dotnet
UnqualifiedDesugaredType does not return an unqualified type
Example:
typedef int const* pcint;
pcint g();
Given the decl for g in variable gDecl, gDecl.ReturnType.CanonicalType.PointeeType.CanonicalType.UnqualifiedDesugaredType returns a BuiltinType that still represents const int.
Poking around in the sources suggests that the issue is in the fact that IsSugared returns false for qualified types. What I'd really like here is to be able to get a Type object for Handle.UnqualifiedType, which doesn't seem to exist at the moment.
IsSugared is just calling Ty->isSugared(): https://github.com/dotnet/ClangSharp/blob/f0501f7370c01064676f3e8100c4fe76dc3a7c62/sources/libClangSharp/ClangSharp.cpp#L5235-L5247
You'll note that UnqualifiedDesugaredType (https://source.clangsharp.dev/#ClangSharp/Types/Type.cs,2de64541a028759e) is itself just matching the behavior of Type::getUnqalifiedDesugaredType: https://clang.llvm.org/doxygen/Type_8cpp_source.html#l00605
In general ClangSharp tends to just mirror what Clang does and so you'll need to do whatever it is that Clang would expect you to do here.
I think the core issue here is that ClangSharp does not have a QualType equivalent; instead, a Type represents a full QualType, but only mirrors the API of Clang's Type*. As I mentioned, I think this is resolvable by simply exposing UnqualifiedType on Type.