Question about DECL_UID of struct field

["Haifeng He" <hehaifeng2nd at gmail dot com>]

Hi,

I am trying to write a pass to do value profiling of struct fields.
For example, given a struct
struct S {
   a;
   b;
}
I would like to profile values of every instance of S.a and S.b.

Currently I use DECL_UID(a) and DELC_UID(b) to represent the two fields.
However, I found out that, for different compilation units (i.e.,
different source files), the DECL_UID are different. Therefore, S.a
and S.b will be treated
differently for different source files.  Is there a way that I can get
a global unique identification of
struct fields?

thanks

Haifeng