1 files changed, 54 insertions, 40 deletions

diff --git a/ext/ripper/tools/preproc.rb b/ext/ripper/tools/preproc.rb
index b838a78db7..a54302fb91 100644
--- a/ext/ripper/tools/preproc.rb
+++ b/ext/ripper/tools/preproc.rb
@@ -5,11 +5,15 @@ require 'optparse'
 
 def main
   output = nil
+  template = nil
   parser = OptionParser.new
-  parser.banner = "Usage: #{File.basename($0)} [--output=PATH] <parse.y>"
+  parser.banner = "Usage: #{File.basename($0)} [--output=PATH] [--template=PATH] <parse.y>"
   parser.on('--output=PATH', 'An output file.') {|path|
     output = path
   }
+  parser.on('--template=PATH', 'An template file.') {|path|
+    template = path
+  }
   parser.on('--help', 'Prints this message and quit.') {
     puts parser.help
     exit true
@@ -17,59 +21,56 @@ def main
   begin
     parser.parse!
   rescue OptionParser::ParseError => err
-    $stderr.puts err.message
-    $stderr.puts parser.help
-    exit false
-  end
-  unless ARGV.size == 1
-    abort "wrong number of arguments (#{ARGV.size} for 1)"
+    warn err.message
+    abort parser.help
   end
   out = "".dup
-  File.open(ARGV[0]) {|f|
-    prelude f, out
-    grammar f, out
-    usercode f, out
-  }
-  if output
-    File.open(output, 'w') {|f|
-      f.write out
+  if ARGV[0] == "-"
+    unless ARGV.size == 2
+      abort "wrong number of arguments (#{ARGV.size} for 2)"
+    end
+    process STDIN, out, ARGV[1], template
+  else
+    unless ARGV.size == 1
+      abort "wrong number of arguments (#{ARGV.size} for 1)"
+    end
+    File.open(ARGV[0]) {|f|
+      process f, out, ARGV[0], template
     }
+  end
+  if output
+    File.write(output, out)
   else
     print out
   end
 end
 
+def process(f, out, path, template)
+  prelude f, out
+  grammar f, out
+  usercode f, out, path, template
+end
+
 def prelude(f, out)
   @exprs = {}
-  lex_state_def = false
   while line = f.gets
     case line
     when /\A%%/
       out << "%%\n"
       return
-    when /\A%token/
-      out << line.sub(/<\w+>/, '<val>')
-    when /\A%type/
-      out << line.sub(/<\w+>/, '<val>')
-    when /^enum lex_state_(?:bits|e) \{/
-      lex_state_def = true
-      out << line
-    when /^\}/
-      lex_state_def = false
-      out << line
     else
-      out << line
-    end
-    if lex_state_def
-      case line
-      when /^\s*(EXPR_\w+),\s+\/\*(.+)\*\//
-        @exprs[$1.chomp("_bit")] = $2.strip
-      when /^\s*(EXPR_\w+)\s+=\s+(.+)$/
-        name = $1
-        val = $2.chomp(",")
-        @exprs[name] = "equals to " + (val.start_with?("(") ? "<tt>#{val}</tt>" : "+#{val}+")
+      if (/^enum lex_state_(?:bits|e) \{/ =~ line)..(/^\}/ =~ line)
+        case line
+        when /^\s*(EXPR_\w+),\s+\/\*(.+)\*\//
+          @exprs[$1.chomp("_bit")] = $2.strip
+        when /^\s*(EXPR_\w+)\s+=\s+(.+)$/
+          name = $1
+          val = $2.chomp(",")
+          @exprs[name] = "equals to " + (val.start_with?("(") ? "<tt>#{val}</tt>" : "+#{val}+")
+        end
       end
     end
+    out << line
   end
 end
 
@@ -95,13 +96,26 @@ def grammar(f, out)
   end
 end
 
-def usercode(f, out)
+def usercode(f, out, path, template)
   require 'erb'
+  lineno = nil
+  src = nil
   compiler = ERB::Compiler.new('%-')
   compiler.put_cmd = compiler.insert_cmd = "out.<<"
-  lineno = f.lineno
-  src, = compiler.compile(f.read)
-  eval(src, binding, f.path, lineno)
+
+  if template
+    File.open(template) do |f|
+      out.clear
+      lineno = f.lineno
+      src, = compiler.compile(f.read)
+      path = template
+    end
+  else
+    lineno = f.lineno
+    src, = compiler.compile(f.read)
+  end
+
+  eval(src, binding, path, lineno)
 end
 
 main