Intermediate changes

1 files changed, 579 insertions, 0 deletions

diff --git a/contrib/libs/antlr4_cpp_runtime/src/atn/PredictionContext.cpp b/contrib/libs/antlr4_cpp_runtime/src/atn/PredictionContext.cpp
new file mode 100644
index 00000000000..704408f04d5
--- /dev/null
+++ b/contrib/libs/antlr4_cpp_runtime/src/atn/PredictionContext.cpp
@@ -0,0 +1,579 @@
+/* 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/SingletonPredictionContext.h"
+#include "misc/MurmurHash.h"
+#include "atn/ArrayPredictionContext.h"
+#include "atn/PredictionContextCache.h"
+#include "atn/PredictionContextMergeCache.h"
+#include "RuleContext.h"
+#include "ParserRuleContext.h"
+#include "atn/RuleTransition.h"
+#include "support/Arrays.h"
+#include "support/CPPUtils.h"
+#include "support/Casts.h"
+
+#include "atn/PredictionContext.h"
+
+using namespace antlr4;
+using namespace antlr4::misc;
+using namespace antlr4::atn;
+using namespace antlrcpp;
+
+namespace {
+
+  void combineCommonParents(std::vector<Ref<const PredictionContext>> &parents) {
+    std::unordered_set<Ref<const PredictionContext>> uniqueParents;
+    uniqueParents.reserve(parents.size());
+    for (const auto &parent : parents) {
+      uniqueParents.insert(parent);
+    }
+    for (auto &parent : parents) {
+      parent = *uniqueParents.find(parent);
+    }
+  }
+
+  Ref<const PredictionContext> getCachedContextImpl(const Ref<const PredictionContext> &context,
+                                                    PredictionContextCache &contextCache,
+                                                    std::unordered_map<Ref<const PredictionContext>,
+                                                    Ref<const PredictionContext>> &visited) {
+    if (context->isEmpty()) {
+      return context;
+    }
+
+    {
+      auto iterator = visited.find(context);
+      if (iterator != visited.end()) {
+        return iterator->second; // Not necessarly the same as context.
+      }
+    }
+
+    auto cached = contextCache.get(context);
+    if (cached) {
+      visited[context] = cached;
+      return cached;
+    }
+
+    bool changed = false;
+
+    std::vector<Ref<const PredictionContext>> parents(context->size());
+    for (size_t i = 0; i < parents.size(); i++) {
+      auto parent = getCachedContextImpl(context->getParent(i), contextCache, visited);
+      if (changed || parent != context->getParent(i)) {
+        if (!changed) {
+          parents.clear();
+          for (size_t j = 0; j < context->size(); j++) {
+            parents.push_back(context->getParent(j));
+          }
+
+          changed = true;
+        }
+
+        parents[i] = std::move(parent);
+      }
+    }
+
+    if (!changed) {
+      visited[context] = context;
+      contextCache.put(context);
+      return context;
+    }
+
+    Ref<const PredictionContext> updated;
+    if (parents.empty()) {
+      updated = PredictionContext::EMPTY;
+    } else if (parents.size() == 1) {
+      updated = SingletonPredictionContext::create(std::move(parents[0]), context->getReturnState(0));
+      contextCache.put(updated);
+    } else {
+      updated = std::make_shared<ArrayPredictionContext>(std::move(parents), downCast<const ArrayPredictionContext*>(context.get())->returnStates);
+      contextCache.put(updated);
+    }
+
+    visited[updated] = updated;
+    visited[context] = updated;
+
+    return updated;
+  }
+
+  void getAllContextNodesImpl(const Ref<const PredictionContext> &context,
+                              std::vector<Ref<const PredictionContext>> &nodes,
+                              std::unordered_set<const PredictionContext*> &visited) {
+
+    if (visited.find(context.get()) != visited.end()) {
+      return; // Already done.
+    }
+
+    visited.insert(context.get());
+    nodes.push_back(context);
+
+    for (size_t i = 0; i < context->size(); i++) {
+      getAllContextNodesImpl(context->getParent(i), nodes, visited);
+    }
+  }
+
+  size_t insertOrAssignNodeId(std::unordered_map<const PredictionContext*, size_t> &nodeIds, size_t &nodeId, const PredictionContext *node) {
+    auto existing = nodeIds.find(node);
+    if (existing != nodeIds.end()) {
+      return existing->second;
+    }
+    return nodeIds.insert({node, nodeId++}).first->second;
+  }
+
+}
+
+const Ref<const PredictionContext> PredictionContext::EMPTY = std::make_shared<SingletonPredictionContext>(nullptr, PredictionContext::EMPTY_RETURN_STATE);
+
+//----------------- PredictionContext ----------------------------------------------------------------------------------
+
+PredictionContext::PredictionContext(PredictionContextType contextType) : _contextType(contextType), _hashCode(0) {}
+
+PredictionContext::PredictionContext(PredictionContext&& other) : _contextType(other._contextType), _hashCode(other._hashCode.exchange(0, std::memory_order_relaxed)) {}
+
+Ref<const PredictionContext> PredictionContext::fromRuleContext(const ATN &atn, RuleContext *outerContext) {
+  if (outerContext == nullptr) {
+    return PredictionContext::EMPTY;
+  }
+
+  // if we are in RuleContext of start rule, s, then PredictionContext
+  // is EMPTY. Nobody called us. (if we are empty, return empty)
+  if (outerContext->parent == nullptr || outerContext == &ParserRuleContext::EMPTY) {
+    return PredictionContext::EMPTY;
+  }
+
+  // If we have a parent, convert it to a PredictionContext graph
+  auto parent = PredictionContext::fromRuleContext(atn, RuleContext::is(outerContext->parent) ? downCast<RuleContext*>(outerContext->parent) : nullptr);
+  const auto *transition = downCast<const RuleTransition*>(atn.states[outerContext->invokingState]->transitions[0].get());
+  return SingletonPredictionContext::create(std::move(parent), transition->followState->stateNumber);
+}
+
+bool PredictionContext::hasEmptyPath() const {
+  // since EMPTY_RETURN_STATE can only appear in the last position, we check last one
+  return getReturnState(size() - 1) == EMPTY_RETURN_STATE;
+}
+
+size_t PredictionContext::hashCode() const {
+  auto hash = cachedHashCode();
+  if (hash == 0) {
+    hash = hashCodeImpl();
+    if (hash == 0) {
+      hash = std::numeric_limits<size_t>::max();
+    }
+    _hashCode.store(hash, std::memory_order_relaxed);
+  }
+  return hash;
+}
+
+Ref<const PredictionContext> PredictionContext::merge(Ref<const PredictionContext> a, Ref<const PredictionContext> b,
+                                                      bool rootIsWildcard, PredictionContextMergeCache *mergeCache) {
+  assert(a && b);
+
+  // share same graph if both same
+  if (a == b || *a == *b) {
+    return a;
+  }
+
+  const auto aType = a->getContextType();
+  const auto bType = b->getContextType();
+
+  if (aType == PredictionContextType::SINGLETON && bType == PredictionContextType::SINGLETON) {
+    return mergeSingletons(std::static_pointer_cast<const SingletonPredictionContext>(std::move(a)),
+                           std::static_pointer_cast<const SingletonPredictionContext>(std::move(b)), rootIsWildcard, mergeCache);
+  }
+
+  // At least one of a or b is array.
+  // If one is $ and rootIsWildcard, return $ as * wildcard.
+  if (rootIsWildcard) {
+    if (a == PredictionContext::EMPTY) {
+      return a;
+    }
+    if (b == PredictionContext::EMPTY) {
+      return b;
+    }
+  }
+
+  // convert singleton so both are arrays to normalize
+  Ref<const ArrayPredictionContext> left;
+  if (aType == PredictionContextType::SINGLETON) {
+    left = std::make_shared<ArrayPredictionContext>(downCast<const SingletonPredictionContext&>(*a));
+  } else {
+    left = std::static_pointer_cast<const ArrayPredictionContext>(std::move(a));
+  }
+  Ref<const ArrayPredictionContext> right;
+  if (bType == PredictionContextType::SINGLETON) {
+    right = std::make_shared<ArrayPredictionContext>(downCast<const SingletonPredictionContext&>(*b));
+  } else {
+    right = std::static_pointer_cast<const ArrayPredictionContext>(std::move(b));
+  }
+  return mergeArrays(std::move(left), std::move(right), rootIsWildcard, mergeCache);
+}
+
+Ref<const PredictionContext> PredictionContext::mergeSingletons(Ref<const SingletonPredictionContext> a, Ref<const SingletonPredictionContext> b,
+                                                                bool rootIsWildcard, PredictionContextMergeCache *mergeCache) {
+
+  if (mergeCache) {
+    auto existing = mergeCache->get(a, b);
+    if (existing) {
+      return existing;
+    }
+    existing = mergeCache->get(b, a);
+    if (existing) {
+      return existing;
+    }
+  }
+
+  auto rootMerge = mergeRoot(a, b, rootIsWildcard);
+  if (rootMerge) {
+    if (mergeCache) {
+      return mergeCache->put(a, b, std::move(rootMerge));
+    }
+    return rootMerge;
+  }
+
+  const auto& parentA = a->parent;
+  const auto& parentB = b->parent;
+  if (a->returnState == b->returnState) { // a == b
+    auto parent = merge(parentA, parentB, rootIsWildcard, mergeCache);
+
+    // If parent is same as existing a or b parent or reduced to a parent, return it.
+    if (parent == parentA) { // ax + bx = ax, if a=b
+      return a;
+    }
+    if (parent == parentB) { // ax + bx = bx, if a=b
+      return b;
+    }
+
+    // else: ax + ay = a'[x,y]
+    // merge parents x and y, giving array node with x,y then remainders
+    // of those graphs.  dup a, a' points at merged array
+    // new joined parent so create new singleton pointing to it, a'
+    auto c = SingletonPredictionContext::create(std::move(parent), a->returnState);
+    if (mergeCache) {
+      return mergeCache->put(a, b, std::move(c));
+    }
+    return c;
+  }
+  // a != b payloads differ
+  // see if we can collapse parents due to $+x parents if local ctx
+  Ref<const PredictionContext> singleParent;
+  if (a == b || (*parentA == *parentB)) { // ax + bx = [a,b]x
+    singleParent = parentA;
+  }
+  if (singleParent) { // parents are same, sort payloads and use same parent
+    std::vector<size_t> payloads = { a->returnState, b->returnState };
+    if (a->returnState > b->returnState) {
+      payloads[0] = b->returnState;
+      payloads[1] = a->returnState;
+    }
+    std::vector<Ref<const PredictionContext>> parents = { singleParent, singleParent };
+    auto c = std::make_shared<ArrayPredictionContext>(std::move(parents), std::move(payloads));
+    if (mergeCache) {
+      return mergeCache->put(a, b, std::move(c));
+    }
+    return c;
+  }
+
+  // parents differ and can't merge them. Just pack together
+  // into array; can't merge.
+  // ax + by = [ax,by]
+  if (a->returnState > b->returnState) { // sort by payload
+    std::vector<size_t> payloads = { b->returnState, a->returnState };
+    std::vector<Ref<const PredictionContext>> parents = { b->parent, a->parent };
+    auto c = std::make_shared<ArrayPredictionContext>(std::move(parents), std::move(payloads));
+    if (mergeCache) {
+      return mergeCache->put(a, b, std::move(c));
+    }
+    return c;
+  }
+  std::vector<size_t> payloads = {a->returnState, b->returnState};
+  std::vector<Ref<const PredictionContext>> parents = { a->parent, b->parent };
+  auto c = std::make_shared<ArrayPredictionContext>(std::move(parents), std::move(payloads));
+  if (mergeCache) {
+    return mergeCache->put(a, b, std::move(c));
+  }
+  return c;
+}
+
+Ref<const PredictionContext> PredictionContext::mergeRoot(Ref<const SingletonPredictionContext> a, Ref<const SingletonPredictionContext> b,
+                                                          bool rootIsWildcard) {
+  if (rootIsWildcard) {
+    if (a == EMPTY) { // * + b = *
+      return EMPTY;
+    }
+    if (b == EMPTY) { // a + * = *
+      return EMPTY;
+    }
+  } else {
+    if (a == EMPTY && b == EMPTY) { // $ + $ = $
+      return EMPTY;
+    }
+    if (a == EMPTY) { // $ + x = [$,x]
+      std::vector<size_t> payloads = { b->returnState, EMPTY_RETURN_STATE };
+      std::vector<Ref<const PredictionContext>> parents = { b->parent, nullptr };
+      return std::make_shared<ArrayPredictionContext>(std::move(parents), std::move(payloads));
+    }
+    if (b == EMPTY) { // x + $ = [$,x] ($ is always first if present)
+      std::vector<size_t> payloads = { a->returnState, EMPTY_RETURN_STATE };
+      std::vector<Ref<const PredictionContext>> parents = { a->parent, nullptr };
+      return std::make_shared<ArrayPredictionContext>(std::move(parents), std::move(payloads));
+    }
+  }
+  return nullptr;
+}
+
+Ref<const PredictionContext> PredictionContext::mergeArrays(Ref<const ArrayPredictionContext> a, Ref<const ArrayPredictionContext> b,
+                                                            bool rootIsWildcard, PredictionContextMergeCache *mergeCache) {
+
+  if (mergeCache) {
+    auto existing = mergeCache->get(a, b);
+    if (existing) {
+      return existing;
+    }
+    existing = mergeCache->get(b, a);
+    if (existing) {
+      return existing;
+    }
+  }
+
+  // merge sorted payloads a + b => M
+  size_t i = 0; // walks a
+  size_t j = 0; // walks b
+  size_t k = 0; // walks target M array
+
+  std::vector<size_t> mergedReturnStates(a->returnStates.size() + b->returnStates.size());
+  std::vector<Ref<const PredictionContext>> mergedParents(a->returnStates.size() + b->returnStates.size());
+
+  // walk and merge to yield mergedParents, mergedReturnStates
+  while (i < a->returnStates.size() && j < b->returnStates.size()) {
+    const auto& parentA = a->parents[i];
+    const auto& parentB = b->parents[j];
+    if (a->returnStates[i] == b->returnStates[j]) {
+      // same payload (stack tops are equal), must yield merged singleton
+      size_t payload = a->returnStates[i];
+      // $+$ = $
+      bool both$ = payload == EMPTY_RETURN_STATE && !parentA && !parentB;
+      bool ax_ax = (parentA && parentB) && *parentA == *parentB; // ax+ax -> ax
+      if (both$ || ax_ax) {
+        mergedParents[k] = parentA; // choose left
+        mergedReturnStates[k] = payload;
+      } else { // ax+ay -> a'[x,y]
+        mergedParents[k] = merge(parentA, parentB, rootIsWildcard, mergeCache);
+        mergedReturnStates[k] = payload;
+      }
+      i++; // hop over left one as usual
+      j++; // but also skip one in right side since we merge
+    } else if (a->returnStates[i] < b->returnStates[j]) { // copy a[i] to M
+      mergedParents[k] = parentA;
+      mergedReturnStates[k] = a->returnStates[i];
+      i++;
+    } else { // b > a, copy b[j] to M
+      mergedParents[k] = parentB;
+      mergedReturnStates[k] = b->returnStates[j];
+      j++;
+    }
+    k++;
+  }
+
+  // copy over any payloads remaining in either array
+  if (i < a->returnStates.size()) {
+    for (auto p = i; p < a->returnStates.size(); p++) {
+      mergedParents[k] = a->parents[p];
+      mergedReturnStates[k] = a->returnStates[p];
+      k++;
+    }
+  } else {
+    for (auto p = j; p < b->returnStates.size(); p++) {
+      mergedParents[k] = b->parents[p];
+      mergedReturnStates[k] = b->returnStates[p];
+      k++;
+    }
+  }
+
+  // trim merged if we combined a few that had same stack tops
+  if (k < mergedParents.size()) { // write index < last position; trim
+    if (k == 1) { // for just one merged element, return singleton top
+      auto c = SingletonPredictionContext::create(std::move(mergedParents[0]), mergedReturnStates[0]);
+      if (mergeCache) {
+        return mergeCache->put(a, b, std::move(c));
+      }
+      return c;
+    }
+    mergedParents.resize(k);
+    mergedReturnStates.resize(k);
+  }
+
+  ArrayPredictionContext m(std::move(mergedParents), std::move(mergedReturnStates));
+
+  // if we created same array as a or b, return that instead
+  // TODO: track whether this is possible above during merge sort for speed
+  if (m == *a) {
+    if (mergeCache) {
+      return mergeCache->put(a, b, a);
+    }
+    return a;
+  }
+  if (m == *b) {
+    if (mergeCache) {
+      return mergeCache->put(a, b, b);
+    }
+    return b;
+  }
+
+  combineCommonParents(m.parents);
+  auto c = std::make_shared<ArrayPredictionContext>(std::move(m));
+  if (mergeCache) {
+    return mergeCache->put(a, b, std::move(c));
+  }
+  return c;
+}
+
+std::string PredictionContext::toDOTString(const Ref<const PredictionContext> &context) {
+  if (context == nullptr) {
+    return "";
+  }
+
+  std::stringstream ss;
+  ss << "digraph G {\n" << "rankdir=LR;\n";
+
+  std::vector<Ref<const PredictionContext>> nodes = getAllContextNodes(context);
+  std::unordered_map<const PredictionContext*, size_t> nodeIds;
+  size_t nodeId = 0;
+
+  for (const auto &current : nodes) {
+    if (current->getContextType() == PredictionContextType::SINGLETON) {
+      std::string s = std::to_string(insertOrAssignNodeId(nodeIds, nodeId, current.get()));
+      ss << "  s" << s;
+      std::string returnState = std::to_string(current->getReturnState(0));
+      if (current == PredictionContext::EMPTY) {
+        returnState = "$";
+      }
+      ss << " [label=\"" << returnState << "\"];\n";
+      continue;
+    }
+    Ref<const ArrayPredictionContext> arr = std::static_pointer_cast<const ArrayPredictionContext>(current);
+    ss << "  s" << insertOrAssignNodeId(nodeIds, nodeId, arr.get()) << " [shape=box, label=\"" << "[";
+    bool first = true;
+    for (auto inv : arr->returnStates) {
+      if (!first) {
+       ss << ", ";
+      }
+      if (inv == EMPTY_RETURN_STATE) {
+        ss << "$";
+      } else {
+        ss << inv;
+      }
+      first = false;
+    }
+    ss << "]";
+    ss << "\"];\n";
+  }
+
+  for (const auto &current : nodes) {
+    if (current == EMPTY) {
+      continue;
+    }
+    for (size_t i = 0; i < current->size(); i++) {
+      if (!current->getParent(i)) {
+        continue;
+      }
+      ss << "  s" << insertOrAssignNodeId(nodeIds, nodeId, current.get()) << "->" << "s" << insertOrAssignNodeId(nodeIds, nodeId, current->getParent(i).get());
+      if (current->size() > 1) {
+        ss << " [label=\"parent[" << i << "]\"];\n";
+      } else {
+        ss << ";\n";
+      }
+    }
+  }
+
+  ss << "}\n";
+  return ss.str();
+}
+
+// The "visited" map is just a temporary structure to control the retrieval process (which is recursive).
+Ref<const PredictionContext> PredictionContext::getCachedContext(const Ref<const PredictionContext> &context,
+                                                                 PredictionContextCache &contextCache) {
+  std::unordered_map<Ref<const PredictionContext>, Ref<const PredictionContext>> visited;
+  return getCachedContextImpl(context, contextCache, visited);
+}
+
+std::vector<Ref<const PredictionContext>> PredictionContext::getAllContextNodes(const Ref<const PredictionContext> &context) {
+  std::vector<Ref<const PredictionContext>> nodes;
+  std::unordered_set<const PredictionContext*> visited;
+  getAllContextNodesImpl(context, nodes, visited);
+  return nodes;
+}
+
+std::vector<std::string> PredictionContext::toStrings(Recognizer *recognizer, int currentState) const {
+  return toStrings(recognizer, EMPTY, currentState);
+}
+
+std::vector<std::string> PredictionContext::toStrings(Recognizer *recognizer, const Ref<const PredictionContext> &stop, int currentState) const {
+
+  std::vector<std::string> result;
+
+  for (size_t perm = 0; ; perm++) {
+    size_t offset = 0;
+    bool last = true;
+    const PredictionContext *p = this;
+    size_t stateNumber = currentState;
+
+    std::stringstream ss;
+    ss << "[";
+    bool outerContinue = false;
+    while (!p->isEmpty() && p != stop.get()) {
+      size_t index = 0;
+      if (p->size() > 0) {
+        size_t bits = 1;
+        while ((1ULL << bits) < p->size()) {
+          bits++;
+        }
+
+        size_t mask = (1 << bits) - 1;
+        index = (perm >> offset) & mask;
+        last &= index >= p->size() - 1;
+        if (index >= p->size()) {
+          outerContinue = true;
+          break;
+        }
+        offset += bits;
+      }
+
+      if (recognizer != nullptr) {
+        if (ss.tellp() > 1) {
+          // first char is '[', if more than that this isn't the first rule
+          ss << ' ';
+        }
+
+        const ATN &atn = recognizer->getATN();
+        ATNState *s = atn.states[stateNumber];
+        std::string ruleName = recognizer->getRuleNames()[s->ruleIndex];
+        ss << ruleName;
+      } else if (p->getReturnState(index) != EMPTY_RETURN_STATE) {
+        if (!p->isEmpty()) {
+          if (ss.tellp() > 1) {
+            // first char is '[', if more than that this isn't the first rule
+            ss << ' ';
+          }
+
+          ss << p->getReturnState(index);
+        }
+      }
+      stateNumber = p->getReturnState(index);
+      p = p->getParent(index).get();
+    }
+
+    if (outerContinue)
+      continue;
+
+    ss << "]";
+    result.push_back(ss.str());
+
+    if (last) {
+      break;
+    }
+  }
+
+  return result;
+}