os/object.h

   1 /*
   2  * Copyright (c) 2011-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 #ifndef __OS_OBJECT__
  22 #define __OS_OBJECT__
  23
  24 #ifdef __APPLE__
  25 #include <Availability.h>
  26 #include <TargetConditionals.h>
  27 #endif
  28 #ifndef __linux__
  29 #include <os/base.h>
  30 #else
  31 #include <os/linux_base.h>
  32 #endif
  33
  34 /*!
  35  * @header
  36  *
  37  * @preprocinfo
  38  * By default, libSystem objects such as GCD and XPC objects are declared as
  39  * Objective-C types when building with an Objective-C compiler. This allows
  40  * them to participate in ARC, in RR management by the Blocks runtime and in
  41  * leaks checking by the static analyzer, and enables them to be added to Cocoa
  42  * collections.
  43  *
  44  * NOTE: this requires explicit cancellation of dispatch sources and xpc
  45  *       connections whose handler blocks capture the source/connection object,
  46  *       resp. ensuring that such captures do not form retain cycles (e.g. by
  47  *       declaring the source as __weak).
  48  *
  49  * To opt-out of this default behavior, add -DOS_OBJECT_USE_OBJC=0 to your
  50  * compiler flags.
  51  *
  52  * This mode requires a platform with the modern Objective-C runtime, the
  53  * Objective-C GC compiler option to be disabled, and at least a Mac OS X 10.8
  54  * or iOS 6.0 deployment target.
  55  */
  56
  57 #ifndef OS_OBJECT_HAVE_OBJC_SUPPORT
  58 #if !defined(__OBJC__) || defined(__OBJC_GC__)
  59 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
  60 #elif !defined(TARGET_OS_MAC) || !TARGET_OS_MAC
  61 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
  62 #elif TARGET_OS_IOS && __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_6_0
  63 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
  64 #elif TARGET_OS_MAC && !TARGET_OS_IPHONE
  65 #  if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_8
  66 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
  67 #  elif defined(__i386__) && __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_12
  68 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
  69 #  else
  70 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 1
  71 #  endif
  72 #else
  73 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 1
  74 #endif
  75 #endif // OS_OBJECT_HAVE_OBJC_SUPPORT
  76
  77 #if OS_OBJECT_HAVE_OBJC_SUPPORT
  78 #ifndef OS_OBJECT_USE_OBJC
  79 #define OS_OBJECT_USE_OBJC 1
  80 #endif
  81 #elif defined(OS_OBJECT_USE_OBJC) && OS_OBJECT_USE_OBJC
  82 /* Unsupported platform for OS_OBJECT_USE_OBJC=1 */
  83 #undef OS_OBJECT_USE_OBJC
  84 #define OS_OBJECT_USE_OBJC 0
  85 #else
  86 #define OS_OBJECT_USE_OBJC 0
  87 #endif
  88
  89 #ifndef OS_OBJECT_SWIFT3
  90 #if defined(SWIFT_SDK_OVERLAY_DISPATCH_EPOCH) && \
  91                 SWIFT_SDK_OVERLAY_DISPATCH_EPOCH >= 2
  92 #define OS_OBJECT_SWIFT3 1
  93 #else
  94 #define OS_OBJECT_SWIFT3 0
  95 #endif // SWIFT_SDK_OVERLAY_DISPATCH_EPOCH >= 2
  96 #endif // OS_OBJECT_SWIFT3
  97
  98 #if OS_OBJECT_USE_OBJC
  99 #import <objc/NSObject.h>
 100 #if __has_attribute(objc_independent_class)
 101 #define OS_OBJC_INDEPENDENT_CLASS __attribute__((objc_independent_class))
 102 #endif // __has_attribute(objc_independent_class)
 103 #ifndef OS_OBJC_INDEPENDENT_CLASS
 104 #define OS_OBJC_INDEPENDENT_CLASS
 105 #endif
 106 #define OS_OBJECT_CLASS(name) OS_##name
 107 #define OS_OBJECT_DECL_PROTOCOL(name, ...) \
 108                 @protocol OS_OBJECT_CLASS(name) __VA_ARGS__ \
 109                 @end
 110 #define OS_OBJECT_CLASS_IMPLEMENTS_PROTOCOL_IMPL(name, proto) \
 111                 @interface name () <proto> \
 112                 @end
 113 #define OS_OBJECT_CLASS_IMPLEMENTS_PROTOCOL(name, proto) \
 114                 OS_OBJECT_CLASS_IMPLEMENTS_PROTOCOL_IMPL( \
 115                                 OS_OBJECT_CLASS(name), OS_OBJECT_CLASS(proto))
 116 #define OS_OBJECT_DECL_IMPL(name, ...) \
 117                 OS_OBJECT_DECL_PROTOCOL(name, __VA_ARGS__) \
 118                 typedef NSObject<OS_OBJECT_CLASS(name)> \
 119                                 * OS_OBJC_INDEPENDENT_CLASS name##_t
 120 #define OS_OBJECT_DECL_BASE(name, ...) \
 121                 @interface OS_OBJECT_CLASS(name) : __VA_ARGS__ \
 122                 - (instancetype)init OS_SWIFT_UNAVAILABLE("Unavailable in Swift"); \
 123                 @end
 124 #define OS_OBJECT_DECL_IMPL_CLASS(name, ...) \
 125                 OS_OBJECT_DECL_BASE(name, ## __VA_ARGS__) \
 126                 typedef OS_OBJECT_CLASS(name) \
 127                                 * OS_OBJC_INDEPENDENT_CLASS name##_t
 128 #define OS_OBJECT_DECL(name, ...) \
 129                 OS_OBJECT_DECL_IMPL(name, <NSObject>)
 130 #define OS_OBJECT_DECL_SUBCLASS(name, super) \
 131                 OS_OBJECT_DECL_IMPL(name, <OS_OBJECT_CLASS(super)>)
 132 #if __has_attribute(ns_returns_retained)
 133 #define OS_OBJECT_RETURNS_RETAINED __attribute__((__ns_returns_retained__))
 134 #else
 135 #define OS_OBJECT_RETURNS_RETAINED
 136 #endif
 137 #if __has_attribute(ns_consumed)
 138 #define OS_OBJECT_CONSUMED __attribute__((__ns_consumed__))
 139 #else
 140 #define OS_OBJECT_CONSUMED
 141 #endif
 142 #if __has_feature(objc_arc)
 143 #define OS_OBJECT_BRIDGE __bridge
 144 #define OS_WARN_RESULT_NEEDS_RELEASE
 145 #else
 146 #define OS_OBJECT_BRIDGE
 147 #define OS_WARN_RESULT_NEEDS_RELEASE OS_WARN_RESULT
 148 #endif
 149 #if __has_attribute(objc_runtime_visible) && \
 150                 ((defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && \
 151                 __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_12) || \
 152                 (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && \
 153                 !defined(__TV_OS_VERSION_MIN_REQUIRED) && \
 154                 !defined(__WATCH_OS_VERSION_MIN_REQUIRED) && \
 155                 __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_10_0) || \
 156                 (defined(__TV_OS_VERSION_MIN_REQUIRED) && \
 157                 __TV_OS_VERSION_MIN_REQUIRED < __TVOS_10_0) || \
 158                 (defined(__WATCH_OS_VERSION_MIN_REQUIRED) && \
 159                 __WATCH_OS_VERSION_MIN_REQUIRED < __WATCHOS_3_0))
 160 /*
 161  * To provide backward deployment of ObjC objects in Swift on pre-10.12
 162  * SDKs, OS_object classes can be marked as OS_OBJECT_OBJC_RUNTIME_VISIBLE.
 163  * When compiling with a deployment target earlier than OS X 10.12 (iOS 10.0,
 164  * tvOS 10.0, watchOS 3.0) the Swift compiler will only refer to this type at
 165  * runtime (using the ObjC runtime).
 166  */
 167 #define OS_OBJECT_OBJC_RUNTIME_VISIBLE __attribute__((objc_runtime_visible))
 168 #else
 169 #define OS_OBJECT_OBJC_RUNTIME_VISIBLE
 170 #endif
 171 #ifndef OS_OBJECT_USE_OBJC_RETAIN_RELEASE
 172 #if defined(__clang_analyzer__)
 173 #define OS_OBJECT_USE_OBJC_RETAIN_RELEASE 1
 174 #elif __has_feature(objc_arc) && !OS_OBJECT_SWIFT3
 175 #define OS_OBJECT_USE_OBJC_RETAIN_RELEASE 1
 176 #else
 177 #define OS_OBJECT_USE_OBJC_RETAIN_RELEASE 0
 178 #endif
 179 #endif
 180 #if OS_OBJECT_SWIFT3
 181 #define OS_OBJECT_DECL_SWIFT(name) \
 182                 OS_EXPORT OS_OBJECT_OBJC_RUNTIME_VISIBLE \
 183                 OS_OBJECT_DECL_IMPL_CLASS(name, NSObject)
 184 #define OS_OBJECT_DECL_SUBCLASS_SWIFT(name, super) \
 185                 OS_EXPORT OS_OBJECT_OBJC_RUNTIME_VISIBLE \
 186                 OS_OBJECT_DECL_IMPL_CLASS(name, OS_OBJECT_CLASS(super))
 187 OS_EXPORT OS_OBJECT_OBJC_RUNTIME_VISIBLE
 188 OS_OBJECT_DECL_BASE(object, NSObject);
 189 #endif // OS_OBJECT_SWIFT3
 190 #else
 191 /*! @parseOnly */
 192 #define OS_OBJECT_RETURNS_RETAINED
 193 /*! @parseOnly */
 194 #define OS_OBJECT_CONSUMED
 195 /*! @parseOnly */
 196 #define OS_OBJECT_BRIDGE
 197 /*! @parseOnly */
 198 #define OS_WARN_RESULT_NEEDS_RELEASE OS_WARN_RESULT
 199 /*! @parseOnly */
 200 #define OS_OBJECT_OBJC_RUNTIME_VISIBLE
 201 #define OS_OBJECT_USE_OBJC_RETAIN_RELEASE 0
 202 #endif
 203
 204 #if OS_OBJECT_SWIFT3
 205 #define OS_OBJECT_DECL_CLASS(name) \
 206                 OS_OBJECT_DECL_SUBCLASS_SWIFT(name, object)
 207 #elif OS_OBJECT_USE_OBJC
 208 #define OS_OBJECT_DECL_CLASS(name) \
 209                 OS_OBJECT_DECL(name)
 210 #else
 211 #define OS_OBJECT_DECL_CLASS(name) \
 212                 typedef struct name##_s *name##_t
 213 #endif
 214
 215 #define OS_OBJECT_GLOBAL_OBJECT(type, object) ((OS_OBJECT_BRIDGE type)&(object))
 216
 217 __BEGIN_DECLS
 218
 219 /*!
 220  * @function os_retain
 221  *
 222  * @abstract
 223  * Increment the reference count of an os_object.
 224  *
 225  * @discussion
 226  * On a platform with the modern Objective-C runtime this is exactly equivalent
 227  * to sending the object the -[retain] message.
 228  *
 229  * @param object
 230  * The object to retain.
 231  *
 232  * @result
 233  * The retained object.
 234  */
 235 __OSX_AVAILABLE_STARTING(__MAC_10_10,__IPHONE_8_0)
 236 OS_EXPORT OS_SWIFT_UNAVAILABLE("Can't be used with ARC")
 237 void*
 238 os_retain(void *object);
 239 #if OS_OBJECT_USE_OBJC
 240 #undef os_retain
 241 #define os_retain(object) [object retain]
 242 #endif
 243
 244 /*!
 245  * @function os_release
 246  *
 247  * @abstract
 248  * Decrement the reference count of a os_object.
 249  *
 250  * @discussion
 251  * On a platform with the modern Objective-C runtime this is exactly equivalent
 252  * to sending the object the -[release] message.
 253  *
 254  * @param object
 255  * The object to release.
 256  */
 257 __OSX_AVAILABLE_STARTING(__MAC_10_10,__IPHONE_8_0)
 258 OS_EXPORT
 259 void OS_SWIFT_UNAVAILABLE("Can't be used with ARC")
 260 os_release(void *object);
 261 #if OS_OBJECT_USE_OBJC
 262 #undef os_release
 263 #define os_release(object) [object release]
 264 #endif
 265
 266 __END_DECLS
 267
 268 #endif