From d3e377a520d6ad5997f2ef7c8fc1b823d6d0e7f2 Mon Sep 17 00:00:00 2001 From: "Ronald G. Minnich" Date: Sat, 14 Jun 2003 15:07:02 +0000 Subject: new config tool git-svn-id: svn://svn.coreboot.org/coreboot/trunk@878 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- util/newconfig/yappsrt.py | 172 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 util/newconfig/yappsrt.py (limited to 'util/newconfig/yappsrt.py') diff --git a/util/newconfig/yappsrt.py b/util/newconfig/yappsrt.py new file mode 100644 index 0000000000..2ce2480f08 --- /dev/null +++ b/util/newconfig/yappsrt.py @@ -0,0 +1,172 @@ +# Yapps 2.0 Runtime +# +# This module is needed to run generated parsers. + +from string import * +import exceptions +import re + +class SyntaxError(Exception): + """When we run into an unexpected token, this is the exception to use""" + def __init__(self, pos=-1, msg="Bad Token"): + self.pos = pos + self.msg = msg + def __repr__(self): + if self.pos < 0: return "#" + else: return "SyntaxError[@ char " + `self.pos` + ": " + self.msg + "]" + +class NoMoreTokens(Exception): + """Another exception object, for when we run out of tokens""" + pass + +class Scanner: + def __init__(self, patterns, ignore, input): + """Patterns is [(terminal,regex)...] + Ignore is [terminal,...]; + Input is a string""" + self.tokens = [] + self.restrictions = [] + self.input = input + self.pos = 0 + self.ignore = ignore + # The stored patterns are a pair (compiled regex,source + # regex). If the patterns variable passed in to the + # constructor is None, we assume that the class already has a + # proper .patterns list constructed + if patterns is not None: + self.patterns = [] + for k,r in patterns: + self.patterns.append( (k, re.compile(r)) ) + + def token(self, i, restrict=0): + """Get the i'th token, and if i is one past the end, then scan + for another token; restrict is a list of tokens that + are allowed, or 0 for any token.""" + if i == len(self.tokens): self.scan(restrict) + if i < len(self.tokens): + # Make sure the restriction is more restricted + if restrict and self.restrictions[i]: + for r in restrict: + if r not in self.restrictions[i]: + raise "Unimplemented: restriction set changed" + return self.tokens[i] + raise NoMoreTokens() + + def __repr__(self): + """Print the last 10 tokens that have been scanned in""" + output = '' + for t in self.tokens[-10:]: + output = '%s\n (@%s) %s = %s' % (output,t[0],t[2],`t[3]`) + return output + + def scan(self, restrict): + """Should scan another token and add it to the list, self.tokens, + and add the restriction to self.restrictions""" + # Keep looking for a token, ignoring any in self.ignore + while 1: + # Search the patterns for the longest match, with earlier + # tokens in the list having preference + best_match = -1 + best_pat = '(error)' + for p, regexp in self.patterns: + # First check to see if we're ignoring this token + if restrict and p not in restrict and p not in self.ignore: + continue + m = regexp.match(self.input, self.pos) + if m and len(m.group(0)) > best_match: + # We got a match that's better than the previous one + best_pat = p + best_match = len(m.group(0)) + + # If we didn't find anything, raise an error + if best_pat == '(error)' and best_match < 0: + msg = "Bad Token" + if restrict: + msg = "Trying to find one of "+join(restrict,", ") + raise SyntaxError(self.pos, msg) + + # If we found something that isn't to be ignored, return it + if best_pat not in self.ignore: + # Create a token with this data + token = (self.pos, self.pos+best_match, best_pat, + self.input[self.pos:self.pos+best_match]) + self.pos = self.pos + best_match + # Only add this token if it's not in the list + # (to prevent looping) + if not self.tokens or token != self.tokens[-1]: + self.tokens.append(token) + self.restrictions.append(restrict) + return + else: + # This token should be ignored .. + self.pos = self.pos + best_match + +class Parser: + def __init__(self, scanner): + self._scanner = scanner + self._pos = 0 + + def _peek(self, *types): + """Returns the token type for lookahead; if there are any args + then the list of args is the set of token types to allow""" + tok = self._scanner.token(self._pos, types) + return tok[2] + + def _scan(self, type): + """Returns the matched text, and moves to the next token""" + tok = self._scanner.token(self._pos, [type]) + if tok[2] != type: + raise SyntaxError(tok[0], 'Trying to find '+type) + self._pos = 1+self._pos + return tok[3] + + + +def print_error(input, err, scanner): + """This is a really dumb long function to print error messages nicely.""" + p = err.pos + # Figure out the line number + line = count(input[:p], '\n') + print err.msg+" on line "+`line+1`+":" + # Now try printing part of the line + text = input[max(p-80,0):p+80] + p = p - max(p-80,0) + + # Strip to the left + i = rfind(text[:p],'\n') + j = rfind(text[:p],'\r') + if i < 0 or (j < i and j >= 0): i = j + if i >= 0 and i < p: + p = p - i - 1 + text = text[i+1:] + + # Strip to the right + i = find(text,'\n',p) + j = find(text,'\r',p) + if i < 0 or (j < i and j >= 0): i = j + if i >= 0: + text = text[:i] + + # Now shorten the text + while len(text) > 70 and p > 60: + # Cut off 10 chars + text = "..." + text[10:] + p = p - 7 + + # Now print the string, along with an indicator + print '> ',text + print '> ',' '*p + '^' + print 'List of nearby tokens:', scanner + +def wrap_error_reporter(parser, rule): + try: return getattr(parser, rule)() + except SyntaxError, s: + input = parser._scanner.input + try: + print_error(input, s, parser._scanner) + except ImportError: + print 'Syntax Error',s.msg,'on line',1+count(input[:s.pos], '\n') + except NoMoreTokens: + print 'Could not complete parsing; stopped around here:' + print parser._scanner + -- cgit v1.2.3