1 // Copyright (c) 2008 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef BASE_FOUNDATION_UTILS_MAC_H_
6 #define BASE_FOUNDATION_UTILS_MAC_H_
7 #pragma once
8
9 #include <CoreFoundation/CoreFoundation.h>
10 #import <Foundation/Foundation.h>
11
12 // CFTypeRefToNSObjectAutorelease transfers ownership of a Core Foundation
13 // object (one derived from CFTypeRef) to the Foundation memory management
14 // system. In a traditional managed-memory environment, cf_object is
15 // autoreleased and returned as an NSObject. In a garbage-collected
16 // environment, cf_object is marked as eligible for garbage collection.
17 //
18 // This function should only be used to convert a concrete CFTypeRef type to
19 // its equivalent "toll-free bridged" NSObject subclass, for example,
20 // converting a CFStringRef to NSString.
21 //
22 // By calling this function, callers relinquish any ownership claim to
23 // cf_object. In a managed-memory environment, the object's ownership will be
24 // managed by the innermost NSAutoreleasePool, so after this function returns,
25 // callers should not assume that cf_object is valid any longer than the
26 // returned NSObject.
CFTypeRefToNSObjectAutorelease(CFTypeRef cf_object)27 static inline id CFTypeRefToNSObjectAutorelease(CFTypeRef cf_object) {
28 // When GC is on, NSMakeCollectable marks cf_object for GC and autorelease
29 // is a no-op.
30 //
31 // In the traditional GC-less environment, NSMakeCollectable is a no-op,
32 // and cf_object is autoreleased, balancing out the caller's ownership claim.
33 //
34 // NSMakeCollectable returns nil when used on a NULL object.
35 return [NSMakeCollectable(cf_object) autorelease];
36 }
37
38 #endif // BASE_FOUNDATION_UTILS_MAC_H_
39