[ruby-core:66510] [ruby-trunk - Feature #8543] rb_iseq_load

From: normalperson@...
Date: 2014-11-27 03:08:32 UTC
List: ruby-core #66510
Issue #8543 has been updated by Eric Wong.


 Work-in-progress -v5 based on r48597:
 
   http://80x24.org/spew/m/rb_iseq_load-fix-v5@r48597.txt
 
 Still some failures, particularly around:
 
       def x(a, (b, *c), d: false); end
 
 I'm not sure if we handle ISeq#to_a correctly for "(b, *c)"
 right now...
 I might be busy with other stuff for a few days.

----------------------------------------
Feature #8543: rb_iseq_load
https://bugs.ruby-lang.org/issues/8543#change-50122

* Author: Alexey Voskov
* Status: Open
* Priority: Low
* Assignee: Koichi Sasada
* Category: YARV
* Target version: current: 2.2.0
----------------------------------------
I noticed an unusual behaviour of undocumented rb_iseq_load function. 
Its work differs in different Ruby versions. I'm trying to protect some Ruby
source code by its conversion to YARV p-code and using the next strategy:

1. Convert code to array

   ~~~ruby
   data = RubyVM::InstructionSequence.compile_file('hello.rb').to_a
   ~~~

2. Pass a compiled source to the rb_iseq_load function and evaluate it

   ~~~ruby
   iseq = iseq_load.(data)
   iseq.eval
   ~~~

Sample programs are supplied in the attachments.
"hello.rb"

```ruby
puts "tralivali"
def funct(a,b)
  a**b
end

3.times { |i|
  puts "Hello, world#{funct(2,i)}!"
}
```

The differences
Ruby 1.9.3 (ruby 1.9.3p194 (2012-04-20) [i386-mingw32])
Correct work. Output:

```
tralivali
Hello, world1!
Hello, world2!
Hello, world4!
```

Ruby 2.0.0 (ruby 2.0.0p193 (2013-05-14) [x64-mingw32])
Incorrect work (omits the code inside code blocks). Output

```
tralivali
```

Attempts of loading bigger programs by means of rb_iseq_load in Ruby 2.0.0 usually ends with a segmentation fault.

Such behaviour also can be reproduced by means of iseq Ruby extension ("for iseq freaks")
https://github.com/wanabe/iseq

P.S. I understand that it is an undocumented feature.


---Files--------------------------------
hello.rb (102 Bytes)
rb_pack.rb (931 Bytes)
iseq-load-test3.rb (210 Bytes)
iseq-load-test3-file.rb (369 Bytes)
please-fix-rb_iseq_load-thank-you.pdf (444 KB)


-- 
https://bugs.ruby-lang.org/

In This Thread