我正在用Combine和SwiftUI编写一个项目，该项目具有RxSwift，RxCocoa和UIKit的向后兼容性，适用于iOS 12/11。我的项目基于许多协议，关联的类型和泛型。当我在iOS 13上运行该项目时，它可以正常运行，但在iOS 12上，该应用突然崩溃。
我正在尝试对Redux架构进行一些更改。我有减速器，操作（作为枚举），商店和商店提供程序（商店提供程序旨在实例化两个商店：rxstore和Combinestore。（我知道这样做不是最好的方法，但我想了解为什么会出现此错误发生）。
我也有一个所谓的ReduxArchiver和一个ReduxArchiverElement。这个（ReduxArchiver）就像是用来处理和保存redux存储更改的侦听器或委托。 （我也知道这不是最好的解决方案）。当存储具有新状态时，ReduxArchiver处理更改，根据需要修改数据并决定是否在磁盘上保存状态。归档程序还用于在实例化存储时从磁盘加载应用程序状态。
错误为Thread 1: EXC_BAD_accESS (code=1,address=0x10)，当我实例化ReduxArchiver类型的对象时出现。发生这种情况是由于实例化了ReduxArchiverElement<T: Codable>数组（请参见下面的代码或此处的代码：https://github.com/mariusjcb/CrossReduxSOA）
有时它会出现在控制台中：
libMobileGestalt MobileGestalt.c:890: MGIsDeviceoneOfType is not supported
on this platform.
我不知道这是我的错还是一个快速的错误，因为项目中的关联类型/泛型过多。
我同时将Combine和swiftui链接为弱框架，因此缺少SwiftUI / Combine不会有问题。
我的框架和库也以Embed & Sign的形式嵌入到目标设置中。
实际错误：
Thread 1: EXC_BAD_accESS (code=1,address=0x10)
我在做po $ arg1时：
// 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时：
//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)
let defaultStoreArchiver中的EXC_BAD_accESS位于以下行的ExampleArchiver中：
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*,unsigned int)>) + 460
frame #12: 0x00000001063817a8 libswiftCore.dylib`swift::swift_getTypeByMangledNode(swift::MetadataRequest,unsigned int)>) + 520
frame #13: 0x0000000106381d18 libswiftCore.dylib`swift_getTypeByMangledNameImpl(swift::MetadataRequest,llvm::StringRef,unsigned int)>) + 648
frame #14: 0x0000000106380110 libswiftCore.dylib`swift::swift_getTypeByMangledName(swift::MetadataRequest,unsigned int)>) + 520
frame #15: 0x0000000106376a6c libswiftCore.dylib`swift_getassociatedTypeWitnessSlowImpl(swift::MetadataRequest,swift::TargetWitnessTable<swift::InProcess>*,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
对于swift_getassociatedTypeWitness（）中的＃16 0x0000000106375018，实际的程序集如下：
libswiftCore.dylib`swift_getassociatedTypeWitness:
0x106374f68 <+0>: stp x24,x23,[sp,#-0x40]!
0x106374f6c <+4>: stp x22,x21,#0x10]
0x106374f70 <+8>: stp x20,x19,#0x20]
0x106374f74 <+12>: stp x29,x30,#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,#0x30]
0x106374f98 <+48>: ldp x20,#0x20]
0x106374f9c <+52>: ldp x22,#0x10]
0x106374fa0 <+56>: ldp x24,[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::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::TargetProtocolRequirement<swift::InProcess> const*)
-> 0x106375018 <+176>: b 0x106374f94 ; <+44> <<< Thread 1: EXC_BAD_accESS (code=1,address=0x10)
在swift_getWitnessTable（）中也为＃0 0x00000001063746e4，asm如下：
0x106374660 <+260>: adr x26,#0xb57a0 ; AllocationPool
0x106374664 <+264>: nop
0x106374668 <+268>: str x21,#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,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,x20
0x10637469c <+320>: tbz w9,0x1063746ac ; <+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,lsl #2
0x1063746b8 <+348>: ubfx x11,#8,#8
0x1063746bc <+352>: madd x9,x11,x14,x10
0x1063746c0 <+356>: ubfx x13,#16,#1
0x1063746c4 <+360>: add 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,x14
0x1063746d8 <+380>: ldr w10,[x10,x11]
0x1063746dc <+384>: add x9,x10,lsl #3
0x1063746e0 <+388>: ldrh w9,[x9,#0x2]
-> 0x1063746e4 <+392>: ldr w8,[x8,#0x10] <<< ERROR; I don't understand this line... :(