lib/treetop/compiler/grammar_compiler.rb in treetop-1.4.12 vs lib/treetop/compiler/grammar_compiler.rb in treetop-1.4.14

@@ -2,11 +2,16 @@
   module Compiler
     AUTOGENERATED = "# Autogenerated from a Treetop grammar. Edits may be lost.\n"
     class GrammarCompiler
       def compile(source_path, target_path = source_path.gsub(/\.(treetop|tt)\Z/, '.rb'))
         File.open(target_path, 'w') do |target_file|
-          target_file.write(AUTOGENERATED+"\n\n")
-          target_file.write(ruby_source(source_path))
+          ruby = ruby_source(source_path)
+          if ruby =~ /\A#.*\n/
+            ruby.sub!(/\n/, "\n"+AUTOGENERATED+"\n\n")
+          else
+            ruby = AUTOGENERATED+"\n\n"+ruby
+          end
+          target_file.write(ruby)
         end
       end
 
       # compile a treetop file into ruby
       def ruby_source(source_path)