Compiler crash (regression) relating to typed throws and primary associated types

[lawrence-forooghian]

Description

Some combination of primary associated types and typed throws is causing a compiler crash in Xcode 16.3 which wasn't there in Xcode 16.1.

Reproduction

enum MyError: Error {}

protocol MyProtocolWithPrimaryAssociatedType<T>: AnyObject {
    associatedtype T
    func next() async throws(MyError) -> (any MyProtocolWithPrimaryAssociatedType<T>)
}

final class MyProtocolImpl<T>: MyProtocolWithPrimaryAssociatedType {
    func next() async throws(MyError) -> (any MyProtocolWithPrimaryAssociatedType<T>) {
        fatalError()
    }
}

gives

Stack dump:
0.	Program arguments: /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -interpret repro.swift -Xllvm -aarch64-use-tbi -enable-objc-interop -stack-check -sdk /Applications/Xcode-16.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.4.sdk -new-driver-path /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-driver -empty-abi-descriptor -resource-dir /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -module-name repro -disable-clang-spi -target-sdk-version 15.4 -target-sdk-name macosx15.4 -external-plugin-path /Applications/Xcode-16.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/lib/swift/host/plugins#/Applications/Xcode-16.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -external-plugin-path /Applications/Xcode-16.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/local/lib/swift/host/plugins#/Applications/Xcode-16.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -in-process-plugin-server-path /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Applications/Xcode-16.3.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/local/lib/swift/host/plugins
1.	Apple Swift version 6.1 (swiftlang-6.1.0.110.21 clang-1700.0.13.3)
2.	Compiling with effective version 5.10
3.	While running user code "repro.swift"
4.	While evaluating request IRGenRequest(IR Generation for module repro)
5.	While emitting IR SIL function "@$s5repro14MyProtocolImplCyxGAA0bC25WithPrimaryAssociatedTypeA2aEP4nextAaE_p1TQzAIRS_XPyYaAA0B5ErrorOYKFTW".
 for 'next()' (at repro.swift:9:5)
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010705ac28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x0000000107058a60 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x000000010705b264 SignalHandler(int) + 360
3  libsystem_platform.dylib 0x00000001840df624 _sigtramp + 56
4  swift-frontend           0x00000001012e79d0 (anonymous namespace)::AsyncCallEmission::setFromCallee() + 728
5  swift-frontend           0x00000001012e79d0 (anonymous namespace)::AsyncCallEmission::setFromCallee() + 728
6  swift-frontend           0x00000001012cd3c0 swift::irgen::getCallEmission(swift::irgen::IRGenFunction&, llvm::Value*, swift::irgen::Callee&&) + 888
7  swift-frontend           0x0000000101547888 (anonymous namespace)::IRGenSILFunction::visitFullApplySite(swift::FullApplySite) + 3268
8  swift-frontend           0x00000001015184e4 (anonymous namespace)::IRGenSILFunction::visitSILBasicBlock(swift::SILBasicBlock*) + 2636
9  swift-frontend           0x000000010151638c (anonymous namespace)::IRGenSILFunction::emitSILFunction() + 15860
10 swift-frontend           0x00000001015120e0 swift::irgen::IRGenModule::emitSILFunction(swift::SILFunction*) + 2788
11 swift-frontend           0x0000000101335560 swift::irgen::IRGenerator::emitGlobalTopLevel(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>> const&) + 2044
12 swift-frontend           0x00000001014c39fc swift::IRGenRequest::evaluate(swift::Evaluator&, swift::IRGenDescriptor) const + 4296
13 swift-frontend           0x000000010151133c swift::SimpleRequest<swift::IRGenRequest, swift::GeneratedModule (swift::IRGenDescriptor), (swift::RequestFlags)17>::evaluateRequest(swift::IRGenRequest const&, swift::Evaluator&) + 180
14 swift-frontend           0x00000001014ccf28 swift::IRGenRequest::OutputType swift::Evaluator::getResultUncached<swift::IRGenRequest, swift::IRGenRequest::OutputType swift::evaluateOrFatal<swift::IRGenRequest>(swift::Evaluator&, swift::IRGenRequest)::'lambda'()>(swift::IRGenRequest const&, swift::IRGenRequest::OutputType swift::evaluateOrFatal<swift::IRGenRequest>(swift::Evaluator&, swift::IRGenRequest)::'lambda'()) + 812
15 swift-frontend           0x00000001014c5450 swift::performIRGeneration(swift::ModuleDecl*, swift::IRGenOptions const&, swift::TBDGenOptions const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, llvm::StringRef, swift::PrimarySpecificPaths const&, llvm::ArrayRef<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, llvm::GlobalVariable**) + 1588
16 swift-frontend           0x0000000100f1a13c generateModule(swift::CompilerInstance const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>) + 332
17 swift-frontend           0x0000000100f1adcc swift::EagerSwiftMaterializationUnit::materialize(std::__1::unique_ptr<llvm::orc::MaterializationResponsibility, std::__1::default_delete<llvm::orc::MaterializationResponsibility>>) + 68
18 swift-frontend           0x0000000100f31ba8 llvm::orc::MaterializationTask::run() + 44
19 swift-frontend           0x0000000100f34468 llvm::orc::ExecutionSession::dispatchOutstandingMUs() + 284
20 swift-frontend           0x0000000100f429e8 llvm::orc::InProgressFullLookupState::complete(std::__1::unique_ptr<llvm::orc::InProgressLookupState, std::__1::default_delete<llvm::orc::InProgressLookupState>>) + 5428
21 swift-frontend           0x0000000100f2c8b0 llvm::orc::ExecutionSession::OL_applyQueryPhase1(std::__1::unique_ptr<llvm::orc::InProgressLookupState, std::__1::default_delete<llvm::orc::InProgressLookupState>>, llvm::Error) + 4256
22 swift-frontend           0x0000000100f2b7c4 llvm::orc::ExecutionSession::lookup(llvm::orc::LookupKind, std::__1::vector<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>, std::__1::allocator<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>>> const&, llvm::orc::SymbolLookupSet, llvm::orc::SymbolState, llvm::unique_function<void (llvm::Expected<llvm::DenseMap<llvm::orc::SymbolStringPtr, llvm::orc::ExecutorSymbolDef, llvm::DenseMapInfo<llvm::orc::SymbolStringPtr, void>, llvm::detail::DenseMapPair<llvm::orc::SymbolStringPtr, llvm::orc::ExecutorSymbolDef>>>)>, std::__1::function<void (llvm::DenseMap<llvm::orc::JITDylib*, llvm::DenseSet<llvm::orc::SymbolStringPtr, llvm::DenseMapInfo<llvm::orc::SymbolStringPtr, void>>, llvm::DenseMapInfo<llvm::orc::JITDylib*, void>, llvm::detail::DenseMapPair<llvm::orc::JITDylib*, llvm::DenseSet<llvm::orc::SymbolStringPtr, llvm::DenseMapInfo<llvm::orc::SymbolStringPtr, void>>>> const&)>) + 1168
23 swift-frontend           0x0000000100f34604 llvm::orc::ExecutionSession::lookup(std::__1::vector<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>, std::__1::allocator<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>>> const&, llvm::orc::SymbolLookupSet, llvm::orc::LookupKind, llvm::orc::SymbolState, std::__1::function<void (llvm::DenseMap<llvm::orc::JITDylib*, llvm::DenseSet<llvm::orc::SymbolStringPtr, llvm::DenseMapInfo<llvm::orc::SymbolStringPtr, void>>, llvm::DenseMapInfo<llvm::orc::JITDylib*, void>, llvm::detail::DenseMapPair<llvm::orc::JITDylib*, llvm::DenseSet<llvm::orc::SymbolStringPtr, llvm::DenseMapInfo<llvm::orc::SymbolStringPtr, void>>>> const&)>) + 308
24 swift-frontend           0x0000000100f349d0 llvm::orc::ExecutionSession::lookup(std::__1::vector<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>, std::__1::allocator<std::__1::pair<llvm::orc::JITDylib*, llvm::orc::JITDylibLookupFlags>>> const&, llvm::orc::SymbolStringPtr, llvm::orc::SymbolState) + 272
25 swift-frontend           0x0000000100f177b8 swift::SwiftJIT::runMain(llvm::ArrayRef<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>) + 476
26 swift-frontend           0x0000000100f24c3c swift::RunImmediately(swift::CompilerInstance&, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>> const&, swift::IRGenOptions const&, swift::SILOptions const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>&&) + 1052
27 swift-frontend           0x0000000100eb1840 processCommandLineAndRunImmediately(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>&&, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::FrontendObserver*, int&) + 504
28 swift-frontend           0x0000000100eacffc performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 1980
29 swift-frontend           0x0000000100eac71c swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 2688
30 swift-frontend           0x0000000100eafe44 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 3796
31 swift-frontend           0x0000000100eadfd8 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3716
32 swift-frontend           0x0000000100e320bc swift::mainEntry(int, char const**) + 5428
33 dyld                     0x0000000183d06b4c start + 6000

Expected behavior

It should compile, like it did in Xcode 16.1

Environment

swift-driver version: 1.120.5 Apple Swift version 6.1 (swiftlang-6.1.0.110.21 clang-1700.0.13.3)
Target: arm64-apple-macosx15.0

Additional information

No response