1 files changed, 75 insertions, 0 deletions
diff --git a/tool/lib/iseq_loader_checker.rb b/tool/lib/iseq_loader_checker.rb
new file mode 100644
index 0000000000..1a1a694834
--- /dev/null
+++ b/tool/lib/iseq_loader_checker.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+begin
+  require '-test-/iseq_load/iseq_load'
+rescue LoadError
+end
+require 'tempfile'
+
+class RubyVM::InstructionSequence
+  def disasm_if_possible
+    begin
+      self.disasm
+    rescue Encoding::CompatibilityError, EncodingError, SecurityError
+      nil
+    end
+  end
+
+  def self.compare_dump_and_load i1, dumper, loader
+    dump = dumper.call(i1)
+    return i1 unless dump
+    i2 = loader.call(dump)
+
+    # compare disassembled result
+    d1 = i1.disasm_if_possible
+    d2 = i2.disasm_if_possible
+
+    if d1 != d2
+      STDERR.puts "expected:"
+      STDERR.puts d1
+      STDERR.puts "actual:"
+      STDERR.puts d2
+
+      t1 = Tempfile.new("expected"); t1.puts d1; t1.close
+      t2 = Tempfile.new("actual"); t2.puts d2; t2.close
+      system("diff -u #{t1.path} #{t2.path}") # use diff if available
+      exit(1)
+    end
+    i2
+  end
+
+  CHECK_TO_A      = ENV['RUBY_ISEQ_DUMP_DEBUG'] == 'to_a'
+  CHECK_TO_BINARY = ENV['RUBY_ISEQ_DUMP_DEBUG'] == 'to_binary'
+
+  def self.translate i1
+    # check to_a/load_iseq
+    compare_dump_and_load(i1,
+                                   proc{|iseq|
+                                     ary = iseq.to_a
+                                     ary[9] == :top ? ary : nil
+                                   },
+                                   proc{|ary|
+                                     RubyVM::InstructionSequence.iseq_load(ary)
+                                   }) if CHECK_TO_A && defined?(RubyVM::InstructionSequence.iseq_load)
+
+    # check to_binary
+    i2_bin = compare_dump_and_load(i1,
+                                   proc{|iseq|
+                                     begin
+                                       iseq.to_binary
+                                     rescue RuntimeError # not a toplevel
+                                       # STDERR.puts [:failed, $!, iseq].inspect
+                                       nil
+                                     end
+                                   },
+                                   proc{|bin|
+                                     iseq = RubyVM::InstructionSequence.load_from_binary(bin)
+                                     # STDERR.puts iseq.inspect
+                                     iseq
+                                   }) if CHECK_TO_BINARY
+    # return value
+    i2_bin if CHECK_TO_BINARY
+  end if CHECK_TO_A || CHECK_TO_BINARY
+end
+
+#require_relative 'x'; exit(1)