[clang] [Clang] prevent assertion failure by avoiding casts on type declarations that require complete types (PR #101426)

[Mital Ashok via cfe-commits]

MitalAshok wrote:

I think the issue is here somewhere:

https://github.com/llvm/llvm-project/blob/7088a5ed880f29129ec844c66068e8cb61ca98bf/clang/lib/Sema/SemaDecl.cpp#L8753-L8764

An incomplete struct passes `CheckC23ConstexprVarType` (which it should, incomplete types should fail later) so it goes on to the next check. We should only check `RequireLiteralType` in C++. The cast isn't failing because it's expecting a complete type, it's failing because it's expecting a `CXXRecordDecl` when we only have a C `RecordDecl`.


https://github.com/llvm/llvm-project/pull/101426