iOS之Xcode运行时环境变量汇总说明

变量名	说明	解释
OBJC_PRINT_OPTIONS	list which options are set	输出OBJC已设置的选项
OBJC_PRINT_IMAGES	log image and library names as they are loaded	输出已load的image信息
OBJC_PRINT_LOAD_METHODS	log calls to class and category +load methods	打印 Class 及 Category 的 + (void)load 方法的调用信息
OBJC_PRINT_INITIALIZE_METHODS	log calls to class +initialize methods	打印 Class 的 + (void)initialize 的调用信息
OBJC_PRINT_RESOLVED_METHODS	log methods created by +resolveClassMethod and +resolveInstanceMethod	打印通过 +resolveClassMethod: 或 +resolveInstanceMethod: 生成的类方法
OBJC_PRINT_CLASS_SETUP	log progress of class and category setup	打印 Class 及 Category 的设置过程
OBJC_PRINT_PROTOCOL_SETUP	log progress of protocol setup	打印 Protocol 的设置过程
OBJC_PRINT_IVAR_SETUP	log processing of non-fragile ivars	打印 Ivar 的设置过程
OBJC_PRINT_VTABLE_SETUP	log processing of class vtables	打印 vtable 的设置过程
OBJC_PRINT_VTABLE_IMAGES	print vtable images showing overridden methods	打印 vtable 被覆盖的方法
OBJC_PRINT_CACHE_SETUP	log processing of method caches	打印方法缓存的设置过程
OBJC_PRINT_FUTURE_CLASSES	log use of future classes for toll-free bridging	打印从 CFType 无缝转换到 NSObject 将要使用的类(如 CFArrayRef 到 NSArray * )
OBJC_PRINT_GC	log some GC operations	打印一些垃圾回收操作
OBJC_PRINT_PREOPTIMIZATION	log preoptimization courtesy of dyld shared cache	打印 dyld 共享缓存优化前的问候语
OBJC_PRINT_CXX_CTORS	log calls to C++ ctors and dtors for instance variables	打印类实例中的 C++ 对象的构造与析构调用
OBJC_PRINT_EXCEPTIONS	log exception handling	打印异常处理
OBJC_PRINT_EXCEPTION_THROW	log backtrace of every objc_exception_throw()	打印所有异常抛出时的 Backtrace
OBJC_PRINT_ALT_HANDLERS	log processing of exception alt handlers	打印 alt 操作异常处理
OBJC_PRINT_REPLACED_METHODS	log methods replaced by category implementations	打印被 Category 替换的方法
OBJC_PRINT_DEPRECATION_WARNINGS	warn about calls to deprecated runtime functions	打印所有过时的方法调用
OBJC_PRINT_POOL_HIGHWATER	log high-water marks for autorelease pools	打印 autoreleasepool 高水位警告
OBJC_PRINT_CUSTOM_RR	log classes with un-optimized custom retain/release methods	打印含有未优化的自定义 retain/release 方法的类
OBJC_PRINT_CUSTOM_AWZ	log classes with un-optimized custom allocWithZone methods	打印含有未优化的自定义 allocWithZone 方法的类
OBJC_PRINT_RAW_ISA	log classes that require raw pointer isa fields	打印需要访问原始 isa 指针的类
OBJC_DEBUG_UNLOAD	warn about poorly-behaving bundles when unloaded	卸载有不良行为的 Bundle 时打印警告
OBJC_DEBUG_FRAGILE_SUPERCLASSES	warn about subclasses that may have been broken by subsequent changes to superclasses	当子类可能被对父类的修改破坏时打印警告
OBJC_DEBUG_FINALIZERS	warn about classes that implement -dealloc but not -finalize	警告实现了 -dealloc 却没有实现 -finalize 的类
OBJC_DEBUG_NIL_SYNC	warn about @synchronized(nil), which does no synchronization	警告 @synchronized(nil) 调用，这种情况不会加锁
OBJC_DEBUG_NONFRAGILE_IVARS	capriciously rearrange non-fragile ivars	打印突发地重新布置 non-fragile ivars 的行为
OBJC_DEBUG_ALT_HANDLERS	record more info about bad alt handler use	记录更多的 alt 操作错误信息
OBJC_DEBUG_MISSING_POOLS	warn about autorelease with no pool in place, which may be a leak	警告没有 pool 的情况下使用 autorelease，可能内存泄漏
OBJC_DEBUG_DUPLICATE_CLASSES	halt when multiple classes with the same name are present	当出现类重名时停机
OBJC_USE_INTERNAL_ZONE	allocate runtime data in a dedicated malloc zone	在一个专用的 malloc 区分配运行时数据
OBJC_DISABLE_GC	force GC OFF, even if the executable wants it on	强行关闭自动垃圾回收，即使可执行文件需要垃圾回收
OBJC_DISABLE_VTABLES	disable vtable dispatch	关闭 vtable 分发
OBJC_DISABLE_PREOPTIMIZATION	disable preoptimization courtesy of dyld shared cache	关闭 dyld 共享缓存优化前的问候语
OBJC_DISABLE_TAGGED_POINTERS	disable tagged pointer optimization of NSNumber et al.	关闭 NSNumber 等的 tagged pointer 优化
OBJC_DISABLE_NONPOINTER_ISA	disable non-pointer isa fields	关闭 non-pointer isa 字段的访问