Compiler crash with value and type pack when used in a method vs free function

[PopFlamingo]

Description

This simple example demonstrates a compiler crash when a function is defined as a method instead of a free function.

Reproduction

class Foo {
    init() {}
    func unchanged<each T>(_ value: ()->(repeat each T)) -> (repeat each T) {
        return (repeat (each value()))
    }
}

func unchanged<each T>(_ value: ()->(repeat each T)) -> (repeat each T) {
    return (repeat (each value()))
}
let foo = Foo()



print(foo.unchanged { "xyz" }) // Command SwiftCompile failed with a nonzero exit code + Command SwiftEmitModule failed with a nonzero exit code
// But this compiles fine: print(unchanged { "xyz" })

Stack dump

0  swift-frontend           0x0000000107ccff3c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x0000000107ccf0f8 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x0000000107cd0544 SignalHandler(int) + 360
3  libsystem_platform.dylib 0x000000018d52b584 _sigtramp + 56
4  swift-frontend           0x0000000102bdbdcc swift::Lowering::ResultPlanBuilder::buildForPackExpansion(llvm::Optional<llvm::ArrayRef<swift::Lowering::Initialization*>>, swift::Lowering::AbstractionPattern, swift::ArrayRefView<swift::TupleTypeElt, swift::CanType, swift::getCanTupleEltType(swift::TupleTypeElt const&), false>) + 1080
5  swift-frontend           0x0000000102bdbdcc swift::Lowering::ResultPlanBuilder::buildForPackExpansion(llvm::Optional<llvm::ArrayRef<swift::Lowering::Initialization*>>, swift::Lowering::AbstractionPattern, swift::ArrayRefView<swift::TupleTypeElt, swift::CanType, swift::getCanTupleEltType(swift::TupleTypeElt const&), false>) + 1080
6  swift-frontend           0x0000000102be0900 void llvm::function_ref<void (swift::Lowering::TupleElementGenerator&)>::callback_fn<(anonymous namespace)::TupleInitializationResultPlan::TupleInitializationResultPlan(swift::Lowering::ResultPlanBuilder&, swift::Lowering::Initialization*, swift::Lowering::AbstractionPattern, swift::CanType, bool)::'lambda'(swift::Lowering::TupleElementGenerator&)>(long, swift::Lowering::TupleElementGenerator&) + 236
7  swift-frontend           0x0000000103452404 swift::Lowering::AbstractionPattern::forEachTupleElement(swift::CanType, llvm::function_ref<void (swift::Lowering::TupleElementGenerator&)>) const + 188
8  swift-frontend           0x0000000102bdb11c swift::Lowering::ResultPlanBuilder::buildForTuple(swift::Lowering::Initialization*, swift::Lowering::AbstractionPattern, swift::CanType) + 1300
9  swift-frontend           0x0000000102bdab04 swift::Lowering::ResultPlanBuilder::buildTopLevelResult(swift::Lowering::Initialization*, swift::SILLocation) + 2592
10 swift-frontend           0x0000000102c01c90 (anonymous namespace)::CallEmission::apply(swift::Lowering::SGFContext) + 3848
11 swift-frontend           0x0000000102bff7bc swift::Lowering::SILGenFunction::emitApplyExpr(swift::ApplyExpr*, swift::Lowering::SGFContext) + 3060
12 swift-frontend           0x0000000102c6af2c swift::Lowering::SILGenFunction::emitRValueAsSingleValue(swift::Expr*, swift::Lowering::SGFContext) + 40
13 swift-frontend           0x0000000102c90864 swift::Lowering::ManagedValue llvm::function_ref<swift::Lowering::ManagedValue (swift::Lowering::SGFContext)>::callback_fn<(anonymous namespace)::RValueEmitter::visitErasureExpr(swift::ErasureExpr*, swift::Lowering::SGFContext)::$_10>(long, swift::Lowering::SGFContext) + 64
14 swift-frontend           0x0000000102c4f428 void llvm::function_ref<void (swift::SILValue)>::callback_fn<swift::Lowering::SILGenFunction::emitExistentialErasure(swift::SILLocation, swift::CanType, swift::Lowering::TypeLowering const&, swift::Lowering::TypeLowering const&, llvm::ArrayRef<swift::ProtocolConformanceRef>, swift::Lowering::SGFContext, llvm::function_ref<swift::Lowering::ManagedValue (swift::Lowering::SGFContext)>, bool)::$_6>(long, swift::SILValue) + 308
15 swift-frontend           0x0000000102c2c4a0 swift::Lowering::SILGenBuilder::bufferForExpr(swift::SILLocation, swift::SILType, swift::Lowering::TypeLowering const&, swift::Lowering::SGFContext, llvm::function_ref<void (swift::SILValue)>) + 136
16 swift-frontend           0x0000000102c4ad70 swift::Lowering::SILGenFunction::emitExistentialErasure(swift::SILLocation, swift::CanType, swift::Lowering::TypeLowering const&, swift::Lowering::TypeLowering const&, llvm::ArrayRef<swift::ProtocolConformanceRef>, swift::Lowering::SGFContext, llvm::function_ref<swift::Lowering::ManagedValue (swift::Lowering::SGFContext)>, bool) + 1132
17 swift-frontend           0x0000000102c84480 (anonymous namespace)::RValueEmitter::visitErasureExpr(swift::ErasureExpr*, swift::Lowering::SGFContext) + 732
18 swift-frontend           0x0000000102c682cc swift::Lowering::SILGenFunction::emitExprInto(swift::Expr*, swift::Lowering::Initialization*, llvm::Optional<swift::SILLocation>) + 128
19 swift-frontend           0x0000000102bd55ec swift::Lowering::ArgumentSource::forwardInto(swift::Lowering::SILGenFunction&, swift::Lowering::Initialization*) && + 76
20 swift-frontend           0x0000000102c8dee4 (anonymous namespace)::RValueEmitter::visitCollectionExpr(swift::CollectionExpr*, swift::Lowering::SGFContext) + 1916
21 swift-frontend           0x0000000102c6af2c swift::Lowering::SILGenFunction::emitRValueAsSingleValue(swift::Expr*, swift::Lowering::SGFContext) + 40
22 swift-frontend           0x0000000102c0ec04 (anonymous namespace)::ArgEmitter::emit(swift::Lowering::ArgumentSource&&, swift::Lowering::AbstractionPattern, llvm::Optional<swift::AnyFunctionType::Param>) + 4684
23 swift-frontend           0x0000000102bfceb8 (anonymous namespace)::ArgEmitter::emitSingleArg(swift::Lowering::ArgumentSource&&, swift::Lowering::AbstractionPattern, llvm::Optional<swift::AnyFunctionType::Param>) + 224
24 swift-frontend           0x0000000102c0d6a0 (anonymous namespace)::ArgEmitter::emitPreparedArgs(swift::Lowering::PreparedArguments&&, swift::Lowering::AbstractionPattern) + 260
25 swift-frontend           0x0000000102c19fb4 (anonymous namespace)::CallSite::emit(swift::Lowering::SILGenFunction&, swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::SILFunctionType>, (anonymous namespace)::ParamLowering&, llvm::SmallVectorImpl<swift::Lowering::ManagedValue>&, llvm::SmallVectorImpl<(anonymous namespace)::DelayedArgument>&, swift::ForeignInfo const&) && + 672
26 swift-frontend           0x0000000102c199cc (anonymous namespace)::CallEmission::emitArgumentsForNormalApply(swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::SILFunctionType>, swift::ForeignInfo const&, llvm::SmallVectorImpl<swift::Lowering::ManagedValue>&, llvm::Optional<swift::SILLocation>&) + 1000
27 swift-frontend           0x0000000102c01d68 (anonymous namespace)::CallEmission::apply(swift::Lowering::SGFContext) + 4064
28 swift-frontend           0x0000000102bff7bc swift::Lowering::SILGenFunction::emitApplyExpr(swift::ApplyExpr*, swift::Lowering::SGFContext) + 3060
29 swift-frontend           0x0000000102c6b618 swift::Lowering::SILGenFunction::emitIgnoredExpr(swift::Expr*) + 892
30 swift-frontend           0x0000000102d0f970 swift::ASTVisitor<swift::Lowering::SILGenTopLevel, void, void, void, void, void, void>::visit(swift::Decl*) + 1860
31 swift-frontend           0x0000000102d0e5e0 swift::Lowering::SILGenModule::emitEntryPoint(swift::SourceFile*, swift::SILFunction*) + 1180
32 swift-frontend           0x0000000102bf2a48 swift::ASTLoweringRequest::evaluate(swift::Evaluator&, swift::ASTLoweringDescriptor) const + 1400
33 swift-frontend           0x0000000102d01f1c swift::SimpleRequest<swift::ASTLoweringRequest, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>> (swift::ASTLoweringDescriptor), (swift::RequestFlags)9>::evaluateRequest(swift::ASTLoweringRequest const&, swift::Evaluator&) + 196
34 swift-frontend           0x0000000102bf5f44 llvm::Expected<swift::ASTLoweringRequest::OutputType> swift::Evaluator::getResultUncached<swift::ASTLoweringRequest>(swift::ASTLoweringRequest const&) + 584
35 swift-frontend           0x00000001025cd408 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 548
36 swift-frontend           0x00000001025d1694 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1448
37 swift-frontend           0x00000001025cf6d0 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 4968
38 swift-frontend           0x000000010255ee8c swift::mainEntry(int, char const**) + 2612
39 dyld                     0x000000018d1720e0 start + 2360

Expected behavior

Both should be compiling fine

Environment

swift-driver version: 1.90.11.1 Apple Swift version 5.10 (swiftlang-5.10.0.13 clang-1500.3.9.4)
Target: arm64-apple-macosx14.0

Additional information

I suppose (although not sure at all) it may be related to #73209 as it follows the same pattern where a method causes an issue and not a free function, but #73209 causes a runtime crash whereas the present issue causes a compiler crash, and both issues also have slightly different code.

[hborla]

This is fixed in 6.0 and on main.