Lambda with Template parameter list in C++11 hits "Unexpected placeholder builtin type!" assertion

[erichkeane]

https://godbolt.org/z/PvEq49njP

-std=c++11 -Wall

void foo() {
    auto Y = []<typename T>(T X) {};
    Y(4);
}

Unexpected placeholder builtin type!
UNREACHABLE executed at /root/llvm-project/clang/lib/CodeGen/CodeGenTypes.cpp:641!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++11 -Wall <source>
1.	<eof> parser at end of file
2.	<source>:3:6: LLVM IR generation of declaration 'foo'
3.	<source>:3:6: Generating code for declaration 'foo'
 #0 0x000055be4ba0cd3f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #1 0x000055be4ba0aa64 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3c0aa64)
 #2 0x000055be4b93f7a8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007fdd5b7843c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x143c0)
 #4 0x00007fdd5b25103b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4303b)
 #5 0x00007fdd5b230859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x000055be4b948c4a (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b48c4a)
 #7 0x000055be4bf075e3 clang::CodeGen::CodeGenTypes::ConvertType(clang::QualType) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x41075e3)
 #8 0x000055be4c089e52 clang::CodeGen::CodeGenTypes::arrangeLLVMFunctionInfo(clang::CanQual<clang::Type>, bool, bool, llvm::ArrayRef<clang::CanQual<clang::Type>>, clang::FunctionType::ExtInfo, llvm::ArrayRef<clang::FunctionType::ExtParameterInfo>, clang::CodeGen::RequiredArgs) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4289e52)
 #9 0x000055be4c08a44d arrangeLLVMFunctionInfo(clang::CodeGen::CodeGenTypes&, bool, llvm::SmallVectorImpl<clang::CanQual<clang::Type>>&, clang::CanQual<clang::FunctionProtoType>) CGCall.cpp:0:0
#10 0x000055be4c08fed7 clang::CodeGen::CodeGenTypes::arrangeCXXMethodType(clang::CXXRecordDecl const*, clang::FunctionProtoType const*, clang::CXXMethodDecl const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x428fed7)
#11 0x000055be4c091a88 clang::CodeGen::CodeGenTypes::arrangeCXXMethodDeclaration(clang::CXXMethodDecl const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4291a88)
#12 0x000055be4c122030 clang::CodeGen::CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(clang::CallExpr const*, clang::CXXMethodDecl const*, clang::CodeGen::ReturnValueSlot, bool, clang::NestedNameSpecifier*, bool, clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4322030)
#13 0x000055be4c1231ef clang::CodeGen::CodeGenFunction::EmitCXXOperatorMemberCallExpr(clang::CXXOperatorCallExpr const*, clang::CXXMethodDecl const*, clang::CodeGen::ReturnValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x43231ef)
#14 0x000055be4c10ffea clang::CodeGen::CodeGenFunction::EmitCallExpr(clang::CallExpr const*, clang::CodeGen::ReturnValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x430ffea)
#15 0x000055be4c142f98 (anonymous namespace)::ScalarExprEmitter::VisitCallExpr(clang::CallExpr const*) CGExprScalar.cpp:0:0
#16 0x000055be4c14029b (anonymous namespace)::ScalarExprEmitter::Visit(clang::Expr*) CGExprScalar.cpp:0:0
#17 0x000055be4c1425b6 clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x43425b6)
#18 0x000055be4c0f172f clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x42f172f)
#19 0x000055be4c10e149 clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x430e149)
#20 0x000055be4be11b0a clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4011b0a)
#21 0x000055be4be175b4 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40175b4)
#22 0x000055be4be6a3b3 clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x406a3b3)
#23 0x000055be4be7aa5c clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x407aa5c)
#24 0x000055be4bec814b clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40c814b)
#25 0x000055be4bec435d clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40c435d)
#26 0x000055be4bec4a6b clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40c4a6b)
#27 0x000055be4becba9a clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.8101) CodeGenModule.cpp:0:0
#28 0x000055be4cadbf8d (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#29 0x000055be4cad15ce clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cd15ce)
#30 0x000055be4da8cda4 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5c8cda4)
#31 0x000055be4cad9320 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cd9320)
#32 0x000055be4c44f519 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x464f519)
#33 0x000055be4c3e934a clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x45e934a)
#34 0x000055be4c51ca23 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x471ca23)
#35 0x000055be492507b1 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x14507b1)
#36 0x000055be49249939 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#37 0x000055be4c27c925 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#38 0x000055be4b93fd93 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b3fd93)
#39 0x000055be4c27ecb6 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x447ecb6)
#40 0x000055be4c24dada clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x444dada)
#41 0x000055be4c24e76f clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x444e76f)
#42 0x000055be4c256c9a clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4456c9a)
#43 0x000055be4924ea7c clang_main(int, char**) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x144ea7c)
#44 0x00007fdd5b2320b3 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b3)
#45 0x000055be492491aa _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x14491aa)
clang-15: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-clang-codegen

[philnik777]

Closing this one as the duplicate, since the newer one has some discussion.