Running ruby1.9 bytecode

Ruby
1

Hi all,

I just found out about the VM::InstructionSequence.compile method for
turning Ruby code strings into ruby1.9 bytecode. Is there a standard
method
of de/serializing this bytecode to/from files, and is there a way of
running
bytecode directly? I’m looking at generating bytecode from another
language
to get it to run on Ruby.

2

Originally posted to Ruby T., trying my luck here to see if it gets a
response:

---------- Forwarded message ----------
From: James C. [email protected]
Date: 2009/4/6
Subject: Running ruby1.9 bytecode
To: ruby-talk ML [email protected]

Hi all,

I just found out about the VM::InstructionSequence.compile method for
turning Ruby code strings into ruby1.9 bytecode. Is there a standard
method
of de/serializing this bytecode to/from files, and is there a way of
running
bytecode directly? I’m looking at generating bytecode from another
language
to get it to run on Ruby.

3

On Mon, Apr 6, 2009 at 2:48 PM, James C. [email protected]
wrote:

Hi all,

I just found out about the VM::InstructionSequence.compile method for
turning Ruby code strings into ruby1.9 bytecode. Is there a standard method
of de/serializing this bytecode to/from files, and is there a way of running
bytecode directly? I’m looking at generating bytecode from another language
to get it to run on Ruby.
Quoting from the Pickaxe book
no, because the bytecode verifier is not ready yet, that seems the
only missing bit.
HTH
Robert

4

Well that’s part of it. But, if by “generating bytecode from another
language” means, for instance, executing JVM bytecodes, I don’t think it
will fly. The term bytecode here is being used rather generically. The YARV
“bytecodes” aren’t the same as the JVM bytecodes, any more than
Smalltalk-80
bytecodes are the same as either…

Getting another language to produce YARV bytecodes would be an exercise for
the reader.

I meant that I’d like to try and generate YARV bytecode from non-Ruby
source. Mostly a pie-in-the-sky idea, only just writing my first
AST-walking
interpreter, just wondering if it’s possible.

5

James C. wrote:

I meant that I’d like to try and generate YARV bytecode from non-Ruby
source. Mostly a pie-in-the-sky idea, only just writing my first AST-walking
interpreter, just wondering if it’s possible.

It’s definitely possible. I suggest you take a look at the parrot
interpreter. It is a one-for-all interpreter (well, that’s the aim,
anyway), which began life as an April Fool’s joke that someone took one
step further. It officially hit version 1.0 the other day, so it should
be a good example for you. By one-for-all I mean, it’s a generic
interpreter that can handle many languages, much like .NET and the clr,
I guess.

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6

On Mon, Apr 6, 2009 at 3:27 PM, Robert D. [email protected]
wrote:

language

to get it to run on Ruby.
Quoting from the Pickaxe book
no, because the bytecode verifier is not ready yet, that seems the
only missing bit.
HTH
Robert

Well that’s part of it. But, if by “generating bytecode from another
language” means, for instance, executing JVM bytecodes, I don’t think it
will fly. The term bytecode here is being used rather generically. The
YARV
“bytecodes” aren’t the same as the JVM bytecodes, any more than
Smalltalk-80
bytecodes are the same as either.

It’s like the difference between an Intel and Motorola processor, both
have
instruction sets with binary representations, but those instruction sets
aren’t necessarily interchangeable.

Getting another language to produce YARV bytecodes would be an exercise
for
the reader.

Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Twitter: http://twitter.com/RickDeNatale
WWR: http://www.workingwithrails.com/person/9021-rick-denatale
LinkedIn: http://www.linkedin.com/in/rickdenatale

7

On Mon, Apr 6, 2009 at 11:03 PM, James C. [email protected]
wrote:

I meant that I’d like to try and generate YARV bytecode from non-Ruby
source. Mostly a pie-in-the-sky idea, only just writing my first AST-walking
interpreter, just wondering if it’s possible.
Having YARV/Rubinius as a backend for other languages is certainly a
very reasonable idea.
And if I understood correctly it is planned to be possible in the
(near?) future.

Cheers
R.

8

Hi James,

I just found out about the VM::InstructionSequence.compile method for
turning Ruby code strings into ruby1.9 bytecode. Is there a standard method
of de/serializing this bytecode to/from files, and is there a way of running
bytecode directly? I’m looking at generating bytecode from another language
to get it to run on Ruby.

You can at least load bytecode directly, transform ruby to bytecode and
at
the end evaluate everything:

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iseqFromCode = RubyVM::InstructionSequence.new “a = 1; a += a; puts a”

=> <RubyVM::InstructionSequence:@>

iseqFromCode.eval

2

=> nil

iseqRawArr = iseqFromCode.to_a

=> [“YARVInstructionSequence/SimpleDataFormat”, 1, 1, 1,

{:arg_size=>0, :local_size=>2, :stack_max=>2}, “”,

“”, :top, [:a], 0, [], [1, [:trace, 1],

[:putobject, 1], [:setlocal, 2], [:trace, 1], [:getlocal, 2],

[:getlocal, 2], [:opt_plus], [:setlocal, 2], [:trace, 1],

[:putnil], [:getlocal, 2], [:send, :puts, 1, nil, 8, nil],

[:leave]]]

iseqRawArr.class

=> Array

iseqFromArr = RubyVM::InstructionSequence.load iseqRawArr

=> <RubyVM::InstructionSequence:@>

iseqFromArr.eval

2

=> nil

But for this you have to apply this to the source code:

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boviAir:src danielbovensiepen$ svn diff iseq.c
Index: iseq.c

— iseq.c (revision 21348)
+++ iseq.c (working copy)
@@ -1451,7 +1451,7 @@
rb_define_method(rb_cISeq, “eval”, iseq_eval, 0);

 /* disable this feature because there is no verifier. */
  • /* rb_define_singleton_method(rb_cISeq, “load”, iseq_s_load, -1);
    */

  • rb_define_singleton_method(rb_cISeq, “load”, iseq_s_load, -1);
    (void)iseq_s_load;

    rb_define_singleton_method(rb_cISeq, “compile”, iseq_s_compile,
    -1);
    boviAir:src danielbovensiepen$

Of course, the comments are very clear: you shouldn’t do this!

MfG
Daniel