Why is the linker giving errors for C/C++ functions being called from C++/C functions?, C++ FAQ

C++ FAQ

From Marshall Cline: Bjarne Stroustrup, Herb Sutter, Andrei Alexandrescu, Pearson / Addison-Wesley Publishers and I collaborated to create a new C++ Super-FAQ! It's a team effort, with huge contributions from each of us and with amazing support from dozens of brilliant editors. The result is "awesomer" than ever! I originally wrote/published the FAQ in 1991 and now look forward to this new phase - and to continue working with it for another 20 years!

On a personal note, I'm at Oculus VR and it is amazing - fabulous people doing fabulous work. We're hiring more fabulous people so write me if that's you!

FAQ: Why is the linker giving errors for C/C++ functions being called from C++/C functions? ←(in the new Super-FAQ)

It's in Section: How to mix C and C++:

FAQ: What do I need to know when mixing C and C++ code?
FAQ: How can I include a standard C header file in my C++ code?
FAQ: How can I include a non-system C header file in my C++ code?
FAQ: How can I modify my own C header files so it's easier to #include them in C++ code?
FAQ: How can I call a non-system C function f(int,char,float) from my C++ code?
FAQ: How can I create a C++ function f(int,char,float) that is callable by my C code?
FAQ: Why is the linker giving errors for C/C++ functions being called from C++/C functions? (this FAQ)
FAQ: How can I pass an object of a C++ class to/from a C function?
FAQ: Can my C function directly access data in an object of a C++ class?
FAQ: Why do I feel like I'm "further from the machine" in C++ as opposed to C?