[C++] Devirtualize hand rolled RTTI for performance

runtime/Cpp/runtime/src/RuleContext.cpp

@@ -16,11 +16,11 @@ using namespace antlr4;
 using namespace antlr4::atn;
 using namespace antlr4::tree;
 
-RuleContext::RuleContext() {
+RuleContext::RuleContext() : ParseTree(ParseTreeType::RULE) {
   InitializeInstanceFields();
 }
 
-RuleContext::RuleContext(RuleContext *parent_, size_t invokingState_) {
+RuleContext::RuleContext(RuleContext *parent_, size_t invokingState_) : ParseTree(ParseTreeType::RULE) {
   InitializeInstanceFields();
   this->parent = parent_;
   this->invokingState = invokingState_;
@@ -138,10 +138,6 @@ std::string RuleContext::toString(Recognizer *recog, RuleContext *stop) {
   return toString(recog->getRuleNames(), stop);
 }
 
-ParseTreeType RuleContext::getTreeType() const {
-  return ParseTreeType::RULE;
-}
-
 void RuleContext::InitializeInstanceFields() {
   invokingState = INVALID_INDEX;
 }

runtime/Cpp/runtime/src/RuleContext.h

@@ -128,8 +128,6 @@ namespace antlr4 {
 
     virtual std::string toString(const std::vector<std::string> &ruleNames, RuleContext *stop);
 
-    tree::ParseTreeType getTreeType() const final;
-
     bool operator == (const RuleContext &other) { return this == &other; } // Simple address comparison.
 
   private:

runtime/Cpp/runtime/src/atn/ATNState.h

@@ -93,7 +93,7 @@ namespace atn {
     /// Track the transitions emanating from this ATN state.
     std::vector<ConstTransitionPtr> transitions;
 
-    ATNState() = default;
+    ATNState() = delete;
 
     ATNState(ATNState const&) = delete;
 
@@ -114,14 +114,20 @@ namespace atn {
 
     virtual bool isNonGreedyExitState() const;
     virtual std::string toString() const;
-    virtual ATNStateType getStateType() const = 0;
+
+    ATNStateType getStateType() const { return _stateType; }
+
+  protected:
+    explicit ATNState(ATNStateType stateType) : _stateType(stateType) {}
 
   private:
     /// Used to cache lookahead during parsing, not used during construction.
 
     misc::IntervalSet _nextTokenWithinRule;
     std::atomic<bool> _nextTokenUpdated { false };
 
+    ATNStateType _stateType;
+
     friend class ATN;
   };
 

runtime/Cpp/runtime/src/atn/ActionTransition.cpp

@@ -8,15 +8,11 @@
 using namespace antlr4::atn;
 
 ActionTransition::ActionTransition(ATNState *target, size_t ruleIndex)
-  : Transition(target), ruleIndex(ruleIndex), actionIndex(INVALID_INDEX), isCtxDependent(false) {
+  : Transition(TransitionType::ACTION, target), ruleIndex(ruleIndex), actionIndex(INVALID_INDEX), isCtxDependent(false) {
 }
 
 ActionTransition::ActionTransition(ATNState *target, size_t ruleIndex, size_t actionIndex, bool isCtxDependent)
-  : Transition(target), ruleIndex(ruleIndex), actionIndex(actionIndex), isCtxDependent(isCtxDependent) {
-}
-
-TransitionType ActionTransition::getTransitionType() const {
-  return TransitionType::ACTION;
+  : Transition(TransitionType::ACTION, target), ruleIndex(ruleIndex), actionIndex(actionIndex), isCtxDependent(isCtxDependent) {
 }
 
 bool ActionTransition::isEpsilon() const {

runtime/Cpp/runtime/src/atn/ActionTransition.h

@@ -20,8 +20,6 @@ namespace atn {
 
     ActionTransition(ATNState *target, size_t ruleIndex, size_t actionIndex, bool isCtxDependent);
 
-    TransitionType getTransitionType() const override;
-
     virtual bool isEpsilon() const override;
 
     virtual bool matches(size_t symbol, size_t minVocabSymbol, size_t maxVocabSymbol) const override;

runtime/Cpp/runtime/src/atn/ArrayPredictionContext.cpp

@@ -16,15 +16,11 @@ ArrayPredictionContext::ArrayPredictionContext(Ref<const SingletonPredictionCont
 
 ArrayPredictionContext::ArrayPredictionContext(std::vector<Ref<const PredictionContext>> parents,
                                                std::vector<size_t> returnStates)
-  : PredictionContext(calculateHashCode(parents, returnStates)), parents(std::move(parents)), returnStates(std::move(returnStates)) {
+  : PredictionContext(PredictionContextType::ARRAY, calculateHashCode(parents, returnStates)), parents(std::move(parents)), returnStates(std::move(returnStates)) {
     assert(this->parents.size() > 0);
     assert(this->returnStates.size() > 0);
 }
 
-PredictionContextType ArrayPredictionContext::getContextType() const {
-  return PredictionContextType::ARRAY;
-}
-
 bool ArrayPredictionContext::isEmpty() const {
   // Since EMPTY_RETURN_STATE can only appear in the last position, we don't need to verify that size == 1.
   return returnStates[0] == EMPTY_RETURN_STATE;

runtime/Cpp/runtime/src/atn/ArrayPredictionContext.h

@@ -29,8 +29,6 @@ namespace atn {
 
     ArrayPredictionContext(std::vector<Ref<const PredictionContext>> parents, std::vector<size_t> returnStates);
 
-    PredictionContextType getContextType() const override;
-
     virtual bool isEmpty() const override;
     virtual size_t size() const override;
     virtual Ref<const PredictionContext> getParent(size_t index) const override;

runtime/Cpp/runtime/src/atn/AtomTransition.cpp

@@ -11,11 +11,7 @@
 using namespace antlr4::misc;
 using namespace antlr4::atn;
 
-AtomTransition::AtomTransition(ATNState *target, size_t label) : Transition(target), _label(label) {
-}
-
-TransitionType AtomTransition::getTransitionType() const {
-  return TransitionType::ATOM;
+AtomTransition::AtomTransition(ATNState *target, size_t label) : Transition(TransitionType::ATOM, target), _label(label) {
 }
 
 IntervalSet AtomTransition::label() const {

runtime/Cpp/runtime/src/atn/AtomTransition.h

@@ -19,8 +19,6 @@ namespace atn {
 
     AtomTransition(ATNState *target, size_t label);
 
-    TransitionType getTransitionType() const override;
-
     virtual misc::IntervalSet label() const override;
     virtual bool matches(size_t symbol, size_t minVocabSymbol, size_t maxVocabSymbol) const override;
 

runtime/Cpp/runtime/src/atn/BasicBlockStartState.h

@@ -13,8 +13,7 @@ namespace atn {
 
   class ANTLR4CPP_PUBLIC BasicBlockStartState final : public BlockStartState {
   public:
-    virtual ATNStateType getStateType() const override;
-
+    BasicBlockStartState() : BlockStartState(ATNStateType::BLOCK_START) {}
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/BasicState.h

@@ -12,8 +12,7 @@ namespace atn {
 
   class ANTLR4CPP_PUBLIC BasicState final : public ATNState {
   public:
-    virtual ATNStateType getStateType() const override;
-
+    BasicState() : ATNState(ATNStateType::BASIC) {}
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/BlockEndState.h

@@ -15,7 +15,7 @@ namespace atn {
   public:
     BlockStartState *startState = nullptr;
 
-    virtual ATNStateType getStateType() const override;
+    BlockEndState() : ATNState(ATNStateType::BLOCK_END) {}
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/BlockStartState.h

@@ -14,6 +14,9 @@ namespace atn {
   class ANTLR4CPP_PUBLIC BlockStartState : public DecisionState {
   public:
     BlockEndState *endState = nullptr;
+
+  protected:
+    using DecisionState::DecisionState;
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/DecisionState.h

@@ -15,9 +15,10 @@ namespace atn {
     int decision = -1;
     bool nonGreedy = false;
 
-    DecisionState() = default;
-
     virtual std::string toString() const override;
+
+  protected:
+    using ATNState::ATNState;
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/EpsilonTransition.cpp

@@ -11,17 +11,13 @@ EpsilonTransition::EpsilonTransition(ATNState *target) : EpsilonTransition(targe
 }
 
 EpsilonTransition::EpsilonTransition(ATNState *target, size_t outermostPrecedenceReturn)
-  : Transition(target), _outermostPrecedenceReturn(outermostPrecedenceReturn) {
+  : Transition(TransitionType::EPSILON, target), _outermostPrecedenceReturn(outermostPrecedenceReturn) {
 }
 
 size_t EpsilonTransition::outermostPrecedenceReturn() const {
   return _outermostPrecedenceReturn;
 }
 
-TransitionType EpsilonTransition::getTransitionType() const {
-  return TransitionType::EPSILON;
-}
-
 bool EpsilonTransition::isEpsilon() const {
   return true;
 }

runtime/Cpp/runtime/src/atn/EpsilonTransition.h

@@ -24,7 +24,6 @@ namespace atn {
      * @since 4.4.1
      */
     size_t outermostPrecedenceReturn() const;
-    TransitionType getTransitionType() const override;
 
     virtual bool isEpsilon() const override;
     virtual bool matches(size_t symbol, size_t minVocabSymbol, size_t maxVocabSymbol) const override;

runtime/Cpp/runtime/src/atn/LexerAction.h

@@ -27,7 +27,7 @@ namespace atn {
     /// Gets the serialization type of the lexer action.
     /// </summary>
     /// <returns> The serialization type of the lexer action. </returns>
-    virtual LexerActionType getActionType() const = 0;
+    LexerActionType getActionType() const { return _actionType; }
 
     /// <summary>
     /// Gets whether the lexer action is position-dependent. Position-dependent
@@ -60,6 +60,12 @@ namespace atn {
     }
 
     virtual std::string toString() const = 0;
+
+  protected:
+    explicit LexerAction(LexerActionType actionType) : _actionType(actionType) {}
+
+  private:
+    const LexerActionType _actionType;
   };
 
 } // namespace atn

runtime/Cpp/runtime/src/atn/LexerChannelAction.cpp

@@ -11,17 +11,13 @@
 using namespace antlr4::atn;
 using namespace antlr4::misc;
 
-LexerChannelAction::LexerChannelAction(int channel) : _channel(channel) {
+LexerChannelAction::LexerChannelAction(int channel) : LexerAction(LexerActionType::CHANNEL), _channel(channel) {
 }
 
 int LexerChannelAction::getChannel() const {
   return _channel;
 }
 
-LexerActionType LexerChannelAction::getActionType() const {
-  return LexerActionType::CHANNEL;
-}
-
 bool LexerChannelAction::isPositionDependent() const {
   return false;
 }

runtime/Cpp/runtime/src/atn/LexerChannelAction.h

@@ -33,11 +33,6 @@ namespace atn {
     /// <returns> The channel to use for the <seealso cref="Token"/> created by the lexer. </returns>
     int getChannel() const;
 
-    /// <summary>
-    /// {@inheritDoc} </summary>
-    /// <returns> This method returns <seealso cref="LexerActionType#CHANNEL"/>. </returns>
-    virtual LexerActionType getActionType() const override;
-
     /// <summary>
     /// {@inheritDoc} </summary>
     /// <returns> This method returns {@code false}. </returns>

runtime/Cpp/runtime/src/atn/LexerCustomAction.cpp

@@ -13,7 +13,7 @@ using namespace antlr4;
 using namespace antlr4::atn;
 using namespace antlr4::misc;
 
-LexerCustomAction::LexerCustomAction(size_t ruleIndex, size_t actionIndex) : _ruleIndex(ruleIndex), _actionIndex(actionIndex) {
+LexerCustomAction::LexerCustomAction(size_t ruleIndex, size_t actionIndex) : LexerAction(LexerActionType::CUSTOM), _ruleIndex(ruleIndex), _actionIndex(actionIndex) {
 }
 
 size_t LexerCustomAction::getRuleIndex() const {
@@ -24,10 +24,6 @@ size_t LexerCustomAction::getActionIndex() const {
   return _actionIndex;
 }
 
-LexerActionType LexerCustomAction::getActionType() const {
-  return LexerActionType::CUSTOM;
-}
-
 bool LexerCustomAction::isPositionDependent() const {
   return true;
 }

runtime/Cpp/runtime/src/atn/LexerCustomAction.h

@@ -48,12 +48,6 @@ namespace atn {
     /// <returns> The action index for the custom action. </returns>
     size_t getActionIndex() const;
 
-    /// <summary>
-    /// {@inheritDoc}
-    /// </summary>
-    /// <returns> This method returns <seealso cref="LexerActionType#CUSTOM"/>. </returns>
-    virtual LexerActionType getActionType() const override;
-
     /// <summary>
     /// Gets whether the lexer action is position-dependent. Position-dependent
     /// actions may have different semantics depending on the <seealso cref="CharStream"/>

runtime/Cpp/runtime/src/atn/LexerIndexedCustomAction.cpp

@@ -14,7 +14,7 @@ using namespace antlr4::atn;
 using namespace antlr4::misc;
 
 LexerIndexedCustomAction::LexerIndexedCustomAction(int offset, Ref<LexerAction> action)
-  : _offset(offset), _action(std::move(action)) {
+  : LexerAction(action->getActionType()), _offset(offset), _action(std::move(action)) {
 }
 
 int LexerIndexedCustomAction::getOffset() const {
@@ -25,10 +25,6 @@ Ref<LexerAction> LexerIndexedCustomAction::getAction() const {
   return _action;
 }
 
-LexerActionType LexerIndexedCustomAction::getActionType() const {
-  return _action->getActionType();
-}
-
 bool LexerIndexedCustomAction::isPositionDependent() const {
   return true;
 }

runtime/Cpp/runtime/src/atn/LexerIndexedCustomAction.h

@@ -55,13 +55,6 @@ namespace atn {
     /// <returns> A <seealso cref="LexerAction"/> object which executes the lexer action. </returns>
     Ref<LexerAction> getAction() const;
 
-    /// <summary>
-    /// {@inheritDoc}
-    /// </summary>
-    /// <returns> This method returns the result of calling <seealso cref="#getActionType"/>
-    /// on the <seealso cref="LexerAction"/> returned by <seealso cref="#getAction"/>. </returns>
-    virtual LexerActionType getActionType() const override;
-
     /// <summary>
     /// {@inheritDoc} </summary>
     /// <returns> This method returns {@code true}. </returns>