1 files changed, 44 insertions, 0 deletions
diff --git a/tool/ruby_vm/models/c_expr.rb b/tool/ruby_vm/models/c_expr.rb
new file mode 100644
index 0000000000..095ff4f1d9
--- /dev/null
+++ b/tool/ruby_vm/models/c_expr.rb
@@ -0,0 +1,44 @@
+# -*- Ruby -*-
+# -*- frozen_string_literal: true; -*-
+# -*- warn_indent: true; -*-
+#
+# Copyright (c) 2017 Urabe, Shyouhei.  All rights reserved.
+#
+# This file is  a part of the programming language  Ruby.  Permission is hereby
+# granted, to  either redistribute and/or  modify this file, provided  that the
+# conditions  mentioned in  the file  COPYING are  met.  Consult  the file  for
+# details.
+
+require_relative '../helpers/c_escape.rb'
+
+class RubyVM::CExpr
+  include RubyVM::CEscape
+
+  attr_reader :__FILE__, :__LINE__, :expr
+
+  def initialize opts = {}
+    @__FILE__  = opts[:location][0]
+    @__LINE__  = opts[:location][1]
+    @expr      = opts[:expr]
+  end
+
+  # blank, in sense of C program.
+  RE = %r'\A{\g<s>*}\z|\A(?<s>\s|/[*][^*]*[*]+([^*/][^*]*[*]+)*/)*\z'
+  if RUBY_VERSION > '2.4' then
+    def blank?
+      RE.match? @expr
+    end
+  else
+    def blank?
+      RE =~ @expr
+    end
+  end
+
+  def inspect
+    if @__LINE__
+      sprintf "#<%s:%d %s>", @__FILE__, @__LINE__, @expr
+    else
+      sprintf "#<%s %s>", @__FILE__, @expr
+    end
+  end
+end