From 0e9f0f3e5f16a45951423a1229af42dc2fd798c3 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 10 Dec 2012 15:25:21 -0500
Subject: [PATCH] Fix atomic ops on iOS

Patch from John Ralls.
---
 src/hb-atomic-private.hh | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/hb-atomic-private.hh b/src/hb-atomic-private.hh
index a4d6cbeb3..111d7a0f4 100644
--- a/src/hb-atomic-private.hh
+++ b/src/hb-atomic-private.hh
@@ -69,15 +69,17 @@ typedef long hb_atomic_int_t;
 #elif !defined(HB_NO_MT) && defined(__APPLE__)
 
 #include <libkern/OSAtomic.h>
+#ifdef __MAC_OS_X_MIN_REQUIRED
 #include <AvailabilityMacros.h>
+#elif defined(__IPHONE_OS_MIN_REQUIRED)
+#include <Availability.h>
+#endif
 
 typedef int32_t hb_atomic_int_t;
 #define hb_atomic_int_add(AI, V)	(OSAtomicAdd32Barrier ((V), &(AI)) - (V))
 
 #define hb_atomic_ptr_get(P)		(OSMemoryBarrier (), (void *) *(P))
-#if (MAX_OS_X_VERSION_MAX_ALLOWED >= MAX_OS_X_VERSION_10_5)
-/* XXX We should expand the above check to also allow iPhone OS >= 2.0, but I can't find any info re
- * AvailabilityMacros.h for iOS.  Is it even available there? */
+#if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_VERSION_MIN_REQUIRED >= 20100)
 #define hb_atomic_ptr_cmpexch(P,O,N)	OSAtomicCompareAndSwapPtrBarrier ((void *) (O), (void *) (N), (void **) (P))
 #else
 #if __ppc64__ || __x86_64__