You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
365 lines
12 KiB
365 lines
12 KiB
"""ANTLR3 exception hierarchy"""
|
|
|
|
# begin[licence]
|
|
#
|
|
# [The "BSD licence"]
|
|
# Copyright (c) 2005-2008 Terence Parr
|
|
# All rights reserved.
|
|
#
|
|
# Redistribution and use in source and binary forms, with or without
|
|
# modification, are permitted provided that the following conditions
|
|
# are met:
|
|
# 1. Redistributions of source code must retain the above copyright
|
|
# notice, this list of conditions and the following disclaimer.
|
|
# 2. 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.
|
|
# 3. The name of the author may not be used to endorse or promote products
|
|
# derived from this software without specific prior written permission.
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
|
|
#
|
|
# end[licence]
|
|
|
|
from antlr3.constants import INVALID_TOKEN_TYPE
|
|
|
|
|
|
class BacktrackingFailed(Exception):
|
|
"""@brief Raised to signal failed backtrack attempt"""
|
|
|
|
pass
|
|
|
|
|
|
class RecognitionException(Exception):
|
|
"""@brief The root of the ANTLR exception hierarchy.
|
|
|
|
To avoid English-only error messages and to generally make things
|
|
as flexible as possible, these exceptions are not created with strings,
|
|
but rather the information necessary to generate an error. Then
|
|
the various reporting methods in Parser and Lexer can be overridden
|
|
to generate a localized error message. For example, MismatchedToken
|
|
exceptions are built with the expected token type.
|
|
So, don't expect getMessage() to return anything.
|
|
|
|
Note that as of Java 1.4, you can access the stack trace, which means
|
|
that you can compute the complete trace of rules from the start symbol.
|
|
This gives you considerable context information with which to generate
|
|
useful error messages.
|
|
|
|
ANTLR generates code that throws exceptions upon recognition error and
|
|
also generates code to catch these exceptions in each rule. If you
|
|
want to quit upon first error, you can turn off the automatic error
|
|
handling mechanism using rulecatch action, but you still need to
|
|
override methods mismatch and recoverFromMismatchSet.
|
|
|
|
In general, the recognition exceptions can track where in a grammar a
|
|
problem occurred and/or what was the expected input. While the parser
|
|
knows its state (such as current input symbol and line info) that
|
|
state can change before the exception is reported so current token index
|
|
is computed and stored at exception time. From this info, you can
|
|
perhaps print an entire line of input not just a single token, for example.
|
|
Better to just say the recognizer had a problem and then let the parser
|
|
figure out a fancy report.
|
|
|
|
"""
|
|
|
|
def __init__(self, input=None):
|
|
Exception.__init__(self)
|
|
|
|
# What input stream did the error occur in?
|
|
self.input = None
|
|
|
|
# What is index of token/char were we looking at when the error
|
|
# occurred?
|
|
self.index = None
|
|
|
|
# The current Token when an error occurred. Since not all streams
|
|
# can retrieve the ith Token, we have to track the Token object.
|
|
# For parsers. Even when it's a tree parser, token might be set.
|
|
self.token = None
|
|
|
|
# If this is a tree parser exception, node is set to the node with
|
|
# the problem.
|
|
self.node = None
|
|
|
|
# The current char when an error occurred. For lexers.
|
|
self.c = None
|
|
|
|
# Track the line at which the error occurred in case this is
|
|
# generated from a lexer. We need to track this since the
|
|
# unexpected char doesn't carry the line info.
|
|
self.line = None
|
|
|
|
self.charPositionInLine = None
|
|
|
|
# If you are parsing a tree node stream, you will encounter som
|
|
# imaginary nodes w/o line/col info. We now search backwards looking
|
|
# for most recent token with line/col info, but notify getErrorHeader()
|
|
# that info is approximate.
|
|
self.approximateLineInfo = False
|
|
|
|
|
|
if input is not None:
|
|
self.input = input
|
|
self.index = input.index()
|
|
|
|
# late import to avoid cyclic dependencies
|
|
from antlr3.streams import TokenStream, CharStream
|
|
from antlr3.tree import TreeNodeStream
|
|
|
|
if isinstance(self.input, TokenStream):
|
|
self.token = self.input.LT(1)
|
|
self.line = self.token.line
|
|
self.charPositionInLine = self.token.charPositionInLine
|
|
|
|
if isinstance(self.input, TreeNodeStream):
|
|
self.extractInformationFromTreeNodeStream(self.input)
|
|
|
|
else:
|
|
if isinstance(self.input, CharStream):
|
|
self.c = self.input.LT(1)
|
|
self.line = self.input.line
|
|
self.charPositionInLine = self.input.charPositionInLine
|
|
|
|
else:
|
|
self.c = self.input.LA(1)
|
|
|
|
def extractInformationFromTreeNodeStream(self, nodes):
|
|
from antlr3.tree import Tree, CommonTree
|
|
from antlr3.tokens import CommonToken
|
|
|
|
self.node = nodes.LT(1)
|
|
adaptor = nodes.adaptor
|
|
payload = adaptor.getToken(self.node)
|
|
if payload is not None:
|
|
self.token = payload
|
|
if payload.line <= 0:
|
|
# imaginary node; no line/pos info; scan backwards
|
|
i = -1
|
|
priorNode = nodes.LT(i)
|
|
while priorNode is not None:
|
|
priorPayload = adaptor.getToken(priorNode)
|
|
if priorPayload is not None and priorPayload.line > 0:
|
|
# we found the most recent real line / pos info
|
|
self.line = priorPayload.line
|
|
self.charPositionInLine = priorPayload.charPositionInLine
|
|
self.approximateLineInfo = True
|
|
break
|
|
|
|
i -= 1
|
|
priorNode = nodes.LT(i)
|
|
|
|
else: # node created from real token
|
|
self.line = payload.line
|
|
self.charPositionInLine = payload.charPositionInLine
|
|
|
|
elif isinstance(self.node, Tree):
|
|
self.line = self.node.line
|
|
self.charPositionInLine = self.node.charPositionInLine
|
|
if isinstance(self.node, CommonTree):
|
|
self.token = self.node.token
|
|
|
|
else:
|
|
type = adaptor.getType(self.node)
|
|
text = adaptor.getText(self.node)
|
|
self.token = CommonToken(type=type, text=text)
|
|
|
|
|
|
def getUnexpectedType(self):
|
|
"""Return the token type or char of the unexpected input element"""
|
|
|
|
from antlr3.streams import TokenStream
|
|
from antlr3.tree import TreeNodeStream
|
|
|
|
if isinstance(self.input, TokenStream):
|
|
return self.token.type
|
|
|
|
elif isinstance(self.input, TreeNodeStream):
|
|
adaptor = self.input.treeAdaptor
|
|
return adaptor.getType(self.node)
|
|
|
|
else:
|
|
return self.c
|
|
|
|
unexpectedType = property(getUnexpectedType)
|
|
|
|
|
|
class MismatchedTokenException(RecognitionException):
|
|
"""@brief A mismatched char or Token or tree node."""
|
|
|
|
def __init__(self, expecting, input):
|
|
RecognitionException.__init__(self, input)
|
|
self.expecting = expecting
|
|
|
|
|
|
def __str__(self):
|
|
#return "MismatchedTokenException("+self.expecting+")"
|
|
return "MismatchedTokenException(%r!=%r)" % (
|
|
self.getUnexpectedType(), self.expecting
|
|
)
|
|
__repr__ = __str__
|
|
|
|
|
|
class UnwantedTokenException(MismatchedTokenException):
|
|
"""An extra token while parsing a TokenStream"""
|
|
|
|
def getUnexpectedToken(self):
|
|
return self.token
|
|
|
|
|
|
def __str__(self):
|
|
exp = ", expected %s" % self.expecting
|
|
if self.expecting == INVALID_TOKEN_TYPE:
|
|
exp = ""
|
|
|
|
if self.token is None:
|
|
return "UnwantedTokenException(found=%s%s)" % (None, exp)
|
|
|
|
return "UnwantedTokenException(found=%s%s)" % (self.token.text, exp)
|
|
__repr__ = __str__
|
|
|
|
|
|
class MissingTokenException(MismatchedTokenException):
|
|
"""
|
|
We were expecting a token but it's not found. The current token
|
|
is actually what we wanted next.
|
|
"""
|
|
|
|
def __init__(self, expecting, input, inserted):
|
|
MismatchedTokenException.__init__(self, expecting, input)
|
|
|
|
self.inserted = inserted
|
|
|
|
|
|
def getMissingType(self):
|
|
return self.expecting
|
|
|
|
|
|
def __str__(self):
|
|
if self.inserted is not None and self.token is not None:
|
|
return "MissingTokenException(inserted %r at %r)" % (
|
|
self.inserted, self.token.text)
|
|
|
|
if self.token is not None:
|
|
return "MissingTokenException(at %r)" % self.token.text
|
|
|
|
return "MissingTokenException"
|
|
__repr__ = __str__
|
|
|
|
|
|
class MismatchedRangeException(RecognitionException):
|
|
"""@brief The next token does not match a range of expected types."""
|
|
|
|
def __init__(self, a, b, input):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.a = a
|
|
self.b = b
|
|
|
|
|
|
def __str__(self):
|
|
return "MismatchedRangeException(%r not in [%r..%r])" % (
|
|
self.getUnexpectedType(), self.a, self.b
|
|
)
|
|
__repr__ = __str__
|
|
|
|
|
|
class MismatchedSetException(RecognitionException):
|
|
"""@brief The next token does not match a set of expected types."""
|
|
|
|
def __init__(self, expecting, input):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.expecting = expecting
|
|
|
|
|
|
def __str__(self):
|
|
return "MismatchedSetException(%r not in %r)" % (
|
|
self.getUnexpectedType(), self.expecting
|
|
)
|
|
__repr__ = __str__
|
|
|
|
|
|
class MismatchedNotSetException(MismatchedSetException):
|
|
"""@brief Used for remote debugger deserialization"""
|
|
|
|
def __str__(self):
|
|
return "MismatchedNotSetException(%r!=%r)" % (
|
|
self.getUnexpectedType(), self.expecting
|
|
)
|
|
__repr__ = __str__
|
|
|
|
|
|
class NoViableAltException(RecognitionException):
|
|
"""@brief Unable to decide which alternative to choose."""
|
|
|
|
def __init__(
|
|
self, grammarDecisionDescription, decisionNumber, stateNumber, input
|
|
):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.grammarDecisionDescription = grammarDecisionDescription
|
|
self.decisionNumber = decisionNumber
|
|
self.stateNumber = stateNumber
|
|
|
|
|
|
def __str__(self):
|
|
return "NoViableAltException(%r!=[%r])" % (
|
|
self.unexpectedType, self.grammarDecisionDescription
|
|
)
|
|
__repr__ = __str__
|
|
|
|
|
|
class EarlyExitException(RecognitionException):
|
|
"""@brief The recognizer did not match anything for a (..)+ loop."""
|
|
|
|
def __init__(self, decisionNumber, input):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.decisionNumber = decisionNumber
|
|
|
|
|
|
class FailedPredicateException(RecognitionException):
|
|
"""@brief A semantic predicate failed during validation.
|
|
|
|
Validation of predicates
|
|
occurs when normally parsing the alternative just like matching a token.
|
|
Disambiguating predicate evaluation occurs when we hoist a predicate into
|
|
a prediction decision.
|
|
"""
|
|
|
|
def __init__(self, input, ruleName, predicateText):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.ruleName = ruleName
|
|
self.predicateText = predicateText
|
|
|
|
|
|
def __str__(self):
|
|
return "FailedPredicateException("+self.ruleName+",{"+self.predicateText+"}?)"
|
|
__repr__ = __str__
|
|
|
|
|
|
class MismatchedTreeNodeException(RecognitionException):
|
|
"""@brief The next tree mode does not match the expected type."""
|
|
|
|
def __init__(self, expecting, input):
|
|
RecognitionException.__init__(self, input)
|
|
|
|
self.expecting = expecting
|
|
|
|
def __str__(self):
|
|
return "MismatchedTreeNodeException(%r!=%r)" % (
|
|
self.getUnexpectedType(), self.expecting
|
|
)
|
|
__repr__ = __str__
|