[clang] Crash in C mode with -fblocks after invalid global __block declaration #183974
Description
Reproducer:
https://godbolt.org/z/xnP4ox8rE
__block int x;
int x[0];Backtrace:
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 -x c -fblocks <source>
1. <eof> parser at end of file
#0 0x000000000440ac38 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x440ac38)
#1 0x0000000004408084 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4408084)
#2 0x0000000004347e88 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x00007e318c642520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x0000000000ca287a clang::Sema::CheckCompleteVariableDeclaration(clang::VarDecl*) (.cold) SemaDecl.cpp:0:0
#5 0x0000000006d85f19 clang::Sema::ActOnEndOfTranslationUnit() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6d85f19)
#6 0x0000000006beda9a clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6beda9a)
#7 0x0000000006bcefda clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6bcefda)
#8 0x0000000004ee4ef8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ee4ef8)
#9 0x00000000051eb615 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51eb615)
#10 0x00000000051698fe clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51698fe)
#11 0x00000000052e72dd clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x52e72dd)
#12 0x0000000000df063e cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdf063e)
#13 0x0000000000de6faa ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) driver.cpp:0:0
#14 0x0000000000de712d 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
#15 0x0000000004f59659 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
#16 0x00000000043482c4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x43482c4)
#17 0x0000000004f59c6f 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
#18 0x0000000004f19952 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f19952)
#19 0x0000000004f1a8fe 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+++0x4f1a8fe)
#20 0x0000000004f22645 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f22645)
#21 0x0000000000dec9ae clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdec9ae)
#22 0x0000000000ca4d0a main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xca4d0a)
#23 0x00007e318c629d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#24 0x00007e318c629e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#25 0x0000000000de6a45 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xde6a45)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Compiler returned: 139