OSX/utilities/src/SecCFRelease.h

   1 /*
   2  * Copyright (c) 2012,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 #ifndef _SECCFRELEASE_H_
  26 #define _SECCFRELEASE_H_
  27
  28 #include <CoreFoundation/CFBase.h>
  29
  30 // Retains its argument unless it's NULL.  Always returns its argument.
  31 #define CFRetainSafe(CF) ({ __typeof__(CF) _cf = (CF); _cf ? (CFRetain(_cf), _cf) : _cf; })
  32
  33 // Assume VAR1 is NULL or an already retained object and CFReleaseSafe VAR1 and assigns VAR2 to VAR1. Returns VAR2.
  34 #define CFTransferRetained(VAR1, VAR2) ({ \
  35     __typeof__(VAR1) *const _pvar1 = &(VAR1); \
  36     __typeof__(VAR2) *const _pvar2 = &(VAR2); \
  37     __typeof__(VAR2) _var2 = *_pvar2; \
  38     (*_pvar2) = NULL; \
  39     (*_pvar1) = *_pvar1 ? (CFRelease(*_pvar1), _var2) : _var2; \
  40 })
  41
  42 // Assume CF is NULL or an already retained object and CFReleaseSafe VAR and assigns CF to VAR. Returns CF.
  43 #define CFAssignRetained(VAR,CF) ({ \
  44     __typeof__(VAR) *const _pvar = &(VAR); \
  45     __typeof__(CF) _cf = (CF); \
  46     (*_pvar) = *_pvar ? (CFRelease(*_pvar), _cf) : _cf; \
  47 })
  48
  49 // CFRetainSafe CF and CFReleaseSafe VAR and assigns CF to VAR. Returns CF.
  50 #define CFRetainAssign(VAR,CF) ({ \
  51     __typeof__(VAR) *const _pvar = &(VAR); \
  52     __typeof__(CF) _cf = (CF); \
  53     (((*_pvar) == _cf) ? _cf \
  54     : ((*_pvar) = (_cf ? (CFRetain(_cf), (*_pvar ? (CFRelease(*_pvar), _cf) : _cf)) \
  55                    : (CFRelease(*_pvar), ((__typeof__(_cf))0))))); \
  56 })
  57
  58 // Releases CF unless it's NULL.  Always returns NULL, for your convenience and constructs like:
  59 // return CFReleaseSafe(foo);
  60 #define CFReleaseSafe(CF) ({ __typeof__(CF) _cf = (CF); (_cf ? (CFRelease(_cf), ((__typeof__(CF))0)) : _cf); })
  61
  62 // Assigns NULL to CF. Releases the value stored at CF unless it was NULL.  Always returns NULL, for your convenience
  63 #define CFReleaseNull(CF) ({ __typeof__(CF) *const _pcf = &(CF), _cf = *_pcf; (_cf ? (*_pcf) = ((__typeof__(CF))0), (CFRelease(_cf), ((__typeof__(CF))0)) : _cf); })
  64
  65
  66 #endif /* _SECCFRELEASE_H_ */