Getting AST for an expression

Hi all,

I am new to Clang and am trying to create a plugin for Clang.
At some point, I have a C (boolean) expression and I want to extract the AST for the expression.
Is there a way I could use call the parser to give me the AST (without worrying about types / semantics)?

Thanks,
Saswat

No, AST is built by Sema.