chore(3p/abseil_cpp): unvendor abseil_cpp r/3786

we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 698 deletions

diff --git a/third_party/abseil_cpp/absl/synchronization/internal/graphcycles.cc b/third_party/abseil_cpp/absl/synchronization/internal/graphcycles.cc
deleted file mode 100644
index 27fec21681dc..000000000000
--- a/third_party/abseil_cpp/absl/synchronization/internal/graphcycles.cc
+++ /dev/null
@@ -1,698 +0,0 @@
-// Copyright 2017 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// GraphCycles provides incremental cycle detection on a dynamic
-// graph using the following algorithm:
-//
-// A dynamic topological sort algorithm for directed acyclic graphs
-// David J. Pearce, Paul H. J. Kelly
-// Journal of Experimental Algorithmics (JEA) JEA Homepage archive
-// Volume 11, 2006, Article No. 1.7
-//
-// Brief summary of the algorithm:
-//
-// (1) Maintain a rank for each node that is consistent
-//     with the topological sort of the graph. I.e., path from x to y
-//     implies rank[x] < rank[y].
-// (2) When a new edge (x->y) is inserted, do nothing if rank[x] < rank[y].
-// (3) Otherwise: adjust ranks in the neighborhood of x and y.
-
-#include "absl/base/attributes.h"
-// This file is a no-op if the required LowLevelAlloc support is missing.
-#include "absl/base/internal/low_level_alloc.h"
-#ifndef ABSL_LOW_LEVEL_ALLOC_MISSING
-
-#include "absl/synchronization/internal/graphcycles.h"
-
-#include <algorithm>
-#include <array>
-#include <limits>
-#include "absl/base/internal/hide_ptr.h"
-#include "absl/base/internal/raw_logging.h"
-#include "absl/base/internal/spinlock.h"
-
-// Do not use STL.   This module does not use standard memory allocation.
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace synchronization_internal {
-
-namespace {
-
-// Avoid LowLevelAlloc's default arena since it calls malloc hooks in
-// which people are doing things like acquiring Mutexes.
-ABSL_CONST_INIT static absl::base_internal::SpinLock arena_mu(
-    absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY);
-ABSL_CONST_INIT static base_internal::LowLevelAlloc::Arena* arena;
-
-static void InitArenaIfNecessary() {
-  arena_mu.Lock();
-  if (arena == nullptr) {
-    arena = base_internal::LowLevelAlloc::NewArena(0);
-  }
-  arena_mu.Unlock();
-}
-
-// Number of inlined elements in Vec.  Hash table implementation
-// relies on this being a power of two.
-static const uint32_t kInline = 8;
-
-// A simple LowLevelAlloc based resizable vector with inlined storage
-// for a few elements.  T must be a plain type since constructor
-// and destructor are not run on elements of type T managed by Vec.
-template <typename T>
-class Vec {
- public:
-  Vec() { Init(); }
-  ~Vec() { Discard(); }
-
-  void clear() {
-    Discard();
-    Init();
-  }
-
-  bool empty() const { return size_ == 0; }
-  uint32_t size() const { return size_; }
-  T* begin() { return ptr_; }
-  T* end() { return ptr_ + size_; }
-  const T& operator[](uint32_t i) const { return ptr_[i]; }
-  T& operator[](uint32_t i) { return ptr_[i]; }
-  const T& back() const { return ptr_[size_-1]; }
-  void pop_back() { size_--; }
-
-  void push_back(const T& v) {
-    if (size_ == capacity_) Grow(size_ + 1);
-    ptr_[size_] = v;
-    size_++;
-  }
-
-  void resize(uint32_t n) {
-    if (n > capacity_) Grow(n);
-    size_ = n;
-  }
-
-  void fill(const T& val) {
-    for (uint32_t i = 0; i < size(); i++) {
-      ptr_[i] = val;
-    }
-  }
-
-  // Guarantees src is empty at end.
-  // Provided for the hash table resizing code below.
-  void MoveFrom(Vec<T>* src) {
-    if (src->ptr_ == src->space_) {
-      // Need to actually copy
-      resize(src->size_);
-      std::copy(src->ptr_, src->ptr_ + src->size_, ptr_);
-      src->size_ = 0;
-    } else {
-      Discard();
-      ptr_ = src->ptr_;
-      size_ = src->size_;
-      capacity_ = src->capacity_;
-      src->Init();
-    }
-  }
-
- private:
-  T* ptr_;
-  T space_[kInline];
-  uint32_t size_;
-  uint32_t capacity_;
-
-  void Init() {
-    ptr_ = space_;
-    size_ = 0;
-    capacity_ = kInline;
-  }
-
-  void Discard() {
-    if (ptr_ != space_) base_internal::LowLevelAlloc::Free(ptr_);
-  }
-
-  void Grow(uint32_t n) {
-    while (capacity_ < n) {
-      capacity_ *= 2;
-    }
-    size_t request = static_cast<size_t>(capacity_) * sizeof(T);
-    T* copy = static_cast<T*>(
-        base_internal::LowLevelAlloc::AllocWithArena(request, arena));
-    std::copy(ptr_, ptr_ + size_, copy);
-    Discard();
-    ptr_ = copy;
-  }
-
-  Vec(const Vec&) = delete;
-  Vec& operator=(const Vec&) = delete;
-};
-
-// A hash set of non-negative int32_t that uses Vec for its underlying storage.
-class NodeSet {
- public:
-  NodeSet() { Init(); }
-
-  void clear() { Init(); }
-  bool contains(int32_t v) const { return table_[FindIndex(v)] == v; }
-
-  bool insert(int32_t v) {
-    uint32_t i = FindIndex(v);
-    if (table_[i] == v) {
-      return false;
-    }
-    if (table_[i] == kEmpty) {
-      // Only inserting over an empty cell increases the number of occupied
-      // slots.
-      occupied_++;
-    }
-    table_[i] = v;
-    // Double when 75% full.
-    if (occupied_ >= table_.size() - table_.size()/4) Grow();
-    return true;
-  }
-
-  void erase(uint32_t v) {
-    uint32_t i = FindIndex(v);
-    if (static_cast<uint32_t>(table_[i]) == v) {
-      table_[i] = kDel;
-    }
-  }
-
-  // Iteration: is done via HASH_FOR_EACH
-  // Example:
-  //    HASH_FOR_EACH(elem, node->out) { ... }
-#define HASH_FOR_EACH(elem, eset) \
-  for (int32_t elem, _cursor = 0; (eset).Next(&_cursor, &elem); )
-  bool Next(int32_t* cursor, int32_t* elem) {
-    while (static_cast<uint32_t>(*cursor) < table_.size()) {
-      int32_t v = table_[*cursor];
-      (*cursor)++;
-      if (v >= 0) {
-        *elem = v;
-        return true;
-      }
-    }
-    return false;
-  }
-
- private:
-  enum : int32_t { kEmpty = -1, kDel = -2 };
-  Vec<int32_t> table_;
-  uint32_t occupied_;     // Count of non-empty slots (includes deleted slots)
-
-  static uint32_t Hash(uint32_t a) { return a * 41; }
-
-  // Return index for storing v.  May return an empty index or deleted index
-  int FindIndex(int32_t v) const {
-    // Search starting at hash index.
-    const uint32_t mask = table_.size() - 1;
-    uint32_t i = Hash(v) & mask;
-    int deleted_index = -1;  // If >= 0, index of first deleted element we see
-    while (true) {
-      int32_t e = table_[i];
-      if (v == e) {
-        return i;
-      } else if (e == kEmpty) {
-        // Return any previously encountered deleted slot.
-        return (deleted_index >= 0) ? deleted_index : i;
-      } else if (e == kDel && deleted_index < 0) {
-        // Keep searching since v might be present later.
-        deleted_index = i;
-      }
-      i = (i + 1) & mask;  // Linear probing; quadratic is slightly slower.
-    }
-  }
-
-  void Init() {
-    table_.clear();
-    table_.resize(kInline);
-    table_.fill(kEmpty);
-    occupied_ = 0;
-  }
-
-  void Grow() {
-    Vec<int32_t> copy;
-    copy.MoveFrom(&table_);
-    occupied_ = 0;
-    table_.resize(copy.size() * 2);
-    table_.fill(kEmpty);
-
-    for (const auto& e : copy) {
-      if (e >= 0) insert(e);
-    }
-  }
-
-  NodeSet(const NodeSet&) = delete;
-  NodeSet& operator=(const NodeSet&) = delete;
-};
-
-// We encode a node index and a node version in GraphId.  The version
-// number is incremented when the GraphId is freed which automatically
-// invalidates all copies of the GraphId.
-
-inline GraphId MakeId(int32_t index, uint32_t version) {
-  GraphId g;
-  g.handle =
-      (static_cast<uint64_t>(version) << 32) | static_cast<uint32_t>(index);
-  return g;
-}
-
-inline int32_t NodeIndex(GraphId id) {
-  return static_cast<uint32_t>(id.handle & 0xfffffffful);
-}
-
-inline uint32_t NodeVersion(GraphId id) {
-  return static_cast<uint32_t>(id.handle >> 32);
-}
-
-struct Node {
-  int32_t rank;               // rank number assigned by Pearce-Kelly algorithm
-  uint32_t version;           // Current version number
-  int32_t next_hash;          // Next entry in hash table
-  bool visited;               // Temporary marker used by depth-first-search
-  uintptr_t masked_ptr;       // User-supplied pointer
-  NodeSet in;                 // List of immediate predecessor nodes in graph
-  NodeSet out;                // List of immediate successor nodes in graph
-  int priority;               // Priority of recorded stack trace.
-  int nstack;                 // Depth of recorded stack trace.
-  void* stack[40];            // stack[0,nstack-1] holds stack trace for node.
-};
-
-// Hash table for pointer to node index lookups.
-class PointerMap {
- public:
-  explicit PointerMap(const Vec<Node*>* nodes) : nodes_(nodes) {
-    table_.fill(-1);
-  }
-
-  int32_t Find(void* ptr) {
-    auto masked = base_internal::HidePtr(ptr);
-    for (int32_t i = table_[Hash(ptr)]; i != -1;) {
-      Node* n = (*nodes_)[i];
-      if (n->masked_ptr == masked) return i;
-      i = n->next_hash;
-    }
-    return -1;
-  }
-
-  void Add(void* ptr, int32_t i) {
-    int32_t* head = &table_[Hash(ptr)];
-    (*nodes_)[i]->next_hash = *head;
-    *head = i;
-  }
-
-  int32_t Remove(void* ptr) {
-    // Advance through linked list while keeping track of the
-    // predecessor slot that points to the current entry.
-    auto masked = base_internal::HidePtr(ptr);
-    for (int32_t* slot = &table_[Hash(ptr)]; *slot != -1; ) {
-      int32_t index = *slot;
-      Node* n = (*nodes_)[index];
-      if (n->masked_ptr == masked) {
-        *slot = n->next_hash;  // Remove n from linked list
-        n->next_hash = -1;
-        return index;
-      }
-      slot = &n->next_hash;
-    }
-    return -1;
-  }
-
- private:
-  // Number of buckets in hash table for pointer lookups.
-  static constexpr uint32_t kHashTableSize = 8171;  // should be prime
-
-  const Vec<Node*>* nodes_;
-  std::array<int32_t, kHashTableSize> table_;
-
-  static uint32_t Hash(void* ptr) {
-    return reinterpret_cast<uintptr_t>(ptr) % kHashTableSize;
-  }
-};
-
-}  // namespace
-
-struct GraphCycles::Rep {
-  Vec<Node*> nodes_;
-  Vec<int32_t> free_nodes_;  // Indices for unused entries in nodes_
-  PointerMap ptrmap_;
-
-  // Temporary state.
-  Vec<int32_t> deltaf_;  // Results of forward DFS
-  Vec<int32_t> deltab_;  // Results of backward DFS
-  Vec<int32_t> list_;    // All nodes to reprocess
-  Vec<int32_t> merged_;  // Rank values to assign to list_ entries
-  Vec<int32_t> stack_;   // Emulates recursion stack for depth-first searches
-
-  Rep() : ptrmap_(&nodes_) {}
-};
-
-static Node* FindNode(GraphCycles::Rep* rep, GraphId id) {
-  Node* n = rep->nodes_[NodeIndex(id)];
-  return (n->version == NodeVersion(id)) ? n : nullptr;
-}
-
-GraphCycles::GraphCycles() {
-  InitArenaIfNecessary();
-  rep_ = new (base_internal::LowLevelAlloc::AllocWithArena(sizeof(Rep), arena))
-      Rep;
-}
-
-GraphCycles::~GraphCycles() {
-  for (auto* node : rep_->nodes_) {
-    node->Node::~Node();
-    base_internal::LowLevelAlloc::Free(node);
-  }
-  rep_->Rep::~Rep();
-  base_internal::LowLevelAlloc::Free(rep_);
-}
-
-bool GraphCycles::CheckInvariants() const {
-  Rep* r = rep_;
-  NodeSet ranks;  // Set of ranks seen so far.
-  for (uint32_t x = 0; x < r->nodes_.size(); x++) {
-    Node* nx = r->nodes_[x];
-    void* ptr = base_internal::UnhidePtr<void>(nx->masked_ptr);
-    if (ptr != nullptr && static_cast<uint32_t>(r->ptrmap_.Find(ptr)) != x) {
-      ABSL_RAW_LOG(FATAL, "Did not find live node in hash table %u %p", x, ptr);
-    }
-    if (nx->visited) {
-      ABSL_RAW_LOG(FATAL, "Did not clear visited marker on node %u", x);
-    }
-    if (!ranks.insert(nx->rank)) {
-      ABSL_RAW_LOG(FATAL, "Duplicate occurrence of rank %d", nx->rank);
-    }
-    HASH_FOR_EACH(y, nx->out) {
-      Node* ny = r->nodes_[y];
-      if (nx->rank >= ny->rank) {
-        ABSL_RAW_LOG(FATAL, "Edge %u->%d has bad rank assignment %d->%d", x, y,
-                     nx->rank, ny->rank);
-      }
-    }
-  }
-  return true;
-}
-
-GraphId GraphCycles::GetId(void* ptr) {
-  int32_t i = rep_->ptrmap_.Find(ptr);
-  if (i != -1) {
-    return MakeId(i, rep_->nodes_[i]->version);
-  } else if (rep_->free_nodes_.empty()) {
-    Node* n =
-        new (base_internal::LowLevelAlloc::AllocWithArena(sizeof(Node), arena))
-            Node;
-    n->version = 1;  // Avoid 0 since it is used by InvalidGraphId()
-    n->visited = false;
-    n->rank = rep_->nodes_.size();
-    n->masked_ptr = base_internal::HidePtr(ptr);
-    n->nstack = 0;
-    n->priority = 0;
-    rep_->nodes_.push_back(n);
-    rep_->ptrmap_.Add(ptr, n->rank);
-    return MakeId(n->rank, n->version);
-  } else {
-    // Preserve preceding rank since the set of ranks in use must be
-    // a permutation of [0,rep_->nodes_.size()-1].
-    int32_t r = rep_->free_nodes_.back();
-    rep_->free_nodes_.pop_back();
-    Node* n = rep_->nodes_[r];
-    n->masked_ptr = base_internal::HidePtr(ptr);
-    n->nstack = 0;
-    n->priority = 0;
-    rep_->ptrmap_.Add(ptr, r);
-    return MakeId(r, n->version);
-  }
-}
-
-void GraphCycles::RemoveNode(void* ptr) {
-  int32_t i = rep_->ptrmap_.Remove(ptr);
-  if (i == -1) {
-    return;
-  }
-  Node* x = rep_->nodes_[i];
-  HASH_FOR_EACH(y, x->out) {
-    rep_->nodes_[y]->in.erase(i);
-  }
-  HASH_FOR_EACH(y, x->in) {
-    rep_->nodes_[y]->out.erase(i);
-  }
-  x->in.clear();
-  x->out.clear();
-  x->masked_ptr = base_internal::HidePtr<void>(nullptr);
-  if (x->version == std::numeric_limits<uint32_t>::max()) {
-    // Cannot use x any more
-  } else {
-    x->version++;  // Invalidates all copies of node.
-    rep_->free_nodes_.push_back(i);
-  }
-}
-
-void* GraphCycles::Ptr(GraphId id) {
-  Node* n = FindNode(rep_, id);
-  return n == nullptr ? nullptr
-                      : base_internal::UnhidePtr<void>(n->masked_ptr);
-}
-
-bool GraphCycles::HasNode(GraphId node) {
-  return FindNode(rep_, node) != nullptr;
-}
-
-bool GraphCycles::HasEdge(GraphId x, GraphId y) const {
-  Node* xn = FindNode(rep_, x);
-  return xn && FindNode(rep_, y) && xn->out.contains(NodeIndex(y));
-}
-
-void GraphCycles::RemoveEdge(GraphId x, GraphId y) {
-  Node* xn = FindNode(rep_, x);
-  Node* yn = FindNode(rep_, y);
-  if (xn && yn) {
-    xn->out.erase(NodeIndex(y));
-    yn->in.erase(NodeIndex(x));
-    // No need to update the rank assignment since a previous valid
-    // rank assignment remains valid after an edge deletion.
-  }
-}
-
-static bool ForwardDFS(GraphCycles::Rep* r, int32_t n, int32_t upper_bound);
-static void BackwardDFS(GraphCycles::Rep* r, int32_t n, int32_t lower_bound);
-static void Reorder(GraphCycles::Rep* r);
-static void Sort(const Vec<Node*>&, Vec<int32_t>* delta);
-static void MoveToList(
-    GraphCycles::Rep* r, Vec<int32_t>* src, Vec<int32_t>* dst);
-
-bool GraphCycles::InsertEdge(GraphId idx, GraphId idy) {
-  Rep* r = rep_;
-  const int32_t x = NodeIndex(idx);
-  const int32_t y = NodeIndex(idy);
-  Node* nx = FindNode(r, idx);
-  Node* ny = FindNode(r, idy);
-  if (nx == nullptr || ny == nullptr) return true;  // Expired ids
-
-  if (nx == ny) return false;  // Self edge
-  if (!nx->out.insert(y)) {
-    // Edge already exists.
-    return true;
-  }
-
-  ny->in.insert(x);
-
-  if (nx->rank <= ny->rank) {
-    // New edge is consistent with existing rank assignment.
-    return true;
-  }
-
-  // Current rank assignments are incompatible with the new edge.  Recompute.
-  // We only need to consider nodes that fall in the range [ny->rank,nx->rank].
-  if (!ForwardDFS(r, y, nx->rank)) {
-    // Found a cycle.  Undo the insertion and tell caller.
-    nx->out.erase(y);
-    ny->in.erase(x);
-    // Since we do not call Reorder() on this path, clear any visited
-    // markers left by ForwardDFS.
-    for (const auto& d : r->deltaf_) {
-      r->nodes_[d]->visited = false;
-    }
-    return false;
-  }
-  BackwardDFS(r, x, ny->rank);
-  Reorder(r);
-  return true;
-}
-
-static bool ForwardDFS(GraphCycles::Rep* r, int32_t n, int32_t upper_bound) {
-  // Avoid recursion since stack space might be limited.
-  // We instead keep a stack of nodes to visit.
-  r->deltaf_.clear();
-  r->stack_.clear();
-  r->stack_.push_back(n);
-  while (!r->stack_.empty()) {
-    n = r->stack_.back();
-    r->stack_.pop_back();
-    Node* nn = r->nodes_[n];
-    if (nn->visited) continue;
-
-    nn->visited = true;
-    r->deltaf_.push_back(n);
-
-    HASH_FOR_EACH(w, nn->out) {
-      Node* nw = r->nodes_[w];
-      if (nw->rank == upper_bound) {
-        return false;  // Cycle
-      }
-      if (!nw->visited && nw->rank < upper_bound) {
-        r->stack_.push_back(w);
-      }
-    }
-  }
-  return true;
-}
-
-static void BackwardDFS(GraphCycles::Rep* r, int32_t n, int32_t lower_bound) {
-  r->deltab_.clear();
-  r->stack_.clear();
-  r->stack_.push_back(n);
-  while (!r->stack_.empty()) {
-    n = r->stack_.back();
-    r->stack_.pop_back();
-    Node* nn = r->nodes_[n];
-    if (nn->visited) continue;
-
-    nn->visited = true;
-    r->deltab_.push_back(n);
-
-    HASH_FOR_EACH(w, nn->in) {
-      Node* nw = r->nodes_[w];
-      if (!nw->visited && lower_bound < nw->rank) {
-        r->stack_.push_back(w);
-      }
-    }
-  }
-}
-
-static void Reorder(GraphCycles::Rep* r) {
-  Sort(r->nodes_, &r->deltab_);
-  Sort(r->nodes_, &r->deltaf_);
-
-  // Adds contents of delta lists to list_ (backwards deltas first).
-  r->list_.clear();
-  MoveToList(r, &r->deltab_, &r->list_);
-  MoveToList(r, &r->deltaf_, &r->list_);
-
-  // Produce sorted list of all ranks that will be reassigned.
-  r->merged_.resize(r->deltab_.size() + r->deltaf_.size());
-  std::merge(r->deltab_.begin(), r->deltab_.end(),
-             r->deltaf_.begin(), r->deltaf_.end(),
-             r->merged_.begin());
-
-  // Assign the ranks in order to the collected list.
-  for (uint32_t i = 0; i < r->list_.size(); i++) {
-    r->nodes_[r->list_[i]]->rank = r->merged_[i];
-  }
-}
-
-static void Sort(const Vec<Node*>& nodes, Vec<int32_t>* delta) {
-  struct ByRank {
-    const Vec<Node*>* nodes;
-    bool operator()(int32_t a, int32_t b) const {
-      return (*nodes)[a]->rank < (*nodes)[b]->rank;
-    }
-  };
-  ByRank cmp;
-  cmp.nodes = &nodes;
-  std::sort(delta->begin(), delta->end(), cmp);
-}
-
-static void MoveToList(
-    GraphCycles::Rep* r, Vec<int32_t>* src, Vec<int32_t>* dst) {
-  for (auto& v : *src) {
-    int32_t w = v;
-    v = r->nodes_[w]->rank;         // Replace v entry with its rank
-    r->nodes_[w]->visited = false;  // Prepare for future DFS calls
-    dst->push_back(w);
-  }
-}
-
-int GraphCycles::FindPath(GraphId idx, GraphId idy, int max_path_len,
-                          GraphId path[]) const {
-  Rep* r = rep_;
-  if (FindNode(r, idx) == nullptr || FindNode(r, idy) == nullptr) return 0;
-  const int32_t x = NodeIndex(idx);
-  const int32_t y = NodeIndex(idy);
-
-  // Forward depth first search starting at x until we hit y.
-  // As we descend into a node, we push it onto the path.
-  // As we leave a node, we remove it from the path.
-  int path_len = 0;
-
-  NodeSet seen;
-  r->stack_.clear();
-  r->stack_.push_back(x);
-  while (!r->stack_.empty()) {
-    int32_t n = r->stack_.back();
-    r->stack_.pop_back();
-    if (n < 0) {
-      // Marker to indicate that we are leaving a node
-      path_len--;
-      continue;
-    }
-
-    if (path_len < max_path_len) {
-      path[path_len] = MakeId(n, rep_->nodes_[n]->version);
-    }
-    path_len++;
-    r->stack_.push_back(-1);  // Will remove tentative path entry
-
-    if (n == y) {
-      return path_len;
-    }
-
-    HASH_FOR_EACH(w, r->nodes_[n]->out) {
-      if (seen.insert(w)) {
-        r->stack_.push_back(w);
-      }
-    }
-  }
-
-  return 0;
-}
-
-bool GraphCycles::IsReachable(GraphId x, GraphId y) const {
-  return FindPath(x, y, 0, nullptr) > 0;
-}
-
-void GraphCycles::UpdateStackTrace(GraphId id, int priority,
-                                   int (*get_stack_trace)(void** stack, int)) {
-  Node* n = FindNode(rep_, id);
-  if (n == nullptr || n->priority >= priority) {
-    return;
-  }
-  n->nstack = (*get_stack_trace)(n->stack, ABSL_ARRAYSIZE(n->stack));
-  n->priority = priority;
-}
-
-int GraphCycles::GetStackTrace(GraphId id, void*** ptr) {
-  Node* n = FindNode(rep_, id);
-  if (n == nullptr) {
-    *ptr = nullptr;
-    return 0;
-  } else {
-    *ptr = n->stack;
-    return n->nstack;
-  }
-}
-
-}  // namespace synchronization_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_LOW_LEVEL_ALLOC_MISSING