Getting the name of the file to compile

[albino aiello]

Hi all,
i'm writing a new option pass. For more reason, i have to know the name 
of the file .c to compile. For example: if the user writing in the shell 
the following command :
- gcc filename.c
i want to obtain the variable char* that contain the value filename.
I have seen in the file gcc.c that it exist argc and argv variables but 
i have not access to they in the passes.c .
Thanks to all,
Albino