[SR-7412] Swift crashes when a class conforms to a protocol with associated type as AnyObject #49955
Description
| Previous ID | SR-7412 |
| Radar | None |
| Original Reporter | iulian.corcoja (JIRA User) |
| Type | Bug |
| Status | Resolved |
| Resolution | Duplicate |
Attachment: Download
Environment
System Version: macOS 10.13.4 (17E199)
Model Name: MacBook Pro
Model Identifier: MacBookPro11,5
Xcode 9.2:
Version: 9.2
Obtained from: Apple
Xcode:
Version: 9.3
Obtained from: Mac App Store
Additional Detail from JIRA
| Votes | 0 |
| Component/s | Compiler |
| Labels | Bug |
| Assignee | None |
| Priority | Medium |
md5: 88a96e0fa13427206c7a2339f609d60d
duplicates:
Issue Description:
Summary
Within Xcode (or Playground), when creating a new class which conforms to a generic protocol with associatedtype with a type constraint, defining the typealias with a protocol composition causes the compiler to crash.
I couldn't reproduce this in REPL (see attached screenshot).
How to reproduce?
Tested with Xcode 9.2, i. e. toolchain for Swift 4.0.3 Release
protocol Observable {
associatedtype Observer: AnyObject
func addObserver(_ observer: Observer)
}
// MARK: - Default Implementation
extension Observable {
func addObserver(_ observer: Observer) {
print("Observer added!")
}
}
// MARK: - Some Delegate
protocol SomeDelegate: class {
func someFunc(_ someClass: SomeClass)
}
// MARK: - Some Class
class SomeClass: NSObject, Observable {
typealias Observer = SomeDelegate & AnyObject
}Error
Command failed due to signal: Abort trap: 6
Stack Trace
Assertion failed: (expectedSchema.size() == IGF.IGM.getExplosionSize(applyContextArchetypes(IGF, substTy))), function reemitAsUnsubstituted, file /Users/buildnode/jenkins/workspace/oss-swift-4.0-package-osx/swift/lib/IRGen/GenPoly.cpp, line 66.
0 swift 0x000000010f527f38 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1 swift 0x000000010f526e96 llvm::sys::RunSignalHandlers() + 86
2 swift 0x000000010f5284fe SignalHandler(int) + 366
3 libsystem_platform.dylib 0x00007fff65999f5a _sigtramp + 26
4 libsystem_platform.dylib 000000000000000000 _sigtramp + 2590400704
5 libsystem_c.dylib 0x00007fff657371ae abort + 127
6 libsystem_c.dylib 0x00007fff656ff1ac basename_r + 0
7 swift 0x000000010c5b7962 swift::irgen::reemitAsUnsubstituted(swift::irgen::IRGenFunction&, swift::SILType, swift::SILType, swift::irgen::Explosion&, swift::irgen::Explosion&) + 658
8 swift 0x000000010c62ebd6 emitApplyArgument((anonymous namespace)::IRGenSILFunction&, swift::SILValue, swift::SILType, swift::irgen::Explosion&) + 294
9 swift 0x000000010c62dfa3 (anonymous namespace)::IRGenSILFunction::visitFullApplySite(swift::FullApplySite) + 2035
10 swift 0x000000010c616e92 (anonymous namespace)::IRGenSILFunction::emitSILFunction() + 7330
11 swift 0x000000010c614cfe swift::irgen::IRGenModule::emitSILFunction(swift::SILFunction*) + 1358
12 swift 0x000000010c5306bb swift::irgen::IRGenerator::emitLazyDefinitions() + 987
13 swift 0x000000010c5f25d6 performIRGeneration(swift::IRGenOptions&, swift::ModuleDecl*, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::StringRef, llvm::LLVMContext&, swift::SourceFile*, llvm::GlobalVariable**, unsigned int) + 1350
14 swift 0x000000010c5f2b46 swift::performIRGeneration(swift::IRGenOptions&, swift::SourceFile&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::StringRef, llvm::LLVMContext&, unsigned int, llvm::GlobalVariable**) + 86
15 swift 0x000000010c4b6825 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 12533
16 swift 0x000000010c4b2845 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3493
17 swift 0x000000010c474950 main + 3312
18 libdyld.dylib 0x00007fff6568b015 start + 1
1. While emitting IR SIL function "@_T07TestBug9SomeClassCAA10ObservableA2aDP11addObservery0G0QzFTW".
for 'addObserver(_:)' at /Users/iuliancorcoja/Desktop/TestBug/TestBug/TestBug/main.swift:19:2
The exact same code though, doesn't cause the compiler to crash in the latest Xcode (Xcode 9.3, Swift 4.1 Release). Instead, I get the following error when compiling:
Error
Type 'SomeClass' does not conform to protocol 'Observable'
Possibly intended match 'SomeClass.Observer' (aka 'SomeDelegate & AnyObject') does not conform to 'AnyObject'
It doesn't really make sense since SomeClass.Observer does conform to AnyObject.
Remark
Changing the parameter in the addObserver(_:) method of the Observable protocol from Observer to anything else, e. g. AnyObject, doesn't throw any errors in Swift 4.0.3, but throws the same error as above in Swift 4.1
Error
Type 'SomeClass' does not conform to protocol 'Observable'
Possibly intended match 'SomeClass.Observer' (aka 'SomeDelegate & AnyObject') does not conform to 'AnyObject'
Code
protocol Observable {
associatedtype Observer: AnyObject
func addObserver(_ observer: AnyObject)
}
extension Observable {
func addObserver(_ observer: AnyObject) {
print("Observer added!")
}
}
protocol SomeDelegate: class {
func someFunc(_ someClass: SomeClass)
}
class SomeClass: NSObject, Observable {
typealias Observer = SomeDelegate & AnyObject
}