call a function on a different compilation unit

Hi,

I am trying to solve an issue on gnome photos and now I am thinking that 
it could be fixed by calling a function inside photos-searchbar.c the 
thing is that this function takes as parameter an object (you guessed!) 
PhotosSearchbar, actually a pointer to an object of that Class... and 
all the functions inside that file are static functions, as someone said 
I can not call a function of that file from another .c file is there a 
way around this? another thing is that there is no reference to the 
PhotosSearchbar object on the photos-embed.c file, so I can not pass it 
as an argument either...

any help or guidance is appreciated

Julio Ordonez Viales