xnu-2050.24.15

EXTERNAL_HEADERS/Availability.h

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+/*
+ * Copyright (c) 2007-2011 by 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 __AVAILABILITY__
+#define __AVAILABILITY__
+ /*     
+    These macros are for use in OS header files. They enable function prototypes
+    and Objective-C methods to be tagged with the OS version in which they
+    were first available; and, if applicable, the OS version in which they 
+    became deprecated.  
+     
+    The desktop Mac OS X and the iPhone OS X each have different version numbers.
+    The __OSX_AVAILABLE_STARTING() macro allows you to specify both the desktop
+    and phone OS version numbers.  For instance:
+        __OSX_AVAILABLE_STARTING(__MAC_10_2,__IPHONE_2_0)
+    means the function/method was first available on Mac OS X 10.2 on the desktop
+    and first available in OS X 2.0 on the iPhone.
+    
+    If a function is available on one platform, but not the other a _NA (not
+    applicable) parameter is used.  For instance:
+            __OSX_AVAILABLE_STARTING(__MAC_10_3,__IPHONE_NA)
+    means that the function/method was first available on Mac OS X 10.3, and it
+    currently not implemented on the iPhone.
+
+    At some point, a function/method may be deprecated.  That means Apple
+    recommends applications stop using the function, either because there is a 
+    better replacement or the functionality is being phased out.  Deprecated
+    functions/methods can be tagged with a __OSX_AVAILABLE_BUT_DEPRECATED()
+    macro which specifies the OS version where the function became available
+    as well as the OS version in which it became deprecated.  For instance:
+        __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_0,__MAC_10_5,__IPHONE_NA,__IPHONE_NA)
+    means that the function/method was introduced in Mac OS X 10.0, then
+    became deprecated beginning in Mac OS X 10.5.  On the iPhone the function 
+    has never been available.  
+    
+    For these macros to function properly, a program must specify the OS version range 
+    it is targeting.  The min OS version is specified as an option to the compiler:
+    -mmacosx-version-min=10.x when building for Mac OS X, and -miphoneos-version-min=x.x
+    when building for the iPhone.  The upper bound for the OS version is rarely needed,
+    but it can be set on the command line via: -D__MAC_OS_X_VERSION_MAX_ALLOWED=10xx for
+    Mac OS X and __IPHONE_OS_VERSION_MAX_ALLOWED = 1xxx for iPhone.  
+    
+    Examples:
+
+        A function available in Mac OS X 10.5 and later, but not on the phone:
+        
+            extern void mymacfunc() __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_NA);
+
+
+        An Objective-C method in Mac OS X 10.5 and later, but not on the phone:
+        
+            @interface MyClass : NSObject
+            -(void) mymacmethod __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_NA);
+            @end
+
+        
+        An enum available on the phone, but not available on Mac OS X:
+        
+            #if __IPHONE_OS_VERSION_MIN_REQUIRED
+                enum { myEnum = 1 };
+            #endif
+           Note: this works when targeting the Mac OS X platform because 
+           __IPHONE_OS_VERSION_MIN_REQUIRED is undefined which evaluates to zero. 
+        
+
+        An enum with values added in different iPhoneOS versions:
+		
+			enum {
+			    myX  = 1,	// Usable on iPhoneOS 2.1 and later
+			    myY  = 2,	// Usable on iPhoneOS 3.0 and later
+			    myZ  = 3,	// Usable on iPhoneOS 3.0 and later
+				...
+		      Note: you do not want to use #if with enumeration values
+			  when a client needs to see all values at compile time
+			  and use runtime logic to only use the viable values.
+			  
+
+    It is also possible to use the *_VERSION_MIN_REQUIRED in source code to make one
+    source base that can be compiled to target a range of OS versions.  It is best
+    to not use the _MAC_* and __IPHONE_* macros for comparisons, but rather their values.
+    That is because you might get compiled on an old OS that does not define a later
+    OS version macro, and in the C preprocessor undefined values evaluate to zero
+    in expresssions, which could cause the #if expression to evaluate in an unexpected
+    way.
+    
+        #ifdef __MAC_OS_X_VERSION_MIN_REQUIRED
+            // code only compiled when targeting Mac OS X and not iPhone
+            // note use of 1050 instead of __MAC_10_5
+            #if __MAC_OS_X_VERSION_MIN_REQUIRED < 1050
+                // code in here might run on pre-Leopard OS
+            #else
+                // code here can assume Leopard or later
+            #endif
+        #endif
+
+
+*/
+
+#define __MAC_10_0      1000
+#define __MAC_10_1      1010
+#define __MAC_10_2      1020
+#define __MAC_10_3      1030
+#define __MAC_10_4      1040
+#define __MAC_10_5      1050
+#define __MAC_10_6      1060
+#define __MAC_10_7      1070
+#define __MAC_10_8      1080
+#define __MAC_NA        9999   /* not available */
+
+#define __IPHONE_2_0     20000
+#define __IPHONE_2_1     20100
+#define __IPHONE_2_2     20200
+#define __IPHONE_3_0     30000
+#define __IPHONE_3_1     30100
+#define __IPHONE_3_2     30200
+#define __IPHONE_4_0     40000
+#define __IPHONE_4_1     40100
+#define __IPHONE_4_2     40200
+#define __IPHONE_4_3     40300
+#define __IPHONE_5_0     50000
+#define __IPHONE_5_1     50100
+#define __IPHONE_NA      99999  /* not available */
+
+#include <AvailabilityInternal.h>
+
+
+#ifdef __IPHONE_OS_VERSION_MIN_REQUIRED
+    #define __OSX_AVAILABLE_STARTING(_osx, _ios) __AVAILABILITY_INTERNAL##_ios
+    #define __OSX_AVAILABLE_BUT_DEPRECATED(_osxIntro, _osxDep, _iosIntro, _iosDep) \
+                                                    __AVAILABILITY_INTERNAL##_iosIntro##_DEP##_iosDep
+
+#elif defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
+    #define __OSX_AVAILABLE_STARTING(_osx, _ios) __AVAILABILITY_INTERNAL##_osx
+    #define __OSX_AVAILABLE_BUT_DEPRECATED(_osxIntro, _osxDep, _iosIntro, _iosDep) \
+                                                    __AVAILABILITY_INTERNAL##_osxIntro##_DEP##_osxDep
+
+#else
+    #define __OSX_AVAILABLE_STARTING(_osx, _ios)
+    #define __OSX_AVAILABLE_BUT_DEPRECATED(_osxIntro, _osxDep, _iosIntro, _iosDep) 
+#endif
+
+
+#endif /* __AVAILABILITY__ */