1/* 2 * Copyright (c) 1999-2007 Apple Inc. All Rights Reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24/*********************************************************************** 25* objc-runtime-old.m 26* Support for old-ABI classes and images. 27**********************************************************************/ 28 29/*********************************************************************** 30 * Class loading and connecting (GrP 2004-2-11) 31 * 32 * When images are loaded (during program startup or otherwise), the 33 * runtime needs to load classes and categories from the images, connect 34 * classes to superclasses and categories to parent classes, and call 35 * +load methods. 36 * 37 * The Objective-C runtime can cope with classes arriving in any order. 38 * That is, a class may be discovered by the runtime before some 39 * superclass is known. To handle out-of-order class loads, the 40 * runtime uses a "pending class" system. 41 * 42 * (Historical note) 43 * Panther and earlier: many classes arrived out-of-order because of 44 * the poorly-ordered callback from dyld. However, the runtime's 45 * pending mechanism only handled "missing superclass" and not 46 * "present superclass but missing higher class". See Radar #3225652. 47 * Tiger: The runtime's pending mechanism was augmented to handle 48 * arbitrary missing classes. In addition, dyld was rewritten and 49 * now sends the callbacks in strictly bottom-up link order. 50 * The pending mechanism may now be needed only for rare and 51 * hard to construct programs. 52 * (End historical note) 53 * 54 * A class when first seen in an image is considered "unconnected". 55 * It is stored in `unconnected_class_hash`. If all of the class's 56 * superclasses exist and are already "connected", then the new class 57 * can be connected to its superclasses and moved to `class_hash` for 58 * normal use. Otherwise, the class waits in `unconnected_class_hash` 59 * until the superclasses finish connecting. 60 * 61 * A "connected" class is 62 * (1) in `class_hash`, 63 * (2) connected to its superclasses, 64 * (3) has no unconnected superclasses, 65 * (4) is otherwise initialized and ready for use, and 66 * (5) is eligible for +load if +load has not already been called. 67 * 68 * An "unconnected" class is 69 * (1) in `unconnected_class_hash`, 70 * (2) not connected to its superclasses, 71 * (3) has an immediate superclass which is either missing or unconnected, 72 * (4) is not ready for use, and 73 * (5) is not yet eligible for +load. 74 * 75 * Image mapping is NOT CURRENTLY THREAD-SAFE with respect to just about 76 * anything. Image mapping IS RE-ENTRANT in several places: superclass 77 * lookup may cause ZeroLink to load another image, and +load calls may 78 * cause dyld to load another image. 79 * 80 * Image mapping sequence: 81 * 82 * Read all classes in all new images. 83 * Add them all to unconnected_class_hash. 84 * Note any +load implementations before categories are attached. 85 * Attach any pending categories. 86 * Read all categories in all new images. 87 * Attach categories whose parent class exists (connected or not), 88 * and pend the rest. 89 * Mark them all eligible for +load (if implemented), even if the 90 * parent class is missing. 91 * Try to connect all classes in all new images. 92 * If the superclass is missing, pend the class 93 * If the superclass is unconnected, try to recursively connect it 94 * If the superclass is connected: 95 * connect the class 96 * mark the class eligible for +load, if implemented 97 * fix up any pended classrefs referring to the class 98 * connect any pended subclasses of the class 99 * Resolve selector refs and class refs in all new images. 100 * Class refs whose classes still do not exist are pended. 101 * Fix up protocol objects in all new images. 102 * Call +load for classes and categories. 103 * May include classes or categories that are not in these images, 104 * but are newly eligible because of these image. 105 * Class +loads will be called superclass-first because of the 106 * superclass-first nature of the connecting process. 107 * Category +load needs to be deferred until the parent class is 108 * connected and has had its +load called. 109 * 110 * Performance: all classes are read before any categories are read. 111 * Fewer categories need be pended for lack of a parent class. 112 * 113 * Performance: all categories are attempted to be attached before 114 * any classes are connected. Fewer class caches need be flushed. 115 * (Unconnected classes and their respective subclasses are guaranteed 116 * to be un-messageable, so their caches will be empty.) 117 * 118 * Performance: all classes are read before any classes are connected. 119 * Fewer classes need be pended for lack of a superclass. 120 * 121 * Correctness: all selector and class refs are fixed before any 122 * protocol fixups or +load methods. libobjc itself contains selector 123 * and class refs which are used in protocol fixup and +load. 124 * 125 * Correctness: +load methods are scheduled in bottom-up link order. 126 * This constraint is in addition to superclass order. Some +load 127 * implementations expect to use another class in a linked-to library, 128 * even if the two classes don't share a direct superclass relationship. 129 * 130 * Correctness: all classes are scanned for +load before any categories 131 * are attached. Otherwise, if a category implements +load and its class 132 * has no class methods, the class's +load scan would find the category's 133 * +load method, which would then be called twice. 134 * 135 * Correctness: pended class refs are not fixed up until the class is 136 * connected. Classes with missing weak superclasses remain unconnected. 137 * Class refs to classes with missing weak superclasses must be nil. 138 * Therefore class refs to unconnected classes must remain un-fixed. 139 * 140 **********************************************************************/ 141 142#if !__OBJC2__ 143 144#include "objc-private.h" 145#include "objc-runtime-old.h" 146#include "objc-file-old.h" 147#include "objc-cache-old.h" 148#include "objc-loadmethod.h" 149 150 151typedef struct _objc_unresolved_category 152{ 153 struct _objc_unresolved_category *next; 154 old_category *cat; // may be nil 155 long version; 156} _objc_unresolved_category; 157 158typedef struct _PendingSubclass 159{ 160 Class subclass; // subclass to finish connecting; may be nil 161 struct _PendingSubclass *next; 162} PendingSubclass; 163 164typedef struct _PendingClassRef 165{ 166 Class *ref; // class reference to fix up; may be nil 167 // (ref & 1) is a metaclass reference 168 struct _PendingClassRef *next; 169} PendingClassRef; 170 171 172static uintptr_t classHash(void *info, Class data); 173static int classIsEqual(void *info, Class name, Class cls); 174static int _objc_defaultClassHandler(const char *clsName); 175static inline NXMapTable *pendingClassRefsMapTable(void); 176static inline NXMapTable *pendingSubclassesMapTable(void); 177static void pendClassInstallation(Class cls, const char *superName); 178static void pendClassReference(Class *ref, const char *className, BOOL isMeta); 179static void resolve_references_to_class(Class cls); 180static void resolve_subclasses_of_class(Class cls); 181static void really_connect_class(Class cls, Class supercls); 182static BOOL connect_class(Class cls); 183static void map_method_descs (struct objc_method_description_list * methods, BOOL copy); 184static void _objcTweakMethodListPointerForClass(Class cls); 185static inline void _objc_add_category(Class cls, old_category *category, int version); 186static BOOL _objc_add_category_flush_caches(Class cls, old_category *category, int version); 187static _objc_unresolved_category *reverse_cat(_objc_unresolved_category *cat); 188static void resolve_categories_for_class(Class cls); 189static BOOL _objc_register_category(old_category *cat, int version); 190 191 192// Function called when a class is loaded from an image 193void (*callbackFunction)(Class, Category) = 0; 194 195// Hash table of classes 196NXHashTable * class_hash = 0; 197static NXHashTablePrototype classHashPrototype = 198{ 199 (uintptr_t (*) (const void *, const void *)) classHash, 200 (int (*)(const void *, const void *, const void *)) classIsEqual, 201 NXNoEffectFree, 0 202}; 203 204// Hash table of unconnected classes 205static NXHashTable *unconnected_class_hash = nil; 206 207// Exported copy of class_hash variable (hook for debugging tools) 208NXHashTable *_objc_debug_class_hash = nil; 209 210// Category and class registries 211// Keys are COPIES of strings, to prevent stale pointers with unloaded bundles 212// Use NXMapKeyCopyingInsert and NXMapKeyFreeingRemove 213static NXMapTable * category_hash = nil; 214 215// Keys are COPIES of strings, to prevent stale pointers with unloaded bundles 216// Use NXMapKeyCopyingInsert and NXMapKeyFreeingRemove 217static NXMapTable * pendingClassRefsMap = nil; 218static NXMapTable * pendingSubclassesMap = nil; 219 220// Protocols 221static NXMapTable *protocol_map = nil; // name -> protocol 222static NXMapTable *protocol_ext_map = nil; // protocol -> protocol ext 223 224// Function pointer objc_getClass calls through when class is not found 225static int (*objc_classHandler) (const char *) = _objc_defaultClassHandler; 226 227// Function pointer called by objc_getClass and objc_lookupClass when 228// class is not found. _objc_classLoader is called before objc_classHandler. 229static BOOL (*_objc_classLoader)(const char *) = nil; 230 231 232/*********************************************************************** 233* objc_dump_class_hash. Log names of all known classes. 234**********************************************************************/ 235void objc_dump_class_hash(void) 236{ 237 NXHashTable *table; 238 unsigned count; 239 Class data; 240 NXHashState state; 241 242 table = class_hash; 243 count = 0; 244 state = NXInitHashState (table); 245 while (NXNextHashState (table, &state, (void **) &data)) 246 printf ("class %d: %s\n", ++count, data->nameForLogging()); 247} 248 249 250/*********************************************************************** 251* _objc_init_class_hash. Return the class lookup table, create it if 252* necessary. 253**********************************************************************/ 254void _objc_init_class_hash(void) 255{ 256 // Do nothing if class hash table already exists 257 if (class_hash) 258 return; 259 260 // class_hash starts small, with only enough capacity for libobjc itself. 261 // If a second library is found by map_images(), class_hash is immediately 262 // resized to capacity 1024 to cut down on rehashes. 263 // Old numbers: A smallish Foundation+AppKit program will have 264 // about 520 classes. Larger apps (like IB or WOB) have more like 265 // 800 classes. Some customers have massive quantities of classes. 266 // Foundation-only programs aren't likely to notice the ~6K loss. 267 class_hash = NXCreateHashTableFromZone (classHashPrototype, 268 16, 269 nil, 270 _objc_internal_zone ()); 271 _objc_debug_class_hash = class_hash; 272} 273 274 275/*********************************************************************** 276* objc_getClassList. Return the known classes. 277**********************************************************************/ 278int objc_getClassList(Class *buffer, int bufferLen) 279{ 280 NXHashState state; 281 Class cls; 282 int cnt, num; 283 284 mutex_lock(&classLock); 285 if (!class_hash) { 286 mutex_unlock(&classLock); 287 return 0; 288 } 289 num = NXCountHashTable(class_hash); 290 if (nil == buffer) { 291 mutex_unlock(&classLock); 292 return num; 293 } 294 cnt = 0; 295 state = NXInitHashState(class_hash); 296 while (cnt < bufferLen && 297 NXNextHashState(class_hash, &state, (void **)&cls)) 298 { 299 buffer[cnt++] = cls; 300 } 301 mutex_unlock(&classLock); 302 return num; 303} 304 305 306/*********************************************************************** 307* objc_copyClassList 308* Returns pointers to all classes. 309* This requires all classes be realized, which is regretfully non-lazy. 310* 311* outCount may be nil. *outCount is the number of classes returned. 312* If the returned array is not nil, it is nil-terminated and must be 313* freed with free(). 314* Locking: acquires classLock 315**********************************************************************/ 316Class * 317objc_copyClassList(unsigned int *outCount) 318{ 319 Class *result; 320 unsigned int count; 321 322 mutex_lock(&classLock); 323 result = nil; 324 count = class_hash ? NXCountHashTable(class_hash) : 0; 325 326 if (count > 0) { 327 Class cls; 328 NXHashState state = NXInitHashState(class_hash); 329 result = (Class *)malloc((1+count) * sizeof(Class)); 330 count = 0; 331 while (NXNextHashState(class_hash, &state, (void **)&cls)) { 332 result[count++] = cls; 333 } 334 result[count] = nil; 335 } 336 mutex_unlock(&classLock); 337 338 if (outCount) *outCount = count; 339 return result; 340} 341 342 343/*********************************************************************** 344* objc_copyProtocolList 345* Returns pointers to all protocols. 346* Locking: acquires classLock 347**********************************************************************/ 348Protocol * __unsafe_unretained * 349objc_copyProtocolList(unsigned int *outCount) 350{ 351 int count, i; 352 Protocol *proto; 353 const char *name; 354 NXMapState state; 355 Protocol **result; 356 357 mutex_lock(&classLock); 358 359 count = NXCountMapTable(protocol_map); 360 if (count == 0) { 361 mutex_unlock(&classLock); 362 if (outCount) *outCount = 0; 363 return nil; 364 } 365 366 result = (Protocol **)calloc(1 + count, sizeof(Protocol *)); 367 368 i = 0; 369 state = NXInitMapState(protocol_map); 370 while (NXNextMapState(protocol_map, &state, 371 (const void **)&name, (const void **)&proto)) 372 { 373 result[i++] = proto; 374 } 375 376 result[i++] = nil; 377 assert(i == count+1); 378 379 mutex_unlock(&classLock); 380 381 if (outCount) *outCount = count; 382 return result; 383} 384 385 386/*********************************************************************** 387* objc_getClasses. Return class lookup table. 388* 389* NOTE: This function is very dangerous, since you cannot safely use 390* the hashtable without locking it, and the lock is private! 391**********************************************************************/ 392void *objc_getClasses(void) 393{ 394 OBJC_WARN_DEPRECATED; 395 396 // Return the class lookup hash table 397 return class_hash; 398} 399 400 401/*********************************************************************** 402* classHash. 403**********************************************************************/ 404static uintptr_t classHash(void *info, Class data) 405{ 406 // Nil classes hash to zero 407 if (!data) 408 return 0; 409 410 // Call through to real hash function 411 return _objc_strhash (data->mangledName()); 412} 413 414/*********************************************************************** 415* classIsEqual. Returns whether the class names match. If we ever 416* check more than the name, routines like objc_lookUpClass have to 417* change as well. 418**********************************************************************/ 419static int classIsEqual(void *info, Class name, Class cls) 420{ 421 // Standard string comparison 422 return strcmp(name->mangledName(), cls->mangledName()) == 0; 423} 424 425 426// Unresolved future classes 427static NXHashTable *future_class_hash = nil; 428 429// Resolved future<->original classes 430static NXMapTable *future_class_to_original_class_map = nil; 431static NXMapTable *original_class_to_future_class_map = nil; 432 433// CF requests about 20 future classes; HIToolbox requests one. 434#define FUTURE_COUNT 32 435 436 437/*********************************************************************** 438* setOriginalClassForFutureClass 439* Record resolution of a future class. 440**********************************************************************/ 441static void setOriginalClassForFutureClass(Class futureClass, 442 Class originalClass) 443{ 444 if (!future_class_to_original_class_map) { 445 future_class_to_original_class_map = 446 NXCreateMapTableFromZone (NXPtrValueMapPrototype, FUTURE_COUNT, 447 _objc_internal_zone ()); 448 original_class_to_future_class_map = 449 NXCreateMapTableFromZone (NXPtrValueMapPrototype, FUTURE_COUNT, 450 _objc_internal_zone ()); 451 } 452 453 NXMapInsert (future_class_to_original_class_map, 454 futureClass, originalClass); 455 NXMapInsert (original_class_to_future_class_map, 456 originalClass, futureClass); 457 458 if (PrintFuture) { 459 _objc_inform("FUTURE: using %p instead of %p for %s", (void*)futureClass, (void*)originalClass, originalClass->name); 460 } 461} 462 463/*********************************************************************** 464* getOriginalClassForFutureClass 465* getFutureClassForOriginalClass 466* Switch between a future class and its corresponding original class. 467* The future class is the one actually in use. 468* The original class is the one from disk. 469**********************************************************************/ 470/* 471static Class 472getOriginalClassForFutureClass(Class futureClass) 473{ 474 if (!future_class_to_original_class_map) return Nil; 475 return NXMapGet (future_class_to_original_class_map, futureClass); 476} 477*/ 478static Class 479getFutureClassForOriginalClass(Class originalClass) 480{ 481 if (!original_class_to_future_class_map) return Nil; 482 return (Class)NXMapGet(original_class_to_future_class_map, originalClass); 483} 484 485 486/*********************************************************************** 487* makeFutureClass 488* Initialize the memory in *cls with an unresolved future class with the 489* given name. The memory is recorded in future_class_hash. 490**********************************************************************/ 491static void makeFutureClass(Class cls, const char *name) 492{ 493 // CF requests about 20 future classes, plus HIToolbox has one. 494 if (!future_class_hash) { 495 future_class_hash = 496 NXCreateHashTableFromZone(classHashPrototype, FUTURE_COUNT, 497 nil, _objc_internal_zone()); 498 } 499 500 cls->name = _strdup_internal(name); 501 NXHashInsert(future_class_hash, cls); 502 503 if (PrintFuture) { 504 _objc_inform("FUTURE: reserving %p for %s", (void*)cls, name); 505 } 506} 507 508 509/*********************************************************************** 510* _objc_allocateFutureClass 511* Allocate an unresolved future class for the given class name. 512* Returns any existing allocation if one was already made. 513* Assumes the named class doesn't exist yet. 514* Not thread safe. 515**********************************************************************/ 516Class _objc_allocateFutureClass(const char *name) 517{ 518 Class cls; 519 520 if (future_class_hash) { 521 objc_class query; 522 query.name = name; 523 if ((cls = (Class)NXHashGet(future_class_hash, &query))) { 524 // Already have a future class for this name. 525 return cls; 526 } 527 } 528 529 cls = _calloc_class(sizeof(objc_class)); 530 makeFutureClass(cls, name); 531 return cls; 532} 533 534 535/*********************************************************************** 536* objc_getFutureClass. Return the id of the named class. 537* If the class does not exist, return an uninitialized class 538* structure that will be used for the class when and if it 539* does get loaded. 540* Not thread safe. 541**********************************************************************/ 542Class objc_getFutureClass(const char *name) 543{ 544 Class cls; 545 546 // YES unconnected, NO class handler 547 // (unconnected is OK because it will someday be the real class) 548 cls = look_up_class(name, YES, NO); 549 if (cls) { 550 if (PrintFuture) { 551 _objc_inform("FUTURE: found %p already in use for %s", 552 (void*)cls, name); 553 } 554 return cls; 555 } 556 557 // No class or future class with that name yet. Make one. 558 // fixme not thread-safe with respect to 559 // simultaneous library load or getFutureClass. 560 return _objc_allocateFutureClass(name); 561} 562 563 564/*********************************************************************** 565* objc_setFutureClass. 566* Like objc_getFutureClass, but uses the provided memory block. 567* If the class already exists, a posing-like substitution is performed. 568* Not thread safe. 569**********************************************************************/ 570void objc_setFutureClass(Class cls, const char *name) 571{ 572 Class oldcls; 573 Class newcls = cls; // Not a real class! 574 575 if ((oldcls = look_up_class(name, NO/*unconnected*/, NO/*classhandler*/))) { 576 setOriginalClassForFutureClass(newcls, oldcls); 577 // fixme hack 578 memcpy(newcls, oldcls, sizeof(struct objc_class)); 579 newcls->info &= ~CLS_EXT; 580 581 mutex_lock(&classLock); 582 NXHashRemove(class_hash, oldcls); 583 objc_removeRegisteredClass(oldcls); 584 change_class_references(newcls, oldcls, nil, YES); 585 NXHashInsert(class_hash, newcls); 586 objc_addRegisteredClass(newcls); 587 mutex_unlock(&classLock); 588 } else { 589 makeFutureClass(newcls, name); 590 } 591} 592 593 594BOOL _class_isFutureClass(Class cls) 595{ 596 return cls && future_class_hash && NXHashGet(future_class_hash, cls); 597} 598 599 600/*********************************************************************** 601* _objc_defaultClassHandler. Default objc_classHandler. Does nothing. 602**********************************************************************/ 603static int _objc_defaultClassHandler(const char *clsName) 604{ 605 // Return zero so objc_getClass doesn't bother re-searching 606 return 0; 607} 608 609/*********************************************************************** 610* objc_setClassHandler. Set objc_classHandler to the specified value. 611* 612* NOTE: This should probably deal with userSuppliedHandler being nil, 613* because the objc_classHandler caller does not check... it would bus 614* error. It would make sense to handle nil by restoring the default 615* handler. Is anyone hacking with this, though? 616**********************************************************************/ 617void objc_setClassHandler(int (*userSuppliedHandler)(const char *)) 618{ 619 OBJC_WARN_DEPRECATED; 620 621 objc_classHandler = userSuppliedHandler; 622} 623 624 625/*********************************************************************** 626* _objc_setClassLoader 627* Similar to objc_setClassHandler, but objc_classLoader is used for 628* both objc_getClass() and objc_lookupClass(), and objc_classLoader 629* pre-empts objc_classHandler. 630**********************************************************************/ 631void _objc_setClassLoader(BOOL (*newClassLoader)(const char *)) 632{ 633 _objc_classLoader = newClassLoader; 634} 635 636 637/*********************************************************************** 638* objc_getProtocol 639* Get a protocol by name, or nil. 640**********************************************************************/ 641Protocol *objc_getProtocol(const char *name) 642{ 643 Protocol *result; 644 if (!protocol_map) return nil; 645 mutex_lock(&classLock); 646 result = (Protocol *)NXMapGet(protocol_map, name); 647 mutex_unlock(&classLock); 648 return result; 649} 650 651 652/*********************************************************************** 653* look_up_class 654* Map a class name to a class using various methods. 655* This is the common implementation of objc_lookUpClass and objc_getClass, 656* and is also used internally to get additional search options. 657* Sequence: 658* 1. class_hash 659* 2. unconnected_class_hash (optional) 660* 3. classLoader callback 661* 4. classHandler callback (optional) 662**********************************************************************/ 663Class look_up_class(const char *aClassName, BOOL includeUnconnected, BOOL includeClassHandler) 664{ 665 BOOL includeClassLoader = YES; // class loader cannot be skipped 666 Class result = nil; 667 struct objc_class query; 668 669 query.name = aClassName; 670 671 retry: 672 673 if (!result && class_hash) { 674 // Check ordinary classes 675 mutex_lock (&classLock); 676 result = (Class)NXHashGet(class_hash, &query); 677 mutex_unlock (&classLock); 678 } 679 680 if (!result && includeUnconnected && unconnected_class_hash) { 681 // Check not-yet-connected classes 682 mutex_lock(&classLock); 683 result = (Class)NXHashGet(unconnected_class_hash, &query); 684 mutex_unlock(&classLock); 685 } 686 687 if (!result && includeClassLoader && _objc_classLoader) { 688 // Try class loader callback 689 if ((*_objc_classLoader)(aClassName)) { 690 // Re-try lookup without class loader 691 includeClassLoader = NO; 692 goto retry; 693 } 694 } 695 696 if (!result && includeClassHandler && objc_classHandler) { 697 // Try class handler callback 698 if ((*objc_classHandler)(aClassName)) { 699 // Re-try lookup without class handler or class loader 700 includeClassLoader = NO; 701 includeClassHandler = NO; 702 goto retry; 703 } 704 } 705 706 return result; 707} 708 709 710/*********************************************************************** 711* objc_class::isConnected 712* Returns TRUE if class cls is connected. 713* A connected class has either a connected superclass or a nil superclass, 714* and is present in class_hash. 715**********************************************************************/ 716bool objc_class::isConnected() 717{ 718 bool result; 719 mutex_lock(&classLock); 720 result = NXHashMember(class_hash, this); 721 mutex_unlock(&classLock); 722 return result; 723} 724 725 726/*********************************************************************** 727* pendingClassRefsMapTable. Return a pointer to the lookup table for 728* pending class refs. 729**********************************************************************/ 730static inline NXMapTable *pendingClassRefsMapTable(void) 731{ 732 // Allocate table if needed 733 if (!pendingClassRefsMap) { 734 pendingClassRefsMap = 735 NXCreateMapTableFromZone(NXStrValueMapPrototype, 736 10, _objc_internal_zone ()); 737 } 738 739 // Return table pointer 740 return pendingClassRefsMap; 741} 742 743 744/*********************************************************************** 745* pendingSubclassesMapTable. Return a pointer to the lookup table for 746* pending subclasses. 747**********************************************************************/ 748static inline NXMapTable *pendingSubclassesMapTable(void) 749{ 750 // Allocate table if needed 751 if (!pendingSubclassesMap) { 752 pendingSubclassesMap = 753 NXCreateMapTableFromZone(NXStrValueMapPrototype, 754 10, _objc_internal_zone ()); 755 } 756 757 // Return table pointer 758 return pendingSubclassesMap; 759} 760 761 762/*********************************************************************** 763* pendClassInstallation 764* Finish connecting class cls when its superclass becomes connected. 765* Check for multiple pends of the same class because connect_class does not. 766**********************************************************************/ 767static void pendClassInstallation(Class cls, const char *superName) 768{ 769 NXMapTable *table; 770 PendingSubclass *pending; 771 PendingSubclass *oldList; 772 PendingSubclass *l; 773 774 // Create and/or locate pending class lookup table 775 table = pendingSubclassesMapTable (); 776 777 // Make sure this class isn't already in the pending list. 778 oldList = (PendingSubclass *)NXMapGet(table, superName); 779 for (l = oldList; l != nil; l = l->next) { 780 if (l->subclass == cls) return; // already here, nothing to do 781 } 782 783 // Create entry referring to this class 784 pending = (PendingSubclass *)_malloc_internal(sizeof(PendingSubclass)); 785 pending->subclass = cls; 786 787 // Link new entry into head of list of entries for this class 788 pending->next = oldList; 789 790 // (Re)place entry list in the table 791 NXMapKeyCopyingInsert (table, superName, pending); 792} 793 794 795/*********************************************************************** 796* pendClassReference 797* Fix up a class ref when the class with the given name becomes connected. 798**********************************************************************/ 799static void pendClassReference(Class *ref, const char *className, BOOL isMeta) 800{ 801 NXMapTable *table; 802 PendingClassRef *pending; 803 804 // Create and/or locate pending class lookup table 805 table = pendingClassRefsMapTable (); 806 807 // Create entry containing the class reference 808 pending = (PendingClassRef *)_malloc_internal(sizeof(PendingClassRef)); 809 pending->ref = ref; 810 if (isMeta) { 811 pending->ref = (Class *)((uintptr_t)pending->ref | 1); 812 } 813 814 // Link new entry into head of list of entries for this class 815 pending->next = (PendingClassRef *)NXMapGet(table, className); 816 817 // (Re)place entry list in the table 818 NXMapKeyCopyingInsert (table, className, pending); 819 820 if (PrintConnecting) { 821 _objc_inform("CONNECT: pended reference to class '%s%s' at %p", 822 className, isMeta ? " (meta)" : "", (void *)ref); 823 } 824} 825 826 827/*********************************************************************** 828* resolve_references_to_class 829* Fix up any pending class refs to this class. 830**********************************************************************/ 831static void resolve_references_to_class(Class cls) 832{ 833 PendingClassRef *pending; 834 835 if (!pendingClassRefsMap) return; // no unresolved refs for any class 836 837 pending = (PendingClassRef *)NXMapGet(pendingClassRefsMap, cls->name); 838 if (!pending) return; // no unresolved refs for this class 839 840 NXMapKeyFreeingRemove(pendingClassRefsMap, cls->name); 841 842 if (PrintConnecting) { 843 _objc_inform("CONNECT: resolving references to class '%s'", cls->name); 844 } 845 846 while (pending) { 847 PendingClassRef *next = pending->next; 848 if (pending->ref) { 849 BOOL isMeta = ((uintptr_t)pending->ref & 1) ? YES : NO; 850 Class *ref = 851 (Class *)((uintptr_t)pending->ref & ~(uintptr_t)1); 852 *ref = isMeta ? cls->ISA() : cls; 853 } 854 _free_internal(pending); 855 pending = next; 856 } 857 858 if (NXCountMapTable(pendingClassRefsMap) == 0) { 859 NXFreeMapTable(pendingClassRefsMap); 860 pendingClassRefsMap = nil; 861 } 862} 863 864 865/*********************************************************************** 866* resolve_subclasses_of_class 867* Fix up any pending subclasses of this class. 868**********************************************************************/ 869static void resolve_subclasses_of_class(Class cls) 870{ 871 PendingSubclass *pending; 872 873 if (!pendingSubclassesMap) return; // no unresolved subclasses 874 875 pending = (PendingSubclass *)NXMapGet(pendingSubclassesMap, cls->name); 876 if (!pending) return; // no unresolved subclasses for this class 877 878 NXMapKeyFreeingRemove(pendingSubclassesMap, cls->name); 879 880 // Destroy the pending table if it's now empty, to save memory. 881 if (NXCountMapTable(pendingSubclassesMap) == 0) { 882 NXFreeMapTable(pendingSubclassesMap); 883 pendingSubclassesMap = nil; 884 } 885 886 if (PrintConnecting) { 887 _objc_inform("CONNECT: resolving subclasses of class '%s'", cls->name); 888 } 889 890 while (pending) { 891 PendingSubclass *next = pending->next; 892 if (pending->subclass) connect_class(pending->subclass); 893 _free_internal(pending); 894 pending = next; 895 } 896} 897 898 899/*********************************************************************** 900* really_connect_class 901* Connect cls to superclass supercls unconditionally. 902* Also adjust the class hash tables and handle pended subclasses. 903* 904* This should be called from connect_class() ONLY. 905**********************************************************************/ 906static void really_connect_class(Class cls, 907 Class supercls) 908{ 909 Class oldCls; 910 911 // Connect superclass pointers. 912 set_superclass(cls, supercls, YES); 913 914 // Update GC layouts 915 // For paranoia, this is a conservative update: 916 // only non-strong -> strong and weak -> strong are corrected. 917 if (UseGC && supercls && 918 (cls->info & CLS_EXT) && (supercls->info & CLS_EXT)) 919 { 920 BOOL layoutChanged; 921 layout_bitmap ivarBitmap = 922 layout_bitmap_create(cls->ivar_layout, 923 cls->instance_size, 924 cls->instance_size, NO); 925 926 layout_bitmap superBitmap = 927 layout_bitmap_create(supercls->ivar_layout, 928 supercls->instance_size, 929 supercls->instance_size, NO); 930 931 // non-strong -> strong: bits set in super should be set in sub 932 layoutChanged = layout_bitmap_or(ivarBitmap, superBitmap, cls->name); 933 layout_bitmap_free(superBitmap); 934 935 if (layoutChanged) { 936 layout_bitmap weakBitmap = {}; 937 BOOL weakLayoutChanged = NO; 938 939 if (cls->ext && cls->ext->weak_ivar_layout) { 940 // weak -> strong: strong bits should be cleared in weak layout 941 // This is a subset of non-strong -> strong 942 weakBitmap = 943 layout_bitmap_create(cls->ext->weak_ivar_layout, 944 cls->instance_size, 945 cls->instance_size, YES); 946 947 weakLayoutChanged = 948 layout_bitmap_clear(weakBitmap, ivarBitmap, cls->name); 949 } else { 950 // no existing weak ivars, so no weak -> strong changes 951 } 952 953 // Rebuild layout strings. 954 if (PrintIvars) { 955 _objc_inform("IVARS: gc layout changed " 956 "for class %s (super %s)", 957 cls->name, supercls->name); 958 if (weakLayoutChanged) { 959 _objc_inform("IVARS: gc weak layout changed " 960 "for class %s (super %s)", 961 cls->name, supercls->name); 962 } 963 } 964 cls->ivar_layout = layout_string_create(ivarBitmap); 965 if (weakLayoutChanged) { 966 cls->ext->weak_ivar_layout = layout_string_create(weakBitmap); 967 } 968 969 layout_bitmap_free(weakBitmap); 970 } 971 972 layout_bitmap_free(ivarBitmap); 973 } 974 975 // Done! 976 cls->info |= CLS_CONNECTED; 977 978 mutex_lock(&classLock); 979 980 // Update hash tables. 981 NXHashRemove(unconnected_class_hash, cls); 982 oldCls = (Class)NXHashInsert(class_hash, cls); 983 objc_addRegisteredClass(cls); 984 985 // Delete unconnected_class_hash if it is now empty. 986 if (NXCountHashTable(unconnected_class_hash) == 0) { 987 NXFreeHashTable(unconnected_class_hash); 988 unconnected_class_hash = nil; 989 } 990 991 // No duplicate classes allowed. 992 // Duplicates should have been rejected by _objc_read_classes_from_image. 993 assert(!oldCls); 994 995 mutex_unlock(&classLock); 996 997 // Fix up pended class refs to this class, if any 998 resolve_references_to_class(cls); 999 1000 // Connect newly-connectable subclasses 1001 resolve_subclasses_of_class(cls); 1002 1003 // GC debugging: make sure all classes with -dealloc also have -finalize 1004 if (DebugFinalizers) { 1005 extern IMP findIMPInClass(Class cls, SEL sel); 1006 if (findIMPInClass(cls, sel_getUid("dealloc")) && 1007 ! findIMPInClass(cls, sel_getUid("finalize"))) 1008 { 1009 _objc_inform("GC: class '%s' implements -dealloc but not -finalize", cls->name); 1010 } 1011 } 1012 1013 // Debugging: if this class has ivars, make sure this class's ivars don't 1014 // overlap with its super's. This catches some broken fragile base classes. 1015 // Do not use super->instance_size vs. self->ivar[0] to check this. 1016 // Ivars may be packed across instance_size boundaries. 1017 if (DebugFragileSuperclasses && cls->ivars && cls->ivars->ivar_count) { 1018 Class ivar_cls = supercls; 1019 1020 // Find closest superclass that has some ivars, if one exists. 1021 while (ivar_cls && 1022 (!ivar_cls->ivars || ivar_cls->ivars->ivar_count == 0)) 1023 { 1024 ivar_cls = ivar_cls->superclass; 1025 } 1026 1027 if (ivar_cls) { 1028 // Compare superclass's last ivar to this class's first ivar 1029 old_ivar *super_ivar = 1030 &ivar_cls->ivars->ivar_list[ivar_cls->ivars->ivar_count - 1]; 1031 old_ivar *self_ivar = 1032 &cls->ivars->ivar_list[0]; 1033 1034 // fixme could be smarter about super's ivar size 1035 if (self_ivar->ivar_offset <= super_ivar->ivar_offset) { 1036 _objc_inform("WARNING: ivars of superclass '%s' and " 1037 "subclass '%s' overlap; superclass may have " 1038 "changed since subclass was compiled", 1039 ivar_cls->name, cls->name); 1040 } 1041 } 1042 } 1043} 1044 1045 1046/*********************************************************************** 1047* connect_class 1048* Connect class cls to its superclasses, if possible. 1049* If cls becomes connected, move it from unconnected_class_hash 1050* to connected_class_hash. 1051* Returns TRUE if cls is connected. 1052* Returns FALSE if cls could not be connected for some reason 1053* (missing superclass or still-unconnected superclass) 1054**********************************************************************/ 1055static BOOL connect_class(Class cls) 1056{ 1057 if (cls->isConnected()) { 1058 // This class is already connected to its superclass. 1059 // Do nothing. 1060 return TRUE; 1061 } 1062 else if (cls->superclass == nil) { 1063 // This class is a root class. 1064 // Connect it to itself. 1065 1066 if (PrintConnecting) { 1067 _objc_inform("CONNECT: class '%s' now connected (root class)", 1068 cls->name); 1069 } 1070 1071 really_connect_class(cls, nil); 1072 return TRUE; 1073 } 1074 else { 1075 // This class is not a root class and is not yet connected. 1076 // Connect it if its superclass and root class are already connected. 1077 // Otherwise, add this class to the to-be-connected list, 1078 // pending the completion of its superclass and root class. 1079 1080 // At this point, cls->superclass and cls->ISA()->ISA() are still STRINGS 1081 char *supercls_name = (char *)cls->superclass; 1082 Class supercls; 1083 1084 // YES unconnected, YES class handler 1085 if (nil == (supercls = look_up_class(supercls_name, YES, YES))) { 1086 // Superclass does not exist yet. 1087 // pendClassInstallation will handle duplicate pends of this class 1088 pendClassInstallation(cls, supercls_name); 1089 1090 if (PrintConnecting) { 1091 _objc_inform("CONNECT: class '%s' NOT connected (missing super)", cls->name); 1092 } 1093 return FALSE; 1094 } 1095 1096 if (! connect_class(supercls)) { 1097 // Superclass exists but is not yet connected. 1098 // pendClassInstallation will handle duplicate pends of this class 1099 pendClassInstallation(cls, supercls_name); 1100 1101 if (PrintConnecting) { 1102 _objc_inform("CONNECT: class '%s' NOT connected (unconnected super)", cls->name); 1103 } 1104 return FALSE; 1105 } 1106 1107 // Superclass exists and is connected. 1108 // Connect this class to the superclass. 1109 1110 if (PrintConnecting) { 1111 _objc_inform("CONNECT: class '%s' now connected", cls->name); 1112 } 1113 1114 really_connect_class(cls, supercls); 1115 return TRUE; 1116 } 1117} 1118 1119 1120/*********************************************************************** 1121* _objc_read_categories_from_image. 1122* Read all categories from the given image. 1123* Install them on their parent classes, or register them for later 1124* installation. 1125* Returns YES if some method caches now need to be flushed. 1126**********************************************************************/ 1127static BOOL _objc_read_categories_from_image (header_info * hi) 1128{ 1129 Module mods; 1130 size_t midx; 1131 BOOL needFlush = NO; 1132 1133 if (_objcHeaderIsReplacement(hi)) { 1134 // Ignore any categories in this image 1135 return NO; 1136 } 1137 1138 1139 // Major loop - process all modules in the header 1140 mods = hi->mod_ptr; 1141 1142 // NOTE: The module and category lists are traversed backwards 1143 // to preserve the pre-10.4 processing order. Changing the order 1144 // would have a small chance of introducing binary compatibility bugs. 1145 midx = hi->mod_count; 1146 while (midx-- > 0) { 1147 unsigned int index; 1148 unsigned int total; 1149 1150 // Nothing to do for a module without a symbol table 1151 if (mods[midx].symtab == nil) 1152 continue; 1153 1154 // Total entries in symbol table (class entries followed 1155 // by category entries) 1156 total = mods[midx].symtab->cls_def_cnt + 1157 mods[midx].symtab->cat_def_cnt; 1158 1159 // Minor loop - register all categories from given module 1160 index = total; 1161 while (index-- > mods[midx].symtab->cls_def_cnt) { 1162 old_category *cat = (old_category *)mods[midx].symtab->defs[index]; 1163 needFlush |= _objc_register_category(cat, (int)mods[midx].version); 1164 } 1165 } 1166 1167 return needFlush; 1168} 1169 1170 1171/*********************************************************************** 1172* _objc_read_classes_from_image. 1173* Read classes from the given image, perform assorted minor fixups, 1174* scan for +load implementation. 1175* Does not connect classes to superclasses. 1176* Does attach pended categories to the classes. 1177* Adds all classes to unconnected_class_hash. class_hash is unchanged. 1178**********************************************************************/ 1179static void _objc_read_classes_from_image(header_info *hi) 1180{ 1181 unsigned int index; 1182 unsigned int midx; 1183 Module mods; 1184 int isBundle = headerIsBundle(hi); 1185 1186 if (_objcHeaderIsReplacement(hi)) { 1187 // Ignore any classes in this image 1188 return; 1189 } 1190 1191 // class_hash starts small, enough only for libobjc itself. 1192 // If other Objective-C libraries are found, immediately resize 1193 // class_hash, assuming that Foundation and AppKit are about 1194 // to add lots of classes. 1195 mutex_lock(&classLock); 1196 if (hi->mhdr != libobjc_header && _NXHashCapacity(class_hash) < 1024) { 1197 _NXHashRehashToCapacity(class_hash, 1024); 1198 } 1199 mutex_unlock(&classLock); 1200 1201 // Major loop - process all modules in the image 1202 mods = hi->mod_ptr; 1203 for (midx = 0; midx < hi->mod_count; midx += 1) 1204 { 1205 // Skip module containing no classes 1206 if (mods[midx].symtab == nil) 1207 continue; 1208 1209 // Minor loop - process all the classes in given module 1210 for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1) 1211 { 1212 Class newCls, oldCls; 1213 BOOL rejected; 1214 1215 // Locate the class description pointer 1216 newCls = (Class)mods[midx].symtab->defs[index]; 1217 1218 // Classes loaded from Mach-O bundles can be unloaded later. 1219 // Nothing uses this class yet, so cls->setInfo is not needed. 1220 if (isBundle) newCls->info |= CLS_FROM_BUNDLE; 1221 if (isBundle) newCls->ISA()->info |= CLS_FROM_BUNDLE; 1222 1223 // Use common static empty cache instead of nil 1224 if (newCls->cache == nil) 1225 newCls->cache = (Cache) &_objc_empty_cache; 1226 if (newCls->ISA()->cache == nil) 1227 newCls->ISA()->cache = (Cache) &_objc_empty_cache; 1228 1229 // Set metaclass version 1230 newCls->ISA()->version = mods[midx].version; 1231 1232 // methodLists is nil or a single list, not an array 1233 newCls->info |= CLS_NO_METHOD_ARRAY|CLS_NO_PROPERTY_ARRAY; 1234 newCls->ISA()->info |= CLS_NO_METHOD_ARRAY|CLS_NO_PROPERTY_ARRAY; 1235 1236 // class has no subclasses for cache flushing 1237 newCls->info |= CLS_LEAF; 1238 newCls->ISA()->info |= CLS_LEAF; 1239 1240 if (mods[midx].version >= 6) { 1241 // class structure has ivar_layout and ext fields 1242 newCls->info |= CLS_EXT; 1243 newCls->ISA()->info |= CLS_EXT; 1244 } 1245 1246 // Check for +load implementation before categories are attached 1247 if (_class_hasLoadMethod(newCls)) { 1248 newCls->ISA()->info |= CLS_HAS_LOAD_METHOD; 1249 } 1250 1251 // Install into unconnected_class_hash. 1252 mutex_lock(&classLock); 1253 1254 if (future_class_hash) { 1255 Class futureCls = (Class) 1256 NXHashRemove(future_class_hash, newCls); 1257 if (futureCls) { 1258 // Another class structure for this class was already 1259 // prepared by objc_getFutureClass(). Use it instead. 1260 _free_internal((char *)futureCls->name); 1261 memcpy(futureCls, newCls, sizeof(objc_class)); 1262 setOriginalClassForFutureClass(futureCls, newCls); 1263 newCls = futureCls; 1264 1265 if (NXCountHashTable(future_class_hash) == 0) { 1266 NXFreeHashTable(future_class_hash); 1267 future_class_hash = nil; 1268 } 1269 } 1270 } 1271 1272 if (!unconnected_class_hash) { 1273 unconnected_class_hash = 1274 NXCreateHashTableFromZone(classHashPrototype, 128, 1275 nil, _objc_internal_zone()); 1276 } 1277 1278 if ((oldCls = (Class)NXHashGet(class_hash, newCls)) || 1279 (oldCls = (Class)NXHashGet(unconnected_class_hash, newCls))) 1280 { 1281 // Another class with this name exists. Complain and reject. 1282 inform_duplicate(newCls->name, oldCls, newCls); 1283 rejected = YES; 1284 } 1285 else { 1286 NXHashInsert(unconnected_class_hash, newCls); 1287 rejected = NO; 1288 } 1289 1290 mutex_unlock(&classLock); 1291 1292 if (!rejected) { 1293 // Attach pended categories for this class, if any 1294 resolve_categories_for_class(newCls); 1295 } 1296 } 1297 } 1298} 1299 1300 1301/*********************************************************************** 1302* _objc_connect_classes_from_image. 1303* Connect the classes in the given image to their superclasses, 1304* or register them for later connection if any superclasses are missing. 1305**********************************************************************/ 1306static void _objc_connect_classes_from_image(header_info *hi) 1307{ 1308 unsigned int index; 1309 unsigned int midx; 1310 Module mods; 1311 BOOL replacement = _objcHeaderIsReplacement(hi); 1312 1313 // Major loop - process all modules in the image 1314 mods = hi->mod_ptr; 1315 for (midx = 0; midx < hi->mod_count; midx += 1) 1316 { 1317 // Skip module containing no classes 1318 if (mods[midx].symtab == nil) 1319 continue; 1320 1321 // Minor loop - process all the classes in given module 1322 for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1) 1323 { 1324 Class cls = (Class)mods[midx].symtab->defs[index]; 1325 if (! replacement) { 1326 BOOL connected; 1327 Class futureCls = getFutureClassForOriginalClass(cls); 1328 if (futureCls) { 1329 // objc_getFutureClass() requested a different class 1330 // struct. Fix up the original struct's superclass 1331 // field for [super ...] use, but otherwise perform 1332 // fixups on the new class struct only. 1333 const char *super_name = (const char *) cls->superclass; 1334 if (super_name) cls->superclass = objc_getClass(super_name); 1335 cls = futureCls; 1336 } 1337 connected = connect_class(cls); 1338 if (connected && callbackFunction) { 1339 (*callbackFunction)(cls, 0); 1340 } 1341 } else { 1342 // Replacement image - fix up superclass only (#3704817) 1343 // And metaclass's superclass (#5351107) 1344 const char *super_name = (const char *) cls->superclass; 1345 if (super_name) { 1346 cls->superclass = objc_getClass(super_name); 1347 // metaclass's superclass is superclass's metaclass 1348 cls->ISA()->superclass = cls->superclass->ISA(); 1349 } else { 1350 // Replacement for a root class 1351 // cls->superclass already nil 1352 // root metaclass's superclass is root class 1353 cls->ISA()->superclass = cls; 1354 } 1355 } 1356 } 1357 } 1358} 1359 1360 1361/*********************************************************************** 1362* _objc_map_class_refs_for_image. Convert the class ref entries from 1363* a class name string pointer to a class pointer. If the class does 1364* not yet exist, the reference is added to a list of pending references 1365* to be fixed up at a later date. 1366**********************************************************************/ 1367static void fix_class_ref(Class *ref, const char *name, BOOL isMeta) 1368{ 1369 Class cls; 1370 1371 // Get pointer to class of this name 1372 // NO unconnected, YES class loader 1373 // (real class with weak-missing superclass is unconnected now) 1374 cls = look_up_class(name, NO, YES); 1375 if (cls) { 1376 // Referenced class exists. Fix up the reference. 1377 *ref = isMeta ? cls->ISA() : cls; 1378 } else { 1379 // Referenced class does not exist yet. Insert nil for now 1380 // (weak-linking) and fix up the reference if the class arrives later. 1381 pendClassReference (ref, name, isMeta); 1382 *ref = nil; 1383 } 1384} 1385 1386static void _objc_map_class_refs_for_image (header_info * hi) 1387{ 1388 Class *cls_refs; 1389 size_t count; 1390 unsigned int index; 1391 1392 // Locate class refs in image 1393 cls_refs = _getObjcClassRefs (hi, &count); 1394 if (cls_refs) { 1395 // Process each class ref 1396 for (index = 0; index < count; index += 1) { 1397 // Ref is initially class name char* 1398 const char *name = (const char *) cls_refs[index]; 1399 if (!name) continue; 1400 fix_class_ref(&cls_refs[index], name, NO /*never meta*/); 1401 } 1402 } 1403} 1404 1405 1406/*********************************************************************** 1407* _objc_remove_pending_class_refs_in_image 1408* Delete any pending class ref fixups for class refs in the given image, 1409* because the image is about to be unloaded. 1410**********************************************************************/ 1411static void removePendingReferences(Class *refs, size_t count) 1412{ 1413 Class *end = refs + count; 1414 1415 if (!refs) return; 1416 if (!pendingClassRefsMap) return; 1417 1418 // Search the pending class ref table for class refs in this range. 1419 // The class refs may have already been stomped with nil, 1420 // so there's no way to recover the original class name. 1421 1422 { 1423 const char *key; 1424 PendingClassRef *pending; 1425 NXMapState state = NXInitMapState(pendingClassRefsMap); 1426 while(NXNextMapState(pendingClassRefsMap, &state, 1427 (const void **)&key, (const void **)&pending)) 1428 { 1429 for ( ; pending != nil; pending = pending->next) { 1430 if (pending->ref >= refs && pending->ref < end) { 1431 pending->ref = nil; 1432 } 1433 } 1434 } 1435 } 1436} 1437 1438static void _objc_remove_pending_class_refs_in_image(header_info *hi) 1439{ 1440 Class *cls_refs; 1441 size_t count; 1442 1443 // Locate class refs in this image 1444 cls_refs = _getObjcClassRefs(hi, &count); 1445 removePendingReferences(cls_refs, count); 1446} 1447 1448 1449/*********************************************************************** 1450* map_selrefs. For each selector in the specified array, 1451* replace the name pointer with a uniqued selector. 1452* If copy is TRUE, all selector data is always copied. This is used 1453* for registering selectors from unloadable bundles, so the selector 1454* can still be used after the bundle's data segment is unmapped. 1455* Returns YES if dst was written to, NO if it was unchanged. 1456**********************************************************************/ 1457static inline void map_selrefs(SEL *sels, size_t count, BOOL copy) 1458{ 1459 size_t index; 1460 1461 if (!sels) return; 1462 1463 sel_lock(); 1464 1465 // Process each selector 1466 for (index = 0; index < count; index += 1) 1467 { 1468 SEL sel; 1469 1470 // Lookup pointer to uniqued string 1471 sel = sel_registerNameNoLock((const char *) sels[index], copy); 1472 1473 // Replace this selector with uniqued one (avoid 1474 // modifying the VM page if this would be a NOP) 1475 if (sels[index] != sel) { 1476 sels[index] = sel; 1477 } 1478 } 1479 1480 sel_unlock(); 1481} 1482 1483 1484/*********************************************************************** 1485* map_method_descs. For each method in the specified method list, 1486* replace the name pointer with a uniqued selector. 1487* If copy is TRUE, all selector data is always copied. This is used 1488* for registering selectors from unloadable bundles, so the selector 1489* can still be used after the bundle's data segment is unmapped. 1490**********************************************************************/ 1491static void map_method_descs (struct objc_method_description_list * methods, BOOL copy) 1492{ 1493 int index; 1494 1495 if (!methods) return; 1496 1497 sel_lock(); 1498 1499 // Process each method 1500 for (index = 0; index < methods->count; index += 1) 1501 { 1502 struct objc_method_description * method; 1503 SEL sel; 1504 1505 // Get method entry to fix up 1506 method = &methods->list[index]; 1507 1508 // Lookup pointer to uniqued string 1509 sel = sel_registerNameNoLock((const char *) method->name, copy); 1510 1511 // Replace this selector with uniqued one (avoid 1512 // modifying the VM page if this would be a NOP) 1513 if (method->name != sel) 1514 method->name = sel; 1515 } 1516 1517 sel_unlock(); 1518} 1519 1520 1521/*********************************************************************** 1522* ext_for_protocol 1523* Returns the protocol extension for the given protocol. 1524* Returns nil if the protocol has no extension. 1525**********************************************************************/ 1526static old_protocol_ext *ext_for_protocol(old_protocol *proto) 1527{ 1528 if (!proto) return nil; 1529 if (!protocol_ext_map) return nil; 1530 else return (old_protocol_ext *)NXMapGet(protocol_ext_map, proto); 1531} 1532 1533 1534/*********************************************************************** 1535* lookup_method 1536* Search a protocol method list for a selector. 1537**********************************************************************/ 1538static struct objc_method_description * 1539lookup_method(struct objc_method_description_list *mlist, SEL aSel) 1540{ 1541 if (mlist) { 1542 int i; 1543 for (i = 0; i < mlist->count; i++) { 1544 if (mlist->list[i].name == aSel) { 1545 return mlist->list+i; 1546 } 1547 } 1548 } 1549 return nil; 1550} 1551 1552 1553/*********************************************************************** 1554* lookup_protocol_method 1555* Search for a selector in a protocol 1556* (and optionally recursively all incorporated protocols) 1557**********************************************************************/ 1558struct objc_method_description * 1559lookup_protocol_method(old_protocol *proto, SEL aSel, 1560 BOOL isRequiredMethod, BOOL isInstanceMethod, 1561 BOOL recursive) 1562{ 1563 struct objc_method_description *m = nil; 1564 old_protocol_ext *ext; 1565 1566 if (isRequiredMethod) { 1567 if (isInstanceMethod) { 1568 m = lookup_method(proto->instance_methods, aSel); 1569 } else { 1570 m = lookup_method(proto->class_methods, aSel); 1571 } 1572 } else if ((ext = ext_for_protocol(proto))) { 1573 if (isInstanceMethod) { 1574 m = lookup_method(ext->optional_instance_methods, aSel); 1575 } else { 1576 m = lookup_method(ext->optional_class_methods, aSel); 1577 } 1578 } 1579 1580 if (!m && recursive && proto->protocol_list) { 1581 int i; 1582 for (i = 0; !m && i < proto->protocol_list->count; i++) { 1583 m = lookup_protocol_method(proto->protocol_list->list[i], aSel, 1584 isRequiredMethod,isInstanceMethod,true); 1585 } 1586 } 1587 1588 return m; 1589} 1590 1591 1592/*********************************************************************** 1593* protocol_getName 1594* Returns the name of the given protocol. 1595**********************************************************************/ 1596const char *protocol_getName(Protocol *p) 1597{ 1598 old_protocol *proto = oldprotocol(p); 1599 if (!proto) return "nil"; 1600 return proto->protocol_name; 1601} 1602 1603 1604/*********************************************************************** 1605* protocol_getMethodDescription 1606* Returns the description of a named method. 1607* Searches either required or optional methods. 1608* Searches either instance or class methods. 1609**********************************************************************/ 1610struct objc_method_description 1611protocol_getMethodDescription(Protocol *p, SEL aSel, 1612 BOOL isRequiredMethod, BOOL isInstanceMethod) 1613{ 1614 struct objc_method_description empty = {nil, nil}; 1615 old_protocol *proto = oldprotocol(p); 1616 struct objc_method_description *desc; 1617 if (!proto) return empty; 1618 1619 desc = lookup_protocol_method(proto, aSel, 1620 isRequiredMethod, isInstanceMethod, true); 1621 if (desc) return *desc; 1622 else return empty; 1623} 1624 1625 1626/*********************************************************************** 1627* protocol_copyMethodDescriptionList 1628* Returns an array of method descriptions from a protocol. 1629* Copies either required or optional methods. 1630* Copies either instance or class methods. 1631**********************************************************************/ 1632struct objc_method_description * 1633protocol_copyMethodDescriptionList(Protocol *p, 1634 BOOL isRequiredMethod, 1635 BOOL isInstanceMethod, 1636 unsigned int *outCount) 1637{ 1638 struct objc_method_description_list *mlist = nil; 1639 old_protocol *proto = oldprotocol(p); 1640 old_protocol_ext *ext; 1641 unsigned int i, count; 1642 struct objc_method_description *result; 1643 1644 if (!proto) { 1645 if (outCount) *outCount = 0; 1646 return nil; 1647 } 1648 1649 if (isRequiredMethod) { 1650 if (isInstanceMethod) { 1651 mlist = proto->instance_methods; 1652 } else { 1653 mlist = proto->class_methods; 1654 } 1655 } else if ((ext = ext_for_protocol(proto))) { 1656 if (isInstanceMethod) { 1657 mlist = ext->optional_instance_methods; 1658 } else { 1659 mlist = ext->optional_class_methods; 1660 } 1661 } 1662 1663 if (!mlist) { 1664 if (outCount) *outCount = 0; 1665 return nil; 1666 } 1667 1668 count = mlist->count; 1669 result = (struct objc_method_description *) 1670 calloc(count + 1, sizeof(struct objc_method_description)); 1671 for (i = 0; i < count; i++) { 1672 result[i] = mlist->list[i]; 1673 } 1674 1675 if (outCount) *outCount = count; 1676 return result; 1677} 1678 1679 1680objc_property_t protocol_getProperty(Protocol *p, const char *name, 1681 BOOL isRequiredProperty, BOOL isInstanceProperty) 1682{ 1683 old_protocol *proto = oldprotocol(p); 1684 old_protocol_ext *ext; 1685 old_protocol_list *proto_list; 1686 1687 if (!proto || !name) return nil; 1688 1689 if (!isRequiredProperty || !isInstanceProperty) { 1690 // Only required instance properties are currently supported 1691 return nil; 1692 } 1693 1694 if ((ext = ext_for_protocol(proto))) { 1695 old_property_list *plist; 1696 if ((plist = ext->instance_properties)) { 1697 uint32_t i; 1698 for (i = 0; i < plist->count; i++) { 1699 old_property *prop = property_list_nth(plist, i); 1700 if (0 == strcmp(name, prop->name)) { 1701 return (objc_property_t)prop; 1702 } 1703 } 1704 } 1705 } 1706 1707 if ((proto_list = proto->protocol_list)) { 1708 int i; 1709 for (i = 0; i < proto_list->count; i++) { 1710 objc_property_t prop = 1711 protocol_getProperty((Protocol *)proto_list->list[i], name, 1712 isRequiredProperty, isInstanceProperty); 1713 if (prop) return prop; 1714 } 1715 } 1716 1717 return nil; 1718} 1719 1720 1721objc_property_t *protocol_copyPropertyList(Protocol *p, unsigned int *outCount) 1722{ 1723 old_property **result = nil; 1724 old_protocol_ext *ext; 1725 old_property_list *plist; 1726 1727 old_protocol *proto = oldprotocol(p); 1728 if (! (ext = ext_for_protocol(proto))) { 1729 if (outCount) *outCount = 0; 1730 return nil; 1731 } 1732 1733 plist = ext->instance_properties; 1734 result = copyPropertyList(plist, outCount); 1735 1736 return (objc_property_t *)result; 1737} 1738 1739 1740/*********************************************************************** 1741* protocol_copyProtocolList 1742* Copies this protocol's incorporated protocols. 1743* Does not copy those protocol's incorporated protocols in turn. 1744**********************************************************************/ 1745Protocol * __unsafe_unretained * 1746protocol_copyProtocolList(Protocol *p, unsigned int *outCount) 1747{ 1748 unsigned int count = 0; 1749 Protocol **result = nil; 1750 old_protocol *proto = oldprotocol(p); 1751 1752 if (!proto) { 1753 if (outCount) *outCount = 0; 1754 return nil; 1755 } 1756 1757 if (proto->protocol_list) { 1758 count = (unsigned int)proto->protocol_list->count; 1759 } 1760 if (count > 0) { 1761 unsigned int i; 1762 result = (Protocol **)malloc((count+1) * sizeof(Protocol *)); 1763 1764 for (i = 0; i < count; i++) { 1765 result[i] = (Protocol *)proto->protocol_list->list[i]; 1766 } 1767 result[i] = nil; 1768 } 1769 1770 if (outCount) *outCount = count; 1771 return result; 1772} 1773 1774 1775BOOL protocol_conformsToProtocol(Protocol *self_gen, Protocol *other_gen) 1776{ 1777 old_protocol *self = oldprotocol(self_gen); 1778 old_protocol *other = oldprotocol(other_gen); 1779 1780 if (!self || !other) { 1781 return NO; 1782 } 1783 1784 if (0 == strcmp(self->protocol_name, other->protocol_name)) { 1785 return YES; 1786 } 1787 1788 if (self->protocol_list) { 1789 int i; 1790 for (i = 0; i < self->protocol_list->count; i++) { 1791 old_protocol *proto = self->protocol_list->list[i]; 1792 if (0 == strcmp(other->protocol_name, proto->protocol_name)) { 1793 return YES; 1794 } 1795 if (protocol_conformsToProtocol((Protocol *)proto, other_gen)) { 1796 return YES; 1797 } 1798 } 1799 } 1800 1801 return NO; 1802} 1803 1804 1805BOOL protocol_isEqual(Protocol *self, Protocol *other) 1806{ 1807 if (self == other) return YES; 1808 if (!self || !other) return NO; 1809 1810 if (!protocol_conformsToProtocol(self, other)) return NO; 1811 if (!protocol_conformsToProtocol(other, self)) return NO; 1812 1813 return YES; 1814} 1815 1816 1817/*********************************************************************** 1818* _protocol_getMethodTypeEncoding 1819* Return the @encode string for the requested protocol method. 1820* Returns nil if the compiler did not emit any extended @encode data. 1821* Locking: runtimeLock must not be held by the caller 1822**********************************************************************/ 1823const char * 1824_protocol_getMethodTypeEncoding(Protocol *proto_gen, SEL sel, 1825 BOOL isRequiredMethod, BOOL isInstanceMethod) 1826{ 1827 old_protocol *proto = oldprotocol(proto_gen); 1828 if (!proto) return nil; 1829 old_protocol_ext *ext = ext_for_protocol(proto); 1830 if (!ext) return nil; 1831 if (ext->size < offsetof(old_protocol_ext, extendedMethodTypes) + sizeof(ext->extendedMethodTypes)) return nil; 1832 if (! ext->extendedMethodTypes) return nil; 1833 1834 struct objc_method_description *m = 1835 lookup_protocol_method(proto, sel, 1836 isRequiredMethod, isInstanceMethod, false); 1837 if (!m) { 1838 // No method with that name. Search incorporated protocols. 1839 if (proto->protocol_list) { 1840 for (int i = 0; i < proto->protocol_list->count; i++) { 1841 const char *enc = 1842 _protocol_getMethodTypeEncoding((Protocol *)proto->protocol_list->list[i], sel, isRequiredMethod, isInstanceMethod); 1843 if (enc) return enc; 1844 } 1845 } 1846 return nil; 1847 } 1848 1849 int i = 0; 1850 if (isRequiredMethod && isInstanceMethod) { 1851 i += ((uintptr_t)m - (uintptr_t)proto->instance_methods) / sizeof(proto->instance_methods->list[0]); 1852 goto done; 1853 } else if (proto->instance_methods) { 1854 i += proto->instance_methods->count; 1855 } 1856 1857 if (isRequiredMethod && !isInstanceMethod) { 1858 i += ((uintptr_t)m - (uintptr_t)proto->class_methods) / sizeof(proto->class_methods->list[0]); 1859 goto done; 1860 } else if (proto->class_methods) { 1861 i += proto->class_methods->count; 1862 } 1863 1864 if (!isRequiredMethod && isInstanceMethod) { 1865 i += ((uintptr_t)m - (uintptr_t)ext->optional_instance_methods) / sizeof(ext->optional_instance_methods->list[0]); 1866 goto done; 1867 } else if (ext->optional_instance_methods) { 1868 i += ext->optional_instance_methods->count; 1869 } 1870 1871 if (!isRequiredMethod && !isInstanceMethod) { 1872 i += ((uintptr_t)m - (uintptr_t)ext->optional_class_methods) / sizeof(ext->optional_class_methods->list[0]); 1873 goto done; 1874 } else if (ext->optional_class_methods) { 1875 i += ext->optional_class_methods->count; 1876 } 1877 1878 done: 1879 return ext->extendedMethodTypes[i]; 1880} 1881 1882 1883/*********************************************************************** 1884* objc_allocateProtocol 1885* Creates a new protocol. The protocol may not be used until 1886* objc_registerProtocol() is called. 1887* Returns nil if a protocol with the same name already exists. 1888* Locking: acquires classLock 1889**********************************************************************/ 1890Protocol * 1891objc_allocateProtocol(const char *name) 1892{ 1893 Class cls = objc_getClass("__IncompleteProtocol"); 1894 1895 mutex_lock(&classLock); 1896 1897 if (NXMapGet(protocol_map, name)) { 1898 mutex_unlock(&classLock); 1899 return nil; 1900 } 1901 1902 old_protocol *result = (old_protocol *) 1903 _calloc_internal(1, sizeof(old_protocol) 1904 + sizeof(old_protocol_ext)); 1905 old_protocol_ext *ext = (old_protocol_ext *)(result+1); 1906 1907 result->isa = cls; 1908 result->protocol_name = _strdup_internal(name); 1909 ext->size = sizeof(old_protocol_ext); 1910 1911 // fixme reserve name without installing 1912 1913 NXMapInsert(protocol_ext_map, result, result+1); 1914 1915 mutex_unlock(&classLock); 1916 1917 return (Protocol *)result; 1918} 1919 1920 1921/*********************************************************************** 1922* objc_registerProtocol 1923* Registers a newly-constructed protocol. The protocol is now 1924* ready for use and immutable. 1925* Locking: acquires classLock 1926**********************************************************************/ 1927void objc_registerProtocol(Protocol *proto_gen) 1928{ 1929 old_protocol *proto = oldprotocol(proto_gen); 1930 1931 Class oldcls = objc_getClass("__IncompleteProtocol"); 1932 Class cls = objc_getClass("Protocol"); 1933 1934 mutex_lock(&classLock); 1935 1936 if (proto->isa == cls) { 1937 _objc_inform("objc_registerProtocol: protocol '%s' was already " 1938 "registered!", proto->protocol_name); 1939 mutex_unlock(&classLock); 1940 return; 1941 } 1942 if (proto->isa != oldcls) { 1943 _objc_inform("objc_registerProtocol: protocol '%s' was not allocated " 1944 "with objc_allocateProtocol!", proto->protocol_name); 1945 mutex_unlock(&classLock); 1946 return; 1947 } 1948 1949 proto->isa = cls; 1950 1951 NXMapKeyCopyingInsert(protocol_map, proto->protocol_name, proto); 1952 1953 mutex_unlock(&classLock); 1954} 1955 1956 1957/*********************************************************************** 1958* protocol_addProtocol 1959* Adds an incorporated protocol to another protocol. 1960* No method enforcement is performed. 1961* `proto` must be under construction. `addition` must not. 1962* Locking: acquires classLock 1963**********************************************************************/ 1964void 1965protocol_addProtocol(Protocol *proto_gen, Protocol *addition_gen) 1966{ 1967 old_protocol *proto = oldprotocol(proto_gen); 1968 old_protocol *addition = oldprotocol(addition_gen); 1969 1970 Class cls = objc_getClass("__IncompleteProtocol"); 1971 1972 if (!proto_gen) return; 1973 if (!addition_gen) return; 1974 1975 mutex_lock(&classLock); 1976 1977 if (proto->isa != cls) { 1978 _objc_inform("protocol_addProtocol: modified protocol '%s' is not " 1979 "under construction!", proto->protocol_name); 1980 mutex_unlock(&classLock); 1981 return; 1982 } 1983 if (addition->isa == cls) { 1984 _objc_inform("protocol_addProtocol: added protocol '%s' is still " 1985 "under construction!", addition->protocol_name); 1986 mutex_unlock(&classLock); 1987 return; 1988 } 1989 1990 old_protocol_list *protolist = proto->protocol_list; 1991 if (protolist) { 1992 size_t size = sizeof(old_protocol_list) 1993 + protolist->count * sizeof(protolist->list[0]); 1994 protolist = (old_protocol_list *) 1995 _realloc_internal(protolist, size); 1996 } else { 1997 protolist = (old_protocol_list *) 1998 _calloc_internal(1, sizeof(old_protocol_list)); 1999 } 2000 2001 protolist->list[protolist->count++] = addition; 2002 proto->protocol_list = protolist; 2003 2004 mutex_unlock(&classLock); 2005} 2006 2007 2008/*********************************************************************** 2009* protocol_addMethodDescription 2010* Adds a method to a protocol. The protocol must be under construction. 2011* Locking: acquires classLock 2012**********************************************************************/ 2013static void 2014_protocol_addMethod(struct objc_method_description_list **list, SEL name, const char *types) 2015{ 2016 if (!*list) { 2017 *list = (struct objc_method_description_list *) 2018 _calloc_internal(sizeof(struct objc_method_description_list), 1); 2019 } else { 2020 size_t size = sizeof(struct objc_method_description_list) 2021 + (*list)->count * sizeof(struct objc_method_description); 2022 *list = (struct objc_method_description_list *) 2023 _realloc_internal(*list, size); 2024 } 2025 2026 struct objc_method_description *desc = &(*list)->list[(*list)->count++]; 2027 desc->name = name; 2028 desc->types = _strdup_internal(types ?: ""); 2029} 2030 2031void 2032protocol_addMethodDescription(Protocol *proto_gen, SEL name, const char *types, 2033 BOOL isRequiredMethod, BOOL isInstanceMethod) 2034{ 2035 old_protocol *proto = oldprotocol(proto_gen); 2036 2037 Class cls = objc_getClass("__IncompleteProtocol"); 2038 2039 if (!proto_gen) return; 2040 2041 mutex_lock(&classLock); 2042 2043 if (proto->isa != cls) { 2044 _objc_inform("protocol_addMethodDescription: protocol '%s' is not " 2045 "under construction!", proto->protocol_name); 2046 mutex_unlock(&classLock); 2047 return; 2048 } 2049 2050 if (isRequiredMethod && isInstanceMethod) { 2051 _protocol_addMethod(&proto->instance_methods, name, types); 2052 } else if (isRequiredMethod && !isInstanceMethod) { 2053 _protocol_addMethod(&proto->class_methods, name, types); 2054 } else if (!isRequiredMethod && isInstanceMethod) { 2055 old_protocol_ext *ext = (old_protocol_ext *)(proto+1); 2056 _protocol_addMethod(&ext->optional_instance_methods, name, types); 2057 } else /* !isRequiredMethod && !isInstanceMethod) */ { 2058 old_protocol_ext *ext = (old_protocol_ext *)(proto+1); 2059 _protocol_addMethod(&ext->optional_class_methods, name, types); 2060 } 2061 2062 mutex_unlock(&classLock); 2063} 2064 2065 2066/*********************************************************************** 2067* protocol_addProperty 2068* Adds a property to a protocol. The protocol must be under construction. 2069* Locking: acquires classLock 2070**********************************************************************/ 2071static void 2072_protocol_addProperty(old_property_list **plist, const char *name, 2073 const objc_property_attribute_t *attrs, 2074 unsigned int count) 2075{ 2076 if (!*plist) { 2077 *plist = (old_property_list *) 2078 _calloc_internal(sizeof(old_property_list), 1); 2079 (*plist)->entsize = sizeof(old_property); 2080 } else { 2081 *plist = (old_property_list *) 2082 _realloc_internal(*plist, sizeof(old_property_list) 2083 + (*plist)->count * (*plist)->entsize); 2084 } 2085 2086 old_property *prop = property_list_nth(*plist, (*plist)->count++); 2087 prop->name = _strdup_internal(name); 2088 prop->attributes = copyPropertyAttributeString(attrs, count); 2089} 2090 2091void 2092protocol_addProperty(Protocol *proto_gen, const char *name, 2093 const objc_property_attribute_t *attrs, 2094 unsigned int count, 2095 BOOL isRequiredProperty, BOOL isInstanceProperty) 2096{ 2097 old_protocol *proto = oldprotocol(proto_gen); 2098 2099 Class cls = objc_getClass("__IncompleteProtocol"); 2100 2101 if (!proto) return; 2102 if (!name) return; 2103 2104 mutex_lock(&classLock); 2105 2106 if (proto->isa != cls) { 2107 _objc_inform("protocol_addProperty: protocol '%s' is not " 2108 "under construction!", proto->protocol_name); 2109 mutex_unlock(&classLock); 2110 return; 2111 } 2112 2113 old_protocol_ext *ext = ext_for_protocol(proto); 2114 2115 if (isRequiredProperty && isInstanceProperty) { 2116 _protocol_addProperty(&ext->instance_properties, name, attrs, count); 2117 } 2118 //else if (isRequiredProperty && !isInstanceProperty) { 2119 // _protocol_addProperty(&ext->class_properties, name, attrs, count); 2120 //} else if (!isRequiredProperty && isInstanceProperty) { 2121 // _protocol_addProperty(&ext->optional_instance_properties, name, attrs, count); 2122 //} else /* !isRequiredProperty && !isInstanceProperty) */ { 2123 // _protocol_addProperty(&ext->optional_class_properties, name, attrs, count); 2124 //} 2125 2126 mutex_unlock(&classLock); 2127} 2128 2129 2130/*********************************************************************** 2131* _objc_fixup_protocol_objects_for_image. For each protocol in the 2132* specified image, selectorize the method names and add to the protocol hash. 2133**********************************************************************/ 2134 2135static BOOL versionIsExt(uintptr_t version, const char *names, size_t size) 2136{ 2137 // CodeWarrior used isa field for string "Protocol" 2138 // from section __OBJC,__class_names. rdar://4951638 2139 // gcc (10.4 and earlier) used isa field for version number; 2140 // the only version number used on Mac OS X was 2. 2141 // gcc (10.5 and later) uses isa field for ext pointer 2142 2143 if (version < 4096 /* not PAGE_SIZE */) { 2144 return NO; 2145 } 2146 2147 if (version >= (uintptr_t)names && version < (uintptr_t)(names + size)) { 2148 return NO; 2149 } 2150 2151 return YES; 2152} 2153 2154static void fix_protocol(old_protocol *proto, Class protocolClass, 2155 BOOL isBundle, const char *names, size_t names_size) 2156{ 2157 uintptr_t version; 2158 if (!proto) return; 2159 2160 version = (uintptr_t)proto->isa; 2161 2162 // Set the protocol's isa 2163 proto->isa = protocolClass; 2164 2165 // Fix up method lists 2166 // fixme share across duplicates 2167 map_method_descs (proto->instance_methods, isBundle); 2168 map_method_descs (proto->class_methods, isBundle); 2169 2170 // Fix up ext, if any 2171 if (versionIsExt(version, names, names_size)) { 2172 old_protocol_ext *ext = (old_protocol_ext *)version; 2173 NXMapInsert(protocol_ext_map, proto, ext); 2174 map_method_descs (ext->optional_instance_methods, isBundle); 2175 map_method_descs (ext->optional_class_methods, isBundle); 2176 } 2177 2178 // Record the protocol it if we don't have one with this name yet 2179 // fixme bundles - copy protocol 2180 // fixme unloading 2181 if (!NXMapGet(protocol_map, proto->protocol_name)) { 2182 NXMapKeyCopyingInsert(protocol_map, proto->protocol_name, proto); 2183 if (PrintProtocols) { 2184 _objc_inform("PROTOCOLS: protocol at %p is %s", 2185 proto, proto->protocol_name); 2186 } 2187 } else { 2188 // duplicate - do nothing 2189 if (PrintProtocols) { 2190 _objc_inform("PROTOCOLS: protocol at %p is %s (duplicate)", 2191 proto, proto->protocol_name); 2192 } 2193 } 2194} 2195 2196static void _objc_fixup_protocol_objects_for_image (header_info * hi) 2197{ 2198 Class protocolClass = objc_getClass("Protocol"); 2199 size_t count, i; 2200 old_protocol **protos; 2201 int isBundle = headerIsBundle(hi); 2202 const char *names; 2203 size_t names_size; 2204 2205 mutex_lock(&classLock); 2206 2207 // Allocate the protocol registry if necessary. 2208 if (!protocol_map) { 2209 protocol_map = 2210 NXCreateMapTableFromZone(NXStrValueMapPrototype, 32, 2211 _objc_internal_zone()); 2212 } 2213 if (!protocol_ext_map) { 2214 protocol_ext_map = 2215 NXCreateMapTableFromZone(NXPtrValueMapPrototype, 32, 2216 _objc_internal_zone()); 2217 } 2218 2219 protos = _getObjcProtocols(hi, &count); 2220 names = _getObjcClassNames(hi, &names_size); 2221 for (i = 0; i < count; i++) { 2222 fix_protocol(protos[i], protocolClass, isBundle, names, names_size); 2223 } 2224 2225 mutex_unlock(&classLock); 2226} 2227 2228 2229/*********************************************************************** 2230* _objc_fixup_selector_refs. Register all of the selectors in each 2231* image, and fix them all up. 2232**********************************************************************/ 2233static void _objc_fixup_selector_refs (const header_info *hi) 2234{ 2235 size_t count; 2236 SEL *sels; 2237 2238 if (PrintPreopt) { 2239 if (sel_preoptimizationValid(hi)) { 2240 _objc_inform("PREOPTIMIZATION: honoring preoptimized selectors in %s", 2241 hi->fname); 2242 } 2243 else if (_objcHeaderOptimizedByDyld(hi)) { 2244 _objc_inform("PREOPTIMIZATION: IGNORING preoptimized selectors in %s", 2245 hi->fname); 2246 } 2247 } 2248 2249 if (sel_preoptimizationValid(hi)) return; 2250 2251 sels = _getObjcSelectorRefs (hi, &count); 2252 2253 map_selrefs(sels, count, headerIsBundle(hi)); 2254} 2255 2256static inline BOOL _is_threaded() { 2257#if TARGET_OS_WIN32 2258 return YES; 2259#else 2260 return pthread_is_threaded_np() != 0; 2261#endif 2262} 2263 2264#if !TARGET_OS_WIN32 2265/*********************************************************************** 2266* unmap_image 2267* Process the given image which is about to be unmapped by dyld. 2268* mh is mach_header instead of headerType because that's what 2269* dyld_priv.h says even for 64-bit. 2270**********************************************************************/ 2271void 2272unmap_image(const struct mach_header *mh, intptr_t vmaddr_slide) 2273{ 2274 recursive_mutex_lock(&loadMethodLock); 2275 unmap_image_nolock(mh); 2276 recursive_mutex_unlock(&loadMethodLock); 2277} 2278 2279 2280/*********************************************************************** 2281* map_images 2282* Process the given images which are being mapped in by dyld. 2283* Calls ABI-agnostic code after taking ABI-specific locks. 2284**********************************************************************/ 2285const char * 2286map_images(enum dyld_image_states state, uint32_t infoCount, 2287 const struct dyld_image_info infoList[]) 2288{ 2289 const char *err; 2290 2291 recursive_mutex_lock(&loadMethodLock); 2292 err = map_images_nolock(state, infoCount, infoList); 2293 recursive_mutex_unlock(&loadMethodLock); 2294 2295 return err; 2296} 2297 2298 2299/*********************************************************************** 2300* load_images 2301* Process +load in the given images which are being mapped in by dyld. 2302* Calls ABI-agnostic code after taking ABI-specific locks. 2303* 2304* Locking: acquires classLock and loadMethodLock 2305**********************************************************************/ 2306const char * 2307load_images(enum dyld_image_states state, uint32_t infoCount, 2308 const struct dyld_image_info infoList[]) 2309{ 2310 BOOL found; 2311 2312 recursive_mutex_lock(&loadMethodLock); 2313 2314 // Discover +load methods 2315 found = load_images_nolock(state, infoCount, infoList); 2316 2317 // Call +load methods (without classLock - re-entrant) 2318 if (found) { 2319 call_load_methods(); 2320 } 2321 2322 recursive_mutex_unlock(&loadMethodLock); 2323 2324 return nil; 2325} 2326#endif 2327 2328 2329/*********************************************************************** 2330* _read_images 2331* Perform metadata processing for hCount images starting with firstNewHeader 2332**********************************************************************/ 2333void _read_images(header_info **hList, uint32_t hCount) 2334{ 2335 uint32_t i; 2336 BOOL categoriesLoaded = NO; 2337 2338 if (!class_hash) _objc_init_class_hash(); 2339 2340 // Parts of this order are important for correctness or performance. 2341 2342 // Read classes from all images. 2343 for (i = 0; i < hCount; i++) { 2344 _objc_read_classes_from_image(hList[i]); 2345 } 2346 2347 // Read categories from all images. 2348 // But not if any other threads are running - they might 2349 // call a category method before the fixups below are complete. 2350 if (!_is_threaded()) { 2351 BOOL needFlush = NO; 2352 for (i = 0; i < hCount; i++) { 2353 needFlush |= _objc_read_categories_from_image(hList[i]); 2354 } 2355 if (needFlush) flush_marked_caches(); 2356 categoriesLoaded = YES; 2357 } 2358 2359 // Connect classes from all images. 2360 for (i = 0; i < hCount; i++) { 2361 _objc_connect_classes_from_image(hList[i]); 2362 } 2363 2364 // Fix up class refs, selector refs, and protocol objects from all images. 2365 for (i = 0; i < hCount; i++) { 2366 _objc_map_class_refs_for_image(hList[i]); 2367 _objc_fixup_selector_refs(hList[i]); 2368 _objc_fixup_protocol_objects_for_image(hList[i]); 2369 } 2370 2371 // Read categories from all images. 2372 // But not if this is the only thread - it's more 2373 // efficient to attach categories earlier if safe. 2374 if (!categoriesLoaded) { 2375 BOOL needFlush = NO; 2376 for (i = 0; i < hCount; i++) { 2377 needFlush |= _objc_read_categories_from_image(hList[i]); 2378 } 2379 if (needFlush) flush_marked_caches(); 2380 } 2381 2382 // Multi-threaded category load MUST BE LAST to avoid a race. 2383} 2384 2385 2386/*********************************************************************** 2387* prepare_load_methods 2388* Schedule +load for classes in this image, any un-+load-ed 2389* superclasses in other images, and any categories in this image. 2390**********************************************************************/ 2391// Recursively schedule +load for cls and any un-+load-ed superclasses. 2392// cls must already be connected. 2393static void schedule_class_load(Class cls) 2394{ 2395 if (cls->info & CLS_LOADED) return; 2396 if (cls->superclass) schedule_class_load(cls->superclass); 2397 add_class_to_loadable_list(cls); 2398 cls->info |= CLS_LOADED; 2399} 2400 2401void prepare_load_methods(header_info *hi) 2402{ 2403 Module mods; 2404 unsigned int midx; 2405 2406 2407 if (_objcHeaderIsReplacement(hi)) { 2408 // Ignore any classes in this image 2409 return; 2410 } 2411 2412 // Major loop - process all modules in the image 2413 mods = hi->mod_ptr; 2414 for (midx = 0; midx < hi->mod_count; midx += 1) 2415 { 2416 unsigned int index; 2417 2418 // Skip module containing no classes 2419 if (mods[midx].symtab == nil) 2420 continue; 2421 2422 // Minor loop - process all the classes in given module 2423 for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1) 2424 { 2425 // Locate the class description pointer 2426 Class cls = (Class)mods[midx].symtab->defs[index]; 2427 if (cls->info & CLS_CONNECTED) { 2428 schedule_class_load(cls); 2429 } 2430 } 2431 } 2432 2433 2434 // Major loop - process all modules in the header 2435 mods = hi->mod_ptr; 2436 2437 // NOTE: The module and category lists are traversed backwards 2438 // to preserve the pre-10.4 processing order. Changing the order 2439 // would have a small chance of introducing binary compatibility bugs. 2440 midx = (unsigned int)hi->mod_count; 2441 while (midx-- > 0) { 2442 unsigned int index; 2443 unsigned int total; 2444 Symtab symtab = mods[midx].symtab; 2445 2446 // Nothing to do for a module without a symbol table 2447 if (mods[midx].symtab == nil) 2448 continue; 2449 // Total entries in symbol table (class entries followed 2450 // by category entries) 2451 total = mods[midx].symtab->cls_def_cnt + 2452 mods[midx].symtab->cat_def_cnt; 2453 2454 // Minor loop - register all categories from given module 2455 index = total; 2456 while (index-- > mods[midx].symtab->cls_def_cnt) { 2457 old_category *cat = (old_category *)symtab->defs[index]; 2458 add_category_to_loadable_list((Category)cat); 2459 } 2460 } 2461} 2462 2463 2464#if TARGET_OS_WIN32 2465 2466void unload_class(Class cls) 2467{ 2468} 2469 2470#else 2471 2472/*********************************************************************** 2473* _objc_remove_classes_in_image 2474* Remove all classes in the given image from the runtime, because 2475* the image is about to be unloaded. 2476* Things to clean up: 2477* class_hash 2478* unconnected_class_hash 2479* pending subclasses list (only if class is still unconnected) 2480* loadable class list 2481* class's method caches 2482* class refs in all other images 2483**********************************************************************/ 2484// Re-pend any class references in refs that point into [start..end) 2485static void rependClassReferences(Class *refs, size_t count, 2486 uintptr_t start, uintptr_t end) 2487{ 2488 size_t i; 2489 2490 if (!refs) return; 2491 2492 // Process each class ref 2493 for (i = 0; i < count; i++) { 2494 if ((uintptr_t)(refs[i]) >= start && (uintptr_t)(refs[i]) < end) { 2495 pendClassReference(&refs[i], refs[i]->name, 2496 (refs[i]->info & CLS_META) ? YES : NO); 2497 refs[i] = nil; 2498 } 2499 } 2500} 2501 2502 2503void try_free(const void *p) 2504{ 2505 if (p && malloc_size(p)) free((void *)p); 2506} 2507 2508// Deallocate all memory in a method list 2509static void unload_mlist(old_method_list *mlist) 2510{ 2511 int i; 2512 for (i = 0; i < mlist->method_count; i++) { 2513 try_free(mlist->method_list[i].method_types); 2514 } 2515 try_free(mlist); 2516} 2517 2518static void unload_property_list(old_property_list *proplist) 2519{ 2520 uint32_t i; 2521 2522 if (!proplist) return; 2523 2524 for (i = 0; i < proplist->count; i++) { 2525 old_property *prop = property_list_nth(proplist, i); 2526 try_free(prop->name); 2527 try_free(prop->attributes); 2528 } 2529 try_free(proplist); 2530} 2531 2532 2533// Deallocate all memory in a class. 2534void unload_class(Class cls) 2535{ 2536 // Free method cache 2537 // This dereferences the cache contents; do this before freeing methods 2538 if (cls->cache && cls->cache != &_objc_empty_cache) { 2539 _cache_free(cls->cache); 2540 } 2541 2542 // Free ivar lists 2543 if (cls->ivars) { 2544 int i; 2545 for (i = 0; i < cls->ivars->ivar_count; i++) { 2546 try_free(cls->ivars->ivar_list[i].ivar_name); 2547 try_free(cls->ivars->ivar_list[i].ivar_type); 2548 } 2549 try_free(cls->ivars); 2550 } 2551 2552 // Free fixed-up method lists and method list array 2553 if (cls->methodLists) { 2554 // more than zero method lists 2555 if (cls->info & CLS_NO_METHOD_ARRAY) { 2556 // one method list 2557 unload_mlist((old_method_list *)cls->methodLists); 2558 } 2559 else { 2560 // more than one method list 2561 old_method_list **mlistp; 2562 for (mlistp = cls->methodLists; 2563 *mlistp != nil && *mlistp != END_OF_METHODS_LIST; 2564 mlistp++) 2565 { 2566 unload_mlist(*mlistp); 2567 } 2568 free(cls->methodLists); 2569 } 2570 } 2571 2572 // Free protocol list 2573 old_protocol_list *protos = cls->protocols; 2574 while (protos) { 2575 old_protocol_list *dead = protos; 2576 protos = protos->next; 2577 try_free(dead); 2578 } 2579 2580 if ((cls->info & CLS_EXT)) { 2581 if (cls->ext) { 2582 // Free property lists and property list array 2583 if (cls->ext->propertyLists) { 2584 // more than zero property lists 2585 if (cls->info & CLS_NO_PROPERTY_ARRAY) { 2586 // one property list 2587 old_property_list *proplist = 2588 (old_property_list *)cls->ext->propertyLists; 2589 unload_property_list(proplist); 2590 } else { 2591 // more than one property list 2592 old_property_list **plistp; 2593 for (plistp = cls->ext->propertyLists; 2594 *plistp != nil; 2595 plistp++) 2596 { 2597 unload_property_list(*plistp); 2598 } 2599 try_free(cls->ext->propertyLists); 2600 } 2601 } 2602 2603 // Free weak ivar layout 2604 try_free(cls->ext->weak_ivar_layout); 2605 2606 // Free ext 2607 try_free(cls->ext); 2608 } 2609 2610 // Free non-weak ivar layout 2611 try_free(cls->ivar_layout); 2612 } 2613 2614 // Free class name 2615 try_free(cls->name); 2616 2617 // Free cls 2618 try_free(cls); 2619} 2620 2621 2622static void _objc_remove_classes_in_image(header_info *hi) 2623{ 2624 unsigned int index; 2625 unsigned int midx; 2626 Module mods; 2627 2628 mutex_lock(&classLock); 2629 2630 // Major loop - process all modules in the image 2631 mods = hi->mod_ptr; 2632 for (midx = 0; midx < hi->mod_count; midx += 1) 2633 { 2634 // Skip module containing no classes 2635 if (mods[midx].symtab == nil) 2636 continue; 2637 2638 // Minor loop - process all the classes in given module 2639 for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1) 2640 { 2641 Class cls; 2642 2643 // Locate the class description pointer 2644 cls = (Class)mods[midx].symtab->defs[index]; 2645 2646 // Remove from loadable class list, if present 2647 remove_class_from_loadable_list(cls); 2648 2649 // Remove from unconnected_class_hash and pending subclasses 2650 if (unconnected_class_hash && NXHashMember(unconnected_class_hash, cls)) { 2651 NXHashRemove(unconnected_class_hash, cls); 2652 if (pendingSubclassesMap) { 2653 // Find this class in its superclass's pending list 2654 char *supercls_name = (char *)cls->superclass; 2655 PendingSubclass *pending = (PendingSubclass *) 2656 NXMapGet(pendingSubclassesMap, supercls_name); 2657 for ( ; pending != nil; pending = pending->next) { 2658 if (pending->subclass == cls) { 2659 pending->subclass = Nil; 2660 break; 2661 } 2662 } 2663 } 2664 } 2665 2666 // Remove from class_hash 2667 NXHashRemove(class_hash, cls); 2668 objc_removeRegisteredClass(cls); 2669 2670 // Free heap memory pointed to by the class 2671 unload_class(cls->ISA()); 2672 unload_class(cls); 2673 } 2674 } 2675 2676 2677 // Search all other images for class refs that point back to this range. 2678 // Un-fix and re-pend any such class refs. 2679 2680 // Get the location of the dying image's __OBJC segment 2681 uintptr_t seg; 2682 unsigned long seg_size; 2683 seg = (uintptr_t)getsegmentdata(hi->mhdr, "__OBJC", &seg_size); 2684 2685 header_info *other_hi; 2686 for (other_hi = FirstHeader; other_hi != nil; other_hi = other_hi->next) { 2687 Class *other_refs; 2688 size_t count; 2689 if (other_hi == hi) continue; // skip the image being unloaded 2690 2691 // Fix class refs in the other image 2692 other_refs = _getObjcClassRefs(other_hi, &count); 2693 rependClassReferences(other_refs, count, seg, seg+seg_size); 2694 } 2695 2696 mutex_unlock(&classLock); 2697} 2698 2699 2700/*********************************************************************** 2701* _objc_remove_categories_in_image 2702* Remove all categories in the given image from the runtime, because 2703* the image is about to be unloaded. 2704* Things to clean up: 2705* unresolved category list 2706* loadable category list 2707**********************************************************************/ 2708static void _objc_remove_categories_in_image(header_info *hi) 2709{ 2710 Module mods; 2711 unsigned int midx; 2712 2713 // Major loop - process all modules in the header 2714 mods = hi->mod_ptr; 2715 2716 for (midx = 0; midx < hi->mod_count; midx++) { 2717 unsigned int index; 2718 unsigned int total; 2719 Symtab symtab = mods[midx].symtab; 2720 2721 // Nothing to do for a module without a symbol table 2722 if (symtab == nil) continue; 2723 2724 // Total entries in symbol table (class entries followed 2725 // by category entries) 2726 total = symtab->cls_def_cnt + symtab->cat_def_cnt; 2727 2728 // Minor loop - check all categories from given module 2729 for (index = symtab->cls_def_cnt; index < total; index++) { 2730 old_category *cat = (old_category *)symtab->defs[index]; 2731 2732 // Clean up loadable category list 2733 remove_category_from_loadable_list((Category)cat); 2734 2735 // Clean up category_hash 2736 if (category_hash) { 2737 _objc_unresolved_category *cat_entry = (_objc_unresolved_category *)NXMapGet(category_hash, cat->class_name); 2738 for ( ; cat_entry != nil; cat_entry = cat_entry->next) { 2739 if (cat_entry->cat == cat) { 2740 cat_entry->cat = nil; 2741 break; 2742 } 2743 } 2744 } 2745 } 2746 } 2747} 2748 2749 2750/*********************************************************************** 2751* unload_paranoia 2752* Various paranoid debugging checks that look for poorly-behaving 2753* unloadable bundles. 2754* Called by _objc_unmap_image when OBJC_UNLOAD_DEBUG is set. 2755**********************************************************************/ 2756static void unload_paranoia(header_info *hi) 2757{ 2758 // Get the location of the dying image's __OBJC segment 2759 uintptr_t seg; 2760 unsigned long seg_size; 2761 seg = (uintptr_t)getsegmentdata(hi->mhdr, "__OBJC", &seg_size); 2762 2763 _objc_inform("UNLOAD DEBUG: unloading image '%s' [%p..%p]", 2764 hi->fname, (void *)seg, (void*)(seg+seg_size)); 2765 2766 mutex_lock(&classLock); 2767 2768 // Make sure the image contains no categories on surviving classes. 2769 { 2770 Module mods; 2771 unsigned int midx; 2772 2773 // Major loop - process all modules in the header 2774 mods = hi->mod_ptr; 2775 2776 for (midx = 0; midx < hi->mod_count; midx++) { 2777 unsigned int index; 2778 unsigned int total; 2779 Symtab symtab = mods[midx].symtab; 2780 2781 // Nothing to do for a module without a symbol table 2782 if (symtab == nil) continue; 2783 2784 // Total entries in symbol table (class entries followed 2785 // by category entries) 2786 total = symtab->cls_def_cnt + symtab->cat_def_cnt; 2787 2788 // Minor loop - check all categories from given module 2789 for (index = symtab->cls_def_cnt; index < total; index++) { 2790 old_category *cat = (old_category *)symtab->defs[index]; 2791 struct objc_class query; 2792 2793 query.name = cat->class_name; 2794 if (NXHashMember(class_hash, &query)) { 2795 _objc_inform("UNLOAD DEBUG: dying image contains category '%s(%s)' on surviving class '%s'!", cat->class_name, cat->category_name, cat->class_name); 2796 } 2797 } 2798 } 2799 } 2800 2801 // Make sure no surviving class is in the dying image. 2802 // Make sure no surviving class has a superclass in the dying image. 2803 // fixme check method implementations too 2804 { 2805 Class cls; 2806 NXHashState state; 2807 2808 state = NXInitHashState(class_hash); 2809 while (NXNextHashState(class_hash, &state, (void **)&cls)) { 2810 if ((vm_address_t)cls >= seg && 2811 (vm_address_t)cls < seg+seg_size) 2812 { 2813 _objc_inform("UNLOAD DEBUG: dying image contains surviving class '%s'!", cls->name); 2814 } 2815 2816 if ((vm_address_t)cls->superclass >= seg && 2817 (vm_address_t)cls->superclass < seg+seg_size) 2818 { 2819 _objc_inform("UNLOAD DEBUG: dying image contains superclass '%s' of surviving class '%s'!", cls->superclass->name, cls->name); 2820 } 2821 } 2822 } 2823 2824 mutex_unlock(&classLock); 2825} 2826 2827 2828/*********************************************************************** 2829* _unload_image 2830* Only handles MH_BUNDLE for now. 2831* Locking: loadMethodLock acquired by unmap_image 2832**********************************************************************/ 2833void _unload_image(header_info *hi) 2834{ 2835 recursive_mutex_assert_locked(&loadMethodLock); 2836 2837 // Cleanup: 2838 // Remove image's classes from the class list and free auxiliary data. 2839 // Remove image's unresolved or loadable categories and free auxiliary data 2840 // Remove image's unresolved class refs. 2841 _objc_remove_classes_in_image(hi); 2842 _objc_remove_categories_in_image(hi); 2843 _objc_remove_pending_class_refs_in_image(hi); 2844 2845 // Perform various debugging checks if requested. 2846 if (DebugUnload) unload_paranoia(hi); 2847} 2848 2849#endif 2850 2851 2852/*********************************************************************** 2853* objc_addClass. Add the specified class to the table of known classes, 2854* after doing a little verification and fixup. 2855**********************************************************************/ 2856void objc_addClass (Class cls) 2857{ 2858 OBJC_WARN_DEPRECATED; 2859 2860 // Synchronize access to hash table 2861 mutex_lock (&classLock); 2862 2863 // Make sure both the class and the metaclass have caches! 2864 // Clear all bits of the info fields except CLS_CLASS and CLS_META. 2865 // Normally these bits are already clear but if someone tries to cons 2866 // up their own class on the fly they might need to be cleared. 2867 if (cls->cache == nil) { 2868 cls->cache = (Cache) &_objc_empty_cache; 2869 cls->info = CLS_CLASS; 2870 } 2871 2872 if (cls->ISA()->cache == nil) { 2873 cls->ISA()->cache = (Cache) &_objc_empty_cache; 2874 cls->ISA()->info = CLS_META; 2875 } 2876 2877 // methodLists should be: 2878 // 1. nil (Tiger and later only) 2879 // 2. A -1 terminated method list array 2880 // In either case, CLS_NO_METHOD_ARRAY remains clear. 2881 // If the user manipulates the method list directly, 2882 // they must use the magic private format. 2883 2884 // Add the class to the table 2885 (void) NXHashInsert (class_hash, cls); 2886 objc_addRegisteredClass(cls); 2887 2888 // Superclass is no longer a leaf for cache flushing 2889 if (cls->superclass && (cls->superclass->info & CLS_LEAF)) { 2890 cls->superclass->clearInfo(CLS_LEAF); 2891 cls->superclass->ISA()->clearInfo(CLS_LEAF); 2892 } 2893 2894 // Desynchronize 2895 mutex_unlock (&classLock); 2896} 2897 2898/*********************************************************************** 2899* _objcTweakMethodListPointerForClass. 2900* Change the class's method list pointer to a method list array. 2901* Does nothing if the method list pointer is already a method list array. 2902* If the class is currently in use, methodListLock must be held by the caller. 2903**********************************************************************/ 2904static void _objcTweakMethodListPointerForClass(Class cls) 2905{ 2906 old_method_list * originalList; 2907 const int initialEntries = 4; 2908 size_t mallocSize; 2909 old_method_list ** ptr; 2910 2911 // Do nothing if methodLists is already an array. 2912 if (cls->methodLists && !(cls->info & CLS_NO_METHOD_ARRAY)) return; 2913 2914 // Remember existing list 2915 originalList = (old_method_list *) cls->methodLists; 2916 2917 // Allocate and zero a method list array 2918 mallocSize = sizeof(old_method_list *) * initialEntries; 2919 ptr = (old_method_list **) _calloc_internal(1, mallocSize); 2920 2921 // Insert the existing list into the array 2922 ptr[initialEntries - 1] = END_OF_METHODS_LIST; 2923 ptr[0] = originalList; 2924 2925 // Replace existing list with array 2926 cls->methodLists = ptr; 2927 cls->clearInfo(CLS_NO_METHOD_ARRAY); 2928} 2929 2930 2931/*********************************************************************** 2932* _objc_insertMethods. 2933* Adds methods to a class. 2934* Does not flush any method caches. 2935* Does not take any locks. 2936* If the class is already in use, use class_addMethods() instead. 2937**********************************************************************/ 2938void _objc_insertMethods(Class cls, old_method_list *mlist, old_category *cat) 2939{ 2940 old_method_list ***list; 2941 old_method_list **ptr; 2942 ptrdiff_t endIndex; 2943 size_t oldSize; 2944 size_t newSize; 2945 2946 if (!cls->methodLists) { 2947 // cls has no methods - simply use this method list 2948 cls->methodLists = (old_method_list **)mlist; 2949 cls->setInfo(CLS_NO_METHOD_ARRAY); 2950 return; 2951 } 2952 2953 // Log any existing methods being replaced 2954 if (PrintReplacedMethods) { 2955 int i; 2956 for (i = 0; i < mlist->method_count; i++) { 2957 extern IMP findIMPInClass(Class cls, SEL sel); 2958 SEL sel = sel_registerName((char *)mlist->method_list[i].method_name); 2959 IMP newImp = mlist->method_list[i].method_imp; 2960 IMP oldImp; 2961 2962 if ((oldImp = findIMPInClass(cls, sel))) { 2963 logReplacedMethod(cls->name, sel, ISMETA(cls), 2964 cat ? cat->category_name : nil, 2965 oldImp, newImp); 2966 } 2967 } 2968 } 2969 2970 // Create method list array if necessary 2971 _objcTweakMethodListPointerForClass(cls); 2972 2973 list = &cls->methodLists; 2974 2975 // Locate unused entry for insertion point 2976 ptr = *list; 2977 while ((*ptr != 0) && (*ptr != END_OF_METHODS_LIST)) 2978 ptr += 1; 2979 2980 // If array is full, add to it 2981 if (*ptr == END_OF_METHODS_LIST) 2982 { 2983 // Calculate old and new dimensions 2984 endIndex = ptr - *list; 2985 oldSize = (endIndex + 1) * sizeof(void *); 2986 newSize = oldSize + sizeof(old_method_list *); // only increase by 1 2987 2988 // Grow the method list array by one. 2989 // This block may be from user code; don't use _realloc_internal 2990 *list = (old_method_list **)realloc(*list, newSize); 2991 2992 // Zero out addition part of new array 2993 bzero (&((*list)[endIndex]), newSize - oldSize); 2994 2995 // Place new end marker 2996 (*list)[(newSize/sizeof(void *)) - 1] = END_OF_METHODS_LIST; 2997 2998 // Insertion point corresponds to old array end 2999 ptr = &((*list)[endIndex]); 3000 } 3001 3002 // Right shift existing entries by one 3003 bcopy (*list, (*list) + 1, (uint8_t *)ptr - (uint8_t *)*list); 3004 3005 // Insert at method list at beginning of array 3006 **list = mlist; 3007} 3008 3009/*********************************************************************** 3010* _objc_removeMethods. 3011* Remove methods from a class. 3012* Does not take any locks. 3013* Does not flush any method caches. 3014* If the class is currently in use, use class_removeMethods() instead. 3015**********************************************************************/ 3016void _objc_removeMethods(Class cls, old_method_list *mlist) 3017{ 3018 old_method_list ***list; 3019 old_method_list **ptr; 3020 3021 if (cls->methodLists == nil) { 3022 // cls has no methods 3023 return; 3024 } 3025 if (cls->methodLists == (old_method_list **)mlist) { 3026 // mlist is the class's only method list - erase it 3027 cls->methodLists = nil; 3028 return; 3029 } 3030 if (cls->info & CLS_NO_METHOD_ARRAY) { 3031 // cls has only one method list, and this isn't it - do nothing 3032 return; 3033 } 3034 3035 // cls has a method list array - search it 3036 3037 list = &cls->methodLists; 3038 3039 // Locate list in the array 3040 ptr = *list; 3041 while (*ptr != mlist) { 3042 // fix for radar # 2538790 3043 if ( *ptr == END_OF_METHODS_LIST ) return; 3044 ptr += 1; 3045 } 3046 3047 // Remove this entry 3048 *ptr = 0; 3049 3050 // Left shift the following entries 3051 while (*(++ptr) != END_OF_METHODS_LIST) 3052 *(ptr-1) = *ptr; 3053 *(ptr-1) = 0; 3054} 3055 3056/*********************************************************************** 3057* _objc_add_category. Install the specified category's methods and 3058* protocols into the class it augments. 3059* The class is assumed not to be in use yet: no locks are taken and 3060* no method caches are flushed. 3061**********************************************************************/ 3062static inline void _objc_add_category(Class cls, old_category *category, int version) 3063{ 3064 if (PrintConnecting) { 3065 _objc_inform("CONNECT: attaching category '%s (%s)'", cls->name, category->category_name); 3066 } 3067 3068 // Augment instance methods 3069 if (category->instance_methods) 3070 _objc_insertMethods (cls, category->instance_methods, category); 3071 3072 // Augment class methods 3073 if (category->class_methods) 3074 _objc_insertMethods (cls->ISA(), category->class_methods, category); 3075 3076 // Augment protocols 3077 if ((version >= 5) && category->protocols) 3078 { 3079 if (cls->ISA()->version >= 5) 3080 { 3081 category->protocols->next = cls->protocols; 3082 cls->protocols = category->protocols; 3083 cls->ISA()->protocols = category->protocols; 3084 } 3085 else 3086 { 3087 _objc_inform ("unable to add protocols from category %s...\n", category->category_name); 3088 _objc_inform ("class `%s' must be recompiled\n", category->class_name); 3089 } 3090 } 3091 3092 // Augment properties 3093 if (version >= 7 && category->instance_properties) { 3094 if (cls->ISA()->version >= 6) { 3095 _class_addProperties(cls, category->instance_properties); 3096 } else { 3097 _objc_inform ("unable to add properties from category %s...\n", category->category_name); 3098 _objc_inform ("class `%s' must be recompiled\n", category->class_name); 3099 } 3100 } 3101} 3102 3103/*********************************************************************** 3104* _objc_add_category_flush_caches. Install the specified category's 3105* methods into the class it augments, and flush the class' method cache. 3106* Return YES if some method caches now need to be flushed. 3107**********************************************************************/ 3108static BOOL _objc_add_category_flush_caches(Class cls, old_category *category, int version) 3109{ 3110 BOOL needFlush = NO; 3111 3112 // Install the category's methods into its intended class 3113 mutex_lock(&methodListLock); 3114 _objc_add_category (cls, category, version); 3115 mutex_unlock(&methodListLock); 3116 3117 // Queue for cache flushing so category's methods can get called 3118 if (category->instance_methods) { 3119 cls->setInfo(CLS_FLUSH_CACHE); 3120 needFlush = YES; 3121 } 3122 if (category->class_methods) { 3123 cls->ISA()->setInfo(CLS_FLUSH_CACHE); 3124 needFlush = YES; 3125 } 3126 3127 return needFlush; 3128} 3129 3130 3131/*********************************************************************** 3132* reverse_cat 3133* Reverse the given linked list of pending categories. 3134* The pending category list is built backwards, and needs to be 3135* reversed before actually attaching the categories to a class. 3136* Returns the head of the new linked list. 3137**********************************************************************/ 3138static _objc_unresolved_category *reverse_cat(_objc_unresolved_category *cat) 3139{ 3140 _objc_unresolved_category *prev; 3141 _objc_unresolved_category *cur; 3142 _objc_unresolved_category *ahead; 3143 3144 if (!cat) return nil; 3145 3146 prev = nil; 3147 cur = cat; 3148 ahead = cat->next; 3149 3150 while (cur) { 3151 ahead = cur->next; 3152 cur->next = prev; 3153 prev = cur; 3154 cur = ahead; 3155 } 3156 3157 return prev; 3158} 3159 3160 3161/*********************************************************************** 3162* resolve_categories_for_class. 3163* Install all existing categories intended for the specified class. 3164* cls must be a true class and not a metaclass. 3165**********************************************************************/ 3166static void resolve_categories_for_class(Class cls) 3167{ 3168 _objc_unresolved_category * pending; 3169 _objc_unresolved_category * next; 3170 3171 // Nothing to do if there are no categories at all 3172 if (!category_hash) return; 3173 3174 // Locate and remove first element in category list 3175 // associated with this class 3176 pending = (_objc_unresolved_category *) 3177 NXMapKeyFreeingRemove (category_hash, cls->name); 3178 3179 // Traverse the list of categories, if any, registered for this class 3180 3181 // The pending list is built backwards. Reverse it and walk forwards. 3182 pending = reverse_cat(pending); 3183 3184 while (pending) { 3185 if (pending->cat) { 3186 // Install the category 3187 // use the non-flush-cache version since we are only 3188 // called from the class intialization code 3189 _objc_add_category(cls, pending->cat, (int)pending->version); 3190 } 3191 3192 // Delink and reclaim this registration 3193 next = pending->next; 3194 _free_internal(pending); 3195 pending = next; 3196 } 3197} 3198 3199 3200/*********************************************************************** 3201* _objc_resolve_categories_for_class. 3202* Public version of resolve_categories_for_class. This was 3203* exported pre-10.4 for Omni et al. to workaround a problem 3204* with too-lazy category attachment. 3205* cls should be a class, but this function can also cope with metaclasses. 3206**********************************************************************/ 3207void _objc_resolve_categories_for_class(Class cls) 3208{ 3209 // If cls is a metaclass, get the class. 3210 // resolve_categories_for_class() requires a real class to work correctly. 3211 if (ISMETA(cls)) { 3212 if (strncmp(cls->name, "_%", 2) == 0) { 3213 // Posee's meta's name is smashed and isn't in the class_hash, 3214 // so objc_getClass doesn't work. 3215 const char *baseName = strchr(cls->name, '%'); // get posee's real name 3216 cls = objc_getClass(baseName); 3217 } else { 3218 cls = objc_getClass(cls->name); 3219 } 3220 } 3221 3222 resolve_categories_for_class(cls); 3223} 3224 3225 3226/*********************************************************************** 3227* _objc_register_category. 3228* Process a category read from an image. 3229* If the category's class exists, attach the category immediately. 3230* Classes that need cache flushing are marked but not flushed. 3231* If the category's class does not exist yet, pend the category for 3232* later attachment. Pending categories are attached in the order 3233* they were discovered. 3234* Returns YES if some method caches now need to be flushed. 3235**********************************************************************/ 3236static BOOL _objc_register_category(old_category *cat, int version) 3237{ 3238 _objc_unresolved_category * new_cat; 3239 _objc_unresolved_category * old; 3240 Class theClass; 3241 3242 // If the category's class exists, attach the category. 3243 if ((theClass = objc_lookUpClass(cat->class_name))) { 3244 return _objc_add_category_flush_caches(theClass, cat, version); 3245 } 3246 3247 // If the category's class exists but is unconnected, 3248 // then attach the category to the class but don't bother 3249 // flushing any method caches (because they must be empty). 3250 // YES unconnected, NO class_handler 3251 if ((theClass = look_up_class(cat->class_name, YES, NO))) { 3252 _objc_add_category(theClass, cat, version); 3253 return NO; 3254 } 3255 3256 3257 // Category's class does not exist yet. 3258 // Save the category for later attachment. 3259 3260 if (PrintConnecting) { 3261 _objc_inform("CONNECT: pending category '%s (%s)'", cat->class_name, cat->category_name); 3262 } 3263 3264 // Create category lookup table if needed 3265 if (!category_hash) 3266 category_hash = NXCreateMapTableFromZone (NXStrValueMapPrototype, 3267 128, 3268 _objc_internal_zone ()); 3269 3270 // Locate an existing list of categories, if any, for the class. 3271 old = (_objc_unresolved_category *) 3272 NXMapGet (category_hash, cat->class_name); 3273 3274 // Register the category to be fixed up later. 3275 // The category list is built backwards, and is reversed again 3276 // by resolve_categories_for_class(). 3277 new_cat = (_objc_unresolved_category *) 3278 _malloc_internal(sizeof(_objc_unresolved_category)); 3279 new_cat->next = old; 3280 new_cat->cat = cat; 3281 new_cat->version = version; 3282 (void) NXMapKeyCopyingInsert (category_hash, cat->class_name, new_cat); 3283 3284 return NO; 3285} 3286 3287 3288const char ** 3289_objc_copyClassNamesForImage(header_info *hi, unsigned int *outCount) 3290{ 3291 Module mods; 3292 unsigned int m; 3293 const char **list; 3294 int count; 3295 int allocated; 3296 3297 list = nil; 3298 count = 0; 3299 allocated = 0; 3300 3301 mods = hi->mod_ptr; 3302 for (m = 0; m < hi->mod_count; m++) { 3303 int d; 3304 3305 if (!mods[m].symtab) continue; 3306 3307 for (d = 0; d < mods[m].symtab->cls_def_cnt; d++) { 3308 Class cls = (Class)mods[m].symtab->defs[d]; 3309 // fixme what about future-ified classes? 3310 if (cls->isConnected()) { 3311 if (count == allocated) { 3312 allocated = allocated*2 + 16; 3313 list = (const char **) 3314 realloc((void *)list, allocated * sizeof(char *)); 3315 } 3316 list[count++] = cls->name; 3317 } 3318 } 3319 } 3320 3321 if (count > 0) { 3322 // nil-terminate non-empty list 3323 if (count == allocated) { 3324 allocated = allocated+1; 3325 list = (const char **) 3326 realloc((void *)list, allocated * sizeof(char *)); 3327 } 3328 list[count] = nil; 3329 } 3330 3331 if (outCount) *outCount = count; 3332 return list; 3333} 3334 3335Class gdb_class_getClass(Class cls) 3336{ 3337 const char *className = cls->name; 3338 if(!className || !strlen(className)) return Nil; 3339 Class rCls = look_up_class(className, NO, NO); 3340 return rCls; 3341 3342} 3343 3344Class gdb_object_getClass(id obj) 3345{ 3346 if (!obj) return nil; 3347 return gdb_class_getClass(obj->getIsa()); 3348} 3349 3350 3351/*********************************************************************** 3352* Lock management 3353**********************************************************************/ 3354rwlock_t selLock = {}; 3355mutex_t classLock = MUTEX_INITIALIZER; 3356mutex_t methodListLock = MUTEX_INITIALIZER; 3357mutex_t cacheUpdateLock = MUTEX_INITIALIZER; 3358recursive_mutex_t loadMethodLock = RECURSIVE_MUTEX_INITIALIZER; 3359 3360void lock_init(void) 3361{ 3362 rwlock_init(&selLock); 3363 recursive_mutex_init(&loadMethodLock); 3364} 3365 3366 3367#endif 3368