src/python/m5/util/grammar.py

   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
  27 import os
  28
  29 import ply.lex
  30 import ply.yacc
  31
  32 class ParseError(Exception):
  33     def __init__(self, message, token=None):
  34         Exception.__init__(self, message)
  35         self.token = token
  36
  37 class 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, \
  51                     'The output file must end with .py'
  52             kwargs['outputdir'] = dir
  53             kwargs['tabmodule'] = tab[:-3]
  54
  55         self.yacc_kwargs = kwargs
  56
  57     def __getattr__(self, attr):
  58         if attr == 'lexers':
  59             self.lexers = []
  60             return self.lexers
  61
  62         if attr == 'lex_kwargs':
  63             self.setupLexerFactory()
  64             return self.lex_kwargs
  65
  66         if attr == 'yacc_kwargs':
  67             self.setupParserFactory()
  68             return self.yacc_kwargs
  69
  70         if attr == 'lex':
  71             self.lex = ply.lex.lex(module=self, **self.lex_kwargs)
  72             return self.lex
  73
  74         if attr == 'yacc':
  75             self.yacc = ply.yacc.yacc(module=self, **self.yacc_kwargs)
  76             return self.yacc
  77
  78         if attr == 'current_lexer':
  79             if not self.lexers:
  80                 return None
  81             return self.lexers[-1][0]
  82
  83         if attr == 'current_source':
  84             if not self.lexers:
  85                 return '<none>'
  86             return self.lexers[-1][1]
  87
  88         if attr == 'current_line':
  89             if not self.lexers:
  90                 return -1
  91             return self.current_lexer.lineno
  92
  93         raise AttributeError, \
  94             "'%s' object has no attribute '%s'" % (type(self), attr)
  95
  96     def parse_string(self, data, source='<string>', debug=None, tracking=0):
  97         if not isinstance(data, basestring):
  98             raise AttributeError, \
  99                 "argument must be a string, was '%s'" % type(f)
 100
 101         import new
 102         lexer = self.lex.clone()
 103         lexer.input(data)
 104         self.lexers.append((lexer, source))
 105         dict = {
 106             'productions' : self.yacc.productions,
 107             'action'      : self.yacc.action,
 108             'goto'        : self.yacc.goto,
 109             'errorfunc'   : self.yacc.errorfunc,
 110             }
 111         parser = new.instance(ply.yacc.LRParser, dict)
 112         result = parser.parse(lexer=lexer, debug=debug, tracking=tracking)
 113         self.lexers.pop()
 114         return result
 115
 116     def parse_file(self, f, **kwargs):
 117         if isinstance(f, basestring):
 118             source = f
 119             f = file(f, 'r')
 120         elif isinstance(f, file):
 121             source = f.name
 122         else:
 123             raise AttributeError, \
 124                 "argument must be either a string or file, was '%s'" % type(f)
 125
 126         return self.parse_string(f.read(), source, **kwargs)
 127
 128     def p_error(self, t):
 129         if t:
 130             msg = "Syntax error at %s:%d:%d\n>>%s<<" % \
 131                   (self.current_source, t.lineno, t.lexpos + 1, t.value)
 132         else:
 133             msg = "Syntax error at end of %s" % (self.current_source, )
 134         raise ParseError(msg, t)
 135
 136     def t_error(self, t):
 137         msg = "Illegal character %s @ %d:%d" % \
 138             (`t.value[0]`, t.lineno, t.lexpos)
 139         raise ParseError(msg, t)