diff options
Diffstat (limited to 'other-licenses/ply')
| -rw-r--r-- | other-licenses/ply/COPYING | 28 | ||||
| -rw-r--r-- | other-licenses/ply/README | 9 | ||||
| -rw-r--r-- | other-licenses/ply/ply/__init__.py | 4 | ||||
| -rw-r--r-- | other-licenses/ply/ply/lex.py | 1058 | ||||
| -rw-r--r-- | other-licenses/ply/ply/yacc.py | 3276 |
5 files changed, 4375 insertions, 0 deletions
diff --git a/other-licenses/ply/COPYING b/other-licenses/ply/COPYING new file mode 100644 index 000000000..3b107de45 --- /dev/null +++ b/other-licenses/ply/COPYING @@ -0,0 +1,28 @@ +Copyright (C) 2001-2009, +David M. Beazley (Dabeaz LLC) +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +* Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. +* Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. +* Neither the name of the David Beazley or Dabeaz LLC may be used to + endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/other-licenses/ply/README b/other-licenses/ply/README new file mode 100644 index 000000000..2459c4901 --- /dev/null +++ b/other-licenses/ply/README @@ -0,0 +1,9 @@ +David Beazley's PLY (Python Lex-Yacc) +http://www.dabeaz.com/ply/ + +Licensed under BSD. + +This directory contains just the code and license from PLY version 3.3; +the full distribution (see the URL) also contains examples, tests, +documentation, and a longer README. + diff --git a/other-licenses/ply/ply/__init__.py b/other-licenses/ply/ply/__init__.py new file mode 100644 index 000000000..853a98554 --- /dev/null +++ b/other-licenses/ply/ply/__init__.py @@ -0,0 +1,4 @@ +# PLY package +# Author: David Beazley (dave@dabeaz.com) + +__all__ = ['lex','yacc'] diff --git a/other-licenses/ply/ply/lex.py b/other-licenses/ply/ply/lex.py new file mode 100644 index 000000000..267ec100f --- /dev/null +++ b/other-licenses/ply/ply/lex.py @@ -0,0 +1,1058 @@ +# ----------------------------------------------------------------------------- +# ply: lex.py +# +# Copyright (C) 2001-2009, +# David M. Beazley (Dabeaz LLC) +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright notice, +# this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright notice, +# this list of conditions and the following disclaimer in the documentation +# and/or other materials provided with the distribution. +# * Neither the name of the David Beazley or Dabeaz LLC may be used to +# endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# ----------------------------------------------------------------------------- + +__version__ = "3.3" +__tabversion__ = "3.2" # Version of table file used + +import re, sys, types, copy, os + +# This tuple contains known string types +try: + # Python 2.6 + StringTypes = (types.StringType, types.UnicodeType) +except AttributeError: + # Python 3.0 + StringTypes = (str, bytes) + +# Extract the code attribute of a function. Different implementations +# are for Python 2/3 compatibility. + +if sys.version_info[0] < 3: + def func_code(f): + return f.func_code +else: + def func_code(f): + return f.__code__ + +# This regular expression is used to match valid token names +_is_identifier = re.compile(r'^[a-zA-Z0-9_]+$') + +# Exception thrown when invalid token encountered and no default error +# handler is defined. + +class LexError(Exception): + def __init__(self,message,s): + self.args = (message,) + self.text = s + +# Token class. This class is used to represent the tokens produced. +class LexToken(object): + def __str__(self): + return "LexToken(%s,%r,%d,%d)" % (self.type,self.value,self.lineno,self.lexpos) + def __repr__(self): + return str(self) + +# This object is a stand-in for a logging object created by the +# logging module. + +class PlyLogger(object): + def __init__(self,f): + self.f = f + def critical(self,msg,*args,**kwargs): + self.f.write((msg % args) + "\n") + + def warning(self,msg,*args,**kwargs): + self.f.write("WARNING: "+ (msg % args) + "\n") + + def error(self,msg,*args,**kwargs): + self.f.write("ERROR: " + (msg % args) + "\n") + + info = critical + debug = critical + +# Null logger is used when no output is generated. Does nothing. +class NullLogger(object): + def __getattribute__(self,name): + return self + def __call__(self,*args,**kwargs): + return self + +# ----------------------------------------------------------------------------- +# === Lexing Engine === +# +# The following Lexer class implements the lexer runtime. There are only +# a few public methods and attributes: +# +# input() - Store a new string in the lexer +# token() - Get the next token +# clone() - Clone the lexer +# +# lineno - Current line number +# lexpos - Current position in the input string +# ----------------------------------------------------------------------------- + +class Lexer: + def __init__(self): + self.lexre = None # Master regular expression. This is a list of + # tuples (re,findex) where re is a compiled + # regular expression and findex is a list + # mapping regex group numbers to rules + self.lexretext = None # Current regular expression strings + self.lexstatere = {} # Dictionary mapping lexer states to master regexs + self.lexstateretext = {} # Dictionary mapping lexer states to regex strings + self.lexstaterenames = {} # Dictionary mapping lexer states to symbol names + self.lexstate = "INITIAL" # Current lexer state + self.lexstatestack = [] # Stack of lexer states + self.lexstateinfo = None # State information + self.lexstateignore = {} # Dictionary of ignored characters for each state + self.lexstateerrorf = {} # Dictionary of error functions for each state + self.lexreflags = 0 # Optional re compile flags + self.lexdata = None # Actual input data (as a string) + self.lexpos = 0 # Current position in input text + self.lexlen = 0 # Length of the input text + self.lexerrorf = None # Error rule (if any) + self.lextokens = None # List of valid tokens + self.lexignore = "" # Ignored characters + self.lexliterals = "" # Literal characters that can be passed through + self.lexmodule = None # Module + self.lineno = 1 # Current line number + self.lexoptimize = 0 # Optimized mode + + def clone(self,object=None): + c = copy.copy(self) + + # If the object parameter has been supplied, it means we are attaching the + # lexer to a new object. In this case, we have to rebind all methods in + # the lexstatere and lexstateerrorf tables. + + if object: + newtab = { } + for key, ritem in self.lexstatere.items(): + newre = [] + for cre, findex in ritem: + newfindex = [] + for f in findex: + if not f or not f[0]: + newfindex.append(f) + continue + newfindex.append((getattr(object,f[0].__name__),f[1])) + newre.append((cre,newfindex)) + newtab[key] = newre + c.lexstatere = newtab + c.lexstateerrorf = { } + for key, ef in self.lexstateerrorf.items(): + c.lexstateerrorf[key] = getattr(object,ef.__name__) + c.lexmodule = object + return c + + # ------------------------------------------------------------ + # writetab() - Write lexer information to a table file + # ------------------------------------------------------------ + def writetab(self,tabfile,outputdir=""): + if isinstance(tabfile,types.ModuleType): + return + basetabfilename = tabfile.split(".")[-1] + filename = os.path.join(outputdir,basetabfilename)+".py" + tf = open(filename,"w") + tf.write("# %s.py. This file automatically created by PLY (version %s). Don't edit!\n" % (tabfile,__version__)) + tf.write("_tabversion = %s\n" % repr(__version__)) + tf.write("_lextokens = %s\n" % repr(self.lextokens)) + tf.write("_lexreflags = %s\n" % repr(self.lexreflags)) + tf.write("_lexliterals = %s\n" % repr(self.lexliterals)) + tf.write("_lexstateinfo = %s\n" % repr(self.lexstateinfo)) + + tabre = { } + # Collect all functions in the initial state + initial = self.lexstatere["INITIAL"] + initialfuncs = [] + for part in initial: + for f in part[1]: + if f and f[0]: + initialfuncs.append(f) + + for key, lre in self.lexstatere.items(): + titem = [] + for i in range(len(lre)): + titem.append((self.lexstateretext[key][i],_funcs_to_names(lre[i][1],self.lexstaterenames[key][i]))) + tabre[key] = titem + + tf.write("_lexstatere = %s\n" % repr(tabre)) + tf.write("_lexstateignore = %s\n" % repr(self.lexstateignore)) + + taberr = { } + for key, ef in self.lexstateerrorf.items(): + if ef: + taberr[key] = ef.__name__ + else: + taberr[key] = None + tf.write("_lexstateerrorf = %s\n" % repr(taberr)) + tf.close() + + # ------------------------------------------------------------ + # readtab() - Read lexer information from a tab file + # ------------------------------------------------------------ + def readtab(self,tabfile,fdict): + if isinstance(tabfile,types.ModuleType): + lextab = tabfile + else: + if sys.version_info[0] < 3: + exec("import %s as lextab" % tabfile) + else: + env = { } + exec("import %s as lextab" % tabfile, env,env) + lextab = env['lextab'] + + if getattr(lextab,"_tabversion","0.0") != __version__: + raise ImportError("Inconsistent PLY version") + + self.lextokens = lextab._lextokens + self.lexreflags = lextab._lexreflags + self.lexliterals = lextab._lexliterals + self.lexstateinfo = lextab._lexstateinfo + self.lexstateignore = lextab._lexstateignore + self.lexstatere = { } + self.lexstateretext = { } + for key,lre in lextab._lexstatere.items(): + titem = [] + txtitem = [] + for i in range(len(lre)): + titem.append((re.compile(lre[i][0],lextab._lexreflags | re.VERBOSE),_names_to_funcs(lre[i][1],fdict))) + txtitem.append(lre[i][0]) + self.lexstatere[key] = titem + self.lexstateretext[key] = txtitem + self.lexstateerrorf = { } + for key,ef in lextab._lexstateerrorf.items(): + self.lexstateerrorf[key] = fdict[ef] + self.begin('INITIAL') + + # ------------------------------------------------------------ + # input() - Push a new string into the lexer + # ------------------------------------------------------------ + def input(self,s): + # Pull off the first character to see if s looks like a string + c = s[:1] + if not isinstance(c,StringTypes): + raise ValueError("Expected a string") + self.lexdata = s + self.lexpos = 0 + self.lexlen = len(s) + + # ------------------------------------------------------------ + # begin() - Changes the lexing state + # ------------------------------------------------------------ + def begin(self,state): + if not state in self.lexstatere: + raise ValueError("Undefined state") + self.lexre = self.lexstatere[state] + self.lexretext = self.lexstateretext[state] + self.lexignore = self.lexstateignore.get(state,"") + self.lexerrorf = self.lexstateerrorf.get(state,None) + self.lexstate = state + + # ------------------------------------------------------------ + # push_state() - Changes the lexing state and saves old on stack + # ------------------------------------------------------------ + def push_state(self,state): + self.lexstatestack.append(self.lexstate) + self.begin(state) + + # ------------------------------------------------------------ + # pop_state() - Restores the previous state + # ------------------------------------------------------------ + def pop_state(self): + self.begin(self.lexstatestack.pop()) + + # ------------------------------------------------------------ + # current_state() - Returns the current lexing state + # ------------------------------------------------------------ + def current_state(self): + return self.lexstate + + # ------------------------------------------------------------ + # skip() - Skip ahead n characters + # ------------------------------------------------------------ + def skip(self,n): + self.lexpos += n + + # ------------------------------------------------------------ + # opttoken() - Return the next token from the Lexer + # + # Note: This function has been carefully implemented to be as fast + # as possible. Don't make changes unless you really know what + # you are doing + # ------------------------------------------------------------ + def token(self): + # Make local copies of frequently referenced attributes + lexpos = self.lexpos + lexlen = self.lexlen + lexignore = self.lexignore + lexdata = self.lexdata + + while lexpos < lexlen: + # This code provides some short-circuit code for whitespace, tabs, and other ignored characters + if lexdata[lexpos] in lexignore: + lexpos += 1 + continue + + # Look for a regular expression match + for lexre,lexindexfunc in self.lexre: + m = lexre.match(lexdata,lexpos) + if not m: continue + + # Create a token for return + tok = LexToken() + tok.value = m.group() + tok.lineno = self.lineno + tok.lexpos = lexpos + + i = m.lastindex + func,tok.type = lexindexfunc[i] + + if not func: + # If no token type was set, it's an ignored token + if tok.type: + self.lexpos = m.end() + return tok + else: + lexpos = m.end() + break + + lexpos = m.end() + + # If token is processed by a function, call it + + tok.lexer = self # Set additional attributes useful in token rules + self.lexmatch = m + self.lexpos = lexpos + + newtok = func(tok) + + # Every function must return a token, if nothing, we just move to next token + if not newtok: + lexpos = self.lexpos # This is here in case user has updated lexpos. + lexignore = self.lexignore # This is here in case there was a state change + break + + # Verify type of the token. If not in the token map, raise an error + if not self.lexoptimize: + if not newtok.type in self.lextokens: + raise LexError("%s:%d: Rule '%s' returned an unknown token type '%s'" % ( + func_code(func).co_filename, func_code(func).co_firstlineno, + func.__name__, newtok.type),lexdata[lexpos:]) + + return newtok + else: + # No match, see if in literals + if lexdata[lexpos] in self.lexliterals: + tok = LexToken() + tok.value = lexdata[lexpos] + tok.lineno = self.lineno + tok.type = tok.value + tok.lexpos = lexpos + self.lexpos = lexpos + 1 + return tok + + # No match. Call t_error() if defined. + if self.lexerrorf: + tok = LexToken() + tok.value = self.lexdata[lexpos:] + tok.lineno = self.lineno + tok.type = "error" + tok.lexer = self + tok.lexpos = lexpos + self.lexpos = lexpos + newtok = self.lexerrorf(tok) + if lexpos == self.lexpos: + # Error method didn't change text position at all. This is an error. + raise LexError("Scanning error. Illegal character '%s'" % (lexdata[lexpos]), lexdata[lexpos:]) + lexpos = self.lexpos + if not newtok: continue + return newtok + + self.lexpos = lexpos + raise LexError("Illegal character '%s' at index %d" % (lexdata[lexpos],lexpos), lexdata[lexpos:]) + + self.lexpos = lexpos + 1 + if self.lexdata is None: + raise RuntimeError("No input string given with input()") + return None + + # Iterator interface + def __iter__(self): + return self + + def next(self): + t = self.token() + if t is None: + raise StopIteration + return t + + __next__ = next + +# ----------------------------------------------------------------------------- +# ==== Lex Builder === +# +# The functions and classes below are used to collect lexing information +# and build a Lexer object from it. +# ----------------------------------------------------------------------------- + +# ----------------------------------------------------------------------------- +# get_caller_module_dict() +# +# This function returns a dictionary containing all of the symbols defined within +# a caller further down the call stack. This is used to get the environment +# associated with the yacc() call if none was provided. +# ----------------------------------------------------------------------------- + +def get_caller_module_dict(levels): + try: + raise RuntimeError + except RuntimeError: + e,b,t = sys.exc_info() + f = t.tb_frame + while levels > 0: + f = f.f_back + levels -= 1 + ldict = f.f_globals.copy() + if f.f_globals != f.f_locals: + ldict.update(f.f_locals) + + return ldict + +# ----------------------------------------------------------------------------- +# _funcs_to_names() +# +# Given a list of regular expression functions, this converts it to a list +# suitable for output to a table file +# ----------------------------------------------------------------------------- + +def _funcs_to_names(funclist,namelist): + result = [] + for f,name in zip(funclist,namelist): + if f and f[0]: + result.append((name, f[1])) + else: + result.append(f) + return result + +# ----------------------------------------------------------------------------- +# _names_to_funcs() +# +# Given a list of regular expression function names, this converts it back to +# functions. +# ----------------------------------------------------------------------------- + +def _names_to_funcs(namelist,fdict): + result = [] + for n in namelist: + if n and n[0]: + result.append((fdict[n[0]],n[1])) + else: + result.append(n) + return result + +# ----------------------------------------------------------------------------- +# _form_master_re() +# +# This function takes a list of all of the regex components and attempts to +# form the master regular expression. Given limitations in the Python re +# module, it may be necessary to break the master regex into separate expressions. +# ----------------------------------------------------------------------------- + +def _form_master_re(relist,reflags,ldict,toknames): + if not relist: return [] + regex = "|".join(relist) + try: + lexre = re.compile(regex,re.VERBOSE | reflags) + + # Build the index to function map for the matching engine + lexindexfunc = [ None ] * (max(lexre.groupindex.values())+1) + lexindexnames = lexindexfunc[:] + + for f,i in lexre.groupindex.items(): + handle = ldict.get(f,None) + if type(handle) in (types.FunctionType, types.MethodType): + lexindexfunc[i] = (handle,toknames[f]) + lexindexnames[i] = f + elif handle is not None: + lexindexnames[i] = f + if f.find("ignore_") > 0: + lexindexfunc[i] = (None,None) + else: + lexindexfunc[i] = (None, toknames[f]) + + return [(lexre,lexindexfunc)],[regex],[lexindexnames] + except Exception: + m = int(len(relist)/2) + if m == 0: m = 1 + llist, lre, lnames = _form_master_re(relist[:m],reflags,ldict,toknames) + rlist, rre, rnames = _form_master_re(relist[m:],reflags,ldict,toknames) + return llist+rlist, lre+rre, lnames+rnames + +# ----------------------------------------------------------------------------- +# def _statetoken(s,names) +# +# Given a declaration name s of the form "t_" and a dictionary whose keys are +# state names, this function returns a tuple (states,tokenname) where states +# is a tuple of state names and tokenname is the name of the token. For example, +# calling this with s = "t_foo_bar_SPAM" might return (('foo','bar'),'SPAM') +# ----------------------------------------------------------------------------- + +def _statetoken(s,names): + nonstate = 1 + parts = s.split("_") + for i in range(1,len(parts)): + if not parts[i] in names and parts[i] != 'ANY': break + if i > 1: + states = tuple(parts[1:i]) + else: + states = ('INITIAL',) + + if 'ANY' in states: + states = tuple(names) + + tokenname = "_".join(parts[i:]) + return (states,tokenname) + + +# ----------------------------------------------------------------------------- +# LexerReflect() +# +# This class represents information needed to build a lexer as extracted from a +# user's input file. +# ----------------------------------------------------------------------------- +class LexerReflect(object): + def __init__(self,ldict,log=None,reflags=0): + self.ldict = ldict + self.error_func = None + self.tokens = [] + self.reflags = reflags + self.stateinfo = { 'INITIAL' : 'inclusive'} + self.files = {} + self.error = 0 + + if log is None: + self.log = PlyLogger(sys.stderr) + else: + self.log = log + + # Get all of the basic information + def get_all(self): + self.get_tokens() + self.get_literals() + self.get_states() + self.get_rules() + + # Validate all of the information + def validate_all(self): + self.validate_tokens() + self.validate_literals() + self.validate_rules() + return self.error + + # Get the tokens map + def get_tokens(self): + tokens = self.ldict.get("tokens",None) + if not tokens: + self.log.error("No token list is defined") + self.error = 1 + return + + if not isinstance(tokens,(list, tuple)): + self.log.error("tokens must be a list or tuple") + self.error = 1 + return + + if not tokens: + self.log.error("tokens is empty") + self.error = 1 + return + + self.tokens = tokens + + # Validate the tokens + def validate_tokens(self): + terminals = {} + for n in self.tokens: + if not _is_identifier.match(n): + self.log.error("Bad token name '%s'",n) + self.error = 1 + if n in terminals: + self.log.warning("Token '%s' multiply defined", n) + terminals[n] = 1 + + # Get the literals specifier + def get_literals(self): + self.literals = self.ldict.get("literals","") + + # Validate literals + def validate_literals(self): + try: + for c in self.literals: + if not isinstance(c,StringTypes) or len(c) > 1: + self.log.error("Invalid literal %s. Must be a single character", repr(c)) + self.error = 1 + continue + + except TypeError: + self.log.error("Invalid literals specification. literals must be a sequence of characters") + self.error = 1 + + def get_states(self): + self.states = self.ldict.get("states",None) + # Build statemap + if self.states: + if not isinstance(self.states,(tuple,list)): + self.log.error("states must be defined as a tuple or list") + self.error = 1 + else: + for s in self.states: + if not isinstance(s,tuple) or len(s) != 2: + self.log.error("Invalid state specifier %s. Must be a tuple (statename,'exclusive|inclusive')",repr(s)) + self.error = 1 + continue + name, statetype = s + if not isinstance(name,StringTypes): + self.log.error("State name %s must be a string", repr(name)) + self.error = 1 + continue + if not (statetype == 'inclusive' or statetype == 'exclusive'): + self.log.error("State type for state %s must be 'inclusive' or 'exclusive'",name) + self.error = 1 + continue + if name in self.stateinfo: + self.log.error("State '%s' already defined",name) + self.error = 1 + continue + self.stateinfo[name] = statetype + + # Get all of the symbols with a t_ prefix and sort them into various + # categories (functions, strings, error functions, and ignore characters) + + def get_rules(self): + tsymbols = [f for f in self.ldict if f[:2] == 't_' ] + + # Now build up a list of functions and a list of strings + + self.toknames = { } # Mapping of symbols to token names + self.funcsym = { } # Symbols defined as functions + self.strsym = { } # Symbols defined as strings + self.ignore = { } # Ignore strings by state + self.errorf = { } # Error functions by state + + for s in self.stateinfo: + self.funcsym[s] = [] + self.strsym[s] = [] + + if len(tsymbols) == 0: + self.log.error("No rules of the form t_rulename are defined") + self.error = 1 + return + + for f in tsymbols: + t = self.ldict[f] + states, tokname = _statetoken(f,self.stateinfo) + self.toknames[f] = tokname + + if hasattr(t,"__call__"): + if tokname == 'error': + for s in states: + self.errorf[s] = t + elif tokname == 'ignore': + line = func_code(t).co_firstlineno + file = func_code(t).co_filename + self.log.error("%s:%d: Rule '%s' must be defined as a string",file,line,t.__name__) + self.error = 1 + else: + for s in states: + self.funcsym[s].append((f,t)) + elif isinstance(t, StringTypes): + if tokname == 'ignore': + for s in states: + self.ignore[s] = t + if "\\" in t: + self.log.warning("%s contains a literal backslash '\\'",f) + + elif tokname == 'error': + self.log.error("Rule '%s' must be defined as a function", f) + self.error = 1 + else: + for s in states: + self.strsym[s].append((f,t)) + else: + self.log.error("%s not defined as a function or string", f) + self.error = 1 + + # Sort the functions by line number + for f in self.funcsym.values(): + if sys.version_info[0] < 3: + f.sort(lambda x,y: cmp(func_code(x[1]).co_firstlineno,func_code(y[1]).co_firstlineno)) + else: + # Python 3.0 + f.sort(key=lambda x: func_code(x[1]).co_firstlineno) + + # Sort the strings by regular expression length + for s in self.strsym.values(): + if sys.version_info[0] < 3: + s.sort(lambda x,y: (len(x[1]) < len(y[1])) - (len(x[1]) > len(y[1]))) + else: + # Python 3.0 + s.sort(key=lambda x: len(x[1]),reverse=True) + + # Validate all of the t_rules collected + def validate_rules(self): + for state in self.stateinfo: + # Validate all rules defined by functions + + + + for fname, f in self.funcsym[state]: + line = func_code(f).co_firstlineno + file = func_code(f).co_filename + self.files[file] = 1 + + tokname = self.toknames[fname] + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = func_code(f).co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule '%s' has too many arguments",file,line,f.__name__) + self.error = 1 + continue + + if nargs < reqargs: + self.log.error("%s:%d: Rule '%s' requires an argument", file,line,f.__name__) + self.error = 1 + continue + + if not f.__doc__: + self.log.error("%s:%d: No regular expression defined for rule '%s'",file,line,f.__name__) + self.error = 1 + continue + + try: + c = re.compile("(?P<%s>%s)" % (fname,f.__doc__), re.VERBOSE | self.reflags) + if c.match(""): + self.log.error("%s:%d: Regular expression for rule '%s' matches empty string", file,line,f.__name__) + self.error = 1 + except re.error: + _etype, e, _etrace = sys.exc_info() + self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file,line,f.__name__,e) + if '#' in f.__doc__: + self.log.error("%s:%d. Make sure '#' in rule '%s' is escaped with '\\#'",file,line, f.__name__) + self.error = 1 + + # Validate all rules defined by strings + for name,r in self.strsym[state]: + tokname = self.toknames[name] + if tokname == 'error': + self.log.error("Rule '%s' must be defined as a function", name) + self.error = 1 + continue + + if not tokname in self.tokens and tokname.find("ignore_") < 0: + self.log.error("Rule '%s' defined for an unspecified token %s",name,tokname) + self.error = 1 + continue + + try: + c = re.compile("(?P<%s>%s)" % (name,r),re.VERBOSE | self.reflags) + if (c.match("")): + self.log.error("Regular expression for rule '%s' matches empty string",name) + self.error = 1 + except re.error: + _etype, e, _etrace = sys.exc_info() + self.log.error("Invalid regular expression for rule '%s'. %s",name,e) + if '#' in r: + self.log.error("Make sure '#' in rule '%s' is escaped with '\\#'",name) + self.error = 1 + + if not self.funcsym[state] and not self.strsym[state]: + self.log.error("No rules defined for state '%s'",state) + self.error = 1 + + # Validate the error function + efunc = self.errorf.get(state,None) + if efunc: + f = efunc + line = func_code(f).co_firstlineno + file = func_code(f).co_filename + self.files[file] = 1 + + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = func_code(f).co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule '%s' has too many arguments",file,line,f.__name__) + self.error = 1 + + if nargs < reqargs: + self.log.error("%s:%d: Rule '%s' requires an argument", file,line,f.__name__) + self.error = 1 + + for f in self.files: + self.validate_file(f) + + + # ----------------------------------------------------------------------------- + # validate_file() + # + # This checks to see if there are duplicated t_rulename() functions or strings + # in the parser input file. This is done using a simple regular expression + # match on each line in the given file. + # ----------------------------------------------------------------------------- + + def validate_file(self,filename): + import os.path + base,ext = os.path.splitext(filename) + if ext != '.py': return # No idea what the file is. Return OK + + try: + f = open(filename) + lines = f.readlines() + f.close() + except IOError: + return # Couldn't find the file. Don't worry about it + + fre = re.compile(r'\s*def\s+(t_[a-zA-Z_0-9]*)\(') + sre = re.compile(r'\s*(t_[a-zA-Z_0-9]*)\s*=') + + counthash = { } + linen = 1 + for l in lines: + m = fre.match(l) + if not m: + m = sre.match(l) + if m: + name = m.group(1) + prev = counthash.get(name) + if not prev: + counthash[name] = linen + else: + self.log.error("%s:%d: Rule %s redefined. Previously defined on line %d",filename,linen,name,prev) + self.error = 1 + linen += 1 + +# ----------------------------------------------------------------------------- +# lex(module) +# +# Build all of the regular expression rules from definitions in the supplied module +# ----------------------------------------------------------------------------- +def lex(module=None,object=None,debug=0,optimize=0,lextab="lextab",reflags=0,nowarn=0,outputdir="", debuglog=None, errorlog=None): + global lexer + ldict = None + stateinfo = { 'INITIAL' : 'inclusive'} + lexobj = Lexer() + lexobj.lexoptimize = optimize + global token,input + + if errorlog is None: + errorlog = PlyLogger(sys.stderr) + + if debug: + if debuglog is None: + debuglog = PlyLogger(sys.stderr) + + # Get the module dictionary used for the lexer + if object: module = object + + if module: + _items = [(k,getattr(module,k)) for k in dir(module)] + ldict = dict(_items) + else: + ldict = get_caller_module_dict(2) + + # Collect parser information from the dictionary + linfo = LexerReflect(ldict,log=errorlog,reflags=reflags) + linfo.get_all() + if not optimize: + if linfo.validate_all(): + raise SyntaxError("Can't build lexer") + + if optimize and lextab: + try: + lexobj.readtab(lextab,ldict) + token = lexobj.token + input = lexobj.input + lexer = lexobj + return lexobj + + except ImportError: + pass + + # Dump some basic debugging information + if debug: + debuglog.info("lex: tokens = %r", linfo.tokens) + debuglog.info("lex: literals = %r", linfo.literals) + debuglog.info("lex: states = %r", linfo.stateinfo) + + # Build a dictionary of valid token names + lexobj.lextokens = { } + for n in linfo.tokens: + lexobj.lextokens[n] = 1 + + # Get literals specification + if isinstance(linfo.literals,(list,tuple)): + lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals) + else: + lexobj.lexliterals = linfo.literals + + # Get the stateinfo dictionary + stateinfo = linfo.stateinfo + + regexs = { } + # Build the master regular expressions + for state in stateinfo: + regex_list = [] + + # Add rules defined by functions first + for fname, f in linfo.funcsym[state]: + line = func_code(f).co_firstlineno + file = func_code(f).co_filename + regex_list.append("(?P<%s>%s)" % (fname,f.__doc__)) + if debug: + debuglog.info("lex: Adding rule %s -> '%s' (state '%s')",fname,f.__doc__, state) + + # Now add all of the simple rules + for name,r in linfo.strsym[state]: + regex_list.append("(?P<%s>%s)" % (name,r)) + if debug: + debuglog.info("lex: Adding rule %s -> '%s' (state '%s')",name,r, state) + + regexs[state] = regex_list + + # Build the master regular expressions + + if debug: + debuglog.info("lex: ==== MASTER REGEXS FOLLOW ====") + + for state in regexs: + lexre, re_text, re_names = _form_master_re(regexs[state],reflags,ldict,linfo.toknames) + lexobj.lexstatere[state] = lexre + lexobj.lexstateretext[state] = re_text + lexobj.lexstaterenames[state] = re_names + if debug: + for i in range(len(re_text)): + debuglog.info("lex: state '%s' : regex[%d] = '%s'",state, i, re_text[i]) + + # For inclusive states, we need to add the regular expressions from the INITIAL state + for state,stype in stateinfo.items(): + if state != "INITIAL" and stype == 'inclusive': + lexobj.lexstatere[state].extend(lexobj.lexstatere['INITIAL']) + lexobj.lexstateretext[state].extend(lexobj.lexstateretext['INITIAL']) + lexobj.lexstaterenames[state].extend(lexobj.lexstaterenames['INITIAL']) + + lexobj.lexstateinfo = stateinfo + lexobj.lexre = lexobj.lexstatere["INITIAL"] + lexobj.lexretext = lexobj.lexstateretext["INITIAL"] + lexobj.lexreflags = reflags + + # Set up ignore variables + lexobj.lexstateignore = linfo.ignore + lexobj.lexignore = lexobj.lexstateignore.get("INITIAL","") + + # Set up error functions + lexobj.lexstateerrorf = linfo.errorf + lexobj.lexerrorf = linfo.errorf.get("INITIAL",None) + if not lexobj.lexerrorf: + errorlog.warning("No t_error rule is defined") + + # Check state information for ignore and error rules + for s,stype in stateinfo.items(): + if stype == 'exclusive': + if not s in linfo.errorf: + errorlog.warning("No error rule is defined for exclusive state '%s'", s) + if not s in linfo.ignore and lexobj.lexignore: + errorlog.warning("No ignore rule is defined for exclusive state '%s'", s) + elif stype == 'inclusive': + if not s in linfo.errorf: + linfo.errorf[s] = linfo.errorf.get("INITIAL",None) + if not s in linfo.ignore: + linfo.ignore[s] = linfo.ignore.get("INITIAL","") + + # Create global versions of the token() and input() functions + token = lexobj.token + input = lexobj.input + lexer = lexobj + + # If in optimize mode, we write the lextab + if lextab and optimize: + lexobj.writetab(lextab,outputdir) + + return lexobj + +# ----------------------------------------------------------------------------- +# runmain() +# +# This runs the lexer as a main program +# ----------------------------------------------------------------------------- + +def runmain(lexer=None,data=None): + if not data: + try: + filename = sys.argv[1] + f = open(filename) + data = f.read() + f.close() + except IndexError: + sys.stdout.write("Reading from standard input (type EOF to end):\n") + data = sys.stdin.read() + + if lexer: + _input = lexer.input + else: + _input = input + _input(data) + if lexer: + _token = lexer.token + else: + _token = token + + while 1: + tok = _token() + if not tok: break + sys.stdout.write("(%s,%r,%d,%d)\n" % (tok.type, tok.value, tok.lineno,tok.lexpos)) + +# ----------------------------------------------------------------------------- +# @TOKEN(regex) +# +# This decorator function can be used to set the regex expression on a function +# when its docstring might need to be set in an alternative way +# ----------------------------------------------------------------------------- + +def TOKEN(r): + def set_doc(f): + if hasattr(r,"__call__"): + f.__doc__ = r.__doc__ + else: + f.__doc__ = r + return f + return set_doc + +# Alternative spelling of the TOKEN decorator +Token = TOKEN + diff --git a/other-licenses/ply/ply/yacc.py b/other-licenses/ply/ply/yacc.py new file mode 100644 index 000000000..e9f5c6575 --- /dev/null +++ b/other-licenses/ply/ply/yacc.py @@ -0,0 +1,3276 @@ +# ----------------------------------------------------------------------------- +# ply: yacc.py +# +# Copyright (C) 2001-2009, +# David M. Beazley (Dabeaz LLC) +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright notice, +# this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright notice, +# this list of conditions and the following disclaimer in the documentation +# and/or other materials provided with the distribution. +# * Neither the name of the David Beazley or Dabeaz LLC may be used to +# endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# ----------------------------------------------------------------------------- +# +# This implements an LR parser that is constructed from grammar rules defined +# as Python functions. The grammer is specified by supplying the BNF inside +# Python documentation strings. The inspiration for this technique was borrowed +# from John Aycock's Spark parsing system. PLY might be viewed as cross between +# Spark and the GNU bison utility. +# +# The current implementation is only somewhat object-oriented. The +# LR parser itself is defined in terms of an object (which allows multiple +# parsers to co-exist). However, most of the variables used during table +# construction are defined in terms of global variables. Users shouldn't +# notice unless they are trying to define multiple parsers at the same +# time using threads (in which case they should have their head examined). +# +# This implementation supports both SLR and LALR(1) parsing. LALR(1) +# support was originally implemented by Elias Ioup (ezioup@alumni.uchicago.edu), +# using the algorithm found in Aho, Sethi, and Ullman "Compilers: Principles, +# Techniques, and Tools" (The Dragon Book). LALR(1) has since been replaced +# by the more efficient DeRemer and Pennello algorithm. +# +# :::::::: WARNING ::::::: +# +# Construction of LR parsing tables is fairly complicated and expensive. +# To make this module run fast, a *LOT* of work has been put into +# optimization---often at the expensive of readability and what might +# consider to be good Python "coding style." Modify the code at your +# own risk! +# ---------------------------------------------------------------------------- + +__version__ = "3.3" +__tabversion__ = "3.2" # Table version + +#----------------------------------------------------------------------------- +# === User configurable parameters === +# +# Change these to modify the default behavior of yacc (if you wish) +#----------------------------------------------------------------------------- + +yaccdebug = 1 # Debugging mode. If set, yacc generates a + # a 'parser.out' file in the current directory + +debug_file = 'parser.out' # Default name of the debugging file +tab_module = 'parsetab' # Default name of the table module +default_lr = 'LALR' # Default LR table generation method + +error_count = 3 # Number of symbols that must be shifted to leave recovery mode + +yaccdevel = 0 # Set to True if developing yacc. This turns off optimized + # implementations of certain functions. + +resultlimit = 40 # Size limit of results when running in debug mode. + +pickle_protocol = 0 # Protocol to use when writing pickle files + +import re, types, sys, os.path + +# Compatibility function for python 2.6/3.0 +if sys.version_info[0] < 3: + def func_code(f): + return f.func_code +else: + def func_code(f): + return f.__code__ + +# Compatibility +try: + MAXINT = sys.maxint +except AttributeError: + MAXINT = sys.maxsize + +# Python 2.x/3.0 compatibility. +def load_ply_lex(): + if sys.version_info[0] < 3: + import lex + else: + import ply.lex as lex + return lex + +# This object is a stand-in for a logging object created by the +# logging module. PLY will use this by default to create things +# such as the parser.out file. If a user wants more detailed +# information, they can create their own logging object and pass +# it into PLY. + +class PlyLogger(object): + def __init__(self,f): + self.f = f + def debug(self,msg,*args,**kwargs): + self.f.write((msg % args) + "\n") + info = debug + + def warning(self,msg,*args,**kwargs): + self.f.write("WARNING: "+ (msg % args) + "\n") + + def error(self,msg,*args,**kwargs): + self.f.write("ERROR: " + (msg % args) + "\n") + + critical = debug + +# Null logger is used when no output is generated. Does nothing. +class NullLogger(object): + def __getattribute__(self,name): + return self + def __call__(self,*args,**kwargs): + return self + +# Exception raised for yacc-related errors +class YaccError(Exception): pass + +# Format the result message that the parser produces when running in debug mode. +def format_result(r): + repr_str = repr(r) + if '\n' in repr_str: repr_str = repr(repr_str) + if len(repr_str) > resultlimit: + repr_str = repr_str[:resultlimit]+" ..." + result = "<%s @ 0x%x> (%s)" % (type(r).__name__,id(r),repr_str) + return result + + +# Format stack entries when the parser is running in debug mode +def format_stack_entry(r): + repr_str = repr(r) + if '\n' in repr_str: repr_str = repr(repr_str) + if len(repr_str) < 16: + return repr_str + else: + return "<%s @ 0x%x>" % (type(r).__name__,id(r)) + +#----------------------------------------------------------------------------- +# === LR Parsing Engine === +# +# The following classes are used for the LR parser itself. These are not +# used during table construction and are independent of the actual LR +# table generation algorithm +#----------------------------------------------------------------------------- + +# This class is used to hold non-terminal grammar symbols during parsing. +# It normally has the following attributes set: +# .type = Grammar symbol type +# .value = Symbol value +# .lineno = Starting line number +# .endlineno = Ending line number (optional, set automatically) +# .lexpos = Starting lex position +# .endlexpos = Ending lex position (optional, set automatically) + +class YaccSymbol: + def __str__(self): return self.type + def __repr__(self): return str(self) + +# This class is a wrapper around the objects actually passed to each +# grammar rule. Index lookup and assignment actually assign the +# .value attribute of the underlying YaccSymbol object. +# The lineno() method returns the line number of a given +# item (or 0 if not defined). The linespan() method returns +# a tuple of (startline,endline) representing the range of lines +# for a symbol. The lexspan() method returns a tuple (lexpos,endlexpos) +# representing the range of positional information for a symbol. + +class YaccProduction: + def __init__(self,s,stack=None): + self.slice = s + self.stack = stack + self.lexer = None + self.parser= None + def __getitem__(self,n): + if n >= 0: return self.slice[n].value + else: return self.stack[n].value + + def __setitem__(self,n,v): + self.slice[n].value = v + + def __getslice__(self,i,j): + return [s.value for s in self.slice[i:j]] + + def __len__(self): + return len(self.slice) + + def lineno(self,n): + return getattr(self.slice[n],"lineno",0) + + def set_lineno(self,n,lineno): + self.slice[n].lineno = lineno + + def linespan(self,n): + startline = getattr(self.slice[n],"lineno",0) + endline = getattr(self.slice[n],"endlineno",startline) + return startline,endline + + def lexpos(self,n): + return getattr(self.slice[n],"lexpos",0) + + def lexspan(self,n): + startpos = getattr(self.slice[n],"lexpos",0) + endpos = getattr(self.slice[n],"endlexpos",startpos) + return startpos,endpos + + def error(self): + raise SyntaxError + + +# ----------------------------------------------------------------------------- +# == LRParser == +# +# The LR Parsing engine. +# ----------------------------------------------------------------------------- + +class LRParser: + def __init__(self,lrtab,errorf): + self.productions = lrtab.lr_productions + self.action = lrtab.lr_action + self.goto = lrtab.lr_goto + self.errorfunc = errorf + + def errok(self): + self.errorok = 1 + + def restart(self): + del self.statestack[:] + del self.symstack[:] + sym = YaccSymbol() + sym.type = '$end' + self.symstack.append(sym) + self.statestack.append(0) + + def parse(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None): + if debug or yaccdevel: + if isinstance(debug,int): + debug = PlyLogger(sys.stderr) + return self.parsedebug(input,lexer,debug,tracking,tokenfunc) + elif tracking: + return self.parseopt(input,lexer,debug,tracking,tokenfunc) + else: + return self.parseopt_notrack(input,lexer,debug,tracking,tokenfunc) + + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # parsedebug(). + # + # This is the debugging enabled version of parse(). All changes made to the + # parsing engine should be made here. For the non-debugging version, + # copy this code to a method parseopt() and delete all of the sections + # enclosed in: + # + # #--! DEBUG + # statements + # #--! DEBUG + # + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + def parsedebug(self,input=None,lexer=None,debug=None,tracking=0,tokenfunc=None): + lookahead = None # Current lookahead symbol + lookaheadstack = [ ] # Stack of lookahead symbols + actions = self.action # Local reference to action table (to avoid lookup on self.) + goto = self.goto # Local reference to goto table (to avoid lookup on self.) + prod = self.productions # Local reference to production list (to avoid lookup on self.) + pslice = YaccProduction(None) # Production object passed to grammar rules + errorcount = 0 # Used during error recovery + + # --! DEBUG + debug.info("PLY: PARSE DEBUG START") + # --! DEBUG + + # If no lexer was given, we will try to use the lex module + if not lexer: + lex = load_ply_lex() + lexer = lex.lexer + + # Set up the lexer and parser objects on pslice + pslice.lexer = lexer + pslice.parser = self + + # If input was supplied, pass to lexer + if input is not None: + lexer.input(input) + + if tokenfunc is None: + # Tokenize function + get_token = lexer.token + else: + get_token = tokenfunc + + # Set up the state and symbol stacks + + statestack = [ ] # Stack of parsing states + self.statestack = statestack + symstack = [ ] # Stack of grammar symbols + self.symstack = symstack + + pslice.stack = symstack # Put in the production + errtoken = None # Err token + + # The start state is assumed to be (0,$end) + + statestack.append(0) + sym = YaccSymbol() + sym.type = "$end" + symstack.append(sym) + state = 0 + while 1: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + # --! DEBUG + debug.debug('') + debug.debug('State : %s', state) + # --! DEBUG + + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = "$end" + + # --! DEBUG + debug.debug('Stack : %s', + ("%s . %s" % (" ".join([xx.type for xx in symstack][1:]), str(lookahead))).lstrip()) + # --! DEBUG + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + + if t is not None: + if t > 0: + # shift a symbol on the stack + statestack.append(t) + state = t + + # --! DEBUG + debug.debug("Action : Shift and goto state %s", t) + # --! DEBUG + + symstack.append(lookahead) + lookahead = None + + # Decrease error count on successful shift + if errorcount: errorcount -=1 + continue + + if t < 0: + # reduce a symbol on the stack, emit a production + p = prod[-t] + pname = p.name + plen = p.len + + # Get production function + sym = YaccSymbol() + sym.type = pname # Production name + sym.value = None + + # --! DEBUG + if plen: + debug.info("Action : Reduce rule [%s] with %s and goto state %d", p.str, "["+",".join([format_stack_entry(_v.value) for _v in symstack[-plen:]])+"]",-t) + else: + debug.info("Action : Reduce rule [%s] with %s and goto state %d", p.str, [],-t) + + # --! DEBUG + + if plen: + targ = symstack[-plen-1:] + targ[0] = sym + + # --! TRACKING + if tracking: + t1 = targ[1] + sym.lineno = t1.lineno + sym.lexpos = t1.lexpos + t1 = targ[-1] + sym.endlineno = getattr(t1,"endlineno",t1.lineno) + sym.endlexpos = getattr(t1,"endlexpos",t1.lexpos) + + # --! TRACKING + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # below as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + del symstack[-plen:] + del statestack[-plen:] + p.callable(pslice) + # --! DEBUG + debug.info("Result : %s", format_result(pslice[0])) + # --! DEBUG + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + else: + + # --! TRACKING + if tracking: + sym.lineno = lexer.lineno + sym.lexpos = lexer.lexpos + # --! TRACKING + + targ = [ sym ] + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # above as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + p.callable(pslice) + # --! DEBUG + debug.info("Result : %s", format_result(pslice[0])) + # --! DEBUG + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + if t == 0: + n = symstack[-1] + result = getattr(n,"value",None) + # --! DEBUG + debug.info("Done : Returning %s", format_result(result)) + debug.info("PLY: PARSE DEBUG END") + # --! DEBUG + return result + + if t == None: + + # --! DEBUG + debug.error('Error : %s', + ("%s . %s" % (" ".join([xx.type for xx in symstack][1:]), str(lookahead))).lstrip()) + # --! DEBUG + + # We have some kind of parsing error here. To handle + # this, we are going to push the current token onto + # the tokenstack and replace it with an 'error' token. + # If there are any synchronization rules, they may + # catch it. + # + # In addition to pushing the error token, we call call + # the user defined p_error() function if this is the + # first syntax error. This function is only called if + # errorcount == 0. + if errorcount == 0 or self.errorok: + errorcount = error_count + self.errorok = 0 + errtoken = lookahead + if errtoken.type == "$end": + errtoken = None # End of file! + if self.errorfunc: + global errok,token,restart + errok = self.errok # Set some special functions available in error recovery + token = get_token + restart = self.restart + if errtoken and not hasattr(errtoken,'lexer'): + errtoken.lexer = lexer + tok = self.errorfunc(errtoken) + del errok, token, restart # Delete special functions + + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken,"lineno"): lineno = lookahead.lineno + else: lineno = 0 + if lineno: + sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type)) + else: + sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type) + else: + sys.stderr.write("yacc: Parse error in input. EOF\n") + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != "$end": + lookahead = None + errtoken = None + state = 0 + # Nuke the pushback stack + del lookaheadstack[:] + continue + + # case 2: the statestack has a couple of entries on it, but we're + # at the end of the file. nuke the top entry and generate an error token + + # Start nuking entries on the stack + if lookahead.type == "$end": + # Whoa. We're really hosed here. Bail out + return + + if lookahead.type != 'error': + sym = symstack[-1] + if sym.type == 'error': + # Hmmm. Error is on top of stack, we'll just nuke input + # symbol and continue + lookahead = None + continue + t = YaccSymbol() + t.type = 'error' + if hasattr(lookahead,"lineno"): + t.lineno = lookahead.lineno + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + symstack.pop() + statestack.pop() + state = statestack[-1] # Potential bug fix + + continue + + # Call an error function here + raise RuntimeError("yacc: internal parser error!!!\n") + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # parseopt(). + # + # Optimized version of parse() method. DO NOT EDIT THIS CODE DIRECTLY. + # Edit the debug version above, then copy any modifications to the method + # below while removing #--! DEBUG sections. + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + def parseopt(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None): + lookahead = None # Current lookahead symbol + lookaheadstack = [ ] # Stack of lookahead symbols + actions = self.action # Local reference to action table (to avoid lookup on self.) + goto = self.goto # Local reference to goto table (to avoid lookup on self.) + prod = self.productions # Local reference to production list (to avoid lookup on self.) + pslice = YaccProduction(None) # Production object passed to grammar rules + errorcount = 0 # Used during error recovery + + # If no lexer was given, we will try to use the lex module + if not lexer: + lex = load_ply_lex() + lexer = lex.lexer + + # Set up the lexer and parser objects on pslice + pslice.lexer = lexer + pslice.parser = self + + # If input was supplied, pass to lexer + if input is not None: + lexer.input(input) + + if tokenfunc is None: + # Tokenize function + get_token = lexer.token + else: + get_token = tokenfunc + + # Set up the state and symbol stacks + + statestack = [ ] # Stack of parsing states + self.statestack = statestack + symstack = [ ] # Stack of grammar symbols + self.symstack = symstack + + pslice.stack = symstack # Put in the production + errtoken = None # Err token + + # The start state is assumed to be (0,$end) + + statestack.append(0) + sym = YaccSymbol() + sym.type = '$end' + symstack.append(sym) + state = 0 + while 1: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = '$end' + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + + if t is not None: + if t > 0: + # shift a symbol on the stack + statestack.append(t) + state = t + + symstack.append(lookahead) + lookahead = None + + # Decrease error count on successful shift + if errorcount: errorcount -=1 + continue + + if t < 0: + # reduce a symbol on the stack, emit a production + p = prod[-t] + pname = p.name + plen = p.len + + # Get production function + sym = YaccSymbol() + sym.type = pname # Production name + sym.value = None + + if plen: + targ = symstack[-plen-1:] + targ[0] = sym + + # --! TRACKING + if tracking: + t1 = targ[1] + sym.lineno = t1.lineno + sym.lexpos = t1.lexpos + t1 = targ[-1] + sym.endlineno = getattr(t1,"endlineno",t1.lineno) + sym.endlexpos = getattr(t1,"endlexpos",t1.lexpos) + + # --! TRACKING + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # below as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + del symstack[-plen:] + del statestack[-plen:] + p.callable(pslice) + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + else: + + # --! TRACKING + if tracking: + sym.lineno = lexer.lineno + sym.lexpos = lexer.lexpos + # --! TRACKING + + targ = [ sym ] + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # above as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + p.callable(pslice) + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + if t == 0: + n = symstack[-1] + return getattr(n,"value",None) + + if t == None: + + # We have some kind of parsing error here. To handle + # this, we are going to push the current token onto + # the tokenstack and replace it with an 'error' token. + # If there are any synchronization rules, they may + # catch it. + # + # In addition to pushing the error token, we call call + # the user defined p_error() function if this is the + # first syntax error. This function is only called if + # errorcount == 0. + if errorcount == 0 or self.errorok: + errorcount = error_count + self.errorok = 0 + errtoken = lookahead + if errtoken.type == '$end': + errtoken = None # End of file! + if self.errorfunc: + global errok,token,restart + errok = self.errok # Set some special functions available in error recovery + token = get_token + restart = self.restart + if errtoken and not hasattr(errtoken,'lexer'): + errtoken.lexer = lexer + tok = self.errorfunc(errtoken) + del errok, token, restart # Delete special functions + + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken,"lineno"): lineno = lookahead.lineno + else: lineno = 0 + if lineno: + sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type)) + else: + sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type) + else: + sys.stderr.write("yacc: Parse error in input. EOF\n") + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != '$end': + lookahead = None + errtoken = None + state = 0 + # Nuke the pushback stack + del lookaheadstack[:] + continue + + # case 2: the statestack has a couple of entries on it, but we're + # at the end of the file. nuke the top entry and generate an error token + + # Start nuking entries on the stack + if lookahead.type == '$end': + # Whoa. We're really hosed here. Bail out + return + + if lookahead.type != 'error': + sym = symstack[-1] + if sym.type == 'error': + # Hmmm. Error is on top of stack, we'll just nuke input + # symbol and continue + lookahead = None + continue + t = YaccSymbol() + t.type = 'error' + if hasattr(lookahead,"lineno"): + t.lineno = lookahead.lineno + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + symstack.pop() + statestack.pop() + state = statestack[-1] # Potential bug fix + + continue + + # Call an error function here + raise RuntimeError("yacc: internal parser error!!!\n") + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # parseopt_notrack(). + # + # Optimized version of parseopt() with line number tracking removed. + # DO NOT EDIT THIS CODE DIRECTLY. Copy the optimized version and remove + # code in the #--! TRACKING sections + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + def parseopt_notrack(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None): + lookahead = None # Current lookahead symbol + lookaheadstack = [ ] # Stack of lookahead symbols + actions = self.action # Local reference to action table (to avoid lookup on self.) + goto = self.goto # Local reference to goto table (to avoid lookup on self.) + prod = self.productions # Local reference to production list (to avoid lookup on self.) + pslice = YaccProduction(None) # Production object passed to grammar rules + errorcount = 0 # Used during error recovery + + # If no lexer was given, we will try to use the lex module + if not lexer: + lex = load_ply_lex() + lexer = lex.lexer + + # Set up the lexer and parser objects on pslice + pslice.lexer = lexer + pslice.parser = self + + # If input was supplied, pass to lexer + if input is not None: + lexer.input(input) + + if tokenfunc is None: + # Tokenize function + get_token = lexer.token + else: + get_token = tokenfunc + + # Set up the state and symbol stacks + + statestack = [ ] # Stack of parsing states + self.statestack = statestack + symstack = [ ] # Stack of grammar symbols + self.symstack = symstack + + pslice.stack = symstack # Put in the production + errtoken = None # Err token + + # The start state is assumed to be (0,$end) + + statestack.append(0) + sym = YaccSymbol() + sym.type = '$end' + symstack.append(sym) + state = 0 + while 1: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = '$end' + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + + if t is not None: + if t > 0: + # shift a symbol on the stack + statestack.append(t) + state = t + + symstack.append(lookahead) + lookahead = None + + # Decrease error count on successful shift + if errorcount: errorcount -=1 + continue + + if t < 0: + # reduce a symbol on the stack, emit a production + p = prod[-t] + pname = p.name + plen = p.len + + # Get production function + sym = YaccSymbol() + sym.type = pname # Production name + sym.value = None + + if plen: + targ = symstack[-plen-1:] + targ[0] = sym + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # below as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + del symstack[-plen:] + del statestack[-plen:] + p.callable(pslice) + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + else: + + targ = [ sym ] + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # The code enclosed in this section is duplicated + # above as a performance optimization. Make sure + # changes get made in both locations. + + pslice.slice = targ + + try: + # Call the grammar rule with our special slice object + p.callable(pslice) + symstack.append(sym) + state = goto[statestack[-1]][pname] + statestack.append(state) + except SyntaxError: + # If an error was set. Enter error recovery state + lookaheadstack.append(lookahead) + symstack.pop() + statestack.pop() + state = statestack[-1] + sym.type = 'error' + lookahead = sym + errorcount = error_count + self.errorok = 0 + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + if t == 0: + n = symstack[-1] + return getattr(n,"value",None) + + if t == None: + + # We have some kind of parsing error here. To handle + # this, we are going to push the current token onto + # the tokenstack and replace it with an 'error' token. + # If there are any synchronization rules, they may + # catch it. + # + # In addition to pushing the error token, we call call + # the user defined p_error() function if this is the + # first syntax error. This function is only called if + # errorcount == 0. + if errorcount == 0 or self.errorok: + errorcount = error_count + self.errorok = 0 + errtoken = lookahead + if errtoken.type == '$end': + errtoken = None # End of file! + if self.errorfunc: + global errok,token,restart + errok = self.errok # Set some special functions available in error recovery + token = get_token + restart = self.restart + if errtoken and not hasattr(errtoken,'lexer'): + errtoken.lexer = lexer + tok = self.errorfunc(errtoken) + del errok, token, restart # Delete special functions + + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken,"lineno"): lineno = lookahead.lineno + else: lineno = 0 + if lineno: + sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type)) + else: + sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type) + else: + sys.stderr.write("yacc: Parse error in input. EOF\n") + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != '$end': + lookahead = None + errtoken = None + state = 0 + # Nuke the pushback stack + del lookaheadstack[:] + continue + + # case 2: the statestack has a couple of entries on it, but we're + # at the end of the file. nuke the top entry and generate an error token + + # Start nuking entries on the stack + if lookahead.type == '$end': + # Whoa. We're really hosed here. Bail out + return + + if lookahead.type != 'error': + sym = symstack[-1] + if sym.type == 'error': + # Hmmm. Error is on top of stack, we'll just nuke input + # symbol and continue + lookahead = None + continue + t = YaccSymbol() + t.type = 'error' + if hasattr(lookahead,"lineno"): + t.lineno = lookahead.lineno + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + symstack.pop() + statestack.pop() + state = statestack[-1] # Potential bug fix + + continue + + # Call an error function here + raise RuntimeError("yacc: internal parser error!!!\n") + +# ----------------------------------------------------------------------------- +# === Grammar Representation === +# +# The following functions, classes, and variables are used to represent and +# manipulate the rules that make up a grammar. +# ----------------------------------------------------------------------------- + +import re + +# regex matching identifiers +_is_identifier = re.compile(r'^[a-zA-Z0-9_-]+$') + +# ----------------------------------------------------------------------------- +# class Production: +# +# This class stores the raw information about a single production or grammar rule. +# A grammar rule refers to a specification such as this: +# +# expr : expr PLUS term +# +# Here are the basic attributes defined on all productions +# +# name - Name of the production. For example 'expr' +# prod - A list of symbols on the right side ['expr','PLUS','term'] +# prec - Production precedence level +# number - Production number. +# func - Function that executes on reduce +# file - File where production function is defined +# lineno - Line number where production function is defined +# +# The following attributes are defined or optional. +# +# len - Length of the production (number of symbols on right hand side) +# usyms - Set of unique symbols found in the production +# ----------------------------------------------------------------------------- + +class Production(object): + reduced = 0 + def __init__(self,number,name,prod,precedence=('right',0),func=None,file='',line=0): + self.name = name + self.prod = tuple(prod) + self.number = number + self.func = func + self.callable = None + self.file = file + self.line = line + self.prec = precedence + + # Internal settings used during table construction + + self.len = len(self.prod) # Length of the production + + # Create a list of unique production symbols used in the production + self.usyms = [ ] + for s in self.prod: + if s not in self.usyms: + self.usyms.append(s) + + # List of all LR items for the production + self.lr_items = [] + self.lr_next = None + + # Create a string representation + if self.prod: + self.str = "%s -> %s" % (self.name," ".join(self.prod)) + else: + self.str = "%s -> <empty>" % self.name + + def __str__(self): + return self.str + + def __repr__(self): + return "Production("+str(self)+")" + + def __len__(self): + return len(self.prod) + + def __nonzero__(self): + return 1 + + def __getitem__(self,index): + return self.prod[index] + + # Return the nth lr_item from the production (or None if at the end) + def lr_item(self,n): + if n > len(self.prod): return None + p = LRItem(self,n) + + # Precompute the list of productions immediately following. Hack. Remove later + try: + p.lr_after = Prodnames[p.prod[n+1]] + except (IndexError,KeyError): + p.lr_after = [] + try: + p.lr_before = p.prod[n-1] + except IndexError: + p.lr_before = None + + return p + + # Bind the production function name to a callable + def bind(self,pdict): + if self.func: + self.callable = pdict[self.func] + +# This class serves as a minimal standin for Production objects when +# reading table data from files. It only contains information +# actually used by the LR parsing engine, plus some additional +# debugging information. +class MiniProduction(object): + def __init__(self,str,name,len,func,file,line): + self.name = name + self.len = len + self.func = func + self.callable = None + self.file = file + self.line = line + self.str = str + def __str__(self): + return self.str + def __repr__(self): + return "MiniProduction(%s)" % self.str + + # Bind the production function name to a callable + def bind(self,pdict): + if self.func: + self.callable = pdict[self.func] + + +# ----------------------------------------------------------------------------- +# class LRItem +# +# This class represents a specific stage of parsing a production rule. For +# example: +# +# expr : expr . PLUS term +# +# In the above, the "." represents the current location of the parse. Here +# basic attributes: +# +# name - Name of the production. For example 'expr' +# prod - A list of symbols on the right side ['expr','.', 'PLUS','term'] +# number - Production number. +# +# lr_next Next LR item. Example, if we are ' expr -> expr . PLUS term' +# then lr_next refers to 'expr -> expr PLUS . term' +# lr_index - LR item index (location of the ".") in the prod list. +# lookaheads - LALR lookahead symbols for this item +# len - Length of the production (number of symbols on right hand side) +# lr_after - List of all productions that immediately follow +# lr_before - Grammar symbol immediately before +# ----------------------------------------------------------------------------- + +class LRItem(object): + def __init__(self,p,n): + self.name = p.name + self.prod = list(p.prod) + self.number = p.number + self.lr_index = n + self.lookaheads = { } + self.prod.insert(n,".") + self.prod = tuple(self.prod) + self.len = len(self.prod) + self.usyms = p.usyms + + def __str__(self): + if self.prod: + s = "%s -> %s" % (self.name," ".join(self.prod)) + else: + s = "%s -> <empty>" % self.name + return s + + def __repr__(self): + return "LRItem("+str(self)+")" + +# ----------------------------------------------------------------------------- +# rightmost_terminal() +# +# Return the rightmost terminal from a list of symbols. Used in add_production() +# ----------------------------------------------------------------------------- +def rightmost_terminal(symbols, terminals): + i = len(symbols) - 1 + while i >= 0: + if symbols[i] in terminals: + return symbols[i] + i -= 1 + return None + +# ----------------------------------------------------------------------------- +# === GRAMMAR CLASS === +# +# The following class represents the contents of the specified grammar along +# with various computed properties such as first sets, follow sets, LR items, etc. +# This data is used for critical parts of the table generation process later. +# ----------------------------------------------------------------------------- + +class GrammarError(YaccError): pass + +class Grammar(object): + def __init__(self,terminals): + self.Productions = [None] # A list of all of the productions. The first + # entry is always reserved for the purpose of + # building an augmented grammar + + self.Prodnames = { } # A dictionary mapping the names of nonterminals to a list of all + # productions of that nonterminal. + + self.Prodmap = { } # A dictionary that is only used to detect duplicate + # productions. + + self.Terminals = { } # A dictionary mapping the names of terminal symbols to a + # list of the rules where they are used. + + for term in terminals: + self.Terminals[term] = [] + + self.Terminals['error'] = [] + + self.Nonterminals = { } # A dictionary mapping names of nonterminals to a list + # of rule numbers where they are used. + + self.First = { } # A dictionary of precomputed FIRST(x) symbols + + self.Follow = { } # A dictionary of precomputed FOLLOW(x) symbols + + self.Precedence = { } # Precedence rules for each terminal. Contains tuples of the + # form ('right',level) or ('nonassoc', level) or ('left',level) + + self.UsedPrecedence = { } # Precedence rules that were actually used by the grammer. + # This is only used to provide error checking and to generate + # a warning about unused precedence rules. + + self.Start = None # Starting symbol for the grammar + + + def __len__(self): + return len(self.Productions) + + def __getitem__(self,index): + return self.Productions[index] + + # ----------------------------------------------------------------------------- + # set_precedence() + # + # Sets the precedence for a given terminal. assoc is the associativity such as + # 'left','right', or 'nonassoc'. level is a numeric level. + # + # ----------------------------------------------------------------------------- + + def set_precedence(self,term,assoc,level): + assert self.Productions == [None],"Must call set_precedence() before add_production()" + if term in self.Precedence: + raise GrammarError("Precedence already specified for terminal '%s'" % term) + if assoc not in ['left','right','nonassoc']: + raise GrammarError("Associativity must be one of 'left','right', or 'nonassoc'") + self.Precedence[term] = (assoc,level) + + # ----------------------------------------------------------------------------- + # add_production() + # + # Given an action function, this function assembles a production rule and + # computes its precedence level. + # + # The production rule is supplied as a list of symbols. For example, + # a rule such as 'expr : expr PLUS term' has a production name of 'expr' and + # symbols ['expr','PLUS','term']. + # + # Precedence is determined by the precedence of the right-most non-terminal + # or the precedence of a terminal specified by %prec. + # + # A variety of error checks are performed to make sure production symbols + # are valid and that %prec is used correctly. + # ----------------------------------------------------------------------------- + + def add_production(self,prodname,syms,func=None,file='',line=0): + + if prodname in self.Terminals: + raise GrammarError("%s:%d: Illegal rule name '%s'. Already defined as a token" % (file,line,prodname)) + if prodname == 'error': + raise GrammarError("%s:%d: Illegal rule name '%s'. error is a reserved word" % (file,line,prodname)) + if not _is_identifier.match(prodname): + raise GrammarError("%s:%d: Illegal rule name '%s'" % (file,line,prodname)) + + # Look for literal tokens + for n,s in enumerate(syms): + if s[0] in "'\"": + try: + c = eval(s) + if (len(c) > 1): + raise GrammarError("%s:%d: Literal token %s in rule '%s' may only be a single character" % (file,line,s, prodname)) + if not c in self.Terminals: + self.Terminals[c] = [] + syms[n] = c + continue + except SyntaxError: + pass + if not _is_identifier.match(s) and s != '%prec': + raise GrammarError("%s:%d: Illegal name '%s' in rule '%s'" % (file,line,s, prodname)) + + # Determine the precedence level + if '%prec' in syms: + if syms[-1] == '%prec': + raise GrammarError("%s:%d: Syntax error. Nothing follows %%prec" % (file,line)) + if syms[-2] != '%prec': + raise GrammarError("%s:%d: Syntax error. %%prec can only appear at the end of a grammar rule" % (file,line)) + precname = syms[-1] + prodprec = self.Precedence.get(precname,None) + if not prodprec: + raise GrammarError("%s:%d: Nothing known about the precedence of '%s'" % (file,line,precname)) + else: + self.UsedPrecedence[precname] = 1 + del syms[-2:] # Drop %prec from the rule + else: + # If no %prec, precedence is determined by the rightmost terminal symbol + precname = rightmost_terminal(syms,self.Terminals) + prodprec = self.Precedence.get(precname,('right',0)) + + # See if the rule is already in the rulemap + map = "%s -> %s" % (prodname,syms) + if map in self.Prodmap: + m = self.Prodmap[map] + raise GrammarError("%s:%d: Duplicate rule %s. " % (file,line, m) + + "Previous definition at %s:%d" % (m.file, m.line)) + + # From this point on, everything is valid. Create a new Production instance + pnumber = len(self.Productions) + if not prodname in self.Nonterminals: + self.Nonterminals[prodname] = [ ] + + # Add the production number to Terminals and Nonterminals + for t in syms: + if t in self.Terminals: + self.Terminals[t].append(pnumber) + else: + if not t in self.Nonterminals: + self.Nonterminals[t] = [ ] + self.Nonterminals[t].append(pnumber) + + # Create a production and add it to the list of productions + p = Production(pnumber,prodname,syms,prodprec,func,file,line) + self.Productions.append(p) + self.Prodmap[map] = p + + # Add to the global productions list + try: + self.Prodnames[prodname].append(p) + except KeyError: + self.Prodnames[prodname] = [ p ] + return 0 + + # ----------------------------------------------------------------------------- + # set_start() + # + # Sets the starting symbol and creates the augmented grammar. Production + # rule 0 is S' -> start where start is the start symbol. + # ----------------------------------------------------------------------------- + + def set_start(self,start=None): + if not start: + start = self.Productions[1].name + if start not in self.Nonterminals: + raise GrammarError("start symbol %s undefined" % start) + self.Productions[0] = Production(0,"S'",[start]) + self.Nonterminals[start].append(0) + self.Start = start + + # ----------------------------------------------------------------------------- + # find_unreachable() + # + # Find all of the nonterminal symbols that can't be reached from the starting + # symbol. Returns a list of nonterminals that can't be reached. + # ----------------------------------------------------------------------------- + + def find_unreachable(self): + + # Mark all symbols that are reachable from a symbol s + def mark_reachable_from(s): + if reachable[s]: + # We've already reached symbol s. + return + reachable[s] = 1 + for p in self.Prodnames.get(s,[]): + for r in p.prod: + mark_reachable_from(r) + + reachable = { } + for s in list(self.Terminals) + list(self.Nonterminals): + reachable[s] = 0 + + mark_reachable_from( self.Productions[0].prod[0] ) + + return [s for s in list(self.Nonterminals) + if not reachable[s]] + + # ----------------------------------------------------------------------------- + # infinite_cycles() + # + # This function looks at the various parsing rules and tries to detect + # infinite recursion cycles (grammar rules where there is no possible way + # to derive a string of only terminals). + # ----------------------------------------------------------------------------- + + def infinite_cycles(self): + terminates = {} + + # Terminals: + for t in self.Terminals: + terminates[t] = 1 + + terminates['$end'] = 1 + + # Nonterminals: + + # Initialize to false: + for n in self.Nonterminals: + terminates[n] = 0 + + # Then propagate termination until no change: + while 1: + some_change = 0 + for (n,pl) in self.Prodnames.items(): + # Nonterminal n terminates iff any of its productions terminates. + for p in pl: + # Production p terminates iff all of its rhs symbols terminate. + for s in p.prod: + if not terminates[s]: + # The symbol s does not terminate, + # so production p does not terminate. + p_terminates = 0 + break + else: + # didn't break from the loop, + # so every symbol s terminates + # so production p terminates. + p_terminates = 1 + + if p_terminates: + # symbol n terminates! + if not terminates[n]: + terminates[n] = 1 + some_change = 1 + # Don't need to consider any more productions for this n. + break + + if not some_change: + break + + infinite = [] + for (s,term) in terminates.items(): + if not term: + if not s in self.Prodnames and not s in self.Terminals and s != 'error': + # s is used-but-not-defined, and we've already warned of that, + # so it would be overkill to say that it's also non-terminating. + pass + else: + infinite.append(s) + + return infinite + + + # ----------------------------------------------------------------------------- + # undefined_symbols() + # + # Find all symbols that were used the grammar, but not defined as tokens or + # grammar rules. Returns a list of tuples (sym, prod) where sym in the symbol + # and prod is the production where the symbol was used. + # ----------------------------------------------------------------------------- + def undefined_symbols(self): + result = [] + for p in self.Productions: + if not p: continue + + for s in p.prod: + if not s in self.Prodnames and not s in self.Terminals and s != 'error': + result.append((s,p)) + return result + + # ----------------------------------------------------------------------------- + # unused_terminals() + # + # Find all terminals that were defined, but not used by the grammar. Returns + # a list of all symbols. + # ----------------------------------------------------------------------------- + def unused_terminals(self): + unused_tok = [] + for s,v in self.Terminals.items(): + if s != 'error' and not v: + unused_tok.append(s) + + return unused_tok + + # ------------------------------------------------------------------------------ + # unused_rules() + # + # Find all grammar rules that were defined, but not used (maybe not reachable) + # Returns a list of productions. + # ------------------------------------------------------------------------------ + + def unused_rules(self): + unused_prod = [] + for s,v in self.Nonterminals.items(): + if not v: + p = self.Prodnames[s][0] + unused_prod.append(p) + return unused_prod + + # ----------------------------------------------------------------------------- + # unused_precedence() + # + # Returns a list of tuples (term,precedence) corresponding to precedence + # rules that were never used by the grammar. term is the name of the terminal + # on which precedence was applied and precedence is a string such as 'left' or + # 'right' corresponding to the type of precedence. + # ----------------------------------------------------------------------------- + + def unused_precedence(self): + unused = [] + for termname in self.Precedence: + if not (termname in self.Terminals or termname in self.UsedPrecedence): + unused.append((termname,self.Precedence[termname][0])) + + return unused + + # ------------------------------------------------------------------------- + # _first() + # + # Compute the value of FIRST1(beta) where beta is a tuple of symbols. + # + # During execution of compute_first1, the result may be incomplete. + # Afterward (e.g., when called from compute_follow()), it will be complete. + # ------------------------------------------------------------------------- + def _first(self,beta): + + # We are computing First(x1,x2,x3,...,xn) + result = [ ] + for x in beta: + x_produces_empty = 0 + + # Add all the non-<empty> symbols of First[x] to the result. + for f in self.First[x]: + if f == '<empty>': + x_produces_empty = 1 + else: + if f not in result: result.append(f) + + if x_produces_empty: + # We have to consider the next x in beta, + # i.e. stay in the loop. + pass + else: + # We don't have to consider any further symbols in beta. + break + else: + # There was no 'break' from the loop, + # so x_produces_empty was true for all x in beta, + # so beta produces empty as well. + result.append('<empty>') + + return result + + # ------------------------------------------------------------------------- + # compute_first() + # + # Compute the value of FIRST1(X) for all symbols + # ------------------------------------------------------------------------- + def compute_first(self): + if self.First: + return self.First + + # Terminals: + for t in self.Terminals: + self.First[t] = [t] + + self.First['$end'] = ['$end'] + + # Nonterminals: + + # Initialize to the empty set: + for n in self.Nonterminals: + self.First[n] = [] + + # Then propagate symbols until no change: + while 1: + some_change = 0 + for n in self.Nonterminals: + for p in self.Prodnames[n]: + for f in self._first(p.prod): + if f not in self.First[n]: + self.First[n].append( f ) + some_change = 1 + if not some_change: + break + + return self.First + + # --------------------------------------------------------------------- + # compute_follow() + # + # Computes all of the follow sets for every non-terminal symbol. The + # follow set is the set of all symbols that might follow a given + # non-terminal. See the Dragon book, 2nd Ed. p. 189. + # --------------------------------------------------------------------- + def compute_follow(self,start=None): + # If already computed, return the result + if self.Follow: + return self.Follow + + # If first sets not computed yet, do that first. + if not self.First: + self.compute_first() + + # Add '$end' to the follow list of the start symbol + for k in self.Nonterminals: + self.Follow[k] = [ ] + + if not start: + start = self.Productions[1].name + + self.Follow[start] = [ '$end' ] + + while 1: + didadd = 0 + for p in self.Productions[1:]: + # Here is the production set + for i in range(len(p.prod)): + B = p.prod[i] + if B in self.Nonterminals: + # Okay. We got a non-terminal in a production + fst = self._first(p.prod[i+1:]) + hasempty = 0 + for f in fst: + if f != '<empty>' and f not in self.Follow[B]: + self.Follow[B].append(f) + didadd = 1 + if f == '<empty>': + hasempty = 1 + if hasempty or i == (len(p.prod)-1): + # Add elements of follow(a) to follow(b) + for f in self.Follow[p.name]: + if f not in self.Follow[B]: + self.Follow[B].append(f) + didadd = 1 + if not didadd: break + return self.Follow + + + # ----------------------------------------------------------------------------- + # build_lritems() + # + # This function walks the list of productions and builds a complete set of the + # LR items. The LR items are stored in two ways: First, they are uniquely + # numbered and placed in the list _lritems. Second, a linked list of LR items + # is built for each production. For example: + # + # E -> E PLUS E + # + # Creates the list + # + # [E -> . E PLUS E, E -> E . PLUS E, E -> E PLUS . E, E -> E PLUS E . ] + # ----------------------------------------------------------------------------- + + def build_lritems(self): + for p in self.Productions: + lastlri = p + i = 0 + lr_items = [] + while 1: + if i > len(p): + lri = None + else: + lri = LRItem(p,i) + # Precompute the list of productions immediately following + try: + lri.lr_after = self.Prodnames[lri.prod[i+1]] + except (IndexError,KeyError): + lri.lr_after = [] + try: + lri.lr_before = lri.prod[i-1] + except IndexError: + lri.lr_before = None + + lastlri.lr_next = lri + if not lri: break + lr_items.append(lri) + lastlri = lri + i += 1 + p.lr_items = lr_items + +# ----------------------------------------------------------------------------- +# == Class LRTable == +# +# This basic class represents a basic table of LR parsing information. +# Methods for generating the tables are not defined here. They are defined +# in the derived class LRGeneratedTable. +# ----------------------------------------------------------------------------- + +class VersionError(YaccError): pass + +class LRTable(object): + def __init__(self): + self.lr_action = None + self.lr_goto = None + self.lr_productions = None + self.lr_method = None + + def read_table(self,module): + if isinstance(module,types.ModuleType): + parsetab = module + else: + if sys.version_info[0] < 3: + exec("import %s as parsetab" % module) + else: + env = { } + exec("import %s as parsetab" % module, env, env) + parsetab = env['parsetab'] + + if parsetab._tabversion != __tabversion__: + raise VersionError("yacc table file version is out of date") + + self.lr_action = parsetab._lr_action + self.lr_goto = parsetab._lr_goto + + self.lr_productions = [] + for p in parsetab._lr_productions: + self.lr_productions.append(MiniProduction(*p)) + + self.lr_method = parsetab._lr_method + return parsetab._lr_signature + + def read_pickle(self,filename): + try: + import cPickle as pickle + except ImportError: + import pickle + + in_f = open(filename,"rb") + + tabversion = pickle.load(in_f) + if tabversion != __tabversion__: + raise VersionError("yacc table file version is out of date") + self.lr_method = pickle.load(in_f) + signature = pickle.load(in_f) + self.lr_action = pickle.load(in_f) + self.lr_goto = pickle.load(in_f) + productions = pickle.load(in_f) + + self.lr_productions = [] + for p in productions: + self.lr_productions.append(MiniProduction(*p)) + + in_f.close() + return signature + + # Bind all production function names to callable objects in pdict + def bind_callables(self,pdict): + for p in self.lr_productions: + p.bind(pdict) + +# ----------------------------------------------------------------------------- +# === LR Generator === +# +# The following classes and functions are used to generate LR parsing tables on +# a grammar. +# ----------------------------------------------------------------------------- + +# ----------------------------------------------------------------------------- +# digraph() +# traverse() +# +# The following two functions are used to compute set valued functions +# of the form: +# +# F(x) = F'(x) U U{F(y) | x R y} +# +# This is used to compute the values of Read() sets as well as FOLLOW sets +# in LALR(1) generation. +# +# Inputs: X - An input set +# R - A relation +# FP - Set-valued function +# ------------------------------------------------------------------------------ + +def digraph(X,R,FP): + N = { } + for x in X: + N[x] = 0 + stack = [] + F = { } + for x in X: + if N[x] == 0: traverse(x,N,stack,F,X,R,FP) + return F + +def traverse(x,N,stack,F,X,R,FP): + stack.append(x) + d = len(stack) + N[x] = d + F[x] = FP(x) # F(X) <- F'(x) + + rel = R(x) # Get y's related to x + for y in rel: + if N[y] == 0: + traverse(y,N,stack,F,X,R,FP) + N[x] = min(N[x],N[y]) + for a in F.get(y,[]): + if a not in F[x]: F[x].append(a) + if N[x] == d: + N[stack[-1]] = MAXINT + F[stack[-1]] = F[x] + element = stack.pop() + while element != x: + N[stack[-1]] = MAXINT + F[stack[-1]] = F[x] + element = stack.pop() + +class LALRError(YaccError): pass + +# ----------------------------------------------------------------------------- +# == LRGeneratedTable == +# +# This class implements the LR table generation algorithm. There are no +# public methods except for write() +# ----------------------------------------------------------------------------- + +class LRGeneratedTable(LRTable): + def __init__(self,grammar,method='LALR',log=None): + if method not in ['SLR','LALR']: + raise LALRError("Unsupported method %s" % method) + + self.grammar = grammar + self.lr_method = method + + # Set up the logger + if not log: + log = NullLogger() + self.log = log + + # Internal attributes + self.lr_action = {} # Action table + self.lr_goto = {} # Goto table + self.lr_productions = grammar.Productions # Copy of grammar Production array + self.lr_goto_cache = {} # Cache of computed gotos + self.lr0_cidhash = {} # Cache of closures + + self._add_count = 0 # Internal counter used to detect cycles + + # Diagonistic information filled in by the table generator + self.sr_conflict = 0 + self.rr_conflict = 0 + self.conflicts = [] # List of conflicts + + self.sr_conflicts = [] + self.rr_conflicts = [] + + # Build the tables + self.grammar.build_lritems() + self.grammar.compute_first() + self.grammar.compute_follow() + self.lr_parse_table() + + # Compute the LR(0) closure operation on I, where I is a set of LR(0) items. + + def lr0_closure(self,I): + self._add_count += 1 + + # Add everything in I to J + J = I[:] + didadd = 1 + while didadd: + didadd = 0 + for j in J: + for x in j.lr_after: + if getattr(x,"lr0_added",0) == self._add_count: continue + # Add B --> .G to J + J.append(x.lr_next) + x.lr0_added = self._add_count + didadd = 1 + + return J + + # Compute the LR(0) goto function goto(I,X) where I is a set + # of LR(0) items and X is a grammar symbol. This function is written + # in a way that guarantees uniqueness of the generated goto sets + # (i.e. the same goto set will never be returned as two different Python + # objects). With uniqueness, we can later do fast set comparisons using + # id(obj) instead of element-wise comparison. + + def lr0_goto(self,I,x): + # First we look for a previously cached entry + g = self.lr_goto_cache.get((id(I),x),None) + if g: return g + + # Now we generate the goto set in a way that guarantees uniqueness + # of the result + + s = self.lr_goto_cache.get(x,None) + if not s: + s = { } + self.lr_goto_cache[x] = s + + gs = [ ] + for p in I: + n = p.lr_next + if n and n.lr_before == x: + s1 = s.get(id(n),None) + if not s1: + s1 = { } + s[id(n)] = s1 + gs.append(n) + s = s1 + g = s.get('$end',None) + if not g: + if gs: + g = self.lr0_closure(gs) + s['$end'] = g + else: + s['$end'] = gs + self.lr_goto_cache[(id(I),x)] = g + return g + + # Compute the LR(0) sets of item function + def lr0_items(self): + + C = [ self.lr0_closure([self.grammar.Productions[0].lr_next]) ] + i = 0 + for I in C: + self.lr0_cidhash[id(I)] = i + i += 1 + + # Loop over the items in C and each grammar symbols + i = 0 + while i < len(C): + I = C[i] + i += 1 + + # Collect all of the symbols that could possibly be in the goto(I,X) sets + asyms = { } + for ii in I: + for s in ii.usyms: + asyms[s] = None + + for x in asyms: + g = self.lr0_goto(I,x) + if not g: continue + if id(g) in self.lr0_cidhash: continue + self.lr0_cidhash[id(g)] = len(C) + C.append(g) + + return C + + # ----------------------------------------------------------------------------- + # ==== LALR(1) Parsing ==== + # + # LALR(1) parsing is almost exactly the same as SLR except that instead of + # relying upon Follow() sets when performing reductions, a more selective + # lookahead set that incorporates the state of the LR(0) machine is utilized. + # Thus, we mainly just have to focus on calculating the lookahead sets. + # + # The method used here is due to DeRemer and Pennelo (1982). + # + # DeRemer, F. L., and T. J. Pennelo: "Efficient Computation of LALR(1) + # Lookahead Sets", ACM Transactions on Programming Languages and Systems, + # Vol. 4, No. 4, Oct. 1982, pp. 615-649 + # + # Further details can also be found in: + # + # J. Tremblay and P. Sorenson, "The Theory and Practice of Compiler Writing", + # McGraw-Hill Book Company, (1985). + # + # ----------------------------------------------------------------------------- + + # ----------------------------------------------------------------------------- + # compute_nullable_nonterminals() + # + # Creates a dictionary containing all of the non-terminals that might produce + # an empty production. + # ----------------------------------------------------------------------------- + + def compute_nullable_nonterminals(self): + nullable = {} + num_nullable = 0 + while 1: + for p in self.grammar.Productions[1:]: + if p.len == 0: + nullable[p.name] = 1 + continue + for t in p.prod: + if not t in nullable: break + else: + nullable[p.name] = 1 + if len(nullable) == num_nullable: break + num_nullable = len(nullable) + return nullable + + # ----------------------------------------------------------------------------- + # find_nonterminal_trans(C) + # + # Given a set of LR(0) items, this functions finds all of the non-terminal + # transitions. These are transitions in which a dot appears immediately before + # a non-terminal. Returns a list of tuples of the form (state,N) where state + # is the state number and N is the nonterminal symbol. + # + # The input C is the set of LR(0) items. + # ----------------------------------------------------------------------------- + + def find_nonterminal_transitions(self,C): + trans = [] + for state in range(len(C)): + for p in C[state]: + if p.lr_index < p.len - 1: + t = (state,p.prod[p.lr_index+1]) + if t[1] in self.grammar.Nonterminals: + if t not in trans: trans.append(t) + state = state + 1 + return trans + + # ----------------------------------------------------------------------------- + # dr_relation() + # + # Computes the DR(p,A) relationships for non-terminal transitions. The input + # is a tuple (state,N) where state is a number and N is a nonterminal symbol. + # + # Returns a list of terminals. + # ----------------------------------------------------------------------------- + + def dr_relation(self,C,trans,nullable): + dr_set = { } + state,N = trans + terms = [] + + g = self.lr0_goto(C[state],N) + for p in g: + if p.lr_index < p.len - 1: + a = p.prod[p.lr_index+1] + if a in self.grammar.Terminals: + if a not in terms: terms.append(a) + + # This extra bit is to handle the start state + if state == 0 and N == self.grammar.Productions[0].prod[0]: + terms.append('$end') + + return terms + + # ----------------------------------------------------------------------------- + # reads_relation() + # + # Computes the READS() relation (p,A) READS (t,C). + # ----------------------------------------------------------------------------- + + def reads_relation(self,C, trans, empty): + # Look for empty transitions + rel = [] + state, N = trans + + g = self.lr0_goto(C[state],N) + j = self.lr0_cidhash.get(id(g),-1) + for p in g: + if p.lr_index < p.len - 1: + a = p.prod[p.lr_index + 1] + if a in empty: + rel.append((j,a)) + + return rel + + # ----------------------------------------------------------------------------- + # compute_lookback_includes() + # + # Determines the lookback and includes relations + # + # LOOKBACK: + # + # This relation is determined by running the LR(0) state machine forward. + # For example, starting with a production "N : . A B C", we run it forward + # to obtain "N : A B C ." We then build a relationship between this final + # state and the starting state. These relationships are stored in a dictionary + # lookdict. + # + # INCLUDES: + # + # Computes the INCLUDE() relation (p,A) INCLUDES (p',B). + # + # This relation is used to determine non-terminal transitions that occur + # inside of other non-terminal transition states. (p,A) INCLUDES (p', B) + # if the following holds: + # + # B -> LAT, where T -> epsilon and p' -L-> p + # + # L is essentially a prefix (which may be empty), T is a suffix that must be + # able to derive an empty string. State p' must lead to state p with the string L. + # + # ----------------------------------------------------------------------------- + + def compute_lookback_includes(self,C,trans,nullable): + + lookdict = {} # Dictionary of lookback relations + includedict = {} # Dictionary of include relations + + # Make a dictionary of non-terminal transitions + dtrans = {} + for t in trans: + dtrans[t] = 1 + + # Loop over all transitions and compute lookbacks and includes + for state,N in trans: + lookb = [] + includes = [] + for p in C[state]: + if p.name != N: continue + + # Okay, we have a name match. We now follow the production all the way + # through the state machine until we get the . on the right hand side + + lr_index = p.lr_index + j = state + while lr_index < p.len - 1: + lr_index = lr_index + 1 + t = p.prod[lr_index] + + # Check to see if this symbol and state are a non-terminal transition + if (j,t) in dtrans: + # Yes. Okay, there is some chance that this is an includes relation + # the only way to know for certain is whether the rest of the + # production derives empty + + li = lr_index + 1 + while li < p.len: + if p.prod[li] in self.grammar.Terminals: break # No forget it + if not p.prod[li] in nullable: break + li = li + 1 + else: + # Appears to be a relation between (j,t) and (state,N) + includes.append((j,t)) + + g = self.lr0_goto(C[j],t) # Go to next set + j = self.lr0_cidhash.get(id(g),-1) # Go to next state + + # When we get here, j is the final state, now we have to locate the production + for r in C[j]: + if r.name != p.name: continue + if r.len != p.len: continue + i = 0 + # This look is comparing a production ". A B C" with "A B C ." + while i < r.lr_index: + if r.prod[i] != p.prod[i+1]: break + i = i + 1 + else: + lookb.append((j,r)) + for i in includes: + if not i in includedict: includedict[i] = [] + includedict[i].append((state,N)) + lookdict[(state,N)] = lookb + + return lookdict,includedict + + # ----------------------------------------------------------------------------- + # compute_read_sets() + # + # Given a set of LR(0) items, this function computes the read sets. + # + # Inputs: C = Set of LR(0) items + # ntrans = Set of nonterminal transitions + # nullable = Set of empty transitions + # + # Returns a set containing the read sets + # ----------------------------------------------------------------------------- + + def compute_read_sets(self,C, ntrans, nullable): + FP = lambda x: self.dr_relation(C,x,nullable) + R = lambda x: self.reads_relation(C,x,nullable) + F = digraph(ntrans,R,FP) + return F + + # ----------------------------------------------------------------------------- + # compute_follow_sets() + # + # Given a set of LR(0) items, a set of non-terminal transitions, a readset, + # and an include set, this function computes the follow sets + # + # Follow(p,A) = Read(p,A) U U {Follow(p',B) | (p,A) INCLUDES (p',B)} + # + # Inputs: + # ntrans = Set of nonterminal transitions + # readsets = Readset (previously computed) + # inclsets = Include sets (previously computed) + # + # Returns a set containing the follow sets + # ----------------------------------------------------------------------------- + + def compute_follow_sets(self,ntrans,readsets,inclsets): + FP = lambda x: readsets[x] + R = lambda x: inclsets.get(x,[]) + F = digraph(ntrans,R,FP) + return F + + # ----------------------------------------------------------------------------- + # add_lookaheads() + # + # Attaches the lookahead symbols to grammar rules. + # + # Inputs: lookbacks - Set of lookback relations + # followset - Computed follow set + # + # This function directly attaches the lookaheads to productions contained + # in the lookbacks set + # ----------------------------------------------------------------------------- + + def add_lookaheads(self,lookbacks,followset): + for trans,lb in lookbacks.items(): + # Loop over productions in lookback + for state,p in lb: + if not state in p.lookaheads: + p.lookaheads[state] = [] + f = followset.get(trans,[]) + for a in f: + if a not in p.lookaheads[state]: p.lookaheads[state].append(a) + + # ----------------------------------------------------------------------------- + # add_lalr_lookaheads() + # + # This function does all of the work of adding lookahead information for use + # with LALR parsing + # ----------------------------------------------------------------------------- + + def add_lalr_lookaheads(self,C): + # Determine all of the nullable nonterminals + nullable = self.compute_nullable_nonterminals() + + # Find all non-terminal transitions + trans = self.find_nonterminal_transitions(C) + + # Compute read sets + readsets = self.compute_read_sets(C,trans,nullable) + + # Compute lookback/includes relations + lookd, included = self.compute_lookback_includes(C,trans,nullable) + + # Compute LALR FOLLOW sets + followsets = self.compute_follow_sets(trans,readsets,included) + + # Add all of the lookaheads + self.add_lookaheads(lookd,followsets) + + # ----------------------------------------------------------------------------- + # lr_parse_table() + # + # This function constructs the parse tables for SLR or LALR + # ----------------------------------------------------------------------------- + def lr_parse_table(self): + Productions = self.grammar.Productions + Precedence = self.grammar.Precedence + goto = self.lr_goto # Goto array + action = self.lr_action # Action array + log = self.log # Logger for output + + actionp = { } # Action production array (temporary) + + log.info("Parsing method: %s", self.lr_method) + + # Step 1: Construct C = { I0, I1, ... IN}, collection of LR(0) items + # This determines the number of states + + C = self.lr0_items() + + if self.lr_method == 'LALR': + self.add_lalr_lookaheads(C) + + # Build the parser table, state by state + st = 0 + for I in C: + # Loop over each production in I + actlist = [ ] # List of actions + st_action = { } + st_actionp = { } + st_goto = { } + log.info("") + log.info("state %d", st) + log.info("") + for p in I: + log.info(" (%d) %s", p.number, str(p)) + log.info("") + + for p in I: + if p.len == p.lr_index + 1: + if p.name == "S'": + # Start symbol. Accept! + st_action["$end"] = 0 + st_actionp["$end"] = p + else: + # We are at the end of a production. Reduce! + if self.lr_method == 'LALR': + laheads = p.lookaheads[st] + else: + laheads = self.grammar.Follow[p.name] + for a in laheads: + actlist.append((a,p,"reduce using rule %d (%s)" % (p.number,p))) + r = st_action.get(a,None) + if r is not None: + # Whoa. Have a shift/reduce or reduce/reduce conflict + if r > 0: + # Need to decide on shift or reduce here + # By default we favor shifting. Need to add + # some precedence rules here. + sprec,slevel = Productions[st_actionp[a].number].prec + rprec,rlevel = Precedence.get(a,('right',0)) + if (slevel < rlevel) or ((slevel == rlevel) and (rprec == 'left')): + # We really need to reduce here. + st_action[a] = -p.number + st_actionp[a] = p + if not slevel and not rlevel: + log.info(" ! shift/reduce conflict for %s resolved as reduce",a) + self.sr_conflicts.append((st,a,'reduce')) + Productions[p.number].reduced += 1 + elif (slevel == rlevel) and (rprec == 'nonassoc'): + st_action[a] = None + else: + # Hmmm. Guess we'll keep the shift + if not rlevel: + log.info(" ! shift/reduce conflict for %s resolved as shift",a) + self.sr_conflicts.append((st,a,'shift')) + elif r < 0: + # Reduce/reduce conflict. In this case, we favor the rule + # that was defined first in the grammar file + oldp = Productions[-r] + pp = Productions[p.number] + if oldp.line > pp.line: + st_action[a] = -p.number + st_actionp[a] = p + chosenp,rejectp = pp,oldp + Productions[p.number].reduced += 1 + Productions[oldp.number].reduced -= 1 + else: + chosenp,rejectp = oldp,pp + self.rr_conflicts.append((st,chosenp,rejectp)) + log.info(" ! reduce/reduce conflict for %s resolved using rule %d (%s)", a,st_actionp[a].number, st_actionp[a]) + else: + raise LALRError("Unknown conflict in state %d" % st) + else: + st_action[a] = -p.number + st_actionp[a] = p + Productions[p.number].reduced += 1 + else: + i = p.lr_index + a = p.prod[i+1] # Get symbol right after the "." + if a in self.grammar.Terminals: + g = self.lr0_goto(I,a) + j = self.lr0_cidhash.get(id(g),-1) + if j >= 0: + # We are in a shift state + actlist.append((a,p,"shift and go to state %d" % j)) + r = st_action.get(a,None) + if r is not None: + # Whoa have a shift/reduce or shift/shift conflict + if r > 0: + if r != j: + raise LALRError("Shift/shift conflict in state %d" % st) + elif r < 0: + # Do a precedence check. + # - if precedence of reduce rule is higher, we reduce. + # - if precedence of reduce is same and left assoc, we reduce. + # - otherwise we shift + rprec,rlevel = Productions[st_actionp[a].number].prec + sprec,slevel = Precedence.get(a,('right',0)) + if (slevel > rlevel) or ((slevel == rlevel) and (rprec == 'right')): + # We decide to shift here... highest precedence to shift + Productions[st_actionp[a].number].reduced -= 1 + st_action[a] = j + st_actionp[a] = p + if not rlevel: + log.info(" ! shift/reduce conflict for %s resolved as shift",a) + self.sr_conflicts.append((st,a,'shift')) + elif (slevel == rlevel) and (rprec == 'nonassoc'): + st_action[a] = None + else: + # Hmmm. Guess we'll keep the reduce + if not slevel and not rlevel: + log.info(" ! shift/reduce conflict for %s resolved as reduce",a) + self.sr_conflicts.append((st,a,'reduce')) + + else: + raise LALRError("Unknown conflict in state %d" % st) + else: + st_action[a] = j + st_actionp[a] = p + + # Print the actions associated with each terminal + _actprint = { } + for a,p,m in actlist: + if a in st_action: + if p is st_actionp[a]: + log.info(" %-15s %s",a,m) + _actprint[(a,m)] = 1 + log.info("") + # Print the actions that were not used. (debugging) + not_used = 0 + for a,p,m in actlist: + if a in st_action: + if p is not st_actionp[a]: + if not (a,m) in _actprint: + log.debug(" ! %-15s [ %s ]",a,m) + not_used = 1 + _actprint[(a,m)] = 1 + if not_used: + log.debug("") + + # Construct the goto table for this state + + nkeys = { } + for ii in I: + for s in ii.usyms: + if s in self.grammar.Nonterminals: + nkeys[s] = None + for n in nkeys: + g = self.lr0_goto(I,n) + j = self.lr0_cidhash.get(id(g),-1) + if j >= 0: + st_goto[n] = j + log.info(" %-30s shift and go to state %d",n,j) + + action[st] = st_action + actionp[st] = st_actionp + goto[st] = st_goto + st += 1 + + + # ----------------------------------------------------------------------------- + # write() + # + # This function writes the LR parsing tables to a file + # ----------------------------------------------------------------------------- + + def write_table(self,modulename,outputdir='',signature=""): + basemodulename = modulename.split(".")[-1] + filename = os.path.join(outputdir,basemodulename) + ".py" + try: + f = open(filename,"w") + + f.write(""" +# %s +# This file is automatically generated. Do not edit. +_tabversion = %r + +_lr_method = %r + +_lr_signature = %r + """ % (filename, __tabversion__, self.lr_method, signature)) + + # Change smaller to 0 to go back to original tables + smaller = 1 + + # Factor out names to try and make smaller + if smaller: + items = { } + + for s,nd in self.lr_action.items(): + for name,v in nd.items(): + i = items.get(name) + if not i: + i = ([],[]) + items[name] = i + i[0].append(s) + i[1].append(v) + + f.write("\n_lr_action_items = {") + for k,v in items.items(): + f.write("%r:([" % k) + for i in v[0]: + f.write("%r," % i) + f.write("],[") + for i in v[1]: + f.write("%r," % i) + + f.write("]),") + f.write("}\n") + + f.write(""" +_lr_action = { } +for _k, _v in _lr_action_items.items(): + for _x,_y in zip(_v[0],_v[1]): + if not _x in _lr_action: _lr_action[_x] = { } + _lr_action[_x][_k] = _y +del _lr_action_items +""") + + else: + f.write("\n_lr_action = { "); + for k,v in self.lr_action.items(): + f.write("(%r,%r):%r," % (k[0],k[1],v)) + f.write("}\n"); + + if smaller: + # Factor out names to try and make smaller + items = { } + + for s,nd in self.lr_goto.items(): + for name,v in nd.items(): + i = items.get(name) + if not i: + i = ([],[]) + items[name] = i + i[0].append(s) + i[1].append(v) + + f.write("\n_lr_goto_items = {") + for k,v in items.items(): + f.write("%r:([" % k) + for i in v[0]: + f.write("%r," % i) + f.write("],[") + for i in v[1]: + f.write("%r," % i) + + f.write("]),") + f.write("}\n") + + f.write(""" +_lr_goto = { } +for _k, _v in _lr_goto_items.items(): + for _x,_y in zip(_v[0],_v[1]): + if not _x in _lr_goto: _lr_goto[_x] = { } + _lr_goto[_x][_k] = _y +del _lr_goto_items +""") + else: + f.write("\n_lr_goto = { "); + for k,v in self.lr_goto.items(): + f.write("(%r,%r):%r," % (k[0],k[1],v)) + f.write("}\n"); + + # Write production table + f.write("_lr_productions = [\n") + for p in self.lr_productions: + if p.func: + f.write(" (%r,%r,%d,%r,%r,%d),\n" % (p.str,p.name, p.len, p.func,p.file,p.line)) + else: + f.write(" (%r,%r,%d,None,None,None),\n" % (str(p),p.name, p.len)) + f.write("]\n") + f.close() + + except IOError: + e = sys.exc_info()[1] + sys.stderr.write("Unable to create '%s'\n" % filename) + sys.stderr.write(str(e)+"\n") + return + + + # ----------------------------------------------------------------------------- + # pickle_table() + # + # This function pickles the LR parsing tables to a supplied file object + # ----------------------------------------------------------------------------- + + def pickle_table(self,filename,signature=""): + try: + import cPickle as pickle + except ImportError: + import pickle + outf = open(filename,"wb") + pickle.dump(__tabversion__,outf,pickle_protocol) + pickle.dump(self.lr_method,outf,pickle_protocol) + pickle.dump(signature,outf,pickle_protocol) + pickle.dump(self.lr_action,outf,pickle_protocol) + pickle.dump(self.lr_goto,outf,pickle_protocol) + + outp = [] + for p in self.lr_productions: + if p.func: + outp.append((p.str,p.name, p.len, p.func,p.file,p.line)) + else: + outp.append((str(p),p.name,p.len,None,None,None)) + pickle.dump(outp,outf,pickle_protocol) + outf.close() + +# ----------------------------------------------------------------------------- +# === INTROSPECTION === +# +# The following functions and classes are used to implement the PLY +# introspection features followed by the yacc() function itself. +# ----------------------------------------------------------------------------- + +# ----------------------------------------------------------------------------- +# get_caller_module_dict() +# +# This function returns a dictionary containing all of the symbols defined within +# a caller further down the call stack. This is used to get the environment +# associated with the yacc() call if none was provided. +# ----------------------------------------------------------------------------- + +def get_caller_module_dict(levels): + try: + raise RuntimeError + except RuntimeError: + e,b,t = sys.exc_info() + f = t.tb_frame + while levels > 0: + f = f.f_back + levels -= 1 + ldict = f.f_globals.copy() + if f.f_globals != f.f_locals: + ldict.update(f.f_locals) + + return ldict + +# ----------------------------------------------------------------------------- +# parse_grammar() +# +# This takes a raw grammar rule string and parses it into production data +# ----------------------------------------------------------------------------- +def parse_grammar(doc,file,line): + grammar = [] + # Split the doc string into lines + pstrings = doc.splitlines() + lastp = None + dline = line + for ps in pstrings: + dline += 1 + p = ps.split() + if not p: continue + try: + if p[0] == '|': + # This is a continuation of a previous rule + if not lastp: + raise SyntaxError("%s:%d: Misplaced '|'" % (file,dline)) + prodname = lastp + syms = p[1:] + else: + prodname = p[0] + lastp = prodname + syms = p[2:] + assign = p[1] + if assign != ':' and assign != '::=': + raise SyntaxError("%s:%d: Syntax error. Expected ':'" % (file,dline)) + + grammar.append((file,dline,prodname,syms)) + except SyntaxError: + raise + except Exception: + raise SyntaxError("%s:%d: Syntax error in rule '%s'" % (file,dline,ps.strip())) + + return grammar + +# ----------------------------------------------------------------------------- +# ParserReflect() +# +# This class represents information extracted for building a parser including +# start symbol, error function, tokens, precedence list, action functions, +# etc. +# ----------------------------------------------------------------------------- +class ParserReflect(object): + def __init__(self,pdict,log=None): + self.pdict = pdict + self.start = None + self.error_func = None + self.tokens = None + self.files = {} + self.grammar = [] + self.error = 0 + + if log is None: + self.log = PlyLogger(sys.stderr) + else: + self.log = log + + # Get all of the basic information + def get_all(self): + self.get_start() + self.get_error_func() + self.get_tokens() + self.get_precedence() + self.get_pfunctions() + + # Validate all of the information + def validate_all(self): + self.validate_start() + self.validate_error_func() + self.validate_tokens() + self.validate_precedence() + self.validate_pfunctions() + self.validate_files() + return self.error + + # Compute a signature over the grammar + def signature(self): + try: + from hashlib import md5 + except ImportError: + from md5 import md5 + try: + sig = md5() + if self.start: + sig.update(self.start.encode('latin-1')) + if self.prec: + sig.update("".join(["".join(p) for p in self.prec]).encode('latin-1')) + if self.tokens: + sig.update(" ".join(self.tokens).encode('latin-1')) + for f in self.pfuncs: + if f[3]: + sig.update(f[3].encode('latin-1')) + except (TypeError,ValueError): + pass + return sig.digest() + + # ----------------------------------------------------------------------------- + # validate_file() + # + # This method checks to see if there are duplicated p_rulename() functions + # in the parser module file. Without this function, it is really easy for + # users to make mistakes by cutting and pasting code fragments (and it's a real + # bugger to try and figure out why the resulting parser doesn't work). Therefore, + # we just do a little regular expression pattern matching of def statements + # to try and detect duplicates. + # ----------------------------------------------------------------------------- + + def validate_files(self): + # Match def p_funcname( + fre = re.compile(r'\s*def\s+(p_[a-zA-Z_0-9]*)\(') + + for filename in self.files.keys(): + base,ext = os.path.splitext(filename) + if ext != '.py': return 1 # No idea. Assume it's okay. + + try: + f = open(filename) + lines = f.readlines() + f.close() + except IOError: + continue + + counthash = { } + for linen,l in enumerate(lines): + linen += 1 + m = fre.match(l) + if m: + name = m.group(1) + prev = counthash.get(name) + if not prev: + counthash[name] = linen + else: + self.log.warning("%s:%d: Function %s redefined. Previously defined on line %d", filename,linen,name,prev) + + # Get the start symbol + def get_start(self): + self.start = self.pdict.get('start') + + # Validate the start symbol + def validate_start(self): + if self.start is not None: + if not isinstance(self.start,str): + self.log.error("'start' must be a string") + + # Look for error handler + def get_error_func(self): + self.error_func = self.pdict.get('p_error') + + # Validate the error function + def validate_error_func(self): + if self.error_func: + if isinstance(self.error_func,types.FunctionType): + ismethod = 0 + elif isinstance(self.error_func, types.MethodType): + ismethod = 1 + else: + self.log.error("'p_error' defined, but is not a function or method") + self.error = 1 + return + + eline = func_code(self.error_func).co_firstlineno + efile = func_code(self.error_func).co_filename + self.files[efile] = 1 + + if (func_code(self.error_func).co_argcount != 1+ismethod): + self.log.error("%s:%d: p_error() requires 1 argument",efile,eline) + self.error = 1 + + # Get the tokens map + def get_tokens(self): + tokens = self.pdict.get("tokens",None) + if not tokens: + self.log.error("No token list is defined") + self.error = 1 + return + + if not isinstance(tokens,(list, tuple)): + self.log.error("tokens must be a list or tuple") + self.error = 1 + return + + if not tokens: + self.log.error("tokens is empty") + self.error = 1 + return + + self.tokens = tokens + + # Validate the tokens + def validate_tokens(self): + # Validate the tokens. + if 'error' in self.tokens: + self.log.error("Illegal token name 'error'. Is a reserved word") + self.error = 1 + return + + terminals = {} + for n in self.tokens: + if n in terminals: + self.log.warning("Token '%s' multiply defined", n) + terminals[n] = 1 + + # Get the precedence map (if any) + def get_precedence(self): + self.prec = self.pdict.get("precedence",None) + + # Validate and parse the precedence map + def validate_precedence(self): + preclist = [] + if self.prec: + if not isinstance(self.prec,(list,tuple)): + self.log.error("precedence must be a list or tuple") + self.error = 1 + return + for level,p in enumerate(self.prec): + if not isinstance(p,(list,tuple)): + self.log.error("Bad precedence table") + self.error = 1 + return + + if len(p) < 2: + self.log.error("Malformed precedence entry %s. Must be (assoc, term, ..., term)",p) + self.error = 1 + return + assoc = p[0] + if not isinstance(assoc,str): + self.log.error("precedence associativity must be a string") + self.error = 1 + return + for term in p[1:]: + if not isinstance(term,str): + self.log.error("precedence items must be strings") + self.error = 1 + return + preclist.append((term,assoc,level+1)) + self.preclist = preclist + + # Get all p_functions from the grammar + def get_pfunctions(self): + p_functions = [] + for name, item in self.pdict.items(): + if name[:2] != 'p_': continue + if name == 'p_error': continue + if isinstance(item,(types.FunctionType,types.MethodType)): + line = func_code(item).co_firstlineno + file = func_code(item).co_filename + p_functions.append((line,file,name,item.__doc__)) + + # Sort all of the actions by line number + p_functions.sort() + self.pfuncs = p_functions + + + # Validate all of the p_functions + def validate_pfunctions(self): + grammar = [] + # Check for non-empty symbols + if len(self.pfuncs) == 0: + self.log.error("no rules of the form p_rulename are defined") + self.error = 1 + return + + for line, file, name, doc in self.pfuncs: + func = self.pdict[name] + if isinstance(func, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + if func_code(func).co_argcount > reqargs: + self.log.error("%s:%d: Rule '%s' has too many arguments",file,line,func.__name__) + self.error = 1 + elif func_code(func).co_argcount < reqargs: + self.log.error("%s:%d: Rule '%s' requires an argument",file,line,func.__name__) + self.error = 1 + elif not func.__doc__: + self.log.warning("%s:%d: No documentation string specified in function '%s' (ignored)",file,line,func.__name__) + else: + try: + parsed_g = parse_grammar(doc,file,line) + for g in parsed_g: + grammar.append((name, g)) + except SyntaxError: + e = sys.exc_info()[1] + self.log.error(str(e)) + self.error = 1 + + # Looks like a valid grammar rule + # Mark the file in which defined. + self.files[file] = 1 + + # Secondary validation step that looks for p_ definitions that are not functions + # or functions that look like they might be grammar rules. + + for n,v in self.pdict.items(): + if n[0:2] == 'p_' and isinstance(v, (types.FunctionType, types.MethodType)): continue + if n[0:2] == 't_': continue + if n[0:2] == 'p_' and n != 'p_error': + self.log.warning("'%s' not defined as a function", n) + if ((isinstance(v,types.FunctionType) and func_code(v).co_argcount == 1) or + (isinstance(v,types.MethodType) and func_code(v).co_argcount == 2)): + try: + doc = v.__doc__.split(" ") + if doc[1] == ':': + self.log.warning("%s:%d: Possible grammar rule '%s' defined without p_ prefix", + func_code(v).co_filename, func_code(v).co_firstlineno,n) + except Exception: + pass + + self.grammar = grammar + +# ----------------------------------------------------------------------------- +# yacc(module) +# +# Build a parser +# ----------------------------------------------------------------------------- + +def yacc(method='LALR', debug=yaccdebug, module=None, tabmodule=tab_module, start=None, + check_recursion=1, optimize=0, write_tables=1, debugfile=debug_file,outputdir='', + debuglog=None, errorlog = None, picklefile=None): + + global parse # Reference to the parsing method of the last built parser + + # If pickling is enabled, table files are not created + + if picklefile: + write_tables = 0 + + if errorlog is None: + errorlog = PlyLogger(sys.stderr) + + # Get the module dictionary used for the parser + if module: + _items = [(k,getattr(module,k)) for k in dir(module)] + pdict = dict(_items) + else: + pdict = get_caller_module_dict(2) + + # Collect parser information from the dictionary + pinfo = ParserReflect(pdict,log=errorlog) + pinfo.get_all() + + if pinfo.error: + raise YaccError("Unable to build parser") + + # Check signature against table files (if any) + signature = pinfo.signature() + + # Read the tables + try: + lr = LRTable() + if picklefile: + read_signature = lr.read_pickle(picklefile) + else: + read_signature = lr.read_table(tabmodule) + if optimize or (read_signature == signature): + try: + lr.bind_callables(pinfo.pdict) + parser = LRParser(lr,pinfo.error_func) + parse = parser.parse + return parser + except Exception: + e = sys.exc_info()[1] + errorlog.warning("There was a problem loading the table file: %s", repr(e)) + except VersionError: + e = sys.exc_info() + errorlog.warning(str(e)) + except Exception: + pass + + if debuglog is None: + if debug: + debuglog = PlyLogger(open(debugfile,"w")) + else: + debuglog = NullLogger() + + debuglog.info("Created by PLY version %s (http://www.dabeaz.com/ply)", __version__) + + + errors = 0 + + # Validate the parser information + if pinfo.validate_all(): + raise YaccError("Unable to build parser") + + if not pinfo.error_func: + errorlog.warning("no p_error() function is defined") + + # Create a grammar object + grammar = Grammar(pinfo.tokens) + + # Set precedence level for terminals + for term, assoc, level in pinfo.preclist: + try: + grammar.set_precedence(term,assoc,level) + except GrammarError: + e = sys.exc_info()[1] + errorlog.warning("%s",str(e)) + + # Add productions to the grammar + for funcname, gram in pinfo.grammar: + file, line, prodname, syms = gram + try: + grammar.add_production(prodname,syms,funcname,file,line) + except GrammarError: + e = sys.exc_info()[1] + errorlog.error("%s",str(e)) + errors = 1 + + # Set the grammar start symbols + try: + if start is None: + grammar.set_start(pinfo.start) + else: + grammar.set_start(start) + except GrammarError: + e = sys.exc_info()[1] + errorlog.error(str(e)) + errors = 1 + + if errors: + raise YaccError("Unable to build parser") + + # Verify the grammar structure + undefined_symbols = grammar.undefined_symbols() + for sym, prod in undefined_symbols: + errorlog.error("%s:%d: Symbol '%s' used, but not defined as a token or a rule",prod.file,prod.line,sym) + errors = 1 + + unused_terminals = grammar.unused_terminals() + if unused_terminals: + debuglog.info("") + debuglog.info("Unused terminals:") + debuglog.info("") + for term in unused_terminals: + errorlog.warning("Token '%s' defined, but not used", term) + debuglog.info(" %s", term) + + # Print out all productions to the debug log + if debug: + debuglog.info("") + debuglog.info("Grammar") + debuglog.info("") + for n,p in enumerate(grammar.Productions): + debuglog.info("Rule %-5d %s", n, p) + + # Find unused non-terminals + unused_rules = grammar.unused_rules() + for prod in unused_rules: + errorlog.warning("%s:%d: Rule '%s' defined, but not used", prod.file, prod.line, prod.name) + + if len(unused_terminals) == 1: + errorlog.warning("There is 1 unused token") + if len(unused_terminals) > 1: + errorlog.warning("There are %d unused tokens", len(unused_terminals)) + + if len(unused_rules) == 1: + errorlog.warning("There is 1 unused rule") + if len(unused_rules) > 1: + errorlog.warning("There are %d unused rules", len(unused_rules)) + + if debug: + debuglog.info("") + debuglog.info("Terminals, with rules where they appear") + debuglog.info("") + terms = list(grammar.Terminals) + terms.sort() + for term in terms: + debuglog.info("%-20s : %s", term, " ".join([str(s) for s in grammar.Terminals[term]])) + + debuglog.info("") + debuglog.info("Nonterminals, with rules where they appear") + debuglog.info("") + nonterms = list(grammar.Nonterminals) + nonterms.sort() + for nonterm in nonterms: + debuglog.info("%-20s : %s", nonterm, " ".join([str(s) for s in grammar.Nonterminals[nonterm]])) + debuglog.info("") + + if check_recursion: + unreachable = grammar.find_unreachable() + for u in unreachable: + errorlog.warning("Symbol '%s' is unreachable",u) + + infinite = grammar.infinite_cycles() + for inf in infinite: + errorlog.error("Infinite recursion detected for symbol '%s'", inf) + errors = 1 + + unused_prec = grammar.unused_precedence() + for term, assoc in unused_prec: + errorlog.error("Precedence rule '%s' defined for unknown symbol '%s'", assoc, term) + errors = 1 + + if errors: + raise YaccError("Unable to build parser") + + # Run the LRGeneratedTable on the grammar + if debug: + errorlog.debug("Generating %s tables", method) + + lr = LRGeneratedTable(grammar,method,debuglog) + + if debug: + num_sr = len(lr.sr_conflicts) + + # Report shift/reduce and reduce/reduce conflicts + if num_sr == 1: + errorlog.warning("1 shift/reduce conflict") + elif num_sr > 1: + errorlog.warning("%d shift/reduce conflicts", num_sr) + + num_rr = len(lr.rr_conflicts) + if num_rr == 1: + errorlog.warning("1 reduce/reduce conflict") + elif num_rr > 1: + errorlog.warning("%d reduce/reduce conflicts", num_rr) + + # Write out conflicts to the output file + if debug and (lr.sr_conflicts or lr.rr_conflicts): + debuglog.warning("") + debuglog.warning("Conflicts:") + debuglog.warning("") + + for state, tok, resolution in lr.sr_conflicts: + debuglog.warning("shift/reduce conflict for %s in state %d resolved as %s", tok, state, resolution) + + already_reported = {} + for state, rule, rejected in lr.rr_conflicts: + if (state,id(rule),id(rejected)) in already_reported: + continue + debuglog.warning("reduce/reduce conflict in state %d resolved using rule (%s)", state, rule) + debuglog.warning("rejected rule (%s) in state %d", rejected,state) + errorlog.warning("reduce/reduce conflict in state %d resolved using rule (%s)", state, rule) + errorlog.warning("rejected rule (%s) in state %d", rejected, state) + already_reported[state,id(rule),id(rejected)] = 1 + + warned_never = [] + for state, rule, rejected in lr.rr_conflicts: + if not rejected.reduced and (rejected not in warned_never): + debuglog.warning("Rule (%s) is never reduced", rejected) + errorlog.warning("Rule (%s) is never reduced", rejected) + warned_never.append(rejected) + + # Write the table file if requested + if write_tables: + lr.write_table(tabmodule,outputdir,signature) + + # Write a pickled version of the tables + if picklefile: + lr.pickle_table(picklefile,signature) + + # Build the parser + lr.bind_callables(pinfo.pdict) + parser = LRParser(lr,pinfo.error_func) + + parse = parser.parse + return parser |