Experimental lexer generator: default action fix.

tools/lexer_generator/code_generator.py

 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 71 matching lines @@
 
     for key, s in state.transitions().items():
       code += CodeGenerator.key_to_code(key)
       code += ''' {
         goto code_%s;
     }
 ''' % s.node_number()
 
     if action:
       code += '%s\nBACK();\ngoto code_%s;\n' % (action.data(),
-                                                             start_node_number)
+                                                start_node_number)
     else:
       code += 'goto default_action;'
     return code
 
   @staticmethod
   def rule_processor_to_code(rule_processor):
     dfa = rule_processor.default_automata().dfa()
     start_node_number = dfa.start_state().node_number()
     code = '''
 #include "lexer/even-more-experimental-scanner.h"
 
 namespace v8 {
 namespace internal {
 uint32_t EvenMoreExperimentalScanner::DoLex() {
   YYCTYPE yych = *cursor_;
   goto code_%s;
 ''' % start_node_number
     def f(state, code):
       code += CodeGenerator.dfa_state_to_code(state, start_node_number)
       return code
     code = dfa.visit_all_states(f, code)
     code += '''
   CHECK(false);
 default_action:
   //fprintf(stderr, "default action\\n");
   %s
-  BACK();
   goto code_%s;
   return 0;
 }
 
 }
 }
 ''' % (rule_processor.default_action, start_node_number)
     return code