Security-59306.11.20.tar.gz

[apple/security.git] / OSX / utilities / SecCFRelease.h

diff --git a/OSX/utilities/SecCFRelease.h b/OSX/utilities/SecCFRelease.h
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+/*
+ * Copyright (c) 2012,2014 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+#ifndef _SECCFRELEASE_H_
+#define _SECCFRELEASE_H_
+
+#include <CoreFoundation/CFBase.h>
+
+// Retains its argument unless it's NULL.  Always returns its argument.
+#define CFRetainSafe(CF) ({ __typeof__(CF) _cf = (CF); _cf ? (CFRetain(_cf), _cf) : _cf; })
+
+// Releases CF unless it's NULL.  Always returns NULL, for your convenience and constructs like:
+// return CFReleaseSafe(foo);
+#define CFReleaseSafe(CF) ({ __typeof__(CF) _cf = (CF); (_cf ? (CFRelease(_cf), ((__typeof__(CF))0)) : _cf); })
+
+
+#if 0
+// Objective-C defines &<bridged-object> to be a constant reference, which we can't assign to, so we
+// suffer multiple evaluations of arguments (avoid using it with side-effects) to make things compile well
+
+#define CFTransferRetained(VAR1, VAR2) ({ CFReleaseSafe(VAR1); VAR1 = VAR2; VAR2 = ((__typeof__(VAR2))0)); })
+
+#define CFAssignRetained(VAR, CF) ({ CFReleaseSafe(VAR); VAR1 = CF; CF = ((__typeof__(CF))0)); })
+
+#define CFRetainAssign(VAR,CF) ({ CFReleaseSafe(VAR); VAR = CFRetainSafe(CF); })
+
+#define CFReleaseNull(CF) ({ CFReleaseSafe(CF); CF = ((__typeof__(CF))0)); })
+
+#else
+
+// Assume VAR1 is NULL or an already retained object and CFReleaseSafe VAR1 and assigns VAR2 to VAR1. Returns VAR2.
+#define CFTransferRetained(VAR1, VAR2) ({ \
+    __typeof__(VAR1) *const _pvar1 = &(VAR1); \
+    __typeof__(VAR2) *const _pvar2 = &(VAR2); \
+    __typeof__(VAR2) _var2 = *_pvar2; \
+    (*_pvar2) = NULL; \
+    (*_pvar1) = *_pvar1 ? (CFRelease(*_pvar1), _var2) : _var2; \
+})
+
+
+// Assume CF is NULL or an already retained object and CFReleaseSafe VAR and assigns CF to VAR. Returns CF.
+#define CFAssignRetained(VAR,CF) ({ \
+    __typeof__(VAR) *const _pvar = &(VAR); \
+    __typeof__(CF) _cf = (CF); \
+    (*_pvar) = *_pvar ? (CFRelease(*_pvar), _cf) : _cf; \
+})
+
+// CFRetainSafe CF and CFReleaseSafe VAR and assigns CF to VAR. Returns CF.
+#define CFRetainAssign(VAR,CF) ({ \
+    __typeof__(VAR) *const _pvar = &(VAR); \
+    __typeof__(CF) _cf = (CF); \
+    (((*_pvar) == _cf) ? _cf \
+    : ((*_pvar) = (_cf ? (CFRetain(_cf), (*_pvar ? (CFRelease(*_pvar), _cf) : _cf)) \
+                   : (CFRelease(*_pvar), ((__typeof__(_cf))0))))); \
+})
+
+
+// Assigns NULL to CF. Releases the value stored at CF unless it was NULL.  Always returns NULL, for your convenience
+#define CFReleaseNull(CF) ({ __typeof__(CF) *const _pcf = &(CF), _cf = *_pcf; (_cf ? (*_pcf) = ((__typeof__(CF))0), (CFRelease(_cf), ((__typeof__(CF))0)) : _cf); })
+
+#endif
+
+#endif /* _SECCFRELEASE_H_ */