/*
* 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-class.m
* Copyright 1988-1997, Apple Computer, Inc.
* Author: s. naroff
**********************************************************************/
/***********************************************************************
* Lazy method list arrays and method list locking (2004-10-19)
*
* cls->methodLists may be in one of three forms:
* 1. nil: The class has no methods.
* 2. non-nil, with CLS_NO_METHOD_ARRAY set: cls->methodLists points
* to a single method list, which is the class's only method list.
* 3. non-nil, with CLS_NO_METHOD_ARRAY clear: cls->methodLists points to
* an array of method list pointers. The end of the array's block
* is set to -1. If the actual number of method lists is smaller
* than that, the rest of the array is nil.
*
* Attaching categories and adding and removing classes may change
* the form of the class list. In addition, individual method lists
* may be reallocated when fixed up.
*
* Classes are initially read as #1 or #2. If a category is attached
* or other methods added, the class is changed to #3. Once in form #3,
* the class is never downgraded to #1 or #2, even if methods are removed.
* Classes added with objc_addClass are initially either #1 or #3.
*
* Accessing and manipulating a class's method lists are synchronized,
* to prevent races when one thread restructures the list. However,
* if the class is not yet in use (i.e. not in class_hash), then the
* thread loading the class may access its method lists without locking.
*
* The following functions acquire methodListLock:
* class_getInstanceMethod
* class_getClassMethod
* class_nextMethodList
* class_addMethods
* class_removeMethods
* class_respondsToMethod
* _class_lookupMethodAndLoadCache
* lookupMethodInClassAndLoadCache
* _objc_add_category_flush_caches
*
* The following functions don't acquire methodListLock because they
* only access method lists during class load and unload:
* _objc_register_category
* _resolve_categories_for_class (calls _objc_add_category)
* add_class_to_loadable_list
* _objc_addClass
* _objc_remove_classes_in_image
*
* The following functions use method lists without holding methodListLock.
* The caller must either hold methodListLock, or be loading the class.
* _getMethod (called by class_getInstanceMethod, class_getClassMethod,
* and class_respondsToMethod)
* _findMethodInClass (called by _class_lookupMethodAndLoadCache,
* lookupMethodInClassAndLoadCache, _getMethod)
* _findMethodInList (called by _findMethodInClass)
* nextMethodList (called by _findMethodInClass and class_nextMethodList
* fixupSelectorsInMethodList (called by nextMethodList)
* _objc_add_category (called by _objc_add_category_flush_caches,
* resolve_categories_for_class and _objc_register_category)
* _objc_insertMethods (called by class_addMethods and _objc_add_category)
* _objc_removeMethods (called by class_removeMethods)
* _objcTweakMethodListPointerForClass (called by _objc_insertMethods)
* get_base_method_list (called by add_class_to_loadable_list)
* lookupNamedMethodInMethodList (called by add_class_to_loadable_list)
***********************************************************************/
/***********************************************************************
* Thread-safety of class info bits (2004-10-19)
*
* Some class info bits are used to store mutable runtime state.
* Modifications of the info bits at particular times need to be
* synchronized to prevent races.
*
* Three thread-safe modification functions are provided:
* cls->setInfo() // atomically sets some bits
* cls->clearInfo() // atomically clears some bits
* cls->changeInfo() // atomically sets some bits and clears others
* These replace CLS_SETINFO() for the multithreaded cases.
*
* Three modification windows are defined:
* - compile time
* - class construction or image load (before +load) in one thread
* - multi-threaded messaging and method caches
*
* Info bit modification at compile time and class construction do not
* need to be locked, because only one thread is manipulating the class.
* Info bit modification during messaging needs to be locked, because
* there may be other threads simultaneously messaging or otherwise
* manipulating the class.
*
* Modification windows for each flag:
*
* CLS_CLASS: compile-time and class load
* CLS_META: compile-time and class load
* CLS_INITIALIZED: +initialize
* CLS_POSING: messaging
* CLS_MAPPED: compile-time
* CLS_FLUSH_CACHE: class load and messaging
* CLS_GROW_CACHE: messaging
* CLS_NEED_BIND: unused
* CLS_METHOD_ARRAY: unused
* CLS_JAVA_HYBRID: JavaBridge only
* CLS_JAVA_CLASS: JavaBridge only
* CLS_INITIALIZING: messaging
* CLS_FROM_BUNDLE: class load
* CLS_HAS_CXX_STRUCTORS: compile-time and class load
* CLS_NO_METHOD_ARRAY: class load and messaging
* CLS_HAS_LOAD_METHOD: class load
*
* CLS_INITIALIZED and CLS_INITIALIZING have additional thread-safety
* constraints to support thread-safe +initialize. See "Thread safety
* during class initialization" for details.
*
* CLS_JAVA_HYBRID and CLS_JAVA_CLASS are set immediately after JavaBridge
* calls objc_addClass(). The JavaBridge does not use an atomic update,
* but the modification counts as "class construction" unless some other
* thread quickly finds the class via the class list. This race is
* small and unlikely in well-behaved code.
*
* Most info bits that may be modified during messaging are also never
* read without a lock. There is no general read lock for the info bits.
* CLS_INITIALIZED: classInitLock
* CLS_FLUSH_CACHE: cacheUpdateLock
* CLS_GROW_CACHE: cacheUpdateLock
* CLS_NO_METHOD_ARRAY: methodListLock
* CLS_INITIALIZING: classInitLock
***********************************************************************/
/***********************************************************************
* Imports.
**********************************************************************/
#include "objc-private.h"
#include "objc-abi.h"
#include <objc/message.h>
/***********************************************************************
* Information about multi-thread support:
*
* Since we do not lock many operations which walk the superclass, method
* and ivar chains, these chains must remain intact once a class is published
* by inserting it into the class hashtable. All modifications must be
* atomic so that someone walking these chains will always geta valid
* result.
***********************************************************************/
/***********************************************************************
* object_getClass.
* Locking: None. If you add locking, tell gdb (rdar://7516456).
**********************************************************************/
Class object_getClass(id obj)
{
if (obj) return obj->getIsa();
else return Nil;
}
/***********************************************************************
* object_setClass.
**********************************************************************/
Class object_setClass(id obj, Class cls)
{
if (!obj) return nil;
// Prevent a deadlock between the weak reference machinery
// and the +initialize machinery by ensuring that no
// weakly-referenced object has an un-+initialized isa.
// Unresolved future classes are not so protected.
if (!cls->isFuture() && !cls->isInitialized()) {
// use lookUpImpOrNil to indirectly provoke +initialize
// to avoid duplicating the code to actually send +initialize
lookUpImpOrNil(nil, @selector(initialize), cls, LOOKUP_INITIALIZE);
}
return obj->changeIsa(cls);
}
/***********************************************************************
* object_isClass.
**********************************************************************/
BOOL object_isClass(id obj)
{
if (!obj) return NO;
return obj->isClass();
}
/***********************************************************************
* object_getClassName.
**********************************************************************/
const char *object_getClassName(id obj)
{
return class_getName(obj ? obj->getIsa() : nil);
}
/***********************************************************************
* object_getMethodImplementation.
**********************************************************************/
IMP object_getMethodImplementation(id obj, SEL name)
{
Class cls = (obj ? obj->getIsa() : nil);
return class_getMethodImplementation(cls, name);
}
/***********************************************************************
* object_getMethodImplementation_stret.
**********************************************************************/
#if SUPPORT_STRET
IMP object_getMethodImplementation_stret(id obj, SEL name)
{
Class cls = (obj ? obj->getIsa() : nil);
return class_getMethodImplementation_stret(cls, name);
}
#endif
static bool isScanned(ptrdiff_t ivar_offset, const uint8_t *layout)
{
if (!layout) return NO;
ptrdiff_t index = 0, ivar_index = ivar_offset / sizeof(void*);
uint8_t byte;
while ((byte = *layout++)) {
unsigned skips = (byte >> 4);
unsigned scans = (byte & 0x0F);
index += skips;
if (index > ivar_index) return NO;
index += scans;
if (index > ivar_index) return YES;
}
return NO;
}
/***********************************************************************
* _class_lookUpIvar
* Given an object and an ivar in it, look up some data about that ivar:
* - its offset
* - its memory management behavior
* The ivar is assumed to be word-aligned and of of object type.
**********************************************************************/
static void
_class_lookUpIvar(Class cls, Ivar ivar, ptrdiff_t& ivarOffset,
objc_ivar_memory_management_t& memoryManagement)
{
ivarOffset = ivar_getOffset(ivar);
// Look for ARC variables and ARC-style weak.
// Preflight the hasAutomaticIvars check
// because _class_getClassForIvar() may need to take locks.
bool hasAutomaticIvars = NO;
for (Class c = cls; c; c = c->superclass) {
if (c->hasAutomaticIvars()) {
hasAutomaticIvars = YES;
break;
}
}
if (hasAutomaticIvars) {
Class ivarCls = _class_getClassForIvar(cls, ivar);
if (ivarCls->hasAutomaticIvars()) {
// ARC layout bitmaps encode the class's own ivars only.
// Use alignedInstanceStart() because unaligned bytes at the start
// of this class's ivars are not represented in the layout bitmap.
ptrdiff_t localOffset =
ivarOffset - ivarCls->alignedInstanceStart();
if (isScanned(localOffset, class_getIvarLayout(ivarCls))) {
memoryManagement = objc_ivar_memoryStrong;
return;
}
if (isScanned(localOffset, class_getWeakIvarLayout(ivarCls))) {
memoryManagement = objc_ivar_memoryWeak;
return;
}
// Unretained is only for true ARC classes.
if (ivarCls->isARC()) {
memoryManagement = objc_ivar_memoryUnretained;
return;
}
}
}
memoryManagement = objc_ivar_memoryUnknown;
}
/***********************************************************************
* _class_getIvarMemoryManagement
* SPI for KVO and others to decide what memory management to use
* when setting instance variables directly.
**********************************************************************/
objc_ivar_memory_management_t
_class_getIvarMemoryManagement(Class cls, Ivar ivar)
{
ptrdiff_t offset;
objc_ivar_memory_management_t memoryManagement;
_class_lookUpIvar(cls, ivar, offset, memoryManagement);
return memoryManagement;
}
static ALWAYS_INLINE
void _object_setIvar(id obj, Ivar ivar, id value, bool assumeStrong)
{
if (!obj || !ivar || obj->isTaggedPointer()) return;
ptrdiff_t offset;
objc_ivar_memory_management_t memoryManagement;
_class_lookUpIvar(obj->ISA(), ivar, offset, memoryManagement);
if (memoryManagement == objc_ivar_memoryUnknown) {
if (assumeStrong) memoryManagement = objc_ivar_memoryStrong;
else memoryManagement = objc_ivar_memoryUnretained;
}
id *location = (id *)((char *)obj + offset);
switch (memoryManagement) {
case objc_ivar_memoryWeak: objc_storeWeak(location, value); break;
case objc_ivar_memoryStrong: objc_storeStrong(location, value); break;
case objc_ivar_memoryUnretained: *location = value; break;
case objc_ivar_memoryUnknown: _objc_fatal("impossible");
}
}
void object_setIvar(id obj, Ivar ivar, id value)
{
return _object_setIvar(obj, ivar, value, false /*not strong default*/);
}
void object_setIvarWithStrongDefault(id obj, Ivar ivar, id value)
{
return _object_setIvar(obj, ivar, value, true /*strong default*/);
}
id object_getIvar(id obj, Ivar ivar)
{
if (!obj || !ivar || obj->isTaggedPointer()) return nil;
ptrdiff_t offset;
objc_ivar_memory_management_t memoryManagement;
_class_lookUpIvar(obj->ISA(), ivar, offset, memoryManagement);
id *location = (id *)((char *)obj + offset);
if (memoryManagement == objc_ivar_memoryWeak) {
return objc_loadWeak(location);
} else {
return *location;
}
}
static ALWAYS_INLINE
Ivar _object_setInstanceVariable(id obj, const char *name, void *value,
bool assumeStrong)
{
Ivar ivar = nil;
if (obj && name && !obj->isTaggedPointer()) {
if ((ivar = _class_getVariable(obj->ISA(), name))) {
_object_setIvar(obj, ivar, (id)value, assumeStrong);
}
}
return ivar;
}
Ivar object_setInstanceVariable(id obj, const char *name, void *value)
{
return _object_setInstanceVariable(obj, name, value, false);
}
Ivar object_setInstanceVariableWithStrongDefault(id obj, const char *name,
void *value)
{
return _object_setInstanceVariable(obj, name, value, true);
}
Ivar object_getInstanceVariable(id obj, const char *name, void **value)
{
if (obj && name && !obj->isTaggedPointer()) {
Ivar ivar;
if ((ivar = class_getInstanceVariable(obj->ISA(), name))) {
if (value) *value = (void *)object_getIvar(obj, ivar);
return ivar;
}
}
if (value) *value = nil;
return nil;
}
/***********************************************************************
* object_cxxDestructFromClass.
* Call C++ destructors on obj, starting with cls's
* dtor method (if any) followed by superclasses' dtors (if any),
* stopping at cls's dtor (if any).
* Uses methodListLock and cacheUpdateLock. The caller must hold neither.
**********************************************************************/
static void object_cxxDestructFromClass(id obj, Class cls)
{
void (*dtor)(id);
// Call cls's dtor first, then superclasses's dtors.
for ( ; cls; cls = cls->superclass) {
if (!cls->hasCxxDtor()) return;
dtor = (void(*)(id))
lookupMethodInClassAndLoadCache(cls, SEL_cxx_destruct);
if (dtor != (void(*)(id))_objc_msgForward_impcache) {
if (PrintCxxCtors) {
_objc_inform("CXX: calling C++ destructors for class %s",
cls->nameForLogging());
}
(*dtor)(obj);
}
}
}
/***********************************************************************
* object_cxxDestruct.
* Call C++ destructors on obj, if any.
* Uses methodListLock and cacheUpdateLock. The caller must hold neither.
**********************************************************************/
void object_cxxDestruct(id obj)
{
if (!obj) return;
if (obj->isTaggedPointer()) return;
object_cxxDestructFromClass(obj, obj->ISA());
}
/***********************************************************************
* object_cxxConstructFromClass.
* Recursively call C++ constructors on obj, starting with base class's
* ctor method (if any) followed by subclasses' ctors (if any), stopping
* at cls's ctor (if any).
* Does not check cls->hasCxxCtor(). The caller should preflight that.
* Returns self if construction succeeded.
* Returns nil if some constructor threw an exception. The exception is
* caught and discarded. Any partial construction is destructed.
* Uses methodListLock and cacheUpdateLock. The caller must hold neither.
*
* .cxx_construct returns id. This really means:
* return self: construction succeeded
* return nil: construction failed because a C++ constructor threw an exception
**********************************************************************/
id
object_cxxConstructFromClass(id obj, Class cls, int flags)
{
ASSERT(cls->hasCxxCtor()); // required for performance, not correctness
id (*ctor)(id);
Class supercls;
supercls = cls->superclass;
// Call superclasses' ctors first, if any.
if (supercls && supercls->hasCxxCtor()) {
bool ok = object_cxxConstructFromClass(obj, supercls, flags);
if (slowpath(!ok)) return nil; // some superclass's ctor failed - give up
}
// Find this class's ctor, if any.
ctor = (id(*)(id))lookupMethodInClassAndLoadCache(cls, SEL_cxx_construct);
if (ctor == (id(*)(id))_objc_msgForward_impcache) return obj; // no ctor - ok
// Call this class's ctor.
if (PrintCxxCtors) {
_objc_inform("CXX: calling C++ constructors for class %s",
cls->nameForLogging());
}
if (fastpath((*ctor)(obj))) return obj; // ctor called and succeeded - ok
supercls = cls->superclass; // this reload avoids a spill on the stack
// This class's ctor was called and failed.
// Call superclasses's dtors to clean up.
if (supercls) object_cxxDestructFromClass(obj, supercls);
if (flags & OBJECT_CONSTRUCT_FREE_ONFAILURE) free(obj);
if (flags & OBJECT_CONSTRUCT_CALL_BADALLOC) {
return _objc_callBadAllocHandler(cls);
}
return nil;
}
/***********************************************************************
* fixupCopiedIvars
* Fix up ARC strong and ARC-style weak variables
* after oldObject was memcpy'd to newObject.
**********************************************************************/
void fixupCopiedIvars(id newObject, id oldObject)
{
for (Class cls = oldObject->ISA(); cls; cls = cls->superclass) {
if (cls->hasAutomaticIvars()) {
// Use alignedInstanceStart() because unaligned bytes at the start
// of this class's ivars are not represented in the layout bitmap.
size_t instanceStart = cls->alignedInstanceStart();
const uint8_t *strongLayout = class_getIvarLayout(cls);
if (strongLayout) {
id *newPtr = (id *)((char*)newObject + instanceStart);
unsigned char byte;
while ((byte = *strongLayout++)) {
unsigned skips = (byte >> 4);
unsigned scans = (byte & 0x0F);
newPtr += skips;
while (scans--) {
// ensure strong references are properly retained.
id value = *newPtr++;
if (value) objc_retain(value);
}
}
}
const uint8_t *weakLayout = class_getWeakIvarLayout(cls);
// fix up weak references if any.
if (weakLayout) {
id *newPtr = (id *)((char*)newObject + instanceStart), *oldPtr = (id *)((char*)oldObject + instanceStart);
unsigned char byte;
while ((byte = *weakLayout++)) {
unsigned skips = (byte >> 4);
unsigned weaks = (byte & 0x0F);
newPtr += skips, oldPtr += skips;
while (weaks--) {
objc_copyWeak(newPtr, oldPtr);
++newPtr, ++oldPtr;
}
}
}
}
}
}
/***********************************************************************
* class_getClassMethod. Return the class method for the specified
* class and selector.
**********************************************************************/
Method class_getClassMethod(Class cls, SEL sel)
{
if (!cls || !sel) return nil;
return class_getInstanceMethod(cls->getMeta(), sel);
}
/***********************************************************************
* class_getInstanceVariable. Return the named instance variable.
**********************************************************************/
Ivar class_getInstanceVariable(Class cls, const char *name)
{
if (!cls || !name) return nil;
return _class_getVariable(cls, name);
}
/***********************************************************************
* class_getClassVariable. Return the named class variable.
**********************************************************************/
Ivar class_getClassVariable(Class cls, const char *name)
{
if (!cls) return nil;
return class_getInstanceVariable(cls->ISA(), name);
}
/***********************************************************************
* gdb_objc_class_changed
* Tell gdb that a class changed. Currently used for OBJC2 ivar layouts only
* Does nothing; gdb sets a breakpoint on it.
**********************************************************************/
BREAKPOINT_FUNCTION(
void gdb_objc_class_changed(Class cls, unsigned long changes, const char *classname)
);
/***********************************************************************
* class_respondsToSelector.
**********************************************************************/
BOOL class_respondsToMethod(Class cls, SEL sel)
{
OBJC_WARN_DEPRECATED;
return class_respondsToSelector(cls, sel);
}
BOOL class_respondsToSelector(Class cls, SEL sel)
{
return class_respondsToSelector_inst(nil, sel, cls);
}
// inst is an instance of cls or a subclass thereof, or nil if none is known.
// Non-nil inst is faster in some cases. See lookUpImpOrForward() for details.
NEVER_INLINE BOOL
class_respondsToSelector_inst(id inst, SEL sel, Class cls)
{
// Avoids +initialize because it historically did so.
// We're not returning a callable IMP anyway.
return sel && cls && lookUpImpOrNil(inst, sel, cls, LOOKUP_RESOLVER);
}
/***********************************************************************
* class_getMethodImplementation.
* Returns the IMP that would be invoked if [obj sel] were sent,
* where obj is an instance of class cls.
**********************************************************************/
IMP class_lookupMethod(Class cls, SEL sel)
{
OBJC_WARN_DEPRECATED;
// No one responds to zero!
if (!sel) {
__objc_error(cls, "invalid selector (null)");
}
return class_getMethodImplementation(cls, sel);
}
IMP class_getMethodImplementation(Class cls, SEL sel)
{
IMP imp;
if (!cls || !sel) return nil;
imp = lookUpImpOrNil(nil, sel, cls, LOOKUP_INITIALIZE | LOOKUP_RESOLVER);
// Translate forwarding function to C-callable external version
if (!imp) {
return _objc_msgForward;
}
return imp;
}
#if SUPPORT_STRET
IMP class_getMethodImplementation_stret(Class cls, SEL sel)
{
IMP imp = class_getMethodImplementation(cls, sel);
// Translate forwarding function to struct-returning version
if (imp == (IMP)&_objc_msgForward /* not _internal! */) {
return (IMP)&_objc_msgForward_stret;
}
return imp;
}
#endif
/***********************************************************************
* instrumentObjcMessageSends
**********************************************************************/
// Define this everywhere even if it isn't used to simplify fork() safety code.
spinlock_t objcMsgLogLock;
#if !SUPPORT_MESSAGE_LOGGING
void instrumentObjcMessageSends(BOOL flag)
{
}
#else
bool objcMsgLogEnabled = false;
static int objcMsgLogFD = -1;
bool logMessageSend(bool isClassMethod,
const char *objectsClass,
const char *implementingClass,
SEL selector)
{
char buf[ 1024 ];
// Create/open the log file
if (objcMsgLogFD == (-1))
{
snprintf (buf, sizeof(buf), "/tmp/msgSends-%d", (int) getpid ());
objcMsgLogFD = secure_open (buf, O_WRONLY | O_CREAT, geteuid());
if (objcMsgLogFD < 0) {
// no log file - disable logging
objcMsgLogEnabled = false;
objcMsgLogFD = -1;
return true;
}
}
// Make the log entry
snprintf(buf, sizeof(buf), "%c %s %s %s\n",
isClassMethod ? '+' : '-',
objectsClass,
implementingClass,
sel_getName(selector));
objcMsgLogLock.lock();
write (objcMsgLogFD, buf, strlen(buf));
objcMsgLogLock.unlock();
// Tell caller to not cache the method
return false;
}
void instrumentObjcMessageSends(BOOL flag)
{
bool enable = flag;
// Shortcut NOP
if (objcMsgLogEnabled == enable)
return;
// If enabling, flush all method caches so we get some traces
if (enable)
_objc_flush_caches(Nil);
// Sync our log file
if (objcMsgLogFD != -1)
fsync (objcMsgLogFD);
objcMsgLogEnabled = enable;
}
// SUPPORT_MESSAGE_LOGGING
#endif
Class _calloc_class(size_t size)
{
return (Class) calloc(1, size);
}
Class class_getSuperclass(Class cls)
{
if (!cls) return nil;
return cls->superclass;
}
BOOL class_isMetaClass(Class cls)
{
if (!cls) return NO;
return cls->isMetaClass();
}
size_t class_getInstanceSize(Class cls)
{
if (!cls) return 0;
return cls->alignedInstanceSize();
}
/***********************************************************************
* method_getNumberOfArguments.
**********************************************************************/
unsigned int method_getNumberOfArguments(Method m)
{
if (!m) return 0;
return encoding_getNumberOfArguments(method_getTypeEncoding(m));
}
void method_getReturnType(Method m, char *dst, size_t dst_len)
{
encoding_getReturnType(method_getTypeEncoding(m), dst, dst_len);
}
char * method_copyReturnType(Method m)
{
return encoding_copyReturnType(method_getTypeEncoding(m));
}
void method_getArgumentType(Method m, unsigned int index,
char *dst, size_t dst_len)
{
encoding_getArgumentType(method_getTypeEncoding(m),
index, dst, dst_len);
}
char * method_copyArgumentType(Method m, unsigned int index)
{
return encoding_copyArgumentType(method_getTypeEncoding(m), index);
}
/***********************************************************************
* _class_createInstancesFromZone
* Batch-allocating version of _class_createInstanceFromZone.
* Attempts to allocate num_requested objects, each with extraBytes.
* Returns the number of allocated objects (possibly zero), with
* the allocated pointers in *results.
**********************************************************************/
unsigned
_class_createInstancesFromZone(Class cls, size_t extraBytes, void *zone,
id *results, unsigned num_requested)
{
unsigned num_allocated;
if (!cls) return 0;
size_t size = cls->instanceSize(extraBytes);
num_allocated =
malloc_zone_batch_malloc((malloc_zone_t *)(zone ? zone : malloc_default_zone()),
size, (void**)results, num_requested);
for (unsigned i = 0; i < num_allocated; i++) {
bzero(results[i], size);
}
// Construct each object, and delete any that fail construction.
unsigned shift = 0;
bool ctor = cls->hasCxxCtor();
for (unsigned i = 0; i < num_allocated; i++) {
id obj = results[i];
obj->initIsa(cls); // fixme allow nonpointer
if (ctor) {
obj = object_cxxConstructFromClass(obj, cls,
OBJECT_CONSTRUCT_FREE_ONFAILURE);
}
if (obj) {
results[i-shift] = obj;
} else {
shift++;
}
}
return num_allocated - shift;
}
/***********************************************************************
* inform_duplicate. Complain about duplicate class implementations.
**********************************************************************/
void
inform_duplicate(const char *name, Class oldCls, Class newCls)
{
#if TARGET_OS_WIN32
(DebugDuplicateClasses ? _objc_fatal : _objc_inform)
("Class %s is implemented in two different images.", name);
#else
const header_info *oldHeader = _headerForClass(oldCls);
const header_info *newHeader = _headerForClass(newCls);
const char *oldName = oldHeader ? oldHeader->fname() : "??";
const char *newName = newHeader ? newHeader->fname() : "??";
(DebugDuplicateClasses ? _objc_fatal : _objc_inform)
("Class %s is implemented in both %s (%p) and %s (%p). "
"One of the two will be used. Which one is undefined.",
name, oldName, oldCls, newName, newCls);
#endif
}
const char *
copyPropertyAttributeString(const objc_property_attribute_t *attrs,
unsigned int count)
{
char *result;
unsigned int i;
if (count == 0) return strdup("");
#if DEBUG
// debug build: sanitize input
for (i = 0; i < count; i++) {
ASSERT(attrs[i].name);
ASSERT(strlen(attrs[i].name) > 0);
ASSERT(! strchr(attrs[i].name, ','));
ASSERT(! strchr(attrs[i].name, '"'));
if (attrs[i].value) ASSERT(! strchr(attrs[i].value, ','));
}
#endif
size_t len = 0;
for (i = 0; i < count; i++) {
if (attrs[i].value) {
size_t namelen = strlen(attrs[i].name);
if (namelen > 1) namelen += 2; // long names get quoted
len += namelen + strlen(attrs[i].value) + 1;
}
}
result = (char *)malloc(len + 1);
char *s = result;
for (i = 0; i < count; i++) {
if (attrs[i].value) {
size_t namelen = strlen(attrs[i].name);
if (namelen > 1) {
s += sprintf(s, "\"%s\"%s,", attrs[i].name, attrs[i].value);
} else {
s += sprintf(s, "%s%s,", attrs[i].name, attrs[i].value);
}
}
}
// remove trailing ',' if any
if (s > result) s[-1] = '\0';
return result;
}
/*
Property attribute string format:
- Comma-separated name-value pairs.
- Name and value may not contain ,
- Name may not contain "
- Value may be empty
- Name is single char, value follows
- OR Name is double-quoted string of 2+ chars, value follows
Grammar:
attribute-string: \0
attribute-string: name-value-pair (',' name-value-pair)*
name-value-pair: unquoted-name optional-value
name-value-pair: quoted-name optional-value
unquoted-name: [^",]
quoted-name: '"' [^",]{2,} '"'
optional-value: [^,]*
*/
static unsigned int
iteratePropertyAttributes(const char *attrs,
bool (*fn)(unsigned int index,
void *ctx1, void *ctx2,
const char *name, size_t nlen,
const char *value, size_t vlen),
void *ctx1, void *ctx2)
{
if (!attrs) return 0;
#if DEBUG
const char *attrsend = attrs + strlen(attrs);
#endif
unsigned int attrcount = 0;
while (*attrs) {
// Find the next comma-separated attribute
const char *start = attrs;
const char *end = start + strcspn(attrs, ",");
// Move attrs past this attribute and the comma (if any)
attrs = *end ? end+1 : end;
assert(attrs <= attrsend);
assert(start <= attrsend);
assert(end <= attrsend);
// Skip empty attribute
if (start == end) continue;
// Process one non-empty comma-free attribute [start,end)
const char *nameStart;
const char *nameEnd;
ASSERT(start < end);
ASSERT(*start);
if (*start != '\"') {
// single-char short name
nameStart = start;
nameEnd = start+1;
start++;
}
else {
// double-quoted long name
nameStart = start+1;
nameEnd = nameStart + strcspn(nameStart, "\",");
start++; // leading quote
start += nameEnd - nameStart; // name
if (*start == '\"') start++; // trailing quote, if any
}
// Process one possibly-empty comma-free attribute value [start,end)
const char *valueStart;
const char *valueEnd;
ASSERT(start <= end);
valueStart = start;
valueEnd = end;
bool more = (*fn)(attrcount, ctx1, ctx2,
nameStart, nameEnd-nameStart,
valueStart, valueEnd-valueStart);
attrcount++;
if (!more) break;
}
return attrcount;
}
static bool
copyOneAttribute(unsigned int index, void *ctxa, void *ctxs,
const char *name, size_t nlen, const char *value, size_t vlen)
{
objc_property_attribute_t **ap = (objc_property_attribute_t**)ctxa;
char **sp = (char **)ctxs;
objc_property_attribute_t *a = *ap;
char *s = *sp;
a->name = s;
memcpy(s, name, nlen);
s += nlen;
*s++ = '\0';
a->value = s;
memcpy(s, value, vlen);
s += vlen;
*s++ = '\0';
a++;
*ap = a;
*sp = s;
return YES;
}
objc_property_attribute_t *
copyPropertyAttributeList(const char *attrs, unsigned int *outCount)
{
if (!attrs) {
if (outCount) *outCount = 0;
return nil;
}
// Result size:
// number of commas plus 1 for the attributes (upper bound)
// plus another attribute for the attribute array terminator
// plus strlen(attrs) for name/value string data (upper bound)
// plus count*2 for the name/value string terminators (upper bound)
unsigned int attrcount = 1;
const char *s;
for (s = attrs; s && *s; s++) {
if (*s == ',') attrcount++;
}
size_t size =
attrcount * sizeof(objc_property_attribute_t) +
sizeof(objc_property_attribute_t) +
strlen(attrs) +
attrcount * 2;
objc_property_attribute_t *result = (objc_property_attribute_t *)
calloc(size, 1);
objc_property_attribute_t *ra = result;
char *rs = (char *)(ra+attrcount+1);
attrcount = iteratePropertyAttributes(attrs, copyOneAttribute, &ra, &rs);
ASSERT((uint8_t *)(ra+1) <= (uint8_t *)result+size);
ASSERT((uint8_t *)rs <= (uint8_t *)result+size);
if (attrcount == 0) {
free(result);
result = nil;
}
if (outCount) *outCount = attrcount;
return result;
}
static bool
findOneAttribute(unsigned int index, void *ctxa, void *ctxs,
const char *name, size_t nlen, const char *value, size_t vlen)
{
const char *query = (char *)ctxa;
char **resultp = (char **)ctxs;
if (strlen(query) == nlen && 0 == strncmp(name, query, nlen)) {
char *result = (char *)calloc(vlen+1, 1);
memcpy(result, value, vlen);
result[vlen] = '\0';
*resultp = result;
return NO;
}
return YES;
}
char *copyPropertyAttributeValue(const char *attrs, const char *name)
{
char *result = nil;
iteratePropertyAttributes(attrs, findOneAttribute, (void*)name, &result);
return result;
}