Can I enable invokedynamic in JRUBYC command

Ruby JRuby
1

Hi I’ve read from the JRuby release log here
JRuby 1.7.5 Released — JRuby.org that the invokedynamic
has been disabled since JRuby 1.7.5. However, it still can be enabled
using -Xcompile.invokedynamic=true command.

I’m currently working on a research project in which I need to produce
the java class files explicitly and analyze those invokedynamic commands
in the byte codes. I tried to use a JRuby version later than 1.7.4 and
issued the following command:

jrubyc Xcompile.invokedynamic=true myfile.rb

But I get the following error:

OptionParser::InvalidOption: invalid option:

-Xcompile.invokedynamic=true
complete at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1542
catch at org/jruby/RubyKernel.java:1282
complete at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1540
parse_in_order at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1380
catch at org/jruby/RubyKernel.java:1282
parse_in_order at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1347
order! at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1341
permute! at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1432
parse! at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:1453
compile_argv at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/shared/jruby/compiler.rb:83
initialize at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/1.9/optparse.rb:882
compile_argv at
/Users/x5lai/.rvm/rubies/jruby-1.7.5/lib/ruby/shared/jruby/compiler.rb:35
(root) at /Users/x5lai/.rvm/rubies/jruby-1.7.5/bin/jrubyc:5

Is it that this command flag is only present for the ‘jruby’ command and
not the ‘jrubyc’ command? Is there an equivalent parameter in jrubyc
command that I could turn on the invokedynamic in the byte codes
produced?

2

I can’t answer your jrubyc question, but have you tried
-Xcompile.dump=true
with jruby rather than jrubyc? I can see the indy instructions when I
use
this.

This lets you see the byte code generated. It’s not in a class file, but
if
you really want a file on disk for some reason you could probably write
the
generated code to disk instead of passing it to a class loader when
JRuby
compiles it.

Chris

3

Thank you for your reply. But the output looks more like a dynamic call
sequence, which is not what I’m looking for–byte codes that are
generated statically.

Nevertheless, my teacher has found a way to deal with this issue so I
post his solution here in case anyone else is looking for similar
solution:

export JRUBY_OPTS=-Xcompile.invokedynamic=true

Chris S. wrote in post #1154612:

I can’t answer your jrubyc question, but have you tried
-Xcompile.dump=true
with jruby rather than jrubyc? I can see the indy instructions when I
use
this.

This lets you see the byte code generated. It’s not in a class file, but
if
you really want a file on disk for some reason you could probably write
the
generated code to disk instead of passing it to a class loader when
JRuby
compiles it.

Chris