UnknownSec Bypass 403

: /lib/python3/dist-packages/twisted/words/xish/ [ drwxr-xr-x ]
name : xpathparser.g # -*- test-case-name: twisted.words.test.test_xpath -*- # Copyright (c) Twisted Matrix Laboratories. # See LICENSE for details. # pylint: disable=W9401,W9402 # DO NOT EDIT xpathparser.py! # # It is generated from xpathparser.g using Yapps. Make needed changes there. # This also means that the generated Python may not conform to Twisted's coding # standards, so it is wrapped in exec to prevent automated checkers from # complaining. # HOWTO Generate me: # # 1.) Grab a copy of yapps2: # https://github.com/smurfix/yapps # # Note: Do NOT use the package in debian/ubuntu as it has incompatible # modifications. The original at http://theory.stanford.edu/~amitp/yapps/ # hasn't been touched since 2003 and has not been updated to work with # Python 3. # # 2.) Generate the grammar: # # yapps2 xpathparser.g xpathparser.py.proto # # 3.) Edit the output to depend on the embedded runtime, and remove extraneous # imports: # # sed -e '/^# Begin/,${/^[^ ].*mport/d}' -e 's/runtime\.//g' \ # -e "s/^\(from __future\)/exec(r'''\n\1/" -e"\$a''')" # xpathparser.py.proto > xpathparser.py """ XPath Parser. Besides the parser code produced by Yapps, this module also defines the parse-time exception classes, a scanner class, a base class for parsers produced by Yapps, and a context class that keeps track of the parse stack. These have been copied from the Yapps runtime module. """ from __future__ import print_function import sys, re MIN_WINDOW=4096 # File lookup window class SyntaxError(Exception): """When we run into an unexpected token, this is the exception to use""" def __init__(self, pos=None, msg="Bad Token", context=None): Exception.__init__(self) self.pos = pos self.msg = msg self.context = context def __str__(self): if not self.pos: return 'SyntaxError' else: return 'SyntaxError@%s(%s)' % (repr(self.pos), self.msg) class NoMoreTokens(Exception): """Another exception object, for when we run out of tokens""" pass class Token(object): """Yapps token. This is a container for a scanned token. """ def __init__(self, type,value, pos=None): """Initialize a token.""" self.type = type self.value = value self.pos = pos def __repr__(self): output = '<%s: %s' % (self.type, repr(self.value)) if self.pos: output += " @ " if self.pos[0]: output += "%s:" % self.pos[0] if self.pos[1]: output += "%d" % self.pos[1] if self.pos[2] is not None: output += ".%d" % self.pos[2] output += ">" return output in_name=0 class Scanner(object): """Yapps scanner. The Yapps scanner can work in context sensitive or context insensitive modes. The token(i) method is used to retrieve the i-th token. It takes a restrict set that limits the set of tokens it is allowed to return. In context sensitive mode, this restrict set guides the scanner. In context insensitive mode, there is no restriction (the set is always the full set of tokens). """ def __init__(self, patterns, ignore, input="", file=None,filename=None,stacked=False): """Initialize the scanner. Parameters: patterns : [(terminal, uncompiled regex), ...] or None ignore : {terminal:None, ...} input : string If patterns is None, we assume that the subclass has defined self.patterns : [(terminal, compiled regex), ...]. Note that the patterns parameter expects uncompiled regexes, whereas the self.patterns field expects compiled regexes. The 'ignore' value is either None or a callable, which is called with the scanner and the to-be-ignored match object; this can be used for include file or comment handling. """ if not filename: global in_name filename="<f.%d>" % in_name in_name += 1 self.input = input self.ignore = ignore self.file = file self.filename = filename self.pos = 0 self.del_pos = 0 # skipped self.line = 1 self.del_line = 0 # skipped self.col = 0 self.tokens = [] self.stack = None self.stacked = stacked self.last_read_token = None self.last_token = None self.last_types = None if patterns is not None: # Compile the regex strings into regex objects self.patterns = [] for terminal, regex in patterns: self.patterns.append( (terminal, re.compile(regex)) ) def stack_input(self, input="", file=None, filename=None): """Temporarily parse from a second file.""" # Already reading from somewhere else: Go on top of that, please. if self.stack: # autogenerate a recursion-level-identifying filename if not filename: filename = 1 else: try: filename += 1 except TypeError: pass # now pass off to the include file self.stack.stack_input(input,file,filename) else: try: filename += 0 except TypeError: pass else: filename = "<str_%d>" % filename # self.stack = object.__new__(self.__class__) # Scanner.__init__(self.stack,self.patterns,self.ignore,input,file,filename, stacked=True) # Note that the pattern+ignore are added by the generated # scanner code self.stack = self.__class__(input,file,filename, stacked=True) def get_pos(self): """Return a file/line/char tuple.""" if self.stack: return self.stack.get_pos() return (self.filename, self.line+self.del_line, self.col) # def __repr__(self): # """Print the last few tokens that have been scanned in""" # output = '' # for t in self.tokens: # output += '%s\n' % (repr(t),) # return output def print_line_with_pointer(self, pos, length=0, out=sys.stderr): """Print the line of 'text' that includes position 'p', along with a second line with a single caret (^) at position p""" file,line,p = pos if file != self.filename: if self.stack: return self.stack.print_line_with_pointer(pos,length=length,out=out) print >>out, "(%s: not in input buffer)" % file return text = self.input p += length-1 # starts at pos 1 origline=line line -= self.del_line spos=0 if line > 0: while 1: line = line - 1 try: cr = text.index("\n",spos) except ValueError: if line: text = "" break if line == 0: text = text[spos:cr] break spos = cr+1 else: print >>out, "(%s:%d not in input buffer)" % (file,origline) return # Now try printing part of the line text = text[max(p-80, 0):p+80] p = p - max(p-80, 0) # Strip to the left i = text[:p].rfind('\n') j = text[:p].rfind('\r') if i < 0 or (0 <= j < i): i = j if 0 <= i < p: p = p - i - 1 text = text[i+1:] # Strip to the right i = text.find('\n', p) j = text.find('\r', p) if i < 0 or (0 <= j < i): 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 >>out, '> ',text print >>out, '> ',' '*p + '^' def grab_input(self): """Get more input if possible.""" if not self.file: return if len(self.input) - self.pos >= MIN_WINDOW: return data = self.file.read(MIN_WINDOW) if data is None or data == "": self.file = None # Drop bytes from the start, if necessary. if self.pos > 2*MIN_WINDOW: self.del_pos += MIN_WINDOW self.del_line += self.input[:MIN_WINDOW].count("\n") self.pos -= MIN_WINDOW self.input = self.input[MIN_WINDOW:] + data else: self.input = self.input + data def getchar(self): """Return the next character.""" self.grab_input() c = self.input[self.pos] self.pos += 1 return c def token(self, restrict, context=None): """Scan for another token.""" while 1: if self.stack: try: return self.stack.token(restrict, context) except StopIteration: self.stack = None # Keep looking for a token, ignoring any in self.ignore self.grab_input() # special handling for end-of-file if self.stacked and self.pos==len(self.input): raise StopIteration # Search the patterns for the longest match, with earlier # tokens in the list having preference best_match = -1 best_pat = '(error)' best_m = None 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 m.end()-m.start() > best_match: # We got a match that's better than the previous one best_pat = p best_match = m.end()-m.start() best_m = m # 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.get_pos(), msg, context=context) ignore = best_pat in self.ignore value = self.input[self.pos:self.pos+best_match] if not ignore: tok=Token(type=best_pat, value=value, pos=self.get_pos()) self.pos += best_match npos = value.rfind("\n") if npos > -1: self.col = best_match-npos self.line += value.count("\n") else: self.col += best_match # If we found something that isn't to be ignored, return it if not ignore: if len(self.tokens) >= 10: del self.tokens[0] self.tokens.append(tok) self.last_read_token = tok # print repr(tok) return tok else: ignore = self.ignore[best_pat] if ignore: ignore(self, best_m) def peek(self, *types, **kw): """Returns the token type for lookahead; if there are any args then the list of args is the set of token types to allow""" context = kw.get("context",None) if self.last_token is None: self.last_types = types self.last_token = self.token(types,context) elif self.last_types: for t in types: if t not in self.last_types: raise NotImplementedError("Unimplemented: restriction set changed") return self.last_token.type def scan(self, type, **kw): """Returns the matched text, and moves to the next token""" context = kw.get("context",None) if self.last_token is None: tok = self.token([type],context) else: if self.last_types and type not in self.last_types: raise NotImplementedError("Unimplemented: restriction set changed") tok = self.last_token self.last_token = None if tok.type != type: if not self.last_types: self.last_types=[] raise SyntaxError(tok.pos, 'Trying to find '+type+': '+ ', '.join(self.last_types)+", got "+tok.type, context=context) return tok.value class Parser(object): """Base class for Yapps-generated parsers. """ def __init__(self, scanner): self._scanner = scanner def _stack(self, input="",file=None,filename=None): """Temporarily read from someplace else""" self._scanner.stack_input(input,file,filename) self._tok = None def _peek(self, *types, **kw): """Returns the token type for lookahead; if there are any args then the list of args is the set of token types to allow""" return self._scanner.peek(*types, **kw) def _scan(self, type, **kw): """Returns the matched text, and moves to the next token""" return self._scanner.scan(type, **kw) class Context(object): """Class to represent the parser's call stack. Every rule creates a Context that links to its parent rule. The contexts can be used for debugging. """ def __init__(self, parent, scanner, rule, args=()): """Create a new context. Args: parent: Context object or None scanner: Scanner object rule: string (name of the rule) args: tuple listing parameters to the rule """ self.parent = parent self.scanner = scanner self.rule = rule self.args = args while scanner.stack: scanner = scanner.stack self.token = scanner.last_read_token def __str__(self): output = '' if self.parent: output = str(self.parent) + ' > ' output += self.rule return output def print_error(err, scanner, max_ctx=None): """Print error messages, the parser stack, and the input text -- for human-readable error messages.""" # NOTE: this function assumes 80 columns :-( # Figure out the line number pos = err.pos if not pos: pos = scanner.get_pos() file_name, line_number, column_number = pos print('%s:%d:%d: %s' % (file_name, line_number, column_number, err.msg), file=sys.stderr) scanner.print_line_with_pointer(pos) context = err.context token = None while context: print('while parsing %s%s:' % (context.rule, tuple(context.args)), file=sys.stderr) if context.token: token = context.token if token: scanner.print_line_with_pointer(token.pos, length=len(token.value)) context = context.parent if max_ctx: max_ctx = max_ctx-1 if not max_ctx: break def wrap_error_reporter(parser, rule, *args,**kw): try: return getattr(parser, rule)(*args,**kw) except SyntaxError as e: print_error(e, parser._scanner) except NoMoreTokens: print('Could not complete parsing; stopped around here:', file=sys.stderr) print(parser._scanner, file=sys.stderr) from twisted.words.xish.xpath import AttribValue, BooleanValue, CompareValue from twisted.words.xish.xpath import Function, IndexValue, LiteralValue from twisted.words.xish.xpath import _AnyLocation, _Location %% parser XPathParser: ignore: "\\s+" token INDEX: "[0-9]+" token WILDCARD: "\*" token IDENTIFIER: "[a-zA-Z][a-zA-Z0-9_\-]*" token ATTRIBUTE: "\@[a-zA-Z][a-zA-Z0-9_\-]*" token FUNCNAME: "[a-zA-Z][a-zA-Z0-9_]*" token CMP_EQ: "\=" token CMP_NE: "\!\=" token STR_DQ: '"([^"]|(\\"))*?"' token STR_SQ: "'([^']|(\\'))*?'" token OP_AND: "and" token OP_OR: "or" token END: "$" rule XPATH: PATH {{ result = PATH; current = result }} ( PATH {{ current.childLocation = PATH; current = current.childLocation }} ) * END {{ return result }} rule PATH: ("/" {{ result = _Location() }} | "//" {{ result = _AnyLocation() }} ) ( IDENTIFIER {{ result.elementName = IDENTIFIER }} | WILDCARD {{ result.elementName = None }} ) ( "\[" PREDICATE {{ result.predicates.append(PREDICATE) }} "\]")* {{ return result }} rule PREDICATE: EXPR {{ return EXPR }} | INDEX {{ return IndexValue(INDEX) }} rule EXPR: FACTOR {{ e = FACTOR }} ( BOOLOP FACTOR {{ e = BooleanValue(e, BOOLOP, FACTOR) }} )* {{ return e }} rule BOOLOP: ( OP_AND {{ return OP_AND }} | OP_OR {{ return OP_OR }} ) rule FACTOR: TERM {{ return TERM }} | "\(" EXPR "\)" {{ return EXPR }} rule TERM: VALUE {{ t = VALUE }} [ CMP VALUE {{ t = CompareValue(t, CMP, VALUE) }} ] {{ return t }} rule VALUE: "@" IDENTIFIER {{ return AttribValue(IDENTIFIER) }} | FUNCNAME {{ f = Function(FUNCNAME); args = [] }} "\(" [ VALUE {{ args.append(VALUE) }} ( "," VALUE {{ args.append(VALUE) }} )* ] "\)" {{ f.setParams(*args); return f }} | STR {{ return LiteralValue(STR[1:len(STR)-1]) }} rule CMP: (CMP_EQ {{ return CMP_EQ }} | CMP_NE {{ return CMP_NE }}) rule STR: (STR_DQ {{ return STR_DQ }} | STR_SQ {{ return STR_SQ }})