Fix #2727: improve setTokenFactory in Cpp target

Change the setTokenFactory template functions and the getTokenFactory
functions to use a plain pointer rather than a Ref. This makes the
caller of setTokenFactory responsible for managing the lifetime and
memory of the token factory instance they pass in. Change
CommonTokenFactory::DEFAULT to be a unique_ptr, and correct all places
using it as a Ref.

runtime/Cpp/runtime/src/CommonTokenFactory.cpp

@@ -11,7 +11,7 @@
 
 using namespace antlr4;
 
-const Ref<TokenFactory<CommonToken>> CommonTokenFactory::DEFAULT = std::make_shared<CommonTokenFactory>();
+const std::unique_ptr<TokenFactory<CommonToken>> CommonTokenFactory::DEFAULT(new CommonTokenFactory);
 
 CommonTokenFactory::CommonTokenFactory(bool copyText_) : copyText(copyText_) {
 }

runtime/Cpp/runtime/src/CommonTokenFactory.h

@@ -22,7 +22,7 @@ namespace antlr4 {
      * This token factory does not explicitly copy token text when constructing
      * tokens.</p>
      */
-    static const Ref<TokenFactory<CommonToken>> DEFAULT;
+    static const std::unique_ptr<TokenFactory<CommonToken>> DEFAULT;
 
   protected:
     /**

runtime/Cpp/runtime/src/Lexer.cpp

@@ -136,7 +136,7 @@ size_t Lexer::popMode() {
 }
 
 
-Ref<TokenFactory<CommonToken>> Lexer::getTokenFactory() {
+TokenFactory<CommonToken>* Lexer::getTokenFactory() {
   return _factory;
 }
 
@@ -284,7 +284,7 @@ size_t Lexer::getNumberOfSyntaxErrors() {
 void Lexer::InitializeInstanceFields() {
   _syntaxErrors = 0;
   token = nullptr;
-  _factory = CommonTokenFactory::DEFAULT;
+  _factory = CommonTokenFactory::DEFAULT.get();
   tokenStartCharIndex = INVALID_INDEX;
   tokenStartLine = 0;
   tokenStartCharPositionInLine = 0;

runtime/Cpp/runtime/src/Lexer.h

@@ -31,7 +31,7 @@ namespace antlr4 {
 
   protected:
     /// How to create token objects.
-    Ref<TokenFactory<CommonToken>> _factory;
+    TokenFactory<CommonToken> *_factory;
 
   public:
     /// The goal of all lexer rules/methods is to create a token object.
@@ -100,7 +100,7 @@ namespace antlr4 {
       this->_factory = factory;
     }
 
-    virtual Ref<TokenFactory<CommonToken>> getTokenFactory() override;
+    virtual TokenFactory<CommonToken>* getTokenFactory() override;
 
     /// Set the char stream and reset the lexer
     virtual void setInputStream(IntStream *input) override;

runtime/Cpp/runtime/src/ListTokenSource.cpp

@@ -82,11 +82,11 @@ std::string ListTokenSource::getSourceName() {
   return "List";
 }
 
-Ref<TokenFactory<CommonToken>> ListTokenSource::getTokenFactory() {
+TokenFactory<CommonToken>* ListTokenSource::getTokenFactory() {
   return _factory;
 }
 
 void ListTokenSource::InitializeInstanceFields() {
   i = 0;
-  _factory = CommonTokenFactory::DEFAULT;
+  _factory = CommonTokenFactory::DEFAULT.get();
 }

runtime/Cpp/runtime/src/ListTokenSource.h

@@ -40,7 +40,7 @@ namespace antlr4 {
   private:
     /// This is the backing field for <seealso cref="#getTokenFactory"/> and
     /// <seealso cref="setTokenFactory"/>.
-    Ref<TokenFactory<CommonToken>> _factory = CommonTokenFactory::DEFAULT;
+    TokenFactory<CommonToken> *_factory = CommonTokenFactory::DEFAULT.get();
 
   public:
     /// Constructs a new <seealso cref="ListTokenSource"/> instance from the specified
@@ -79,7 +79,7 @@ namespace antlr4 {
       this->_factory = factory;
     }
 
-    virtual Ref<TokenFactory<CommonToken>> getTokenFactory() override;
+    virtual TokenFactory<CommonToken>* getTokenFactory() override;
 
   private:
     void InitializeInstanceFields();

runtime/Cpp/runtime/src/Parser.cpp

@@ -208,7 +208,7 @@ size_t Parser::getNumberOfSyntaxErrors() {
   return _syntaxErrors;
 }
 
-Ref<TokenFactory<CommonToken>> Parser::getTokenFactory() {
+TokenFactory<CommonToken>* Parser::getTokenFactory() {
   return _input->getTokenSource()->getTokenFactory();
 }
 

runtime/Cpp/runtime/src/Parser.h

@@ -193,7 +193,7 @@ namespace antlr4 {
     /// <seealso cref= #notifyErrorListeners </seealso>
     virtual size_t getNumberOfSyntaxErrors();
 
-    virtual Ref<TokenFactory<CommonToken>> getTokenFactory() override;
+    virtual TokenFactory<CommonToken>* getTokenFactory() override;
 
     /// <summary>
     /// Tell our token source and error strategy about a new way to create tokens. </summary>

runtime/Cpp/runtime/src/Recognizer.h

@@ -138,7 +138,7 @@ namespace antlr4 {
 
     virtual void setInputStream(IntStream *input) = 0;
 
-    virtual Ref<TokenFactory<CommonToken>> getTokenFactory() = 0;
+    virtual TokenFactory<CommonToken>* getTokenFactory() = 0;
 
     template<typename T1>
     void setTokenFactory(TokenFactory<T1> *input);

runtime/Cpp/runtime/src/TokenSource.h

@@ -79,7 +79,7 @@ namespace antlr4 {
     /// creating <seealso cref="Token"/> objects from the input.
     /// </summary>
     /// <returns> The <seealso cref="TokenFactory"/> currently used by this token source. </returns>
-    virtual Ref<TokenFactory<CommonToken>> getTokenFactory() = 0;
+    virtual TokenFactory<CommonToken>* getTokenFactory() = 0;
   };
 
 } // namespace antlr4