Level to do such a modification...

[吴曦]

Hi,
I am working on gcc 4.0.0. I want to use gcc to intercept each call to
read, and taint the data readed in. For example:
transform
        read(fd, buf, size)
to
        read(fd, buf, size)
        if(is_socket(fd))
                taint(buf, size)
So, what is the best suitable level to do this modification in gcc? My
own thought is in finish_function, before calling c_genericize,as I
discovered that in c front-end, there's no GENERIC tree... In
c_genericize, it directly calls gimplify_function_tree.