Clang assertion trunk crash on va_arg (aarch64)

[int6]

https://godbolt.org/z/Mq95K9hMa

main.c

typedef __builtin_va_list va_list;
#define va_start(ap, param) __builtin_va_start(ap, param)
#define va_end(ap)          __builtin_va_end(ap)
#define va_arg(ap, type)    __builtin_va_arg(ap, type)

struct T {};

struct T A(int x, ...)
{
    va_list args;
    va_start(args, x);

    struct T val = va_arg(args, struct T);

    va_end(args);

    return val;
}

clang: /root/llvm-project/clang/include/clang/CodeGen/CGFunctionInfo.h:349: llvm::Type* clang::CodeGen::ABIArgInfo::getCoerceToType() const: Assertion `canHaveCoerceToType() && "Invalid kind!"' failed.
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 -S --gcc-toolchain=/opt/compiler-explorer/gcc-9.2.0 -fcolor-diagnostics -fno-crash-diagnostics -target aarch64-linux-gnu <source>
1.	<eof> parser at end of file
2.	<source>:8:10: LLVM IR generation of declaration 'A'
3.	<source>:8:10: Generating code for declaration 'A'
 #0 0x000055d38026d764 PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #1 0x000055d38026b4fc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3f7c4fc)
 #2 0x000055d3801a6e48 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007faa6dc83420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007faa6d75000b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007faa6d72f859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007faa6d72f729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007faa6d740fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x000055d38088613f (anonymous namespace)::AArch64ABIInfo::EmitAAPCSVAArg(clang::CodeGen::Address, clang::QualType, clang::CodeGen::CodeGenFunction&) const TargetInfo.cpp:0:0
 #9 0x000055d380886425 (anonymous namespace)::AArch64ABIInfo::EmitVAArg(clang::CodeGen::CodeGenFunction&, clang::CodeGen::Address, clang::QualType) const TargetInfo.cpp:0:0
#10 0x000055d380a9450f (anonymous namespace)::AggExprEmitter::Visit(clang::Expr*) CGExprAgg.cpp:0:0
#11 0x000055d380a96103 clang::CodeGen::CodeGenFunction::EmitAggExpr(clang::Expr const*, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x47a7103)
#12 0x000055d380a3cb4c clang::CodeGen::CodeGenFunction::EmitExprAsInit(clang::Expr const*, clang::ValueDecl const*, clang::CodeGen::LValue, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x474db4c)
#13 0x000055d380a473f9 clang::CodeGen::CodeGenFunction::EmitAutoVarInit(clang::CodeGen::CodeGenFunction::AutoVarEmission const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x47583f9)
#14 0x000055d380a488d2 clang::CodeGen::CodeGenFunction::EmitVarDecl(clang::VarDecl const&) (.part.0) CGDecl.cpp:0:0
#15 0x000055d380a48b90 clang::CodeGen::CodeGenFunction::EmitDecl(clang::Decl const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4759b90)
#16 0x000055d3806df4f7 clang::CodeGen::CodeGenFunction::EmitDeclStmt(clang::DeclStmt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x43f04f7)
#17 0x000055d3806f34c7 clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x44044c7)
#18 0x000055d3806ec83c clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x43fd83c)
#19 0x000055d3806f2dc4 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4403dc4)
#20 0x000055d380751d9e clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4462d9e)
#21 0x000055d3807642d4 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x44752d4)
#22 0x000055d3807c2e69 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x44d3e69)
#23 0x000055d3807be0d5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x44cf0d5)
#24 0x000055d3807be773 clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x44cf773)
#25 0x000055d3807c74d2 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#26 0x000055d3815a3c59 (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#27 0x000055d381595a40 clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x52a6a40)
#28 0x000055d38286ba14 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x657ca14)
#29 0x000055d3815a0c28 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x52b1c28)
#30 0x000055d380e319d9 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4b429d9)
#31 0x000055d380db84ce clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4ac94ce)
#32 0x000055d380f170c3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4c280c3)
#33 0x000055d37d76aae4 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x147bae4)
#34 0x000055d37d766907 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#35 0x000055d380c22549 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
#36 0x000055d3801a75ea llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3eb85ea)
#37 0x000055d380c22d9f clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#38 0x000055d380bec0f9 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x48fd0f9)
#39 0x000055d380becb7d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x48fdb7d)
#40 0x000055d380bf661c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x490761c)
#41 0x000055d37d7690f2 clang_main(int, char**) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x147a0f2)
#42 0x00007faa6d731083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#43 0x000055d37d76223e _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x147323e)
clang-16: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-clang-codegen

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

[DavidSpickett]

Any relation to #58794 ? There is a fix posted for that one.

[int6]

Seems crash here in line 6005

llvm-project/clang/lib/CodeGen/TargetInfo.cpp

Lines 5996 to 6006 in 2656fb3

	Address AArch64ABIInfo::EmitAAPCSVAArg(Address VAListAddr, QualType Ty,
	CodeGenFunction &CGF) const {
	ABIArgInfo AI = classifyArgumentType(Ty, /*IsVariadic=*/true,
	CGF.CurFnInfo->getCallingConvention());
	bool IsIndirect = AI.isIndirect();
	llvm::Type *BaseTy = CGF.ConvertType(Ty);
	if (IsIndirect)
	BaseTy = llvm::PointerType::getUnqual(BaseTy);
	else if (AI.getCoerceToType())
	BaseTy = AI.getCoerceToType();

AI.getCoerceToType has assert that AI's kind is one of Direct, Extend, Indirect, but when the vaarg is an empty record type, AI's kind actually is Ignore

getCoerceToType

llvm-project/clang/include/clang/CodeGen/CGFunctionInfo.h

Lines 348 to 351 in bc0fea0

	llvm::Type *getCoerceToType() const {
	assert(canHaveCoerceToType() && "Invalid kind!");
	return TypeData;
	}

canHaveCoerceToType

llvm-project/clang/include/clang/CodeGen/CGFunctionInfo.h

Lines 305 to 307 in bc0fea0

	bool canHaveCoerceToType() const {
	return isDirect() || isExtend() || isCoerceAndExpand();
	}

[yronglin]

I try to fix it in https://reviews.llvm.org/D138511

[yronglin]

Fix by ebe530e