grammar.py revision 13670:8a98db5a481f
1# Copyright (c) 2006-2011 Nathan Binkert <nate@binkert.org> 2# All rights reserved. 3# 4# Redistribution and use in source and binary forms, with or without 5# modification, are permitted provided that the following conditions are 6# met: redistributions of source code must retain the above copyright 7# notice, this list of conditions and the following disclaimer; 8# redistributions in binary form must reproduce the above copyright 9# notice, this list of conditions and the following disclaimer in the 10# documentation and/or other materials provided with the distribution; 11# neither the name of the copyright holders nor the names of its 12# contributors may be used to endorse or promote products derived from 13# this software without specific prior written permission. 14# 15# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 27import os 28 29import ply.lex 30import ply.yacc 31 32class ParseError(Exception): 33 def __init__(self, message, token=None): 34 Exception.__init__(self, message) 35 self.token = token 36 37class Grammar(object): 38 def setupLexerFactory(self, **kwargs): 39 if 'module' in kwargs: 40 raise AttributeError("module is an illegal attribute") 41 self.lex_kwargs = kwargs 42 43 def setupParserFactory(self, **kwargs): 44 if 'module' in kwargs: 45 raise AttributeError("module is an illegal attribute") 46 47 if 'output' in kwargs: 48 dir,tab = os.path.split(output) 49 if not tab.endswith('.py'): 50 raise AttributeError('The output file must end with .py') 51 kwargs['outputdir'] = dir 52 kwargs['tabmodule'] = tab[:-3] 53 54 self.yacc_kwargs = kwargs 55 56 def __getattr__(self, attr): 57 if attr == 'lexers': 58 self.lexers = [] 59 return self.lexers 60 61 if attr == 'lex_kwargs': 62 self.setupLexerFactory() 63 return self.lex_kwargs 64 65 if attr == 'yacc_kwargs': 66 self.setupParserFactory() 67 return self.yacc_kwargs 68 69 if attr == 'lex': 70 self.lex = ply.lex.lex(module=self, **self.lex_kwargs) 71 return self.lex 72 73 if attr == 'yacc': 74 self.yacc = ply.yacc.yacc(module=self, **self.yacc_kwargs) 75 return self.yacc 76 77 if attr == 'current_lexer': 78 if not self.lexers: 79 return None 80 return self.lexers[-1][0] 81 82 if attr == 'current_source': 83 if not self.lexers: 84 return '<none>' 85 return self.lexers[-1][1] 86 87 if attr == 'current_line': 88 if not self.lexers: 89 return -1 90 return self.current_lexer.lineno 91 92 raise AttributeError( 93 "'%s' object has no attribute '%s'" % (type(self), attr)) 94 95 def parse_string(self, data, source='<string>', debug=None, tracking=0): 96 if not isinstance(data, basestring): 97 raise AttributeError( 98 "argument must be a string, was '%s'" % type(f)) 99 100 import new 101 lexer = self.lex.clone() 102 lexer.input(data) 103 self.lexers.append((lexer, source)) 104 dict = { 105 'productions' : self.yacc.productions, 106 'action' : self.yacc.action, 107 'goto' : self.yacc.goto, 108 'errorfunc' : self.yacc.errorfunc, 109 } 110 parser = new.instance(ply.yacc.LRParser, dict) 111 result = parser.parse(lexer=lexer, debug=debug, tracking=tracking) 112 self.lexers.pop() 113 return result 114 115 def parse_file(self, f, **kwargs): 116 if isinstance(f, basestring): 117 source = f 118 f = open(f, 'r') 119 elif isinstance(f, file): 120 source = f.name 121 else: 122 raise AttributeError( 123 "argument must be either a string or file, was '%s'" % type(f)) 124 125 return self.parse_string(f.read(), source, **kwargs) 126 127 def p_error(self, t): 128 if t: 129 msg = "Syntax error at %s:%d:%d\n>>%s<<" % \ 130 (self.current_source, t.lineno, t.lexpos + 1, t.value) 131 else: 132 msg = "Syntax error at end of %s" % (self.current_source, ) 133 raise ParseError(msg, t) 134 135 def t_error(self, t): 136 msg = "Illegal character %s @ %d:%d" % \ 137 (`t.value[0]`, t.lineno, t.lexpos) 138 raise ParseError(msg, t) 139