Merge pull request #2398 from mike-lischke/issue-2164

Fix for antlr#2164.

runtime/Cpp/runtime/src/NoViableAltException.cpp

@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
  * Use of this file is governed by the BSD 3-clause license that
  * can be found in the LICENSE.txt file in the project root.
  */
@@ -11,12 +11,18 @@ using namespace antlr4;
 
 NoViableAltException::NoViableAltException(Parser *recognizer)
   : NoViableAltException(recognizer, recognizer->getTokenStream(), recognizer->getCurrentToken(),
-                         recognizer->getCurrentToken(), nullptr, recognizer->getContext()) {
+                         recognizer->getCurrentToken(), nullptr, recognizer->getContext(), false) {
 }
 
 NoViableAltException::NoViableAltException(Parser *recognizer, TokenStream *input,Token *startToken,
-  Token *offendingToken, atn::ATNConfigSet *deadEndConfigs, ParserRuleContext *ctx)
+  Token *offendingToken, atn::ATNConfigSet *deadEndConfigs, ParserRuleContext *ctx, bool deleteConfigs)
-  : RecognitionException("No viable alternative", recognizer, input, ctx, offendingToken), _deadEndConfigs(deadEndConfigs), _startToken(startToken) {
+  : RecognitionException("No viable alternative", recognizer, input, ctx, offendingToken),
+    _deadEndConfigs(deadEndConfigs), _startToken(startToken), _deleteConfigs(deleteConfigs) {
+}
+
+NoViableAltException::~NoViableAltException() {
+  if (_deleteConfigs)
+    delete _deadEndConfigs;
 }
 
 Token* NoViableAltException::getStartToken() const {

runtime/Cpp/runtime/src/NoViableAltException.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
  * Use of this file is governed by the BSD 3-clause license that
  * can be found in the LICENSE.txt file in the project root.
  */
@@ -19,7 +19,8 @@ namespace antlr4 {
   public:
     NoViableAltException(Parser *recognizer); // LL(1) error
     NoViableAltException(Parser *recognizer, TokenStream *input,Token *startToken,
-      Token *offendingToken, atn::ATNConfigSet *deadEndConfigs, ParserRuleContext *ctx);
+      Token *offendingToken, atn::ATNConfigSet *deadEndConfigs, ParserRuleContext *ctx, bool deleteConfigs);
+    ~NoViableAltException();
     
     virtual Token* getStartToken() const;
     virtual atn::ATNConfigSet* getDeadEndConfigs() const;
@@ -28,6 +29,9 @@ namespace antlr4 {
     /// Which configurations did we try at input.index() that couldn't match input.LT(1)?
     atn::ATNConfigSet* _deadEndConfigs;
 
+    // Flag that indicates if we own the dead end config set and have to delete it on destruction.
+    bool _deleteConfigs;
+
     /// The token object at the start index; the input stream might
     /// not be buffering tokens so get a reference to it. (At the
     /// time the error occurred, of course the stream needs to keep a

runtime/Cpp/runtime/src/atn/ParserATNSimulator.cpp

@@ -176,7 +176,7 @@ size_t ParserATNSimulator::execATN(dfa::DFA &dfa, dfa::DFAState *s0, TokenStream
       // ATN states in SLL implies LL will also get nowhere.
       // If conflict in states that dip out, choose min since we
       // will get error no matter what.
-      NoViableAltException e = noViableAlt(input, outerContext, previousD->configs.get(), startIndex);
+      NoViableAltException e = noViableAlt(input, outerContext, previousD->configs.get(), startIndex, false);
       input->seek(startIndex);
       size_t alt = getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previousD->configs.get(), outerContext);
       if (alt != ATN::INVALID_ALT_NUMBER) {
@@ -236,7 +236,7 @@ size_t ParserATNSimulator::execATN(dfa::DFA &dfa, dfa::DFAState *s0, TokenStream
       BitSet alts = evalSemanticContext(D->predicates, outerContext, true);
       switch (alts.count()) {
         case 0:
-          throw noViableAlt(input, outerContext, D->configs.get(), startIndex);
+          throw noViableAlt(input, outerContext, D->configs.get(), startIndex, false);
 
         case 1:
           return alts.nextSetBit(0);
@@ -351,7 +351,7 @@ size_t ParserATNSimulator::execATNWithFullContext(dfa::DFA &dfa, dfa::DFAState *
       // ATN states in SLL implies LL will also get nowhere.
       // If conflict in states that dip out, choose min since we
       // will get error no matter what.
-      NoViableAltException e = noViableAlt(input, outerContext, previous, startIndex);
+      NoViableAltException e = noViableAlt(input, outerContext, previous, startIndex, previous != s0);
       input->seek(startIndex);
       size_t alt = getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previous, outerContext);
       if (alt != ATN::INVALID_ALT_NUMBER) {
@@ -1229,8 +1229,8 @@ void ParserATNSimulator::dumpDeadEndConfigs(NoViableAltException &nvae) {
 }
 
 NoViableAltException ParserATNSimulator::noViableAlt(TokenStream *input, ParserRuleContext *outerContext,
-  ATNConfigSet *configs, size_t startIndex) {
+  ATNConfigSet *configs, size_t startIndex, bool deleteConfigs) {
-  return NoViableAltException(parser, input, input->get(startIndex), input->LT(1), configs, outerContext);
+  return NoViableAltException(parser, input, input->get(startIndex), input->LT(1), configs, outerContext, deleteConfigs);
 }
 
 size_t ParserATNSimulator::getUniqueAlt(ATNConfigSet *configs) {

runtime/Cpp/runtime/src/atn/ParserATNSimulator.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
  * Use of this file is governed by the BSD 3-clause license that
  * can be found in the LICENSE.txt file in the project root.
  */
@@ -836,7 +836,7 @@ namespace atn {
     virtual antlrcpp::BitSet getConflictingAltsOrUniqueAlt(ATNConfigSet *configs);
 
     virtual NoViableAltException noViableAlt(TokenStream *input, ParserRuleContext *outerContext,
-                                              ATNConfigSet *configs, size_t startIndex);
+                                              ATNConfigSet *configs, size_t startIndex, bool deleteConfigs);
 
     static size_t getUniqueAlt(ATNConfigSet *configs);