DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (66531295716a)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsAutoPtr_h
#define nsAutoPtr_h

#include "nsCOMPtr.h"
#include "mozilla/RefPtr.h"
#include "mozilla/TypeTraits.h"

#include "nsCycleCollectionNoteChild.h"
#include "mozilla/MemoryReporting.h"

/*****************************************************************************/

// template <class T> class nsAutoPtrGetterTransfers;

template <class T>
class nsAutoPtr {
 private:
  static_assert(!mozilla::IsScalar<T>::value,
                "If you are using "
                "nsAutoPtr to hold an array, use UniquePtr<T[]> instead");

  void** begin_assignment() {
    assign(0);
    return reinterpret_cast<void**>(&mRawPtr);
  }

  void assign(T* aNewPtr) {
    T* oldPtr = mRawPtr;

    if (aNewPtr && aNewPtr == oldPtr) {
      MOZ_CRASH("Logic flaw in the caller");
    }

    mRawPtr = aNewPtr;
    delete oldPtr;
  }

  // |class Ptr| helps us prevent implicit "copy construction"
  // through |operator T*() const| from a |const nsAutoPtr<T>|
  // because two implicit conversions in a row aren't allowed.
  // It still allows assignment from T* through implicit conversion
  // from |T*| to |nsAutoPtr<T>::Ptr|
  class Ptr {
   public:
    MOZ_IMPLICIT Ptr(T* aPtr) : mPtr(aPtr) {}

    operator T*() const { return mPtr; }

   private:
    T* MOZ_NON_OWNING_REF mPtr;
  };

 private:
  T* MOZ_OWNING_REF mRawPtr;

 public:
  typedef T element_type;

  ~nsAutoPtr() { delete mRawPtr; }

  // Constructors

  nsAutoPtr()
      : mRawPtr(0)
  // default constructor
  {}

  MOZ_IMPLICIT nsAutoPtr(Ptr aRawPtr)
      : mRawPtr(aRawPtr)
  // construct from a raw pointer (of the right type)
  {}

  // This constructor shouldn't exist; we should just use the &&
  // constructor.
  nsAutoPtr(nsAutoPtr<T>& aSmartPtr)
      : mRawPtr(aSmartPtr.forget())
  // Construct by transferring ownership from another smart pointer.
  {}

  template <typename I>
  MOZ_IMPLICIT nsAutoPtr(nsAutoPtr<I>& aSmartPtr)
      : mRawPtr(aSmartPtr.forget())
  // Construct by transferring ownership from another smart pointer.
  {}

  nsAutoPtr(nsAutoPtr<T>&& aSmartPtr)
      : mRawPtr(aSmartPtr.forget())
  // Construct by transferring ownership from another smart pointer.
  {}

  template <typename I>
  MOZ_IMPLICIT nsAutoPtr(nsAutoPtr<I>&& aSmartPtr)
      : mRawPtr(aSmartPtr.forget())
  // Construct by transferring ownership from another smart pointer.
  {}

  // Assignment operators

  nsAutoPtr<T>& operator=(T* aRhs)
  // assign from a raw pointer (of the right type)
  {
    assign(aRhs);
    return *this;
  }

  nsAutoPtr<T>& operator=(nsAutoPtr<T>& aRhs)
  // assign by transferring ownership from another smart pointer.
  {
    assign(aRhs.forget());
    return *this;
  }

  template <typename I>
  nsAutoPtr<T>& operator=(nsAutoPtr<I>& aRhs)
  // assign by transferring ownership from another smart pointer.
  {
    assign(aRhs.forget());
    return *this;
  }

  nsAutoPtr<T>& operator=(nsAutoPtr<T>&& aRhs) {
    assign(aRhs.forget());
    return *this;
  }

  template <typename I>
  nsAutoPtr<T>& operator=(nsAutoPtr<I>&& aRhs) {
    assign(aRhs.forget());
    return *this;
  }

  // Other pointer operators

  T* get() const
  /*
    Prefer the implicit conversion provided automatically by
    |operator T*() const|.  Use |get()| _only_ to resolve
    ambiguity.
  */
  {
    return mRawPtr;
  }

  operator T*() const
  /*
    ...makes an |nsAutoPtr| act like its underlying raw pointer
    type  whenever it is used in a context where a raw pointer
    is expected.  It is this operator that makes an |nsAutoPtr|
    substitutable for a raw pointer.

    Prefer the implicit use of this operator to calling |get()|,
    except where necessary to resolve ambiguity.
  */
  {
    return get();
  }

  T* forget() {
    T* temp = mRawPtr;
    mRawPtr = 0;
    return temp;
  }

  T* operator->() const {
    MOZ_ASSERT(mRawPtr != 0,
               "You can't dereference a NULL nsAutoPtr with operator->().");
    return get();
  }

  template <typename R, typename... Args>
  class Proxy {
    typedef R (T::*member_function)(Args...);
    T* mRawPtr;
    member_function mFunction;

   public:
    Proxy(T* aRawPtr, member_function aFunction)
        : mRawPtr(aRawPtr), mFunction(aFunction) {}
    template <typename... ActualArgs>
    R operator()(ActualArgs&&... aArgs) {
      return ((*mRawPtr).*mFunction)(std::forward<ActualArgs>(aArgs)...);
    }
  };

  template <typename R, typename C, typename... Args>
  Proxy<R, Args...> operator->*(R (C::*aFptr)(Args...)) const {
    MOZ_ASSERT(mRawPtr != 0,
               "You can't dereference a NULL nsAutoPtr with operator->*().");
    return Proxy<R, Args...>(get(), aFptr);
  }

  nsAutoPtr<T>* get_address()
  // This is not intended to be used by clients.  See |address_of|
  // below.
  {
    return this;
  }

  const nsAutoPtr<T>* get_address() const
  // This is not intended to be used by clients.  See |address_of|
  // below.
  {
    return this;
  }

 public:
  T& operator*() const {
    MOZ_ASSERT(mRawPtr != 0,
               "You can't dereference a NULL nsAutoPtr with operator*().");
    return *get();
  }

  T** StartAssignment() {
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
    return reinterpret_cast<T**>(begin_assignment());
#else
    assign(0);
    return reinterpret_cast<T**>(&mRawPtr);
#endif
  }
};

template <class T>
inline nsAutoPtr<T>* address_of(nsAutoPtr<T>& aPtr) {
  return aPtr.get_address();
}

template <class T>
inline const nsAutoPtr<T>* address_of(const nsAutoPtr<T>& aPtr) {
  return aPtr.get_address();
}

template <class T>
class nsAutoPtrGetterTransfers
/*
  ...

  This class is designed to be used for anonymous temporary objects in the
  argument list of calls that return COM interface pointers, e.g.,

    nsAutoPtr<IFoo> fooP;
    ...->GetTransferedPointer(getter_Transfers(fooP))

  DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE.  Use |getter_Transfers()| instead.

  When initialized with a |nsAutoPtr|, as in the example above, it returns
  a |void**|, a |T**|, or an |nsISupports**| as needed, that the
  outer call (|GetTransferedPointer| in this case) can fill in.

  This type should be a nested class inside |nsAutoPtr<T>|.
*/
{
 public:
  explicit nsAutoPtrGetterTransfers(nsAutoPtr<T>& aSmartPtr)
      : mTargetSmartPtr(aSmartPtr) {
    // nothing else to do
  }

  operator void**() {
    return reinterpret_cast<void**>(mTargetSmartPtr.StartAssignment());
  }

  operator T**() { return mTargetSmartPtr.StartAssignment(); }

  T*& operator*() { return *(mTargetSmartPtr.StartAssignment()); }

 private:
  nsAutoPtr<T>& mTargetSmartPtr;
};

template <class T>
inline nsAutoPtrGetterTransfers<T> getter_Transfers(nsAutoPtr<T>& aSmartPtr)
/*
  Used around a |nsAutoPtr| when
  ...makes the class |nsAutoPtrGetterTransfers<T>| invisible.
*/
{
  return nsAutoPtrGetterTransfers<T>(aSmartPtr);
}

// Comparing two |nsAutoPtr|s

template <class T, class U>
inline bool operator==(const nsAutoPtr<T>& aLhs, const nsAutoPtr<U>& aRhs) {
  return static_cast<const T*>(aLhs.get()) == static_cast<const U*>(aRhs.get());
}

template <class T, class U>
inline bool operator!=(const nsAutoPtr<T>& aLhs, const nsAutoPtr<U>& aRhs) {
  return static_cast<const T*>(aLhs.get()) != static_cast<const U*>(aRhs.get());
}

// Comparing an |nsAutoPtr| to a raw pointer

template <class T, class U>
inline bool operator==(const nsAutoPtr<T>& aLhs, const U* aRhs) {
  return static_cast<const T*>(aLhs.get()) == static_cast<const U*>(aRhs);
}

template <class T, class U>
inline bool operator==(const U* aLhs, const nsAutoPtr<T>& aRhs) {
  return static_cast<const U*>(aLhs) == static_cast<const T*>(aRhs.get());
}

template <class T, class U>
inline bool operator!=(const nsAutoPtr<T>& aLhs, const U* aRhs) {
  return static_cast<const T*>(aLhs.get()) != static_cast<const U*>(aRhs);
}

template <class T, class U>
inline bool operator!=(const U* aLhs, const nsAutoPtr<T>& aRhs) {
  return static_cast<const U*>(aLhs) != static_cast<const T*>(aRhs.get());
}

template <class T, class U>
inline bool operator==(const nsAutoPtr<T>& aLhs, U* aRhs) {
  return static_cast<const T*>(aLhs.get()) == const_cast<const U*>(aRhs);
}

template <class T, class U>
inline bool operator==(U* aLhs, const nsAutoPtr<T>& aRhs) {
  return const_cast<const U*>(aLhs) == static_cast<const T*>(aRhs.get());
}

template <class T, class U>
inline bool operator!=(const nsAutoPtr<T>& aLhs, U* aRhs) {
  return static_cast<const T*>(aLhs.get()) != const_cast<const U*>(aRhs);
}

template <class T, class U>
inline bool operator!=(U* aLhs, const nsAutoPtr<T>& aRhs) {
  return const_cast<const U*>(aLhs) != static_cast<const T*>(aRhs.get());
}

// Comparing an |nsAutoPtr| to |nullptr|

template <class T>
inline bool operator==(const nsAutoPtr<T>& aLhs, decltype(nullptr)) {
  return aLhs.get() == nullptr;
}

template <class T>
inline bool operator==(decltype(nullptr), const nsAutoPtr<T>& aRhs) {
  return nullptr == aRhs.get();
}

template <class T>
inline bool operator!=(const nsAutoPtr<T>& aLhs, decltype(nullptr)) {
  return aLhs.get() != nullptr;
}

template <class T>
inline bool operator!=(decltype(nullptr), const nsAutoPtr<T>& aRhs) {
  return nullptr != aRhs.get();
}

/*****************************************************************************/

#endif  // !defined(nsAutoPtr_h)