void AntlrInput::lexerError(pANTLR3_BASE_RECOGNIZER recognizer) {
pANTLR3_LEXER lexer = (pANTLR3_LEXER)(recognizer->super);
assert(lexer!=NULL);
Parser *parser = (Parser*)(lexer->super);
assert(parser!=NULL);
AntlrInput *input = (AntlrInput*) parser->getInput();
assert(input!=NULL);
/* Call the error display routine *if* there's not already a
* parse error pending. If a parser error is pending, this
* error is probably less important, so we just drop it. */
if( input->d_parser->rec->state->error == ANTLR3_FALSE ) {
input->parseError("Error finding next token.");
}
}
/* *** CVC4 NOTE ***
* This function is has been modified in not-completely-trivial ways from its
* libantlr3c implementation to support more informative error messages and to
* invoke the error reporting mechanism of the Input class instead of the
* default error printer.
*/
void AntlrInput::reportError(pANTLR3_BASE_RECOGNIZER recognizer) {
pANTLR3_EXCEPTION ex = recognizer->state->exception;
pANTLR3_UINT8 * tokenNames = recognizer->state->tokenNames;
stringstream ss;
// Dig the CVC4 objects out of the ANTLR3 mess
pANTLR3_PARSER antlr3Parser = (pANTLR3_PARSER)(recognizer->super);
assert(antlr3Parser!=NULL);
Parser *parser = (Parser*)(antlr3Parser->super);
assert(parser!=NULL);
AntlrInput *input = (AntlrInput*) parser->getInput() ;
assert(input!=NULL);
// Signal we are in error recovery now
recognizer->state->errorRecovery = ANTLR3_TRUE;
// Indicate this recognizer had an error while processing.
recognizer->state->errorCount++;
// Call the builtin error formatter
// recognizer->displayRecognitionError(recognizer, recognizer->state->tokenNames);
/* TODO: Make error messages more useful, maybe by including more expected tokens and information
* about the current token. */
switch(ex->type) {
case ANTLR3_UNWANTED_TOKEN_EXCEPTION:
// Indicates that the recognizer was fed a token which seems to be
// spurious input. We can detect this when the token that follows
// this unwanted token would normally be part of the syntactically
// correct stream. Then we can see that the token we are looking at
// is just something that should not be there and throw this exception.
//
if(tokenNames == NULL) {
ss << "Unexpected token." ;
} else {
if(ex->expecting == ANTLR3_TOKEN_EOF) {
ss << "Expected end of file.";
} else {
ss << "Expected " << tokenNames[ex->expecting]
<< ", found '" << tokenText((pANTLR3_COMMON_TOKEN)ex->token) << "'.";
}
}
break;
case ANTLR3_MISSING_TOKEN_EXCEPTION:
// Indicates that the recognizer detected that the token we just
// hit would be valid syntactically if preceded by a particular
// token. Perhaps a missing ';' at line end or a missing ',' in an
// expression list, and such like.
//
if(tokenNames == NULL) {
ss << "Missing token (" << ex->expecting << ").";
} else {
if(ex->expecting == ANTLR3_TOKEN_EOF) {
ss << "Missing end of file marker.";
} else if( ex->expecting == 0 ) {
ss << "Unexpected token: '" << tokenText((pANTLR3_COMMON_TOKEN)ex->token) << "'.";
if( std::string(tokenText((pANTLR3_COMMON_TOKEN)ex->token)) == std::string("IN") ) {
ss << " Did you mean: `IS_IN'?";
}
} else {
ss << "Missing " << tokenNames[ex->expecting] << ".";
}
}
break;
case ANTLR3_RECOGNITION_EXCEPTION:
// Indicates that the recognizer received a token
// in the input that was not predicted. This is the basic exception type
// from which all others are derived. So we assume it was a syntax error.
// You may get this if there are not more tokens and more are needed
// to complete a parse for instance.
//
ss <<"Syntax error.";
break;
case ANTLR3_MISMATCHED_TOKEN_EXCEPTION:
// We were expecting to see one thing and got another. This is the
// most common error if we could not detect a missing or unwanted token.
// Here you can spend your efforts to
// derive more useful error messages based on the expected
// token set and the last token and so on. The error following
// bitmaps do a good job of reducing the set that we were looking
// for down to something small. Knowing what you are parsing may be
// able to allow you to be even more specific about an error.
//
if(tokenNames == NULL) {
ss << "Syntax error.";
} else {
if(ex->expecting == ANTLR3_TOKEN_EOF) {
ss << "Expected end of file.";
} else if( ex->expecting == 0 ) {
ss << "Unexpected token: '" << tokenText((pANTLR3_COMMON_TOKEN)ex->token) << "'.";
} else {
ss << "Expected " << tokenNames[ex->expecting] << ".";
}
}
break;
case ANTLR3_NO_VIABLE_ALT_EXCEPTION:
// We could not pick any alt decision from the input given
// so god knows what happened - however when you examine your grammar,
// you should. It means that at the point where the current token occurred
// that the DFA indicates nowhere to go from here.
//
ss << "Unexpected token: '" << tokenText((pANTLR3_COMMON_TOKEN)ex->token) << "'.";
break;
case ANTLR3_MISMATCHED_SET_EXCEPTION:
{
ANTLR3_UINT32 count;
ANTLR3_UINT32 bit;
ANTLR3_UINT32 size;
ANTLR3_UINT32 numbits;
pANTLR3_BITSET errBits;
// This means we were able to deal with one of a set of
// possible tokens at this point, but we did not see any
// member of that set.
//
ss << "Unexpected input: '" << tokenText((pANTLR3_COMMON_TOKEN)ex->token)
<< "'. Expected one of: ";
// What tokens could we have accepted at this point in the
// parse?
//
count = 0;
errBits = antlr3BitsetLoad(ex->expectingSet);
numbits = errBits->numBits(errBits);
size = errBits->size(errBits);
if(size > 0) {
// However many tokens we could have dealt with here, it is usually
// not useful to print ALL of the set here. I arbitrarily chose 8
// here, but you should do whatever makes sense for you of course.
// No token number 0, so look for bit 1 and on.
//
for(bit = 1; bit < numbits && count < 8 && count < size; bit++) {
// TODO: This doesn;t look right - should be asking if the bit is set!!
//
if(tokenNames[bit]) {
if( count++ > 0 ) {
ss << ", ";
}
ss << tokenNames[bit];
}
}
} else {
assert(false);//("Parse error with empty set of expected tokens.");
}
}
break;
case ANTLR3_EARLY_EXIT_EXCEPTION:
// We entered a loop requiring a number of token sequences
// but found a token that ended that sequence earlier than
// we should have done.
//
ss << "Sequence terminated early by token: '"
<< tokenText((pANTLR3_COMMON_TOKEN)ex->token) << "'.";
break;
default:
// We don't handle any other exceptions here, but you can
// if you wish. If we get an exception that hits this point
// then we are just going to report what we know about the
// token.
//
assert(false);//("Unexpected exception in parser.");
break;
}
// Call the error display routine
input->parseError(ss.str(), ((pANTLR3_COMMON_TOKEN)ex->token)->type == ANTLR3_TOKEN_EOF);
}