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Diffstat (limited to 'antlr/libantlr3c-3.4/src/antlr3baserecognizer.c')
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1 files changed, 2235 insertions, 0 deletions
diff --git a/antlr/libantlr3c-3.4/src/antlr3baserecognizer.c b/antlr/libantlr3c-3.4/src/antlr3baserecognizer.c new file mode 100644 index 0000000..e2eccc6 --- /dev/null +++ b/antlr/libantlr3c-3.4/src/antlr3baserecognizer.c @@ -0,0 +1,2235 @@ +/** \file + * Contains the base functions that all recognizers require. + * Any function can be overridden by a lexer/parser/tree parser or by the + * ANTLR3 programmer. + * + * \addtogroup pANTLR3_BASE_RECOGNIZER + * @{ + */ +#include <antlr3baserecognizer.h> + +// [The "BSD licence"] +// Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC +// http://www.temporal-wave.com +// http://www.linkedin.com/in/jimidle +// +// 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. + +#ifdef ANTLR3_WINDOWS +#pragma warning( disable : 4100 ) +#endif + +/* Interface functions -standard implementations cover parser and treeparser + * almost completely but are overridden by the parser or tree parser as needed. Lexer overrides + * most of these functions. + */ +static void beginResync (pANTLR3_BASE_RECOGNIZER recognizer); +static pANTLR3_BITSET computeErrorRecoverySet (pANTLR3_BASE_RECOGNIZER recognizer); +static void endResync (pANTLR3_BASE_RECOGNIZER recognizer); +static void beginBacktrack (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 level); +static void endBacktrack (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 level, ANTLR3_BOOLEAN successful); + +static void * match (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow); +static void matchAny (pANTLR3_BASE_RECOGNIZER recognizer); +static void mismatch (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow); +static ANTLR3_BOOLEAN mismatchIsUnwantedToken (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, ANTLR3_UINT32 ttype); +static ANTLR3_BOOLEAN mismatchIsMissingToken (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, pANTLR3_BITSET_LIST follow); +static void reportError (pANTLR3_BASE_RECOGNIZER recognizer); +static pANTLR3_BITSET computeCSRuleFollow (pANTLR3_BASE_RECOGNIZER recognizer); +static pANTLR3_BITSET combineFollows (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_BOOLEAN exact); +static void displayRecognitionError (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_UINT8 * tokenNames); +static void recover (pANTLR3_BASE_RECOGNIZER recognizer); +static void * recoverFromMismatchedToken (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow); +static void * recoverFromMismatchedSet (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET_LIST follow); +static ANTLR3_BOOLEAN recoverFromMismatchedElement(pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET_LIST follow); +static void consumeUntil (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 tokenType); +static void consumeUntilSet (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET set); +static pANTLR3_STACK getRuleInvocationStack (pANTLR3_BASE_RECOGNIZER recognizer); +static pANTLR3_STACK getRuleInvocationStackNamed (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_UINT8 name); +static pANTLR3_HASH_TABLE toStrings (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_HASH_TABLE); +static ANTLR3_MARKER getRuleMemoization (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_INTKEY ruleIndex, ANTLR3_MARKER ruleParseStart); +static ANTLR3_BOOLEAN alreadyParsedRule (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_MARKER ruleIndex); +static void memoize (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_MARKER ruleIndex, ANTLR3_MARKER ruleParseStart); +static ANTLR3_BOOLEAN synpred (pANTLR3_BASE_RECOGNIZER recognizer, void * ctx, void (*predicate)(void * ctx)); +static void reset (pANTLR3_BASE_RECOGNIZER recognizer); +static void freeBR (pANTLR3_BASE_RECOGNIZER recognizer); +static void * getCurrentInputSymbol (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM istream); +static void * getMissingSymbol (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM istream, pANTLR3_EXCEPTION e, + ANTLR3_UINT32 expectedTokenType, pANTLR3_BITSET_LIST follow); +static ANTLR3_UINT32 getNumberOfSyntaxErrors (pANTLR3_BASE_RECOGNIZER recognizer); + +ANTLR3_API pANTLR3_BASE_RECOGNIZER +antlr3BaseRecognizerNew(ANTLR3_UINT32 type, ANTLR3_UINT32 sizeHint, pANTLR3_RECOGNIZER_SHARED_STATE state) +{ + pANTLR3_BASE_RECOGNIZER recognizer; + + // Allocate memory for the structure + // + recognizer = (pANTLR3_BASE_RECOGNIZER) ANTLR3_MALLOC((size_t)sizeof(ANTLR3_BASE_RECOGNIZER)); + + if (recognizer == NULL) + { + // Allocation failed + // + return NULL; + } + + + // If we have been supplied with a pre-existing recognizer state + // then we just install it, otherwise we must create one from scratch + // + if (state == NULL) + { + recognizer->state = (pANTLR3_RECOGNIZER_SHARED_STATE) ANTLR3_CALLOC(1, (size_t)sizeof(ANTLR3_RECOGNIZER_SHARED_STATE)); + + if (recognizer->state == NULL) + { + ANTLR3_FREE(recognizer); + return NULL; + } + + // Initialize any new recognizer state + // + recognizer->state->errorRecovery = ANTLR3_FALSE; + recognizer->state->lastErrorIndex = -1; + recognizer->state->failed = ANTLR3_FALSE; + recognizer->state->errorCount = 0; + recognizer->state->backtracking = 0; + recognizer->state->following = NULL; + recognizer->state->ruleMemo = NULL; + recognizer->state->tokenNames = NULL; + recognizer->state->sizeHint = sizeHint; + recognizer->state->tokSource = NULL; + recognizer->state->tokFactory = NULL; + + // Rather than check to see if we must initialize + // the stack every time we are asked for an new rewrite stream + // we just always create an empty stack and then just + // free it when the base recognizer is freed. + // + recognizer->state->rStreams = antlr3VectorNew(0); // We don't know the size. + + if (recognizer->state->rStreams == NULL) + { + // Out of memory + // + ANTLR3_FREE(recognizer->state); + ANTLR3_FREE(recognizer); + return NULL; + } + } + else + { + // Install the one we were given, and do not reset it here + // as it will either already have been initialized or will + // be in a state that needs to be preserved. + // + recognizer->state = state; + } + + // Install the BR API + // + recognizer->alreadyParsedRule = alreadyParsedRule; + recognizer->beginResync = beginResync; + recognizer->combineFollows = combineFollows; + recognizer->beginBacktrack = beginBacktrack; + recognizer->endBacktrack = endBacktrack; + recognizer->computeCSRuleFollow = computeCSRuleFollow; + recognizer->computeErrorRecoverySet = computeErrorRecoverySet; + recognizer->consumeUntil = consumeUntil; + recognizer->consumeUntilSet = consumeUntilSet; + recognizer->displayRecognitionError = displayRecognitionError; + recognizer->endResync = endResync; + recognizer->exConstruct = antlr3MTExceptionNew; + recognizer->getRuleInvocationStack = getRuleInvocationStack; + recognizer->getRuleInvocationStackNamed = getRuleInvocationStackNamed; + recognizer->getRuleMemoization = getRuleMemoization; + recognizer->match = match; + recognizer->matchAny = matchAny; + recognizer->memoize = memoize; + recognizer->mismatch = mismatch; + recognizer->mismatchIsUnwantedToken = mismatchIsUnwantedToken; + recognizer->mismatchIsMissingToken = mismatchIsMissingToken; + recognizer->recover = recover; + recognizer->recoverFromMismatchedElement= recoverFromMismatchedElement; + recognizer->recoverFromMismatchedSet = recoverFromMismatchedSet; + recognizer->recoverFromMismatchedToken = recoverFromMismatchedToken; + recognizer->getNumberOfSyntaxErrors = getNumberOfSyntaxErrors; + recognizer->reportError = reportError; + recognizer->reset = reset; + recognizer->synpred = synpred; + recognizer->toStrings = toStrings; + recognizer->getCurrentInputSymbol = getCurrentInputSymbol; + recognizer->getMissingSymbol = getMissingSymbol; + recognizer->debugger = NULL; + + recognizer->free = freeBR; + + /* Initialize variables + */ + recognizer->type = type; + + + return recognizer; +} +static void +freeBR (pANTLR3_BASE_RECOGNIZER recognizer) +{ + pANTLR3_EXCEPTION thisE; + + // Did we have a state allocated? + // + if (recognizer->state != NULL) + { + // Free any rule memoization we set up + // + if (recognizer->state->ruleMemo != NULL) + { + recognizer->state->ruleMemo->free(recognizer->state->ruleMemo); + recognizer->state->ruleMemo = NULL; + } + + // Free any exception space we have left around + // + thisE = recognizer->state->exception; + if (thisE != NULL) + { + thisE->freeEx(thisE); + } + + // Free any rewrite streams we have allocated + // + if (recognizer->state->rStreams != NULL) + { + recognizer->state->rStreams->free(recognizer->state->rStreams); + } + + // Free up any token factory we created (error recovery for instance) + // + if (recognizer->state->tokFactory != NULL) + { + recognizer->state->tokFactory->close(recognizer->state->tokFactory); + } + // Free the shared state memory + // + ANTLR3_FREE(recognizer->state); + } + + // Free the actual recognizer space + // + ANTLR3_FREE(recognizer); +} + +/** + * Creates a new Mismatched Token Exception and inserts in the recognizer + * exception stack. + * + * \param recognizer + * Context pointer for this recognizer + * + */ +ANTLR3_API void +antlr3MTExceptionNew(pANTLR3_BASE_RECOGNIZER recognizer) +{ + /* Create a basic recognition exception structure + */ + antlr3RecognitionExceptionNew(recognizer); + + /* Now update it to indicate this is a Mismatched token exception + */ + recognizer->state->exception->name = ANTLR3_MISMATCHED_EX_NAME; + recognizer->state->exception->type = ANTLR3_MISMATCHED_TOKEN_EXCEPTION; + + return; +} + +ANTLR3_API void +antlr3RecognitionExceptionNew(pANTLR3_BASE_RECOGNIZER recognizer) +{ + pANTLR3_EXCEPTION ex; + pANTLR3_LEXER lexer; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + + pANTLR3_INPUT_STREAM ins; + pANTLR3_INT_STREAM is; + pANTLR3_COMMON_TOKEN_STREAM cts; + pANTLR3_TREE_NODE_STREAM tns; + + ins = NULL; + cts = NULL; + tns = NULL; + is = NULL; + lexer = NULL; + parser = NULL; + tparser = NULL; + + switch (recognizer->type) + { + case ANTLR3_TYPE_LEXER: + + lexer = (pANTLR3_LEXER) (recognizer->super); + ins = lexer->input; + is = ins->istream; + + break; + + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + cts = (pANTLR3_COMMON_TOKEN_STREAM)(parser->tstream->super); + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + tns = tparser->ctnstream->tnstream; + is = tns->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function antlr3RecognitionExceptionNew called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + /* Create a basic exception structure + */ + ex = antlr3ExceptionNew(ANTLR3_RECOGNITION_EXCEPTION, + (void *)ANTLR3_RECOGNITION_EX_NAME, + NULL, + ANTLR3_FALSE); + + /* Rest of information depends on the base type of the + * input stream. + */ + switch (is->type & ANTLR3_INPUT_MASK) + { + case ANTLR3_CHARSTREAM: + + ex->c = is->_LA (is, 1); /* Current input character */ + ex->line = ins->getLine (ins); /* Line number comes from stream */ + ex->charPositionInLine = ins->getCharPositionInLine (ins); /* Line offset also comes from the stream */ + ex->index = is->index (is); + ex->streamName = ins->fileName; + ex->message = "Unexpected character"; + break; + + case ANTLR3_TOKENSTREAM: + + ex->token = cts->tstream->_LT (cts->tstream, 1); /* Current input token */ + ex->line = ((pANTLR3_COMMON_TOKEN)(ex->token))->getLine (ex->token); + ex->charPositionInLine = ((pANTLR3_COMMON_TOKEN)(ex->token))->getCharPositionInLine (ex->token); + ex->index = cts->tstream->istream->index (cts->tstream->istream); + if (((pANTLR3_COMMON_TOKEN)(ex->token))->type == ANTLR3_TOKEN_EOF) + { + ex->streamName = NULL; + } + else + { + ex->streamName = ((pANTLR3_COMMON_TOKEN)(ex->token))->input->fileName; + } + ex->message = "Unexpected token"; + break; + + case ANTLR3_COMMONTREENODE: + + ex->token = tns->_LT (tns, 1); /* Current input tree node */ + ex->line = ((pANTLR3_BASE_TREE)(ex->token))->getLine (ex->token); + ex->charPositionInLine = ((pANTLR3_BASE_TREE)(ex->token))->getCharPositionInLine (ex->token); + ex->index = tns->istream->index (tns->istream); + + // Are you ready for this? Deep breath now... + // + { + pANTLR3_COMMON_TREE tnode; + + tnode = ((pANTLR3_COMMON_TREE)(((pANTLR3_BASE_TREE)(ex->token))->super)); + + if (tnode->token == NULL) + { + ex->streamName = ((pANTLR3_BASE_TREE)(ex->token))->strFactory->newStr(((pANTLR3_BASE_TREE)(ex->token))->strFactory, (pANTLR3_UINT8)"-unknown source-"); + } + else + { + if (tnode->token->input == NULL) + { + ex->streamName = NULL; + } + else + { + ex->streamName = tnode->token->input->fileName; + } + } + ex->message = "Unexpected node"; + } + break; + } + + ex->input = is; + ex->nextException = recognizer->state->exception; /* So we don't leak the memory */ + recognizer->state->exception = ex; + recognizer->state->error = ANTLR3_TRUE; /* Exception is outstanding */ + + return; +} + + +/// Match current input symbol against ttype. Upon error, do one token +/// insertion or deletion if possible. +/// To turn off single token insertion or deletion error +/// recovery, override mismatchRecover() and have it call +/// plain mismatch(), which does not recover. Then any error +/// in a rule will cause an exception and immediate exit from +/// rule. Rule would recover by resynchronizing to the set of +/// symbols that can follow rule ref. +/// +static void * +match( pANTLR3_BASE_RECOGNIZER recognizer, + ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + void * matchedSymbol; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'match' called by unknown parser type - provide override for this function\n"); + return ANTLR3_FALSE; + + break; + } + + // Pick up the current input token/node for assignment to labels + // + matchedSymbol = recognizer->getCurrentInputSymbol(recognizer, is); + + if (is->_LA(is, 1) == ttype) + { + // The token was the one we were told to expect + // + is->consume(is); // Consume that token from the stream + recognizer->state->errorRecovery = ANTLR3_FALSE; // Not in error recovery now (if we were) + recognizer->state->failed = ANTLR3_FALSE; // The match was a success + return matchedSymbol; // We are done + } + + // We did not find the expected token type, if we are backtracking then + // we just set the failed flag and return. + // + if (recognizer->state->backtracking > 0) + { + // Backtracking is going on + // + recognizer->state->failed = ANTLR3_TRUE; + return matchedSymbol; + } + + // We did not find the expected token and there is no backtracking + // going on, so we mismatch, which creates an exception in the recognizer exception + // stack. + // + matchedSymbol = recognizer->recoverFromMismatchedToken(recognizer, ttype, follow); + return matchedSymbol; +} + +/// Consumes the next token, whatever it is, and resets the recognizer state +/// so that it is not in error. +/// +/// \param recognizer +/// Recognizer context pointer +/// +static void +matchAny(pANTLR3_BASE_RECOGNIZER recognizer) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'matchAny' called by unknown parser type - provide override for this function\n"); + return; + + break; + } + recognizer->state->errorRecovery = ANTLR3_FALSE; + recognizer->state->failed = ANTLR3_FALSE; + is->consume(is); + + return; +} +/// +/// +static ANTLR3_BOOLEAN +mismatchIsUnwantedToken(pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, ANTLR3_UINT32 ttype) +{ + ANTLR3_UINT32 nextt; + + nextt = is->_LA(is, 2); + + if (nextt == ttype) + { + if (recognizer->state->exception != NULL) + { + recognizer->state->exception->expecting = nextt; + } + return ANTLR3_TRUE; // This token is unknown, but the next one is the one we wanted + } + else + { + return ANTLR3_FALSE; // Neither this token, nor the one following is the one we wanted + } +} + +/// +/// +static ANTLR3_BOOLEAN +mismatchIsMissingToken(pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, pANTLR3_BITSET_LIST follow) +{ + ANTLR3_BOOLEAN retcode; + pANTLR3_BITSET followClone; + pANTLR3_BITSET viableTokensFollowingThisRule; + + if (follow == NULL) + { + // There is no information about the tokens that can follow the last one + // hence we must say that the current one we found is not a member of the + // follow set and does not indicate a missing token. We will just consume this + // single token and see if the parser works it out from there. + // + return ANTLR3_FALSE; + } + + followClone = NULL; + viableTokensFollowingThisRule = NULL; + + // The C bitset maps are laid down at compile time by the + // C code generation. Hence we cannot remove things from them + // and so on. So, in order to remove EOR (if we need to) then + // we clone the static bitset. + // + followClone = antlr3BitsetLoad(follow); + if (followClone == NULL) + { + return ANTLR3_FALSE; + } + + // Compute what can follow this grammar reference + // + if (followClone->isMember(followClone, ANTLR3_EOR_TOKEN_TYPE)) + { + // EOR can follow, but if we are not the start symbol, we + // need to remove it. + // + if (recognizer->state->following->vector->count >= 0) + { + followClone->remove(followClone, ANTLR3_EOR_TOKEN_TYPE); + } + + // Now compute the visiable tokens that can follow this rule, according to context + // and make them part of the follow set. + // + viableTokensFollowingThisRule = recognizer->computeCSRuleFollow(recognizer); + followClone->borInPlace(followClone, viableTokensFollowingThisRule); + } + + /// if current token is consistent with what could come after set + /// then we know we're missing a token; error recovery is free to + /// "insert" the missing token + /// + /// BitSet cannot handle negative numbers like -1 (EOF) so I leave EOR + /// in follow set to indicate that the fall of the start symbol is + /// in the set (EOF can follow). + /// + if ( followClone->isMember(followClone, is->_LA(is, 1)) + || followClone->isMember(followClone, ANTLR3_EOR_TOKEN_TYPE) + ) + { + retcode = ANTLR3_TRUE; + } + else + { + retcode = ANTLR3_FALSE; + } + + if (viableTokensFollowingThisRule != NULL) + { + viableTokensFollowingThisRule->free(viableTokensFollowingThisRule); + } + if (followClone != NULL) + { + followClone->free(followClone); + } + + return retcode; + +} + +/// Factor out what to do upon token mismatch so tree parsers can behave +/// differently. Override and call mismatchRecover(input, ttype, follow) +/// to get single token insertion and deletion. Use this to turn off +/// single token insertion and deletion. Override mismatchRecover +/// to call this instead. +/// +/// \remark mismatch only works for parsers and must be overridden for anything else. +/// +static void +mismatch(pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + // Install a mismatched token exception in the exception stack + // + antlr3MTExceptionNew(recognizer); + recognizer->state->exception->expecting = ttype; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'mismatch' called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + if (mismatchIsUnwantedToken(recognizer, is, ttype)) + { + // Create a basic recognition exception structure + // + antlr3RecognitionExceptionNew(recognizer); + + // Now update it to indicate this is an unwanted token exception + // + recognizer->state->exception->name = ANTLR3_UNWANTED_TOKEN_EXCEPTION_NAME; + recognizer->state->exception->type = ANTLR3_UNWANTED_TOKEN_EXCEPTION; + + return; + } + + if (mismatchIsMissingToken(recognizer, is, follow)) + { + // Create a basic recognition exception structure + // + antlr3RecognitionExceptionNew(recognizer); + + // Now update it to indicate this is an unwanted token exception + // + recognizer->state->exception->name = ANTLR3_MISSING_TOKEN_EXCEPTION_NAME; + recognizer->state->exception->type = ANTLR3_MISSING_TOKEN_EXCEPTION; + + return; + } + + // Just a mismatched token is all we can dtermine + // + antlr3MTExceptionNew(recognizer); + + return; +} +/// Report a recognition problem. +/// +/// This method sets errorRecovery to indicate the parser is recovering +/// not parsing. Once in recovery mode, no errors are generated. +/// To get out of recovery mode, the parser must successfully match +/// a token (after a resync). So it will go: +/// +/// 1. error occurs +/// 2. enter recovery mode, report error +/// 3. consume until token found in resynch set +/// 4. try to resume parsing +/// 5. next match() will reset errorRecovery mode +/// +/// If you override, make sure to update errorCount if you care about that. +/// +static void +reportError (pANTLR3_BASE_RECOGNIZER recognizer) +{ + // Invoke the debugger event if there is a debugger listening to us + // + if (recognizer->debugger != NULL) + { + recognizer->debugger->recognitionException(recognizer->debugger, recognizer->state->exception); + } + + if (recognizer->state->errorRecovery == ANTLR3_TRUE) + { + // Already in error recovery so don't display another error while doing so + // + return; + } + + // 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 error display routine + // + recognizer->displayRecognitionError(recognizer, recognizer->state->tokenNames); +} + +static void +beginBacktrack (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 level) +{ + if (recognizer->debugger != NULL) + { + recognizer->debugger->beginBacktrack(recognizer->debugger, level); + } +} + +static void +endBacktrack (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 level, ANTLR3_BOOLEAN successful) +{ + if (recognizer->debugger != NULL) + { + recognizer->debugger->endBacktrack(recognizer->debugger, level, successful); + } +} +static void +beginResync (pANTLR3_BASE_RECOGNIZER recognizer) +{ + if (recognizer->debugger != NULL) + { + recognizer->debugger->beginResync(recognizer->debugger); + } +} + +static void +endResync (pANTLR3_BASE_RECOGNIZER recognizer) +{ + if (recognizer->debugger != NULL) + { + recognizer->debugger->endResync(recognizer->debugger); + } +} + +/// Compute the error recovery set for the current rule. +/// Documentation below is from the Java implementation. +/// +/// During rule invocation, the parser pushes the set of tokens that can +/// follow that rule reference on the stack; this amounts to +/// computing FIRST of what follows the rule reference in the +/// enclosing rule. This local follow set only includes tokens +/// from within the rule; i.e., the FIRST computation done by +/// ANTLR stops at the end of a rule. +// +/// EXAMPLE +// +/// When you find a "no viable alt exception", the input is not +/// consistent with any of the alternatives for rule r. The best +/// thing to do is to consume tokens until you see something that +/// can legally follow a call to r *or* any rule that called r. +/// You don't want the exact set of viable next tokens because the +/// input might just be missing a token--you might consume the +/// rest of the input looking for one of the missing tokens. +/// +/// Consider grammar: +/// +/// a : '[' b ']' +/// | '(' b ')' +/// ; +/// b : c '^' INT ; +/// c : ID +/// | INT +/// ; +/// +/// At each rule invocation, the set of tokens that could follow +/// that rule is pushed on a stack. Here are the various "local" +/// follow sets: +/// +/// FOLLOW(b1_in_a) = FIRST(']') = ']' +/// FOLLOW(b2_in_a) = FIRST(')') = ')' +/// FOLLOW(c_in_b) = FIRST('^') = '^' +/// +/// Upon erroneous input "[]", the call chain is +/// +/// a -> b -> c +/// +/// and, hence, the follow context stack is: +/// +/// depth local follow set after call to rule +/// 0 <EOF> a (from main()) +/// 1 ']' b +/// 3 '^' c +/// +/// Notice that ')' is not included, because b would have to have +/// been called from a different context in rule a for ')' to be +/// included. +/// +/// For error recovery, we cannot consider FOLLOW(c) +/// (context-sensitive or otherwise). We need the combined set of +/// all context-sensitive FOLLOW sets--the set of all tokens that +/// could follow any reference in the call chain. We need to +/// resync to one of those tokens. Note that FOLLOW(c)='^' and if +/// we resync'd to that token, we'd consume until EOF. We need to +/// sync to context-sensitive FOLLOWs for a, b, and c: {']','^'}. +/// In this case, for input "[]", LA(1) is in this set so we would +/// not consume anything and after printing an error rule c would +/// return normally. It would not find the required '^' though. +/// At this point, it gets a mismatched token error and throws an +/// exception (since LA(1) is not in the viable following token +/// set). The rule exception handler tries to recover, but finds +/// the same recovery set and doesn't consume anything. Rule b +/// exits normally returning to rule a. Now it finds the ']' (and +/// with the successful match exits errorRecovery mode). +/// +/// So, you can see that the parser walks up call chain looking +/// for the token that was a member of the recovery set. +/// +/// Errors are not generated in errorRecovery mode. +/// +/// ANTLR's error recovery mechanism is based upon original ideas: +/// +/// "Algorithms + Data Structures = Programs" by Niklaus Wirth +/// +/// and +/// +/// "A note on error recovery in recursive descent parsers": +/// http://portal.acm.org/citation.cfm?id=947902.947905 +/// +/// Later, Josef Grosch had some good ideas: +/// +/// "Efficient and Comfortable Error Recovery in Recursive Descent +/// Parsers": +/// ftp://www.cocolab.com/products/cocktail/doca4.ps/ell.ps.zip +/// +/// Like Grosch I implemented local FOLLOW sets that are combined +/// at run-time upon error to avoid overhead during parsing. +/// +static pANTLR3_BITSET +computeErrorRecoverySet (pANTLR3_BASE_RECOGNIZER recognizer) +{ + return recognizer->combineFollows(recognizer, ANTLR3_FALSE); +} + +/// Compute the context-sensitive FOLLOW set for current rule. +/// Documentation below is from the Java runtime. +/// +/// This is the set of token types that can follow a specific rule +/// reference given a specific call chain. You get the set of +/// viable tokens that can possibly come next (look ahead depth 1) +/// given the current call chain. Contrast this with the +/// definition of plain FOLLOW for rule r: +/// +/// FOLLOW(r)={x | S=>*alpha r beta in G and x in FIRST(beta)} +/// +/// where x in T* and alpha, beta in V*; T is set of terminals and +/// V is the set of terminals and non terminals. In other words, +/// FOLLOW(r) is the set of all tokens that can possibly follow +/// references to r in///any* sentential form (context). At +/// runtime, however, we know precisely which context applies as +/// we have the call chain. We may compute the exact (rather +/// than covering superset) set of following tokens. +/// +/// For example, consider grammar: +/// +/// stat : ID '=' expr ';' // FOLLOW(stat)=={EOF} +/// | "return" expr '.' +/// ; +/// expr : atom ('+' atom)* ; // FOLLOW(expr)=={';','.',')'} +/// atom : INT // FOLLOW(atom)=={'+',')',';','.'} +/// | '(' expr ')' +/// ; +/// +/// The FOLLOW sets are all inclusive whereas context-sensitive +/// FOLLOW sets are precisely what could follow a rule reference. +/// For input input "i=(3);", here is the derivation: +/// +/// stat => ID '=' expr ';' +/// => ID '=' atom ('+' atom)* ';' +/// => ID '=' '(' expr ')' ('+' atom)* ';' +/// => ID '=' '(' atom ')' ('+' atom)* ';' +/// => ID '=' '(' INT ')' ('+' atom)* ';' +/// => ID '=' '(' INT ')' ';' +/// +/// At the "3" token, you'd have a call chain of +/// +/// stat -> expr -> atom -> expr -> atom +/// +/// What can follow that specific nested ref to atom? Exactly ')' +/// as you can see by looking at the derivation of this specific +/// input. Contrast this with the FOLLOW(atom)={'+',')',';','.'}. +/// +/// You want the exact viable token set when recovering from a +/// token mismatch. Upon token mismatch, if LA(1) is member of +/// the viable next token set, then you know there is most likely +/// a missing token in the input stream. "Insert" one by just not +/// throwing an exception. +/// +static pANTLR3_BITSET +computeCSRuleFollow (pANTLR3_BASE_RECOGNIZER recognizer) +{ + return recognizer->combineFollows(recognizer, ANTLR3_FALSE); +} + +/// Compute the current followset for the input stream. +/// +static pANTLR3_BITSET +combineFollows (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_BOOLEAN exact) +{ + pANTLR3_BITSET followSet; + pANTLR3_BITSET localFollowSet; + ANTLR3_UINT32 top; + ANTLR3_UINT32 i; + + top = recognizer->state->following->size(recognizer->state->following); + + followSet = antlr3BitsetNew(0); + localFollowSet = NULL; + + for (i = top; i>0; i--) + { + localFollowSet = antlr3BitsetLoad((pANTLR3_BITSET_LIST) recognizer->state->following->get(recognizer->state->following, i-1)); + + if (localFollowSet != NULL) + { + followSet->borInPlace(followSet, localFollowSet); + + if (exact == ANTLR3_TRUE) + { + if (localFollowSet->isMember(localFollowSet, ANTLR3_EOR_TOKEN_TYPE) == ANTLR3_FALSE) + { + // Only leave EOR in the set if at top (start rule); this lets us know + // if we have to include the follow(start rule); I.E., EOF + // + if (i>1) + { + followSet->remove(followSet, ANTLR3_EOR_TOKEN_TYPE); + } + } + else + { + break; // Cannot see End Of Rule from here, just drop out + } + } + localFollowSet->free(localFollowSet); + localFollowSet = NULL; + } + } + + if (localFollowSet != NULL) + { + localFollowSet->free(localFollowSet); + } + return followSet; +} + +/// Standard/Example error display method. +/// No generic error message display funciton coudl possibly do everything correctly +/// for all possible parsers. Hence you are provided with this example routine, which +/// you should override in your parser/tree parser to do as you will. +/// +/// Here we depart somewhat from the Java runtime as that has now split up a lot +/// of the error display routines into spearate units. However, ther is little advantage +/// to this in the C version as you will probably implement all such routines as a +/// separate translation unit, rather than install them all as pointers to functions +/// in the base recognizer. +/// +static void +displayRecognitionError (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_UINT8 * tokenNames) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + pANTLR3_STRING ttext; + pANTLR3_STRING ftext; + pANTLR3_EXCEPTION ex; + pANTLR3_COMMON_TOKEN theToken; + pANTLR3_BASE_TREE theBaseTree; + pANTLR3_COMMON_TREE theCommonTree; + + // Retrieve some info for easy reading. + // + ex = recognizer->state->exception; + ttext = NULL; + + // See if there is a 'filename' we can use + // + if (ex->streamName == NULL) + { + if (((pANTLR3_COMMON_TOKEN)(ex->token))->type == ANTLR3_TOKEN_EOF) + { + ANTLR3_FPRINTF(stderr, "-end of input-("); + } + else + { + ANTLR3_FPRINTF(stderr, "-unknown source-("); + } + } + else + { + ftext = ex->streamName->to8(ex->streamName); + ANTLR3_FPRINTF(stderr, "%s(", ftext->chars); + } + + // Next comes the line number + // + + ANTLR3_FPRINTF(stderr, "%d) ", recognizer->state->exception->line); + ANTLR3_FPRINTF(stderr, " : error %d : %s", + recognizer->state->exception->type, + (pANTLR3_UINT8) (recognizer->state->exception->message)); + + + // How we determine the next piece is dependent on which thing raised the + // error. + // + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + // Prepare the knowledge we know we have + // + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + theToken = (pANTLR3_COMMON_TOKEN)(recognizer->state->exception->token); + ttext = theToken->toString(theToken); + + ANTLR3_FPRINTF(stderr, ", at offset %d", recognizer->state->exception->charPositionInLine); + if (theToken != NULL) + { + if (theToken->type == ANTLR3_TOKEN_EOF) + { + ANTLR3_FPRINTF(stderr, ", at <EOF>"); + } + else + { + // Guard against null text in a token + // + ANTLR3_FPRINTF(stderr, "\n near %s\n ", ttext == NULL ? (pANTLR3_UINT8)"<no text for the token>" : ttext->chars); + } + } + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + theBaseTree = (pANTLR3_BASE_TREE)(recognizer->state->exception->token); + ttext = theBaseTree->toStringTree(theBaseTree); + + if (theBaseTree != NULL) + { + theCommonTree = (pANTLR3_COMMON_TREE) theBaseTree->super; + + if (theCommonTree != NULL) + { + theToken = (pANTLR3_COMMON_TOKEN) theBaseTree->getToken(theBaseTree); + } + ANTLR3_FPRINTF(stderr, ", at offset %d", theBaseTree->getCharPositionInLine(theBaseTree)); + ANTLR3_FPRINTF(stderr, ", near %s", ttext->chars); + } + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function displayRecognitionError called by unknown parser type - provide override for this function\n"); + return; + break; + } + + // Although this function should generally be provided by the implementation, this one + // should be as helpful as possible for grammar developers and serve as an example + // of what you can do with each exception type. In general, when you make up your + // 'real' handler, you should debug the routine with all possible errors you expect + // which will then let you be as specific as possible about all circumstances. + // + // Note that in the general case, errors thrown by tree parsers indicate a problem + // with the output of the parser or with the tree grammar itself. The job of the parser + // is to produce a perfect (in traversal terms) syntactically correct tree, so errors + // at that stage should really be semantic errors that your own code determines and handles + // in whatever way is appropriate. + // + switch (ex->type) + { + case ANTLR3_UNWANTED_TOKEN_EXCEPTION: + + // Indicates that the recognizer was fed a token which seesm 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) + { + ANTLR3_FPRINTF(stderr, " : Extraneous input..."); + } + else + { + if (ex->expecting == ANTLR3_TOKEN_EOF) + { + ANTLR3_FPRINTF(stderr, " : Extraneous input - expected <EOF>\n"); + } + else + { + ANTLR3_FPRINTF(stderr, " : Extraneous input - expected %s ...\n", tokenNames[ex->expecting]); + } + } + break; + + case ANTLR3_MISSING_TOKEN_EXCEPTION: + + // Indicates that the recognizer detected that the token we just + // hit would be valid syntactically if preceeded by a particular + // token. Perhaps a missing ';' at line end or a missing ',' in an + // expression list, and such like. + // + if (tokenNames == NULL) + { + ANTLR3_FPRINTF(stderr, " : Missing token (%d)...\n", ex->expecting); + } + else + { + if (ex->expecting == ANTLR3_TOKEN_EOF) + { + ANTLR3_FPRINTF(stderr, " : Missing <EOF>\n"); + } + else + { + ANTLR3_FPRINTF(stderr, " : Missing %s \n", 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. + // + ANTLR3_FPRINTF(stderr, " : syntax error...\n"); + break; + + case ANTLR3_MISMATCHED_TOKEN_EXCEPTION: + + // We were expecting to see one thing and got another. This is the + // most common error if we coudl 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) + { + ANTLR3_FPRINTF(stderr, " : syntax error...\n"); + } + else + { + if (ex->expecting == ANTLR3_TOKEN_EOF) + { + ANTLR3_FPRINTF(stderr, " : expected <EOF>\n"); + } + else + { + ANTLR3_FPRINTF(stderr, " : expected %s ...\n", 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. + // + ANTLR3_FPRINTF(stderr, " : cannot match to any predicted input...\n"); + + 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. + // + ANTLR3_FPRINTF(stderr, " : unexpected input...\n 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]) + { + ANTLR3_FPRINTF(stderr, "%s%s", count > 0 ? ", " : "", tokenNames[bit]); + count++; + } + } + ANTLR3_FPRINTF(stderr, "\n"); + } + else + { + ANTLR3_FPRINTF(stderr, "Actually dude, we didn't seem to be expecting anything here, or at least\n"); + ANTLR3_FPRINTF(stderr, "I could not work out what I was expecting, like so many of us these days!\n"); + } + } + 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. + // + ANTLR3_FPRINTF(stderr, " : missing elements...\n"); + 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. + // + ANTLR3_FPRINTF(stderr, " : syntax not recognized...\n"); + break; + } + + // Here you have the token that was in error which if this is + // the standard implementation will tell you the line and offset + // and also record the address of the start of the line in the + // input stream. You could therefore print the source line and so on. + // Generally though, I would expect that your lexer/parser will keep + // its own map of lines and source pointers or whatever as there + // are a lot of specific things you need to know about the input + // to do something like that. + // Here is where you do it though :-). + // +} + +/// Return how many syntax errors were detected by this recognizer +/// +static ANTLR3_UINT32 +getNumberOfSyntaxErrors(pANTLR3_BASE_RECOGNIZER recognizer) +{ + return recognizer->state->errorCount; +} + +/// Recover from an error found on the input stream. Mostly this is +/// NoViableAlt exceptions, but could be a mismatched token that +/// the match() routine could not recover from. +/// +static void +recover (pANTLR3_BASE_RECOGNIZER recognizer) +{ + // Used to compute the follow set of tokens + // + pANTLR3_BITSET followSet; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function recover called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + // Are we about to repeat the same error? + // + if (recognizer->state->lastErrorIndex == is->index(is)) + { + // The last error was at the same token index point. This must be a case + // where LT(1) is in the recovery token set so nothing is + // consumed. Consume a single token so at least to prevent + // an infinite loop; this is a failsafe. + // + is->consume(is); + } + + // Record error index position + // + recognizer->state->lastErrorIndex = is->index(is); + + // Work out the follows set for error recovery + // + followSet = recognizer->computeErrorRecoverySet(recognizer); + + // Call resync hook (for debuggers and so on) + // + recognizer->beginResync(recognizer); + + // Consume tokens until we have resynced to something in the follows set + // + recognizer->consumeUntilSet(recognizer, followSet); + + // End resync hook + // + recognizer->endResync(recognizer); + + // Destroy the temporary bitset we produced. + // + followSet->free(followSet); + + // Reset the inError flag so we don't re-report the exception + // + recognizer->state->error = ANTLR3_FALSE; + recognizer->state->failed = ANTLR3_FALSE; +} + + +/// Attempt to recover from a single missing or extra token. +/// +/// EXTRA TOKEN +/// +/// LA(1) is not what we are looking for. If LA(2) has the right token, +/// however, then assume LA(1) is some extra spurious token. Delete it +/// and LA(2) as if we were doing a normal match(), which advances the +/// input. +/// +/// MISSING TOKEN +/// +/// If current token is consistent with what could come after +/// ttype then it is ok to "insert" the missing token, else throw +/// exception For example, Input "i=(3;" is clearly missing the +/// ')'. When the parser returns from the nested call to expr, it +/// will have call chain: +/// +/// stat -> expr -> atom +/// +/// and it will be trying to match the ')' at this point in the +/// derivation: +/// +/// => ID '=' '(' INT ')' ('+' atom)* ';' +/// ^ +/// match() will see that ';' doesn't match ')' and report a +/// mismatched token error. To recover, it sees that LA(1)==';' +/// is in the set of tokens that can follow the ')' token +/// reference in rule atom. It can assume that you forgot the ')'. +/// +/// The exception that was passed in, in the java implementation is +/// sorted in the recognizer exception stack in the C version. To 'throw' it we set the +/// error flag and rules cascade back when this is set. +/// +static void * +recoverFromMismatchedToken (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 ttype, pANTLR3_BITSET_LIST follow) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + void * matchedSymbol; + + + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function recoverFromMismatchedToken called by unknown parser type - provide override for this function\n"); + return NULL; + + break; + } + + // Create an exception if we need one + // + if (recognizer->state->exception == NULL) + { + antlr3RecognitionExceptionNew(recognizer); + } + + // If the next token after the one we are looking at in the input stream + // is what we are looking for then we remove the one we have discovered + // from the stream by consuming it, then consume this next one along too as + // if nothing had happened. + // + if ( recognizer->mismatchIsUnwantedToken(recognizer, is, ttype) == ANTLR3_TRUE) + { + recognizer->state->exception->type = ANTLR3_UNWANTED_TOKEN_EXCEPTION; + recognizer->state->exception->message = ANTLR3_UNWANTED_TOKEN_EXCEPTION_NAME; + + // Call resync hook (for debuggers and so on) + // + if (recognizer->debugger != NULL) + { + recognizer->debugger->beginResync(recognizer->debugger); + } + + // "delete" the extra token + // + recognizer->beginResync(recognizer); + is->consume(is); + recognizer->endResync(recognizer); + // End resync hook + // + if (recognizer->debugger != NULL) + { + recognizer->debugger->endResync(recognizer->debugger); + } + + // Print out the error after we consume so that ANTLRWorks sees the + // token in the exception. + // + recognizer->reportError(recognizer); + + // Return the token we are actually matching + // + matchedSymbol = recognizer->getCurrentInputSymbol(recognizer, is); + + // Consume the token that the rule actually expected to get as if everything + // was hunky dory. + // + is->consume(is); + + recognizer->state->error = ANTLR3_FALSE; // Exception is not outstanding any more + + return matchedSymbol; + } + + // Single token deletion (Unwanted above) did not work + // so we see if we can insert a token instead by calculating which + // token would be missing + // + if (mismatchIsMissingToken(recognizer, is, follow)) + { + // We can fake the missing token and proceed + // + matchedSymbol = recognizer->getMissingSymbol(recognizer, is, recognizer->state->exception, ttype, follow); + recognizer->state->exception->type = ANTLR3_MISSING_TOKEN_EXCEPTION; + recognizer->state->exception->message = ANTLR3_MISSING_TOKEN_EXCEPTION_NAME; + recognizer->state->exception->token = matchedSymbol; + recognizer->state->exception->expecting = ttype; + + // Print out the error after we insert so that ANTLRWorks sees the + // token in the exception. + // + recognizer->reportError(recognizer); + + recognizer->state->error = ANTLR3_FALSE; // Exception is not outstanding any more + + return matchedSymbol; + } + + + // Neither deleting nor inserting tokens allows recovery + // must just report the exception. + // + recognizer->state->error = ANTLR3_TRUE; + return NULL; +} + +static void * +recoverFromMismatchedSet (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET_LIST follow) +{ + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + pANTLR3_COMMON_TOKEN matchedSymbol; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function recoverFromMismatchedSet called by unknown parser type - provide override for this function\n"); + return NULL; + + break; + } + + if (recognizer->mismatchIsMissingToken(recognizer, is, follow) == ANTLR3_TRUE) + { + // We can fake the missing token and proceed + // + matchedSymbol = recognizer->getMissingSymbol(recognizer, is, recognizer->state->exception, ANTLR3_TOKEN_INVALID, follow); + recognizer->state->exception->type = ANTLR3_MISSING_TOKEN_EXCEPTION; + recognizer->state->exception->token = matchedSymbol; + + // Print out the error after we insert so that ANTLRWorks sees the + // token in the exception. + // + recognizer->reportError(recognizer); + + recognizer->state->error = ANTLR3_FALSE; // Exception is not outstanding any more + + return matchedSymbol; + } + + // TODO - Single token deletion like in recoverFromMismatchedToken() + // + recognizer->state->error = ANTLR3_TRUE; + recognizer->state->failed = ANTLR3_TRUE; + return NULL; +} + +/// This code is factored out from mismatched token and mismatched set +/// recovery. It handles "single token insertion" error recovery for +/// both. No tokens are consumed to recover from insertions. Return +/// true if recovery was possible else return false. +/// +static ANTLR3_BOOLEAN +recoverFromMismatchedElement (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET_LIST followBits) +{ + pANTLR3_BITSET viableToksFollowingRule; + pANTLR3_BITSET follow; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function recover called by unknown parser type - provide override for this function\n"); + return ANTLR3_FALSE; + + break; + } + + follow = antlr3BitsetLoad(followBits); + + if (follow == NULL) + { + /* The follow set is NULL, which means we don't know what can come + * next, so we "hit and hope" by just signifying that we cannot + * recover, which will just cause the next token to be consumed, + * which might dig us out. + */ + return ANTLR3_FALSE; + } + + /* We have a bitmap for the follow set, hence we can compute + * what can follow this grammar element reference. + */ + if (follow->isMember(follow, ANTLR3_EOR_TOKEN_TYPE) == ANTLR3_TRUE) + { + /* First we need to know which of the available tokens are viable + * to follow this reference. + */ + viableToksFollowingRule = recognizer->computeCSRuleFollow(recognizer); + + /* Remove the EOR token, which we do not wish to compute with + */ + follow->remove(follow, ANTLR3_EOR_TOKEN_TYPE); + viableToksFollowingRule->free(viableToksFollowingRule); + /* We now have the computed set of what can follow the current token + */ + } + + /* We can now see if the current token works with the set of tokens + * that could follow the current grammar reference. If it looks like it + * is consistent, then we can "insert" that token by not throwing + * an exception and assuming that we saw it. + */ + if ( follow->isMember(follow, is->_LA(is, 1)) == ANTLR3_TRUE) + { + /* report the error, but don't cause any rules to abort and stuff + */ + recognizer->reportError(recognizer); + if (follow != NULL) + { + follow->free(follow); + } + recognizer->state->error = ANTLR3_FALSE; + recognizer->state->failed = ANTLR3_FALSE; + return ANTLR3_TRUE; /* Success in recovery */ + } + + if (follow != NULL) + { + follow->free(follow); + } + + /* We could not find anything viable to do, so this is going to + * cause an exception. + */ + return ANTLR3_FALSE; +} + +/// Eat tokens from the input stream until we get one of JUST the right type +/// +static void +consumeUntil (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_UINT32 tokenType) +{ + ANTLR3_UINT32 ttype; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'consumeUntil' called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + // What do have at the moment? + // + ttype = is->_LA(is, 1); + + // Start eating tokens until we get to the one we want. + // + while (ttype != ANTLR3_TOKEN_EOF && ttype != tokenType) + { + is->consume(is); + ttype = is->_LA(is, 1); + } +} + +/// Eat tokens from the input stream until we find one that +/// belongs to the supplied set. +/// +static void +consumeUntilSet (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_BITSET set) +{ + ANTLR3_UINT32 ttype; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'consumeUntilSet' called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + // What do have at the moment? + // + ttype = is->_LA(is, 1); + + // Start eating tokens until we get to one we want. + // + while (ttype != ANTLR3_TOKEN_EOF && set->isMember(set, ttype) == ANTLR3_FALSE) + { + is->consume(is); + ttype = is->_LA(is, 1); + } +} + +/** Return the rule invocation stack (how we got here in the parse. + * In the java version Ter just asks the JVM for all the information + * but in C we don't get this information, so I am going to do nothing + * right now. + */ +static pANTLR3_STACK +getRuleInvocationStack (pANTLR3_BASE_RECOGNIZER recognizer) +{ + return NULL; +} + +static pANTLR3_STACK +getRuleInvocationStackNamed (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_UINT8 name) +{ + return NULL; +} + +/** Convenience method for template rewrites - NYI. + */ +static pANTLR3_HASH_TABLE +toStrings (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_HASH_TABLE tokens) +{ + return NULL; +} + +static void ANTLR3_CDECL +freeIntTrie (void * trie) +{ + ((pANTLR3_INT_TRIE)trie)->free((pANTLR3_INT_TRIE)trie); +} + + +/** Pointer to a function to return whether the rule has parsed input starting at the supplied + * start index before. If the rule has not parsed input starting from the supplied start index, + * then it will return ANTLR3_MEMO_RULE_UNKNOWN. If it has parsed from the suppled start point + * then it will return the point where it last stopped parsing after that start point. + * + * \remark + * The rule memos are an ANTLR3_LIST of ANTLR3_LISTS, however if this becomes any kind of performance + * issue (it probably won't, the hash tables are pretty quick) then we could make a special int only + * version of the table. + */ +static ANTLR3_MARKER +getRuleMemoization (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_INTKEY ruleIndex, ANTLR3_MARKER ruleParseStart) +{ + /* The rule memos are an ANTLR3_LIST of ANTLR3_LIST. + */ + pANTLR3_INT_TRIE ruleList; + ANTLR3_MARKER stopIndex; + pANTLR3_TRIE_ENTRY entry; + + /* See if we have a list in the ruleMemos for this rule, and if not, then create one + * as we will need it eventually if we are being asked for the memo here. + */ + entry = recognizer->state->ruleMemo->get(recognizer->state->ruleMemo, (ANTLR3_INTKEY)ruleIndex); + + if (entry == NULL) + { + /* Did not find it, so create a new one for it, with a bit depth based on the + * size of the input stream. We need the bit depth to incorporate the number if + * bits required to represent the largest possible stop index in the input, which is the + * last character. An int stream is free to return the largest 64 bit offset if it has + * no idea of the size, but you should remember that this will cause the leftmost + * bit match algorithm to run to 63 bits, which will be the whole time spent in the trie ;-) + */ + ruleList = antlr3IntTrieNew(63); /* Depth is theoretically 64 bits, but probably not ;-) */ + + if (ruleList != NULL) + { + recognizer->state->ruleMemo->add(recognizer->state->ruleMemo, (ANTLR3_INTKEY)ruleIndex, ANTLR3_HASH_TYPE_STR, 0, ANTLR3_FUNC_PTR(ruleList), freeIntTrie); + } + + /* We cannot have a stopIndex in a trie we have just created of course + */ + return MEMO_RULE_UNKNOWN; + } + + ruleList = (pANTLR3_INT_TRIE) (entry->data.ptr); + + /* See if there is a stop index associated with the supplied start index. + */ + stopIndex = 0; + + entry = ruleList->get(ruleList, ruleParseStart); + if (entry != NULL) + { + stopIndex = (ANTLR3_MARKER)(entry->data.intVal); + } + + if (stopIndex == 0) + { + return MEMO_RULE_UNKNOWN; + } + + return stopIndex; +} + +/** Has this rule already parsed input at the current index in the + * input stream? Return ANTLR3_TRUE if we have and ANTLR3_FALSE + * if we have not. + * + * This method has a side-effect: if we have seen this input for + * this rule and successfully parsed before, then seek ahead to + * 1 past the stop token matched for this rule last time. + */ +static ANTLR3_BOOLEAN +alreadyParsedRule (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_MARKER ruleIndex) +{ + ANTLR3_MARKER stopIndex; + pANTLR3_LEXER lexer; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + lexer = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + lexer = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + case ANTLR3_TYPE_LEXER: + + lexer = (pANTLR3_LEXER) (recognizer->super); + parser = NULL; + tparser = NULL; + is = lexer->input->istream; + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'alreadyParsedRule' called by unknown parser type - provide override for this function\n"); + return ANTLR3_FALSE; + + break; + } + + /* See if we have a memo marker for this. + */ + stopIndex = recognizer->getRuleMemoization(recognizer, ruleIndex, is->index(is)); + + if (stopIndex == MEMO_RULE_UNKNOWN) + { + return ANTLR3_FALSE; + } + + if (stopIndex == MEMO_RULE_FAILED) + { + recognizer->state->failed = ANTLR3_TRUE; + } + else + { + is->seek(is, stopIndex+1); + } + + /* If here then the rule was executed for this input already + */ + return ANTLR3_TRUE; +} + +/** Record whether or not this rule parsed the input at this position + * successfully. + */ +static void +memoize (pANTLR3_BASE_RECOGNIZER recognizer, ANTLR3_MARKER ruleIndex, ANTLR3_MARKER ruleParseStart) +{ + /* The rule memos are an ANTLR3_LIST of ANTLR3_LIST. + */ + pANTLR3_INT_TRIE ruleList; + pANTLR3_TRIE_ENTRY entry; + ANTLR3_MARKER stopIndex; + pANTLR3_LEXER lexer; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + case ANTLR3_TYPE_LEXER: + + lexer = (pANTLR3_LEXER) (recognizer->super); + parser = NULL; + tparser = NULL; + is = lexer->input->istream; + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function consumeUntilSet called by unknown parser type - provide override for this function\n"); + return; + + break; + } + + stopIndex = recognizer->state->failed == ANTLR3_TRUE ? MEMO_RULE_FAILED : is->index(is) - 1; + + entry = recognizer->state->ruleMemo->get(recognizer->state->ruleMemo, (ANTLR3_INTKEY)ruleIndex); + + if (entry != NULL) + { + ruleList = (pANTLR3_INT_TRIE)(entry->data.ptr); + + /* If we don't already have this entry, append it. The memoize trie does not + * accept duplicates so it won't add it if already there and we just ignore the + * return code as we don't care if it is there already. + */ + ruleList->add(ruleList, ruleParseStart, ANTLR3_HASH_TYPE_INT, stopIndex, NULL, NULL); + } +} +/** A syntactic predicate. Returns true/false depending on whether + * the specified grammar fragment matches the current input stream. + * This resets the failed instance var afterwards. + */ +static ANTLR3_BOOLEAN +synpred (pANTLR3_BASE_RECOGNIZER recognizer, void * ctx, void (*predicate)(void * ctx)) +{ + ANTLR3_MARKER start; + pANTLR3_PARSER parser; + pANTLR3_TREE_PARSER tparser; + pANTLR3_INT_STREAM is; + + switch (recognizer->type) + { + case ANTLR3_TYPE_PARSER: + + parser = (pANTLR3_PARSER) (recognizer->super); + tparser = NULL; + is = parser->tstream->istream; + + break; + + case ANTLR3_TYPE_TREE_PARSER: + + tparser = (pANTLR3_TREE_PARSER) (recognizer->super); + parser = NULL; + is = tparser->ctnstream->tnstream->istream; + + break; + + default: + + ANTLR3_FPRINTF(stderr, "Base recognizer function 'synPred' called by unknown parser type - provide override for this function\n"); + return ANTLR3_FALSE; + + break; + } + + /* Begin backtracking so we can get back to where we started after trying out + * the syntactic predicate. + */ + start = is->mark(is); + recognizer->state->backtracking++; + + /* Try the syntactical predicate + */ + predicate(ctx); + + /* Reset + */ + is->rewind(is, start); + recognizer->state->backtracking--; + + if (recognizer->state->failed == ANTLR3_TRUE) + { + /* Predicate failed + */ + recognizer->state->failed = ANTLR3_FALSE; + return ANTLR3_FALSE; + } + else + { + /* Predicate was successful + */ + recognizer->state->failed = ANTLR3_FALSE; + return ANTLR3_TRUE; + } +} + +static void +reset(pANTLR3_BASE_RECOGNIZER recognizer) +{ + if (recognizer->state->following != NULL) + { + recognizer->state->following->free(recognizer->state->following); + } + + // Reset the state flags + // + recognizer->state->errorRecovery = ANTLR3_FALSE; + recognizer->state->lastErrorIndex = -1; + recognizer->state->failed = ANTLR3_FALSE; + recognizer->state->errorCount = 0; + recognizer->state->backtracking = 0; + recognizer->state->following = NULL; + + if (recognizer->state != NULL) + { + if (recognizer->state->ruleMemo != NULL) + { + recognizer->state->ruleMemo->free(recognizer->state->ruleMemo); + recognizer->state->ruleMemo = antlr3IntTrieNew(15); /* 16 bit depth is enough for 32768 rules! */ + } + } + + + // Install a new following set + // + recognizer->state->following = antlr3StackNew(8); + +} + +// Default implementation is for parser and assumes a token stream as supplied by the runtime. +// You MAY need override this function if the standard TOKEN_STREAM is not what you are using. +// +static void * +getCurrentInputSymbol (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM istream) +{ + return ((pANTLR3_TOKEN_STREAM)istream->super)->_LT((pANTLR3_TOKEN_STREAM)istream->super, 1); +} + +// Default implementation is for parser and assumes a token stream as supplied by the runtime. +// You MAY need override this function if the standard COMMON_TOKEN_STREAM is not what you are using. +// +static void * +getMissingSymbol (pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM istream, pANTLR3_EXCEPTION e, + ANTLR3_UINT32 expectedTokenType, pANTLR3_BITSET_LIST follow) +{ + pANTLR3_TOKEN_STREAM ts; + pANTLR3_COMMON_TOKEN_STREAM cts; + pANTLR3_COMMON_TOKEN token; + pANTLR3_COMMON_TOKEN current; + pANTLR3_STRING text; + + // Dereference the standard pointers + // + ts = (pANTLR3_TOKEN_STREAM)istream->super; + cts = (pANTLR3_COMMON_TOKEN_STREAM)ts->super; + + // Work out what to use as the current symbol to make a line and offset etc + // If we are at EOF, we use the token before EOF + // + current = ts->_LT(ts, 1); + if (current->getType(current) == ANTLR3_TOKEN_EOF) + { + current = ts->_LT(ts, -1); + } + + // Create a new empty token + // + if (recognizer->state->tokFactory == NULL) + { + // We don't yet have a token factory for making tokens + // we just need a fake one using the input stream of the current + // token. + // + recognizer->state->tokFactory = antlr3TokenFactoryNew(current->input); + } + token = recognizer->state->tokFactory->newToken(recognizer->state->tokFactory); + + // Set some of the token properties based on the current token + // + token->setLine (token, current->getLine(current)); + token->setCharPositionInLine (token, current->getCharPositionInLine(current)); + token->setChannel (token, ANTLR3_TOKEN_DEFAULT_CHANNEL); + token->setType (token, expectedTokenType); + token->user1 = current->user1; + token->user2 = current->user2; + token->user3 = current->user3; + token->custom = current->custom; + token->lineStart = current->lineStart; + + // Create the token text that shows it has been inserted + // + token->setText8(token, (pANTLR3_UINT8)"<missing "); + text = token->getText(token); + + if (text != NULL) + { + text->append8(text, (const char *)recognizer->state->tokenNames[expectedTokenType]); + text->append8(text, (const char *)">"); + } + + // Finally return the pointer to our new token + // + return token; +} + + +#ifdef ANTLR3_WINDOWS +#pragma warning( default : 4100 ) +#endif + +/// @} +/// + |