runtime/objc-private.h

   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  *      objc-private.h
  25  *      Copyright 1988-1996, NeXT Software, Inc.
  26  */
  27
  28 #ifndef _OBJC_PRIVATE_H_
  29 #define _OBJC_PRIVATE_H_
  30
  31 #include "objc-config.h"
  32
  33 /* Isolate ourselves from the definitions of id and Class in the compiler
  34  * and public headers.
  35  */
  36
  37 #ifdef _OBJC_OBJC_H_
  38 #error include objc-private.h before other headers
  39 #endif
  40
  41 #define OBJC_TYPES_DEFINED 1
  42 #define OBJC_OLD_DISPATCH_PROTOTYPES 0
  43
  44 #include <cstddef>  // for nullptr_t
  45 #include <stdint.h>
  46 #include <assert.h>
  47
  48 struct objc_class;
  49 struct objc_object;
  50
  51 typedef struct objc_class *Class;
  52 typedef struct objc_object *id;
  53
  54 namespace {
  55     struct SideTable;
  56 };
  57
  58
  59 #if (!SUPPORT_NONPOINTER_ISA && !SUPPORT_PACKED_ISA && !SUPPORT_INDEXED_ISA) ||\
  60     ( SUPPORT_NONPOINTER_ISA &&  SUPPORT_PACKED_ISA && !SUPPORT_INDEXED_ISA) ||\
  61     ( SUPPORT_NONPOINTER_ISA && !SUPPORT_PACKED_ISA &&  SUPPORT_INDEXED_ISA)
  62     // good config
  63 #else
  64 #   error bad config
  65 #endif
  66
  67
  68 union isa_t
  69 {
  70     isa_t() { }
  71     isa_t(uintptr_t value) : bits(value) { }
  72
  73     Class cls;
  74     uintptr_t bits;
  75
  76 #if SUPPORT_PACKED_ISA
  77
  78     // extra_rc must be the MSB-most field (so it matches carry/overflow flags)
  79     // nonpointer must be the LSB (fixme or get rid of it)
  80     // shiftcls must occupy the same bits that a real class pointer would
  81     // bits + RC_ONE is equivalent to extra_rc + 1
  82     // RC_HALF is the high bit of extra_rc (i.e. half of its range)
  83
  84     // future expansion:
  85     // uintptr_t fast_rr : 1;     // no r/r overrides
  86     // uintptr_t lock : 2;        // lock for atomic property, @synch
  87     // uintptr_t extraBytes : 1;  // allocated with extra bytes
  88
  89 # if __arm64__
  90 #   define ISA_MASK        0x0000000ffffffff8ULL
  91 #   define ISA_MAGIC_MASK  0x000003f000000001ULL
  92 #   define ISA_MAGIC_VALUE 0x000001a000000001ULL
  93     struct {
  94         uintptr_t nonpointer        : 1;
  95         uintptr_t has_assoc         : 1;
  96         uintptr_t has_cxx_dtor      : 1;
  97         uintptr_t shiftcls          : 33; // MACH_VM_MAX_ADDRESS 0x1000000000
  98         uintptr_t magic             : 6;
  99         uintptr_t weakly_referenced : 1;
 100         uintptr_t deallocating      : 1;
 101         uintptr_t has_sidetable_rc  : 1;
 102         uintptr_t extra_rc          : 19;
 103 #       define RC_ONE   (1ULL<<45)
 104 #       define RC_HALF  (1ULL<<18)
 105     };
 106
 107 # elif __x86_64__
 108 #   define ISA_MASK        0x00007ffffffffff8ULL
 109 #   define ISA_MAGIC_MASK  0x001f800000000001ULL
 110 #   define ISA_MAGIC_VALUE 0x001d800000000001ULL
 111     struct {
 112         uintptr_t nonpointer        : 1;
 113         uintptr_t has_assoc         : 1;
 114         uintptr_t has_cxx_dtor      : 1;
 115         uintptr_t shiftcls          : 44; // MACH_VM_MAX_ADDRESS 0x7fffffe00000
 116         uintptr_t magic             : 6;
 117         uintptr_t weakly_referenced : 1;
 118         uintptr_t deallocating      : 1;
 119         uintptr_t has_sidetable_rc  : 1;
 120         uintptr_t extra_rc          : 8;
 121 #       define RC_ONE   (1ULL<<56)
 122 #       define RC_HALF  (1ULL<<7)
 123     };
 124
 125 # else
 126 #   error unknown architecture for packed isa
 127 # endif
 128
 129 // SUPPORT_PACKED_ISA
 130 #endif
 131
 132
 133 #if SUPPORT_INDEXED_ISA
 134
 135 # if  __ARM_ARCH_7K__ >= 2
 136
 137 #   define ISA_INDEX_IS_NPI      1
 138 #   define ISA_INDEX_MASK        0x0001FFFC
 139 #   define ISA_INDEX_SHIFT       2
 140 #   define ISA_INDEX_BITS        15
 141 #   define ISA_INDEX_COUNT       (1 << ISA_INDEX_BITS)
 142 #   define ISA_INDEX_MAGIC_MASK  0x001E0001
 143 #   define ISA_INDEX_MAGIC_VALUE 0x001C0001
 144     struct {
 145         uintptr_t nonpointer        : 1;
 146         uintptr_t has_assoc         : 1;
 147         uintptr_t indexcls          : 15;
 148         uintptr_t magic             : 4;
 149         uintptr_t has_cxx_dtor      : 1;
 150         uintptr_t weakly_referenced : 1;
 151         uintptr_t deallocating      : 1;
 152         uintptr_t has_sidetable_rc  : 1;
 153         uintptr_t extra_rc          : 7;
 154 #       define RC_ONE   (1ULL<<25)
 155 #       define RC_HALF  (1ULL<<6)
 156     };
 157
 158 # else
 159 #   error unknown architecture for indexed isa
 160 # endif
 161
 162 // SUPPORT_INDEXED_ISA
 163 #endif
 164
 165 };
 166
 167
 168 struct objc_object {
 169 private:
 170     isa_t isa;
 171
 172 public:
 173
 174     // ISA() assumes this is NOT a tagged pointer object
 175     Class ISA();
 176
 177     // getIsa() allows this to be a tagged pointer object
 178     Class getIsa();
 179
 180     // initIsa() should be used to init the isa of new objects only.
 181     // If this object already has an isa, use changeIsa() for correctness.
 182     // initInstanceIsa(): objects with no custom RR/AWZ
 183     // initClassIsa(): class objects
 184     // initProtocolIsa(): protocol objects
 185     // initIsa(): other objects
 186     void initIsa(Class cls /*nonpointer=false*/);
 187     void initClassIsa(Class cls /*nonpointer=maybe*/);
 188     void initProtocolIsa(Class cls /*nonpointer=maybe*/);
 189     void initInstanceIsa(Class cls, bool hasCxxDtor);
 190
 191     // changeIsa() should be used to change the isa of existing objects.
 192     // If this is a new object, use initIsa() for performance.
 193     Class changeIsa(Class newCls);
 194
 195     bool hasNonpointerIsa();
 196     bool isTaggedPointer();
 197     bool isBasicTaggedPointer();
 198     bool isExtTaggedPointer();
 199     bool isClass();
 200
 201     // object may have associated objects?
 202     bool hasAssociatedObjects();
 203     void setHasAssociatedObjects();
 204
 205     // object may be weakly referenced?
 206     bool isWeaklyReferenced();
 207     void setWeaklyReferenced_nolock();
 208
 209     // object may have -.cxx_destruct implementation?
 210     bool hasCxxDtor();
 211
 212     // Optimized calls to retain/release methods
 213     id retain();
 214     void release();
 215     id autorelease();
 216
 217     // Implementations of retain/release methods
 218     id rootRetain();
 219     bool rootRelease();
 220     id rootAutorelease();
 221     bool rootTryRetain();
 222     bool rootReleaseShouldDealloc();
 223     uintptr_t rootRetainCount();
 224
 225     // Implementation of dealloc methods
 226     bool rootIsDeallocating();
 227     void clearDeallocating();
 228     void rootDealloc();
 229
 230 private:
 231     void initIsa(Class newCls, bool nonpointer, bool hasCxxDtor);
 232
 233     // Slow paths for inline control
 234     id rootAutorelease2();
 235     bool overrelease_error();
 236
 237 #if SUPPORT_NONPOINTER_ISA
 238     // Unified retain count manipulation for nonpointer isa
 239     id rootRetain(bool tryRetain, bool handleOverflow);
 240     bool rootRelease(bool performDealloc, bool handleUnderflow);
 241     id rootRetain_overflow(bool tryRetain);
 242     bool rootRelease_underflow(bool performDealloc);
 243
 244     void clearDeallocating_slow();
 245
 246     // Side table retain count overflow for nonpointer isa
 247     void sidetable_lock();
 248     void sidetable_unlock();
 249
 250     void sidetable_moveExtraRC_nolock(size_t extra_rc, bool isDeallocating, bool weaklyReferenced);
 251     bool sidetable_addExtraRC_nolock(size_t delta_rc);
 252     size_t sidetable_subExtraRC_nolock(size_t delta_rc);
 253     size_t sidetable_getExtraRC_nolock();
 254 #endif
 255
 256     // Side-table-only retain count
 257     bool sidetable_isDeallocating();
 258     void sidetable_clearDeallocating();
 259
 260     bool sidetable_isWeaklyReferenced();
 261     void sidetable_setWeaklyReferenced_nolock();
 262
 263     id sidetable_retain();
 264     id sidetable_retain_slow(SideTable& table);
 265
 266     uintptr_t sidetable_release(bool performDealloc = true);
 267     uintptr_t sidetable_release_slow(SideTable& table, bool performDealloc = true);
 268
 269     bool sidetable_tryRetain();
 270
 271     uintptr_t sidetable_retainCount();
 272 #if DEBUG
 273     bool sidetable_present();
 274 #endif
 275 };
 276
 277
 278 #if __OBJC2__
 279 typedef struct method_t *Method;
 280 typedef struct ivar_t *Ivar;
 281 typedef struct category_t *Category;
 282 typedef struct property_t *objc_property_t;
 283 #else
 284 typedef struct old_method *Method;
 285 typedef struct old_ivar *Ivar;
 286 typedef struct old_category *Category;
 287 typedef struct old_property *objc_property_t;
 288 #endif
 289
 290 // Public headers
 291
 292 #include "objc.h"
 293 #include "runtime.h"
 294 #include "objc-os.h"
 295 #include "objc-abi.h"
 296 #include "objc-api.h"
 297 #include "objc-config.h"
 298 #include "objc-internal.h"
 299 #include "maptable.h"
 300 #include "hashtable2.h"
 301
 302 /* Do not include message.h here. */
 303 /* #include "message.h" */
 304
 305 #define __APPLE_API_PRIVATE
 306 #include "objc-gdb.h"
 307 #undef __APPLE_API_PRIVATE
 308
 309
 310 // Private headers
 311
 312 #if __OBJC2__
 313 #include "objc-runtime-new.h"
 314 #else
 315 #include "objc-runtime-old.h"
 316 #endif
 317
 318 #include "objc-references.h"
 319 #include "objc-initialize.h"
 320 #include "objc-loadmethod.h"
 321
 322
 323 #if SUPPORT_PREOPT  &&  __cplusplus
 324 #include <objc-shared-cache.h>
 325 using objc_selopt_t = const objc_opt::objc_selopt_t;
 326 #else
 327 struct objc_selopt_t;
 328 #endif
 329
 330
 331 #define STRINGIFY(x) #x
 332 #define STRINGIFY2(x) STRINGIFY(x)
 333
 334 __BEGIN_DECLS
 335
 336 struct header_info;
 337
 338 // Split out the rw data from header info.  For now put it in a huge array
 339 // that more than exceeds the space needed.  In future we'll just allocate
 340 // this in the shared cache builder.
 341 typedef struct header_info_rw {
 342
 343     bool getLoaded() const {
 344         return isLoaded;
 345     }
 346
 347     void setLoaded(bool v) {
 348         isLoaded = v ? 1: 0;
 349     }
 350
 351     bool getAllClassesRealized() const {
 352         return allClassesRealized;
 353     }
 354
 355     void setAllClassesRealized(bool v) {
 356         allClassesRealized = v ? 1: 0;
 357     }
 358
 359     header_info *getNext() const {
 360         return (header_info *)(next << 2);
 361     }
 362
 363     void setNext(header_info *v) {
 364         next = ((uintptr_t)v) >> 2;
 365     }
 366
 367 private:
 368 #ifdef __LP64__
 369     uintptr_t isLoaded              : 1;
 370     uintptr_t allClassesRealized    : 1;
 371     uintptr_t next                  : 62;
 372 #else
 373     uintptr_t isLoaded              : 1;
 374     uintptr_t allClassesRealized    : 1;
 375     uintptr_t next                  : 30;
 376 #endif
 377 } header_info_rw;
 378
 379 struct header_info_rw* getPreoptimizedHeaderRW(const struct header_info *const hdr);
 380
 381 typedef struct header_info {
 382 private:
 383     // Note, this is no longer a pointer, but instead an offset to a pointer
 384     // from this location.
 385     intptr_t mhdr_offset;
 386
 387     // Note, this is no longer a pointer, but instead an offset to a pointer
 388     // from this location.
 389     intptr_t info_offset;
 390
 391     // Do not add fields without editing ObjCModernAbstraction.hpp
 392 public:
 393
 394     header_info_rw *getHeaderInfoRW() {
 395         header_info_rw *preopt =
 396             isPreoptimized() ? getPreoptimizedHeaderRW(this) : nil;
 397         if (preopt) return preopt;
 398         else return &rw_data[0];
 399     }
 400
 401     const headerType *mhdr() const {
 402         return (const headerType *)(((intptr_t)&mhdr_offset) + mhdr_offset);
 403     }
 404
 405     void setmhdr(const headerType *mhdr) {
 406         mhdr_offset = (intptr_t)mhdr - (intptr_t)&mhdr_offset;
 407     }
 408
 409     const objc_image_info *info() const {
 410         return (const objc_image_info *)(((intptr_t)&info_offset) + info_offset);
 411     }
 412
 413     void setinfo(const objc_image_info *info) {
 414         info_offset = (intptr_t)info - (intptr_t)&info_offset;
 415     }
 416
 417     bool isLoaded() {
 418         return getHeaderInfoRW()->getLoaded();
 419     }
 420
 421     void setLoaded(bool v) {
 422         getHeaderInfoRW()->setLoaded(v);
 423     }
 424
 425     bool areAllClassesRealized() {
 426         return getHeaderInfoRW()->getAllClassesRealized();
 427     }
 428
 429     void setAllClassesRealized(bool v) {
 430         getHeaderInfoRW()->setAllClassesRealized(v);
 431     }
 432
 433     header_info *getNext() {
 434         return getHeaderInfoRW()->getNext();
 435     }
 436
 437     void setNext(header_info *v) {
 438         getHeaderInfoRW()->setNext(v);
 439     }
 440
 441     bool isBundle() {
 442         return mhdr()->filetype == MH_BUNDLE;
 443     }
 444
 445     const char *fname() const {
 446         return dyld_image_path_containing_address(mhdr());
 447     }
 448
 449     bool isPreoptimized() const;
 450
 451 #if !__OBJC2__
 452     struct old_protocol **proto_refs;
 453     struct objc_module *mod_ptr;
 454     size_t              mod_count;
 455 # if TARGET_OS_WIN32
 456     struct objc_module **modules;
 457     size_t moduleCount;
 458     struct old_protocol **protocols;
 459     size_t protocolCount;
 460     void *imageinfo;
 461     size_t imageinfoBytes;
 462     SEL *selrefs;
 463     size_t selrefCount;
 464     struct objc_class **clsrefs;
 465     size_t clsrefCount;
 466     TCHAR *moduleName;
 467 # endif
 468 #endif
 469
 470 private:
 471     // Images in the shared cache will have an empty array here while those
 472     // allocated at run time will allocate a single entry.
 473     header_info_rw rw_data[];
 474 } header_info;
 475
 476 extern header_info *FirstHeader;
 477 extern header_info *LastHeader;
 478 extern int HeaderCount;
 479
 480 extern void appendHeader(header_info *hi);
 481 extern void removeHeader(header_info *hi);
 482
 483 extern objc_image_info *_getObjcImageInfo(const headerType *head, size_t *size);
 484 extern bool _hasObjcContents(const header_info *hi);
 485
 486
 487 // Mach-O segment and section names are 16 bytes and may be un-terminated.
 488
 489 static inline bool segnameEquals(const char *lhs, const char *rhs) {
 490     return 0 == strncmp(lhs, rhs, 16);
 491 }
 492
 493 static inline bool segnameStartsWith(const char *segname, const char *prefix) {
 494     return 0 == strncmp(segname, prefix, strlen(prefix));
 495 }
 496
 497 static inline bool sectnameEquals(const char *lhs, const char *rhs) {
 498     return segnameEquals(lhs, rhs);
 499 }
 500
 501 static inline bool sectnameStartsWith(const char *sectname, const char *prefix){
 502     return segnameStartsWith(sectname, prefix);
 503 }
 504
 505
 506 /* selectors */
 507 extern void sel_init(size_t selrefCount);
 508 extern SEL sel_registerNameNoLock(const char *str, bool copy);
 509 extern void sel_lock(void);
 510 extern void sel_unlock(void);
 511
 512 extern SEL SEL_load;
 513 extern SEL SEL_initialize;
 514 extern SEL SEL_resolveClassMethod;
 515 extern SEL SEL_resolveInstanceMethod;
 516 extern SEL SEL_cxx_construct;
 517 extern SEL SEL_cxx_destruct;
 518 extern SEL SEL_retain;
 519 extern SEL SEL_release;
 520 extern SEL SEL_autorelease;
 521 extern SEL SEL_retainCount;
 522 extern SEL SEL_alloc;
 523 extern SEL SEL_allocWithZone;
 524 extern SEL SEL_dealloc;
 525 extern SEL SEL_copy;
 526 extern SEL SEL_new;
 527 extern SEL SEL_forwardInvocation;
 528 extern SEL SEL_tryRetain;
 529 extern SEL SEL_isDeallocating;
 530 extern SEL SEL_retainWeakReference;
 531 extern SEL SEL_allowsWeakReference;
 532
 533 /* preoptimization */
 534 extern void preopt_init(void);
 535 extern void disableSharedCacheOptimizations(void);
 536 extern bool isPreoptimized(void);
 537 extern bool noMissingWeakSuperclasses(void);
 538 extern header_info *preoptimizedHinfoForHeader(const headerType *mhdr);
 539
 540 extern objc_selopt_t *preoptimizedSelectors(void);
 541
 542 extern Protocol *getPreoptimizedProtocol(const char *name);
 543
 544 extern Class getPreoptimizedClass(const char *name);
 545 extern Class* copyPreoptimizedClasses(const char *name, int *outCount);
 546
 547 extern Class _calloc_class(size_t size);
 548
 549 /* method lookup */
 550 extern IMP lookUpImpOrNil(Class, SEL, id obj, bool initialize, bool cache, bool resolver);
 551 extern IMP lookUpImpOrForward(Class, SEL, id obj, bool initialize, bool cache, bool resolver);
 552
 553 extern IMP lookupMethodInClassAndLoadCache(Class cls, SEL sel);
 554 extern bool class_respondsToSelector_inst(Class cls, SEL sel, id inst);
 555
 556 extern bool objcMsgLogEnabled;
 557 extern bool logMessageSend(bool isClassMethod,
 558                     const char *objectsClass,
 559                     const char *implementingClass,
 560                     SEL selector);
 561
 562 /* message dispatcher */
 563 extern IMP _class_lookupMethodAndLoadCache3(id, SEL, Class);
 564
 565 #if !OBJC_OLD_DISPATCH_PROTOTYPES
 566 extern void _objc_msgForward_impcache(void);
 567 #else
 568 extern id _objc_msgForward_impcache(id, SEL, ...);
 569 #endif
 570
 571 /* errors */
 572 extern void __objc_error(id, const char *, ...) __attribute__((format (printf, 2, 3), noreturn));
 573 extern void _objc_inform(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 574 extern void _objc_inform_on_crash(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 575 extern void _objc_inform_now_and_on_crash(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 576 extern void _objc_inform_deprecated(const char *oldname, const char *newname) __attribute__((noinline));
 577 extern void inform_duplicate(const char *name, Class oldCls, Class cls);
 578
 579 /* magic */
 580 extern Class _objc_getFreedObjectClass (void);
 581
 582 /* map table additions */
 583 extern void *NXMapKeyCopyingInsert(NXMapTable *table, const void *key, const void *value);
 584 extern void *NXMapKeyFreeingRemove(NXMapTable *table, const void *key);
 585
 586 /* hash table additions */
 587 extern unsigned _NXHashCapacity(NXHashTable *table);
 588 extern void _NXHashRehashToCapacity(NXHashTable *table, unsigned newCapacity);
 589
 590 /* property attribute parsing */
 591 extern const char *copyPropertyAttributeString(const objc_property_attribute_t *attrs, unsigned int count);
 592 extern objc_property_attribute_t *copyPropertyAttributeList(const char *attrs, unsigned int *outCount);
 593 extern char *copyPropertyAttributeValue(const char *attrs, const char *name);
 594
 595 /* locking */
 596 extern void lock_init(void);
 597 extern rwlock_t selLock;
 598 extern mutex_t cacheUpdateLock;
 599 extern recursive_mutex_t loadMethodLock;
 600 #if __OBJC2__
 601 extern rwlock_t runtimeLock;
 602 #else
 603 extern mutex_t classLock;
 604 extern mutex_t methodListLock;
 605 #endif
 606
 607 class monitor_locker_t : nocopy_t {
 608     monitor_t& lock;
 609   public:
 610     monitor_locker_t(monitor_t& newLock) : lock(newLock) { lock.enter(); }
 611     ~monitor_locker_t() { lock.leave(); }
 612 };
 613
 614 class mutex_locker_t : nocopy_t {
 615     mutex_t& lock;
 616   public:
 617     mutex_locker_t(mutex_t& newLock)
 618         : lock(newLock) { lock.lock(); }
 619     ~mutex_locker_t() { lock.unlock(); }
 620 };
 621
 622 class recursive_mutex_locker_t : nocopy_t {
 623     recursive_mutex_t& lock;
 624   public:
 625     recursive_mutex_locker_t(recursive_mutex_t& newLock)
 626         : lock(newLock) { lock.lock(); }
 627     ~recursive_mutex_locker_t() { lock.unlock(); }
 628 };
 629
 630 class rwlock_reader_t : nocopy_t {
 631     rwlock_t& lock;
 632   public:
 633     rwlock_reader_t(rwlock_t& newLock) : lock(newLock) { lock.read(); }
 634     ~rwlock_reader_t() { lock.unlockRead(); }
 635 };
 636
 637 class rwlock_writer_t : nocopy_t {
 638     rwlock_t& lock;
 639   public:
 640     rwlock_writer_t(rwlock_t& newLock) : lock(newLock) { lock.write(); }
 641     ~rwlock_writer_t() { lock.unlockWrite(); }
 642 };
 643
 644
 645 /* Exceptions */
 646 struct alt_handler_list;
 647 extern void exception_init(void);
 648 extern void _destroyAltHandlerList(struct alt_handler_list *list);
 649
 650 /* Class change notifications (gdb only for now) */
 651 #define OBJC_CLASS_ADDED (1<<0)
 652 #define OBJC_CLASS_REMOVED (1<<1)
 653 #define OBJC_CLASS_IVARS_CHANGED (1<<2)
 654 #define OBJC_CLASS_METHODS_CHANGED (1<<3)
 655 extern void gdb_objc_class_changed(Class cls, unsigned long changes, const char *classname)
 656     __attribute__((noinline));
 657
 658
 659 // Settings from environment variables
 660 #define OPTION(var, env, help) extern bool var;
 661 #include "objc-env.h"
 662 #undef OPTION
 663
 664 extern void environ_init(void);
 665
 666 extern void logReplacedMethod(const char *className, SEL s, bool isMeta, const char *catName, IMP oldImp, IMP newImp);
 667
 668
 669 // objc per-thread storage
 670 typedef struct {
 671     struct _objc_initializing_classes *initializingClasses; // for +initialize
 672     struct SyncCache *syncCache;  // for @synchronize
 673     struct alt_handler_list *handlerList;  // for exception alt handlers
 674     char *printableNames[4];  // temporary demangled names for logging
 675
 676     // If you add new fields here, don't forget to update
 677     // _objc_pthread_destroyspecific()
 678
 679 } _objc_pthread_data;
 680
 681 extern _objc_pthread_data *_objc_fetch_pthread_data(bool create);
 682 extern void tls_init(void);
 683
 684 // encoding.h
 685 extern unsigned int encoding_getNumberOfArguments(const char *typedesc);
 686 extern unsigned int encoding_getSizeOfArguments(const char *typedesc);
 687 extern unsigned int encoding_getArgumentInfo(const char *typedesc, unsigned int arg, const char **type, int *offset);
 688 extern void encoding_getReturnType(const char *t, char *dst, size_t dst_len);
 689 extern char * encoding_copyReturnType(const char *t);
 690 extern void encoding_getArgumentType(const char *t, unsigned int index, char *dst, size_t dst_len);
 691 extern char *encoding_copyArgumentType(const char *t, unsigned int index);
 692
 693 // sync.h
 694 extern void _destroySyncCache(struct SyncCache *cache);
 695
 696 // arr
 697 extern void arr_init(void);
 698 extern id objc_autoreleaseReturnValue(id obj);
 699
 700 // block trampolines
 701 extern IMP _imp_implementationWithBlockNoCopy(id block);
 702
 703 // layout.h
 704 typedef struct {
 705     uint8_t *bits;
 706     size_t bitCount;
 707     size_t bitsAllocated;
 708     bool weak;
 709 } layout_bitmap;
 710 extern layout_bitmap layout_bitmap_create(const unsigned char *layout_string, size_t layoutStringInstanceSize, size_t instanceSize, bool weak);
 711 extern layout_bitmap layout_bitmap_create_empty(size_t instanceSize, bool weak);
 712 extern void layout_bitmap_free(layout_bitmap bits);
 713 extern const unsigned char *layout_string_create(layout_bitmap bits);
 714 extern void layout_bitmap_set_ivar(layout_bitmap bits, const char *type, size_t offset);
 715 extern void layout_bitmap_grow(layout_bitmap *bits, size_t newCount);
 716 extern void layout_bitmap_slide(layout_bitmap *bits, size_t oldPos, size_t newPos);
 717 extern void layout_bitmap_slide_anywhere(layout_bitmap *bits, size_t oldPos, size_t newPos);
 718 extern bool layout_bitmap_splat(layout_bitmap dst, layout_bitmap src,
 719                                 size_t oldSrcInstanceSize);
 720 extern bool layout_bitmap_or(layout_bitmap dst, layout_bitmap src, const char *msg);
 721 extern bool layout_bitmap_clear(layout_bitmap dst, layout_bitmap src, const char *msg);
 722 extern void layout_bitmap_print(layout_bitmap bits);
 723
 724
 725 // fixme runtime
 726 extern Class look_up_class(const char *aClassName, bool includeUnconnected, bool includeClassHandler);
 727 extern "C" void map_2_images(unsigned count, const char * const paths[],
 728                              const struct mach_header * const mhdrs[]);
 729 extern void map_images_nolock(unsigned count, const char * const paths[],
 730                               const struct mach_header * const mhdrs[]);
 731 extern void load_images(const char *path, const struct mach_header *mh);
 732 extern void unmap_image(const char *path, const struct mach_header *mh);
 733 extern void unmap_image_nolock(const struct mach_header *mh);
 734 extern void _read_images(header_info **hList, uint32_t hCount, int totalClasses, int unoptimizedTotalClass);
 735 extern void _unload_image(header_info *hi);
 736 extern const char ** _objc_copyClassNamesForImage(header_info *hi, unsigned int *outCount);
 737
 738
 739 extern const header_info *_headerForClass(Class cls);
 740
 741 extern Class _class_remap(Class cls);
 742 extern Class _class_getNonMetaClass(Class cls, id obj);
 743 extern Ivar _class_getVariable(Class cls, const char *name);
 744
 745 extern unsigned _class_createInstancesFromZone(Class cls, size_t extraBytes, void *zone, id *results, unsigned num_requested);
 746 extern id _objc_constructOrFree(id bytes, Class cls);
 747
 748 extern const char *_category_getName(Category cat);
 749 extern const char *_category_getClassName(Category cat);
 750 extern Class _category_getClass(Category cat);
 751 extern IMP _category_getLoadMethod(Category cat);
 752
 753 extern id object_cxxConstructFromClass(id obj, Class cls);
 754 extern void object_cxxDestruct(id obj);
 755
 756 extern void _class_resolveMethod(Class cls, SEL sel, id inst);
 757
 758 extern void fixupCopiedIvars(id newObject, id oldObject);
 759 extern Class _class_getClassForIvar(Class cls, Ivar ivar);
 760
 761
 762 #define OBJC_WARN_DEPRECATED \
 763     do { \
 764         static int warned = 0; \
 765         if (!warned) { \
 766             warned = 1; \
 767             _objc_inform_deprecated(__FUNCTION__, NULL); \
 768         } \
 769     } while (0) \
 770
 771 __END_DECLS
 772
 773
 774 #ifndef STATIC_ASSERT
 775 #   define STATIC_ASSERT(x) _STATIC_ASSERT2(x, __LINE__)
 776 #   define _STATIC_ASSERT2(x, line) _STATIC_ASSERT3(x, line)
 777 #   define _STATIC_ASSERT3(x, line)                                     \
 778         typedef struct {                                                \
 779             int _static_assert[(x) ? 0 : -1];                           \
 780         } _static_assert_ ## line __attribute__((unavailable))
 781 #endif
 782
 783 #define countof(arr) (sizeof(arr) / sizeof((arr)[0]))
 784
 785
 786 static __inline uint32_t _objc_strhash(const char *s) {
 787     uint32_t hash = 0;
 788     for (;;) {
 789         int a = *s++;
 790         if (0 == a) break;
 791         hash += (hash << 8) + a;
 792     }
 793     return hash;
 794 }
 795
 796 #if __cplusplus
 797
 798 template <typename T>
 799 static inline T log2u(T x) {
 800     return (x<2) ? 0 : log2u(x>>1)+1;
 801 }
 802
 803 template <typename T>
 804 static inline T exp2u(T x) {
 805     return (1 << x);
 806 }
 807
 808 template <typename T>
 809 static T exp2m1u(T x) {
 810     return (1 << x) - 1;
 811 }
 812
 813 #endif
 814
 815 // Misalignment-safe integer types
 816 __attribute__((aligned(1))) typedef uintptr_t unaligned_uintptr_t;
 817 __attribute__((aligned(1))) typedef  intptr_t unaligned_intptr_t;
 818 __attribute__((aligned(1))) typedef  uint64_t unaligned_uint64_t;
 819 __attribute__((aligned(1))) typedef   int64_t unaligned_int64_t;
 820 __attribute__((aligned(1))) typedef  uint32_t unaligned_uint32_t;
 821 __attribute__((aligned(1))) typedef   int32_t unaligned_int32_t;
 822 __attribute__((aligned(1))) typedef  uint16_t unaligned_uint16_t;
 823 __attribute__((aligned(1))) typedef   int16_t unaligned_int16_t;
 824
 825
 826 // Global operator new and delete. We must not use any app overrides.
 827 // This ALSO REQUIRES each of these be in libobjc's unexported symbol list.
 828 #if __cplusplus
 829 #pragma clang diagnostic push
 830 #pragma clang diagnostic ignored "-Winline-new-delete"
 831 #include <new>
 832 inline void* operator new(std::size_t size) throw (std::bad_alloc) { return malloc(size); }
 833 inline void* operator new[](std::size_t size) throw (std::bad_alloc) { return malloc(size); }
 834 inline void* operator new(std::size_t size, const std::nothrow_t&) throw() { return malloc(size); }
 835 inline void* operator new[](std::size_t size, const std::nothrow_t&) throw() { return malloc(size); }
 836 inline void operator delete(void* p) throw() { free(p); }
 837 inline void operator delete[](void* p) throw() { free(p); }
 838 inline void operator delete(void* p, const std::nothrow_t&) throw() { free(p); }
 839 inline void operator delete[](void* p, const std::nothrow_t&) throw() { free(p); }
 840 #pragma clang diagnostic pop
 841 #endif
 842
 843
 844 class TimeLogger {
 845     uint64_t mStart;
 846     bool mRecord;
 847  public:
 848     TimeLogger(bool record = true)
 849      : mStart(nanoseconds())
 850      , mRecord(record)
 851     { }
 852
 853     void log(const char *msg) {
 854         if (mRecord) {
 855             uint64_t end = nanoseconds();
 856             _objc_inform("%.2f ms: %s", (end - mStart) / 1000000.0, msg);
 857             mStart = nanoseconds();
 858         }
 859     }
 860 };
 861
 862
 863 // StripedMap<T> is a map of void* -> T, sized appropriately
 864 // for cache-friendly lock striping.
 865 // For example, this may be used as StripedMap<spinlock_t>
 866 // or as StripedMap<SomeStruct> where SomeStruct stores a spin lock.
 867 template<typename T>
 868 class StripedMap {
 869
 870     enum { CacheLineSize = 64 };
 871
 872 #if TARGET_OS_EMBEDDED
 873     enum { StripeCount = 8 };
 874 #else
 875     enum { StripeCount = 64 };
 876 #endif
 877
 878     struct PaddedT {
 879         T value alignas(CacheLineSize);
 880     };
 881
 882     PaddedT array[StripeCount];
 883
 884     static unsigned int indexForPointer(const void *p) {
 885         uintptr_t addr = reinterpret_cast<uintptr_t>(p);
 886         return ((addr >> 4) ^ (addr >> 9)) % StripeCount;
 887     }
 888
 889  public:
 890     T& operator[] (const void *p) {
 891         return array[indexForPointer(p)].value;
 892     }
 893     const T& operator[] (const void *p) const {
 894         return const_cast<StripedMap<T>>(this)[p];
 895     }
 896
 897 #if DEBUG
 898     StripedMap() {
 899         // Verify alignment expectations.
 900         uintptr_t base = (uintptr_t)&array[0].value;
 901         uintptr_t delta = (uintptr_t)&array[1].value - base;
 902         assert(delta % CacheLineSize == 0);
 903         assert(base % CacheLineSize == 0);
 904     }
 905 #endif
 906 };
 907
 908
 909 // DisguisedPtr<T> acts like pointer type T*, except the
 910 // stored value is disguised to hide it from tools like `leaks`.
 911 // nil is disguised as itself so zero-filled memory works as expected,
 912 // which means 0x80..00 is also disguised as itself but we don't care.
 913 // Note that weak_entry_t knows about this encoding.
 914 template <typename T>
 915 class DisguisedPtr {
 916     uintptr_t value;
 917
 918     static uintptr_t disguise(T* ptr) {
 919         return -(uintptr_t)ptr;
 920     }
 921
 922     static T* undisguise(uintptr_t val) {
 923         return (T*)-val;
 924     }
 925
 926  public:
 927     DisguisedPtr() { }
 928     DisguisedPtr(T* ptr)
 929         : value(disguise(ptr)) { }
 930     DisguisedPtr(const DisguisedPtr<T>& ptr)
 931         : value(ptr.value) { }
 932
 933     DisguisedPtr<T>& operator = (T* rhs) {
 934         value = disguise(rhs);
 935         return *this;
 936     }
 937     DisguisedPtr<T>& operator = (const DisguisedPtr<T>& rhs) {
 938         value = rhs.value;
 939         return *this;
 940     }
 941
 942     operator T* () const {
 943         return undisguise(value);
 944     }
 945     T* operator -> () const {
 946         return undisguise(value);
 947     }
 948     T& operator * () const {
 949         return *undisguise(value);
 950     }
 951     T& operator [] (size_t i) const {
 952         return undisguise(value)[i];
 953     }
 954
 955     // pointer arithmetic operators omitted
 956     // because we don't currently use them anywhere
 957 };
 958
 959 // fixme type id is weird and not identical to objc_object*
 960 static inline bool operator == (DisguisedPtr<objc_object> lhs, id rhs) {
 961     return lhs == (objc_object *)rhs;
 962 }
 963 static inline bool operator != (DisguisedPtr<objc_object> lhs, id rhs) {
 964     return lhs != (objc_object *)rhs;
 965 }
 966
 967
 968 // Pointer hash function.
 969 // This is not a terrific hash, but it is fast
 970 // and not outrageously flawed for our purposes.
 971
 972 // Based on principles from http://locklessinc.com/articles/fast_hash/
 973 // and evaluation ideas from http://floodyberry.com/noncryptohashzoo/
 974 #if __LP64__
 975 static inline uint32_t ptr_hash(uint64_t key)
 976 {
 977     key ^= key >> 4;
 978     key *= 0x8a970be7488fda55;
 979     key ^= __builtin_bswap64(key);
 980     return (uint32_t)key;
 981 }
 982 #else
 983 static inline uint32_t ptr_hash(uint32_t key)
 984 {
 985     key ^= key >> 4;
 986     key *= 0x5052acdb;
 987     key ^= __builtin_bswap32(key);
 988     return key;
 989 }
 990 #endif
 991
 992 /*
 993   Higher-quality hash function. This is measurably slower in some workloads.
 994 #if __LP64__
 995  uint32_t ptr_hash(uint64_t key)
 996 {
 997     key -= __builtin_bswap64(key);
 998     key *= 0x8a970be7488fda55;
 999     key ^= __builtin_bswap64(key);
1000     key *= 0x8a970be7488fda55;
1001     key ^= __builtin_bswap64(key);
1002     return (uint32_t)key;
1003 }
1004 #else
1005 static uint32_t ptr_hash(uint32_t key)
1006 {
1007     key -= __builtin_bswap32(key);
1008     key *= 0x5052acdb;
1009     key ^= __builtin_bswap32(key);
1010     key *= 0x5052acdb;
1011     key ^= __builtin_bswap32(key);
1012     return key;
1013 }
1014 #endif
1015 */
1016
1017
1018 // Inlined parts of objc_object's implementation
1019 #include "objc-object.h"
1020
1021 #endif /* _OBJC_PRIVATE_H_ */
1022