aliases in different scopes

Hi LLVM-Developers,

I am looking for an analysis which figures out, if via function
argument dereferencing a given value can be modified within that
function.
Or stated differently: Is in a called function an alias to a given
value being modified? The current Basic Alias Analysis seems not to
support
values in different scopes, so I can't use it for this purpose. Is it
supported by a different Alias Analysis?

What is the preferred way asking such kind of questions?

Thank you and best regards,
Gordon Haak