Do i need to include *.c files for the functions called inside S function ?

I am creating a S-function from C-code and working directory contains all C files and H files required for execution.

I am calling a function named as "XYZ" inside "static void mdlOutputs(SimStruct *S, int_T tid)" of S function.Then i have to include "XYZ.c" which contains the definition of function "XYZ" and is executing without errors in visual studio.

If XYZ contains any other function suppose A() then again i need to include "A.c" which contains the definition of function "A".

Do i need to include *.c files for the functions called inside S function ?

[Kaustubha Govind]

I'm not sure I understand your question. It looks like you already know that you need to include source/header files for all functions called directly or indirectly from your S-function - can you elaborate a little more?