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swift-mirror/stdlib/public/runtime/SwiftObject.mm
Mike Ash fe7e13bba5 [Runtime][IRGen] Sign type context descriptor pointers. 
Ensure that context descriptor pointers are signed in the runtime by putting the ptrauth_struct attribute on the types.

We use the new __builtin_ptrauth_struct_key/disc to conditionally apply ptrauth_struct to TrailingObjects based on the signing of the base type, so that pointers to TrailingObjects get signed when used with a context descriptor pointer.

We add new runtime entrypoints that take signed pointers where appropriate, and have the compiler emit calls to the new entrypoints when targeting a sufficiently new OS.

rdar://111480914
2023-07-07 18:10:35 -04:00

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//===--- SwiftObject.mm - Native Swift Object root class ------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This implements the Objective-C root class that provides basic `id`-
// compatibility and `NSObject` protocol conformance for pure Swift classes.
//
//===----------------------------------------------------------------------===//
#include "swift/Runtime/Config.h"
#if SWIFT_OBJC_INTEROP
#include <objc/NSObject.h>
#include <objc/runtime.h>
#include <objc/message.h>
#include <objc/objc.h>
#endif
#include "llvm/ADT/StringRef.h"
#include "swift/Basic/Lazy.h"
#include "swift/Runtime/Bincompat.h"
#include "swift/Runtime/Casting.h"
#include "swift/Runtime/CustomRRABI.h"
#include "swift/Runtime/Debug.h"
#include "swift/Runtime/EnvironmentVariables.h"
#include "swift/Runtime/Heap.h"
#include "swift/Runtime/HeapObject.h"
#include "swift/Runtime/Metadata.h"
#include "swift/Runtime/ObjCBridge.h"
#include "swift/Runtime/Portability.h"
#include "swift/Strings.h"
#include "swift/shims/RuntimeShims.h"
#include "swift/shims/AssertionReporting.h"
#include "../CompatibilityOverride/CompatibilityOverride.h"
#include "ErrorObject.h"
#include "Private.h"
#include "SwiftObject.h"
#include "SwiftValue.h"
#include "WeakReference.h"
#if SWIFT_OBJC_INTEROP
#include <dlfcn.h>
#endif
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <unordered_map>
#if SWIFT_OBJC_INTEROP
# import <CoreFoundation/CFBase.h> // for CFTypeID
# import <Foundation/Foundation.h>
# include <malloc/malloc.h>
# include <dispatch/dispatch.h>
#endif
using namespace swift;
using namespace hashable_support;
#if SWIFT_HAS_ISA_MASKING
OBJC_EXPORT __attribute__((__weak_import__))
const uintptr_t objc_debug_isa_class_mask;
uintptr_t swift::swift_isaMask = SWIFT_ISA_MASK;
#endif
const ClassMetadata *swift::_swift_getClass(const void *object) {
#if SWIFT_OBJC_INTEROP
if (!isObjCTaggedPointer(object))
return _swift_getClassOfAllocated(object);
return reinterpret_cast<const ClassMetadata*>(
object_getClass(id_const_cast(object)));
#else
return _swift_getClassOfAllocated(object);
#endif
}
#if SWIFT_OBJC_INTEROP
/// Replacement for ObjC object_isClass(), which is unavailable on
/// deployment targets macOS 10.9 and iOS 7.
static bool objcObjectIsClass(id object) {
// same as object_isClass(object)
return class_isMetaClass(object_getClass(object));
}
/// Same as _swift_getClassOfAllocated() but returns type Class.
static Class _swift_getObjCClassOfAllocated(const void *object) {
return class_const_cast(_swift_getClassOfAllocated(object));
}
/// Fetch the ObjC class object associated with the formal dynamic
/// type of the given (possibly Objective-C) object. The formal
/// dynamic type ignores dynamic subclasses such as those introduced
/// by KVO.
///
/// The object pointer may be a tagged pointer, but cannot be null.
const ClassMetadata *swift::swift_getObjCClassFromObject(HeapObject *object) {
auto classAsMetadata = _swift_getClass(object);
// Walk up the superclass chain skipping over artificial Swift classes.
// If we find a non-Swift class use the result of [object class] instead.
while (classAsMetadata && classAsMetadata->isTypeMetadata()) {
if (!classAsMetadata->isArtificialSubclass())
return classAsMetadata;
classAsMetadata = classAsMetadata->Superclass;
}
id objcObject = reinterpret_cast<id>(object);
Class objcClass = [objcObject class];
if (objcObjectIsClass(objcObject)) {
// Original object is a class. We want a
// metaclass but +class doesn't give that to us.
objcClass = object_getClass(objcClass);
}
classAsMetadata = reinterpret_cast<const ClassMetadata *>(objcClass);
return classAsMetadata;
}
#endif
/// Fetch the type metadata associated with the formal dynamic
/// type of the given (possibly Objective-C) object. The formal
/// dynamic type ignores dynamic subclasses such as those introduced
/// by KVO.
///
/// The object pointer may be a tagged pointer, but cannot be null.
const Metadata *swift::swift_getObjectType(HeapObject *object) {
auto classAsMetadata = _swift_getClass(object);
#if SWIFT_OBJC_INTEROP
// Walk up the superclass chain skipping over artificial Swift classes.
// If we find a non-Swift class use the result of [object class] instead.
while (classAsMetadata && classAsMetadata->isTypeMetadata()) {
if (!classAsMetadata->isArtificialSubclass())
return classAsMetadata;
classAsMetadata = classAsMetadata->Superclass;
}
id objcObject = reinterpret_cast<id>(object);
Class objcClass = [objcObject class];
if (objcObjectIsClass(objcObject)) {
// Original object is a class. We want a
// metaclass but +class doesn't give that to us.
objcClass = object_getClass(objcClass);
}
classAsMetadata = reinterpret_cast<const ClassMetadata *>(objcClass);
return swift_getObjCClassMetadata(classAsMetadata);
#else
assert(classAsMetadata &&
classAsMetadata->isTypeMetadata() &&
!classAsMetadata->isArtificialSubclass());
return classAsMetadata;
#endif
}
#if SWIFT_OBJC_INTEROP
static SwiftObject *_allocHelper(Class cls) {
// XXX FIXME
// When we have layout information, do precise alignment rounding
// For now, assume someone is using hardware vector types
#if defined(__x86_64__) || defined(__i386__)
const size_t mask = 32 - 1;
#else
const size_t mask = 16 - 1;
#endif
return reinterpret_cast<SwiftObject *>(swift::swift_allocObject(
reinterpret_cast<HeapMetadata const *>(cls),
class_getInstanceSize(cls), mask));
}
SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_API
Class _swift_classOfObjCHeapObject(OpaqueValue *value) {
return _swift_getObjCClassOfAllocated(value);
}
SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_API
id swift_stdlib_getDescription(OpaqueValue *value,
const Metadata *type);
id swift::getDescription(OpaqueValue *value, const Metadata *type) {
id result = swift_stdlib_getDescription(value, type);
type->vw_destroy(value);
return [result autorelease];
}
static id _getObjectDescription(SwiftObject *obj) {
swift_retain((HeapObject*)obj);
return getDescription((OpaqueValue*)&obj,
_swift_getClassOfAllocated(obj));
}
static id _getClassDescription(Class cls) {
const char *name = class_getName(cls);
int len = strlen(name);
return [swift_stdlib_NSStringFromUTF8(name, len) autorelease];
}
@implementation SwiftObject
+ (void)initialize {
#if SWIFT_HAS_ISA_MASKING && !TARGET_OS_SIMULATOR && !NDEBUG
uintptr_t libObjCMask = (uintptr_t)&objc_absolute_packed_isa_class_mask;
assert(libObjCMask);
# if __arm64__ && !__has_feature(ptrauth_calls)
// When we're built ARM64 but running on ARM64e hardware, we will get an
// ARM64e libobjc with an ARM64e ISA mask. This mismatch is harmless and we
// shouldn't assert.
assert(libObjCMask == SWIFT_ISA_MASK || libObjCMask == SWIFT_ISA_MASK_PTRAUTH);
# else
assert(libObjCMask == SWIFT_ISA_MASK);
# endif
#endif
}
+ (instancetype)allocWithZone:(struct _NSZone *)zone {
assert(zone == nullptr);
return _allocHelper(self);
}
+ (instancetype)alloc {
// we do not support "placement new" or zones,
// so there is no need to call allocWithZone
return _allocHelper(self);
}
+ (Class)class {
return self;
}
- (Class)class {
return _swift_getObjCClassOfAllocated(self);
}
+ (Class)superclass {
return (Class)((const ClassMetadata*) self)->Superclass;
}
- (Class)superclass {
return (Class)_swift_getClassOfAllocated(self)->Superclass;
}
+ (BOOL)isMemberOfClass:(Class)cls {
return cls == _swift_getObjCClassOfAllocated(self);
}
- (BOOL)isMemberOfClass:(Class)cls {
return cls == _swift_getObjCClassOfAllocated(self);
}
- (instancetype)self {
return self;
}
- (BOOL)isProxy {
return NO;
}
- (struct _NSZone *)zone {
auto zone = malloc_zone_from_ptr(self);
return (struct _NSZone *)(zone ? zone : malloc_default_zone());
}
- (void)doesNotRecognizeSelector: (SEL) sel {
Class cls = _swift_getObjCClassOfAllocated(self);
fatalError(/* flags = */ 0,
"Unrecognized selector %c[%s %s]\n",
class_isMetaClass(cls) ? '+' : '-',
class_getName(cls), sel_getName(sel));
}
STANDARD_OBJC_METHOD_IMPLS_FOR_SWIFT_OBJECTS
// Retaining the class object itself is a no-op.
+ (id)retain {
return self;
}
+ (void)release {
/* empty */
}
+ (id)autorelease {
return self;
}
+ (NSUInteger)retainCount {
return ULONG_MAX;
}
+ (BOOL)_isDeallocating {
return NO;
}
+ (BOOL)_tryRetain {
return YES;
}
+ (BOOL)allowsWeakReference {
return YES;
}
+ (BOOL)retainWeakReference {
return YES;
}
- (BOOL)isKindOfClass:(Class)someClass {
for (auto cls = _swift_getClassOfAllocated(self); cls != nullptr;
cls = cls->Superclass)
if (cls == (const ClassMetadata*) someClass)
return YES;
return NO;
}
+ (BOOL)isSubclassOfClass:(Class)someClass {
for (auto cls = (const ClassMetadata*) self; cls != nullptr;
cls = cls->Superclass)
if (cls == (const ClassMetadata*) someClass)
return YES;
return NO;
}
+ (BOOL)respondsToSelector:(SEL)sel {
if (!sel) return NO;
return class_respondsToSelector(_swift_getObjCClassOfAllocated(self), sel);
}
- (BOOL)respondsToSelector:(SEL)sel {
if (!sel) return NO;
return class_respondsToSelector(_swift_getObjCClassOfAllocated(self), sel);
}
+ (BOOL)instancesRespondToSelector:(SEL)sel {
if (!sel) return NO;
return class_respondsToSelector(self, sel);
}
+ (IMP)methodForSelector:(SEL)sel {
return class_getMethodImplementation(object_getClass((id)self), sel);
}
- (IMP)methodForSelector:(SEL)sel {
return class_getMethodImplementation(object_getClass(self), sel);
}
+ (IMP)instanceMethodForSelector:(SEL)sel {
return class_getMethodImplementation(self, sel);
}
- (BOOL)conformsToProtocol:(Protocol*)proto {
if (!proto) return NO;
auto selfClass = _swift_getObjCClassOfAllocated(self);
// Walk the superclass chain.
while (selfClass) {
if (class_conformsToProtocol(selfClass, proto))
return YES;
selfClass = class_getSuperclass(selfClass);
}
return NO;
}
+ (BOOL)conformsToProtocol:(Protocol*)proto {
if (!proto) return NO;
// Walk the superclass chain.
Class selfClass = self;
while (selfClass) {
if (class_conformsToProtocol(selfClass, proto))
return YES;
selfClass = class_getSuperclass(selfClass);
}
return NO;
}
- (NSUInteger)hash {
return (NSUInteger)self;
}
- (BOOL)isEqual:(id)object {
return self == object;
}
- (id)performSelector:(SEL)aSelector {
return ((id(*)(id, SEL))objc_msgSend)(self, aSelector);
}
- (id)performSelector:(SEL)aSelector withObject:(id)object {
return ((id(*)(id, SEL, id))objc_msgSend)(self, aSelector, object);
}
- (id)performSelector:(SEL)aSelector withObject:(id)object1
withObject:(id)object2 {
return ((id(*)(id, SEL, id, id))objc_msgSend)(self, aSelector, object1,
object2);
}
- (id /* NSString */)description {
return _getObjectDescription(self);
}
- (id /* NSString */)debugDescription {
return _getObjectDescription(self);
}
+ (id /* NSString */)description {
return _getClassDescription(self);
}
+ (id /* NSString */)debugDescription {
return _getClassDescription(self);
}
- (id /* NSString */)_copyDescription {
// The NSObject version of this pushes an autoreleasepool in case -description
// autoreleases, but we're OK with leaking things if we're at the top level
// of the main thread with no autorelease pool.
return [[self description] retain];
}
- (CFTypeID)_cfTypeID {
return (CFTypeID)1; //NSObject's CFTypeID is constant
}
// Foundation collections expect these to be implemented.
- (BOOL)isNSArray__ { return NO; }
- (BOOL)isNSCFConstantString__ { return NO; }
- (BOOL)isNSData__ { return NO; }
- (BOOL)isNSDate__ { return NO; }
- (BOOL)isNSDictionary__ { return NO; }
- (BOOL)isNSObject__ { return NO; }
- (BOOL)isNSOrderedSet__ { return NO; }
- (BOOL)isNSNumber__ { return NO; }
- (BOOL)isNSSet__ { return NO; }
- (BOOL)isNSString__ { return NO; }
- (BOOL)isNSTimeZone__ { return NO; }
- (BOOL)isNSValue__ { return NO; }
@end
#endif
/// Decide dynamically whether the given class uses native Swift
/// reference-counting.
bool swift::usesNativeSwiftReferenceCounting(const ClassMetadata *theClass) {
#if SWIFT_OBJC_INTEROP
if (!theClass->isTypeMetadata()) return false;
return (theClass->getFlags() & ClassFlags::UsesSwiftRefcounting);
#else
return true;
#endif
}
/// Decide dynamically whether the given type metadata uses native Swift
/// reference-counting. The metadata is known to correspond to a class
/// type, but note that does not imply being known to be a ClassMetadata
/// due to the existence of ObjCClassWrapper.
SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_SPI
bool
_swift_objcClassUsesNativeSwiftReferenceCounting(const Metadata *theClass) {
#if SWIFT_OBJC_INTEROP
// If this is ObjC wrapper metadata, the class is definitely not using
// Swift ref-counting.
if (isa<ObjCClassWrapperMetadata>(theClass)) return false;
// Otherwise, it's class metadata.
return usesNativeSwiftReferenceCounting(cast<ClassMetadata>(theClass));
#else
return true;
#endif
}
// The non-pointer bits, excluding the tag bits.
static auto const unTaggedNonNativeBridgeObjectBits
= heap_object_abi::SwiftSpareBitsMask
& ~heap_object_abi::ObjCReservedBitsMask
& ~heap_object_abi::BridgeObjectTagBitsMask;
#if SWIFT_OBJC_INTEROP
#if defined(__x86_64__)
static uintptr_t const objectPointerIsObjCBit = 0x4000000000000000ULL;
#elif defined(__LP64__)
static uintptr_t const objectPointerIsObjCBit = 0x4000000000000000ULL;
#else
static uintptr_t const objectPointerIsObjCBit = 0x00000002U;
#endif
void *swift::swift_unknownObjectRetain_n(void *object, int n) {
if (isObjCTaggedPointerOrNull(object)) return object;
if (objectUsesNativeSwiftReferenceCounting(object)) {
return swift_retain_n(static_cast<HeapObject *>(object), n);
}
for (int i = 0; i < n; ++i)
objc_retain(static_cast<id>(object));
return object;
}
void swift::swift_unknownObjectRelease_n(void *object, int n) {
if (isObjCTaggedPointerOrNull(object)) return;
if (objectUsesNativeSwiftReferenceCounting(object))
return swift_release_n(static_cast<HeapObject *>(object), n);
for (int i = 0; i < n; ++i)
objc_release(static_cast<id>(object));
}
void *swift::swift_unknownObjectRetain(void *object) {
if (isObjCTaggedPointerOrNull(object)) return object;
if (objectUsesNativeSwiftReferenceCounting(object)) {
return swift_retain(static_cast<HeapObject *>(object));
}
return objc_retain(static_cast<id>(object));
}
void swift::swift_unknownObjectRelease(void *object) {
if (isObjCTaggedPointerOrNull(object)) return;
if (objectUsesNativeSwiftReferenceCounting(object))
return swift_release(static_cast<HeapObject *>(object));
return objc_release(static_cast<id>(object));
}
void *swift::swift_nonatomic_unknownObjectRetain_n(void *object, int n) {
if (isObjCTaggedPointerOrNull(object)) return object;
if (objectUsesNativeSwiftReferenceCounting(object)) {
return swift_nonatomic_retain_n(static_cast<HeapObject *>(object), n);
}
for (int i = 0; i < n; ++i)
objc_retain(static_cast<id>(object));
return object;
}
void swift::swift_nonatomic_unknownObjectRelease_n(void *object, int n) {
if (isObjCTaggedPointerOrNull(object)) return;
if (objectUsesNativeSwiftReferenceCounting(object))
return swift_nonatomic_release_n(static_cast<HeapObject *>(object), n);
for (int i = 0; i < n; ++i)
objc_release(static_cast<id>(object));
}
void *swift::swift_nonatomic_unknownObjectRetain(void *object) {
if (isObjCTaggedPointerOrNull(object)) return object;
if (objectUsesNativeSwiftReferenceCounting(object)) {
return swift_nonatomic_retain(static_cast<HeapObject *>(object));
}
return objc_retain(static_cast<id>(object));
}
void swift::swift_nonatomic_unknownObjectRelease(void *object) {
if (isObjCTaggedPointerOrNull(object)) return;
if (objectUsesNativeSwiftReferenceCounting(object))
return swift_release(static_cast<HeapObject *>(object));
return objc_release(static_cast<id>(object));
}
/// Return true iff the given BridgeObject is not known to use native
/// reference-counting.
///
/// Precondition: object does not encode a tagged pointer
static bool isNonNative_unTagged_bridgeObject(void *object) {
static_assert((heap_object_abi::SwiftSpareBitsMask & objectPointerIsObjCBit) ==
objectPointerIsObjCBit,
"isObjC bit not within spare bits");
return (uintptr_t(object) & objectPointerIsObjCBit) != 0
&& (uintptr_t(object) & heap_object_abi::BridgeObjectTagBitsMask) == 0;
}
/// Return true iff the given BridgeObject is a tagged value.
static bool isBridgeObjectTaggedPointer(void *object) {
return (uintptr_t(object) & heap_object_abi::BridgeObjectTagBitsMask) != 0;
}
#endif
// Mask out the spare bits in a bridgeObject, returning the object it
// encodes.
///
/// Precondition: object does not encode a tagged pointer
static void* toPlainObject_unTagged_bridgeObject(void *object) {
return (void*)(uintptr_t(object) & ~unTaggedNonNativeBridgeObjectBits);
}
#if SWIFT_OBJC_INTEROP
#if __arm64__
// Marking this as noinline allows swift_bridgeObjectRetain to avoid emitting
// a stack frame for the swift_retain path on ARM64. It makes for worse codegen
// on x86-64, though, so limit it to ARM64.
SWIFT_NOINLINE
#endif
static void *objcRetainAndReturn(void *object) {
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
objc_retain(static_cast<id>(objectRef));
return object;
}
#endif
void *swift::swift_bridgeObjectRetain(void *object) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return object;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object)) {
return swift_retain(static_cast<HeapObject *>(objectRef));
}
// Put the call to objc_retain in a separate function, tail-called here. This
// allows the fast path of swift_bridgeObjectRetain to avoid creating a stack
// frame on ARM64. We can't directly tail-call objc_retain, because
// swift_bridgeObjectRetain returns the pointer with objectPointerIsObjCBit
// set, so we have to make a non-tail call and then return the value with the
// bit set.
SWIFT_MUSTTAIL return objcRetainAndReturn(object);
#else
// No tail call here. When !SWIFT_OBJC_INTEROP, the value of objectRef may be
// different from that of object, e.g. on Linux ARM64.
swift_retain(static_cast<HeapObject *>(objectRef));
return object;
#endif
}
CUSTOM_RR_ENTRYPOINTS_DEFINE_ENTRYPOINTS(swift_bridgeObjectRetain)
SWIFT_RUNTIME_EXPORT
void *swift::swift_nonatomic_bridgeObjectRetain(void *object) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return object;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object)) {
swift_nonatomic_retain(static_cast<HeapObject *>(objectRef));
return object;
}
objc_retain(static_cast<id>(objectRef));
return object;
#else
swift_nonatomic_retain(static_cast<HeapObject *>(objectRef));
return object;
#endif
}
SWIFT_RUNTIME_EXPORT
void swift::swift_bridgeObjectRelease(void *object) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object))
return swift_release(static_cast<HeapObject *>(objectRef));
return objc_release(static_cast<id>(objectRef));
#else
swift_release(static_cast<HeapObject *>(objectRef));
#endif
}
CUSTOM_RR_ENTRYPOINTS_DEFINE_ENTRYPOINTS(swift_bridgeObjectRelease)
void swift::swift_nonatomic_bridgeObjectRelease(void *object) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object))
return swift_nonatomic_release(static_cast<HeapObject *>(objectRef));
return objc_release(static_cast<id>(objectRef));
#else
swift_nonatomic_release(static_cast<HeapObject *>(objectRef));
#endif
}
void *swift::swift_bridgeObjectRetain_n(void *object, int n) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return object;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object)) {
swift_retain_n(static_cast<HeapObject *>(objectRef), n);
return object;
}
for (int i = 0;i < n; ++i)
objc_retain(static_cast<id>(objectRef));
return object;
#else
swift_retain_n(static_cast<HeapObject *>(objectRef), n);
return object;
#endif
}
void swift::swift_bridgeObjectRelease_n(void *object, int n) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object))
return swift_release_n(static_cast<HeapObject *>(objectRef), n);
for (int i = 0; i < n; ++i)
objc_release(static_cast<id>(objectRef));
#else
swift_release_n(static_cast<HeapObject *>(objectRef), n);
#endif
}
void *swift::swift_nonatomic_bridgeObjectRetain_n(void *object, int n) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return object;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object)) {
swift_nonatomic_retain_n(static_cast<HeapObject *>(objectRef), n);
return object;
}
for (int i = 0;i < n; ++i)
objc_retain(static_cast<id>(objectRef));
return object;
#else
swift_nonatomic_retain_n(static_cast<HeapObject *>(objectRef), n);
return object;
#endif
}
void swift::swift_nonatomic_bridgeObjectRelease_n(void *object, int n) {
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object) || isBridgeObjectTaggedPointer(object))
return;
#endif
auto const objectRef = toPlainObject_unTagged_bridgeObject(object);
#if SWIFT_OBJC_INTEROP
if (!isNonNative_unTagged_bridgeObject(object))
return swift_nonatomic_release_n(static_cast<HeapObject *>(objectRef), n);
for (int i = 0; i < n; ++i)
objc_release(static_cast<id>(objectRef));
#else
swift_nonatomic_release_n(static_cast<HeapObject *>(objectRef), n);
#endif
}
#if SWIFT_OBJC_INTEROP
/*****************************************************************************/
/************************ UNKNOWN UNOWNED REFERENCES *************************/
/*****************************************************************************/
// Swift's native unowned references are implemented purely with
// reference-counting: as long as an unowned reference is held to an object,
// it can be destroyed but never deallocated, being that it remains fully safe
// to pass around a pointer and perform further reference-counting operations.
//
// For imported class types (meaning ObjC, for now, but in principle any
// type which supports ObjC-style weak references but not directly Swift-style
// unowned references), we have to implement this on top of the weak-reference
// support, at least for now. But we'd like to be able to statically take
// advantage of Swift's representational advantages when we know that all the
// objects involved are Swift-native. That means that whatever scheme we use
// for unowned references needs to interoperate with code just doing naive
// loads and stores, at least when the ObjC case isn't triggered.
//
// We have to be sensitive about making unreasonable assumptions about the
// implementation of ObjC weak references, and we definitely cannot modify
// memory owned by the ObjC runtime. In the long run, direct support from
// the ObjC runtime can allow an efficient implementation that doesn't violate
// those requirements, both by allowing us to directly check whether a weak
// reference was cleared by deallocation vs. just initialized to nil and by
// guaranteeing a bit pattern that distinguishes Swift references. In the
// meantime, out-of-band allocation is inefficient but not ridiculously so.
//
// Note that unowned references need not provide guaranteed behavior in
// the presence of read/write or write/write races on the reference itself.
// Furthermore, and unlike weak references, they also do not need to be
// safe against races with the deallocation of the object. It is the user's
// responsibility to ensure that the reference remains valid at the time
// that the unowned reference is read.
namespace {
/// An Objective-C unowned reference. Given an unknown unowned reference
/// in memory, it is an ObjC unowned reference if the IsObjCFlag bit
/// is set; if so, the pointer stored in the reference actually points
/// to out-of-line storage containing an ObjC weak reference.
///
/// It is an invariant that this out-of-line storage is only ever
/// allocated and constructed for non-null object references, so if the
/// weak load yields null, it can only be because the object was deallocated.
struct ObjCUnownedReference : UnownedReference {
// Pretending that there's a subclass relationship here means that
// accesses to objects formally constructed as UnownedReferences will
// technically be aliasing violations. However, the language runtime
// will generally not see any such objects.
enum : uintptr_t { IsObjCMask = 0x1, IsObjCFlag = 0x1 };
/// The out-of-line storage of an ObjC unowned reference.
struct Storage {
/// A weak reference registered with the ObjC runtime.
mutable id WeakRef;
Storage(id ref) {
assert(ref && "creating storage for null reference?");
objc_initWeak(&WeakRef, ref);
}
Storage(const Storage &other) {
objc_copyWeak(&WeakRef, &other.WeakRef);
}
Storage &operator=(const Storage &other) = delete;
Storage &operator=(id ref) {
objc_storeWeak(&WeakRef, ref);
return *this;
}
~Storage() {
objc_destroyWeak(&WeakRef);
}
// Don't use the C++ allocator.
void *operator new(size_t size) { return malloc(size); }
void operator delete(void *ptr) { free(ptr); }
};
Storage *storage() {
assert(isa<ObjCUnownedReference>(this));
return reinterpret_cast<Storage*>(
reinterpret_cast<uintptr_t>(Value) & ~IsObjCMask);
}
static void initialize(UnownedReference *dest, id value) {
initializeWithStorage(dest, new Storage(value));
}
static void initializeWithCopy(UnownedReference *dest, Storage *src) {
initializeWithStorage(dest, new Storage(*src));
}
static void initializeWithStorage(UnownedReference *dest,
Storage *storage) {
dest->Value = (HeapObject*) (uintptr_t(storage) | IsObjCFlag);
}
static bool classof(const UnownedReference *ref) {
return (uintptr_t(ref->Value) & IsObjCMask) == IsObjCFlag;
}
};
}
static bool isObjCForUnownedReference(void *value) {
return (isObjCTaggedPointer(value) ||
!objectUsesNativeSwiftReferenceCounting(value));
}
UnownedReference *swift::swift_unknownObjectUnownedInit(UnownedReference *dest,
void *value) {
// Note that LLDB also needs to know about the memory layout of unowned
// references. The implementation here needs to be kept in sync with
// lldb_private::SwiftLanguageRuntime.
if (!value) {
dest->Value = nullptr;
} else if (isObjCForUnownedReference(value)) {
ObjCUnownedReference::initialize(dest, (id) value);
} else {
swift_unownedInit(dest, (HeapObject*) value);
}
return dest;
}
UnownedReference *
swift::swift_unknownObjectUnownedAssign(UnownedReference *dest, void *value) {
if (!value) {
swift_unknownObjectUnownedDestroy(dest);
dest->Value = nullptr;
} else if (isObjCForUnownedReference(value)) {
if (auto objcDest = dyn_cast<ObjCUnownedReference>(dest)) {
objc_storeWeak(&objcDest->storage()->WeakRef, (id) value);
} else {
swift_unownedDestroy(dest);
ObjCUnownedReference::initialize(dest, (id) value);
}
} else {
if (auto objcDest = dyn_cast<ObjCUnownedReference>(dest)) {
delete objcDest->storage();
swift_unownedInit(dest, (HeapObject*) value);
} else {
swift_unownedAssign(dest, (HeapObject*) value);
}
}
return dest;
}
void *swift::swift_unknownObjectUnownedLoadStrong(UnownedReference *ref) {
if (!ref->Value) {
return nullptr;
} else if (auto objcRef = dyn_cast<ObjCUnownedReference>(ref)) {
auto result = (void*) objc_loadWeakRetained(&objcRef->storage()->WeakRef);
if (result == nullptr) {
swift::swift_abortRetainUnowned(nullptr);
}
return result;
} else {
return swift_unownedLoadStrong(ref);
}
}
void *swift::swift_unknownObjectUnownedTakeStrong(UnownedReference *ref) {
if (!ref->Value) {
return nullptr;
} else if (auto objcRef = dyn_cast<ObjCUnownedReference>(ref)) {
auto storage = objcRef->storage();
auto result = (void*) objc_loadWeakRetained(&objcRef->storage()->WeakRef);
if (result == nullptr) {
swift::swift_abortRetainUnowned(nullptr);
}
delete storage;
return result;
} else {
return swift_unownedTakeStrong(ref);
}
}
void swift::swift_unknownObjectUnownedDestroy(UnownedReference *ref) {
if (!ref->Value) {
// Nothing to do.
return;
} else if (auto objcRef = dyn_cast<ObjCUnownedReference>(ref)) {
delete objcRef->storage();
} else {
swift_unownedDestroy(ref);
}
}
UnownedReference *
swift::swift_unknownObjectUnownedCopyInit(UnownedReference *dest,
UnownedReference *src) {
assert(dest != src);
if (!src->Value) {
dest->Value = nullptr;
} else if (auto objcSrc = dyn_cast<ObjCUnownedReference>(src)) {
ObjCUnownedReference::initializeWithCopy(dest, objcSrc->storage());
} else {
swift_unownedCopyInit(dest, src);
}
return dest;
}
UnownedReference *
swift::swift_unknownObjectUnownedTakeInit(UnownedReference *dest,
UnownedReference *src) {
assert(dest != src);
dest->Value = src->Value;
return dest;
}
UnownedReference *
swift::swift_unknownObjectUnownedCopyAssign(UnownedReference *dest,
UnownedReference *src) {
if (dest == src) return dest;
if (auto objcSrc = dyn_cast<ObjCUnownedReference>(src)) {
if (auto objcDest = dyn_cast<ObjCUnownedReference>(dest)) {
// ObjC unfortunately doesn't expose a copy-assign operation.
objc_destroyWeak(&objcDest->storage()->WeakRef);
objc_copyWeak(&objcDest->storage()->WeakRef,
&objcSrc->storage()->WeakRef);
return dest;
}
swift_unownedDestroy(dest);
ObjCUnownedReference::initializeWithCopy(dest, objcSrc->storage());
} else {
if (auto objcDest = dyn_cast<ObjCUnownedReference>(dest)) {
delete objcDest->storage();
swift_unownedCopyInit(dest, src);
} else {
swift_unownedCopyAssign(dest, src);
}
}
return dest;
}
UnownedReference *
swift::swift_unknownObjectUnownedTakeAssign(UnownedReference *dest,
UnownedReference *src) {
assert(dest != src);
// There's not really anything more efficient to do here than this.
swift_unknownObjectUnownedDestroy(dest);
dest->Value = src->Value;
return dest;
}
bool swift::swift_unknownObjectUnownedIsEqual(UnownedReference *ref,
void *value) {
if (!ref->Value) {
return value == nullptr;
} else if (auto objcRef = dyn_cast<ObjCUnownedReference>(ref)) {
id refValue = objc_loadWeakRetained(&objcRef->storage()->WeakRef);
bool isEqual = (void*)refValue == value;
// This ObjC case has no deliberate unowned check here,
// unlike the Swift case.
[refValue release];
return isEqual;
} else {
return swift_unownedIsEqual(ref, (HeapObject *)value);
}
}
/*****************************************************************************/
/************************** UNKNOWN WEAK REFERENCES **************************/
/*****************************************************************************/
WeakReference *swift::swift_unknownObjectWeakInit(WeakReference *ref,
void *value) {
ref->unknownInit(value);
return ref;
}
WeakReference *swift::swift_unknownObjectWeakAssign(WeakReference *ref,
void *value) {
ref->unknownAssign(value);
return ref;
}
void *swift::swift_unknownObjectWeakLoadStrong(WeakReference *ref) {
return ref->unknownLoadStrong();
}
void *swift::swift_unknownObjectWeakTakeStrong(WeakReference *ref) {
return ref->unknownTakeStrong();
}
void swift::swift_unknownObjectWeakDestroy(WeakReference *ref) {
ref->unknownDestroy();
}
WeakReference *swift::swift_unknownObjectWeakCopyInit(WeakReference *dest,
WeakReference *src) {
dest->unknownCopyInit(src);
return dest;
}
WeakReference *swift::swift_unknownObjectWeakTakeInit(WeakReference *dest,
WeakReference *src) {
dest->unknownTakeInit(src);
return dest;
}
WeakReference *swift::swift_unknownObjectWeakCopyAssign(WeakReference *dest,
WeakReference *src) {
dest->unknownCopyAssign(src);
return dest;
}
WeakReference *swift::swift_unknownObjectWeakTakeAssign(WeakReference *dest,
WeakReference *src) {
dest->unknownTakeAssign(src);
return dest;
}
// SWIFT_OBJC_INTEROP
#endif
/*****************************************************************************/
/******************************* DYNAMIC CASTS *******************************/
/*****************************************************************************/
#if SWIFT_OBJC_INTEROP
static const void *
swift_dynamicCastObjCClassImpl(const void *object,
const ClassMetadata *targetType) {
// FIXME: We need to decide if this is really how we want to treat 'nil'.
if (object == nullptr)
return nullptr;
if ([id_const_cast(object) isKindOfClass:class_const_cast(targetType)]) {
return object;
}
// For casts to NSError or NSObject, we might need to bridge via the Error
// protocol. Try it now.
if (targetType == reinterpret_cast<const ClassMetadata*>(getNSErrorClass()) ||
targetType == reinterpret_cast<const ClassMetadata*>([NSObject class])) {
auto srcType = swift_getObjCClassMetadata(
reinterpret_cast<const ClassMetadata*>(
object_getClass(id_const_cast(object))));
if (auto srcErrorWitness = findErrorWitness(srcType)) {
return dynamicCastValueToNSError((OpaqueValue*)&object, srcType,
srcErrorWitness,
DynamicCastFlags::TakeOnSuccess);
}
}
return nullptr;
}
static const void *
swift_dynamicCastObjCClassUnconditionalImpl(const void *object,
const ClassMetadata *targetType,
const char *filename,
unsigned line, unsigned column) {
// FIXME: We need to decide if this is really how we want to treat 'nil'.
if (object == nullptr)
return nullptr;
if ([id_const_cast(object) isKindOfClass:class_const_cast(targetType)]) {
return object;
}
// For casts to NSError or NSObject, we might need to bridge via the Error
// protocol. Try it now.
if (targetType == reinterpret_cast<const ClassMetadata*>(getNSErrorClass()) ||
targetType == reinterpret_cast<const ClassMetadata*>([NSObject class])) {
auto srcType = swift_getObjCClassMetadata(
reinterpret_cast<const ClassMetadata*>(
object_getClass(id_const_cast(object))));
if (auto srcErrorWitness = findErrorWitness(srcType)) {
return dynamicCastValueToNSError((OpaqueValue*)&object, srcType,
srcErrorWitness,
DynamicCastFlags::TakeOnSuccess);
}
}
Class sourceType = object_getClass(id_const_cast(object));
swift_dynamicCastFailure(reinterpret_cast<const Metadata *>(sourceType),
targetType);
}
static const void *
swift_dynamicCastForeignClassImpl(const void *object,
const ForeignClassMetadata *targetType) {
// FIXME: Actually compare CFTypeIDs, once they are available in the metadata.
return object;
}
static const void *
swift_dynamicCastForeignClassUnconditionalImpl(
const void *object,
const ForeignClassMetadata *targetType,
const char *filename,
unsigned line, unsigned column) {
// FIXME: Actual compare CFTypeIDs, once they are available in the metadata.
return object;
}
bool swift::objectConformsToObjCProtocol(const void *theObject,
ProtocolDescriptorRef protocol) {
return [id_const_cast(theObject)
conformsToProtocol: protocol.getObjCProtocol()];
}
bool swift::classConformsToObjCProtocol(const void *theClass,
ProtocolDescriptorRef protocol) {
return [class_const_cast(theClass)
conformsToProtocol: protocol.getObjCProtocol()];
}
SWIFT_RUNTIME_EXPORT
const Metadata *swift_dynamicCastTypeToObjCProtocolUnconditional(
const Metadata *type,
size_t numProtocols,
Protocol * const *protocols,
const char *filename,
unsigned line, unsigned column) {
Class classObject;
switch (type->getKind()) {
case MetadataKind::Class:
case MetadataKind::ObjCClassWrapper:
// Native class metadata is also the class object.
// ObjC class wrappers get unwrapped.
classObject = type->getObjCClassObject();
break;
// Other kinds of type can never conform to ObjC protocols.
default:
swift_dynamicCastFailure(type, nameForMetadata(type).c_str(),
protocols[0], protocol_getName(protocols[0]));
case MetadataKind::HeapLocalVariable:
case MetadataKind::HeapGenericLocalVariable:
case MetadataKind::ErrorObject:
assert(false && "not type metadata");
break;
}
for (size_t i = 0; i < numProtocols; ++i) {
if (![classObject conformsToProtocol:protocols[i]]) {
swift_dynamicCastFailure(type, nameForMetadata(type).c_str(),
protocols[i], protocol_getName(protocols[i]));
}
}
return type;
}
SWIFT_RUNTIME_EXPORT
const Metadata *swift_dynamicCastTypeToObjCProtocolConditional(
const Metadata *type,
size_t numProtocols,
Protocol * const *protocols) {
Class classObject;
switch (type->getKind()) {
case MetadataKind::Class:
case MetadataKind::ObjCClassWrapper:
// Native class metadata is also the class object.
// ObjC class wrappers get unwrapped.
classObject = type->getObjCClassObject();
break;
// Other kinds of type can never conform to ObjC protocols.
default:
return nullptr;
case MetadataKind::HeapLocalVariable:
case MetadataKind::HeapGenericLocalVariable:
case MetadataKind::ErrorObject:
assert(false && "not type metadata");
break;
}
for (size_t i = 0; i < numProtocols; ++i) {
if (![classObject conformsToProtocol:protocols[i]]) {
return nullptr;
}
}
return type;
}
SWIFT_RUNTIME_EXPORT
id swift_dynamicCastObjCProtocolUnconditional(id object,
size_t numProtocols,
Protocol * const *protocols,
const char *filename,
unsigned line, unsigned column) {
for (size_t i = 0; i < numProtocols; ++i) {
if (![object conformsToProtocol:protocols[i]]) {
Class sourceType = object_getClass(object);
swift_dynamicCastFailure(sourceType, class_getName(sourceType),
protocols[i], protocol_getName(protocols[i]));
}
}
return object;
}
SWIFT_RUNTIME_EXPORT
id swift_dynamicCastObjCProtocolConditional(id object,
size_t numProtocols,
Protocol * const *protocols) {
if (!runtime::bincompat::useLegacySwiftValueUnboxingInCasting()) {
if (getAsSwiftValue(object) != nil) {
// SwiftValue wrapper never holds a class object
return nil;
}
}
for (size_t i = 0; i < numProtocols; ++i) {
if (![object conformsToProtocol:protocols[i]]) {
return nil;
}
}
return object;
}
void swift::swift_instantiateObjCClass(const ClassMetadata *_c) {
static const objc_image_info ImageInfo = {0, 0};
// Ensure the superclass is realized.
Class c = class_const_cast(_c);
[class_getSuperclass(c) class];
// Register the class.
Class registered = objc_readClassPair(c, &ImageInfo);
assert(registered == c
&& "objc_readClassPair failed to instantiate the class in-place");
(void)registered;
}
Class swift::swift_getInitializedObjCClass(Class c) {
// Used when we have class metadata and we want to ensure a class has been
// initialized by the Objective-C runtime. We need to do this because the
// class "c" might be valid metadata, but it hasn't been initialized yet.
// Send a message that's likely not to be overridden to minimize potential
// side effects. Ignore the return value in case it is overridden to
// return something different. See
// https://github.com/apple/swift/issues/52863 for an example.
[c self];
return c;
}
static const ClassMetadata *
swift_dynamicCastObjCClassMetatypeImpl(const ClassMetadata *source,
const ClassMetadata *dest) {
if ([class_const_cast(source) isSubclassOfClass:class_const_cast(dest)])
return source;
return nil;
}
static const ClassMetadata *
swift_dynamicCastObjCClassMetatypeUnconditionalImpl(const ClassMetadata *source,
const ClassMetadata *dest,
const char *filename,
unsigned line, unsigned column) {
if ([class_const_cast(source) isSubclassOfClass:class_const_cast(dest)])
return source;
swift_dynamicCastFailure(source, dest);
}
#endif
static const ClassMetadata *
swift_dynamicCastForeignClassMetatypeImpl(const ClassMetadata *sourceType,
const ClassMetadata *targetType) {
// FIXME: Actually compare CFTypeIDs, once they are available in
// the metadata.
return sourceType;
}
static const ClassMetadata *
swift_dynamicCastForeignClassMetatypeUnconditionalImpl(
const ClassMetadata *sourceType,
const ClassMetadata *targetType,
const char *filename,
unsigned line, unsigned column)
{
// FIXME: Actually compare CFTypeIDs, once they arae available in
// the metadata.
return sourceType;
}
#if SWIFT_OBJC_INTEROP
// Given a non-nil object reference, return true iff the object uses
// native swift reference counting.
static bool usesNativeSwiftReferenceCounting_nonNull(
const void* object
) {
assert(object != nullptr);
return !isObjCTaggedPointer(object) &&
objectUsesNativeSwiftReferenceCounting(object);
}
#endif
bool swift::swift_isUniquelyReferenced_nonNull_native(const HeapObject *object){
assert(object != nullptr);
assert(!object->refCounts.isDeiniting());
return object->refCounts.isUniquelyReferenced();
}
bool swift::swift_isUniquelyReferenced_native(const HeapObject* object) {
return object != nullptr
&& swift::swift_isUniquelyReferenced_nonNull_native(object);
}
bool swift::swift_isUniquelyReferencedNonObjC_nonNull(const void* object) {
assert(object != nullptr);
return
#if SWIFT_OBJC_INTEROP
usesNativeSwiftReferenceCounting_nonNull(object) &&
#endif
swift_isUniquelyReferenced_nonNull_native((const HeapObject*)object);
}
#if SWIFT_OBJC_INTEROP
// It would be nice to weak link instead of doing this, but we can't do that
// until the new API is in the versions of libobjc that we're linking against.
static bool isUniquelyReferenced(id object) {
#if OBJC_ISUNIQUELYREFERENCED_DEFINED
return objc_isUniquelyReferenced(object);
#else
auto objcIsUniquelyRefd = SWIFT_LAZY_CONSTANT(reinterpret_cast<bool (*)(id)>(
dlsym(RTLD_NEXT, "objc_isUniquelyReferenced")));
return objcIsUniquelyRefd && objcIsUniquelyRefd(object);
#endif /* OBJC_ISUNIQUELYREFERENCED_DEFINED */
}
#endif
bool swift::swift_isUniquelyReferenced_nonNull(const void *object) {
assert(object != nullptr);
#if SWIFT_OBJC_INTEROP
if (isObjCTaggedPointer(object))
return false;
if (!usesNativeSwiftReferenceCounting_nonNull(object)) {
return isUniquelyReferenced(id_const_cast(object));
}
#endif
return swift_isUniquelyReferenced_nonNull_native(
static_cast<const HeapObject *>(object));
}
// Given an object reference, return true iff it is non-nil and refers
// to a native swift object with strong reference count of 1.
bool swift::swift_isUniquelyReferencedNonObjC(
const void* object
) {
return object != nullptr
&& swift_isUniquelyReferencedNonObjC_nonNull(object);
}
// Given an object reference, return true if it is non-nil and refers
// to an ObjC or native swift object with a strong reference count of 1.
bool swift::swift_isUniquelyReferenced(const void *object) {
return object != nullptr && swift_isUniquelyReferenced_nonNull(object);
}
/// Return true if the given bits of a Builtin.BridgeObject refer to a
/// native swift object whose strong reference count is 1.
bool swift::swift_isUniquelyReferencedNonObjC_nonNull_bridgeObject(
uintptr_t bits
) {
auto bridgeObject = (void*)bits;
if (isObjCTaggedPointer(bridgeObject))
return false;
const auto object = toPlainObject_unTagged_bridgeObject(bridgeObject);
// Note: we could just return false if all spare bits are set,
// but in that case the cost of a deeper check for a unique native
// object is going to be a negligible cost for a possible big win.
#if SWIFT_OBJC_INTEROP
return !isNonNative_unTagged_bridgeObject(bridgeObject)
? swift_isUniquelyReferenced_nonNull_native(
(const HeapObject *)object)
: swift_isUniquelyReferencedNonObjC_nonNull(object);
#else
return swift_isUniquelyReferenced_nonNull_native((const HeapObject *)object);
#endif
}
/// Return true if the given bits of a Builtin.BridgeObject refer to
/// an object whose strong reference count is 1.
bool swift::swift_isUniquelyReferenced_nonNull_bridgeObject(uintptr_t bits) {
auto bridgeObject = reinterpret_cast<void *>(bits);
if (isObjCTaggedPointer(bridgeObject))
return false;
const auto object = toPlainObject_unTagged_bridgeObject(bridgeObject);
#if SWIFT_OBJC_INTEROP
return !isNonNative_unTagged_bridgeObject(bridgeObject)
? swift_isUniquelyReferenced_nonNull_native(
(const HeapObject *)object)
: swift_isUniquelyReferenced_nonNull(object);
#else
return swift_isUniquelyReferenced_nonNull_native((const HeapObject *)object);
#endif
}
// Given a non-@objc object reference, return true iff the
// object is non-nil and has a strong reference count greater than 1
bool swift::swift_isEscapingClosureAtFileLocation(const HeapObject *object,
const unsigned char *filename,
int32_t filenameLength,
int32_t line, int32_t column,
unsigned verificationType) {
assert((verificationType == 0 || verificationType == 1) &&
"Unknown verification type");
bool isEscaping =
object != nullptr && !object->refCounts.isUniquelyReferenced();
// Print a message if the closure escaped.
if (isEscaping) {
auto *message = (verificationType == 0)
? "closure argument was escaped in "
"withoutActuallyEscaping block"
: "closure argument passed as @noescape "
"to Objective-C has escaped";
auto messageLength = strlen(message);
char *log;
swift_asprintf(
&log, "%.*s: file %.*s, line %" PRIu32 ", column %" PRIu32 " \n",
(int)messageLength, message, filenameLength, filename, line, column);
printCurrentBacktrace(2/*framesToSkip*/);
if (_swift_shouldReportFatalErrorsToDebugger()) {
RuntimeErrorDetails details = {
.version = RuntimeErrorDetails::currentVersion,
.errorType = "escaping-closure-violation",
.currentStackDescription = "Closure has escaped",
.framesToSkip = 1,
};
_swift_reportToDebugger(RuntimeErrorFlagFatal, log, &details);
}
swift_reportError(RuntimeErrorFlagFatal, log);
free(log);
}
return isEscaping;
}
struct ClassExtents {
size_t negative;
size_t positive;
};
SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_SPI
ClassExtents
_swift_getSwiftClassInstanceExtents(const Metadata *c) {
assert(c && c->isClassObject());
auto metaData = c->getClassObject();
return ClassExtents{
metaData->getInstanceAddressPoint(),
metaData->getInstanceSize() - metaData->getInstanceAddressPoint()
};
}
#if SWIFT_OBJC_INTEROP
SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_SPI
ClassExtents
_swift_getObjCClassInstanceExtents(const ClassMetadata* c) {
// Pure ObjC classes never have negative extents.
if (c->isPureObjC())
return ClassExtents{0, class_getInstanceSize(class_const_cast(c))};
return _swift_getSwiftClassInstanceExtents(c);
}
SWIFT_CC(swift)
SWIFT_RUNTIME_EXPORT
void swift_objc_swift3ImplicitObjCEntrypoint(id self, SEL selector,
const char *filename,
size_t filenameLength,
size_t line, size_t column,
std::atomic<bool> *didLog) {
// Only log once. We should have been given a unique zero-initialized
// atomic flag for each entry point.
if (didLog->exchange(true))
return;
// Figure out how much reporting we want by querying the environment
// variable SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT. We have four meaningful
// levels:
//
// 0: Don't report anything
// 1: Complain about uses of implicit @objc entrypoints.
// 2: Complain about uses of implicit @objc entrypoints, with backtraces
// if possible.
// 3: Complain about uses of implicit @objc entrypoints, then abort().
//
// The default, if SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT is not set, is 2.
uint8_t reportLevel =
runtime::environment::SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT();
if (reportLevel < 1) return;
// Report the error.
uint32_t flags = 0;
if (reportLevel >= 2)
flags |= 1 << 0; // Backtrace
bool isInstanceMethod = !class_isMetaClass(object_getClass(self));
void (*reporter)(uint32_t, const char *, ...) =
reportLevel > 2 ? swift::fatalError : swift::warning;
if (filenameLength > INT_MAX)
filenameLength = INT_MAX;
char *message, *nullTerminatedFilename;
swift_asprintf(&message,
"implicit Objective-C entrypoint %c[%s %s] is deprecated and will "
"be removed in Swift 4",
isInstanceMethod ? '-' : '+',
class_getName([self class]),
sel_getName(selector));
swift_asprintf(&nullTerminatedFilename, "%*s", (int)filenameLength, filename);
RuntimeErrorDetails::FixIt fixit = {
.filename = nullTerminatedFilename,
.startLine = line,
.startColumn = column,
.endLine = line,
.endColumn = column,
.replacementText = "@objc "
};
RuntimeErrorDetails::Note note = {
.description = "add '@objc' to expose this Swift declaration to Objective-C",
.numFixIts = 1,
.fixIts = &fixit
};
RuntimeErrorDetails details = {
.version = RuntimeErrorDetails::currentVersion,
.errorType = "implicit-objc-entrypoint",
.framesToSkip = 1,
.numNotes = 1,
.notes = &note
};
uintptr_t runtime_error_flags = RuntimeErrorFlagNone;
if (reporter == swift::fatalError)
runtime_error_flags = RuntimeErrorFlagFatal;
_swift_reportToDebugger(runtime_error_flags, message, &details);
reporter(flags,
"*** %s:%zu:%zu: %s; add explicit '@objc' to the declaration to "
"emit the Objective-C entrypoint in Swift 4 and suppress this "
"message\n",
nullTerminatedFilename, line, column, message);
free(message);
free(nullTerminatedFilename);
}
const Metadata *swift::getNSObjectMetadata() {
return SWIFT_LAZY_CONSTANT(
swift_getObjCClassMetadata((const ClassMetadata *)[NSObject class]));
}
const Metadata *swift::getNSStringMetadata() {
return SWIFT_LAZY_CONSTANT(swift_getObjCClassMetadata(
(const ClassMetadata *)objc_lookUpClass("NSString")
));
}
const HashableWitnessTable *
swift::hashable_support::getNSStringHashableConformance() {
return SWIFT_LAZY_CONSTANT(
reinterpret_cast<const HashableWitnessTable *>(
swift_conformsToProtocolCommon(
getNSStringMetadata(),
&HashableProtocolDescriptor
)
)
);
}
#endif
const ClassMetadata *swift::getRootSuperclass() {
#if SWIFT_OBJC_INTEROP
static Lazy<const ClassMetadata *> SwiftObjectClass;
return SwiftObjectClass.get([](void *ptr) {
*((const ClassMetadata **) ptr) =
(const ClassMetadata *)[SwiftObject class];
});
#else
return nullptr;
#endif
}
#define OVERRIDE_OBJC COMPATIBILITY_OVERRIDE
#include COMPATIBILITY_OVERRIDE_INCLUDE_PATH
#define OVERRIDE_FOREIGN COMPATIBILITY_OVERRIDE
#include COMPATIBILITY_OVERRIDE_INCLUDE_PATH
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