First commit

runtime-linux/antlr4-runtime/atn/ATNDeserializer.cpp

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+/* 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.
+ */
+
+#include "atn/ATNDeserializationOptions.h"
+
+#include "atn/ATNType.h"
+#include "atn/ATNState.h"
+#include "atn/ATN.h"
+
+#include "atn/LoopEndState.h"
+#include "atn/DecisionState.h"
+#include "atn/RuleStartState.h"
+#include "atn/RuleStopState.h"
+#include "atn/TokensStartState.h"
+#include "atn/RuleTransition.h"
+#include "atn/EpsilonTransition.h"
+#include "atn/PlusLoopbackState.h"
+#include "atn/PlusBlockStartState.h"
+#include "atn/StarLoopbackState.h"
+#include "atn/BasicBlockStartState.h"
+#include "atn/BasicState.h"
+#include "atn/BlockEndState.h"
+#include "atn/StarLoopEntryState.h"
+
+#include "atn/AtomTransition.h"
+#include "atn/StarBlockStartState.h"
+#include "atn/RangeTransition.h"
+#include "atn/PredicateTransition.h"
+#include "atn/PrecedencePredicateTransition.h"
+#include "atn/ActionTransition.h"
+#include "atn/SetTransition.h"
+#include "atn/NotSetTransition.h"
+#include "atn/WildcardTransition.h"
+#include "Token.h"
+
+#include "misc/IntervalSet.h"
+#include "Exceptions.h"
+#include "support/CPPUtils.h"
+#include "support/StringUtils.h"
+
+#include "atn/LexerCustomAction.h"
+#include "atn/LexerChannelAction.h"
+#include "atn/LexerModeAction.h"
+#include "atn/LexerMoreAction.h"
+#include "atn/LexerPopModeAction.h"
+#include "atn/LexerPushModeAction.h"
+#include "atn/LexerSkipAction.h"
+#include "atn/LexerTypeAction.h"
+
+#include "atn/ATNDeserializer.h"
+
+#include <string>
+
+using namespace antlr4;
+using namespace antlr4::atn;
+using namespace antlrcpp;
+
+const size_t ATNDeserializer::SERIALIZED_VERSION = 3;
+
+namespace {
+
+uint32_t deserializeInt32(const std::vector<uint16_t>& data, size_t offset) {
+  return (uint32_t)data[offset] | ((uint32_t)data[offset + 1] << 16);
+}
+
+ssize_t readUnicodeInt(const std::vector<uint16_t>& data, int& p) {
+  return static_cast<ssize_t>(data[p++]);
+}
+
+ssize_t readUnicodeInt32(const std::vector<uint16_t>& data, int& p) {
+  auto result = deserializeInt32(data, p);
+  p += 2;
+  return static_cast<ssize_t>(result);
+}
+
+// We templatize this on the function type so the optimizer can inline
+// the 16- or 32-bit readUnicodeInt/readUnicodeInt32 as needed.
+template <typename F>
+void deserializeSets(
+  const std::vector<uint16_t>& data,
+  int& p,
+  std::vector<misc::IntervalSet>& sets,
+  F readUnicode) {
+  int nsets = data[p++];
+  for (int i = 0; i < nsets; i++) {
+    int nintervals = data[p++];
+    misc::IntervalSet set;
+
+    bool containsEof = data[p++] != 0;
+    if (containsEof) {
+      set.add(-1);
+    }
+
+    for (int j = 0; j < nintervals; j++) {
+      auto a = readUnicode(data, p);
+      auto b = readUnicode(data, p);
+      set.add(a, b);
+    }
+    sets.push_back(set);
+  }
+}
+
+}
+
+ATNDeserializer::ATNDeserializer(): ATNDeserializer(ATNDeserializationOptions::getDefaultOptions()) {
+}
+
+ATNDeserializer::ATNDeserializer(const ATNDeserializationOptions& dso): deserializationOptions(dso) {
+}
+
+ATNDeserializer::~ATNDeserializer() {
+}
+
+/**
+ * This value should never change. Updates following this version are
+ * reflected as change in the unique ID SERIALIZED_UUID.
+ */
+Guid ATNDeserializer::ADDED_PRECEDENCE_TRANSITIONS() {
+  return Guid("1DA0C57D-6C06-438A-9B27-10BCB3CE0F61");
+}
+
+Guid ATNDeserializer::ADDED_LEXER_ACTIONS() {
+  return Guid("AADB8D7E-AEEF-4415-AD2B-8204D6CF042E");
+}
+
+Guid ATNDeserializer::ADDED_UNICODE_SMP() {
+  return Guid("59627784-3BE5-417A-B9EB-8131A7286089");
+}
+
+Guid ATNDeserializer::SERIALIZED_UUID() {
+  return ADDED_UNICODE_SMP();
+}
+
+Guid ATNDeserializer::BASE_SERIALIZED_UUID() {
+  return Guid("33761B2D-78BB-4A43-8B0B-4F5BEE8AACF3");
+}
+
+std::vector<Guid>& ATNDeserializer::SUPPORTED_UUIDS() {
+  static std::vector<Guid> singleton = { BASE_SERIALIZED_UUID(), ADDED_PRECEDENCE_TRANSITIONS(), ADDED_LEXER_ACTIONS(), ADDED_UNICODE_SMP() };
+  return singleton;
+}
+
+bool ATNDeserializer::isFeatureSupported(const Guid &feature, const Guid &actualUuid) {
+  auto featureIterator = std::find(SUPPORTED_UUIDS().begin(), SUPPORTED_UUIDS().end(), feature);
+  if (featureIterator == SUPPORTED_UUIDS().end()) {
+    return false;
+  }
+  auto actualIterator = std::find(SUPPORTED_UUIDS().begin(), SUPPORTED_UUIDS().end(), actualUuid);
+  if (actualIterator == SUPPORTED_UUIDS().end()) {
+    return false;
+  }
+
+  return std::distance(featureIterator, actualIterator) >= 0;
+}
+
+ATN ATNDeserializer::deserialize(const std::vector<uint16_t>& input) {
+  // Don't adjust the first value since that's the version number.
+  std::vector<uint16_t> data(input.size());
+  data[0] = input[0];
+  for (size_t i = 1; i < input.size(); ++i) {
+    data[i] = input[i] - 2;
+  }
+
+  int p = 0;
+  int version = data[p++];
+  if (version != SERIALIZED_VERSION) {
+    std::string reason = "Could not deserialize ATN with version" + std::to_string(version) + "(expected " + std::to_string(SERIALIZED_VERSION) + ").";
+
+    throw UnsupportedOperationException(reason);
+  }
+
+  Guid uuid = toUUID(data.data(), p);
+  p += 8;
+  auto uuidIterator = std::find(SUPPORTED_UUIDS().begin(), SUPPORTED_UUIDS().end(), uuid);
+  if (uuidIterator == SUPPORTED_UUIDS().end()) {
+    std::string reason = "Could not deserialize ATN with UUID " + uuid.toString() + " (expected " +
+      SERIALIZED_UUID().toString() + " or a legacy UUID).";
+
+    throw UnsupportedOperationException(reason);
+  }
+
+  bool supportsPrecedencePredicates = isFeatureSupported(ADDED_PRECEDENCE_TRANSITIONS(), uuid);
+  bool supportsLexerActions = isFeatureSupported(ADDED_LEXER_ACTIONS(), uuid);
+
+  ATNType grammarType = (ATNType)data[p++];
+  size_t maxTokenType = data[p++];
+  ATN atn(grammarType, maxTokenType);
+
+  //
+  // STATES
+  //
+  std::vector<std::pair<LoopEndState*, size_t>> loopBackStateNumbers;
+  std::vector<std::pair<BlockStartState*, size_t>> endStateNumbers;
+  size_t nstates = data[p++];
+  for (size_t i = 0; i < nstates; i++) {
+    size_t stype = data[p++];
+    // ignore bad type of states
+    if (stype == ATNState::ATN_INVALID_TYPE) {
+      atn.addState(nullptr);
+      continue;
+    }
+
+    size_t ruleIndex = data[p++];
+    if (ruleIndex == 0xFFFF) {
+      ruleIndex = INVALID_INDEX;
+    }
+
+    ATNState *s = stateFactory(stype, ruleIndex);
+    if (stype == ATNState::LOOP_END) { // special case
+      int loopBackStateNumber = data[p++];
+      loopBackStateNumbers.push_back({ (LoopEndState*)s,  loopBackStateNumber });
+    } else if (is<BlockStartState*>(s)) {
+      int endStateNumber = data[p++];
+      endStateNumbers.push_back({ (BlockStartState*)s, endStateNumber });
+    }
+    atn.addState(s);
+  }
+
+  // delay the assignment of loop back and end states until we know all the state instances have been initialized
+  for (auto &pair : loopBackStateNumbers) {
+    pair.first->loopBackState = atn.states[pair.second];
+  }
+
+  for (auto &pair : endStateNumbers) {
+    pair.first->endState = (BlockEndState*)atn.states[pair.second];
+  }
+
+  size_t numNonGreedyStates = data[p++];
+  for (size_t i = 0; i < numNonGreedyStates; i++) {
+    size_t stateNumber = data[p++];
+    // The serialized ATN must be specifying the right states, so that the
+    // cast below is correct.
+    ((DecisionState *)atn.states[stateNumber])->nonGreedy = true;
+  }
+
+  if (supportsPrecedencePredicates) {
+    size_t numPrecedenceStates = data[p++];
+    for (size_t i = 0; i < numPrecedenceStates; i++) {
+      size_t stateNumber = data[p++];
+      ((RuleStartState *)atn.states[stateNumber])->isLeftRecursiveRule = true;
+    }
+  }
+
+  //
+  // RULES
+  //
+  size_t nrules = data[p++];
+  for (size_t i = 0; i < nrules; i++) {
+    size_t s = data[p++];
+    // Also here, the serialized atn must ensure to point to the correct class type.
+    RuleStartState *startState = (RuleStartState*)atn.states[s];
+    atn.ruleToStartState.push_back(startState);
+    if (atn.grammarType == ATNType::LEXER) {
+      size_t tokenType = data[p++];
+      if (tokenType == 0xFFFF) {
+        tokenType = Token::EOF;
+      }
+
+      atn.ruleToTokenType.push_back(tokenType);
+
+      if (!isFeatureSupported(ADDED_LEXER_ACTIONS(), uuid)) {
+        // this piece of unused metadata was serialized prior to the
+        // addition of LexerAction
+        //int actionIndexIgnored = data[p++];
+        p++;
+      }
+    }
+  }
+
+  atn.ruleToStopState.resize(nrules);
+  for (ATNState *state : atn.states) {
+    if (!is<RuleStopState*>(state)) {
+      continue;
+    }
+
+    RuleStopState *stopState = static_cast<RuleStopState*>(state);
+    atn.ruleToStopState[state->ruleIndex] = stopState;
+    atn.ruleToStartState[state->ruleIndex]->stopState = stopState;
+  }
+
+  //
+  // MODES
+  //
+  size_t nmodes = data[p++];
+  for (size_t i = 0; i < nmodes; i++) {
+    size_t s = data[p++];
+    atn.modeToStartState.push_back(static_cast<TokensStartState*>(atn.states[s]));
+  }
+
+  //
+  // SETS
+  //
+  std::vector<misc::IntervalSet> sets;
+
+  // First, deserialize sets with 16-bit arguments <= U+FFFF.
+  deserializeSets(data, p, sets, readUnicodeInt);
+
+  // Next, if the ATN was serialized with the Unicode SMP feature,
+  // deserialize sets with 32-bit arguments <= U+10FFFF.
+  if (isFeatureSupported(ADDED_UNICODE_SMP(), uuid)) {
+    deserializeSets(data, p, sets, readUnicodeInt32);
+  }
+
+  //
+  // EDGES
+  //
+  int nedges = data[p++];
+  for (int i = 0; i < nedges; i++) {
+    size_t src = data[p];
+    size_t trg = data[p + 1];
+    size_t ttype = data[p + 2];
+    size_t arg1 = data[p + 3];
+    size_t arg2 = data[p + 4];
+    size_t arg3 = data[p + 5];
+    Transition *trans = edgeFactory(atn, ttype, src, trg, arg1, arg2, arg3, sets);
+    ATNState *srcState = atn.states[src];
+    srcState->addTransition(trans);
+    p += 6;
+  }
+
+  // edges for rule stop states can be derived, so they aren't serialized
+  for (ATNState *state : atn.states) {
+    for (size_t i = 0; i < state->transitions.size(); i++) {
+      Transition *t = state->transitions[i];
+      if (!is<RuleTransition*>(t)) {
+        continue;
+      }
+
+      RuleTransition *ruleTransition = static_cast<RuleTransition*>(t);
+      size_t outermostPrecedenceReturn = INVALID_INDEX;
+      if (atn.ruleToStartState[ruleTransition->target->ruleIndex]->isLeftRecursiveRule) {
+        if (ruleTransition->precedence == 0) {
+          outermostPrecedenceReturn = ruleTransition->target->ruleIndex;
+        }
+      }
+
+      EpsilonTransition *returnTransition = new EpsilonTransition(ruleTransition->followState, outermostPrecedenceReturn); /* mem check: freed in ANTState d-tor */
+      atn.ruleToStopState[ruleTransition->target->ruleIndex]->addTransition(returnTransition);
+    }
+  }
+
+  for (ATNState *state : atn.states) {
+    if (is<BlockStartState *>(state)) {
+      BlockStartState *startState = static_cast<BlockStartState *>(state);
+
+      // we need to know the end state to set its start state
+      if (startState->endState == nullptr) {
+        throw IllegalStateException();
+      }
+
+      // block end states can only be associated to a single block start state
+      if (startState->endState->startState != nullptr) {
+        throw IllegalStateException();
+      }
+
+      startState->endState->startState = static_cast<BlockStartState*>(state);
+    }
+
+    if (is<PlusLoopbackState*>(state)) {
+      PlusLoopbackState *loopbackState = static_cast<PlusLoopbackState *>(state);
+      for (size_t i = 0; i < loopbackState->transitions.size(); i++) {
+        ATNState *target = loopbackState->transitions[i]->target;
+        if (is<PlusBlockStartState *>(target)) {
+          (static_cast<PlusBlockStartState *>(target))->loopBackState = loopbackState;
+        }
+      }
+    } else if (is<StarLoopbackState *>(state)) {
+      StarLoopbackState *loopbackState = static_cast<StarLoopbackState *>(state);
+      for (size_t i = 0; i < loopbackState->transitions.size(); i++) {
+        ATNState *target = loopbackState->transitions[i]->target;
+        if (is<StarLoopEntryState *>(target)) {
+          (static_cast<StarLoopEntryState*>(target))->loopBackState = loopbackState;
+        }
+      }
+    }
+  }
+
+  //
+  // DECISIONS
+  //
+  size_t ndecisions = data[p++];
+  for (size_t i = 1; i <= ndecisions; i++) {
+    size_t s = data[p++];
+    DecisionState *decState = dynamic_cast<DecisionState*>(atn.states[s]);
+    if (decState == nullptr)
+      throw IllegalStateException();
+
+    atn.decisionToState.push_back(decState);
+    decState->decision = (int)i - 1;
+  }
+
+  //
+  // LEXER ACTIONS
+  //
+  if (atn.grammarType == ATNType::LEXER) {
+    if (supportsLexerActions) {
+      atn.lexerActions.resize(data[p++]);
+      for (size_t i = 0; i < atn.lexerActions.size(); i++) {
+        LexerActionType actionType = (LexerActionType)data[p++];
+        int data1 = data[p++];
+        if (data1 == 0xFFFF) {
+          data1 = -1;
+        }
+
+        int data2 = data[p++];
+        if (data2 == 0xFFFF) {
+          data2 = -1;
+        }
+
+        atn.lexerActions[i] = lexerActionFactory(actionType, data1, data2);
+      }
+    } else {
+      // for compatibility with older serialized ATNs, convert the old
+      // serialized action index for action transitions to the new
+      // form, which is the index of a LexerCustomAction
+      for (ATNState *state : atn.states) {
+        for (size_t i = 0; i < state->transitions.size(); i++) {
+          Transition *transition = state->transitions[i];
+          if (!is<ActionTransition *>(transition)) {
+            continue;
+          }
+
+          size_t ruleIndex = static_cast<ActionTransition *>(transition)->ruleIndex;
+          size_t actionIndex = static_cast<ActionTransition *>(transition)->actionIndex;
+          Ref<LexerCustomAction> lexerAction = std::make_shared<LexerCustomAction>(ruleIndex, actionIndex);
+          state->transitions[i] = new ActionTransition(transition->target, ruleIndex, atn.lexerActions.size(), false); /* mem-check freed in ATNState d-tor */
+          delete transition; // ml: no longer needed since we just replaced it.
+          atn.lexerActions.push_back(lexerAction);
+        }
+      }
+    }
+  }
+
+  markPrecedenceDecisions(atn);
+
+  if (deserializationOptions.isVerifyATN()) {
+    verifyATN(atn);
+  }
+
+  if (deserializationOptions.isGenerateRuleBypassTransitions() && atn.grammarType == ATNType::PARSER) {
+    atn.ruleToTokenType.resize(atn.ruleToStartState.size());
+    for (size_t i = 0; i < atn.ruleToStartState.size(); i++) {
+      atn.ruleToTokenType[i] = int(atn.maxTokenType + i + 1);
+    }
+
+    for (std::vector<RuleStartState*>::size_type i = 0; i < atn.ruleToStartState.size(); i++) {
+      BasicBlockStartState *bypassStart = new BasicBlockStartState(); /* mem check: freed in ATN d-tor */
+      bypassStart->ruleIndex = (int)i;
+      atn.addState(bypassStart);
+
+      BlockEndState *bypassStop = new BlockEndState(); /* mem check: freed in ATN d-tor */
+      bypassStop->ruleIndex = (int)i;
+      atn.addState(bypassStop);
+
+      bypassStart->endState = bypassStop;
+      atn.defineDecisionState(bypassStart);
+
+      bypassStop->startState = bypassStart;
+
+      ATNState *endState;
+      Transition *excludeTransition = nullptr;
+      if (atn.ruleToStartState[i]->isLeftRecursiveRule) {
+        // wrap from the beginning of the rule to the StarLoopEntryState
+        endState = nullptr;
+        for (ATNState *state : atn.states) {
+          if (state->ruleIndex != i) {
+            continue;
+          }
+
+          if (!is<StarLoopEntryState*>(state)) {
+            continue;
+          }
+
+          ATNState *maybeLoopEndState = state->transitions[state->transitions.size() - 1]->target;
+          if (!is<LoopEndState*>(maybeLoopEndState)) {
+            continue;
+          }
+
+          if (maybeLoopEndState->epsilonOnlyTransitions && is<RuleStopState*>(maybeLoopEndState->transitions[0]->target)) {
+            endState = state;
+            break;
+          }
+        }
+
+        if (endState == nullptr) {
+          throw UnsupportedOperationException("Couldn't identify final state of the precedence rule prefix section.");
+
+        }
+
+        excludeTransition = (static_cast<StarLoopEntryState*>(endState))->loopBackState->transitions[0];
+      } else {
+        endState = atn.ruleToStopState[i];
+      }
+
+      // all non-excluded transitions that currently target end state need to target blockEnd instead
+      for (ATNState *state : atn.states) {
+        for (Transition *transition : state->transitions) {
+          if (transition == excludeTransition) {
+            continue;
+          }
+
+          if (transition->target == endState) {
+            transition->target = bypassStop;
+          }
+        }
+      }
+
+      // all transitions leaving the rule start state need to leave blockStart instead
+      while (atn.ruleToStartState[i]->transitions.size() > 0) {
+        Transition *transition = atn.ruleToStartState[i]->removeTransition(atn.ruleToStartState[i]->transitions.size() - 1);
+        bypassStart->addTransition(transition);
+      }
+
+      // link the new states
+      atn.ruleToStartState[i]->addTransition(new EpsilonTransition(bypassStart));  /* mem check: freed in ATNState d-tor */
+      bypassStop->addTransition(new EpsilonTransition(endState)); /* mem check: freed in ATNState d-tor */
+
+      ATNState *matchState = new BasicState(); /* mem check: freed in ATN d-tor */
+      atn.addState(matchState);
+      matchState->addTransition(new AtomTransition(bypassStop, atn.ruleToTokenType[i])); /* mem check: freed in ATNState d-tor */
+      bypassStart->addTransition(new EpsilonTransition(matchState)); /* mem check: freed in ATNState d-tor */
+    }
+
+    if (deserializationOptions.isVerifyATN()) {
+      // reverify after modification
+      verifyATN(atn);
+    }
+  }
+
+  return atn;
+}
+
+/**
+ * Analyze the {@link StarLoopEntryState} states in the specified ATN to set
+ * the {@link StarLoopEntryState#isPrecedenceDecision} field to the
+ * correct value.
+ *
+ * @param atn The ATN.
+ */
+void ATNDeserializer::markPrecedenceDecisions(const ATN &atn) {
+  for (ATNState *state : atn.states) {
+    if (!is<StarLoopEntryState *>(state)) {
+      continue;
+    }
+
+    /* We analyze the ATN to determine if this ATN decision state is the
+     * decision for the closure block that determines whether a
+     * precedence rule should continue or complete.
+     */
+    if (atn.ruleToStartState[state->ruleIndex]->isLeftRecursiveRule) {
+      ATNState *maybeLoopEndState = state->transitions[state->transitions.size() - 1]->target;
+      if (is<LoopEndState *>(maybeLoopEndState)) {
+        if (maybeLoopEndState->epsilonOnlyTransitions && is<RuleStopState *>(maybeLoopEndState->transitions[0]->target)) {
+          static_cast<StarLoopEntryState *>(state)->isPrecedenceDecision = true;
+        }
+      }
+    }
+  }
+}
+
+void ATNDeserializer::verifyATN(const ATN &atn) {
+  // verify assumptions
+  for (ATNState *state : atn.states) {
+    if (state == nullptr) {
+      continue;
+    }
+
+    checkCondition(state->epsilonOnlyTransitions || state->transitions.size() <= 1);
+
+    if (is<PlusBlockStartState *>(state)) {
+      checkCondition((static_cast<PlusBlockStartState *>(state))->loopBackState != nullptr);
+    }
+
+    if (is<StarLoopEntryState *>(state)) {
+      StarLoopEntryState *starLoopEntryState = static_cast<StarLoopEntryState*>(state);
+      checkCondition(starLoopEntryState->loopBackState != nullptr);
+      checkCondition(starLoopEntryState->transitions.size() == 2);
+
+      if (is<StarBlockStartState *>(starLoopEntryState->transitions[0]->target)) {
+        checkCondition(static_cast<LoopEndState *>(starLoopEntryState->transitions[1]->target) != nullptr);
+        checkCondition(!starLoopEntryState->nonGreedy);
+      } else if (is<LoopEndState *>(starLoopEntryState->transitions[0]->target)) {
+        checkCondition(is<StarBlockStartState *>(starLoopEntryState->transitions[1]->target));
+        checkCondition(starLoopEntryState->nonGreedy);
+      } else {
+        throw IllegalStateException();
+
+      }
+    }
+
+    if (is<StarLoopbackState *>(state)) {
+      checkCondition(state->transitions.size() == 1);
+      checkCondition(is<StarLoopEntryState *>(state->transitions[0]->target));
+    }
+
+    if (is<LoopEndState *>(state)) {
+      checkCondition((static_cast<LoopEndState *>(state))->loopBackState != nullptr);
+    }
+
+    if (is<RuleStartState *>(state)) {
+      checkCondition((static_cast<RuleStartState *>(state))->stopState != nullptr);
+    }
+
+    if (is<BlockStartState *>(state)) {
+      checkCondition((static_cast<BlockStartState *>(state))->endState != nullptr);
+    }
+
+    if (is<BlockEndState *>(state)) {
+      checkCondition((static_cast<BlockEndState *>(state))->startState != nullptr);
+    }
+
+    if (is<DecisionState *>(state)) {
+      DecisionState *decisionState = static_cast<DecisionState *>(state);
+      checkCondition(decisionState->transitions.size() <= 1 || decisionState->decision >= 0);
+    } else {
+      checkCondition(state->transitions.size() <= 1 || is<RuleStopState *>(state));
+    }
+  }
+}
+
+void ATNDeserializer::checkCondition(bool condition) {
+  checkCondition(condition, "");
+}
+
+void ATNDeserializer::checkCondition(bool condition, const std::string &message) {
+  if (!condition) {
+    throw IllegalStateException(message);
+  }
+}
+
+Guid ATNDeserializer::toUUID(const unsigned short *data, size_t offset) {
+  return Guid((uint16_t *)data + offset, true);
+}
+
+/* mem check: all created instances are freed in the d-tor of the ATNState they are added to. */
+Transition *ATNDeserializer::edgeFactory(const ATN &atn, size_t type, size_t /*src*/, size_t trg, size_t arg1,
+                                         size_t arg2, size_t arg3,
+  const std::vector<misc::IntervalSet> &sets) {
+
+  ATNState *target = atn.states[trg];
+  switch (type) {
+    case Transition::EPSILON:
+      return new EpsilonTransition(target);
+    case Transition::RANGE:
+      if (arg3 != 0) {
+        return new RangeTransition(target, Token::EOF, arg2);
+      } else {
+        return new RangeTransition(target, arg1, arg2);
+      }
+    case Transition::RULE:
+      return new RuleTransition(static_cast<RuleStartState*>(atn.states[arg1]), arg2, (int)arg3, target);
+    case Transition::PREDICATE:
+      return new PredicateTransition(target, arg1, arg2, arg3 != 0);
+    case Transition::PRECEDENCE:
+      return new PrecedencePredicateTransition(target, (int)arg1);
+    case Transition::ATOM:
+      if (arg3 != 0) {
+        return new AtomTransition(target, Token::EOF);
+      } else {
+        return new AtomTransition(target, arg1);
+      }
+    case Transition::ACTION:
+      return new ActionTransition(target, arg1, arg2, arg3 != 0);
+    case Transition::SET:
+      return new SetTransition(target, sets[arg1]);
+    case Transition::NOT_SET:
+      return new NotSetTransition(target, sets[arg1]);
+    case Transition::WILDCARD:
+      return new WildcardTransition(target);
+  }
+
+  throw IllegalArgumentException("The specified transition type is not valid.");
+}
+
+/* mem check: all created instances are freed in the d-tor of the ATN. */
+ATNState* ATNDeserializer::stateFactory(size_t type, size_t ruleIndex) {
+  ATNState *s;
+  switch (type) {
+    case ATNState::ATN_INVALID_TYPE:
+      return nullptr;
+    case ATNState::BASIC :
+      s = new BasicState();
+      break;
+    case ATNState::RULE_START :
+      s = new RuleStartState();
+      break;
+    case ATNState::BLOCK_START :
+      s = new BasicBlockStartState();
+      break;
+    case ATNState::PLUS_BLOCK_START :
+      s = new PlusBlockStartState();
+      break;
+    case ATNState::STAR_BLOCK_START :
+      s = new StarBlockStartState();
+      break;
+    case ATNState::TOKEN_START :
+      s = new TokensStartState();
+      break;
+    case ATNState::RULE_STOP :
+      s = new RuleStopState();
+      break;
+    case ATNState::BLOCK_END :
+      s = new BlockEndState();
+      break;
+    case ATNState::STAR_LOOP_BACK :
+      s = new StarLoopbackState();
+      break;
+    case ATNState::STAR_LOOP_ENTRY :
+      s = new StarLoopEntryState();
+      break;
+    case ATNState::PLUS_LOOP_BACK :
+      s = new PlusLoopbackState();
+      break;
+    case ATNState::LOOP_END :
+      s = new LoopEndState();
+      break;
+    default :
+      std::string message = "The specified state type " + std::to_string(type) + " is not valid.";
+      throw IllegalArgumentException(message);
+  }
+
+  s->ruleIndex = ruleIndex;
+  return s;
+}
+
+Ref<LexerAction> ATNDeserializer::lexerActionFactory(LexerActionType type, int data1, int data2) {
+  switch (type) {
+    case LexerActionType::CHANNEL:
+      return std::make_shared<LexerChannelAction>(data1);
+
+    case LexerActionType::CUSTOM:
+      return std::make_shared<LexerCustomAction>(data1, data2);
+
+    case LexerActionType::MODE:
+      return std::make_shared< LexerModeAction>(data1);
+
+    case LexerActionType::MORE:
+      return LexerMoreAction::getInstance();
+
+    case LexerActionType::POP_MODE:
+      return LexerPopModeAction::getInstance();
+
+    case LexerActionType::PUSH_MODE:
+      return std::make_shared<LexerPushModeAction>(data1);
+
+    case LexerActionType::SKIP:
+      return LexerSkipAction::getInstance();
+
+    case LexerActionType::TYPE:
+      return std::make_shared<LexerTypeAction>(data1);
+
+    default:
+      throw IllegalArgumentException("The specified lexer action type " + std::to_string(static_cast<size_t>(type)) +
+                                     " is not valid.");
+  }
+}