If you write an application in C, you must link it with the C library, even if it makes no direct use of C library functions. This is because the compiler might implicitly generate calls to C library functions to improve your application, even though calls to such functions might not exist in your source code.

Even if your application does not have a main() function, meaning that the C library is not initialized, some C library functions are still legitimately available and the compiler might implicitly generate calls to these functions.