iOS 12 错误 swift_getAssociatedTypeWitnessSlowImpl EXC_BAD_ACCESS 汇编代码
iOS 12 error swift_getAssociatedTypeWitnessSlowImpl EXC_BAD_ACCESS in assembly code
我正在用 Combine 和 SwiftUI 编写一个项目，向后兼容 iOS 12/11 与 RxSwift、RxCocoa 和 UIKit。我的项目基于很多协议、关联类型和泛型。当我在 运行 iOS 13 上的项目工作正常但在 iOS 12 上应用程序突然崩溃。
我正在尝试对 Redux 架构进行一些更改。我有 reducer、actions（作为枚举）、stores 和 store providers（store provider 旨在实例化两个商店：rxstore 和 combinestore 。（我知道这不是最好的方法，但我想了解为什么这个错误发生）。
我还有一个所谓的ReduxArchiver和一个ReduxArchiverElement。这个 (ReduxArchiver) 就像一个监听器或一个用于处理和保存 redux 存储更改的委托。 （我也知道这不是最好的解决方案）。当商店有新状态时，ReduxArchiver 处理更改，根据需要修改数据并决定是否将状态保存在磁盘上。 Archiver 还旨在在实例化商店时从磁盘加载应用程序状态。
错误是 Thread 1: EXC_BAD_ACCESS (code=1, address=0x10) 并且在我实例化 ReduxArchiver 类型的对象时出现。这是因为 ReduxArchiverElement<T: Codable> 数组的实例化（请参阅下面或此处的代码：https://github.com/mariusjcb/CrossReduxSOA）
有时会出现在控制台中：
libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not supported
on this platform.
我不知道这是我的错还是只是一个 swift 错误，因为项目中关联的 types/generics 太多。
我将 combine 和 swiftui 都链接为弱框架，因此缺少 SwiftUI/Combine.
没有问题
我的框架和库也嵌入到目标设置中 Embed & Sign。
实际错误：
Thread 1: EXC_BAD_ACCESS (code=1, address=0x10)
当我在做 po $arg1:
// On #0 0x0000000108f6a93f in swift_getWitnessTable ():
(lldb) po $arg1
<nil>
// On #16 0x0000000108f6b308 in swift_getAssociatedTypeWitness ():
(lldb) po $arg1
error: Couldn't materialize: couldn't read the value of register rdi
error: errored out in DoExecute, couldn't PrepareToExecuteJITExpression
当我检查 $rdi:
//Xcode: 11.2
(lldb) register read
General Purpose Registers:
rbx = 0x000000010ff7bdb8 libswiftCore.dylib`InitialAllocationPool + 4304
rbp = 0x00007ffee39a3990
rsp = 0x00007ffee39a3960
r12 = 0x000000010cc69448 Models`protocol requirements base descriptor for Redux.Reducer
r13 = 0x00000000000000ff
r14 = 0x000000010cc69478 Models`associated type descriptor for StateType
r15 = 0x000000010d1ba718 type metadata for Reducers.ExampleReducer
rip = 0x000000010fea2308 libswiftCore.dylib`swift_getAssociatedTypeWitness + 152
13 registers were unavailable.
//Xcode 11.1
(lldb) register read --all
General Purpose Registers:
rax = 0x0000000000000000
rbx = 0x0000000105d1db74 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 16
rcx = 0x0000000000000000
rdx = 0x0000000000030000
rdi = 0x0000000000000000
rsi = 0x0000000105d1db78 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 20
rbp = 0x00007ffeea8fa960
rsp = 0x00007ffeea8fa8d0
r8 = 0x0000000000000000
r9 = 0x0000000105d1db50 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Encodable in Models + 20
r10 = 0x0000000108fc10a4 libswiftCore.dylib`method descriptor for Swift.Encodable.encode(to: Swift.Encoder) throws -> ()
r11 = 0x0000000000000001
r12 = 0x0000000105d9c3b0 Models`__unnamed_24
r13 = 0x0000000000000000
r14 = 0x0000000105d1db74 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 16
r15 = 0x0000000105d1db64 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models
rip = 0x0000000108f6a93f libswiftCore.dylib`swift_getWitnessTable + 447
rflags = 0x0000000000000247
cs = 0x000000000000002b
fs = 0x0000000000000000
对象的实例化：
// In AppDelegate (as property):
// ...
let state = ExampleStoreBuilder.build()
// The Build Method from ExampleStoreBuilder
let archiveListeners = [GenericReduxArchiverLogger("example_archiver")]
var listeners: [ReduceStoreOutputDelegate] = [GenericReduxStoreLogger("example_logger")]
ERROR>> let defaultStoreArchiver = ExampleArchiver<ExampleRxStore>(outputDelegates: archiveListeners) <<<< Error: EXC_BAD_ACCESS
listeners.append(defaultStoreArchiver)
listeners.append(contentsOf: archiveListeners)
if #available(iOS 13.0, *) {
listeners.append(ExampleArchiver<ExampleCombineStore>(outputDelegates: archiveListeners))
}
let reducer = ExampleReduceBuilder.build()
let initialState = defaultStoreArchiver.statesHistory.last?.state ?? .emptyState
return ReduxState<ExampleStoreProvider<ExampleReducer>>(initialState,
reducedBy: reducer,
outputDelegates: listeners)
来自 let defaultStoreArchiver 的 EXC_BAD_ACCESS 位于 ExampleArchiver 线上：
public var statesHistory = [ReduxArchiveElement<StoreType.ReducerType.StateType>]()
ReduxArchiverElement 定义为：
public struct ReduxArchiveElement<T: Codable>: Codable {
public let date: Date
public let state: T
public init(date: Date, state: T) {
self.date = date
self.state = state
}
}
最后 StoreType 和 Reducer 定义为：
// ReduceStoreInitializable protocol
public protocol ReduceStoreInitializable {
associatedtype ReducerType: Reducer
...
// Store:
public protocol ReduceStore: class, ReduceStoreInitializable {
var reducer: ReducerType! { get set }
...
// Reducer:
public protocol Reducer: class {
associatedtype ActionType
associatedtype ItemType: Codable
associatedtype StateType: Codable
associatedtype ErrorType: Error
关于堆栈的实际错误：
Thread 1 Queue : com.apple.main-thread (serial)
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x10)
frame #0: 0x00000001063746e4 libswiftCore.dylib`swift_getWitnessTable + 392
frame #1: 0x0000000105802e38 Models`lazy protocol witness table accessor for type ExampleModel and conformance ExampleModel at <compiler-generated>:0
frame #2: 0x0000000105802cf4 Models`instantiation function for generic protocol witness table for ExampleModel at <compiler-generated>:0
frame #3: 0x0000000106374c08 libswiftCore.dylib`swift_getWitnessTable + 1708
frame #4: 0x0000000106385ee8 libswiftCore.dylib`swift::TargetProtocolConformanceDescriptor<swift::InProcess>::getWitnessTable(swift::TargetMetadata<swift::InProcess> const*) const + 496
frame #5: 0x0000000105112fd8 ExampleApp-SwiftUI`swift::swift50override_conformsToProtocol(swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*, swift::TargetWitnessTable<swift::InProcess> const* (*)(swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*)) + 60
frame #6: 0x00000001063607fc libswiftCore.dylib`swift::_conformsToProtocol(swift::OpaqueValue const*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptorRef<swift::InProcess>, swift::TargetWitnessTable<swift::InProcess> const**) + 44
frame #7: 0x00000001063863b0 libswiftCore.dylib`swift::_checkGenericRequirements(llvm::ArrayRef<swift::TargetGenericRequirementDescriptor<swift::InProcess> >, std::__1::vector<void const*, std::__1::allocator<void const*> >&, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 1160
frame #8: 0x0000000106383410 libswiftCore.dylib`(anonymous namespace)::DecodedMetadataBuilder::createBoundGenericType(swift::TargetContextDescriptor<swift::InProcess> const*, llvm::ArrayRef<swift::TargetMetadata<swift::InProcess> const*>, swift::TargetMetadata<swift::InProcess> const*) const + 576
frame #9: 0x0000000106382ac4 libswiftCore.dylib`swift::Demangle::TypeDecoder<(anonymous namespace)::DecodedMetadataBuilder>::decodeMangledType(swift::Demangle::Node* const&) + 2832
frame #10: 0x0000000106382100 libswiftCore.dylib`swift::Demangle::TypeDecoder<(anonymous namespace)::DecodedMetadataBuilder>::decodeMangledType(swift::Demangle::Node* const&) + 332
frame #11: 0x00000001063819e8 libswiftCore.dylib`swift_getTypeByMangledNodeImpl(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 460
frame #12: 0x00000001063817a8 libswiftCore.dylib`swift::swift_getTypeByMangledNode(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 520
frame #13: 0x0000000106381d18 libswiftCore.dylib`swift_getTypeByMangledNameImpl(swift::MetadataRequest, llvm::StringRef, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 648
frame #14: 0x0000000106380110 libswiftCore.dylib`swift::swift_getTypeByMangledName(swift::MetadataRequest, llvm::StringRef, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 520
frame #15: 0x0000000106376a6c libswiftCore.dylib`swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*) + 492
frame #16: 0x0000000106375018 libswiftCore.dylib`swift_getAssociatedTypeWitness + 176
frame #17: 0x00000001056df53c Stores`ExampleArchiver.init(storeLocation=nil, outputDelegates=1 value, self=0x00000001c0463840) at ExampleArchiver.swift:18:85
frame #18: 0x00000001056df38c Stores`ExampleArchiver.__allocating_init(storeLocation:outputDelegates:) at ExampleArchiver.swift:0
frame #19: 0x00000001056ebc48 Stores`static ExampleStoreBuilder.build(self=Stores.ExampleStoreBuilder) at ExampleStoreBuilder.swift:23:64
frame #20: 0x0000000105000d20 ExampleApp-SwiftUI`AppDelegate.init() at AppDelegate.swift:17:36
frame #21: 0x0000000105000e28 ExampleApp-SwiftUI`@objc AppDelegate.init() at <compiler-generated>:0
frame #22: 0x000000018e4a8a00 UIKit`_UIApplicationMainPreparations + 1688
frame #23: 0x000000018e39d724 UIKit`UIApplicationMain + 184
frame #24: 0x0000000105001404 ExampleApp-SwiftUI`main at AppDelegate.swift:14:7
* frame #25: 0x0000000183e11fc0 libdyld.dylib`start + 4
for #16 0x0000000106375018 in swift_getAssociatedTypeWitness () 实际程序集如下所示：
libswiftCore.dylib`swift_getAssociatedTypeWitness:
0x106374f68 <+0>: stp x24, x23, [sp, #-0x40]!
0x106374f6c <+4>: stp x22, x21, [sp, #0x10]
0x106374f70 <+8>: stp x20, x19, [sp, #0x20]
0x106374f74 <+12>: stp x29, x30, [sp, #0x30]
0x106374f78 <+16>: add x29, sp, #0x30 ; =0x30
0x106374f7c <+20>: mov x23, x0
0x106374f80 <+24>: sub x8, x4, x3
0x106374f84 <+28>: lsr x8, x8, #3
0x106374f88 <+32>: ldr x0, [x1, w8, uxtw #3]
0x106374f8c <+36>: tbnz w0, #0x0, 0x106374fa8 ; <+64>
0x106374f90 <+40>: mov x1, #0x0
0x106374f94 <+44>: ldp x29, x30, [sp, #0x30]
0x106374f98 <+48>: ldp x20, x19, [sp, #0x20]
0x106374f9c <+52>: ldp x22, x21, [sp, #0x10]
0x106374fa0 <+56>: ldp x24, x23, [sp], #0x40
0x106374fa4 <+60>: ret
0x106374fa8 <+64>: mov x19, x4
0x106374fac <+68>: mov x20, x3
0x106374fb0 <+72>: mov x21, x2
0x106374fb4 <+76>: mov x22, x1
0x106374fb8 <+80>: adr x0, #0xcd130 ; swift_getAssociatedTypeWitnessSlow::Predicate
0x106374fbc <+84>: nop
0x106374fc0 <+88>: adr x1, #0x3690 ; swift_getAssociatedTypeWitnessSlow::$_8::__invoke(void*)
0x106374fc4 <+92>: nop
0x106374fc8 <+96>: mov x2, #0x0
0x106374fcc <+100>: bl 0x106385ad4 ; swift_once
0x106374fd0 <+104>: nop
0x106374fd4 <+108>: ldr x8, #0xcd10c ; swift_getAssociatedTypeWitnessSlow::Override
0x106374fd8 <+112>: cbz x8, 0x106375000 ; <+152>
0x106374fdc <+116>: adr x5, #0x18a4 ; swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*)
0x106374fe0 <+120>: nop
0x106374fe4 <+124>: mov x0, x23
0x106374fe8 <+128>: mov x1, x22
0x106374fec <+132>: mov x2, x21
0x106374ff0 <+136>: mov x3, x20
0x106374ff4 <+140>: mov x4, x19
0x106374ff8 <+144>: blr x8
0x106374ffc <+148>: b 0x106374f94 ; <+44>
0x106375000 <+152>: mov x0, x23
0x106375004 <+156>: mov x1, x22
0x106375008 <+160>: mov x2, x21
0x10637500c <+164>: mov x3, x20
0x106375010 <+168>: mov x4, x19
0x106375014 <+172>: bl 0x106376880 ; swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*)
-> 0x106375018 <+176>: b 0x106374f94 ; <+44> <<< Thread 1: EXC_BAD_ACCESS (code=1, address=0x10)
同样对于 swift_getWitnessTable 中的 #0 0x00000001063746e4 () asm 看起来像：
0x106374660 <+260>: adr x26, #0xb57a0 ; AllocationPool
0x106374664 <+264>: nop
0x106374668 <+268>: str x21, [sp, #0x30]
0x10637466c <+272>: ldar x24, [x28]
0x106374670 <+276>: cbnz x24, 0x1063747c8 ; <+620>
0x106374674 <+280>: b 0x106374688 ; <+300>
0x106374678 <+284>: add x8, x24, #0x8 ; =0x8
0x10637467c <+288>: csel x28, x24, x8, lo
0x106374680 <+292>: ldar x24, [x28]
0x106374684 <+296>: cbnz x24, 0x1063747c8 ; <+620>
0x106374688 <+300>: cbnz x23, 0x1063747b0 ; <+596>
0x10637468c <+304>: ldrsw x9, [x20]
0x106374690 <+308>: cbz w9, 0x1063746a8 ; <+332>
0x106374694 <+312>: and x8, x9, #0xfffffffffffffffe
0x106374698 <+316>: add x8, x8, x20
0x10637469c <+320>: tbz w9, #0x0, 0x1063746ac ; <+336>
0x1063746a0 <+324>: ldr x8, [x8]
0x1063746a4 <+328>: b 0x1063746ac ; <+336>
0x1063746a8 <+332>: mov x8, #0x0
0x1063746ac <+336>: ldr w12, [x20, #0xc]
0x1063746b0 <+340>: ubfx x9, x12, #6, #1
0x1063746b4 <+344>: add x10, x21, x9, lsl #2
0x1063746b8 <+348>: ubfx x11, x12, #8, #8
0x1063746bc <+352>: madd x9, x11, x14, x10
0x1063746c0 <+356>: ubfx x13, x12, #16, #1
0x1063746c4 <+360>: add x9, x9, x13, lsl #2
0x1063746c8 <+364>: tbnz w12, #0x10, 0x1063746d4 ; <+376>
0x1063746cc <+368>: mov x10, #0x0
0x1063746d0 <+372>: b 0x1063746dc ; <+384>
0x1063746d4 <+376>: mul x11, x11, x14
0x1063746d8 <+380>: ldr w10, [x10, x11]
0x1063746dc <+384>: add x9, x9, x10, lsl #3
0x1063746e0 <+388>: ldrh w9, [x9, #0x2]
-> 0x1063746e4 <+392>: ldr w8, [x8, #0x10] <<< ERROR; I don't understand this line... :(
我不完全理解问题的根本原因，但我能够通过删除对我的一个协议的 Identifiable 一致性来解决这个问题。我的部署目标是 iOS 10，所以事后看来，我不确定为什么我的框架能够在没有 @available 检查的情况下编译。
在构建设置中，针对您的项目寻找
DEAD_CODE_STRIPPING = No
应该可以解决问题。
我正在用 Combine 和 SwiftUI 编写一个项目，向后兼容 iOS 12/11 与 RxSwift、RxCocoa 和 UIKit。我的项目基于很多协议、关联类型和泛型。当我在 运行 iOS 13 上的项目工作正常但在 iOS 12 上应用程序突然崩溃。
我正在尝试对 Redux 架构进行一些更改。我有 reducer、actions（作为枚举）、stores 和 store providers（store provider 旨在实例化两个商店：rxstore 和 combinestore 。（我知道这不是最好的方法，但我想了解为什么这个错误发生）。
我还有一个所谓的ReduxArchiver和一个ReduxArchiverElement。这个 (ReduxArchiver) 就像一个监听器或一个用于处理和保存 redux 存储更改的委托。 （我也知道这不是最好的解决方案）。当商店有新状态时，ReduxArchiver 处理更改，根据需要修改数据并决定是否将状态保存在磁盘上。 Archiver 还旨在在实例化商店时从磁盘加载应用程序状态。
错误是 Thread 1: EXC_BAD_ACCESS (code=1, address=0x10) 并且在我实例化 ReduxArchiver 类型的对象时出现。这是因为 ReduxArchiverElement<T: Codable> 数组的实例化（请参阅下面或此处的代码：https://github.com/mariusjcb/CrossReduxSOA）
有时会出现在控制台中：
libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not supported
on this platform.
我不知道这是我的错还是只是一个 swift 错误，因为项目中关联的 types/generics 太多。
我将 combine 和 swiftui 都链接为弱框架，因此缺少 SwiftUI/Combine.
没有问题我的框架和库也嵌入到目标设置中 Embed & Sign。
实际错误：
Thread 1: EXC_BAD_ACCESS (code=1, address=0x10)
当我在做 po $arg1:
// On #0 0x0000000108f6a93f in swift_getWitnessTable ():
(lldb) po $arg1
<nil>
// On #16 0x0000000108f6b308 in swift_getAssociatedTypeWitness ():
(lldb) po $arg1
error: Couldn't materialize: couldn't read the value of register rdi
error: errored out in DoExecute, couldn't PrepareToExecuteJITExpression
当我检查 $rdi:
//Xcode: 11.2
(lldb) register read
General Purpose Registers:
rbx = 0x000000010ff7bdb8 libswiftCore.dylib`InitialAllocationPool + 4304
rbp = 0x00007ffee39a3990
rsp = 0x00007ffee39a3960
r12 = 0x000000010cc69448 Models`protocol requirements base descriptor for Redux.Reducer
r13 = 0x00000000000000ff
r14 = 0x000000010cc69478 Models`associated type descriptor for StateType
r15 = 0x000000010d1ba718 type metadata for Reducers.ExampleReducer
rip = 0x000000010fea2308 libswiftCore.dylib`swift_getAssociatedTypeWitness + 152
13 registers were unavailable.
//Xcode 11.1
(lldb) register read --all
General Purpose Registers:
rax = 0x0000000000000000
rbx = 0x0000000105d1db74 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 16
rcx = 0x0000000000000000
rdx = 0x0000000000030000
rdi = 0x0000000000000000
rsi = 0x0000000105d1db78 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 20
rbp = 0x00007ffeea8fa960
rsp = 0x00007ffeea8fa8d0
r8 = 0x0000000000000000
r9 = 0x0000000105d1db50 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Encodable in Models + 20
r10 = 0x0000000108fc10a4 libswiftCore.dylib`method descriptor for Swift.Encodable.encode(to: Swift.Encoder) throws -> ()
r11 = 0x0000000000000001
r12 = 0x0000000105d9c3b0 Models`__unnamed_24
r13 = 0x0000000000000000
r14 = 0x0000000105d1db74 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models + 16
r15 = 0x0000000105d1db64 Models`protocol conformance descriptor for Models.ExampleModel : Swift.Identifiable in Models
rip = 0x0000000108f6a93f libswiftCore.dylib`swift_getWitnessTable + 447
rflags = 0x0000000000000247
cs = 0x000000000000002b
fs = 0x0000000000000000
对象的实例化：
// In AppDelegate (as property):
// ...
let state = ExampleStoreBuilder.build()
// The Build Method from ExampleStoreBuilder
let archiveListeners = [GenericReduxArchiverLogger("example_archiver")]
var listeners: [ReduceStoreOutputDelegate] = [GenericReduxStoreLogger("example_logger")]
ERROR>> let defaultStoreArchiver = ExampleArchiver<ExampleRxStore>(outputDelegates: archiveListeners) <<<< Error: EXC_BAD_ACCESS
listeners.append(defaultStoreArchiver)
listeners.append(contentsOf: archiveListeners)
if #available(iOS 13.0, *) {
listeners.append(ExampleArchiver<ExampleCombineStore>(outputDelegates: archiveListeners))
}
let reducer = ExampleReduceBuilder.build()
let initialState = defaultStoreArchiver.statesHistory.last?.state ?? .emptyState
return ReduxState<ExampleStoreProvider<ExampleReducer>>(initialState,
reducedBy: reducer,
outputDelegates: listeners)
来自 let defaultStoreArchiver 的 EXC_BAD_ACCESS 位于 ExampleArchiver 线上：
public var statesHistory = [ReduxArchiveElement<StoreType.ReducerType.StateType>]()
ReduxArchiverElement 定义为：
public struct ReduxArchiveElement<T: Codable>: Codable {
public let date: Date
public let state: T
public init(date: Date, state: T) {
self.date = date
self.state = state
}
}
最后 StoreType 和 Reducer 定义为：
// ReduceStoreInitializable protocol
public protocol ReduceStoreInitializable {
associatedtype ReducerType: Reducer
...
// Store:
public protocol ReduceStore: class, ReduceStoreInitializable {
var reducer: ReducerType! { get set }
...
// Reducer:
public protocol Reducer: class {
associatedtype ActionType
associatedtype ItemType: Codable
associatedtype StateType: Codable
associatedtype ErrorType: Error
关于堆栈的实际错误：
Thread 1 Queue : com.apple.main-thread (serial)
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x10)
frame #0: 0x00000001063746e4 libswiftCore.dylib`swift_getWitnessTable + 392
frame #1: 0x0000000105802e38 Models`lazy protocol witness table accessor for type ExampleModel and conformance ExampleModel at <compiler-generated>:0
frame #2: 0x0000000105802cf4 Models`instantiation function for generic protocol witness table for ExampleModel at <compiler-generated>:0
frame #3: 0x0000000106374c08 libswiftCore.dylib`swift_getWitnessTable + 1708
frame #4: 0x0000000106385ee8 libswiftCore.dylib`swift::TargetProtocolConformanceDescriptor<swift::InProcess>::getWitnessTable(swift::TargetMetadata<swift::InProcess> const*) const + 496
frame #5: 0x0000000105112fd8 ExampleApp-SwiftUI`swift::swift50override_conformsToProtocol(swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*, swift::TargetWitnessTable<swift::InProcess> const* (*)(swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*)) + 60
frame #6: 0x00000001063607fc libswiftCore.dylib`swift::_conformsToProtocol(swift::OpaqueValue const*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptorRef<swift::InProcess>, swift::TargetWitnessTable<swift::InProcess> const**) + 44
frame #7: 0x00000001063863b0 libswiftCore.dylib`swift::_checkGenericRequirements(llvm::ArrayRef<swift::TargetGenericRequirementDescriptor<swift::InProcess> >, std::__1::vector<void const*, std::__1::allocator<void const*> >&, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 1160
frame #8: 0x0000000106383410 libswiftCore.dylib`(anonymous namespace)::DecodedMetadataBuilder::createBoundGenericType(swift::TargetContextDescriptor<swift::InProcess> const*, llvm::ArrayRef<swift::TargetMetadata<swift::InProcess> const*>, swift::TargetMetadata<swift::InProcess> const*) const + 576
frame #9: 0x0000000106382ac4 libswiftCore.dylib`swift::Demangle::TypeDecoder<(anonymous namespace)::DecodedMetadataBuilder>::decodeMangledType(swift::Demangle::Node* const&) + 2832
frame #10: 0x0000000106382100 libswiftCore.dylib`swift::Demangle::TypeDecoder<(anonymous namespace)::DecodedMetadataBuilder>::decodeMangledType(swift::Demangle::Node* const&) + 332
frame #11: 0x00000001063819e8 libswiftCore.dylib`swift_getTypeByMangledNodeImpl(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 460
frame #12: 0x00000001063817a8 libswiftCore.dylib`swift::swift_getTypeByMangledNode(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 520
frame #13: 0x0000000106381d18 libswiftCore.dylib`swift_getTypeByMangledNameImpl(swift::MetadataRequest, llvm::StringRef, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 648
frame #14: 0x0000000106380110 libswiftCore.dylib`swift::swift_getTypeByMangledName(swift::MetadataRequest, llvm::StringRef, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 520
frame #15: 0x0000000106376a6c libswiftCore.dylib`swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*) + 492
frame #16: 0x0000000106375018 libswiftCore.dylib`swift_getAssociatedTypeWitness + 176
frame #17: 0x00000001056df53c Stores`ExampleArchiver.init(storeLocation=nil, outputDelegates=1 value, self=0x00000001c0463840) at ExampleArchiver.swift:18:85
frame #18: 0x00000001056df38c Stores`ExampleArchiver.__allocating_init(storeLocation:outputDelegates:) at ExampleArchiver.swift:0
frame #19: 0x00000001056ebc48 Stores`static ExampleStoreBuilder.build(self=Stores.ExampleStoreBuilder) at ExampleStoreBuilder.swift:23:64
frame #20: 0x0000000105000d20 ExampleApp-SwiftUI`AppDelegate.init() at AppDelegate.swift:17:36
frame #21: 0x0000000105000e28 ExampleApp-SwiftUI`@objc AppDelegate.init() at <compiler-generated>:0
frame #22: 0x000000018e4a8a00 UIKit`_UIApplicationMainPreparations + 1688
frame #23: 0x000000018e39d724 UIKit`UIApplicationMain + 184
frame #24: 0x0000000105001404 ExampleApp-SwiftUI`main at AppDelegate.swift:14:7
* frame #25: 0x0000000183e11fc0 libdyld.dylib`start + 4
for #16 0x0000000106375018 in swift_getAssociatedTypeWitness () 实际程序集如下所示：
libswiftCore.dylib`swift_getAssociatedTypeWitness:
0x106374f68 <+0>: stp x24, x23, [sp, #-0x40]!
0x106374f6c <+4>: stp x22, x21, [sp, #0x10]
0x106374f70 <+8>: stp x20, x19, [sp, #0x20]
0x106374f74 <+12>: stp x29, x30, [sp, #0x30]
0x106374f78 <+16>: add x29, sp, #0x30 ; =0x30
0x106374f7c <+20>: mov x23, x0
0x106374f80 <+24>: sub x8, x4, x3
0x106374f84 <+28>: lsr x8, x8, #3
0x106374f88 <+32>: ldr x0, [x1, w8, uxtw #3]
0x106374f8c <+36>: tbnz w0, #0x0, 0x106374fa8 ; <+64>
0x106374f90 <+40>: mov x1, #0x0
0x106374f94 <+44>: ldp x29, x30, [sp, #0x30]
0x106374f98 <+48>: ldp x20, x19, [sp, #0x20]
0x106374f9c <+52>: ldp x22, x21, [sp, #0x10]
0x106374fa0 <+56>: ldp x24, x23, [sp], #0x40
0x106374fa4 <+60>: ret
0x106374fa8 <+64>: mov x19, x4
0x106374fac <+68>: mov x20, x3
0x106374fb0 <+72>: mov x21, x2
0x106374fb4 <+76>: mov x22, x1
0x106374fb8 <+80>: adr x0, #0xcd130 ; swift_getAssociatedTypeWitnessSlow::Predicate
0x106374fbc <+84>: nop
0x106374fc0 <+88>: adr x1, #0x3690 ; swift_getAssociatedTypeWitnessSlow::$_8::__invoke(void*)
0x106374fc4 <+92>: nop
0x106374fc8 <+96>: mov x2, #0x0
0x106374fcc <+100>: bl 0x106385ad4 ; swift_once
0x106374fd0 <+104>: nop
0x106374fd4 <+108>: ldr x8, #0xcd10c ; swift_getAssociatedTypeWitnessSlow::Override
0x106374fd8 <+112>: cbz x8, 0x106375000 ; <+152>
0x106374fdc <+116>: adr x5, #0x18a4 ; swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*)
0x106374fe0 <+120>: nop
0x106374fe4 <+124>: mov x0, x23
0x106374fe8 <+128>: mov x1, x22
0x106374fec <+132>: mov x2, x21
0x106374ff0 <+136>: mov x3, x20
0x106374ff4 <+140>: mov x4, x19
0x106374ff8 <+144>: blr x8
0x106374ffc <+148>: b 0x106374f94 ; <+44>
0x106375000 <+152>: mov x0, x23
0x106375004 <+156>: mov x1, x22
0x106375008 <+160>: mov x2, x21
0x10637500c <+164>: mov x3, x20
0x106375010 <+168>: mov x4, x19
0x106375014 <+172>: bl 0x106376880 ; swift_getAssociatedTypeWitnessSlowImpl(swift::MetadataRequest, swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*)
-> 0x106375018 <+176>: b 0x106374f94 ; <+44> <<< Thread 1: EXC_BAD_ACCESS (code=1, address=0x10)
同样对于 swift_getWitnessTable 中的 #0 0x00000001063746e4 () asm 看起来像：
0x106374660 <+260>: adr x26, #0xb57a0 ; AllocationPool
0x106374664 <+264>: nop
0x106374668 <+268>: str x21, [sp, #0x30]
0x10637466c <+272>: ldar x24, [x28]
0x106374670 <+276>: cbnz x24, 0x1063747c8 ; <+620>
0x106374674 <+280>: b 0x106374688 ; <+300>
0x106374678 <+284>: add x8, x24, #0x8 ; =0x8
0x10637467c <+288>: csel x28, x24, x8, lo
0x106374680 <+292>: ldar x24, [x28]
0x106374684 <+296>: cbnz x24, 0x1063747c8 ; <+620>
0x106374688 <+300>: cbnz x23, 0x1063747b0 ; <+596>
0x10637468c <+304>: ldrsw x9, [x20]
0x106374690 <+308>: cbz w9, 0x1063746a8 ; <+332>
0x106374694 <+312>: and x8, x9, #0xfffffffffffffffe
0x106374698 <+316>: add x8, x8, x20
0x10637469c <+320>: tbz w9, #0x0, 0x1063746ac ; <+336>
0x1063746a0 <+324>: ldr x8, [x8]
0x1063746a4 <+328>: b 0x1063746ac ; <+336>
0x1063746a8 <+332>: mov x8, #0x0
0x1063746ac <+336>: ldr w12, [x20, #0xc]
0x1063746b0 <+340>: ubfx x9, x12, #6, #1
0x1063746b4 <+344>: add x10, x21, x9, lsl #2
0x1063746b8 <+348>: ubfx x11, x12, #8, #8
0x1063746bc <+352>: madd x9, x11, x14, x10
0x1063746c0 <+356>: ubfx x13, x12, #16, #1
0x1063746c4 <+360>: add x9, x9, x13, lsl #2
0x1063746c8 <+364>: tbnz w12, #0x10, 0x1063746d4 ; <+376>
0x1063746cc <+368>: mov x10, #0x0
0x1063746d0 <+372>: b 0x1063746dc ; <+384>
0x1063746d4 <+376>: mul x11, x11, x14
0x1063746d8 <+380>: ldr w10, [x10, x11]
0x1063746dc <+384>: add x9, x9, x10, lsl #3
0x1063746e0 <+388>: ldrh w9, [x9, #0x2]
-> 0x1063746e4 <+392>: ldr w8, [x8, #0x10] <<< ERROR; I don't understand this line... :(
我不完全理解问题的根本原因，但我能够通过删除对我的一个协议的 Identifiable 一致性来解决这个问题。我的部署目标是 iOS 10，所以事后看来，我不确定为什么我的框架能够在没有 @available 检查的情况下编译。
在构建设置中，针对您的项目寻找
DEAD_CODE_STRIPPING = No
应该可以解决问题。