objc-runtime-old.mm [plain text]
/*
* Copyright (c) 1999-2007 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/***********************************************************************
* objc-runtime-old.m
* Support for old-ABI classes and images.
**********************************************************************/
/***********************************************************************
* Class loading and connecting (GrP 2004-2-11)
*
* When images are loaded (during program startup or otherwise), the
* runtime needs to load classes and categories from the images, connect
* classes to superclasses and categories to parent classes, and call
* +load methods.
*
* The Objective-C runtime can cope with classes arriving in any order.
* That is, a class may be discovered by the runtime before some
* superclass is known. To handle out-of-order class loads, the
* runtime uses a "pending class" system.
*
* (Historical note)
* Panther and earlier: many classes arrived out-of-order because of
* the poorly-ordered callback from dyld. However, the runtime's
* pending mechanism only handled "missing superclass" and not
* "present superclass but missing higher class". See Radar #3225652.
* Tiger: The runtime's pending mechanism was augmented to handle
* arbitrary missing classes. In addition, dyld was rewritten and
* now sends the callbacks in strictly bottom-up link order.
* The pending mechanism may now be needed only for rare and
* hard to construct programs.
* (End historical note)
*
* A class when first seen in an image is considered "unconnected".
* It is stored in `unconnected_class_hash`. If all of the class's
* superclasses exist and are already "connected", then the new class
* can be connected to its superclasses and moved to `class_hash` for
* normal use. Otherwise, the class waits in `unconnected_class_hash`
* until the superclasses finish connecting.
*
* A "connected" class is
* (1) in `class_hash`,
* (2) connected to its superclasses,
* (3) has no unconnected superclasses,
* (4) is otherwise initialized and ready for use, and
* (5) is eligible for +load if +load has not already been called.
*
* An "unconnected" class is
* (1) in `unconnected_class_hash`,
* (2) not connected to its superclasses,
* (3) has an immediate superclass which is either missing or unconnected,
* (4) is not ready for use, and
* (5) is not yet eligible for +load.
*
* Image mapping is NOT CURRENTLY THREAD-SAFE with respect to just about
* anything. Image mapping IS RE-ENTRANT in several places: superclass
* lookup may cause ZeroLink to load another image, and +load calls may
* cause dyld to load another image.
*
* Image mapping sequence:
*
* Read all classes in all new images.
* Add them all to unconnected_class_hash.
* Note any +load implementations before categories are attached.
* Attach any pending categories.
* Read all categories in all new images.
* Attach categories whose parent class exists (connected or not),
* and pend the rest.
* Mark them all eligible for +load (if implemented), even if the
* parent class is missing.
* Try to connect all classes in all new images.
* If the superclass is missing, pend the class
* If the superclass is unconnected, try to recursively connect it
* If the superclass is connected:
* connect the class
* mark the class eligible for +load, if implemented
* fix up any pended classrefs referring to the class
* connect any pended subclasses of the class
* Resolve selector refs and class refs in all new images.
* Class refs whose classes still do not exist are pended.
* Fix up protocol objects in all new images.
* Call +load for classes and categories.
* May include classes or categories that are not in these images,
* but are newly eligible because of these image.
* Class +loads will be called superclass-first because of the
* superclass-first nature of the connecting process.
* Category +load needs to be deferred until the parent class is
* connected and has had its +load called.
*
* Performance: all classes are read before any categories are read.
* Fewer categories need be pended for lack of a parent class.
*
* Performance: all categories are attempted to be attached before
* any classes are connected. Fewer class caches need be flushed.
* (Unconnected classes and their respective subclasses are guaranteed
* to be un-messageable, so their caches will be empty.)
*
* Performance: all classes are read before any classes are connected.
* Fewer classes need be pended for lack of a superclass.
*
* Correctness: all selector and class refs are fixed before any
* protocol fixups or +load methods. libobjc itself contains selector
* and class refs which are used in protocol fixup and +load.
*
* Correctness: +load methods are scheduled in bottom-up link order.
* This constraint is in addition to superclass order. Some +load
* implementations expect to use another class in a linked-to library,
* even if the two classes don't share a direct superclass relationship.
*
* Correctness: all classes are scanned for +load before any categories
* are attached. Otherwise, if a category implements +load and its class
* has no class methods, the class's +load scan would find the category's
* +load method, which would then be called twice.
*
* Correctness: pended class refs are not fixed up until the class is
* connected. Classes with missing weak superclasses remain unconnected.
* Class refs to classes with missing weak superclasses must be nil.
* Therefore class refs to unconnected classes must remain un-fixed.
*
**********************************************************************/
#if !__OBJC2__
#include "objc-private.h"
#include "objc-runtime-old.h"
#include "objc-file-old.h"
#include "objc-cache-old.h"
#include "objc-loadmethod.h"
typedef struct _objc_unresolved_category
{
struct _objc_unresolved_category *next;
old_category *cat; // may be nil
long version;
} _objc_unresolved_category;
typedef struct _PendingSubclass
{
Class subclass; // subclass to finish connecting; may be nil
struct _PendingSubclass *next;
} PendingSubclass;
typedef struct _PendingClassRef
{
Class *ref; // class reference to fix up; may be nil
// (ref & 1) is a metaclass reference
struct _PendingClassRef *next;
} PendingClassRef;
static uintptr_t classHash(void *info, Class data);
static int classIsEqual(void *info, Class name, Class cls);
static int _objc_defaultClassHandler(const char *clsName);
static inline NXMapTable *pendingClassRefsMapTable(void);
static inline NXMapTable *pendingSubclassesMapTable(void);
static void pendClassInstallation(Class cls, const char *superName);
static void pendClassReference(Class *ref, const char *className, bool isMeta);
static void resolve_references_to_class(Class cls);
static void resolve_subclasses_of_class(Class cls);
static void really_connect_class(Class cls, Class supercls);
static bool connect_class(Class cls);
static void map_method_descs (struct objc_method_description_list * methods, bool copy);
static void _objcTweakMethodListPointerForClass(Class cls);
static inline void _objc_add_category(Class cls, old_category *category, int version);
static bool _objc_add_category_flush_caches(Class cls, old_category *category, int version);
static _objc_unresolved_category *reverse_cat(_objc_unresolved_category *cat);
static void resolve_categories_for_class(Class cls);
static bool _objc_register_category(old_category *cat, int version);
// Function called when a class is loaded from an image
void (*callbackFunction)(Class, Category) = 0;
// Hash table of classes
NXHashTable * class_hash = 0;
static NXHashTablePrototype classHashPrototype =
{
(uintptr_t (*) (const void *, const void *)) classHash,
(int (*)(const void *, const void *, const void *)) classIsEqual,
NXNoEffectFree, 0
};
// Hash table of unconnected classes
static NXHashTable *unconnected_class_hash = nil;
// Exported copy of class_hash variable (hook for debugging tools)
NXHashTable *_objc_debug_class_hash = nil;
// Category and class registries
// Keys are COPIES of strings, to prevent stale pointers with unloaded bundles
// Use NXMapKeyCopyingInsert and NXMapKeyFreeingRemove
static NXMapTable * category_hash = nil;
// Keys are COPIES of strings, to prevent stale pointers with unloaded bundles
// Use NXMapKeyCopyingInsert and NXMapKeyFreeingRemove
static NXMapTable * pendingClassRefsMap = nil;
static NXMapTable * pendingSubclassesMap = nil;
// Protocols
static NXMapTable *protocol_map = nil; // name -> protocol
static NXMapTable *protocol_ext_map = nil; // protocol -> protocol ext
// Function pointer objc_getClass calls through when class is not found
static int (*objc_classHandler) (const char *) = _objc_defaultClassHandler;
// Function pointer called by objc_getClass and objc_lookupClass when
// class is not found. _objc_classLoader is called before objc_classHandler.
static BOOL (*_objc_classLoader)(const char *) = nil;
/***********************************************************************
* objc_dump_class_hash. Log names of all known classes.
**********************************************************************/
void objc_dump_class_hash(void)
{
NXHashTable *table;
unsigned count;
Class data;
NXHashState state;
table = class_hash;
count = 0;
state = NXInitHashState (table);
while (NXNextHashState (table, &state, (void **) &data))
printf ("class %d: %s\n", ++count, data->nameForLogging());
}
/***********************************************************************
* _objc_init_class_hash. Return the class lookup table, create it if
* necessary.
**********************************************************************/
void _objc_init_class_hash(void)
{
// Do nothing if class hash table already exists
if (class_hash)
return;
// class_hash starts small, with only enough capacity for libobjc itself.
// If a second library is found by map_images(), class_hash is immediately
// resized to capacity 1024 to cut down on rehashes.
// Old numbers: A smallish Foundation+AppKit program will have
// about 520 classes. Larger apps (like IB or WOB) have more like
// 800 classes. Some customers have massive quantities of classes.
// Foundation-only programs aren't likely to notice the ~6K loss.
class_hash = NXCreateHashTable(classHashPrototype, 16, nil);
_objc_debug_class_hash = class_hash;
}
/***********************************************************************
* objc_getClassList. Return the known classes.
**********************************************************************/
int objc_getClassList(Class *buffer, int bufferLen)
{
NXHashState state;
Class cls;
int cnt, num;
mutex_locker_t lock(classLock);
if (!class_hash) return 0;
num = NXCountHashTable(class_hash);
if (nil == buffer) return num;
cnt = 0;
state = NXInitHashState(class_hash);
while (cnt < bufferLen &&
NXNextHashState(class_hash, &state, (void **)&cls))
{
buffer[cnt++] = cls;
}
return num;
}
/***********************************************************************
* objc_copyClassList
* Returns pointers to all classes.
* This requires all classes be realized, which is regretfully non-lazy.
*
* outCount may be nil. *outCount is the number of classes returned.
* If the returned array is not nil, it is nil-terminated and must be
* freed with free().
* Locking: acquires classLock
**********************************************************************/
Class *
objc_copyClassList(unsigned int *outCount)
{
Class *result;
unsigned int count;
mutex_locker_t lock(classLock);
result = nil;
count = class_hash ? NXCountHashTable(class_hash) : 0;
if (count > 0) {
Class cls;
NXHashState state = NXInitHashState(class_hash);
result = (Class *)malloc((1+count) * sizeof(Class));
count = 0;
while (NXNextHashState(class_hash, &state, (void **)&cls)) {
result[count++] = cls;
}
result[count] = nil;
}
if (outCount) *outCount = count;
return result;
}
/***********************************************************************
* objc_copyProtocolList
* Returns pointers to all protocols.
* Locking: acquires classLock
**********************************************************************/
Protocol * __unsafe_unretained *
objc_copyProtocolList(unsigned int *outCount)
{
int count, i;
Protocol *proto;
const char *name;
NXMapState state;
Protocol **result;
mutex_locker_t lock(classLock);
count = NXCountMapTable(protocol_map);
if (count == 0) {
if (outCount) *outCount = 0;
return nil;
}
result = (Protocol **)calloc(1 + count, sizeof(Protocol *));
i = 0;
state = NXInitMapState(protocol_map);
while (NXNextMapState(protocol_map, &state,
(const void **)&name, (const void **)&proto))
{
result[i++] = proto;
}
result[i++] = nil;
assert(i == count+1);
if (outCount) *outCount = count;
return result;
}
/***********************************************************************
* objc_getClasses. Return class lookup table.
*
* NOTE: This function is very dangerous, since you cannot safely use
* the hashtable without locking it, and the lock is private!
**********************************************************************/
void *objc_getClasses(void)
{
OBJC_WARN_DEPRECATED;
// Return the class lookup hash table
return class_hash;
}
/***********************************************************************
* classHash.
**********************************************************************/
static uintptr_t classHash(void *info, Class data)
{
// Nil classes hash to zero
if (!data)
return 0;
// Call through to real hash function
return _objc_strhash (data->mangledName());
}
/***********************************************************************
* classIsEqual. Returns whether the class names match. If we ever
* check more than the name, routines like objc_lookUpClass have to
* change as well.
**********************************************************************/
static int classIsEqual(void *info, Class name, Class cls)
{
// Standard string comparison
return strcmp(name->mangledName(), cls->mangledName()) == 0;
}
// Unresolved future classes
static NXHashTable *future_class_hash = nil;
// Resolved future<->original classes
static NXMapTable *future_class_to_original_class_map = nil;
static NXMapTable *original_class_to_future_class_map = nil;
// CF requests about 20 future classes; HIToolbox requests one.
#define FUTURE_COUNT 32
/***********************************************************************
* setOriginalClassForFutureClass
* Record resolution of a future class.
**********************************************************************/
static void setOriginalClassForFutureClass(Class futureClass,
Class originalClass)
{
if (!future_class_to_original_class_map) {
future_class_to_original_class_map =
NXCreateMapTable(NXPtrValueMapPrototype, FUTURE_COUNT);
original_class_to_future_class_map =
NXCreateMapTable(NXPtrValueMapPrototype, FUTURE_COUNT);
}
NXMapInsert (future_class_to_original_class_map,
futureClass, originalClass);
NXMapInsert (original_class_to_future_class_map,
originalClass, futureClass);
if (PrintFuture) {
_objc_inform("FUTURE: using %p instead of %p for %s", (void*)futureClass, (void*)originalClass, originalClass->name);
}
}
/***********************************************************************
* getOriginalClassForFutureClass
* getFutureClassForOriginalClass
* Switch between a future class and its corresponding original class.
* The future class is the one actually in use.
* The original class is the one from disk.
**********************************************************************/
/*
static Class
getOriginalClassForFutureClass(Class futureClass)
{
if (!future_class_to_original_class_map) return Nil;
return NXMapGet (future_class_to_original_class_map, futureClass);
}
*/
static Class
getFutureClassForOriginalClass(Class originalClass)
{
if (!original_class_to_future_class_map) return Nil;
return (Class)NXMapGet(original_class_to_future_class_map, originalClass);
}
/***********************************************************************
* makeFutureClass
* Initialize the memory in *cls with an unresolved future class with the
* given name. The memory is recorded in future_class_hash.
**********************************************************************/
static void makeFutureClass(Class cls, const char *name)
{
// CF requests about 20 future classes, plus HIToolbox has one.
if (!future_class_hash) {
future_class_hash =
NXCreateHashTable(classHashPrototype, FUTURE_COUNT, nil);
}
cls->name = strdup(name);
NXHashInsert(future_class_hash, cls);
if (PrintFuture) {
_objc_inform("FUTURE: reserving %p for %s", (void*)cls, name);
}
}
/***********************************************************************
* _objc_allocateFutureClass
* Allocate an unresolved future class for the given class name.
* Returns any existing allocation if one was already made.
* Assumes the named class doesn't exist yet.
* Not thread safe.
**********************************************************************/
Class _objc_allocateFutureClass(const char *name)
{
Class cls;
if (future_class_hash) {
objc_class query;
query.name = name;
if ((cls = (Class)NXHashGet(future_class_hash, &query))) {
// Already have a future class for this name.
return cls;
}
}
cls = _calloc_class(sizeof(objc_class));
makeFutureClass(cls, name);
return cls;
}
/***********************************************************************
* objc_getFutureClass. Return the id of the named class.
* If the class does not exist, return an uninitialized class
* structure that will be used for the class when and if it
* does get loaded.
* Not thread safe.
**********************************************************************/
Class objc_getFutureClass(const char *name)
{
Class cls;
// YES unconnected, NO class handler
// (unconnected is OK because it will someday be the real class)
cls = look_up_class(name, YES, NO);
if (cls) {
if (PrintFuture) {
_objc_inform("FUTURE: found %p already in use for %s",
(void*)cls, name);
}
return cls;
}
// No class or future class with that name yet. Make one.
// fixme not thread-safe with respect to
// simultaneous library load or getFutureClass.
return _objc_allocateFutureClass(name);
}
BOOL _class_isFutureClass(Class cls)
{
return cls && cls->isFuture();
}
bool objc_class::isFuture()
{
return future_class_hash && NXHashGet(future_class_hash, this);
}
/***********************************************************************
* _objc_defaultClassHandler. Default objc_classHandler. Does nothing.
**********************************************************************/
static int _objc_defaultClassHandler(const char *clsName)
{
// Return zero so objc_getClass doesn't bother re-searching
return 0;
}
/***********************************************************************
* objc_setClassHandler. Set objc_classHandler to the specified value.
*
* NOTE: This should probably deal with userSuppliedHandler being nil,
* because the objc_classHandler caller does not check... it would bus
* error. It would make sense to handle nil by restoring the default
* handler. Is anyone hacking with this, though?
**********************************************************************/
void objc_setClassHandler(int (*userSuppliedHandler)(const char *))
{
OBJC_WARN_DEPRECATED;
objc_classHandler = userSuppliedHandler;
}
/***********************************************************************
* _objc_setClassLoader
* Similar to objc_setClassHandler, but objc_classLoader is used for
* both objc_getClass() and objc_lookupClass(), and objc_classLoader
* pre-empts objc_classHandler.
**********************************************************************/
void _objc_setClassLoader(BOOL (*newClassLoader)(const char *))
{
_objc_classLoader = newClassLoader;
}
/***********************************************************************
* objc_getProtocol
* Get a protocol by name, or nil.
**********************************************************************/
Protocol *objc_getProtocol(const char *name)
{
mutex_locker_t lock(classLock);
if (!protocol_map) return nil;
return (Protocol *)NXMapGet(protocol_map, name);
}
/***********************************************************************
* look_up_class
* Map a class name to a class using various methods.
* This is the common implementation of objc_lookUpClass and objc_getClass,
* and is also used internally to get additional search options.
* Sequence:
* 1. class_hash
* 2. unconnected_class_hash (optional)
* 3. classLoader callback
* 4. classHandler callback (optional)
**********************************************************************/
Class look_up_class(const char *aClassName, bool includeUnconnected,
bool includeClassHandler)
{
bool includeClassLoader = YES; // class loader cannot be skipped
Class result = nil;
struct objc_class query;
query.name = aClassName;
retry:
if (!result && class_hash) {
// Check ordinary classes
mutex_locker_t lock(classLock);
result = (Class)NXHashGet(class_hash, &query);
}
if (!result && includeUnconnected && unconnected_class_hash) {
// Check not-yet-connected classes
mutex_locker_t lock(classLock);
result = (Class)NXHashGet(unconnected_class_hash, &query);
}
if (!result && includeClassLoader && _objc_classLoader) {
// Try class loader callback
if ((*_objc_classLoader)(aClassName)) {
// Re-try lookup without class loader
includeClassLoader = NO;
goto retry;
}
}
if (!result && includeClassHandler && objc_classHandler) {
// Try class handler callback
if ((*objc_classHandler)(aClassName)) {
// Re-try lookup without class handler or class loader
includeClassLoader = NO;
includeClassHandler = NO;
goto retry;
}
}
return result;
}
/***********************************************************************
* objc_class::isConnected
* Returns TRUE if class cls is connected.
* A connected class has either a connected superclass or a nil superclass,
* and is present in class_hash.
**********************************************************************/
bool objc_class::isConnected()
{
mutex_locker_t lock(classLock);
return NXHashMember(class_hash, this);
}
/***********************************************************************
* pendingClassRefsMapTable. Return a pointer to the lookup table for
* pending class refs.
**********************************************************************/
static inline NXMapTable *pendingClassRefsMapTable(void)
{
// Allocate table if needed
if (!pendingClassRefsMap) {
pendingClassRefsMap = NXCreateMapTable(NXStrValueMapPrototype, 10);
}
// Return table pointer
return pendingClassRefsMap;
}
/***********************************************************************
* pendingSubclassesMapTable. Return a pointer to the lookup table for
* pending subclasses.
**********************************************************************/
static inline NXMapTable *pendingSubclassesMapTable(void)
{
// Allocate table if needed
if (!pendingSubclassesMap) {
pendingSubclassesMap = NXCreateMapTable(NXStrValueMapPrototype, 10);
}
// Return table pointer
return pendingSubclassesMap;
}
/***********************************************************************
* pendClassInstallation
* Finish connecting class cls when its superclass becomes connected.
* Check for multiple pends of the same class because connect_class does not.
**********************************************************************/
static void pendClassInstallation(Class cls, const char *superName)
{
NXMapTable *table;
PendingSubclass *pending;
PendingSubclass *oldList;
PendingSubclass *l;
// Create and/or locate pending class lookup table
table = pendingSubclassesMapTable ();
// Make sure this class isn't already in the pending list.
oldList = (PendingSubclass *)NXMapGet(table, superName);
for (l = oldList; l != nil; l = l->next) {
if (l->subclass == cls) return; // already here, nothing to do
}
// Create entry referring to this class
pending = (PendingSubclass *)malloc(sizeof(PendingSubclass));
pending->subclass = cls;
// Link new entry into head of list of entries for this class
pending->next = oldList;
// (Re)place entry list in the table
NXMapKeyCopyingInsert (table, superName, pending);
}
/***********************************************************************
* pendClassReference
* Fix up a class ref when the class with the given name becomes connected.
**********************************************************************/
static void pendClassReference(Class *ref, const char *className, bool isMeta)
{
NXMapTable *table;
PendingClassRef *pending;
// Create and/or locate pending class lookup table
table = pendingClassRefsMapTable ();
// Create entry containing the class reference
pending = (PendingClassRef *)malloc(sizeof(PendingClassRef));
pending->ref = ref;
if (isMeta) {
pending->ref = (Class *)((uintptr_t)pending->ref | 1);
}
// Link new entry into head of list of entries for this class
pending->next = (PendingClassRef *)NXMapGet(table, className);
// (Re)place entry list in the table
NXMapKeyCopyingInsert (table, className, pending);
if (PrintConnecting) {
_objc_inform("CONNECT: pended reference to class '%s%s' at %p",
className, isMeta ? " (meta)" : "", (void *)ref);
}
}
/***********************************************************************
* resolve_references_to_class
* Fix up any pending class refs to this class.
**********************************************************************/
static void resolve_references_to_class(Class cls)
{
PendingClassRef *pending;
if (!pendingClassRefsMap) return; // no unresolved refs for any class
pending = (PendingClassRef *)NXMapGet(pendingClassRefsMap, cls->name);
if (!pending) return; // no unresolved refs for this class
NXMapKeyFreeingRemove(pendingClassRefsMap, cls->name);
if (PrintConnecting) {
_objc_inform("CONNECT: resolving references to class '%s'", cls->name);
}
while (pending) {
PendingClassRef *next = pending->next;
if (pending->ref) {
bool isMeta = (uintptr_t)pending->ref & 1;
Class *ref =
(Class *)((uintptr_t)pending->ref & ~(uintptr_t)1);
*ref = isMeta ? cls->ISA() : cls;
}
free(pending);
pending = next;
}
if (NXCountMapTable(pendingClassRefsMap) == 0) {
NXFreeMapTable(pendingClassRefsMap);
pendingClassRefsMap = nil;
}
}
/***********************************************************************
* resolve_subclasses_of_class
* Fix up any pending subclasses of this class.
**********************************************************************/
static void resolve_subclasses_of_class(Class cls)
{
PendingSubclass *pending;
if (!pendingSubclassesMap) return; // no unresolved subclasses
pending = (PendingSubclass *)NXMapGet(pendingSubclassesMap, cls->name);
if (!pending) return; // no unresolved subclasses for this class
NXMapKeyFreeingRemove(pendingSubclassesMap, cls->name);
// Destroy the pending table if it's now empty, to save memory.
if (NXCountMapTable(pendingSubclassesMap) == 0) {
NXFreeMapTable(pendingSubclassesMap);
pendingSubclassesMap = nil;
}
if (PrintConnecting) {
_objc_inform("CONNECT: resolving subclasses of class '%s'", cls->name);
}
while (pending) {
PendingSubclass *next = pending->next;
if (pending->subclass) connect_class(pending->subclass);
free(pending);
pending = next;
}
}
/***********************************************************************
* really_connect_class
* Connect cls to superclass supercls unconditionally.
* Also adjust the class hash tables and handle pended subclasses.
*
* This should be called from connect_class() ONLY.
**********************************************************************/
static void really_connect_class(Class cls,
Class supercls)
{
Class oldCls;
// Connect superclass pointers.
set_superclass(cls, supercls, YES);
// Done!
cls->info |= CLS_CONNECTED;
{
mutex_locker_t lock(classLock);
// Update hash tables.
NXHashRemove(unconnected_class_hash, cls);
oldCls = (Class)NXHashInsert(class_hash, cls);
// Delete unconnected_class_hash if it is now empty.
if (NXCountHashTable(unconnected_class_hash) == 0) {
NXFreeHashTable(unconnected_class_hash);
unconnected_class_hash = nil;
}
// No duplicate classes allowed.
// Duplicates should have been rejected by _objc_read_classes_from_image
assert(!oldCls);
}
// Fix up pended class refs to this class, if any
resolve_references_to_class(cls);
// Connect newly-connectable subclasses
resolve_subclasses_of_class(cls);
// Debugging: if this class has ivars, make sure this class's ivars don't
// overlap with its super's. This catches some broken fragile base classes.
// Do not use super->instance_size vs. self->ivar[0] to check this.
// Ivars may be packed across instance_size boundaries.
if (DebugFragileSuperclasses && cls->ivars && cls->ivars->ivar_count) {
Class ivar_cls = supercls;
// Find closest superclass that has some ivars, if one exists.
while (ivar_cls &&
(!ivar_cls->ivars || ivar_cls->ivars->ivar_count == 0))
{
ivar_cls = ivar_cls->superclass;
}
if (ivar_cls) {
// Compare superclass's last ivar to this class's first ivar
old_ivar *super_ivar =
&ivar_cls->ivars->ivar_list[ivar_cls->ivars->ivar_count - 1];
old_ivar *self_ivar =
&cls->ivars->ivar_list[0];
// fixme could be smarter about super's ivar size
if (self_ivar->ivar_offset <= super_ivar->ivar_offset) {
_objc_inform("WARNING: ivars of superclass '%s' and "
"subclass '%s' overlap; superclass may have "
"changed since subclass was compiled",
ivar_cls->name, cls->name);
}
}
}
}
/***********************************************************************
* connect_class
* Connect class cls to its superclasses, if possible.
* If cls becomes connected, move it from unconnected_class_hash
* to connected_class_hash.
* Returns TRUE if cls is connected.
* Returns FALSE if cls could not be connected for some reason
* (missing superclass or still-unconnected superclass)
**********************************************************************/
static bool connect_class(Class cls)
{
if (cls->isConnected()) {
// This class is already connected to its superclass.
// Do nothing.
return TRUE;
}
else if (cls->superclass == nil) {
// This class is a root class.
// Connect it to itself.
if (PrintConnecting) {
_objc_inform("CONNECT: class '%s' now connected (root class)",
cls->name);
}
really_connect_class(cls, nil);
return TRUE;
}
else {
// This class is not a root class and is not yet connected.
// Connect it if its superclass and root class are already connected.
// Otherwise, add this class to the to-be-connected list,
// pending the completion of its superclass and root class.
// At this point, cls->superclass and cls->ISA()->ISA() are still STRINGS
char *supercls_name = (char *)cls->superclass;
Class supercls;
// YES unconnected, YES class handler
if (nil == (supercls = look_up_class(supercls_name, YES, YES))) {
// Superclass does not exist yet.
// pendClassInstallation will handle duplicate pends of this class
pendClassInstallation(cls, supercls_name);
if (PrintConnecting) {
_objc_inform("CONNECT: class '%s' NOT connected (missing super)", cls->name);
}
return FALSE;
}
if (! connect_class(supercls)) {
// Superclass exists but is not yet connected.
// pendClassInstallation will handle duplicate pends of this class
pendClassInstallation(cls, supercls_name);
if (PrintConnecting) {
_objc_inform("CONNECT: class '%s' NOT connected (unconnected super)", cls->name);
}
return FALSE;
}
// Superclass exists and is connected.
// Connect this class to the superclass.
if (PrintConnecting) {
_objc_inform("CONNECT: class '%s' now connected", cls->name);
}
really_connect_class(cls, supercls);
return TRUE;
}
}
/***********************************************************************
* _objc_read_categories_from_image.
* Read all categories from the given image.
* Install them on their parent classes, or register them for later
* installation.
* Returns YES if some method caches now need to be flushed.
**********************************************************************/
static bool _objc_read_categories_from_image (header_info * hi)
{
Module mods;
size_t midx;
bool needFlush = NO;
if (hi->info()->isReplacement()) {
// Ignore any categories in this image
return NO;
}
// Major loop - process all modules in the header
mods = hi->mod_ptr;
// NOTE: The module and category lists are traversed backwards
// to preserve the pre-10.4 processing order. Changing the order
// would have a small chance of introducing binary compatibility bugs.
midx = hi->mod_count;
while (midx-- > 0) {
unsigned int index;
unsigned int total;
// Nothing to do for a module without a symbol table
if (mods[midx].symtab == nil)
continue;
// Total entries in symbol table (class entries followed
// by category entries)
total = mods[midx].symtab->cls_def_cnt +
mods[midx].symtab->cat_def_cnt;
// Minor loop - register all categories from given module
index = total;
while (index-- > mods[midx].symtab->cls_def_cnt) {
old_category *cat = (old_category *)mods[midx].symtab->defs[index];
needFlush |= _objc_register_category(cat, (int)mods[midx].version);
}
}
return needFlush;
}
/***********************************************************************
* _objc_read_classes_from_image.
* Read classes from the given image, perform assorted minor fixups,
* scan for +load implementation.
* Does not connect classes to superclasses.
* Does attach pended categories to the classes.
* Adds all classes to unconnected_class_hash. class_hash is unchanged.
**********************************************************************/
static void _objc_read_classes_from_image(header_info *hi)
{
unsigned int index;
unsigned int midx;
Module mods;
int isBundle = headerIsBundle(hi);
if (hi->info()->isReplacement()) {
// Ignore any classes in this image
return;
}
// class_hash starts small, enough only for libobjc itself.
// If other Objective-C libraries are found, immediately resize
// class_hash, assuming that Foundation and AppKit are about
// to add lots of classes.
{
mutex_locker_t lock(classLock);
if (hi->mhdr() != libobjc_header && _NXHashCapacity(class_hash) < 1024) {
_NXHashRehashToCapacity(class_hash, 1024);
}
}
// Major loop - process all modules in the image
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx += 1)
{
// Skip module containing no classes
if (mods[midx].symtab == nil)
continue;
// Minor loop - process all the classes in given module
for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1)
{
Class newCls, oldCls;
bool rejected;
// Locate the class description pointer
newCls = (Class)mods[midx].symtab->defs[index];
// Classes loaded from Mach-O bundles can be unloaded later.
// Nothing uses this class yet, so cls->setInfo is not needed.
if (isBundle) newCls->info |= CLS_FROM_BUNDLE;
if (isBundle) newCls->ISA()->info |= CLS_FROM_BUNDLE;
// Use common static empty cache instead of nil
if (newCls->cache == nil)
newCls->cache = (Cache) &_objc_empty_cache;
if (newCls->ISA()->cache == nil)
newCls->ISA()->cache = (Cache) &_objc_empty_cache;
// Set metaclass version
newCls->ISA()->version = mods[midx].version;
// methodLists is nil or a single list, not an array
newCls->info |= CLS_NO_METHOD_ARRAY|CLS_NO_PROPERTY_ARRAY;
newCls->ISA()->info |= CLS_NO_METHOD_ARRAY|CLS_NO_PROPERTY_ARRAY;
// class has no subclasses for cache flushing
newCls->info |= CLS_LEAF;
newCls->ISA()->info |= CLS_LEAF;
if (mods[midx].version >= 6) {
// class structure has ivar_layout and ext fields
newCls->info |= CLS_EXT;
newCls->ISA()->info |= CLS_EXT;
}
// Check for +load implementation before categories are attached
if (_class_hasLoadMethod(newCls)) {
newCls->ISA()->info |= CLS_HAS_LOAD_METHOD;
}
// Install into unconnected_class_hash.
{
mutex_locker_t lock(classLock);
if (future_class_hash) {
Class futureCls = (Class)
NXHashRemove(future_class_hash, newCls);
if (futureCls) {
// Another class structure for this class was already
// prepared by objc_getFutureClass(). Use it instead.
free((char *)futureCls->name);
memcpy(futureCls, newCls, sizeof(objc_class));
setOriginalClassForFutureClass(futureCls, newCls);
newCls = futureCls;
if (NXCountHashTable(future_class_hash) == 0) {
NXFreeHashTable(future_class_hash);
future_class_hash = nil;
}
}
}
if (!unconnected_class_hash) {
unconnected_class_hash =
NXCreateHashTable(classHashPrototype, 128, nil);
}
if ((oldCls = (Class)NXHashGet(class_hash, newCls)) ||
(oldCls = (Class)NXHashGet(unconnected_class_hash, newCls)))
{
// Another class with this name exists. Complain and reject.
inform_duplicate(newCls->name, oldCls, newCls);
rejected = YES;
}
else {
NXHashInsert(unconnected_class_hash, newCls);
rejected = NO;
}
}
if (!rejected) {
// Attach pended categories for this class, if any
resolve_categories_for_class(newCls);
}
}
}
}
/***********************************************************************
* _objc_connect_classes_from_image.
* Connect the classes in the given image to their superclasses,
* or register them for later connection if any superclasses are missing.
**********************************************************************/
static void _objc_connect_classes_from_image(header_info *hi)
{
unsigned int index;
unsigned int midx;
Module mods;
bool replacement = hi->info()->isReplacement();
// Major loop - process all modules in the image
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx += 1)
{
// Skip module containing no classes
if (mods[midx].symtab == nil)
continue;
// Minor loop - process all the classes in given module
for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1)
{
Class cls = (Class)mods[midx].symtab->defs[index];
if (! replacement) {
bool connected;
Class futureCls = getFutureClassForOriginalClass(cls);
if (futureCls) {
// objc_getFutureClass() requested a different class
// struct. Fix up the original struct's superclass
// field for [super ...] use, but otherwise perform
// fixups on the new class struct only.
const char *super_name = (const char *) cls->superclass;
if (super_name) cls->superclass = objc_getClass(super_name);
cls = futureCls;
}
connected = connect_class(cls);
if (connected && callbackFunction) {
(*callbackFunction)(cls, 0);
}
} else {
// Replacement image - fix up superclass only (#3704817)
// And metaclass's superclass (#5351107)
const char *super_name = (const char *) cls->superclass;
if (super_name) {
cls->superclass = objc_getClass(super_name);
// metaclass's superclass is superclass's metaclass
cls->ISA()->superclass = cls->superclass->ISA();
} else {
// Replacement for a root class
// cls->superclass already nil
// root metaclass's superclass is root class
cls->ISA()->superclass = cls;
}
}
}
}
}
/***********************************************************************
* _objc_map_class_refs_for_image. Convert the class ref entries from
* a class name string pointer to a class pointer. If the class does
* not yet exist, the reference is added to a list of pending references
* to be fixed up at a later date.
**********************************************************************/
static void fix_class_ref(Class *ref, const char *name, bool isMeta)
{
Class cls;
// Get pointer to class of this name
// NO unconnected, YES class loader
// (real class with weak-missing superclass is unconnected now)
cls = look_up_class(name, NO, YES);
if (cls) {
// Referenced class exists. Fix up the reference.
*ref = isMeta ? cls->ISA() : cls;
} else {
// Referenced class does not exist yet. Insert nil for now
// (weak-linking) and fix up the reference if the class arrives later.
pendClassReference (ref, name, isMeta);
*ref = nil;
}
}
static void _objc_map_class_refs_for_image (header_info * hi)
{
Class *cls_refs;
size_t count;
unsigned int index;
// Locate class refs in image
cls_refs = _getObjcClassRefs (hi, &count);
if (cls_refs) {
// Process each class ref
for (index = 0; index < count; index += 1) {
// Ref is initially class name char*
const char *name = (const char *) cls_refs[index];
if (!name) continue;
fix_class_ref(&cls_refs[index], name, NO /*never meta*/);
}
}
}
/***********************************************************************
* _objc_remove_pending_class_refs_in_image
* Delete any pending class ref fixups for class refs in the given image,
* because the image is about to be unloaded.
**********************************************************************/
static void removePendingReferences(Class *refs, size_t count)
{
Class *end = refs + count;
if (!refs) return;
if (!pendingClassRefsMap) return;
// Search the pending class ref table for class refs in this range.
// The class refs may have already been stomped with nil,
// so there's no way to recover the original class name.
{
const char *key;
PendingClassRef *pending;
NXMapState state = NXInitMapState(pendingClassRefsMap);
while(NXNextMapState(pendingClassRefsMap, &state,
(const void **)&key, (const void **)&pending))
{
for ( ; pending != nil; pending = pending->next) {
if (pending->ref >= refs && pending->ref < end) {
pending->ref = nil;
}
}
}
}
}
static void _objc_remove_pending_class_refs_in_image(header_info *hi)
{
Class *cls_refs;
size_t count;
// Locate class refs in this image
cls_refs = _getObjcClassRefs(hi, &count);
removePendingReferences(cls_refs, count);
}
/***********************************************************************
* map_selrefs. For each selector in the specified array,
* replace the name pointer with a uniqued selector.
* If copy is TRUE, all selector data is always copied. This is used
* for registering selectors from unloadable bundles, so the selector
* can still be used after the bundle's data segment is unmapped.
* Returns YES if dst was written to, NO if it was unchanged.
**********************************************************************/
static inline void map_selrefs(SEL *sels, size_t count, bool copy)
{
size_t index;
if (!sels) return;
mutex_locker_t lock(selLock);
// Process each selector
for (index = 0; index < count; index += 1)
{
SEL sel;
// Lookup pointer to uniqued string
sel = sel_registerNameNoLock((const char *) sels[index], copy);
// Replace this selector with uniqued one (avoid
// modifying the VM page if this would be a NOP)
if (sels[index] != sel) {
sels[index] = sel;
}
}
}
/***********************************************************************
* map_method_descs. For each method in the specified method list,
* replace the name pointer with a uniqued selector.
* If copy is TRUE, all selector data is always copied. This is used
* for registering selectors from unloadable bundles, so the selector
* can still be used after the bundle's data segment is unmapped.
**********************************************************************/
static void map_method_descs (struct objc_method_description_list * methods, bool copy)
{
int index;
if (!methods) return;
mutex_locker_t lock(selLock);
// Process each method
for (index = 0; index < methods->count; index += 1)
{
struct objc_method_description * method;
SEL sel;
// Get method entry to fix up
method = &methods->list[index];
// Lookup pointer to uniqued string
sel = sel_registerNameNoLock((const char *) method->name, copy);
// Replace this selector with uniqued one (avoid
// modifying the VM page if this would be a NOP)
if (method->name != sel)
method->name = sel;
}
}
/***********************************************************************
* ext_for_protocol
* Returns the protocol extension for the given protocol.
* Returns nil if the protocol has no extension.
**********************************************************************/
static old_protocol_ext *ext_for_protocol(old_protocol *proto)
{
if (!proto) return nil;
if (!protocol_ext_map) return nil;
else return (old_protocol_ext *)NXMapGet(protocol_ext_map, proto);
}
/***********************************************************************
* lookup_method
* Search a protocol method list for a selector.
**********************************************************************/
static struct objc_method_description *
lookup_method(struct objc_method_description_list *mlist, SEL aSel)
{
if (mlist) {
int i;
for (i = 0; i < mlist->count; i++) {
if (mlist->list[i].name == aSel) {
return mlist->list+i;
}
}
}
return nil;
}
/***********************************************************************
* lookup_protocol_method
* Search for a selector in a protocol
* (and optionally recursively all incorporated protocols)
**********************************************************************/
struct objc_method_description *
lookup_protocol_method(old_protocol *proto, SEL aSel,
bool isRequiredMethod, bool isInstanceMethod,
bool recursive)
{
struct objc_method_description *m = nil;
old_protocol_ext *ext;
if (isRequiredMethod) {
if (isInstanceMethod) {
m = lookup_method(proto->instance_methods, aSel);
} else {
m = lookup_method(proto->class_methods, aSel);
}
} else if ((ext = ext_for_protocol(proto))) {
if (isInstanceMethod) {
m = lookup_method(ext->optional_instance_methods, aSel);
} else {
m = lookup_method(ext->optional_class_methods, aSel);
}
}
if (!m && recursive && proto->protocol_list) {
int i;
for (i = 0; !m && i < proto->protocol_list->count; i++) {
m = lookup_protocol_method(proto->protocol_list->list[i], aSel,
isRequiredMethod,isInstanceMethod,true);
}
}
return m;
}
/***********************************************************************
* protocol_getName
* Returns the name of the given protocol.
**********************************************************************/
const char *protocol_getName(Protocol *p)
{
old_protocol *proto = oldprotocol(p);
if (!proto) return "nil";
return proto->protocol_name;
}
/***********************************************************************
* protocol_getMethodDescription
* Returns the description of a named method.
* Searches either required or optional methods.
* Searches either instance or class methods.
**********************************************************************/
struct objc_method_description
protocol_getMethodDescription(Protocol *p, SEL aSel,
BOOL isRequiredMethod, BOOL isInstanceMethod)
{
struct objc_method_description empty = {nil, nil};
old_protocol *proto = oldprotocol(p);
struct objc_method_description *desc;
if (!proto) return empty;
desc = lookup_protocol_method(proto, aSel,
isRequiredMethod, isInstanceMethod, true);
if (desc) return *desc;
else return empty;
}
/***********************************************************************
* protocol_copyMethodDescriptionList
* Returns an array of method descriptions from a protocol.
* Copies either required or optional methods.
* Copies either instance or class methods.
**********************************************************************/
struct objc_method_description *
protocol_copyMethodDescriptionList(Protocol *p,
BOOL isRequiredMethod,
BOOL isInstanceMethod,
unsigned int *outCount)
{
struct objc_method_description_list *mlist = nil;
old_protocol *proto = oldprotocol(p);
old_protocol_ext *ext;
unsigned int i, count;
struct objc_method_description *result;
if (!proto) {
if (outCount) *outCount = 0;
return nil;
}
if (isRequiredMethod) {
if (isInstanceMethod) {
mlist = proto->instance_methods;
} else {
mlist = proto->class_methods;
}
} else if ((ext = ext_for_protocol(proto))) {
if (isInstanceMethod) {
mlist = ext->optional_instance_methods;
} else {
mlist = ext->optional_class_methods;
}
}
if (!mlist) {
if (outCount) *outCount = 0;
return nil;
}
count = mlist->count;
result = (struct objc_method_description *)
calloc(count + 1, sizeof(struct objc_method_description));
for (i = 0; i < count; i++) {
result[i] = mlist->list[i];
}
if (outCount) *outCount = count;
return result;
}
objc_property_t
protocol_getProperty(Protocol *p, const char *name,
BOOL isRequiredProperty, BOOL isInstanceProperty)
{
old_protocol *proto = oldprotocol(p);
old_protocol_ext *ext;
old_protocol_list *proto_list;
if (!proto || !name) return nil;
if (!isRequiredProperty) {
// Only required properties are currently supported
return nil;
}
if ((ext = ext_for_protocol(proto))) {
old_property_list *plist;
if (isInstanceProperty) plist = ext->instance_properties;
else if (ext->hasClassPropertiesField()) plist = ext->class_properties;
else plist = nil;
if (plist) {
uint32_t i;
for (i = 0; i < plist->count; i++) {
old_property *prop = property_list_nth(plist, i);
if (0 == strcmp(name, prop->name)) {
return (objc_property_t)prop;
}
}
}
}
if ((proto_list = proto->protocol_list)) {
int i;
for (i = 0; i < proto_list->count; i++) {
objc_property_t prop =
protocol_getProperty((Protocol *)proto_list->list[i], name,
isRequiredProperty, isInstanceProperty);
if (prop) return prop;
}
}
return nil;
}
objc_property_t *
protocol_copyPropertyList2(Protocol *p, unsigned int *outCount,
BOOL isRequiredProperty, BOOL isInstanceProperty)
{
old_property **result = nil;
old_protocol_ext *ext;
old_property_list *plist;
old_protocol *proto = oldprotocol(p);
if (! (ext = ext_for_protocol(proto)) || !isRequiredProperty) {
// Only required properties are currently supported.
if (outCount) *outCount = 0;
return nil;
}
if (isInstanceProperty) plist = ext->instance_properties;
else if (ext->hasClassPropertiesField()) plist = ext->class_properties;
else plist = nil;
result = copyPropertyList(plist, outCount);
return (objc_property_t *)result;
}
objc_property_t *protocol_copyPropertyList(Protocol *p, unsigned int *outCount)
{
return protocol_copyPropertyList2(p, outCount, YES, YES);
}
/***********************************************************************
* protocol_copyProtocolList
* Copies this protocol's incorporated protocols.
* Does not copy those protocol's incorporated protocols in turn.
**********************************************************************/
Protocol * __unsafe_unretained *
protocol_copyProtocolList(Protocol *p, unsigned int *outCount)
{
unsigned int count = 0;
Protocol **result = nil;
old_protocol *proto = oldprotocol(p);
if (!proto) {
if (outCount) *outCount = 0;
return nil;
}
if (proto->protocol_list) {
count = (unsigned int)proto->protocol_list->count;
}
if (count > 0) {
unsigned int i;
result = (Protocol **)malloc((count+1) * sizeof(Protocol *));
for (i = 0; i < count; i++) {
result[i] = (Protocol *)proto->protocol_list->list[i];
}
result[i] = nil;
}
if (outCount) *outCount = count;
return result;
}
BOOL protocol_conformsToProtocol(Protocol *self_gen, Protocol *other_gen)
{
old_protocol *self = oldprotocol(self_gen);
old_protocol *other = oldprotocol(other_gen);
if (!self || !other) {
return NO;
}
if (0 == strcmp(self->protocol_name, other->protocol_name)) {
return YES;
}
if (self->protocol_list) {
int i;
for (i = 0; i < self->protocol_list->count; i++) {
old_protocol *proto = self->protocol_list->list[i];
if (0 == strcmp(other->protocol_name, proto->protocol_name)) {
return YES;
}
if (protocol_conformsToProtocol((Protocol *)proto, other_gen)) {
return YES;
}
}
}
return NO;
}
BOOL protocol_isEqual(Protocol *self, Protocol *other)
{
if (self == other) return YES;
if (!self || !other) return NO;
if (!protocol_conformsToProtocol(self, other)) return NO;
if (!protocol_conformsToProtocol(other, self)) return NO;
return YES;
}
/***********************************************************************
* _protocol_getMethodTypeEncoding
* Return the @encode string for the requested protocol method.
* Returns nil if the compiler did not emit any extended @encode data.
* Locking: runtimeLock must not be held by the caller
**********************************************************************/
const char *
_protocol_getMethodTypeEncoding(Protocol *proto_gen, SEL sel,
BOOL isRequiredMethod, BOOL isInstanceMethod)
{
old_protocol *proto = oldprotocol(proto_gen);
if (!proto) return nil;
old_protocol_ext *ext = ext_for_protocol(proto);
if (!ext) return nil;
if (ext->size < offsetof(old_protocol_ext, extendedMethodTypes) + sizeof(ext->extendedMethodTypes)) return nil;
if (! ext->extendedMethodTypes) return nil;
struct objc_method_description *m =
lookup_protocol_method(proto, sel,
isRequiredMethod, isInstanceMethod, false);
if (!m) {
// No method with that name. Search incorporated protocols.
if (proto->protocol_list) {
for (int i = 0; i < proto->protocol_list->count; i++) {
const char *enc =
_protocol_getMethodTypeEncoding((Protocol *)proto->protocol_list->list[i], sel, isRequiredMethod, isInstanceMethod);
if (enc) return enc;
}
}
return nil;
}
int i = 0;
if (isRequiredMethod && isInstanceMethod) {
i += ((uintptr_t)m - (uintptr_t)proto->instance_methods) / sizeof(proto->instance_methods->list[0]);
goto done;
} else if (proto->instance_methods) {
i += proto->instance_methods->count;
}
if (isRequiredMethod && !isInstanceMethod) {
i += ((uintptr_t)m - (uintptr_t)proto->class_methods) / sizeof(proto->class_methods->list[0]);
goto done;
} else if (proto->class_methods) {
i += proto->class_methods->count;
}
if (!isRequiredMethod && isInstanceMethod) {
i += ((uintptr_t)m - (uintptr_t)ext->optional_instance_methods) / sizeof(ext->optional_instance_methods->list[0]);
goto done;
} else if (ext->optional_instance_methods) {
i += ext->optional_instance_methods->count;
}
if (!isRequiredMethod && !isInstanceMethod) {
i += ((uintptr_t)m - (uintptr_t)ext->optional_class_methods) / sizeof(ext->optional_class_methods->list[0]);
goto done;
} else if (ext->optional_class_methods) {
i += ext->optional_class_methods->count;
}
done:
return ext->extendedMethodTypes[i];
}
/***********************************************************************
* objc_allocateProtocol
* Creates a new protocol. The protocol may not be used until
* objc_registerProtocol() is called.
* Returns nil if a protocol with the same name already exists.
* Locking: acquires classLock
**********************************************************************/
Protocol *
objc_allocateProtocol(const char *name)
{
Class cls = objc_getClass("__IncompleteProtocol");
assert(cls);
mutex_locker_t lock(classLock);
if (NXMapGet(protocol_map, name)) return nil;
old_protocol *result = (old_protocol *)
calloc(1, sizeof(old_protocol)
+ sizeof(old_protocol_ext));
old_protocol_ext *ext = (old_protocol_ext *)(result+1);
result->isa = cls;
result->protocol_name = strdup(name);
ext->size = sizeof(old_protocol_ext);
// fixme reserve name without installing
NXMapInsert(protocol_ext_map, result, result+1);
return (Protocol *)result;
}
/***********************************************************************
* objc_registerProtocol
* Registers a newly-constructed protocol. The protocol is now
* ready for use and immutable.
* Locking: acquires classLock
**********************************************************************/
void objc_registerProtocol(Protocol *proto_gen)
{
old_protocol *proto = oldprotocol(proto_gen);
Class oldcls = objc_getClass("__IncompleteProtocol");
Class cls = objc_getClass("Protocol");
mutex_locker_t lock(classLock);
if (proto->isa == cls) {
_objc_inform("objc_registerProtocol: protocol '%s' was already "
"registered!", proto->protocol_name);
return;
}
if (proto->isa != oldcls) {
_objc_inform("objc_registerProtocol: protocol '%s' was not allocated "
"with objc_allocateProtocol!", proto->protocol_name);
return;
}
proto->isa = cls;
NXMapKeyCopyingInsert(protocol_map, proto->protocol_name, proto);
}
/***********************************************************************
* protocol_addProtocol
* Adds an incorporated protocol to another protocol.
* No method enforcement is performed.
* `proto` must be under construction. `addition` must not.
* Locking: acquires classLock
**********************************************************************/
void
protocol_addProtocol(Protocol *proto_gen, Protocol *addition_gen)
{
old_protocol *proto = oldprotocol(proto_gen);
old_protocol *addition = oldprotocol(addition_gen);
Class cls = objc_getClass("__IncompleteProtocol");
if (!proto_gen) return;
if (!addition_gen) return;
mutex_locker_t lock(classLock);
if (proto->isa != cls) {
_objc_inform("protocol_addProtocol: modified protocol '%s' is not "
"under construction!", proto->protocol_name);
return;
}
if (addition->isa == cls) {
_objc_inform("protocol_addProtocol: added protocol '%s' is still "
"under construction!", addition->protocol_name);
return;
}
old_protocol_list *protolist = proto->protocol_list;
if (protolist) {
size_t size = sizeof(old_protocol_list)
+ protolist->count * sizeof(protolist->list[0]);
protolist = (old_protocol_list *)
realloc(protolist, size);
} else {
protolist = (old_protocol_list *)
calloc(1, sizeof(old_protocol_list));
}
protolist->list[protolist->count++] = addition;
proto->protocol_list = protolist;
}
/***********************************************************************
* protocol_addMethodDescription
* Adds a method to a protocol. The protocol must be under construction.
* Locking: acquires classLock
**********************************************************************/
static void
_protocol_addMethod(struct objc_method_description_list **list, SEL name, const char *types)
{
if (!*list) {
*list = (struct objc_method_description_list *)
calloc(sizeof(struct objc_method_description_list), 1);
} else {
size_t size = sizeof(struct objc_method_description_list)
+ (*list)->count * sizeof(struct objc_method_description);
*list = (struct objc_method_description_list *)
realloc(*list, size);
}
struct objc_method_description *desc = &(*list)->list[(*list)->count++];
desc->name = name;
desc->types = strdup(types ?: "");
}
void
protocol_addMethodDescription(Protocol *proto_gen, SEL name, const char *types,
BOOL isRequiredMethod, BOOL isInstanceMethod)
{
old_protocol *proto = oldprotocol(proto_gen);
Class cls = objc_getClass("__IncompleteProtocol");
if (!proto_gen) return;
mutex_locker_t lock(classLock);
if (proto->isa != cls) {
_objc_inform("protocol_addMethodDescription: protocol '%s' is not "
"under construction!", proto->protocol_name);
return;
}
if (isRequiredMethod && isInstanceMethod) {
_protocol_addMethod(&proto->instance_methods, name, types);
} else if (isRequiredMethod && !isInstanceMethod) {
_protocol_addMethod(&proto->class_methods, name, types);
} else if (!isRequiredMethod && isInstanceMethod) {
old_protocol_ext *ext = (old_protocol_ext *)(proto+1);
_protocol_addMethod(&ext->optional_instance_methods, name, types);
} else /* !isRequiredMethod && !isInstanceMethod) */ {
old_protocol_ext *ext = (old_protocol_ext *)(proto+1);
_protocol_addMethod(&ext->optional_class_methods, name, types);
}
}
/***********************************************************************
* protocol_addProperty
* Adds a property to a protocol. The protocol must be under construction.
* Locking: acquires classLock
**********************************************************************/
static void
_protocol_addProperty(old_property_list **plist, const char *name,
const objc_property_attribute_t *attrs,
unsigned int count)
{
if (!*plist) {
*plist = (old_property_list *)
calloc(sizeof(old_property_list), 1);
(*plist)->entsize = sizeof(old_property);
} else {
*plist = (old_property_list *)
realloc(*plist, sizeof(old_property_list)
+ (*plist)->count * (*plist)->entsize);
}
old_property *prop = property_list_nth(*plist, (*plist)->count++);
prop->name = strdup(name);
prop->attributes = copyPropertyAttributeString(attrs, count);
}
void
protocol_addProperty(Protocol *proto_gen, const char *name,
const objc_property_attribute_t *attrs,
unsigned int count,
BOOL isRequiredProperty, BOOL isInstanceProperty)
{
old_protocol *proto = oldprotocol(proto_gen);
Class cls = objc_getClass("__IncompleteProtocol");
if (!proto) return;
if (!name) return;
mutex_locker_t lock(classLock);
if (proto->isa != cls) {
_objc_inform("protocol_addProperty: protocol '%s' is not "
"under construction!", proto->protocol_name);
return;
}
old_protocol_ext *ext = ext_for_protocol(proto);
if (isRequiredProperty && isInstanceProperty) {
_protocol_addProperty(&ext->instance_properties, name, attrs, count);
}
else if (isRequiredProperty && !isInstanceProperty) {
_protocol_addProperty(&ext->class_properties, name, attrs, count);
}
// else if (!isRequiredProperty && isInstanceProperty) {
// _protocol_addProperty(&ext->optional_instance_properties, name, attrs, count);
//}
// else /* !isRequiredProperty && !isInstanceProperty) */ {
// _protocol_addProperty(&ext->optional_class_properties, name, attrs, count);
//}
}
/***********************************************************************
* _objc_fixup_protocol_objects_for_image. For each protocol in the
* specified image, selectorize the method names and add to the protocol hash.
**********************************************************************/
static bool versionIsExt(uintptr_t version, const char *names, size_t size)
{
// CodeWarrior used isa field for string "Protocol"
// from section __OBJC,__class_names. rdar://4951638
// gcc (10.4 and earlier) used isa field for version number;
// the only version number used on Mac OS X was 2.
// gcc (10.5 and later) uses isa field for ext pointer
if (version < 4096 /* not PAGE_SIZE */) {
return NO;
}
if (version >= (uintptr_t)names && version < (uintptr_t)(names + size)) {
return NO;
}
return YES;
}
static void fix_protocol(old_protocol *proto, Class protocolClass,
bool isBundle, const char *names, size_t names_size)
{
uintptr_t version;
if (!proto) return;
version = (uintptr_t)proto->isa;
// Set the protocol's isa
proto->isa = protocolClass;
// Fix up method lists
// fixme share across duplicates
map_method_descs (proto->instance_methods, isBundle);
map_method_descs (proto->class_methods, isBundle);
// Fix up ext, if any
if (versionIsExt(version, names, names_size)) {
old_protocol_ext *ext = (old_protocol_ext *)version;
NXMapInsert(protocol_ext_map, proto, ext);
map_method_descs (ext->optional_instance_methods, isBundle);
map_method_descs (ext->optional_class_methods, isBundle);
}
// Record the protocol it if we don't have one with this name yet
// fixme bundles - copy protocol
// fixme unloading
if (!NXMapGet(protocol_map, proto->protocol_name)) {
NXMapKeyCopyingInsert(protocol_map, proto->protocol_name, proto);
if (PrintProtocols) {
_objc_inform("PROTOCOLS: protocol at %p is %s",
proto, proto->protocol_name);
}
} else {
// duplicate - do nothing
if (PrintProtocols) {
_objc_inform("PROTOCOLS: protocol at %p is %s (duplicate)",
proto, proto->protocol_name);
}
}
}
static void _objc_fixup_protocol_objects_for_image (header_info * hi)
{
Class protocolClass = objc_getClass("Protocol");
size_t count, i;
old_protocol **protos;
int isBundle = headerIsBundle(hi);
const char *names;
size_t names_size;
mutex_locker_t lock(classLock);
// Allocate the protocol registry if necessary.
if (!protocol_map) {
protocol_map =
NXCreateMapTable(NXStrValueMapPrototype, 32);
}
if (!protocol_ext_map) {
protocol_ext_map =
NXCreateMapTable(NXPtrValueMapPrototype, 32);
}
protos = _getObjcProtocols(hi, &count);
names = _getObjcClassNames(hi, &names_size);
for (i = 0; i < count; i++) {
fix_protocol(protos[i], protocolClass, isBundle, names, names_size);
}
}
/***********************************************************************
* _objc_fixup_selector_refs. Register all of the selectors in each
* image, and fix them all up.
**********************************************************************/
static void _objc_fixup_selector_refs (const header_info *hi)
{
size_t count;
SEL *sels;
bool preoptimized = hi->isPreoptimized();
if (PrintPreopt) {
if (preoptimized) {
_objc_inform("PREOPTIMIZATION: honoring preoptimized selectors in %s",
hi->fname());
}
else if (hi->info()->optimizedByDyld()) {
_objc_inform("PREOPTIMIZATION: IGNORING preoptimized selectors in %s",
hi->fname());
}
}
if (preoptimized) return;
sels = _getObjcSelectorRefs (hi, &count);
map_selrefs(sels, count, headerIsBundle(hi));
}
static inline bool _is_threaded() {
#if TARGET_OS_WIN32
return YES;
#else
return pthread_is_threaded_np() != 0;
#endif
}
#if !TARGET_OS_WIN32
/***********************************************************************
* unmap_image
* Process the given image which is about to be unmapped by dyld.
* mh is mach_header instead of headerType because that's what
* dyld_priv.h says even for 64-bit.
**********************************************************************/
void
unmap_image(const char *path __unused, const struct mach_header *mh)
{
recursive_mutex_locker_t lock(loadMethodLock);
unmap_image_nolock(mh);
}
/***********************************************************************
* map_images
* Process the given images which are being mapped in by dyld.
* Calls ABI-agnostic code after taking ABI-specific locks.
**********************************************************************/
void
map_images(unsigned count, const char * const paths[],
const struct mach_header * const mhdrs[])
{
recursive_mutex_locker_t lock(loadMethodLock);
map_images_nolock(count, paths, mhdrs);
}
/***********************************************************************
* load_images
* Process +load in the given images which are being mapped in by dyld.
*
* Locking: acquires classLock and loadMethodLock
**********************************************************************/
extern void prepare_load_methods(const headerType *mhdr);
void
load_images(const char *path __unused, const struct mach_header *mh)
{
recursive_mutex_locker_t lock(loadMethodLock);
// Discover +load methods
prepare_load_methods((const headerType *)mh);
// Call +load methods (without classLock - re-entrant)
call_load_methods();
}
#endif
/***********************************************************************
* _read_images
* Perform metadata processing for hCount images starting with firstNewHeader
**********************************************************************/
void _read_images(header_info **hList, uint32_t hCount, int totalClasses, int unoptimizedTotalClass)
{
uint32_t i;
bool categoriesLoaded = NO;
if (!class_hash) _objc_init_class_hash();
// Parts of this order are important for correctness or performance.
// Read classes from all images.
for (i = 0; i < hCount; i++) {
_objc_read_classes_from_image(hList[i]);
}
// Read categories from all images.
// But not if any other threads are running - they might
// call a category method before the fixups below are complete.
if (!_is_threaded()) {
bool needFlush = NO;
for (i = 0; i < hCount; i++) {
needFlush |= _objc_read_categories_from_image(hList[i]);
}
if (needFlush) flush_marked_caches();
categoriesLoaded = YES;
}
// Connect classes from all images.
for (i = 0; i < hCount; i++) {
_objc_connect_classes_from_image(hList[i]);
}
// Fix up class refs, selector refs, and protocol objects from all images.
for (i = 0; i < hCount; i++) {
_objc_map_class_refs_for_image(hList[i]);
_objc_fixup_selector_refs(hList[i]);
_objc_fixup_protocol_objects_for_image(hList[i]);
}
// Read categories from all images.
// But not if this is the only thread - it's more
// efficient to attach categories earlier if safe.
if (!categoriesLoaded) {
bool needFlush = NO;
for (i = 0; i < hCount; i++) {
needFlush |= _objc_read_categories_from_image(hList[i]);
}
if (needFlush) flush_marked_caches();
}
// Multi-threaded category load MUST BE LAST to avoid a race.
}
/***********************************************************************
* prepare_load_methods
* Schedule +load for classes in this image, any un-+load-ed
* superclasses in other images, and any categories in this image.
**********************************************************************/
// Recursively schedule +load for cls and any un-+load-ed superclasses.
// cls must already be connected.
static void schedule_class_load(Class cls)
{
if (cls->info & CLS_LOADED) return;
if (cls->superclass) schedule_class_load(cls->superclass);
add_class_to_loadable_list(cls);
cls->info |= CLS_LOADED;
}
void prepare_load_methods(const headerType *mhdr)
{
Module mods;
unsigned int midx;
header_info *hi;
for (hi = FirstHeader; hi; hi = hi->getNext()) {
if (mhdr == hi->mhdr()) break;
}
if (!hi) return;
if (hi->info()->isReplacement()) {
// Ignore any classes in this image
return;
}
// Major loop - process all modules in the image
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx += 1)
{
unsigned int index;
// Skip module containing no classes
if (mods[midx].symtab == nil)
continue;
// Minor loop - process all the classes in given module
for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1)
{
// Locate the class description pointer
Class cls = (Class)mods[midx].symtab->defs[index];
if (cls->info & CLS_CONNECTED) {
schedule_class_load(cls);
}
}
}
// Major loop - process all modules in the header
mods = hi->mod_ptr;
// NOTE: The module and category lists are traversed backwards
// to preserve the pre-10.4 processing order. Changing the order
// would have a small chance of introducing binary compatibility bugs.
midx = (unsigned int)hi->mod_count;
while (midx-- > 0) {
unsigned int index;
unsigned int total;
Symtab symtab = mods[midx].symtab;
// Nothing to do for a module without a symbol table
if (mods[midx].symtab == nil)
continue;
// Total entries in symbol table (class entries followed
// by category entries)
total = mods[midx].symtab->cls_def_cnt +
mods[midx].symtab->cat_def_cnt;
// Minor loop - register all categories from given module
index = total;
while (index-- > mods[midx].symtab->cls_def_cnt) {
old_category *cat = (old_category *)symtab->defs[index];
add_category_to_loadable_list((Category)cat);
}
}
}
#if TARGET_OS_WIN32
void unload_class(Class cls)
{
}
#else
/***********************************************************************
* _objc_remove_classes_in_image
* Remove all classes in the given image from the runtime, because
* the image is about to be unloaded.
* Things to clean up:
* class_hash
* unconnected_class_hash
* pending subclasses list (only if class is still unconnected)
* loadable class list
* class's method caches
* class refs in all other images
**********************************************************************/
// Re-pend any class references in refs that point into [start..end)
static void rependClassReferences(Class *refs, size_t count,
uintptr_t start, uintptr_t end)
{
size_t i;
if (!refs) return;
// Process each class ref
for (i = 0; i < count; i++) {
if ((uintptr_t)(refs[i]) >= start && (uintptr_t)(refs[i]) < end) {
pendClassReference(&refs[i], refs[i]->name,
refs[i]->info & CLS_META);
refs[i] = nil;
}
}
}
void try_free(const void *p)
{
if (p && malloc_size(p)) free((void *)p);
}
// Deallocate all memory in a method list
static void unload_mlist(old_method_list *mlist)
{
int i;
for (i = 0; i < mlist->method_count; i++) {
try_free(mlist->method_list[i].method_types);
}
try_free(mlist);
}
static void unload_property_list(old_property_list *proplist)
{
uint32_t i;
if (!proplist) return;
for (i = 0; i < proplist->count; i++) {
old_property *prop = property_list_nth(proplist, i);
try_free(prop->name);
try_free(prop->attributes);
}
try_free(proplist);
}
// Deallocate all memory in a class.
void unload_class(Class cls)
{
// Free method cache
// This dereferences the cache contents; do this before freeing methods
if (cls->cache && cls->cache != &_objc_empty_cache) {
_cache_free(cls->cache);
}
// Free ivar lists
if (cls->ivars) {
int i;
for (i = 0; i < cls->ivars->ivar_count; i++) {
try_free(cls->ivars->ivar_list[i].ivar_name);
try_free(cls->ivars->ivar_list[i].ivar_type);
}
try_free(cls->ivars);
}
// Free fixed-up method lists and method list array
if (cls->methodLists) {
// more than zero method lists
if (cls->info & CLS_NO_METHOD_ARRAY) {
// one method list
unload_mlist((old_method_list *)cls->methodLists);
}
else {
// more than one method list
old_method_list **mlistp;
for (mlistp = cls->methodLists;
*mlistp != nil && *mlistp != END_OF_METHODS_LIST;
mlistp++)
{
unload_mlist(*mlistp);
}
free(cls->methodLists);
}
}
// Free protocol list
old_protocol_list *protos = cls->protocols;
while (protos) {
old_protocol_list *dead = protos;
protos = protos->next;
try_free(dead);
}
if ((cls->info & CLS_EXT)) {
if (cls->ext) {
// Free property lists and property list array
if (cls->ext->propertyLists) {
// more than zero property lists
if (cls->info & CLS_NO_PROPERTY_ARRAY) {
// one property list
old_property_list *proplist =
(old_property_list *)cls->ext->propertyLists;
unload_property_list(proplist);
} else {
// more than one property list
old_property_list **plistp;
for (plistp = cls->ext->propertyLists;
*plistp != nil;
plistp++)
{
unload_property_list(*plistp);
}
try_free(cls->ext->propertyLists);
}
}
// Free weak ivar layout
try_free(cls->ext->weak_ivar_layout);
// Free ext
try_free(cls->ext);
}
// Free non-weak ivar layout
try_free(cls->ivar_layout);
}
// Free class name
try_free(cls->name);
// Free cls
try_free(cls);
}
static void _objc_remove_classes_in_image(header_info *hi)
{
unsigned int index;
unsigned int midx;
Module mods;
mutex_locker_t lock(classLock);
// Major loop - process all modules in the image
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx += 1)
{
// Skip module containing no classes
if (mods[midx].symtab == nil)
continue;
// Minor loop - process all the classes in given module
for (index = 0; index < mods[midx].symtab->cls_def_cnt; index += 1)
{
Class cls;
// Locate the class description pointer
cls = (Class)mods[midx].symtab->defs[index];
// Remove from loadable class list, if present
remove_class_from_loadable_list(cls);
// Remove from unconnected_class_hash and pending subclasses
if (unconnected_class_hash && NXHashMember(unconnected_class_hash, cls)) {
NXHashRemove(unconnected_class_hash, cls);
if (pendingSubclassesMap) {
// Find this class in its superclass's pending list
char *supercls_name = (char *)cls->superclass;
PendingSubclass *pending = (PendingSubclass *)
NXMapGet(pendingSubclassesMap, supercls_name);
for ( ; pending != nil; pending = pending->next) {
if (pending->subclass == cls) {
pending->subclass = Nil;
break;
}
}
}
}
// Remove from class_hash
NXHashRemove(class_hash, cls);
// Free heap memory pointed to by the class
unload_class(cls->ISA());
unload_class(cls);
}
}
// Search all other images for class refs that point back to this range.
// Un-fix and re-pend any such class refs.
// Get the location of the dying image's __OBJC segment
uintptr_t seg;
unsigned long seg_size;
seg = (uintptr_t)getsegmentdata(hi->mhdr(), "__OBJC", &seg_size);
header_info *other_hi;
for (other_hi = FirstHeader; other_hi != nil; other_hi = other_hi->getNext()) {
Class *other_refs;
size_t count;
if (other_hi == hi) continue; // skip the image being unloaded
// Fix class refs in the other image
other_refs = _getObjcClassRefs(other_hi, &count);
rependClassReferences(other_refs, count, seg, seg+seg_size);
}
}
/***********************************************************************
* _objc_remove_categories_in_image
* Remove all categories in the given image from the runtime, because
* the image is about to be unloaded.
* Things to clean up:
* unresolved category list
* loadable category list
**********************************************************************/
static void _objc_remove_categories_in_image(header_info *hi)
{
Module mods;
unsigned int midx;
// Major loop - process all modules in the header
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx++) {
unsigned int index;
unsigned int total;
Symtab symtab = mods[midx].symtab;
// Nothing to do for a module without a symbol table
if (symtab == nil) continue;
// Total entries in symbol table (class entries followed
// by category entries)
total = symtab->cls_def_cnt + symtab->cat_def_cnt;
// Minor loop - check all categories from given module
for (index = symtab->cls_def_cnt; index < total; index++) {
old_category *cat = (old_category *)symtab->defs[index];
// Clean up loadable category list
remove_category_from_loadable_list((Category)cat);
// Clean up category_hash
if (category_hash) {
_objc_unresolved_category *cat_entry = (_objc_unresolved_category *)NXMapGet(category_hash, cat->class_name);
for ( ; cat_entry != nil; cat_entry = cat_entry->next) {
if (cat_entry->cat == cat) {
cat_entry->cat = nil;
break;
}
}
}
}
}
}
/***********************************************************************
* unload_paranoia
* Various paranoid debugging checks that look for poorly-behaving
* unloadable bundles.
* Called by _objc_unmap_image when OBJC_UNLOAD_DEBUG is set.
**********************************************************************/
static void unload_paranoia(header_info *hi)
{
// Get the location of the dying image's __OBJC segment
uintptr_t seg;
unsigned long seg_size;
seg = (uintptr_t)getsegmentdata(hi->mhdr(), "__OBJC", &seg_size);
_objc_inform("UNLOAD DEBUG: unloading image '%s' [%p..%p]",
hi->fname(), (void *)seg, (void*)(seg+seg_size));
mutex_locker_t lock(classLock);
// Make sure the image contains no categories on surviving classes.
{
Module mods;
unsigned int midx;
// Major loop - process all modules in the header
mods = hi->mod_ptr;
for (midx = 0; midx < hi->mod_count; midx++) {
unsigned int index;
unsigned int total;
Symtab symtab = mods[midx].symtab;
// Nothing to do for a module without a symbol table
if (symtab == nil) continue;
// Total entries in symbol table (class entries followed
// by category entries)
total = symtab->cls_def_cnt + symtab->cat_def_cnt;
// Minor loop - check all categories from given module
for (index = symtab->cls_def_cnt; index < total; index++) {
old_category *cat = (old_category *)symtab->defs[index];
struct objc_class query;
query.name = cat->class_name;
if (NXHashMember(class_hash, &query)) {
_objc_inform("UNLOAD DEBUG: dying image contains category '%s(%s)' on surviving class '%s'!", cat->class_name, cat->category_name, cat->class_name);
}
}
}
}
// Make sure no surviving class is in the dying image.
// Make sure no surviving class has a superclass in the dying image.
// fixme check method implementations too
{
Class cls;
NXHashState state;
state = NXInitHashState(class_hash);
while (NXNextHashState(class_hash, &state, (void **)&cls)) {
if ((vm_address_t)cls >= seg &&
(vm_address_t)cls < seg+seg_size)
{
_objc_inform("UNLOAD DEBUG: dying image contains surviving class '%s'!", cls->name);
}
if ((vm_address_t)cls->superclass >= seg &&
(vm_address_t)cls->superclass < seg+seg_size)
{
_objc_inform("UNLOAD DEBUG: dying image contains superclass '%s' of surviving class '%s'!", cls->superclass->name, cls->name);
}
}
}
}
/***********************************************************************
* _unload_image
* Only handles MH_BUNDLE for now.
* Locking: loadMethodLock acquired by unmap_image
**********************************************************************/
void _unload_image(header_info *hi)
{
loadMethodLock.assertLocked();
// Cleanup:
// Remove image's classes from the class list and free auxiliary data.
// Remove image's unresolved or loadable categories and free auxiliary data
// Remove image's unresolved class refs.
_objc_remove_classes_in_image(hi);
_objc_remove_categories_in_image(hi);
_objc_remove_pending_class_refs_in_image(hi);
if (hi->proto_refs) try_free(hi->proto_refs);
// Perform various debugging checks if requested.
if (DebugUnload) unload_paranoia(hi);
}
#endif
/***********************************************************************
* objc_addClass. Add the specified class to the table of known classes,
* after doing a little verification and fixup.
**********************************************************************/
void objc_addClass (Class cls)
{
OBJC_WARN_DEPRECATED;
// Synchronize access to hash table
mutex_locker_t lock(classLock);
// Make sure both the class and the metaclass have caches!
// Clear all bits of the info fields except CLS_CLASS and CLS_META.
// Normally these bits are already clear but if someone tries to cons
// up their own class on the fly they might need to be cleared.
if (cls->cache == nil) {
cls->cache = (Cache) &_objc_empty_cache;
cls->info = CLS_CLASS;
}
if (cls->ISA()->cache == nil) {
cls->ISA()->cache = (Cache) &_objc_empty_cache;
cls->ISA()->info = CLS_META;
}
// methodLists should be:
// 1. nil (Tiger and later only)
// 2. A -1 terminated method list array
// In either case, CLS_NO_METHOD_ARRAY remains clear.
// If the user manipulates the method list directly,
// they must use the magic private format.
// Add the class to the table
(void) NXHashInsert (class_hash, cls);
// Superclass is no longer a leaf for cache flushing
if (cls->superclass && (cls->superclass->info & CLS_LEAF)) {
cls->superclass->clearInfo(CLS_LEAF);
cls->superclass->ISA()->clearInfo(CLS_LEAF);
}
}
/***********************************************************************
* _objcTweakMethodListPointerForClass.
* Change the class's method list pointer to a method list array.
* Does nothing if the method list pointer is already a method list array.
* If the class is currently in use, methodListLock must be held by the caller.
**********************************************************************/
static void _objcTweakMethodListPointerForClass(Class cls)
{
old_method_list * originalList;
const int initialEntries = 4;
size_t mallocSize;
old_method_list ** ptr;
// Do nothing if methodLists is already an array.
if (cls->methodLists && !(cls->info & CLS_NO_METHOD_ARRAY)) return;
// Remember existing list
originalList = (old_method_list *) cls->methodLists;
// Allocate and zero a method list array
mallocSize = sizeof(old_method_list *) * initialEntries;
ptr = (old_method_list **) calloc(1, mallocSize);
// Insert the existing list into the array
ptr[initialEntries - 1] = END_OF_METHODS_LIST;
ptr[0] = originalList;
// Replace existing list with array
cls->methodLists = ptr;
cls->clearInfo(CLS_NO_METHOD_ARRAY);
}
/***********************************************************************
* _objc_insertMethods.
* Adds methods to a class.
* Does not flush any method caches.
* Does not take any locks.
* If the class is already in use, use class_addMethods() instead.
**********************************************************************/
void _objc_insertMethods(Class cls, old_method_list *mlist, old_category *cat)
{
old_method_list ***list;
old_method_list **ptr;
ptrdiff_t endIndex;
size_t oldSize;
size_t newSize;
if (!cls->methodLists) {
// cls has no methods - simply use this method list
cls->methodLists = (old_method_list **)mlist;
cls->setInfo(CLS_NO_METHOD_ARRAY);
return;
}
// Log any existing methods being replaced
if (PrintReplacedMethods) {
int i;
for (i = 0; i < mlist->method_count; i++) {
extern IMP findIMPInClass(Class cls, SEL sel);
SEL sel = sel_registerName((char *)mlist->method_list[i].method_name);
IMP newImp = mlist->method_list[i].method_imp;
IMP oldImp;
if ((oldImp = findIMPInClass(cls, sel))) {
logReplacedMethod(cls->name, sel, ISMETA(cls),
cat ? cat->category_name : nil,
oldImp, newImp);
}
}
}
// Create method list array if necessary
_objcTweakMethodListPointerForClass(cls);
list = &cls->methodLists;
// Locate unused entry for insertion point
ptr = *list;
while ((*ptr != 0) && (*ptr != END_OF_METHODS_LIST))
ptr += 1;
// If array is full, add to it
if (*ptr == END_OF_METHODS_LIST)
{
// Calculate old and new dimensions
endIndex = ptr - *list;
oldSize = (endIndex + 1) * sizeof(void *);
newSize = oldSize + sizeof(old_method_list *); // only increase by 1
// Grow the method list array by one.
*list = (old_method_list **)realloc(*list, newSize);
// Zero out addition part of new array
bzero (&((*list)[endIndex]), newSize - oldSize);
// Place new end marker
(*list)[(newSize/sizeof(void *)) - 1] = END_OF_METHODS_LIST;
// Insertion point corresponds to old array end
ptr = &((*list)[endIndex]);
}
// Right shift existing entries by one
bcopy (*list, (*list) + 1, (uint8_t *)ptr - (uint8_t *)*list);
// Insert at method list at beginning of array
**list = mlist;
}
/***********************************************************************
* _objc_removeMethods.
* Remove methods from a class.
* Does not take any locks.
* Does not flush any method caches.
* If the class is currently in use, use class_removeMethods() instead.
**********************************************************************/
void _objc_removeMethods(Class cls, old_method_list *mlist)
{
old_method_list ***list;
old_method_list **ptr;
if (cls->methodLists == nil) {
// cls has no methods
return;
}
if (cls->methodLists == (old_method_list **)mlist) {
// mlist is the class's only method list - erase it
cls->methodLists = nil;
return;
}
if (cls->info & CLS_NO_METHOD_ARRAY) {
// cls has only one method list, and this isn't it - do nothing
return;
}
// cls has a method list array - search it
list = &cls->methodLists;
// Locate list in the array
ptr = *list;
while (*ptr != mlist) {
// fix for radar # 2538790
if ( *ptr == END_OF_METHODS_LIST ) return;
ptr += 1;
}
// Remove this entry
*ptr = 0;
// Left shift the following entries
while (*(++ptr) != END_OF_METHODS_LIST)
*(ptr-1) = *ptr;
*(ptr-1) = 0;
}
/***********************************************************************
* _objc_add_category. Install the specified category's methods and
* protocols into the class it augments.
* The class is assumed not to be in use yet: no locks are taken and
* no method caches are flushed.
**********************************************************************/
static inline void _objc_add_category(Class cls, old_category *category, int version)
{
if (PrintConnecting) {
_objc_inform("CONNECT: attaching category '%s (%s)'", cls->name, category->category_name);
}
// Augment instance methods
if (category->instance_methods)
_objc_insertMethods (cls, category->instance_methods, category);
// Augment class methods
if (category->class_methods)
_objc_insertMethods (cls->ISA(), category->class_methods, category);
// Augment protocols
if ((version >= 5) && category->protocols)
{
if (cls->ISA()->version >= 5)
{
category->protocols->next = cls->protocols;
cls->protocols = category->protocols;
cls->ISA()->protocols = category->protocols;
}
else
{
_objc_inform ("unable to add protocols from category %s...\n", category->category_name);
_objc_inform ("class `%s' must be recompiled\n", category->class_name);
}
}
// Augment instance properties
if (version >= 7 && category->instance_properties) {
if (cls->ISA()->version >= 6) {
_class_addProperties(cls, category->instance_properties);
} else {
_objc_inform ("unable to add instance properties from category %s...\n", category->category_name);
_objc_inform ("class `%s' must be recompiled\n", category->class_name);
}
}
// Augment class properties
if (version >= 7 && category->hasClassPropertiesField() &&
category->class_properties)
{
if (cls->ISA()->version >= 6) {
_class_addProperties(cls->ISA(), category->class_properties);
} else {
_objc_inform ("unable to add class properties from category %s...\n", category->category_name);
_objc_inform ("class `%s' must be recompiled\n", category->class_name);
}
}
}
/***********************************************************************
* _objc_add_category_flush_caches. Install the specified category's
* methods into the class it augments, and flush the class' method cache.
* Return YES if some method caches now need to be flushed.
**********************************************************************/
static bool _objc_add_category_flush_caches(Class cls, old_category *category, int version)
{
bool needFlush = NO;
// Install the category's methods into its intended class
{
mutex_locker_t lock(methodListLock);
_objc_add_category (cls, category, version);
}
// Queue for cache flushing so category's methods can get called
if (category->instance_methods) {
cls->setInfo(CLS_FLUSH_CACHE);
needFlush = YES;
}
if (category->class_methods) {
cls->ISA()->setInfo(CLS_FLUSH_CACHE);
needFlush = YES;
}
return needFlush;
}
/***********************************************************************
* reverse_cat
* Reverse the given linked list of pending categories.
* The pending category list is built backwards, and needs to be
* reversed before actually attaching the categories to a class.
* Returns the head of the new linked list.
**********************************************************************/
static _objc_unresolved_category *reverse_cat(_objc_unresolved_category *cat)
{
_objc_unresolved_category *prev;
_objc_unresolved_category *cur;
_objc_unresolved_category *ahead;
if (!cat) return nil;
prev = nil;
cur = cat;
ahead = cat->next;
while (cur) {
ahead = cur->next;
cur->next = prev;
prev = cur;
cur = ahead;
}
return prev;
}
/***********************************************************************
* resolve_categories_for_class.
* Install all existing categories intended for the specified class.
* cls must be a true class and not a metaclass.
**********************************************************************/
static void resolve_categories_for_class(Class cls)
{
_objc_unresolved_category * pending;
_objc_unresolved_category * next;
// Nothing to do if there are no categories at all
if (!category_hash) return;
// Locate and remove first element in category list
// associated with this class
pending = (_objc_unresolved_category *)
NXMapKeyFreeingRemove (category_hash, cls->name);
// Traverse the list of categories, if any, registered for this class
// The pending list is built backwards. Reverse it and walk forwards.
pending = reverse_cat(pending);
while (pending) {
if (pending->cat) {
// Install the category
// use the non-flush-cache version since we are only
// called from the class intialization code
_objc_add_category(cls, pending->cat, (int)pending->version);
}
// Delink and reclaim this registration
next = pending->next;
free(pending);
pending = next;
}
}
/***********************************************************************
* _objc_resolve_categories_for_class.
* Public version of resolve_categories_for_class. This was
* exported pre-10.4 for Omni et al. to workaround a problem
* with too-lazy category attachment.
* cls should be a class, but this function can also cope with metaclasses.
**********************************************************************/
void _objc_resolve_categories_for_class(Class cls)
{
// If cls is a metaclass, get the class.
// resolve_categories_for_class() requires a real class to work correctly.
if (ISMETA(cls)) {
if (strncmp(cls->name, "_%", 2) == 0) {
// Posee's meta's name is smashed and isn't in the class_hash,
// so objc_getClass doesn't work.
const char *baseName = strchr(cls->name, '%'); // get posee's real name
cls = objc_getClass(baseName);
} else {
cls = objc_getClass(cls->name);
}
}
resolve_categories_for_class(cls);
}
/***********************************************************************
* _objc_register_category.
* Process a category read from an image.
* If the category's class exists, attach the category immediately.
* Classes that need cache flushing are marked but not flushed.
* If the category's class does not exist yet, pend the category for
* later attachment. Pending categories are attached in the order
* they were discovered.
* Returns YES if some method caches now need to be flushed.
**********************************************************************/
static bool _objc_register_category(old_category *cat, int version)
{
_objc_unresolved_category * new_cat;
_objc_unresolved_category * old;
Class theClass;
// If the category's class exists, attach the category.
if ((theClass = objc_lookUpClass(cat->class_name))) {
return _objc_add_category_flush_caches(theClass, cat, version);
}
// If the category's class exists but is unconnected,
// then attach the category to the class but don't bother
// flushing any method caches (because they must be empty).
// YES unconnected, NO class_handler
if ((theClass = look_up_class(cat->class_name, YES, NO))) {
_objc_add_category(theClass, cat, version);
return NO;
}
// Category's class does not exist yet.
// Save the category for later attachment.
if (PrintConnecting) {
_objc_inform("CONNECT: pending category '%s (%s)'", cat->class_name, cat->category_name);
}
// Create category lookup table if needed
if (!category_hash)
category_hash = NXCreateMapTable(NXStrValueMapPrototype, 128);
// Locate an existing list of categories, if any, for the class.
old = (_objc_unresolved_category *)
NXMapGet (category_hash, cat->class_name);
// Register the category to be fixed up later.
// The category list is built backwards, and is reversed again
// by resolve_categories_for_class().
new_cat = (_objc_unresolved_category *)
malloc(sizeof(_objc_unresolved_category));
new_cat->next = old;
new_cat->cat = cat;
new_cat->version = version;
(void) NXMapKeyCopyingInsert (category_hash, cat->class_name, new_cat);
return NO;
}
const char **objc_copyImageNames(unsigned int *outCount)
{
header_info *hi;
int count = 0;
int max = HeaderCount;
#if TARGET_OS_WIN32
const TCHAR **names = (const TCHAR **)calloc(max+1, sizeof(TCHAR *));
#else
const char **names = (const char **)calloc(max+1, sizeof(char *));
#endif
for (hi = FirstHeader; hi != NULL && count < max; hi = hi->getNext()) {
#if TARGET_OS_WIN32
if (hi->moduleName) {
names[count++] = hi->moduleName;
}
#else
const char *fname = hi->fname();
if (fname) {
names[count++] = fname;
}
#endif
}
names[count] = NULL;
if (count == 0) {
// Return NULL instead of empty list if there are no images
free((void *)names);
names = NULL;
}
if (outCount) *outCount = count;
return names;
}
static const char **
_objc_copyClassNamesForImage(header_info *hi, unsigned int *outCount)
{
Module mods;
unsigned int m;
const char **list;
int count;
int allocated;
list = nil;
count = 0;
allocated = 0;
mods = hi->mod_ptr;
for (m = 0; m < hi->mod_count; m++) {
int d;
if (!mods[m].symtab) continue;
for (d = 0; d < mods[m].symtab->cls_def_cnt; d++) {
Class cls = (Class)mods[m].symtab->defs[d];
// fixme what about future-ified classes?
if (cls->isConnected()) {
if (count == allocated) {
allocated = allocated*2 + 16;
list = (const char **)
realloc((void *)list, allocated * sizeof(char *));
}
list[count++] = cls->name;
}
}
}
if (count > 0) {
// nil-terminate non-empty list
if (count == allocated) {
allocated = allocated+1;
list = (const char **)
realloc((void *)list, allocated * sizeof(char *));
}
list[count] = nil;
}
if (outCount) *outCount = count;
return list;
}
/**********************************************************************
*
**********************************************************************/
const char **
objc_copyClassNamesForImage(const char *image, unsigned int *outCount)
{
header_info *hi;
if (!image) {
if (outCount) *outCount = 0;
return NULL;
}
// Find the image.
for (hi = FirstHeader; hi != NULL; hi = hi->getNext()) {
#if TARGET_OS_WIN32
if (0 == wcscmp((TCHAR *)image, hi->moduleName)) break;
#else
if (0 == strcmp(image, hi->fname())) break;
#endif
}
if (!hi) {
if (outCount) *outCount = 0;
return NULL;
}
return _objc_copyClassNamesForImage(hi, outCount);
}
/**********************************************************************
*
**********************************************************************/
const char **
objc_copyClassNamesForImageHeader(const struct mach_header *mh, unsigned int *outCount)
{
header_info *hi;
if (!mh) {
if (outCount) *outCount = 0;
return NULL;
}
// Find the image.
for (hi = FirstHeader; hi != NULL; hi = hi->getNext()) {
if (hi->mhdr() == (const headerType *)mh) break;
}
if (!hi) {
if (outCount) *outCount = 0;
return NULL;
}
return _objc_copyClassNamesForImage(hi, outCount);
}
Class gdb_class_getClass(Class cls)
{
const char *className = cls->name;
if(!className || !strlen(className)) return Nil;
Class rCls = look_up_class(className, NO, NO);
return rCls;
}
Class gdb_object_getClass(id obj)
{
if (!obj) return nil;
return gdb_class_getClass(obj->getIsa());
}
/***********************************************************************
* objc_setMultithreaded.
**********************************************************************/
void objc_setMultithreaded (BOOL flag)
{
OBJC_WARN_DEPRECATED;
// Nothing here. Thread synchronization in the runtime is always active.
}
/***********************************************************************
* Lock management
**********************************************************************/
mutex_t selLock;
mutex_t classLock;
mutex_t methodListLock;
mutex_t cacheUpdateLock;
recursive_mutex_t loadMethodLock;
void lock_init(void)
{
}
#endif