diff --git a/DIR_METADATA b/DIR_METADATA new file mode 100644 index 000000000000..983ea0140f45 --- /dev/null +++ b/DIR_METADATA @@ -0,0 +1,3 @@ +monorail { + component: "Tools" +} diff --git a/LICENSE b/LICENSE new file mode 100644 index 000000000000..b2738663454b --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +PLY (Python Lex-Yacc) Version 3.4 + +Copyright (C) 2001-2011, +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. \ No newline at end of file diff --git a/OWNERS b/OWNERS new file mode 100644 index 000000000000..93a641dd7a3e --- /dev/null +++ b/OWNERS @@ -0,0 +1,3 @@ +rockot@google.com + +file://tools/idl_parser/OWNERS diff --git a/README.chromium b/README.chromium new file mode 100644 index 000000000000..45e10b87b6b6 --- /dev/null +++ b/README.chromium @@ -0,0 +1,25 @@ +Name: PLY (Python Lex-Yacc) +Current version: 3.11 +URL: http://www.dabeaz.com/ply/ply-3.11.tar.gz +License: BSD +License File: LICENSE +Security Critical: no +Version: 3.11 + +PLY is used by (at least) the Mojo python bindings, the PPAPI +IDL generator, and the Blink IDL generator. + +This directory contains a copy of these ply-3.11 components: + +README ply-3.11/README.md +Sources ply-3.11/ply/__init__.py + ply-3.11/ply/lex.py + ply-3.11/ply/yacc.py + + +The license is in LICENSE. + +Modifications made: +- Added the file README.chromium (this file) +- Applies license.patch +- Added ply.gni to list sources diff --git a/README.md b/README.md new file mode 100644 index 000000000000..05df32a5b9fc --- /dev/null +++ b/README.md @@ -0,0 +1,275 @@ +# PLY (Python Lex-Yacc) Version 3.11 + +[![Build Status](https://travis-ci.org/dabeaz/ply.svg?branch=master)](https://travis-ci.org/dabeaz/ply) + +Copyright (C) 2001-2018 +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. + +Introduction +============ + +PLY is a 100% Python implementation of the common parsing tools lex +and yacc. Here are a few highlights: + + - PLY is very closely modeled after traditional lex/yacc. + If you know how to use these tools in C, you will find PLY + to be similar. + + - PLY provides *very* extensive error reporting and diagnostic + information to assist in parser construction. The original + implementation was developed for instructional purposes. As + a result, the system tries to identify the most common types + of errors made by novice users. + + - PLY provides full support for empty productions, error recovery, + precedence specifiers, and moderately ambiguous grammars. + + - Parsing is based on LR-parsing which is fast, memory efficient, + better suited to large grammars, and which has a number of nice + properties when dealing with syntax errors and other parsing problems. + Currently, PLY builds its parsing tables using the LALR(1) + algorithm used in yacc. + + - PLY uses Python introspection features to build lexers and parsers. + This greatly simplifies the task of parser construction since it reduces + the number of files and eliminates the need to run a separate lex/yacc + tool before running your program. + + - PLY can be used to build parsers for "real" programming languages. + Although it is not ultra-fast due to its Python implementation, + PLY can be used to parse grammars consisting of several hundred + rules (as might be found for a language like C). The lexer and LR + parser are also reasonably efficient when parsing typically + sized programs. People have used PLY to build parsers for + C, C++, ADA, and other real programming languages. + +How to Use +========== + +PLY consists of two files : lex.py and yacc.py. These are contained +within the 'ply' directory which may also be used as a Python package. +To use PLY, simply copy the 'ply' directory to your project and import +lex and yacc from the associated 'ply' package. For example: + + import ply.lex as lex + import ply.yacc as yacc + +Alternatively, you can copy just the files lex.py and yacc.py +individually and use them as modules. For example: + + import lex + import yacc + +The file setup.py can be used to install ply using distutils. + +The file doc/ply.html contains complete documentation on how to use +the system. + +The example directory contains several different examples including a +PLY specification for ANSI C as given in K&R 2nd Ed. + +A simple example is found at the end of this document + +Requirements +============ +PLY requires the use of Python 2.6 or greater. However, you should +use the latest Python release if possible. It should work on just +about any platform. PLY has been tested with both CPython and Jython. +It also seems to work with IronPython. + +Resources +========= +More information about PLY can be obtained on the PLY webpage at: + + http://www.dabeaz.com/ply + +For a detailed overview of parsing theory, consult the excellent +book "Compilers : Principles, Techniques, and Tools" by Aho, Sethi, and +Ullman. The topics found in "Lex & Yacc" by Levine, Mason, and Brown +may also be useful. + +The GitHub page for PLY can be found at: + + https://github.com/dabeaz/ply + +An old and relatively inactive discussion group for PLY is found at: + + http://groups.google.com/group/ply-hack + +Acknowledgments +=============== +A special thanks is in order for all of the students in CS326 who +suffered through about 25 different versions of these tools :-). + +The CHANGES file acknowledges those who have contributed patches. + +Elias Ioup did the first implementation of LALR(1) parsing in PLY-1.x. +Andrew Waters and Markus Schoepflin were instrumental in reporting bugs +and testing a revised LALR(1) implementation for PLY-2.0. + +Special Note for PLY-3.0 +======================== +PLY-3.0 the first PLY release to support Python 3. However, backwards +compatibility with Python 2.6 is still preserved. PLY provides dual +Python 2/3 compatibility by restricting its implementation to a common +subset of basic language features. You should not convert PLY using +2to3--it is not necessary and may in fact break the implementation. + +Example +======= + +Here is a simple example showing a PLY implementation of a calculator +with variables. + + # ----------------------------------------------------------------------------- + # calc.py + # + # A simple calculator with variables. + # ----------------------------------------------------------------------------- + + tokens = ( + 'NAME','NUMBER', + 'PLUS','MINUS','TIMES','DIVIDE','EQUALS', + 'LPAREN','RPAREN', + ) + + # Tokens + + t_PLUS = r'\+' + t_MINUS = r'-' + t_TIMES = r'\*' + t_DIVIDE = r'/' + t_EQUALS = r'=' + t_LPAREN = r'\(' + t_RPAREN = r'\)' + t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*' + + def t_NUMBER(t): + r'\d+' + t.value = int(t.value) + return t + + # Ignored characters + t_ignore = " \t" + + def t_newline(t): + r'\n+' + t.lexer.lineno += t.value.count("\n") + + def t_error(t): + print("Illegal character '%s'" % t.value[0]) + t.lexer.skip(1) + + # Build the lexer + import ply.lex as lex + lex.lex() + + # Precedence rules for the arithmetic operators + precedence = ( + ('left','PLUS','MINUS'), + ('left','TIMES','DIVIDE'), + ('right','UMINUS'), + ) + + # dictionary of names (for storing variables) + names = { } + + def p_statement_assign(p): + 'statement : NAME EQUALS expression' + names[p[1]] = p[3] + + def p_statement_expr(p): + 'statement : expression' + print(p[1]) + + def p_expression_binop(p): + '''expression : expression PLUS expression + | expression MINUS expression + | expression TIMES expression + | expression DIVIDE expression''' + if p[2] == '+' : p[0] = p[1] + p[3] + elif p[2] == '-': p[0] = p[1] - p[3] + elif p[2] == '*': p[0] = p[1] * p[3] + elif p[2] == '/': p[0] = p[1] / p[3] + + def p_expression_uminus(p): + 'expression : MINUS expression %prec UMINUS' + p[0] = -p[2] + + def p_expression_group(p): + 'expression : LPAREN expression RPAREN' + p[0] = p[2] + + def p_expression_number(p): + 'expression : NUMBER' + p[0] = p[1] + + def p_expression_name(p): + 'expression : NAME' + try: + p[0] = names[p[1]] + except LookupError: + print("Undefined name '%s'" % p[1]) + p[0] = 0 + + def p_error(p): + print("Syntax error at '%s'" % p.value) + + import ply.yacc as yacc + yacc.yacc() + + while True: + try: + s = raw_input('calc > ') # use input() on Python 3 + except EOFError: + break + yacc.parse(s) + + +Bug Reports and Patches +======================= +My goal with PLY is to simply have a decent lex/yacc implementation +for Python. As a general rule, I don't spend huge amounts of time +working on it unless I receive very specific bug reports and/or +patches to fix problems. I also try to incorporate submitted feature +requests and enhancements into each new version. Please visit the PLY +github page at https://github.com/dabeaz/ply to submit issues and pull +requests. To contact me about bugs and/or new features, please send +email to dave@dabeaz.com. + +-- Dave + + + + + + + + + diff --git a/__init__.py b/__init__.py new file mode 100644 index 000000000000..e48880f50fbc --- /dev/null +++ b/__init__.py @@ -0,0 +1,37 @@ +# PLY package +# Author: David Beazley (dave@dabeaz.com) +# ----------------------------------------------------------------------------- +# ply: __init__.py +# +# Copyright (C) 2001-2018 +# 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__ = '3.11' +__all__ = ['lex','yacc'] diff --git a/lex.py b/lex.py new file mode 100644 index 000000000000..f95bcdbf1bb5 --- /dev/null +++ b/lex.py @@ -0,0 +1,1098 @@ +# ----------------------------------------------------------------------------- +# ply: lex.py +# +# Copyright (C) 2001-2018 +# 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__ = '3.11' +__tabversion__ = '3.10' + +import re +import sys +import types +import copy +import os +import inspect + +# This tuple contains known string types +try: + # Python 2.6 + StringTypes = (types.StringType, types.UnicodeType) +except AttributeError: + # Python 3.0 + StringTypes = (str, bytes) + +# 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.lexstateeoff = {} # Dictionary of eof 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.lexeoff = None # EOF 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 = False # 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, lextab, outputdir=''): + if isinstance(lextab, types.ModuleType): + raise IOError("Won't overwrite existing lextab module") + basetabmodule = lextab.split('.')[-1] + filename = os.path.join(outputdir, basetabmodule) + '.py' + with open(filename, 'w') as tf: + tf.write('# %s.py. This file automatically created by PLY (version %s). Don\'t edit!\n' % (basetabmodule, __version__)) + tf.write('_tabversion = %s\n' % repr(__tabversion__)) + tf.write('_lextokens = set(%s)\n' % repr(tuple(sorted(self.lextokens)))) + tf.write('_lexreflags = %s\n' % repr(int(self.lexreflags))) + tf.write('_lexliterals = %s\n' % repr(self.lexliterals)) + tf.write('_lexstateinfo = %s\n' % repr(self.lexstateinfo)) + + # Rewrite the lexstatere table, replacing function objects with function names + tabre = {} + for statename, lre in self.lexstatere.items(): + titem = [] + for (pat, func), retext, renames in zip(lre, self.lexstateretext[statename], self.lexstaterenames[statename]): + titem.append((retext, _funcs_to_names(func, renames))) + tabre[statename] = titem + + tf.write('_lexstatere = %s\n' % repr(tabre)) + tf.write('_lexstateignore = %s\n' % repr(self.lexstateignore)) + + taberr = {} + for statename, ef in self.lexstateerrorf.items(): + taberr[statename] = ef.__name__ if ef else None + tf.write('_lexstateerrorf = %s\n' % repr(taberr)) + + tabeof = {} + for statename, ef in self.lexstateeoff.items(): + tabeof[statename] = ef.__name__ if ef else None + tf.write('_lexstateeoff = %s\n' % repr(tabeof)) + + # ------------------------------------------------------------ + # readtab() - Read lexer information from a tab file + # ------------------------------------------------------------ + def readtab(self, tabfile, fdict): + if isinstance(tabfile, types.ModuleType): + lextab = tabfile + else: + exec('import %s' % tabfile) + lextab = sys.modules[tabfile] + + if getattr(lextab, '_tabversion', '0.0') != __tabversion__: + raise ImportError('Inconsistent PLY version') + + self.lextokens = lextab._lextokens + self.lexreflags = lextab._lexreflags + self.lexliterals = lextab._lexliterals + self.lextokens_all = self.lextokens | set(self.lexliterals) + self.lexstateinfo = lextab._lexstateinfo + self.lexstateignore = lextab._lexstateignore + self.lexstatere = {} + self.lexstateretext = {} + for statename, lre in lextab._lexstatere.items(): + titem = [] + txtitem = [] + for pat, func_name in lre: + titem.append((re.compile(pat, lextab._lexreflags), _names_to_funcs(func_name, fdict))) + + self.lexstatere[statename] = titem + self.lexstateretext[statename] = txtitem + + self.lexstateerrorf = {} + for statename, ef in lextab._lexstateerrorf.items(): + self.lexstateerrorf[statename] = fdict[ef] + + self.lexstateeoff = {} + for statename, ef in lextab._lexstateeoff.items(): + self.lexstateeoff[statename] = 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 state not 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.lexeoff = self.lexstateeoff.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 newtok.type not in self.lextokens_all: + raise LexError("%s:%d: Rule '%s' returned an unknown token type '%s'" % ( + func.__code__.co_filename, func.__code__.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:]) + + if self.lexeoff: + tok = LexToken() + tok.type = 'eof' + tok.value = '' + tok.lineno = self.lineno + tok.lexpos = lexpos + tok.lexer = self + self.lexpos = lexpos + newtok = self.lexeoff(tok) + return newtok + + 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_regex(func) +# +# Returns the regular expression assigned to a function either as a doc string +# or as a .regex attribute attached by the @TOKEN decorator. +# ----------------------------------------------------------------------------- +def _get_regex(func): + return getattr(func, 'regex', func.__doc__) + +# ----------------------------------------------------------------------------- +# 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): + f = sys._getframe(levels) + 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, 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): + parts = s.split('_') + for i, part in enumerate(parts[1:], 1): + if part not in names and part != '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.modules = set() + self.error = False + self.log = PlyLogger(sys.stderr) if log is None else 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 = True + return + + if not isinstance(tokens, (list, tuple)): + self.log.error('tokens must be a list or tuple') + self.error = True + return + + if not tokens: + self.log.error('tokens is empty') + self.error = True + 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 = True + 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', '') + if not self.literals: + self.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 = True + + except TypeError: + self.log.error('Invalid literals specification. literals must be a sequence of characters') + self.error = True + + 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 = True + 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 = True + continue + name, statetype = s + if not isinstance(name, StringTypes): + self.log.error('State name %s must be a string', repr(name)) + self.error = True + continue + if not (statetype == 'inclusive' or statetype == 'exclusive'): + self.log.error("State type for state %s must be 'inclusive' or 'exclusive'", name) + self.error = True + continue + if name in self.stateinfo: + self.log.error("State '%s' already defined", name) + self.error = True + 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 + self.eoff = {} # EOF 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 = True + 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 == 'eof': + for s in states: + self.eoff[s] = t + elif tokname == 'ignore': + line = t.__code__.co_firstlineno + file = t.__code__.co_filename + self.log.error("%s:%d: Rule '%s' must be defined as a string", file, line, t.__name__) + self.error = True + 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 = True + 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 = True + + # Sort the functions by line number + for f in self.funcsym.values(): + f.sort(key=lambda x: x[1].__code__.co_firstlineno) + + # Sort the strings by regular expression length + for s in self.strsym.values(): + 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 = f.__code__.co_firstlineno + file = f.__code__.co_filename + module = inspect.getmodule(f) + self.modules.add(module) + + tokname = self.toknames[fname] + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = f.__code__.co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule '%s' has too many arguments", file, line, f.__name__) + self.error = True + continue + + if nargs < reqargs: + self.log.error("%s:%d: Rule '%s' requires an argument", file, line, f.__name__) + self.error = True + continue + + if not _get_regex(f): + self.log.error("%s:%d: No regular expression defined for rule '%s'", file, line, f.__name__) + self.error = True + continue + + try: + c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), self.reflags) + if c.match(''): + self.log.error("%s:%d: Regular expression for rule '%s' matches empty string", file, line, f.__name__) + self.error = True + except re.error as e: + self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file, line, f.__name__, e) + if '#' in _get_regex(f): + self.log.error("%s:%d. Make sure '#' in rule '%s' is escaped with '\\#'", file, line, f.__name__) + self.error = True + + # 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 = True + continue + + if tokname not in self.tokens and tokname.find('ignore_') < 0: + self.log.error("Rule '%s' defined for an unspecified token %s", name, tokname) + self.error = True + continue + + try: + c = re.compile('(?P<%s>%s)' % (name, r), self.reflags) + if (c.match('')): + self.log.error("Regular expression for rule '%s' matches empty string", name) + self.error = True + except re.error as e: + 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 = True + + if not self.funcsym[state] and not self.strsym[state]: + self.log.error("No rules defined for state '%s'", state) + self.error = True + + # Validate the error function + efunc = self.errorf.get(state, None) + if efunc: + f = efunc + line = f.__code__.co_firstlineno + file = f.__code__.co_filename + module = inspect.getmodule(f) + self.modules.add(module) + + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = f.__code__.co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule '%s' has too many arguments", file, line, f.__name__) + self.error = True + + if nargs < reqargs: + self.log.error("%s:%d: Rule '%s' requires an argument", file, line, f.__name__) + self.error = True + + for module in self.modules: + self.validate_module(module) + + # ----------------------------------------------------------------------------- + # validate_module() + # + # 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 source code of the given module. + # ----------------------------------------------------------------------------- + + def validate_module(self, module): + try: + lines, linen = inspect.getsourcelines(module) + except IOError: + return + + 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 line in lines: + m = fre.match(line) + if not m: + m = sre.match(line) + if m: + name = m.group(1) + prev = counthash.get(name) + if not prev: + counthash[name] = linen + else: + filename = inspect.getsourcefile(module) + self.log.error('%s:%d: Rule %s redefined. Previously defined on line %d', filename, linen, name, prev) + self.error = True + linen += 1 + +# ----------------------------------------------------------------------------- +# lex(module) +# +# Build all of the regular expression rules from definitions in the supplied module +# ----------------------------------------------------------------------------- +def lex(module=None, object=None, debug=False, optimize=False, lextab='lextab', + reflags=int(re.VERBOSE), nowarn=False, outputdir=None, debuglog=None, errorlog=None): + + if lextab is None: + lextab = 'lextab' + + 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 + + # Get the module dictionary used for the parser + if module: + _items = [(k, getattr(module, k)) for k in dir(module)] + ldict = dict(_items) + # If no __file__ attribute is available, try to obtain it from the __module__ instead + if '__file__' not in ldict: + ldict['__file__'] = sys.modules[ldict['__module__']].__file__ + else: + ldict = get_caller_module_dict(2) + + # Determine if the module is package of a package or not. + # If so, fix the tabmodule setting so that tables load correctly + pkg = ldict.get('__package__') + if pkg and isinstance(lextab, str): + if '.' not in lextab: + lextab = pkg + '.' + lextab + + # 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 = set() + for n in linfo.tokens: + lexobj.lextokens.add(n) + + # Get literals specification + if isinstance(linfo.literals, (list, tuple)): + lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals) + else: + lexobj.lexliterals = linfo.literals + + lexobj.lextokens_all = lexobj.lextokens | set(lexobj.lexliterals) + + # 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]: + regex_list.append('(?P<%s>%s)' % (fname, _get_regex(f))) + if debug: + debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", fname, _get_regex(f), 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, text in enumerate(re_text): + debuglog.info("lex: state '%s' : regex[%d] = '%s'", state, i, text) + + # 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') + + # Set up eof functions + lexobj.lexstateeoff = linfo.eoff + lexobj.lexeoff = linfo.eoff.get('INITIAL', None) + + # Check state information for ignore and error rules + for s, stype in stateinfo.items(): + if stype == 'exclusive': + if s not in linfo.errorf: + errorlog.warning("No error rule is defined for exclusive state '%s'", s) + if s not in linfo.ignore and lexobj.lexignore: + errorlog.warning("No ignore rule is defined for exclusive state '%s'", s) + elif stype == 'inclusive': + if s not in linfo.errorf: + linfo.errorf[s] = linfo.errorf.get('INITIAL', None) + if s not 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: + if outputdir is None: + # If no output directory is set, the location of the output files + # is determined according to the following rules: + # - If lextab specifies a package, files go into that package directory + # - Otherwise, files go in the same directory as the specifying module + if isinstance(lextab, types.ModuleType): + srcfile = lextab.__file__ + else: + if '.' not in lextab: + srcfile = ldict['__file__'] + else: + parts = lextab.split('.') + pkgname = '.'.join(parts[:-1]) + exec('import %s' % pkgname) + srcfile = getattr(sys.modules[pkgname], '__file__', '') + outputdir = os.path.dirname(srcfile) + try: + lexobj.writetab(lextab, outputdir) + if lextab in sys.modules: + del sys.modules[lextab] + except IOError as e: + errorlog.warning("Couldn't write lextab module %r. %s" % (lextab, e)) + + 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 True: + 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_regex(f): + if hasattr(r, '__call__'): + f.regex = _get_regex(r) + else: + f.regex = r + return f + return set_regex + +# Alternative spelling of the TOKEN decorator +Token = TOKEN diff --git a/license.patch b/license.patch new file mode 100644 index 000000000000..b6cdff196c4b --- /dev/null +++ b/license.patch @@ -0,0 +1,42 @@ +diff --git a/third_party/ply/__init__.py b/third_party/ply/__init__.py +index 853a985..f3da03e 100644 +--- a/third_party/ply/__init__.py ++++ b/third_party/ply/__init__.py +@@ -1,4 +1,36 @@ + # PLY package + # Author: David Beazley (dave@dabeaz.com) ++# ----------------------------------------------------------------------------- ++# ply: __init__.py ++# ++# Copyright (C) 2001-2018 ++# 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__ = '3.11' + __all__ = ['lex','yacc'] diff --git a/ply.gni b/ply.gni new file mode 100644 index 000000000000..6a2db436f125 --- /dev/null +++ b/ply.gni @@ -0,0 +1,5 @@ +ply_sources = [ + "//third_party/ply/__init__.py", + "//third_party/ply/lex.py", + "//third_party/ply/yacc.py", +] diff --git a/yacc.py b/yacc.py new file mode 100644 index 000000000000..88188a1e8ead --- /dev/null +++ b/yacc.py @@ -0,0 +1,3502 @@ +# ----------------------------------------------------------------------------- +# ply: yacc.py +# +# Copyright (C) 2001-2018 +# 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 grammar 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! +# ---------------------------------------------------------------------------- + +import re +import types +import sys +import os.path +import inspect +import warnings + +__version__ = '3.11' +__tabversion__ = '3.10' + +#----------------------------------------------------------------------------- +# === User configurable parameters === +# +# Change these to modify the default behavior of yacc (if you wish) +#----------------------------------------------------------------------------- + +yaccdebug = True # 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 = False # 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 + +# String type-checking compatibility +if sys.version_info[0] < 3: + string_types = basestring +else: + string_types = str + +MAXINT = sys.maxsize + +# 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)) + +# Panic mode error recovery support. This feature is being reworked--much of the +# code here is to offer a deprecation/backwards compatible transition + +_errok = None +_token = None +_restart = None +_warnmsg = '''PLY: Don't use global functions errok(), token(), and restart() in p_error(). +Instead, invoke the methods on the associated parser instance: + + def p_error(p): + ... + # Use parser.errok(), parser.token(), parser.restart() + ... + + parser = yacc.yacc() +''' + +def errok(): + warnings.warn(_warnmsg) + return _errok() + +def restart(): + warnings.warn(_warnmsg) + return _restart() + +def token(): + warnings.warn(_warnmsg) + return _token() + +# Utility function to call the p_error() function with some deprecation hacks +def call_errorfunc(errorfunc, token, parser): + global _errok, _token, _restart + _errok = parser.errok + _token = parser.token + _restart = parser.restart + r = errorfunc(token) + try: + del _errok, _token, _restart + except NameError: + pass + return 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 isinstance(n, slice): + return [s.value for s in self.slice[n]] + elif 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 set_lexpos(self, n, lexpos): + self.slice[n].lexpos = lexpos + + 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 + self.set_defaulted_states() + self.errorok = True + + def errok(self): + self.errorok = True + + def restart(self): + del self.statestack[:] + del self.symstack[:] + sym = YaccSymbol() + sym.type = '$end' + self.symstack.append(sym) + self.statestack.append(0) + + # Defaulted state support. + # This method identifies parser states where there is only one possible reduction action. + # For such states, the parser can make a choose to make a rule reduction without consuming + # the next look-ahead token. This delayed invocation of the tokenizer can be useful in + # certain kinds of advanced parsing situations where the lexer and parser interact with + # each other or change states (i.e., manipulation of scope, lexer states, etc.). + # + # See: http://www.gnu.org/software/bison/manual/html_node/Default-Reductions.html#Default-Reductions + def set_defaulted_states(self): + self.defaulted_states = {} + for state, actions in self.action.items(): + rules = list(actions.values()) + if len(rules) == 1 and rules[0] < 0: + self.defaulted_states[state] = rules[0] + + def disable_defaulted_states(self): + self.defaulted_states = {} + + def parse(self, input=None, lexer=None, debug=False, tracking=False, 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. Optimized versions of this function + # are automatically created by the ply/ygen.py script. This script cuts out + # sections enclosed in markers such as this: + # + # #--! DEBUG + # statements + # #--! DEBUG + # + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + def parsedebug(self, input=None, lexer=None, debug=False, tracking=False, tokenfunc=None): + #--! parsedebug-start + 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.) + defaulted_states = self.defaulted_states # Local reference to defaulted states + 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: + from . import 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 the parser() token method (sometimes used in error recovery) + self.token = get_token + + # 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 = '$end' + symstack.append(sym) + state = 0 + while True: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + #--! DEBUG + debug.debug('') + debug.debug('State : %s', state) + #--! DEBUG + + if state not in defaulted_states: + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = '$end' + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + else: + t = defaulted_states[state] + #--! DEBUG + debug.debug('Defaulted state %s: Reduce using %d', state, -t) + #--! DEBUG + + #--! DEBUG + debug.debug('Stack : %s', + ('%s . %s' % (' '.join([xx.type for xx in symstack][1:]), str(lookahead))).lstrip()) + #--! DEBUG + + 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:]])+']', + goto[statestack[-1-plen]][pname]) + else: + debug.info('Action : Reduce rule [%s] with %s and goto state %d', p.str, [], + goto[statestack[-1]][pname]) + + #--! 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:] + self.state = state + p.callable(pslice) + del statestack[-plen:] + #--! 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) # Save the current lookahead token + symstack.extend(targ[1:-1]) # Put the production slice back on the stack + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + 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 + self.state = state + 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) # Save the current lookahead token + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + 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 is 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 = False + errtoken = lookahead + if errtoken.type == '$end': + errtoken = None # End of file! + if self.errorfunc: + if errtoken and not hasattr(errtoken, 'lexer'): + errtoken.lexer = lexer + self.state = state + tok = call_errorfunc(self.errorfunc, errtoken, self) + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken, 'lineno'): + lineno = lookahead.lineno + else: + lineno = 0 + if lineno: + sys.stderr.write('yacc: Syntax error at line %d, token=%s\n' % (lineno, errtoken.type)) + else: + sys.stderr.write('yacc: Syntax error, token=%s' % errtoken.type) + else: + sys.stderr.write('yacc: Parse error in input. EOF\n') + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != '$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 + #--! TRACKING + if tracking: + sym.endlineno = getattr(lookahead, 'lineno', sym.lineno) + sym.endlexpos = getattr(lookahead, 'lexpos', sym.lexpos) + #--! TRACKING + lookahead = None + continue + + # Create the error symbol for the first time and make it the new lookahead symbol + t = YaccSymbol() + t.type = 'error' + + if hasattr(lookahead, 'lineno'): + t.lineno = t.endlineno = lookahead.lineno + if hasattr(lookahead, 'lexpos'): + t.lexpos = t.endlexpos = lookahead.lexpos + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + sym = symstack.pop() + #--! TRACKING + if tracking: + lookahead.lineno = sym.lineno + lookahead.lexpos = sym.lexpos + #--! TRACKING + statestack.pop() + state = statestack[-1] + + continue + + # Call an error function here + raise RuntimeError('yacc: internal parser error!!!\n') + + #--! parsedebug-end + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # parseopt(). + # + # Optimized version of parse() method. DO NOT EDIT THIS CODE DIRECTLY! + # This code is automatically generated by the ply/ygen.py script. Make + # changes to the parsedebug() method instead. + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + def parseopt(self, input=None, lexer=None, debug=False, tracking=False, tokenfunc=None): + #--! parseopt-start + 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.) + defaulted_states = self.defaulted_states # Local reference to defaulted states + 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: + from . import 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 the parser() token method (sometimes used in error recovery) + self.token = get_token + + # 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 = '$end' + symstack.append(sym) + state = 0 + while True: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + + if state not in defaulted_states: + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = '$end' + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + else: + t = defaulted_states[state] + + + 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:] + self.state = state + p.callable(pslice) + del statestack[-plen:] + 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) # Save the current lookahead token + symstack.extend(targ[1:-1]) # Put the production slice back on the stack + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + 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 + self.state = state + 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) # Save the current lookahead token + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + if t == 0: + n = symstack[-1] + result = getattr(n, 'value', None) + return result + + if t is 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 = False + errtoken = lookahead + if errtoken.type == '$end': + errtoken = None # End of file! + if self.errorfunc: + if errtoken and not hasattr(errtoken, 'lexer'): + errtoken.lexer = lexer + self.state = state + tok = call_errorfunc(self.errorfunc, errtoken, self) + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken, 'lineno'): + lineno = lookahead.lineno + else: + lineno = 0 + if lineno: + sys.stderr.write('yacc: Syntax error at line %d, token=%s\n' % (lineno, errtoken.type)) + else: + sys.stderr.write('yacc: Syntax error, token=%s' % errtoken.type) + else: + sys.stderr.write('yacc: Parse error in input. EOF\n') + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != '$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 + #--! TRACKING + if tracking: + sym.endlineno = getattr(lookahead, 'lineno', sym.lineno) + sym.endlexpos = getattr(lookahead, 'lexpos', sym.lexpos) + #--! TRACKING + lookahead = None + continue + + # Create the error symbol for the first time and make it the new lookahead symbol + t = YaccSymbol() + t.type = 'error' + + if hasattr(lookahead, 'lineno'): + t.lineno = t.endlineno = lookahead.lineno + if hasattr(lookahead, 'lexpos'): + t.lexpos = t.endlexpos = lookahead.lexpos + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + sym = symstack.pop() + #--! TRACKING + if tracking: + lookahead.lineno = sym.lineno + lookahead.lexpos = sym.lexpos + #--! TRACKING + statestack.pop() + state = statestack[-1] + + continue + + # Call an error function here + raise RuntimeError('yacc: internal parser error!!!\n') + + #--! parseopt-end + + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + # parseopt_notrack(). + # + # Optimized version of parseopt() with line number tracking removed. + # DO NOT EDIT THIS CODE DIRECTLY. This code is automatically generated + # by the ply/ygen.py script. Make changes to the parsedebug() method instead. + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + def parseopt_notrack(self, input=None, lexer=None, debug=False, tracking=False, tokenfunc=None): + #--! parseopt-notrack-start + 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.) + defaulted_states = self.defaulted_states # Local reference to defaulted states + 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: + from . import 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 the parser() token method (sometimes used in error recovery) + self.token = get_token + + # 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 = '$end' + symstack.append(sym) + state = 0 + while True: + # Get the next symbol on the input. If a lookahead symbol + # is already set, we just use that. Otherwise, we'll pull + # the next token off of the lookaheadstack or from the lexer + + + if state not in defaulted_states: + if not lookahead: + if not lookaheadstack: + lookahead = get_token() # Get the next token + else: + lookahead = lookaheadstack.pop() + if not lookahead: + lookahead = YaccSymbol() + lookahead.type = '$end' + + # Check the action table + ltype = lookahead.type + t = actions[state].get(ltype) + else: + t = defaulted_states[state] + + + 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:] + self.state = state + p.callable(pslice) + del statestack[-plen:] + 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) # Save the current lookahead token + symstack.extend(targ[1:-1]) # Put the production slice back on the stack + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + 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 + self.state = state + 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) # Save the current lookahead token + statestack.pop() # Pop back one state (before the reduce) + state = statestack[-1] + sym.type = 'error' + sym.value = 'error' + lookahead = sym + errorcount = error_count + self.errorok = False + + continue + # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + if t == 0: + n = symstack[-1] + result = getattr(n, 'value', None) + return result + + if t is 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 = False + errtoken = lookahead + if errtoken.type == '$end': + errtoken = None # End of file! + if self.errorfunc: + if errtoken and not hasattr(errtoken, 'lexer'): + errtoken.lexer = lexer + self.state = state + tok = call_errorfunc(self.errorfunc, errtoken, self) + if self.errorok: + # User must have done some kind of panic + # mode recovery on their own. The + # returned token is the next lookahead + lookahead = tok + errtoken = None + continue + else: + if errtoken: + if hasattr(errtoken, 'lineno'): + lineno = lookahead.lineno + else: + lineno = 0 + if lineno: + sys.stderr.write('yacc: Syntax error at line %d, token=%s\n' % (lineno, errtoken.type)) + else: + sys.stderr.write('yacc: Syntax error, token=%s' % errtoken.type) + else: + sys.stderr.write('yacc: Parse error in input. EOF\n') + return + + else: + errorcount = error_count + + # case 1: the statestack only has 1 entry on it. If we're in this state, the + # entire parse has been rolled back and we're completely hosed. The token is + # discarded and we just keep going. + + if len(statestack) <= 1 and lookahead.type != '$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 == '$end': + # Whoa. We're really hosed here. Bail out + return + + if lookahead.type != 'error': + sym = symstack[-1] + if sym.type == 'error': + # Hmmm. Error is on top of stack, we'll just nuke input + # symbol and continue + lookahead = None + continue + + # Create the error symbol for the first time and make it the new lookahead symbol + t = YaccSymbol() + t.type = 'error' + + if hasattr(lookahead, 'lineno'): + t.lineno = t.endlineno = lookahead.lineno + if hasattr(lookahead, 'lexpos'): + t.lexpos = t.endlexpos = lookahead.lexpos + t.value = lookahead + lookaheadstack.append(lookahead) + lookahead = t + else: + sym = symstack.pop() + statestack.pop() + state = statestack[-1] + + continue + + # Call an error function here + raise RuntimeError('yacc: internal parser error!!!\n') + + #--! parseopt-notrack-end + +# ----------------------------------------------------------------------------- +# === Grammar Representation === +# +# The following functions, classes, and variables are used to represent and +# manipulate the rules that make up a grammar. +# ----------------------------------------------------------------------------- + +# regex matching identifiers +_is_identifier = re.compile(r'^[a-zA-Z0-9_-]+$') + +# ----------------------------------------------------------------------------- +# 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 -> ' % 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. + try: + p.lr_after = self.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 -> ' % 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 = set() # 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 %r' % 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 %r. Already defined as a token' % (file, line, prodname)) + if prodname == 'error': + raise GrammarError('%s:%d: Illegal rule name %r. error is a reserved word' % (file, line, prodname)) + if not _is_identifier.match(prodname): + raise GrammarError('%s:%d: Illegal rule name %r' % (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 %r may only be a single character' % + (file, line, s, prodname)) + if c not 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 %r in rule %r' % (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) + if not prodprec: + raise GrammarError('%s:%d: Nothing known about the precedence of %r' % (file, line, precname)) + else: + self.UsedPrecedence.add(precname) + 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 prodname not 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 t not 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] + + # ----------------------------------------------------------------------------- + # 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 s in reachable: + return + reachable.add(s) + for p in self.Prodnames.get(s, []): + for r in p.prod: + mark_reachable_from(r) + + reachable = set() + mark_reachable_from(self.Productions[0].prod[0]) + return [s for s in self.Nonterminals if s not in reachable] + + # ----------------------------------------------------------------------------- + # 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] = True + + terminates['$end'] = True + + # Nonterminals: + + # Initialize to false: + for n in self.Nonterminals: + terminates[n] = False + + # Then propagate termination until no change: + while True: + some_change = False + 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 = False + break + else: + # didn't break from the loop, + # so every symbol s terminates + # so production p terminates. + p_terminates = True + + if p_terminates: + # symbol n terminates! + if not terminates[n]: + terminates[n] = True + some_change = True + # 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 s not in self.Prodnames and s not 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 s not in self.Prodnames and s not 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 = False + + # Add all the non- symbols of First[x] to the result. + for f in self.First[x]: + if f == '': + x_produces_empty = True + 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('') + + 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'] = ['$end'] + + # Nonterminals: + + # Initialize to the empty set: + for n in self.Nonterminals: + self.First[n] = [] + + # Then propagate symbols until no change: + while True: + some_change = False + for n in self.Nonterminals: + for p in self.Prodnames[n]: + for f in self._first(p.prod): + if f not in self.First[n]: + self.First[n].append(f) + some_change = True + if not some_change: + break + + return self.First + + # --------------------------------------------------------------------- + # compute_follow() + # + # Computes all of the follow sets for every non-terminal symbol. The + # follow set is the set of all symbols that might follow a given + # non-terminal. See the Dragon book, 2nd Ed. p. 189. + # --------------------------------------------------------------------- + def compute_follow(self, start=None): + # If already computed, return the result + if self.Follow: + return self.Follow + + # If first sets not computed yet, do that first. + if not self.First: + self.compute_first() + + # Add '$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 True: + didadd = False + for p in self.Productions[1:]: + # Here is the production set + for i, B in enumerate(p.prod): + if B in self.Nonterminals: + # Okay. We got a non-terminal in a production + fst = self._first(p.prod[i+1:]) + hasempty = False + for f in fst: + if f != '' and f not in self.Follow[B]: + self.Follow[B].append(f) + didadd = True + if f == '': + hasempty = True + 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 = True + 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 True: + 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: + exec('import %s' % module) + parsetab = sys.modules[module] + + 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 + + if not os.path.exists(filename): + raise ImportError + + 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 = True + while didadd: + didadd = False + 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 = True + + 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)) + 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) + 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)) + if not s1: + s1 = {} + s[id(n)] = s1 + gs.append(n) + s = s1 + g = s.get('$end') + 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 or 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 = set() + num_nullable = 0 + while True: + for p in self.grammar.Productions[1:]: + if p.len == 0: + nullable.add(p.name) + continue + for t in p.prod: + if t not in nullable: + break + else: + nullable.add(p.name) + 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 stateno, state in enumerate(C): + for p in state: + if p.lr_index < p.len - 1: + t = (stateno, p.prod[p.lr_index+1]) + if t[1] in self.grammar.Nonterminals: + if t not in trans: + trans.append(t) + 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): + 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 p.prod[li] not 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 i not 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 state not 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, 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) + 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. + + # Shift precedence comes from the token + sprec, slevel = Precedence.get(a, ('right', 0)) + + # Reduce precedence comes from rule being reduced (p) + rprec, rlevel = Productions[p.number].prec + + 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) + 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 + + # Shift precedence comes from the token + sprec, slevel = Precedence.get(a, ('right', 0)) + + # Reduce precedence comes from the rule that could have been reduced + rprec, rlevel = Productions[st_actionp[a].number].prec + + 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, tabmodule, outputdir='', signature=''): + if isinstance(tabmodule, types.ModuleType): + raise IOError("Won't overwrite existing tabmodule") + + basemodulename = tabmodule.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. +# pylint: disable=W,C,R +_tabversion = %r + +_lr_method = %r + +_lr_signature = %r + ''' % (os.path.basename(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, os.path.basename(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 as e: + raise + + + # ----------------------------------------------------------------------------- + # 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 + with open(filename, 'wb') as outf: + 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, os.path.basename(p.file), p.line)) + else: + outp.append((str(p), p.name, p.len, None, None, None)) + pickle.dump(outp, outf, pickle_protocol) + +# ----------------------------------------------------------------------------- +# === 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): + f = sys._getframe(levels) + 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 %r' % (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.modules = set() + self.grammar = [] + self.error = False + + 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_modules() + return self.error + + # Compute a signature over the grammar + def signature(self): + parts = [] + try: + if self.start: + parts.append(self.start) + if self.prec: + parts.append(''.join([''.join(p) for p in self.prec])) + if self.tokens: + parts.append(' '.join(self.tokens)) + for f in self.pfuncs: + if f[3]: + parts.append(f[3]) + except (TypeError, ValueError): + pass + return ''.join(parts) + + # ----------------------------------------------------------------------------- + # validate_modules() + # + # 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_modules(self): + # Match def p_funcname( + fre = re.compile(r'\s*def\s+(p_[a-zA-Z_0-9]*)\(') + + for module in self.modules: + try: + lines, linen = inspect.getsourcelines(module) + except IOError: + continue + + counthash = {} + for linen, line in enumerate(lines): + linen += 1 + m = fre.match(line) + if m: + name = m.group(1) + prev = counthash.get(name) + if not prev: + counthash[name] = linen + else: + filename = inspect.getsourcefile(module) + 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, string_types): + 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 = True + return + + eline = self.error_func.__code__.co_firstlineno + efile = self.error_func.__code__.co_filename + module = inspect.getmodule(self.error_func) + self.modules.add(module) + + argcount = self.error_func.__code__.co_argcount - ismethod + if argcount != 1: + self.log.error('%s:%d: p_error() requires 1 argument', efile, eline) + self.error = True + + # Get the tokens map + def get_tokens(self): + tokens = self.pdict.get('tokens') + if not tokens: + self.log.error('No token list is defined') + self.error = True + return + + if not isinstance(tokens, (list, tuple)): + self.log.error('tokens must be a list or tuple') + self.error = True + return + + if not tokens: + self.log.error('tokens is empty') + self.error = True + return + + self.tokens = sorted(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 = True + return + + terminals = set() + for n in self.tokens: + if n in terminals: + self.log.warning('Token %r multiply defined', n) + terminals.add(n) + + # Get the precedence map (if any) + def get_precedence(self): + self.prec = self.pdict.get('precedence') + + # 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 = True + return + for level, p in enumerate(self.prec): + if not isinstance(p, (list, tuple)): + self.log.error('Bad precedence table') + self.error = True + return + + if len(p) < 2: + self.log.error('Malformed precedence entry %s. Must be (assoc, term, ..., term)', p) + self.error = True + return + assoc = p[0] + if not isinstance(assoc, string_types): + self.log.error('precedence associativity must be a string') + self.error = True + return + for term in p[1:]: + if not isinstance(term, string_types): + self.log.error('precedence items must be strings') + self.error = True + 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 not name.startswith('p_') or name == 'p_error': + continue + if isinstance(item, (types.FunctionType, types.MethodType)): + line = getattr(item, 'co_firstlineno', item.__code__.co_firstlineno) + module = inspect.getmodule(item) + p_functions.append((line, module, name, item.__doc__)) + + # Sort all of the actions by line number; make sure to stringify + # modules to make them sortable, since `line` may not uniquely sort all + # p functions + p_functions.sort(key=lambda p_function: ( + p_function[0], + str(p_function[1]), + p_function[2], + p_function[3])) + 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 = True + return + + for line, module, name, doc in self.pfuncs: + file = inspect.getsourcefile(module) + func = self.pdict[name] + if isinstance(func, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + if func.__code__.co_argcount > reqargs: + self.log.error('%s:%d: Rule %r has too many arguments', file, line, func.__name__) + self.error = True + elif func.__code__.co_argcount < reqargs: + self.log.error('%s:%d: Rule %r requires an argument', file, line, func.__name__) + self.error = True + elif not func.__doc__: + self.log.warning('%s:%d: No documentation string specified in function %r (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 as e: + self.log.error(str(e)) + self.error = True + + # Looks like a valid grammar rule + # Mark the file in which defined. + self.modules.add(module) + + # 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.startswith('p_') and isinstance(v, (types.FunctionType, types.MethodType)): + continue + if n.startswith('t_'): + continue + if n.startswith('p_') and n != 'p_error': + self.log.warning('%r not defined as a function', n) + if ((isinstance(v, types.FunctionType) and v.__code__.co_argcount == 1) or + (isinstance(v, types.MethodType) and v.__func__.__code__.co_argcount == 2)): + if v.__doc__: + try: + doc = v.__doc__.split(' ') + if doc[1] == ':': + self.log.warning('%s:%d: Possible grammar rule %r defined without p_ prefix', + v.__code__.co_filename, v.__code__.co_firstlineno, n) + except IndexError: + pass + + self.grammar = grammar + +# ----------------------------------------------------------------------------- +# yacc(module) +# +# Build a parser +# ----------------------------------------------------------------------------- + +def yacc(method='LALR', debug=yaccdebug, module=None, tabmodule=tab_module, start=None, + check_recursion=True, optimize=False, write_tables=True, debugfile=debug_file, + outputdir=None, debuglog=None, errorlog=None, picklefile=None): + + if tabmodule is None: + tabmodule = tab_module + + # Reference to the parsing method of the last built parser + global parse + + # 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) + # If no __file__ or __package__ attributes are available, try to obtain them + # from the __module__ instead + if '__file__' not in pdict: + pdict['__file__'] = sys.modules[pdict['__module__']].__file__ + if '__package__' not in pdict and '__module__' in pdict: + if hasattr(sys.modules[pdict['__module__']], '__package__'): + pdict['__package__'] = sys.modules[pdict['__module__']].__package__ + else: + pdict = get_caller_module_dict(2) + + if outputdir is None: + # If no output directory is set, the location of the output files + # is determined according to the following rules: + # - If tabmodule specifies a package, files go into that package directory + # - Otherwise, files go in the same directory as the specifying module + if isinstance(tabmodule, types.ModuleType): + srcfile = tabmodule.__file__ + else: + if '.' not in tabmodule: + srcfile = pdict['__file__'] + else: + parts = tabmodule.split('.') + pkgname = '.'.join(parts[:-1]) + exec('import %s' % pkgname) + srcfile = getattr(sys.modules[pkgname], '__file__', '') + outputdir = os.path.dirname(srcfile) + + # Determine if the module is package of a package or not. + # If so, fix the tabmodule setting so that tables load correctly + pkg = pdict.get('__package__') + if pkg and isinstance(tabmodule, str): + if '.' not in tabmodule: + tabmodule = pkg + '.' + tabmodule + + + + # Set start symbol if it's specified directly using an argument + if start is not None: + pdict['start'] = start + + # 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 as e: + errorlog.warning('There was a problem loading the table file: %r', e) + except VersionError as e: + errorlog.warning(str(e)) + except ImportError: + pass + + if debuglog is None: + if debug: + try: + debuglog = PlyLogger(open(os.path.join(outputdir, debugfile), 'w')) + except IOError as e: + errorlog.warning("Couldn't open %r. %s" % (debugfile, e)) + debuglog = NullLogger() + else: + debuglog = NullLogger() + + debuglog.info('Created by PLY version %s (http://www.dabeaz.com/ply)', __version__) + + errors = False + + # 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 as e: + errorlog.warning('%s', 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 as e: + errorlog.error('%s', e) + errors = True + + # Set the grammar start symbols + try: + if start is None: + grammar.set_start(pinfo.start) + else: + grammar.set_start(start) + except GrammarError as e: + errorlog.error(str(e)) + errors = True + + 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 %r used, but not defined as a token or a rule', prod.file, prod.line, sym) + errors = True + + unused_terminals = grammar.unused_terminals() + if unused_terminals: + debuglog.info('') + debuglog.info('Unused terminals:') + debuglog.info('') + for term in unused_terminals: + errorlog.warning('Token %r 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 %r 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 %r is unreachable', u) + + infinite = grammar.infinite_cycles() + for inf in infinite: + errorlog.error('Infinite recursion detected for symbol %r', inf) + errors = True + + unused_prec = grammar.unused_precedence() + for term, assoc in unused_prec: + errorlog.error('Precedence rule %r defined for unknown symbol %r', assoc, term) + errors = True + + 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 = set() + 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.add((state, id(rule), id(rejected))) + + 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: + try: + lr.write_table(tabmodule, outputdir, signature) + if tabmodule in sys.modules: + del sys.modules[tabmodule] + except IOError as e: + errorlog.warning("Couldn't create %r. %s" % (tabmodule, e)) + + # Write a pickled version of the tables + if picklefile: + try: + lr.pickle_table(picklefile, signature) + except IOError as e: + errorlog.warning("Couldn't create %r. %s" % (picklefile, e)) + + # Build the parser + lr.bind_callables(pinfo.pdict) + parser = LRParser(lr, pinfo.error_func) + + parse = parser.parse + return parser