C++ interop - Crash on defining a function ptr that takes a std string

[ronald-baldonado]

Description

The Swift Compiler crashes when I try to define a function pointer declared from C++ in swift code. The function takes in a std::string and returns void.

Reproduction

Swift Code

var callback : printCallback = { (s1: std.string) -> Void in
    
    let swiftStr = String(s1);
    print(swiftStr)
}

C++ Code

#include <string>

typedef void (*printCallback)(std::string);

Stack dump

0  swift-frontend           0x0000000103011abc llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x0000000105c77cb0 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x00000001059e1054 SignalHandler(int) + 352
3  libsystem_platform.dylib 0x0000000193f37584 _sigtramp + 56
4  swift-frontend           0x00000001022e8244 (anonymous namespace)::DestructureInputs::visit(swift::ValueOwnership, bool, swift::Lowering::AbstractionPattern, swift::CanType, bool) + 732
5  swift-frontend           0x0000000103f61cd8 (anonymous namespace)::DestructureInputs::visit(swift::Lowering::AbstractionPattern, swift::AnyFunctionType::Param, bool) + 268
6  swift-frontend           0x0000000103f65768 void llvm::function_ref<void (swift::Lowering::FunctionParamGenerator&)>::callback_fn<(anonymous namespace)::DestructureInputs::visitTopLevelParams(swift::Lowering::AbstractionPattern, swift::ArrayRefView<swift::AnyFunctionType::Param, swift::AnyFunctionType::CanParam, swift::AnyFunctionType::CanParam::getFromParam(swift::AnyFunctionType::Param const&), true>, swift::SILExtInfoBuilder, bool&)::'lambda'(swift::Lowering::FunctionParamGenerator&)>(long, swift::Lowering::FunctionParamGenerator&) + 672
7  swift-frontend           0x0000000102245e00 swift::Lowering::AbstractionPattern::forEachFunctionParam(swift::ArrayRefView<swift::AnyFunctionType::Param, swift::AnyFunctionType::CanParam, swift::AnyFunctionType::CanParam::getFromParam(swift::AnyFunctionType::Param const&), true>, bool, llvm::function_ref<void (swift::Lowering::FunctionParamGenerator&)>) const + 208
8  swift-frontend           0x00000001022e7838 (anonymous namespace)::DestructureInputs::destructure(swift::Lowering::AbstractionPattern, swift::ArrayRefView<swift::AnyFunctionType::Param, swift::AnyFunctionType::CanParam, swift::AnyFunctionType::CanParam::getFromParam(swift::AnyFunctionType::Param const&), true>, swift::SILExtInfoBuilder, bool&) + 380
9  swift-frontend           0x0000000103f5d6c0 getSILFunctionType(swift::Lowering::TypeConverter&, swift::TypeExpansionContext, swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::AnyFunctionType>, swift::SILExtInfoBuilder, (anonymous namespace)::Conventions const&, swift::ForeignInfo const&, llvm::Optional<swift::SILDeclRef>, llvm::Optional<swift::SILDeclRef>, llvm::Optional<swift::SubstitutionMap>, swift::ProtocolConformanceRef) + 2672
10 swift-frontend           0x0000000103f49890 getNativeSILFunctionType(swift::Lowering::TypeConverter&, swift::TypeExpansionContext, swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::AnyFunctionType>, swift::SILExtInfoBuilder, llvm::Optional<swift::SILDeclRef>, llvm::Optional<swift::SILDeclRef>, llvm::Optional<swift::SubstitutionMap>, swift::ProtocolConformanceRef) (.llvm.13406110992970554804) + 2028
11 swift-frontend           0x0000000102428350 swift::Lowering::TypeConverter::computeLoweredRValueType(swift::TypeExpansionContext, swift::Lowering::AbstractionPattern, swift::CanType)::LoweredRValueTypeVisitor::visitAnyFunctionType(swift::CanTypeWrapper<swift::AnyFunctionType>) + 812
12 swift-frontend           0x00000001023efc34 swift::Lowering::TypeConverter::getTypeLowering(swift::Lowering::AbstractionPattern, swift::Type, swift::TypeExpansionContext) + 556
13 swift-frontend           0x00000001036e778c swift::Lowering::SILGenModule::getSILGlobalVariable(swift::VarDecl*, swift::ForDefinition_t) + 948
14 swift-frontend           0x0000000100b36f58 swift::Lowering::SILGenFunction::emitInitializationForVarDecl(swift::VarDecl*, bool, bool) + 1056
15 swift-frontend           0x0000000101148e30 swift::Lowering::SILGenFunction::emitPatternBinding(swift::PatternBindingDecl*, unsigned int, bool) + 260
16 swift-frontend           0x00000001011e69b0 swift::Lowering::SILGenFunction::emitLazyGlobalInitializer(swift::PatternBindingDecl*, unsigned int) + 480
17 swift-frontend           0x00000001033499c8 swift::Lowering::SILGenModule::emitLazyGlobalInitializer(llvm::StringRef, swift::PatternBindingDecl*, unsigned int) + 916
18 swift-frontend           0x00000001036ea0dc swift::Lowering::SILGenModule::emitGlobalInitialization(swift::PatternBindingDecl*, unsigned int) + 716
19 swift-frontend           0x000000010332e77c swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visit(swift::Decl*) + 424
20 swift-frontend           0x0000000103353600 swift::ASTLoweringRequest::evaluate(swift::Evaluator&, swift::ASTLoweringDescriptor) const + 2908
21 swift-frontend           0x0000000103a22f98 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&) + 200
22 swift-frontend           0x00000001033799ac llvm::Expected<swift::ASTLoweringRequest::OutputType> swift::Evaluator::getResultUncached<swift::ASTLoweringRequest>(swift::ASTLoweringRequest const&) + 584
23 swift-frontend           0x00000001055549c4 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1680
24 swift-frontend           0x0000000105558854 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 4568
25 swift-frontend           0x00000001055bfd44 swift::mainEntry(int, char const**) + 4408
26 dyld                     0x0000000193b7e0e0 start + 2360

Expected behavior

I expected the compiler to parse cpp-defined function ptrs using a Swift closure.

Environment

swift-driver version: 1.87.3 Apple Swift version 5.9.2 (swiftlang-5.9.2.2.56 clang-1500.1.0.2.5)

Additional information

No response

[hamishknight]

This no longer crashes on 6.0, looks like it was fixed by #73193