Issue #1677 - Part 3: Create shim definitions for V8-specific code in new regexp implementation

1 files changed, 356 insertions, 0 deletions

diff --git a/js/src/regexp/util/zone.h b/js/src/regexp/util/zone.h
new file mode 100644
index 000000000..32487f06a
--- /dev/null
+++ b/js/src/regexp/util/zone.h
@@ -0,0 +1,356 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UTIL_ZONE_H_
+#define V8_UTIL_ZONE_H_
+
+#include <list>
+#include <map>
+#include <set>
+#include <unordered_map>
+#include <vector>
+
+#include "ds/LifoAlloc.h"
+#include "regexp/util/vector.h"
+
+namespace v8 {
+namespace internal {
+
+// V8::Zone ~= LifoAlloc
+class Zone {
+ public:
+  Zone(size_t defaultChunkSize) : lifoAlloc_(defaultChunkSize) {
+    lifoAlloc_.setAsInfallibleByDefault();
+  }
+
+  void* New(size_t size) { return lifoAlloc_.alloc(size); }
+
+  void DeleteAll() { lifoAlloc_.freeAll(); }
+
+  // Returns true if the total memory allocated exceeds a threshold.
+  static const size_t kExcessLimit = 256 * 1024 * 1024;
+  bool excess_allocation() const {
+    return lifoAlloc_.peakSizeOfExcludingThis() > kExcessLimit;
+  }
+private:
+  js::LifoAlloc lifoAlloc_;
+};
+
+// Superclass for classes allocated in a Zone.
+// Origin: https://github.com/v8/v8/blob/7b3332844212d78ee87a9426f3a6f7f781a8fbfa/src/zone/zone.h#L138-L155
+class ZoneObject {
+ public:
+  // Allocate a new ZoneObject of 'size' bytes in the Zone.
+  void* operator new(size_t size, Zone* zone) { return zone->New(size); }
+
+  // Ideally, the delete operator should be private instead of
+  // public, but unfortunately the compiler sometimes synthesizes
+  // (unused) destructors for classes derived from ZoneObject, which
+  // require the operator to be visible. MSVC requires the delete
+  // operator to be public.
+
+  // ZoneObjects should never be deleted individually; use
+  // Zone::DeleteAll() to delete all zone objects in one go.
+  void operator delete(void*, size_t) { MOZ_CRASH("unreachable"); }
+  void operator delete(void* pointer, Zone* zone) { MOZ_CRASH("unreachable"); }
+};
+
+// ZoneLists are growable lists with constant-time access to the
+// elements. The list itself and all its elements are allocated in the
+// Zone. ZoneLists cannot be deleted individually; you can delete all
+// objects in the Zone by calling Zone::DeleteAll().
+// Used throughout irregexp.
+// Origin: https://github.com/v8/v8/blob/5e514a969376dc63517d575b062758efd36cd757/src/zone/zone.h#L173-L318
+// Inlines: https://github.com/v8/v8/blob/5e514a969376dc63517d575b062758efd36cd757/src/zone/zone-list-inl.h#L17-L155
+template <typename T>
+class ZoneList final {
+ public:
+  // Construct a new ZoneList with the given capacity; the length is
+  // always zero. The capacity must be non-negative.
+  ZoneList(int capacity, Zone* zone) { Initialize(capacity, zone); }
+  // Construct a new ZoneList from a std::initializer_list
+  ZoneList(std::initializer_list<T> list, Zone* zone) {
+    Initialize(static_cast<int>(list.size()), zone);
+    for (auto& i : list) Add(i, zone);
+  }
+  // Construct a new ZoneList by copying the elements of the given ZoneList.
+  ZoneList(const ZoneList<T>& other, Zone* zone) {
+    Initialize(other.length(), zone);
+    AddAll(other, zone);
+  }
+
+  void* operator new(size_t size, Zone* zone) { return zone->New(size); }
+
+  // Returns a reference to the element at index i. This reference is not safe
+  // to use after operations that can change the list's backing store
+  // (e.g. Add).
+  inline T& operator[](int i) const {
+    MOZ_ASSERT(0 < i);
+    MOZ_ASSERT(static_cast<unsigned>(i) < static_cast<unsigned>(length_));
+    return data_[i];
+  }
+  inline T& at(int i) const { return operator[](i); }
+  inline T& last() const { return at(length_ - 1); }
+  inline T& first() const { return at(0); }
+
+  using iterator = T*;
+  inline iterator begin() const { return &data_[0]; }
+  inline iterator end() const { return &data_[length_]; }
+
+  inline bool is_empty() const { return length_ == 0; }
+  inline int length() const { return length_; }
+  inline int capacity() const { return capacity_; }
+
+  Vector<T> ToVector() const { return Vector<T>(data_, length_); }
+  Vector<T> ToVector(int start, int length) const {
+    return Vector<T>(data_ + start, std::min(length_ - start, length));
+  }
+
+  Vector<const T> ToConstVector() const {
+    return Vector<const T>(data_, length_);
+  }
+
+  inline void Initialize(int capacity, Zone* zone) {
+    MOZ_ASSERT(capacity >= 0);
+    data_ = (capacity > 0) ? NewData(capacity, zone) : nullptr;
+    capacity_ = capacity;
+    length_ = 0;
+  }
+
+  // Adds a copy of the given 'element' to the end of the list,
+  // expanding the list if necessary.
+  void Add(const T& element, Zone* zone) {
+    if (length_ < capacity_) {
+      data_[length_++] = element;
+    } else {
+      ZoneList<T>::ResizeAdd(element, zone);
+    }
+  }
+  // Add all the elements from the argument list to this list.
+  void AddAll(const ZoneList<T>& other, Zone* zone) {
+    AddAll(other.ToVector(), zone);
+  }
+  // Add all the elements from the vector to this list.
+  void AddAll(const Vector<T>& other, Zone* zone) {
+    int result_length = length_ + other.length();
+    if (capacity_ < result_length) {
+      Resize(result_length, zone);
+    }
+    if (std::is_fundamental<T>()) {
+      memcpy(data_ + length_, other.begin(), sizeof(*data_) * other.length());
+    } else {
+      for (int i = 0; i < other.length(); i++) {
+	data_[length_ + i] = other.at(i);
+      }
+    }
+    length_ = result_length;
+  }
+
+  // Overwrites the element at the specific index.
+  void Set(int index, const T& element) {
+    MOZ_ASSERT(index >= 0 && index <= length_);
+    data_[index] = element;
+  }
+
+  // Removes the i'th element without deleting it even if T is a
+  // pointer type; moves all elements above i "down". Returns the
+  // removed element.  This function's complexity is linear in the
+  // size of the list.
+  T Remove(int i) {
+    T element = at(i);
+    length_--;
+    while (i < length_) {
+      data_[i] = data_[i + 1];
+      i++;
+    }
+    return element;
+  }
+
+  // Removes the last element without deleting it even if T is a
+  // pointer type. Returns the removed element.
+  inline T RemoveLast() { return Remove(length_ - 1); }
+
+  // Clears the list by freeing the storage memory. If you want to keep the
+  // memory, use Rewind(0) instead. Be aware, that even if T is a
+  // pointer type, clearing the list doesn't delete the entries.
+  inline void Clear() {
+    data_ = nullptr;
+    capacity_ = 0;
+    length_ = 0;
+  }
+
+  // Drops all but the first 'pos' elements from the list.
+  inline void Rewind(int pos) {
+    MOZ_ASSERT(0 <= pos && pos <= length_);
+    length_ = pos;
+  }
+
+  inline bool Contains(const T& elm) const {
+    for (int i = 0; i < length_; i++) {
+      if (data_[i] == elm) return true;
+    }
+    return false;
+  }
+
+  template <typename CompareFunction>
+  void StableSort(CompareFunction cmp, size_t s, size_t l) {
+    std::stable_sort(begin() + s, begin() + s + l,
+		     [cmp](const T& a, const T& b) { return cmp(&a, &b) < 0; });
+  }
+
+  void operator delete(void* pointer) { MOZ_CRASH("unreachable"); }
+  void operator delete(void* pointer, Zone* zone) { MOZ_CRASH("unreachable"); }
+
+ private:
+  T* data_;
+  int capacity_;
+  int length_;
+
+  inline T* NewData(int n, Zone* zone) {
+    return static_cast<T*>(zone->New(n * sizeof(T)));
+  }
+
+  // Increase the capacity of a full list, and add an element.
+  // List must be full already.
+  void ResizeAdd(const T& element, Zone* zone) {
+    MOZ_ASSERT(length_ >= capacity_);
+    // Grow the list capacity by 100%, but make sure to let it grow
+    // even when the capacity is zero (possible initial case).
+    int new_capacity = 1 + 2 * capacity_;
+    // Since the element reference could be an element of the list, copy
+    // it out of the old backing storage before resizing.
+    T temp = element;
+    Resize(new_capacity, zone);
+    data_[length_++] = temp;
+  }
+
+  // Resize the list.
+  void Resize(int new_capacity, Zone* zone) {
+    MOZ_ASSERT(length_ <= new_capacity);
+    T* new_data = NewData(new_capacity, zone);
+    if (length_ > 0) {
+      memcpy(new_data, data_, length_ * sizeof(T));
+    }
+    data_ = new_data;
+    capacity_ = new_capacity;
+  }
+
+  ZoneList& operator=(const ZoneList&) = delete;
+  ZoneList() = delete;
+  ZoneList(const ZoneList&) = delete;
+};
+
+// Origin: https://github.com/v8/v8/blob/5e514a969376dc63517d575b062758efd36cd757/src/zone/zone-allocator.h#L14-L77
+template <typename T>
+class ZoneAllocator {
+public:
+  using pointer = T*;
+  using const_pointer = const T*;
+  using reference = T&;
+  using const_reference = const T&;
+  using value_type = T;
+  using size_type = size_t;
+  using difference_type = ptrdiff_t;
+  template <class O>
+  struct rebind {
+    using other = ZoneAllocator<O>;
+  };
+
+  explicit ZoneAllocator(Zone* zone) : zone_(zone) {}
+  template <typename U>
+  ZoneAllocator(const ZoneAllocator<U>& other)
+      : ZoneAllocator<T>(other.zone_) {}
+  template <typename U>
+  friend class ZoneAllocator;
+
+  T* allocate(size_t n) { return static_cast<T*>(zone_->New(n * sizeof(T))); }
+  void deallocate(T* p, size_t) {}  // noop for zones
+
+  bool operator==(ZoneAllocator const& other) const {
+    return zone_ == other.zone_;
+  }
+  bool operator!=(ZoneAllocator const& other) const {
+    return zone_ != other.zone_;
+  }
+
+private:
+  Zone* zone_;
+};
+
+// Zone wrappers for std containers:
+// Origin: https://github.com/v8/v8/blob/5e514a969376dc63517d575b062758efd36cd757/src/zone/zone-containers.h#L25-L169
+
+// A wrapper subclass for std::vector to make it easy to construct one
+// that uses a zone allocator.
+// Used throughout irregexp
+template <typename T>
+class ZoneVector : public std::vector<T, ZoneAllocator<T>> {
+public:
+  ZoneVector(Zone* zone)
+    : std::vector<T, ZoneAllocator<T>>(ZoneAllocator<T>(zone)) {}
+
+  // Constructs a new vector and fills it with the contents of the range
+  // [first, last).
+  template <class Iter>
+  ZoneVector(Iter first, Iter last, Zone* zone)
+      : std::vector<T, ZoneAllocator<T>>(first, last, ZoneAllocator<T>(zone)) {}
+};
+
+// A wrapper subclass for std::list to make it easy to construct one
+// that uses a zone allocator.
+// Used in regexp-bytecode-peephole.cc
+template <typename T>
+class ZoneLinkedList : public std::list<T, ZoneAllocator<T>> {
+ public:
+  // Constructs an empty list.
+  explicit ZoneLinkedList(Zone* zone)
+      : std::list<T, ZoneAllocator<T>>(ZoneAllocator<T>(zone)) {}
+};
+
+// A wrapper subclass for std::set to make it easy to construct one that uses
+// a zone allocator.
+// Used in regexp-parser.cc
+template <typename K, typename Compare = std::less<K>>
+class ZoneSet : public std::set<K, Compare, ZoneAllocator<K>> {
+ public:
+  // Constructs an empty set.
+  explicit ZoneSet(Zone* zone)
+      : std::set<K, Compare, ZoneAllocator<K>>(Compare(),
+                                               ZoneAllocator<K>(zone)) {}
+};
+
+// A wrapper subclass for std::map to make it easy to construct one that uses
+// a zone allocator.
+// Used in regexp-bytecode-peephole.cc
+template <typename K, typename V, typename Compare = std::less<K>>
+class ZoneMap
+    : public std::map<K, V, Compare, ZoneAllocator<std::pair<const K, V>>> {
+ public:
+  // Constructs an empty map.
+  explicit ZoneMap(Zone* zone)
+      : std::map<K, V, Compare, ZoneAllocator<std::pair<const K, V>>>(
+            Compare(), ZoneAllocator<std::pair<const K, V>>(zone)) {}
+};
+
+// A wrapper subclass for std::unordered_map to make it easy to construct one
+// that uses a zone allocator.
+// Used in regexp-bytecode-peephole.cc
+template <typename K, typename V, typename Hash = std::hash<K>,
+          typename KeyEqual = std::equal_to<K>>
+class ZoneUnorderedMap
+    : public std::unordered_map<K, V, Hash, KeyEqual,
+                                ZoneAllocator<std::pair<const K, V>>> {
+ public:
+  // Constructs an empty map.
+  explicit ZoneUnorderedMap(Zone* zone, size_t bucket_count = 100)
+      : std::unordered_map<K, V, Hash, KeyEqual,
+                           ZoneAllocator<std::pair<const K, V>>>(
+            bucket_count, Hash(), KeyEqual(),
+            ZoneAllocator<std::pair<const K, V>>(zone)) {}
+};
+
+} // namespace internal
+} // namespace v8
+
+#endif  // V8_UTIL_FLAG_H_