(root)'".rpartition(/:\d+(?:$|:in )/).first
end

foo

(Here, the access of Object triggers a dummy scope)

The fix is trivial. I'm trying to set up a test case, and then I'll commit.

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Charles Oliver Nutter added a comment - The issue was that rpartition and partition were not specified as needing access to the caller's backref (reads = BACKREF, writes = BACKREF in @JRubyMethod), and as a result no scope was being set up for the caller. In this particular case, a dummy scope was being set up for the caller (for one of the other calls or constructs in the method) and DummyDynamicScope always returns nil for backref. Trivial reproduction: def foo Object "/Users/headius/projects/jruby/tmp/perfer/examples/file_stat.rb:4:in `(root)'".rpartition(/:\d+(?:$|:in )/).first end foo (Here, the access of Object triggers a dummy scope) The fix is trivial. I'm trying to set up a test case, and then I'll commit.
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Charles Oliver Nutter added a comment - 
commit ff42564963ac0d5b8b6471f23fd3441fb2db6fba
Author: Charles Oliver Nutter <headius@headius.com>
Date:   Wed Aug 22 18:42:34 2012 -0500

    Fix JRUBY-6827
    
    ClassCastException with DummyDynamicScope in String#rpartition? with -X+C
    
    String#partition and rpartition need read/write of backref.

:100644 100644 278c7ff... cf60086... M	spec/compiler/general_spec.rb
:100644 100644 48e0a15... 93d6813... M	src/org/jruby/RubyString.java
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Charles Oliver Nutter added a comment - commit ff42564963ac0d5b8b6471f23fd3441fb2db6fba Author: Charles Oliver Nutter <headius@headius.com> Date: Wed Aug 22 18:42:34 2012 -0500 Fix JRUBY-6827 ClassCastException with DummyDynamicScope in String#rpartition? with -X+C String#partition and rpartition need read/write of backref. :100644 100644 278c7ff... cf60086... M spec/compiler/general_spec.rb :100644 100644 48e0a15... 93d6813... M src/org/jruby/RubyString.java
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Benoit Daloze added a comment -

Awesome, thanks for the explanation, I'll hopefully be able to patch this myself next time I encounter something like that!

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Benoit Daloze added a comment - Awesome, thanks for the explanation, I'll hopefully be able to patch this myself next time I encounter something like that!

People

  • Assignee:
    Charles Oliver Nutter
    Reporter:
    Benoit Daloze
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