How to create DSN from custom ODBC Driver? - c++

Question

For the last couple of weeks I'm struggling with ODBC in general. Made some progress but now I am stuck in setting up a dsn with custom ODBC driver.
What I understood, looking through postgres open source code.
I need to make a dll that contains two functions
1.ConfigDsn
2ConfigDriver
Here is example of my code
#include "pch.h"
#include <Windows.h>
BOOL WINAPI DllMain(HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
BOOL ConfigDSN(
HWND hwndParent,
WORD fRequest,
LPCSTR lpszDriver,
LPCSTR lpszAttributes) {
MessageBox(NULL, L"TU", L"OVDJE", 0);
return TRUE;
}
BOOL ConfigDriver(
HWND hwndParent,
WORD fRequest,
LPCSTR lpszDriver,
LPCSTR lpszArgs,
LPSTR lpszMsg,
WORD cbMsgMax,
WORD* pcbMsgOut) {
MessageBox(NULL, L"TU", L"OVDJE", 0);
return TRUE;
}
When I try to Add a new DSN none of the message box shows.
If I add Message box call inside a DLLMain function, then the message box is displayed.
I'm assuming I missing a fundamental c++ knowledge in building dlls. Because I saw some .def files in resource folder inside postgres source code.
My question is how I need to make this dll so I could create a DSN with my own driver ?

Answer 1

Since you are building C++ code, all function names will be mangled. The ODBC functionslity probably expects to use the un-mangled names.
Use extern "C" to prevent name mangling:
extern "C" BOOL ConfigDSN(...) { ... }
extern "C" BOOL ConfigDriver(...) { ... }