Accessing identifier's information

Dear all:

How can I access an identifier's information? For example, consider
the following example which I am trying to parse through Clang:

int Array [][];

void myFunction Array[][]
{
body of the function;
}

I want to get all the information of "Array " variable; what is its
scope? whether it has already been declared or not? etc.

Where to start ? which function to call in the parser to get these information.