In the Keil ARM 4.6 version, the Functions window displays list of all opened c-files and it's functions normally, but since 4.7 version (5.0 have this trouble too!) the Functions window have a two files only: system_stm32Fxx.c and file contains the main() function. I know about right-click menu inside window, there is ok all with checkboxes.
It's a Bug or not (it's only on the my IDE or not???)