Constructing Modified Function Calls

[Herr Witten]

I need to forward modified arguments, but I have know idea how the data 
returned by __builtin_apply_args() function is organized so that I can 
do this. I took a look at the builtins.c file, and it was nothing but 
Greek to me (way beyond my level!). If anyone could help me to modify 
the variables, especially the first one, I would greatly appreciate it.

Herr Witten

PS

I noticed that the builtin.c file contains a function for returning the 
size of the data returned by __builtin_apply_args(), yet it is declared 
static. Why is this function not global? Thanks