manipulating @llvm.var.annotation in AST?

Is there anyway to manipulate @llvm.var.annotation at the AST level?

In the source file you could do something like
attribute((annotate(“GlobalValAnnotation”)));

Is it possible todo something like that with a Clang::DeclRefExpr? Could something be done to @llvm.var.annotation “by hand”? How do you access this?

Please send questions about the clang AST to cfe-dev.

-Eli