/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include <memory>

namespace unique_ptr {

struct X {
  int field;
  int get() { return field; }
  void set(int value) { field = value; }
};

int empty_ptr_access() {
  std::unique_ptr<int> x;
  int* p = x.get(); // no dereference
  if (p) {
    return 1;
  }
  return 0;
}

int FN_empty_ptr_deref_bad() {
  std::unique_ptr<int> x;
  return *x;
}

int FN_empty_array_ptr_deref_bad() {
  std::unique_ptr<int[]> x;
  return x[0];
}

int FN_nullptr_ptr_deref_bad() {
  std::unique_ptr<int> x(nullptr);
  return *x;
}

int FN_nullptr_array_ptr_deref_bad() {
  std::unique_ptr<int[]> x(nullptr);
  return x[2];
}

int FN_empty_ptr_field_deref_bad() {
  std::unique_ptr<X> x;
  return x.get()->field;
}

int FN_empty_ptr_field_deref2_bad() {
  std::unique_ptr<X> x;
  return x->field;
}

int FN_empty_ptr_method_deref_bad() {
  std::unique_ptr<X> x;
  return x->get();
}

// FP is memory leak
int FN_FP_reset_ptr_null_deref_bad() {
  std::unique_ptr<int> x(new int);
  x.reset();
  return *x;
}

int FN_FP_reset_ptr_null_deref2_bad() {
  std::unique_ptr<int> x(new int);
  x.reset(new int);
  x.reset();
  return *x;
}

int FP_reset_ptr_deref_ok() {
  std::unique_ptr<int> x;
  x.reset(new int);
  return *x;
}

int FP_reset_ptr_deref2_ok() {
  std::unique_ptr<int> x;
  x.reset();
  x.reset(new int);
  return *x;
}

int FN_unique_ptr_copy_null_deref_bad() {
  std::unique_ptr<int> p1;
  std::unique_ptr<int> p2 = std::move(p1);
  return *p2;
}

int FN_unique_ptr_assign_null_deref_bad() {
  std::unique_ptr<int> p1(new int);
  std::unique_ptr<int> p2;
  p1 = std::move(p2);
  return *p1;
}

int FP_unique_ptr_move_deref_ok() {
  std::unique_ptr<int> p1(new int);
  std::unique_ptr<int> p2 = std::move(p1);
  return *p2;
}

int unique_ptr_assign_deref_ok() {
  std::unique_ptr<int> p1(new int);
  std::unique_ptr<int> p2;
  p2 = std::move(p1);
  p1.reset();
  return *p2;
}

int FN_unique_ptr_move_null_deref_bad() {
  std::unique_ptr<int> p1(new int);
  std::unique_ptr<int> p2 = std::move(p1);
  return *p1;
}

} // namespace unique_ptr

namespace unique_ptr_with_deleter {

/* This is just a compilation test */

template <class T>
class Pointer {
 public:
  /* No constructor with only one T* argument */
  /* implicit */ Pointer(std::nullptr_t = nullptr) noexcept {}
  Pointer(T* ptr, int n) noexcept {}

  friend bool operator==(Pointer a, Pointer b) noexcept { return true; }
  friend bool operator!=(Pointer a, Pointer b) noexcept { return true; }
  explicit operator bool() const noexcept { return true; }
  T* operator->() const noexcept { return get(); }
  T& operator*() const noexcept { return *get(); }
  T* get() const noexcept { return nullptr; }
};

template <class T>
struct Deleter {
  using pointer = Pointer<T>;

  void operator()(pointer ptr) const {}
};

template <class T>
using my_unique_ptr = std::unique_ptr<T, Deleter<T>>;

bool instantiate() {
  my_unique_ptr<int> p;
  my_unique_ptr<int[]> q;
  return p != nullptr && q != nullptr;
}
} // namespace unique_ptr_with_deleter