Assertion fail for generic struct definition after non-generic pre-declaration

[john-h-kastner]

struct hash;
struct hash _For_any(K) {};

clang: /home/john/checkedc-clang/clang/lib/Sema/CheckedCSubst.cpp:302: bool clang::Sema::DiagnoseExpandingCycles(clang::RecordDecl*, clang::SourceLocation): Assertion `Base->isGenericOrItypeGeneric() && "Can only check expanding cycles for generic structs"' failed.
PLEASE submit a bug report to https://github.com/Microsoft/checkedc-clang/issues and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: clang -c hash.c 
1.	hash.c:2:27: current parser token ';'
2.	hash.c:2:1: parsing struct/union body 'hash'
 #0 0x000055c26848f381 llvm::sys::PrintStackTrace(llvm::raw_ostream&) /home/john/checkedc-clang/llvm/build/../lib/Support/Unix/Signals.inc:564:22
 #1 0x000055c26848f418 PrintStackTraceSignalHandler(void*) /home/john/checkedc-clang/llvm/build/../lib/Support/Unix/Signals.inc:625:1
 #2 0x000055c26848d16b llvm::sys::RunSignalHandlers() /home/john/checkedc-clang/llvm/build/../lib/Support/Signals.cpp:68:20
 #3 0x000055c26848eb87 llvm::sys::CleanupOnSignal(unsigned long) /home/john/checkedc-clang/llvm/build/../lib/Support/Unix/Signals.inc:361:31
 #4 0x000055c2683cf728 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) /home/john/checkedc-clang/llvm/build/../lib/Support/CrashRecoveryContext.cpp:77:5
 #5 0x000055c2683cfc1a CrashRecoverySignalHandler(int) /home/john/checkedc-clang/llvm/build/../lib/Support/CrashRecoveryContext.cpp:383:1
 #6 0x00007fc9f787c3c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x153c0)
 #7 0x00007fc9f731c18b raise /build/glibc-eX1tMB/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
 #8 0x00007fc9f72fb859 abort /build/glibc-eX1tMB/glibc-2.31/stdlib/abort.c:81:7
 #9 0x00007fc9f72fb729 get_sysdep_segment_value /build/glibc-eX1tMB/glibc-2.31/intl/loadmsgcat.c:509:8
#10 0x00007fc9f72fb729 _nl_load_domain /build/glibc-eX1tMB/glibc-2.31/intl/loadmsgcat.c:970:34
#11 0x00007fc9f730cf36 (/lib/x86_64-linux-gnu/libc.so.6+0x36f36)
#12 0x000055c26b617e71 clang::Sema::DiagnoseExpandingCycles(clang::RecordDecl*, clang::SourceLocation) /home/john/checkedc-clang/clang/lib/Sema/CheckedCSubst.cpp:302:3
#13 0x000055c26b544be2 clang::Parser::ParseStructUnionBody(clang::SourceLocation, clang::TypeSpecifierType, clang::RecordDecl*) /home/john/checkedc-clang/clang/lib/Parse/ParseDecl.cpp:4572:9
#14 0x000055c26b566ad8 clang::Parser::ParseClassSpecifier(clang::tok::TokenKind, clang::SourceLocation, clang::DeclSpec&, clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier, bool, clang::Parser::DeclSpecContext, clang::Parser::ParsedAttributesWithRange&) /home/john/checkedc-clang/clang/lib/Parse/ParseDeclCXX.cpp:2054:20
#15 0x000055c26b542cdf clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*) /home/john/checkedc-clang/clang/lib/Parse/ParseDecl.cpp:4067:26
#16 0x000055c26b51a843 clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) /home/john/checkedc-clang/clang/lib/Parse/Parser.cpp:1042:57
#17 0x000055c26b51af67 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) /home/john/checkedc-clang/clang/lib/Parse/Parser.cpp:1154:57
#18 0x000055c26b51a2d1 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) (.localalias) /home/john/checkedc-clang/clang/lib/Parse/Parser.cpp:956:58
#19 0x000055c26b51942a clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, bool) /home/john/checkedc-clang/clang/lib/Parse/Parser.cpp:704:42
#20 0x000055c26b514d88 clang::ParseAST(clang::Sema&, bool, bool) /home/john/checkedc-clang/clang/lib/Parse/ParseAST.cpp:158:37
#21 0x000055c2690e0b11 clang::ASTFrontendAction::ExecuteAction() /home/john/checkedc-clang/clang/lib/Frontend/FrontendAction.cpp:1057:11
#22 0x000055c269a5d7e3 clang::CodeGenAction::ExecuteAction() /home/john/checkedc-clang/clang/lib/CodeGen/CodeGenAction.cpp:1185:1
#23 0x000055c2690e0468 clang::FrontendAction::Execute() /home/john/checkedc-clang/clang/lib/Frontend/FrontendAction.cpp:954:38
#24 0x000055c269070d6f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /home/john/checkedc-clang/clang/lib/Frontend/CompilerInstance.cpp:984:42
#25 0x000055c26927c4db clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /home/john/checkedc-clang/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:278:38
#26 0x000055c266b1a91b cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /home/john/checkedc-clang/clang/tools/driver/cc1_main.cpp:240:40
#27 0x000055c266b0f7e3 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) /home/john/checkedc-clang/clang/tools/driver/driver.cpp:330:20
#28 0x000055c268f66659 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'()::operator()() const /home/john/checkedc-clang/clang/lib/Driver/Job.cpp:400:32
#29 0x000055c268f66f22 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) /home/john/checkedc-clang/llvm/include/llvm/ADT/STLExtras.h:186:40
#30 0x000055c2683c2636 llvm::function_ref<void ()>::operator()() const /home/john/checkedc-clang/llvm/build/../include/llvm/ADT/STLExtras.h:203:62
#31 0x000055c2683cfe2c llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) /home/john/checkedc-clang/llvm/build/../lib/Support/CrashRecoveryContext.cpp:419:10
#32 0x000055c268f66881 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, bool*) const /home/john/checkedc-clang/clang/lib/Driver/Job.cpp:400:7
#33 0x000055c268f196af clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const /home/john/checkedc-clang/clang/lib/Driver/Compilation.cpp:195:22
#34 0x000055c268f19a12 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) const /home/john/checkedc-clang/clang/lib/Driver/Compilation.cpp:246:53
#35 0x000055c268f298c2 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) /home/john/checkedc-clang/clang/lib/Driver/Driver.cpp:1509:28
#36 0x000055c266b107b7 main /home/john/checkedc-clang/clang/tools/driver/driver.cpp:502:39
#37 0x00007fc9f72fd0b3 __libc_start_main /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:342:3
#38 0x000055c266b0de7e _start (/home/john/checkedc-clang/llvm/build/bin/clang-11+0x2601e7e)

The assertion fail goes away if I switch the order, defining the generic struct first before declaring it without the _For_any. It is also fixed if the pre-declaration declares the struct with the generic (struct hash _For_any(K)).

Presumably this related to the unfinished work on generic structs for issue #644