2 smaller changes

- Changed the empty return state PredictionContext to max int (instead fixing it on int 16), like it's done in the Java runtime.
- Converted 2 static init lambdas in the Cpp.stg to normal code, as VS doesn't allow us to access private class members in such lambdas.

runtime/Cpp/runtime/atn/ATNConfig.cpp

@@ -70,6 +70,9 @@ ATNConfig::ATNConfig(Ref<ATNConfig> c, ATNState *state, Ref<PredictionContext> c
   : state(state), alt(c->alt), context(context), semanticContext(semanticContext), reachesIntoOuterContext(c->reachesIntoOuterContext) {
 }
 
+ATNConfig::~ATNConfig() {
+}
+
 size_t ATNConfig::hashCode() const {
   size_t hashCode = misc::MurmurHash::initialize(7);
   hashCode = misc::MurmurHash::update(hashCode, (size_t)state->stateNumber);

runtime/Cpp/runtime/atn/ATNConfig.h

@@ -99,6 +99,8 @@ namespace atn {
     ATNConfig(Ref<ATNConfig> c, ATNState *state, Ref<PredictionContext> context);
     ATNConfig(Ref<ATNConfig> c, ATNState *state, Ref<PredictionContext> context, Ref<SemanticContext> semanticContext);
 
+    virtual ~ATNConfig();
+
     virtual size_t hashCode() const;
 
     struct ATNConfigHasher

runtime/Cpp/runtime/atn/LexerATNSimulator.cpp

@@ -414,8 +414,8 @@ Ref<LexerATNConfig> LexerATNSimulator::getEpsilonTarget(CharStream *input, Ref<L
       RuleTransition *ruleTransition = static_cast<RuleTransition*>(t);
       Ref<PredictionContext> newContext = SingletonPredictionContext::create(config->context, ruleTransition->followState->stateNumber);
       c = std::make_shared<LexerATNConfig>(config, t->target, newContext);
-    }
       break;
+    }
 
     case Transition::PRECEDENCE:
       throw UnsupportedOperationException("Precedence predicates are not supported in lexers.");
@@ -447,8 +447,8 @@ Ref<LexerATNConfig> LexerATNSimulator::getEpsilonTarget(CharStream *input, Ref<L
       if (evaluatePredicate(input, pt->ruleIndex, pt->predIndex, speculative)) {
         c = std::make_shared<LexerATNConfig>(config, t->target);
       }
-    }
       break;
+    }
 
     case Transition::ACTION:
       if (config->context == nullptr|| config->context->hasEmptyPath()) {

runtime/Cpp/runtime/atn/PredictionContext.h

@@ -56,7 +56,7 @@ namespace atn {
     /// Represents $ in an array in full context mode, when $
     /// doesn't mean wildcard: $ + x = [$,x]. Here,
     /// $ = EMPTY_RETURN_STATE.
-    static const int EMPTY_RETURN_STATE = INT16_MAX;
+    static const int EMPTY_RETURN_STATE = INT_MAX;
 
   private:
     static const int INITIAL_HASH = 1;

tool/resources/org/antlr/v4/tool/templates/codegen/Cpp/Cpp.stg

@@ -206,8 +206,10 @@ std::vector\<std::wstring> <lexer.name>::_symbolicNames = {
 
 Ref\<dfa::Vocabulary> <lexer.name>::_vocabulary = std::make_shared\<dfa::VocabularyImpl>(_literalNames, _symbolicNames);
 
-std::vector\<std::wstring> <lexer.name>::_tokenNames = []() {
-  std::vector\<std::wstring> result;
+std::vector\<std::wstring> <lexer.name>::_tokenNames;
+
+<lexer.name>::Initializer::Initializer() {
+  // This code could be in a static initializer lambda, but VS doesn't allow access to private class members from there. 
 	for (size_t i = 0; i \< _symbolicNames.size(); ++i) {
 		std::wstring name = _vocabulary->getLiteralName(i);
 		if (name.empty()) {
@@ -220,10 +222,7 @@ std::vector\<std::wstring> <lexer.name>::_tokenNames = []() {
       _tokenNames.push_back(name);
     }
 	}
-  return result;
-}();
-
-<lexer.name>::Initializer::Initializer() {
+  
   <atn>
 }
 
@@ -382,24 +381,23 @@ std::vector\<std::wstring> <parser.name>::_symbolicNames = {
 
 Ref\<dfa::Vocabulary> <parser.name>::_vocabulary = std::make_shared\<dfa::VocabularyImpl>(_literalNames, _symbolicNames);
 
-std::vector\<std::wstring> <parser.name>::_tokenNames = []() {
-  std::vector\<std::wstring> result;
-	for (size_t i = 0; i \< <parser.name>::_symbolicNames.size(); ++i) {
-		std::wstring name = <parser.name>::_vocabulary->getLiteralName(i);
+std::vector\<std::wstring> <parser.name>::_tokenNames;
+
+<parser.name>::Initializer::Initializer() {
+  // This code could be in a static initializer lambda, but VS doesn't allow access to private class members from there. 
+	for (size_t i = 0; i \< _symbolicNames.size(); ++i) {
+		std::wstring name = _vocabulary->getLiteralName(i);
 		if (name.empty()) {
-			name = <parser.name>::_vocabulary->getSymbolicName(i);
+			name = _vocabulary->getSymbolicName(i);
 		}
 
 		if (name.empty()) {
-			result.push_back(L"\<INVALID>");
+			_tokenNames.push_back(L"\<INVALID>");
 		} else {
-      result.push_back(name);
+      _tokenNames.push_back(name);
     }
 	}
-  return result;
-}();
 
-<parser.name>::Initializer::Initializer() {
   <atn>
 }