--- /dev/null
+# Copyright (c) 2006-2009 Nathan Binkert <nate@binkert.org>
+# 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 with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from ply import lex, yacc
+
+class TokenError(lex.LexError):
+ def __init__(self, msg, t):
+ super(TokenError, self).__init__(msg)
+ self.token = t
+
+class ParseError(yacc.YaccError):
+ def __init__(self, message, token=None):
+ super(ParseError, self).__init__(message)
+ self.token = token
+
+class Tokenizer(object):
+ def __init__(self, lexer, data):
+ if isinstance(data, basestring):
+ indata = [ data ]
+ elif isinstance(data, file):
+ indata = data.xreadlines()
+ else:
+ indata = data
+
+ def _input():
+ for i,line in enumerate(indata):
+ lexer.lineno = i + 1
+ lexer.input(line)
+ while True:
+ tok = lexer.token()
+ if not tok:
+ break
+ yield tok
+ self.input = _input()
+
+ def next(self):
+ return self.input.next()
+
+ def __iter__(self):
+ return self
+
+ def token(self):
+ try:
+ return self.next()
+ except StopIteration:
+ return None
+
+class Grammar(object):
+ def __init__(self, output=None, debug=False):
+ self.yacc_args = {}
+ self.yacc_args['debug'] = debug
+
+ if output:
+ import os
+
+ dir,tab = os.path.split(output)
+ if not tab.endswith('.py'):
+ raise AttributeError, 'The output file must end with .py'
+ self.yacc_args['outputdir'] = dir
+ self.yacc_args['tabmodule'] = tab[:-3]
+
+ def t_error(self, t):
+ raise lex.LexError("Illegal character %s @ %d:%d" % \
+ (`t.value[0]`, t.lineno, t.lexpos), `t.value[0]`)
+
+ def p_error(self, t):
+ if t:
+ msg = "Syntax error at %d:%d\n>>%s<<" % \
+ (t.lineno, t.lexpos + 1, t.value)
+ else:
+ msg = "Syntax error at end of input"
+ raise ParseError(msg, t)
+
+ def __getattr__(self, attr):
+ if attr == 'parser':
+ import ply.yacc
+ parser = ply.yacc.yacc(module=self, **self.yacc_args)
+ self.parser = parser
+ return parser
+
+ if attr == 'lexer':
+ import ply.lex
+ lexer = ply.lex.lex(module=self)
+ self.lexer = lexer
+ return lexer
+
+ raise AttributeError, "'%s' object has no attribute '%s'" % \
+ (self.__class__.__name__, attr)
+
+ def parse(self, stmt, **kwargs):
+ self.lexer.lineno = 1
+ result = self.parser.parse(lexer=Tokenizer(self.lexer, stmt), **kwargs)
+ self.parser.restart()
+
+ return result
+