Combination of -g and -O flags with Embedded Swift crashes swiftc in IRGen

[MaxDesiatov]

Description

Build the source snippet pasted in this issue with swiftc -enable-experimental-feature Embedded -wmo repro.swift -g -O with latest development snapshot off the main branch of the compiler to observe the crash.

Reproduction

struct Plotter {
    let width: Int

    func plot(_ storage: UnsafeMutableBufferPointer<Float>) {
        let samplesPerPixel = storage.count / self.width

        var sampleCounter = 0
        var averageCounter = 0
        var average: Float = 0
        
        for sample in storage {
            average += sample

            if sampleCounter < samplesPerPixel {
                sampleCounter += 1
                average += sample
            } else {
                averageCounter += 1 
                average = 0
                sampleCounter = 0
            }
        }
    }
}

let buffer = UnsafeMutableBufferPointer<Float>.allocate(capacity: 42)
Plotter(width: 1000).plot(buffer)

Stack dump

1.      Apple Swift version 6.0-dev (LLVM 7fe091223bc821e, Swift 92f5eeeefc88005)
2.      Compiling with effective version 5.10
3.      While evaluating request IRGenRequest(IR Generation for module repro)
4.      While emitting IR SIL function "@$s5repro7PlotterV4plotyySrySfGF".
 for 'plot(_:)' (at repro.swift:4:5)
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x0000000106216e18 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x00000001062155e4 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x0000000106217460 SignalHandler(int) + 304
3  libsystem_platform.dylib 0x00000001970e3584 _sigtramp + 56
4  libsystem_pthread.dylib  0x00000001970b2c20 pthread_kill + 288
5  libsystem_c.dylib        0x0000000196fbfa20 abort + 180
6  libsystem_c.dylib        0x0000000196fbed10 err + 0
7  swift-frontend           0x000000010629b44c void llvm::function_ref<void (swift::irgen::IRGenFunction&)>::callback_fn<getAllocateBoxedOpaqueExistentialBufferFunction(swift::irgen::IRGenModule&, (anonymous namespace)::OpaqueExistentialLayout)::$_4>(long, swift::irgen::IRGenFunction&) (.cold.1) + 0
8  swift-frontend           0x000000010122541c void llvm::function_ref<void (swift::irgen::IRGenFunction&)>::callback_fn<getAllocateBoxedOpaqueExistentialBufferFunction(swift::irgen::IRGenModule&, (anonymous namespace)::OpaqueExistentialLayout)::$_4>(long, swift::irgen::IRGenFunction&) + 0
9  swift-frontend           0x00000001012c371c swift::irgen::IRGenModule::getTypeInfoForUnlowered(swift::Type) + 88
10 swift-frontend           0x00000001012f5844 (anonymous namespace)::IRGenDebugInfoImpl::collectGenericParams(swift::BoundGenericType*) + 216
11 swift-frontend           0x00000001012f3558 (anonymous namespace)::IRGenDebugInfoImpl::createType(swift::irgen::DebugTypeInfo, llvm::StringRef, llvm::DIScope*, llvm::DIFile*) + 3284
12 swift-frontend           0x00000001012f1f54 (anonymous namespace)::IRGenDebugInfoImpl::getOrCreateType(swift::irgen::DebugTypeInfo) + 2892
13 swift-frontend           0x00000001012f2b94 (anonymous namespace)::IRGenDebugInfoImpl::createType(swift::irgen::DebugTypeInfo, llvm::StringRef, llvm::DIScope*, llvm::DIFile*) + 784
14 swift-frontend           0x00000001012f1f54 (anonymous namespace)::IRGenDebugInfoImpl::getOrCreateType(swift::irgen::DebugTypeInfo) + 2892
15 swift-frontend           0x00000001012f78d0 (anonymous namespace)::IRGenDebugInfoImpl::createMemberType(swift::irgen::DebugTypeInfo, llvm::StringRef, unsigned int&, llvm::DIScope*, llvm::DIFile*, llvm::DINode::DIFlags) + 100
16 swift-frontend           0x00000001012f47a4 (anonymous namespace)::IRGenDebugInfoImpl::createStructType(swift::irgen::DebugTypeInfo, swift::NominalTypeDecl*, swift::Type, llvm::DIScope*, llvm::DIFile*, unsigned int, unsigned int, unsigned int, llvm::DINode::DIFlags, llvm::DIType*, unsigned int, llvm::StringRef) + 592
17 swift-frontend           0x00000001012f3250 (anonymous namespace)::IRGenDebugInfoImpl::createType(swift::irgen::DebugTypeInfo, llvm::StringRef, llvm::DIScope*, llvm::DIFile*) + 2508
18 swift-frontend           0x00000001012f1f54 (anonymous namespace)::IRGenDebugInfoImpl::getOrCreateType(swift::irgen::DebugTypeInfo) + 2892
19 swift-frontend           0x00000001012ebd90 (anonymous namespace)::IRGenDebugInfoImpl::emitVariableDeclaration(swift::irgen::IRBuilder&, llvm::ArrayRef<llvm::Value*>, swift::irgen::DebugTypeInfo, swift::SILDebugScope const*, std::__1::optional<swift::SILLocation>, swift::SILDebugVariable, swift::irgen::IndirectionKind, swift::irgen::ArtificialKind, swift::irgen::AddrDbgInstrKind) + 404
20 swift-frontend           0x00000001012ebbb0 swift::irgen::IRGenDebugInfo::emitVariableDeclaration(swift::irgen::IRBuilder&, llvm::ArrayRef<llvm::Value*>, swift::irgen::DebugTypeInfo, swift::SILDebugScope const*, std::__1::optional<swift::SILLocation>, swift::SILDebugVariable, swift::irgen::IndirectionKind, swift::irgen::ArtificialKind, swift::irgen::AddrDbgInstrKind) + 224
21 swift-frontend           0x0000000101340144 (anonymous namespace)::IRGenSILFunction::visitSILBasicBlock(swift::SILBasicBlock*) + 73892
22 swift-frontend           0x000000010132cf08 (anonymous namespace)::IRGenSILFunction::emitSILFunction() + 9164
23 swift-frontend           0x000000010132a5f4 swift::irgen::IRGenModule::emitSILFunction(swift::SILFunction*) + 1524
24 swift-frontend           0x00000001011cffcc 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&) + 740
25 swift-frontend           0x00000001012dd69c swift::IRGenRequest::evaluate(swift::Evaluator&, swift::IRGenDescriptor) const + 2160
26 swift-frontend           0x0000000101329af4 swift::GeneratedModule swift::SimpleRequest<swift::IRGenRequest, swift::GeneratedModule (swift::IRGenDescriptor), (swift::RequestFlags)9>::callDerived<0ul>(swift::Evaluator&, std::__1::integer_sequence<unsigned long, 0ul>) const + 200
27 swift-frontend           0x00000001012e5f14 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'()) + 212
28 swift-frontend           0x00000001012de760 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**) + 1400
29 swift-frontend           0x0000000100dfbe28 generateIR(swift::IRGenOptions const&, swift::TBDGenOptions const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, swift::PrimarySpecificPaths const&, llvm::StringRef, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, llvm::GlobalVariable*&, llvm::ArrayRef<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>) + 272
30 swift-frontend           0x0000000100df8058 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*) + 1416
31 swift-frontend           0x0000000100df7724 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1164
32 swift-frontend           0x0000000100e0865c withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 160
33 swift-frontend           0x0000000100df9b10 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 708
34 swift-frontend           0x0000000100df8a7c swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2368
35 swift-frontend           0x0000000100c2f4dc swift::mainEntry(int, char const**) + 3096
36 dyld                     0x0000000196d2a0e0 start + 2360

Expected behavior

No crash or an actionable diagnostic error message

Environment

Apple Swift version 6.0-dev (LLVM 7fe091223bc821e, Swift 92f5eee)
Target: arm64-apple-macosx14.0

Additional information

No response