gProcessInfo的声明：
struct dyld_all_image_infos* gProcessInfo = &dyld_all_image_infos;
struct dyld_all_image_infos { uint32_t version; /* 1 in Mac OS X 10.4 and 10.5 */ uint32_t infoArrayCount;#if defined(__cplusplus) && (BUILDING_LIBDYLD || BUILDING_DYLD) std::atomic<const struct dyld_image_info*> infoArray;#else const struct dyld_image_info* infoArray;#endif dyld_image_notifier notification; bool processDetachedFromSharedRegion; /* the following fields are only in version 2 (Mac OS X 10.6, iPhoneOS 2.0) and later */ bool libSystemInitialized; const struct mach_header* dyldImageLoadAddress; /* the following field is only in version 3 (Mac OS X 10.6, iPhoneOS 3.0) and later */ void* jitInfo; /* the following fields are only in version 5 (Mac OS X 10.6, iPhoneOS 3.0) and later */ const char* dyldVersion; const char* errorMessage; uintptr_t terminationFlags; /* the following field is only in version 6 (Mac OS X 10.6, iPhoneOS 3.1) and later */ void* coreSymbolicationShmPage; /* the following field is only in version 7 (Mac OS X 10.6, iPhoneOS 3.1) and later */ uintptr_t systemOrderFlag; /* the following field is only in version 8 (Mac OS X 10.7, iPhoneOS 3.1) and later */ uintptr_t uuidArrayCount; const struct dyld_uuid_info* uuidArray; /* only images not in dyld shared cache */ /* the following field is only in version 9 (Mac OS X 10.7, iOS 4.0) and later */ struct dyld_all_image_infos* dyldAllImageInfosAddress; /* the following field is only in version 10 (Mac OS X 10.7, iOS 4.2) and later */ uintptr_t initialImageCount; /* the following field is only in version 11 (Mac OS X 10.7, iOS 4.2) and later */ uintptr_t errorKind; const char* errorClientOfDylibPath; const char* errorTargetDylibPath; const char* errorSymbol; /* the following field is only in version 12 (Mac OS X 10.7, iOS 4.3) and later */ uintptr_t sharedCacheSlide; /* the following field is only in version 13 (Mac OS X 10.9, iOS 7.0) and later */ uint8_t sharedCacheUUID[16]; /* the following field is only in version 15 (macOS 10.12, iOS 10.0) and later */ uintptr_t sharedCacheBaseAddress;#if defined(__cplusplus) && (BUILDING_LIBDYLD || BUILDING_DYLD) // We want this to be atomic in libdyld so that we can see updates when we map it shared std::atomic<uint64_t> infoArrayChangeTimestamp;#else uint64_t infoArrayChangeTimestamp;#endif const char* dyldPath; mach_port_t notifyPorts[DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT];#if __LP64__ uintptr_t reserved[11-(DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT/2)];#else uintptr_t reserved[9-DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT];#endif // The following fields were added in version 18 (previously they were reserved padding fields) uint64_t sharedCacheFSID; uint64_t sharedCacheFSObjID; /* the following field is only in version 16 (macOS 10.13, iOS 11.0) and later */ uintptr_t compact_dyld_image_info_addr; size_t compact_dyld_image_info_size; uint32_t platform; // FIXME: really a dyld_platform_t, but those aren't exposed here. /* the following field is only in version 17 (macOS 10.16) and later */ uint32_t aotInfoCount; const struct dyld_aot_image_info* aotInfoArray; uint64_t aotInfoArrayChangeTimestamp; uintptr_t aotSharedCacheBaseAddress; uint8_t aotSharedCacheUUID[16];};
// 这是从dyldMain.cpp中提取出来的，以支持利用crt1.o的旧macOS应用步伐void APIs::runAllInitializersForMain(){ // 起首运行libSystem的初始化器 const_cast<Loader*>(this->libSystemLoader)->beginInitializers(*this); this->libSystemLoader->runInitializers(*this); gProcessInfo->libSystemInitialized = true; // 在运行libSystem的初始化器后，告诉objc在libSystem的子dylibs上运行任何+load方法 this->notifyObjCInit(this->libSystemLoader); // <rdar://problem/32209809> 调用'init'函数对全部已经init'ed的图像 (below libSystem) // 利用下标举行迭代，以便在+加载dloopen时数组不会在我们下面增长 for ( uint32_t i = 0; i != this->loaded.size(); ++i ) { const Loader* ldr = this->loaded; if ( ldr->analyzer(*this)->isDylib() && (strncmp(ldr->analyzer(*this)->installName(), "/usr/lib/system/lib", 19) == 0) ) { // 查抄安装名称而不是路径，以处置惩罚libsystem子dylibs的DYLD_LIBRARY_PATH覆盖 const_cast<Loader*>(ldr)->beginInitializers(*this); this->notifyObjCInit(ldr); } } // 自底向上运行全部其他初始化器，起首运行插入的dylib初始化器 // 利用下标举行迭代，以便在初始化式dloopen时数组不会在下面增长 for ( uint32_t i = 0; i != this->loaded.size(); ++i ) { const Loader* ldr = this->loaded; ldr->runInitializersBottomUpPlusUpwardLinks(*this); // stop as soon as we did main executable // normally this is first image, but if there are inserted N dylibs, it is Nth in the list if ( ldr->analyzer(*this)->isMainExecutable() ) break; }}
latform basePlatform; dyld3:
bjc_opt_t* objCCacheInfo; const SwiftOptimizationHeader* swiftCacheInfo; dyld3:
ermanentRanges*> _next = nullptr; uintptr_t _rangeCount = 0; Range _ranges[1]; }; // keep dlopen counts in a side table because it is rarely used, so it would waste space for each Loader object to have its own count field friend class Reaper; friend class RecursiveAutoLock; struct DlopenCount { const Loader* loader; uintptr_t refCount; }; // when a thread_local is first accessed on a thread, the thunk calls into dyld // to allocate the variables. The pthread_key is the index used to find the // TLV_Info which then describes how much to allocate and how to initalize that memory. struct TLV_Info { const MachOAnalyzer* ma; pthread_key_t key; uint32_t initialContentOffset; uint32_t initialContentSize; }; // used to record _tlv_atexit() entries to clean up on thread exit struct TLV_Terminator { TLV_TermFunc termFunc; void* objAddr; }; struct TLV_TerminatorList { TLV_TerminatorList* next = nullptr; uintptr_t count = 0; TLV_Terminator elements[7]; void reverseWalkChain(void (^work)(TLV_TerminatorList*)); }; struct RegisteredDOF { const Loader* ldr; int registrationID; }; struct MissingFlatSymbol { const Loader* ldr; const char* symbolName; uintptr_t* bindLoc; }; struct DynamicReference { const Loader* from; const Loader* to; }; struct HiddenCacheAddr { const void* cacheAddr; const void* replacementAddr; }; enum { kMaxBootTokenSize = 128 }; void appendInterposingTuples(const Loader* ldr, const uint8_t* dylibTuples, uint32_t tupleCount); void garbageCollectImages(); void garbageCollectInner(); void removeLoaders(const dyld3::Array<const Loader*>& loadersToRemove); void withTLVLock(void (^work)()); void setUpLogging(); void buildAppPrebuiltLoaderSetPath(bool createDirs); bool fileAlreadyHasBootToken(const char* path, const Array<uint8_t>& bootToken) const; bool buildBootToken(dyld3::Array<uint8_t>& bootToken) const; void loadAppPrebuiltLoaderSet(); bool allowOsProgramsToSaveUpdatedClosures() const; bool allowNonOsProgramsToSaveUpdatedClosures() const; void allocateProcessArrays(uintptr_t count); void checkHiddenCacheAddr(const Loader* t, const void* targetAddr, const char* symbolName, dyld3::OverflowSafeArray<HiddenCacheAddr>& hiddenCacheAddrs) const; _dyld_objc_notify_mapped _notifyObjCMapped = nullptr; _dyld_objc_notify_init _notifyObjCInit = nullptr; _dyld_objc_notify_unmapped _notifyObjCUnmapped = nullptr; Vector<NotifyFunc> _notifyAddImage; Vector<NotifyFunc> _notifyRemoveImage; Vector<LoadNotifyFunc> _notifyLoadImage; Vector<BulkLoadNotifier> _notifyBulkLoadImage; Vector<TLV_Info> _tlvInfos; Vector<RegisteredDOF> _loadersNeedingDOFUnregistration; Vector<MissingFlatSymbol> _missingFlatLazySymbols; Vector<DynamicReference> _dynamicReferences; const PrebuiltLoaderSet* _cachedDylibsPrebuiltLoaderSet = nullptr; uint8_t* _cachedDylibsStateArray = nullptr; const char* _processPrebuiltLoaderSetPath = nullptr; const PrebuiltLoaderSet* _processPrebuiltLoaderSet = nullptr; uint8_t* _processDylibStateArray = nullptr; const MachOLoaded** _processLoadedAddressArray = nullptr; bool _saveAppClosureFile; bool _failIfCouldBuildAppClosureFile; PermanentRanges* _permanentRanges = nullptr; MainFunc _driverKitMain = nullptr; Vector<DlopenCount> _dlopenRefCounts; Vector<const Loader*> _dynamicNeverUnloads; std::atomic<int32_t> _gcCount = 0; pthread_key_t _tlvTerminatorsKey = 0; pthread_key_t _dlerrorPthreadKey = 0; int _logDescriptor = -1; bool _logToSyslog = false; bool _logSetUp = false; bool _hasOverriddenCachedDylib = false; bool _wrotePrebuiltLoaderSet = false;#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR bool _vmAccountingSuspended = false;#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR};
