disasm.rb

x = RubyVM::InstructionSequence.new(%q{
class Foo
  def hello
    "hello"
  end
end

f = Foo.new
f.hello()
})

puts x.disasm

foo.disasm

== disasm: <RubyVM::InstructionSequence:<compiled>@<compiled>>==========
local table (size: 2, argc: 0 [opts: 0, rest: -1, post: 0, block: -1, keyword: 0@3] s1)
[ 2] f          
0000 trace            1                                               (   2)
0002 putspecialobject 3
0004 putnil           
0005 defineclass      :Foo, <class:Foo>, 0
0009 pop              
0010 trace            1                                               (   8)
0012 getinlinecache   19, <is:0>
0015 getconstant      :Foo
0017 setinlinecache   <is:0>
0019 opt_send_simple  <callinfo!mid:new, argc:0, ARGS_SKIP>
0021 setlocal_OP__WC__0 2
0023 trace            1                                               (   9)
0025 getlocal_OP__WC__0 2
0027 opt_send_simple  <callinfo!mid:hello, argc:0, ARGS_SKIP>
0029 leave            
== disasm: <RubyVM::InstructionSequence:<class:Foo>@<compiled>>=========
0000 trace            2                                               (   2)
0002 trace            1                                               (   3)
0004 putspecialobject 1
0006 putspecialobject 2
0008 putobject        :hello
0010 putiseq          hello
0012 opt_send_simple  <callinfo!mid:core#define_method, argc:3, ARGS_SKIP>
0014 trace            4                                               (   6)
0016 leave                                                            (   3)
== disasm: <RubyVM::InstructionSequence:hello@<compiled>>===============
0000 trace            8                                               (   3)
0002 trace            1                                               (   4)
0004 putstring        "hello"
0006 trace            16                                              (   5)
0008 leave                                                            (   4)

foo.rb

class Foo
  def hello
    "hello"
  end
end

f = Foo.new
f.hello()