Experimental parser: fixup unit tests

tools/lexer_generator/rule_parser.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 161 matching lines @@
     '''code_fragments : CODE_FRAGMENT code_fragments
                       | empty'''
     p[0] = p[1]
     if len(p) == 3 and p[2]:
       p[0] = p[1] + p[2]
 
   def p_empty(self, p):
     'empty :'
 
   def p_error(self, p):
-    raise Exception("Syntax error in input '%s'" % p)
+    raise Exception("Syntax error in input '%s'" % str(p))
 
   def build(self, **kwargs):
     self.parser = yacc.yacc(module=self, debug=0, write_tables=0, **kwargs)
     self.lexer = RuleLexer()
     self.lexer.build(**kwargs)
 
   __static_instance = None
   @staticmethod
   def parse(data, parser_state):
-    if not RuleParser.__static_instance:
-      RuleParser.__static_instance = RuleParser()
-      RuleParser.__static_instance.build()
     parser = RuleParser.__static_instance
+    if not parser:
+      parser = RuleParser()
+      parser.build()
+      RuleParser.__static_instance = parser
     parser.__state = parser_state
-    parser.parser.parse(data, lexer=parser.lexer.lexer)
+    try:
+      parser.parser.parse(data, lexer=parser.lexer.lexer)
+    except Exception as e:
+      RuleParser.__static_instance = None
+      raise e
     parser.__state = None