| Issue |
177807
|
| Summary |
Clang crashes during codegen of variadic expansion involving an implicitly lambda-captured reference template parameter
|
| Labels |
clang,
clang:codegen,
crash-on-valid
|
| Assignees |
|
| Reporter |
Il-Capitano
|
Godbolt link: https://godbolt.org/z/77YTKPWbW
I found this while trying out Clang 22.1.0-rc1.
The following code causes an assertion failure in Clang during code generation, both on main, and the latest release candidate 22.1.0-rc1:
```c++
template<int &global>
auto foo(auto ...args) {
[](auto ...args) {
((args, global), ...);
}(0);
}
int i = 0;
auto test() {
return foo<i>(0, 1);
}
```
```
clang++: /root/llvm-project/llvm/include/llvm/Support/Casting.h:572: decltype(auto) llvm::cast(From*) [with To = clang::CallExpr; From = const clang::Expr]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' 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++ -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 <source>
1. <eof> parser at end of file
2. Per-file LLVM IR generation
3. <source>:3:5: Generating code for declaration 'foo(int, int)::(lambda)::operator()'
#0 0x0000000004309af8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4309af8)
#1 0x0000000004306f54 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4306f54)
#2 0x0000000004249938 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x000074de0b642520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x000074de0b6969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#5 0x000074de0b642476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#6 0x000074de0b6287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#7 0x000074de0b62871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#8 0x000074de0b639e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#9 0x000000000468a97f clang::CodeGen::CodeGenFunction::EmitLValueHelper(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x468a97f)
#10 0x000000000468aae7 void llvm::function_ref<void ()>::callback_fn<clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t)::'lambda'()>(long) CGExpr.cpp:0:0
#11 0x0000000008575611 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x8575611)
#12 0x0000000004651fdc clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4651fdc)
#13 0x0000000004689fc3 clang::CodeGen::CodeGenFunction::EmitLValueHelper(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4689fc3)
#14 0x000000000468aae7 void llvm::function_ref<void ()>::callback_fn<clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t)::'lambda'()>(long) CGExpr.cpp:0:0
#15 0x0000000008575611 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x8575611)
#16 0x0000000004651fdc clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4651fdc)
#17 0x000000000467bf54 clang::CodeGen::CodeGenFunction::EmitBinaryOperatorLValue(clang::BinaryOperator const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x467bf54)
#18 0x000000000468a5a6 clang::CodeGen::CodeGenFunction::EmitLValueHelper(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x468a5a6)
#19 0x000000000468aae7 void llvm::function_ref<void ()>::callback_fn<clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t)::'lambda'()>(long) CGExpr.cpp:0:0
#20 0x0000000008575611 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x8575611)
#21 0x0000000004651fdc clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4651fdc)
#22 0x0000000004689fc3 clang::CodeGen::CodeGenFunction::EmitLValueHelper(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4689fc3)
#23 0x000000000468aae7 void llvm::function_ref<void ()>::callback_fn<clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t)::'lambda'()>(long) CGExpr.cpp:0:0
#24 0x0000000008575611 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x8575611)
#25 0x0000000004651fdc clang::CodeGen::CodeGenFunction::EmitLValue(clang::Expr const*, clang::CodeGen::KnownNonNull_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4651fdc)
#26 0x000000000466816e clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x466816e)
#27 0x0000000004815e67 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4815e67)
#28 0x000000000481e46b clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x481e46b)
#29 0x0000000004886e16 clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4886e16)
#30 0x0000000004898924 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4898924)
#31 0x00000000049065f0 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49065f0)
#32 0x0000000004901264 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4901264)
#33 0x000000000490e82c clang::CodeGen::CodeGenModule::EmitDeferred() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x490e82c)
#34 0x000000000490e748 clang::CodeGen::CodeGenModule::EmitDeferred() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x490e748)
#35 0x00000000049124c3 clang::CodeGen::CodeGenModule::Release() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49124c3)
#36 0x0000000004c74fee (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&) ModuleBuilder.cpp:0:0
#37 0x0000000004c72a05 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c72a05)
#38 0x0000000006a6331c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a6331c)
#39 0x0000000004c731e8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c731e8)
#40 0x0000000004f6e525 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f6e525)
#41 0x0000000004eedf4e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4eedf4e)
#42 0x00000000050696ed clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x50696ed)
#43 0x0000000000ddd95e cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xddd95e)
#44 0x0000000000dd432a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) driver.cpp:0:0
#45 0x0000000000dd44ad int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::'lambda'(llvm::SmallVectorImpl<char const*>&)>(long, llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#46 0x0000000004ce6c29 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#47 0x0000000004249dd4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4249dd4)
#48 0x0000000004ce723f clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#49 0x0000000004ca7c12 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ca7c12)
#50 0x0000000004ca8bbe 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+++0x4ca8bbe)
#51 0x0000000004cb0005 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cb0005)
#52 0x0000000000dd9cd1 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdd9cd1)
#53 0x0000000000c96d24 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc96d24)
#54 0x000074de0b629d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#55 0x000074de0b629e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#56 0x0000000000dd3dc5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdd3dc5)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
```
@c-rhodes Bringing this to your attention to see if we could get this fixed by the 22.1.0 release.
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