//
//  GTMObjC2Runtime.h
//
//  Copyright 2007-2008 Google Inc.
//
//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
//  use this file except in compliance with the License.  You may obtain a copy
//  of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
//  License for the specific language governing permissions and limitations under
//  the License.
//

#import <objc/objc-api.h>
#import <objc/objc-auto.h>
#import "GTMDefines.h"

// These functions exist for code that we want to compile on both the < 10.5
// sdks and on the >= 10.5 sdks without warnings. It basically reimplements
// certain parts of the objc2 runtime in terms of the objc1 runtime. It is not
// a complete implementation as I've only implemented the routines I know we
// use. Feel free to add more as necessary.
// These functions are not documented because they conform to the documentation
// for the ObjC2 Runtime.

#if OBJC_API_VERSION >= 2  // Only have optional and req'd keywords in ObjC2.
#define AT_OPTIONAL @optional
#define AT_REQUIRED @required
#else
#define AT_OPTIONAL
#define AT_REQUIRED
#endif

// The file objc-runtime.h was moved to runtime.h and in Leopard, objc-runtime.h
// was just a wrapper around runtime.h. For the iPhone SDK, this objc-runtime.h
// is removed in the iPhoneOS2.0 SDK.
//
// The |Object| class was removed in the iPhone2.0 SDK too.
#if GTM_IPHONE_SDK
#import <objc/runtime.h>
#else
#import <objc/objc-runtime.h>
#import <objc/Object.h>
#endif

#import <libkern/OSAtomic.h>

#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
#import "objc/Protocol.h"

OBJC_EXPORT Class object_getClass(id obj);
OBJC_EXPORT const char *class_getName(Class cls);
OBJC_EXPORT BOOL class_conformsToProtocol(Class cls, Protocol *protocol);
OBJC_EXPORT BOOL class_respondsToSelector(Class cls, SEL sel);
OBJC_EXPORT Class class_getSuperclass(Class cls);
OBJC_EXPORT Method *class_copyMethodList(Class cls, unsigned int *outCount);
OBJC_EXPORT SEL method_getName(Method m);
OBJC_EXPORT void method_exchangeImplementations(Method m1, Method m2);
OBJC_EXPORT IMP method_getImplementation(Method method);
OBJC_EXPORT IMP method_setImplementation(Method method, IMP imp);
OBJC_EXPORT struct objc_method_description protocol_getMethodDescription(Protocol *p,
                                                                         SEL aSel,
                                                                         BOOL isRequiredMethod,
                                                                         BOOL isInstanceMethod);

// If building for 10.4 but using the 10.5 SDK, don't include these.
#if MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_5
// atomics
// On Leopard these are GC aware
// Intentionally did not include the non-barrier versions, because I couldn't
// come up with a case personally where you wouldn't want to use the
// barrier versions.
GTM_INLINE bool OSAtomicCompareAndSwapPtrBarrier(void *predicate,
                                                 void *replacement,
                                                 void * volatile *theValue) {
#if defined(__LP64__) && __LP64__
  return OSAtomicCompareAndSwap64Barrier((int64_t)predicate,
                                         (int64_t)replacement,
                                         (int64_t *)theValue);
#else  // defined(__LP64__) && __LP64__
  return OSAtomicCompareAndSwap32Barrier((int32_t)predicate,
                                         (int32_t)replacement,
                                         (int32_t *)theValue);
#endif  // defined(__LP64__) && __LP64__
}

#endif  // MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_5
#endif  // MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5

#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5

GTM_INLINE BOOL objc_atomicCompareAndSwapGlobalBarrier(id predicate,
                                                       id replacement,
                                                       volatile id *objectLocation) {
  return OSAtomicCompareAndSwapPtrBarrier(predicate,
                                          replacement,
                                          (void * volatile *)objectLocation);
}
GTM_INLINE BOOL objc_atomicCompareAndSwapInstanceVariableBarrier(id predicate,
                                                                 id replacement,
                                                                 volatile id *objectLocation) {
  return OSAtomicCompareAndSwapPtrBarrier(predicate,
                                          replacement,
                                          (void * volatile *)objectLocation);
}
#endif  // MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5