Writing a option pass

[albino aiello]

Hi all,
i must add a new pass to gcc.  I want  to receive from command line an 
integer value at compilation time. I have modify the file common.opt but 
tha value of the variable is alwais 0.
I have add the following row:

my-variable=
Common Var (my_variable)init(-1).
Comments

I want to obtain some like this: gcc -my-variable=5
Init(-1) is for the default value. When i go to see the value of 
my_variable from the file passes.c he is alwais 0.
Can anyone help me??

Thanks to all,
Antony