grammar: better encapsulation of a grammar and parsing
This makes it possible to use the grammar multiple times and use the multiple
instances concurrently. This makes implementing an include statement as part
of a grammar possible.
diff --git a/src/python/m5/util/grammar.py b/src/python/m5/util/grammar.py
index ab5f358..07702cf 100644
--- a/src/python/m5/util/grammar.py
+++ b/src/python/m5/util/grammar.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2006-2009 Nathan Binkert <nate@binkert.org>
+# Copyright (c) 2006-2011 Nathan Binkert <nate@binkert.org>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
@@ -24,100 +24,116 @@
# (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
+import os
-class TokenError(lex.LexError):
- def __init__(self, msg, t):
- super(TokenError, self).__init__(msg)
- self.token = t
+import ply.lex
+import ply.yacc
-class ParseError(yacc.YaccError):
+class ParseError(Exception):
def __init__(self, message, token=None):
- super(ParseError, self).__init__(message)
+ Exception.__init__(self, 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()
- self.lexer = lexer
-
- def next(self):
- return self.input.next()
-
- def __iter__(self):
- return self
-
- def token(self):
- try:
- return self.next()
- except StopIteration:
- return None
-
- def __getattr__(self, attr):
- return getattr(self.lexer, attr)
-
class Grammar(object):
- def __init__(self, output=None, debug=False):
- self.yacc_args = {}
- self.yacc_args['debug'] = debug
+ def setupLexerFactory(self, **kwargs):
+ if 'module' in kwargs:
+ raise AttributeError, "module is an illegal attribute"
+ self.lex_kwargs = kwargs
- if output:
- import os
+ def setupParserFactory(self, **kwargs):
+ if 'module' in kwargs:
+ raise AttributeError, "module is an illegal attribute"
+ if 'output' in kwargs:
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]
+ raise AttributeError, \
+ 'The output file must end with .py'
+ kwargs['outputdir'] = dir
+ kwargs['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]`)
+ self.yacc_kwargs = kwargs
+
+ def __getattr__(self, attr):
+ if attr == 'lexers':
+ self.lexers = []
+ return self.lexers
+
+ if attr == 'lex_kwargs':
+ self.setupLexerFactory()
+ return self.lex_kwargs
+
+ if attr == 'yacc_kwargs':
+ self.setupParserFactory()
+ return self.yacc_kwargs
+
+ if attr == 'lex':
+ self.lex = ply.lex.lex(module=self, **self.lex_kwargs)
+ return self.lex
+
+ if attr == 'yacc':
+ self.yacc = ply.yacc.yacc(module=self, **self.yacc_kwargs)
+ return self.yacc
+
+ if attr == 'current_lexer':
+ if not self.lexers:
+ return None
+ return self.lexers[-1][0]
+
+ if attr == 'current_source':
+ if not self.lexers:
+ return '<none>'
+ return self.lexers[-1][1]
+
+ if attr == 'current_line':
+ if not self.lexers:
+ return -1
+ return self.current_lexer.lineno
+
+ raise AttributeError, \
+ "'%s' object has no attribute '%s'" % (type(self), attr)
+
+ def parse_string(self, data, source='<string>', debug=None, tracking=0):
+ if not isinstance(data, basestring):
+ raise AttributeError, \
+ "argument must be a string, was '%s'" % type(f)
+
+ import new
+ lexer = self.lex.clone()
+ lexer.input(data)
+ self.lexers.append((lexer, source))
+ dict = {
+ 'productions' : self.yacc.productions,
+ 'action' : self.yacc.action,
+ 'goto' : self.yacc.goto,
+ 'errorfunc' : self.yacc.errorfunc,
+ }
+ parser = new.instance(ply.yacc.LRParser, dict)
+ result = parser.parse(lexer=lexer, debug=debug, tracking=tracking)
+ self.lexers.pop()
+ return result
+
+ def parse_file(self, f, **kwargs):
+ if isinstance(f, basestring):
+ source = f
+ f = file(f, 'r')
+ elif isinstance(f, file):
+ source = f.name
+ else:
+ raise AttributeError, \
+ "argument must be either a string or file, was '%s'" % type(f)
+
+ return self.parse_string(f.read(), source, **kwargs)
def p_error(self, t):
if t:
- msg = "Syntax error at %d:%d\n>>%s<<" % \
- (t.lineno, t.lexpos + 1, t.value)
+ msg = "Syntax error at %s:%d:%d\n>>%s<<" % \
+ (self.current_source, t.lineno, t.lexpos + 1, t.value)
else:
- msg = "Syntax error at end of input"
+ msg = "Syntax error at end of %s" % (self.current_source, )
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
-
+ def t_error(self, t):
+ msg = "Illegal character %s @ %d:%d" % \
+ (`t.value[0]`, t.lineno, t.lexpos)
+ raise ParseError(msg, t)
