Vivado HLS and the “no function body” error: Using a C++ function in plain C code

It’s quite well-known, that in order to call a function in C, which has been compiled in a C++ source file, there’s need for an extern “C” statement. So if this appears on a C++ source file: void my_puts(const char *str) { … } and there’s an attempt to call my_puts() in a plain C [...]