Description
When I pass a std::string_view to the asm() statement outside of any function, Clang crashes instead of producing a compilation error.
Example (crashes Clang):
constexpr std::string_view code2 = R"(.intel_syntax noprefix
hello:
push rbp
mov rbp, rsp
mov eax, 5
mov dword ptr [ebp-4], eax
mov rsp, rbp
pop rbp
ret
.att_syntax)";
asm((code2));
int main() {
...
}
Example (works fine with a literal):
asm(R"(
// same thing here
)")
int main() {
...
}
This appears to be a frontend crash in Clang. It should accept the code.
Files: https://filebin.net/hwb2cwq6kyyqz4sx
Stack dump:
0. Program arguments: /home/pyxiion/llvm21/llvm-project/build/bin/clang++ -g -std=c++26 -fcolor-diagnostics -fconstexpr-depth=20000 -MD -MT CMakeFiles/pxccc.dir/src/main.cpp.o -MF CMakeFiles/pxccc.dir/src/main.cpp.o.d @CMakeFiles/pxccc.dir/src/main.cpp.o.modmap -o CMakeFiles/pxccc.dir/src/main.cpp.o -c /home/pyxiion/CLionProjects/pxccc/src/main.cpp
1. /home/pyxiion/CLionProjects/pxccc/src/main.cpp:26:1: current parser token 'int'
2. /home/pyxiion/CLionProjects/pxccc/src/main.cpp:24:1: LLVM IR generation of declaration
#0 0x00005e125339a8f2 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x3cb18f2)
#1 0x00005e125339865c llvm::sys::CleanupOnSignal(unsigned long) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x3caf65c)
#2 0x00005e12532dca28 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x00007e6fbc645330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x00007e6fbc788f90 __memcpy_avx_unaligned_erms ./string/../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:833:0
#5 0x00007e6fbcb68755 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_mutate(unsigned long, unsigned long, char const*, unsigned long) (/lib/x86_64-linux-gnu/libstdc++.so.6+0x168755)
#6 0x00007e6fbcb6a050 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_append(char const*, unsigned long) (/lib/x86_64-linux-gnu/libstdc++.so.6+0x16a050)
#7 0x00005e12538d9c10 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#8 0x00005e1253c7bb88 (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#9 0x00005e1253c680d7 clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x457f0d7)
#10 0x00005e1255501ac4 clang::ParseAST(clang::Sema&, bool, bool) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x5e18ac4)
#11 0x00005e1253fa0f6e clang::FrontendAction::Execute() (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x48b7f6e)
#12 0x00005e1253f20983 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x4837983)
#13 0x00005e125407d06b clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x499406b)
#14 0x00005e1250580e2e cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0xe97e2e)
#15 0x00005e125057789a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#16 0x00005e1253ceab9d 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
#17 0x00005e12532dce57 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x3bf3e57)
#18 0x00005e1253ceb291 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
#19 0x00005e1253caeb0a clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x45c5b0a)
#20 0x00005e1253cafb89 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x45c6b89)
#21 0x00005e1253cc46ac clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0x45db6ac)
#22 0x00005e125057c6e8 clang_main(int, char**, llvm::ToolContext const&) (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0xe936e8)
#23 0x00005e12503f1d3a main (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0xd08d3a)
#24 0x00007e6fbc62a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#25 0x00007e6fbc62a28b call_init ./csu/../csu/libc-start.c:128:20
#26 0x00007e6fbc62a28b __libc_start_main ./csu/../csu/libc-start.c:347:5
#27 0x00005e12505772d5 _start (/home/pyxiion/llvm21/llvm-project/build/bin/clang+++0xe8e2d5)
clang++: error: clang frontend command failed with exit code 139 (use -v to see invocation)
clang version 21.0.0git (https://github.com/llvm/llvm-project.git 0c495ce9c4237f0f090b672efd94839e52cb5f18)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/pyxiion/llvm21/llvm-project/build/bin
clang++: note: diagnostic msg: