Missing diagnostics "warning: cv qualifiers ignored for a base class"

[fsb4000]

http://eel.is/c++draft/class.derived.general#2.sentence-2

Everything works correctly but such diagnostic would be good.

class Base { 
public:
   int base;
};

typedef const Base ConstBase;

class CDerived: public ConstBase {
public:
   int derived;
};

https://godbolt.org/z/1ns8Tc7Ko

[manoj-al]

Hi,
I wanted to fix this issue, is -Wignored-qualifiers is the right flag to add this warning?
Thanks.

[fsb4000]

is -Wignored-qualifiers is the right flag to add this warning?

Yes, I think it would be great!

[a-tarasyuk]

@AaronBallman @erichkeane should all of the following qualifiers be handled?

llvm-project/clang/lib/Sema/SemaType.cpp

Lines 2885 to 2889 in 1e49228

	{ "const", DeclSpec::TQ_const, ConstQualLoc },
	{ "volatile", DeclSpec::TQ_volatile, VolatileQualLoc },
	{ "restrict", DeclSpec::TQ_restrict, RestrictQualLoc },
	{ "__unaligned", DeclSpec::TQ_unaligned, UnalignedQualLoc },
	{ "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc }

[erichkeane]

@AaronBallman @erichkeane should all of the following qualifiers be handled?

llvm-project/clang/lib/Sema/SemaType.cpp

Lines 2885 to 2889 in 1e49228

	{ "const", DeclSpec::TQ_const, ConstQualLoc },
	{ "volatile", DeclSpec::TQ_volatile, VolatileQualLoc },
	{ "restrict", DeclSpec::TQ_restrict, RestrictQualLoc },
	{ "__unaligned", DeclSpec::TQ_unaligned, UnalignedQualLoc },
	{ "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc }

I would think ANY qualifier would be ignored in this case and should be diagnosed. That said, I'm not sure which of those would actually be able to be used, so testing them might be difficult.