A C file implies a compilation unit. For the projects I write I like to have a single compilation unit per binary (what's called a unity build). In the case of C, this doesn't bring much speed to the table, but it allows for a simpler build toolchain none the less.
If yes, then you can do #include “sds.c“ in some random source file. In fact, that's what so-called header-only libraries in C implicitly do. shudder