Is there a reference for DLL function decorations in the lpProcName of GetProcAddress?

Question

I am trying to understand and anticipate how to reference functions in a DLL.

When we reference some functions in a couple of DLLs that we are accessing to do some calculations, in some of the functions, we simply use the process name as the argument lpProcName (e.g. "my_calc_function"). However, in some of the other functions (for a different DLL) we have to add various decorations to the lpProcName (e.g. "?my_other_calc_function@@YA....")

in one case

m_lpfn_my_calc_function_pointer = (lpfn_my_calc_func)::GetProcAddress(m_hOneDll,"this_address_works");

in another case

m_lpfn_my_other_calc_function_pointer = (lpfn_my_calc_func)::GetProcAddress(m_hAnotherDll,"?this_address_has@@YAXNPEAN00PEAH@Z");

Both of these work, however, I would like to understand what the decorations mean and where I can reference them so that I can anticipate them when I am writing my code.

Answer 1

The decorations (or, name mangling) are based to the fact that you can have functions with the same name but different arguments.

DLL exports do not include function signatures, only a name. Therefore, the name is "decorated" to reflect on these arguments (classes, namespaces, arguments, return type, calling convention etc).

To remove the decoration, declare the function inside an extern "C" block.