.diff

diff --git a/spec/compiler/general_spec.rb b/spec/compiler/general_spec.rb
index 8fd1ec296d..26aa511bf1 100644
--- a/spec/compiler/general_spec.rb
+++ b/spec/compiler/general_spec.rb
@@ -26,6 +26,65 @@ module InterpreterSpecUtils
   def self.name; "interpreter"; end
 end
 
+module PersistenceSpecUtils
+  include CompilerSpecUtils
+
+  def run_in_method(src, filename = caller_locations[0].path, line = caller_locations[0].lineno)
+    run( "def __temp; #{src}; end; __temp", filename, line)
+  end
+
+  def run(src, filename = caller_locations[0].path, line = caller_locations[0].lineno)
+    yield encode_decode_run(src, filename, line) unless (ENV['PERSISTENCE_TEST'] == 'false')
+  end
+
+  def self.name; "persistence"; end
+
+  private
+
+  def encode_decode(src, filename, line)
+    node = JRuby.parse(src, filename, false, line)
+    runtime = JRuby.runtime
+
+    # This logic is a mix of logic from InterpretedIRMethod's JIT, o.j.Ruby's script compilation, and IRScriptBody's
+    # interpret. We need to figure out a cleaner path.
+
+    scope = node.getStaticScope
+    currModule = scope.getModule
+    if currModule == nil
+      scope.setModule currModule = runtime.top_self.class
+    end
+
+    manager = runtime.getIRManager()
+    method = org.jruby.ir.IRBuilder.build_root(manager, node).scope
+
+    # encode and decode
+    baos = java.io.ByteArrayOutputStream.new
+    writer = org.jruby.ir.persistence.IRWriterStream.new(baos)
+    org.jruby.ir.persistence.IRWriter.persist(writer, method)
+
+    bais = java.io.ByteArrayInputStream.new(baos.to_byte_array)
+    reader = org.jruby.ir.persistence.IRReaderStream.new(manager, bais, org.jruby.util.ByteList.new(filename.to_java.getBytes))
+    method = org.jruby.ir.persistence.IRReader.load(manager, reader)
+
+    return org.jruby.internal.runtime.methods.InterpretedIRMethod.new(
+        method,
+        org.jruby.runtime.Visibility::PUBLIC,
+        currModule)
+  end
+
+  def encode_decode_run(src, filename, line)
+    cls = encode_decode(src, filename, line - 1) # compiler expects zero-based lines
+
+    cls.call(
+        JRuby.runtime.current_context,
+        JRuby.runtime.top_self,
+        JRuby.runtime.top_self.class,
+        "script",
+        IRubyObject[0].new,
+        Block::NULL_BLOCK)
+  end
+end
+
 module JITSpecUtils
   include CompilerSpecUtils
 
@@ -91,6 +150,7 @@ end
 
 modes = []
 modes << InterpreterSpecUtils unless (ENV['INTERPRETER_TEST'] == 'false')
+modes << PersistenceSpecUtils unless (ENV['PERSISTENCE_TEST'] == 'false')
 modes << JITSpecUtils unless (ENV['COMPILER_TEST'] == 'false')
 
 Block = org.jruby.runtime.Block